JPH03233403A - Glass provided with improved reflecting film excellent in durability - Google Patents

Abstract

PURPOSE:To improve the durability of a glass by forming a improved reflecting film formed on the surface of the glass essentially by a multiple oxide of Ti, Ta and Si. CONSTITUTION:The improved reflecting film coated on the surface of a glass is formed essentially by a multiple oxide of Ti, Ta and Si. Namely, the resistance to chemicals such as acid and alkali is improved by the Ta oxide, the smoothness of the film is improved by the Si oxide, and the durability against the contaminants such as org. acids and grease is enhanced. As a result, an improved reflecting film excellent in durability is obtained by screen printing at a low cost and with good productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a highly durable glass with an increased reflection film, and particularly to a highly durable combiner for a head-up display that can be put to practical use.

[Prior Art] Conventionally, it has been known to provide a metal oxide reflective film on a glass substrate and use this as a HUD combiner, and some of these have also been commercialized. Industrially, sol-gel methods such as dip coating, spray printing, transfer printing, and screen printing are inexpensive methods for obtaining reflective coatings, and screen printing in particular is said to be the most promising as a mass production technique. However, since the screen printing method contains a large amount of organic components in the printing material, the film quality is more likely to be porous than the vacuum method or other sol-gel methods.
There was a risk that chemical durability such as chemical resistance would deteriorate.

[Problem to be solved by the invention] Conventionally, Ti oxide or T obtained by screen printing
A film made of an i-Si composite oxide has a problem that it is not suitable for use in an exposed state because the film undergoes deterioration, dissolution, etc. in a long-term chemical resistance test.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems,
The reflection-enhancing film is made of a composite oxide of Ti, Dina, and Si and has excellent durability. That is,
The present invention provides a glass having a reflection-enhancing film on its surface, and the reflection-enhancing film is made of Ti.

The present invention provides a glass with an enhanced reflection film having excellent durability and characterized in that the film is mainly composed of a composite oxide of Ta and Si.

In the present invention, the reflective film is a film whose main component is a composite oxide of Ti, Ta, and SL. In Figure 1, Ti,
The properties of the film are shown depending on the composition of Ta and Si.

In the figure, the ratio is expressed as a weight ratio of Ti oxide (in terms of TiO□), Ta oxide (in terms of 20 g of Ta), and Si oxide (in terms of SiO2) to the entire oxide component in the film. (Hereinafter, Si for the entire oxide component
Oxide content (SiO□ conversion), Ti oxide content (
TiOz equivalent), Ta oxide content (Ta20s equivalent) is shown as a, b, c (wt%), respectively) 0 < a < 4
0 (wt%) and b:C=100:O~90:l
The area where O is present (the area indicated by B in FIG. 1) has poor chemical resistance, particularly acid resistance. Also, 0<a<10 (wt%),
In addition, the region where b: c to 90: 10 to O: 100 (the portion indicated by C in FIG. 1) has poor durability against dirt such as oil and fat, that is, poor dirt resistance.

In order for the reflection-enhancing film in the present invention to function as a reflection-enhancing film, it is preferable that the refractive index is higher than that of glass. Although the necessary refractive index varies depending on the application, it is preferable that the refractive index is 1.8 or more, especially as a combiner for a head-up display. As a combiner for head-up displays, the refractive index is 1.8.
This is because if it is less than that, it is difficult to obtain a preferable reflectance even if the film thickness is increased. The refractive index of the constituent elements of the reflection enhancing film of the present invention is about 2.2 to 2.3 for TiO□, and about 20. is about 2.1 to 2.0, and Sin is about 1.5, so if the content of Si oxide and Ta oxide is large, the film tends to have a relatively low refractive index.

That is, the area where a > 50 (wt%) and 10 <
a < 50 (wt%), and b: c = 5
The region of 0+ 50 to O: 100 (the part shown in the middle of FIG. 1) has a low refractive index and is not preferable as a reflection enhancing film.

From the above, the reflection-enhancing film of the present invention has the following characteristics: (i) 10≦a≦40 and b:C=90:1O~
50:500 composition, or (ii) 40≦a≦50 and b:c=100:O~
50:50 (b:c=100:
It is preferable to have a composition (white area in FIG. 1) (excluding O). In particular, 20≦a≦50 and b:c=9
A composition of 0:10 to 50:50 is most preferred.

The reflection enhancing film of the present invention may contain P (phosphorus) in order to improve the sinterability when sintering after coating by screen printing or the like, and to improve the abrasion resistance of the film.

When used in a combiner for a head-up display, the thickness of the reflective coating is determined in order to increase the surface reflectance and to make the difference in color tone less noticeable compared to the area where the reflective coating is not formed. The optical film thickness (product of refractive index n and actual film thickness d) is 400 to 2,300 people, especially 400
~1500 people, preferably 700 to 1200 people. If the optical film thickness is within this range, variations in film thickness will not be noticeable, which is preferable in terms of appearance and also improves productivity. Further, it is preferable that the optical film thickness is from 400 to 1,500, since a particularly neutral appearance can be easily obtained.

The method for producing the reflection-enhancing film is not particularly limited, but vacuum film forming methods such as vacuum evaporation, sputtering, and ion blasting, as well as sol-gel methods such as dipping and printing can also be used.

Among these, a method of screen printing and firing an ink containing a metal alkoxide as a metal oxide raw material is preferred because it has the highest productivity and is low cost.

In this way, when using the screen printing method, in order to ensure printing stability and stability over time, an ink is used in which the alkoxide is dissolved in a high boiling point solvent such as Octatool or a mixture of phenyl cellosolve, and the ink is thickened with ethyl cellulose, etc. This is desirable.

When the highly durable reflective increasing film of the present invention is used as a combiner for a head-up display on a windshield,
From the point of view of safety, such windshield glass is usually
A laminated glass made by bonding two sheets of glass together via a plastic interlayer film is used, but the laminated glass is not limited to this, and may be made of a single glass.

The glass with an increased reflection film of the present invention can be used not only for combiners for head-up displays, but also for various other applications such as automobiles, architecture, and electronic parts.

[Function] In the reflection-enhancing film of the present invention, Ta oxide mainly contains acids,
It is thought that it increases the durability against chemicals such as alkalis, and also improves the smoothness of the film, thereby increasing the durability against dirt such as organic acids and oils and fats. .

[Example] <Sample 1> 2mmmm cerium oxide polished, washed with water, and thoroughly dried
Prepare the Wakuriyada Lime glass substrate and paste it.
A screen printing ink containing alkoxides of i and a in a ratio of 50:50 (weight ratio in terms of oxide) was printed. The ink contains 2.0 wt% of metal alkoxide in terms of metal oxide, and the viscosity of the ink is 360Q.
It was cps. After baking at 600℃ for 10 minutes, a transparent oxide with a film thickness of 500 mm and a refractive index of 1.89 (λ = 6328 mm) was formed on the glass surface, and the visible light transmittance was 83% and the visible light reflectance was 15%. there were.

<Sample 2> Ink containing Ti, Ta, and SL alkoxides in proportions of 49%, 21%, and 30% (weight ratio in terms of oxide), respectively, was applied to a thoroughly washed and dried 2 mm mm waxy lime glass substrate. It was screen printed. The metal alkoxide in the ink is 2.0 wt% in terms of metal oxide.
The viscosity was 4300 cps. 1 at 600℃
The film thickness after firing for 0 minutes was 500, the refractive index was 1.92, Tv=81%, and Rv=17%.

<Sample 3> 4 ml each of Ti, Ta, and Si alkoxides were placed on a thoroughly washed and dried 2 mm mm waxy lime glass substrate.
Screen printing was performed using inks containing 2%, 18%, and 40% (weight ratio in terms of oxide). The metal alkoxide content in the ink is 2.0 wt% in terms of metal oxide.
The viscosity of the ink was 4100 cps. 1 at 600℃
Film thickness after firing for 0 minutes is 500, refractive index 1.90, Tv
= 82%, Rv = 16%.

Sample 4> Ink containing Ti, Ta, and SL alkoxides in proportions of 46%, 42%, and 11% (weight ratio in terms of oxide), respectively, was applied to a thoroughly washed and dried 2 mm mm waxy lime glass substrate. It was screen printed. The ink contains 1.8 wt% of metal alkoxide in terms of metal oxide.
The viscosity was 5200 cps. 1 at 600℃
The film thickness after firing for 0 minutes was 500, the refractive index was 1.89, Tv=83.3%, and Rv=14.8%.

Sample 5> Ink containing Ti, Ta, and Si alkoxides in proportions of 40%, 36%, and 24% (weight ratio in terms of oxide), respectively, was applied to a thoroughly washed and dried 2 mm mm waxy lime glass substrate. It was screen printed. The metal alkoxide content in the ink is 2.0wt in terms of metal oxide.
%, and the viscosity of the ink was 5340 cps. 600℃
After firing for 10 minutes, the film thickness was 600 mm, refractive index 1.88,
Tv=82%, Rv=16%.

<Sample 6> 90% each of Ti and Si alkoxides were added to a 2 mm mm waxy lime glass substrate that had been thoroughly washed and dried.
Screen printing was performed using an ink containing 10% (metal alkoxide content in the ink: 1 wt%,
Ink viscosity: 3800CI)S)600°
The film thickness after firing for 10 minutes at C was 350, the refractive index was 2.0, Tv = 81%, and Rv = 17%.

Acid resistance test (0,1N
H2SO, room temperature immersion for 10 days), alkali resistance test (
Durability to a 10-day immersion in 0.1N NaOH at room temperature) and a fat resistance test (1-day immersion in an organic acid/organic substance mixture) was evaluated by the change in visible light transmittance Tv before and after each test.

As shown in Table 1, it was confirmed that good durability was achieved when predetermined amounts of Ti oxide, Ta oxide, and Si oxide were included. In addition, in samples 1 to 6, the refractive index is the value for t = 6328 people, and in the Ellip table * table, no change means that the Tv change width before and after the test is 1%.
In the case of less than

In addition, samples 1 to 4 were subjected to the Taber test (C8-10F
All samples had Tv and haze changes of 2% or less, which were within the range of almost no problem.

[Effects of the Invention] The present invention provides an enhanced reflection film with excellent durability that is inexpensive, highly productive, and can be realized by screen printing.
By containing Ta and Si oxides in predetermined proportions, it is recognized that the film has the effect of being able to have chemical durability comparable to that of a vacuum-deposited film.

INDUSTRIAL APPLICABILITY The present invention can provide a highly durable combiner for head-up displays that can be put to practical use.

[Brief explanation of drawings]

FIG. 1 is a composition diagram showing film properties depending on the contents of Ti oxide, Ta oxide, and Si oxide.

Claims (1)

[Claims] 1. A durable glass having a reflection-enhancing film on its surface, characterized in that the reflection-enhancing film is a film whose main component is a composite oxide of Ti, Ta, and Si. Glass with excellent reflective coating. 2. The above-mentioned reflection-enhancing film has S
i oxide content (in terms of SiO_2), Ti oxide content (in terms of TiO_2), Ta oxide content (in terms of Ta_2O_
5 conversion) are respectively a, b, and c (wt%), (i) 10≦a≦40, and b:c=90:10~5
0:50 composition, or (ii) 40≦a≦50 and b:c=100:0~
The highly durable glass with an increased reflection film according to claim 1, having a composition of 50:50 (excluding b:c=100:0). 3. The above reflective film satisfies 20≦a≦50 and b:c=
The highly durable glass with an increased reflection film according to claim 2, having a composition of 90:10 to 50:50. 4. A combiner for a head-up display using a highly durable glass coated with an increased reflection film having the structure according to any one of claims 1 to 3.