US4680047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the manufacture of glass bodies
Assignee: US Philips Corp
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Filing: 1986-01-09
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Granted: 1987-07-14
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Expires: 2006-01-09
Abstract
Abstract A method for the manufacture of glass bodies, in which a thixotropic suspension, being the starting material for the glass body, is used to form a porous green body which is subsequently purified and sintered, the starting material being liquefied in a mould by subjecting it to mechanical forces, and subsequently freeing it of the influence of the said forces, after which it solidifies again to form a green body.
Inventors
- 👤 Rolf Clasen
- 👤 Heinz Scholz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:21
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/016; C03B17/00; C03B17/04; C03B19/00; C03B19/12
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
80 words
A method for the manufacture of a porous green body wherein the green body is subsequently purified and sintered to form a glass body, said method comprising introducing a gelled thixotropic suspension of silicon dioxide particles in a dispersion liquid into a mold, liquefying said gel, while in sail mold, by applying mechanical forces to said gel and removing said mechanical forces from the resultant liquefied suspension therby allowing said liquefied thixotropic suspension to gellify to form said green body.
Claim 2
Independent Claim
80 words
A method for the manufacture of a porous green body wherein the green body is subsequently purified and sintered to form a glass body, said method comprising introducing a gelled thixotropic suspension of silicon dioxide particles in a dispersion liquid into a mold, liquefying said gel, while in sail mold, by applying mechanical forces to said gel and removing said mechanical forces from the resultant liquefied suspension therby allowing said liquefied thixotropic suspension to gellify to form said green body.
Claim 3
Dependent Claim
37 words
A method as claimed in claim 1, characterized wherein a suspension is used as the starting material for the green body, which comprises SiO 2 particles having a diameter in the range from 10 to 500 nm.
Claim 4
Dependent Claim
15 words
A method as claimed in claim 1, wherein water is used as a dispersing fluid.
Claim 5
Dependent Claim
25 words
A method as claimed in claim 1 wherein a suspension is used having a weight ratio between solid and water of from 1:1 to 2.5:1.
Claim 6
Dependent Claim
26 words
A method as claimed in claim 1, wherein an ionogenic additive is added to the suspension, which moves the pH-value of the suspension towards acidity (pH<3).
Claim 7
Dependent Claim
17 words
A method as claimed in claim 5, wherein the hydrochloric acid HCl is used as an additive.
Claim 8
Dependent Claim
30 words
A method as claimed claim 1, wherein an alkaline ionogenic additive is added to the suspension thus causing the pH-value of the suspension to move towards a pH of ≈5.5-8.
Claim 9
Dependent Claim
16 words
A method as claimed in claim 7, wherein an ammonia compound is used as the additive.
Claim 10
Dependent Claim
28 words
A method as claimed in claim 1, wherein such an amount of an ionogenic additive is added to the suspension that a very viscous, solid gel is obtained.
Claim 11
Dependent Claim
29 words
A method as claimed in claim 9, wherein the ionongenic additive is added in an amount between 0.2 and 5% by weight of the solids content of the suspension.
Claim 12
Dependent Claim
69 words
A method as claimed in claim 10, wherein an aqueous suspension is used as the thixotropic suspension, which suspension comprises SiO 2 particles having an average diameter of 40 nm and a weight ratio between solid and water of 1:0.53, and to which suspension an aqueous 25% ammonia solution is as the ionogenic additive in an amount corresponding to 0.75% by weight of the solids content of the suspension.
Claim 13
Dependent Claim
25 words
A method as claimed in claim 1, wherein the gel is liquefied by the application of sound (frequency f=20-200 Hz) or ultrasonics (frequency f=20-50 Khz).
Claim 14
Dependent Claim
42 words
A method as claimed in claim 1, wherein the gel is deformed in an arrangement comprising a receptacle in which the gel is liquefied and which is provided with an outlet which determines the shape of the glass body to be manufactured.
Claim 15
Dependent Claim
27 words
A method as claimed in claim 1, wherein the gel is liquefied and thin resolidified in a mould which corresponds to the shape of the glass body.
Claim 16
Dependent Claim
21 words
A method as claimed in claim 14, wherein the mould is disposable and is destroyed after the starting material has solidified.
Claim 17
Dependent Claim
15 words
A method as claimed in claim 15, wherein a synthetic-resin hose is the disposable mould.
Claim 18
Dependent Claim
27 words
The method of claim 2 wherein the suspension comprises SiO 2 particles having diameters from 15 to 100 nm and an average size diameter of 40 nm.
References Cited (Backward Citations)
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US4419115A
Cited
JPS59131538A
Cited
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Cited
US4574063A
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JPS6054928A
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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) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |