JP6129037B2 - Foam for composite, composite and component for transportation equipment - Google Patents

Description

  The present invention relates to a foam for a composite, a composite, and a member for constituting a transportation device.

  In recent years, in the field of transportation equipment such as automobiles, airplanes, railway vehicles, and ships, the weight of transportation equipment has been reduced for the purpose of reducing the fuel used. Also, in the fields of household appliances such as refrigerators and air conditioners, information terminals such as personal computers, mobile phones and smartphones, furniture such as desks, chairs and storage shelves, weight reduction is aimed at improving handling. Yes.

  Also, in any field, the product is required to have a beautiful appearance, and the surface of the base material has been conventionally coated. However, there is a problem that the paint used for the coating may adversely affect the environment. have.

  Therefore, in order to achieve both improvement in lightness and appearance of the product and environmental protection, a decorative film is laminated and integrated on the surface of the foam to give a beautiful appearance to the product.

  Furthermore, with the recent increase in consumer preference, molded products having complex shapes are required, and molded products having complex shapes are also required to have a beautiful appearance.

In-mold foam molding has been conventionally used as a foam production method, and Patent Document 1 discloses cutting a strand-like foam obtained by extrusion foaming an aromatic polyester resin using a nozzle mold. The bulk density was 0.08 to 0.15 g / cm ³ , the maximum particle diameter was 1.0 to 2.4 mm, and the bubble diameter in the extrusion direction was divided by the bubble diameter in the direction perpendicular to the extrusion direction. After impregnating the primary expanded particles having a value of 3.0 to 6.0 and the particle length divided by the maximum diameter of 1.2 to 1.6 with a pressurized gas, the temperature is 55 to 55. A mold having a bulk density of 0.02 to 0.06 g / cm ³ obtained by heating to 90 ° C. and re-foaming, and a value obtained by dividing the particle length by the maximum diameter is 0.7 to 1.2 Aromatic polyester resin pre-expanded particles for inner foam molding are disclosed.

  However, since the foam obtained by in-mold foam molding using the above-mentioned aromatic polyester-based resin pre-foamed particles for in-mold foam molding has insufficient heat resistance, it presses the heated thermoplastic resin film. If the layers are integrated, the surface of the foam is deformed, and the thermoplastic resin film cannot be beautifully laminated and integrated on the surface of the foam. In particular, the above problem appears remarkably when a thermoplastic resin film is laminated and integrated on the surface of the foam in a state where the foam is placed under a reduced pressure of less than atmospheric pressure.

JP 2011-347535 A

  The present invention is a composite that can easily produce a composite having an excellent appearance by pressing a surface sheet such as a synthetic resin film in a heated state or a fiber reinforced plastic sheet on the surface and laminating and integrating them in a beautiful state. Provided are a foam for body, a composite using the foam for composite, and a member for constituting a transportation device.

  The composite foam according to the present invention is produced by heat-sealing and integrating secondary foamed particles obtained by secondary foaming of thermoplastic resin foamed particles in a mold cavity, and the surface is in a heated state. A foam for a composite body used by pressing and laminating a sheet, and having a dimensional change rate of −1 to 1 when left in an atmosphere at a vacuum of 0.1 MPa and 100 ° C. for 15 minutes %. In addition, a vacuum degree is a gauge pressure of the pressure below atmospheric pressure.

  The foam for a composite of the present invention is produced by in-mold foam molding. In-mold foam molding is the filling of thermoplastic resin foam particles into the mold cavity and heating and foaming the thermoplastic resin foam particles with a heating medium such as hot water or water vapor to foam the thermoplastic resin foam particles. This is a method for producing a foam having a desired shape by thermally fusing and integrating secondary foamed particles obtained by secondary foaming of thermoplastic resin foamed particles.

  The thermoplastic resin constituting the thermoplastic 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, and polymethacrylimides. Examples thereof include resins, polyamide resins, modified polyphenylene ether resins, cyclic olefin resins, styrene-methacrylic acid-methyl methacrylate copolymers, thermoplastic polyester resins are preferred, and aromatic polyester resins are more preferred. In addition, a thermoplastic resin may be used independently or 2 or more types may be used together. As the thermoplastic resin, a recycled material recovered 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, an aromatic polyester-type resin may be used independently or 2 or more types may be used together.

  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 foaming properties and physical properties of 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 arco such as Or the like may also contain Lumpur.

  As long as the polylactic acid resin does not affect the physical properties of the 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.

  The thermoplastic resin may be crosslinked by a crosslinking agent. As a crosslinking agent, a well-known thing is used, For example, the compound which has an acid anhydride group, a polyfunctional epoxy compound, an oxazoline compound, an oxazine compound etc. are mentioned, The compound which has an acid anhydride group is preferable. In addition, a crosslinking agent may be used independently or 2 or more types may be used together.

  The compound having an acid anhydride group is not particularly limited, and for example, it may belong to any of aromatic, alicyclic and aliphatic, and may be a halogenated acid anhydride. Examples of the compound having an acid anhydride group include pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, diphenylsulfonetetracarboxylic dianhydride, and the like. In addition, the compound which has an acid anhydride group may be used independently, or 2 or more types may be used together.

  When the thermoplastic resin is crosslinked with a crosslinking agent, for example, the crosslinking agent may be supplied to the extruder together with the thermoplastic resin. If the amount of the crosslinking agent supplied to the extruder is too small, the melt viscosity at the time of melting the thermoplastic resin becomes small, the foaming ratio of the thermoplastic resin foam particles may not be increased, and if too large, Since the melt viscosity at the time of melting of the thermoplastic resin becomes too large and extrusion foaming may become difficult, 0.01 to 5 parts by weight is preferable with respect to 100 parts by weight of the thermoplastic resin, and 0.1 to 1 Part by weight is more preferred.

  First, an example of a manufacturing apparatus used for manufacturing thermoplastic 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 thermoplastic resin. As shown in FIG. 2, a plurality of nozzle outlet portions 11, 11... Are formed on the same virtual circle A at equal intervals on the front end surface 1 a of the nozzle mold 1. The nozzle mold attached to the front end of the extruder is not particularly limited as long as the thermoplastic resin does not foam in the nozzle.

  In the portion surrounded by the nozzle outlets 11, 11,... On the front end face 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.

  As 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 11, 11,. The thermoplastic resin extrudate that moves on the virtual circle A and is extruded from the nozzle outlets 11, 11,...

  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. The temperature of the cooling liquid 42 is preferably 10 to 40 ° C. 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 coolant 42 is not particularly limited as long as the thermoplastic 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 foamed thermoplastic resin particles and the coolant 42 can be discharged continuously.

  The thermoplastic resin expanded particles are preferably produced by extrusion foaming. For example, a thermoplastic resin is supplied to an extruder, melted and kneaded in the presence of a foaming agent, and cut from the nozzle mold 1 attached to the front end of the extruder by the rotary blade 5 while extrusion foaming the thermoplastic resin extrudate. A particulate cut product is produced, and the thermoplastic resin foam particles are produced by cooling the particulate cut product.

  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.

  When the amount of the foaming agent supplied to the extruder is too small, the foamed thermoplastic resin particles may not be foamed to the desired foaming ratio. On the other hand, when the amount is too large, the foaming agent acts as a plasticizer. Therefore, the viscoelasticity of the thermoplastic resin in a molten state is too low, and foamability may be reduced, and it may not be possible to obtain good thermoplastic resin foam particles. Therefore, 0.1 parts by weight with respect to 100 parts by weight of the thermoplastic resin. -5 parts by weight is preferable, 0.2-4 parts by weight is more preferable, and 0.3-3 parts by weight is particularly preferable.

  In addition, it is preferable that a bubble regulator is supplied to an extruder. As such a bubble adjusting agent, polytetrafluoroethylene powder, polytetrafluoroethylene powder modified with an acrylic resin, talc and the like are preferable.

  On the other hand, if the amount of the air conditioner supplied to the extruder is too small, the foam of the thermoplastic resin foam particles becomes coarse, and the surface smoothness of the resulting foam for composites may decrease. If the amount of the air conditioner supplied to the extruder is too large, bubbles may be broken when the thermoplastic resin is extruded and foamed, and the closed cell ratio of the thermoplastic resin foam particles may be lowered. Therefore, the amount of the air conditioner supplied to the extruder is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight with respect to 100 parts by weight of the thermoplastic resin, and 0.1 to 2 parts. Part by weight is particularly preferred.

  Then, the thermoplastic resin extrudate extruded from the nozzle mold 1 continues to the cutting step. The thermoplastic 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 being in contact with the front end face 1a of the nozzle mold 1, and the thermoplastic resin extrudate extruded and foamed from the nozzle mold 1 is composed of the rotary blade 5 and the nozzle mold 1. Due to the shearing stress generated between the nozzle 11 and the edge of the outlet 11 of the nozzle, the particles are cut in the atmosphere at regular time intervals to form particulate cuts. At this time, water may be sprayed onto the thermoplastic resin extrudate in a range in which the particulate cut product is not excessively cooled.

  The thermoplastic resin is prevented from foaming in the nozzle of the nozzle mold 1. The thermoplastic resin is not yet foamed immediately after being ejected from the nozzle outlet portion 11 of the nozzle mold 1, and begins to foam after a short time has elapsed since ejection. Therefore, the thermoplastic resin extrudate is in the process of foaming extruded before the unfoamed portion, which continues from the unfoamed portion immediately after being discharged from the nozzle outlet portion 11 of the nozzle mold 1 and the unfoamed portion. It consists of a foamed part.

  The non-foamed portion maintains its state from when it is projected from the outlet 11 of the nozzle 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 11 of the nozzle mold 1, the amount of foaming agent, and the like. When the resin pressure at the nozzle outlet 11 of the nozzle mold 1 is high, the thermoplastic resin extrudate does not foam immediately after being extruded from the nozzle mold 1 and maintains an unfoamed state. The resin pressure at the nozzle outlet 11 of the nozzle mold 1 can be adjusted by the nozzle diameter, the extrusion amount, the melt viscosity and the melt tension of the thermoplastic resin. By adjusting the amount of the foaming agent to an appropriate amount, the thermoplastic 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 thermoplastic resin extrudate while being always in contact with the front end surface 1a of the nozzle mold 1, the thermoplastic resin extrudate is used as the nozzle of the nozzle mold 1. Cut at the unfoamed part immediately after being discharged from the outlet part 11 to produce a particulate cut product.

  In the obtained particulate cut product, since the thermoplastic resin extrudate is cut at the unfoamed portion, there is little or no bubble cross section on the surface of the cut portion. The entire surface of the thermoplastic resin foam particles obtained by cooling the particulate cut product is covered with a skin layer having no or a slight cross section of bubbles. Accordingly, the thermoplastic resin foam particles have excellent foamability without foaming gas removal, a low open cell ratio, and excellent surface heat-fusibility.

  When the thermoplastic resin foam particles are used for in-mold foam molding, the surface of the thermoplastic resin foam particles is formed from a skin layer in which there are no or only a few cell cross sections. In addition, the heat-fusibility between the expanded particles is good, and the resulting foam for composites has excellent surface smoothness with almost no surface unevenness and almost no bubble cross section appearing on the surface. It has mechanical strength.

  The particulate cut material obtained as described above is scattered toward the cooling drum 41 simultaneously with the cutting by the cutting stress of the rotary blade 5, and covers the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41. The thermoplastic resin foam particles are produced by immediately colliding with the cooling liquid 42 and being cooled. The particulate cut product continues to foam until it collides with the cooling drum 41, and the particulate cut product has grown into a substantially spherical shape by foaming. Accordingly, the thermoplastic resin foam particles have a substantially spherical shape, and when the foamed thermoplastic resin particles are filled into the mold cavity and the foam molding is performed in the mold, the foamed thermoplastic resin particles enter the mold cavity. It is possible to obtain a foam for a composite that is excellent in filling property, can be uniformly filled with thermoplastic resin foam particles in a mold cavity, and is excellent in surface smoothness.

  In the above, although the case where the manufacturing apparatus shown in FIGS. 1 and 2 was used as a method for manufacturing the thermoplastic resin expanded particles was described, the present invention is not limited to the above manufacturing method. For example, (1) extrusion of thermoplastic resin A strand-shaped thermoplastic resin extrudate is produced by extrusion foaming from a nozzle die attached to the front end of the extruder, and is supplied to a machine and melt-kneaded in the presence of a foaming agent. A method of producing thermoplastic resin foam particles by cutting a thermoplastic resin extrudate into particles using a pelletizer after cooling the product, (2) In the presence of a foaming agent by supplying the thermoplastic resin to an extruder The thermoplastic resin foam sheet is manufactured from a T die attached to the front end of the extruder by melt kneading, and after cooling the thermoplastic resin foam sheet, the thermoplastic resin foam sheet is cut into particles and the thermoplastic resin (3) A thermoplastic resin is supplied to an extruder, melt-kneaded in the presence of a foaming agent, and an annular thermoplastic resin extrudate is produced from a circular die attached to the front end of the extruder. The annular thermoplastic resin extrudate was continuously cut across the inner and outer peripheral surfaces in the extrusion direction, and the annular thermoplastic resin extrudate was developed to produce a thermoplastic foam sheet. Thereafter, a method of producing foamed thermoplastic resin particles by cutting the foamed thermoplastic resin sheet into particles may be used.

  If the open cell ratio of the thermoplastic resin foam particles is too high, the retention of the foam gas will be reduced, and the foaming pressure of the thermoplastic resin foam particles at the time of in-mold foam molding will be insufficient, resulting in the heat between the secondary foam particles. Since the fusion may be insufficient and the mechanical strength and surface smoothness of the composite foam 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 thermoplastic resin foam particles is adjusted by adjusting the extrusion foaming temperature of the thermoplastic resin from the extruder, the supply amount of the foaming agent to the extruder, and the like.

Here, the open cell ratio of the thermoplastic 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 thermoplastic resin expanded particles in an amount satisfying about 80% of the sample cup is measured. Next, the volume B (cm ³ ) of the entire thermoplastic resin expanded particles is measured by a 1-1 / 2-atmosphere 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 the thermoplastic resin foam particles are put in the wire mesh container, the wire mesh container is immersed in water, and the wire mesh container and the wire mesh container in the state of being immersed in water are placed in the wire mesh container. The combined weight D (g) of the total thermoplastic resin foam particles is measured.

Then, the apparent volume E (cm ³ ) of the thermoplastic resin foam particles is calculated based on the following formula, and the heat is expressed by the following formula based on the apparent volume E and the total volume B (cm ³ ) of the thermoplastic resin foam particles. The open cell ratio of the plastic resin expanded 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 thermoplastic resin foam particles is small, the open cell ratio of the thermoplastic resin foam particles increases, and the foaming force necessary for the thermoplastic resin foam particles cannot be imparted during foaming in the in-mold foam molding. On the other hand, if it is large, the foamed thermoplastic resin foam particles are non-uniform, and the foamability of the thermoplastic resin foam particles during in-mold foam molding may be insufficient. 0.05 to 0.7 g / cm ³ is preferable, 0.07 to 0.6 g / cm ³ is more preferable, and 0.08 to 0.5 g / cm ³ is particularly preferable. The bulk density of the thermoplastic resin foam particles can be adjusted by the resin pressure at the nozzle outlet 11 of the nozzle mold 1, the amount of foaming agent, and the like. The resin pressure at the nozzle outlet 11 of the nozzle mold 1 can be adjusted by adjusting the nozzle diameter, the amount of extrusion, and the melt viscosity of the thermoplastic resin.

  In addition, the bulk density of the thermoplastic resin expanded particles refers to that measured in accordance with JIS K6911: 1995 “General Test Method for Thermosetting Plastics”. That is, it can be measured using an apparent density measuring instrument based on JIS K6911, and the bulk density of the thermoplastic resin expanded particles can be measured based on the following formula.

Bulk density of thermoplastic resin expanded 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 thermoplastic resin foam particles is covered with a skin layer in which there are no or only a few cell cross sections, and the open cell ratio is low, Excellent retention.

  When the thermoplastic resin constituting the thermoplastic resin foamed particles contains a crystalline resin, if the thermoplastic resin foamed particles have an excessively high degree of crystallinity, the heat-fusibility between the foamed particles decreases during in-mold foam molding. Therefore, it is preferably less than 15%, more preferably 10% or less. The degree of crystallinity of the foamed thermoplastic resin particles is adjusted by the time from when the thermoplastic resin extrudate is extruded from the nozzle mold 1 until the particulate cut material collides with the coolant 42 and the temperature of the coolant 42. be able to.

Here, the degree of crystallinity of the thermoplastic 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 thermoplastic resin foamed particles is too small, the foaming power of the thermoplastic resin foamed particles is reduced in the in-mold foam molding, and the secondary foam obtained by secondary foaming of the thermoplastic resin foamed particles. The heat-fusability between the foamed particles is reduced, the mechanical strength of the resulting composite foam is reduced, or the surface smoothness of the resulting composite foam is reduced, and a heated surface sheet is obtained. When laminating and integrating on the surface of the composite foam, the surface sheet enters into the gap between the secondary foam particles formed on the surface of the composite foam, wrinkles occur on the surface sheet, The appearance of the resulting composite is degraded. If the content of the foaming agent in the thermoplastic resin expanded particles is too large, the amount of the remaining foaming agent in the obtained composite foam increases, and the composite foam is then expanded into the composite foam. In the step of laminating and integrating the surface sheet on the surface of the body, the foam is deformed by foaming by contact with the heated surface sheet, or the composite foam and the surface of the composite foam are laminated and integrated The gas generated from the composite foam accumulates at the interface with the surface sheet to be transformed, so that the surface sheet generates wrinkles or the surface sheet is laminated and integrated beautifully on the surface of the composite foam. Inability to do so reduces the appearance of the resulting composite. Therefore, the content of the foaming agent in the thermoplastic resin foamed particles is preferably 0.05 to 0.8 parts by weight with respect to 100 parts by weight of the thermoplastic resin constituting the thermoplastic resin foamed particles. -0.5 weight part is more preferable.

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

Samples of thermoplastic resin expanded particles 10-30 mg are placed in a 20 mL vial and precisely weighed. The vial is sealed and set on a gas chromatograph with an autosampler, and the vial is heated at 210 ° C. for 20 minutes. The gas in the upper space of the vial is quantitatively analyzed by the MHE (Multiple Headspace Extraction) method, and the content W ₁ of the foaming agent in the thermoplastic 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 relative to 100 parts by weight of the thermoplastic resin constituting the thermoplastic resin expanded particles can be calculated based on the following formula.
Content W _{2 of} thermoplastic resin constituting thermoplastic resin expanded particles
= Weight of thermoplastic resin expanded particles-Content of foaming agent in thermoplastic resin expanded particles W ₁
Foaming agent content (parts by weight) = 100 × W ₁ / W _{2 with} respect to 100 parts by weight of the thermoplastic resin constituting the thermoplastic resin foam particles

  Furthermore, before the in-mold foam molding described later, the thermoplastic resin foam particles may be further impregnated with an inert gas to improve the foaming power of the thermoplastic resin foam particles. By improving the foaming power of the thermoplastic resin foam particles in this way, the fusibility between the thermoplastic resin foam particles is improved during in-mold foam molding, and the resulting foam for composites has even better mechanical strength. Have Examples of the inert gas include carbon dioxide, nitrogen, helium, and argon, and carbon dioxide is preferable.

  After impregnating the thermoplastic resin expanded particles with an inert gas, the foamed thermoplastic resin particles are pre-expanded into pre-expanded particles, and the pre-expanded particles are filled into the mold cavity and heated. The foam for a composite may be formed by foaming the foamed particles. The pre-expanded particles may be further impregnated with the inert gas in the same manner as the method of impregnating the thermoplastic resin expanded particles with the inert gas.

  A method for producing a foam for a composite will be described by in-mold foam molding using the thermoplastic resin foam particles. First, the thermoplastic resin foam particles are filled into the mold cavity. Next, a heating medium is supplied into the mold cavity to heat the foamed thermoplastic resin particles, the foamed thermoplastic resin particles are secondarily foamed, and the foamed thermoplastic resin foamed particles are secondary foamed. The particles are heat-fused and integrated with each other by their foaming pressure to produce a foamed molded product, and this foamed molded product is aged to produce a composite foam. In the process of in-mold foam molding of the thermoplastic resin foam particles, sufficient heat is applied to heat-fuse and integrate the secondary foam particles formed by secondary foaming of the thermoplastic resin foam particles, and the heat-fusibility And a composite foam having excellent heat resistance. The heating medium for the thermoplastic resin foam particles filled in the cavity of the mold is not particularly limited, and examples thereof include hot air and hot water in addition to water vapor, and water vapor is preferred.

  Since the composite foam is manufactured by in-mold foam molding, the composite foam having a desired shape can be easily manufactured by changing the shape of the cavity of the mold. .

  In order to supply a heating medium into the cavity of the mold, a heating medium supply port for connecting and communicating the inside and outside of the cavity is formed in the mold. Since the heating medium supply port is usually larger than the thermoplastic resin foamed particles, the heating medium supply port has a frame like a lattice window so that the thermoplastic resin particles filled in the cavity do not flow out of the cavity. The body is arranged.

  On the other hand, since the thermoplastic resin particles filled in the mold are in close contact with the inner surface of the cavity by the foaming pressure during the foaming process, the frame disposed on the heating medium supply port on the surface of the resulting composite foam The shape of the body is transferred. As described above, when the shape of the frame is transferred, the surface smoothness of the foam for the composite deteriorates, and when the surface sheet is laminated and integrated on the surface of the foam for the composite, the foam for composite The shape of the frame formed on the surface may be transferred to the surface sheet, and the appearance of the composite may deteriorate.

  In such a case, it is preferable to arrange a sintered metal in place of the frame at the heating medium supply port of the mold. The sintered metal is a porous metal, and innumerable fine holes connected and communicated in a network are formed inside, and the fine holes are opened innumerably on the entire surface. Therefore, a heating medium such as water vapor can smoothly pass through the sintered metal through the fine holes. Unlike a frame such as a lattice window, this sintered metal does not have slits and has a smooth surface. Accordingly, by disposing the sintered metal at the heating medium supply port of the mold, the cavity inner surface of the mold can be formed entirely on a smooth surface, and the surface smoothness of the resulting composite foam can be improved. Can be improved. Since the foam for a composite is excellent in surface smoothness, the surface sheet is beautiful without generating wrinkles or elongation in the surface sheet even when the heated surface sheet is pressed and laminated and integrated. In such a state, the composite foam can be laminated and integrated on the surface of the composite foam, and a composite having a beautiful appearance can be obtained.

  The sintered metal is not particularly limited, and examples thereof include a stainless steel sintered metal and a copper sintered metal, and a stainless steel sintered metal is preferable because it has a high porosity and a low coefficient of linear expansion. The diameter of the micropores formed in the sintered metal is preferably 2 to 150 μm, more preferably 40 to 150 μm.

  When the gauge pressure of the heating medium supplied into the cavity of the mold is too low, the heat-fusibility between the secondary foamed particles obtained by secondary foaming of the thermoplastic resin foamed particles is reduced, and the foamed molded product On the surface of the foam for composites due to insufficient mechanical strength of the foam for composites. In some cases, it is not possible to obtain a composite by laminating and integrating the surface sheets. Even if a composite can be obtained, only a composite having a low appearance and mechanical strength may be obtained. If the pressure is too high, the pressure of the heating medium crushes the surface of the resulting foam molded article, resulting in a decrease in the appearance of the resulting composite foam, and the surface sheet is laminated and integrated on the surface of the composite foam. The appearance of the resulting composite may deteriorate In, preferably 0.05～0.15MPa, more preferably 0.05~0.12MPa, 0.06~0.12MPa is particularly preferred.

  If the total time for supplying the heating medium into the cavity of the mold is too short, the heat-fusability between the secondary foamed particles obtained by secondary foaming of the thermoplastic resin foamed particles decreases, and the foamed molded product On the surface of the foam for composites due to insufficient mechanical strength of the foam for composites. In some cases, it is impossible to obtain a composite by laminating and integrating the surface sheets. Even if a composite can be obtained, only a composite having a low appearance and mechanical strength may be obtained. If it is too high, heat shrinkage will occur on the surface of the resulting foamed molded product, resulting in irregularities on the surface of the resulting composite foam, and a surface sheet laminated and integrated on the surface of the composite foam. 30-9 because the appearance of the resulting composite may deteriorate It is preferably from 0 sec, and more preferably 35 to 800 seconds.

  If the temperature of the heating medium supplied into the mold cavity is too low, the heat-fusability between the secondary foamed particles obtained by secondary foaming of the thermoplastic resin foamed particles will be reduced, and the foamed molded product will be Cannot be obtained, or the heat-fusability between the secondary foamed particles is reduced, so that the surface of the composite foam is inadequate due to insufficient mechanical strength of the composite foam. Sometimes it is not possible to obtain a composite by laminating sheets, and even if a composite can be obtained, only a composite having a low appearance and mechanical strength may be obtained, which is too high. And the secondary foaming of the thermoplastic resin foamed particles, the crystallinity of the secondary foamed particles is increased, the heat-fusibility between the secondary foamed particles is reduced, or the appearance of the resulting foam for composites Or since mechanical strength may fall, it is 100-13. ° C., more preferably from 105 to 128 ° C., particularly preferably one hundred twelve to one hundred twenty-eight ° C..

  When the thermoplastic resin constituting the obtained foamed molding contains a crystalline resin, the heat resistance of the resulting foam for composites is reduced if the crystallinity of the surface portion is too low in the foamed molding. When the composite foam is heated by the heated surface sheet, the composite foam expands or contracts and deforms, and as a result, wrinkles or elongation occurs in the surface sheet. The appearance of the resulting composite may be degraded. If the crystallinity of the surface portion is too high, the resulting composite foam may become too hard and brittle. Therefore, the crystallinity of the surface portion of the foamed molded product is preferably 16 to 30%, more preferably 20 to 29%. The definition of the surface part of the foamed molded product and the method for measuring the crystallinity of the surface part are the same as the definition of the surface part and the method of measuring the crystallinity of the surface part in the composite foam described later. Description is omitted.

  The obtained foamed molded product is aged to reduce the amount of the foaming agent contained in the foamed molded product to obtain a composite foam. If the ambient temperature for aging the foamed molded product is too low, the amount of the foaming agent contained in the foamed molded product may not be reduced, and if it is too high, the foamed molded product may be deformed. In addition, since the appearance of the obtained composite foam may be deteriorated, 40 to 80 ° C is preferable, and 50 to 70 ° C is more preferable.

  If the time for aging the foamed molded product is too short, the amount of the foaming agent contained in the foamed molded product may not be reduced. If it is too long, foam molding may be performed depending on the aging temperature of the foamed molded product. Since the body may be deformed and the appearance of the resulting composite foam may deteriorate, 48 to 216 hours are preferred, and 72 to 168 hours are more preferred.

  The dimensional change rate when the composite foam is left in an atmosphere at a vacuum of 0.1 MPa and 100 ° C. for 15 minutes (hereinafter sometimes simply referred to as “dimensional change rate”) is its absolute value. When the surface sheet in a heated state is pressed against the surface of the composite foam, the composite foam expands or contracts by the heat of the surface sheet, and the composite foam is deformed as the composite foam is deformed. As a result, the surface smoothness of the foam for use is reduced, and as a result, wrinkles or elongation occurs in the surface sheet laminated and integrated on the surface of the composite foam, or deformation of the composite foam is caused by the foam for composite. In the case of the residual foaming agent contained therein, the foaming agent accumulates between the opposing surfaces of the foam for composite and the top sheet, the top sheet is swollen, and the appearance of the resulting composite is deteriorated. Therefore, in the composite foam, the rate of dimensional change when left in an atmosphere at a vacuum of 0.1 MPa and 100 ° C. for 15 minutes is limited to −1 to 1%, and −0.8 to 0.8% is preferable, and -0.5 to 0.5% is more preferable.

  The rate of dimensional change when the foam for a composite is left in an atmosphere of 0.1 MPa in vacuum and 100 ° C. for 15 minutes is a value measured in the following manner. A rectangular parallelepiped test piece having a length of 40 mm, a width of 40 mm and a thickness of 30 mm is cut out from the composite foam, and the test piece is allowed to stand at 23 ° C. and a relative humidity of 60% for 24 hours. The thickness of this test piece is measured at three arbitrary locations, and the arithmetic average value of the thicknesses at these three locations is taken as the “dimension before heating” of the test piece.

Next, after supplying the test piece into an oven maintained at 100 ° C., the degree of vacuum in the oven was set to 0.1 MPa, and the test piece was left in the oven for 15 minutes. Thereafter, the test piece was taken out of the oven and allowed to stand for 1 hour at 23 ° C. and 60% relative humidity under normal pressure. The thickness of the test piece is measured at the same three places measured before heating, and the arithmetic average value of the thicknesses at these three places is taken as the “dimension after heating” of the test piece. The dimensional change rate is calculated based on the following formula. When the dimensional change rate becomes a negative value, the test piece is contracted. When the dimensional change rate becomes a positive value, the test piece is expanded. In addition, as an oven, the vacuum oven marketed with the brand name "LHV-112" from the TABAI ESPEC CORP company can be used.
Dimensional change rate (%) = 100 × (size after heating−size before heating) / size before heating

  If the amount of the remaining foaming agent in the composite foam is too large, the composite foam will be on the surface when the heated surface sheet is pressed onto the surface of the composite foam to be laminated and integrated. Heated by the sheet and deformed by foaming of the composite foam, resulting in a decrease in surface smoothness, or a composite foam and a surface sheet laminated and integrated on the surface of the composite foam The gas generated from the composite foam accumulates at the interface, and the surface sheet cannot be laminated and integrated in a beautiful state on the surface of the composite foam by causing wrinkles or elongation on the surface sheet. Therefore, 0.7 parts by weight or less is preferable with respect to 100 parts by weight of the thermoplastic resin constituting the composite foam, more preferably 0.05 to 0.7 parts by weight, and 0.1 to 0 .6 parts by weight is particularly preferred.

The amount of the remaining foaming agent in the composite foam can be measured in the same manner as when measuring the content of the foaming agent in the thermoplastic resin foam particles. Specifically, 10 to 30 mg of a test piece is taken from the composite foam, and the content W ₃ of the foaming agent contained in the test piece is determined as the content of the foaming agent in the thermoplastic 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 thermoplastic resin constituting the test piece can be calculated based on the following formula.
Content of thermoplastic resin constituting test specimen W ₄
= Weight of test piece-content of foaming agent in test piece W ₃
Content of foaming agent (parts by weight) = 100 × W ₃ / W _{4 with} respect to 100 parts by weight of the thermoplastic resin constituting the composite foam.

  When the thermoplastic resin constituting the composite foam contains a crystalline resin, if the crystallinity of the surface portion is too low in the composite foam, the heat resistance of the composite foam will decrease. When the composite foam is heated by the heated top sheet, the composite foam expands or contracts and deforms, resulting in wrinkles or elongation of the top sheet. The appearance of the resulting composite may deteriorate. If the crystallinity of the surface portion is too high, the composite foam may become too hard and brittle. Accordingly, the crystallinity of the surface portion of the composite foam is preferably 16 to 30%, more preferably 20 to 29%.

  The composite foam part existing between the surface of the composite foam and the part perpendicular to the surface by 2 mm is defined as the surface part. 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.

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

The crystallinity of the surface sample was measured by using a differential scanning calorimeter (DSC) according to the measurement method described in JIS K7121 while raising the temperature at a heating rate of 10 ° C./min. It can be calculated based on the heat of formation 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)]. The arithmetic average value of the crystallinity of each of the five surface samples is defined as the crystallinity of the surface portion of the composite foam.

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

  When the thermoplastic resin constituting the composite foam includes an amorphous resin, if the glass transition temperature of the amorphous resin is too low, the heat resistance of the composite foam decreases, and the composite When the foam for heating is heated by the surface sheet in a heated state, the foam for composite expands or contracts and deforms, and as a result, wrinkles or elongation occurs in the surface sheet. Appearance may deteriorate. Accordingly, the glass transition temperature of the amorphous resin is preferably 100 ° C. or higher, more preferably 105 ° C. or higher, and particularly preferably 110 ° C. or higher.

  The glass transition temperature of the amorphous resin refers to a value measured by the method described in JIS K7121: 1987 “Method for measuring plastic transition temperature”. For example, using a differential scanning calorimeter (trade name “DSC6220 type” manufactured by SII Nano Technology Co., Ltd.), about 6 mg of a sample is filled so that there is no gap in the bottom of an aluminum measurement container, and a nitrogen gas flow rate of 20 mL / min The sample was heated from 30 ° C. to 200 ° C. at a rate of temperature increase of 20 ° C./minute and held for 10 minutes, then the sample was removed from the heating furnace and allowed to cool in air at 25 ± 10 ° C. Thereafter, a DSC curve is obtained when heated from 30 ° C. to 200 ° C. at a rate of temperature increase of 20 ° C./min. The extrapolated glass transition start temperature specified in JIS K7121: 1987 in the obtained DSC curve is defined as the glass transition temperature Tg. In the present invention, the glass transition temperature Tg is calculated at the stepwise change portion of the glass transition of the DSC curve. The difference Δ (mW) between the low-temperature side baseline and the high-temperature side baseline in the vertical axis direction is 0. When it is 02 mW or less, it is not regarded as a step change of the glass transition.

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 open cell ratio of the composite foam is too low, the surface of the composite foam tends to swell when the heated surface sheet comes into contact with the surface of the composite foam. The appearance may deteriorate, and if it is too high, when the heated topsheet is pressed against the surface of the composite foam under reduced pressure, the topsheet constitutes the composite foam Since it may be sucked into the recesses formed between the foamed particles and wrinkles may be generated on the surface sheet, the appearance of the composite may be lowered, so 1 to 15% is preferable, and 1.5 to 13 % Is more preferable, and 2 to 10% is particularly preferable. In addition, the open cell rate of the foam for composites is measured in the following manner based on 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

  If the arithmetic mean roughness Ra of the surface of the composite foam is too large, when the surface sheet in a heated state is laminated and integrated on the surface of the composite foam, the surface sheet is formed on the surface of the composite foam. Accordingly, the surface sheet may be wrinkled or stretched, and the appearance of the composite may be deteriorated. Therefore, the thickness is preferably 25 μm or less, more preferably 22 μm or less, and particularly preferably 15 μm or less.

  In addition, arithmetic mean roughness Ra of the surface of the foam for composite_body | complex says the value measured based on JISB0601-1994 "surface roughness-definition and display." For example, a reference length of 0. 0 is measured using a measuring apparatus equipped with a high-precision laser measuring instrument (trade name “LT-9000” manufactured by Keyence Corporation) and a roughness measuring system (trade name “MAP-2DS” manufactured by COMMS Corporation). It can be measured under conditions of 8 mm, evaluation length 10 mm, measurement pitch 2 μm, and speed 500 μm / sec.

  Next, an example of a method for laminating and integrating a surface sheet on the surface of the composite foam of the present invention will be described. The vacuum forming apparatus 6 for laminating and integrating the surface sheet on the surface of the composite foam will be described.

  As shown in FIG. 3, the vacuum forming apparatus 6 has an upper forming member 61 and a lower forming member 62, and the upper forming member 61 has an upper forming chamber 61a that opens downward, The side molding chamber 62 has a lower molding chamber 62a that opens upward.

  The upper molding member 61 is configured to be displaceable in the vertical direction relative to the lower molding member 62 by the driving member 7. When the upper molding member 61 is displaced downward, the upper molding member 61, 62 The upper and lower molding chambers 61a and 62a are aligned with each other so that the upper and lower molding chambers 61a and 62a form one hermetically sealed joint molding chamber 63.

  A table 62b for placing the composite foam J is disposed in the lower molding member 62, while the upper molding member 61 is below the lower molding member 62 as will be described later. A heater 61b for heating the topsheet K disposed in a stretched state at the open end of the side molding chamber 62a is disposed. The table 62b is configured to be displaced in the vertical direction by the driving member 8.

  Further, the upper and lower molding chambers 61a and 62a of the upper and lower molding members 61 and 62 are connected to a vacuum pump (not shown) for sucking the air in the upper and lower molding chambers 61a and 62a and reducing the pressure. Openable and closable open valves (not shown) are provided in the upper and lower molding chambers 61a and 62a for supplying air into the chambers 61a and 62a to release the decompressed state in the upper and lower molding chambers 61a and 62a.

  A procedure for stacking and integrating the top sheet K on the surface of the composite foam J using the vacuum forming apparatus 6 will be described. First, as shown in FIG. 3, after the composite foam J is placed on the table in the lower molding chamber 62a of the lower molding member 62, the lower molding chamber 62a of the lower molding member 62 is placed. A top sheet K is disposed over the open end in a fully stretched state. The top sheet K is held by a chuck body 62c disposed at the open end of the lower molding chamber 62a. The open valves of the upper and lower molding members 61 and 62 are closed.

  Here, the top sheet K only needs to be able to deform along the surface of the composite foam when pressed against the surface of the composite foam in the heated state. Examples of the surface sheet K include a synthetic resin film such as a thermoplastic resin film, a fiber reinforced plastic sheet, and the like, and a thermoplastic resin film and a fiber reinforced plastic sheet are preferable. A sheet in which a synthetic resin film is laminated and integrated on the surface of a fiber reinforced plastic sheet may be used as the surface sheet.

  The thermoplastic resin constituting the thermoplastic resin film is not particularly limited, and examples thereof include polyolefin resins such as polypropylene resins and polyethylene resins, polyester resins, polyvinyl chloride resins, acrylic resins, and polyurethanes. Resin, fluorine resin, ABS resin, and the like, and polyester resin, acrylic resin, and ABS resin are preferable because of excellent heat resistance, moldability, and durability.

  The fiber reinforced plastic sheet is formed by impregnating a reinforcing fiber into a reinforcing fiber. The reinforcing fibers can be bonded and integrated by the impregnated reinforcing synthetic resin. By using a fiber reinforced plastic sheet as the top sheet, the resulting composite has excellent mechanical strength.

  As the reinforcing fibers constituting the fiber reinforced plastic sheet, inorganic fibers such as glass fibers, carbon fibers, silicon carbide fibers, alumina fibers, Tyranno fibers, basalt fibers and ceramic fibers; metal fibers such as stainless fibers and steel fibers; Organic fiber such as aramid fiber, polyethylene fiber, polyparaphenylene benzoxador (PBO) fiber; boron fiber, etc. are mentioned, and fiber reinforced plastic sheet has excellent mechanical strength despite being lightweight Therefore, carbon fiber, glass fiber and aramid fiber are preferable, and carbon fiber is more preferable. In addition, a reinforcing fiber may be used independently or 2 or more types may be used together.

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

  The thermoplastic resin is not particularly limited, and examples thereof include olefin resins, polyester resins, thermoplastic epoxy resins, amide resins, thermoplastic polyurethane resins, sulfide resins, acrylic resins, and the like. Polyester resins and thermoplastic epoxy resins are preferred because they are excellent in adhesiveness to the foam or adhesiveness between the reinforcing fibers constituting the fiber-reinforced plastic sheet. In addition, a thermoplastic resin may be used independently or 2 or more types may be used together.

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

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

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

  If the thickness of the surface sheet is too thin, wrinkles may easily occur on the surface sheet, the handleability may be reduced, or minor irregularities formed on the surface of the composite foam may be present on the surface sheet. If it is transferred, the appearance of the composite foam may deteriorate. If it is too thick, not only will the lightness of the composite foam be reduced, but it will also sag due to its own weight during vacuum forming, and the surface of the composite foam When the surface sheet is laminated on the surface sheet, wrinkles may occur in the surface sheet, so 0.1 to 1 mm is preferable, 0.1 to 0.8 mm is more preferable, and 0.2 to 0.5 mm is particularly preferable.

  A printed layer may be formed on the surface of the top sheet for decoration. It is preferable that an adhesive layer is formed on the back surface of the top sheet because the top sheet can be more firmly integrated with the surface of the foam for composite. The adhesive constituting the adhesive layer is not particularly limited. For example, in addition to an acrylic pressure-sensitive adhesive and a rubber-based pressure sensitive adhesive, acrylic, polyurethane, polyolefin, polyester, nylon Hot-melt type adhesives such as a system are mentioned. As the adhesive, an acrylic pressure-sensitive adhesive, an acrylic hot melt adhesive, and a polyester hot melt adhesive are preferable because of excellent heat resistance and adhesiveness. The thickness of the adhesive layer is preferably 0.05 to 0.2 mm.

  A protective layer may be formed on the printed layer formed on the top sheet to protect the printed layer. The protective layer is preferably transparent so as not to impair the visibility of the printed layer. The protective layer is usually composed of a synthetic resin. The synthetic resin is not particularly limited, and for example, acrylic resins and polyurethane resins are preferable. The thickness of the protective layer is preferably 0.05 to 0.1 mm. A heat stabilizer and a light stabilizer may be mix | blended with a protective layer as needed.

  Next, as shown in FIG. 4, the drive member 7 is driven to displace the upper molding member 61 downward, so that the open ends of the upper and lower molding chambers 61a and 62a of the upper and lower molding members 61 and 62 are matched. Thus, the upper and lower molding chambers 61a and 62a are hermetically sealed to form one combined molding chamber 63. The upper and lower molding chambers 61a and 62a constituting the combined molding chamber 63 are completely separated and separated from each other by the surface sheet K.

  Thereafter, as shown in FIG. 5, air is sucked and removed from the joint molding chamber 63 of the vacuum molding apparatus 6, that is, the upper and lower molding chambers 61 a and 62 a through an open valve, and the upper and lower molding chambers 61 a and 62 a are both large. The pressure is reduced to less than atmospheric pressure (preferably the degree of vacuum is 0.03 to 0.1 MPa). Next, the heater 61b disposed in the upper molding chamber 61a of the upper molding member 61 is operated to heat the top sheet K.

  Next, as shown in FIG. 6, when the top sheet K is heated and softened, the table 62b disposed in the lower molding chamber 62a is driven to drive the driving member 8 upward. The composite foam J placed on the table 62b is pressed toward the top sheet K, and a part of the top sheet K is brought into close contact with the composite foam J.

  With this state maintained, air is supplied by opening the release valve into the upper molding chamber 61a of the upper molding member 61 to release the reduced pressure state, and the upper molding chamber 61a is brought to a normal pressure state. Then, since the inside of the lower molding chamber 62a of the lower molding member 62 is in a reduced pressure state, the top sheet K is sucked and pressed toward the composite foam J by the pressure difference, and the composite foam J Are stacked in close contact with each other (see FIG. 7). In addition, when the adhesive layer is formed in the back surface of the surface sheet K, ie, the surface facing the composite foam J, the top sheet K becomes the surface of the composite foam J by the adhesive layer. Are more strongly laminated and integrated.

  Next, the top sheet K is cooled as necessary, and air is supplied by releasing an open valve in the lower molding chamber 62a of the lower molding member 62 to release the decompression state, thereby lowering the lower molding chamber 61a. After the inside is in a normal pressure state, as shown in FIG. 8, the upper molding member 61 and the lower molding member 62 are separated by moving the upper molding member 61 upward by driving the driving member 7. After that, the surface sheet K is cut at a portion that is not laminated and integrated with the surface of the composite foam J, and the composite L is taken out.

  The composite foam of the present invention has a dimensional change rate of −1 to 1% when left in an atmosphere of 0.1 MPa in vacuum and 100 ° C. for 15 minutes. Even if the sheet comes into contact with the surface of the composite foam under reduced pressure, the composite foam is hardly deformed by expansion or contraction, and the composite foam is caused by the deformation. The surface smoothness of the body is not impaired. Therefore, when the surface sheet in a heated state is laminated and integrated on the surface of the composite foam, the surface sheet is greatly extended due to the expansion of the composite foam, or the composite foam is The surface sheet is not slackened by shrinkage, and the surface sheet can be beautifully laminated and integrated with the surface of the foam for composite without wrinkles or slack, and the composite has a beautiful appearance. Can be obtained.

  As described above, the surface of the foam for composite can be covered with a single surface sheet in one step by sucking and pressing the heated top sheet toward the surface of the composite foam. Can easily produce a seamless surface sheet, that is, a single surface sheet coated with a majority of the composite foam (preferably 30-90% of the surface area of the composite foam). can do.

  In particular, the composite foam according to the present invention hardly undergoes deformation such as expansion or contraction in spite of the heat generated by the heated surface sheet under reduced pressure. Therefore, the composite foam has a complicated shape. Even in such a case, the surface sheet can be laminated and integrated into a desired portion in a beautiful state without wrinkles or slack on the surface of the composite foam, and thus the composite foam of the present invention According to the body, a composite body having a desired shape and a beautiful appearance can be easily produced.

  The composite obtained in this way has a beautiful appearance and partly includes a foam for composite that is excellent in light weight, and is excellent in light weight, both lightweight and appearance. Can be used in a wide range of applications such as automobiles, airplanes, railway vehicles, ships, and other transportation equipment fields, home appliance fields, information terminal fields, and furniture fields.

  For example, the composite is a transportation equipment component, a transportation equipment constituent member including a structural member constituting the body of the transportation equipment, a cushioning material for a helmet, an agricultural box, a heat storage container, a packaging container for parts, etc. Can be suitably used.

  The composite foam of the present invention has the configuration as described above, and a surface sheet can be laminated and integrated on the surface in a beautiful state without wrinkles, elongation, slackness or breakage, and has an appearance and light weight. A composite having excellent properties can be produced.

  Furthermore, the foam for a composite of the present invention is produced by heat-sealing and integrating secondary foam particles obtained by secondary foaming of thermoplastic resin foam particles in a mold cavity. The desired shape can be obtained by changing the cavity shape, and a composite having the desired shape can be produced.

  In the foam for composite of the present invention, the foamed thermoplastic resin particles contain a crystalline resin, the crystallinity of the surface portion is 16 to 30%, and the amount of residual foaming agent constitutes the foam for composite When the amount is 0.7 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin, the surface of the foam for composite is more excellent in heat resistance, and deformation such as expansion or contraction due to heat of the surface sheet Can be more reliably prevented. Further, since the amount of the remaining foaming agent in the composite foam is small, gas is generated from the composite foam even when the surface sheet in the heated state comes into contact with the composite foam. There is almost no gas accumulation at the interface with the surface sheet, and the surface sheet can be laminated and integrated in a state in which the surface sheet is more closely attached to the surface of the composite foam, and a composite having an excellent appearance is produced. Can do.

  In the composite foam of the present invention, when the open cell ratio is 1 to 15%, when the surface sheet in a heated state is sucked and pressed toward the surface of the composite foam by a pressure difference, Even if there is, the surface sheet in which the bubbles in the composite foam are in a reduced pressure state due to the opening of the bubbles inside the composite foam, and the composite foam is laminated on the surface of the composite foam Can be substantially prevented from generating wrinkles by being sucked into the bubbles of the composite foam. Therefore, according to the composite foam of the present invention, the appearance is more excellent A composite can be produced.

  In the composite foam of the present invention, when the arithmetic average roughness Ra of the surface is 25 μm or less, the surface sheet in the heated state is laminated and integrated in a state of being in close contact with the surface of the composite foam. The composite foam of the present invention can produce a composite having a more excellent appearance.

It is the schematic cross section which showed an example of the manufacturing apparatus of a thermoplastic 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 a part of process of manufacturing a composite_body | complex using the foam for composite_body | complex. It is the schematic cross section which showed a part of process of manufacturing a composite_body | complex using the foam for composite_body | complex. It is the schematic cross section which showed a part of process of manufacturing a composite_body | complex using the foam for composite_body | complex. It is the schematic cross section which showed a part of process of manufacturing a composite_body | complex using the foam for composite_body | complex. It is the schematic cross section which showed a part of process of manufacturing a composite_body | complex using the foam for composite_body | complex. It is the schematic cross section which showed a part of process of manufacturing a composite_body | complex using the foam for 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.

(Examples 1-4, Comparative Examples 1-3)
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 kneading was carried out at 0 ° C.

  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 polyethylene terephthalate composition in a molten state so as to have the amount shown in Table 1 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 an outlet portion 11 having a diameter of 1 mm, and all the outlet portions 11 of the nozzle are assumed to have a diameter of 139 on 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 11 of each nozzle of the multi-nozzle mold 1 Was cut with a rotary blade 5 to produce a substantially spherical polyethylene terephthalate particulate cut product. 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 11 of the nozzle, and the polyethylene terephthalate extrudate was cut at the unfoamed portion.

  In the production of the polyethylene terephthalate expanded particles described above, 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 11 of the nozzle. 5 to produce polyethylene terephthalate particulate cuts.

  The polyethylene terephthalate particulate cut is blown outward or forward by the cutting stress of the rotary blade 5, and the cooling water 42 flows along the inner surface of the cooling drum 41 of the cooling member 4. Colliding with the surface of the cooling water 42 so as to follow the cooling water 42 from the upstream side to the downstream side of the flow, the polyethylene terephthalate particulate cut material enters the cooling water 42 and immediately cools down. As a result, expanded polyethylene terephthalate particles were obtained.

  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.

  Table 1 shows the open cell ratio, bulk density and crystallinity of the polyethylene terephthalate expanded particles.

  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. In addition, a stainless steel sintered metal was disposed at the heating medium supply port of the mold.

  The mold cavity was filled with polyethylene terephthalate foam particles in the mold cavity of the in-mold foam molding machine. Thereafter, the polyethylene terephthalate foamed particles were subjected to secondary foaming by supplying water vapor having the temperature shown in Table 1 into the mold cavity at the gauge pressure shown in Table 1 only for the time shown in Table 1. After the foaming step), water vapor of the temperature shown in Table 1 is further supplied into the mold cavity at the gauge pressure shown in Table 1 for the time shown in Table 1 to secondary foam the polyethylene terephthalate foamed particles ( Second foaming step), secondary foamed particles obtained by secondary foaming of polyethylene terephthalate foamed particles are thermally fused and integrated by these foaming pressures to form a rectangular parallelepiped having a length of 300 mm × width of 300 mm × height of 30 mm. A foamed molded product was obtained.

  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 article was allowed to stand at 60 ° C. under atmospheric pressure for the time shown in Table 1 for aging (aging process) to obtain a foam for composite.

  The dimensional change rate, surface portion crystallinity, residual foaming agent amount, open cell ratio and surface arithmetic average roughness Ra of the obtained composite foam were measured as described above, and the results are shown in Table 1. Indicated.

  The vacuum forming apparatus (Three-Dimension Overlay Mold (TOM; NGF-0609) molding machine NGF-0609) 6 manufactured by Fuse Vacuum Co., Ltd. 6 was prepared. First, as shown in FIG. 3, after the composite foam J is placed on the table in the lower molding chamber 62a of the lower molding member 62, the lower molding chamber 62a of the lower molding member 62 is placed. The synthetic resin film K was disposed on the entire open end using the chuck bodies 62c and 62c. As the synthetic resin film K, a synthetic resin film commercially available from CI Kasei under the trade name “Belbian SW-107” was used. This synthetic resin film K was formed from a polyvinyl chloride resin film having a thickness of 0.15 mm, and a pressure-sensitive adhesive layer containing 50 μm acrylic adhesive was formed on the entire back surface. The adhesive layer of the synthetic resin film K was set to the composite foam J side.

  Next, as shown in FIG. 4, the drive member 7 is driven to displace the upper molding member 61 downward, so that the open ends of the upper and lower molding chambers 61a and 62a of the upper and lower molding members 61 and 62 are matched. Thus, the upper and lower molding chambers 61a and 62a were hermetically sealed to form one combined molding chamber 63. The upper and lower molding chambers 61a and 62a constituting the combined molding chamber 63 are completely separated and separated from each other by the synthetic resin film K in an airtight manner.

  Thereafter, as shown in FIG. 5, air is sucked and removed from the combined molding chamber 63 of the vacuum molding apparatus 6, that is, the upper and lower molding chambers 61a and 62a, and the upper and lower molding chambers 61a and 62a are both vacuumed to 0.1 MPa The reduced pressure state. Next, the heater 61b disposed in the upper molding chamber 61a of the upper molding member 61 was operated to heat the synthetic resin film K to 95 ° C.

  Next, as shown in FIG. 6, when the synthetic resin film K is heated to 95 ° C. and becomes flexible, the table 62b disposed in the lower molding chamber 62a is displaced upward. The composite foam J placed on the table 62b was pressed toward the synthetic resin film K, and a part of the synthetic resin film K was brought into close contact with the composite foam J.

  While maintaining this state, air is supplied by opening an open valve in the upper molding chamber 61a of the upper molding member 61 to release the reduced pressure state, and the inside of the upper molding chamber 61a is brought to a normal pressure state. Was sucked and pressed toward the composite foam J by the pressure difference between the upper and lower molding chambers 61a and 62a and laminated in a state of being in close contact with the surface of the composite foam J (see FIG. 7).

  Next, after the synthetic resin film K is cooled, as shown in FIG. 8, the upper molding member 61 and the lower molding member 62 are displaced by moving the upper molding member 61 upward by driving the driving member 7. Then, the synthetic resin film K was cut at a portion that was not laminated and integrated on the surface of the composite foam J, and the composite L was taken out.

(Example 5)
A carbon fiber reinforced plastic sheet having a thickness of 0.23 mm (trade name “Pyrofil Prepreg TR3523 381GMP” manufactured by Mitsubishi Rayon Co., Ltd.) was used instead of the synthetic resin film, and the carbon fiber reinforced plastic sheet was heated to 105 ° C. A complex L was produced in the same manner as in Example 1. The carbon fiber reinforced plastic sheet was formed by impregnating a carbon fiber with a thermosetting epoxy resin. In the carbon fiber reinforced plastic sheet, the content of the thermosetting epoxy resin was 40% by weight.

(Example 6)
In place of the polyethylene terephthalate composition, a styrene-methacrylic acid-methyl methacrylate copolymer (trade name “MM290” manufactured by PS Japan Co., Ltd., styrene unit content: 84 wt%, methacrylic acid unit content: 11 wt% , Methyl methacrylate unit content: 5% by weight, glass transition temperature: 124 ° C., 100 parts by weight, and styrene-methacrylic acid-methyl methacrylate copolymer (trade name “MM290” manufactured by PS Japan Co., Ltd.), styrene unit Content: 84 wt%, methacrylic acid unit content: 11 wt%, methyl methacrylate unit content: 5 wt%, glass transition temperature: 124 ° C. (Methacrylic acid-methyl methacrylate copolymer content: 60% by weight, talc content: 40% by weight) Using a styrene-based resin composition containing parts by weight and from the middle of the extruder, butane comprising 35% by weight of isobutane and 65% by weight of normal butane was added to 100 parts by weight of a styrene-methacrylic acid-methyl methacrylate copolymer. 3 parts by weight into a molten styrene resin composition and uniformly dispersed in a styrene-methacrylic acid-methyl methacrylate copolymer. At the front end of the extruder, the molten styrene The composite was made in the same manner as in Example 1 except that the styrene-based resin composition was extruded and foamed from each nozzle of the multi-nozzle mold 1 attached to the front end of the extruder after being cooled to 200 ° C. L was produced.

(Example 7)
In place of the polyethylene terephthalate composition, a styrene-methacrylic acid-methyl methacrylate copolymer (trade name “MM290” manufactured by PS Japan Co., Ltd., styrene unit content: 84 wt%, methacrylic acid unit content: 11 wt% , Methyl methacrylate unit content: 5% by weight, glass transition temperature: 124 ° C., 100 parts by weight, and styrene-methacrylic acid-methyl methacrylate copolymer (trade name “MM290” manufactured by PS Japan Co., Ltd.), styrene unit Content: 84 wt%, methacrylic acid unit content: 11 wt%, methyl methacrylate unit content: 5 wt%, glass transition temperature: 124 ° C. (Methacrylic acid-methyl methacrylate copolymer content: 60% by weight, talc content: 40% by weight) Using a styrene-based resin composition containing parts by weight and from the middle of the extruder, butane comprising 35% by weight of isobutane and 65% by weight of normal butane was added to 100 parts by weight of a styrene-methacrylic acid-methyl methacrylate copolymer. 3 parts by weight into a molten styrene resin composition and uniformly dispersed in a styrene-methacrylic acid-methyl methacrylate copolymer. At the front end of the extruder, the molten styrene The composite was made in the same manner as in Example 5 except that the styrene resin composition was extruded and foamed from each nozzle of the multi-nozzle mold 1 attached to the front end of the extruder after the system resin composition was cooled to 200 ° C. L was produced.

  About the obtained composite_body | complex, the coverage and external appearance of a surface sheet were measured by the following method, and the result was shown in Table 1.

(Surface sheet coverage)
With measuring the total surface area S ₁ of the composite-body foam, among the complex-body foam, the total surface area S ₂ of the portion covered by the topsheet was measured and calculated according to the following equation.
Covering ratio of top sheet (%) = 100 × S ₂ / S ₁

(appearance)
The height of the peaks and valleys formed on the surface of the composite is determined according to JIS B0601 “Product Geometric Specifications-Surface Properties: Contour Curve Method-Terminology, Definitions and Surface Properties Parameters”-(FY2001) Standard length 0.8 mm, evaluation length using a measuring device equipped with a laser measuring instrument (trade name “LT-9000” manufactured by Keyence Corporation) and a roughness measurement system (trade name “MAP-2DS” manufactured by COMMS Corporation) The measurement was performed under the conditions of a thickness of 100 mm, a measurement pitch of 2 μm, and a speed of 500 μm / second. Specifically, a test piece having a length of 100 mm, a width of 100 mm, and a height of 10 mm was cut out from the composite, and the heights of peaks and valleys were measured on the surface of any of ten surface sheets of the test piece. The total number of portions where the height of the valley is 0.10 mm or more was counted and evaluated based on the following criteria.
A: No.
○: 1 or more and less than 10.
X: 10 or more.

1 Nozzle mold 2 Rotating shaft 3 Drive member 4 Cooling member
41 Cooling drum
42 Coolant 5 Rotary blade J Composite foam K Surface sheet L Composite

Claims (5)

In the cavity of the mold, it is produced by heat-sealing and integrating secondary foamed particles obtained by secondary foaming of thermoplastic resin foamed particles containing polyethylene terephthalate and having a crystallinity of less than 15%, and Foam for a composite used by pressing a surface sheet in a heated state on the surface and integrating the layers, and dimensional change when left in an atmosphere at a vacuum of 0.1 MPa and 100 ° C. for 15 minutes rate is Ri -1 to 1% der, together with the crystallinity of the surface portion is 16 to 30%, the residual blowing agent weight relative to 100 parts by weight of the thermoplastic resin constituting the composite-body foam And 0.7 parts by weight or less . The foam for a composite according to claim 1 , wherein the open cell ratio is 1 to 15%. The composite foam according to claim 1 or 2 , wherein the surface has an arithmetic average roughness Ra of 25 µm or less. A composite comprising a surface of the foam for a composite according to any one of claims 1 to 3 and one surface sheet laminated and integrated on 30 to 90% of the surface area. A member for transportation equipment comprising the foam for a composite according to any one of claims 1 to 3 or the composite according to claim 4 .

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