JP2011170295A - Light reflection plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the saturation of reflected light relatively by enhancing light in other wavelength regions by suppressing light in a specific wavelength region in a visible light region, And the light reflector which can change the hue of the object illuminated by them is provided.
In the light reflecting plate A of the present invention, a light absorbing layer 2 containing a light absorbing agent that absorbs light in the visible light region is laminated and integrated on one surface of a first light reflecting layer 1. A second light reflecting layer 3 containing a synthetic resin and a light reflecting filler is laminated and integrated on one surface of the light absorbing layer 2.
[Selection] Figure 1

Description

  The present invention is a light reflecting plate containing a light absorber and a light reflective filler, and is lit by a lighting or display device by suppressing reflected light in a specific wavelength region in the visible light region. The present invention relates to a light reflecting plate that can change the hue of an object and express a hue that cannot be expressed by a conventional white and silver reflecting plate.

  Currently, in the display field such as TV and monitor, in the lighting field such as ceiling light, downlight, security light, emergency light and insect light, in the electric signboard field such as advertising light, etc., from the light source such as fluorescent lamp and cold cathode tube In order to effectively use the light, a highly reflective light reflecting plate is used behind the light source. This reflector is silver or white and reflects in the visible light region without changing the spectrum of light emitted from the light source.

  In recent years, in the display field, in order to produce a hue that could not be expressed only by CCFL (cold cathode tube), by using CCFL and LED (light emitting diode) that emits light of a specific wavelength, Attempts have been made to change the hue of the display.

  In addition, there has been proposed illumination using light of some wavelengths, such as an artificial light used for a crime prevention light and an insect light. Each method uses a special light source that emits light in a specific wavelength region, and thus has a problem that the cost is high. There is a demand for technology that changes

  In illumination using light in some wavelength regions, it is necessary to suppress light outside the required wavelength region. For example, a security light that uses blue light uses the fact that blue light has a sedative effect that calms emotions by acting on human parasympathetic nerves. If there is too much light other than blue light, The sedative effect may be reduced.

  In addition, when a cold beverage is placed on the product display shelf, it is possible to give the beverage a cool feeling by visually recognizing the cold beverage in a state close to a blue hue. When there is too much, there exists a possibility that the cool feeling of a drink may reduce.

  Conversely, when a warm beverage is placed on the product line shelf, it is possible to give a warm impression to the beverage by making the warm beverage visually close to a red hue, but other than red light If too much light is present, the warm impression of the beverage may be reduced.

  In Patent Document 1, (A) an ultraviolet absorbing layer composed of a film having a visible light transmittance of 70% or more, an ultraviolet transmittance of 0 to 30%, and a film thickness of 5 to 150 μm, and (B) a film thickness thereof. There is proposed a fluorescent colored layer having a fluorescent coloring layer of 50 to 200 μm and (C) a reflection layer having a concealment ratio of 70% or more and a thickness of 5 to 50 μm.

  Patent Document 2 proposes a white film for a surface light source reflector, in which a coating layer containing a substance having ultraviolet absorbing ability and a fluorescent brightening agent is provided on at least one side of a white film containing bubbles. Has been.

  However, both the fluorescent sheet and the white film for the surface light source reflector are intended only to increase the whiteness and the reflectance with the fluorescent agent, and suppress the light reflectance in a part of the wavelength region of the visible light region. , Because the light reflectance in other wavelength regions cannot be relatively increased and the saturation of reflected light is poor, the hue of the illumination or display device and the object illuminated by them, or The saturation of the reflected light could not be increased, and the reflected light could not be used for the above applications.

JP-A-4-345835 JP 2002-40214 A

  The present invention suppresses light in a specific wavelength region in the visible light region, thereby relatively enhancing the light in other wavelength regions and increasing the saturation of reflected light, and lighting and display devices, and The light reflector can change the hue of the object illuminated by the light and can express the hue that cannot be expressed by the conventional white and silver reflectors.

  In the light reflecting plate A of the present invention, a light absorbing layer 2 containing a light absorbing agent that absorbs light in the visible light region is laminated and integrated on one surface of the first light reflecting layer 1, and the light absorbing layer The second light reflecting layer 3 containing a synthetic resin and a light reflective filler is laminated and integrated on one surface of the sheet 2.

  As said 1st light reflection layer 1, what is necessary is just to be able to reflect the light of the visible region which permeate | transmitted the light absorption layer 2 to the light absorption layer 2 side. The total light reflectance of the first light reflecting layer 1 is preferably 80% or more, and more preferably 85% or more. In addition, the light beam total reflectance of the 1st light reflection layer 1 says the value measured based on JISZ8722.

  As such a 1st light reflection layer 1, a synthetic resin sheet is preferable and a thermoplastic resin sheet is more preferable. Examples of the first light reflection layer 1 include a light reflective non-foamed sheet or foamed sheet containing particles such as titanium oxide and silica, and a sheet made of a mixed resin obtained by mixing mutually incompatible synthetic resins. A non-foamed sheet formed by stretching a plurality of voids, a non-foamed sheet formed by stretching a sheet containing a filler to form a large number of voids, and a light-reflective foamed sheet containing a large amount of fine bubbles And those that can be thermoformed are preferred. In addition, the 1st light reflection layer 1 may select the said non-foamed sheet or a foamed sheet | seat suitably, and may be what laminated | stacked and integrated multiple layers. Further, a foam layer or a non-foam layer may be laminated and integrated on the other surface of the first light reflection layer 1 for the purpose of improving the rigidity and moldability of the light reflection plate.

  As shown in FIG. 2, the first light reflection layer 1 is configured such that the non-foamed sheet 1a and the foamed sheet 1b are laminated and integrated, and the non-foamed sheet 1a is on the light absorption layer side. It is preferable because the first light reflecting layer can be provided with strength, self-shaping property or moldability.

  Further, when the first light reflecting layer 1 is configured such that the non-foamed sheet 1a and the foamed sheet 1b are laminated and integrated, and the non-foamed sheet 1a is on the light absorbing layer side, the first light In order to improve the light reflectivity of the reflective layer 1, the foamed sheet preferably contains titanium oxide.

  If the content of titanium oxide in the foamed sheet 1b is small, the effect of improving the light reflectivity may not be manifested, and if it is large, the lightness of the light reflecting plate may be reduced. 5 to 50 parts by weight is preferable with respect to 100 parts by weight of the synthetic resin being used, and 10 to 40 parts by weight is more preferable.

  The synthetic resin constituting the first light reflecting layer 1 is not particularly limited, and examples thereof include polyolefin resins such as low density polyethylene, high density polyethylene, ethylene-α-olefin copolymer, polypropylene, and cyclic polyolefin. Polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polylactic acid, polyamide resins such as nylon-6 and nylon-6,6, polystyrene resins such as polystyrene, ABS resin, AS resin, polycarbonate, polyester Examples thereof include polycarbonate resins such as carbonate, chlorine resins such as polyvinyl chloride and polyvinylidene chloride, and thermoplastic resins such as acrylic resins such as polymethyl methacrylate and polyethyl methacrylate. In addition, a synthetic resin may be used independently or 2 or more types may be used together. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene and the like.

  Examples of the particles contained in the light-reflective non-foamed sheet or foamed sheet include zinc oxide, zinc white, talc, calcium carbonate, titanium oxide, and the like. High titanium oxide is preferred.

  Titanium oxide includes rutile type, anatase type, and brucite type, but rutile type titanium oxide is preferable. Since titanium oxide usually degrades the resin by its photocatalytic action, it is preferable to subject the titanium oxide to a surface treatment.

When the content of titanium oxide in the synthetic resin sheet is small, the light reflecting performance of the light reflecting plate is lowered. On the other hand, when the content is large, the light weight of the light reflecting plate is also lowered. -200 g / m < ² > is preferable and 40-150 g / m < ² > is more preferable. In addition, when there are a plurality of synthetic resin sheets containing titanium oxide in the first light reflecting layer 1, the content of titanium oxide in the synthetic resin sheet means that the plurality of synthetic resin sheets The total content of titanium oxide contained.

  Next, the light absorption layer 2 laminated and integrated on the first light reflection layer 1 will be described. The light absorption layer 2 contains a light absorber that absorbs light in the visible light region in a synthetic resin.

  As described above, the light absorbing layer 2 contains a light absorbing agent that absorbs light in the visible light region, so that in the visible light region, light in a wavelength region different from the wavelength region absorbed by the light absorbing agent can be relative. It enhances the saturation of the reflected light and enhances the saturation of the reflected light, can express hues that could not be expressed by conventional light reflectors, and is suitable for applications that emphasize hue such as display devices and lighting Can be used.

  Since the synthetic resin constituting the light absorbing layer 2 is the same as the synthetic resin constituting the first light reflecting layer 1, description thereof is omitted. The synthetic resin constituting the light absorbing layer 2 and the synthetic resin constituting the first light reflecting layer 1 may be different.

  The light absorber constituting the light absorption layer 2 only needs to be able to absorb light in the visible light region (wavelength region of 360 to 740 nm), and can absorb light in the wavelength region of 400 to 740 nm. It is preferable that light can be absorbed in a wavelength region of 450 to 740 nm.

The light absorber is not particularly limited and includes, for example, indigo, quinacridone, alizarin, PB ₃ O ₄ , Fe ₂ O ₃ , and others, red lead, yellow lead, zinc yellow, ultramarine blue, prussian Inorganic pigments such as blue, xanthene, coumarin, perylene, naphthalimide, acridine, thioflavine, diaminostilbene, imidazole, thiazole, oxazole, pyrazoline, anthraquinone, methine, benzopyran In addition, a pigment or dye having a thioindigo, azo, or phthalocyanine pigment structure that does not emit light may be used. In addition, the said light absorber may be used independently or 2 or more types may be used together.

  As the light absorber, trade names “Lionol Red498”, “Linogen violet 6140”, “Cosmos Blue 2712” and “Lionol Green 8930” from Toyo Ink Co., Ltd. and trade names “OPLAS RED330” and “OPLAS VIOLET 730” from Orient Chemical Industries, Ltd. , “OPLAS GREEN530” and “OPLAS YELLOW136”.

  If the total amount of the light absorbing agent in the light absorbing layer 2 is small, the absorption of light in a specific wavelength region in the visible light region is lowered, and the light in other wavelength regions is relatively emphasized or the saturation of reflected light. In some cases, the amount is preferably 0.01 parts by weight or more with respect to 100 parts by weight of the synthetic resin, and at most, there is often no change in the effect of containing the light absorber. 65 parts by weight or less is preferable with respect to 100 parts by weight, and 30 parts by weight or less is more preferable.

  Further, a second light reflecting layer 3 is laminated and integrated on one surface of the light absorbing layer 2, and the second light reflecting layer 3 contains a synthetic resin and a light reflecting filler, specifically, A light-reflective filler is contained in the synthetic resin.

  Further, the second light reflection layer 3 absorbs light as much as possible in the light absorber in the light absorption layer 2 and relatively emphasizes light in a wavelength region different from the wavelength region absorbed by the light absorber, and Reflection reflected at the interface between the synthetic resin constituting the second light reflecting layer 3 and the light reflective filler contained in the second light reflecting layer 3 in order to increase the saturation of the reflected light. The light wavelength region preferably overlaps with the light absorption wavelength region in the light absorbent contained in the light absorption layer 2.

  The wavelength region of reflected light reflected at the interface between the synthetic resin constituting the second light reflecting layer 3 and the light reflecting filler, and the light absorption wavelength region in the light absorbent contained in the light absorbing layer 2 By selecting the light-reflective filler so as to overlap with each other, the light incident on the light absorption layer 2 is transmitted through the light absorption layer 2 without being absorbed by the light absorber, and the first light reflection layer 1 The light that has been reflected to the light absorption layer 2 side but is not absorbed by the light absorber but transmitted through the light absorption layer 2 is reflected again by the second light reflection layer 3 toward the light absorption layer 2. By making the light absorbing layer 2 incident on the light absorbing layer 2, the light absorbing agent in the light absorbing layer 2 absorbs light efficiently, and light in a wavelength region different from the wavelength region absorbed by the light absorbing agent is relatively more It can enhance and enhance the saturation of reflected light, and change the hue of reflected light by the light reflector more reliably Door can be.

  The synthetic resin constituting the second light reflecting layer 3 is not particularly limited. For example, polyolefin resin such as low density polyethylene, high density polyethylene, ethylene-α-olefin copolymer, polypropylene, cyclic polyolefin, Polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polylactic acid, polyamide resins such as nylon-6 and nylon-6,6, polystyrene resins such as polystyrene, ABS resin, AS resin, polycarbonate, polyester Examples thereof include polycarbonate resins such as carbonate, chlorine resins such as polyvinyl chloride and polyvinylidene chloride, and thermoplastic resins such as acrylic resins such as polymethyl methacrylate and polyethyl methacrylate. In addition, a synthetic resin may be used independently or 2 or more types may be used together. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene and the like.

  The light reflective filler is not particularly limited as long as it has light reflectivity, and examples thereof include synthetic resin particles and pigments having light reflectivity. Pigments are preferred, white pigments Is more preferable.

  The synthetic resin constituting the synthetic resin particles is not particularly limited as long as it is a synthetic resin having a refractive index different from that of the synthetic resin constituting the second light reflecting layer 3. Polyolefin resins such as density polyethylene, high density polyethylene, polypropylene, and cyclic polyolefin, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polylactic acid, and polyamide resins such as nylon-6 and nylon-6,6 And thermoplastic resins such as polystyrene resins such as polystyrene, ABS resin and AS resin, chlorine resins such as polyvinyl chloride and polyvinylidene chloride, and acrylic resins such as polymethyl methacrylate and polyethyl methacrylate. In addition, a synthetic resin may be used independently or 2 or more types may be used together.

  The pigment is not particularly limited as long as it has a refractive index different from the refractive index of the synthetic resin constituting the second light reflecting layer 3. For example, white pigment such as zinc white, lead white, titanium oxide, etc. Inorganic pigments such as pigments, red lead, yellow lead, zinc yellow, ultramarine blue, prussian blue, xanthene, coumarin, perylene, naphthalimide, acridine, thioflavine, diaminostilbene, imidazole, thiazole Organic pigments having an oxazole-based, pyrazoline-based, anthraquinone-based, methine-based, benzopyran-based, thioindigo-based, azo-based, or phthalocyanine-based hue structure, and the like, and white pigments are preferred.

  The white pigment is not particularly limited. For example, magnesium sulfate, magnesium carbonate, alumina, lead oxide, barium carbonate, barium sulfate, potassium titanate, zinc oxide, zinc white, lead white, talc, calcium carbonate, titanium oxide. Since the refractive index is high and the difference from the refractive index of the synthetic resin constituting the second light reflecting layer 3 is large, titanium oxide is preferable.

  Further, if the difference between the refractive index of the light reflective filler and the refractive index of the synthetic resin constituting the second light reflective layer is small, the light reflective filler and the second light reflective layer are configured. The light reflectivity at the interface with the synthetic resin may decrease, so 0.05 or more is preferable, and 0.10 or more is more preferable.

  If the content of the light reflective filler in the second light reflecting layer is small, the amount of light absorbed by the light absorber is small, and if it is large, the amount of light incident on the light absorbing layer may be too small. Therefore, 0.05-5 weight part is preferable with respect to 100 weight part of synthetic resins which comprise the 2nd light reflection layer 3, and 0.1-4 weight part is more preferable.

  In the reflection spectrum of the light reflector in the wavelength region of 450 to 740 nm, if the difference Δ between the maximum light reflectance and the minimum light reflectance is small, the light in the desired wavelength region in the visible light region is sufficiently enhanced or reflected light. 35% or more is preferable because it may not be possible to increase the saturation.

  In the reflection spectrum of the light reflection plate in the wavelength region of 450 to 740 nm, it is preferable that the maximum light reflectance is 90% or more and the minimum light reflectance is 55% or less. If the maximum light reflectance is less than 90% or the minimum light reflectance exceeds 55%, the light in the desired wavelength region in the visible light region cannot be sufficiently enhanced or the saturation of the reflected light cannot be increased. Because there is.

  The light reflectance of the light reflecting plate is measured as follows. First, the light reflectance of the light reflector is based on JIS Z8722, and using a spectrocolorimeter, a wavelength region of 450 to 740 nm under the condition that the room temperature of the measurement atmosphere is 20 ° C. and the relative humidity of the measurement atmosphere is 60%. Measure at every 10 nm. And in the obtained light reflectivity, the maximum light reflectivity and the minimum light reflectivity can be calculated | required in the 450-740 nm wavelength range.

  The first light reflecting layer 1, the light absorbing layer 2, and the second light reflecting layer 3 are stable in the range not impairing their physical properties, such as a light stabilizer, an ultraviolet absorber, an antioxidant, and a metal deactivator. Additives such as an agent, an antistatic agent and a flame retardant may be added.

  Examples of the light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis (N-methyl-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, Bis (1,2,2,6,6-pentamethyl-4-piperidinyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate, tetrakis (2, 2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butane-tetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2 , 3,4-Butane-tetracarboxylate, (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butane-tetracarboxylate and (2,2,6,6) -Tetramethyl-4- Lidecyl) -1,2,3,4-butane-tetracarboxylate, (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butane-tetracarboxylate And a mixture of (1,2,2,6,6-pentamethyl-4-tridecyl) -1,2,3,4-butane-tetracarboxylate, {2,2,6,6-tetramethyl-4 -Piperidyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethyl} -1,2,3,4-butane-tetracarboxylate and {2,2,6 6-tetramethyl-β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethyl} -1,2,3 A mixture with 4, -butane-tetracarboxylate, { 1,2,2,6,6-pentamethyl-4-piperidyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethyl} 1,2,3,4-butane Tetracarboxylate and {1,2,2,6,6-pentamethyl-β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5 , 5) Undecane] diethyl} 1,2,3,4-butane-tetracarboxylate mixture, poly [6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine -2,4-diyl], [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino], 4 -Hydroxy-2,2,6,6-tetramethyl-1-pipe A mixture of ginethanol and dimethyl succinate polymer, N, N ′, N ″, N ′ ″-tetrakis {4,6-bis [butyl- (N-methyl-2,2,6,6-tetra Methylpiperidyl-4-yl) amino] -triazin-2-yl} -4,7-diazadecane-1,10-diamine and the like, and may be used alone or in combination of two or more.

  If the content of the light stabilizer in the first light reflecting layer 1, the light absorbing layer 2 or the second light reflecting layer 3 is small, the resin deterioration of the light reflecting plate cannot be suppressed. There is no change in the effect of suppressing the resin deterioration of the plate, and the first light reflecting layer 1, the light absorbing layer 2 or the second light has a negative effect such as reducing the light reflectivity of the light reflecting plate by coloring the light stabilizer itself. 0.01-0.8 weight part is preferable with respect to 100 weight part of synthetic resins which comprise the reflection layer 3, and 0.05-0.5 weight part is more preferable.

  Examples of the ultraviolet absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzyl) phenyl]. -Benzotriazole, 2- (2'-hydroxy-3 ', 5-di-t-butylphenyl) -benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl)- 5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-) t-amyl) benzotriazole, 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyrate) Benzo-6- (2N-benzotriazol-2-yl) phenol], 2,4-dihydroxy-benzophenone, 2-hydroxy-4-methoxy-benzophenone, 2-hydroxy-4- Methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octyl-benzophenone, 2-hydroxy-4-n-dodecyloxy-benzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2 , 2'-dihydroxy-4-methoxy-benzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone and other benzophenone UV absorbers, salicylate phenyl, salicylate such as 4-t-butylphenyl salicylate UV absorber, ethyl-2-si Cyanoacrylate-based ultraviolet absorbers such as NO-3,3-diphenyl-acrylate and 2-ethylhexyl-2-cyano-3,3′-diphenyl-acrylate, 2-ethoxy-3-tert-butyl-2′-ethyl- Oxanilic acid anilide UV absorbers such as oxalic acid bisanilide, 2-ethoxy-2'-ethyl-oxalic acid bisanilide, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4 -Benzoate ultraviolet absorbers such as hydroxybenzoate, 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5-hydroxyphenol, 2- (2 , 4-Dihydroxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (2-hydro) Examples include triazine-based ultraviolet absorbers such as cis-4-butoxyphenyl) -6- (2,4-dibutoxyphenyl) -1,3,5-triazine, and two or more of them may be used alone or in combination. May be.

  If the content of the ultraviolet absorber in the first light reflection layer 1, the light absorption layer 2 or the second light reflection layer 3 is small, it is impossible to suppress the light reflectivity of the light reflection plate. Since there is no change in the effect of suppressing the decrease in light reflectivity of the light reflecting plate, 100 parts by weight of the synthetic resin constituting the first light reflecting layer 1, the light absorbing layer 2 or the second light reflecting layer 3 is used. 0.01-0.8 weight part is preferable and 0.05-0.5 weight part is more preferable.

  Furthermore, a foam layer may be laminated and integrated on the other surface of the first light reflecting layer of the light reflecting plate in order to give the light reflecting plate strength, self-holding property or moldability. Since the synthetic resin constituting the foam layer is the same as the synthetic resin constituting the first light reflecting layer, description thereof is omitted.

  Next, the manufacturing method of the light reflecting plate of this invention is demonstrated. It does not specifically limit as a manufacturing method of a light reflection board. The present invention is a light reflecting plate including a first reflecting layer, a light absorbing layer, and a second reflecting layer, and (1) a manufacturing method in which the first reflecting layer, the light absorbing layer, and the second reflecting layer are manufactured by coextrusion. (2) The thermoplastic resin film constituting the light absorbing layer is laminated and integrated on the light reflecting plate constituting the first light reflecting layer, and the second light reflecting layer is formed on the thermoplastic resin film. (3) A light absorption layer is formed on a light reflecting plate having a light reflecting property constituting a first light reflecting layer. It can be manufactured by applying a coating containing a light absorber, drying, and further by a manufacturing method in which a light reflecting plate having light reflectivity constituting the second light reflecting layer is laminated and integrated on the light absorbing layer. Since the thickness of each layer can be easily controlled and the productivity is high, the coextrusion of (1) above can be used. It is preferable to produce. For example, the thermoplastic resin composition for the first light reflecting layer containing the thermoplastic resin and the particles is supplied to the first extruder and melt-kneaded, and the heat for the light absorbing layer containing the thermoplastic resin and the light absorber. The thermoplastic resin composition is supplied to the second extruder and melt-kneaded, and the thermoplastic resin composition for the second light reflecting layer containing the thermoplastic resin and the light reflecting filler is supplied to the third extruder and melted. A thermoplastic resin composition for the first light-reflecting layer, a thermoplastic resin composition for the light-absorbing layer, and a thermoplastic resin composition for the second light-reflecting layer on the same die kneaded and connected to the first to third extruders A light-absorbing layer made of the thermoplastic resin composition for the light-absorbing layer is laminated and integrated on one surface of the first light-reflecting layer made of the thermoplastic resin composition for the first light-reflecting layer. And a thermoplastic resin group for the second light reflecting layer on one surface of the light absorbing layer. A method of the second light reflecting layer made of the object to produce a light reflection plate which is integrally laminated and the like. In addition, when forming a 1st light reflection layer from a foam, a foaming agent should be press-fit into a 1st extruder, and the thermoplastic resin composition for 1st light reflection layers should just be made foamable.

  A method for producing a light reflecting plate in which the first light reflecting layer is formed by laminating and integrating a non-foamed sheet and a foamed sheet will be described. As a method for producing the light reflecting plate, a general-purpose method is used. For example, the thermoplastic resin composition for the first light reflecting layer containing the thermoplastic resin and the particles is supplied to the first extruder and melt kneaded. The thermoplastic resin composition for the light absorption layer containing the thermoplastic resin and the light absorber is supplied to the second extruder and melt-kneaded, and the second light reflection containing the thermoplastic resin and the light reflective filler. The thermoplastic resin composition for the layer is supplied to a third extruder, melt-kneaded, and a thermoplastic resin composition containing an additive such as a thermoplastic resin and a rutile-type titanium oxide contained as necessary is extruded into a fourth. Supply to the machine, melt and knead, press the foaming agent into the fourth extruder, melt and knead to form a foamable thermoplastic resin composition, and extrude to the merged die connected to the first to fourth extruder, Thermoplastic resin composition for two-light reflection layer, thermoplastic for light absorption layer The laminate is formed by laminating the oil composition, the thermoplastic resin composition for the first light reflecting layer, and the foamable thermoplastic resin composition in this order, and this laminate is extruded and foamed from a die attached to the tip of the merging die. One surface of the first light-reflecting layer in which a non-foamed sheet composed of the thermoplastic resin composition for the first light-reflecting layer is laminated and integrated on one surface of the foamed sheet obtained by foaming the foamable thermoplastic resin composition The light absorption layer made of the thermoplastic resin composition for the light absorption layer is laminated and integrated, and the second light reflection layer made of the thermoplastic resin composition for the second light reflection layer is laminated and integrated on one surface of the light absorption layer. A light reflector can be manufactured. When the non-foamed sheet of the first light reflecting layer is formed from the foamed sheet, the first light reflecting layer thermoplastic resin composition may be made foamable by pressing a foaming agent into the first extruder. In this case, when the first light reflecting layer is composed of a single foam sheet, the fourth extruder may not be connected to the joining die. The die is not particularly limited as long as it is widely used in extrusion foaming, and examples thereof include a T die and an annular die.

  In the above manufacturing method, when a T-die is used as the die, the light reflecting plate having the above-described configuration can be manufactured by extrusion foaming into a sheet form from an extruder.

  When an annular die is used as the die, a cylindrical body is produced by extrusion foaming from the annular die into a cylindrical shape, and the cylindrical body is gradually expanded in diameter and then supplied to a cooling mandrel for cooling. After that, the light reflector having the above-described configuration can be manufactured by cutting the cylindrical body continuously between the inner and outer peripheral surfaces in the direction of extrusion, and opening and developing the cylindrical body.

  The blowing agent is not particularly limited, and is an organic gas such as saturated aliphatic hydrocarbons such as propane, butane and pentane, and halogenated hydrocarbons such as tetrafluoroethane, chlorodifluoroethane and difluoroethane; carbon dioxide and nitrogen gas. Gaseous inorganic compounds such as water; liquid inorganic compounds such as water; mixtures of organic acids or salts thereof with bicarbonate, such as a mixture of sodium bicarbonate and citric acid, dinitrosopentamethylenetetramine, etc. Solid foaming agents and the like are mentioned, and it is preferable to use a mixture of an organic acid or a salt thereof and bicarbonate and an organic gas, and a mixture of sodium bicarbonate and citric acid and an organic gas are preferably used. It is more preferable to use together.

  The light reflection plate thus obtained contains a light absorber that absorbs light in the visible light region in the light absorption layer 2, and absorbs visible light incident on the light absorption layer 2 of the light reflection plate. The agent absorbs, relatively enhances visible light having a wavelength region other than the absorbed visible light, and increases the saturation of reflected light.

  Further, the second light reflecting layer 3 is laminated and integrated on one surface of the light absorbing layer 2, that is, the light incident surface side of the light reflecting plate, and the second light reflecting layer 3 contains a light reflecting filler. The amount of light incident on the light absorption layer 2 is limited.

  And the wavelength region of the reflected light reflected at the interface between the synthetic resin constituting the second light reflecting layer and the light reflecting filler contained in the second light reflecting layer is the light absorbing layer. In the case where it overlaps with the light absorption wavelength region in the contained light absorber, it is incident on the light absorption layer, but is not absorbed by the light absorber and reflected by the first light reflection layer, and further the light absorption Light that is not absorbed by the light absorber of the layer but is emitted again from the light absorption layer is reflected again by the second light reflection layer toward the light absorption layer, and is incident on the light absorption layer. By absorbing the light in the light absorber, it is possible to exert an effect of relatively enhancing visible light having a wavelength region other than the absorbed visible light and increasing the saturation of reflected light.

  In addition, incident light that has passed through the light absorption layer 2 without being absorbed by the light absorber is reflected by the first light reflection layer 1 toward the light absorption layer 2, and passes through the light absorption layer 2 again. It can be absorbed by a light absorber. Therefore, the light absorber of the light absorption layer 2 can absorb more light.

  Therefore, according to the light reflecting plate A of the present invention, the reflected light of the specific wavelength region in the visible light region is emphasized by the light absorbing action of the light absorbing agent in the light absorbing layer 2, and the hue of the reflected light from the light reflecting plate is increased. Is reliably changed and the saturation is high, it can be suitably used for applications in which hue is important, such as a display device or illumination.

  Since the light reflector of the present invention has the above-described configuration, the reflected light absorbs light in a part of the wavelength region of the visible light region, so that the reflected light absorbs light in the visible light region. Since the light in the wavelength region other than the wavelength region absorbed by the agent is relatively emphasized and the saturation is enhanced, the hue of the illumination or display device and the object illuminated by them is changed, The hue can not be expressed by the silver reflector, and can be suitably used in applications where the hue is important, such as a display device or illumination.

It is the longitudinal cross-sectional view which showed the light reflection board of this invention. It is the longitudinal cross-sectional view which showed another example of the light reflection board of this invention. 5 is a graph showing reflection spectra of light reflecting plates of Examples 1 and 2 and Comparative Example 1. FIG.

Example 1
Master batch (trade name “PPM 1KB662 WHT FD”, manufactured by Toyo Ink Co., Ltd.), ethylene-propylene block copolymer containing 100 parts by weight of polypropylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd.) and ethylene-propylene block copolymer Propylene block copolymer: Rutile-type titanium oxide = 30 wt%: 70 wt%) A thermoplastic resin composition for the first light reflection layer containing 100 parts by weight is supplied to the first extruder, melt-kneaded, and polypropylene ( Master batch (trade name “G09-052”, manufactured by Dainichi Seika Co., Ltd., 90% by weight) containing 100 parts by weight of an azo-based red pigment as a light absorber and trade name “PL500A” manufactured by Sun Allomer Co., Ltd. A thermoplastic resin composition for a light absorbing layer containing 2 parts by weight is supplied to a second extruder, melt-kneaded, and Second light reflection containing 100 parts by weight of propylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd., refractive index: 1.48) and 1 part by weight of rutile titanium oxide (refractive index: 2.71) as a light reflective filler. The thermoplastic resin composition for the first light-reflective layer is supplied to the same junction die connected to the first to third extruders by supplying the thermoplastic resin composition for the layers to the third extruder and melt-kneaded. The thermoplastic resin composition for the first light-reflecting layer is supplied by co-extrusion from the T die that is supplied with the thermoplastic resin composition for the layer and the thermoplastic resin composition for the second light-reflecting layer and is connected to the joining die. A light absorption layer made of a thermoplastic resin composition for a light absorption layer is laminated and integrated on one surface of the first light reflection layer, and a thermoplastic resin composition for the second light reflection layer is formed on one surface of the light absorption layer. Light in which the second light reflecting layer made of is laminated and integrated A reflector was manufactured.

The light reflecting plate has an overall thickness of 0.25 mm, a density of 1.3 g / cm ³ , a first light reflecting layer thickness of 0.15 mm, a light absorbing layer thickness of 0.05 mm, The thickness of the two-light reflecting layer was 0.05 mm.

  The azo red pigment had an absorption region at 400 to 600 nm. In the 2nd light reflection layer 3, the reflection wavelength range of the reflected light reflected in the interface of a polypropylene and a rutile type titanium oxide was 380-780 nm.

(Example 2)
A light reflecting plate was produced in the same manner as in Example 1 except that the amount of rutile-type titanium oxide in the thermoplastic resin composition for the second reflective layer was changed to 4 parts by weight instead of 1 part by weight.

(Example 3)
25 parts by weight of polypropylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd.), 75 parts by weight of polypropylene (trade name “FB3312” manufactured by Nippon Polypro Co., Ltd.), a masterbatch containing rutile titanium oxide in an ethylene-propylene block copolymer (Trade name “PPM 1KB662 WHT FD” manufactured by Toyo Ink Co., Ltd .: ethylene-propylene block copolymer: rutile titanium oxide = 30 wt%: 70 wt%) 25 parts by weight and a mixture of sodium bicarbonate and citric acid as a blowing agent A foamable thermoplastic resin composition containing 1.4 parts by weight is supplied to a first extruder and melt-kneaded, and 100 parts by weight of polypropylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd.) and an azo red pigment as a light absorber. Containing 10% by weight (trade name “G09-0” manufactured by Dainichi Seika Co., Ltd. 2 ”, homopolypropylene: 90% by weight) 2 parts by weight of thermoplastic resin composition for light absorption layer is supplied to a second extruder and melt-kneaded to obtain polypropylene (trade name“ PL500A ”manufactured by Sun Allomer Co., Ltd., refractive index) : 1.48) A thermoplastic resin composition for the second light reflecting layer containing 100 parts by weight and 1 part by weight of rutile type titanium oxide (refractive index: 2.71) as a light reflecting filler is supplied to the third extruder. Then, the mixture is melt-kneaded and extruded into a converging die connected with the first to third extruders, the second light-reflecting layer thermoplastic resin composition, the light-absorbing layer thermoplastic resin composition, and the foamable thermoplastic resin. A cylindrical laminate is formed by laminating the composition from the outside to the inside in this order, and this cylindrical laminate is extruded and foamed from an annular die attached to the tip of a converging die to produce a cylindrical body. Gradually expand the cylindrical body After supplying and cooling to the cooling mandrel above, the cylindrical body is continuously cut in the extrusion direction across the inner and outer peripheral surfaces, opened, and expanded to expand the foamable thermoplastic resin composition. A light absorption layer made of a thermoplastic resin composition for a light absorption layer is laminated and integrated on one surface of the first light reflection layer, and a first light reflection layer made of a thermoplastic resin composition for a second light reflection layer is formed on one surface of the light absorption layer. A light reflecting plate in which two light reflecting layers were laminated and integrated was manufactured.

The light reflecting plate has an overall thickness of 0.6 mm, a density of 0.6 g / cm ³ , a thickness of the first light reflecting layer of 0.5 mm, a thickness of the light absorbing layer of 0.05 mm, The thickness of the two-light reflecting layer was 0.05 mm.

  The azo red pigment had an absorption region at 400 to 600 nm. In the 2nd light reflection layer 3, the reflection wavelength range of the reflected light reflected in the interface of a polypropylene and a rutile type titanium oxide was 380-780 nm.

Example 4
A light reflecting plate was produced in the same manner as in Example 3 except that the amount of rutile-type titanium oxide in the thermoplastic resin composition for the second reflective layer was changed to 4 parts by weight instead of 1 part by weight.

(Example 5)
Master batch (trade name “PPM 1KB662 WHT FD”, manufactured by Toyo Ink Co., Ltd.), ethylene-propylene block copolymer containing 100 parts by weight of polypropylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd.) and ethylene-propylene block copolymer Propylene block copolymer: Titanium oxide = 30% by weight: 70% by weight) 100 parts by weight of the thermoplastic resin composition for the first light reflecting layer is supplied to the first extruder and melt-kneaded to obtain polypropylene (sun allomer). (Product name “PL500A”) 100 parts by weight and a masterbatch containing 10% by weight of an azo red pigment as a light absorber (trade name “G09-052” manufactured by Dainichi Seika Co., Ltd., homopolypropylene: 90% by weight) 2 The thermoplastic resin composition for the light absorbing layer containing parts by weight is supplied to the second extruder, melt-kneaded, and Second light reflecting layer containing 100 parts by weight of Lopylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd., refractive index: 1.48) and 1 part by weight of rutile titanium oxide (refractive index: 2.71) as a light reflective filler. The thermoplastic resin composition for use is supplied to a third extruder and melt-kneaded, and 50 parts by weight of polypropylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd.), 50 parts by weight of polypropylene (trade name “FB3312” manufactured by Nippon Polypro Co., Ltd.) and A converging die in which a foamable thermoplastic resin composition containing 1 part by weight of a mixture of sodium bicarbonate and citric acid as a foaming agent is supplied to a fourth extruder and melt-kneaded, and the first to fourth extruders are connected. The thermoplastic resin composition for the second light reflecting layer, the thermoplastic resin composition for the light absorbing layer, the thermoplastic resin composition for the first light reflecting layer, and the foamable thermoplastic resin composition are extruded in this order. A cylindrical laminated body is formed by laminating from the outside to the inside, and this cylindrical laminated body is extruded and foamed from an annular die attached to the tip of the converging die to produce a cylindrical body. After being expanded and supplied to a cooling mandrel for cooling, the cylindrical body is continuously cut in the extruding direction between the inner and outer peripheral surfaces, cut open, and developed, thereby being used as a thermoplastic for the first light reflecting layer. A light absorption layer made of a thermoplastic resin composition for a light absorption layer is laminated and integrated on one surface of a first light reflection layer made of a resin composition, and a thermoplastic resin composition for a second light reflection layer is integrated on one surface of the light absorption layer A light obtained by laminating and integrating a second light reflecting layer made of a product and a foam layer formed by foaming a foamable thermoplastic resin composition on the other surface of the first light reflecting layer. A reflector was manufactured.

The light reflecting plate has an overall thickness of 0.65 mm, a density of 0.7 g / cm ³ , a first light reflecting layer thickness of 0.15 mm, a light absorbing layer thickness of 0.05 mm, The thickness of the two-light reflecting layer was 0.05 mm, and the thickness of the foam layer was 0.4 mm.

  The azo red pigment had an absorption region at 400 to 600 nm. In the 2nd light reflection layer 3, the reflection wavelength range of the reflected light reflected in the interface of a polypropylene and a rutile type titanium oxide was 380-780 nm.

(Example 6)
A light reflecting plate was produced in the same manner as in Example 5 except that the amount of rutile-type titanium oxide in the thermoplastic resin composition for the second reflective layer was changed to 4 parts by weight instead of 1 part by weight.

(Example 7)
Master batch (trade name “PPM 1KB662 WHT FD”, manufactured by Toyo Ink Co., Ltd.), ethylene-propylene block copolymer containing 100 parts by weight of polypropylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd.) and ethylene-propylene block copolymer Propylene block copolymer: Titanium oxide = 30% by weight: 70% by weight) 100 parts by weight of the thermoplastic resin composition for the first light reflecting layer is supplied to the first extruder and melt-kneaded to obtain polypropylene (sun allomer). (Product name “PL500A”) 100 parts by weight and a masterbatch containing 10% by weight of an azo red pigment as a light absorber (trade name “G09-052” manufactured by Dainichi Seika Co., Ltd., homopolypropylene: 90% by weight) 2 The thermoplastic resin composition for the light absorbing layer containing parts by weight is supplied to the second extruder, melt-kneaded, and Second light reflecting layer containing 100 parts by weight of Lopylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd., refractive index: 1.48) and 1 part by weight of rutile titanium oxide (refractive index: 2.71) as a light reflective filler. The thermoplastic resin composition for use is supplied to a third extruder and melt-kneaded, 25 parts by weight of polypropylene (trade name “PL500A” manufactured by Sun Allomer Co., Ltd.), 75 parts by weight of polypropylene (trade name “FB3312” manufactured by Nippon Polypro Co., Ltd.), Master batch containing rutile titanium oxide in an ethylene-propylene block copolymer (trade name “PPM 1KB662 WHT FD” manufactured by Toyo Ink Co., Ltd.) ethylene-propylene block copolymer: rutile titanium oxide = 30 wt%: 70 Foam containing 25 parts by weight) and 1.4 parts by weight of a mixture of sodium bicarbonate and citric acid as a blowing agent The thermoplastic resin composition is supplied to the fourth extruder, melted and kneaded, and extruded to a converging die connected to the first to fourth extruders. The thermoplastic resin composition for the second light reflecting layer, light absorption A layered thermoplastic resin composition, a first light-reflecting layer thermoplastic resin composition and a foamable thermoplastic resin composition are laminated in this order from the outside to the inside. The laminated body is extruded and foamed from an annular die attached to the tip of the converging die to produce a cylindrical body, and this cylindrical body is gradually expanded and then supplied to a cooling mandrel for cooling. The thermoplastic resin composition for the first light reflecting layer is formed on one surface of the foamed sheet obtained by foaming the foamable thermoplastic resin composition by continuously cutting in the extruding direction between the inner and outer peripheral surfaces, and opening and developing. Non-foamed sheets made of material are laminated and integrated A light absorption layer made of a thermoplastic resin composition for a light absorption layer is laminated and integrated on one surface of the first light reflection layer, and a thermoplastic resin composition for a second light reflection layer is formed on one surface of the light absorption layer. A light reflecting plate in which the second light reflecting layer made of the above was laminated and integrated was manufactured.

The light reflecting plate has a total thickness of 0.75 mm, a density of 0.7 g / cm ³ , a non-foamed sheet constituting the first light reflecting layer has a thickness of 0.15 mm, and a foamed sheet Was 0.5 mm, the thickness of the light absorption layer was 0.05 mm, and the thickness of the second light reflection layer was 0.05 mm.

  The azo red pigment had an absorption region at 400 to 600 nm. In the 2nd light reflection layer 3, the reflection wavelength range of the reflected light reflected in the interface of a polypropylene and a rutile type titanium oxide was 380-780 nm.

(Example 8)
A light reflecting plate was produced in the same manner as in Example 7 except that the amount of rutile-type titanium oxide in the thermoplastic resin composition for the second reflective layer was changed to 4 parts by weight instead of 1 part by weight.

(Comparative Example 1)
A light reflecting plate was obtained in the same manner as in Example 1 except that the third extruder was not connected to the joining die and the second light reflecting layer was not formed.

(Comparative Example 2)
A light reflecting plate was obtained in the same manner as in Example 3 except that the third extruder was not connected to the joining die and the second light reflecting layer was not formed.

(Comparative Example 3)
A light reflecting plate was obtained in the same manner as in Example 5 except that the third extruder was not connected to the converging die and the second light reflecting layer was not formed.

(Comparative Example 4)
A light reflecting plate was obtained in the same manner as in Example 7 except that the third extruder was not connected to the joining die and the second light reflecting layer was not formed.

  About the obtained light reflecting plate, the maximum light reflectance and the minimum light reflectance in the reflection spectrum in the wavelength region of 450 to 740 nm are measured as follows, and the difference Δ between the maximum light reflectance and the minimum light reflectance is obtained. The results are shown in Table 1 and FIG. In addition, the reflection spectrum of Examples 1-3 and the comparative example 1 was shown in FIG. Table 1 shows the total content of titanium oxide in the first light reflecting layer.

(Light reflectance)
A spectrocolorimeter (trade name “CM-2600d” manufactured by Konica Minolta Co., Ltd.) is used for the measurement of the light reflectance of the light reflector, and the measurement atmosphere is 20 ° C. according to JIS Z8722, relative to the measurement atmosphere. Under the condition where the humidity is 60%, the light reflectance of the light reflecting plate was measured every 10 nm in the wavelength region of 450 to 740 nm.

  In the obtained light reflectivity, the maximum light reflectivity and the minimum light reflectivity were obtained in a wavelength region of 450 to 740 nm, and a difference Δ between the maximum light reflectivity and the minimum light reflectivity was calculated.

1 First light reflecting layer
1a Non-foamed sheet
1b Foam sheet 2 Light absorption layer 3 Second light reflection layer A Light reflection plate

Claims (8)

A light-absorbing layer containing a light absorbing agent that absorbs light in the visible light region is laminated and integrated on one surface of the first light-reflecting layer, and a synthetic resin and a light-reflective filling are disposed on one surface of the light-absorbing layer. A light reflecting plate, wherein a second light reflecting layer containing a material is laminated and integrated. The wavelength region of the reflected light reflected at the interface between the synthetic resin constituting the second light reflecting layer and the light reflective filler contained in the second light reflecting layer is contained in the light absorbing layer. The light reflecting plate according to claim 1, wherein the light reflecting plate overlaps with a light absorption wavelength region in the light absorbent. 3. The light according to claim 1, wherein a difference Δ between the maximum light reflectance and the minimum light reflectance in a wavelength region of 450 to 740 nm is 35% or more in the reflection spectrum of the light reflection plate. a reflector. 4. The reflection spectrum of the light reflection plate, wherein the maximum light reflectance in a wavelength region of 450 to 740 nm is 90% or more and the minimum light reflectance is 55% or less. Item 1. A light reflector according to item 1. 5. The difference between the refractive index of the synthetic resin constituting the second light reflecting layer and the refractive index of the light reflective filler is 0.05 or more. Item 1. A light reflector according to item 1. The light reflecting filler is contained in an amount of 0.05 to 5 parts by weight with respect to 100 parts by weight of the synthetic resin in the second light reflecting layer, according to any one of claims 1 to 5. The light reflecting plate as described. The light reflection plate according to any one of claims 1 to 6, wherein the first light reflection layer is formed of a foam. The light reflecting plate according to any one of claims 1 to 7, wherein a part of the first light reflecting layer is formed of a foam.

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