Composite material laminate

Abstract

To provide a composite material laminate excellent in bending rigidity, and productivity.SOLUTION: A composite material laminate includes: a foamed resin layer; a first resin adhesion layer bonded to one plane of the foamed resin layer; a second resin adhesion layer bonded to another plane of the foamed resin layer; a first metal layer bonded to a plane opposite side to a plane of the first resin adhesion layer bonded to the foamed resin layer: and a second metal layer bonded to a plane opposite side to a plane of the second resin adhesion layer bonded to the foamed resin layer, where the first resin adhesion layer includes laminating a first stretched film, and two or more layers of first adhesive resin layers, the second resin adhesion layer includes laminating the second stretched film, and two or more layers of the second adhesive resin layers, the tensile elastic modulus of at least one of the first and second stretched films is 2 GPa or more, and the composite material laminate includes laminating respective layers in the order of the first metal layer, the first adhesive resin layer, the first stretched film, the foamed resin layer, the second stretched film, the second adhesive resin layer, and the second metal layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a composite material laminate.

Background Art

[0002] A composite material laminate in which a metal material and a foamed material are laminated is used, for example, as a shock-absorbing member in various technical fields such as members of vehicles or electric devices, or structural materials of buildings or containers. As the composite material laminate, a laminate in which a metal and a resin foam are joined by an adhesive layer is known. Also, a method of laminating a metal and a resin foam is known. For example, as an example of the former, the techniques of Patent Documents 1 and 2 can be cited. Patent Document 1 discloses a laminate in which a metal and a resin foam are joined using a resin adhesive layer having the same composition as the resin foam. Further, Patent Document 2 discloses a method in which a raw material of a foamed resin material and the metal preform are placed in the same mold, and the metal preform and the foamed resin material are joined while foaming the raw material in the mold.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique of Patent Document 1 above, although the adhesive layer is defined, there is a problem that the thickness and tensile rigidity of the adhesive layer composition are insufficient, resulting in a decrease in the bending rigidity of the composite material laminate. Further, in the technique of Patent Document 2 above, no consideration has been given to the adhesive layer at the interface between the metal and the resin foam layer and its adhesive strength. Therefore, an object of the present disclosure is to provide a composite material laminate excellent in bending rigidity and productivity, and a method for manufacturing the same.

Means for Solving the Problem

[0005] In view of the above problems, the present inventor has conducted intensive research and repeated experiments. As a result, it has been found that the above problems can be solved by using a stretch film for the interface adhesive layer between the metal and the foam layer, and the present invention has been completed. That is, the present invention is as follows.

[0006] [1] A foam resin layer, A first resin adhesive layer adhered to one surface of the foam resin layer, A second resin adhesive layer adhered to the other surface of the foam resin layer, A first metal layer adhered to the surface of the first resin adhesive layer opposite to the surface adhered to the foam resin layer, A second metal layer adhered to the surface of the second resin adhesive layer opposite to the surface adhered to the foam resin layer, A composite material laminate comprising: The first resin adhesive layer includes two or more layers of a first stretch film and a first adhesive resin layer laminated together, The second resin adhesive layer includes two or more layers of a second stretch film and a second adhesive resin layer laminated together, At least one of the first and second stretch films has a tensile elastic modulus of 2 GPa or more, A composite material laminate including the layers laminated in the order of the first metal layer, the first adhesive resin layer, the first stretch film, the foam resin layer, the second stretch film, the second adhesive resin layer, and the second metal layer. Composite material laminate. [2] The composite material laminate according to [1], wherein the thermal shrinkage rate of at least one of the first and second stretch films at the glass transition temperature is 10% or more in at least one of the MD direction and the TD direction. [3] The composite material laminate according to [1] or [2], wherein at least one of the first and second stretch films and the foam resin layer contains the same resin material. [4] The first resin adhesive layer includes two or more layers of a first stretched film with an average thickness of 500 μm or less and a first adhesive resin layer with an average thickness of 100 μm or less laminated together. The second resin adhesive layer includes two or more layers of a second stretched film with an average thickness of 500 μm or less and a second adhesive resin layer with an average thickness of 100 μm or less laminated together. The composite material laminate according to any one of [1] to [3]. [5] The composite material laminate according to any one of [1] to [4], wherein the average thickness of at least one of the first and second stretched films is 100 μm or less. [6] The composite material laminate according to any one of [1] to [5], wherein the Tg of at least one of the first and second adhesive resin layers is -10°C or higher. [7] The composite material laminate according to any one of [1] to [6], wherein the foamed resin layer contains a bead resin foam. [8] A method for manufacturing a composite material laminate according to any one of [1] to [7], In a processing apparatus capable of supplying pressure and heat, the first metal layer, the first resin adhesive layer, the raw material of the foamed resin layer, the second resin adhesive layer, and the second metal layer are laminated and installed in the order of the first metal layer, the first adhesive resin layer, the first stretched film, the raw material of the foamed resin layer, the second stretched film, the second adhesive resin layer, and the second metal layer. While foaming the raw material of the foamed resin layer to form a foamed resin layer, the first metal layer is adhered to one surface of the foamed resin layer via the first resin adhesive layer, and the second metal layer is adhered to the other surface of the foamed resin layer via the second resin adhesive layer to obtain the composite material laminate, a foaming bonding step A method for manufacturing a composite material laminate including the above. [9] A method for manufacturing a composite material laminate according to any one of [1] to [7], In the same mold, the first metal layer, the first resin adhesive layer, the foamed resin layer, the second resin adhesive layer, and the second metal layer are laminated and installed in the order of the first metal layer, the first adhesive resin layer, the first stretched film, the foamed resin layer, the second stretched film, the second adhesive resin layer, and the second metal layer. An installation step; By heating the mold, the first metal layer is adhered to one surface of the foamed resin layer via the first resin adhesive layer, and the second metal layer is adhered to the other surface of the foamed resin layer via the second resin adhesive layer to obtain the composite material laminate. A bonding step; A method for manufacturing a composite material laminate, comprising:

Advantages of the Invention

[0007] According to the present disclosure, a composite material laminate excellent in bending rigidity and productivity can be provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. However, the present invention is not limited to the following description, and various modifications can be made within the scope of the gist thereof. In the present embodiment, "A (numerical value) to B (numerical value)" means A or more and B or less.

[0010] The composite material laminate of this embodiment can be used, for example, as a shock-absorbing member that absorbs impacts received from the outside of an article and protects components or members installed inside the article from impacts. The composite material laminate of this embodiment can be suitably used as an outer cover of an article, for example, an under cover attached to the lower part of an automobile to protect the battery loaded in the automobile from impacts. The composite material laminate of this embodiment is a foamed resin layer, a first resin adhesive layer adhered to one surface of the foamed resin layer, a second resin adhesive layer adhered to the other surface of the foamed resin layer, a first metal layer adhered to the surface of the first resin adhesive layer opposite to the surface adhered to the foamed resin layer, a second metal layer adhered to the surface of the second resin adhesive layer opposite to the surface adhered to the foamed resin layer, and includes. The first resin adhesive layer includes two or more layers of a first stretched film and a first adhesive resin layer laminated. The second resin adhesive layer includes two or more layers of a second stretched film and a second adhesive resin layer laminated. The tensile elastic modulus of at least one of the first and second stretched films is 2 GPa or more. The composite material laminate includes each layer laminated in the order of the first metal layer, the first adhesive resin layer, the first stretched film, the foamed resin layer, the second stretched film, the second adhesive resin layer, and the second metal layer. Note that the names of the components with "first" and "second" are only for convenience to distinguish two similar components included in the composite material laminate. In particular, the component with "first" attached refers to the component on the side that can receive impacts (for example, the "first metal layer" refers to the panel attached to the lower part of the automobile), and the component with "second" attached refers to the plate member on the side where components or members to be protected from impacts (for example, the battery loaded in the automobile) can be installed (for example, the "second metal layer" refers to the base plate or plate member).

[0011] If the shear fracture strength at the interface between the metal substrate and the adhesive layer is 0.4 MPa or more, the interfacial strain between the metal substrate and the adhesive layer due to expansion and contraction in the actual use environment can be absorbed. When it is 1.0 MPa or more, the adhesiveness can be maintained in an environment exposed to a vibrating state, and moreover, it has the effect of being able to absorb the strain of expansion and contraction of the material accompanying changes in the humid heat environment. More preferably, the upper limit of the shear fracture strength at the interface between the metal substrate and the adhesive layer is 30 MPa or less, and particularly preferably 23 MPa or less. Hereinafter, with reference to the drawings, the composite material laminate of the present embodiment will be described. As shown in FIG. 1, the composite material laminate 1 is a laminate having a metal substrate 4, an adhesive layer 3 provided on one surface of the metal substrate 4, and a foam layer 2 provided on one surface of the adhesive layer 3. Further, in FIG. 1, as a preferred form of the composite material laminate 1, a resin melt layer 5, which is an optional component described later, is shown in a form provided on the surface of the foam layer 2.

[0012] The thickness of the composite material laminate 1 in the present embodiment is preferably 2 to 100 mm, and more preferably 5 to 80 mm. The thickness of the composite material laminate 1 is calculated by the method described in the examples described later.

[0013] Hereinafter, after explaining the preferred characteristics of the composite material laminate 1 of the present embodiment, the foam layer 2, the adhesive layer 3, and the metal substrate 4, which are the components of the composite material laminate 1 of the present embodiment, will be described. "Preferred characteristics of the composite material laminate" In the present embodiment, the compressive strength of 75% compression of the composite material laminate 1 at a temperature [Tm (°C) or Tg (°C) - 20 °C] obtained by subtracting 20 °C from the melting point (Tm) or glass transition temperature (Tg) of the foam layer 2 is preferably 0.3 MPa or more, more preferably 0.35 MPa or more and 5 MPa or less, and even more preferably 0.4 MPa or more and 3 MPa or less. When measuring the compressive strength of 75% compression of the composite material laminate 1 of the present embodiment at a temperature [Tm (°C) or Tg (°C) - 20°C] obtained by subtracting 20°C from the melting point (Tm) or glass transition temperature (Tg) of the foam layer 2, in the pretreatment of the adhesion step, the foam surface is heated directly by heat transfer from the metal substrate 4 side or indirectly by infrared irradiation or the like. Subsequently, in the adhesion step, even if a sufficient load is applied from the metal substrate 4 side or the foam layer 2 side, the effect that the load can be applied to the adhesive layer 3 due to the compressive deformation of the foam layer 2 adjacent to the adhesive layer 3 can be quantitatively grasped, which is preferable from this viewpoint. And when the compressive strength of 75% compression of the composite material laminate 1 of the present embodiment at the said temperature is 0.3 MPa or more, it is preferable from the viewpoint that generation | occurrence | production of a void can be suppressed and resin intrusion into an uneven | corrugated part can be promoted when forming the adhesive layer 3. Furthermore, when the said compressive strength is 0.3 MPa or more, it becomes easy to control the shear fracture strength (S) of the interface between the said metal base material 4 and the adhesive layer 3 and the ratio (S / F) which divided the shear fracture strength (S) of the said interface by the bending elastic modulus (F) of the foam layer 2 into a predetermined range. Moreover, as the temperature [Tm (°C) or Tg (°C) - 20°C] obtained by subtracting 20°C from the melting point (Tm) or glass transition temperature (Tg) of the foam layer 2, specifically, it is preferably 40 to 300°C, and more preferably 100 to 250°C.

[0014] In the present embodiment, the loss coefficient (η 23 ) in the measurement using the center excitation method at room temperature (23°C) in the range of 50 to 2000 Hz is preferably 0.05 or more, and more preferably 0.06 to 0.5. When the loss coefficient (η 23 ) is 0.05 or more, when impact energy is applied to the composite material laminate 1, due to the viscoelastic characteristics of the foam (layer), the transmission of energy due to the vibration of the metal (substrate) can be suppressed, and the energy can be dispersed over a wide area, which is preferable from this viewpoint. By the transmission of energy due to the vibration of the metal (substrate), it is possible to suppress the problem that energy propagates to the welding part or the like for fixing the composite material laminate 1 and detaches. In the present embodiment, the loss coefficient (η 80) is preferably 1.2 times or more, more preferably 1.3 to 10 times, of the loss coefficient (η 23 ) at room temperature (23 °C) within the range of 50 to 2000 Hz. When the loss coefficient (η 23 ) of the composite material laminate 1 of the present embodiment in the measurement using the center excitation method at room temperature (23 °C) is 0.05 or more, and the loss coefficient (η 80 ) in the measurement using the center excitation method at 80 °C shows 1.2 times or more of the loss coefficient (η 23 ) at room temperature (23 °C) within the range of 50 to 2000 Hz, it can be confirmed that the material is excellent in vibration damping property with fast vibration attenuation. In the present embodiment, the loss coefficient (η 80 ) of 50 to 2000 Hz in the measurement using the center excitation method at 80 °C is preferably 0.06 to 0.6, more preferably 0.072 to 0.5. Note that the measurement method of the loss coefficient is as described in the column of Examples. Based on JIS K7391, the loss coefficient is calculated by the half-value width method from the peak of the second resonance of the frequency response function measured by the center excitation method.

[0015] "Foam layer" The composite material laminate 1 of the present embodiment has a foam layer 2. And the foam layer 2 in the present embodiment preferably has a flexural modulus of 20 to 2000 MPa and a heat dimensional stability of less than 3%. The foam layer 2 in the present embodiment is preferably a closed-cell foam. The closed-cell foam is a foam obtained by a closed-cell bead foaming molding method. More specifically, the closed-cell foam has closed cells separated by a resin film and is formed by a mechanism in which the foamed particles fuse with each other due to the expansion of the cells, so that the cell structure of the usually obtained foam is basically a closed-cell structure. Therefore, the sound insulation characteristics due to rigidity are more likely to be exhibited.

[0016] <Flexural modulus> In this embodiment, the flexural modulus of the foam layer 2 is preferably 20 to 2000 MPa, more preferably 25 to 1500 MPa or more, and even more preferably 30 to 1000 MPa.

[0017] When the flexural modulus of the foam layer 2 is 20 MPa or more, due to the elastic characteristics of the foam, the loss factor in the frequency range of 50 to 1000 Hz at room temperature (23°C) becomes a high value, and a vibration damping effect can be obtained. On the other hand, when the elastic modulus of the foam layer is 2000 MPa or less, sufficient lightness can be ensured as a vibration damping material.

[0018] In this embodiment, the elastic modulus of the foam layer 2 can be measured and evaluated by measuring the flexural modulus of the foam layer 2. The larger the numerical value of the flexural modulus, the better the rigidity. The flexural modulus of the foam layer 2 can be measured according to JIS K7171 (2008). The flexural modulus of the foam layer 2 can be controlled by the foaming ratio of the foam constituting the foam layer 2, the rigidity of the foam resin, etc. Also, the flexural rigidity of the foam layer 2 can be adjusted by adjusting the thickness or material of the foam layer 2.

[0019] <Thickness> The thickness of the foam layer 2 in this embodiment is preferably 2 to 100 mm, more preferably 5 to 80 mm. The thickness here refers to the number average value of the thickness of the foam layer 2 in the composite material laminate 1 according to the present invention. In this specification, the layer thickness means the number average value of the results of measuring the foam layer 6 times with a length measuring instrument such as a vernier caliper.

[0020] When the thickness of the foam layer 2 is 2 mm or more, the foam layer 2 has self-supporting properties and is preferably used as a structural member, more preferably 5 mm or more. Also, when the thickness of the foam layer 2 is 80 mm or less, it is preferable in that a molded product can be obtained by a hot press machine or a foam molding machine.

[0021] <Average bubble diameter> In the present embodiment, it is preferable that the average cell diameter of the foam layer 2 is 10 to 300 μm, more preferably in the range of 20 to 280 μm, and still more preferably in the range of 30 to 270 μm. When the average cell diameter of the foam layer 2 is within the above range, it is preferable from the viewpoint that the impact absorption energy by the air layer in the closed cells can be dispersed and the buckling of the closed cells can be suppressed. Further, when the average cell diameter of the foam layer 2 is within the above range, it becomes easy to control the shear fracture strength (S) of the interface between the metal base material 4 and the adhesive layer 3 and the ratio (S / F) obtained by dividing the shear fracture strength (S) of the interface by the flexural modulus (F) of the foam layer 2 within a predetermined range. The method for measuring the average cell diameter of the foam layer 2 shall be the method described in the column of Examples.

[0022] <Closed cell ratio> In the present embodiment, the closed cell ratio of the foam layer 2 is not particularly limited, but is preferably 30% or more and 99% or less. When the closed cell ratio is within this range, an elastic repulsive force is maintained during compression, the followability to the mold is improved, and a design surface with high surface smoothness can be formed. The closed cell ratio of the foam layer 2 of the present embodiment is more preferably 80% or more and 99% or less, and still more preferably 85% or more and 99% or less, from the viewpoint of improving the strength of the composite material laminate 1 and making it difficult for water to be taken into the resin that can occur in the open cell portion, and making it difficult to reduce the density of the foam layer 2. The closed cell ratio S (%) is calculated by the formula represented by the following formula (1). S (%) = {(Vx - W / ρ) / (Va - W / ρ)} × 100 ···(1) In the above formula (1), Vx is the true volume (cm 3 ) of the foam layer 2, Va is the apparent volume (cm 3 ) of the foam layer 2, W is the weight (g) of the foam layer 2, and ρ is the resin density (g / cm 3 ) of the foam layer 2.

[0023] From the perspective of weight reduction, the expansion ratio of the foamed particles constituting the foam layer 2 in this embodiment is preferably 3.0 times or more, and more preferably 5.0 times or more. Also, from the perspective of maintaining the elastic resilience during compression, it is preferably less than 30 times, and more preferably 20 times or less. Here, the expansion ratio means how much the volume has expanded from the state of the base resin through the inclusion (impregnation) of the foaming agent, pre-foaming, and final-stage foaming.

[0024] The expansion ratio of the foamed particles constituting the foam layer 2 in this embodiment can be calculated by dividing the density of the base resin (starting material) constituting the foam layer 2 by the apparent density of the foam layer portion. Alternatively, it may be calculated by dividing the density of the base resin by the apparent density of the foam layer 2 which is an intermediate product. The foamed particles constituting the foam layer 2 are less likely to be affected by the pressure compression during the manufacturing process of the foam layer 2 due to the presence of the foamed particles constituting the foam layer 2, and can maintain the expansion ratio immediately before pressure compression. More specifically, the expansion ratio can be calculated by the method described in the examples below.

[0025] <Composition of the foam layer> The foam layer 2 of the present invention contains the first resin in the form of foamed particles. And the first resin is preferably a thermoplastic resin.

[0026] Here, the "foamed particles" in this specification are the particles constituting the foam layer in this embodiment, and refer to the expanded particles after performing the final-stage foaming on the pre-foamed particles.

[0027] Also, the "pre-foamed particles" in this specification refer to the foamable particles on which the final-stage foaming has not been performed, and include the state before and after the implementation of the preliminary foaming that is not the final stage.

[0028] The above-mentioned thermoplastic resin is not particularly limited. For example, polyacetal, polystyrene, poly-α-methylstyrene, styrene maleic anhydride copolymer, blend or graft polymer of polyphenylene oxide and polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene polymer, styrene-butadiene copolymer, high-impact polystyrene and other styrene polymers; polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, post-chlorinated polyvinyl chloride, copolymer of ethylene or propylene and vinyl chloride and other vinyl chloride polymers; polyvinylidene chloride copolymer resin; nylon-6, nylon-6,6 and other homopolymer and copolymer polyamide resins; polybutylene terephthalate or polyethylene terephthalate and other homopolymer and copolymer polyester resins; polyether resin such as polyethersulfone or polyetheretherketone; modified polyphenylene ether resin (phenylene ether-polystyrene alloy resin); polycarbonate resin; imide resins such as polyamideimide, polyimide, polyetherimide, methacrylimide; polyphenylene sulfide resin; polysulfone resin; polyethersulfone resin; phenol resin; urethane resin; polyolefin resins such as polypropylene or polymethylpentene; polyester resins; fluorine resins such as polyvinylidene fluoride or polytetrafluoroethylene; and the like.

[0029] Examples of the above-mentioned polyolefin resins include polypropylene resins such as polypropylene polymerized using a Ziegler catalyst or a metallocene catalyst, ethylene-propylene random copolymer, propylene-butene random copolymer, ethylene-propylene block copolymer, ethylene-propylene-butene terpolymer, etc., and polyethylene resins such as low-density polyethylene, medium-density polyethylene, linear low-density polyethylene, linear ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ionomer resin, etc. These polyolefin resins can be used alone or in combination.

[0030] Particularly preferred thermoplastic resins include polyolefin resins, polyamide resins, polyester resins, polyether resins, methacrylic resins, modified polyether resins (phenylene ether-polystyrene alloy resins), and the like. Among them, polyamide resins are excellent in heat resistance, chemical resistance, and solvent resistance and are suitable for use as high heat-resistant foam structure materials. Modified polyether resins (phenylene ether-polystyrene alloy resins) are excellent in heat resistance and high-temperature rigidity.

[0031] As the above-mentioned thermoplastic resin, the surface tension at 20°C is preferably 35 mN / m or more and 60 mN / m or less, more preferably 36 mN / m or more and 57 mN / m or less, and still more preferably 37 mN / m or more and 55 mN / m. If the surface tension of the thermoplastic resin is within the above range, a foam molded body with high mechanical strength can be obtained, and rigidity can be imparted to the design surface.

[0032] The surface tension of the above-mentioned thermoplastic resin uses the value measured by changing the measurement temperature to 20°C in the method described in JIS K6768:1999 "Plastics - Films and Sheets - Method for Measuring Wettability Tension".

[0033] The above-mentioned thermoplastic resin may be used in an uncrosslinked state or may be crosslinked by a peroxide or radiation and then used.

[0034] In the foam layer in this embodiment, with respect to the total amount (100% by mass) of the foam layer 2, the thermoplastic resin preferably contains 50 to 99% by mass, more preferably 70 to 95% by mass, and still more preferably 80 to 90% by mass. Impact resistance and vibration damping properties are more likely to be exhibited.

[0035] In this embodiment, it is preferable that the total amount of the metal compound is 0.2 to 10% by mass, more preferably 0.5 to 8% by mass, and even more preferably 0.8 to 7.5% by mass with respect to the total amount (100% by mass) of the foam layer 2. When the total amount of the metal compound contained in the foam layer is 0.2 to 10% by mass, the effect of increasing the adhesive force with the above adhesive material is more likely to be exhibited.

[0036] Examples of the metal compound include metals or metal oxides. Examples of the metal include silver, gold, calcium, potassium, iron, various steel agents, copper, nickel, neodymium, titanium, zinc, niobium, manganese, chromium, tin, silicon, aluminum, or alloys thereof.

[0037] Examples of the metal oxide include oxides of the above metals. Specifically, silver oxide, calcium oxide, magnesium oxide (including talc), potassium oxide, iron oxide, copper oxide, nickel oxide, neodymium oxide, titanium oxide, zinc oxide, niobium oxide, manganese oxide, chromium oxide, tin oxide, silicon oxide (including silica and fused silica), and aluminum oxide are preferable. Further, the above metal or metal oxide may be surface-modified by a known method. In this embodiment, the metal compound may be used alone or in combination of two or more.

[0038] In addition to the above-mentioned first resin as an essential component and the above metal compound as an optional component, the foam layer 2 in this embodiment may further contain a compounding agent as necessary.

[0039] Examples of the compounding agent include, in addition to the above-mentioned metal compounds, antioxidants, light stabilizers, ultraviolet absorbers, flame retardants, bubble regulators, foaming agents, colorants such as dyes or pigments, plasticizers, lubricants, crystallization nucleating agents, and inorganic fillers such as calcium carbonate. In this embodiment, the compounding agent may be used alone or in combination of two or more.

[0040] As the above-mentioned flame retardant, flame retardants such as bromine-based and phosphorus-based ones can be used. As the above-mentioned antioxidant, antioxidants such as phenol-based, phosphorus-based, and sulfur-based ones can be used. As the above-mentioned light stabilizer, light stabilizers such as hindered amine-based and benzophenone-based ones can be used.

[0041] In addition, in this embodiment, when it is necessary to adjust the average cell diameter of the pre-expanded particles when forming the foam layer 2, a cell regulator may be contained. Examples of the cell regulator include talc, silica, calcium silicate, calcium carbonate, aluminum oxide, titanium oxide, diatomaceous earth, clay, sodium bicarbonate, alumina, barium sulfate, aluminum oxide, bentonite, etc. The amount used is usually 0.005 to 2 parts by mass with respect to 100 parts by mass of the total amount of the raw materials of the pre-expanded particles.

[0042] The above-mentioned pre-expanded particles can be obtained by containing (impregnating) a foaming agent in the pelletized above-mentioned first resin (for example, a thermoplastic resin) to cause foaming. This foaming is pre-foaming that is not the final-stage foaming.

[0043] Examples of the foaming agent used in the production of the above-mentioned pre-expanded particles include volatile foaming agents. Examples of the above-mentioned volatile foaming agents include chain or cyclic lower aliphatic hydrocarbons such as methane, ethane, propane, butane, isobutane, pentane, isopentane, neopentane, hexane, heptane, cyclopentane, cyclohexane, and methylcyclopentane; halogenated hydrocarbons such as dichlorodifluoromethane, trichloromonofluoromethane, 1-chloro-1,1-difluoroethane, and 1-chloro-2,2,2-trifluoroethane; and inorganic gas-based foaming agents such as nitrogen, air, and carbon dioxide.

[0044] The amount of the compounding agent in the foam layer 2 in this embodiment can be appropriately selected within a range that does not prevent the effects of the present invention.

[0045] The average particle diameter of the above-mentioned pre-expanded particles can be measured by a classification method using standard sieves defined in JIS Z8801-1:2006 for 100 g of the pre-expanded particles. The average particle diameter of the above-mentioned pre-expanded particles is preferably 0.8 to 4.0 mm, more preferably 1.0 to 3.0 mm. If the average particle diameter is less than 1.0 mm, it is difficult to handle in the manufacturing process, and if it exceeds 4.0 mm, the surface accuracy of complex molded products tends to decrease, which is not preferable. Note that the shape of the pre-expanded particles of the present embodiment is not particularly limited and may be various shapes.

[0046] In the present embodiment, as a method for manufacturing pre-expanded particles, (i) a method using a thermoplastic resin as the first resin and utilizing its thermoplasticity, (ii) a method by post-processing such as cutting solid-state first resin particles, etc. are possible, and any method can be applied as long as it can impart a desired outer shape to the particles. Among them, as a method excellent in productivity and capable of manufacturing particles with a stable shape, a profile extrusion method using a die provided with a discharge cross-section can be preferably used. As the profile extrusion method, a method of melting and extruding the first resin (for example, a thermoplastic resin) by an extruder, pelletizing the obtained base resin pellets by an industrially commonly used method such as strand cutting or underwater cutting, and then foaming to obtain pre-expanded particles; and a method of injecting a foaming agent into the middle of the barrel of the extruder and foaming simultaneously with discharge, and after cooling, directly obtaining pre-expanded particles by underwater cutting or strand cutting; a method of melting a thermoplastic resin in an extruder, extruding it from a die having a desired cross-sectional shape, cooling, and then cutting it to a predetermined length by a pelletizer to manufacture base resin pellets, impregnating the base resin pellets with a foaming agent, and heating to foam at a predetermined expansion ratio; etc., can be manufactured by arbitrarily applying conventionally known methods.

[0047] The method of containing (impregnating) a foaming agent in the first resin is not particularly limited and may be a generally used method.

[0048] Such methods are not particularly limited. For example, there are methods performed using an aqueous medium in a suspension system such as water (suspension impregnation), methods using a thermal decomposition type foaming agent such as sodium bicarbonate (foaming agent decomposition), methods of making a gas into a liquid phase state with an atmosphere above the critical pressure and bringing it into contact with the base resin (liquid phase impregnation), methods of making a gas into a gas phase state with an atmosphere below the critical pressure and bringing it into contact with the base resin (gas phase impregnation), and the like.

[0049] "Metal base material" The composite material laminate of the present embodiment has a metal base material 4. And the metal base material 4 in the present embodiment is not particularly limited and can be appropriately selected according to the application. For example, when emphasizing weight reduction, as the material of the metal base material, for example, an aluminum plate, an aluminum alloy plate, a magnesium plate, or a magnesium alloy plate is preferable. When emphasizing mechanical strength, as the metal base material 4, iron, steel materials, stainless steel, copper, copper alloy, manganese, manganese alloy, titanium, or titanium alloy is preferable. When emphasizing vibration damping properties, as the metal base material, magnesium, magnesium alloy, iron-based alloy, copper alloy, or manganese alloy is preferable. Further, the shape of the metal base material 4 can be appropriately selected according to the purpose of use as long as it has a surface that can be in close contact with the adhesive layer 3 or the foam layer 2, and so-called flat plates or curved plates can be mentioned.

[0050] The average thickness of the metal base material 4 in the present embodiment is not particularly limited, but for example, it is preferably 0.2 mm or more, more preferably 0.5 to 3 mm, and even more preferably 0.7 to 2 mm. If the average thickness of the metal base material 4 is less than 0.2 mm, the mechanical strength is insufficient and it becomes difficult to manufacture the vibration damping metal plate. Note that the average thickness of the metal base material 4 is calculated by the method described in the examples described later.

[0051] In this embodiment, the surface of the metal substrate 4, particularly the surface in contact with the adhesive layer 3, may be subjected to surface treatment if necessary. Examples of such surface treatment include sandblasting, polishing, degreasing, etching, surface treatment by dipping or spraying a rust preventive agent, chromate conversion treatment, phosphate conversion treatment, sulfide conversion treatment, anodic oxidation film formation, or fluororesin coating. Also, in this embodiment, a method of oxidizing and etching the surface of the metal substrate 4 using chemicals such as acids, alkalis, or oxidants to improve the affinity for the adhesive layer 3 or the foam layer 2, a method of oxidizing and etching the surface of the metal substrate 4 using ozone, plasma, ultraviolet rays, etc. to improve the affinity for the adhesive layer 3 or the foam layer 2, or a method of applying a primer treatment such as silane or titanate to the metal substrate 4 to improve the affinity for the adhesive layer 3 or the foam layer 2 may be applied.

[0052] In this embodiment, the surface roughness (10-point average maximum height (Rz), reference length 0.25 mm) of the surface of the metal substrate 4 that is in contact with the adhesive layer 3, i.e., the adhesive surface of the metal substrate 4, is preferably 0.5 μm or more and less than 300 μm, preferably 0.5 to 150 μm, and more preferably 0.8 to 100 μm. When the surface roughness of the surface of the metal substrate 4 on the adhesive layer 3 side in the metal substrate 4 is within the above range, it is preferable from the viewpoint that the adhesive layer 3 can penetrate into the rough surface to exhibit an anchor effect and suppress the generation of bubbles in the rough surface during adhesion.

[0053] <Resin adhesive layer> The composite material laminate 1 of this embodiment includes first and second resin adhesive layers. The first resin adhesive layer includes two or more layers of a first stretched film and a first adhesive resin layer laminated together. The second resin adhesive layer includes two or more layers of a second stretched film and a second adhesive resin layer laminated together.

[0054] <Stretched film> In this embodiment, the first and second stretched films are layers that adhere to the foamed resin layer in the first and second resin adhesive layers, respectively. By using a stretched film as the layer that adheres to the foamed resin layer, the bending strength of the resin adhesive layer is increased. Thereby, a composite laminate having high bending rigidity can be obtained.

[0055] Examples of the stretched film generally include an aluminum foil, glassine paper, a film made of a thermoplastic resin, etc. From the viewpoints of easy incinerability, recyclability, print readability, etc. at the time of disposal, a film containing a thermoplastic resin is preferable, and a film made of a thermoplastic resin is more preferable. The thermoplastic resin is not particularly limited as long as it can be formed into a film shape, and examples thereof include styrenic resins, olefinic resins such as ethylene-based resins and propylene-based resins, ester-based resins (including polylactic acid), amide-based resins, etc. One of these can be used alone, or two or more can be used in combination. Among the thermoplastic resins, styrenic resins are preferably used from the viewpoints of rigidity and brittleness.

[0056] The styrenic resin is a homopolymer or copolymer of a styrenic monomer and a mixture composition thereof. Examples of the styrenic monomer include styrene (e.g., GPPS), alkyl styrenes such as α-methylstyrene, etc. The copolymer of the styrenic monomer is a styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylate copolymer, styrene-(meth)acrylic acid-(meth)acrylate copolymer, styrene - maleic anhydride copolymer, styrene - butadiene copolymer, high impact polystyrene (e.g., HIPS), styrene - α-methylstyrene copolymer, etc., in which the styrene component is 50 mass% (wt%) or more. In addition, polymer alloys (m-PPE) of polystyrene and polyphenylene ether resin are also used for styrenic resins.

[0057] Among these, more preferably, at least one selected from the group consisting of a styrene-acrylic acid copolymer, a styrene-methacrylic acid copolymer, a styrene-maleic anhydride copolymer, and a terpolymer resin containing an ester component as an additional monomer component to two monomer components constituting any one of these three copolymers is used.

[0058] Examples of the ester component of the terpolymer resin include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, and the like. These ester components are effective in improving the thermal stability of the resin when heat is continuously applied, such as during melt processing in an extruder.

[0059] Among the above, a styrene-methacrylic acid copolymer and a terpolymer resin containing an ester component therein are more preferable in terms of ease of extrusion stretching film formation.

[0060] When forming a stretched film from a thermoplastic resin, a filler, particularly an inorganic filler, may be blended with the thermoplastic resin. Examples of the inorganic filler include amorphous aluminosilicate, silica, alumina, talc, kaolin, mica, wollastonite, clay, calcium carbonate, glass fiber, aluminum sulfate, and the like.

[0061] In addition, additives commonly used in the art, such as metal soaps for assisting the dispersion of the above inorganic fillers, colorants, plasticizers, antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, antistatic agents, etc., may be blended with the stretched film, or treatments such as corona treatment, plasma treatment, ultraviolet treatment, AC (anchor coat) treatment, etc. for improving the characteristics of printing and vapor deposition treatment may be performed. It is okay.

[0062] As a typical example of a method for manufacturing a stretched film, a thermoplastic resin (a resin compounded with an inorganic filler at a predetermined ratio if necessary) is melt-kneaded by a screw extruder or the like, formed into a sheet by a T-die, and then uniaxially stretched by roll stretching or tenter stretching, a method of biaxially stretching by following roll stretching with tenter stretching, a method of stretching by an inflation method, and the like can be mentioned.

[0063] In the present embodiment, the thermal shrinkage rate at the glass transition temperature of at least one, preferably both, of the first and second stretched films is preferably 10% or more, more preferably 15% or more, and even more preferably 30% or more in at least one, preferably both, of the MD direction and the TD direction. Here, the direction in which the maximum heating dimensional shrinkage rate occurs is defined as the "MD direction", and the direction perpendicular thereto is defined as the "TD direction". If the thermal shrinkage rate at the glass transition temperature of the stretched film is equal to or higher than the above lower limit, the elastic modulus of the stretched film increases, and thus the bending strength of the resin adhesive layer increases. Thereby, a composite material laminate having high bending rigidity can be obtained.

[0064] In the present embodiment, if the total thickness of the resin adhesive layer including the stretched film is too thick, simultaneous bending processing with the metal layer becomes difficult. Therefore, the average thickness of the first and second stretched films is preferably 500 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less for at least one, preferably both, of the first and second stretched films. Also, from the viewpoint of ensuring adhesiveness with the metal layer, the average thickness of at least one, preferably both, of the first and second stretched films is preferably 10 μm or more, and more preferably 20 μm or more.

[0065] In the present embodiment, the tensile elastic modulus of at least one of the first and second stretched films is 2 GPa or more, preferably 2.1 GPa or more, and more preferably 2.2 GPa or more. If the elastic modulus of the stretched film is high, the bending strength of the resin adhesive layer increases. Thereby, a composite material laminate having high bending rigidity can be obtained.

[0066] In this embodiment, as the materials of the first and second stretched films, from the viewpoint that if the same type of resin materials are included, the same type of resin materials are likely to adhere to each other, at least one, preferably both of the first and second stretched films, and the foamed resin layer preferably contain the same type of resin material.

[0067] <Adhesive resin layer> In this embodiment, the first adhesive resin layer is a layer that adheres to the first metal layer in the first resin adhesive layer. The second adhesive resin layer is a layer that adheres to the second metal layer in the second resin adhesive layer. By using an adhesive resin layer as the layer that adheres to the metal layer, the adhesive strength between the resin adhesive layer and the metal layer is increased. Thereby, the mold followability of the resin adhesive layer when deforming the metal layer by bending during the production of the composite material laminate becomes good.

[0068] The type of the adhesive resin preferably mainly comprises at least one selected from the group consisting of a polyurethane-based resin, a polyester-based resin, an acrylic-based resin, and a vinyl acetate-based copolymer. In the adhesive resin, within a range that does not impair the properties of the adhesive resin, for example, a polyvinyl butyral-based resin, a vinyl benzene-based resin, a polyamide-based resin, a vinyl chloride-vinyl acetate-based copolymer, a vinyl chloride-polyester-based resin, chlorinated polyolefins (chlorinated polypropylene, chlorinated polyethylene, etc.), a styrene-based block copolymer and its derivatives (styrene-isoprene block copolymer, styrene-butadiene block copolymer, and their hydrogenated products and maleic anhydride-modified products, etc.) may be preferably contained in a range of less than 50% by mass, more preferably in a range of less than 40% by mass, and particularly preferably in a range of less than 30% by mass.

[0069] --Polyurethane-based resin-- The polyurethane-based resin is a reaction product of a polyisocyanate and a polyol.

[0070] The polyisocyanate compound used in the synthesis of the polyurethane-based resin is not particularly limited as long as it is an organic polyisocyanate compound containing two or more isocyanate groups in one molecule. Examples include tolylene diisocyanate, diphenylmethane diisocyanate, cyclohexane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate (HDI), trimethylhexane diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, 2,6-diisocyanatemethyl caproate, isophorone diisocyanate (IPDI), methylcyclohexane-2,4-(or 2,6-)diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and other aromatic, aliphatic, and alicyclic organic diisocyanates. One of these can be used alone, or two or more can be mixed and used. From the perspective of preventing coloring, aliphatic isocyanate is preferred, and from the perspective of resin strength, aromatic isocyanate is preferred.

[0071] Examples of the polyol used in the synthesis of the polyurethane-based resin include polyester diol, polyether diol, polyester polyol, polyacrylic diol, polyester amide diol, polycarbonate diol, or high molecular polyols such as mixtures or copolymers thereof. Examples of the polyether diol include polyoxyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, polyoxypentamethylene glycol, a copolymerized polyether glycol composed of a tetramethylene group and a 2,2-dimethylpropylene group, a copolymerized polyether glycol composed of a tetramethylene group and a 3-methyltetramethylene group, or a mixture thereof. Examples of the polyester diol include esterification reaction products of polycarboxylic acids and their acid anhydrides with alkyl polyols, and esterification reaction products obtained by polymerizing hydroxycarboxylic acids and / or lactones, which are internal esters thereof, using alkyl polyols as initiators. Examples of the polycarboxylic acid include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, 2,3-dimethylsuccinic acid, hexylsuccinic acid, glutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylglutaric acid, 3,3-diethylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,1-cyclobutanedicarboxylic acid, and the like. Specific examples of the alkyl polyol constituting the polyester polyol include ethylene glycol, 1,3-propanediol, propylene glycol, 2,3-butanediol, 1,4-butanediol, 2-ethylbutane-1,4-diol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,9-decanediol, 1,4-cyclohexanediol, 1,4-dimethylolcyclohexane, 2,2-diethylpropane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 3-methylpentane-1,4-diol, 2,2-diethylbutane-1,3-diol, 4,5-nonanediol, diethylene glycol, triethylene glycol, dipropylene glycol, neopentyl glycol, glycerin, pentaerythritol, erythritol, sorbitol, mannitol, trimethylolpropane, trimethylolethane, and the like. Among these, polyester diol is preferable from the viewpoint of resin strength.

[0072] --Polyester resin-- The polyester resin is a polymer synthesized by a polycondensation reaction of a polyvalent carboxylic acid and a polyvalent alcohol, and various raw materials can be used. As the type of polyester resin, any of saturated homopolyester resin (having no unsaturated bond in the polyester main chain), saturated copolymerized polyester resin, alkyd resin, and unsaturated polyester resin (having an unsaturated bond in the polyester main chain) may be used. From the viewpoint of excellent low-temperature heat sealability and blocking resistance, saturated copolymerized polyester resin is preferred. Examples of the polyvalent carboxylic acid for polycondensation include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, phthalic acid, citric acid, etc. Examples of the polyvalent alcohol for polycondensation include ethylene glycol, propanediol, butanediol, glycerin, etc. These may be used alone or in combination of two or more. Examples of the polyester resin include a resin composed of one kind of polyvalent carboxylic acid (e.g., phthalic acid, etc.) and two kinds of polyvalent alcohols (e.g., ethylene glycol and butanediol, etc.).

[0073] --Acrylic resin-- An acrylic resin is a polymer containing, as a monomer component, an ethylenically unsaturated monomer having at least one carboxyl group or carboxylic acid ester group, and may be a homopolymer or copolymer of an ethylenically unsaturated monomer having at least one carboxyl group or carboxylic acid ester group, or a copolymer with another monomer copolymerizable therewith. Further, the acrylic resin may be an alkali metal salt, amine salt, or ammonium salt of the carboxyl group (carboxylic acid) of the above homopolymer or copolymer. Examples of the ethylenically unsaturated monomer having a carboxyl group or carboxylic acid ester group include methacrylic acid, acrylic acid, methacrylic acid ester, acrylic acid ester, etc. When the acrylic resin is a copolymer, examples of the "other monomer" include ethylene; aromatic vinyl monomers such as styrene, α-methylstyrene (vinyltoluene), and chlorostyrene; cyano group-containing ethylenically unsaturated monomers such as acrylonitrile and methacrylonitrile; acrylamide-based monomers such as acrylamide, N-methylol methacrylamide, and N-butoxymethyl acrylamide; and the like.

[0074] Specific examples of the case where the acrylic resin is a copolymer include methacrylic acid ester-acrylic acid ester copolymer, acrylic acid ester-acrylic acid ester copolymer, ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-acrylic acid ester copolymer, and the like. By appropriately changing the types and ratios of the monomers to be copolymerized, the glass transition temperature can be adjusted. When the acrylic resin is a copolymer, it is preferable that the proportion of the structural unit having an acrylic structure accounts for 20% or more of the entire copolymer.

[0075] --Vinyl acetate copolymer-- The vinyl acetate copolymer is a copolymer of vinyl acetate and at least one or more monomers copolymerizable with vinyl acetate. Examples of the monomers copolymerizable with vinyl acetate include alkyl (meth)acrylates such as ethylene, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate; and acrylic acid. Specific examples of the vinyl acetate copolymer include, for example, ethylene vinyl acetate copolymer. In the vinyl acetate copolymer, it is preferable that the proportion of the structural unit having a vinyl acetate structure accounts for 20% or more of the entire copolymer.

[0076] In the present embodiment, from the perspective that if the total thickness of the resin adhesive layer including the adhesive resin layer is too thick, simultaneous bending with the metal layer becomes difficult, the average thickness of at least one, preferably both, of the first and second adhesive resin layers is preferably 100 μm or less, and more preferably 50 μm or less. Also, from the perspective of ensuring adhesiveness with the metal layer, the average thickness of at least one, preferably both, of the first and second adhesive resin layers is preferably 5 μm or more, and more preferably 10 μm or more.

[0077] In the present embodiment, the Tg of at least one of the first and second adhesive resin layers is preferably -10°C or higher, more preferably 0°C or higher, still more preferably 5°C or higher, and still more preferably 10°C or higher. If the Tg of the adhesive resin layer is high, the adhesive strength of the adhesive resin layer can be sufficiently ensured. Also, the Tg of at least one of the first and second adhesive resin layers is preferably 30°C or lower, more preferably 28°C or lower, and still more preferably 25°C or lower. If the Tg of the adhesive resin layer is too high, the adhesive force of the adhesive resin layer becomes excessive, and there is a possibility that it may hinder the manufacturing operation of the composite material laminate. Therefore, it is preferable that the Tg is not too high.

[0078] In the present embodiment, the materials of the first and second adhesive resin layers are not particularly limited, and examples include acrylate-based latex, acrylonitrile-butadiene-based latex, styrene-butadiene-based latex, and the like.

[0079] <Handling property of the adhesive film> When manufacturing the composite material laminate, it can be preferably manufactured if there is a step of temporarily fixing the adhesive film to the metal plate. If the Tg of at least one of the first and second adhesive resin layers exceeds 30°C, the adhesive force is strong and glue residue occurs, so rework cannot be performed when misalignment occurs during temporary fixing. Also, if the Tg of at least one of the first and second adhesive resin layers is less than -10°C, the adhesive force is weak, and it is insufficient for temporary fixing at low loads, resulting in a decrease in handling property.

[0080] (Manufacturing Method 1 of Composite Material Laminate: Manufacturing Method by Film Set + Press) The composite material laminate 1 in this embodiment In the same mold, the first metal layer, the first resin adhesive layer, the foamed resin layer, the second resin adhesive layer, and the second metal layer are laminated and installed in the order of the first metal layer, the first adhesive resin layer, the first stretched film, the foamed resin layer, the second stretched film, the second adhesive resin layer, and the second metal layer, an installation step; In the mold, the first metal layer is adhered to one surface of the foamed resin layer via the first resin adhesive layer, and the second metal layer is adhered to the other surface of the foamed resin layer via the second resin adhesive layer to obtain the composite material laminate, a foaming bonding step; It can also be manufactured by a manufacturing method of a composite material laminate including As such a manufacturing method, for example, the composite material laminate 1 in this embodiment can be manufactured by laminating the adhesive layer 3 and the foam layer 2 on the metal base material 4. For example, in the manufacturing method of the composite material laminate 1 of this embodiment, a preheating step of preheating the first resin constituting the foam used as the foam layer 2 may be performed before forming the foam layer 2 on the metal layer 4 or the adhesive layer 3. More specifically, the preheating temperature can be adjusted according to whether the first resin is an amorphous resin or the first resin is a crystalline resin. That is, the preheating step is preferably a step of heating at a temperature equal to or higher than the glass transition temperature of the first resin (when the first resin is an amorphous thermoplastic resin) or at a temperature equal to or higher than the melting point temperature of the first resin (when the first resin is a crystalline thermoplastic resin). By performing the preheating step, the surface portion of the foam can be melted and fluidized, and the portion where the resin melting layer or the foam melting layer is to be formed can be selectively heated and softened. Thereafter, by performing a compression and rapid cooling step of the mold, a composite material laminate 1 having a relatively smooth layer with good image clarity formed on the surface portion of the foam layer 2 or near the adhesion surface between the foam layer and the metal base material can be obtained. The various conditions of this manufacturing method can be appropriately adjusted based on, for example, the conditions described below or known conditions, etc.

[0081] When the first resin used for the foam layer is an amorphous resin, the heating temperature of the foam in the preheating step is preferably not less than the glass transition temperature “Tg (°C)” and less than (Tg + 100) °C, and more preferably not less than (Tg + 10) °C and less than (Tg + 90) °C. If the heating temperature of the foam is too low, the fluidity of the molten resin is poor, and the bubbles generated on the obtained design surface do not disappear, which may reduce the design property of the design surface of the foam (layer). Also, if the heating temperature of the foam is too high, the inside of the foam layer is heated and shrinks during cooling, so an elastic repulsive force cannot be obtained during compression, and the surface smoothness may decrease.

[0082] Note that the glass transition temperature of the amorphous resin refers to the value measured by differential scanning calorimetry (DSC) in accordance with JIS K7121. The peak indicating the endotherm that appears in the measurement is regarded as the peak indicating the melting of the resin, and the temperature at the peak indicating the endotherm that appears on the highest temperature side is taken as the glass transition temperature. As the measuring device, a commercially available differential scanning calorimeter may be used, and examples include the product name “DSC6220 type” from SII NanoTechnology Inc.

[0083] In the present disclosure, when the first resin used for the foam layer is an amorphous resin, its glass transition temperature is measured by the method described in JIS K7121:1987 “Method for Measuring the Transition Temperature of Plastics”. However, the sampling method and temperature conditions are as follows. Using a differential scanning calorimeter device, about 6 mg of the sample is filled in the bottom of an aluminum measurement container without gaps, and under a nitrogen gas flow rate of 20 mL / min, the sample is heated from 30 °C to 290 °C (1st Heating), held at 290 °C for 10 minutes, then cooled from 290 °C to 30 °C (Cooling), held at 30 °C for 10 minutes, and then heated from 30 °C to 290 °C (2nd Heating) to obtain a DSC curve. All heating rates and cooling rates are performed at 10 °C / min, and alumina is used as the reference substance.

[0084] When the first resin used for the foam layer is a crystalline resin, when its melting point temperature is defined as "Tm (°C)", it is preferably not less than Tm °C and less than (Tm + 100) °C, and more preferably not less than (Tm + 10) °C and less than (Tm + 90) °C. If the heating temperature of the foam (layer) is too low, the fluidity of the molten resin is poor, and the bubbles generated on the designed surface obtained do not disappear, which may reduce the design property of the foam (layer). On the other hand, if the heating temperature of the foam (layer) is too high, the inside of the foam layer is heated and shrinks during cooling, so that an elastic repulsive force cannot be obtained during compression, and the surface smoothness may be reduced.

[0085] When the first resin used for the foam layer is a crystalline resin, its melting point is measured according to the following procedure. 6 mg of the first resin used for the foam layer is collected as a sample. Using a differential scanning calorimeter device, the sample is heated from 30 °C to 290 °C at a heating rate of 10 °C / min under a nitrogen gas flow of 20 mL / min in the device and held at 290 °C for 10 minutes. Then, the sample is quickly taken out of the device and cooled to 30 °C, and then the melting point (midpoint) is calculated from the DSC curve obtained when the sample is heated again to 290 °C at a heating rate of 10 °C / min under a nitrogen gas flow of 20 mL / min in the device. Alumina is used as a reference substance in the measurement. As the differential scanning calorimeter device, for example, a differential scanning calorimeter device commercially available under the trade name "DSC6220 type" from SII NanoTechnology Inc. can be used.

[0086] (Manufacturing Method 2 of Composite Material Laminate: Manufacturing Method by Film Set + Foaming Molding) The manufacturing method of the composite material laminate (laminated foam) of the present invention is In a processing apparatus capable of supplying pressure and heat, the first metal layer, the first resin adhesive layer, the raw material of the foamed resin layer, the second resin adhesive layer, and the second metal layer are laminated and installed in the order of the first metal layer, the first adhesive resin layer, the first stretched film, the raw material of the foamed resin layer, the second stretched film, the second adhesive resin layer, and the second metal layer (for example, a method for manufacturing a laminated foam including laminating one or more metal layers and one or more foam layers, and in the molding material filling space of the above mold, storing a laminated molding material including a foam layer composed of foam beads or pellets and two insert layers present on both sides of the foam layer (laminated molding material storage (film set) step)) and While foaming the raw material of the foamed resin layer to form a foamed resin layer, the first metal layer is adhered to one surface of the foamed resin layer via the first resin adhesive layer, and the second metal layer is adhered to the other surface of the foamed resin layer via the second resin adhesive layer to obtain the composite material laminate (for example, a step of introducing steam into the first steam conduction path and the second steam conduction path, heating the laminated molding material in the molding material filling space, and molding a laminated foam from the laminated molding material by foam molding (foam molding step)) and A method for manufacturing a composite material laminate (laminated foam) including a foam bonding step. Further, the method for manufacturing a composite material laminate of the present invention may be a method for manufacturing a composite material laminate (laminated foam) further including a step of removing the molded laminated foam from the molding material filling space (laminated foam removal step). The various conditions of this manufacturing method can be appropriately adjusted based on, for example, the above-described conditions or known conditions.

[0087] "Preferred form of the composite material laminate" A preferred form of the composite material laminate in the present embodiment is that the difference in transmission loss at 1000 Hz represented by the following formula (2) is 2 dB or more. (Formula 2): Transmission loss of the entire composite material laminate (B) - Transmission loss of the metal base material used for the composite material laminate (A) If the difference in the above-mentioned transmission loss is 2 dB or more, excellent vibration damping and sound absorption effects can be expected. The sound absorption performance in the range of 200 to 5000 Hz is mainly due to the internal bubble structure of the foam layer absorbing air vibration. Therefore, the greater the proportion of the transmission loss of the foam layer, the greater the sound absorption effect.

[0088] Moreover, it is more preferable that the difference in the transmission loss at 1000 Hz, represented by the following formula (2), is 0.1 to 20 dB, and even more preferably 1 to 20 dB.

[0089] Another preferred form of the composite material laminate in the present embodiment is a composite material laminate having a metal substrate, an adhesive layer formed on the surface of the metal substrate, and a resin foam layer formed on the surface of the adhesive layer, wherein the elastic modulus of the foam layer is 20 to 200 MPa, The following formula (I):

Number

[0090] When the total thickness is 5 mm or less, the mold following property of the resin adhesive layer when deforming the metal layer by bending the composite material laminate is good.

Example

[0091] Hereinafter, the content of the present invention will be described more specifically with reference to examples and comparative examples. It should be noted that the present invention It is not limited to these examples.

[0092] The materials used in the examples and comparative examples are as follows. (1) Stretched film (i) PS-based film 1: OPS film (manufactured by Asahi Kasei Corporation) GM25 with a thickness of 25 mm GM30 with a thickness of 30 mm GM50 with a thickness of 50 mm (ii) PET-based film: Ester film manufactured by Toyobo Co., Ltd. E5100 with a thickness of 25 μm (iii) PS-based film 3: Polystyrene film (manufactured by Towa Chemical Industry Co., Ltd.) CPS film with a thickness of 25 μm (iv) PP-based film: OPP film manufactured by Santox PA20 with a thickness of 25 μm (v) PP-based film: CPP film manufactured by Toyobo Co., Ltd. Pyren film CT with a thickness of 25 μm

[0093] (2) Adhesive resin (i) Styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, A7787) (ii) Styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, A7090) (iii) Styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, L7430) (iv) Styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, L2301) (v) Styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, L7708) (vi) Styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, L7850)

[0094] (3) Foaming material (i) Modified PPE foamed beads Sunforce BE-190 manufactured by Asahi Kasei Corporation In Examples 1, 2, 4, 5, 7 to 12, foamed molded articles were obtained by foaming foamed beads in a mold. (i) Modified PPE Foamed Beads Sunforce BE-190, manufactured by Asahi Kasei Corporation (ii) Modified PPE Foamed Material Sunforce BE, Foaming Ratio 5 times, manufactured by Asahi Kasei Corporation (iii) PP Foamed Material (manufactured by Kaneka, Eperan PP)

[0095] The measurement and evaluation methods applied in the examples and comparative examples are shown below.

[0096] [Flexural Rigidity] As shown in Figure 2, the composite material laminate 1 was placed on the support column 22 of the measuring device with the first metal layer on top, and a load was applied to the central part of the first metal layer with the measuring jig 21 to measure the flexural rigidity and evaluate it according to the following criteria. The test piece thickness was 10 mm in width and 7 mm in thickness (the total thickness of the foamed material and the adhesive film layer was 5 mm, and the thickness of the aluminum was 1 mm), and the distance between the fulcrums during measurement was 64 mm. A: Flexural strength is 75 MPa or more B: Flexural strength is 70 MPa or more C: Flexural strength is 60 MPa or more D: Flexural strength is less than 60 MPa

[0097] Samples of the 120°C heat shrinkage rate in the MD (longitudinal) direction and TD (width) direction were cut into 100 mm squares in the MD / TD direction, placed in a hot air dryer heated to 120°C, and the dimensional shrinkage rate after 1 hour was determined. The samples were placed on copy paper or the like so as not to adhere to the inner wall of the dryer or the like and so that the samples did not fuse together. The MD direction heat shrinkage rate and TD direction heat shrinkage rate are calculated by the following formulas respectively. MD direction heat shrinkage rate (%) = (100 - MD direction dimension after heating) / 100 × 100 (%) TD direction heat shrinkage rate (%) = (100 - TD direction dimension after heating) / 100 × 100 (%)

[0098] In accordance with JIS K7127, the tensile elastic modulus in each of the MD and TD directions was measured. A strip-shaped test piece (length 150 mm × width 10 mm) was cut out from the adherent film base material. The end of this test piece was attached to a precision universal testing machine (manufactured by Shimadzu Corporation, Autograph) so that the distance between the chucks was 50 mm. The movement was carried out at a moving speed of 200 mm / min between the chucks, and the load at 2% elongation was taken as the tensile elastic modulus (MPa). The values measured for 10 test pieces were averaged to obtain the tensile elastic modulus.

[0099] [Tackiness] In an environment of 23°C and 55% RH, an adhesive film cut to a width of 10 mm and a length of 100 mm was joined using a pressure roller for peel test (Imada Co., Ltd. APR-97-2K) so that the adhesive resin layer was in contact with the aluminum material A6061. The tackiness was evaluated according to the following criteria. SS: Does not fall after 24 hours after fixation. Rework of peeling is possible. S: Does not fall after 24 hours after fixation. There is adhesive residue on the aluminum surface during peeling. A: Falls after 24 hours after fixation. B: Falls within 5 minutes after fixation. S: Does not fall after 24 hours after fixation. Cannot be peeled off.

[0100] (Examples 1 to 12, Comparative Example 1) [Example 1] On one side of a PS-based film 1 (OPS film GM25), alphabetic characters in red Gothic font with a character size of 7 points were printed using a gravure printing machine with a screen ruling of 230 lines / inch and a plate depth of 20 μm. Then, a heat-sealing agent (urethane 1) was coated thereon using a plate with a screen ruling of 80 lines / inch and a plate depth of 130 μm. Before coating, the heat-sealing agent was diluted with water so that the non-volatile content was 40% by mass and the viscosity was 100 mPa·s to 10 00 mPa·s. After coating, it was dried in a hot air dryer set at 100°C for 5 seconds to obtain a film.

[0101] ● Film set + press: "Manufacturing method 1 of composite material laminate" described in this specification ● Film set + Foam molding: "Manufacturing method 2 of composite material laminate" described in this specification For Examples 2 to 12 and Comparative Example 1, in the same manner as in Example 1, a measurement sample of the composite material laminate 1 was prepared using the materials and manufacturing method described in Table 1. For Examples 1 to 12 and Comparative Example 1, the flexural rigidity and handleability were evaluated. The results are shown in Table 1.

[0102]

Table 1

Industrial Applicability

[0103] According to the present disclosure, a composite material laminate excellent in flexural rigidity and productivity can be provided.

Explanation of Signs

[0104] 1 Composite material laminate 2 Foamed resin layer 3a First resin adhesive layer 3b Second resin adhesive layer 4a First metal layer 4b Second metal layer 5a First stretched film 5b Second stretched film 6a First adhesive resin layer 6b Second adhesive resin layer 11 Mold 21 Measuring jig 22 Support column H Heating C Cooling

Claims

1. A foamed resin layer, A first resin adhesive layer adhered to one surface of the foamed resin layer, A second resin adhesive layer adhered to the other surface of the foamed resin layer, A first metal layer adhered to the surface of the first resin adhesive layer opposite to the surface adhered to the foamed resin layer, A second metal layer adhered to the surface of the second resin adhesive layer opposite to the surface adhered to the foamed resin layer, A composite material laminate comprising: The first resin adhesive layer includes two or more layers of a first stretched film and a first adhesive resin layer laminated together, The second resin adhesive layer includes two or more layers of a second stretched film and a second adhesive resin layer laminated together, At least one of the first and second stretched films has a tensile elastic modulus of 2 GPa or more, The composite material laminate includes the layers laminated in the order of the first metal layer, the first adhesive resin layer, the first stretched film, the foamed resin layer, the second stretched film, the second adhesive resin layer, and the second metal layer. Composite material laminate.

2. The composite material laminate according to claim 1, wherein the thermal shrinkage rate of at least one of the first and second stretched films at the glass transition temperature is 10% or more in at least one of the MD direction and the TD direction.

3. The composite material laminate according to claim 1 or 2, wherein at least one of the first and second stretched films and the foamed resin layer contains the same resin material.

4. The first resin adhesive layer includes two or more layers of a first stretched film with an average thickness of 500 μm or less and a first adhesive resin layer with an average thickness of 100 μm or less laminated together, The second resin adhesive layer includes two or more layers of a second stretched film with an average thickness of 500 μm or less and a second adhesive resin layer with an average thickness of 100 μm or less laminated together, The composite material laminate according to claim 1 or 2.

5. The composite material laminate according to claim 1, wherein the average thickness of at least one of the first and second stretched films is 100 μm or less.

6. The composite material laminate according to claim 1, wherein the Tg of at least one of the first and second adhesive resin layers is -10°C or higher.

7. The composite material laminate according to claim 1, wherein the foamed resin layer contains a bead resin foam.

8. A method for manufacturing the composite material laminate according to any one of claims 1 to 7, In a processing apparatus capable of supplying pressure and heat, the first metal layer, the first resin adhesive layer, the raw material of the foamed resin layer, the second resin adhesive layer, and the second metal layer are laminated and installed in the order of the first metal layer, the first adhesive resin layer, the first stretched film, the raw material of the foamed resin layer, the second stretched film, the second adhesive resin layer, and the second metal layer. While foaming the raw material of the foamed resin layer to form a foamed resin layer, the first metal layer is adhered to one surface of the foamed resin layer via the first resin adhesive layer, and the second metal layer is adhered to the other surface of the foamed resin layer via the second resin adhesive layer to obtain the composite material laminate. Foaming bonding step A method for manufacturing a composite material laminate including the above.

9. A method for manufacturing the composite material laminate according to any one of claims 1 to 7, In the same mold, the first metal layer, the first resin adhesive layer, the foamed resin layer, the second resin adhesive layer, and the second metal layer are laminated and installed in the order of the first metal layer, the first adhesive resin layer, the first stretched film, the foamed resin layer, the second stretched film, the second adhesive resin layer, and the second metal layer. Installation step, By heating the mold, the first metal layer is adhered to one surface of the foamed resin layer via the first resin adhesive layer, and the second metal layer is adhered to the other surface of the foamed resin layer via the second resin adhesive layer to obtain the composite material laminate. Bonding step, A method for manufacturing a composite material laminate including

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