Laminated Foam Sheet, Laminated Molded Body, and Method for Producing the Same

Abstract

To provide a laminated foam sheet which has suede-like appearance and has high elasticity and abrasion resistance, a laminated molding, and a method for manufacturing them.SOLUTION: A laminated foam sheet contains a thermoplastic resin layer and a surface treatment layer, wherein the thermoplastic resin layer contains a first foam thermoplastic resin layer containing a thermoplastic resin and expanded thermally expandable microcapsules, the surface treatment layer is arranged on a first surface of the first foam thermoplastic resin layer, a thickness of the first foam thermoplastic resin layer is 300 μm or more and 2,000 μm or less, a thickness of the surface treatment layer is 8.0 μm or more and 25 μm or less, and an arithmetical average height Sa defined by ISO 25178 on the surface treatment layer side is 5 μm or more and 30 μm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminated foam sheet, a laminated molded body, and a method for manufacturing the same, which can be suitably used as a vehicle interior material.

Background Art

[0002] In vehicle interior materials such as automotive interior materials using synthetic resins, in order to achieve a certain texture, a warm suede-like appearance is imparted. For example, in Patent Document 1, as a decorative material having a suede-like appearance, it is composed of a laminate having a base material, an intermediate layer, and a surface layer. The intermediate layer is formed by dispersing thermally expanded microcapsules in a synthetic resin with a 100% modulus of 20 to 150 kg / cm 2 and a decorative material is proposed in which the microcapsules are 2 to 30% by weight based on 100% by weight of the intermediate layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the decorative material described in Patent Document 1 may have insufficient elasticity (cushioning property) and abrasion resistance.

[0005] The present invention provides a laminated foam sheet, a laminated molded body, and a method for manufacturing the same, which have a suede-like appearance and high elasticity and abrasion resistance.

Means for Solving the Problems

[0006] The present invention relates to a laminated foamed sheet including a thermoplastic resin layer and a surface treatment layer, wherein the thermoplastic resin layer includes a first foamed thermoplastic resin layer containing a thermoplastic resin and expanded thermally expandable microcapsules, the surface treatment layer is disposed on a first surface of the first foamed thermoplastic resin layer, the thickness of the first foamed thermoplastic resin layer is 300 μm or more and 2000 μm or less, the thickness of the surface treatment layer is 8.0 μm or more and 25 μm or less, and the arithmetic mean height Sa defined by ISO 25178 on the surface treatment layer side is 5 μm or more and 30 μm or less.

[0007] The present invention also relates to a laminated molded body in which the laminated foamed sheet is molded into a predetermined shape.

[0008] The present invention also relates to a method for manufacturing a laminated foamed sheet, including the steps of: forming a first unfoamed thermoplastic resin sheet by sheet-molding a thermoplastic resin composition containing a thermoplastic resin and thermally expandable microcapsules at a temperature equal to or higher than the melting point of the thermoplastic resin and lower than the expansion start temperature of the thermally expandable microcapsules; applying a surface treatment agent to one surface of the first unfoamed thermoplastic resin sheet to form a surface treatment layer; and heating the obtained laminate at a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsules to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer.

[0009] The present invention also relates to a method for manufacturing the laminated molded body, which includes a step of forming a first unfoamed thermoplastic resin sheet by sheet molding a thermoplastic resin composition containing a thermoplastic resin and thermally expandable microcapsules at a temperature equal to or higher than the melting point of the thermoplastic resin and lower than the expansion start temperature of the thermally expandable microcapsules (the temperature at which the volume change of the thermally expandable microcapsules starts due to heating); a step of applying a surface treatment agent to one surface of the first unfoamed thermoplastic resin sheet to form a surface treatment layer; and a step of molding the obtained laminate into a laminated molded body having a predetermined shape. In the molding step of the laminated molded body, the laminate is heated at a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsules to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet and form a first foamed thermoplastic resin layer.

Effects of the Invention

[0010] The present invention can provide a laminated foamed sheet and a laminated molded body having a suede-like appearance, high elasticity, and high abrasion resistance. Moreover, according to the manufacturing method of the present invention, a laminated foamed sheet and a laminated molded body having a suede-like appearance, high elasticity, and high abrasion resistance can be obtained.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0012] The inventors of the present invention have intensively studied to solve the above problems. As a result, a laminated foam sheet is configured to include a thermoplastic resin layer and a surface treatment layer, and the thermoplastic resin layer is configured to include a first foamed thermoplastic resin layer containing a thermoplastic resin and expanded thermally expandable microcapsules. A surface treatment layer is disposed on the first surface of the first foamed thermoplastic resin layer. The thickness of the first foamed thermoplastic resin layer is 300 μm or more and 2000 μm or less, and the thickness of the surface treatment layer is 8.0 μm or more and 25 μm or less. By setting the arithmetic mean height Sa defined by ISO 25178 on the surface treatment layer side to 5 μm or more and 30 μm or less, it has been found that a laminated foam sheet having a suede-like appearance, high elasticity and abrasion resistance can be provided, which can be suitably used as an automotive interior material.

[0013] (Laminated foam sheet) The thermoplastic resin layer includes a first foamed thermoplastic resin layer containing a thermoplastic resin and expanded thermally expandable microcapsules. By including expanded thermally expandable microcapsules in the first foamed thermoplastic resin layer, a fine uneven shape can be imparted to the surface of the laminated foam sheet, and a touch feeling with an appropriate roughness and a warm suede-like appearance can be expressed.

[0014] The first foamed thermoplastic resin layer preferably contains 1 to 15 parts by weight, more preferably 1.5 to 10 parts by weight, and still more preferably 2 to 8 parts by weight of thermally expandable microcapsules with respect to 100 parts by weight of the thermoplastic resin. If the content of the thermally expandable microcapsules is too small, it tends to be difficult to obtain a suede-like appearance. If the content of the thermally expandable microcapsules is too large, the abrasion resistance may be inferior.

[0015] The thermally expandable microcapsules are capsule-shaped foaming agents in which a liquid low-boiling compound is encapsulated in a shell of a thermoplastic resin, and the capsules expanded by heating function as foaming agents. Specifically, the thermally expandable microcapsules have a core-shell structure, the core is composed of a liquid low-boiling hydrocarbon, the shell encloses the core, and is composed of a thermoplastic resin.

[0016] The hydrocarbons constituting the core of the thermally expandable microcapsules are not particularly limited, and examples thereof include pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, and structural isomers of these hydrocarbons.

[0017] The thermoplastic resin constituting the shell of the thermally expandable microcapsules preferably contains a nitrile monomer. Examples of the nitrile monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxyacrylonitrile, fumaronitrile, and the like. The thermoplastic resin constituting the shell of the thermally expandable microcapsules may further contain one or more monomers selected from the group consisting of (meth)acrylate monomers, aromatic vinyl monomers, diene monomers, vinyl monomers having a carboxyl group, and monomers having one or more reactive functional groups selected from the group consisting of a methylol group, a hydroxyl group, an amino group, an epoxy group, and an isocyanate group.

[0018] The expanded thermally expandable microcapsules are not particularly limited. For example, from the viewpoint of more favorably exhibiting a better touch feeling and a suede-like appearance, the average bubble diameter (also referred to as the average particle diameter) is preferably 30 μm or more, more preferably 35 μm or more, and even more preferably 40 μm or more. Further, the expanded thermally expandable microcapsules are not particularly limited. For example, from the viewpoint of enhancing the abrasion resistance, the average bubble diameter (average particle diameter) is preferably 200 μm or less, more preferably 160 μm or less, and even more preferably 120 μm or less. Specifically, the expanded thermally expandable microcapsules preferably have an average bubble diameter of 30 μm or more and 200 μm or less, more preferably 35 μm or more and 160 μm or less, and even more preferably 40 μm or more and 120 μm or less. The average bubble diameter of the expanded thermally expandable microcapsules can be measured as described below.

[0019] Thermally expandable microcapsules usually expand from the average particle diameter before expansion to a range of approximately 3 times or more and 5 times or less when heated. From the perspective of easily adjusting the average bubble diameter of the expanded thermally expandable microcapsules to the above-mentioned range, the average particle diameter of the thermally expandable microcapsules before expansion is preferably 6 μm or more and 50 μm or less, more preferably 10 μm or more and 45 μm or less, and even more preferably 15 μm or more and 40 μm or less. The average particle diameter of the thermally expandable microcapsules before expansion can be measured, for example, by observing 30 capsules magnified 500 times with a digital microscope "VHX-7000" manufactured by Keyence Corporation (detection limit: 0.01 μm) and taking the average value.

[0020] The thermoplastic resin in the first foamed thermoplastic resin layer is not particularly limited. For example, from the viewpoints of easily imparting a suede-like appearance and softness, polyolefin-based resins, vinyl chloride-based resins, olefin-based thermoplastic elastomers, etc. can be preferably used, and it is preferable to contain one or more selected from the group consisting of olefin-based thermoplastic elastomers and polyolefin-based resins. From the viewpoints of excellent rubber elasticity during high-temperature and long-time deformation and high heat resistance, it is more preferable to contain an olefin-based thermoplastic elastomer, and it is even more preferable to contain an olefin-based thermoplastic elastomer and a polyolefin-based resin.

[0021] The olefin-based thermoplastic elastomer is not particularly limited and may be any of a blend type, a polymerization type (also referred to as reactor TPO), and a dynamic crosslinking type (also referred to as TPV). The olefin-based thermoplastic elastomer may be used alone or in combination of two or more. From the viewpoints of cost and performance, it is preferable to use the polymerization type and the dynamic crosslinking type in combination.

[0022] The polyolefin resin may be a polymer of olefins and is not particularly limited. For example, homopolymers of olefins such as ethylene, propylene, 1-butene, isobutene, 4-methyl-1-pentene, etc., copolymers of two or more olefins, copolymers of olefins and other monomers, etc. may be mentioned. The copolymer may be a random copolymer or a block copolymer. The copolymer may also be a terpolymer. In the copolymer of an olefin and other monomers, it is desirable that the olefin be 50% by weight or more. Examples of other monomers include dienes, cyclopentadiene, and vinyl compounds. Specific examples of the polyolefin resin include homopolypropylene, ethylene-propylene copolymer, random polypropylene (hereinafter also referred to as R-PP), block polypropylene, ethylene-1-butene copolymer, high-density polyethylene, low-density polyethylene, linear low-density polyethylene (hereinafter also referred to as LLDPE), etc. The polyolefin resin may be used alone or in combination of two or more kinds.

[0023] The first foamed thermoplastic resin layer has a thickness of 300 μm or more and 2000 μm or less. Thereby, a laminated foamed sheet excellent in elasticity can be obtained. From the viewpoint of elasticity, the thickness of the first foamed thermoplastic resin layer is preferably 400 μm or more, more preferably 500 μm or more, further preferably 650 μm or more, and particularly preferably 750 μm or more. From the viewpoints of cost and sheet processability, the thickness of the first foamed thermoplastic resin layer is preferably 1800 μm or less, more preferably 1600 μm or less, and further preferably 1400 μm or less.

[0024] In addition to the first foamed thermoplastic resin layer, the thermoplastic resin layer can further include an unfoamed thermoplastic resin layer disposed on the side opposite to the first surface on which the surface treatment layer of the first foamed thermoplastic resin layer is disposed, from the viewpoint of preventing tearing or breaking of the sheet when stretched in the longitudinal direction (the longitudinal direction of the sheet) or the transverse direction (the direction perpendicular to the longitudinal direction). The unfoamed thermoplastic resin layer can appropriately contain the thermoplastic resins listed as the thermoplastic resins used for the first foamed thermoplastic resin layer. The first foamed thermoplastic resin layer and the unfoamed thermoplastic resin layer may be directly joined by heating the surfaces to be joined to a temperature equal to or higher than the melting point of the constituent resin and then pressing them together, or may be joined via an adhesive.

[0025] The thickness of the unfoamed thermoplastic resin layer is not particularly limited. For example, from the viewpoint of preventing tearing or breaking of the sheet when stretched in the longitudinal direction or the transverse direction, it may be 100 μm or more and 800 μm or less, may be 150 μm or more and 700 μm or less, or may be 200 μm or more and 600 μm or less.

[0026] The laminated sheet includes a surface treatment layer disposed on the first surface of the first foamed thermoplastic resin layer. The surface treatment agent constituting the surface treatment layer is not particularly limited. For example, it includes an aqueous polyurethane dispersion (also referred to as an aqueous urethane paint), a solvent-based polyurethane dispersion (also referred to as a solvent-based urethane paint), etc., and may contain silicon, silicon beads, urethane beads, etc. The surface treatment layer may be composed of only a top layer, or may be composed of a top layer and a primer layer. The top layer can be composed of a surface treatment agent for the top, and the primer layer can be composed of a surface treatment agent for the primer.

[0027] The surface treatment layer has a thickness of 8.0 μm or more and 25 μm or less. Thereby, while maintaining the suede-like appearance imparted by the first foamed thermoplastic resin layer, the abrasion resistance can be enhanced. From the viewpoint of abrasion resistance, the thickness of the surface treatment layer is preferably 8.5 μm or more, more preferably 9.0 μm or more, still more preferably 9.5 μm or more, and particularly preferably 10.0 μm or more. From the viewpoint of the suede-like appearance, the thickness of the surface treatment layer is preferably 20 μm or less, more preferably 18 μm or less, still more preferably 16 μm or less, and particularly preferably 14 μm or less.

[0028] In the laminated foamed sheet, the arithmetic mean height Sa defined by ISO 25178 on the surface treatment layer side is 5 μm or more and 30 μm or less. Thereby, the laminated foamed sheet is likely to exhibit a suede-like appearance and has good abrasion resistance. The arithmetic mean height Sa is preferably 8 μm or more and 25 μm or less, and more preferably 10 μm or more and 20 μm or less.

[0029] In the laminated foamed sheet, from the viewpoints of the suede-like appearance and abrasion resistance, the ten-point mean roughness Rzjis defined by ISO 25178 on the surface treatment layer side is preferably 50 μm or more and 120 μm or less, more preferably 60 μm or more and 110 μm or less, and still more preferably 75 μm or more and 95 μm or less.

[0030] The laminated foamed sheet is not particularly limited, but from the viewpoint of enhancing elasticity, it can further include a cushion layer disposed on the side opposite to the side where the surface treatment layer of the thermoplastic resin layer is disposed.

[0031] The cushion layer is not particularly limited, and for example, a material having a foam or space layer can be appropriately used. Specifically, cross-linked resin foams, polyurethane sheets, fiber structures, etc. can be mentioned. As the fiber structure, non-woven fabrics, double raschel, etc. may be used. Even when the cushion layer is composed of a cross-linked resin foam, it has a configuration different from that of the thermoplastic resin layer. In one or more embodiments of the present invention, the thermoplastic resin layer is composed of a first foamed thermoplastic resin layer, or is composed of a first foamed thermoplastic resin layer and a non-foamed thermoplastic resin layer.

[0032] From the viewpoint of elasticity, the cushion layer preferably has a compression recovery rate of 95% or more. Here, the compression recovery rate is measured under conditions according to the compression set test specified in JIS K6767.

[0033] The cross-linked resin foam is not particularly limited, but from the viewpoints of heat resistance and surface smoothness, it is preferably a cross-linked polyolefin-based resin foam. The cross-linked polyolefin-based resin foam is not particularly limited, and it may be obtained by cross-linking a polyolefin-based resin by a conventionally known method and then foaming it. As the polyolefin-based resin, those listed as the polyolefin-based resin used for the first foamed thermoplastic resin layer can be appropriately used. The method for forming the cross-linked structure is not particularly limited, and examples include methods of irradiating ionizing radiation such as α-rays, β-rays, γ-rays, and electron beams, methods of irradiating ultraviolet rays, and methods using cross-linking agents such as organic peroxides and silane compounds. The foaming method is not particularly limited, and examples include extrusion foaming, in-mold foaming, normal pressure foaming, chemical reaction foaming, etc. As the foaming agent, inorganic gases, hydrocarbons or halogenated hydrocarbons having a boiling point of -50 to 120°C, water, thermally decomposable foaming agents, etc. can be used.

[0034] The cross-linked resin foam is not particularly limited, and for example, from the viewpoint of moldability, the cross-linking degree may be 30% or more and 65% or less, or may be 40% or more and 55% or less. The cross-linking degree of the cross-linked resin foam can be measured, for example, by the weight attenuation rate after dissolving the part other than the cross-linked part using an organic solvent.

[0035] The crosslinked resin foam is not particularly limited. For example, from the viewpoints of flexibility and cushioning feeling, the expansion ratio may be 5 times or more and 40 times or less. The expansion ratio of the crosslinked resin foam can be calculated, for example, by measuring the specific volume (unit: cm 3 / g) of the foamable resin sheet before foaming and the crosslinked resin foam sheet, and using the ratio of the specific volume of the crosslinked resin foam sheet to the specific volume of the foamable resin sheet before foaming.

[0036] The crosslinked resin foam may contain additives such as a foaming aid, a softening agent, a lubricant, an antioxidant, an antistatic agent, a flame retardant, an ultraviolet absorber, a light stabilizer, a coloring agent, and an inorganic filler, as necessary.

[0037] The thickness of the cushion layer is not particularly limited. For example, from the viewpoint of elasticity, it may be 0.5 mm or more and 5.0 mm or less, may be 1.0 mm or more and 4.5 mm or less, or may be 1.5 mm or more and 4.0 mm or less.

[0038] The thermoplastic resin layer and the cushion layer may be directly joined by heating the surfaces to be joined to a temperature equal to or higher than the melting point of the constituent resin, or may be joined via an adhesive.

[0039] From the viewpoint of excellent elasticity, the laminated foam sheet preferably has a 0.1 mm compression hardness of 25 N or less, more preferably 20 N or less, and even more preferably 15 N or less, as measured on the load surface of the surface treatment layer. The lower limit of the 0.1 mm compression hardness of the laminated foam sheet is not particularly limited, but may be 1 N or more from the viewpoint of increasing the compression recovery rate. The compression hardness can be measured as described later.

[0040] From the viewpoint of excellent elasticity, the laminated foamed sheet preferably has a 25% compression hardness of 100 N or less, more preferably 95 N or less, and even more preferably 85 N or less, as measured on the surface treatment layer as the load-bearing surface. The lower limit of the 25% compression hardness of the laminated foamed sheet is not particularly limited, but from the viewpoint that the compression hardness improves as the thickness of the laminated foamed sheet decreases, it may be 10 N or more. Further, from the viewpoint of excellent elasticity, the laminated foamed sheet preferably has a 50% compression hardness of 300 N or less, more preferably 280 N or less, and even more preferably 260 N or less, as measured on the surface treatment layer as the load-bearing surface. The lower limit of the 50% compression hardness of the laminated foamed sheet is not particularly limited, but from the viewpoint that the compression hardness improves as the thickness of the laminated foamed sheet decreases, it may be 30 N or more. The compression hardness can be measured as described later.

[0041] In the laminated foamed sheet, from the viewpoint of excellent elasticity, the cross-sectional bubble ratio of the thermoplastic resin layer is preferably 5% or more and 65% or less, more preferably 10% or more and 60% or less, even more preferably 15% or more and 55% or less, and particularly preferably 25% or more and 50% or less. Specifically, the cross-sectional bubble ratio can be measured as described later.

[0042] From the viewpoint of wear resistance, the Shore A hardness on the surface treatment layer side of the laminated foamed sheet is preferably 30 or more and 80 or less, more preferably 35 or more and 75 or less, and even more preferably 40 or more and 60 or less. Specifically, the Shore A hardness can be measured as described later.

[0043] From the viewpoint of wear resistance, in the Taber abrasion test (abrasion wheel CS-10, load 4.9 N) conforming to JIS K 7204:1999, the number of rotations of the laminated foamed sheet is preferably 100 or more, more preferably 200 or more, even more preferably 300 or more, even more preferably 400 or more, and particularly preferably 500 or more.

[0044] From the viewpoint of abrasion resistance, the laminated foamed sheet preferably has a peel strength of 2 N / mm or more, more preferably 3 N / mm or more, still more preferably 4 N / mm or more, and particularly preferably 5 N / mm or more in terms of the peel strength of a 15 mm sample width by a 180° peel test between the surface treatment layer and the thermoplastic resin. The peel strength between the surface treatment layer and the thermoplastic resin in the laminated foamed sheet can be measured as described below.

[0045] From the viewpoint of easily exhibiting a suede-like appearance, the gloss on the surface treatment layer side of the laminated foamed sheet is preferably 2.0 or less, more preferably 1.8 or less, and still more preferably 1.4 or less. The gloss on the surface treatment layer side of the laminated foamed sheet can be measured as described below.

[0046] From the viewpoint of excellent secondary moldability such as vacuum molding, the laminated foamed sheet preferably has an elongation at break of 60% or more, more preferably 70% or more, and still more preferably 80% or more at 160°C. The upper limit of the elongation at break of the laminated foamed sheet at 160°C is not particularly limited, but may be 400% or less from the viewpoint of the limit of the complexity of the shape of the mold. From the viewpoint of excellent secondary moldability such as vacuum molding, the laminated foamed sheet preferably has a tensile stress of 20 kPa or more, more preferably 25 kPa or more, still more preferably 30 kPa or more, and particularly preferably 35 kPa or more at 160°C. The upper limit of the tensile stress of the laminated foamed sheet at 160°C is not particularly limited, but may be 280 kPa or less from the viewpoint of the drawdown amount during molding. The elongation at break and the tensile stress of the laminated foamed sheet at 160°C can be specifically measured as described below.

[0047] From the perspective of excellent secondary moldability such as vacuum forming, the laminated foamed sheet preferably has a tensile elongation at 23°C of 150% or more, more preferably 200% or more, and even more preferably 260% or more. The upper limit of the tensile elongation at 23°C of the laminated foamed sheet is not particularly limited, but may be 700% or less from the perspective of molding with a low expansion rate or pasting process. From the perspective of excellent secondary moldability such as vacuum forming, the laminated foamed sheet preferably has a tensile stress at 23°C of 1.0 MPa or more, more preferably 1.2 MPa or more, even more preferably 1.5 MPa or more, and particularly preferably 1.8 MPa or more. The upper limit of the tensile stress at 23°C of the laminated foamed sheet is not particularly limited, but may be 9.9 MPa or less from the perspective of no breakage occurring due to sewing process. The tensile elongation and tensile stress at 23°C can be specifically measured as described later.

[0048] Figure 1 is a schematic cross-sectional view of a laminated foamed sheet according to an example of the present invention. In this embodiment, the laminated foamed sheet 1 includes a thermoplastic resin layer 2 and a surface treatment layer 3. The thermoplastic resin layer 2 is composed of a first foamed thermoplastic resin layer 20 containing a thermoplastic resin and expanded thermally expandable microcapsules 10. The surface treatment layer 3 is disposed on the first surface of the first foamed thermoplastic resin layer 20.

[0049] Figure 2 is a schematic cross-sectional view of a laminated foamed sheet according to an example of the present invention. In this embodiment, the laminated foamed sheet 11 includes a thermoplastic resin layer 2 and a surface treatment layer 3. The thermoplastic resin layer 2 is composed of a first foamed thermoplastic resin layer 20 containing a thermoplastic resin and expanded thermally expandable microcapsules 10 and a non-foamed thermoplastic resin layer 30. The surface treatment layer 3 is disposed on the first surface of the first foamed thermoplastic resin layer 20.

[0050] Figure 3 is a schematic cross-sectional view of a laminated foam sheet according to an example of the present invention. In this embodiment, the laminated foam sheet 21 includes a thermoplastic resin layer 2, a surface treatment layer 3, and a cushion layer 4. The thermoplastic resin layer 2 is composed of a first foamed thermoplastic resin layer 20 containing a thermoplastic resin and expanded thermally expandable microcapsules 10. The surface treatment layer 3 is disposed on the first surface of the first foamed thermoplastic resin layer 20. The cushion layer 4 is disposed on the side opposite to the side where the surface treatment layer 3 of the thermoplastic resin layer 2 is disposed.

[0051] The laminated foam sheet may include a first foamed thermoplastic resin layer, an unfoamed thermoplastic resin layer, and a cushion layer. In this case, it will be arranged in the order of the surface treatment layer, the thermoplastic resin layer, and the cushion layer, that is, in the order of the surface treatment layer, the first foamed thermoplastic resin layer, the unfoamed thermoplastic resin layer, and the cushion layer.

[0052] The laminated foam sheet is not particularly limited, but for example, it can be suitably used as the skin material of vehicle interior materials. Examples of vehicle interior materials include instrument panels, door trims, trunk trims, seat covers, pillar covers, ceiling materials, rear trays, console boxes, airbag covers, armrests, headrests, meter covers, crash pads, etc. of vehicles such as automobiles.

[0053] (Method for manufacturing a laminated foam sheet) The laminated foam sheet is not particularly limited, but for example, a thermoplastic resin composition containing a thermoplastic resin and thermally expandable microcapsules is sheet-molded at a temperature equal to or higher than the melting point of the thermoplastic resin and lower than the expansion start temperature of the thermally expandable microcapsules to form a first unfoamed thermoplastic resin sheet. A surface treatment agent is applied to one surface of the obtained first unfoamed thermoplastic resin sheet to form a surface treatment layer. The obtained laminate is heated at a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsules to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer, thereby producing the laminated foam sheet.

[0054] As the thermoplastic resin and the thermally expandable microcapsules, those described above can be appropriately used.

[0055] When the thermoplastic resin contains a plurality of thermoplastic resins, "above the melting point of the thermoplastic resin" in the step of forming the first unfoamed thermoplastic resin sheet means above the melting point of the thermoplastic resin having the highest melting point.

[0056] The thermally expandable microcapsules are not particularly limited, but from the viewpoint of suppressing foaming in the step of forming the first unfoamed thermoplastic resin sheet, the expansion start temperature (also referred to as the initial decomposition temperature) is preferably 160°C or higher, preferably 170°C or higher, more preferably 180°C or higher, and particularly preferably 185°C or higher. Also, from the viewpoint of facilitating the formation of the first foamed thermoplastic resin layer, it may be 215°C or lower, or may be 210°C or lower.

[0057] The thermally expandable microcapsules are not particularly limited, but from the viewpoint of suppressing foaming in the step of forming the first unfoamed thermoplastic resin sheet and facilitating the formation of the first foamed thermoplastic resin layer, the expansion start temperature is preferably 185°C or higher and 215°C or lower, more preferably 190°C or higher and 215°C or lower.

[0058] The thermally expandable microcapsules are not particularly limited, but from the viewpoint of suppressing foaming in the step of forming the first unfoamed thermoplastic resin sheet and facilitating the formation of the first foamed thermoplastic resin layer, the maximum expansion temperature (also referred to as the maximum foaming temperature) is preferably 190°C or higher and 240°C or lower, more preferably 195°C or higher and 235°C or lower, and even more preferably 200°C or higher and 230°C or lower.

[0059] The expansion start temperature and the maximum expansion temperature of the thermally expandable microcapsules are measured using a thermomechanical analyzer (TMA).

[0060] The thermoplastic resin composition may contain, if necessary, one or more additives such as a softening agent, an inorganic filler, an antioxidant, a light stabilizer, an ultraviolet absorber, an antistatic agent, a lubricant, and a colorant. The additive may be, for example, 10 parts by weight or less based on 100 parts by weight of the thermoplastic resin.

[0061] The sheet forming is not particularly limited and may be calender forming or extrusion forming.

[0062] As the surface treatment agent, those described above can be appropriately used. From the viewpoint of abrasion resistance, the surface treatment agent preferably has a tensile stress of 3 MPa or more and a tensile elongation of 30% or more measured by a tensile test performed under the conditions of a temperature of 23°C, a relative humidity of 65%, and a tensile speed of 500 mm / min for the coating film of the surface treatment agent, and a peel strength of 2 N / mm or more for a sample width of 15 mm by a 180° peel test. The tensile stress of the coating film of the surface treatment agent is more preferably 4 MPa or more and 35 MPa or less. The tensile elongation of the coating film of the surface treatment agent is more preferably 35% or more and 500% or less. The peel strength of the coating film of the surface treatment agent is more preferably 3 N / mm or more and 25 N / mm or less. The tensile stress, tensile elongation, and peel strength of the coating film of the surface treatment agent at 23°C can be specifically measured as described below.

[0063] The surface treatment layer can be formed, for example, by coating one surface of the first unfoamed thermoplastic resin sheet with a surface treatment agent such as a polyurethane dispersion for top and primer, and drying at a temperature of 50°C or higher and 140°C or lower. The coating and drying may be performed two or more times.

[0064] When the thermoplastic resin layer includes an unfoamed thermoplastic resin layer in addition to the first foamed thermoplastic resin layer, in the step of forming the first unfoamed thermoplastic resin sheet, a thermoplastic resin composition containing a thermoplastic resin and thermally expandable microcapsules and a thermoplastic resin composition containing a thermoplastic resin (not containing a foaming agent) are co-extruded at a temperature lower than the expansion start temperature of the thermally expandable microcapsules, whereby a two-layer sheet of the first unfoamed thermoplastic resin sheet and the unfoamed thermoplastic resin sheet can be formed. Alternatively, the first unfoamed thermoplastic resin sheet obtained by calendering or extrusion molding may be thermally laminated on the surface of the unfoamed thermoplastic resin sheet formed by sheet molding the thermoplastic resin composition containing a thermoplastic resin (not containing a foaming agent).

[0065] When the laminated foam sheet includes a cushion layer, after forming the surface treatment layer, the obtained laminate is heated at a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsules, and when expanding the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form the first foamed thermoplastic resin layer, a cushion material such as a crosslinked resin foam for forming the cushion layer can be bonded to the thermoplastic resin layer directly or via an adhesive.

[0066] (Laminated molded body and manufacturing method) The laminated molded body is obtained by molding a laminated foam sheet into a predetermined shape. When the laminated molded body is a skin material for a vehicle interior material, the laminated foam sheet can be molded to fit the shape of the vehicle interior material. Examples of the vehicle interior material include an instrument panel, door trim, trunk trim, seat, pillar cover, ceiling material, rear tray, console box, airbag cover, armrest, headrest, meter cover, crash pad, etc. of a vehicle such as an automobile.

[0067] The laminated molded body may be produced by directly molding a laminated foam sheet. Alternatively, the laminated molded body is formed by sheet-molding a thermoplastic resin composition containing a thermoplastic resin and thermally expandable microcapsules at a temperature equal to or higher than the melting point of the thermoplastic resin and lower than the initial decomposition temperature of the thermally expandable microcapsules to form a first unfoamed thermoplastic resin sheet. A surface treatment agent is applied to one surface of the obtained first unfoamed thermoplastic resin sheet to form a surface treatment layer. The obtained laminate is heated at a temperature equal to or higher than the maximum foaming temperature of the thermally expandable microcapsules to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer, and a laminated molded body can be obtained by molding it into a predetermined shape. The molding of the laminated molded body can be performed by vacuum molding, and male mold vacuum molding is preferable to obtain a more suede-like texture.

Examples

[0068] Hereinafter, the present invention will be described more specifically using examples. Note that the present invention is not limited to the following examples.

[0069] The measurement methods and evaluation methods used in the examples and comparative examples will be described.

[0070] (Tensile test and peel test of the coating film of the surface treatment agent) The surface treatment agent was thinly coated on a release film with a bar coater and dried in an oven (solvent-based: 80 °C, 1 min, water-based: 80 °C, 2 min). After obtaining a coating film composed only of the surface treatment agent with a coating film thickness of 15 to 20 μm, the coating film was punched out with a No. 2 dumbbell, and using the obtained test piece, a tensile test was performed under the conditions of a temperature of 23 °C and a relative humidity of 65% at a tensile speed of 500 mm / min, and the tensile stress and tensile elongation were measured. Also, under the conditions of a temperature of 23 °C and a relative humidity of 65%, a hot melt tape (fixed with an iron at 180 °C for 3 min) was attached to the coating film of the surface treatment agent, and a 180° peel (peeling) test was performed to measure the peel strength.

[0071] (Arithmetic mean height Sa and ten-point mean roughness Rzjis) The arithmetic mean height Sa and the ten-point mean roughness Rzjis on the surface treatment layer side were measured based on ISO 25178 using a "VR-5000" manufactured by Keyence Corporation.

[0072] (Cross-sectional bubble ratio) The laminated foam sheet was cut perpendicularly from the surface treatment agent side in the thickness direction with a cutter, and the cross-section of the laminated foam sheet was observed at a magnification of 150 times using a digital microscope ("VHX-7000" manufactured by Keyence Corporation). In the OPT-SEM (Optical Shadow Effect Mode) image of the obtained thermoplastic resin layer, the area of the specified range was measured as the total area, the bubble area in the specified range was measured, and the cross-sectional bubble ratio was calculated using the following formula 1. [Formula 1] Cross-sectional bubble ratio (%) = Bubble area / Total area × 100

[0073] (Shore A hardness) In accordance with JIS K 7215, using an "Asker rubber hardness tester type A" manufactured by Kobunshi Keiki Co., Ltd., the average value of three readings taken immediately after the indenter contacted the surface was taken as the Shore A hardness.

[0074] (Average bubble diameter of expanded thermally expandable microcapsules) The thermally expandable microcapsules heated above the expansion temperature, the foam sheet containing the thermally expandable microcapsules, or the laminated foam sheet was cut perpendicularly from the surface treatment layer side in the thickness direction with a cutter, and 30 bubbles on the cross-section were observed at a magnification of 50 times using a "VHX-7000" manufactured by Keyence Corporation. The bubble diameter was measured by the in-machine measurement system and taken as the average value.

[0075] (Compressive hardness) Measured based on JIS K 6767. (1) The laminated foam sheet was cut into a 20 mm square, six sheets were stacked as a sample, and the initial thickness of the sample was measured with a vernier caliper. (2) The sample was set in a compression testing machine (manufactured by Shimadzu Corporation, model number "AGM-1"), and through a pressure plate with a diameter of φ35, with the surface treatment layer as the load surface, an initial load of 0.5 N was applied, and this position was taken as the origin. Apply pressure at a constant speed (1 mm / min) and measure the 0.1 mm compression hardness (0.1 mm from the origin), 25% compression (1.265 mm from the origin), and 50% compression (2.53 mm from the origin) stress. The value measured by the in-machine measurement system was taken as the compression hardness.

[0076] (Tensile Test and Peel Test of the Laminated Foam Sheet) Punch out the laminated foam sheet with a dumbbell No. 2, and using the obtained test piece, conduct a tensile test at a tensile speed of 500 mm / min and measure the tensile stress and tensile elongation. Also, using a hot melt tape, attach a hot melt tape (ironed at 180 °C for 3 min) to the surface treatment layer side of the laminated foam sheet and conduct a 180° peel (separation) test to measure the peel strength.

[0077] (Wear Test) Perform a Taber wear test (wear wheel CS-10, load 4.9 N) according to JIS K 7204:1999, measure the number of rotations, and make a judgment based on the following criteria. <Judgment Criteria> A: There is no peeling or change in the coating film of the surface treatment layer. B: There is no peeling in the coating film of the surface treatment layer, and slight whitening can be seen. C: Part of the coating film of the surface treatment layer peels off, and whitening can be seen. D: The coating film of the surface treatment layer peels off, and the base material can be confirmed.

[0078] (Appearance) Visually observe the laminated foam sheet by three measurers, make a judgment based on the following criteria, and when two or more agree or when the judgments of the three are different, take the judgment of the measurer in the middle as the appearance judgment. A: There is whitening like fluff, a warm feeling, and it looks like suede. B: There is whitening like fluff and it looks like suede. C: It looks slightly fluffy and slightly like suede. D: There is no fluffiness and it does not look like suede.

[0079] (Gloss) The surface treatment layer was measured for 60° specular glossiness in accordance with JIS Z8741 using "UNI GLOSS 60Plus" manufactured by Konica Minolta, and the average value of three measurements was taken as the gloss.

[0080] (Secondary moldability) Using a test vacuum forming machine, both sides of the laminated foam sheet were heated to 180°C to 230°C, and vacuum forming was performed in a box shape with a length of 150 mm, a width of 100 mm, and a depth of 50 mm, and the determination was made according to the following criteria. A: The appearance and shape are good. B: The appearance and shape are slightly good. C: Defects occur in either the appearance or the shape. D: Appearance and shape defects due to tearing occur.

[0081] The thermoplastic resin compositions used in the examples and comparative examples will be described. Thermoplastic resin composition 1: 25.0 parts by weight of a dynamically crosslinked type olefin-based thermoplastic elastomer (manufactured by Mitsui Chemicals, Milastomer (registered trademark) "5030NHS", partially crosslinked, melting point 158°C, Shore A hardness 50), 25.0 parts by weight of a dynamically crosslinked type olefin-based thermoplastic elastomer (manufactured by Mitsui Chemicals, Milastomer (registered trademark) "8030NHS", partially crosslinked, melting point 158°C, Shore A hardness 85), 25.0 parts by weight of a dynamically crosslinked type olefin-based thermoplastic elastomer (manufactured by Sumitomo Chemical, Espolex (registered trademark) "WT485A", melting point 157°C, partially crosslinked, Shore A hardness 60), 5.0 parts by weight of random polypropylene (manufactured by Prime Polymer Co., Ltd. "B-241", melting point 141°C), 20.0 parts by weight of linear low density polyethylene (manufactured by Sumitomo Chemical "FW201-0", melting point 119°C) in 100 parts by weight of a thermoplastic resin (mixed resin), a total of 0.75 parts by weight of a lubricant, an antioxidant and an ultraviolet absorber, and 6.0 parts by weight of a pigment were added Thermoplastic resin composition 2: 85.0 parts by weight of a dynamically crosslinked type olefinic thermoplastic elastomer (manufactured by Mitsubishi Chemical Corporation, TREXPRENE "TV-010N", partially crosslinked, melting point 118°C, Shore A hardness 63), 5.0 parts by weight of an α-olefin copolymer (manufactured by Mitsui Chemicals, Inc., TUFMER (registered trademark) "PN3525", melting point 160°C, Shore A hardness 72), and 10.0 parts by weight of an olefin block copolymer (manufactured by The Dow Chemical Company, INFUSE "9107", melting point 121°C, Shore A hardness 60). A total of 0.75 parts by weight of a lubricant, an antioxidant, and an ultraviolet absorber, and 6.0 parts by weight of a pigment are added to 100 parts by weight of the thermoplastic resin (mixed resin) thus obtained. Thermoplastic resin composition 3: 40.0 parts by weight of a dynamically crosslinked type olefinic thermoplastic elastomer (manufactured by Mitsubishi Chemical Corporation, TREXPRENE "TV-010N", partially crosslinked, melting point 118°C, Shore A hardness 63), 40.0 parts by weight of a dynamically crosslinked type olefinic thermoplastic elastomer (manufactured by ExxonMobil Chemical Company, Santoprene "201-55", fully crosslinked, melting point 152°C, Shore A hardness 59), 10.0 parts by weight of an α-olefin copolymer (manufactured by Mitsui Chemicals, Inc., TUFMER (registered trademark) "PN3525", melting point 160°C, Shore A hardness 72), 5.0 parts by weight of an olefin block copolymer (manufactured by The Dow Chemical Company, INFUSE "9107", melting point 121°C, Shore A hardness 60), and 5.0 parts by weight of linear low density polyethylene (manufactured by Sumitomo Chemical Company, Limited, "FW201-0", melting point 119°C). A total of 0.75 parts by weight of a lubricant, an antioxidant, and an ultraviolet absorber, and 6.0 parts by weight of a pigment are added to 100 parts by weight of the thermoplastic resin (mixed resin) thus obtained.

[0082] In the examples and comparative examples, the blowing agents shown in Table 1 below were used. As the masterbatch of the thermally expandable microcapsule 1, polyethylene (manufactured by Tosoh Corporation, product name "Petrosen 248") was used as the carrier resin, and a masterbatch containing 50% by weight of the thermally expandable microcapsule 1 was used. As the masterbatch of the thermally expandable microcapsule 2, TPO (manufactured by ExxonMobil Japan Co., Ltd., product name "Vistamax 3000") was used as the carrier resin, and a masterbatch containing 50% by weight of the thermally expandable microcapsule 2 was used.

[0083]

Table 1

[0084] In the examples and comparative examples, the surface treatment agent (urethane paint) shown in Table 2 below was used. Also, the 23°C tensile test of the coating film of the surface treatment agent was conducted as described above, and the results are shown in Table 3 below.

[0085]

Table 2

[0086]

Table 3

[0087] (Example 1) (Production of laminated foamed sheet) To 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 1, a masterbatch of the thermally expandable microcapsule 1 was added to the thermoplastic resin composition 1 so that the compounding amount of the thermally expandable microcapsule 1 was as shown in Table 4 below. The obtained thermoplastic resin composition was kneaded at 185°C and calendered to form a first unfoamed thermoplastic resin sheet. On one surface of the obtained first unfoamed thermoplastic resin sheet, a surface treatment agent was coated from the primer layer under the conditions shown in Table 4 below (drying temperature: 120°C) to form a surface treatment layer having a top layer and a primer layer. The obtained laminate was heated at the temperature shown in 230°C to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: about 688 μm), thereby obtaining a laminated foamed sheet having the structure shown in FIG. 1. (Production of laminated molded body) Using the laminated foamed sheet obtained above, it was heated using an infrared heater installed in a vacuum molding machine so that the surface temperature became 220°C or higher, pressed against a molding die, held in shape by vacuum suction, cooled, and released from the mold to produce a laminated molded body.

[0088] (Example 2) The thermoplastic resin composition 1 was kneaded at 190°C and calendered to obtain an unfoamed thermoplastic resin sheet (unfoamed thermoplastic resin layer, thickness of about 600 μm). On one surface of the unfoamed thermoplastic resin sheet, a thermoplastic resin composition containing the thermally expandable microcapsules 1 was kneaded at 185°C and thermally laminated by calendering to form a laminate of the unfoamed thermoplastic resin sheet and the first unfoamed thermoplastic resin sheet. The thermoplastic resin composition containing the thermally expandable microcapsules 1 was obtained by adding a masterbatch of the thermally expandable microcapsules 1 to the thermoplastic resin composition 1 so that the thermally expandable microcapsules 1 had the compounding amounts shown in Table 4 below with respect to 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 1. A surface treatment layer having a top layer and a primer layer was formed in the same manner as in Example 1 on one surface of the first unfoamed thermoplastic resin sheet of the obtained laminate. The obtained laminate was heated at 230°C to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness of about 688 μm), thereby obtaining a laminated foamed sheet having the structure shown in FIG. 2. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1 except that the laminated foamed sheet obtained above was used.

[0089] (Example 3) (Production of laminated foamed sheet) A laminate of the first unfoamed thermoplastic resin sheet and the surface treatment layer was obtained in the same manner as in Example 1. The obtained laminate was laminated with a crosslinked resin foam such that the crosslinked resin foam was located on the side opposite to the side where the surface treatment layer of the first unfoamed thermoplastic resin sheet was disposed, and heated at 230°C to expand the thermal expansion microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: about 688 μm). By joining the first foamed thermoplastic resin layer and the crosslinked resin foam, a laminated foam sheet having the structure shown in FIG. 3 was obtained. As the crosslinked resin foam, a crosslinked polyolefin resin foam (manufactured by Toray Industries, Inc., "JP17-15025"), crosslinking degree: 43%, foaming ratio: 15 times, thickness: 2.5 mm, compression recovery rate: 92%) was used. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

[0090] (Example 4) (Production of laminated foam sheet) A laminate of an unfoamed thermoplastic resin sheet (unfoamed thermoplastic resin layer, thickness: about 500 μm) and a first unfoamed thermoplastic resin sheet was formed in the same manner as in Example 2, except that thermoplastic resin composition 2 was used instead of thermoplastic resin composition 1 and the blending amount of thermal expansion microcapsules 1 was as shown in Table 4 below. A surface treatment agent was applied from the primer layer under the conditions shown in Table 4 below (drying temperature: 130°C) to the surface of the obtained laminate on the side opposite to the side where the unfoamed thermoplastic resin sheet of the first unfoamed thermoplastic resin sheet was disposed, to form a surface treatment layer having a top layer and a primer layer. The obtained laminate was heated at 230°C to expand the thermal expansion microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: about 690 μm), thereby obtaining a laminated foam sheet having the structure shown in FIG. 2. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

[0091] (Example 5) (Production of laminated foam sheet) To 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 2, a masterbatch of the thermally expandable microcapsules 1 was added to the thermoplastic resin composition 2 so that the compounding amount of the thermally expandable microcapsules 1 was as shown in Table 4 below. The obtained thermoplastic resin composition was kneaded at 185°C and calendered to form a first unfoamed thermoplastic resin sheet. On one surface of the obtained first unfoamed thermoplastic resin sheet, a surface treatment agent was applied from the primer layer under the conditions shown in Table 4 below (drying temperature: 120°C) to form a surface treatment layer having a top layer and a primer layer. The obtained laminate was heated at the temperature shown in 230°C to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: about 1187 μm), thereby obtaining a laminated foamed sheet having the structure shown in FIG. 1. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1 except that the laminated foamed sheet obtained above was used.

[0092] (Example 6) (Production of laminated foamed sheet) A laminate of an unfoamed thermoplastic resin sheet (unfoamed thermoplastic resin layer, thickness: about 400 μm) and a first unfoamed thermoplastic resin sheet was formed in the same manner as in Example 4 except that the thermoplastic resin composition 3 was used instead of the thermoplastic resin composition 2. On one surface of the obtained first unfoamed thermoplastic resin sheet, a surface treatment agent was applied from the primer layer under the conditions shown in Table 4 below (drying temperature: 120°C) to form a surface treatment layer having a top layer and a primer layer. The obtained laminate was heated at the temperature shown in 230°C to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: about 690 μm), thereby obtaining a laminated foamed sheet having the structure shown in FIG. 2. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1 except that the laminated foamed sheet obtained above was used.

[0093] (Example 7) (Production of laminated foamed sheet) A laminated foamed sheet having the structure shown in Fig. 2 was produced in the same manner as in Example 4, except that the surface treatment agent shown in Table 1 below was used. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1, except that the laminated foamed sheet obtained above was used.

[0094] (Example 8) A laminated foamed sheet and a laminated molded body having the structure shown in Fig. 1 were produced in the same manner as in Example 1, except that the amount of the thermal expansion microcapsules 1 was adjusted to the compounding amount shown in Table 4 below and the surface treatment agent was applied under the conditions shown in Table 4 below.

[0095] (Comparative Example 1) (Production of laminated sheet) The thermoplastic resin composition 1 was kneaded at 185°C and calendered to obtain an unfoamed thermoplastic resin sheet. A surface treatment agent was applied from the primer layer to one surface of the obtained unfoamed thermoplastic resin sheet under the conditions shown in Table 5 below (drying temperature: 120°C) to form a surface treatment layer having a top layer and a primer layer, thereby obtaining a laminated sheet. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1, except that the laminated sheet obtained above was used.

[0096] (Comparative Example 2) (Production of laminated sheet) The thermoplastic resin composition 1 was kneaded at 185°C and calendered to obtain an unfoamed thermoplastic resin sheet. A surface treatment agent was applied from the primer layer to one surface of the obtained unfoamed thermoplastic resin sheet under the conditions shown in Table 5 below (drying temperature: 120°C) to form a surface treatment layer having a top layer and a primer layer, thereby obtaining a laminated sheet. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1, except that the laminated sheet obtained above was used.

[0097] (Comparative Example 3) (Production of laminated foamed sheet) The thermoplastic resin composition 2 was kneaded at 185°C and calendered to obtain an unfoamed thermoplastic resin sheet (thickness: 401 μm). On one surface of the unfoamed thermoplastic resin sheet, a thermoplastic resin composition containing the thermally expandable microcapsules 1 was kneaded at 185°C and thermally laminated by calendering to form a laminate of the unfoamed thermoplastic resin sheet and the first unfoamed thermoplastic resin sheet. The thermoplastic resin composition containing the thermally expandable microcapsules 1 was obtained by adding a masterbatch of the thermally expandable microcapsules 1 to the thermoplastic resin composition 2 so that the thermally expandable microcapsules 1 had the compounding amounts shown in Table 5 with respect to 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 2. On the surface of the obtained laminate on the side opposite to the side where the unfoamed thermoplastic resin sheet of the first unfoamed thermoplastic resin sheet was disposed, the thermoplastic resin composition 2 was kneaded at 180°C and thermally laminated by calendering to obtain a laminate having a three-layer structure composed of an unfoamed thermoplastic resin sheet, the first unfoamed thermoplastic resin sheet, and an unfoamed thermoplastic resin sheet (thickness: 1192 μm). On the surface of one of the obtained laminates on the side opposite to the side in contact with the first unfoamed thermoplastic resin sheet of the unfoamed thermoplastic resin sheet, a surface treatment agent was applied from the primer layer under the conditions shown in Table 5 below (drying temperature: 120°C) to form a surface treatment layer having a top layer and a primer layer. The obtained laminate was heated at 230°C to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: 1504 μm), thereby obtaining a laminated foamed sheet. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1 except that the laminated foamed sheet obtained above was used.

[0098] (Comparative Example 4) A laminated foamed sheet and a laminated molded body were produced in the same manner as in Example 1 except that a surface treatment agent was applied from the primer layer under the conditions shown in Table 5 below (drying temperature: 120°C) to form a surface treatment layer having a top layer and a primer layer.

[0099] (Comparative Example 5) A laminated foamed sheet and a laminated molded body were produced in the same manner as in Example 1, except that a surface treatment agent was applied from the primer layer under the conditions shown in Table 5 below (drying temperature: 120°C) to form a surface treatment layer having a top layer and a primer layer.

[0100] (Comparative Example 6) (Production of Laminated Foamed Sheet) A powder-type chemical foaming agent was added to the thermoplastic resin composition 3 so that the blending amount of the foaming agent was as shown in Table 5 below with respect to 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 3. The obtained thermoplastic resin composition was kneaded at 175°C and calendered to form a first unfoamed thermoplastic resin sheet. A surface treatment layer having a top layer and a primer layer was formed on one surface of the obtained first unfoamed thermoplastic resin sheet in the same manner as in Example 1. The obtained laminate was heated at the temperature shown in 215°C to foam the foaming agent in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: about 1300 μm), thereby obtaining a laminated foamed sheet having the structure shown in FIG. 1. (Production of Laminated Molded Body) A laminated molded body was produced in the same manner as in Example 1, except that the laminated foamed sheet obtained above was used.

[0101] (Comparative Example 7) (Production of Laminated Foamed Sheet) The thermoplastic resin composition 1 was kneaded at 180°C and calendered to form an unfoamed thermoplastic resin sheet. A surface treatment agent was applied from the primer layer under the conditions shown in Table 5 below (drying temperature: 120°C) to one surface of the obtained unfoamed thermoplastic resin sheet to form a surface treatment layer having a top layer and a primer layer. At this time, 5% by weight of the thermally expandable microcapsules 2 was added to the surface treatment agent for the primer layer in advance, and the surface treatment agent containing the thermally expandable microcapsules stirred and mixed was used. 2 ) and used. The obtained laminate was heated at a temperature of 230°C to expand the thermal expansion microcapsules in the primer layer of the surface treatment agent, thereby forming a foamed surface treatment agent primer layer (thickness: about 49 μm), and a laminated foamed sheet having a structure in which the primer layer forms a foamed layer was obtained. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1, except that the laminated foamed sheet obtained above was used.

[0102] (Comparative Example 8) (Production of laminated foamed sheet) The thermoplastic resin composition 1 was kneaded at 180°C and calendered to form an unfoamed thermoplastic resin sheet. On one surface of the obtained unfoamed thermoplastic resin sheet, a surface treatment agent was applied from the primer layer under the conditions shown in Table 5 below (drying temperature: 120°C) to form a surface treatment layer having a top layer and a primer layer. At this time, 5% by weight of the thermal expansion microcapsules 2 was added to the surface treatment agent for the top layer in advance, and a surface treatment agent containing the thermal expansion microcapsules that had been stirred and mixed was used. 2 ) The obtained laminate was heated at a temperature of 230°C to expand the thermal expansion microcapsules in the top layer of the surface treatment agent, thereby forming a foamed surface treatment agent top layer (thickness: about 51 μm), and a laminated foamed sheet having a structure in which the top layer forms a foamed layer was obtained. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1, except that the laminated foamed sheet obtained above was used.

[0103] (Comparative Example 9) To 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 1, a masterbatch of the thermal expansion microcapsules 2 was added so that the blending amount shown in Table 5 below was obtained. When the obtained thermoplastic resin composition was kneaded at 158°C and calendered, the thermal expansion microcapsules foamed (expanded), and a first unfoamed thermoplastic resin sheet could not be formed.

[0104] (Comparative Example 10) To 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 1, the thermally expandable microcapsules 3 were added to the thermoplastic resin composition 1 so that the compounding amounts shown in Table 5 below were obtained. When the obtained thermoplastic resin composition was kneaded at 180° C. and subjected to calender molding, the thermally expandable microcapsules foamed (expanded), and the first unfoamed thermoplastic resin sheet could not be formed.

[0105] (Comparative Example 11) (Production of laminated foamed sheet) A laminate of an unfoamed thermoplastic resin sheet (thickness: 600 μm) and a first unfoamed thermoplastic resin sheet was formed in the same manner as in Example 4, except that the thermoplastic resin composition 3 was used instead of the thermoplastic resin composition 2. On the surface of the first unfoamed thermoplastic resin sheet of the obtained laminate on the side not in contact with the unfoamed thermoplastic resin sheet, a surface treatment agent (primer) shown in Table 5 below and a surface treatment agent having self-healing properties (manufactured by DIC Corporation, product numbers “BX-800S” and “DN-902S” mixed at 100:2.8) were applied under the conditions shown in Table 5 below (drying temperature: 120° C.) to form a surface treatment layer. The obtained laminate was heated at the temperature shown in 230° C. to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: 1100 μm), and a laminated foamed sheet was obtained. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1, except that the laminated foamed sheet obtained above was used.

[0106] (Comparative Example 12) (Production of laminated foamed sheet) A laminate of an unfoamed thermoplastic resin sheet (thickness: 500 μm) and a first unfoamed thermoplastic resin sheet was formed in the same manner as in Example 4, except that the thermoplastic resin composition 3 was used instead of the thermoplastic resin composition 2. On the surface of the obtained laminate on the side not in contact with the unfoamed thermoplastic resin sheet of the first unfoamed thermoplastic resin sheet, a surface treatment agent (primer) shown in Table 5 below and a film were applied under the conditions shown in Table 5 below (drying temperature: 130 °C) to form a surface treatment layer. The obtained laminate was heated at the temperature shown in 230 °C to expand the thermal expansion microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: 1098 μm), and a laminated foamed sheet was obtained. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1 except that the laminated foamed sheet obtained above was used.

[0107] (Comparative Example 13) A laminated foamed sheet was obtained in the same manner as in Example 1 except that the thickness of the first foamed thermoplastic resin layer was adjusted to about 280 μm. (Production of laminated molded body) A laminated molded body was produced in the same manner as in Example 1 except that the laminated foamed sheet obtained above was used.

[0108] In the examples and comparative examples, various physical properties were measured and evaluated as described above, and the results are shown in Tables 4 and 5.

[0109]

Table 4

[0110]

Table 5

[0111] As can be seen from Table 4, in the examples, the laminated foamed sheet had a suede-like appearance. Also, the 0.1 mm compression hardness was 20 or less, and the elasticity (cushioning property) was good. Further, in the taper wear test, the number of rotations was 200 or more, and the wear resistance was high.

[0112] On the other hand, as can be seen from Table 5, in Comparative Examples 1 and 2 which do not have a foamed layer and the arithmetic mean height Sa on the surface treatment layer side is less than 5 μm, and in the case of Comparative Example 6 where thermal expansion microcapsules are not used as the foaming agent, a suede-like appearance could not be achieved. Also, in the case of Comparative Example 3 where the surface treatment layer is not disposed on the surface of the foamed layer, a suede-like appearance could not be achieved. In the cases of Comparative Examples 4 and 5 where the thickness of the surface treatment layer is less than 8.0 μm, the abrasion resistance was poor. In the cases of Comparative Examples 7 and 8 where thermal expansion microcapsules were added to the surface treatment layer, they peeled off during foaming, and not only could a suede-like appearance not be achieved, but also the abrasion resistance was poor. In Comparative Examples 11 and 12, the gloss was high, and whitening due to the foamed thermal expansion microcapsules was suppressed, so a suede-like appearance could not be achieved. In the case of Comparative Example 13 where the thickness of the foamed layer is less than 300 μm, the 0.1 mm compression hardness is 28 N, and the elasticity (cushioning property) is poor.

Claims

1. Comprising a thermoplastic resin layer and a surface treatment layer, The thermoplastic resin layer includes a first foamed thermoplastic resin layer containing a thermoplastic resin and expanded thermally expandable microcapsules, In the first foamed thermoplastic resin layer, the thermoplastic resin includes one or more selected from the group consisting of an olefin-based thermoplastic elastomer and a polyolefin-based resin, The surface treatment layer is composed of a coating film of a urethane paint, The surface treatment layer is disposed on the first surface of the first foamed thermoplastic resin layer, The thickness of the first foamed thermoplastic resin layer is 300 μm or more and 2000 μm or less, The thickness of the surface treatment layer is 8.0 μm or more and 25 μm or less, The laminated foamed sheet, wherein the arithmetic mean height Sa defined by ISO 25178 on the surface treatment layer side is 5 μm or more and 30 μm or less.

2. The laminated foamed sheet according to claim 1, wherein the first foamed thermoplastic resin layer contains 1 to 15 parts by weight of thermally expandable microcapsules with respect to 100 parts by weight of the thermoplastic resin.

3. The laminated foamed sheet according to claim 1 or 2, wherein the average bubble diameter of the expanded thermally expandable microcapsules is 30 μm or more and 200 μm or less.

4. The laminated foamed sheet according to any one of claims 1 to 3, wherein the thermoplastic resin layer further includes a non-foamed thermoplastic resin layer.

5. The laminated foamed sheet according to claim 4, wherein the non-foamed thermoplastic resin layer contains one or more thermoplastic resins selected from the group consisting of an olefin-based thermoplastic elastomer and a polyolefin-based resin.

6. The laminated foamed sheet according to any one of claims 1 to 5, further including a cushion layer disposed on the side opposite to the side where the surface treatment layer of the thermoplastic resin layer is disposed.

7. The laminated foamed sheet according to any one of claims 1 to 6, wherein the 25% compression hardness measured with the surface treatment layer as the load surface is 100 N or less.

8. The laminated foamed sheet according to any one of claims 1 to 7, wherein the cross-sectional bubble ratio of the thermoplastic resin layer is 5% or more and 65% or less.

9. The laminated foamed sheet according to any one of claims 1 to 8, which has 200 or more rotations in a Taber abrasion test (abrasion wheel CS-10, load 4.9 N) according to JIS K 7204:1999.

10. A laminated molded body obtained by molding the laminated foamed sheet according to any one of claims 1 to 9 into a predetermined shape.

11. The laminated molded body is the laminated molded body according to claim 10, which is a skin material for a vehicle interior material.

12. A method for manufacturing a laminated foamed sheet according to any one of claims 1 to 9, forming a first unfoamed thermoplastic resin sheet by sheet molding a thermoplastic resin composition containing a thermoplastic resin and thermally expandable microcapsules at a temperature equal to or higher than the melting point of the thermoplastic resin and lower than the expansion start temperature of the thermally expandable microcapsules; coating a surface treatment agent on one surface of the first unfoamed thermoplastic resin sheet to form a surface treatment layer; and heating the obtained laminate at a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsules to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer, The thermoplastic resin contains one or more selected from the group consisting of an olefin-based thermoplastic elastomer and a polyolefin-based resin, The surface treatment agent is a urethane paint, a method for manufacturing a laminated foamed sheet.

13. The method for manufacturing a laminated foamed sheet according to claim 12, wherein the thermally expandable microcapsules have an expansion start temperature of 185°C or higher and 215°C or lower, and a maximum foaming temperature of 190°C or higher and 240°C or lower.

14. The method for manufacturing a laminated foamed sheet according to claim 12 or 13, wherein the surface treatment agent is an aqueous polyurethane dispersion.

15. The coating film of the surface treatment agent has a tensile stress of 3 MPa or more and a tensile elongation of 30% or more measured by a tensile test performed under the conditions of a temperature of 23°C, a relative humidity of 65%, and a tensile speed of 500 mm / min, and a peel strength of 2 N / mm or more for a sample width of 15 mm by a 180° peel test. The method for manufacturing a laminated foamed sheet according to any one of claims 12 to 14.

16. A method for manufacturing a laminated molded body according to claim 10 or 11, forming a first unfoamed thermoplastic resin sheet by sheet molding a thermoplastic resin composition containing a thermoplastic resin and thermally expandable microcapsules at a temperature equal to or higher than the melting point of the thermoplastic resin and lower than the expansion start temperature of the thermally expandable microcapsules; and coating a surface treatment agent on one surface of the first unfoamed thermoplastic resin sheet to form a surface treatment layer, including a step of molding the obtained laminate into a laminated molded body having a predetermined shape, The thermoplastic resin contains one or more selected from the group consisting of an olefin-based thermoplastic elastomer and a polyolefin-based resin, The surface treatment agent is a urethane paint, In the molding step of the laminated molded body, the laminate is heated at a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsules to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer. A method for manufacturing a laminated molded body.

17. The method for manufacturing a laminated molded body according to claim 16, wherein the thermally expandable microcapsules have an expansion start temperature of 185°C or higher and 215°C or lower, and a maximum foaming temperature of 190°C or higher and 240°C or lower.

18. The method for manufacturing a laminated molded body according to claim 16 or 17, wherein the surface treatment agent is an aqueous polyurethane dispersion.

19. The coating film of the surface treatment agent has a tensile stress of 3 MPa or more and a tensile elongation of 30% or more measured by a tensile test performed under the conditions of a temperature of 23°C, a relative humidity of 65%, and a tensile speed of 500 mm / min, and a peel strength of 2 N / mm or more for a sample width of 15 mm by a 180° peel test. The method for manufacturing a laminated molded body according to any one of claims 16 to 18.

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