US4082427A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High refractive index glass compositions
Assignee: Fukuoka Tokushugarasu KK
•
Filing: 1977-02-23
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Granted: 1978-04-04
•
Expires: 1997-02-23
Abstract
Abstract Disclosed are glass compositions that are particularly suited for making colorless and transparent reflex-reflective glass beads with refractive indices over 2.15. These lead-free glass compositions are made with TiO 2 as the main constituent mixed with alkaline earth oxides and alkaline metal oxides, etc.
Inventors
- 👤 Nobuyuki Nakashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:43
CPC Classifications
C; C03; C03C; C03C12/00; C03C12/02; C03C3/00; C03C3/12; C03C3/127; G; G02; G02B; G02B5/00; G02B5/12; G02B5/126; G02B5/128; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/901; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T442/00; Y10T442/20; Y10T442/259; Y10T442/2598
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
121 words
Lead-free colorless and transparent glass suitable for formation at 1300° - 1500° C of colorless, transparent glass, beads having a refractive index exceeding 2.15 for use in reflex-reflective articles, and whose composition by weight percentage is: ______________________________________
% Range Combined Range
______________________________________
TiO.sub.2 55 - 65
BaO 17 - 30
CaO 1 - 10
MgO 0 - 2 18 - 35%
SrO 0 - 6
ZnO 3 - 15
MoO.sub.3 0 - 5
ZrO.sub.2 0 - 5 0.2 - 5%
Na.sub.2 O 0 - 0.5
K.sub.2 O 0 - 0.5
Li.sub.2 O 0 - 0.5 0.1 - 0.5%
B.sub.2 O.sub.3
0 - 2
SiO.sub.2 0 - 2
Al.sub.2 O.sub.3
0 - 2 less than 2%
P.sub.2 O.sub.5
0 - 2
______________________________________
Claim 2
Dependent Claim
121 words
Lead-free colorless and transparent glass suitable for formation at 1300° - 1500° C of colorless, transparent glass, beads having a refractive index exceeding 2.15 for use in reflex-reflective articles, and whose composition by weight percentage is: ______________________________________
% Range Combined Range
______________________________________
TiO.sub.2 55 - 65
BaO 17 - 30
CaO 1 - 10
MgO 0 - 2 18 - 35%
SrO 0 - 6
ZnO 3 - 15
MoO.sub.3 0 - 5
ZrO.sub.2 0 - 5 0.2 - 5%
Na.sub.2 O 0 - 0.5
K.sub.2 O 0 - 0.5
Li.sub.2 O 0 - 0.5 0.1 - 0.5%
B.sub.2 O.sub.3
0 - 2
SiO.sub.2 0 - 2
Al.sub.2 O.sub.3
0 - 2 less than 2%
P.sub.2 O.sub.5
0 - 2
______________________________________
Claim 3
Dependent Claim
90 words
The process for preparing lead-free spherical glass beads of refractive index exceeding 2.15 which comprises the steps of forming a melt of glass having the composition according to claim 1; quenching said melt in a cold liquid medium; comminuting said glass into particles in the size range of 0.03 to 0.1 mm; suspending said particles in an air stream; heating said suspended particles to 1300° - 1500° C until softened whereby the surface tension of the softened glass converts said particles to spheroidal beads; rapidly cooling and collecting said beads.
Claim 4
Dependent Claim
35 words
Reflective articles comprising a support coated with a matrix film comprising a transparent resin polymer, said matrix film including a layer of the glass beads of refractive index greater than 2.15 according to claim 2.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |