JP5890111B2 - Reflector and lighting device - Google Patents

Description

  The present invention relates to a lighting device including a reflector, and more particularly to a lighting device suitable for a vehicular lamp.

  The vehicular lamp has a configuration in which a light source and a reflector are arranged in a lamp chamber formed by a lens and a housing, as disclosed in Patent Document 1, for example. The light emitted from the light source toward the reflector is reflected by the reflector and irradiated to the front of the lamp through the lens.

  As described in Patent Document 1 and Patent Document 2, a reflector is generally a laminate of a base film, a reflective film such as Al, and a protective film on the surface of a synthetic resin substrate. The Al deposited film has a reflectance of about 85 to 90% in the entire visible light region, and is therefore widely used as a reflective film for vehicle lamps such as automobiles and motorcycles. As the underlayer, a resin layer (Patent Document 1) coated with a resin coating or a silicon oxide film (Patent Document 2) formed by plasma CVD using HMDS (hexamethyldisiloxane) as a source gas is used. As the protective film, a paint film (Patent Document 1) or a water-repellent polymer film (silicon oxide film) (Patent Document 2) formed by plasma CVD using HMDS as a source gas is used. In the technique of Patent Document 2, the surface of the underlayer is bombarded to form an activation treatment layer, and the surface of the protective film (water-repellent polymer film) is bombarded to form a hydrophilic treatment layer. Yes.

  On the other hand, in Patent Document 3, a total of one or more elements of Sc, Y, La, Gd, Tb, and Lu are contained in an amount of 0.4 to 2.5 at%, and the balance is formed of an alloy of Al. It has been proposed to do. When this Al alloy film is formed by sputtering, it has a higher reflectance than pure Al, and has excellent alkali resistance, acid resistance, and moisture resistance. It is disclosed that it hardly occurs.

JP-A-10-31909 JP 2010-1542 A JP 2011-21275 A

  The reflector of the structure of Patent Document 2 has a complicated structure including an underlayer (silicon oxide layer-activation treatment layer) -Al reflection film-protection film-hydrophilization treatment layer. In addition, since bombarding is performed to form the activation treatment layer and the hydrophilic treatment layer, there are many steps accompanying the film formation. Since the underlayer and the protective film are formed by the plasma CVD method, a dedicated exhaust system is required, which increases the cost of the apparatus. In the plasma CVD method, the film formation time is long and the manufacturing time is extended. Further, since the underlayer and the protective film are formed by plasma CVD, a silicon oxide film is deposited on the inner wall of the vacuum chamber of the film forming apparatus. When the deposited silicon oxide film is peeled off during film formation, it adheres to the reflective film surface and causes a decrease in yield. In order to prevent this, it is necessary to periodically clean the inner wall of the vacuum chamber, leading to a decrease in production efficiency.

  On the other hand, when the protective film is formed by a coating method as in Patent Document 1, dust easily adheres to the coated surface, and the yield decreases. Moreover, since the resin material containing an organic solvent is used, an environmental load is large. In view of the health of workers, it is desired to reduce the use of organic solvents.

  The Al alloy reflective film described in Patent Document 3 has not been obtained that has both alkali resistance and water resistance sufficient to be required as a vehicular lamp. Moreover, Al alloy has a high material cost.

  An object of the present invention is to provide a reflective film having high production efficiency and excellent water resistance and alkali resistance, and an illumination device including the same.

  In order to achieve the above object, according to the present invention, there is provided a reflecting mirror having an aluminum-containing film as a reflecting film and a zirconium-containing film disposed on the aluminum-containing film.

  It is possible not to provide another layer on the zirconium-containing film and to configure the outermost surface layer of the reflecting mirror to be a zirconium-containing film. The thickness of the zirconium-containing film is preferably 2.5 nm or more and 10 nm or less. As the zirconium-containing film, a pure zirconium film containing inevitable impurities can be used.

  As the aluminum-containing film, a pure aluminum film containing inevitable impurities can be used.

  In the reflecting mirror of the present invention, by stacking a zirconium-containing film on the reflecting film, water resistance and alkali resistance can be improved without significantly impairing the reflectance. The zirconium-containing film can be easily formed by a sputtering method, and since it has low water repellency, it is not necessary to hydrophilize the surface of the zirconium-containing film. Therefore, a reflecting mirror can be manufactured with a simple manufacturing process and high yield.

The block diagram which shows the cross-sectional structure of the headlamp of embodiment of this invention. Sectional drawing which shows the laminated constitution of the reflector of FIG. (A) Explanatory drawing which shows the manufacturing process of the reflector of this embodiment, (b) Explanatory drawing which shows the manufacturing process of the reflector of a prior art. The graph which shows the wavelength dependence of the reflectance of the reflector of an Example and Comparative Examples 1 and 2. FIG.

  An illumination device according to an embodiment of the present invention will be described.

  In the present invention, an aluminum film is used as a reflecting film of the reflector (reflecting mirror), and a zirconium film is laminated on the upper surface of the aluminum film. Thereby, although it is a simple structure, the reflector which has alkali resistance and water resistance can be provided. By using this reflector for a vehicle lighting device, the durability of the vehicle lighting device is improved. This will be specifically described below.

  The vehicle lighting device of this embodiment will be described by taking a headlamp as an example. As shown in FIG. 1, the headlamp of the present embodiment includes a lens cover 40 disposed on the light emitting direction side and a lamp body 50 disposed on the back side, and is formed by the lens cover 40 and the lamp body 50. Inside the lamp chamber 60, the light source 30 and the reflector 20 are arranged. An extension reflector 10 is arranged around the reflector 20 in order to decorate the space between the reflector 20 and the lamp body 50.

  The light emitted from the light source 30 is reflected directly or by the reflector 20, passes through the lens cover 40, and is irradiated forward.

  The film configuration of the reflector 20 will be described with reference to FIG. As shown in FIG. 2, the reflector 20 has a configuration in which an undercoat layer 22, an aluminum film 23 as a reflective film, and a zirconium film 24 as a protective film are sequentially laminated on a resin base material 21.

  The film thickness of the aluminum film 23 is preferably 50 nm or more, and more preferably 150 nm or more and 250 nm or less. The aluminum film 23 is preferably pure aluminum. The aluminum film 23 is formed by a vapor phase growth method such as a sputtering method using pure aluminum as a target or a vapor deposition method using pure aluminum as an evaporation source. The aluminum film 23 may contain inevitable impurities.

  The thickness of the zirconium film 24 is preferably 1.5 nm or more from the viewpoint of alkali resistance, and particularly preferably 2.5 nm or more. Moreover, it is preferable that it is 10 nm or less from a viewpoint of a reflectance, and it is especially preferable that it is 5 nm or less. The zirconium film 24 may be a pure zirconium film or a zirconium compound. In the case of a pure zirconium film, inevitable impurities may be contained. The zirconium film 24 can be easily formed at high speed using a sputtering method, particularly a DC (direct current) sputtering method. Therefore, it is excellent in the stability and economics of the film forming process as compared with other known protective films. It is of course possible to form a film using an RF (alternating current) sputtering method.

  Since the zirconium film 24 formed by the sputtering method has low water repellency, it is not necessary to perform a hydrophilic treatment after the film formation, but it is possible to perform a hydrophilic treatment in order to increase the hydrophilicity.

  Even if the zirconium film 24 is disposed, the reflectance of the reflector 20 does not decrease significantly in the entire wavelength range of visible light, and the gloss color does not change.

  The base material 21 is processed into a desired shape of the reflector 20. As a material of the base material 21, PPS (Polyphenylenesulfide), BMC (Bulk Molding Compound), PET / PBT (Polyethylene Terephthalate / Polybutylene Terephthalate), etc. can be used suitably.

  The undercoat layer 22 is a layer for improving the smoothness and adhesiveness of the resin base material 21, and a known undercoat layer can be used. Specifically, for example, an acrylic resin layer or a silicon oxide layer is disposed as the undercoat layer 22. Moreover, the undercoat layer 22 can be omitted for a substrate having smoothness and adhesion.

  In the present embodiment, by simply forming a thin film of the zirconium film 24 on the aluminum film 23, the reflector 20 excellent in not only alkali resistance but also water resistance and moisture resistance can be obtained. Therefore, a highly reliable lighting device can be provided.

  The manufacturing process of the reflector 20 of this embodiment is demonstrated using Fig.3 (a). First, the base material 20 processed into the shape of the desired reflector 20 is prepared. On top of that, an undercoat layer 22 is formed by wet coating or vapor deposition (step 100). For example, when an acrylic resin film is formed as the undercoat layer 22, it is formed by a wet coating method using an organic solvent. Further, when a silicon oxide film is formed as the undercoat layer 22, it is formed by a plasma CVD method or a sputtering method.

  Next, an aluminum film 23 is formed as a reflective film (step 101). For example, the reflective film 23 is formed by sputtering using pure aluminum as a sputtering target.

  Finally, a zirconium film 24 is formed as a protective film by sputtering (step 102). Thus, the reflector 20 is manufactured by a simple process.

  When the manufacturing process of the reflector 20 of the present embodiment is compared with the conventional manufacturing process of the reflector (described in Patent Document 2) as shown in FIG. A step 401 for forming an aluminum film by bombarding the surface of the formed underlayer, a step 402 for forming a water-repellent protective film (silicon oxide film) by plasma CVD thereon, and a water-repellent type While the step 403 for forming the hydrophilic film by bombarding the surface of the protective film is necessary, the manufacturing method of FIG. 3A of this embodiment does not require the plasma CVD process or the bombardment process. I understand that there is.

  Thus, according to the present embodiment, the plasma CVD process is not necessary, and the manufacturing process can be simplified, so that the manufacturing cost can be reduced.

  Moreover, in this embodiment, since the deposit in a vacuum chamber peels off and the plasma CVD process which can cause generation | occurrence | production of dust becomes unnecessary, a manufacturing yield can be improved.

  Further, it is not necessary to remove the deposited film in the vacuum chamber of the plasma CVD apparatus as in the conventional case, maintenance time can be shortened, production efficiency can be improved, and manufacturing cost can be reduced.

  In addition, the target used for forming the aluminum film and the zirconium film in the present embodiment is not a special alloy, but can be easily and inexpensively obtained because it is a commonly used metal material, and the manufacturing cost can be reduced.

  The illuminating device of this embodiment can be used as a headlight for automobiles and various lighting fixtures. Moreover, the film | membrane structure of the reflector of this embodiment can be used for the use of the reflective film of various displays, the reflective film of various electronic components, and the reflective film of a solar power generation device.

  The reflector 20 of the lighting device of the present invention was manufactured, and the alkali resistance, water resistance and moisture resistance were confirmed.

(Example)
An undercoat layer 22 made of acrylic resin was formed on a substrate 21 made of PPS (Polyphenylenesulfide) resin by a coating method to a thickness of about 20 μm.

  The substrate 21 is put into a sputtering apparatus, and an aluminum film 23 having a thickness of about 160 nm is formed by a DC sputtering method using a pure aluminum (JIS standard A1050) target with an input power of 5000 W, a deposition time of 90 seconds, and a 100% Ar atmosphere. A film was formed.

  Continuously, a zirconium film 24 having a thickness of 2.5 nm was formed in a 100% Ar atmosphere using a zirconium target by DC sputtering with an input power of 100 W, a deposition time of 12 seconds, and a 100% Ar atmosphere. Thereby, the reflector 20 of the Example was manufactured.

(Comparative Example 1)
An acrylic resin undercoat layer was formed on a PPS (Polyphenylenesulfide) resin substrate by a coating method to a thickness of about 20 μm.

  The substrate is placed in a sputtering apparatus, and an aluminum film having a thickness of about 160 nm is formed by DC sputtering using a pure aluminum (JIS standard A1050) target, with an input power of 5000 W, a film formation time of 90 seconds, and a 100% Ar atmosphere. did.

  The substrate is moved to a plasma CVD apparatus, HMDS (hexamethyldisiloxane) is introduced as a source gas, an input power of 3000 W, a film formation time of 20 seconds, and a 20 nm thick silicon oxide film is formed as a protective film by plasma CVD. Filmed. Thereby, the reflector of Comparative Example 1 was manufactured.

(Comparative Example 2)
The reflector manufacturing process of Comparative Example 1 was not performed, and the other processes were performed in the same manner as Comparative Example 1 to manufacture the reflector of Comparative Example 2.

(Measurement of reflectance)
The reflectance in the visible light region of 350 nm to 800 nm was examined for the reflector sample of the example and the reflector samples of Comparative Examples 1 and 2. The result is shown in the graph of FIG. As shown in FIG. 4, the sample of the example has a higher reflectance than the sample having the silicon oxide film of Comparative Example 1 as a protective film, and the reflectance of the sample of Comparative Example 2 in which the aluminum film is not provided without the protective film. However, the reflectance was 84% or more in the entire visible light range. From this value, it was confirmed that the sample of the example had sufficient reflectivity as a reflector.

(Alkali resistance evaluation)
The samples of Examples and Comparative Examples 1 and 2 were subjected to an alkali resistance test. Specifically, after immersing each sample in a 1 wt% KOH solution for 10 minutes, the sample is visually observed, and those having no defects such as show-through, peel-off, and white spot are marked with ○, see-through, peel-off, and white spot. Those with one were evaluated as x.

(Water resistance evaluation)
The samples of Examples and Comparative Examples 1 and 2 were subjected to a water resistance test. Specifically, the sample was immersed in warm water at a temperature of 40 ° C. for 24 hours and then left at room temperature for 1 hour. Thereafter, the sample was visually observed, and those having no defects such as show-through, peeling, and white spots were evaluated as ◯, and those having at least one of show-through, peeling, and white spots were evaluated as x.

(Moisture resistance evaluation)
The samples of Examples and Comparative Examples 1 and 2 were subjected to a moisture resistance test. Specifically, it was exposed to a constant temperature and humidity atmosphere having a humidity of 98% and a temperature of 50 ° C. for 240 hours and then left at room temperature for 1 hour. Thereafter, the sample was visually observed, and those having no defects such as show-through, peeling, and white spots were evaluated as ◯, and those having at least one of show-through, peeling, and white spots were evaluated as x. The evaluation results are shown in Table 1.

  As shown in Table 1, the samples of Examples and Comparative Example 1 did not cause defects in any of the alkali resistance test, the water resistance test, and the moisture resistance test. As shown in Table 1, the aluminum film-only sample without the protective film of Comparative Example 3 was dissolved in the alkali resistance test, and the aluminum film was discolored in the water resistance test. In the moisture resistance test, the reflective film was dissolved.

  From the above, it was confirmed that the sample of the example can provide a reflector having alkali resistance, water resistance and moisture resistance by providing a zirconium film as a protective film.

DESCRIPTION OF SYMBOLS 10 ... Extension reflector, 20 ... Reflector, 21 ... Base material, 22 ... Undercoat, 23 ... Reflecting film, 24 ... Oxygen plasma treatment layer, 30 ... Light source, 40 ... Lens cover, 50 ... Lamp body, 60 ... Lamp chamber

Claims (3)

A reflection having a resin base material processed into a desired reflecting mirror shape, a base layer formed on the base material, and an aluminum-containing film as a reflective film formed on the base layer In the mirror
A pure zirconium film is disposed as an outermost layer on the aluminum-containing film,
A film thickness of the pure zirconium film is 2.5 nm or more and 5 nm or less.   An illumination device comprising the reflecting mirror according to claim 1. Forming a base layer by a coating method on a resin substrate processed into a desired reflector shape;
A step of forming an aluminum-containing film as a reflective film on the underlayer by vapor deposition;
Forming a pure zirconium film as the outermost surface layer on the aluminum-containing film by a sputtering method,
The thickness of the pure zirconium film is 2.5 nm or more and 5 nm or less.

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