JPH0780691B2 - Glass with anti-reflection film with excellent durability - Google Patents

Description

TECHNICAL FIELD The present invention relates to a glass with a reflection-increasing film having excellent durability, and particularly to a highly durable combiner for a head-up display which is put to practical use.

[Prior Art] Conventionally, it is known to provide a metal oxide enhanced reflection film on a glass substrate and use it as a HUD combiner.
Some products have been commercialized. As a method for obtaining a reflection enhancing film, the sol-gel method such as a dip coating method, a spray method, a transfer printing method, and a screen printing method is industrially cheap in terms of cost, and the screen printing method can be said to be the most promising as a mass production technology. . However, since the screen printing method contains a large amount of organic components in the printing material, it tends to become porous compared to the vacuum method and other sol-gel methods in terms of film quality, and chemical resistance such as chemical resistance is low. There was a risk of deterioration.

[Problems to be Solved by the Invention] Conventionally obtained Ti oxide or Ti-S obtained by screen printing
A film made of an i-complex oxide had a problem that it was not suitable for use in an exposed state in a long-term chemical resistance test because the film was deteriorated and dissolved.

[Means for Solving the Problems] The present invention has been made to solve the above problems.
The enhanced reflection film is made of a composite oxide of Ti, Ta, and Si and has excellent durability. That is, the present invention is a glass having a reflection-increasing film on the surface, wherein the reflection-increasing film contains Ti, Ta and Si as a main component, and
The present invention provides a glass with a reflection-increasing film having excellent durability, which is characterized by being a film having a refractive index of 1.8 or more.

In the present invention, the enhanced reflection film is a film whose main component is a composite oxide of Ti, Ta and Si. FIG. 1 shows the properties of the film with respect to the composition of Ti, Ta and Si. In the figure, the ratio is
The weight ratio of Ti oxide (as TiO ₂ equivalent), Ta oxide (as Ta ₂ O ₅ equivalent), and Si oxide (as SiO ₂ equivalent) to the total oxide components was shown. (Si oxide content (SiO ₂ conversion), Ti oxide content (TiO ₂ conversion),
Ta oxide content (Ta ₂ O ₅ conversion) is a, b, c (wt%) respectively
). 0 <a <40 (wt%) and b: c = 100: 0〜
The region of 90:10 (the portion indicated by B in FIG. 1) is inferior in chemical resistance, particularly acid resistance. When 0 <a <10 (wt%),
In addition, the region where b: c = 90: 10 to 0: 100 (the portion indicated by C in FIG. 1) is inferior in durability against stains such as oils and fats, that is, in stain resistance.

In order to exert the function of the enhanced reflection film in the present invention, the enhanced reflection film needs to have a higher refractive index than glass, that is, a refractive index of 1.8 or more. For example, as a combiner for a head-up display, if the refractive index is less than 1.8, it is difficult to obtain a preferable reflectance even if the film thickness is increased. The refractive index of the components of the reflection enhancing film of the present invention is such that TiO ₂ is about 2.2 to 2.3, Ta ₂ O ₅
Is about 2.1-2.0 and SiO ₂ is about 1.5, so Si oxide and T
When the content of a oxide is large, the film tends to have a relatively low refractive index. That is, a> 50 (wt%) area and 10
The region where <a <50 (wt%) and b: c = 50: 50 to 0: 100 (the portion indicated by D in 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 is the portion indicated by the region A in FIG. 1, that is, (i) 10 ≦ a ≦ 40 and b: c = 90: 10 to 50:50, or ( ii) It is preferable to have a composition (white part in FIG. 1) of 40 ≦ a ≦ 50 and b: c = 100: 0 to 50:50 (excluding b: c = 100: 0). In particular, 20 ≦ a ≦ 50, and b: c
Most preferably, the composition is 90:10 to 50:50.

The reflection enhancing film of the present invention may contain P (phosphorus) for the purpose of improving the sinterability when the film is applied by screen printing or the like and then sintered, and for improving the abrasion resistance of the film.

When used in a combiner for head-up display, the film thickness of the reflection enhancing film is to increase the surface reflectance and to make the difference in color tone less noticeable than in the portion where the reflection enhancing film is not formed. , Optical film thickness (product of refractive index n and actual film thickness d) is 400 to 2300Å, especially 400 to 1500
Å, preferably 700 to 1200 Å. When the optical film thickness is within this range, variations in film thickness are not noticeable, which is preferable in terms of appearance and also has good productivity. Further, if the optical film thickness is 400 to 1500 Å, a neutral appearance is likely to be obtained, which is preferable.

The method for producing the enhanced reflection film is not particularly limited, and a vacuum film forming method such as a vacuum deposition method, a sputtering method, an ion plating method, or a sol-gel method such as an immersion method or a printing method can be used. Among them, the method of screen-printing an ink containing a metal alkoxide as a metal oxide raw material and baking the ink is most preferable because it has the highest productivity and is low in cost.

Thus, when using the screen printing method, in order to secure printing stability and stability over time, use an ink in which an alkoxide is dissolved in a high-boiling-point solvent such as octanol or phenyl cellosolve mixture, and thickened with ethyl cellulose or the like. Is desirable.

When using the durable reflective film of the present invention as a combiner for a windshield head-up display,
As such a windshield, it is usually 2 from the viewpoint of safety.
A laminated glass obtained by joining a plurality of glasses through a plastic intermediate film is used, but the invention is not particularly limited to this, and a single glass plate may be used.

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

[Operation] In the reflection-increasing film of the present invention, Ta oxide mainly enhances durability against chemicals such as acids and alkalis, and Si oxide improves smoothness of the film, and as a result, mainly organic acid and It is considered that it works to increase the durability against dirt such as oil and fat.

[Example] <Sample 1> A soda lime glass substrate having a thickness of 2 mm and fully dried after polishing with cerium oxide, washing with water, and alkoxide of Ti and Ta of 50:50 (weight ratio in terms of oxide) were prepared. A screen printing ink was included which was included in proportion. In the ink, metal alkoxide is 2.0 wt% in terms of metal oxide.
%, And the ink viscosity was 3600 cps. At 600 ° C
After baking for 10 minutes, the film thickness is 500Å and the refractive index is 1.89 on the glass surface.
A transparent oxide of (λ = 6328Å) was formed, and the visible light transmittance was 83% and the visible light reflectance was 15%.

<Sample 2> 49%, 21% of Ti, Ta, and Si alkoxides were respectively added to a 2 mm thick soda lime glass substrate that had been thoroughly washed and dried,
Screen printing was performed using an ink containing 30% (weight ratio based on oxide). The ink contained 2.0 wt% of metal alkoxide in terms of metal oxide, and the viscosity was 4300 cps. After baking at 600 ℃ for 10 minutes, the film thickness is 500Å and the refractive index is 1.92.
And Tv = 81% and Rv = 17%.

<Sample 3> 42%, 18% of Ti, Ta and Si alkoxides were respectively added to a 2 mm thick soda lime glass substrate that had been thoroughly washed and dried,
Screen printing was performed using an ink containing 40% (weight ratio based on oxide). The content of metal alkoxide in the ink is 2.0 wt% in terms of metal oxide, and the ink viscosity is 4100 cps.
Met. After baking at 600 ℃ for 10 minutes, the film thickness is 500Å, refractive index
The values were 1.90, Tv = 82%, and Rv = 16%.

<Sample 4> Ti, Ta, and Si alkoxides were 46% and 42%, respectively, on a 2 mm thick soda-lime glass substrate that had been thoroughly washed and dried.
Screen printing was performed using an ink containing 11% (weight ratio as oxide). The ink contained 1.8 wt% of metal alkoxide in terms of metal oxide, and had a viscosity of 5200 cps. After baking at 600 ℃ for 10 minutes, the film thickness is 500Å and the refractive index is 1.89.
And Tv = 83.3% and Rv = 14.8%.

<Sample 5> 40%, 36% of Ti, Ta, and Si alkoxides are added to a 2 mm thick soda lime glass substrate that has been thoroughly washed and dried, respectively.
Screen printing was performed using an ink containing 24% (weight ratio as oxide). The content of metal alkoxide in the ink is 2.0 wt% in terms of metal oxide, and the viscosity of the ink is 5340c.
It was ps. After baking at 600 ° C for 10 minutes, the film thickness was 600Å, the refractive index was 1.88, Tv = 82%, and Rv = 16%.

<Sample 6> A 2 mm thick soda lime glass substrate that had been thoroughly washed and dried was screen-printed with an ink containing Ti and Si alkoxides at 90% and 10%, respectively (the metal alkoxide content in the ink was included). Quantity 1wt%, ink viscosity: 38
00cps). After baking at 600 ℃ for 10 minutes, the film thickness is 350Å, refractive index
It was 2.0, and Tv = 81% and Rv = 17%.

Acid resistance test (0.1NH ₂ S
O ₄ room temperature immersion 10 days), alkali resistance test (0.1N NaOH room temperature immersion 10 days) and fat resistance test (organic acid, organic compound mixture immersion 1 day) durability before and after each test change of visible light transmittance Tv It was evaluated by. As shown in Table 1, it was confirmed that when the Ti oxide, the Ta oxide, and the Si oxide were contained in a predetermined amount, they had good durability. In addition,
In Samples 1 to 6, the refractive index is a value at λ = 6328Å and is measured by an ellipsometer.
Further, Tv and Rv are visible light transmittance and visible light reflectance defined by JIS R-3106.

Further, the samples 1 to 4 were subjected to a taper test (CS-10F wear wheel, load 500 g, 1000 revolutions), and all the samples had a change in Tv and haze of 2% or less, which was within a range of almost no problem.

[Advantages of the Invention] The present invention can provide a reflection enhancing film having excellent durability at low cost with high productivity and can be realized by a screen printing method.
It is recognized that the chemical durability equivalent to that of the vacuum vapor deposition film can be obtained by containing the above-mentioned materials and Si oxide in a predetermined ratio.

INDUSTRIAL APPLICABILITY The present invention can provide a highly durable combiner for a head-up display that is sufficiently practical.

[Brief description of drawings]

FIG. 1 is a composition diagram showing the properties of the film with respect to the contents of Ti oxide, Ta oxide, and Si oxide.

Claims (3)

[Claims] 1. A glass having a surface having a reflection enhancing film, comprising:
A glass with an enhanced reflection film having excellent durability, characterized in that the enhanced reflection film is a film containing a composite oxide of Ti, Ta and Si as a main component and having a refractive index of 1.8 or more. 2. The above-mentioned reflection-increasing film has a Si oxide content (SiO ₂ conversion), a Ti oxide content (TiO ₂ conversion), and a Ta oxide content (Ta ₂ O) with respect to all oxide components in the film. a ₅ equivalent), respectively, b, When c (wt%), (i ) 10 ≦ a ≦ 40 and,, b: c = 90: 10~50: 50 composition, or (ii) 40 ≦ a ≦ The reflection enhancing film having excellent durability according to claim 1, having a composition of 50 and b: c = 100: 0 to 50:50 (excluding b: c = 100: 0). Attached glass. 3. A combiner for head-up display, which uses the glass with a reflection enhancing film having excellent durability according to claim 1.