JP4259317B2 - Retroreflective skin material - Google Patents

Description

  The present invention relates to a material for reducing a summer heat feeling and providing a comfortable thermal environment, and more particularly to a retroreflective skin material suitable for use for the purpose of reducing the temperature rise of a vehicle interior.

  It is well known that the interior of a parked automobile becomes very hot under hot weather. According to the measurement of the indoor temperature in Japan in summer, the indoor temperature when parked under the sun reaches about 70 ° C. In the interior materials, the upper surface of the instrument panel is around 100 ° C, the surface of the ceiling material and the surface of the seat are 70 ° C. It has been reported to reach temperatures as high as around ℃. Needless to say, there is no uncomfortable feeling when riding in such a situation, and radiant heat is generated from the interior material for a long time, and heat is stored on the seat surface, so that the passenger gets uncomfortable by receiving hot air from the seat by heat conduction At the same time, since the room temperature and the interior material temperature are not easily lowered in ventilation or cooling, excessive energy consumption due to cooling is also a problem.

  Conventionally, regarding the problem of parking under the sun, for example, Patent Documents 1 and 2 propose a technique for reflecting infrared rays by containing an infrared reflective pigment in the interior material skin as an object of preventing overheating of the interior material surface. Has been.

  However, in these techniques, since the infrared reflective pigment powder is randomly mixed in the resin, the reflection direction becomes irregular reflection, and most of the reflected light is absorbed by the resin layer and changed to heat. In addition, about half of the sunlight energy is visible light, and in addition, since the window glass for automobiles in recent years has a lot of heat insulating glass that absorbs near-infrared rays, the main factor of the rise in the interior surface temperature is visible light. Therefore, the interior material skin that reflects infrared rays cannot be expected to have a great effect of preventing overheating of the interior material surface.

  As an example of applying an optical reflection function to a vehicle, in addition to reflection on the interior material surface, a reflection function is added to the window glass to prevent ultraviolet rays from entering the vehicle interior. A technique related to layer glass is known (see, for example, Patent Document 3).

  However, the visible light transmittance (Tv) of 70% or more must be ensured for the windshield and the front side glass according to the law. In order to ensure this standard, as the reflection function, only a solar reflectance (Re) of about 20% to 30% can be obtained, and further improvement in performance cannot be expected. The windshield and front side glass have a very large area as a light intrusion route, and it is necessary to take heat countermeasures by other means that there is no further heat countermeasures at the window glass part. It means that there is. The values of solar reflectance (Re), solar transmittance (Te), visible light reflectance (Rv), and visible light transmittance (Tv) described in this specification are in accordance with JIS R3106. It is measured.

As a countermeasure against heat by the other means, a method of reflecting the solar energy by increasing the surface reflectance or brightness of the interior material in order to prevent overheating of the interior material surface can be considered. However, simply increasing the visible light reflectance (Rv) on the interior material surface may cause the reflected light to enter the driver's eyes directly or the interior material to be reflected in the window glass depending on the angle of sunlight. There is a risk of obstructing the person's view. As described above, there is a tradeoff between increasing the reflectance and suppressing the window reflection, and there is a demand for the realization of materials and configurations that can prevent window reflection without impairing the reflection performance.
JP 2001-114149 A Japanese Patent Laid-Open No. 2001-1222044 Japanese Patent No. 3315453

  In response to such demands, the present inventors have used a material that retroreflects light (hereinafter also referred to as “retroreflective material”) as a vehicle interior material, and a reflective surface in the direction in which solar radiation enters. While making the function work, we devised a measure to prevent the reflective surface from being seen from the driver's direct line-of-sight direction or the driver's line-of-sight direction through the reflection of the window glass. The present invention has been completed in view of this viewpoint.

  Therefore, the object of the present invention can be suitably applied to an interior material for a vehicle, can effectively reflect solar radiation energy including visible light, and can suppress an increase in surface temperature of the interior material due to direct sunlight or solar radiation through glass. An object is to provide a reflective skin material.

The present invention for achieving the above object is a retroreflective skin material used in an indoor space having a window glass,
A retroreflective layer that retroreflects light;
A heat insulating layer laminated on the retroreflective layer and transmitting light,
The heat insulating layer has a heat insulating function and a heat holding function ,
The heat insulating layer forms a spatial layer between the plurality of light shielding walls disposed on the retroreflective layer and the retroreflective layer through the light shielding walls spaced from each other. Transparent layer that is transparent, and laminated
The heat shielding layer is provided with the property of transmitting or reflecting incident light and light reflected by the retroreflective layer with angle selectivity by the light shielding wall,
A retroreflective skin having a light-reflective surface on one side and a light-absorbing surface on the other side of the light-shielding wall, the light-reflecting surface facing the window glass It is a material.

According to the retroreflective skin material of the present invention, the retroreflective layer retroreflects light, while the heat insulating layer having a heat insulating function and a heat retaining function suppresses heat release from the retroreflective skin material. Therefore, it can be suitably applied to an interior material used in an indoor space having a window glass, effectively reflects solar energy including visible light, and suppresses an increase in the surface temperature of the interior material due to direct sunlight or solar radiation through the glass. be able to.
In addition, the heat insulating layer forms a spatial layer between the plurality of light shielding walls disposed on the retroreflective layer and the retroreflective layer through the light shielding walls spaced from each other and transmits light. The heat insulating layer reliably exhibits the heat insulating function and the heat holding function, and can further suppress the heat release from the retroreflective skin material, and the surface temperature of the interior material. The rise can be further suppressed.
In addition, the heat shielding layer gives the heat insulating layer the property of transmitting or reflecting the incident light and the light reflected by the retroreflective layer with angle selectivity by the light-shielding wall. It is possible to achieve both.
Furthermore, it has a light-reflective surface on one side of the front and back sides of the light-shielding wall, a light-absorbing surface on the other side, and the light-reflective surface faces the window glass. The effective reflection angle can be expanded to further increase the reflectance of solar radiation, and overheating of the interior material surface can be further prevented.

Hereinafter, one reference quality to the drawings, illustrating a form of implementation details.

FIG. 1 is a cross-sectional view showing a retroreflective skin material 1 according to the first embodiment.

  As illustrated, the retroreflective skin material 1 includes a retroreflective layer 5 that retroreflects light, and a heat insulating layer 2 that is laminated on the retroreflective layer 5 and transmits light. The heat insulating layer 2 has a heat insulating function and a heat holding function.

  The retroreflective skin material 1 having such a configuration can be used for a vehicle interior material, and specifically, can be applied to an instrument panel, a door trim, a rear parcel shelf, a pillar garnish, a steering wheel, and the like. Among these interior materials, instrument panels and rear parcel shelves have large areas, and windshields and window glasses such as rear glass are arranged in the vicinity thereof.

  As is well known, retroreflection, which is an optical characteristic of the retroreflective layer 5, utilizes light refraction of glass beads or a fine three-dimensional prism structure (corner cube), regardless of the light irradiation direction. The property of reflecting light in the irradiation direction. This type of retroreflective material is widely used to improve the visibility of road signs, signboards, and the like. As an example of a retroreflective material, for example, manufactured by Sumitomo 3M Co., Ltd., trade name: Scotchlite capsule lens type reflective sheet, manufactured by Nippon Carbide Industries, trade name: Nikkalite capsule lens type high brightness sheet, encapsulated lens type retroreflective sheet Are commercially available and can be easily obtained industrially.

The heat insulating layer 2 is formed of a transparent film that transmits light. Examples of the material for the transparent film include polyvinyl chloride resin, thermoplastic olefin (TPO) resin, and polyurethane resin.

  When a retroreflective material is used as the skin, reflection of about 60% is expected with respect to solar radiation, and these energies are reflected in the incident direction and are not accumulated as energy on the surface of the skin. On the other hand, the remaining 40% is accumulated on the surface of the epidermis, resulting in an increase in the temperature of the epidermis surface, and further released into the passenger compartment by radiation from the surface, resulting in an increase in the passenger compartment temperature.

  Therefore, the heat insulating layer 2 is provided with a heat insulating function and a heat holding function. In order to impart these functions to the heat insulating layer 2, a plurality of grooves are formed on one surface of the transparent film constituting the heat insulating layer 2, the smooth surface of the transparent film is the upper surface, and the uneven surface is retroreflected. Layer 5 is laminated and bonded. Thereby, the space layer 41 is formed between the retroreflection layer 5 and the uneven | corrugated surface of a transparent film, and the said space layer 41 exhibits the heat insulation function in the heat insulation layer 2, and a heat retention function. The groove of the transparent film is processed into a groove on the outer peripheral surface of the grain roll, pressurizing the transparent film with a hot roll, and thermally transferring the groove shape in the same way as forming a fine unevenness so-called “wrinkle”. Can be formed easily.

  The operation of the first embodiment will be described.

  First, the retroreflective skin material 1 transmits the outermost surface without reflecting sunlight, and prevents a direct increase in temperature of the heat insulating layer 2 that is the outermost skin. The light transmitted through the outermost skin is then divided into a reflection component and an absorption component in the retroreflective layer 5 laminated under the outermost skin. The reflection component passes through the outermost skin layer and is emitted as light in the incident direction, and the absorption component is absorbed by the retroreflection layer 5 to generate heat.

  When the heated retroreflective layer 5 easily transfers heat to the outermost skin, an indirect temperature rise in the passenger compartment is caused. However, since the heat insulating layer 2 has a heat insulating function and a heat retaining function, heat release from the heat insulating layer 2 to the vehicle interior side can be suppressed, and an indirect temperature rise in the vehicle interior can be suppressed. .

  In addition, the heat retention function with which the heat insulation layer 2 is provided is, in other words, a heat collection function. Therefore, the retroreflective skin material is also referred to as a heat collection retroreflective skin material in the present invention.

  As described above, the retroreflective skin material 1 includes the retroreflective layer 5 that retroreflects light and the heat insulating layer 2 that is laminated on the retroreflective layer 5 and transmits light. It is preferable to provide a heat insulating function and a heat holding function.

  According to the retroreflective skin material 1, the retroreflective layer 5 retroreflects light, while the heat insulating layer 2 having a heat insulating function and a heat retaining function suppresses heat release from the retroreflective skin material 1. Therefore, it can be suitably applied to an interior material for a vehicle, can effectively reflect solar radiation energy including visible light, and can suppress an increase in the surface temperature of the interior material due to direct sunlight or solar radiation through glass.

FIG. 2 is a cross-sectional view showing a retroreflective skin material 1a according to the second embodiment.

  The second embodiment is different from the first embodiment in that the configuration of the heat insulating layer 2 is modified.

The heat insulating layer 2 in the second embodiment is a space layer between the plurality of spacers 42 disposed on the retroreflective layer 5 and the retroreflective layer 5 via the spacers 42 spaced apart from each other. 41 and a transparent film 43 (corresponding to a transparent layer) that transmits light and is laminated. In the illustrated example, a spacer 42 is disposed on a transparent film 43 laminated on the retroreflective layer 5.

  With this configuration, the heat insulating layer 2 can be composed of the outermost transparent layer 43 and the space layer 41 that holds air. The transparent layer 43 exhibits a function of transmitting light. Furthermore, the space layer 41 exhibits a function to insulate the re-release of heat absorbed by the retroreflective layer 5, and it is possible to suppress the heat release into the room. The medium filled in the space layer 41 is not particularly limited, but air is suitable for both thermal conductivity and heat capacity. Besides this, it is also possible to use a transparent resin having a low thermal conductivity.

  As described above, the heat insulation layer 2 has the space layer 41 between the plurality of spacers 41 arranged on the retroreflective layer 5 and the retroreflective layer 5 via the spacers 41 arranged at intervals. A transparent layer 43 that is formed and transmits light is preferably laminated.

  With such a configuration, the heat insulating layer 2 can reliably exhibit the heat insulating function and the heat holding function, can further suppress the heat release from the retroreflective skin material 1, and can further suppress the increase in the surface temperature of the interior material. .

  FIG. 3A is a diagram showing the solar retroreflected light 32 and the windowed light path 72 of the sky 70 generated when the retroreflective layer 5 is installed on the instrument panel. FIG. 3B is a diagram for explaining prevention of window reflection when the heat insulating layer 3 laminated on the retroreflective layer has a property of transmitting or reflecting light with angle selectivity.

Referring to FIG. 3A, a light beam 31 incident from the sun 30 returns reflected light 32 in the same direction again by retroreflection at the retroreflective layer 5, and light energy is emitted to the outside. On the other hand, the line of sight 71 from the occupant's viewpoint 10 to the window sees the retroreflective surface through the reflection of the windshield 20, but the retroreflective surface returns the line of sight 73 and passes through the windshield 20 to reflect the sky 70. That is, the occupant may feel a high brightness reflection as if the sky 70 was reflected on the windshield 20.

  Therefore, as shown in FIG. 3B, the heat insulating layer 3 preferably has a property of transmitting or reflecting incident light and light reflected by the retroreflective layer 5 with angle selectivity.

  In the configuration of the second embodiment shown in FIG. 2, the spacer 42 gives the heat insulating layer 3 the property of transmitting or reflecting incident light and light reflected by the retroreflective layer 5 with angle selectivity. It is preferable that it is comprised from the light-shielding wall for.

In this specification, “transmits or reflects light with angle selectivity” means according to the angle of incident light with respect to the normal direction of the surface on the incident side or the normal direction of the surface on the reflective surface side. This means the property of selectively reflecting or transmitting light at an angle within a predetermined range according to the angle of reflected light with respect to.

  The basic function of the light-shielding wall is to block solar radiation, and the light-shielding wall is formed of a film containing a component that blocks solar radiation. For example, the light shielding wall can be formed by applying a black paint in which carbon is dispersed to the spacer 42.

With reference to FIG.3 (B), in the retroreflection skin material 1b which provided the angle selectivity to the heat insulation layer 3, sunlight can be reflected because the incident light 31 from the sun passes. On the other hand, by blocking the line of sight 72 from the occupant and blocking the optical path 73 that reflects the sky 70, it is possible to effectively prevent window reflection without impairing the reflectance. In combination with the above-described heat insulation, it is possible to achieve both improvement of the window reflection prevention performance and improvement of the thermal functional performance.

  As described above, it is preferable that the heat insulating layer 3 has a property of transmitting or reflecting incident light and light reflected by the retroreflective layer 5 with angle selectivity. Moreover, it is preferable that the spacer 42 is comprised from the light-shielding wall for providing the heat insulation layer 3 the property which permeate | transmits or reflects incident light and the light reflected by the retroreflection layer 5 with angle selectivity.

With such a configuration, it is possible to achieve both improvement of the windowing prevention performance and improvement of the thermal function performance.

  FIG. 4A is a cross-sectional view showing a retroreflective skin material 1c in which a light-reflecting surface is formed on one side and a light-absorbing surface is formed on the other side of both sides of the light shielding wall. FIG. 4B is a diagram showing a direct line of sight and a windowed line of sight in the retroreflective skin material 1c shown in FIG.

  In installing the retroreflective skin material 1c with the angle selectivity on the heat insulating layer 3 on the instrument panel, it is important to consider the optical characteristics of the front and back surfaces of the light shielding wall.

  With reference to FIG. 4 (A), it is preferable that the light-shielding wall 42 has a light-reflecting surface 55 on one side of the front and back sides and a light-absorbing surface 54 on the other side. When installing on the instrument panel, as shown in FIG. 4 (B), the surface facing the occupant side of the light shielding wall 42 is the light absorbing surface 54 and the surface facing the vehicle exterior is the light reflecting surface 55. And

  One side of the light shielding wall 42 facing the passenger is reflected on the windshield 20 through the line of sight 12. Therefore, if the surface is too bright, the occupant's field of view is obstructed, so that the brightness is preferably low. Moreover, the said one side is also a surface which a passenger | crew sees directly by the direct line of sight 11 to an instrument panel, and determines the design of interior material. Therefore, in consideration of prevention of reflection and design freedom, it is preferable that the light-absorbing surface 54 of the light shielding wall 42 is colored with a Munsell brightness of 5.0 or less. By limiting the upper limit lightness to about 5.0 or less in Munsell lightness, it is possible to set an arbitrary color tone in accordance with the interior design without hindering the sight of the passenger. The light-absorbing surface 54 is not dazzling as seen directly from the driver or from the reflection of the window glass, and is not required to be reflected, and can be formed of a black paint or a black film.

  On the other hand, a larger effective reflection angle can be obtained by making the light-reflecting surface 55 the surface of the light shielding wall 42 facing the vehicle exterior. That is, as shown in FIG. 5A, when the light-reflecting surface 55 is not formed, the range that can be retroreflected by the retroreflective layer 5 is only the range represented by the effective reflection angle a. By forming the light-reflecting surface 55, the effective reflection angle a is expanded forward (toward the vehicle) by an angle c. The angle c is defined by a straight line connecting the upper end of the light shielding wall 42 and the center of the adjacent light shielding wall 42. Light incident from the region represented by the angle c reaches the retroreflective layer 5 through the light reflective surface 55, and is emitted out of the system by following the same optical path in the reverse direction by retroreflection. Increasing the effective reflection angle not only increases the angle at which the reflection function is exhibited, but also improves the reflectivity by the amount of the area behind the light shielding wall 42, which is great for preventing temperature rise, which is an object of the invention. effective.

  As described above, it is preferable that the light shielding wall has the light reflecting surface 55 on one side of the front and back sides and the light absorbing surface 54 on the other side. Moreover, it is preferable that the light absorptive surface 54 in the light shielding wall is colored 5.0 or less in Munsell brightness.

According to such a configuration, the effective reflection angle of solar radiation can be expanded to further increase the reflectance of solar radiation, and overheating of the interior material surface during parking under hot weather can be further prevented. In addition, it can be set to any color tone according to the interior design without obstructing the sight of the passenger.

  The light reflective surface 55 in the light shielding wall 42 is composed of at least one selected from a metal vapor deposition film, a metal sputtered film, a metal foil, a coating film in which the metal foil is dispersed, or a reflection film in which they are attached to a resin film, It preferably has specular reflection characteristics like a mirror.

  The method of forming such a surface is not particularly limited, but a metal foil such as an aluminum foil, a bright film obtained by vapor deposition or sputtering of metal (metal sputtered film), a coating film in which metal stays are dispersed, or A reflective film in which they are attached to a resin film can be suitably used. In addition, a paint using an aluminum pigment can be used as one that exhibits the same effect.

  However, the reflection characteristic is not limited to regular reflection, and incident energy can be reflected. For example, a scattering reflective surface can be formed on the light-shielding wall by applying a high-lightness paint containing a white pigment such as titanium dioxide or zinc oxide. Although the present invention does not prevent the use of such scattered reflection, considering that the retroreflective principle follows the same optical path as the incident light, the scattered reflection diffused by the optical path is a loss compared to regular reflection. Is big. Therefore, in order to obtain the maximum effect of the invention, it is preferable that the light reflective surface 55 has regular reflection characteristics as described above.

  The forward tilt angle of the light shielding wall 42 from the vertical direction is preferably in the range of 5 ° to 30 °.

  This is because a higher effect can be exhibited by appropriately adjusting the design parameters of the light shielding wall 42 in consideration of the position where the retroreflective skin material is installed, the position of the occupant viewpoint 10 and the incident direction of solar radiation. In other words, it is possible to design so as to widen the effective reflection angle within a range that does not impair the non-reflective characteristics with respect to the sight line direction of the occupant.

  More specifically, referring to FIG. 5 (B), by providing the light shielding wall 42 to be tilted forward from the vertical direction toward the vehicle exterior side, the effective reflection angle is further increased forward (outward direction of the vehicle) by the enlarged portion d due to the forward tilt angle. ). Thereby, the solar radiation from a wider solar position can be reflected, maintaining the non-reflective performance to the passenger | crew side. The forward tilt angle of the light shielding wall 42 varies depending on the type of vehicle and the like, but it is preferable that the forward tilt angle is set in the range of 5 to 30 °.

  The transparent layer 43 is preferably composed of a transparent film 43 having a light transmittance of 30% or more and 98% or less.

  Whereas the light transmittance of the conventional skin is completely 0%, if the light transmittance is as low as 20%, it is generally transparent visually, and the retroreflection according to the present invention. It can be said that the range of the skin material. However, considering this in terms of heat, if the light transmittance is less than 30%, most of the incident light becomes heat on the surface, and the retroreflection and heat insulation effects of the present invention are greatly reduced. Therefore, the light transmittance of the transparent layer 43 is preferably 30% or more. On the other hand, when the light transmittance exceeds 98%, there is no thermal problem. However, if the sheet thickness for obtaining practical strength and durability is secured, the resin absorbs 98% or more. It is difficult to get. Furthermore, when measures are taken to suppress the reflection of the outermost surface of the retroreflective skin material, which will be described later, it becomes difficult to substantially secure a transmittance of 98% or more.

The concept used as light transmittance or transmittance in the present invention is JIS R 310.
6 It is measured by the method described in the test method of solar radiation acquisition rate of transmittance, reflectance and emissivity of plate glass specified in 1998. This is a value calculated by multiplying the spectrally measured light transmittance by the weight coefficient given in Appendix Table 2 in the same JIS in the wavelength range of 300 nm to 2500 nm.

  The thickness of the heat insulating layers 2 and 3 is preferably in the range of 0.2 mm or more and 20 mm or less.

  The heat insulating layers 2 and 3 preferably have a thickness of 0.2 mm or more. When the thickness is less than 0.2 mm, the heat insulating layer is too thin, so the heat retention amount is small, causing heat transfer close to contact heat transfer, leading to an early rise in surface temperature. On the other hand, it is desirable that the upper limit of the thickness does not exceed 20 mm. Although it is better to have a thickness thermally, if it exceeds 20 mm, the degree of dimensional freedom of the component is hindered, and it becomes substantially difficult to use as a skin.

  The surfaces of the heat insulating layers 2 and 3 preferably have an antireflection function. More specifically, the surface of the transparent film 43 preferably has an antireflection function.

  If the outermost surface is too glossy, for example, the sun is at a low position and the light regularly reflected on the interior surface is strong, which may hinder the occupant's field of view. Therefore, it is preferable that the outermost surface of the light transmitting layer has an antireflection function. Since the direct reflection characteristics of the interior skin change depending on the interior shape and surface wrinkles, etc., it is not possible to generally define the performance only by the reflectivity. However, according to experience, in the 60 ° specular glossiness specified in the JIS Z 8741 glossiness measurement method It is often set at about 30% or less. Therefore, it is desirable to set in this range also in the retroreflective skin material of the present invention.

  In addition, in the same JIS, the reflectance defines the reflectance of the black plate glass surface having a predetermined refractive index as 100%. Therefore, when the reflectance of the transparent film is measured by the above method, the reflection on the back surface of the film is also simultaneously performed. From the measurement, the measured value may exceed 100%. Such an example is drawn in the examples described later, but it is not an erroneous measurement.

  There are several methods of antireflection treatment for imparting an antireflection function, but it is preferable to form a fine unevenness so-called “wrinkle” on the surface from the viewpoint of design and mass productivity. For the formation of the “shibo”, generally, the stamping by a known roll or the die transfer by slush molding is used. Of course, matte paint with silica fine powder dispersed on the outermost surface can also be applied, and transparent matte material such as silica fine powder is added to the resin of the light transmission layer to change the surface properties of the resin itself. It doesn't prevent it.

  The transparent layer 43 is preferably composed of at least one transparent film 43 selected from polyvinyl chloride resin, thermoplastic olefin (TPO) resin, or polyurethane resin.

  At the same time, the transparent film 43 requires strength, flexibility, weather resistance, and the like, which are necessary properties as a skin material. A resin having such characteristics and suitable for the present invention is a soft polyvinyl chloride resin. Polyvinyl chloride resin is also widely used in current automobile interior materials, and it can be said that it is a material that is industrially easy to use in terms of both characteristics and price. In addition, a thermoplastic olefin (TPO) resin that has recently begun to be used as an alternative to a soft polyvinyl chloride resin is also suitable for the same reason. Polyurethane resins are also excellent in flexibility and durability and are frequently used as automotive skin materials, and are suitable for use in the transparent layer of the present invention. However, the present invention does not prevent application of a resin having transparency other than those listed here, and can be used as appropriate alone or by copolymerization and mixing with the above-described resins.

  As shown in FIG. 6, any one of the retroreflective skin materials 1, 1 a, 1 b, 1 c, and 1 d described above is selected from the instrument panel 81, door trim 82, rear parcel shelf 83, pillar garnish 84, and steering wheel 85. It is preferable to use at least one kind as a vehicle interior material.

  Since the retroreflective skin material 1, 1a, 1b, 1c, 1d has a retroreflective function and a heat collecting function, when used as the skin of an automobile interior part, the temperature rise of the vehicle interior can be reduced. It is possible to provide a comfortable thermal environment by reducing the feeling of heat in summer.

  The interior parts for automobiles to which the present invention is preferably used include parts that are installed in a part that receives solar radiation and enters the sight of the occupant, that is, the above-described instrument panel 81, the upper part of the door trim 82, or pillars. 84, rear parcel shelf 83, and the like. In particular, the instrument panel 81 is one of the target parts for which the present invention is most effectively used because it is the part that has the highest temperature and the largest area in the room.

  In addition, it cannot be overemphasized that the retroreflective skin material which concerns on this invention is not limited when applied to a vehicle interior material. For example, it can be applied to furniture, home interiors, and the like because of the effect of reflecting solar radiation and suppressing heat dissipation.

  EXAMPLES Hereinafter, although an Example and a comparative example are demonstrated for this invention, this invention is not limited to these Examples.

(Retroreflective sheet)
As the retroreflective sheet constituting the retroreflective layer 5, a product name: Scotchlite capsule lens type reflective sheet manufactured by Sumitomo 3M Limited was used.

( Reference Example 1)
A transparent vinyl chloride resin sheet having a thickness of 1.2 mm was used as a material for the heat insulating layer. A test grain roll was used as the mold, and a groove was repeatedly processed on the grain roll with a pitch of 1.0 mm, a groove depth of 0.75 mm, and a groove width of 0.55 mm in the lateral direction of the roll. And the unevenness | corrugation was formed in one surface of the said transparent resin sheet by pressurizing and thermally transferring the said transparent resin sheet with a heat roll. The resulting smooth surface of the transparent resin sheet was used as the upper surface, and the uneven surface was laminated and adhered to the retroreflective sheet to obtain a heat-collecting retroreflective skin material having a space as shown in FIG. This skin material, 5.0 mmt urethane foam sheet, and 1.2 mmt 30% talc-containing polypropylene plate were sequentially laminated with a room temperature dry rubber adhesive to form a laminate to simulate an automobile interior. A test piece was obtained.

( Reference Example 2)
Using a transparent vinyl chloride resin sheet having a thickness of 1.2 mm as the material of the heat insulating layer, irregularities were formed on one surface of the transparent resin sheet in the same manner as in Reference Example 1. Further, using a stamping roll, a matte black urethane paint was applied to the convex surface formed on the transparent resin sheet to obtain an absorbent surface. The resulting smooth surface of the transparent resin sheet was used as the upper surface, and the uneven surface was laminated and adhered to the retroreflective sheet to obtain a heat-collecting retroreflective skin material having a space as shown in FIG. The skin material was laminated in the same manner as in Reference Example 1 to obtain a laminate, and a test piece simulating an automobile interior was obtained.

( Reference Example 3)
Using a transparent vinyl chloride resin sheet having a thickness of 1.2 mm as the material of the heat insulating layer, irregularities were formed on one surface of the transparent resin sheet in the same manner as in Reference Example 1. Furthermore, using a stamping roll, a urethane paint in which aluminum flakes were dispersed at a high concentration on a urethane resin excellent in flexibility was applied to the convex surface formed on the transparent resin sheet to obtain a reflective surface. With the smooth surface of the obtained transparent resin sheet as the upper surface, the uneven surface was laminated and adhered to the retroreflective sheet, and a heat-collecting retroreflective skin material having a space as shown in FIG. 1 was obtained. The skin material was laminated in the same manner as in Reference Example 1 to form a laminate, and a test piece simulating an automobile interior was obtained.

(Example 1 )
After forming a reflective surface by depositing aluminum on the surface of a transparent vinyl chloride resin sheet with a thickness of 1.2 mm, a matte black urethane paint is applied to form an absorptive surface, and a light shielding layer is formed on the transparent resin sheet A resin sheet was prepared. A test grain roll was used as a mold, and this grain roll was subjected to surface processing with a sawtooth pitch of 1.0 mm, a sawtooth height of 0.97 mm, and a sawtooth inclination angle of 75 degrees. Then, the transparent resin sheet is pressed and thermally transferred with a heat roll, whereby a light shielding wall (a reflective surface and an absorptive surface) is formed on one side of the substantially triangular sawtooth portion having a substantially triangular cross section formed continuously on the transparent resin sheet. An angle-selective transmission layer having a surface was obtained. At that time, the rotation speed of the roll was adjusted so that a shear stress was applied between the resin sheet and the mold, and the side forming the light shielding wall was specified. A transparent vinyl chloride resin sheet having a thickness of 0.1 mm was laminated and adhered to the upper surface of the obtained angle selective transmission layer. This was laminated and adhered on the retroreflective sheet to obtain a heat collecting retroreflective skin material having a space. The skin material was laminated in the same manner as in Reference Example 1 to obtain a laminate, and a test piece simulating an automobile interior was obtained.

(Comparative Example 1)
A soft vinyl chloride black, skinned instrument panel skin used in current vehicles was cut and used. Thereafter, a test piece was obtained by the same operation as in Reference Example 1.

(Comparative Example 2)
The retroreflective sheet used in the examples, manufactured by Sumitomo 3M Co., Ltd., trade name: Scotchlite capsule lens type reflective sheet, was cut and used. Thereafter, a test piece was obtained by the same operation as in Reference Example 1.

(Comparative Example 3)
An angle selective transmission layer was obtained by the same operation as in Example 1 . The difference from Example 1 is that only the angle-selective transmission layer is used, and a substantially triangular cross section formed continuously on the transparent resin sheet is laminated and adhered on the retroreflective sheet without laminating the transparent resin layer on the upper surface. A retroreflective skin material having no closed space on the side of the sawtooth portion was obtained. This skin material, a 5.0 mmt urethane foam sheet, and a 1.2 mmt 30% talc-containing polypropylene plate were sequentially laminated with a room temperature dry rubber adhesive to form a laminate to simulate an automobile interior. A test piece was obtained.

(Measurement and evaluation method)
(Performance evaluation)
About the obtained test piece, the artificial solar radiation test for evaluating the performance of surface temperature rise prevention, and the sensory evaluation for evaluating a visual field were performed.

In addition, in order to verify the effect in an actual vehicle, the vinyl chloride resin skin and the foamed urethane layer on the upper part of the instrument panel of the vehicle are actually removed in a size of 500 mm × 500 mm and obtained on Example 1 on the exposed substrate surface. The skin material was applied with a room temperature dry rubber adhesive and compared with the current part (Comparative Example 1) in an environmental test room.

(Artificial solar radiation test (20 ° incidence))
A heat collecting retroreflective skin material test piece 24 cut into a 300 mm square is installed in a heat insulating box 25 shown in FIG. 7, and an automotive green glass imitating a window glass 3.5 mmt (sunlight transmittance 60%, according to JIS R3106) ) 22 was installed at a distance of about 100 mm from the test piece 24 to simulate the temperature rise in the passenger compartment. With respect to the installation of the test piece 24, it was assumed that the summer solar radiation in the summer from the front of the instrument panel was assumed, and the test piece 24 was tilted by 20 degrees and the reflective surface of the light shielding wall was directed toward the light source.

A thermocouple 23 was installed on the surface of the test piece 24 so that the temperature change of the test piece 24 could be measured. The solar simulator (made by Celic Co., Ltd.) 21 consisting of four 500 W artificial solar lighting lamps was installed above the test piece 24 and the heat load was adjusted so that the irradiation energy on the glass surface was 767 W / m ² . The measurement was performed in a room adjusted to 25 ° C., 60 minutes after the start of light irradiation on the test piece 24, when the temperature rise on the surface of the test piece 24 reached almost equilibrium.

(Sensory evaluation of window reflection)
As shown in FIG. 8, an unmolded flat plate (500 mm × 500 mm) 22 made of green glass for automobile windows 3.5 mmt (60% solar transmittance, according to JIS R3106) is placed on a black lasha paper 27 at an angle of 30 ° from the horizontal. Installed, imitating the windshield of a car. Next, the white plate 28 is installed at a height of about 2 m assuming the sky outdoors, and a 500 W solar simulator (manufactured by Celic) 212 is irradiated to adjust the illuminance at the position of the test specimen to 6000 lux. . A test piece 24 was placed on the black lasha paper 27, and the degree of window reflection was visually evaluated. A level that is not inferior to that of the conventional example is shown as ◯, slightly reflected to a slight extent, a level that does not matter much is considered as △, and a case where white reflection clearly impairs the field of view is determined as X.

(Evaluation according to vehicle mounting condition)
The upper surface flat part of the instrument panel has a size of 300 mm × 300 mm, the skin and the urethane foam layer are peeled off, and the laminate of the angle-selective reflective skin and the urethane foam sheet prepared in Example 1 is cut into the same size and dried at room temperature. The rubber adhesive was used to adhere to the peeled portion of the instrument panel. The vehicle is installed in an environmental test room having an infrared lamp 213 and an air blower / air conditioner as shown in FIG. 9, the environment is set under the following conditions, soaked for 60 minutes, and then an instrument panel with a thermocouple. The surface temperature of was measured.

  As a comparison, the temperature of the unpeeled portion of the vehicle instrument panel, that is, the current skin portion, was simultaneously measured (Comparative Example 1).

The set environmental conditions are
Solar radiation intensity: 767 W / m ²
Temperature: 35 ° C
Humidity: 70% RH
Wind speed: 0.8 m / sec
It is.

(Evaluation results)
FIG. 10 shows the evaluation results.

In the artificial solar radiation test in which the test piece 24 is set at 20 °, the surface temperature drop almost equal to that of the skin having only the angle selectivity function shown in Comparative Example 3 was confirmed in Reference Example 1 without angle selectivity. It was. In other Reference Examples 2, 3 and Example 1 , the temperature reduction allowance was large, and in particular, the effect allowance in Example 1 was not only retroreflective, but also the effect that the heat insulation function and the heat retention function were sufficiently exhibited.

In the window reflection sensory evaluation test, in Reference Examples 1 to 3 and Example 1, the window reflection was well suppressed and a good field of view was obtained.

In the actual vehicle evaluation, a temperature lowering effect of about 30 ° C. was obtained, similar to the result of the experiment using the test piece. From this, it became clear that the present invention is effective even in an actual vehicle.

  The present invention can be applied to a use for improving a temperature rise in a vehicle interior.

It is sectional drawing which shows the retroreflection skin material which concerns on 1st Embodiment. It is sectional drawing which shows the retroreflection skin material which concerns on 2nd Embodiment. FIG. 3A is a diagram showing solar retroreflected light and an empty windowed light path generated when a retroreflective layer is installed on an instrument panel. FIG. 3B is a diagram for explaining prevention of window reflection when a heat insulating layer laminated on the retroreflective layer has a property of transmitting or reflecting light with angle selectivity. FIG. 4A is a cross-sectional view showing a retroreflective skin material in which a light-reflecting surface is formed on one side and a light-absorbing surface is formed on the other side of both sides of the light shielding wall. FIG. 4B is a diagram showing a direct line of sight and a windowed line of sight in the retroreflective skin material shown in FIG. FIG. 5A is a diagram showing an enlargement of the reflection angle when the light-reflecting surface is a light-reflecting surface of the light-shielding wall of the angle-selective transmissive material forming the heat-insulating layer, and FIG. It is a figure which shows the expansion of the reflection angle when the surface which faces the vehicle exterior in the light shielding wall of the angle selective transmission material which makes a layer is made into a light reflective surface, and the light shielding wall is inclined forward. It is a figure where it uses for description of the position which applies the reflective skin material which concerns on this invention to the interior material for vehicles. It is a schematic block diagram which shows the artificial solar radiation test apparatus. It is a schematic block diagram which shows the test apparatus of window reflection sensory evaluation. It is a schematic block diagram which shows the test apparatus which performs vehicle mounting state evaluation. It is a graph which shows an evaluation result.

Explanation of symbols

1, 1a, 1b, 1c, 1d retroreflective skin material,
2, 3 heat insulation layer,
5 retroreflective layer,
20 Windshield,
41 Spatial layer,
42 Spacer, shading wall,
43 Transparent layer, transparent film,
54 light absorbing surfaces,
55 light reflective surface,
81 instrument panel,
82 Door trim,
83 Rear parcel shelf,
84 Pillar Garnish,
85 Steering wheel.

Claims (9)

A retroreflective skin material used in an indoor space having a window glass,
A retroreflective layer that retroreflects light;
A heat insulating layer laminated on the retroreflective layer and transmitting light,
The heat insulating layer has a heat insulating function and a heat holding function ,
The heat insulating layer forms a spatial layer between the plurality of light shielding walls disposed on the retroreflective layer and the retroreflective layer through the light shielding walls spaced from each other. Transparent layer that is transparent, and laminated
The heat shielding layer is provided with the property of transmitting or reflecting incident light and light reflected by the retroreflective layer with angle selectivity by the light shielding wall,
A retroreflective skin having a light-reflective surface on one side and a light-absorbing surface on the other side of the light-shielding wall, the light-reflecting surface facing the window glass Wood. The retroreflective skin material according to claim 1, wherein the light-absorbing surface of the light-shielding wall is colored 5.0 or less in Munsell brightness . The light-reflecting surface of the light-shielding wall comprises at least one selected from a metal vapor-deposited film, a metal sputtered film, a metal foil, a coating film in which the metal foil is dispersed, or a reflective film in which they are attached to a resin film, The retroreflective skin material according to claim 1, which has regular reflection characteristics . The retroreflective skin material according to any one of claims 1 to 3, wherein a forward tilt angle of the light shielding wall from a vertical direction is in a range of 5 ° to 30 ° . The retroreflective skin material according to claim 1, wherein the transparent layer is composed of a transparent film having a light transmittance of 30% or more and 98% or less . The thickness of the said heat insulation layer exists in the range of 0.2 mm or more and 20 mm or less, The retroreflection skin material of Claim 1 characterized by the above-mentioned . The surface of the said heat insulation layer has an antireflection function, The retroreflection skin material of Claim 1 characterized by the above-mentioned . The retroreflective skin material according to claim 1, wherein the transparent layer is composed of at least one transparent film selected from a polyvinyl chloride resin, a thermoplastic olefin (TPO) resin, or a polyurethane resin . The vehicle interior material which uses the retroreflective skin material as described in any one of Claims 1-8 for at least 1 type chosen from an instrument panel, a door trim, a rear parcel shelf, a pillar garnish, and a steering wheel .

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