Radiant heat reflective film and automotive interior materials

Abstract

This invention provides a heat-reflective film and an automotive interior material comprising the heat-reflective film. The heat-reflective film includes a layer that not only has high reflectivity for radiant heat but also good insulation properties. This layer combines the functions of heat reflection and suppression of short circuits with wiring. The heat-reflective film for automotive interior materials of this invention comprises a heat-reflective layer having scale-like metal sheets positioned substantially parallel to each other and a resin that prevents the scale-like metal sheets from contacting each other.

Description

Technical Field

[0001] The present invention relates to a radiant heat reflective film used for an automobile interior material such as an automobile ceiling material, and an automobile interior material using the radiant heat reflective film. Background Art

[0002] Automobile interior materials are manufactured by laminating and bonding a surface material on a base material such as a plastic plate, plastic foam, resin felt made of thermosetting resin, a carton, or a hardboard or cardboard with wood powder or old paper added to a thermosetting resin material, and molding it into a shape corresponding to the installation location. When a car is placed under the scorching sun, the temperature inside the car rises, and the energy consumed to suppress this situation is huge. Therefore, as a means to prevent the temperature from rising without consuming energy, various automobile interior materials with heat insulation properties have been proposed.

[0003] In order to provide an interior material with a heat-blocking effect that does not affect the outer appearance of the outermost surface of a coating film of an automobile or the like, an automotive interior material is proposed, which includes: a core material composed of a resin foam, a base composed of a cushioning material and a surface material laminated on the interior side of the core material; and a layer having an infrared reflection function. The layer having an infrared reflection function is composed of an aluminum foil or a floating aluminum-containing coating film in which aluminum powder floats on the surface of the coating film to form a complete aluminum layer (Patent Document 1).

[0004] In addition, in order to provide an automotive interior material and a substrate thereof that are excellent in rigidity, shape retention characteristics in a high temperature environment, and heat insulation regardless of the orientation of the fibers constituting the substrate, an automotive interior material and a substrate thereof having a surface material, a fiber layer, and a heat insulation layer are proposed, and it is explained that the heat insulation layer can be a metal foil, a sheet on which a metal is vapor-deposited, a sheet coated with a heat insulation paint, a sheet mixed with a heat insulation powder, or a fiber sheet made of fibers mixed with a heat insulation powder (Patent Document 2).

[0005] In order to provide a vehicle interior material that can shorten the so-called molding cycle and avoid an increase in manufacturing costs without impairing the infrared reflection function, wear resistance and oil resistance, a vehicle interior material is proposed that has at least a substrate, a skin layer formed on the front side of the substrate and an anti-air permeability layer formed on the back side of the substrate, the anti-air permeability layer is formed by covering the surface of a resin film A with a metal vapor-deposited film B, and the substrate is bonded to the metal vapor-deposited film B by an adhesive (Patent Document 3).

[0006] In addition, in order to provide a vehicle interior material with excellent productivity and added value, a method for manufacturing a vehicle interior material is proposed, wherein a resin for the substrate is extruded and laminated between the base layer of the long strip for the skin layer and the long strip for the back layer, and a laminate having a base layer made of synthetic resin, a skin layer, and a back layer composed of a base layer and an electromagnetic wave reflection layer is manufactured. It is also described that the electromagnetic wave reflection layer can be composed of, for example, a metal film (e.g., an aluminum vapor-deposited film) vapor-deposited on the back of the base layer (patent document 4). In patent document 4, according to this structure, since the electromagnetic wave reflection layer constituting the back layer is composed of an inorganic material, it has the function of reflecting electromagnetic waves in a wide wavelength range from ultraviolet rays, visible light to infrared rays. By using a vehicle interior material having such an electromagnetic wave reflection layer, even if the body plate is heated up due to the sun, etc., the electromagnetic wave reflection layer can effectively reflect the radiant heat emitted from the body plate. As a result, it is difficult for heat to be transferred to the skin layer side (inner space side) of the vehicle interior material. In contrast, in the existing vehicle interior materials without an electromagnetic wave reflection layer, since all elements are organic (e.g., composed only of resin), electromagnetic waves are absorbed in a wide wavelength range from ultraviolet rays, visible light to infrared rays, and heat insulation performance cannot be expected. In this regard, it is also explained that since the back layer has the function of reflecting electromagnetic waves in a wide wavelength range, the temperature rise of the inner space of the vehicle body plate can be effectively suppressed.

[0007] In addition, Patent Document 5 proposes a technical problem that, in a vehicle interior material constituting a metal vapor-deposited film, it is possible to achieve both protection of the metal vapor-deposited film and prevention of ventilation without damaging the infrared reflection function of the metal vapor-deposited film, and that the material is suitable for mass production. The patent document 5 proposes a structure in which a core material, a first fiber reinforcement material and a second fiber reinforcement material are integrally constituted, and the infrared reflection material is integrally laminated with a metal vapor-deposited film in which a metal with an infrared reflection function is vapor-deposited only on one surface of a synthetic resin film with an anti-ventilation function and infrared transmittance, and a fiber thread surface sheet located on the surface of the metal vapor-deposited surface side of the metal vapor-deposited film, and the layers are arranged in a manner that the surface side of the synthetic resin film of the metal vapor-deposited film is opposite to the top plate.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2001-158306

[0011] Patent Document 2: Japanese Patent Application Publication No. 2009-119711

[0012] Patent Document 3: Japanese Patent Application Publication No. 2013-151245

[0013] Patent Document 4: Japanese Patent Application Publication No. 2014-121948

[0014] Patent Document 5: Japanese Patent Application Publication No. 2014-218052 Summary of the invention

[0015] The technical problem that the invention is intended to solve

[0016] As described above, an example of an automobile interior material having heat insulation properties, in particular, a metal vapor-deposited layer (aluminum vapor-deposited layer) for improving the reflectivity of radiant heat is proposed on the back side of a molded ceiling. If there is a layer with a low surface resistivity such as a metal vapor-deposited layer, there is a risk of short circuits between wiring throughout the automobile and the metal vapor-deposited layer. In particular, when the insulation portion of the wiring gradually deteriorates, the risk of short circuits increases. Therefore, a layer with high reflectivity of radiant heat and good insulation is sought to replace the metal vapor-deposited layer.

[0017] An object of the present invention is to provide a radiant heat reflective film including a layer having not only high radiant heat reflectivity but also good insulation properties, the layer having both a radiant heat reflective function and a function of suppressing short circuits with wiring, and an automobile interior material including the radiant heat reflective film.

[0018] Technical means for solving technical problems

[0019] The gist of the present invention lies in the following radiant heat reflective films for automobile interior materials (1) to (8).

[0020] (1) A radiant heat reflective film for an automobile interior material, wherein the radiant heat reflective film includes a radiant heat reflective layer having flaky metal pieces positioned substantially parallel to each other and a resin that prevents the flaky metal pieces from contacting each other.

[0021] (2) The radiant heat reflective film according to (1), which is used for an automobile interior material having a function of suppressing short circuit with wiring.

[0022] (3) The radiant heat reflective film according to (1) or (2), wherein the blending ratio of the scaly metal sheet and the resin is adjusted so as to achieve both a radiant heat reflective function and a function of suppressing short circuits with wiring.

[0023] (4) The radiant heat reflective film according to any one of (1) to (3), wherein the resin that prevents the scaly metal pieces from contacting each other has a cross-linked structure.

[0024] (5) The radiant heat reflective film according to any one of (1) to (4), wherein the radiant heat reflective layer has 1×10 10 Surface resistivity above Ω / □.

[0025] (6) The radiant heat reflective film according to any one of (1) to (5), wherein the radiant heat reflective film comprises a thermoplastic resin layer and a radiant heat reflective layer.

[0026] (7) The radiant heat reflective film according to (6), wherein an average reflectance of infrared light (2 μm to 20 μm) measured from the radiant heat reflective layer side is 55% or more.

[0027] (8) The radiant heat reflective film according to any one of (1) to (7), which is used for an automobile interior material having at least a surface material, a substrate, and a radiant heat reflective film in this order.

[0028] Furthermore, the gist of the present invention lies in the following automobile interior material (9).

[0029] (9) An automobile interior material comprising at least a surface material, a substrate and a radiant heat reflective film in this order, wherein the radiant heat reflective film is composed of a thermoplastic resin layer and a radiant heat reflective layer, and is arranged in such a manner that one surface is the surface material and the other surface is the radiant heat reflective layer, and the radiant heat reflective film is the radiant heat reflective film described in any one of (1) to (7).

[0030] Effects of the Invention

[0031] (1) The radiant heat reflective film for automobile interior materials of the present invention and the automobile interior material using the same have high average reflectivity of infrared rays (2 μm to 20 μm) and are excellent in radiant heat reflection performance.

[0032] (2) The radiant heat reflective film for an automobile interior material of the present invention and the automobile interior material using the same can suppress short circuits with wiring.

[0033] (3) The radiant heat reflective film for automobile interior materials and the automobile interior material using the same of the present invention have excellent heat resistance to heating despite having a radiant heat reflective layer, and can be applied to a wide range of automobile interior materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is an explanatory diagram of an automobile interior material on which the radiant heat reflective film of the present invention is laminated.

[0035] Figure 2 It is an explanatory diagram of the radiant heat reflective film of the present invention. DETAILED DESCRIPTION

[0036] The radiant heat reflective film 20 of the present invention is a radiant heat reflective film for automobile interior materials, characterized in that it includes a radiant heat reflective layer 22 having both a radiant heat reflective function and a function of suppressing short circuits with wiring. The automobile interior material is press-formed and installed on an automobile body made of steel plates, so the radiant heat reflective film 20 is arranged on a surface opposite to the automobile body (e.g., a roof panel). Thus, even if heat from the sun is transferred to the automobile body, the heat radiated from the automobile body to the automobile interior material is reflected and blocked by the above-mentioned radiant heat reflective layer 22, thereby suppressing the heat from being transferred to the thermoplastic resin layer 21 side of the radiant heat reflective film 20.

[0037] like Figure 1 As shown, the automobile interior material 30 of the present invention is composed of a laminated material having at least a skin material 31, a base material 32 and a radiation heat reflective film 20 in sequence. The laminate is formed integrally by overlapping each layer and heating it with a hot plate to form a base material. The automobile interior material 30 is formed into a shape corresponding to the installation position by cold rolling. When the automobile interior material 30 is installed on the automobile body, the automobile interior material 30 is installed on the automobile body in a manner that the skin material 31 is the inner side of the vehicle interior and the radiation heat reflective film 20 is the automobile body side (the outer side of the vehicle), and the automobile interior material 30 is fixed to the automobile body by a metal or plastic mounting member, such as a bolt or a screw.

[0038] The radiant heat reflective film 20 is composed of a thermoplastic resin layer 21 and a radiant heat reflective layer 22, and the radiant heat reflective layer 22 has the function of reflecting radiant heat. The thermoplastic resin layer 21 is a base film for holding the coating of the radiant heat reflective layer 22, and has the function of blocking ventilation in the thickness direction of the automobile interior material. The radiant heat reflective layer 22 is arranged on the opposite surface opposite to the automobile body, and is formed of a layer composed of scaly metal pieces that are substantially parallel to each other in the layer and a resin (a coating component that remains in the form of a coating after drying) that prevents the metal pieces from contacting each other.

[0039] Thus, the radiant heat reflecting film 20 can be used to reflect the radiant heat from the vehicle body, thereby suppressing the temperature inside the vehicle. More specifically, the radiant heat reflecting film 20 can be used to increase the reflectivity in the infrared region, which accounts for most of the radiant heat, and to increase the reflectivity in the wide wavelength region of 2 μm to 20 μm of infrared light, thereby suppressing the increase in the temperature inside the vehicle.

[0040] Furthermore, regarding the radiant heat reflecting function of the present invention, the infrared reflectivity in the wavelength region of 2 μm to 20 μm measured by the measuring method described in the Examples described later is preferably 55% or more, more preferably 60% or more.

[0041] The radiant heat reflecting layer of the radiant heat reflecting film of the present invention has a function of suppressing short circuit with wiring.

[0042] Generally, in order to fix the automobile interior material to the automobile body, a mounting member is arranged on the periphery of the substrate. Here, when the automobile interior material is arranged, the covering part of the electric wire laid on the automobile body may be damaged due to the mounting member, and the metal wiring is exposed. Therefore, in the prior art, if the automobile interior material is arranged without paying attention to such exposure, the exposed part of the metal wiring will be in contact with the radiant heat reflection layer, and then a short circuit and other problems may occur when the car is driven. Therefore, in the automobile interior material, a material that can avoid such problems such as short circuit is required.

[0043] Therefore, in the present invention, the radiant heat reflecting layer 22 contains a resin that prevents the flaky metal sheets from contacting each other, so that the surface resistivity reaches 1×10 10 Ω / □ (Ωsquare, square resistance) or more, the risk of short circuit can be reduced. In the present invention, the surface resistivity is more preferably 1×10 11 Ω / □ or more, particularly preferably 1×10 12 Ω / □ or more.

[0044] The resin that prevents the flaky metal sheets from contacting each other does not mean that all the flaky metal sheets are not in contact with each other, but means that the flaky metal sheets are prevented from contacting each other so that the surface resistivity (Ω / □) of the radiation heat reflection layer reaches 1×10 10 Ω / □ (Ωsquare) or more. For adjusting the surface resistivity, for example, the mixing ratio of the flaky metal sheet and the resin can be adjusted. For example, by reducing the mixing ratio of the flaky metal sheet and increasing the mixing ratio of the resin, the surface resistivity (Ω / □) can be increased. That is, the mixing ratio can be appropriately adjusted and set according to the target surface resistivity (Ω / □) or the use of the automotive interior material.

[0045] As described above, the radiant heat reflective film 20 according to the present invention can provide the radiant heat reflective layer 22 with a function of suppressing short circuits with wiring without impairing the radiant heat reflective function of the radiant heat reflective layer 22 and is suitable for mass production.

[0046] The automobile interior material 30 used in the present invention is composed of a laminated material including at least a skin material 31 , a base material 32 , and a radiant heat reflecting film 20 in this order.

[0047] The substrate 32 is a layer serving as a support layer in the automobile interior material, and can be made of the same material as that used in the existing automobile interior material without any particular limitation. For example, a fibrous porous material, a hard foam material, a composite material of a hard foam material and a non-woven fabric, etc. can be used. In addition, only one of these substrates can be used, or two or more of them can be used in combination.

[0048] As the above-mentioned fibrous porous material, there can be exemplified a material formed by bonding hard fibers such as glass fiber, PET fiber, and plant fiber with a thermoplastic resin. The fibrous porous material can be combined with a foaming material such as a heat-expandable capsule that can foam and expand between the hard fibers by heating.

[0049] In addition, examples of the rigid foamed material include materials formed by foaming polyurethane (including rigid polyurethane and semi-rigid polyurethane), polyolefin, and other resins. Among these materials, polyurethane foam is preferred, and semi-rigid polyurethane foam is particularly preferred.

[0050] Examples of the composite material of the rigid foam material and nonwoven fabric include a composite material in which a nonwoven fabric made of rigid fibers such as glass fibers is bonded to at least one of the front and back surfaces of the rigid foam material.

[0051] As the surface material 31, the existing materials used as the surface material of the automobile interior material can be used without special restrictions. Specifically, synthetic resin sheets, woven (knitted), non-woven fabrics, etc. implemented with texture patterns, leather processing, etc. can be listed. Woven (knitted) or non-woven fabrics can be formed thinner and easily formed into a shape that is easy to stretch. Therefore, even the surface of the automobile interior material made into a complex shape can be adapted and can be pasted without damaging the appearance.

[0052] The radiant heat reflecting layer 22 is formed by coating a coating material containing flaky metal flakes on the thermoplastic resin layer. The coating material containing flaky metal flakes contains flaky metal flake pigments such as aluminum, gold, silver, indium, copper, etc. and resin. As the flaky metal flake pigment, a leafing aluminum flake pigment is preferred.

[0053] The floating aluminum flake pigment is a material obtained by coating the surface of flaky aluminum powder with a long diameter of 1 to 150 μm with a treatment agent such as stearic acid. When a coating containing the pigment is applied to a thermoplastic resin layer (thermoplastic resin layer such as unstretched nylon film), the flaky aluminum powder floats on the surface of the coating and is arranged in parallel, forming a layer composed of flaky metal flakes that are substantially parallel to each other and a resin that prevents the metal flakes from contacting each other. In the radiant heat reflective film 20 involved in this embodiment, this layer is provided as the radiant heat reflective layer 22. In addition, in the present invention, it is preferred to use floating flaky metal flakes that are arranged substantially in parallel on the surface of the coating, but it is also possible to form a structure using dispersed flaky metal flakes dispersed in the coating.

[0054] As the resin contained in the coating containing flaky metal flakes (resin in the coating film that prevents the flaky metal flakes from contacting each other), conventionally known alkyd resins, acrylic resins, epoxy resins, olefin resins, polyamide resins, polyurethane resins, polyester resins, polybutadiene resins, and their derivatives, etc. can be used. Among these, polyurethane resins are preferred.

[0055] In addition, it is preferred to add a curing agent to the above-mentioned coating. As the curing agent, isocyanate compounds can be cited, and specifically hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, trimethylhexamethylene isocyanate, 1,6,11-undecane triisocyanate, lysine diisocyanate, lysine ester triisocyanate, 1,8-diisocyanate-4-isocyanate methyl octane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, etc. can be cited. In the present invention, a combination in which an isocyanate compound curing agent is added to the polyurethane resin is particularly preferred.

[0056] By adding a curing agent to the resin, the resin of the formed coating film has a cross-linked structure. The cross-linked structure improves the heat resistance of the coating film, and when the substrate of the automotive interior material is formed, the coating film of the radiant heat reflective layer adheres to the hot plate without peeling off.

[0057] In particular, since the flaky metal flakes in the coating film containing flaky metal flakes involved in the present invention float on the surface of the coating film and are arranged, the coating film is easily peeled off by heating or pressurization compared with the coating film in which metal particles are dispersed. In the present invention, in order to suppress the peeling of the coating film, a cross-linked structure is formed by adding a curing agent as described above, which can suppress the peeling of the coating film. The amount of curing agent added also varies depending on the type of coating, and is preferably 2 parts by weight or more, and more preferably 3 parts by weight or more relative to 100 parts by weight of the coating.

[0058] In addition, when the automotive interior material of the present invention is used as a ceiling material, wiring is installed on the radiant heat reflective film side of the ceiling material and assembled in the car. In order to prevent the wiring from falling off from the ceiling material in the harsh use environment of the car, the installation requires durability, and for the radiant heat reflective layer, it is more required that the coating film is difficult to peel off. For this reason, the amount of curing agent added can be 5 parts by weight or more, preferably 8 parts by weight or more, and more preferably 10 parts by weight or more relative to 100 parts by weight of the coating. In addition, it is preferred to add a curing agent that is twice or more, and more preferably three times or more of the appropriate amount of curing agent for commercially available coatings.

[0059] As the solvent used in the coating, there can be mentioned the solvents commonly known as coating solvents, for example: aromatic solvents such as toluene and xylene; alcohol solvents such as methanol, ethanol, isopropanol, and n-propanol; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; glycol solvents such as propylene glycol monomethyl ether, which can be used alone or in the form of a mixture of two or more.

[0060] As the coating method, any method such as spray coating, brush coating, dip coating, gravure coating or roll coating such as a roll coater, flow coating, etc. can be used. In particular, coating using a gravure coater is preferred.

[0061] The dry film thickness of the radiant heat reflecting layer 22 is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm. When the coating thickness is less than 0.1 μm, the radiant heat reflecting function becomes insufficient, while even if it exceeds 10 μm, the radiant heat reflecting effect, that is, the heat blocking effect, is saturated, which is economically disadvantageous.

[0062] In addition, the content of the flaky metal flakes in the radiant heat reflecting layer 22 is preferably 0.1 g / m 2 More than 0.3 g / m 2 More preferably, 0.5 g / m 2 And preferably 5.0 g / m 2 Below, particularly preferably 3.0 g / m 2 Below, more preferably 1.0 g / m 2 When the content of flaky metal flakes is less than 0.1 g / m 2 When the radiant heat reflection function becomes insufficient, on the other hand, even if it exceeds 5.0g / m 2 , the radiation heat reflection effect, that is, the heat blocking effect will also be saturated, which is economically disadvantageous.

[0063] The content of the resin in the radiant heat reflecting layer 22 is preferably 0.1 g / m 2 More than 0.3 g / m 2 More preferably, 0.5 g / m 2 And preferably 5.0 g / m 2 Below, particularly preferably 3.0 g / m 2 Below, more preferably 1.0 g / m 2 When the resin content is less than 0.1g / m 2 When the amount exceeds 5.0 g / m 2 This may result in a decrease in the radiant heat reflection effect.

[0064] Examples of the thermoplastic resin used for the thermoplastic resin layer include polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyamide resins such as nylon 6, nylon 66, copolymers of nylon 6 and nylon 66, nylon 12, and terpolymers of nylon 6, nylon 66 and nylon 12; polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins; cellulose resins such as triacetyl cellulose; polyimide resins; polycarbonate resins; acrylic resins; polyvinyl alcohol resins; ethylene-vinyl alcohol copolymers, etc.

[0065] Among them, resins having a melting point of 200° C. or higher, such as polyester resins and polyamide resins, are particularly preferred because they have heat resistance when the automobile interior material is heated to form a base material.

[0066] The thermoplastic resin layer is preferably a multilayer film, specifically a two-layer film of a heat-resistant resin layer and an adhesive resin layer, or a three-layer film having a heat-resistant resin layer as a core layer and adhesive resin layers as two outer layers.

[0067] The heat-resistant resin layer is preferably a resin layer that has no risk of melting when heated, and preferably has a resin having a higher melting point than the resin forming the adhesive resin layer described later as a main component. In addition, the adhesive resin layer is a resin layer that is fused when the radiant heat reflective film is thermally fused to the substrate, and preferably a resin that melts at a heating temperature.

[0068] As the adhesive resin layer, for example, propylene resins such as propylene-ethylene random copolymers, propylene-ethylene block copolymers, and homopolypropylene; ethylene resins such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene, and copolymers of ethylene and α-olefins (C3 to C8) can be used. The film containing the resin may be a stretched film or an unstretched film, but from the viewpoint of thermal fusion, an unstretched film is preferred.

[0069] As the heat-resistant resin layer, it is preferred that a resin having a melting point exceeding 180°C is used as the main component. As such a resin, in the present invention, examples include: amide resins such as nylon 6, nylon 6,6, nylon 6,10, nylon 11, and nylon 12, or copolymers of these resins; or polyester resins such as polyethylene terephthalate or polybutylene terephthalate. The film containing the resin may be a stretched film or an unstretched film, but an unstretched film having flexibility can be formed in a manner without film cracking during cold rolling, and is therefore preferred. Among them, an unstretched nylon film, especially an unstretched nylon film formed by a copolymer of nylon 6 and nylon 6,6, has both heat resistance and flexibility, and the film does not crack during cold rolling, etc., and is suitable for the heat-resistant resin layer of the present invention.

[0070] More specifically, the following can be cited: a laminated film formed by dry laminating a stretched or unstretched polyethylene terephthalate film and an unstretched polypropylene film; a laminated film formed by co-extrusion lamination of a polyamide resin and a polyethylene resin; a laminated film formed by co-extrusion lamination of three layers of a polyethylene resin, a polyamide resin and a polyethylene resin, etc.

[0071] When a two-layer or three-layer laminated film is formed by coextrusion lamination using a polyethylene resin and a polyamide resin, an acid-modified polyethylene resin or the like may be present as an adhesive resin between the polyethylene resin and the polyamide resin.

[0072] Furthermore, polyamide resin may shrink and curl due to moisture absorption, but curling can be suppressed by forming a three-layer film with polyethylene resin having the same thickness on both sides of the polyamide resin.

[0073] Among these laminated films, from the viewpoint that the coating film of the radiation heat reflective layer is difficult to peel off and the film is unlikely to crack during cold roll forming, a two-layer laminated film obtained by co-extrusion lamination of nylon 6 and nylon 6,6 copolymer / linear low-density polyethylene (radiant heat reflective layer side) and a three-layer laminated film obtained by co-extrusion lamination of linear low-density polyethylene / nylon 6 and nylon 6,6 copolymer / linear low-density polyethylene are preferred.

[0074] These laminated films can be appropriately selected according to the material of the substrate. For example, for a glass fiber substrate, a two-layer laminated film formed by co-extrusion lamination of a copolymer of nylon 6 and nylon 6,6 / linear low-density polyethylene is preferred. In addition, for a substrate composed of foamed polyurethane, an unstretched polypropylene film (single-layer film) is preferred.

[0075] As mentioned above, Figure 1 As shown, the radiant heat reflective film 20 having a radiant heat reflective layer 22 on a thermoplastic resin layer 21 is used for an automobile interior material 30 having at least a skin material 31, a substrate 32 and a radiant heat reflective film 20 in this order. The average reflectivity of infrared rays (2 μm to 20 μm) measured from the radiant heat reflective layer 22 side of the automobile interior material 30 is 55% or more, and the radiant heat reflective film receiving light hardly passes through, and the radiant heat reflective performance is excellent. The radiant heat reflective layer 22 is installed on the automobile body facing outward. It can also be installed on other pillars or doors, etc. in the same manner as when installing on the roof.

[0076] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[0077] Example <Experiment 1>

[0078] Various physical properties of the radiant heat reflective film were measured as shown in the following Table 1. The measurement method is as follows.

[0079] The radiant heat reflective film is used as a car ceiling material, and the car ceiling material is laminated in the order of skin material / base material / radiant heat reflective film from the inside of the car.

[0080] Since the radiant heat reflective film plays a role in reflecting radiant heat from the roof panel (vehicle exterior) side, all the evaluations (1) to (3) below were measured from the roof panel side of the radiant heat reflective film.

[0081] (1) Infrared reflectivity

[0082] The infrared reflectivity (%) was measured using a spectrophotometer 680IR (manufactured by Agilent Technology Co., Ltd.) with a gold-plated integrating sphere. The wavelength was 2 μm to 20 μm, and the data was measured every 0.016 μm. The maximum, minimum, and average values ​​were calculated from the measured data. The infrared reflectivity was calculated as the relative reflectivity when the reflectivity of the gold-plated surface mirror was 100%.

[0083] In addition, based on the measurement results, evaluation was performed according to the following criteria.

[0084] ◎: Average reflectivity is more than 90%

[0085] ○: Average reflectivity is 55% or more

[0086] △: Average reflectivity is more than 50%

[0087] ×: Average reflectivity is less than 50%

[0088] (2) Surface resistivity

[0089] The surface resistivity (Ω / □) was measured under the conditions of 23° C. and 50% RH using a digital ultra-high resistance meter R8340A (manufactured by ADVANTEST CORPORATION) with a voltage of 100 V applied.

[0090] In addition, based on the measurement results, evaluation was performed according to the following criteria.

[0091] ○:1×10 10 Ω / □ or more

[0092] ×: less than 1×10 10 Ω / □

[0093] (3) Heat resistance

[0094] The reason for evaluating heat resistance is explained. Automotive interior materials are processed by heating when they are substrate-based. At this time, since the surface (top plate side) of the radiation reflective film in contact with the hot plate is heated, heat resistance is required. In the case where a biaxially stretched polyethylene terephthalate film (hereinafter referred to as OPET film) (thermoplastic resin layer of the radiation heat reflective film) is the surface, since the OPET film has heat resistance, it can be processed without any problem, but in the case where the radiation heat reflective layer is the surface (top plate side), it is necessary to consider the problem of peeling of the coating film due to heat.

[0095] Therefore, the following heat resistance evaluation was performed to simulate the process of substrate formation by heating. Regarding the evaluation of heat resistance, the radiation heat reflective film was heated by a heat sealing rod, and the degree of peeling of the radiation heat reflective layer after heating was evaluated. The heating by the heat sealing rod was performed by pressing the heat sealing rod against the radiation heat reflective layer through the aluminum foil and heating at 200°C for 1 minute.

[0096] However, in Comparative Example 2 described later, since the thermoplastic resin layer (OPET film) of the radiant heat reflective film was on the top plate side, no evaluation was performed.

[0097] Evaluation The radiant heat reflecting layer after heating was visually observed and evaluated based on the following criteria.

[0098] ○: No peeling was observed.

[0099] △: Slight peeling was observed.

[0100] -: Not measured.

[0101] Next, the film structures and production methods of Examples 1 to 2 and Comparative Examples 1 to 3 in Table 1 below will be described.

[0102] [Example 1]

[0103] A coating liquid in which 100 parts by weight of a metal flake-containing coating material (BelleColor high brightness silver CN, manufactured by SAKATA INX CORPORATION) containing flaky aluminum flakes and a resin and 3 parts by weight of an isocyanate compound (Lamiall R curing agent, manufactured by SAKATA INX CORPORATION) were mixed in a solvent was gravure coated on an OPET film (thermoplastic resin layer of a radiant heat reflective film) and dried to form a radiant heat reflective layer having a thickness of about 1 μm. In the dried radiant heat reflective layer, flaky aluminum flakes floated on the surface of the coating film and segregated and parallelly arranged (floated), and the resin had a cross-linking structure by a cross-linking reaction with the isocyanate compound.

[0104] The radiant heat reflective film thus obtained was disposed as a radiant heat reflective layer on the ceiling side (vehicle exterior side) of an automobile interior material, and the infrared reflectivity (%), surface resistivity (Ω / □) and heat resistance were measured. The measurement results are shown in Table 1 below as Example 1.

[0105] [Example 2]

[0106] A radiant heat reflecting layer was formed in the same manner as in Example 1, except that the isocyanate compound was not mixed into the metal flake-containing coating material to form a heat radiation reflecting layer having no crosslinking structure, thereby forming a radiant heat reflecting film.

[0107] The obtained radiant heat reflective film was placed as a radiant heat reflective layer on the roof side (vehicle exterior) of an automobile interior material, and infrared reflectivity (%), surface resistivity (Ω / □) and heat resistance were measured. The measurement results are shown in Table 1 below as Example 2.

[0108] [Comparative Example 1]

[0109] The radiant heat reflecting layer was formed in the same manner as in Example 2, to form a radiant heat reflecting film, except that a coating liquid containing metal flakes was not used but a common silver coating containing aluminum particles and a resin in a solvent (BelleColor S Silver C, manufactured by SAKATA INX CORPORATION) was used as the coating liquid to be gravure coated on the OPET film (thermoplastic resin layer of the radiant heat reflecting film).

[0110] The obtained radiant heat reflective film was placed as a radiant heat reflective layer on the roof side (vehicle exterior) of an automobile interior material, and infrared reflectivity (%), surface resistivity (Ω / □) and heat resistance were measured. The measurement results are shown in Table 1 below as Comparative Example 1.

[0111] [Comparative Example 2]

[0112] In the radiant heat reflective film obtained in Comparative Example 1, an OPET film (thermoplastic resin of the radiant heat reflective film) was arranged on the roof side (vehicle outer side) of the automobile interior material, and infrared reflectivity (%), surface resistivity (Ω / □) and heat resistance were measured. The measurement results are shown in the following Table 1 as Comparative Example 2.

[0113] [Comparative Example 3]

[0114] An aluminum-deposited OPET film (thickness 12 μm, produced by TORAY ADVANCED FILM Co., Ltd.) was prepared, and the aluminum-deposited layer was used as a radiation heat reflection layer. The radiation heat reflection layer was arranged on the top plate side (vehicle outer side) of the automobile interior material, and the infrared reflectivity (%), surface resistivity (Ω / □) and heat resistance were measured. The measurement results are shown in the following Table 1 as Comparative Example 3.

[0115]

Table 1

[0116]

[0117] Regarding the evaluation item of infrared reflectivity, the OPET film having a vapor-deposited film on the outer layer side of the automobile of Comparative Example 3 showed the highest value, and the OPET film / metal flake-containing paint (without cross-linked structure) of Example 2 showed the second highest value. In addition, the infrared reflectivity was highest in Example 1 and Comparative Example 1. On the other hand, the minimum value of infrared reflectivity of Comparative Example 2 was as low as 1.7%. This is considered to be because light is absorbed in the absorption wavelength region of the OPET film, so the infrared reflectivity drops sharply at a specific wavelength.

[0118] Regarding the evaluation item of surface resistivity, the surface resistivity of Examples 1 and 2 and Comparative Examples 1 and 2 were all 1×10 10 Ω / □ or more, while the surface resistivity of Comparative Example 3 is less than 1×10 10 Ω / □. In addition, regarding the evaluation item of heat resistance, Example 1 was good due to the crosslinked structure formed by the curing agent. On the other hand, in the coating films of Example 2 and Comparative Example 1 without a crosslinked structure, slight peeling of the coating film was observed.

[0119] As described above, the evaluation of the infrared reflectivity and surface resistivity of Examples 1 and 2 and Comparative Examples 1 to 3 shows that the radiant heat reflective film 20 according to the present invention has both the infrared reflectivity function and the function of suppressing short circuits with wiring.

[0120] Experiment 2

[0121] The radiant heat reflective films were evaluated as shown in the following Table 2. The evaluation method is as follows.

[0122] (4) Formability

[0123] The radiant heat reflective film (radiant heat reflective layer / thermoplastic resin layer in order), substrate (porous fiber), and skin (nonwoven fabric) were stacked in the order shown in Table 2, heated by a hot plate, and integrated by cold rolling to form a predetermined shape to be installed on the ceiling. The state of the radiant heat reflective film of the obtained molded body was visually confirmed and evaluated according to the following criteria.

[0124] ○: No problem

[0125] △: Usable, but cracks occurred in the thermoplastic resin layer

[0126] ×: Unable to use

[0127] Next, the film structures and production methods of Examples 3 to 4 in Table 2 below will be described.

[0128] [Example 3]

[0129] An unstretched nylon film (hereinafter referred to as CNY film) and an unstretched polyethylene film (hereinafter referred to as PE film) are sandwiched and laminated using a molten polyethylene resin (hereinafter referred to as PE resin) to form a thermoplastic resin layer, and a radiant heat reflecting layer is formed on the CNY film surface in the same manner as in Example 1.

[0130] The obtained radiant heat reflective film was evaluated by the method of (4) Formability. The results are shown in Table 2 below.

[0131] [Example 4]

[0132] The OPET film and the PE film were dry-laminated by using an adhesive to prepare a thermoplastic resin layer, and a radiant heat reflecting layer was formed on the OPET film surface in the same manner as in Example 1.

[0133] The obtained radiant heat reflective film was evaluated by the method of (4) Formability. The results are shown in Table 2 below.

[0134]

Table 2

[0135]

[0136] In Example 3, in which a CNY film was used as the thermoplastic resin layer, the thermoplastic resin layer did not crack when cold-rolled into a predetermined shape by a die, and molding was possible without any problems. On the other hand, in Example 4, in which an OPET film was used as the thermoplastic resin layer, the thermoplastic resin partially cracked.

[0137] Experiment 3

[0138] The radiant heat reflective films were evaluated as shown in the following Table 3. The evaluation method was as follows.

[0139] (5) Durability

[0140] The surface of the radiant heat reflective layer of the radiant heat reflective film shown in Table 3 was rubbed back and forth 10 times with a plastic eraser (one rubbing length: 50 mm), and the peeling of the radiant heat reflective layer was evaluated based on the following criteria.

[0141] ◎: The radiant heat reflective layer has not peeled off at all

[0142] ○: The radiant heat reflective layer has slight peeling

[0143] Among them, this evaluation is a simulation evaluation of whether the radiant heat reflective layer can be maintained without peeling during the operation of the ceiling manufacturing process, and whether the components such as wiring installed on the surface of the ceiling material can maintain the durability of the installed state even in the harsh usage environment of the car, and evaluates the peeling of the radiant heat reflective layer where components such as wiring are installed.

[0144] Next, the film structures and production methods of Examples 5 to 7 in Table 3 below will be described.

[0145] [Example 5]

[0146] A thermoplastic resin layer is prepared in which a CNY film and a PE film are sandwich-laminated using a PE resin in a molten state.

[0147] A coating liquid prepared by mixing 100 parts by weight of a metal flake-containing paint (BelleColor S high brightness silver CN, manufactured by SAKATA INX CORPORATION) containing flaky aluminum flakes and a resin in a solvent and 3 parts by weight of an isocyanate compound (Lamiall R curing agent, manufactured by SAKATA INX CORPORATION) was prepared so that the content of flaky aluminum flakes was 0.6 g / m 2 The radiant heat reflective layer was formed by gravure coating on the CNY film. The durability evaluation results of the obtained radiant heat reflective film are shown in Table 3.

[0148] [Example 6]

[0149] The same procedure as in Example 10 was carried out except that 10 parts by weight of an isocyanate compound (Lamiall R curing agent, manufactured by SAKATA INX CORPORATION) was mixed with 100 parts by weight of a metal flake-containing coating material (BelleColor S high brightness silver CN, manufactured by SAKATA INX CORPORATION) containing flaky aluminum flakes and a resin in the coating liquid. The durability evaluation results of the obtained radiant heat reflective film are shown in Table 3.

[0150]

Table 3

[0151]

[0152] In Example 5, in which the amount of isocyanate compound added was generally considered to be appropriate (3 parts by weight), there was slight peeling of the coating film (radiant heat reflecting layer), but in Example 6, in which the amount of isocyanate compound added was set to 10 parts by weight, there was no peeling of the coating film at all, and the coating had durability.

[0153] Explanation of symbols

[0154] 20: radiant heat reflective film; 21: thermoplastic resin layer; 22: radiant heat reflective layer; 30: automotive interior material; 31: surface material; 32: substrate.

Claims

1. A radiant heat reflective film used for automotive interior materials, wherein the radiant heat reflective film is characterized by: The radiant heat reflective film comprises a radiant heat reflective layer, The radiant heat reflecting layer has a 1×10 10 The method of having a surface resistivity of Ω / □ or more has flaky metal pieces located substantially parallel to each other and a resin that prevents the flaky metal pieces from contacting each other, The radiant heat reflective film has a function of suppressing a short circuit with wiring.

2. The radiant heat reflective film according to claim 1, characterized in that: The mixing ratio of the flaky metal sheet and the resin is adjusted so as to have both the function of reflecting radiant heat and the function of suppressing short circuit with wiring.

3. The radiant heat reflective film according to claim 1 or 2, characterized in that: The resin that prevents the scaly metal pieces from contacting each other has a cross-linked structure.

4. The radiant heat reflective film according to claim 1 or 2, characterized in that: The radiant heat reflective layer has a 1×10 11 Surface resistivity above Ω / □.

5. The radiant heat reflective film according to claim 1 or 2, characterized in that: The radiant heat reflective film is composed of a thermoplastic resin layer and a radiant heat reflective layer.

6. The radiant heat reflective film according to claim 5, characterized in that: The average reflectivity of infrared rays measured from the radiant heat reflecting layer side is 55% or more, wherein the infrared rays range from 2 μm to 20 μm.

7. The radiant heat reflective film according to claim 1 or 2, characterized in that: An automobile interior material having at least a surface material, a substrate and a radiant heat reflecting film in sequence.

8. An automobile interior material, which comprises at least a surface material, a substrate and a radiant heat reflective film in sequence, wherein the automobile interior material is characterized in that: The radiant heat reflective film is composed of a thermoplastic resin layer and a radiant heat reflective layer. The surface is configured in such a way that one surface is the skin material and the other surface is the radiation heat reflecting layer. The radiant heat reflective film comprises the following radiant heat reflective layer, wherein the radiant heat reflective layer has a 10 The radiant heat reflective film has a surface resistivity of Ω / □ or more, and has flaky metal pieces that are substantially parallel to each other and a resin that prevents the flaky metal pieces from contacting each other, and has a function of suppressing short circuits with wiring.

9. The automotive interior material according to claim 8, characterized in that: The radiant heat reflective film is a film obtained by adjusting the mixing ratio of the scaly metal sheet and the resin so as to have both the radiant heat reflective function and the function of suppressing short circuit with wiring.

10. The automotive interior material according to claim 8 or 9, characterized in that: The radiant heat reflective film is a radiant heat reflective film in which a resin that prevents scaly metal sheets from contacting each other has a cross-linked structure.

11. The automotive interior material according to claim 8 or 9, characterized in that: The radiant heat reflective film is a radiant heat reflective layer having a 1×10 11 Radiant heat reflective film with a surface resistivity of Ω / □ or more.

12. The automotive interior material according to claim 11, characterized in that: The average reflectivity of infrared rays measured from the radiant heat reflecting layer side is 55% or more, wherein the infrared rays range from 2 μm to 20 μm.

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