JP2013203888A - Foamed body for composite, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foamed body for composite, which is excellent in integration with a reinforcing material, and can easily respond to various three-dimensional shapes.SOLUTION: A foamed body for composite is produced by thermally fusing and integrating secondary foamed particles which are obtained by secondarily foaming foamed particles of a synthetic resin within a cavity of a mold, and is used with a reinforcing material being laminated and integrated onto a surface thereof. A groove portion is formed on the surface by continuing recesses formed by the thermally fused and integrated secondary foamed particles, the depth of the groove portion is 300 μm or less, and the number of groove parts with depth of 30-300 μm in the groove portion is 0.5-20 pieces per cm. The content of a foaming agent is 0.3 pts.wt. or less relative to 100 pts.wt. of the synthetic resin constituting the foam for composite body.

Description

  The present invention relates to a foam for a composite and a method for producing the same.

  Since fiber reinforced synthetic resin reinforced with fibers is light and has high mechanical strength, its use is expanding in fields where high mechanical strength and light weight are required, such as in the automobile field and aircraft field. .

  Furthermore, composites using the above-mentioned fiber-reinforced synthetic resin in order to obtain high mechanical strength and using a foam as a core material in order to improve lightness are also used.

  As such a composite, Patent Document 1 discloses a sandwich panel composed of a core material and a skin material including a fiber reinforced resin in which a reinforced fiber disposed on both surfaces of the core material is impregnated with a matrix resin. The reinforcing fiber in the skin material includes a reinforcing fiber having a tensile 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, In addition, a fiber reinforced resin sandwich panel is disclosed in which a resin having an apparent density smaller than that of the skin material is used and the entire thickness of the sandwich panel is in the range of 0.5 to 5 mm.

  However, although foam is used in the examples as the core material used in the fiber reinforced resin sandwich panel, the manufacturing method of this foam is not clearly described, and the sheet-like foam is It is presumed that it is manufactured by cutting from a separately manufactured foam, or is manufactured using a T-die by extrusion foaming or the like, and the former manufacturing method requires cutting and low manufacturing efficiency. The latter manufacturing method has a problem that a desired three-dimensional shape cannot be manufactured.

JP 2005-313613 A

  The present invention provides a foam for a composite that can be suitably used as a core of a composite that is excellent in integration with a reinforcing material and can easily cope with various three-dimensional shapes.

The foam for composite of the present invention is produced by heat-sealing and integrating secondary foam particles obtained by secondary foaming of synthetic resin foam particles in a mold cavity, and a reinforcing material is laminated and integrated on the surface. The composite foam used is formed into a groove, and a groove is formed on the surface by continuous recesses formed by secondary foam particles that are heat-sealed and integrated with each other, and the depth of the groove Is 300 μm or less, and the number of groove portions having a depth of 30 to 300 μm in the groove portion is 0.5 to 20 per 1 cm ² , and the foaming agent content constitutes the composite foam. It is characterized by being 0.3 parts by weight or less with respect to 100 parts by weight of the synthetic resin.

  The foam for a composite of the present invention is produced by in-mold foam molding. In-mold foam molding is the process of filling synthetic resin foam particles in the mold cavity, heating the foamed synthetic resin particles with a heating medium such as hot water or water vapor, and the foaming pressure of the synthetic resin foam particles. This is a method for producing a foamed product having a desired shape by heat-sealing and integrating secondary foamed particles obtained by secondary foaming of synthetic resin foamed particles.

  The synthetic resin constituting the synthetic resin expanded particles is not particularly limited, and examples thereof include thermoplastic polyester resins such as aromatic polyester resins and polylactic acid resins, polycarbonate resins, acrylic resins, polymethacrylimide resins, and the like. Is mentioned. In addition, a synthetic resin may be used independently or 2 or more types may be used together. As the synthetic resin, a recycled material collected and recycled from a used plastic bottle or the like can be used.

  Specific examples of the aromatic polyester resin include polyethylene terephthalate, polybutylene terephthalate, a copolymer of terephthalic acid, isophthalic acid, and ethylene glycol, a copolymer of terephthalic acid, ethylene glycol, and neopentyl glycol, and terephthalic acid. Examples include a copolymer of an acid, ethylene glycol, and cyclohexanedimethanol, and polyethylene terephthalate is preferable. In addition, a thermoplastic polyester-type 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 becomes too small and foamed particles may break, and if it is large, the melt at the time of melting of polyethylene terephthalate. Since viscosity becomes too large and extrusion foaming may be difficult, 0.01 to 5 parts by weight is preferable and 0.1 to 1 part by weight is more preferable with respect to 100 parts by weight of polyethylene terephthalate.

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

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

  As long as the polylactic acid resin does not affect the physical properties of the foaming process and the resulting composite foam, an alkyl group, vinyl group, carbonyl group, aromatic group, ester group, ether group, aldehyde group, amino group, Other functional groups such as a nitrile group and a nitro group may be included. 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.

  First, an example of a manufacturing apparatus used for manufacturing synthetic resin expanded particles will be described. In FIG. 1, reference numeral 1 denotes a nozzle mold attached to the front end of the extruder. This nozzle mold is preferable because it can form uniform fine bubbles by extruding and foaming a synthetic resin. 2, a plurality of nozzle outlet portions 1b, 1b,... Are formed on the same virtual circle A at equal intervals on the front end surface 1a of the nozzle mold 1. As shown in FIG. The nozzle mold attached to the front end of the extruder is not particularly limited as long as the synthetic resin does not foam in the nozzle.

  In the portion surrounded by the nozzle outlets 1b, 1b,... On the front end surface 1a of the nozzle mold 1, the rotary shaft 2 is disposed so as to protrude forward. 2 penetrates the front part 41a of the cooling drum 41 which comprises the cooling member 4 mentioned later, and is connected with drive members 3, such as a motor.

  Further, one or a plurality of rotary blades 5, 5... Are integrally provided on the outer peripheral surface of the rear end portion of the rotary shaft 2, and all the rotary blades 5 are nozzles when rotating. The mold 1 is always in contact with the front end face 1a. When the plurality of rotary blades 5, 5,... Are integrally provided on the rotary shaft 2, the plurality of rotary blades 5, 5,. Each is arranged. 2 shows a case where four rotary blades 5, 5,... Are integrally provided on the outer peripheral surface of the rotary shaft 2 as an example.

  Then, when the rotary shaft 2 rotates, the rotary blades 5, 5,... Are always in contact with the front end surface 1a of the nozzle mold 1 to form nozzle outlet portions 1b, 1b,. The synthetic resin extrudate that moves on the virtual circle A and is extruded from the nozzle outlets 1b, 1b,...

  A cooling member 4 is disposed so as to surround at least the front end of the nozzle mold 1 and the rotating shaft 2. The cooling member 4 has a front circular front portion 41a having a larger diameter than the nozzle mold 1 and a cylindrical peripheral wall portion 41b extending rearward from the outer peripheral edge of the front portion 41a. And a bottom cylindrical cooling drum 41.

  Further, a supply port 41c for supplying the cooling liquid 42 is formed in a portion of the peripheral wall portion 41b of the cooling drum 41 corresponding to the outside of the nozzle mold 1 so as to penetrate between the inner and outer peripheral surfaces. Yes. A supply pipe 41 d for supplying the cooling liquid 42 into the cooling drum 41 is connected to the outer opening of the supply port 41 c of the cooling drum 41.

  The coolant 42 is configured to be supplied obliquely forward along the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41 through the supply pipe 41d. Then, the coolant 42 spirals along the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41 due to the centrifugal force accompanying the flow velocity when being supplied from the supply pipe 41d to the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41. Go forward as you draw. Then, the coolant 42 gradually spreads in the direction perpendicular to the traveling direction while traveling along the inner peripheral surface of the peripheral wall portion 41b, and as a result, the inner surface of the peripheral wall portion 41b in front of the supply port 41c of the cooling drum 41 is increased. The peripheral surface is configured to be entirely covered with the coolant 42.

  The cooling liquid 42 is not particularly limited as long as the synthetic resin foam particles can be cooled, and examples thereof include water, alcohol and the like, but water is preferable in consideration of the treatment after use.

  A discharge port 41e is formed on the lower surface of the front end portion of the peripheral wall portion 41b of the cooling drum 41 so as to penetrate between the inner and outer peripheral surfaces. A discharge pipe 41f is formed at the outer opening of the discharge port 41e. Are connected so that the synthetic resin foam particles and the coolant 42 can be discharged continuously.

  Synthetic resin foam particles are produced by extrusion foaming. For example, a synthetic resin is supplied to an extruder, melted and kneaded in the presence of a foaming agent, and the synthetic resin extrudate is cut by a rotary blade 5 while being extruded and foamed from a nozzle mold 1 attached to the front end of the extruder. Produce expanded particles.

  Further, as the foaming agent, those conventionally used are used, for example, chemical foaming agents such as azodicarbonamide, dinitrosopentamethylenetetramine, hydrazoyldicarbonamide, sodium bicarbonate; propane, normal butane, Saturated aliphatic hydrocarbons such as isobutane, normal pentane, isopentane, hexane, ethers such as dimethyl ether, chlorofluorocarbons such as methyl chloride, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, monochlorodifluoromethane, Examples thereof include physical blowing agents such as carbon dioxide and nitrogen, 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 particularly preferred. In addition, a foaming agent may be used independently or 2 or more types may be used together.

  If the amount of the foaming agent supplied to the extruder is small, the synthetic resin foam particles may not be foamed to the desired foaming ratio. On the other hand, if the foaming agent is large, the foaming agent acts as a plasticizer, so that it melts. Since the viscoelasticity of the synthetic resin in the state is too low and the foamability may be lowered and good synthetic resin expanded particles may not be obtained, 0.1 to 5 parts by weight is preferable with respect to 100 parts by weight of the synthetic resin. 0.2 to 4 parts by weight is more preferable, and 0.3 to 3 parts by weight is particularly preferable.

  Then, the synthetic resin extrudate extruded from the nozzle mold 1 continues to the cutting step. The synthetic resin extrudate is cut by rotating the rotary shaft 2 and rotating the rotary blades 5, 5... Disposed on the front end face 1 a of the nozzle mold 1, preferably at a constant rotational speed of 2000 to 10000 rpm. It is preferable to carry out.

  All the rotary blades 5 are always rotating while in contact with the front end face 1a of the nozzle mold 1, and the synthetic resin extrudate extruded and foamed from the nozzle mold 1 is in the rotary blade 5 and the nozzle mold 1. The sheared stress generated between the nozzle outlet 1b and the edge of the nozzle is cut in the air at regular time intervals to form synthetic resin foam particles. At this time, water may be sprayed on the synthetic resin extrudate in a mist form within a range in which the cooling of the synthetic resin extrudate does not become excessive.

  The synthetic resin is prevented from foaming in the nozzle of the nozzle mold 1. The synthetic resin is not yet foamed immediately after being discharged from the nozzle outlet 1b of the nozzle mold 1 and starts to foam after a short time has elapsed since the discharge. Therefore, the synthetic resin extrudate is an unfoamed portion immediately after being discharged from the nozzle outlet 1b of the nozzle mold 1 and foaming in the process of foaming, which is continuous with the unfoamed portion and is extruded prior to the unfoamed portion. It consists of parts.

  The non-foamed portion maintains its state from when it is protruded from the nozzle outlet 1b of the nozzle mold 1 until foaming is started. The time during which the unfoamed portion is maintained can be adjusted by the resin pressure at the nozzle outlet 1b of the nozzle mold 1, the amount of foaming agent, and the like. When the resin pressure at the nozzle outlet 1b of the nozzle mold 1 is high, the synthetic resin extrudate does not foam immediately after being extruded from the nozzle mold 1 and maintains an unfoamed state. The adjustment of the resin pressure at the nozzle outlet 1b of the nozzle mold 1 can be adjusted by the nozzle diameter, the extrusion amount, the melt viscosity and the melt tension of the synthetic resin. By adjusting the amount of the foaming agent to an appropriate amount, the synthetic resin can be prevented from foaming inside the mold, and the unfoamed portion can be formed reliably.

  Since all the rotary blades 5 cut the synthetic resin extrudate while being always in contact with the front end face 1a of the nozzle mold 1, the synthetic resin extrudate is the outlet of the nozzle of the nozzle mold 1. Synthetic resin foam particles are produced by cutting at the unfoamed portion immediately after being discharged from 1b.

  Since the obtained synthetic resin foamed particles are obtained by cutting the synthetic resin extrudate at its unfoamed portion, there is little or no bubble cross section on the surface of the cut portion. The entire surface of the synthetic resin foamed particles is covered with a skin layer that has no or a slight cross section of bubbles. Therefore, the synthetic resin foamed particles have excellent foamability with no loss of foaming gas, a low open cell ratio, and excellent surface heat-fusibility.

  When the synthetic resin foam particles are used for in-mold foam molding, the surface of the synthetic resin foam particles is formed from a skin layer that has no or only a few cell cross sections. The heat-fusibility between particles is good, and the obtained foamed molded article has no surface unevenness and almost no bubble cross section appears on the surface, and has excellent appearance and excellent mechanical strength. Have.

  The synthetic resin foam particles obtained as described above are scattered toward the cooling drum 41 simultaneously with the cutting by the cutting stress of the rotary blade 5, and immediately collide with the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41. . The synthetic resin foam particles continue to foam until they collide with the cooling drum 41, and the synthetic resin foam particles grow into a substantially spherical shape by foaming. Therefore, when filling synthetic resin foam particles into the mold cavity and performing in-mold foam molding, the synthetic resin foam particles are excellent in filling into the mold cavity, and the synthetic resin foams in the mold cavity. The particles can be filled uniformly, and a homogeneous foamed molded product can be obtained.

  In the above, although the case where the manufacturing apparatus shown in FIGS. 1 and 2 was used as the method for manufacturing the synthetic resin expanded particles was described, the present invention is not limited to the above manufacturing method. Supplying, melt-kneading in the presence of a blowing agent, producing a strand-shaped synthetic resin extrudate by extrusion foaming from a nozzle mold attached to the front end of the extruder, and cooling the strand-shaped synthetic resin extrudate A method of producing synthetic resin expanded particles by cutting the synthetic resin extrudate into particles using a pelletizer or the like later. (2) Supplying the synthetic resin to an extruder, melt-kneading in the presence of a blowing agent, and extrusion. A method of manufacturing a synthetic resin sheet from a T die attached to the front end of the machine, cooling the synthetic resin sheet and then cutting the synthetic resin sheet into particles, and manufacturing synthetic resin foam particles. (3) Extruding the synthetic resin Supply to the machine An annular synthetic resin extrudate is manufactured from a circular die that is melt-kneaded in the presence of a blowing agent and attached to the front end of the extruder, and the annular synthetic resin extrudate is placed between the inner and outer peripheral surfaces in the extrusion direction. Even if the synthetic resin sheet is produced by continuously cutting and developing an annular synthetic resin extrudate to produce a synthetic resin sheet, the synthetic resin sheet is cut into particles. Good.

  If the open cell ratio of the synthetic resin foam particles is high, the retention of the foaming gas will be reduced, and the foaming pressure of the synthetic resin foam particles at the time of in-mold foam molding will be insufficient, resulting in heat fusion between the secondary foam particles. Since it becomes insufficient and the mechanical strength and appearance of the foamed molded article may be lowered, it is preferably less than 30%, more preferably 15% or less, and particularly preferably 7% or less. The open cell ratio of the synthetic resin foam particles is adjusted by adjusting the extrusion foaming temperature of the synthetic resin foam particles from the extruder, the supply amount of the foaming agent to the extruder, and the like.

Here, the open cell ratio of the synthetic resin expanded particles is measured in the following manner. First, a sample cup of a volumetric air comparison type hydrometer is prepared, and the total weight A (g) of synthetic resin expanded particles in an amount satisfying about 80% of the sample cup is measured. Next, the volume B (cm ³ ) of the entire synthetic resin expanded particles is measured by a 1-1 / 2-1 atmospheric pressure method using a hydrometer. The volumetric air comparison type hydrometer is commercially available, for example, from Tokyo Science Co. under the trade name “1000 type”.

  Subsequently, a wire mesh container is prepared, the wire mesh container is immersed in water, and the weight C (g) of the wire mesh container in the state immersed in the water is measured. Next, after all of the synthetic resin foam particles are placed in the wire mesh container, the wire mesh container is immersed in water and placed in the wire mesh container and the wire mesh container. The weight D (g) of the total amount of the synthetic resin expanded particles was measured.

Then, the apparent volume E (cm ³ ) of the synthetic resin foam particles is calculated based on the following formula, and the synthetic resin foam is calculated by the following formula based on the apparent volume E and the total volume B (cm ³ ) of the synthetic resin foam particles. The open cell ratio of the particles can be calculated. The volume of 1 g of water was 1 cm ³ .
E = A + (CD)
Open cell ratio (%) = 100 × (EB) / E

If the bulk density of the synthetic resin foamed particles is small, the open cell ratio of the synthetic resin foamed particles may increase, and the foaming force necessary for the synthetic resin foamed particles may not be imparted during foaming in the in-mold foam molding. On the other hand, if it is large, the bubbles of the resulting synthetic resin foam particles become non-uniform, and the foamability of the synthetic resin foam particles at the time of in-mold foam molding may be insufficient. preferably 7 g / cm ^3, more preferably ^{0.07~0.6g / cm 3, 0.08~0.5g / cm} 3 is particularly preferred. The bulk density of the synthetic resin foam particles can be adjusted by the resin pressure at the nozzle outlet 1b of the nozzle mold 1 and the amount of foaming agent. The resin pressure at the nozzle outlet 1b of the nozzle mold 1 can be adjusted by adjusting the nozzle diameter, the amount of extrusion, and the melt viscosity of the synthetic resin.

  The bulk density of the synthetic resin foamed particles is a value measured according to JIS K6911: 1995 “General Test Method for Thermosetting Plastics”. That is, it can measure using the apparent density measuring device based on JISK6911, and can measure the bulk density of a synthetic resin foamed particle based on a following formula.

Bulk density of synthetic resin foamed particles (g / cm ³ )
= [Mass of measuring cylinder with sample (g) -Mass of measuring cylinder (g)]
/ [Capacity of measuring cylinder (cm ³ )]

  As described above, the entire surface of the obtained synthetic resin foamed particles is covered with a skin layer that has no or only a few cell cross sections, has a low open cell ratio, and maintains foam gas. Excellent in properties.

  When the synthetic resin constituting the synthetic resin foamed particles is a crystalline resin, if the degree of crystallization of the synthetic resin foamed particles is high, the heat-fusability between the foamed particles may be reduced during in-mold foam molding. , Less than 15% is preferable, and 10% or less is more preferable. The degree of crystallinity of the synthetic resin foam particles can be adjusted by the time from when the synthetic resin extrudate is extruded from the nozzle mold 1 until the synthetic resin foam particles collide with the coolant 42 and the temperature of the coolant 42. it can.

Here, the degree of crystallinity of the synthetic resin expanded particles is measured using a differential scanning calorimeter (DSC) while raising the temperature at a rate of temperature increase of 10 ° C./min according to the measurement method described in JIS K7121. It can be calculated based on the heat of crystallization per mg and the heat of fusion per mg. ΔH ₀ means the theoretical heat of fusion when 100% crystallization is performed [the heat of complete crystal melting (theoretical value)]. For example, ΔH ₀ of polyethylene terephthalate is 140.1 mJ / mg, and ΔH ₀ of polylactic acid is 93.0 mJ / mg.

Crystallinity (%)
= 100 × (| heat of fusion (mJ / mg) | − | heat of crystallization (mJ / mg) |) / ΔH ₀

  If the content of the foaming agent in the synthetic resin foamed particles is small, the foaming power of the synthetic resin foamed particles is reduced in the in-mold foam molding, and the secondary foamed particles obtained by secondary foaming of the synthetic resin foamed particles The heat-fusibility decreases, the mechanical strength of the resulting composite foam decreases, or the depth of the groove formed on the surface of the resulting composite foam increases, resulting in foaming for the composite. When a reinforcing material is laminated and integrated on the surface of a body via a synthetic resin or adhesive, the synthetic resin or adhesive enters the groove of the composite foam and is absorbed, and the surface of the composite foam In addition, the reinforcing material cannot be firmly laminated and integrated. If the content of the foaming agent in the synthetic resin foamed particles is too large, the amount of the remaining foaming agent in the obtained composite foam increases, and the composite foam is subsequently changed to the composite foam. When heated in a process such as a process of laminating and reinforcing a reinforcing material on the surface, the foam for composite is deformed by foaming, or the foam for composite and the surface of the foam for composite are deformed. Since the gas generated from the foam for the composite is accumulated at the interface with the reinforcing material to be laminated and integrated, the integration of the foam for the composite and the reinforcing material becomes insufficient, so that synthetic resin foam particles are formed. 0.05-0.8 weight part is preferable with respect to 100 weight part of synthetic resins, and 0.1-0.5 weight part is more preferable.

  The foaming agent content in the synthetic resin foam particles can be measured using a gas chromatograph. For example, the foaming agent content in the synthetic resin foam particles can be measured under the following conditions using the following apparatus. it can.

A sample of synthetic resin foam particles 10 to 30 mg was placed in a 20 mL vial and precisely weighed. The vial was sealed and set on a gas chromatograph with an autosampler, and the vial was heated at 210 ° C. for 20 minutes. The gas in the upper space of the vial is quantitatively analyzed by an MHE (Multiple Headspace Extraction) method, and the content W ₃ of the foaming agent in the synthetic resin foam particles is measured.

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

The content of the foaming agent with respect to 100 parts by weight of the synthetic resin constituting the synthetic resin expanded particles can be calculated based on the following formula.
Synthetic resin content W ₄ constituting the synthetic resin expanded particles
= Weight of synthetic resin expanded particles-content of foaming agent in synthetic resin expanded particles W ₃
Foaming agent content (parts by weight) with respect to 100 parts by weight of the synthetic resin constituting the synthetic resin foam particles
= 100 × W ₃ / W ₄

  Furthermore, before the in-mold foam molding described later, the synthetic resin foam particles may be further impregnated with an inert gas to improve the foaming power of the synthetic resin foam particles. Thus, by improving the foaming force of the synthetic resin foamed particles, the fusibility between the synthetic resin foamed particles is improved at the time of in-mold foam molding, and the resulting foamed molded article has further excellent mechanical strength. Examples of the inert gas include carbon dioxide, nitrogen, helium, and argon, and carbon dioxide is preferable.

  After impregnating the synthetic resin foamed particles with inert gas, the synthetic resin foamed particles are pre-foamed to form pre-foamed particles, and the pre-foamed particles are filled in the mold cavity and heated, and the pre-foamed particles You may shape | mold a foaming molding by making it foam. The pre-foamed particles may be further impregnated with an inert gas in the same manner as the method of impregnating the synthetic resin expanded particles with the inert gas.

  A method for producing a foam for a composite by in-mold foam molding using the synthetic resin foam particles will be described. First, synthetic resin foam particles are filled into a cavity of a mold (filling step). Next, a heating medium is supplied into the mold cavity to heat the synthetic resin foamed particles, the synthetic resin foamed particles are secondarily foamed, and the secondary foamed particles obtained by foaming the synthetic resin foamed particles are bonded together. A foam for a composite is manufactured by heat fusion and integration with each other by the foaming pressure (foaming step). In this foaming step, the crystallinity of the synthetic resin is increased to obtain a foamed molded article having excellent fusion and heat resistance. The heating medium for the synthetic resin foam particles filled in the mold cavity is not particularly limited, and examples include hot air and hot water in addition to water vapor.

  If the gauge pressure of the water vapor supplied into the cavity of the mold is low, the synthetic resin foam particles are not sufficiently heated, and the secondary foam particles obtained by secondary foaming of the synthetic resin foam particles are thermally fused and crystallized. The increase in degree may be insufficient, and the heat resistance and mechanical strength of the resulting foamed molded product may be reduced. If it is high, the synthetic resin foam particles filled in the mold cavity will be located on the outside. The foamed resin foams faster than the synthetic resin foam particles located inside, and the secondary foam particles are heat-sealed together, making it difficult for water vapor to contact the synthetic resin foam particles located inside. Heating and foaming of the synthetic resin foamed particles become insufficient, heat fusion integration between the secondary foamed particles becomes insufficient, and the mechanical strength of the resulting foamed molded article may be lowered. 02 MPa or more and 0. Is preferably less than MPa, 0.05~0.4MPa is more preferable.

  If the time for supplying water vapor into the mold cavity is short, the synthetic resin foam particles are not sufficiently heated, and the secondary foam particles obtained by secondary foaming of the synthetic resin foam particles are thermally fused or crystallized. The rise in heat resistance and mechanical strength of the resulting foamed molded product may be reduced, and even if long, the heat resistance of the resulting foamed molded product may be reduced. Since the amount of water vapor required for heating the particles increases and the production efficiency of the foamed molded product may decrease, 60 to 180 seconds are preferable, and 60 to 120 seconds are more preferable.

  If the temperature of the water vapor supplied into the cavity of the mold is low, the synthetic resin foam particles are not sufficiently heated, and the thermal expansion and crystallization degree of the secondary foam particles obtained by secondary foaming of the synthetic resin foam particles. Is not sufficient, and the heat resistance and mechanical strength of the resulting foamed molded article may be lowered. If the foamed molded article is high, the synthetic resin foamed particles may contract without being able to withstand heat, and therefore 100 to 130 ° C is preferred, and 105 to 125 ° C is more preferred.

  When the content of the foaming agent in the composite foam is large, the resulting composite foam is heated in a process such as a process of stacking and integrating a reinforcing material on the surface of the composite foam. In some cases, the composite foam is deformed by foaming, or is generated from the composite foam at the interface between the composite foam and the reinforcing material laminated and integrated on the surface of the composite foam. Gas is accumulated and the integration of the composite foam and the reinforcing material becomes insufficient, so the amount is limited to 0.3 parts by weight or less with respect to 100 parts by weight of the synthetic resin constituting the composite foam. 0.2 parts by weight or less is preferable.

The content of the foaming agent in the composite foam can be measured in the same manner as in the case of measuring the content of the foaming agent in the synthetic resin foam particles. Specifically, 10 to 30 mg of a test piece is taken from the composite foam, and the content W ₁ of the foaming agent contained in the test piece is set to the content of the foaming agent in the synthetic resin foam particles. Measure in the same way as when measuring.

The content of the foaming agent relative to 100 parts by weight of the synthetic resin constituting the test piece can be calculated based on the following formula.
Synthetic resin content W ₂ constituting the test piece
= Weight of test piece-content of foaming agent in test piece W ₁
Content of foaming agent (parts by weight) = 100 × W ₁ / W _{2 with} respect to 100 parts by weight of the synthetic resin constituting the composite foam.

  Next, after the composite foam obtained as described above is taken out from the cavity in the mold cavity, the composite foam is kept at 40 to 80 ° C. for 80 hours or more. Curing (leaving) (curing process) is preferable.

  As described above, the content of the foaming agent remaining in the composite foam can be further reduced by allowing the composite foam to stand at 40 to 80 ° C. for 80 hours or more. it can.

  By reducing the content of the foaming agent in the composite foam, the resulting composite foam is then heated in a process such as a process of laminating and integrating a reinforcing material on the surface of the composite foam. The composite foam at the interface between the composite foam and the reinforcing material laminated and integrated on the surface of the composite foam. The gas generated from the foam for foaming can be prevented, and the integration of the foam for composite and the reinforcing material can be prevented from becoming insufficient. The foam for composite can be used regardless of the subsequent processing steps. , Excellent mechanical strength and appearance can be maintained.

  In the curing process, if the temperature for holding the composite foam is low, the content of the foaming agent remaining in the composite foam cannot be sufficiently reduced. The foam may be deformed or may cause problems such as insufficient integration between the foam for composite and the reinforcing material. If the foam is high, before the foaming agent in the foam for composite comes out Since the composite foam may be deformed, 40 to 80 ° C is preferable, and 50 to 80 ° C is more preferable.

  In the curing process, if the time for curing the composite foam is short, the content of the foaming agent remaining in the composite foam cannot be sufficiently reduced. Since the foam may be deformed or problems such as insufficient integration between the foam for composite and the reinforcing material may occur, 80 hours or more is preferable, and 100 hours or more is more preferable. On the other hand, in the curing process, even if the time for curing the foam for the composite is long, the content of the foaming agent in the foamed molded product cannot be reduced efficiently, so it is preferably 200 hours or less, and 170 hours or less. Is more preferable.

  As described above, since the composite foam is manufactured by in-mold foam molding, the composite foam having a desired shape can be easily obtained by changing the shape of the cavity of the mold. Can be manufactured.

  The obtained foam for a composite is formed by heat-sealing and integrating secondary foamed particles obtained by secondary foaming of synthetic resin foamed particles. As shown in FIGS. 3 and 4, on the surface of the foam for composite, between the secondary foam particles 61 and 61 which are heat-sealed and integrated with each other, the surfaces 61a and 61a of the secondary foam particles exposed to the outside are provided. Thus, a recess 62 is formed, and the recess 63 is continuous to form a groove 63.

  And the depth of the groove part 63 formed in the surface of the foam for composite_body | complex needs to be 300 micrometers or less in any part. As the depth of the groove 63 increases, the surface properties of the composite foam deteriorate and the appearance deteriorates, and a reinforcing material is laminated on the surface of the composite foam using a binder such as a synthetic resin or an adhesive. When integrating, the binder or adhesive enters the groove part 63, and if the binder or adhesive is not used excessively, the composite foam and the reinforcing material are not sufficiently integrated, and the reinforcing material is combined with the composite. This is because the mechanical strength of the composite obtained by laminating and integrating with the surface of the foam for use may be reduced, or the lightweight property of the composite foam may be reduced.

In the groove portion 63 formed on the surface of the composite foam, the number of groove portions having a depth of 30 to 300 μm is limited to 0.5 to 20 per 1 cm ² , preferably 1 to 20 pieces. .5 to 18 are more preferable. This is because when the number of groove portions having a depth of 30 to 300 μm is small, the reinforcing material is laminated and integrated on the surface of the composite foam through a binder such as a synthetic resin or an adhesive. This is because it cannot be laminated and integrated with sufficient strength on the surface of the composite foam. When the number of groove portions having a depth of 30 to 300 μm is large, the unevenness of the surface of the composite foam becomes large, and the surface smoothness of the composite foam decreases, and the surface of the composite foam is reduced. When the reinforcing material is laminated and integrated through a binder such as a synthetic resin or an adhesive, a large amount of binder or adhesive is required, and the lightweight property of the composite foam is reduced. This is because the surface smoothness of the composite formed by laminating and integrating the reinforcing material on the surface is lowered.

Furthermore, in the groove part 63 formed on the surface of the composite foam, the number of groove parts having a depth of 90 to 300 μm is preferably 0 to 5 and more preferably 0 to 3 per 1 cm ² . The number of groove portions having a depth of 90 to 300 μm means that there is no groove portion having a depth of 90 to 300 μm. With the presence or absence of a groove having a depth of 90 to 300 μm, the reinforcing material is laminated on the surface of the composite foam more firmly through a binder such as a synthetic resin or an adhesive. It can be made. When the number of groove portions having a depth of 90 to 300 μm is too large, a binder or an adhesive is used for laminating and integrating the reinforcing material on the surface of the composite foam through a binder or an adhesive such as a synthetic resin. A large amount is required, the lightness of the composite foam is reduced, and further, the surface smoothness of the composite formed by laminating and integrating the reinforcing material on the surface of the composite foam is reduced.

  When measuring the number of groove portions having a depth to be measured in the composite foam, the groove portion is as long as the depth to be measured continues when the groove portion is viewed in the length direction. The number of is assumed to be one. For example, when measuring the number of groove portions having a depth of 30 to 300 μm, as long as the depth of the groove portion varies within the range of 30 to 300 μm in the length direction of the groove portion, the length of the groove portion Regardless, the number of groove portions is counted as one. Therefore, the depth of the groove portion varies in the range of 30 to 300 μm in the length direction of the groove portion, the depth becomes less than 30 μm at a certain groove portion, and when this depth exceeds a point less than 30 μm, the depth of the groove portion is again reached. When the thickness is 30 to 300 μm, there are two groove portions having a depth of 30 to 300 μm at the boundary of the groove portion having a depth of less than 30 μm.

  The depth of the groove formed on the surface of the composite foam and the number of groove portions having a predetermined range of depth are defined in JIS B0601 “Product Geometrical Specifications—Surface Properties: Contour Curve Method—Term, Definition” And surface texture parameters "-(year 2001). The depth of the groove formed on the surface of the composite foam and the number of grooves having a predetermined range of depth are, for example, a high-precision laser measuring instrument (trade name “LT-9000” manufactured by Keyence Corporation) and rough Measured under the conditions of a standard length of 0.8 mm, an evaluation length of 10 mm, a measurement pitch of 2 μm, and a speed of 500 μm / sec using a measurement device equipped with a thickness measurement system (trade name “MAP-2DS” manufactured by Combs). can do.

Specifically, two imaginary straight lines each having a length of 1 cm are drawn at an arbitrary portion on the surface of the foam for composite so as to be perpendicular to each other at the center in the length direction. Thereafter, the depth of the groove portion existing on each virtual straight line is measured using the measuring device, and the number of groove portions having the depth to be measured is calculated for each virtual straight line. Next, the product of the number of groove portions having a depth to be measured on each imaginary straight line is calculated to obtain the number of groove portions having a depth to be measured per 1 cm ² . When the number of groove portions having depths to be measured on two virtual straight lines is both 0, the number of groove portions on each virtual straight line is both 0, and measurement on each virtual straight line is performed. The product of the number of groove portions having a target depth is calculated. When only the number of groove portions having a depth to be measured on one virtual straight line is zero, the number of groove portions on the virtual straight line is one, and the depth to be measured on each virtual straight line is one. The product of the number of groove portions having a thickness is calculated.

The number of groove portions having a depth to be measured per 1 cm ² for each measurement location is calculated for any 10 locations of the composite foam in the same manner as described above, and the groove portions at these 10 locations are calculated. The arithmetic average value of the number is defined as the number of groove portions having a depth to be measured.

  When the synthetic resin constituting the composite foam is a crystalline resin, in the composite foam, if the crystallinity of the surface portion is low, the heat resistance of the composite foam decreases, When the composite foam is heated in a process such as a process of subsequently laminating and integrating a reinforcing material on the surface of the composite foam, the composite foam may be deformed, so 15% or more It is preferable that

  When the synthetic resin constituting the composite foam is a crystalline resin, the difference between the crystallinity of the surface portion and the internal crystallinity is 7% or less in the composite foam. Is preferred. When the difference between the crystallinity of the surface portion and the internal crystallinity exceeds 7%, the heat resistance of the composite foam decreases, and the composite foam is warped or expanded by heating. This is because it may occur.

  The surface of the composite foam is defined as the surface of the composite foam that exists between the surface of the composite foam and the portion that is 2 mm perpendicular to the surface. A rectangular parallelepiped sample having a thickness of 2 mm and a weight of 3 to 10 mg is cut out from the surface of the composite foam. Next, this sample is cut so as to maintain a thickness of 2 mm and to have a rectangular parallelepiped shape with a weight of about 2 mg, thereby producing a surface sample.

  Further, a sample of a rectangular parallelepiped shape having a thickness of 2 mm and a weight of 3 to 10 mg from the composite foam while not including the surface portion of the composite foam and including the center of gravity of the composite foam. Cut out. Next, this sample is cut so as to maintain a thickness of 2 mm and to have a rectangular parallelepiped shape with a weight of about 2 mg, thereby producing an internal sample.

  Surface samples and internal samples were prepared from four separately prepared foams for composites in the same manner as described above, and a total of five surface samples and internal samples were prepared.

The crystallinity of the surface sample and the internal sample was measured using a differential scanning calorimeter (DSC) according to the measurement method described in JIS K7121 while measuring the temperature at a heating rate of 10 ° C./min. It can be calculated based on the amount of heat of crystallization per unit of heat and the amount of heat of fusion per mg. ΔH ₀ means the theoretical heat of fusion when 100% crystallization is performed [the heat of complete crystal melting (theoretical value)].

Crystallinity (%)
= 100 × (| heat of fusion (mJ / mg) | − | heat of crystallization (mJ / mg) |) / ΔH ₀

  The arithmetic average value of the crystallinity degree of each of the five surface samples is defined as the crystallinity degree of the surface portion of the foam for composite, and the arithmetic average value of each crystallinity degree of the five internal samples is the composite. The crystallinity of the inside of the foam for use.

If the apparent density of the composite foam is small, the mechanical strength such as the compressive strength of the composite foam may decrease. If the apparent density of the composite foam is large, the lightweight property of the composite foam may decrease. Therefore, 0.05 to 0.7 g / cm ³ is preferable, and 0.08 to 0.7 g / cm ³ is more preferable. The apparent density of the composite foam refers to a value obtained by dividing the weight of the composite foam by the apparent volume of the composite foam. The apparent density of the composite foam is a value measured in accordance with JIS K6767: 1999 “Measurement of foamed plastic and rubber-apparent density”.

  If the diameter of the secondary foam particles constituting the composite foam is small, the expansion ratio of the secondary foam particles is small, and as a result, the apparent density of the composite foam is increased and the composite foam is used. The weight of the foam may be reduced. If the foam is large, the depth of the groove formed on the surface of the composite foam increases, and a reinforcing material is added to the surface of the composite foam. Alternatively, when laminating and integrating with a binder, the binder or adhesive enters the groove, and the integration of the composite foam with the reinforcing material becomes insufficient, and the reinforcing material is placed on the surface of the composite foam. Since the mechanical strength of the composite obtained by stacking and integration may be lowered, 1.5 to 5 mm is preferable. In addition, the diameter of the secondary expanded particle which comprises the foam for composite_body | complex can be measured using a caliper, and means the diameter of the minimum true sphere which can surround the secondary expanded particle.

  If the open cell ratio of the composite foam is high, the mechanical strength of the composite foam may be reduced. Therefore, it is preferably less than 30%, more preferably less than 20%, and particularly preferably less than 10%. . The open cell ratio of the composite foam is measured in the following manner according to the measurement method described in ASTM D-2856.

First, the apparent volume of the composite foam is measured to obtain an apparent volume F (cm ³ ). Next, the actual sample volume G (cm ³ ) of the composite foam is measured by a 1-1 / 2-1 atmospheric pressure method using a volumetric air comparative hydrometer. The volumetric air comparison type hydrometer is commercially available, for example, from Tokyo Science Co. under the trade name “1000 type”. Based on the apparent volume F (cm ³ ) of the composite foam and the actual sample volume G (cm ³ ) of the foam, the open cell ratio of the foam can be calculated by the following formula.
Open cell ratio (%) = 100 × (F−G) / F

  The foam for a composite manufactured as described above is used as a composite by integrating a reinforcing material on the surface thereof. Examples of the reinforcing material include a fiber reinforcing material, a metal sheet, and a synthetic resin film, and a fiber reinforcing material is preferable.

  It does not specifically limit as a metal sheet, For example, an aluminum sheet, a stainless steel sheet, an iron sheet, a steel sheet, a titanium sheet etc. are mentioned, Since it is excellent in both lightweight and mechanical strength, an aluminum sheet is preferable. The aluminum sheet includes an aluminum alloy sheet containing 50% by weight or more of aluminum. If the thickness of the metal sheet is thin, the mechanical strength may be reduced, and if it is thick, the lightness is reduced. Therefore, 0.1 to 0.5 mm is preferable, and 0.2 to 0.5 mm is more preferable.

  The fiber constituting the fiber reinforcing material is not particularly limited, and examples thereof include carbon fiber, glass fiber, aramid fiber, boron fiber, metal fiber, etc., and has excellent mechanical strength and heat resistance. Therefore, carbon fiber, glass fiber, and aramid fiber are preferable, and carbon fiber is more preferable.

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

  The fiber reinforcing material is (1) a multilayer surface material formed by laminating a plurality of woven fabrics, knitted fabrics or non-woven fabrics in any combination, and (2) a fiber bundle (strand) in which fibers are aligned in one direction. A plurality of face materials formed by binding (stitching) with synthetic resin yarns such as resin and polyester resin, or stitch yarns such as glass fiber yarns are overlapped so that the fiber directions of the fiber bundles are different from each other. A multi-layered surface material may be used in which the combined face materials are integrated (stitched) with synthetic resin yarns such as polyamide resin and polyester resin, or stitch yarns such as glass fiber yarns.

  The fiber reinforcement is preferably impregnated with a synthetic resin. Examples of the synthetic resin include uncured thermosetting resins and thermoplastic resins. 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 include resins obtained by prepolymerization of acid ester resins, and epoxy resins and vinyl ester resins are preferred because of excellent heat resistance, elastic modulus, and 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 polyolefin resins such as polyethylene resins and polypropylene resins, and acrylic resins.

  If the content of the synthetic resin in the fiber reinforcement is small, the bonds between the fibers constituting the fiber reinforcement are weakened, and the mechanical strength of the resulting composite may be reduced. Since the amount of the synthetic resin present between the fibers constituting the reinforcing material is excessively increased, the mechanical strength of the fiber reinforcing material may be decreased, and the mechanical strength of the resulting composite may be decreased. -70 weight% is preferable and 30-60 weight% is more preferable.

  The method of impregnating the fiber reinforcement with the synthetic resin is not particularly limited. For example, (1) a method of immersing the fiber reinforcement in the synthetic resin and impregnating the fiber reinforcement with the synthetic resin, (2) Examples thereof include a method in which a synthetic resin is applied to a fiber reinforcement and the fiber reinforcement is impregnated with the synthetic resin.

  The method of laminating and integrating the reinforcing material on the surface of the composite foam is not particularly limited. For example, (1) a method of laminating and integrating the reinforcing material on the surface of the composite foam via an adhesive (2) A fiber reinforcing material impregnated with a thermoplastic resin is laminated on the surface of the composite foam, and fibers are formed on the surface of the composite foam using the thermoplastic resin impregnated in the fiber reinforcing material as a binder. (3) Thermosetting in which a fiber reinforcing material impregnated with an uncured thermosetting resin is laminated on the surface of the composite foam and impregnated in the fiber reinforcing material. Examples thereof include a method in which a resin is used as a binder, a thermosetting resin is cured, and a fiber reinforcing material is laminated and integrated on the surface of the composite foam.

  The method (3) will be specifically described with an example. As shown in FIG. 5, a laminated body 8 is formed by laminating a fiber reinforcing material 7 impregnated with an uncured thermosetting resin on the surface of the composite foam 6. In FIG. 5, a plate-like material is used as the composite foam 6, and fiber reinforcing materials 7 and 7 in which both sides of the plate-like composite foam 6 are impregnated with an uncured thermosetting resin. Are stacked to form a laminate 8.

  Further, a breather cloth 11 is laminated on the fiber reinforcement 7 of the laminate 8 via a release film 10. FIG. 5 shows the case where the breather cloth 11 is laminated only on one fiber reinforcement 7 via the release film 10. However, the breather cloth 11 is arranged on both fiber reinforcements 7 via the release film 10. May be laminated.

The release film 10 is configured to be easily peelable from the fiber reinforcement 7.
The release film 10 is made of a synthetic resin film, and may or may not have a through-hole penetrating between the front and back surfaces, but the excess heat curing impregnated in the fiber reinforcement 7 Since the breathable resin can be smoothly absorbed by the breather cloth 11, it is preferable that a through hole is formed.

  When the through hole is not formed in the release film 10, the excess thermosetting resin impregnated in the fiber reinforcement 7 is absorbed by the breather cloth 11 through the outside of the release film 10.

  If the release film 10 has a large number of through-holes penetrating between the front and back surfaces, the breather cloth is made of excess thermosetting resin impregnated in the fiber reinforcement 7 through the through-holes of the release film 10 11 can be absorbed. Examples of the synthetic resin constituting the release film 10 include fluorine resins such as tetrafluoroethylene-ethylene copolymer (tetrafluoroethylene-ethylene copolymer).

  The breather cloth 11 is used to absorb excess thermosetting resin impregnated in the fiber reinforcement 7, and may be any one that does not deform or change in quality when the laminate 8 is heated or pressurized. Non-woven fabric made of amide resin fiber such as nylon fiber, polyester resin fiber, etc., glass cloth, and the like.

  Next, the laminate 8 is placed on the mold 12, and a bagging film 9 is put on the laminate 8, and the laminate 8 is sealed with the bagging film 9. A sealing material 13 is interposed between the entire periphery of the outer peripheral edge of the bagging film 9 and the mold 12 to ensure airtightness. The mounting surface of the laminated body 8 in the mold 12 is subjected to a mold release treatment 121 so that the obtained composite fiber reinforcing material can be easily peeled off.

  In FIG. 5, the case where the laminate 8 is placed on the mold 12, the bagging film 9 is put on the laminate 8, and the laminate 8 is sealed with the bagging film 9 is described, but the bagging film 9 is formed in a bag shape. Alternatively, the laminate 8 may be stored in the bag-like bagging film 9 and sealed with the bagging film 9.

  Thereafter, the space 14 sealed with the bagging film 9 is evacuated to depressurize the space 14. If the degree of vacuum in the space 14 is small, the air that is present in the fiber reinforcement may not be sufficiently removed, and voids are generated in the fiber reinforcement of the resulting composite. The mechanical strength of the body may decrease, and if it is large, the thermosetting resin impregnated in the fiber reinforcing material is also sucked, and the content of the thermosetting resin in the fiber reinforcing material is reduced. Since the mechanical strength of the reinforcing material is lowered and the mechanical strength of the resulting composite may be lowered, 0.08 to 0.14 MPa is preferable, and 0.10 to 0.12 MPa is more preferable.

  Next, the laminated body 8 in the space portion 14 is heated after the pressure reduction in the space portion 14 sealed with the bagging film or simultaneously with the start of the pressure reduction to soften the thermosetting resin in the fiber reinforcement 7. After the thermosetting resin is softened, the laminate is pressurized and the heating is continued. Note that the reduced pressure state in the space 14 is maintained during heating and pressurization of the laminate 8.

  When the pressurization degree of the laminated body 8 is small, the exclusion of air present in the fiber reinforcement becomes insufficient, voids are generated in the fiber reinforcement, and the mechanical strength of the fiber reinforcement is reduced, or Since the thermosetting resin in the fiber reinforcement cannot be well adapted to the entire fiber reinforcement, the fibers constituting the fiber reinforcement cannot be integrated well, and the resulting composite The mechanical strength of the composite may be reduced, or the mechanical strength of the composite obtained by insufficient integration of the fiber reinforcing material and the foam for composite may be reduced. Since there exists a possibility that a foam may deform | transform, 0.05-1.5 MPa is preferable and 0.1-1.0 MPa is more preferable.

  On the other hand, when the laminated body 8 is pressurized, excess thermosetting resin impregnated in the fiber reinforcement may sometimes emerge on the surface of the fiber reinforcement. In such a case, the release film 10 Excess thermosetting resin is absorbed by the breather cloth 11 through the through-hole formed in the surface, and the surface of the fiber composite material of the resulting composite has excellent appearance without the presence of extra thermosetting resin. Yes.

  As described above, heating of the laminated body is continued in a state where the laminated body is pressurized, and the thermosetting resin impregnated in the fiber reinforcing material of the laminated body is cured by this heating. Note that, after the thermosetting resin is softened, the heating temperature of the laminate may be the same or may be changed, but the heating temperature of the laminate is increased in order to accelerate the curing of the thermosetting resin. It is preferable.

  The fibers of the fiber reinforcement are bonded and fixed by the curing of the thermosetting resin, and the fiber reinforcement is heated on the surface of the composite foam in a state of being deformed along the surface of the composite foam. A composite can be obtained by being laminated and integrated with a curable resin.

  Next, after cooling the composite and releasing the pressure applied to the composite, the decompression in the space 14 is released and the space 14 is opened to take out the composite.

  As shown in FIG. 6, the obtained composite has fiber reinforcing materials 7 and 7 in which fibers are bound and solidified by a cured thermosetting resin along the surface of the composite foam 6. Stacked and integrated in close contact.

As described above, when the reinforcing material is laminated and integrated on the surface of the composite foam, an adhesive or a synthetic resin is interposed between the surface of the composite foam and the reinforcing material. On the other hand, a groove portion is formed on the surface of the composite foam, and 0.5 to 20 groove portions having a depth of 30 to 300 μm are formed in this groove portion per 1 cm ² . Accordingly, a groove portion having a depth of 30 to 300 μm formed by an appropriate amount of an adhesive or a synthetic resin interposed between the composite foam and the reinforcing material on the surface of the composite foam. Due to the anchor effect, the foam for composite and the reinforcing material can be integrated. Furthermore, since the groove portion having a depth of 30 to 300 μm is formed with an appropriate number as described above, it does not substantially affect the surface properties of the composite foam. It has excellent surface properties, and a reinforcing material can be laminated and integrated in a beautiful state on this foam for composite, and a composite having excellent appearance can be produced.

  Further, the surface of the composite foam is formed with grooves formed by continuous recesses formed by the secondary foam particles that are heat-sealed and integrated with each other. Air present at the interface with the reinforcing material can be smoothly eliminated through the groove, and if the reinforcing material is a fiber reinforcement, the air contained in the fiber reinforcement is also smoothly eliminated through the groove. The reinforcing material can be firmly laminated and integrated on the surface of the composite foam.

As described above, the foamed synthetic resin particles produced using the production apparatus shown in FIGS. 1 and 2 have little or no bubble cross section of the secondary expanded particles on the surface. Therefore, the foam for composites produced by in-mold foam molding using the synthetic resin foam particles has little or no cell cross section of the secondary foam particles on the surface. is there. Therefore, the amount of the synthetic resin or the adhesive interposed between the foam for the composite and the reinforcing material is reduced by the synthetic resin or the adhesive entering the cell cross section exposed on the surface of the composite foam, Integration of the foam for composite and the reinforcing material does not become insufficient. On the other hand, as described above, 0.5 to 20 groove portions having a depth of 30 to 300 μm are formed per 1 cm ² on the surface of the composite foam, and the composite foam and the reinforcing material The intervening adhesive or synthetic resin can surely penetrate into the groove part having a depth of 30 to 300 μm and firmly integrate the foam for composite and the reinforcing material by an excellent anchor effect. it can.

  Also, in the composite foam produced by in-mold foam molding using synthetic resin foam particles produced using a production apparatus other than the production apparatus shown in FIGS. 1 and 2, at least a reinforcing material is laminated. It is preferable that the cross-section of the secondary expanded particles is not exposed on the surface to be integrated.

The composite foam of the present invention has the above-described configuration, and a groove is formed on the surface thereof. The depth of the groove is 300 μm or less, and the depth of the groove is 30. Since the number of groove portions of ˜300 μm is 0.5 to 20 per 1 cm ² , the synthetic resin is laminated and integrated on the surface of the foam for a composite via a synthetic resin or an adhesive. Alternatively, the reinforcing agent can be firmly laminated and integrated on the surface of the foam for composite by the anchor effect by sufficiently penetrating the adhesive into the groove portion, and a composite excellent in mechanical strength can be obtained.

Furthermore, the composite foam of the present invention has excellent surface properties because the number of groove portions having a depth of 30 to 300 μm formed on the surface thereof is 0.5 to 20 per 1 cm ^2. Thus, the composite obtained by laminating and integrating the surface of the foam for composite has excellent surface properties.

  Further, since the composite foam of the present invention has a groove on the surface thereof, when the reinforcing material is laminated and integrated on the surface of the composite foam, the surface of the composite foam Air that exists at the interface with the reinforcing material can be easily discharged and removed through the groove, and the reinforcing material is firmly laminated and integrated on the surface of the foam for composites, resulting in excellent mechanical strength and appearance. Can be obtained.

  Furthermore, the foam for composite of the present invention is produced by heat-sealing and integrating secondary foamed particles obtained by secondary foaming of synthetic resin foamed particles in the mold cavity. By changing the cavity shape of the mold, the composite foam can be easily adapted to various desired three-dimensional shapes, and thus has the desired shape by using the composite foam of the present invention. The composite can be easily produced.

It is the schematic cross section which showed an example of the manufacturing apparatus of a synthetic resin expanded particle. It is the schematic diagram which looked at the multi-nozzle mold from the front. It is the schematic cross section which showed the cross section of the groove part of the foam for composite bodies. It is the schematic diagram which showed the surface of the foam for composites. It is sectional drawing which showed the manufacturing point of the composite_body | complex. It is the longitudinal cross-sectional view which showed the composite_body | complex.

  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
The manufacturing apparatus shown in FIGS. 1 and 2 was used. First, 100 parts by weight of polyethylene terephthalate (trade name “SA-135” manufactured by Mitsui Chemicals Co., Ltd., melting point: 247.1 ° C.), a master batch comprising polyethylene terephthalate containing talc (polyethylene terephthalate content: 60% by weight, talc) (Content: 40% by weight) A polyethylene terephthalate composition containing 1.8 parts by weight and 0.2 parts by weight of pyromellitic anhydride is fed to a single screw extruder having a diameter of 65 mm and an L / D ratio of 35. Melt-kneaded at a temperature of 0 °

  Subsequently, from the middle of the extruder, butane composed of 35% by weight of isobutane and 65% by weight of normal butane was pressed into the molten polyethylene terephthalate composition so as to be 0.7 parts by weight with respect to 100 parts by weight of polyethylene terephthalate. And uniformly dispersed in polyethylene terephthalate.

  Thereafter, the polyethylene terephthalate composition in a molten state was cooled to 280 ° C. at the front end of the extruder, and then the polyethylene terephthalate composition was extruded and foamed from each nozzle of the multi-nozzle mold 1 attached to the front end of the extruder. .

  The multi-nozzle mold 1 has 20 nozzles having a 1 mm diameter outlet portion 1b. The nozzle outlet portions 1b all have a diameter of 139, which is assumed to be the front end face 1a of the multi-nozzle die 1. It was arranged on a virtual circle A of 5 mm at regular intervals.

  Then, two rotary blades 5 are integrally provided on the outer peripheral surface of the rear end portion of the rotary shaft 2 with a phase difference of 180 ° in the circumferential direction of the rotary shaft 2. It was configured to move on the virtual circle A while always in contact with the front end face 1a of the mold 1.

Further, the cooling member 4 includes a cooling drum 41 including a front circular front part 41a and a cylindrical peripheral wall part 41b extending rearward from the outer peripheral edge of the front part 41a and having an inner diameter of 320 mm. It was. The cooling water 42 at 20 ° C. was supplied into the cooling drum 41 through the supply pipe 41d and the supply port 41c of the cooling drum 41. The volume in the cooling drum 41 was 17684 cm ³ .

  The cooling water 42 is spirally drawn along the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41 by the centrifugal force accompanying the flow velocity when being supplied from the supply pipe 41d to the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41. The cooling liquid 42 gradually spreads in the direction perpendicular to the traveling direction while traveling along the inner peripheral surface of the peripheral wall portion 41b, and as a result, the supply port 41c of the cooling drum 41 The inner peripheral surface of the more peripheral wall portion 41b was in a state of being entirely covered with the coolant 42.

  The rotating blade 5 disposed on the front end face 1a of the multi-nozzle mold 1 is rotated at a rotational speed of 2500 rpm, and the polyethylene terephthalate extrudate extruded and foamed from the outlet portion 1b of each nozzle of the multi-nozzle mold 1 Was cut with a rotary blade 5 to produce substantially spherical polyethylene terephthalate expanded particles. The polyethylene terephthalate extrudate was composed of an unfoamed portion immediately after being extruded from the nozzle of the multi-nozzle mold 1 and a foamed portion in the course of foaming continuous with the unfoamed portion. The polyethylene terephthalate extrudate was cut at the open end of the outlet portion 1b of the nozzle, and the polyethylene terephthalate extrudate was cut at the unfoamed portion.

  In the production of the above-mentioned polyethylene terephthalate expanded particles for in-mold foam molding, first, the rotating shaft 2 was not attached to the multi-nozzle mold 1 and the cooling member 4 was retracted from the multi-nozzle mold 1. In this state, the polyethylene terephthalate extrudate is extruded and foamed from an extruder, and the polyethylene terephthalate extrudate immediately after being extruded from the nozzle of the multi-nozzle mold 1 and in the process of foaming continuous to the unfoamed portion. It confirmed that it consisted of a foaming part. Next, after attaching the rotating shaft 2 to the multi-nozzle mold 1 and disposing the cooling member 4 at a predetermined position, the rotating shaft 2 is rotated, and the polyethylene terephthalate extrudate is rotated at the opening end of the outlet portion 1b of the nozzle. 5 was cut to produce polyethylene terephthalate expanded particles.

  The polyethylene terephthalate foamed particles are blown outward or forward by the cutting stress of the rotary blade 5, and the flow of the cooling water 42 flows into the cooling water 42 flowing along the inner surface of the cooling drum 41 of the cooling member 4. The polyethylene terephthalate foamed particles entered the cooling water 42 and immediately cooled as they collided with the surface of the cooling water 42 so as to follow the cooling water 42 from the upstream side to the downstream side.

  The cooled polyethylene terephthalate expanded particles were discharged together with the cooling water 42 through the discharge port 41e of the cooling drum 41, and then separated from the cooling water 42 by a dehydrator.

The polyethylene terephthalate expanded particles had an open cell ratio of 2%, a bulk density of 0.5 g / cm ³ , and a crystallinity of 5%. The butane content in the polyethylene terephthalate expanded particles was 0.5 parts by weight with respect to 100 parts by weight of polyethylene terephthalate.

  An in-mold foam molding machine equipped with molds (male mold and female mold) was prepared. In a state where the male mold and the female mold are clamped, a rectangular parallelepiped cavity having an internal dimension of 30 mm in length, 300 mm in width, and 300 mm in height is formed between the male and male molds.

  The mold cavity was filled with polyethylene terephthalate foam particles in the mold cavity of the in-mold foam molding machine. Thereafter, 105 ° C. water vapor is supplied into the mold cavity at a gauge pressure of 0.13 MPa for 90 seconds to cause secondary foaming of the polyethylene terephthalate foamed particles and secondary foaming of the polyethylene terephthalate foamed particles. The obtained secondary foamed particles were heat-fused and integrated with each other by these foaming pressures to obtain a rectangular solid-shaped foamed molded product having a length of 30 mm × width of 300 mm × height of 300 mm.

  Next, cooling water was supplied into the mold cavity to cool the foam molded article, and then the cavity was opened to obtain a foam molded article. The obtained foamed molded product was allowed to stand (cured) at 60 ° C. for 168 hours under atmospheric pressure to obtain a composite foam.

  An aluminum plate is prepared as the mold 12, 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 allowed to stand for one day. gave.

Two fiber reinforcements (trade name “TR3523 331KMP” manufactured by Mitsubishi Rayon Co., Ltd., basis weight: 200 g / m ² ) formed from a twill weave made of carbon fiber were prepared. The fiber reinforcing material had a planar rectangular shape of 10 cm long × 30 cm wide. The fiber reinforcement contained 50% by weight of an epoxy resin as a thermosetting resin. Two fiber reinforcements were superposed so that their warp lengths were perpendicular to each other.

  Next, the two laminated fiber reinforcements 7 were placed on the mold release surface 121 of the aluminum plate 12, and the above-described composite foam 6 was placed on these fiber reinforcements 7. .

  Separately from the above, two fiber reinforcements identical to the above were prepared, and the two fiber reinforcements were superposed in the same manner as described above. These two laminated fiber reinforcements 7 were placed on the composite foam 6 to produce a laminate 8.

  Thereafter, a release film (trade name “WL5200B-P” manufactured by AIRTECH) and a breather cloth (trade name “AIRWEAVE N4” manufactured by AIRTECH) were sequentially stacked on the fiber reinforcement 7 on the upper side of the laminate 8. The release film was formed from a tetrafluoroethylene-ethylene copolymer film, and a large number of through-holes that penetrated between both surfaces and through which the thermosetting resin in the fiber reinforcing material could pass were formed. The breather cloth is formed from a nonwoven fabric composed of polyester resin fibers, and is configured to be impregnated with a thermosetting resin.

  A bagging film 9 (trade name “WL7400” manufactured by AIRTECH) is covered on the laminate 8, and a sealant tape (manufactured by AIRTECH) is used as a sealing material 13 between the outer peripheral edge of the bagging film 9 and the aluminum plate facing the bagging film 9. The laminate 8 was sealed with a bagging film 9 in an airtight manner using a product name “GS43MR”). A back valve 15 (trade name “VAC VALVE 402A” manufactured by AIRTECH) was disposed on a part of the bagging film 9 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 15 of the laminated structure is connected to a vacuum line. The inside of the sealed space 14 was depressurized to a vacuum degree of 0.10 MPa. Note that the decompression of the space 14 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 8, and the inside of the autoclave is heated to 90 ° C. for 90 minutes to The thermosetting resin was softened to deform the fiber reinforcing material along the surface of the composite foam 6, and the air present in the fiber reinforcing material was sucked and removed.

  Next, the inside of the autoclave was pressurized to a gauge pressure of 0.05 MPa, a pressing force of 0.05 MPa was applied to the laminate 8, and the inside of the autoclave was heated up to 130 ° C. at a temperature rising rate of 4 ° C./min. The laminated body 8 is heated, and the inside of the autoclave is heated at 130 ° C. for 60 minutes to cure the thermosetting resin in the fiber reinforcing material, and the fiber reinforcing materials 7 and 7 are used as the composite foam 6. A composite was obtained by laminating and integrating both sides of the composite. The excess thermosetting resin in the fiber reinforcement 7 was absorbed by the breather cloth 11 through the through hole of the release film 10 due to the pressurization of the laminate 8.

  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 composite was taken out.

(Example 2)
In the middle of the extruder, except that butane comprising 35% by weight of isobutane and 65% by weight of normal butane was pressed into the molten polyethylene terephthalate composition so as to be 0.9 parts by weight with respect to 100 parts by weight of polyethylene terephthalate. In the same manner as in Example 1, a foam for composite and a composite were produced. The polyethylene terephthalate expanded particles had an open cell ratio of 3%, a bulk density of 0.2 g / cm ³ , and a crystallinity of 5%. The butane content in the polyethylene terephthalate expanded particles was 0.5 parts by weight with respect to 100 parts by weight of polyethylene terephthalate.

(Example 3)
In the middle of the extruder, except that butane comprising 35% by weight of isobutane and 65% by weight of normal butane was pressed into the molten polyethylene terephthalate composition so as to be 1.0 part by weight with respect to 100 parts by weight of polyethylene terephthalate. In the same manner as in Example 1, a foam for composite and a composite were produced. The polyethylene terephthalate expanded particles had an open cell ratio of 5%, a bulk density of 0.1 g / cm ³ , and a crystallinity of 6%. The butane content in the polyethylene terephthalate expanded particles was 0.5 parts by weight with respect to 100 parts by weight of polyethylene terephthalate.

Example 4
Crystalline polylactic acid resin (trade name “TERRAMAC HV-6250H” manufactured by Unitika Ltd.), melting point: 169.1 ° C., D-form ratio: 1.2 mol%, L-form ratio: 98.8 mol%) 100 wt. Part and 0.1 part by weight of polytetrafluoroethylene powder (trade name “Fluon L169J” manufactured by Asahi Glass Co., Ltd.) as an air conditioner were supplied to an extruder and melt-kneaded. In the extruder, the polylactic acid resin was first melt-kneaded at 190 ° C. and then melt-kneaded while raising the temperature to 220 ° C. Subsequently, in the middle of the extruder, butane composed of 35% by weight of isobutane and 65% by weight of normal butane is converted to 1.1 parts by weight with respect to 100 parts by weight of the polylactic acid-based resin. It was press-fitted and dispersed uniformly in the polylactic acid resin.

  Thereafter, after cooling the molten polylactic acid resin to 190 ° C. at the front end of the extruder, the polyethylene terephthalate composition was extruded and foamed from each nozzle of the multi-nozzle mold 1 attached to the front end of the extruder. . Except for the above, a foam for composite and a composite were obtained in the same manner as in Example 1.

The polylactic acid-based resin expanded particles had an open cell ratio of 28%, a bulk density of 0.1 g / cm ³ , and a crystallinity of 17%. The butane content in the polylactic acid resin expanded particles was 0.5 parts by weight with respect to 100 parts by weight of the polylactic acid resin.

(Example 5)
A foam for composite was produced in the same manner as in Example 1. On the surface of the composite foam, a polyolefin hot melt adhesive film having a thickness of 30 μm (trade name “Krambetter X-2300” manufactured by Kurabo Industries Co., Ltd.) is laminated, and further, on the polyolefin hot melt adhesive film, A laminate 8 was produced by laminating aluminum sheets having a thickness of 0.2 mm, and a composite was produced in the same manner as in Example 1 except that this laminate 8 was used. The release film 10 and the breather cloth 11 were laminated on the aluminum sheet of the laminate 8.

(Comparative Example 1)
A foam for composite and a composite were obtained in the same manner as in Example 1 except that water vapor was supplied into the mold cavity for 40 seconds. The obtained foamed molded product had a low crystallinity, and the foamed molded product was deteriorated in surface property in the curing process, and the surface property of the obtained composite foam was poor. The composite obtained using this composite foam also had poor surface properties.

(Comparative Example 2)
A composite was obtained in the same manner as in Example 1 except that the foam molded article was not cured in Example 1 and the foam molded article that was not cured was used instead of the foam for composite.

  About the foam for composites or the foamed molded body obtained in Examples and Comparative Examples, the number of groove portions having a depth of 30 to 300 μm, the number of groove portions having a depth of 90 to 300 μm, and secondary expanded particles The content of the foaming agent, the crystallinity of the surface part, the internal crystallinity, the apparent density, the diameter of the secondary foamed particles and the open cell ratio with respect to 100 parts by weight of the synthetic resin constituting the groove are as described above. The maximum depth and the heating dimensional change rate were measured in the following manner, and the results are shown in Table 1. In Table 1, the foamed molded product of Comparative Example 2 is described in the column of “Composite Foam” for convenience.

  About the composite body obtained by the Example and the comparative example, the surface smoothness and heating dimensional change rate of the fiber reinforcement were measured in the following way, and the result was shown in Table 1.

[Composite foam and foamed molded article]
(Maximum depth of groove)
The depth of the groove formed on the surface of the foam for the composite and the foamed molded product is defined in JIS B0601 “Product Geometrical Specification-Surface Properties: Contour Curve Method—Terminology, Definitions and Surface Properties Parameters”-(FY2001) Measured in conformity. The depth of the groove formed on the surface of the foam for composite and the molded foam is 0.8 mm as the reference length using a high-precision laser measuring instrument (trade name “LT-9000” manufactured by Keyence Corporation), and the evaluation length. The measurement was performed under the conditions of 10 mm, a measurement pitch of 2 μm, and a speed of 500 μm / second.

  Specifically, two imaginary straight lines each having a length of 1 cm were drawn at an arbitrary portion on the surface of the foam for composite so as to be perpendicular to each other at the center in the length direction. Thereafter, the maximum depth of the groove portion existing on each virtual straight line was measured using the high-precision laser measuring instrument.

  Measure the maximum depth of the groove existing on each virtual straight line in the same manner as described above at any 10 locations of the foam for composite using the above high precision laser measuring instrument and exist on each virtual straight line The maximum value of the maximum depth of the groove portion to be performed was defined as “the maximum depth of the groove portion”.

(Heating dimensional change rate)
The heating dimensional change rate of the composite foam and the foamed molded product was measured according to JIS K6767. The heating temperature was 150 ° C., the heating time was 168 hours, and the displacement only in the thickness direction of the composite foam and the foamed molded body was measured (− is contracted, + is expanded), and calculated based on the following formula.
Heating dimensional change rate (%) = 100 × (size after heating−size before heating) / size before heating

[Composite]
(Surface smoothness)
The maximum depth of the groove formed on the surface of the composite was measured in the same manner as in the case of the composite foam. In Comparative Example 2, the surface smoothness of the foam for the composite was excellent, but the foam for the composite foamed during the production of the composite, and the surface smoothness of the resulting composite was reduced. did.

(Heating dimensional change rate)
The heating dimensional change rate of the composite was measured according to JIS K6767. The displacement only in the thickness direction of the composite was measured (+ is contracted, − is expanded), and the heating time was 168 hours.

1 Nozzle mold 2 Rotating shaft 3 Drive member 4 Cooling member
41 Cooling drum
42 Coolant 5 Rotary blade 6 Foam for composite
61 Secondary expanded particles
61a surface
62 recess
63 Groove 7 Fiber reinforcement 8 Laminate 9 Bagging film
10 Release film
11 breather cross
Type 12
13 Encapsulant
14 Space
15 Back valve

Claims (7)

A foam for a composite body produced by heat-sealing and integrating secondary foamed particles obtained by secondary foaming of synthetic resin foamed particles in a mold cavity and using a reinforcing material laminated and integrated on the surface The groove is formed on the surface by continuous recesses formed by secondary expanded particles that are heat-sealed and integrated with each other, and the depth of the groove is 300 μm or less. The number of groove portions having a depth of 30 to 300 μm is 0.5 to 20 per 1 cm ² , and the content of the foaming agent is 100 parts by weight of the synthetic resin constituting the composite foam. A foam for composites, which is 0.3 parts by weight or less. The synthetic resin is a polyester-based resin, the crystallinity of the surface portion is 15% or more, and the difference between the crystallinity of the surface portion and the internal crystallinity is 7% or less. The foam for composite according to claim 1. An apparent density is 0.05-0.7 g / cm < ³ >, The foam for composite bodies of Claim 1 or Claim 2 characterized by the above-mentioned. The composite foam according to any one of claims 1 to 3, wherein the synthetic resin is an aromatic polyester-based resin, and the diameter of the secondary foamed particles is 1.5 to 5 mm. body. The foam for a composite according to any one of claims 1 to 4, wherein a cell cross section of the secondary foam particles is not exposed on a surface on which the reinforcing material is laminated and integrated. Filling the mold cavity with the synthetic resin foam particles, supplying a heating medium into the mold cavity to secondarily foam the synthetic resin foam particles, and secondary foaming the synthetic resin foam particles And a foaming step of producing a foam for composite by heat-sealing and integrating the secondary foam particles obtained by the above process. A method for producing a foam for composite. The method for producing a composite foam according to claim 6, further comprising a curing step in which the composite foam is allowed to stand at 40 to 80 ° C. for 80 hours or more.

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