Patent US3751276A successfully refreshed from Google Patents.
US3751276A
Expired / Lapsed
US
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Refractory laminate based on negative sol or silicate and positive sol
Assignee: EIDP Inc
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Filing: 1971-06-01
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Granted: 1973-08-07
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Expires: 1991-06-01
Abstract
Abstract A rapid process for forming a refractory laminate on the surface of a support structure which comprises dipping the surface alternately, in either order, in (1) a bath comprising a sol of negatively charged colloidal particles and/or a solution of an alkaline ionic silicate and (2) a bath comprising a sol of positively charged colloidal particles, until a laminate of the desired thickness is built up on the surface. In order to increase the rate of laminate build up, particulate refractory material can be included in the baths and/or the coated surface can be stuccoed between dips. Interaction between the negatively charged colloidal particles or silicate and the positively charged colloidal particles results in a setting action which immobilizes the coatings as they are applied, thus making it unnecessary to dry between dips. The process is particularly suited for making expendable, refractory shell molds for precision investment casting of metals by the so-called ''''lostwax'''' technique.
Inventors
- 👤 J Beyer
- 👤 E Moore
- 👤 R Rusher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:50
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; B; B22; B22C; B22C1/00; B22C1/16; B22C1/165; B22C9/00; B22C9/02; B22C9/04; C04B20/00; C04B20/10; C04B20/1055; C04B20/1066; C04B28/00; C04B28/24; C04B35/00; C04B35/622; C04B35/624; C04B35/626; C04B35/63; C04B35/6303; C04B35/6316; C04B35/66; C04B41/45; C04B41/52; C04B41/528; C04B2103/00; C04B2103/10; C04B2103/12; C04B2111/00; C04B2111/00474; C04B2111/00612; C04B2111/00939; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3217; C04B2235/34; C04B2235/3418
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
34 words
a bath comprising a sol of positively charged colloidal particles selected from the group consisting of silica particles and alumina particles until a laminate of the desired thickness is built up on the surface.
Claim 2
Dependent Claim
55 words
Process of claim 1 wherein one dip bath comprises a slurry of particulate refractory material in a sol of negatively charged colloidal silica particles and the other dip bath comprises a slurry of particulate refractory material in a sol of positively charged colloidal particles composed of a silica core coated with a polyvalent metal-oxygen compound.
Claim 3
Dependent Claim
34 words
a bath comprising a sol of positively charged colloidal particles selected from the group consisting of silica particles and alumina particles, until a shell of the desired thickness is built up on the pattern.
Claim 4
Dependent Claim
17 words
Process of claim 2 wherein the positively charged particles are composed of colloidal silica coated with alumina.
Claim 5
Dependent Claim
30 words
A rapid process for forming expendable, refractory shell molds for precision investment casting of metals which comprises dipping a disposable pattern of the metal casting alternately, in either order, in
Claim 6
Dependent Claim
53 words
Process of claim 4 wherein one dip bath comprises a slurry of refractory grain in a sol of negatively charged colloidal silica particles and the other dip bath comprises a slurry of refractory grain in a sol of positively charged colloidal particles composed of a silica core coated with a polyvalent metal-oxygen compound.
Claim 7
Dependent Claim
18 words
Process of claim 5 in which the positively charged particles are composed of colloidal silica coated with alumina.
Claim 8
Dependent Claim
102 words
Process of claim 6 wherein the pattern is first dipped in a first prime coat slurry comprising a relatively fine refractory grain in a sol of positively charged aumina-coated particles, then dipped in a second prime coat slurry comprising a relatively fine refractory grain in a so of negatively charge sol of negatively charged colloidal silica particles, then alternately dipped in a first back up coat clurry of a coarser refractory grain in a sol of positively charged alumina-coated colloidal particles and a second back up coat slurry of a coarser refractory grain in a sol of negatively charged colloidal silica particles.
Claim 9
Dependent Claim
19 words
Process of claim 7 wherein the coated pattern is stuccoed between each dip with a relatively coarse refractory grain.
Claim 10
Dependent Claim
99 words
Process of claim 6 wherein the pattern is dipped in a first prime coat slurry of a relatively fine refractory grain in a sol of negatively charged colloidal silica particles, then dipped in a second prime coat slurry of a relatively fine refractory grain in a sol of positively charged alumina-coated colloidal silica particles, then alternately dipped in a first back up coat slurry of a coarser grain in a sol of negatively charged colloidal silica particles and a second back up coat slurry of a coarser refractory grain in a sol of positively charged alumina-coated colloidal silica particles.
Claim 11
Dependent Claim
19 words
Process of claim 9 wherein the coated pattern is stuccoed between each dip with a relatively coarse refractory grain.
Claim 12
Dependent Claim
57 words
Process of claim 1 wherein one dip bath comprises a slurry of particulate refractory material in a solution of quaternary ammonium, sodium, potassium or lithium silicate and the other dip bath comprises a slurry of particulate refractory material in a sol of positively charged colloidal particles composed of a silica core coated with a polyvalent metal-oxygen compound.
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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) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |