Patent US4906424A successfully refreshed from Google Patents.
US4906424A
Expired / Lapsed
US
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Reaction injection molding of ceramic or metallic greenbodies
Assignee: Hoechst Celanese Chemical Co
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Filing: 1988-02-16
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Granted: 1990-03-06
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Expires: 2008-02-16
Abstract
Abstract Greenbodies are produced by a RIM injection molding process wherein a homogeneous mixture of finely divided ceramic or metallic material and a polymerizable monomeric binder is injected into a mold and held at an elevated temperature for a sufficient time to polymerize the binder and form the greenbody. A preferred monomeric binder includes di- and tri-acrylate or -methacrylate esters of polyols. The low viscosity of the monomeric binder allows a loading of ceramic material of greater than 50 vol. % without adversely affecting the ability to injection mold the mixture.
Inventors
- 👤 O. Richard Hughes
- 👤 John R. Costanza
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:29
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/22; B22F3/225; B22F1/00; B22F1/10; C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/634; C04B35/63404; C04B35/63424; C04B35/638; B22F2998/00
Claims Analysis
Total Claims: 64
Claim 1
Independent Claim
86 words
A RIM process for producing ceramic or metallic greenbodies comprising the steps of: forming a homogeneous RIM mix by dispersing finely divided ceramic or metallic material in a polymerizable monomeric binder comprising multifunctional acrylate or methacrylate esters, injecting said mix into a mold held at a temperature sufficient to polymerize said monomeric binder, maintaining said mix in said mold at said polymerization temperature for a time sufficient to polymerize and harden said binder to produce a molded product, and removing said molded product from said mold.
Claim 2
Dependent Claim
86 words
A RIM process for producing ceramic or metallic greenbodies comprising the steps of: forming a homogeneous RIM mix by dispersing finely divided ceramic or metallic material in a polymerizable monomeric binder comprising multifunctional acrylate or methacrylate esters, injecting said mix into a mold held at a temperature sufficient to polymerize said monomeric binder, maintaining said mix in said mold at said polymerization temperature for a time sufficient to polymerize and harden said binder to produce a molded product, and removing said molded product from said mold.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein said finely divided material comprises at least 50 vol. % of said homogeneous RIM mix.
Claim 4
Dependent Claim
22 words
The process of claim 1 wherein said finely divided material comprises at least about 60 vol. % of said homogeneous RIM mix.
Claim 5
Dependent Claim
22 words
The process of claim 1 wherein said finely divided material comprises at least about 80 vol. % of said homogeneous RIM mix.
Claim 6
Dependent Claim
15 words
The process of claim 1 wherein said homogeneous RIM mix is formed at room temperature.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein said homogeneous RIM mix is injected at room temperature into said mold.
Claim 8
Dependent Claim
19 words
The process of claim 1 wherein said mold is held at an elevated temperature to polymerize said monomeric binder.
Claim 9
Dependent Claim
20 words
The process of claim 7 wherein said mold is held at a temperature of from about 50° to 200° C.
Claim 10
Dependent Claim
45 words
The process of claim 1 wherein said homogeneous RIM mix is maintained in said mold for time sufficient to harden but only partially cure said binder, removing said partially cured molded product from said mold and completing curing of said binder outside of said mold.
Claim 11
Dependent Claim
14 words
The process of claim 1, wherein said finely divided material is a ceramic material.
Claim 12
Dependent Claim
25 words
The process of claim 10 wherein said ceramic material is selected from silica, silicon nitride, silicon carbide, alumina and zirconia, mixtures and solid solutions thereof.
Claim 13
Dependent Claim
13 words
The process of claim 10 wherein said ceramic material further includes ceramic whiskers.
Claim 14
Dependent Claim
13 words
The process of claim 12 wherein said ceramic whiskers are silicon carbide whiskers.
Claim 15
Dependent Claim
14 words
The process of claim 1 wherein said finely divided material is a metallic material.
Claim 16
Dependent Claim
15 words
The process of claim 14 wherein said metallic material comprises free metals or alloys thereof.
Claim 17
Dependent Claim
16 words
The process of claim 1 wherein said RIM mix further includes a thermally decomposable polymerization initiator.
Claim 18
Dependent Claim
16 words
The process of claim 16 wherein said polymerization initiator is a peroxide or combination of peroxides.
Claim 19
Dependent Claim
31 words
The process of claim 17 wherein said peroxide polymerization initiator has a half life of at most 1 minute at temperatures in the range of from 90° C. to 200° C.
Claim 20
Dependent Claim
22 words
The process of claim 17 wherein said peroxide polymerization initiator has a half life at room temperature of at least 8 hours.
Claim 21
Dependent Claim
34 words
The process of claim 1 wherein said esters are derived from diols selected from the group consisting of alkane diols containing 3 to 10 carbon atoms, alkylene glycols, polyalkylene glycols, aryl and alkyl/aryl diols.
Claim 22
Dependent Claim
27 words
The process of claim 1 wherein said esters are derived from triols selected from the group consisting of trimethylol propane, trimethylol alkoxy propane, glycerol and glyceryl alkoxy.
Claim 23
Dependent Claim
13 words
The process of claim 1 wherein said ester is derived from acrylic acid.
Claim 24
Dependent Claim
13 words
The process of claim 1 wherein said ester is derived from methacrylic acid.
Claim 25
Dependent Claim
15 words
The process of claim 1 wherein said monomeric binder is diluted with a monofunctional monomer.
Claim 26
Dependent Claim
16 words
The process of claim 24 wherein said monofunctional monomer comprises monofunctional acrylate or methacrylate alkyl esters.
Claim 27
Dependent Claim
14 words
The process of claim 1 further including removing polymerized binder from said molded product.
Claim 28
Dependent Claim
21 words
The process of claim 26 wherein said polymerized binder is removed by heating said molded article to volatilize said polymerized binder.
Claim 29
Dependent Claim
27 words
The process of claim 27 wherein said molded product is heated to a temperature of from about 450° to about 700° C. to volatilize said polymerized binder.
Claim 30
Dependent Claim
27 words
The process of claim 26 further including sintering the molded product subsequent to removal of said binder at a temperature of from about 1,000° to 2,200° C.
Claim 31
Dependent Claim
98 words
A ceramic RIM process for producing a sintered ceramic article comprising the steps of: forming a homogeneous mixture containing finely divided ceramic material and a polymerizable monomeric binder comprising multifunctional acrylates selected from the polyol esters of polyacrylate or polymethacrylate, injecting said homogeneous mixture into a mold, maintaining said mixture in said mold at a temperature and for a sufficient time to polymerize said monomeric binder and cause the hardening thereof to produce a molded product, removing said binder and subsequently sintering said product at a temperature of from 1,000° and 2,200° C. to produce a sintered product.
Claim 32
Dependent Claim
98 words
A ceramic RIM process for producing a sintered ceramic article comprising the steps of: forming a homogeneous mixture containing finely divided ceramic material and a polymerizable monomeric binder comprising multifunctional acrylates selected from the polyol esters of polyacrylate or polymethacrylate, injecting said homogeneous mixture into a mold, maintaining said mixture in said mold at a temperature and for a sufficient time to polymerize said monomeric binder and cause the hardening thereof to produce a molded product, removing said binder and subsequently sintering said product at a temperature of from 1,000° and 2,200° C. to produce a sintered product.
Claim 33
Dependent Claim
31 words
The process of claim 30 wherein said esters are derived from diols selected from the group consisting of alkane diols containing 3 to 10 carbon atoms, alkylene glycols and polyalkylene glycols.
Claim 34
Dependent Claim
27 words
The process of claim 30 wherein said esters are derived from triols selected from the group consisting of trimethylol propane, trimethylol alkoxy propane, glycerol and glyceryl alkoxy.
Claim 35
Dependent Claim
13 words
The process of claim 30 wherein said ester is derived from acrylic acid.
Claim 36
Dependent Claim
13 words
The process of clam 30 wherein said ester is derived from methacrylic acid.
Claim 37
Dependent Claim
13 words
The process of clam 30 wherein said ester is derived from methacrylic acid.
Claim 38
Dependent Claim
15 words
The process of claim 30 wherein said polymerizable monomer is diluted with a monofunctional monomer.
Claim 39
Dependent Claim
16 words
The process of claim 35 wherein said monofunctional monomer comprises monofunctional acrylate or methacrylate alkyl esters.
Claim 40
Dependent Claim
80 words
A RIM process for producing ceramic or metallic greenbodies comprising the steps of: forming a homogeneous RIM mix by dispersing finely divided ceramic or metallic material in a polymerizable monomeric binder, injecting said mix into a mold held at a temperature sufficient to polymerize said monomeric binder, maintaining said mix in said mold at said polymerization temperature for a time sufficient to polymerize and harden said binder to produce a molded product, and removing said molded product from said mold.
Claim 41
Dependent Claim
80 words
A RIM process for producing ceramic or metallic greenbodies comprising the steps of: forming a homogeneous RIM mix by dispersing finely divided ceramic or metallic material in a polymerizable monomeric binder, injecting said mix into a mold held at a temperature sufficient to polymerize said monomeric binder, maintaining said mix in said mold at said polymerization temperature for a time sufficient to polymerize and harden said binder to produce a molded product, and removing said molded product from said mold.
Claim 42
Dependent Claim
21 words
The process of claim 37 wherein said finely divided material comprises at least 50 vol. % of said homogeneous RIM mix.
Claim 43
Dependent Claim
22 words
The process of claim 37 wherein said finely divided material comprises at least about 60 vol. % of said homogeneous RIM mix.
Claim 44
Dependent Claim
22 words
The process of claim 37 wherein said finely divided material comprises at least about 80 vol. % of said homogeneous RIM mix.
Claim 45
Dependent Claim
15 words
The process of claim 37 wherein said homogeneous RIM mix is formed at room temperature.
Claim 46
Dependent Claim
18 words
The process of claim 37 wherein said homogeneous RIM mix is injected at room temperature into said mold.
Claim 47
Dependent Claim
19 words
The process of claim 37 wherein said mold is held at an elevated temperature to polymerize said monomeric binder.
Claim 48
Dependent Claim
20 words
The process of claim 43 wherein said mold is held at a temperature of from about 50° to 200° C.
Claim 49
Dependent Claim
45 words
The process of claim 37 wherein said homogeneous RIM mix is maintained in said mold for time sufficient to harden but only partially cure said binder, removing said partially cured molded product from said mold and completing curing of said binder outside of said mold.
Claim 50
Dependent Claim
14 words
The process of claim 37, wherein said finely divided material is a ceramic material.
Claim 51
Dependent Claim
25 words
The process of claim 46 wherein said ceramic material is selected from silica, silicon nitride, silicon carbide, alumina and zirconia, mixtures and solid solutions thereof.
Claim 52
Dependent Claim
13 words
The process of claim 46 wherein said ceramic material further includes ceramic whiskers.
Claim 53
Dependent Claim
13 words
The process of claim 48 wherein said ceramic whiskers are silicon carbide whiskers.
Claim 54
Dependent Claim
14 words
The process of claim 37 wherein said finely divided material is a metallic material.
Claim 55
Dependent Claim
15 words
The process of claim 50 wherein said metallic material comprises free metals or alloys thereof.
Claim 56
Dependent Claim
27 words
The process of claim 43 wherein said RIM mix further includes a polymerization initiator which thermally decomposes at the mold temperature to initiate polymerization of said binder.
Claim 57
Dependent Claim
26 words
The process of claim 37 wherein said polymerizable monomeric binder comprises a mixture of distinct monomers capable of reacting with each other to form a polymer.
Claim 58
Dependent Claim
34 words
The process of claim 37 wherein said monomeric binder comprises an oligomer capable of reacting with other monomeric or oligomeric components in the binder to increase the chain length of said binder during polymerization.
Claim 59
Dependent Claim
25 words
The process of claim 37 wherein said RIM mix further includes a catalyst to increase the polymerization rate of said monomeric binder in the mold.
Claim 60
Dependent Claim
14 words
The process of claim 37 further including removing polymerized binder from said molded product.
Claim 61
Dependent Claim
21 words
The process of claim 56 wherein said polymerized binder is removed by heating said molded article to volatilize said polymerized binder.
Claim 62
Dependent Claim
27 words
The process of claim 57 wherein said molded product is heated to a temperature of from about 450° to about 700° C. to volatilize said polymerized binder.
Claim 63
Dependent Claim
27 words
The process of claim 56 further including sintering the molded product subsequent to removal of said binder at a temperature of from about 1,000° to 2,200° C.
Claim 64
Dependent Claim
17 words
The process of claim 47 wherein said ceramic material comprises alumina and further includes silicon carbide whiskers.
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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) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |