JP2019049684A - Reflector having a tray shape - Google Patents

Abstract

The present invention can provide a reflective plate having a tray shape excellent in shape retention, and is suitable for a direct type backlight unit having a small shape change even when exposed to a moist heat environment for a long time, an LED illumination unit, illumination for a plant factory, etc. Provided is a reflector having a tray shape. A reflector having a plurality of independent tray shapes with a depth of 1 mm or more and 20 mm or less, and a through hole at the bottom of the tray shape, heat treated under conditions of 40 ° C. and 95% RH for 500 hours The change rate of the distance between adjacent through holes before and after {(distance between through holes after treatment / distance between through holes before treatment) × 100} is more than 0% and not more than 5%. 【Selection chart】 None

Description

  The present invention relates to a reflector having a tray shape that is suitably used as a component member of a direct-type backlight unit, an LED lighting unit, illumination for a plant factory, and the like.

  In recent years, many displays using liquid crystal have been used as display devices such as personal computers, televisions, smartphones, tablets, and mobile phones. Since these liquid crystal displays themselves are not light emitters, display is possible by providing a surface light source called backlight from the back side and irradiating light. In addition, the backlight has a surface light source structure called edge light type or direct type, in order to meet the requirement that the entire screen should be uniformly irradiated as well as simply irradiated with light. Among them, edge light type, that is, a type of backlight that irradiates light from the side to the screen is applied to thin liquid crystal display applications used for notebook computers, monitors, tablets, etc. where thinness and miniaturization are desired. ing. On the other hand, in the case of a large screen such as a liquid crystal television, a direct type, that is, a type of backlight which emits light to the screen from the back side is applied.

  High light reflection performance is required for lamp reflectors and reflectors (hereinafter sometimes collectively referred to as reflective films, surface light source reflective members, etc.) used for surface light sources for such liquid crystal screens, and conventionally white pigments In addition, films in which fine bubbles are contained or films in which fine bubbles are contained therein are used alone or films obtained by laminating these films with metal plates, plastic plates, etc. have been used. In particular, films containing fine air bubbles inside are widely used because they have the effect of improving the luminance and the uniform effect of the screen luminance (Patent Documents 1 and 2).

  A large-screen TV with a direct backlight is equipped with a function called "local dimming". The liquid crystal backlight is finely divided, and by partially driving the backlight in accordance with the brightness of the displayed image, and adding brightness to each section, it is a technology capable of displaying a clearer image with higher contrast. As a technical problem of "local dimming", there is a problem that light leaks to the adjacent area when the difference between the light and dark of adjacent LEDs is large, and the effect is weakened. Moreover, in the direct type backlight, depending on the configuration, there may be a case where unevenness occurs in which only the portion where the LED is brightened.

  As a method to solve these problems, a light reflection plate (Patent Document 3) or the like having a concave light reflection surface can be used, but the foam sheet has a problem that voids are easily crushed when a load is applied during molding. .

JP 2003-160682 Japanese Examined Patent Publication 8-16175 JP 2012-022089 A

  An object of the present invention is to solve the above-mentioned problems and to provide a reflector suitable for components such as a direct type backlight unit, an LED lighting unit, and illumination for a plant factory.

The present inventors have the following configurations as a result of earnestly examining the subject.
(1) A reflecting plate having a plurality of independent tray shapes having a depth of 1 mm or more and 20 mm or less and having through holes in the bottom portion of the tray shape, before and after heat treatment under conditions of 40 ° C. 95% RH for 500 hours Reflective plate whose change rate of the distance between adjacent through holes in {{the distance between through holes after treatment / the distance between through holes before treatment) x 100} is more than 0% and not more than + 5%.
(2) The dimensional change rate of the depth of the tray shape before and after heat treatment at 40 ° C. and 95% RH for 500 hours {(the depth of the tray shape after the treatment / the depth of the tray shape before the treatment) × 100} The reflective plate as described in (1) which is more than 0% and + 5% or less.
(3) The reflective plate as described in (1) or (2) which has a polyester resin as a main component.
(4) The reflection according to (3), wherein the polyester resin contains 1 to 20 mol% of 2,2-dimethyl-1,3-propanediol (neopentyl glycol) and / or cyclohexane dimethylene glycol in a diol component. Board.
(5) The reflector according to (3) or (4), wherein the polyester resin is a copolyester resin, and the dicarboxylic acid component contains 1 to 20 mol% of isophthalic acid residue.
(6) The reflective plate in any one of (1)-(5) whose specific gravity is 0.5 or more and 1.1 or less.
(7) The reflecting plate in any one of (1)-(6) which is an at least 3 layer structure.
(8) A layer containing a thermoplastic resin A (a layer) containing a thermoplastic resin A and a layer containing a thermoplastic resin B having different properties from the thermoplastic resin A on the reflector according to any one of (1) to (7) An optical member in which a multilayer laminated film in which 101 layers or more of (B layer) are alternately laminated is disposed, and the A layer of the outermost layer is an A (1) layer, n + 30) An optical member in which 20 or more different n are present such that the thickness difference of the layer is 2% or more and less than 5%. However, n is a natural number.
(9) When the layer B adjacent to the outermost layer A is a layer B (1), the difference between the thickness of the layer B (k) and the layer B (k + 30) is 2% or more and less than 5%. The optical member according to (8), wherein 20 or more are present. However, k is a natural number.
(10) The optical member according to (9), wherein the average thickness of the B (k) layer is 10 to 300 nm.
(11) The reflecting plate in any one of (1)-(7) used for a LED lighting unit.
(12) The reflective board in any one of (1)-(7) used for a direct under type LED backlight unit.
The optical member in any one of (8)-(10) used for a LED lighting unit.
The optical member in any one of (8)-(10) used for a direct under type LED backlight unit.

  According to the present invention, it is possible to provide a reflective plate having a tray shape excellent in shape retention, and a tray suitable for a direct-type backlight unit, an LED lighting unit, etc. having a small shape change even when exposed to a wet heat environment for a long time. A reflector having a shape can be provided.

It is a conceptual diagram showing an example of the tray shape in this invention. It is a conceptual diagram showing an example whose tray shape is quadrangular frustum shape. It is a conceptual diagram showing an example whose tray shape is a hexagonal truncated pyramid shape. It is a conceptual diagram showing an example whose tray shape is hemispherical shape. It is a conceptual diagram showing an example whose tray shape is spherical crown shape. It is a conceptual diagram showing an example whose tray shape is cylindrical shape. It is a conceptual diagram showing an example whose tray shape is a square pole shape. It is a conceptual diagram showing an example whose tray shape is an elliptical shape. It is a conceptual diagram showing an example which is a square pole shape which R attached a tray shape. It is a conceptual diagram showing the tray shape of (A) in an Example and a reference example. It is a conceptual diagram showing the tray shape of (B) in an Example and a reference example. It is a conceptual diagram showing the tray shape of (C) in an example and a reference example. It is a conceptual diagram showing the tray shape of (D) in an Example and a reference example. It is a conceptual diagram showing the tray shape of (E) in an Example and a reference example. It is a conceptual diagram showing the tray shape of (F) in an Example and a reference example. It is a conceptual diagram showing the tray shape of (G) in an Example and a reference example. It is a conceptual diagram showing the tray shape of (H) in an Example and a reference example. It is a conceptual diagram showing the tray shape of (I) in an Example and a reference example. It is a conceptual diagram showing the tray shape of (J) in an Example and a reference example.

  As a result of intensive studies on such problems, the present inventors have found that it is important for the reflector to expand due to heat deformation of the reflector, and have reached the present invention. For example, in the case of applying a reflector provided with a shape in order to improve the contrast ratio of the direct-type backlight unit and eliminate unevenness, the shape is optically optimized by fine calculation. The reflector is exposed to the heat from the electrical circuit and the LED after being incorporated into the direct type backlight unit. At that time, when the reflection plate contracts, it is difficult to fix in order to maintain the shape. On the other hand, if it is expansion | swelling, since a deformation | transformation can be suppressed with the housing | casing of a backlight unit, it is easy to hold | maintain shape.

  According to the present inventors' intensive studies, the reflector plate has a plurality of independent tray shapes with a depth of 1 mm or more and 20 mm or less, and has through holes in the bottom portion of the tray shape. The rate of change of the distance between adjacent through holes before and after heat treatment for 500 hours under the condition of% RH {(distance between through holes after treatment / distance between through holes before treatment) × 100} from 0 to + 5% I found that it was important.

[Film composition]
The reflector of the present invention has a plurality of independent tray shapes. By arranging the LEDs on the bottom of each tray shape and controlling them independently, it is possible to increase the contrast with the LEDs arranged on the bottom of another tray. Here, the tray shape is a shape including a bottom portion and an edge connected thereto, and refers to a shape in which the height of the edge is higher than that of the bottom portion. An example of the tray shape in the present invention is shown in FIG. The plurality of trays may have the same shape or different shapes, but preferably have the same shape. Preferably, each tray shape is independent of the adjacent tray shape by the edge. Here, "independent" refers to a shape in which the bottom portion is set separately. Therefore, for example, when a part is connected like a dumbbell shape, it can not be said that they are independent. In this case, they are handled collectively as one tray shape.

  Further, the bottom portion refers to the shape of a portion lower than the edge, and refers to a shape in which four sides are surrounded by an edge higher than the bottom portion. In addition, the detail about the measuring method of the area of a bottom face part is mentioned later.

  Here, the shape in which the edge is higher than the bottom portion means that the bottom portion is recessed from the film or sheet, based on the film or sheet constituting the reflector of the present invention, The edge surrounding the bottom is higher than the bottom. The shape of the bottom of the tray is not particularly limited as long as it is a concave shape lower than the edge, and the bottom has a shape having a bottom parallel to the film or sheet (for example, a frustum shape). It may be a shape that does not have a bottom parallel to the film or sheet (for example, a reverse cylindrical shape or a hemispherical shape). However, in consideration of arranging the LEDs on the bottom of the tray shape, the bottom is more preferably in a shape having a bottom parallel to the film or sheet.

  Further, the shape of the edge surrounding the bottom portion is not limited as long as it is higher than the bottom portion, but it is more preferable that the heights of the edges be equal. That is, a shape in which the height of the edge is uniform is more preferable than a shape in which a specific portion of the edge is higher or lower than the other edges, because the effect of local dimming is more easily exhibited.

  The depth of the tray shape is 1 mm or more and 20 mm or less. When the depth of the tray shape is less than 1 mm, light may leak to the adjacent tray shape. In addition, when the depth of the tray shape exceeds 20 mm, the thickness of a television using the reflector of the present invention may be increased. The depth of the tray shape is more preferably 2 mm or more and 15 mm or less, still more preferably 2.5 mm or more and 12 mm or less, and particularly preferably 3 mm or more and 10 mm or less. The depth of the tray shape is the inner depth and is obtained from the vertical distance between the bottom and the edge.

  Although the shape of the tray is not particularly limited, it has a frustum shape (FIGS. 2 and 3), a hemispherical shape (FIG. 4), a spherical crown (FIG. 5), a columnar shape (FIGS. 6 and 7), a combination thereof, and an intermediate shape The shape may be distorted to have an oval shape (FIG. 8), or may have a rounded shape with rounded corners (FIG. 9). Among them, a quadrangular frustum shape (FIG. 2) and a hexagonal frustum shape (FIG. 3) are preferable because they are easy to fill the screen with the same shape and easily reflect light to the screen side.

  The size of the tray shape in the horizontal direction is preferably such that the independent tray shape fits in 10 mm to 100 mm square. If the size is smaller than 10 mm, the number of required LEDs may be excessive. If it is larger than 100 mm square, the area of the partially driven backlight may become large. The tray shape having a depth of 1 mm or more and 20 mm or less can be obtained by, for example, forming a film or sheet used as a reflector.

  The forming method is not particularly limited, but methods such as vacuum forming, pressure forming, vacuum pressure forming, press forming, a method of forming only a film such as plug assisted vacuum pressure forming, insert molding, three dimension overlay method (TOM) It can be molded by a generally known molding method such as a molding method with a base material such as original laminate molding. Among them, a molding method in which the mold is not in contact with the reflective surface, such as vacuum molding, pressure forming, or vacuum pressure forming, is more preferable. When the mold contacts the reflecting surface, the surface roughness of the reflecting plate may not be sufficiently controlled. In the present invention, a film having a thickness of 400 μm or less is referred to as a “film”, and a film thicker than 400 μm is referred to as a “sheet”. The reflector of the present invention may be either a film or a sheet.

  In the reflector of the present invention, it is preferable that the ratio of the bottom portion to the horizontal projected area of the smallest square or rectangle surrounding one independent tray shape is 30% or more. More preferably, it is 35% or more, more preferably 40% or more. If the angle is less than 30%, the angle of the side portion is shallow, the ridge portion formed by the adjacent tray shapes tends to be thick, and when a reflector having a plurality of tray shapes is incorporated into the backlight, the space between the two tray shapes is It may be dark. The upper limit is not particularly limited, but is preferably 70% or less. If the proportion of the bottom surface portion exceeds 70%, the side surface portions become close to perpendicular to the bottom surface portion, and it may be easy to create a place where a large load is applied to the reflecting plate due to the shape. The minimum square or rectangular horizontal projected area surrounding one independent tray shape is the apparent area when the square or rectangle is observed from directly above. The horizontal projected area of the smallest square or rectangle surrounding one independent tray shape can be rephrased as the area of the tray shape when it is regarded as horizontal without considering the unevenness of the molded product.

  The reflector of the present invention has through holes for arranging the LEDs on the bottom of the tray shape. The size and shape of the holes are not particularly limited as long as the size and shape of the holes do not adversely affect the arrangement of the LEDs, but if the size is too large, the reflection performance may be deteriorated. It is preferable that the hole has a size that fits in the bottom portion. Specifically, it is preferable that the size and shape be larger than 1 mm square and fit in 30 mm square. If the size is smaller than 1 mm square, it may not be possible to secure a sufficient size for arranging the LED. The number of through holes may be one or more in one tray shape, or may be in the middle portion or the side portion of a plurality of tray shapes. Although the method to form a through-hole is not specifically limited, For example, after shape | molding by said method, a through-hole can be formed by stamping.

  In the reflective plate of the present invention, the change rate of the distance between through holes before and after heat treatment for 500 hours under the condition of 40 ° C. and 95% RH {(distance between through holes after treatment / distance between through holes before treatment) × 100} is more than 0% and not more than + 5%. More preferably, it is more than 0% and not more than + 3%, more preferably more than 0% and not more than + 2%, and most preferably more than 0% and not more than + 1%. Here, that the rate of change is a positive value means that the distance between the through holes is expanded (that is, expanded) after the heat treatment compared to before the heat treatment. Further, the fact that the rate of change is zero means that the distance between the through holes does not change after the heat treatment as compared to before the heat treatment, and the fact that the rate of change is a negative value is compared to that before the heat treatment It means that after heat treatment, the distance between the through holes is narrowed (ie, contracted).

  When the change rate of the distance between the through holes is larger than + 5%, the deformation may not be suppressed even in the case of the backlight unit. Moreover, when the change rate of the distance between the through holes is 0% or less, it may be difficult to fix the reflection plate so as not to be deformed. It is preferable to shape | mold the white film manufactured by the manufacturing method mentioned later as said method as a preferable method for the change rate of the distance of through holes to make it over 0% and to make it 5% or less. The rate of change of the distance between the through holes is determined from the shortest distance from the edge of the through hole to the edge of the closest through hole of another independent tray shape in one independent tray shape.

  In the reflective plate of the present invention, the dimensional change of the depth of the tray shape before and after heat treatment for 500 hours under the condition of 40 ° C. and 95% RH {(the depth of the tray shape after processing / the depth of the tray shape before processing) It is preferable that x100} is more than 0% and not more than 5%. More preferably, it is more than 0% and not more than + 3%, still more preferably more than 0% and not more than + 2%. The dimensional change rate of the depth of the tray shape is the dimensional change rate of the inner dimension of the tray shape before and after heat treatment is performed under the conditions of 40 ° C. and 95% RH for 500 hours. Hereinafter, the depth of the inner shape of the tray shape may be simply referred to as the depth of the tray shape. Here, that the rate of change is a positive value means that the inner dimension in the depth direction is expanded (that is, expanded) after the heat treatment compared to before the heat treatment. Further, the fact that the rate of change is zero means that there is no change in the internal dimension in the depth direction after heat treatment compared to before heat treatment, and that the rate of change is a negative value By comparison, it means that the inner dimension in the depth direction becomes narrow (ie, shrinks) after heat treatment.

  When the dimensional change rate of the depth of the tray shape is larger than + 5%, the deformation may not be suppressed even in the case of the backlight unit. When the dimensional change rate of the depth of the tray shape is 0% or less, it may be difficult to fix the reflection plate so as not to be deformed. As a preferable method for setting the dimensional change rate of the depth of the tray shape to more than 0% and + 5% or less, it is preferable to form a white film manufactured by the manufacturing method described later by the above method.

  In the reflector of the present invention, the main component is preferably a polyester resin. If the polyester resin is at least 50% by mass or more in the resin constituting the reflection plate, it can be said to be the main component. If the polyester content is less than 50% by mass, heat resistance and productivity may be reduced.

  Preferred embodiments of the polyester resin are described below. The polyester resin refers to a polymer having an ester bond in the main chain, but the polyester resin used in the present invention is preferably a polyester resin having a structure in which a dicarboxylic acid and a diol are condensation-polymerized. As the dicarboxylic acid component, for example, as aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodium sulfone Aromatic dicarboxylic acids such as dicarboxylic acids, oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acids, aliphatic dicarboxylic acids such as maleic acid and fumaric acid, and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid And each component such as oxycarboxylic acid such as parahydroxybenzoic acid. Moreover, as a dicarboxylic acid ester derivative component, an esterified product of the above dicarboxylic acid compound, such as dimethyl terephthalate, diethyl terephthalate, 2-hydroxyethyl methyl terephthalate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl isophthalate, adipic acid Each component such as dimethyl, diethyl maleate and dimethyl dimer acid can be mentioned. Further, as the diol component, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6 Aliphatic dihydroxy compounds such as hexanediol and 2,2-dimethyl-1,3-propanediol (neopentyl glycol), polyoxyalkylene glycols such as diethylene glycol, polyethylene glycol, polypropylene glycol and polytetramethylene glycol, 1,4 -Each component is mentioned, such as alicyclic dihydroxy compounds, such as cyclohexane dimethanol and spiro glycol, and aromatic dihydroxy compounds, such as bisphenol A and bisphenol S. Each of these may be used alone or in combination of two or more. A copolyester resin may be used as the polyester resin used in the present invention. The copolymerized polyester is preferably copolymerized with two or more selected from the dicarboxylic acid components of the above polyester resin and / or two or more selected from among the listed diol components. As a method of introducing the copolymerization component, the copolymerization component may be added at the time of polymerization of the polyester pellet which is the raw material, and it may be used as a pellet in which the copolymerization component is polymerized in advance. Alternatively, a mixture of independently polymerized pellets and polyethylene terephthalate pellets may be supplied to an extruder and copolymerized by transesterification reaction at the time of melting. In addition, it may be copolymerized with a small amount of trimellitic acid, pyromellitic acid and an ester derivative thereof as long as the film formability is not affected as a film.

  In addition, the polyester resin may contain 5% by mass or less of a resin compatible with the polyester resin other than the polyester resin, as long as the object of the present invention is not impaired.

  In the reflector of the present invention, the polyester is a copolyester, and the diol component contains 1 to 20 mol% of 2,2-dimethyl-1,3-propanediol (neopentyl glycol) and / or cyclohexane dimethylene glycol. Is preferred. More preferably, it is 2-15 mol%, More preferably, it is 3-12 mol%. The inclusion of 1 mol% or more of 2,2-dimethyl-1,3-propanediol and / or cyclohexanedimethylene glycol in the diol component is preferable because the effects of stabilizing the formability and the shape can be obtained. If it is less than 1 mol%, the effect may not be obtained sufficiently. Moreover, when it is more than 20 mol%, heat resistance may fall.

  In the reflector of the present invention, it is preferable that the polyester is a copolyester, and the dicarboxylic acid component contains 1 to 20 mol% of isophthalic acid residue. More preferably, it is 2-15 mol%, More preferably, it is 3-12 mol%. It is preferable that the polyester is a copolyester, and by containing 1 mol% or more of isophthalic acid residue in the dicarboxylic acid component, the effect of stabilizing the formability and the shape can be obtained. If it is less than 1 mol%, the effect may not be obtained sufficiently. Moreover, when it is more than 20 mol%, heat resistance may fall.

  The reflective plate of the present invention preferably has a surface roughness Ra of less than 100 nm. It is more preferably less than 80 nm and even more preferably less than 50 nm. Setting the surface roughness Ra to less than 100 nm is preferable because light is easily specularly reflected. When the surface roughness Ra is 100 nm or more, the optical design may be affected. The method for setting the surface roughness Ra to the above range is not particularly limited, but it is possible by, for example, setting it as a reflecting plate having a three-layer structure as described later and adjusting the particle size and the compounding amount of particles added to the surface layer. .

  The reflective plate of the present invention preferably has a specific gravity of 0.5 or more and 1.1 or less. More preferably, it is 0.6 or more and 1.05 or less, and still more preferably, 0.7 or more and 1.0 or less. If the specific gravity is less than 0.5, the strength of the tray shape may be insufficient. If the specific gravity is greater than 1.1, it may be difficult to sufficiently increase the reflectance of the reflector.

  There is no particular limitation on the specific gravity in such a range, but a method of containing air bubbles in the inside of the reflection plate is preferably used. As a method of containing air bubbles inside, (1) a method of making a thermoplastic resin (C) contain a foaming agent, foaming by foaming or chemical decomposition by heating at the time of film formation or film formation to form air bubbles, (2) Method of adding gas or vaporizable substance at the time of extrusion of thermoplastic resin (C), (3) Thermoplastic resin (D) incompatible with inorganic particles and / or the resin in thermoplastic resin (C) In the present invention, film forming properties, ease of adjustment of the amount of air bubbles contained inside, and production are mentioned in the present invention. It is preferable to use the above method (3) in terms of the cost and the like.

  The inorganic particles in the above method (3) include silica, colloidal silica, calcium carbonate, aluminum silicate, calcium phosphate, alumina, magnesium carbonate, zinc carbonate, titanium oxide, zinc oxide (zinc oxide), antimony oxide, cerium oxide, Inorganic materials such as zirconium oxide, tin oxide, lanthanum oxide, magnesium oxide, barium carbonate, basic lead carbonate (lead white), barium sulfate, calcium sulfate, lead sulfate, zinc sulfide, mica, mica titanium, talc, clay, kaolin, etc. Particles are included. Further, they can be used alone or in combination of two or more types, and among them, barium sulfate particles, titanium dioxide particles and calcium carbonate are particularly preferable because film formation stability can be obtained with high optical characteristics.

  When air bubbles are contained by the inorganic particles, the inorganic particles are preferably contained in an amount of 1 to 50% by mass in the total mass of the reflector of the present invention. When the inorganic particles are less than 1% by mass, it is difficult to make the specific gravity 1.1 or less, and when it is more than 50% by mass, the mechanical strength, heat resistance and manufacturing cost of the thermoplastic resin (C) decrease. There is. More preferably, it is 3-40 mass%, More preferably, it is 5-30 mass%.

  When adding a thermoplastic resin (D) incompatible with the thermoplastic resin (C) and uniaxially or biaxially stretching it to generate fine bubbles, the thermoplastic resin (C) is a polyester It is preferably a resin.

  The thermoplastic resin (D) incompatible with the polyester resin is polyethylene, polypropylene, polybutene, polymethylpentene, olefin resin such as cyclic olefin, styrene resin, polyacrylate resin, polycarbonate resin, polyacrylonitrile resin, Polyphenylene sulfide resin, fluorine-based resin and the like are selected. Among them, an olefin resin or a styrene resin is preferable, and as the olefin resin, polyethylene, polypropylene, poly 4-methylpentene-1 (hereinafter sometimes abbreviated as "polymethylpentene" or "PMP") Ethylene-propylene copolymer, ethylene-butene-1 copolymer, cyclic olefins are preferable, and as a styrene resin, polystyrene, polymethylstyrene, polydimethylstyrene and the like are preferable. These may be homopolymers or copolymers, and two or more thermoplastic resins (D) may be used in combination. The thermoplastic resin (D) is preferably contained in an amount of 1 to 50% by mass in the total mass of the reflector of the present invention. When the thermoplastic resin (D) is less than 1% by mass, it may be difficult to reduce the specific gravity to 1.1 or less, and when it is more than 50% by mass, the mechanical strength, heat resistance and manufacturing cost of the polyester resin May decrease. More preferably, it is 3-40 mass%, More preferably, it is 5-30 mass%.

As a method of calculating | requiring the mass ratio of a polyester resin and a thermoplastic resin (D), the method of combining some analysis according to the kind of each resin can be considered. A method of removing only the polyester resin with a solvent, separating the remaining thermoplastic resin (D) by a centrifugal separator, and determining the mass ratio from the mass of the obtained residue, IR (infrared spectroscopy), ¹ H- After identifying each resin by NMR or ¹³ C-NMR, the polyester resin and the thermoplastic resin (D) are both dissolved in a soluble solvent, centrifuged to remove impurities and inorganic substances, and the concentration is determined by absorbance. Thus, a method of determining the mass ratio can be used. As a solvent in which the polyester resin is soluble, trifluoroacetic acid, 1,1,1,3,3,3-hexafluoro-2-propanol, o-chlorophenol or the like is used.

  The reflecting plate of the present invention is preferably a reflecting plate containing a bubble containing a nucleus. By containing the bubbles, it is possible to improve the reflection performance as a reflecting plate, and by including the nucleus, it is preferable because the bubbles are easily maintained without being crushed at the time of molding. The bubble containing a nucleus is obtained, for example, by adding the above-mentioned inorganic particles or thermoplastic resin (D) incompatible with the resin to the above-mentioned thermoplastic resin (C), and uniaxially or biaxially stretching it. It is obtained by generating fine bubbles in which the particles or the thermoplastic resin (D) becomes a core. In the case of air bubbles without nuclei, although the reflection performance can be improved, the air bubbles may be broken during molding.

  The reflective plate of the present invention is more preferably a reflective plate containing a bubble containing a core of inorganic particles. It is preferable that the inorganic particles become a core, since the bubbles are less likely to be crushed even at high temperatures during molding. The inorganic particles may be used alone or in combination with the thermoplastic resin (D).

  The reflector of the present invention may be a reflector comprising a single layer or a reflector comprising a plurality of layers, but preferably has at least a three-layer configuration. For example, a configuration in which the core layer (Y) containing air bubbles inside and the surface layer (X) are laminated in three layers in the order of X / Y / X is preferable. By laminating the surface layer (X) and the core layer (Y) in the order of X / Y / X, high strength can be obtained, which is preferable. Moreover, although the reflecting plate of this invention may be a structure of four or more layers, a three-layer structure is preferable in consideration of the ease and strength in film formation. Moreover, it is preferable that the surface layer (X) and the core layer (Y) be stretched in two axial directions after being laminated at once in a film forming line by a co-extrusion method. Furthermore, if necessary, re-longitudinal stretching and / or re-lateral stretching may be performed.

  Next, an example of the method for manufacturing a reflector of the present invention will be described, but it is not particularly limited. In a composite film-forming apparatus having two single-screw or twin-screw extruders, a main extruder and a sub-extruder, a resin serving as a material for the core layer (Y) in the main extruder and a material for the surface layer (X) in the co-extruder Charge the resin that Each raw material is preferably dried so as to have a moisture content of 50 ppm or less. Thus, the raw materials can be supplied to the respective extruders, and for example, X / Y / X three-layer laminated films can be formed by two extruders and a feed block or multi-manifold installed on the upper portion of the T die. The extruded unstretched sheet is contact cooled and solidified on a cooled drum to obtain an unstretched laminated film. At this time, in order to obtain a uniform film, a wire-like, tape-like, needle-like or knife-like electrode is used to be in close contact with a cooling body such as a casting drum by electrostatic force and rapidly solidified. It is preferable to

  The unstretched film is heated to a temperature above the glass transition temperature (Tg) of the polymer by roll heating, infrared heating or the like as necessary, and stretched in the longitudinal direction (hereinafter referred to as the longitudinal direction) to obtain a longitudinally stretched film. This stretching is performed using the circumferential speed difference of two or more rolls. The magnification of longitudinal stretching is preferably 2 to 6 times, more preferably 3 to 4 times, depending on the required properties of the application. When it is less than 2 times, the reflectance may be low, and when it is more than 6 times, breakage may easily occur during film formation. The film after longitudinal stretching is subsequently subjected to a process of stretching, heat setting and heat relaxation sequentially in the direction orthogonal to the longitudinal direction (hereinafter referred to as the transverse direction) to obtain a biaxially oriented film, which is a film While driving. At this time, it is preferable to carry out the preheating and stretching temperature for transverse stretching at a glass transition temperature (Tg) or more (Tg + 20 ° C.) or less of the polymer. The magnification of the transverse stretching is preferably 2.5 to 6 times, more preferably 3 to 4 times, depending on the required properties of the application. If it is less than 2.5 times, the reflectance may be low. When it exceeds 6 times, breakage may easily occur during film formation. In order to complete the crystal orientation of the obtained biaxially stretched laminated film and to impart planarity and dimensional stability, a heat treatment is subsequently performed in a tenter at a temperature of 180 to 230 ° C. for 1 to 60 seconds, and uniformity is achieved. After cooling to room temperature, cool to room temperature and wind up on a roll. Such heat treatment may be performed while relaxing the film in its longitudinal direction and / or width direction.

  Further, although the case of drawing by the sequential biaxial drawing method has been described in detail here as an example, the reflector of the present invention may be drawn by any method of the sequential biaxial drawing method and the simultaneous biaxial drawing method, and further If necessary, re-longitudinal stretching and / or re-lateral stretching may be performed after biaxial stretching.

  In order to provide planar stability and dimensional stability to the biaxially stretched laminated film thus obtained, heat treatment (heat setting) is subsequently performed in a tenter, and after uniform cooling gradually to a room temperature, it is taken up after cooling to around room temperature. Thereby, the white film for the reflector of the present invention can be obtained.

  In addition, various coating liquids are applied using known techniques in order to impart slipperiness, antistatic property, ultraviolet light absorption performance, etc. to at least one surface of the white film within the range where the effects of the present invention are not impaired. It may be coated or provided with a hard coat layer or the like to improve impact resistance. The coating may be applied at the time of film production (in-line coating) or may be applied on a white film after film production (off-line coating).

  The reflector of the present invention can be obtained by molding a white film, for example, by the molding method described below. The forming method is not particularly limited, but methods such as vacuum forming, pressure forming, vacuum pressure forming, press forming, a method of forming only a film such as plug assisted vacuum pressure forming, insert molding, three dimension overlay method (TOM) It can be molded by a generally known molding method such as a molding method with a base material such as original laminate molding. Among them, a molding method in which the mold is not in contact with the reflective surface, such as vacuum molding, pressure forming, or vacuum pressure forming, is more preferable. For example, when vacuum pressure forming is performed, the film is heated with a far-infrared heater at 400 ° C. so that the film surface temperature is Tg + 50 ° C. or higher, and vacuum pressure forming is performed along a mold heated to 50 ° C. By performing the pressure: 1 MPa, the reflector of the present invention can be obtained.

  A layer (A layer) containing a thermoplastic resin A and a layer (B layer) containing a thermoplastic resin B having properties different from the thermoplastic resin A are alternately laminated on the reflector of the present invention The optical member on which the multilayer laminated film is disposed, and when the A layer of the outermost layer is the A (1) layer, the difference in thickness of the A (n) layer and the A (n + 30) layer is 2% or more and 5% It is preferable that 20 or more different n which are less than or equal to each other exist. However, n is a natural number.

  The term "having different properties" as used herein means that the refractive index differs by 0.01 or more in any of two orthogonal directions which are arbitrarily selected in the plane of the film and a direction perpendicular to the plane. By adjusting the lamination thickness of the multilayer laminated film, the interference reflection which can reflect the light of the designed wavelength from the relationship between the difference of the refractive index of each layer and the layer thickness is expressed, and the reflection at a specific wavelength is selectively made. It is possible to increase the rate. For example, when a so-called blue LED having a peak emission wavelength of 420 to 500 nm is used as a light source, a multilayer laminated film in which the reflectance at the blue wavelength is selectively increased is disposed on a reflector to provide high reflection efficiency. It is preferable because an optical member can be obtained. In addition, when the number of layers to be stacked is less than 101, high reflectance may not be obtained in a desired band. In addition, as the number of layers increases, the above-mentioned interference reflection can achieve high reflectance to light in a wider wavelength band, and a multilayer laminate film that reflects light in a desired band can be obtained. The number is more preferably 200 or more, still more preferably 300 or more, and particularly preferably 600 or more. Although there is no upper limit to the number of layers, it is realistic because the increase in the number of layers may increase the manufacturing cost due to the increase in the size of the manufacturing apparatus, or the handling may decrease due to the increase in film thickness. The practical range is about 10,000 layers.

  The method for arranging the multilayer laminated film on the reflector of the present invention is not particularly limited, but the raw materials of the reflector and the multilayer laminated film are put into three or more extruders, respectively, and the feed block installed on the T die upper part Or co-extrusion method of laminating with multi manifold, method of providing adhesive layer between reflector and multilayer laminated film, method of bonding by thermal lamination, adhesion state by shape by simultaneously molding reflector and multilayer laminated film A method of holding or the like is used.

  As thermoplastic resins A and B suitably used in the present invention, linear polyolefins such as polyethylene, polypropylene, poly (4-methylpentene-1) and polyacetal, ring-opening metathesis polymerization of norbornenes, addition polymerization, and the like Alicyclic polyolefins which are addition copolymers with olefins, biodegradable polymers such as polylactic acid and polybutyl succinate, polyamides such as nylon 6, nylon 11, nylon 12, nylon 66, aramid, polymethyl methacrylate, Polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, ethylene vinyl acetate copolymer, polyacetal, polyglycolic acid, polystyrene, styrene acrylonitrile copolymer, styrene copolymerized polymethyl methacrylate, polycarbonate G, polypropylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, polyester such as polyethylene-2, 6-naphthalate, polyether sulfone, polyether ether ketone, modified polyphenylene ether, polyphenylene sulfide, polyether imide, polyimide, polyarylate, 4 It is possible to use fluorinated ethylene resin, trifluoroethylene resin, trifluorochlorinated ethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer, polyvinylidene fluoride and the like. Among them, it is preferable to use polyester in particular from the viewpoint of good extrusion molding, strength, heat resistance, transparency and versatility. These may be homopolymers or copolymers, or mixtures.

  As this polyester, polyester obtained by the polymerization from the monomer which has aromatic dicarboxylic acid or aliphatic dicarboxylic acid and diol as a main component is preferable. Here, as the aromatic dicarboxylic acid, for example, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyl Dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid etc. can be mentioned. Examples of aliphatic dicarboxylic acids include adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedioic acid, cyclohexanedicarboxylic acid, decaphosphoric acid and their ester derivatives. Among these, terephthalic acid and 2,6-naphthalenedicarboxylic acid which exhibit high refractive index are preferable. These acid components may be used alone or in combination of two or more. Furthermore, an oxy acid such as hydroxybenzoic acid may be partially copolymerized.

  Also, as the diol component, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis (4- Hydroxyethoxyphenyl) propane, isosorbate, spiroglycol and the like can be mentioned. Among them, ethylene glycol is preferably used. These diol components may be used alone or in combination of two or more.

  Among the above polyesters, the thermoplastic resin A is capable of imparting orientation crystallization by biaxial stretching and heat treatment in order to develop high reflectance, and polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate And polyhexamethylene terephthalate and polyhexamethylene naphthalate are preferable, and polyethylene terephthalate and polyethylene naphthalate are particularly preferable in terms of versatility and moldability. Oriented crystallization induces an increase in refractive index, and can impart high heat resistance and stiffness. On the other hand, as the thermoplastic resin B, it is preferable to use these copolymers from the viewpoint of suppressing appearance defects such as flow marks due to delamination and lamination disorder.

  A multilayer laminated film in which 101 layers or more of layers containing thermoplastic resin A (layer A) and layers containing thermoplastic resin B (layer B) are alternately laminated is manufactured using, for example, a laminating apparatus described in Japanese Patent No. 4552936. be able to. However, the gap and the length of the slit plate are appropriately changed in accordance with the designed layer thickness. That is, the layer thickness distribution of the resulting multilayer laminated film will be different, and the thickness of each layer and its arrangement will be different from those described in the document. When there are 20 or more different n where the difference in thickness of the A (n) layer and the A (n + 30) layer is 2% or more and less than 5% when the A layer of the outermost layer is the A (1) layer, This can be achieved, for example, by adjusting the gap and length of the slit plate.

  When the B layer adjacent to the A layer of the outermost layer of the multilayer laminated film in the present invention is a B (1) layer, the thickness difference between the B (k) layer and the B (k + 30) layer is 2% or more and less than 5% 20 or more different k are preferably present. However, k is a natural number.

  The thickness of such a layer B can be achieved, for example, by adjusting the gap and length of the slit plate. By adjusting the lamination thickness of the multilayer laminated film, it is possible to selectively increase the reflectance at a specific wavelength. For example, when a so-called blue LED having a peak emission wavelength of 420 to 500 nm is used as a light source, a multilayer laminated film in which the reflectance at the blue wavelength is selectively increased is disposed on a reflector to provide high reflection efficiency. It is preferable because an optical member can be obtained.

  Moreover, it is preferable that the average thickness of a B (k) layer is 10-300 nm. Here, the average thickness of the B (k) layer refers to a value obtained by measuring the thicknesses of all the B (k) layers and averaging them.

  Next, an example of the method for producing a multilayer laminated film in the present invention will be described, but it is not particularly limited. In a composite film-forming apparatus having two single-screw or twin-screw extruders, a main extruder and a sub-extruder, a resin serving as a raw material for the layer A (A) in the main extruder and a layer B in the sub-extruder Charge the resin used as the raw material. Each raw material is preferably dried so as to have a moisture content of 50 ppm or less. In the extruder, the resin heated and melted to the melting point or more is made uniform in the extrusion amount of the resin by a gear pump or the like, and foreign substances, denatured resin and the like are removed through a filter or the like. Thus, the raw materials are fed to the respective extruders, fed from different flow paths, and fed to the multilayer laminating apparatus. A multi-manifold die, a feed block, a static mixer or the like can be used as a multi-layer laminating apparatus, but in particular, to efficiently obtain the configuration of the present invention, use a feed block having 101 or more minute slits. Is preferred. When such a feed block is used, the apparatus does not increase in size extremely. Therefore, even if there are few foreign substances due to thermal deterioration and the number of layers is extremely large, highly accurate lamination can be performed. In addition, the lamination accuracy in the width direction is also significantly improved as compared with the prior art. Further, in this device, since the thickness of each layer can be adjusted by the shape (length, width) of the slit, it is possible to achieve an arbitrary layer thickness.

  The molten multilayer laminate thus formed into a desired layer configuration is extruded from a die and solidified by close contact cooling on a cooled drum to obtain an unstretched multilayer laminate film. At this time, in order to obtain a uniform film, it is preferable to use a wire-like, tape-like, needle-like or knife-like electrode, adhere to a cooling body such as a casting drum by electrostatic force and rapidly cool and solidify.

  This unstretched multilayer laminated film is heated to a temperature above the glass transition temperature (Tg) of the polymer by roll heating, infrared heating or the like as necessary, and stretched in the longitudinal direction (hereinafter referred to as the longitudinal direction) to obtain a longitudinally stretched film . This stretching is performed using the circumferential speed difference of two or more rolls. The magnification of longitudinal stretching is preferably 2 to 7 times, more preferably 3 to 5 times, depending on the required properties of the application. When it is less than 2 times, molecular orientation may be low, and when it is more than 7 times, breakage may easily occur during film formation. The film after longitudinal stretching is subsequently subjected to a process of stretching, heat setting and heat relaxation sequentially in the direction orthogonal to the longitudinal direction (hereinafter referred to as the transverse direction) to obtain a biaxially oriented film, which is a film While driving. At this time, it is preferable that the preheating and stretching temperature for transverse stretching be performed at the glass transition temperature (Tg) or more (Tg + 50 ° C.) or less of the polymer. The magnification of the transverse stretching is preferably 2.5 to 7 times, more preferably 3 to 6 times, depending on the required properties of the application. If it is less than 2.5 times, the molecular orientation may be low. If it exceeds 7 times, breakage may easily occur during film formation. In order to complete the crystal orientation of the obtained biaxially stretched multilayer laminate film and to impart planarity and dimensional stability, a heat treatment is subsequently performed for 1 to 60 seconds at a temperature higher than the stretching temperature and lower than the melting point in the tenter. After uniform cooling, cool to room temperature and wind up on a roll. Such heat treatment may be performed while relaxing the film in its longitudinal direction and / or width direction.

  Further, although the case of drawing by the sequential biaxial drawing method has been described in detail here as an example, the reflector of the present invention may be drawn by any method of the sequential biaxial drawing method and the simultaneous biaxial drawing method, and further If necessary, re-longitudinal stretching and / or re-lateral stretching may be performed after biaxial stretching.

  In order to provide planar stability and dimensional stability to the biaxially stretched laminated film thus obtained, heat treatment (heat setting) is subsequently performed in a tenter, and after uniform cooling gradually to a room temperature, it is taken up after cooling to around room temperature. Thereby, a multilayer laminate film used for the optical member of the present invention can be obtained.

  In addition, various coating liquids are applied using known techniques in order to impart lubricity, antistatic property, ultraviolet light absorption performance, etc. to at least one surface of the multilayer laminate film, as long as the effects of the present invention are not impaired. Or a hard coat layer may be provided to enhance impact resistance. The coating may be applied at the time of film production (in-line coating) or may be applied on a multilayer laminated film after film production (off-line coating).

  The reflector and the optical member of the present invention can be suitably used as a reflector for an LED lighting unit. In the case of the LED lighting unit using the reflecting plate and the optical member of the present invention, light leakage of the adjacent LEDs hardly occurs, which is preferable as a lighting application having a partial drive function. In particular, it is preferable as a reflector for a flat type LED lighting unit.

  The reflective plate and the optical member of the present invention can also be suitably used as a reflective plate for a direct type LED backlight unit. In the case of the direct type LED backlight unit using the reflector of the present invention, light leakage of the adjacent LEDs hardly occurs, which is preferable for a backlight having a local dimming function. In particular, it is preferable as a reflector for a direct type LED backlight unit used for a liquid crystal display, a liquid crystal television, a liquid crystal monitor and the like.

  The reflecting plate and the optical member of the present invention can be suitably used as a reflecting member for plant plant illumination. When the reflecting plate of the present invention is used as a reflecting member for plant factory illumination, for example, diffusion of light can be suppressed and directional light can be efficiently irradiated to a plant. Alternatively, it is preferable because the current and voltage required to obtain the same illuminance can be suppressed, and power consumption and heat generation from the light source can be suppressed. In addition, light necessary for the growth of plants is said to be red (wavelength 600 to 700 nm) and blue (wavelength 400 to 500 nm), and this book adjusts the thickness of the multilayer laminated film to enhance the red and blue reflectance The optical member of the invention can be particularly preferably used as a reflecting member for plant plant illumination.

  Hereinafter, the present invention will be described in detail by way of examples. Each characteristic value was measured by the following method.

(1) Depth of tray shape, horizontal projection area, dimensional change rate, bottom area
The shape of the tray was measured using a one-shot 3D shape measuring machine VR-3200 (manufactured by Keyence Corporation).

  The sample measured once was introduced into a constant temperature and humidity chamber whose temperature and temperature are controlled at 40 ° C. and 95% RH, and heat treatment was performed for 500 hours. The shape measurement was similarly performed on the treated sample.

  In addition, in the VR-3000 Series analysis application, the smallest square or rectangle surrounding one independent tray shape was set in the plane measurement window. Specifically, the outline of the tray shape can be traced by checking the automatic edge extraction and drawing the inside of the edge of the tray shape with a line. The smallest square or rectangle circumscribing this contour can be drawn, and the measurement area can be set based on the size and the coordinates of the vertex. If the edge is so smooth that edge automatic extraction can not be performed, a portion corresponding to the ridge between adjacent tray shapes is determined as the outline of the tray shape to obtain the smallest square or rectangle.

  Next, the volume / area measurement window was displayed, the recess was selected in the measurement mode, and the measurement region was set. The measurement area was set to the smallest square or rectangle surrounding one independent tray shape. In the measurement setting, open the setting screen of the height threshold, and manually set the threshold setting bar to overlap the most frequently appearing height on the histogram that indicates the frequency by the height and the length of the bar on the vertical axis. In addition, the height threshold was set to the height + 0.1 mm. The portion lower than the height threshold was taken as the bottom portion. At this time, an area obtained by viewing a cross-sectional area horizontally cut at the height threshold value as viewed from the top is taken as a horizontal projection area of the bottom portion. About the through-hole of a bottom face part, it was set as the horizontal projection area of the bottom face part including the area of a hole. Moreover, although the height of the jig for supporting a measurement stage, a housing | casing, and a molded object may be detected by a through-hole, it excludes about these.

  For the smallest square or rectangular horizontal projection area surrounding one independent tray shape, a volume / area measurement window is displayed in the VR-3000 Series analysis application, a recess is selected in the measurement mode, and a measurement area is set.

  In the height threshold setting screen, setting the height threshold to the maximum value of the height obtained by the histogram representing the frequency mentioned above makes it possible to project the horizontal projection area of the area lower than the threshold Obtained as The area is displayed as a "cross-sectional area" in the analysis application. This “cross-sectional area” is taken as the horizontal projected area of the square or rectangle.

  The flat measurement window was displayed for one independent tray shape, and the smallest square or rectangle surrounding the tray shape was set. The midpoint of each side of this square or rectangle was then determined. When a straight line extending from one middle point to the middle point of the opposite sides is drawn for each of the opposite sides, a point where the tray shape intersects with the tray shape from the one middle point is defined as the tray shape intersection point. The coordinate heights of the intersections (four points) of the tray shape obtained in this manner were read. At this time, the difference between the average of the coordinate heights of the four points and the height threshold value set in the volume / area measurement window was taken as the depth of the inner dimension of the tray shape. Also for the sample after heat treatment, the depth of the inner shape of the tray shape is determined in the same manner, and (the depth of the tray shape after the treatment / the depth of the tray shape before the treatment) × 100 is the depth of the tray shape It was defined as the dimensional change rate.

  The rate of change of the distance between adjacent through holes was determined from the shortest distance from the edge of the through hole to the edge of the nearest through hole of another independent tray shape in one independent tray shape. The edge of the through hole is the outer edge of the lower limit of measurement or the outer edge of the set of points taking the height of the measurement stage, a flat measurement window is displayed, and the shortest distance between the edges of two or more through holes is measured before and after sample processing. , (Distance between through holes after treatment / distance between through holes before treatment) × 100 was a rate of change in distance between adjacent through holes. The rate of change was calculated by measuring at N = 3 using three different samples. When the distance between the through holes exceeds the measurable range of the measuring device, measurement may be performed using a vernier caliper (JIS B 7507: 2016 compliant) or the like.

(2) Specific gravity From a reflection plate, five square samples with one side of 5 cm are cut out and observed from directly above, and each is an electronic hydrometer SD-120L (manufactured by Mirage Trade Co., Ltd.) based on JIS K7112-1980. It measured using. The arithmetic mean of the measured values of a total of 5 points obtained was determined, and this was taken as the specific gravity of the reflecting plate. In addition, even if it has a shape which a part lacks because a hole is opened to a reflecting plate, it can measure without a problem.

(3) Number of Layers of Multilayer Laminated Film, Layer Thickness A sample whose cross section was cut out using a microtome was determined by transmission electron microscope (TEM) observation. That is, using a transmission electron microscope H-7100 FA type (manufactured by Hitachi, Ltd.), the cross section of the film is observed at 10,000 to 40,000 times under conditions of an accelerating voltage of 75 kV, and a cross section photograph is taken. The configuration and thickness of each layer were measured. The average thickness of the B (k) layer was obtained by measuring the thicknesses of all the B (k) layers and averaging them. In some cases, in order to obtain high contrast, known dyeing techniques using RuO ₄ or OsO ₄ were used.

(4) Optical unevenness A reflective plate having trays of 2 rows × 2 columns × 4 squares was formed, and a hole having a diameter of 6 mm was made at the center of each mass. The lens cap was removed from the LED bar of a commercial TV (manufactured by Haier, LE42A7000), and the reflector was set so that the LED could come out of the hole. The optical film group was placed on the reflective plate, the LED was turned on, and the appearance was observed.
:: bright between tray and tray, no optical unevenness visible :: bright between tray and tray, but molding shape can be confirmed x: optical unevenness in which tray and tray are dark can be seen, molding shape is confirmed it can.

(5) Positional Deviation A reflective plate having 2 rows × 2 rows and 4 squares of trays was formed, and a hole of 6 mm in diameter was made at the center of each mass. It fixed to a 2 mm-thick SUS board using a double-sided tape (Nitto Denko KK-made No. 500). A frame was prepared by overlapping a 10 mm wide SUS plate around the four tray-shaped squares, and the edge of the reflective plate was fixed with double-sided tape. The position of the hole was marked on the SUS plate with an oil-based pen, and this was put into a thermostatic / humidity tank kept at 40 ° C. and 95% RH for 500 hours to observe the state.
◎: There was no peeling of the tape and no positional deviation of 1 mm or more in the hole, and the fixed state could be maintained.
○: There was a part where the tape peeled off, but there was no positional deviation of 1 mm or more of the hole, and the fixed state could be maintained.
X: The tape was peeled off and the position of the hole was shifted by 1 mm or more.

(6) Illuminance Measured using an illuminance meter (FT3424 manufactured by HIOKI). It adjusted so that the distance of the gravity center position of all the light sources and the light-receiving part of the illumination meter might be 20 cm, and made the average value of N = 5 illuminance.

[Used raw material]
(1) PET resin (a)
Polymerization was carried out from terephthalic acid and ethylene glycol by antimony trioxide as a catalyst according to a conventional method to obtain polyethylene terephthalate (PET). The glass transition temperature of the obtained PET is 77 ° C., the melting point is 255 ° C., the intrinsic viscosity (hereinafter sometimes referred to as IV) is 0.63 dl / g, and the terminal carboxyl group concentration is 40 eq. It was / t.

(2) Copolymerized polyester resin (b)
From terephthalic acid, ethylene glycol and neopentyl glycol, polymerization was carried out according to a conventional method using antimony trioxide as a catalyst to obtain a copolyester resin (b) containing 17.5 mol% of neopentyl glycol. IV: 0.6 dl / g, carboxylic acid end group weight: 33 eq. It was / t.

(3) Copolymerized polyester resin (c)
From terephthalic acid, isophthalic acid and ethylene glycol, polymerization was carried out by an ordinary method using antimony trioxide as a catalyst to obtain a copolyester resin (c) containing 17.5 mol% of isophthalic acid residue. IV is 0.55 dl / g, carboxylic acid end group weight is 33 eq. It was / t.

(4) Copolymerized polyester resin (d)
A commercially available cyclohexane dimethanol 33 mol% copolyester "GN 001" (manufactured by Eastman) was used.

(5) Cyclic olefin (COC) resin (e)
A commercially available cyclic olefin resin "TOPAS 6017" (Nippon Polyplastics Co., Ltd.) was used.

(6) Barium sulfate 50 mass% master (f)
50 parts by mass of the PET resin (a) and 50 parts by mass of barium sulfate particles (number average particle diameter 0.5 μm) were kneaded by a twin screw extruder to obtain a barium sulfate 50 mass% master (f).

(7) Calcium carbonate 50 mass% master (g)
50 parts by mass of the PET resin (a) and 50 parts by mass of calcium carbonate particles (number average particle diameter 0.5 μm) were kneaded by a twin screw extruder to obtain 50 mass% calcium carbonate master (g).

[Shaped shape]
(A) A tray shape of 2 rows × 2 rows × 4 squares, and a size of one tray is 30 mm × 30 mm, depth 3 mm, and a size of a bottom portion is 15 mm × 15 mm. A square frustum shaped (C) 2 rows by 2 rows by 4 squares, each of which has a tray shape of 2 rows and 4 squares, and the size of one tray is 30 mm × 30 mm, depth 3 mm, and the size of the bottom is 18 mm × 18 mm The shape of one tray is 30 mm × 30 mm, depth 3 mm, and the size of the bottom is 21 mm × 21 mm. The size of the tray is 30 mm × 30 mm, the depth is 1 mm, and the size of the bottom is 18 mm × 18 mm. A square frustum shape (E) 2 rows × 2 rows 4 squares tray shape, one tray is 30 mm in size × 30 mm, depth 5 mm, bottom The tray size is 18mm x 18mm square frustum (F) 2 rows x 2 columns 4 squares tray shape, size of one tray is 80mm x 80mm, depth 10mm, bottom size is 60mm x 60 mm square frustum shape (G) 2 rows × 2 rows 4 squares honeycomb tray shape, one tray size is a regular hexagon with a side of 30 mm, a depth of 3 mm, and a shape of a bottom portion is a side with 18 mm with a square shape It is a tray shape of hexagonal frustum shape (H) 2 rows x 2 rows 4 squares which is square, and the size of one tray is a circle with a diameter of 30 mm, a depth of 3 mm, and the shape of the bottom part is a circle with a diameter of 18 mm. A square frustum shape with a size of one tray of 30 mm × 30 mm, a depth of 5 mm, and a size of a bottom portion of 24 mm × 24 mm. ) 2 rows × 2 columns 4 squares A shape, a tray size of 80 mm × 80 mm, depth 25 mm, truncated quadrangular pyramid shape is 60 mm × 60 mm size of the bottom portion.

(Examples 1 to 18, Comparative examples 2 to 4)
After vacuum drying the raw materials of the composition shown in Tables 1 and 2 at a temperature of 180 ° C for 6 hours, the raw material of the core layer (Y) is supplied to the main extruder and melt extruded at a temperature of 280 ° C and filtered with a 30 μm cut filter. The raw material of the surface layer (X) is supplied to the sub-extruder, melt extruded at a temperature of 280 ° C. and filtered with a 30 μm cut filter, then the surface layer (X) is the core layer (Y) in the T die composite die (X / Y / X) were combined so as to be stacked on both surface layers of

  Then, the sheet was extruded into a molten sheet, and the molten sheet was solidified by adhesion on a drum maintained at a surface temperature of 25 ° C. by an electrostatic application method to obtain an unstretched film. Subsequently, the unstretched film is preheated by a group of rolls heated to a temperature of 80 ° C., and while irradiating from both sides with an infrared heater, stretching is performed 3.3 times in the longitudinal direction (longitudinal direction). It cooled by the roll group of temperature and obtained the uniaxial stretched film. Thereafter, while holding the both ends of the uniaxially stretched film with clips, it was led to a 110 ° C. preheating zone in the tenter and subsequently stretched at 120 ° C. in the direction perpendicular to the longitudinal direction (lateral direction) 3.5 times. Subsequently, a heat treatment at 200 ° C. in the heat treatment zone in the tenter, followed by uniform annealing, was taken up on a roll to obtain a white film.

  Using a Asano Laboratory-made molding machine (FKS-0631-20) with a far-infrared heater at 400 ° C, the film is heated to a temperature of 150 ° C or higher, and the mold is heated to 50 ° C. Vacuum pressure forming (pressure: 1 MPa) was performed along the line. The mold was designed so that it could be molded in the shapes of (A) to (J). After molding, a punching punch was used to form a through hole of 6 mmφ.

(Comparative example 5)
After vacuum drying the raw materials of the composition shown in Tables 1 and 2 at a temperature of 180 ° C for 6 hours, the raw material of the core layer (Y) is supplied to the main extruder and melt extruded at a temperature of 280 ° C and filtered with a 30 μm cut filter. The raw material of the surface layer (X) is supplied to the sub-extruder, melt extruded at a temperature of 280 ° C. and filtered with a 30 μm cut filter, then the surface layer (X) is the core layer (Y) in the T die composite die (X / Y / X) were combined so as to be stacked on both surface layers of

  Then, the sheet was extruded into a molten sheet, and the molten sheet was solidified by adhesion on a drum maintained at a surface temperature of 25 ° C. by an electrostatic application method to obtain an unstretched film. Subsequently, the unstretched film is preheated by a group of rolls heated to a temperature of 80 ° C., and while irradiating from both sides with an infrared heater, stretching is performed 3.3 times in the longitudinal direction (longitudinal direction). It cooled by the roll group of temperature and obtained the uniaxial stretched film. Thereafter, while holding the both ends of the uniaxially stretched film with clips, it was led to a 110 ° C. preheating zone in the tenter and subsequently stretched at 120 ° C. in the direction perpendicular to the longitudinal direction (lateral direction) 3.5 times. Subsequently, a heat treatment at 200 ° C. in the heat treatment zone in the tenter, followed by uniform annealing, was taken up on a roll to obtain a white film.

  A through hole of 6 mmφ was formed in 2 rows × 2 columns at a position overlapping the through hole of the reflection plate of Example 15 in the above white film, and it was set as Comparative Example 5.

  The lens cap was removed from the LED bar of a commercially available TV (manufactured by Haier, LE42A7000), and the reflector was set so that the LEDs would come out from the holes (four locations) of Example 15 and Comparative Example 5. The illuminance was measured by turning on 2 rows × 2 columns of LEDs at 22 V and 20 mA. The illuminance of the working example 15 is improved by 18% relative to that of the comparative example 5.

(Multilayer laminated film)
PET resin (a) was used as a thermoplastic resin (A), and copolyester resin (d) was used as a thermoplastic resin (B). After vacuum drying each raw material at a temperature of 180 ° C for 6 hours, the thermoplastic resin (A) is supplied to the main extruder, and melt extrusion is carried out at a temperature of 280 ° C. The resin (B) was supplied, melt-extruded at a temperature of 280 ° C. and filtered through a 30 μm cut filter, and then they were respectively joined by a feed block of 501 layers after passing through a gear pump. The combined thermoplastic resins (A) and (B) are changed so that the thickness of each layer gradually increases from the surface side to the opposite surface side in the feed block, and 251 layers of the thermoplastic resin (A) The thermoplastic resin (B) was alternately laminated in the thickness direction of 250 layers. In addition, both surface layer portions were made to be the thermoplastic resin (A), and the shapes of the fine slits in the feed block were designed such that the layer thicknesses of the adjacent A layer and B layer were substantially the same. In this design, a reflection band exists at 400 to 550 nm. The laminated body consisting of a total of 501 layers obtained in this manner is extruded into a sheet to form a molten sheet, and the molten sheet is solidified by adhesion cooling on a drum maintained at a surface temperature of 25 ° C. An unstretched film was obtained. Subsequently, the unstretched film is preheated by a group of rolls heated to a temperature of 80 ° C., and while irradiating from both sides with an infrared heater, stretching is performed 3.3 times in the longitudinal direction (longitudinal direction). It cooled by the roll group of temperature and obtained the uniaxial stretched film. Thereafter, while holding the both ends of the uniaxially stretched film with clips, it was led to a 110 ° C. preheating zone in the tenter and subsequently stretched at 120 ° C. in the direction perpendicular to the longitudinal direction (lateral direction) 3.5 times. Subsequently, a heat treatment at 200 ° C. in the heat treatment zone in the tenter, followed by uniform annealing, was wound on a roll to obtain a multilayer laminated film. The thickness of the obtained film was 75 μm.

(Examples 19 and 20)
After vacuum drying the raw materials of the composition shown in Tables 1 and 2 at a temperature of 180 ° C for 6 hours, the raw material of the core layer (Y) is supplied to the main extruder and melt extruded at a temperature of 280 ° C and filtered with a 30 μm cut filter. The raw material of the surface layer (X) is supplied to the sub-extruder, melt extruded at a temperature of 280 ° C. and filtered with a 30 μm cut filter, then the surface layer (X) is the core layer (Y) in the T die composite die (X / Y / X) were combined so as to be stacked on both surface layers of

  Then, the sheet was extruded into a molten sheet, and the molten sheet was solidified by adhesion on a drum maintained at a surface temperature of 25 ° C. by an electrostatic application method to obtain an unstretched film. Subsequently, the unstretched film is preheated by a group of rolls heated to a temperature of 80 ° C., and while irradiating from both sides with an infrared heater, stretching is performed 3.3 times in the longitudinal direction (longitudinal direction). It cooled by the roll group of temperature and obtained the uniaxial stretched film. Thereafter, while holding the both ends of the uniaxially stretched film with clips, it was led to a 110 ° C. preheating zone in the tenter and subsequently stretched at 120 ° C. in the direction perpendicular to the longitudinal direction (lateral direction) 3.5 times. Subsequently, a heat treatment at 200 ° C. in the heat treatment zone in the tenter, followed by uniform annealing, was taken up on a roll to obtain a white film.

  The white film and the multilayer laminated film were adhered via an adhesive layer to prepare a film for an optical member.

  The film for optical members was heated to 50 ° C. with a far-infrared heater at 400 ° C. using a molding machine (FKS-0631-20) manufactured by Asano Research Institute so that the film surface temperature would be 150 ° C. or higher. Vacuum pressure forming (pressure: 1 MPa) was performed along the mold. The mold was designed so that it could be molded in the shapes of (A) to (J). After molding, a punching punch was used to form a through hole of 6 mmφ.

  When the cross section of the multilayer laminated film portion of the optical member is observed by TEM, the difference in thickness between the A (n) layer and the A (n + 30) layer is 3.5% on average, and n is 20% or more and less than 5%. It was confirmed that there were more than one. Similarly, the difference between the thicknesses of the B (k) layer and the B (k + 30) layer was 3.5% on average, and it was confirmed that there were 20 or more k which became 2% or more and less than 5%. The average thickness of the B layer was 75 nm.

  This optical member was particularly excellent in blue reflectance.

(Adhesive layer)
Polyester resin / epoxy resin = 70/30 (mass ratio) mixed solution (AD76P1 manufactured by Toyo Morton Co., Ltd.) 100 parts by mass Isocyanate (CAT10 manufactured by Toyo Morton Co., Ltd.) 10 parts by mass Solvent (toluene / methyl ethyl ketone = 1/1 (mass ratio) ) Mixed solvent so that the solid content is 32% by mass and adjusted. The adhesive layer was produced using this.

(Comparative example 1)
A commercially available white sheet “MCPET-RB” having a thickness of 500 μm was used.

  Using a Asano Laboratory-made molding machine (FKS-0631-20) with a far-infrared heater at 400 ° C, the film is heated to a temperature of 150 ° C or higher, and the mold is heated to 50 ° C. Vacuum pressure forming (pressure: 1 MPa) was performed along the line. The mold was designed to be able to be molded in the shape of (A), but the molding was insufficient and could not follow the mold.

According to the present invention, a reflector having a tray shape excellent in shape retention can be provided, and in particular, a direct type backlight unit having a small shape change even when exposed to a moist heat environment for a long period of time, an LED lighting unit, and illumination for a plant factory Thus, it is possible to provide a reflecting plate having a tray shape suitable for the like.

Claims (14)

A reflective plate having a plurality of independent tray shapes with a depth of 1 mm or more and 20 mm or less and having through holes in the bottom portion of the tray shape, which are adjacent before and after heat treatment under conditions of 40 ° C. 95% RH for 500 hours The reflecting plate whose rate of change of distance between through holes {(distance between through holes after treatment / distance between through holes before treatment) × 100} is more than 0% and not more than + 5%. The dimensional change rate of the depth of the tray shape before and after heat treatment for 500 hours under the condition of 40 ° C. and 95% RH {(the depth of the tray shape after the treatment / the depth of the tray shape before the treatment) × 100} is 0% The reflector according to claim 1, which is more than + 5% or less. The reflector according to claim 1, wherein a polyester resin is a main component. The reflector according to claim 3, wherein the polyester resin contains 1 to 20 mol% of 2,2-dimethyl-1,3-propanediol (neopentyl glycol) and / or cyclohexane dimethylene glycol in a diol component. The reflective plate according to claim 3 or 4, wherein the polyester resin is a copolyester resin, and the dicarboxylic acid component contains 1 to 20 mol% of isophthalic acid residue. The specific gravity is 0.5 or more and 1.1 or less, The reflecting plate in any one of Claims 1-5. The reflector according to any one of claims 1 to 6, which has at least a three-layer structure. A layer (A layer) containing a thermoplastic resin A and a layer (B layer) containing a thermoplastic resin B having different properties from the thermoplastic resin A on the reflection plate according to any one of claims 1 to 7 Is an optical member in which a multilayer laminated film in which 101 layers or more are alternately laminated is disposed, and the A layer of the outermost layer is the A (1) layer, the thickness of the A (n) layer and the A (n + 30) layer An optical member in which 20 or more different n are present such that the difference of is 2% or more and less than 5%. However, n is a natural number. When the B layer adjacent to the outermost A layer is the B (1) layer, the difference in thickness of the B (k) layer and the B (k + 30) layer is 2 or more and less than 5%, and 20 or more different k The optical member according to claim 8, which is present. However, k is a natural number. The optical member according to claim 9, wherein the average thickness of the B (k) layer is 10 to 300 nm. The reflective board in any one of Claims 1-7 used for a LED lighting unit. The reflective board in any one of Claims 1-7 used for a direct under type LED backlight unit. The optical member according to any one of claims 8 to 10 used for an LED lighting unit. The optical member according to any one of claims 8 to 10, which is used in a direct type LED backlight unit.

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