US4017347A
Expired / Lapsed
US
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Method for producing ceramic cellular structure having high cell density
Assignee: GTE Sylvania Inc
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Filing: 1975-10-31
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Granted: 1977-04-12
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Expires: 1995-10-31
Abstract
Abstract A ceramic cellular structure having a cell density of up to 1600 cells per square inch and wall thicknesses down to 2 mils is produced by a process which comprises: (1) forming a slurry consisting essentially of finely divided sinterable solid particles of ceramic raw materials and a controlled amount of a plastic supporting matrix containing thermoplastic resin, a thermosetting resin, a plasticizer, an organic solvent and a small amount of a deflocculant; (2) ball milling the slurry; (3) casting the slurry in the form of a film; (4) removing the solvent to produce a self-supporting green ceramic tape; (6) molding a portion of the tape to form a corrugated first member; (7) providing another portion of the tape to form a substantially flat second member; (8) forming a first bilayer by bonding the second member to the nodes of the first member; (9) mutually bonding a predetermined number of bilayers substantially identical to the first bilayer to form a cellular green structure of a desired shape; and (10) firing the green structure at a temperature sufficient to form a sinter-welded polycrystalline ceramic structure. The fired structures, after being subjected to various finishing operations, are useful as rotary heat regenerators, stationary heat recuperators and catalyst supports.
Inventors
- 👤 Joseph J. Cleveland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:09
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/634; C04B35/63404; C04B35/6342; B; B28; B28B; B28B1/00; B28B1/002; B32; B32B; B32B18/00; C04B35/63448; C04B35/63472; C04B35/6348; C04B35/63484; C04B35/636; C04B35/6365; C04B38/00; C04B38/008; C04B38/0083; F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2803; F01N3/2825; F01N3/2828; F28; F28F; F28F21/00; F28F21/04; C04B2235/00; C04B2235/65; C04B2235/656; C04B2235/6562; C04B2235/6567; C04B2237/00; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/341; C04B2237/343; C04B2237/345; C04B2237/346; C04B2237/348; C04B2237/36; C04B2237/365; C04B2237/368; C04B2237/50; C04B2237/64; C04B2237/70; C04B2237/704; C04B2237/76; C04B2237/82; F01N2330/00; F01N2330/06; Y; Y10; Y10S; Y10S148/00; Y10S148/122; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1025; Y10T428/00; Y10T428/24; Y10T428/24628; Y10T428/24661; Y10T428/24669; Y10T428/24694; Y10T428/24711; Y10T428/24727
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
242 words
A process for producing a ceramic cellular structure comprising: a. corrugating a green ceramic tape having a cell density of from 500 to 1600 cells per square inch of cross-sectional area and wall thicknesses from 2 to 30 mils to produce a corrugated first tape member, said tape consisting essentially of finely divided sinterable solid particles of ceramic raw materials substantially uniformly distributed throughout a fugitive plastic support matrix, the weight ratio of said supporting matrix to said raw materials being from about 1 to 3 to about 1 to 6, said supporting matrix consisting essentially of from about 28.5 to 74.5 weight percent of a two part resin, the resin consisting essentially of polyvinyl butyral in the amount of from 50 to 95 weight percent, remainder an amine thermosetting resin, selected from the group consisting of melamine formaldehyde and urea formaldehyde, and from about 25 to 70 weight percent of a plasticizer selected from the group consisting of alkyl phthalate and dialkyl phthalate plasticizers and from about 0.5 to about 1.5 percent by weight of a deflocculating agent, b. adhering a substantially flat second tape mbember containing substantially the same ceramic raw material and supporting matrix to the nodes of the first corrugated tape member to form a bilayered tape member, and c. adhering said bilayered tape member and a predetermined number of subsequent bilayered tape members to each other to form a cellular structure having alternate corrugated and flat members.
Claim 2
Dependent Claim
242 words
A process for producing a ceramic cellular structure comprising: a. corrugating a green ceramic tape having a cell density of from 500 to 1600 cells per square inch of cross-sectional area and wall thicknesses from 2 to 30 mils to produce a corrugated first tape member, said tape consisting essentially of finely divided sinterable solid particles of ceramic raw materials substantially uniformly distributed throughout a fugitive plastic support matrix, the weight ratio of said supporting matrix to said raw materials being from about 1 to 3 to about 1 to 6, said supporting matrix consisting essentially of from about 28.5 to 74.5 weight percent of a two part resin, the resin consisting essentially of polyvinyl butyral in the amount of from 50 to 95 weight percent, remainder an amine thermosetting resin, selected from the group consisting of melamine formaldehyde and urea formaldehyde, and from about 25 to 70 weight percent of a plasticizer selected from the group consisting of alkyl phthalate and dialkyl phthalate plasticizers and from about 0.5 to about 1.5 percent by weight of a deflocculating agent, b. adhering a substantially flat second tape mbember containing substantially the same ceramic raw material and supporting matrix to the nodes of the first corrugated tape member to form a bilayered tape member, and c. adhering said bilayered tape member and a predetermined number of subsequent bilayered tape members to each other to form a cellular structure having alternate corrugated and flat members.
Claim 3
Dependent Claim
51 words
The method of claim 1 in which the cellular structure is fired at a time and temperature sufficient to substantially sinter the ceramic raw material particles and to mutually sinter weld the portions of said members that are in mutual contact, thereby to convert the structure into a unitary ceramic body.
Claim 4
Dependent Claim
23 words
The process according to claim 2 wherein said firing is carried out at a temperature of from about 1300° to about 1600° C.
Claim 5
Dependent Claim
77 words
The process of claim 1 wherein the green ceramic tape is produced by the steps comprising: a. producing a slurry composition consisting essentially of the tape composition and from about 75 to 120 percent based on the total weight of said tape composition including said ceramic raw materials and said supporting matrix of a volatile liquid organic solvent, b. milling the slurry composition in a non-contaminating media to obtain a uniform distribution of matrix and raw materials,
Claim 6
Dependent Claim
40 words
c. tape casting the slurry into a tape to produce a thickness subsequent to solvent removal of from 2 to 30 mils, and d. heating the tape at a temperature of from 40° to 70° C to remove said solvent.
Claim 7
Dependent Claim
40 words
c. tape casting the slurry into a tape to produce a thickness subsequent to solvent removal of from 2 to 30 mils, and d. heating the tape at a temperature of from 40° to 70° C to remove said solvent.
Claim 8
Dependent Claim
42 words
The method of claim 4 in which the volatile liquid organic solvent comprises a mixture of a volatile aromatic and a volatile alcohol in the volumetric ratio of from about 2:1 to about 4:1 of the volatile aromatic to the volatile alcohol.
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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) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |