US5394269A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reflectance reducing film and method of forming same on glass substrate
Assignee: Central Glass Co Ltd
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Filing: 1993-11-12
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Granted: 1995-02-28
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Expires: 2013-11-12
Abstract
Abstract The invention relates to a reflectance reducing silicon dioxide film formed on a glass substrate by the sol-gel process. To make the film minutely rough, at least two sols are respectively prepared from at least one compound selected from the group consisting of silicon alkoxides and silicon acetylacetonates, such that polymers of the sols have different average molecular weights. Then, the at least two sols are mixed with a solvent so as to prepare a coating solution. The coating solution is applied to the glass substrate so as to form a sol film on the glass substrate. The thus coated glass substrate is heated so as to transform the sol film into a gel film. The gel film which is minutely rough is satisfactory in reflectance reduction.
Inventors
- 👤 Atsushi Takamatsu
- 👤 Osamu Takahashi
- 👤 Hiroaki Arai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:58
CPC Classifications
C; C03; C03C; C03C1/00; C03C1/006; C03C1/008; C03C17/00; C03C17/006; C03C17/007; C03C17/008; C03C17/009; G; G02; G02B; G02B1/00; G02B1/10; G02B1/11; G02B1/113; C03C2217/00; C03C2217/20; C03C2217/21; C03C2217/213; C03C2217/40; C03C2217/425; C03C2217/70; C03C2217/77; C03C2218/00; C03C2218/10; C03C2218/11; C03C2218/113
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
197 words
A method of forming on a glass substrate a silicon dioxide film having a thickness of about 60 to 160 nm and a refractive index of 1.21 to 1.40 and being minutely rough such that the film has micro-pits and/or microscopic land regions, at least one of each micro-pit and each land region having a diameter of 50 to 200 nm, the method comprising the steps of: (a) preparing at least two sols respectively from at least one compound so as to disperse in said at least two sols at least two polymers of said at least one compound, said at least one compound being selected from the group consisting of silicon alkoxides and silicon acetylacetonates, said at least two polymers having different average molecular weights; (b) mixing said at least two sols together with a solvent so as to prepare a coating solution; (c) applying the coating solution to the glass substrate so as to form a sol film on the glass substrate; and (d) heating the glass substrate and the sol film so as to transform the sol film into a gel film which has a minutely rough surface having micro-pits and/or microscopic and regions.
Claim 2
Independent Claim
197 words
A method of forming on a glass substrate a silicon dioxide film having a thickness of about 60 to 160 nm and a refractive index of 1.21 to 1.40 and being minutely rough such that the film has micro-pits and/or microscopic land regions, at least one of each micro-pit and each land region having a diameter of 50 to 200 nm, the method comprising the steps of: (a) preparing at least two sols respectively from at least one compound so as to disperse in said at least two sols at least two polymers of said at least one compound, said at least one compound being selected from the group consisting of silicon alkoxides and silicon acetylacetonates, said at least two polymers having different average molecular weights; (b) mixing said at least two sols together with a solvent so as to prepare a coating solution; (c) applying the coating solution to the glass substrate so as to form a sol film on the glass substrate; and (d) heating the glass substrate and the sol film so as to transform the sol film into a gel film which has a minutely rough surface having micro-pits and/or microscopic and regions.
Claim 3
Dependent Claim
52 words
A method according to claim 1, wherein one polymer of said at least two polymers has an average molecular weight ranging from about 800 to about 5,000, and the other at least one polymer of said at least two polymers has an average molecular weight ranging from about 50,000 to about 400,000.
Claim 4
Dependent Claim
22 words
A method according to claim 2, wherein said one polymer has an average molecular weight ranging from about 2,000 to about 3,000.
Claim 5
Dependent Claim
39 words
A method according to claim 1, wherein at step (b) said one polymer and the other at least one polymer are mixed in the ratio of 1:10 to 30:1 by the number of moles reduced to an oxide basis.
Claim 6
Dependent Claim
13 words
A method according to claim 1, wherein said solvent is an alcohol solution.
Claim 7
Dependent Claim
21 words
A method according to claim 5, wherein said solvent is one selected from the group consisting of isopropyl alcohol and 1-butanol.
Claim 8
Dependent Claim
23 words
A method according to claim 1, wherein the glass substrate is heated at step (d) at a temperature not lower than 100° C.
Claim 9
Dependent Claim
21 words
A method according to claim 1, wherein at step (b) the viscosity of the coating solution is adjusted to 1-10 centipoises.
Claim 10
Dependent Claim
37 words
A method according to claim 1, wherein at step (b) the concentration of said at least two polymers reduced to an oxide basis in the coating solution is in the range from 0.1 to 10 wt %.
Claim 11
Dependent Claim
31 words
A method according to claim 1, wherein at step (c) the coating solution is applied to the glass substrate in an atmosphere having a relative humidity ranging from 40 to 90%.
Claim 12
Dependent Claim
74 words
A reflectance reducing silicon dioxide film formed on a glass substrate, the film having a thickness of about 60 to 160 nm and a refractive index of 1.21 to 1.40 and being minutely rough such that the film has micro-pits and/or microscopic land regions, at least one of each micro-pit and each land region having a diameter of 50 to 200 nm, the film being prepared in accordance with the method of claim 1.
Claim 13
Dependent Claim
15 words
A method according to claim 1, wherein each land region is defined between adjacent micro-pits.
Claim 14
Dependent Claim
15 words
A film according to claim 11, wherein each land region is defined between adjacent micro-pits.
Claim 15
Dependent Claim
26 words
A film according to claim 11, wherein micro-pits and land regions are stable when the film is baked at a temperature not lower than 500° C.
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