WO2008018298A1

WO2008018298A1 - Ag ALLOY REFLECTIVE FILM FOR REFLECTOR, REFLECTOR, AND Ag ALLOY SPUTTERING TARGET FOR FORMATION OF Ag ALLOY REFLECTIVE FILM FOR REFLECTOR

Info

Publication number: WO2008018298A1
Application number: PCT/JP2007/064653
Authority: WO
Inventors: Jun Suzuki; Toshiki Sato; Takao Kawanaka
Original assignee: Kabushiki Kaisha Kobe Seiko Sho
Priority date: 2006-08-10
Filing date: 2007-07-26
Publication date: 2008-02-14
Also published as: JP2008046149A

Abstract

Disclosed are: an Ag alloy reflective film for use in the formation of a reflector which has a high reflectivity and hardly causes the coagulation of Ag by humidity or heat; a reflector; and an Ag alloy sputtering target for use in the formation of an Ag alloy reflective film for a reflector. (1) Disclosed is an Ag alloy reflective film for a reflector, which comprises Ag as the main ingredient and one or more members selected from Ti, V, Cr, Mn, Mg and W in a total amount of more than 3 atm% and not more than 7 atm%. (2) The Ag alloy reflective film may contain one or more members selected from Au, Pt, Pd and Cu in a total amount of 0.3 to 2 atm%. (3) The Ag alloy reflective film may have a reflectivity as measured with light having a wavelength of 650 nm of 85% or greater. (4) The Ag alloy reflective film may be formed by a sputtering process. (5) Also disclosed is a reflector having the Ag alloy reflective film. (6) Further disclosed is a target for use in the formation of an Ag alloy reflective film.

Description

Specification

Ag alloy reflective film for reflectors, reflectors, and Ag alloy sputtering targets for the formation of Ag alloy reflective films for reflectors

Technical field

The present invention belongs to a technical field relating to an Ag alloy reflective film for a reflector, a reflector, and an Ag alloy sputtering target for forming an Ag alloy reflective film for a reflector.

Background art

[0002] Conventionally, Ag thin films have high reflectivity! / And are therefore used for optical mirrors such as reflectors for lamps mounted on automobiles, reflectors for lighting equipment, and liquid crystal displays.

In these applications, automotive lamps and lighting equipment are required to have high heat resistance because they are exposed to a temperature environment of about 100 to 200 ° C. by heat emitted from a light emitter. Furthermore, durability in a high temperature and high humidity environment is required.

[0004] However, since the Ag thin film is not sufficiently durable to the environment, it has been difficult to use it for a long time due to deterioration due to moisture or the like. For this reason, attempts have been made to prevent deterioration of the Ag thin film by forming a UV curable resin, acrylic resin, or ceramic protective film on the Ag thin film. However, these methods not only increase the cost, but the protective film of the resin is inferior in barrier properties, and the ceramic protective film infiltrates moisture from a defect such as a pinhole or a crack. Therefore, it has been difficult to obtain sufficient durability. Moreover, since Ag thin films easily aggregate due to heat, it was difficult to use them in a high temperature environment.

[0005] In view of this, there has been proposed a technique relating to a reflector that improves the heat resistance and weather resistance by improving the barrier property and heat resistance of the resin of the protective film (Japanese Patent Laid-Open No. 2000-106017). Also disclosed is a technique for improving durability by adding other metal components to Ag. Japanese Patent Laid-Open No. 9-135096 proposes a technique in which 3 atomic% of one or more elements of Pd, Cu, Au, Ni, Zn, Cd, Mg, and Al are added to Ag. In the 2001-226765 publication, it is proposed to add 0.1 to 3 atomic% of Pd, Cu, Au to Ag to improve durability.

Patent Document 1: Japanese Patent Laid-Open No. 2000-106017 Patent Document 2: Japanese Patent Laid-Open No. 9-135096

Patent Document 3: Japanese Patent Laid-Open No. 2001-226765

Disclosure of the invention

Problems to be solved by the invention

[0006] The reflective film of the reflector is required to have high reflectivity and durability against humidity, heat, and the like.

However, an Ag thin film satisfying all of these required characteristics has not been obtained yet. Conventional Ag thin films easily aggregate due to humidity and heat, resulting in white spots and turbidity, resulting in lower reflectivity.

[0007] The present invention has been made by paying attention to such a situation, and an object of the present invention is to provide an Ag alloy reflective film for a reflector and a refractor which is difficult to cause aggregation of Ag due to humidity and heat having high reflectivity. We intend to provide an Ag alloy sputtering target for forming an Ag alloy reflective film for reflectors and reflectors.

Means for solving the problem

[0008] As a result of intensive investigations to achieve the above object, the present inventors have added a specific alloy element to Ag in a certain range amount, thereby causing aggregation of Ag due to humidity and heat. The knowledge that it was possible to suppress life was obtained. The present invention has been completed based on such knowledge and the like, and can achieve the above object.

[0009] The present invention, which has been completed in this way and has achieved the above object, is an Ag alloy reflecting film for a reflector, a reflector, and an Ag alloy sputtering target for forming an Ag alloy reflecting film for a reflector. The reflector alloy film for reflectors according to claim 1 to claim 4 (Ag alloy reflector film for reflector according to the first to fourth inventions), the Ag alloy reflector film for reflectors according to claims 5 to 6 An Ag alloy sputtering target for forming (a sputtering target according to the fifth to sixth inventions) and a reflector according to claim 7 (the reflector according to the seventh invention), which has the following configuration.

[0010] That is, the Ag alloy reflective film for a reflector according to claim 1 is an Ag alloy reflective film for a reflector, comprising Ag as a main component and selected from Ti, V, Cr, Mn, Mg, and W. The Ag alloy reflective film for a reflector is characterized by containing a total of more than 3 atom% and not more than 7 atom% [first invention]. [0011] The Ag alloy reflective film for a reflector according to claim 2, wherein the Ag alloy reflective film for a reflector according to claim 1 contains a total of 0.3 to 2 atomic% of at least one selected from Au, Pt, Pd, and Cu. It is a reflective film [second invention].

[0012] The Ag alloy reflective film for reflector according to claim 3 is an Ag alloy reflective film for reflector according to claim 1 or 2, wherein the reflectance measured by light having a wavelength of 650 nm is 85% or more. 3 inventions]. The Ag alloy reflective film for reflector according to claim 4 is the Ag alloy reflective film for reflector according to any one of claims 1 to 3, which is formed by a sputtering method [fourth invention].

[0013] The Ag alloy sputtering target for forming an Ag alloy reflective film for a reflector according to claim 5 is mainly composed of Ag, and includes at least one selected from Ti, V, Cr, Mn, Mg, and W. An Ag alloy sputtering target for forming an Ag alloy reflective film for reflectors, characterized by containing more than 3 atom% and not more than 7 atom% [Fifth Invention]. Claim 6. The reflector according to claim 6, wherein the Ag alloy sputtering target for forming an Ag alloy reflective film contains at least one selected from Au, Pt, Pd, and Cu in a total amount of 0.3 to 2 atomic%. 5. An Ag alloy sputtering target for forming an Ag alloy reflective film for a reflector as described in [5th invention].

[0014] A reflector according to claim 7 is a reflector having the Ag alloy reflective film according to any one of claims 1 to 4! [Seventh invention].

The invention's effect

[0015] The Ag alloy reflective film for a reflector according to the present invention hardly causes aggregation of Ag due to humidity or heat having high reflectivity. Therefore, it can be suitably used as an Ag alloy reflecting film for a reflector, and its function and durability can be improved. Since the reflector according to the present invention is provided with such an Ag alloy reflective film, Ag aggregation due to humidity and heat with high reflectivity is difficult to occur, and the function and durability of the reflector are improved. Is peeled off. According to the Ag alloy sputtering target for forming an Ag alloy reflective film for a reflector according to the present invention, an Ag alloy reflective film can be formed.

BEST MODE FOR CARRYING OUT THE INVENTION

[0016] The inventors put metal plates of various elements on an Ag target, produced Ag alloy thin films of various components' composition by sputtering, and determined the composition and characteristics as a reflective film. evaluated. This property evaluation method can be performed after a high-temperature and high-humidity test (left for 1000 hours in an atmosphere of 60 ° C and 90% humidity), or a salt water immersion test [concentration O. Olmol / liter (hereinafter referred to as L After that, the reflective film was evaluated for the occurrence of white turbidity and white spots, and the change in reflectance was investigated.

[0017] As a result of examination using this evaluation method, an Ag alloy reflective film in which one or more selected from Ti, V, Cr, Mn, Mg, and W is added to Ag is more turbid than pure Ag thin film. It was found that the generation of white spots was significantly suppressed and the decrease in reflectance was small. As described above, white turbidity and white spots are generated by aggregation of Ag due to humidity and heat, and the Ag alloy reflective film can be said to have excellent durability.

[0018] The effect of improving the durability due to the addition of one or more selected from Ti, V, Cr, Mn, Mg, and W varies depending on the amount of addition of this element. It is desirable to have it. When the total amount of elements added is 3 atomic% or less, the Ag aggregation suppressing effect is small and the required durability cannot be obtained. On the other hand, when the added amount of this element increases and exceeds 7 atomic%, the reflectivity decreases and the function as a reflective film is lost. From this point, the addition amount of the above elements for maintaining durability and performance as a reflective film is preferably more than 3 atomic% and 7 atomic% or less, and more preferably 3.5 to 5 atomic%. Is more preferable. Based on the above, the Ag alloy reflective film for a reflector according to the present invention contains Ag as a main component, and one or more selected from Ti, V, Cr, Mn, Mg, and W in total exceeds 3 atomic%. It is characterized by containing not more than atomic% [first invention].

[0019] The Ag alloy reflective film for a reflector according to the present invention further contains at least one selected from Au, Pt, Pd, and Cu in a total amount of 0.3 to 2 atomic%. [Second invention]. This is because by containing 0.3 to 2 atomic% of these elements (one or more selected from Au, Pt, Pd, and Cu), chemical stability is further improved and durability is further increased. If the content of these elements is less than .3 atomic%, the effect of improving chemical stability and durability is small. If it exceeds 2 atomic%, the initial reflectance tends to decrease.

[0020] The Ag alloy reflective film for a reflector according to the present invention has a reflectance measured by light having a wavelength of 650 nm of 85% or more, and can be suitably used as a reflector film for a reflector [Third Invention]. A1 thin film is used for the conventional reflective film for reflectors, and the wavelength is 650nm. The reflectance measured by the light is around 85%. On the other hand, since the A1 thin film is very weak against acids and alkalis, it is essential to coat a protective layer of a transparent resin on the A1 reflective film. Since the formation of this protective layer is expensive, there is a need for a reflective film that can be used for a long time without providing a protective layer. The Ag alloy reflective film for a reflector according to the present invention is a reflective film made of an Ag alloy that is stable against acids and alkalis, and has excellent durability, so a protective layer such as a resin is not required! / Because of this, the cost merit is great.

[0021] It is desirable that the Ag alloy reflective film for a reflector according to the present invention is formed (deposited) by a sputtering method! /, [Fourth Invention]. This is because the Ag alloy reflective film formed by sputtering is dense and excellent in adhesion!

[0022] The thickness of the Ag alloy reflective film for a reflector according to the present invention is preferably in the range of 70 nm to 300 nm, more preferably in the range of 100 nm to 200 nm.

[0023] The Ag alloy reflective film for a reflector according to the present invention hardly causes aggregation of Ag due to humidity or heat with high reflectivity. Therefore, it can be suitably used as an Ag alloy reflecting film for a reflector, and its function and durability can be improved.

[0024] The reflector according to the present invention is provided with such an Ag alloy reflective film. Therefore, Ag aggregation due to humidity or heat with high reflectivity is unlikely to occur, and the function of the reflector is improved. And improved durability [seventh invention]. The Ag alloy reflective film is formed on a base material made of resin or the like.

[0025] An Ag alloy sputtering target for forming an Ag alloy reflective film for a reflector according to the present invention contains Ag as a main component and a total of one or more selected from Ti, V, Cr, Mn, Mg, and W. An Ag alloy sputtering target for forming an Ag alloy reflective film for a reflector, characterized by containing more than 3 atomic percent and not more than 7 atomic percent [Fifth Invention]. According to this Ag alloy sputtering target, the Ag alloy reflective film for optical information recording media according to the first invention of the present invention can be formed. In the case of an Ag alloy sputtering target for forming an Ag alloy reflective film for a reflector according to the present invention, further containing at least one selected from Au, Pt, Pd, and Cu in an amount of 0.3 to 2 atomic% Can form an Ag alloy reflective film for an optical information recording medium according to the second invention of the present invention [Sixth Invention].

Example [0026] Examples and comparative examples of the present invention will be described below. It should be noted that the present invention is not limited to these examples, and can be implemented with appropriate modifications within a range that can be adapted to the gist of the present invention, all of which fall within the technical scope of the present invention. included.

[0027] [Example 1]

Using a DC magnetron sputtering apparatus, an Ag alloy thin film having a thickness of 120 nm was formed on a glass substrate (Counging # 1737) having a diameter of 50 mm and a thickness of 0.7 mm. At this time, the sputtering target used was an Ag target (diameter 101.6 mm, thickness 5 mm) on which metal chips of various additive elements were placed. Deposition conditions are: substrate temperature: room temperature, Ar gas pressure:;! ~ 3m Torr (0.13-0.40Pa), distance between electrodes: 55mm, sputtering power: DC 580W, film formation speed: 5-6 nm / sec film before ultimate vacuum: 3.0 was ^{X 10- 6 ΤΟΓΓ (4 · 0} X 10- 4 Pa).

[0028] For the Ag alloy thin film thus formed, the content of the additive element was measured by ICP emission spectroscopic analysis. In addition, a durability evaluation test was performed.

At this time, the durability evaluation test was performed by a high temperature and high humidity test and a salt water immersion test. In this high-temperature and high-humidity test, the surface of the Ag alloy thin film was visually observed after being left for 1000 hours in an atmosphere at a temperature of 60 ° C and a humidity of 90% RH, and the occurrence of white turbidity and white spots on the film was evaluated. . In the salt water immersion test, the sample was immersed in an aqueous solution of NaCl with a concentration of O. Olmol / L for 1 hour, washed in pure water, and the surface of the Ag alloy thin film was visually observed to evaluate the occurrence of white turbidity and white spots on the film. went.

[0030] Further, the reflectance before and after the high temperature and high humidity test was measured. At this time, light having a wavelength of 650 nm was used as incident light, and the reflectance was measured.

[0031] Table 1 shows the results of measurement of the content of the additive element, durability evaluation test, and reflectance measurement. In Table 1, each mark in the Ag Aggregation Status column indicates the occurrence of white turbidity and white spots, “◯” indicates the absence of white turbidity and white spots, and “△” indicates some. White turbidity-a state where white spots are generated, and "X" indicates a state where white turbidity or white spots are generated on the entire surface. In addition, “X” in the column after the salt water immersion test includes a state in which the film peeling is remarkable.

[0032] As can be seen from Table 1, the samples No. l, 2, 10 (comparative example) had a very high initial reflectivity (reflectance before the high-temperature and high-humidity test) of 91.7 to 96.2%. High humidity test and salt water immersion test Many white turbidity and white spots were generated after the test, and the reflectivity was greatly reduced by the high temperature and high humidity test. The reflectivity after the high temperature and high humidity test was lower than 85%.

[0033] On the other hand, the Ag alloy thin films of Νο · 3 to 5, 7, 8, 11 to 14, 16 to 19 (invention example) have an initial reflectivity of 87 to 95%, Even after the humidity test and the salt water immersion test, the reflectance decreases due to the high-temperature and high-humidity test where no white turbidity or white spots are generated on the film surface. Therefore, the durability is good and the film has sufficient performance as a reflective film.

[0034] In the eighth, eighth and _eighth alloy thin films of Comparative Examples 6, 9 and 15, the generation of white turbidity / white spots due to Ag aggregation was slight, but the content of additive elements was too high and the initial reflectivity was low. Low and insufficient. The Ag alloy thin films of No. 20 to 24 (comparative examples) all had an initial reflectance of 85% or more, but Ag aggregation was observed during the high temperature and high humidity test and the salt water immersion test. Moreover, the decrease in reflectivity due to the high-temperature and high-humidity test was larger than that of the No. 3-5, 7, 8, 11-14, 16-19 (invention example) Ag alloy thin films.

[0035] As described above, the Ag alloy thin film of the present invention has a sufficiently high initial reflectivity, and Ag aggregation is hardly caused by the high-temperature and high-humidity test and the salt water immersion test. Since the decrease is slight, it can be suitably used as a reflective film for a reflector.

[Example 2]

Using the same DC magnetron sputtering apparatus as in Example 1, an Ag alloy thin film having a thickness of 120 nm was formed on the same glass substrate under the same conditions. At this time, as a sputtering target, one type of metal chip selected from Ti, V, Cr, and Mn and one type of metal chip selected from Au, Pt, Pd, and Cu are simultaneously placed on the Ag target. A ternary Ag alloy thin film was deposited.

[0037] With respect to the Ag alloy thin film thus formed, the content of the additive element was measured by ICP emission spectrometry. In addition, a high-temperature and high-humidity test was performed under the same conditions (atmosphere and test time) as in Example 1, and durability was evaluated by the change in reflectance before and after the test.

[0038] Table 2 shows the measurement results of the content of the above-mentioned additive elements and the reflectance measurement results before and after the high-temperature and high-humidity test. As can be seen from Table 2, the reflectance before high-temperature and high-humidity test is slightly reduced by adding Au, Pt, Pd, and Cu to Ag-Ti, Ag-V, Ag-Cr, and Ti-Mn, respectively. However, the decrease in reflectivity after the high temperature and high humidity test is clearly suppressed. No.32, 34, 37 As shown in the figure, the initial reflectivity is lower than 85% when the amount of Au added is large (over 2 atomic%).

[0039] [Table 1] Table 1

[0040] [Table 2]

Table 2

[0041] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. is there. This application is based on a Japanese patent application filed on August 10, 2006 (Japanese Patent Application No. 2006-218593), the contents of which are incorporated herein by reference.

Industrial applicability

[0042] The Ag alloy reflective film for a reflector according to the present invention is less likely to cause aggregation of Ag due to humidity or heat having a high reflectivity, and can be suitably used as an Ag alloy reflective film for a reflector. .

Claims

The scope of the claims

[1] Ag alloy reflective film for reflectors, containing Ag as a main component and containing one or more selected from Ti, V, Cr, Mn, Mg, W in total exceeding 3 at% and up to 7 at% Ag alloy reflective film for reflectors.

[2] The Ag alloy reflective film for a reflector according to claim 1, which contains a total of 0.3 to 2 atomic% of one or more selected from Au, Pt, Pd, and Cu.

[3] The Ag alloy reflective film for reflector according to claim 1 or 2, wherein the reflectance measured by light having a wavelength of 650 nm is 85% or more.

[4] The Ag alloy reflective film for a reflector according to any one of claims 1 to 3, which is formed by a sputtering method.

[5] Ag in the main component, more than 3 atomic% in total of at least one selected from Ti, V, Cr, Mn, Mg, W

An Ag alloy sputtering target for forming an Ag alloy reflective film for a reflector, characterized by containing 7 atomic% or less.

[6] The Ag alloy sputtering target for forming an Ag alloy reflective film for a reflector according to claim 5, which contains a total of 0.3 to 2 atomic% of one or more selected from Au, Pt, Pd, and Cu.

[7] A reflector comprising the Ag alloy reflective film according to any one of [1] to [4].