JP5829028B2 - Light reflecting plate, method for manufacturing light reflecting plate, and illumination member using the same - Google Patents

Description

  The present invention relates to a light reflecting plate, a method for manufacturing the light reflecting plate, and an illumination member using the same.

  Conventionally, as a lighting device provided with a light reflecting member, a light duct, a lighting fixture such as a fluorescent lamp and a mercury lamp, an edge light type backlight of a liquid crystal display device, and the like are known. In such an illuminating device, with the high efficiency and energy saving of illumination, the high reflectance is calculated | required also with respect to the light reflection member with which an illuminating device is equipped.

  As such a light reflecting member, in general, a plate-shaped aluminum material is used as a base body because it is excellent in workability and corrosion resistance and can be reduced in weight, and this aluminum material has a desired shape according to the lighting device. In order to improve the reflectance of the reflective surface of the obtained processed product, a layer made of silver or a silver alloy having a high reflectance is formed by plating or vapor deposition. However, the method of forming a layer made of silver or a silver alloy after processing a plate-shaped aluminum material into a desired shape in advance as described above has a problem that the manufacturing cost increases and applicable applications are limited. There is a problem that it ends up.

  Therefore, there is a demand for a light reflecting plate in which a layer made of silver or a silver alloy having a high reflectance is formed in advance and can be processed into a desired shape. As such a light reflecting plate, for example, in Patent Document 1, a resin layer for improving the adhesion between the base and the reflective layer is formed on a base such as a metal, a plastic plate, or a glass plate. Further, a light reflecting plate is disclosed in which a reflective layer is formed by silver plating using silver mirror reaction or silver vapor deposition, and a protective layer is further formed thereon. In the specific example of Patent Document 1, an example is disclosed in which a resin layer made of an acrylic resin is formed on a substrate by spray coating.

JP 2009-25716 A

  On the other hand, in a light reflector for an illuminating device, heat resistance of 100 ° C. or more is required depending on the type of lamp light source constituting the illuminating device and the usage environment, and further, depending on the usage of the illuminating device. Since it is necessary to process into various shapes, excellent workability is also required.

  However, in the light reflecting plate described in Patent Document 1 described above, the entire surface of the light reflecting plate is colored under a high temperature atmosphere when processed into a lighting member by applying it to a predetermined shape for application to a lighting device. There arises a problem that the reflectance is remarkably lowered. As a cause of this, in a high temperature atmosphere, the residual solvent used when forming the resin layer (for example, a resin layer made of an acrylic resin formed by spray coating) is vaporized, and the reflection layer is fine. This is considered to be due to the interaction with the resin constituting the protective layer through cracking.

  An object of the present invention is to provide a light reflector having excellent heat resistance and reflection characteristics and excellent workability, and a method for producing the same. Another object of the present invention is to provide an illumination member obtained using the light reflecting plate.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a resin layer containing a predetermined polyester resin having a half-crystallization time at 160 ° C. of 80 to 120 seconds on a substrate without using a solvent. As a result, it was found that the above-described object can be achieved, and the present invention has been completed.

That is, according to the present invention, a base, a resin layer formed on the base and including a polyester resin having a half-crystallization time at 160 ° C. of 80 to 120 seconds, formed on the resin layer, silver or A reflective layer made of a silver alloy; and a protective layer formed on the reflective layer and containing a resin. The polyester resin comprises polyethylene terephthalate, a copolymer having ethylene terephthalate as a monomer unit, and polyethylene terephthalate. A polyester resin containing at least one of a blend resin containing, a modified polyethylene terephthalate obtained by modifying or substituting at least one of terephthalic acid which is an acid component in polyethylene terephthalate and ethylene glycol which is an alcohol component, the resin layer contains vaporizable solvent There is not a light reflecting plate is provided.
In the light reflecting plate of the present invention, preferably, the polyester resin is a polyester resin having ethylene terephthalate and ethylene isophthalate as monomer units.

In the light reflecting plate of the present invention, preferably, the polyester resin is a non-oriented polyester resin.
In the light reflecting plate of the present invention, preferably, the intrinsic viscosity of the polyester resin is 0.6 to 1.4.

  According to the present invention, there is provided an illumination member obtained by processing and molding any one of the above light reflecting plates.

Further, according to the present invention, the polyester resin crystallization half-times at 1 60 ° C. is 80 to 120 seconds, the resin layer formed by molding in a state melted by heating without using a solvent, heat sealing And a step of forming a resin layer on the substrate, a step of forming a reflective layer made of silver or a silver alloy on the resin layer, and a protective layer containing a resin on the reflective layer Applying a solution and drying to form a protective layer made of the resin, and as the polyester resin, polyethylene terephthalate, a copolymer having polyethylene terephthalate as a monomer unit, and polyethylene terephthalate And at least one of the blend resin and terephthalic acid which is an acid component in polyethylene terephthalate and ethylene glycol which is an alcohol component. There is also provided a method for producing a light reflecting plate using a polyester resin containing at least one modified polyethylene terephthalate obtained by modifying or substituting one of them.

In the production method of the present invention, the polyester resin has a melting point of 220 to 245 ° C., and the polyester resin is heated to a temperature equal to or higher than the melting point, whereby the polyester resin is laminated on the substrate by heat fusion. The resin layer is preferably formed.
In the manufacturing method of this invention, it is preferable that the intrinsic viscosity of the said polyester resin is 0.6-1.4.

  According to the present invention, a light reflecting plate having excellent heat resistance and reflection characteristics and having excellent processability, a method for producing the same, and a light reflecting plate obtained using the light reflecting plate, and having excellent heat resistance and reflection characteristics. An illumination member can be provided.

FIG. 1 is a diagram illustrating a configuration of a light reflecting plate 10 according to the present embodiment. FIG. 2 is a diagram for explaining a method for measuring the half crystallization time of the polyester resin according to this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of a light reflecting plate 10 according to the present embodiment. As shown in FIG. 1, the substrate 2, the resin layer 4, the reflective layer 6, and the protective layer 8 are formed by laminating in this order.

<Substrate 2>
The substrate 2 may be made of a material that can be processed into a desired shape, but in the present embodiment, a metal plate is used from the viewpoint of excellent workability. The metal plate constituting the substrate 2 is not particularly limited, and examples thereof include a steel plate, an aluminum plate, and an aluminum alloy plate. Among these, an aluminum alloy plate is preferably used from the viewpoint of excellent corrosion resistance.

  Examples of the steel plate include an iron alloy plate having a chromium content of less than 11% by mass, or an iron alloy having a chromium content of 11% by mass or more, a so-called stainless steel plate. In particular, an iron alloy steel sheet having a chromium content of less than 11% by mass is an inexpensive material compared to aluminum and stainless steel, and is therefore suitable for widespread use of products.

  The aluminum alloy plate is mainly made of aluminum, and is alloyed by adding magnesium (Mg), manganese (Mn), silicon (Si) or the like in order to impart strength, workability, corrosion resistance, and the like. Of the aluminum alloy plates, the 1000 type is preferably 0 material (annealed material).

  Further, the metal plate for constituting the substrate 2 may be a surface-treated metal plate subjected to surface treatment. As the surface-treated metal plate, the surface of the above-described metal plate is subjected to various plating (for example, a galvanized steel plate obtained by applying zinc plating or zinc alloy plating to a steel plate), or an alumite treatment on the surface of an aluminum plate. And the like.

  The thickness of the substrate 2 is not particularly limited and may be appropriately selected depending on the intended use, but is usually 0.6 to 1.2 mm, preferably 0.8 to 1.0 mm.

<Resin layer 4>
The resin layer 4 is made of a polyester resin having a half crystallization time at 160 ° C. of 80 to 120 seconds. By providing the resin layer 4, it is possible to improve the adhesion with the base 2 and improve the smoothness of the reflective layer 6.

  In the present embodiment, since a polyester resin having a semi-crystallization time at 160 ° C. of 80 to 120 seconds is used as a material constituting the resin layer 4, when the resin layer 4 is formed on the base 2. The polyester resin is heated and melted, and the heat-melted polyester resin can be formed by a film lamination method or an extrusion lamination method. That is, the resin layer 4 can be formed without using a solvent. Therefore, the light reflecting plate 10 according to the present embodiment is colored due to a problem that occurs when the residual solvent is vaporized under a high temperature environment, for example, the residual solvent interacts with the resin constituting the protective layer 8. It is possible to effectively prevent problems that occur or the reflectance is significantly reduced.

  In addition, as a material constituting the resin layer 4, since a polyester resin having a semi-crystallization time at 160 ° C. of 80 to 120 seconds is used, the adhesiveness with the base 2 can be increased. As a result, when the light reflecting plate 10 is processed into a desired shape, it is possible to effectively prevent a problem that the resin layer 4 is peeled off from the base body 2 due to the processing. That is, in this embodiment, the light reflecting plate 10 is excellent in workability by using a polyester resin having a semi-crystallization time at 160 ° C. of 80 to 120 seconds as a material constituting the resin layer 4. It can be. In addition, the smoothness of the reflective layer 6 can be improved by using a polyester resin having a half crystallization time at 160 ° C. of 80 to 120 seconds as a material constituting the resin layer 4. The reflection characteristics can be improved.

  The polyester resin constituting the resin layer 4 is not particularly limited as long as the half crystallization time at 160 ° C. is in the range of 80 to 120 seconds, but is not particularly limited, but an ethylene terephthalate unit, an ethylene isophthalate unit, a butylene terephthalate unit. Those having an ester unit such as a butylene isophthalate unit are preferred, and a polyester resin having at least one ester unit selected from these as a main constituent unit is preferred. In addition, the polyester resin may be one in which each of the above-mentioned ester units is copolymerized, and further, the polyester resin is obtained by blending two or more homopolymers or copolymerized polymers of each of the above-described ester units. Also good. In addition to those described above, naphthalenedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, etc. are used as the acid component constituting the ester unit, and propylene glycol, diethylene glycol as the alcohol component constituting the ester unit. , Neopentyl glycol, cyclohexane dimethanol, pentaethysitol and the like may be used.

  Moreover, the half crystallization time of the polyester resin which comprises the resin layer 4 is 80-120 second, By making a half crystallization time into such a range, the reflective characteristic of the light reflection board 10 shall be favorable. can do. When a highly crystalline polyester resin having a semi-crystallization time of less than 80 seconds is used, the adhesion with the substrate 2 is poor, and the resin layer 4 peels off when the light reflector 10 is processed into a desired shape. It becomes easy, and it becomes easy to produce a crack and a crack in the resin layer 4. FIG. Further, the reflection characteristics of the light reflecting plate 10 are insufficient. On the other hand, when the semi-crystallization time of the polyester resin is more than 120 seconds, when heating is performed to form the protective layer 8, the resin layer 4 is melted by heating, and wrinkles are generated. As a result, the reflection characteristics of the light reflecting plate 10 become insufficient.

In addition, the half crystallization time of a polyester resin can be measured using a differential scanning calorimeter (DSC), for example. Specifically, after heating to 290 ° C. above the melting temperature of the polyester resin at a temperature rising rate of 100 ° C./min using DSC, melting and holding for 3 minutes, 30 ° C. at a cooling rate of 200 ° C./min. Until the polyester resin is made amorphous. The amorphous resin thus obtained is heated again to 160 ° C. at which the resin crystallizes at a temperature increase rate of 100 ° C./min using DSC, and is held for 20 minutes for crystallization. . At this time, when the endothermic amount after the start of holding at 160 ° C. is continuously measured, the lowest endothermic peak appears after a certain period of time as shown in FIG. Then, the time from the start of holding at 160 ° C. to the appearance of the lowest endothermic peak (ie, T _H in FIG. 2) can be determined as the half-crystallization time.

  Moreover, as a polyester resin which comprises the resin layer 4, it is preferable that it is the range whose intrinsic viscosity is 0.6-1.4, and it is more preferable that it is the range which is 0.8-1.2. If the intrinsic viscosity is too low, the strength of the resin layer 4 is lowered, and when the light reflecting plate 10 is processed into a desired shape, the resin layer 4 is likely to be defective. On the other hand, if the intrinsic viscosity is too high, the melt viscosity when the polyester resin is heated and melted becomes extremely high, which may make it difficult to form the resin layer 4 made of the polyester resin on the substrate 2. is there.

  Moreover, it is preferable that the crystal orientation of the polyester resin which comprises the resin layer 4 is non-orientation. By using a non-oriented polyester resin, it is possible to further improve the molding processability of the light reflecting plate 10, whereby the light reflecting plate 10 can have various shapes depending on the use application of the lighting device. Can be easily processed.

  Furthermore, the melting point of the polyester resin constituting the resin layer 4 is preferably 220 to 245 ° C, more preferably 225 to 243 ° C.

  The thickness of the resin layer 4 is preferably 5 to 60 μm, more preferably 10 to 40 μm. If the thickness of the resin layer 4 is too thin, it is difficult to form the resin layer 4 on the substrate 2, and defects may easily occur in the resin layer 4 when the light reflecting plate 10 is processed into a desired shape. There is. On the other hand, when the thickness of the resin layer 4 is too thick, it becomes economically disadvantageous.

  Further, the surface roughness Ra of the resin layer 4 is preferably 0.1 μm or less. By setting the surface roughness Ra to 0.1 μm or less, the diffuse reflectance can be kept low, and the light reflecting plate 10 should be used favorably as a light reflecting member of an illuminating device used for the purpose of guiding light partially. Can do.

  Further, the ester resin constituting the resin layer 4 may contain an additive such as a lubricant such as silica, a stabilizer or an antioxidant within a range not impairing the effects of the present invention. However, when a lubricant such as silica is contained, in order to keep the surface roughness Ra of the resin layer 4 low, the resin layer 4 has a two-layer structure, and a lubricant such as silica is contained only in the lower layer. Is preferred.

<Reflection layer 6>
The reflective layer 6 is a layer made of silver or a silver alloy. Since silver has a high reflectance in the visible light region among the elements, it is preferable from the viewpoint of increasing the reflection efficiency of the light reflecting plate 10.

  The reflective layer 6 can be formed by an electroless plating method in which silver is reduced and deposited by a silver mirror reaction, for example, a spray plating method. In addition, it can be formed by an electroplating method in which electrolysis is performed in an aqueous solution containing silver ions, an evaporation method in which silver is evaporated in a reduced pressure atmosphere to form a film.

  The thickness of the reflective layer 6 is preferably 0.01 to 0.3 μm, more preferably 0.08 to 0.15 μm. If the thickness of the reflective layer 6 is too thin, pinholes are generated and the reflectance may be reduced. On the other hand, if the thickness of the reflective layer 6 is too thick, a desired glossy surface cannot be obtained, and the reflectance may decrease. Moreover, it is not desirable that the thickness of the reflective layer 6 is too thick economically.

<Protective layer 8>
The protective layer 8 is a layer for protecting the reflective layer 6 and is a layer containing a resin. Since the reflective layer 6 is made of silver or a silver alloy, the reflective layer 6 is likely to be discolored or contaminated when exposed to the atmosphere. In particular, the reflective layer 6 has the property of being easily discolored when the atmosphere contains even a small amount of a sulfur-based gas. Further, when washing dust and dirt adhering to the reflective layer 6, the reflective layer 6 also has the property of easily leaving traces of discoloration due to detergent. Therefore, the protective layer 8 is a layer provided on the light reflecting layer 6 in order to prevent these, and by providing the protective layer 8, it is possible to maintain the performance and maintain the light reflecting plate 10 over a long period of time. .

  The resin constituting the protective layer 8 is not particularly limited, but a resin having high transparency and capable of being thinned is preferably used. Specific examples of the resin constituting the protective layer 8 include polyester resin, acrylic resin, and silicone resin. The protective layer 8 can be formed by a coating method using a protective layer solution containing a resin.

  The thickness of the protective layer 8 is preferably 1 to 15 μm, more preferably 3 to 10 μm. If the thickness of the protective layer 8 is too thin, the protective effect of the reflective layer 6 is reduced, and the reflective layer 6 may be discolored or may be easily contaminated. On the other hand, if the thickness of the protective layer 8 is too thick, the reflectance of the light reflecting plate 10 may be reduced.

<Method for Manufacturing Light Reflector 10>
Next, a method for manufacturing the light reflecting plate 10 of the present invention will be described.

  First, a metal plate for constituting the base 2 is prepared, and the resin layer 4 is formed on the prepared metal plate by a film lamination method or an extrusion lamination method using a polyester resin that constitutes the resin layer 4. Form.

When the resin layer 4 is formed by a film laminating method, first, the polyester resin pellets are heated and melted at a temperature 20 to 40 ° C. higher than the melting temperature of the polyester resin, and then cooled on the cast roll from the T die. And a non-oriented polyester resin film is produced by winding with a coiler without stretching. On the other hand, while unwinding the long strip-shaped metal plate from the uncoiler, the metal plate is heated, and the polyester resin film is unwound and contacted with the heated metal plate. In order to prevent this, the resin layer 4 can be formed by immediately quenching in water.
The metal plate can form the resin layer 4 on a metal plate by heating it to -30 degreeC or more from the melting temperature of a polyester resin. In addition, the adhesiveness of a metal plate and the resin layer 4 becomes higher by heating a metal plate at the temperature 20-40 degreeC higher than the melting temperature of a polyester resin.

  When the resin layer 4 is formed by an extrusion lamination method, the polyester resin pellets are heated and melted at a temperature 20 to 40 ° C. higher than the melting temperature of the polyester resin, and are then unwound from the uncoiler. Then, the resin layer 4 can be formed by immediately quenching in water to prevent crystallization after casting directly from the T die.

  In the film laminating method described above, a primer is applied in advance to a long strip-shaped metal plate, and the metal plate to which the primer has been applied is heated, and a polyester is applied on the surface of the metal plate to which the primer has been applied. A resin film may be contacted.

Next, a reflective layer 6 made of silver or a silver alloy is formed on the resin layer 4. Hereinafter, a method for forming the reflective layer 6 made of silver by an electroless plating method will be described.
First, in order to further improve the adhesion between the resin layer 4 and the reflective layer 6, the surface of the resin layer 4 is subjected to corona discharge treatment or glow discharge treatment.

  Next, an aqueous solution (pretreatment solution) containing stannic chloride, stannous chloride and ferric chloride containing hydrochloric acid is applied to the surface of the resin layer 4, so that tin as a catalyst is added to the resin layer 4. Form on the surface. In addition, it is preferable to use what adjusted pH to 2 or less as a pretreatment solution. Next, the surface of the resin layer 4 on which tin is formed is washed with ion-exchanged water or distilled water, and the pretreatment solution remaining on the surface of the resin layer 4 is removed.

  Next, an aqueous silver nitrate solution is applied to the surface of the resin layer 4. As a result, the silver deposited on the surface of the resin layer 4 replaces the tin formed using the pretreatment solution, and a silver starting nucleus is formed. Next, the surface of the resin layer 4 is washed with ion-exchanged water or distilled water, and the excess silver nitrate aqueous solution remaining on the surface of the resin layer 4 is removed.

  Next, an aqueous ammoniacal silver nitrate solution having a pH of 10 to 13 and a reducing agent aqueous solution having a pH of 8 to 12 containing a reducing agent (for example, hydrazinium sulfate, glyoxal, etc.) are sprayed on the surface of the resin layer 4 on which the silver starting nucleus is formed Are injected at the same time. In this case, as the reducing agent aqueous solution, an aqueous solution obtained by dissolving or diluting the reducing agent in water and adding alkali to sodium hydroxide is used. Thereby, the reflective layer 6 made of silver is formed using silver formed on the surface of the resin layer 4 as a starting nucleus.

  Next, cleaning is performed using ion-exchanged water or distilled water to remove the ammoniacal silver nitrate aqueous solution and the reducing agent aqueous solution remaining on the surface of the reflective layer 6 and adhere to the surface of the reflective layer 6 by air blowing. Blow off the water droplets and then dry. Drying conditions can be 70 degreeC and 20 minutes, for example.

  In the present embodiment, when the reflective layer 6 is formed, an immersion method may be used instead of the above-described spray injection method, and further, instead of the above-described electroless plating method, The reflective layer 6 may be formed by a known electroplating method or vapor deposition method.

  Next, the protective layer 8 is formed on the reflective layer 6. The protective layer 8 can be formed by applying a solution for a protective layer containing a resin constituting the protective layer 8 on the reflective layer 6 and drying. The drying temperature is preferably 70 to 120 ° C, more preferably 80 to 100 ° C. The drying time is preferably 20 to 90 minutes, more preferably 30 to 60 minutes. In the present embodiment, since the resin layer 4 is formed using a polyester resin having a semi-crystallization time at 160 ° C. of 80 to 120 seconds, when the protective layer 8 is formed, the above temperature is set. Even when heating is performed, the resin layer 4 is melted to cause wrinkles, thereby effectively preventing the occurrence of a problem that the reflection characteristics are deteriorated.

  As described above, the light reflecting plate 10 of the present embodiment is manufactured.

  In the light reflecting plate 10 of the present embodiment, since the resin layer 4 is formed using a polyester resin having a semi-crystallization time of 80 to 120 seconds at 160 ° C., the light reflecting plate 10 has excellent heat resistance and reflection characteristics, and is also excellent. It has excellent workability. In particular, the light reflecting plate 10 of this embodiment can maintain excellent heat resistance and reflection characteristics well over a long period of time even after being processed into a desired shape according to the lighting device.

  In addition, according to this embodiment, when the resin layer 4 is formed on the substrate 2, the polyester resin that forms the resin layer 4 is heated and melted, and the polyester resin is heated and melted. Can be formed by a film lamination method or an extrusion lamination method. That is, according to the present embodiment, the resin layer 4 can be formed without using a solvent. Therefore, in the high temperature environment, a problem caused by the evaporation of the residual solvent, for example, the residual solvent is protected. By interacting with the resin constituting the layer 8, it is possible to effectively prevent problems such as coloration and a significant decrease in reflectance. In addition, according to the present embodiment, the resin layer 4 can be formed on the base 2 by thermally fusing the polyester resin to the base 2 without using an adhesive or the like. Is also possible.

  Furthermore, since the light reflecting plate 10 of the present embodiment includes the reflecting layer 6 and the protective layer 8 in advance, when the light reflecting plate 10 of the present embodiment is used as a light reflecting plate for a lighting device, illumination is performed. After processing into a desired shape according to the apparatus, a step of forming a reflective layer by plating or the like and further forming a protective layer thereon can be omitted, so that the manufacturing process can be simplified.

<Lighting member>
The illumination member of the present embodiment is formed by processing and molding the light reflecting plate 10 of the present embodiment described above. A method of processing and shaping the light reflecting plate 10 to obtain an illumination member is not particularly limited as long as it is a method capable of obtaining a desired shape corresponding to the illumination device. And press working. The spatula drawing process is a method of processing into a desired shape while rotating the light reflecting plate 10. In the present embodiment, press working is preferable from the viewpoint that damage to the reflecting surface of the light reflecting plate 10 can be prevented.

  Since the member for illumination of this embodiment is obtained using the light reflecting plate 10 of this embodiment mentioned above, it is excellent in heat resistance and reflection characteristics. Therefore, it can be suitably used as a light reflecting member for various lighting devices. In addition, since the light reflecting plate 10 of the present embodiment includes the reflective layer 6 and the protective layer 8 in advance, and further has excellent workability, according to the present embodiment, it is relatively easy and inexpensive. A lighting member can be obtained.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
In addition, the definition and evaluation method of each characteristic are as follows.

<Semi-crystallization time of polyester resin>
The semi-crystallization time of the polyester resin was measured using a differential scanning calorimeter (DSC) according to the method described above.

<Intrinsic viscosity>
It calculated | required based on ASTM-D2857.

<Reflection characteristics>
The light reflectors obtained in each Example and Comparative Example were processed into a predetermined shape for downlight, and the obtained processed product was totally reflected using a spectrocolorimeter (CM-3500d manufactured by Konica Minolta). The rate was measured. The reflection characteristics were evaluated according to the following criteria.
○: Total reflectance 85% or more △: Total reflectance 70% or more, less than 85% ×: Total reflectance 70% or less

<Heat resistance>
The light reflectors obtained in each of the examples and comparative examples were processed into a predetermined shape for downlighting, and the obtained processed product was completely heated on the surface of the sample for 60 days in a 120 ° C. electric oven. The reflectance and coloring (determined by the display color system b *) were measured with a spectrocolorimeter. The heat resistance was evaluated according to the following criteria.
-Total reflectance ○: "Total reflectance before heat test-Total reflectance after heat test" is -10% or more x: "Total reflectance before heat test-Total reflectance after heat test" Less than -10% Coloring (b *)
○: “b * before heat test—b * after heat test” is 10% or less ×: “b * before heat test—b * after heat test” exceeds 10%

<Illuminance>
The light reflector obtained in each example and comparative example was processed into a predetermined shape for downlight, and a mini-krypton sphere serving as a light source was attached to the obtained processed product to obtain an illumination device. The illuminance was measured at a location 1 m away from the obtained illumination device. The illuminance is measured by installing a lighting device so that the mini-krypton sphere is in a vertically downward state. From the illuminance just below the mini-krypton sphere (only one point) and the light source position of the mini-krypton sphere, From the illuminance on the line extending at an angle of 10 ° (total 4 points) and the light source position of the mini-krypton sphere, the light source position of the mini-krypton sphere and the position directly below The illuminance (total 4 points) on the line extending at an angle of 20 ° with respect to the connecting line was measured and averaged. In addition, the illuminance was measured using an illuminometer (manufactured by Konica Minolta, CL-200).

<Example 1>
Pellet-shaped polyester resin (copolymerized polyester resin having 95 mol% ethylene terephthalate units and 5 mol% ethylene isophthalate units, intrinsic viscosity: 0.9, semi-crystallization time: 113 seconds, melting point 234 ° C) at 280 ° C A non-oriented polyester resin film was produced by heating and melting, casting from a T die onto a cooled cast roll, and winding with a coiler without stretching. In order to prevent crystallization, the obtained polyester resin film is placed on a 1100-thick aluminum alloy plate having a thickness of 1 mm heated to 220 ° C., sandwiched between a pair of laminate rolls, and pressure-bonded. Immediately quenching in water, a laminate of a 28 μm thick polyester resin and an aluminum alloy plate was obtained. Next, a silver plating layer having a thickness of 80 nm was formed on the surface of the obtained laminate on which the polyester resin film was formed by a silver mirror reaction by spraying in accordance with the method described above. Next, a two-pack curable acrylic silicon resin coating (manufactured by Ohashi Chemical Industry Co., Ltd.) is blended on the silver plating layer at a ratio of 60 g of the main agent, 10 g of the curing agent, and 200 g of thinner so that the thickness after drying becomes 7 μm. A light reflection plate having a structure as shown in FIG. 1 was manufactured by forming a protective layer by spray coating and drying at 90 ° C. for 30 minutes.

  And each evaluation of the reflective characteristic after processing shaping | molding, heat resistance, and illumination intensity was performed using the obtained light reflection board. The results are shown in Table 1.

<Examples 2 and 3, Comparative Examples 1 and 2>
A light reflecting plate was produced and evaluated in the same manner as in Example 1 except that the polyester resin shown below was used. The results are shown in Table 1.
Example 2: Copolymerized polyester resin having 98 mol% ethylene terephthalate units and 2 mol% ethylene isophthalate units, intrinsic viscosity: 0.9, semi-crystallization time: 85 seconds, melting point: 243 ° C
Example 3: Copolyester resin having 92 mol% ethylene terephthalate units and 8 mol% ethylene isophthalate units, intrinsic viscosity: 0.7, semi-crystallization time: 118 seconds, melting point: 230 ° C
Comparative Example 1: Copolymerized polyester resin having 92 mol% ethylene terephthalate units and 8 mol% ethylene isophthalate units, intrinsic viscosity: 0.4, half crystallization time: 58 seconds, melting point: 252 ° C
Comparative Example 2: Copolyester resin having 90% by mole of ethylene terephthalate units and 10% by mole of ethylene isophthalate units, intrinsic viscosity: 0.4, semi-crystallization time: 165 seconds, melting point: no clear melting point

<Comparative Example 3>
On the aluminum alloy plate, instead of the polyester resin, a two-component curable acrylic urethane resin paint (manufactured by Ohashi Chemical Industry Co., Ltd.) is blended at a ratio of 50 g of the main agent, 10 g of the curing agent, and 100 g of thinner, and the thickness after drying. It is formed by spray coating so as to have a thickness of 5 μm, and then formed by spray coating. Next, in the same manner as in Example 1, a silver plating layer and a protective layer are formed on the acrylic silicon-based dendritic film, whereby a light reflecting plate Manufactured. The obtained light reflecting plate was evaluated in the same manner. The results are shown in Table 1.

<Comparative Example 4>
A light reflecting plate was produced in the same manner as in Example 1 except that the polyester resin was not formed. That is, in Comparative Example 4, the silver plating layer was formed directly on the aluminum alloy plate. The obtained light reflecting plate was evaluated in the same manner. The results are shown in Table 1.

  As shown in Table 1, when the resin layer 4 is formed using a polyester resin having a semi-crystallization time at 160 ° C. of 80 to 120 seconds, even after processing into a desired shape, Both the heat resistance and the illuminance were excellent (Examples 1 to 3).

On the other hand, when a polyester resin having a half crystallization time at 160 ° C. of less than 80 seconds is used, the adhesion of the resin layer is inferior, and therefore when the resin layer is processed into a desired shape, Peeling occurred between them, resulting in inferior reflection characteristics (Comparative Example 1).
When a polyester resin having a half crystallization time at 160 ° C. of more than 120 seconds was used, the resin layer was wrinkled by heating during the formation of the protective layer, resulting in poor reflection characteristics. . Further, the occurrence of wrinkles diffused light, resulting in a decrease in illuminance (Comparative Example 2).
In addition, when an acrylic urethane resin is used as the resin constituting the resin layer, and the resin layer is formed by spray coating, coloration occurs significantly after the heat resistance test, and the reflection characteristics deteriorate. Further, the illuminance was lowered (Comparative Example 3).
Furthermore, when the resin layer was not formed, the reflectance was low and high illuminance could not be obtained (Comparative Example 4).

Claims (8)

A substrate;
A resin layer comprising a polyester resin formed on the substrate and having a semi-crystallization time at 160 ° C. of 80 to 120 seconds;
A reflective layer formed on the resin layer and made of silver or a silver alloy;
A protective layer formed on the reflective layer and containing a resin,
The polyester resin includes at least one of polyethylene terephthalate, a copolymer having ethylene terephthalate as a monomer unit, a blend resin containing polyethylene terephthalate, and terephthalic acid which is an acid component in polyethylene terephthalate and ethylene glycol which is an alcohol component. A modified or substituted modified polyethylene terephthalate, and at least one polyester resin,
The light reflecting plate does not contain a vaporizable solvent in the resin layer.   The light reflecting plate according to claim 1, wherein the polyester resin is a polyester resin having ethylene terephthalate and ethylene isophthalate as monomer units.   The light reflecting plate according to claim 1, wherein the polyester resin is a non-oriented polyester resin.   The light reflecting plate according to claim 1, wherein the polyester resin has an intrinsic viscosity of 0.6 to 1.4.   The member for illumination formed by processing the light reflecting plate in any one of Claims 1-4. A step of laminating a resin layer formed by heating and melting a polyester resin having a semi-crystallization time of 80 to 120 seconds at 160 ° C. without using a solvent on a substrate by heat fusion; ,
Forming a reflective layer made of silver or a silver alloy on the resin layer;
Applying a protective layer solution containing a resin on the reflective layer and drying to form a protective layer made of the resin, and
As the polyester resin, at least one of polyethylene terephthalate, a copolymer having ethylene terephthalate as a monomer unit, a blend resin containing polyethylene terephthalate, and terephthalic acid which is an acid component in polyethylene terephthalate and ethylene glycol which is an alcohol component. A method for producing a light reflector using a polyester resin containing at least one of modified polyethylene terephthalate which is modified or substituted. The melting point of the polyester resin is 220 to 245 ° C.,
The method for producing a light reflecting plate according to claim 6, wherein the polyester resin is heated to a temperature equal to or higher than the melting point thereof, and the polyester resin is laminated on the substrate by heat fusion to form the resin layer. .   The method for producing a light reflecting plate according to claim 6 or 7, wherein the polyester resin has an intrinsic viscosity of 0.6 to 1.4.

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