JP2023047581A - Laminated foam sheet, laminated molding, and method for manufacturing them - Google Patents

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 The present invention relates to a laminated foam sheet, a laminated molded product, and a method for producing them, which can be suitably used as a vehicle interior material.

BACKGROUND ART Vehicle interior materials such as automobile interior materials using synthetic resins are given a warm suede-like appearance for texture. For example, in Patent Document 1, a decorative material having a suede-like appearance is composed of a laminate having a base material, an intermediate layer, and a surface layer, and the intermediate layer is contained in a synthetic resin having a 100% modulus of 20 to 150 kg/cm ² . A decorative material has been proposed in which thermally expanded microcapsules are dispersed and the microcapsules are 2 to 30% by weight with respect to 100% by weight of the intermediate layer.

JP-A-10-95062

However, the decorative material described in Patent Document 1 may be insufficient in elasticity (cushioning properties) and abrasion resistance.

The present invention provides a laminated foam sheet having a suede-like appearance and high elasticity and abrasion resistance, a laminated molded article, and a method for producing the same.

The present invention includes 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, and the first foamed thermoplastic A surface treatment layer is arranged on the first surface of the 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, It relates to the laminated foam sheet, wherein the surface treatment layer side has an arithmetic mean height Sa defined in ISO 25178 of 5 μm or more and 30 μm or less.

The present invention also relates to a laminated molded product obtained by molding the laminated foam sheet into a predetermined shape.

In the present invention, a thermoplastic resin composition containing a thermoplastic resin and thermally expandable microcapsules is sheet-formed 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. forming a first unfoamed thermoplastic resin sheet, applying a surface treatment agent to one surface of the first unfoamed thermoplastic resin sheet to form a surface treatment layer, and the resulting laminate a step of heating the body to 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 expanded thermoplastic resin layer; It relates to a method for manufacturing a laminated foam sheet containing.

The present invention also provides a method for producing the laminated molded body, wherein a thermoplastic resin composition containing a thermoplastic resin and thermally expandable microcapsules is heated to a temperature higher than the melting point of the thermoplastic resin, and the thermally expandable microcapsules are Forming a first unfoamed thermoplastic resin sheet by sheet molding at a temperature below the expansion start temperature (the temperature at which the thermally expandable microcapsules start to change in volume by heating), the first unfoamed thermoplastic resin sheet. A step of applying a surface treatment agent to one surface of to form a surface treatment layer, a step of forming the obtained laminate into a laminate having a predetermined shape, and in the step of forming the laminate and heating the laminate at a temperature equal to or higher than the expansion starting temperature of the thermally expandable microcapsules to expand the thermally expandable microcapsules in the first unexpanded thermoplastic resin sheet to form a first expanded thermoplastic resin layer. The present invention relates to a method for manufacturing a laminated molded body.

INDUSTRIAL APPLICABILITY The present invention can provide a laminated foam sheet and a laminated molded article having a suede-like appearance and high elasticity and abrasion resistance.
Moreover, according to the production method of the present invention, it is possible to obtain a laminated foam sheet and a laminated molded article having a suede-like appearance and high elasticity and abrasion resistance.

1 is a schematic cross-sectional view of a laminated foam sheet of one example of the present invention; FIG. 1 is a schematic cross-sectional view of a laminated foam sheet of one example of the present invention; FIG. 1 is a schematic cross-sectional view of a laminated foam sheet of one example of the present invention; FIG.

The inventors of the present invention have made intensive studies to solve the above problems. As a result, the laminated foam sheet is configured to include a thermoplastic resin layer and a surface treatment layer, the thermoplastic resin layer is configured to include a first foamed thermoplastic resin layer containing a thermoplastic resin and expanded thermally expandable microcapsules, 1 A surface treatment layer is arranged on the first surface of the 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, and the surface treatment is performed. By setting the arithmetic mean height Sa defined in ISO 25178 on the layer side to 5 μm or more and 30 μm or less, it has a suede-like appearance, high elasticity and abrasion resistance, and is suitable for use as a vehicle interior material. It has been found that a laminated foam sheet can be provided.

(Laminated foam sheet)
The thermoplastic resin layer includes a first foamed thermoplastic resin layer containing thermoplastic resin and expanded thermally expandable microcapsules. The inclusion of thermally expandable microcapsules in the first foamed thermoplastic resin layer gives the surface of the laminated foamed sheet a fine uneven shape, giving it an appropriate rough feel to the touch and a warm suede-like appearance. can be expressed.

The first foamed thermoplastic resin layer preferably contains 1 to 15 parts by weight, more preferably 1.5 to 10 parts by weight, more preferably 2 parts by weight of thermally expandable microcapsules with respect to 100 parts by weight of the thermoplastic resin. Contains ~8 parts by weight. If the content of the thermally expandable microcapsules is too small, it tends to be difficult to obtain a suede-like appearance.

A thermally expandable microcapsule is a capsule foaming agent in which a liquid low-boiling-point compound is enclosed in a thermoplastic resin shell, and the capsules expanded by heating function as the foaming agent. Specifically, the thermally expandable microcapsule has a core-shell structure, the core is composed of a liquid low-boiling-point hydrocarbon, the shell encloses the core, and is composed of a thermoplastic resin.

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

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

The expanded thermally expandable microcapsules are not particularly limited, but for example, from the viewpoint of exhibiting better touch feeling and suede-like appearance, the average cell diameter (also referred to as the average particle diameter) is 30 μm or more. is preferably 35 μm or more, and even more preferably 40 μm or more. In addition, the expanded thermally expandable microcapsules are not particularly limited, but for example, from the viewpoint of further improving abrasion resistance, the average bubble diameter (average particle diameter is preferably 200 μm or less, more preferably 160 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. It is 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 later.

When heated, thermally expandable microcapsules generally expand to a range of about 3 to 5 times the average particle size when unexpanded. The average particle size of the unexpanded thermally expandable microcapsules is preferably 6 μm or more and 50 μm or less from the viewpoint of facilitating adjustment of the average bubble diameter of the expanded thermally expandable microcapsules to the range described above. , 10 μm or more and 45 μm or less, more preferably 15 μm or more and 40 μm or less. The average particle size of the thermally expandable microcapsules when unexpanded is measured, for example, by observing 30 capsules at a magnification of 500 times using a digital microscope "VHX-7000" manufactured by Keyence Corporation (detection limit: 0. 01 μm), which can be measured as the average value thereof.

The thermoplastic resin in the first foamed thermoplastic resin layer is not particularly limited. etc. can be preferably used, and it preferably contains one or more selected from the group consisting of olefinic thermoplastic elastomers and polyolefinic resins. From the viewpoint of excellent rubber elasticity at high temperature and long-term deformation and high heat resistance, it more preferably contains an olefinic thermoplastic elastomer, and more preferably contains an olefinic thermoplastic elastomer and a polyolefinic resin.

The olefinic thermoplastic elastomer is not particularly limited, and may be any of blend type, polymerization type (also called reactor TPO), and dynamic cross-linking type (also called TPV). The olefinic thermoplastic elastomer may be used alone or in combination of two or more. From the viewpoint of cost and performance, it is preferable to use both the polymerization type and the dynamic cross-linking type.

The polyolefin resin is not particularly limited as long as it is an olefin polymer. For example, homopolymers of olefins such as ethylene, propylene, 1-butene, isobutene, 4-methyl-1-pentene, copolymers of two or more olefins, copolymers of olefins and other monomers, etc. is mentioned. The copolymer may be a random copolymer or a block copolymer. The copolymer may be a terpolymer. The olefin content in the copolymer of olefin and other monomers is desirably 50% by weight or more. Other monomers include, for example, dienes, cyclopentadiene, and vinyl compounds. Specific examples of polyolefin resins 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), and the like. Polyolefin-based resins may be used alone or in combination of two or more.

The first foamed thermoplastic resin layer has a thickness of 300 μm or more and 2000 μm or less. Thereby, a laminated foam sheet having excellent 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, even more preferably 650 µm or more, and particularly preferably 750 µm or more. preferable. From the viewpoint 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 even more preferably 1400 μm or less.

The thermoplastic resin layer, in addition to the first foamed thermoplastic resin layer, prevents the sheet from tearing or breaking when stretched in the longitudinal direction (longitudinal direction of the sheet) or in the lateral direction (perpendicular to the longitudinal direction). Therefore, it can further include a non-foamed thermoplastic resin layer disposed on the opposite side of the first surface on which the surface treatment layer of the first foamed thermoplastic resin layer is disposed. The non-foamed thermoplastic resin layer can appropriately contain any of the thermoplastic resins listed as the thermoplastic resin used for the first foamed thermoplastic resin layer. The first foamed thermoplastic resin layer and the non-foamed thermoplastic resin layer may be directly joined by heating the surfaces to be joined to the melting point of the constituent resin or higher and pressing them, or may be joined via an adhesive. good.

The thickness of the non-foamed thermoplastic resin layer is not particularly limited, but may be 100 μm or more and 800 μm or less, or 150 μm or more, from the viewpoint of preventing tearing or breakage of the sheet when stretched in the longitudinal direction or the lateral direction. It may be 700 μm or less, or it may be 200 μm or more and 600 μm or less.

The laminated sheet includes a surface treatment layer arranged on the first surface of the first foamed thermoplastic resin layer. The surface treatment agent that constitutes the surface treatment layer is not particularly limited. and may include silicone, silicone beads, urethane beads, and the like. The surface treatment layer may be composed of only the top layer, or may be composed of the top layer and the primer layer. The top layer can be composed of a top surface treating agent, and the primer layer can be composed of a primer surface treating agent.

The surface treatment layer has a thickness of 8.0 μm or more and 25 μm or less. Thereby, abrasion resistance can be improved while maintaining the suede-like appearance imparted by the first foamed thermoplastic resin layer. 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, even more preferably 9.5 μm or more, and 10.0 μm or more. is particularly preferred. The thickness of the surface treatment layer is preferably 20 μm or less, more preferably 18 μm or less, even more preferably 16 μm or less, and particularly preferably 14 μm or less, from the viewpoint of a suede-like appearance.

In the laminated foam 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. As a result, the laminated foam sheet easily develops 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, more preferably 10 μm or more and 20 μm or less.

In the laminated foam sheet, from the viewpoint of suede-like appearance and abrasion resistance, the ten-point average roughness Rzjis defined by ISO 25178 on the surface treatment layer side is preferably 50 μm or more and 120 μm or less, and 60 μm or more and 110 μm. It is more preferably 75 μm or more and 95 μm or less.

The laminated foam sheet is not particularly limited, but may further include a cushion layer arranged on the opposite side of the thermoplastic resin layer to the side where the surface treatment layer is arranged from the viewpoint of improving elasticity.

Although the cushion layer is not particularly limited, for example, a material having cells or a space layer can be appropriately used. Specific examples include crosslinked resin foams, polyurethane sheets, and fiber structures. A nonwoven fabric, a double raschel, or the like may be used as the fiber structure. Even when the cushion layer is made of a crosslinked resin foam, the configuration is different from that of the thermoplastic resin layer. In one or more embodiments of the present invention, the thermoplastic layer comprises a first expanded thermoplastic layer or alternatively comprises a first expanded thermoplastic layer and an unexpanded thermoplastic layer. .

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 conforming to the compression permanent set test specified in JIS K6767.

The crosslinked resin foam is not particularly limited, but from the viewpoint of heat resistance and surface smoothness, it is preferably a crosslinked polyolefin resin foam. The crosslinked polyolefin resin foam is not particularly limited, and may be a polyolefin resin foamed after being crosslinked by a conventionally known method. 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 a crosslinked structure is not particularly limited, and examples include a method of irradiating with ionizing radiation such as α-rays, β-rays, γ-rays and electron beams, a method of irradiating with ultraviolet rays, organic peroxides and silane compounds, and the like. and the like using a cross-linking agent. The foaming method is not particularly limited, and examples thereof include extrusion foaming, in-mold foaming, normal pressure foaming, and chemical reaction foaming. As the foaming agent, an inorganic gas, a hydrocarbon or a halogenated hydrocarbon having a boiling point of -50 to 120°C, water, a thermal decomposition type foaming agent, or the like can be used.

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

The crosslinked resin foam is not particularly limited, but may have an expansion ratio of 5 times or more and 40 times or less from the viewpoint of flexibility and cushioning. For the expansion ratio of the crosslinked resin foam, for example, the specific volume (unit cm ³ /g) of the expandable resin sheet and the crosslinked resin foam sheet before foaming is measured, and the specific volume of the crosslinked resin foam sheet/before foaming It can be calculated by the specific volume of the expandable resin sheet.

The crosslinked resin foam may optionally contain additives such as foaming aids, softeners, lubricants, antioxidants, antistatic agents, flame retardants, ultraviolet absorbers, light stabilizers, colorants, and inorganic fillers. may include

The thickness of the cushion layer is not particularly limited. It may be greater than or equal to 4.0 mm or less.

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.

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 still more preferably 15 N or less, measured with the surface treatment layer as the load surface. be. Moreover, the lower limit of the 0.1 mm compression hardness of the laminated foam sheet is not particularly limited, but from the viewpoint of increasing the compression recovery rate, it may be 1 N or more. Compressive hardness can be measured as described below.

From the viewpoint of excellent elasticity, the laminated foam sheet preferably has a 25% compression hardness of 100 N or less, more preferably 95 N or less, and more preferably 85 N or less, measured with the surface treatment layer as the load surface. More preferred. Although the lower limit of the 25% compression hardness of the laminated foam sheet is not particularly limited, it may be 10 N or more from the viewpoint that the compression hardness improves as the thickness of the laminated foam sheet becomes thinner. In addition, from the viewpoint of excellent elasticity, the laminated foam sheet preferably has a 50% compression hardness measured with the surface treatment layer as a load surface of 300 N or less, more preferably 280 N or less, and 260 N or less. is more preferred. Although the lower limit of the 50% compression hardness of the laminated foam sheet is not particularly limited, it may be 30 N or more from the viewpoint that the compression hardness improves as the thickness of the laminated foam sheet becomes thinner. Compressive hardness can be measured as described below.

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

From the viewpoint of abrasion resistance, the laminated foam sheet preferably has a Shore A hardness of 30 or more and 80 or less on the surface treatment layer side, more preferably 35 or more and 75 or less, and 40 or more and 60 or less. More preferred. Shore A hardness can be specifically measured as described later.

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

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

In the laminated foam sheet, the gloss on the surface treatment layer side is preferably 2.0 or less, more preferably 1.8 or less, more preferably 1.4, from the viewpoint of easily expressing a suede-like appearance. More preferably: The gloss on the surface treatment layer side of the laminated foam sheet can be measured as described later.

The laminated foam sheet preferably has a tensile elongation at 160° C. of 60% or more, more preferably 70% or more, and 80% or more, from the viewpoint of excellent secondary moldability such as vacuum forming. is more preferred. Although the upper limit of the tensile elongation at 160° C. of the laminated foam sheet is not particularly limited, it may be 400% or less from the viewpoint of the limit of complicating the shape of the mold. The laminated foam sheet preferably has a tensile stress at 160° C. of 20 kPa or more, more preferably 25 kPa or more, and even more preferably 30 kPa or more, from the viewpoint of excellent secondary moldability such as vacuum forming. 35 kPa or more is particularly preferable. Although the upper limit of the tensile stress at 160° C. of the laminated foam sheet is not particularly limited, it may be 280 kPa or less from the viewpoint of the drawdown amount during molding. Specifically, the tensile elongation and tensile stress at 160° C. of the laminated foam sheet can be measured as described later.

The laminated foam sheet preferably has a tensile elongation at 23° C. of 150% or more, more preferably 200% or more, and 260% or more, from the viewpoint of excellent secondary moldability such as vacuum forming. is more preferred. Although the upper limit of the tensile elongation at 23° C. of the laminated foam sheet is not particularly limited, it may be 700% or less from the viewpoint of molding or pasting with a low expansion ratio. The laminated foam sheet preferably has a tensile stress at 23° C. of 1.0 MPa or more, more preferably 1.2 MPa or more, and more preferably 1.5 MPa or more, from the viewpoint of being excellent in secondary moldability such as vacuum forming. 1.8 MPa or more is particularly preferable. The upper limit of the tensile stress at 23° C. of the laminated foam sheet is not particularly limited, but may be 9.9 MPa or less from the viewpoint of preventing breakage due to sewing. Specifically, the tensile elongation and tensile stress at 23°C can be measured as described later.

FIG. 1 is a schematic cross-sectional view of a laminated foam sheet of one example of the present invention. In this embodiment, the laminated foam sheet 1 includes a thermoplastic resin layer 2 and a surface treatment layer 3, and the thermoplastic resin layer 2 is a first foamed thermoplastic resin containing a thermoplastic resin and expanded thermally expandable microcapsules 10. It consists of layers 20 . The surface treatment layer 3 is arranged on the first surface of the first foamed thermoplastic resin layer 20 .

FIG. 2 is a schematic cross-sectional view of a laminated foam sheet of one example of the present invention. In this embodiment, the laminated foam sheet 11 includes a thermoplastic resin layer 2 and a surface treatment layer 3, and the thermoplastic resin layer 2 is a first foamed thermoplastic resin containing a thermoplastic resin and expanded thermally expandable microcapsules 10. It consists of a layer 20 and a non-foamed thermoplastic resin layer 30 . The surface treatment layer 3 is arranged on the first surface of the first foamed thermoplastic resin layer 20 .

FIG. 3 is a schematic cross-sectional view of a laminated foam sheet of one 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, and the thermoplastic resin layer 2 includes a thermoplastic resin and a first thermally expandable microcapsule 10 that has been expanded. It is composed of a foamed thermoplastic resin layer 20 . The surface treatment layer 3 is arranged on the first surface of the first foamed thermoplastic resin layer 20 . The cushion layer 4 is arranged on the side of the thermoplastic resin layer 2 opposite to the side on which the surface treatment layer 3 is arranged.

The laminated foam sheet may include a first foamed thermoplastic resin layer, a non-foamed thermoplastic resin layer and a cushion layer. In this case, the order of the surface treatment layer, the thermoplastic resin layer and the cushion layer, that is, the order of the surface treatment layer, the first foamed thermoplastic resin layer, the non-foamed thermoplastic resin layer and the cushion layer is arranged.

Although the laminated foam sheet is not particularly limited, it can be suitably used, for example, as a skin material for vehicle interior materials. Vehicle interior materials include instrument panels, door trims, trunk trims, seat seats, pillar covers, ceiling materials, rear trays, console boxes, airbag covers, armrests, headrests, meter covers, crash pads, etc. is mentioned.

(Method for producing 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 heated to a temperature above the melting point of the thermoplastic resin and below the expansion start temperature of the thermally expandable microcapsules. forming a first unfoamed thermoplastic resin sheet by sheet molding, applying a surface treatment agent to one surface of the obtained first unfoamed thermoplastic resin sheet, A surface treatment layer is formed, the obtained laminate is heated at a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsules, and the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet are expanded to perform the first expansion. It can be produced by forming a thermoplastic resin layer.

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

When the thermoplastic resin contains a plurality of thermoplastic resins, "the melting point or higher of the thermoplastic resin" in the step of forming the first unfoamed thermoplastic resin sheet means the melting point or higher of the thermoplastic resin having the highest melting point.

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 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. Moreover, from the viewpoint of facilitating the formation of the first foamed thermoplastic resin layer, the temperature may be 215° C. or lower, or 210° C. or lower.

The thermally expandable microcapsules are not particularly limited, but from the viewpoint of easy formation of the first foamed thermoplastic resin layer while suppressing foaming in the step of forming the first unfoamed thermoplastic resin sheet, the expansion start temperature is 185 ° C. It is preferably at least 215°C, and more preferably at least 190°C and not more than 215°C.

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

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

The thermoplastic resin composition may optionally contain one or two additives such as softeners, inorganic fillers, antioxidants, light stabilizers, ultraviolet absorbers, antistatic agents, lubricants, and colorants. It may include the above. The additive may be, for example, 10 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin.

Sheet molding is not particularly limited, and may be calendar molding or extrusion molding.

As the surface treatment agent, those described above can be used as appropriate. As the surface treatment agent, from the viewpoint of wear resistance, the tensile stress measured by a tensile test performed on the coating film of the surface treatment agent under the conditions of 23 ° C., 65% RH, and a tensile speed of 500 mm / min. is 3 MPa or more, the tensile elongation is 30% or more, and the peel strength with a sample width of 15 mm in a 180° peel test is preferably 2 N/mm or more. More preferably, the tensile stress of the coating film of the surface treatment agent is 4 MPa or more and 35 MPa or less. More preferably, the tensile elongation of the coating film of the surface treatment agent is 35% or more and 500% or less. More preferably, the peel strength of the coating film of the surface treatment agent is 3 N/mm or more and 25 N/mm or less. Specifically, the tensile stress, tensile elongation and peel strength of the coating film of the surface treatment agent at 23° C. can be measured as described later.

The surface treatment layer is formed 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, for example, 50° C. or higher and 140° C. or lower. can be formed by Coating and drying may be performed twice or more.

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, the thermoplastic resin and the thermally expandable microcapsules are added. A thermoplastic resin composition containing a thermoplastic resin (not containing a foaming agent) is co-extruded at a temperature below the expansion start temperature of the thermally expandable microcapsules to obtain the first unfoamed heat A two-layer sheet can be formed of a plastic sheet and an unfoamed thermoplastic sheet. Alternatively, a first unfoamed thermoplastic resin obtained by calendar molding or extrusion molding is placed on the surface of an unfoamed thermoplastic resin sheet formed by sheet-molding a thermoplastic resin composition containing a thermoplastic resin (not containing a foaming agent). The sheets may be heat laminated.

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 the first unfoamed thermoplastic resin sheet When the thermally expandable microcapsules are expanded to form the first foamed thermoplastic resin layer, a cushioning material such as a crosslinked resin foam that forms the cushioning layer is attached to the thermoplastic resin layer directly or via an adhesive. be able to.

(Laminated molded product and manufacturing method)
A laminate molded body is obtained by molding a laminated foam sheet into a predetermined shape. When the laminated molded product is a skin material for a vehicle interior material, the laminated foam sheet can be molded so as to match the shape of the vehicle interior material. Vehicle interior materials include instrument panels, door trims, trunk trims, seat seats, pillar covers, ceiling materials, rear trays, console boxes, airbag covers, armrests, headrests, meter covers, crash pads, etc. is mentioned.

A laminated molded article 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. Then, a first unfoamed thermoplastic resin sheet is formed, a surface treatment agent is applied to one surface of the obtained first unfoamed thermoplastic resin sheet, and a surface treatment layer is formed. is formed, the obtained laminate is heated at a temperature equal to or higher than the maximum foaming temperature of the thermally expandable microcapsules, and the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet are expanded to generate the first foaming heat A laminate molded body can be obtained by forming a plastic resin layer and molding a predetermined shape. Molding of the laminate molded body can be carried out by vacuum molding, and male vacuum molding is preferable for obtaining a suede-like appearance.

EXAMPLES The present invention will be described in more detail below using examples. In addition, the present invention is not limited to the following examples.

Measurement methods and evaluation methods used in Examples and Comparative Examples will be described.

(Tensile test and peel test of coating film of surface treatment agent)
Apply the surface treatment agent thinly to the release film with a bar coater, dry it in an oven (solvent system: 80°C, 1 min, water system 80°C, 2 min), and apply a coating consisting of only the surface treatment agent with a coating thickness of 15 to 20 μm. After obtaining the film, the coating film was punched out with a dumbbell No. 2, and the obtained test piece was subjected to a tensile test at a tensile speed of 500 mm / min at a temperature of 23 ° C. and 65% RH. Tensile elongation was measured.
In addition, a 180° peel test was performed by applying a hot-melt tape (fixed with an iron at 180°C for 3 minutes) to the coating film of the surface treatment agent at a temperature of 23°C and 65% RH to measure the peel strength.

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

(Cross-sectional void ratio)
The laminated foam sheet is cut with a cutter perpendicularly from the surface of the surface treatment agent in the thickness direction, and the cross section of the laminated foam sheet is observed at a magnification of 150 using a digital microscope (Keyence "VHX-7000"). In the OPT-SEM (Optical Shadow Effect Mode) image of the thermoplastic resin layer obtained, the area of the specified range is measured to determine the total area, the bubble area in the specified range is measured, and the cross-sectional void ratio is calculated by Equation 1 below. bottom.
[Formula 1]
Cross-sectional bubble ratio (%) = bubble area/total area x 100

(Shore A hardness)
According to JIS K 7215, using "Asker rubber hardness tester A" manufactured by Kobunshi Keiki Co., Ltd., the scale was read three times immediately after contact with the indentor, and the average value was taken as the Shore A hardness.

(Average bubble diameter of expanded thermal expansion microcapsules)
The thermal expansion microcapsules heated to the expansion temperature or higher and the foam sheet containing the thermal expansion microcapsules or the laminated foam sheet are cut perpendicularly from the surface treatment layer surface in the thickness direction with a cutter, and the cross section is cut by Keyence Corporation "VHX- 7000" was used to observe 30 bubbles at a magnification of 50 times, and the diameter of the bubbles was measured by the in-machine measurement system and taken as the average value.

(compressive hardness)
Measured based on JIS K 6767.
(1) The laminated foam sheet was cut into 20 mm squares, six sheets were stacked to form a sample, and the initial thickness of the sample was measured with a vernier caliper.
(2) The sample is set in a compression tester (manufactured by Shimadzu Corporation, model number "AGM-1"), and an initial load of 0.5 N is applied via a φ35 pressure plate with the surface treatment layer as the load surface, This position was taken as the origin.
(3) Pressing at a constant speed (1 mm / min), 0.1 mm compression hardness (0.1 mm from the origin), 25% compression (1.265 mm from the origin), 50% compression (2.53 mm from the origin) stress was measured, and the value measured by the in-machine measurement system was taken as the compression hardness.

(Tensile test and peel test of laminated foam sheet)
The laminated foam sheet was punched out with a dumbbell No. 2, and the resulting test piece was subjected to a tensile test at a tensile speed of 500 mm/min to measure tensile stress and tensile elongation.
In addition, using a hot-melt tape, a hot-melt tape (iron 180° C., fixed for 3 minutes) was applied to the surface treatment layer side of the laminated foam sheet, and a 180° peel test was performed to measure the peel strength.

(Abrasion test)
A Taber abrasion test (wear wheel CS-10, load 4.9 N) was performed according to JIS K 7204:1999, the number of revolutions was measured, and judgment was made according to the following criteria.
<Judgment Criteria>
A: There is no peeling and no change in the coating film of the surface treatment layer.
B: There is no peeling of the coating film of the surface treatment layer, and slight whitening is observed.
C: Part of the coating film of the surface treatment layer is peeled off, and whitening is observed.
D: The coating film of the surface treatment layer is peeled off, and the base material can be confirmed.

(exterior)
The laminated foam sheet is visually observed by three measurers, and the judgment is made according to the following criteria, and if two or more persons agree, or if the judgments of the three persons are different, the judgment of the measurer who is the center of the three persons was determined by appearance.
A: Fluffy whitening, warmth, and suede-like appearance.
B: There is whitening like fluff, and it looks like suede.
C: It looks a little fuzzy and looks a little like suede.
D: There is no feeling of fluffing, and it does not look like suede.

(gross)
Using "UNI GLOSS 60Plus" manufactured by Konica Minolta Co., Ltd., the surface treatment layer was measured for 60° specular gloss according to JIS Z8741, and the average value of three times was taken as the gloss.

(Secondary moldability)
Using a test vacuum forming machine, both sides of the laminated foam sheet are heated to 180°C to 230°C, and vacuum formed into a box shape of 150 mm long, 100 mm wide, and 50 mm deep, and judged according to the following criteria. did
A: Appearance and shape are good.
B: Slightly good appearance and shape.
C: Defects occur in either appearance or shape.
D: Defects in appearance and shape due to breakage occur.

The thermoplastic resin compositions used in Examples and Comparative Examples will be described.
Thermoplastic resin composition 1: dynamic cross-linking type olefinic thermoplastic elastomer (manufactured by Mitsui Chemicals, Milastomer (registered trademark) "5030NHS", partially cross-linked, melting point 158°C, Shore A hardness 50) 25.0 parts by weight, Dynamic cross-linking type olefinic 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, dynamic cross-linking type olefinic elastomer Thermoplastic elastomer (manufactured by Sumitomo Chemical Co., Ltd., Esporex (registered trademark) “WT485A”, melting point 157 ° C., partially crosslinked, Shore A hardness 60) 25.0 parts by weight, random polypropylene (“B-241” manufactured by Prime Polymer Co., Ltd.) , melting point 141 ° C.) 5.0 parts by weight, linear low density polyethylene (manufactured by Sumitomo Chemical Co., Ltd. "FW201-0", melting point 119 ° C.) 20.0 parts by weight Thermoplastic resin (mixed resin) 100 parts by weight , 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. TREXPRENE "TV-010N", partially crosslinked, melting point 118 ° C., Shore A hardness 63) 85.0 parts by weight, and α-olefin copolymer (manufactured by Mitsui Chemicals, Tafmer (registered trademark) "PN3525", melting point 160 ° C., Shore 100 parts by weight of thermoplastic resin (mixed resin) consisting of 5.0 parts by weight of A hardness 72) and 10.0 parts by weight of olefin block copolymer (INFUSE “9107” manufactured by Dow Chemical Company, melting point 121°C, Shore A hardness 60) To, 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. Thermoplastic resin composition 3: dynamic cross-linking type olefinic thermoplastic elastomer , TREXPRENE "TV-010N", partially cross-linked, melting point 118 ° C., Shore A hardness 63) 40.0 parts by weight, dynamic cross-linking type olefinic thermoplastic elastomer (manufactured by ExxonMobil, Santoprene "201-55", completely Crosslinking, melting point 152° C., Shore A hardness 59) 40.0 parts by weight, α-olefin copolymer (Tafmer (registered trademark) “PN3525” manufactured by Mitsui Chemicals, melting point 160° C., Shore A hardness 72) 10.0 parts by weight , olefin block copolymer (manufactured by Dow Chemical Co., INFUSE "9107", melting point 121 ° C., Shore A hardness 60) 5.0 parts by weight, and linear low density polyethylene (manufactured by Sumitomo Chemical Co., Ltd. "FW201-0", melting point 119 ° C.) To 100 parts by weight of a thermoplastic resin (mixed resin) consisting of 5.0 parts by weight, 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.

In Examples and Comparative Examples, foaming agents shown in Table 1 below were used. As a masterbatch of the thermally expandable microcapsules 1, a masterbatch containing 50% by weight of the thermally expandable microcapsules 1 was used, using polyethylene (manufactured by Tosoh Corporation, product name "Petrothene 248") as the carrier resin. As a masterbatch of the thermally expandable microcapsules 2, a masterbatch containing 50% by weight of the thermally expandable microcapsules 2 was used, using TPO (manufactured by Exxon Mobil Japan Ltd., product name "Vistamax3000") as a carrier resin.

In the examples and comparative examples, the surface treatment agents (urethane paint) shown in Table 2 below were used. In addition, the coating film of the surface treatment agent was subjected to a tensile test at 23°C as described above, and the results are shown in Table 3 below.

(Example 1)
(Production of laminated foam sheet)
Thermally expandable microcapsules are added to the thermoplastic resin composition 1 so that the amount of the thermally expandable microcapsules 1 is shown in Table 4 below with respect to 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 1. 1 masterbatch was added. 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, the surface treatment agent was applied from the primer layer (drying temperature 120 ° C.) under the conditions shown in Table 4 below, and the surface treatment having the top layer and the primer layer. formed a layer.
The resulting laminate is heated at a temperature of 230° C. to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (about 688 μm thick). By doing so, a laminated foam sheet having the structure shown in FIG. 1 was obtained.
(Preparation of laminate molded body)
Using the laminated foam sheet obtained above, an infrared heater installed in a vacuum forming machine is used to heat the sheet so that the surface temperature reaches 220°C or higher, and the sheet is pressed against a mold and vacuumed to form a shape. The laminate was held, allowed to cool, and released from the mold to produce a laminated molded body.

(Example 2)
Thermoplastic resin composition 1 was kneaded at 190° C. and calendar-molded to obtain a non-foamed thermoplastic resin sheet (non-foamed thermoplastic resin layer, thickness of about 600 μm). On one surface of a non-foamed thermoplastic resin sheet, a thermoplastic resin composition containing thermally expandable microcapsules 1 is kneaded at 185 ° C., thermally laminated by calendar molding, and the non-foamed thermoplastic resin sheet and the first non-foamed A laminate of foamed thermoplastic resin sheets was formed. The thermoplastic resin composition containing the thermally expandable microcapsules 1 has a compounding amount of the thermally expandable microcapsules 1 shown in Table 4 below with respect to 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 1. Thus, it was obtained by adding a masterbatch of thermally expandable microcapsules 1 to 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 is 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 (about 688 μm thick). , to obtain a laminated foam sheet having the structure shown in FIG.
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Example 3)
(Production of laminated foam sheet)
A laminate of a first unfoamed thermoplastic resin sheet and a surface treatment layer was obtained in the same manner as in Example 1.
The resulting laminate was laminated with the crosslinked resin foam so that the crosslinked resin foam was positioned on the opposite side of the first unfoamed thermoplastic resin sheet to the side on which the surface treatment layer was arranged, and 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), and the first foamed thermoplastic resin layer and the crosslinked resin foam were joined to obtain a laminated foam sheet having the structure shown in FIG. As the crosslinked resin foam, a crosslinked polyolefin resin foam ("JP17-15025" manufactured by Toray Industries, Inc., degree of crosslinking: 43%, expansion ratio: 15 times, thickness: 2.5 mm, compression recovery rate: 92%) was used. .
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Example 4)
(Production of laminated foam sheet)
A non-foamed thermoplastic was prepared in the same manner as in Example 2, except that the thermoplastic resin composition 2 was used instead of the thermoplastic resin composition 1, and the amount of the thermally expandable microcapsules 1 was set as shown in Table 4 below. A laminate of a resin sheet (an unfoamed thermoplastic resin layer, about 500 μm thick) and a first unfoamed thermoplastic resin sheet was formed.
On the surface of the first unfoamed thermoplastic resin sheet of the obtained laminate opposite to the side on which the unfoamed thermoplastic resin sheet is arranged, a surface treatment agent is applied from the primer layer under the conditions shown in Table 4 below. (drying temperature 130° C.) to form a surface treatment layer having a top layer and a primer layer.
The obtained laminate is 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 (about 690 μm thick). , to obtain a laminated foam sheet having the structure shown in FIG.
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Example 5)
(Production of laminated foam sheet)
Thermally expandable microcapsules are added to the thermoplastic resin composition 2 so that the amount of the thermally expandable microcapsules 1 is shown in Table 4 below with respect to 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 2. 1 masterbatch was added. 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, the surface treatment agent was applied from the primer layer (drying temperature 120 ° C.) under the conditions shown in Table 4 below, and the surface treatment having the top layer and the primer layer. formed a layer.
The resulting laminate is heated at a temperature of 230° C. to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (about 1187 μm thick). By doing so, a laminated foam sheet having the structure shown in FIG. 1 was obtained.
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Example 6)
(Production of laminated foam sheet)
In the same manner as in Example 4, except that the thermoplastic resin composition 3 was used instead of the thermoplastic resin composition 2, a non-foamed thermoplastic resin sheet (non-foamed thermoplastic resin layer, thickness of about 400 μm) and a third 1 A laminate of unfoamed thermoplastic resin sheets was formed.
On one surface of the obtained first unfoamed thermoplastic resin sheet, the surface treatment agent was applied from the primer layer (drying temperature 120 ° C.) under the conditions shown in Table 4 below, and the surface treatment having the top layer and the primer layer. formed a layer.
The resulting laminate is heated at a temperature of 230° C. to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (about 690 μm thick). By doing so, a laminated foam sheet having the structure shown in FIG. 2 was obtained.
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Example 7)
(Production of laminated foam sheet)
A laminated foam 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.
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Example 8)
It has the structure shown in FIG. A laminated foam sheet and a laminated molded body were produced.

(Comparative example 1)
(Production of laminated sheet)
The thermoplastic resin composition 1 was kneaded at 185° C. and calendar-molded to obtain a non-foamed thermoplastic resin sheet.
On one surface of the obtained non-foamed thermoplastic resin sheet, a surface treatment agent was applied from the primer layer (drying temperature 120 ° C.) under the conditions shown in Table 5 below to form a surface treatment layer having a top layer and a primer layer. formed to obtain a laminated sheet.
(Preparation of laminate 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.

(Comparative example 2)
(Production of laminated sheet)
The thermoplastic resin composition 1 was kneaded at 185° C. and calendar-molded to obtain a non-foamed thermoplastic resin sheet.
On one surface of the obtained non-foamed thermoplastic resin sheet, a surface treatment agent was applied from the primer layer (drying temperature 120 ° C.) under the conditions shown in Table 5 below to form a surface treatment layer having a top layer and a primer layer. formed to obtain a laminated sheet.
(Preparation of laminate 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.

(Comparative Example 3)
(Production of laminated foam sheet)
Thermoplastic resin composition 2 was kneaded at 185° C. and calendar-molded to obtain a non-foamed thermoplastic resin sheet (thickness: 401 μm). On one surface of a non-foamed thermoplastic resin sheet, a thermoplastic resin composition containing thermally expandable microcapsules 1 is kneaded at 185 ° C., thermally laminated by calendar molding, and the non-foamed thermoplastic resin sheet and the first non-foamed A laminate of foamed thermoplastic resin sheets was formed. The thermoplastic resin composition containing the thermally expandable microcapsules 1 is such that the amount of the thermally expandable microcapsules 1 is shown in Table 5 with respect to 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 2. was obtained by adding a masterbatch of thermally expandable microcapsules 1 to thermoplastic resin composition 2.
The thermoplastic resin composition 2 is kneaded at 180° C. on the surface of the first unfoamed thermoplastic resin sheet of the obtained laminate opposite to the side on which the unfoamed thermoplastic resin sheet is arranged, Thermal lamination was carried out by calendering to obtain a laminate having a three-layer structure consisting of an unfoamed thermoplastic resin sheet, a first unfoamed thermoplastic resin sheet and an unfoamed thermoplastic resin sheet (thickness: 1192 µm).
On the surface of one non-foamed thermoplastic resin sheet of the obtained laminate opposite to the side in contact with the first non-foamed thermoplastic resin sheet, a surface treatment agent was applied from the primer layer under the conditions shown in Table 5 below. It was coated (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), followed by lamination foaming. got a sheet.
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Comparative Example 4)
Laminated foaming in the same manner as in Example 1 except that the surface treatment agent was applied from the primer layer (drying temperature 120 ° C.) under the conditions shown in Table 5 below to form a surface treatment layer having a top layer and a primer layer. A sheet and a laminate were produced.

(Comparative Example 5)
Laminated foaming in the same manner as in Example 1 except that the surface treatment agent was applied from the primer layer (drying temperature 120 ° C.) under the conditions shown in Table 5 below to form a surface treatment layer having a top layer and a primer layer. A sheet and a laminate were produced.

(Comparative Example 6)
(Production of laminated foam sheet)
The thermoplastic resin composition 3 is subjected to powder type chemical foaming so that the amount of the foaming agent is 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. agent was added. 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 in the same manner as in Example 1 on one surface of the obtained first unfoamed thermoplastic resin sheet.
heating the obtained laminate at a temperature of 215° C. to foam the foaming agent in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (about 1300 μm thick); Thus, a laminated foam sheet having the structure shown in FIG. 1 was obtained.
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Comparative Example 7)
(Production of laminated foam sheet)
The thermoplastic resin composition 1 was kneaded at 180° C. and calendered to form a non-foamed thermoplastic resin sheet.
On one surface of the obtained non-foamed thermoplastic resin sheet, a surface treatment agent was applied from the primer layer (drying temperature 120 ° C.) under the conditions shown in Table 5 below to form a surface treatment layer having a top layer and a primer layer. formed. At this time, the surface treatment agent for the primer layer is prepared by previously adding the thermally expandable microcapsules 2 in an amount of 5% by weight of the wet coating amount (g/m ² ) and mixing with stirring. Using.
The resulting laminate is heated at a temperature of 230° C. to expand the thermally expandable microcapsules in the primer layer of the surface treatment agent to form a foamed surface treatment agent primer layer (about 49 μm thick). , to obtain a laminated foam sheet having a structure in which the primer layer forms a foam layer.
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Comparative Example 8)
(Production of laminated foam sheet)
The thermoplastic resin composition 1 was kneaded at 180° C. and calendered to form a non-foamed thermoplastic resin sheet.
On one surface of the obtained non-foamed thermoplastic resin sheet, a surface treatment agent was applied from the primer layer (drying temperature 120 ° C.) under the conditions shown in Table 5 below to form a surface treatment layer having a top layer and a primer layer. formed. At this time, 5% by weight of the wet coating amount (g/m ² ) of the thermally expandable microcapsules 2 was previously added to the surface treating agent for the top layer, and the surface treating agent containing the thermally expandable microcapsules was mixed with stirring. Using.
The resulting laminate is heated at a temperature of 230° C. to expand the thermally expandable microcapsules in the surface treatment agent top layer to form a foamed surface treatment agent top layer (about 51 μm thick). , to obtain a laminated foam sheet having a structure in which the top layer forms a foam layer.
(Preparation of laminate molded body)
A laminate molded body was produced in the same manner as in Example 1, except that the laminated foam sheet obtained above was used.

(Comparative Example 9)
Thermally expandable microcapsules are added to the thermoplastic resin composition 1 so that the amount of the thermally expandable microcapsules 2 is shown in Table 5 below with respect to 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 1. 2 masterbatches were added. When the obtained thermoplastic resin composition was kneaded at 158° C. and calendar-molded, the thermally expandable microcapsules foamed (expanded) to form a first unfoamed thermoplastic resin sheet. could not.

(Comparative Example 10)
Thermally expandable microcapsules are added to the thermoplastic resin composition 1 so that the amount of the thermally expandable microcapsules 3 is shown in Table 5 below with respect to 100 parts by weight of the thermoplastic resin (mixed resin) in the thermoplastic resin composition 1. 3 was added. When the obtained thermoplastic resin composition was kneaded at 180° C. and calendar-molded, the thermally expandable microcapsules foamed (expanded) to form a first unfoamed thermoplastic resin sheet. could not.

(Comparative Example 11)
(Production of laminated foam sheet)
In the same manner as in Example 4, except that the thermoplastic resin composition 3 was used instead of the thermoplastic resin composition 2, an unfoamed thermoplastic resin sheet (thickness 600 μm) and a first unfoamed thermoplastic resin sheet were prepared. A laminate was formed.
A surface treatment agent (primer) shown in Table 5 below and a self-healing surface treatment agent are applied to the surface of the first unfoamed thermoplastic resin sheet of the obtained laminate that is not in contact with the unfoamed thermoplastic resin sheet. (manufactured by DIC, product numbers "BX-800S" and "DN-902S" mixed at 100:2.8)) under the conditions shown in Table 5 below (drying temperature 120 ° C.) to form a surface treatment layer. bottom.
The obtained laminate was heated at a temperature of 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). , to obtain a laminated foam sheet.
(Preparation of laminate 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.

(Comparative Example 12)
(Production of laminated foam sheet)
In the same manner as in Example 4, except that the thermoplastic resin composition 3 was used instead of the thermoplastic resin composition 2, an unfoamed thermoplastic resin sheet (thickness: 500 μm) and a first unfoamed thermoplastic resin sheet were prepared. A laminate was formed.
On the surface of the first unfoamed thermoplastic resin sheet of the obtained laminate that is not in contact with the unfoamed thermoplastic resin sheet, a surface treatment agent (primer) and a film shown in Table 5 below are applied under the conditions shown in Table 5 below. (drying temperature 130° C.) to form a surface treatment layer.
The resulting laminate was heated at a temperature of 230° C. to expand the thermally expandable microcapsules in the first unfoamed thermoplastic resin sheet to form a first foamed thermoplastic resin layer (thickness: 1098 μm). , to obtain a laminated foam sheet.
(Preparation of laminate 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.

(Comparative Example 13)
A laminated foam sheet was obtained in the same manner as in Example 1, except that the thickness of the first foamed thermoplastic resin layer was set to about 280 μm.
(Preparation of laminate 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.

In Examples and Comparative Examples, various physical properties were measured and evaluated as described above, and the results are shown in Tables 4 and 5.

As can be seen from Table 4, in Examples, the laminated foam sheets had a suede-like appearance. In addition, the 0.1 mm compression hardness was 20 or less, and the elasticity (cushioning properties) was good. Moreover, in the taper wear test, the number of revolutions was 200 or more, indicating high wear resistance.

On the other hand, as can be seen from Table 5, Comparative Examples 1 and 2 having no foaming layer and having an arithmetic mean height Sa on the surface treatment layer side of less than 5 μm, and a Comparative Example not using thermally expandable microcapsules as a foaming agent. In the case of 6, a suede-like appearance could not be expressed. Also in the case of Comparative Example 3 in which the surface treatment layer was not arranged on the surface of the foam layer, a suede-like appearance could not be developed.
In Comparative Examples 4 and 5 in which the thickness of the surface treatment layer was less than 8.0 μm, the abrasion resistance was poor.
In Comparative Examples 7 and 8, in which the thermally expandable microcapsules were added to the surface treatment layer, they were peeled off during foaming, failing to develop a suede-like appearance and exhibiting poor abrasion resistance.
In Comparative Examples 11 and 12, the glossiness was high, and whitening due to foamed thermally expandable microcapsules was suppressed, so a suede-like appearance could not be expressed.
In Comparative Example 13, in which the thickness of the foam layer is less than 300 μm, the 0.1 mm compression hardness was 28 N, and the elasticity (cushioning properties) was poor.

Claims (20)

including a thermoplastic resin layer and a surface treatment layer,
The thermoplastic resin layer comprises a first foamed thermoplastic resin layer containing a thermoplastic resin and expanded thermally expandable microcapsules,
The surface treatment layer is arranged 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 surface treatment layer has a thickness of 8.0 μm or more and 25 μm or less,
The laminated foam 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 foam 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 foam sheet according to claim 1, wherein the expanded thermally expandable microcapsules have an average cell diameter of 30 [mu]m or more and 200 [mu]m or less. The laminated foam sheet according to any one of claims 1 to 3, wherein the thermoplastic resin in the first foamed thermoplastic resin layer contains one or more selected from the group consisting of olefinic thermoplastic elastomers and polyolefinic resins. . The laminated foam sheet according to any one of claims 1 to 4, wherein the thermoplastic resin layer further includes a non-foamed thermoplastic resin layer. The laminated foam sheet according to claim 5, wherein the non-foamed thermoplastic resin layer contains one or more thermoplastic resins selected from the group consisting of olefinic thermoplastic elastomers and polyolefinic resins. The laminated foam sheet according to any one of claims 1 to 6, wherein the laminated foam sheet further includes a cushion layer arranged on the side opposite to the side on which the surface treatment layer of the thermoplastic resin layer is arranged. . The laminated foam sheet according to any one of claims 1 to 7, wherein the laminated foam sheet has a 25% compression hardness of 100 N or less measured with the surface treatment layer as a load surface. The laminated foam sheet according to any one of claims 1 to 8, wherein the thermoplastic resin layer has a cross-sectional void content of 5% or more and 65% or less. The laminated foam sheet has a number of revolutions of 200 or more in a Taber abrasion test (wear wheel CS-10, load 4.9 N) according to JIS K 7204: 1999. The laminate according to any one of claims 1 to 9. foam sheet. A laminated molded product obtained by molding the laminated foam sheet according to any one of claims 1 to 10 into a predetermined shape. 11. The laminated molded article according to claim 10, wherein said laminated molded article is a skin material for vehicle interior materials. A method for producing a laminated foam sheet according to any one of claims 1 to 10,
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 forming a thermoplastic resin sheet;
A step of applying a surface treatment agent to one surface of the 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 unexpanded thermoplastic resin sheet to form the first expanded thermoplastic resin layer. A method for producing a laminated foam sheet, comprising the step of forming. The method for producing a laminated foam sheet according to claim 13, 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. The method for producing a laminated foam sheet according to claim 13 or 14, wherein the surface treatment agent is an aqueous polyurethane dispersion. 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 as measured by a tensile test performed at a tensile speed of 500 mm / min in an environment of 23 ° C. and 65% RH, 16. The method for producing a laminated foam sheet according to any one of claims 13 to 15, wherein the peel strength with a sample width of 15 mm in a 180° peel test is 2 N/mm or more. 13. A method for producing a laminate molded article according to claim 11 or 12,
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 forming a thermoplastic resin sheet; and
A step of applying a surface treatment agent to one surface of the first unfoamed thermoplastic resin sheet to form a surface treatment layer;
A step of forming the obtained laminate into a laminated molded article having a predetermined shape,
In the step of molding the laminated molded body, the laminated body 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 the first 1. A method for producing a laminated molded body, comprising forming a foamed thermoplastic resin layer. 18. The method for producing a laminate molded article according to claim 17, 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. 19. The method for producing a laminate molded article according to claim 17 or 18, wherein the surface treatment agent is an aqueous polyurethane dispersion. 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 as measured by a tensile test performed under the conditions of 23° C., 65% RH and a tensile speed of 500 mm/min. 20. The method for producing a laminated molded product according to any one of claims 17 to 19, wherein the peel strength of a sample having a width of 15 mm in a 180° peel test is 2 N/mm or more.

Images