Patent US3894572A successfully refreshed from Google Patents.
US3894572A
Expired / Lapsed
US
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Process for forming a refractory laminate based on positive sols and refractory materials containing chemical setting agents
Assignee: EIDP Inc
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Filing: 1973-07-20
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Granted: 1975-07-15
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Expires: 1993-07-20
Abstract
Abstract A rapid process for forming a refractory laminate on the surface of a support structure which comprises dipping the structure into a bath comprising a sol of positively charged colloidal particles to form a coating on the surface, and applying to the surface a particulate refractory material containing a chemical setting agent. This procedure is repeated until a laminate of the desired thickness is built up on the surface. The chemical setting agent can be coated on or mixed with the refractory particles, and can be (1) an organic or inorganic base, (2) a monofunctional organic acid or salt having an anionic portion containing 6-24 carbon atoms, (3) a polyfunctional organic or inorganic acid or salt, or (4) colloidal silica particles. This technique makes it possible to successively apply and set coatings in very short times without intermediate drying and without sloughing of coats. The process is particularly suited for making expandable refractory shell molds for precision investment casting of metals by the socalled ''''lost-wax'''' technique.
Inventors
- 👤 Jr Earl Phillip Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:40
CPC Classifications
B; B22; B22C; B22C1/00; B22C1/16; B22C1/165
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
152 words
A PROCESS FOR FORMING A REFRACTORY LAMINATE ON THE SURFACE OF A SUPPORT STRUCTURE WHICH COMPRISES: A. DIPPING THE STRUCTURE INTO A BATH COMPRISING A SOL OF POSITIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE TO FORM A COATING ON THE SURFACE, B. APPLYING TO THE SURFACE A PARTICULATE REFRACTORY MATERIAL CONTAINING A CHEMICAL SETTING AGENT FOR THE SOL OF POSITIVELY CHARGED COLLOIDAL PARTICLES, SAID SETTING AGENT BEING SELECTED FROM THE GROUP CONSISTING OF (1) ORGANIC AND INORGANIC BASES, (2) MONOFUNCTIONAL ORGANIC ACIDS AND THEIR SALTS HAVING AN ANIONIC PORTION CONTAINING AT LEAST ONE ALKYL GROUP OF FROM 6 TO ABOUT 24 CARBON ATOMS PER ACID FUNCTIONAL GROUP, (3) POLYFUNCTIONAL ORGANIC AND INORGANIC ACIDS AND THEIR SALTS, AND (4) NEGATIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE, AND C. REPEATING STEPS (A) AND (B) IN THE SAME ORDER UNTIL A REFRACTORY LAMINATE OF THE DESIRED THICKNESS IS BUILT UP ON THE SURFACE.
Claim 2
Dependent Claim
152 words
A PROCESS FOR FORMING A REFRACTORY LAMINATE ON THE SURFACE OF A SUPPORT STRUCTURE WHICH COMPRISES: A. DIPPING THE STRUCTURE INTO A BATH COMPRISING A SOL OF POSITIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE TO FORM A COATING ON THE SURFACE, B. APPLYING TO THE SURFACE A PARTICULATE REFRACTORY MATERIAL CONTAINING A CHEMICAL SETTING AGENT FOR THE SOL OF POSITIVELY CHARGED COLLOIDAL PARTICLES, SAID SETTING AGENT BEING SELECTED FROM THE GROUP CONSISTING OF (1) ORGANIC AND INORGANIC BASES, (2) MONOFUNCTIONAL ORGANIC ACIDS AND THEIR SALTS HAVING AN ANIONIC PORTION CONTAINING AT LEAST ONE ALKYL GROUP OF FROM 6 TO ABOUT 24 CARBON ATOMS PER ACID FUNCTIONAL GROUP, (3) POLYFUNCTIONAL ORGANIC AND INORGANIC ACIDS AND THEIR SALTS, AND (4) NEGATIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE, AND C. REPEATING STEPS (A) AND (B) IN THE SAME ORDER UNTIL A REFRACTORY LAMINATE OF THE DESIRED THICKNESS IS BUILT UP ON THE SURFACE.
Claim 3
Dependent Claim
26 words
Process of claim 1 wherein the positively charged colloidal particles in the bath of step (a) comprise a silica core coated with a polyvalent metal/oxygen compound.
Claim 4
Dependent Claim
11 words
Process of claim 2 wherein the polyvalent metal/oxygen compound is alumina.
Claim 5
Dependent Claim
25 words
Process of claim 3 wherein the bath of step (a) comprises a slurry of particulate refractory material in the sol of positively charged colloidal particles.
Claim 6
Dependent Claim
168 words
A RAPID PROCESS FOR FORMING EXPENDABLE REFRACTORY SHELL MOLDS FOR PRECISION INVESTMENT CASTING OF METALS COMPRISING: A. DIPPING A DISPOSABLE PATTERN OF THEMTAL CASTING IN A BATH COMPRISING A SOL OF POSITIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE TO FORM A COATING N THE PATTERN, B. STUCCOING THE COATED PATTERN WITH A REFRACTORY GRAIN CONTANING A CHEMICAL SETTING AGENT FOR THE SOL OF POSITIVELY CHARGED COLLOIDAL PARTICLES, SAID SETTING AGENT BEING SELECTED FROM THE GROUP CONSISTING OF (1) ORGANIC AND INORGANIC BASES, (2) MONOFUNCTIONAL ORGANIC ACIDS AND THEIR SALTS HAVING AN ANIONIC PORTION CONTAINING AT LEAST ONE ALKYL GROUP OF FROM 6 TO ABOUT 24 CARBON ATOMS PER ACID FUNCTIONAL GROUP, (3) POLYFUNCTIONAL ORGANIC AND INORGANIC ACIDS AND THEIR SALTS CONTAINING UP TO ABOUT 24 CARBON ATOMS PER ACID FUNCTIONAL GROUP AND (4) NEGATIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE, AND C. REPEATING STEPS (A) AND (B) IN THE SAME ORDER UNTIL A REFRACTORY SHELL MOLD OF THE DESIRED THICKNESS IS BUILT UP ON THE PATTERN.
Claim 7
Dependent Claim
168 words
A RAPID PROCESS FOR FORMING EXPENDABLE REFRACTORY SHELL MOLDS FOR PRECISION INVESTMENT CASTING OF METALS COMPRISING: A. DIPPING A DISPOSABLE PATTERN OF THEMTAL CASTING IN A BATH COMPRISING A SOL OF POSITIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE TO FORM A COATING N THE PATTERN, B. STUCCOING THE COATED PATTERN WITH A REFRACTORY GRAIN CONTANING A CHEMICAL SETTING AGENT FOR THE SOL OF POSITIVELY CHARGED COLLOIDAL PARTICLES, SAID SETTING AGENT BEING SELECTED FROM THE GROUP CONSISTING OF (1) ORGANIC AND INORGANIC BASES, (2) MONOFUNCTIONAL ORGANIC ACIDS AND THEIR SALTS HAVING AN ANIONIC PORTION CONTAINING AT LEAST ONE ALKYL GROUP OF FROM 6 TO ABOUT 24 CARBON ATOMS PER ACID FUNCTIONAL GROUP, (3) POLYFUNCTIONAL ORGANIC AND INORGANIC ACIDS AND THEIR SALTS CONTAINING UP TO ABOUT 24 CARBON ATOMS PER ACID FUNCTIONAL GROUP AND (4) NEGATIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE, AND C. REPEATING STEPS (A) AND (B) IN THE SAME ORDER UNTIL A REFRACTORY SHELL MOLD OF THE DESIRED THICKNESS IS BUILT UP ON THE PATTERN.
Claim 8
Dependent Claim
26 words
Process of claim 5 wherein the positively charged colloidal particles in the bath of step (a) comprise a silica core coated with a polyvalent metal/oxygen compound.
Claim 9
Dependent Claim
11 words
Process of claim 6 wherein the polyvalent metal/oxygen compound is alumina.
Claim 10
Dependent Claim
24 words
Process of claim 7 wherein the bath of step (a) is a slurry of refractory grain in the sol of alumina-coated colloidal silica particles.
Claim 11
Dependent Claim
48 words
Process of claim 8 wherein two slurries of refractory grain in a sol of alumina-coated colloidal silica particles are used, the first slurry containing fine refractory grain and being used for the prime coat, and the second slurry containing coarse refractory grain and being used for subsequent coats.
Claim 12
Dependent Claim
19 words
Process of claim 8 wherein the chemical setting agent is present as a coating on the stucco refractory grain.
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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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |