US4031059A
Expired / Lapsed
US
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Low density ablator compositions
Assignee: Lockheed Martin Corp
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Filing: 1976-01-28
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Granted: 1977-06-21
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Expires: 1996-01-28
Abstract
Abstract Two types of highly filled, elastomeric silicone-base abiative compositions whose densities range from about 0.20 g/cc to about 0.30 g/cc. One type is a carbon char forming, high thermal efficiency ablator containing at least 92 percent by volume of low density filler with a total filler-to-resin volumetric ratio of at least 16 to 1. The additives comprise ground cork, silica or glass microspheres, phenolic microballons and silica and/or carbon fibers. The second type is a silica char forming, RF-transparent ablator containing at least 90 percent by volume of low density filler with a total filler-to-resin volumetric ratio of at least 11 to 1. The additives comprise silica or glass microspheres and silica fibers.
Inventors
- 👤 Eric L. Strauss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:42
CPC Classifications
C; C09; C09D; C09D5/00; C09D5/18; B; B64; B64G; B64G1/00; B64G1/22; B64G1/52; B64G1/58; C08; C08K; C08K3/00; C08K3/34; C08K3/36; C08K7/00; C08K7/02; C08K7/04; C08K7/06; C08K7/10; C08K7/16; C08K7/18; C08K7/22; C08L; C08L61/00; C08L61/04; C08L83/00; C08L83/04; C08L97/00; C08L97/007; C08G; C08G77/00; C08G77/04; C08G77/20; C08G77/70; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
166 words
A low density ablator composition having a density of not greater than 0.25 g/cc for providing ablation protection comprising: 100 parts by volume of a siloxane elastomer resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl polysiloxane the viscosity of which is equal to or less than 10,000 centipoise; about 1600 to about 1800 parts by volume of a low density filler comprising about 600 to about 900 parts by volume ground cork sized from 0.0165 to 0.0331 inch per 100 parts of resin; from about 500 to 800 parts by volume of hollow silica or glass microspheres sized from 0.0030 to 0.0080 inch per 100 parts of resin; up to about 260 parts by volume of hollow phenolic resin microballoons sized from 0.0030 to 0.0080 inch per 100 parts of resin; up to about 6 parts by volume carbon fibers per 100 parts of resin; and, up to about 6 parts by volume of silica fibers per 100 parts of resin.
Claim 2
Dependent Claim
166 words
A low density ablator composition having a density of not greater than 0.25 g/cc for providing ablation protection comprising: 100 parts by volume of a siloxane elastomer resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl polysiloxane the viscosity of which is equal to or less than 10,000 centipoise; about 1600 to about 1800 parts by volume of a low density filler comprising about 600 to about 900 parts by volume ground cork sized from 0.0165 to 0.0331 inch per 100 parts of resin; from about 500 to 800 parts by volume of hollow silica or glass microspheres sized from 0.0030 to 0.0080 inch per 100 parts of resin; up to about 260 parts by volume of hollow phenolic resin microballoons sized from 0.0030 to 0.0080 inch per 100 parts of resin; up to about 6 parts by volume carbon fibers per 100 parts of resin; and, up to about 6 parts by volume of silica fibers per 100 parts of resin.
Claim 3
Dependent Claim
35 words
The composition of claim 1 wherein the low density filler constituents selected from the group consisting of ground cork, silica or glass microspheres and phenolic resin microballoons comprise at least 92% of the ablator volume.
Claim 4
Dependent Claim
24 words
The composition of claim 1 wherein the total filler to resin volumetric ratio of the ablator composition is at least about 16 to 1.
Claim 5
Dependent Claim
38 words
The composition of claim 1 wherein 90% of the cork weight consists of particles larger than about 0.0234 in. and 90% of the hollow microballoons and microspheres weight consists of particles greater than about 0.0059 in. in diameter.
Claim 6
Dependent Claim
24 words
The composition of claim 1 wherein the ratio of hollow microballoons to cork particles is not less than about 0.88 on a volume basis.
Claim 7
Dependent Claim
20 words
The composition of claim 1 wherein the volumetric ratio of silica or glass microspheres-to-cork is not less than about 0.60.
Claim 8
Dependent Claim
22 words
The composition of claim 1 wherein the distributing of the fillers in the resin-fiber mixture is achieved with low shear mixing equipment.
Claim 9
Dependent Claim
23 words
The composition of claim 1 wherein the curing of the mixture takes place at a net pressure of less than about 1 atmosphere.
Claim 10
Dependent Claim
19 words
The composition of claim 1 wherein the resulting material forms a virtually crackfree, carbonaceous char during the ablation process.
Claim 11
Dependent Claim
27 words
The composition of claim 1 wherein the tensile elongation of the resulting material is at least 2% at room temperature and at least 1% at -150° F.
Claim 12
Dependent Claim
27 words
The composition of claim 1 wherein the volume of the average cork particle is approximately 15 times that of the average phenolic microballoon or silica/glass microsphere particle.
Claim 13
Dependent Claim
24 words
The composition of claim 1 wherein the fillers are treated with a silane coupling agent to improve bonding and wetting thereof with the resin.
Claim 14
Dependent Claim
15 words
The composition of claim 1 wherein the ablator composition is contained in a honeycomb core.
Claim 15
Independent Claim
158 words
A method of insulating a structure with an ablator composition comprising the steps of: mixing together 100 parts by volume of siloxane resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl polysiloxane the viscosity of which is equal to or less than 10,000centipoise and about 12 parts by volume of fibers selected from the group consisting of silica and carbon fibers and mixtures thereof; distributing uniformly in the resin-fiber mixture 500 to 800 parts by volume silica or glass microspheres sized from 0.0030 to 0.0080 inch, from about 600 to about 900 parts by volume ground cork sized from 0.0165 to 0.0331 inch and up to 260 parts by volume of phenolic microballoons sized from 0.0030 to 0.0080 inch; forming the resulting mixture into a predetermined configuration between the structure and a region subject to high temperature exposure, and curing the mixture for a time at a temperature sufficient to cure the siloxane resin.
Claim 16
Independent Claim
158 words
A method of insulating a structure with an ablator composition comprising the steps of: mixing together 100 parts by volume of siloxane resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl polysiloxane the viscosity of which is equal to or less than 10,000centipoise and about 12 parts by volume of fibers selected from the group consisting of silica and carbon fibers and mixtures thereof; distributing uniformly in the resin-fiber mixture 500 to 800 parts by volume silica or glass microspheres sized from 0.0030 to 0.0080 inch, from about 600 to about 900 parts by volume ground cork sized from 0.0165 to 0.0331 inch and up to 260 parts by volume of phenolic microballoons sized from 0.0030 to 0.0080 inch; forming the resulting mixture into a predetermined configuration between the structure and a region subject to high temperature exposure, and curing the mixture for a time at a temperature sufficient to cure the siloxane resin.
Claim 17
Dependent Claim
37 words
The method of claim 14 wherein the low density filler constituents selected from the group consisting of ground cork, silica or glass microspheres, phenolic resin microballoons and mixtures thereof comprise at least 92% of the ablator volume.
Claim 18
Dependent Claim
24 words
The method of claim 14 wherein the total filler to resin volumetric ratio of the ablator composition is at least about 16 to 1.
Claim 19
Dependent Claim
38 words
The method of claim 14 wherein 90% of the cork weight consists of particles longer than about 0.0234 in. and 90% of the hollow microballoons and microspheres weight consists of particles greater than about 0.0059 in. in diameter.
Claim 20
Dependent Claim
26 words
The method of claim 14 wherein the ratio of hollow microspheres and microballoons to cork particles is not less than about 0.88 on a volume basis.
Claim 21
Dependent Claim
20 words
The method of claim 14 wherein the volumetric ratio of silica or glass microspheres-to-cork is not less than about 0.60.
Claim 22
Dependent Claim
22 words
The method of claim 14 wherein the distributing of the fillers in the resin-fiber mixture is achieved with low shear mixing equipment.
Claim 23
Dependent Claim
23 words
The method of claim 14 wherein the curing of the mixture takes place at a net pressure of less than about 1 atmosphere.
Claim 24
Dependent Claim
18 words
The method of claim 14 wherein the density of the resulting composition is not greater than 0.25 g/cc.
Claim 25
Dependent Claim
85 words
A low density ablator composition having a density not greater than 0.30 g/cc for providing ablation protection comprising: 100 parts by volume of a siloxane elastomer resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl polysiloxane the viscosity of which is equal to or less than 10,000 centipoise; about 1180 parts by volume of filler comprising about 1175 parts by volume silica or glass microspheres sized from 0.0030 to 0.0080 inch per 100 parts resin; and, about 6 parts silica fibers.
Claim 26
Dependent Claim
85 words
A low density ablator composition having a density not greater than 0.30 g/cc for providing ablation protection comprising: 100 parts by volume of a siloxane elastomer resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl polysiloxane the viscosity of which is equal to or less than 10,000 centipoise; about 1180 parts by volume of filler comprising about 1175 parts by volume silica or glass microspheres sized from 0.0030 to 0.0080 inch per 100 parts resin; and, about 6 parts silica fibers.
Claim 27
Dependent Claim
22 words
The composition of claim 23 wherein the distributing of the fillers in the resin-fiber mixture is achieved with low shear mixing equipment.
Claim 28
Dependent Claim
22 words
The composition of claim 23 wherein the curing of the mixture takes place at a net pressure of less than one atmosphere.
Claim 29
Dependent Claim
19 words
The composition of claim 23 wherein the resulting material forms a stable, predominantly siliceous char during the ablation process.
Claim 30
Dependent Claim
16 words
The composition of claim 23 wherein the density of the resulting material is about 0.25 g/cc.
Claim 31
Dependent Claim
19 words
The composition of claim 23 wherein the glass or silica microspheres comprise at least 90% of the ablator volume.
Claim 32
Dependent Claim
19 words
The composition of claim 23 wherein the total filler to resin volumetric ratio is at least 11 to 1.
Claim 33
Dependent Claim
22 words
The composition of claim 23 wherein the percent of transmission of RF signals through the charred ablator composition is greater than 50%.
Claim 34
Dependent Claim
30 words
The composition of claim 23 wherein the tensile elongation of the resulting material is at least 4% at room temperature and at least 1% between -100° F. and -175° F.
Claim 35
Dependent Claim
24 words
The composition of claim 23 wherein the fillers are treated with a silane coupling agent to improve bonding and wetting thereof with the resin.
Claim 36
Dependent Claim
15 words
The composition of claim 23 wherein the ablator composition is contained in a honeycomb core.
Claim 37
Independent Claim
117 words
A method of insulating a structure with an ablator composition comprising the steps of: mixing together 100 parts by weight of siloxane resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl polysiloxane the viscosity of which is equal to or less than 10,000 centipoise and about 5 to 10 parts by volume of silica fibers; distributing uniformly in the resin-fiber mixture about 1000 to 1300 parts by volume silica or glass microspheres sized from 0.0030 to 0.0080 inch; forming the resulting mixture into a predetermined configuration between the structure and a region subject to high temperature exposure; and curing the mixture for a time and at a temperature sufficient to cure the siloxane.
Claim 38
Independent Claim
117 words
A method of insulating a structure with an ablator composition comprising the steps of: mixing together 100 parts by weight of siloxane resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl polysiloxane the viscosity of which is equal to or less than 10,000 centipoise and about 5 to 10 parts by volume of silica fibers; distributing uniformly in the resin-fiber mixture about 1000 to 1300 parts by volume silica or glass microspheres sized from 0.0030 to 0.0080 inch; forming the resulting mixture into a predetermined configuration between the structure and a region subject to high temperature exposure; and curing the mixture for a time and at a temperature sufficient to cure the siloxane.
Claim 39
Dependent Claim
22 words
The method of claim 34 wherein the distributing of the fillers in the resin-fiber mixture is achieved with low shear mixing equipment.
Claim 40
Dependent Claim
22 words
The method of claim 34 wherein the curing of the mixture takes place at a net pressure of less than one atmosphere.
Claim 41
Dependent Claim
19 words
The method of claim 34 wherein the resulting material forms a stable, predominantly siliceous char during the ablation process.
Claim 42
Dependent Claim
16 words
The method of claim 34 wherein the density of the resulting material is about 0.25 g/cc.
Claim 43
Dependent Claim
19 words
The method of claim 34 wherein the glass or silica microspheres comprise at least 90% of the ablator volume.
Claim 44
Dependent Claim
19 words
The method of claim 34 wherein the total filler to resin volumetric ratio is at least 11 to 1.
Claim 45
Dependent Claim
22 words
The method of claim 34 wherein the presence of transmission of RF signals through the charred ablator composition is greater than 50%.
Claim 46
Dependent Claim
30 words
The method of claim 34 wherein the tensile elongation of the resulting material is at least 4% at room temperature and at least 1% between -100° F. and -175° F.
Claim 47
Dependent Claim
24 words
The method of claim 34 wherein the fillers are treated with a silane coupling agent to improve bonding and wetting thereof with the resin.
Claim 48
Dependent Claim
16 words
The method of claim 34 wherein the ablator composition is contained in a honeycomb core structure.
Claim 49
Dependent Claim
26 words
The method of claim 34 wherein the surface of the resulting ablator configuration is scored in two orthogonal directions to compensate for char shrinkage during ablation.
Claim 50
Independent Claim
152 words
A method of insulating a structure with an ablator composition comprising the steps of: mixing together 100 parts by weight of siloxane resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl siloxane and about 6 parts by volume of silica fibers; distributing uniformly in the resin-fiber mixture 1175 parts by volume silica or glass microspheres sized from 0.0030 to 0.0080 inch; forming the resulting mixture into a predetermined configuration between the structure and a region subject to high temperature exposure; and, curing the mixture for a time and at a temperature sufficient to cure the siloxane resin; wherein the viscosity of the siloxane resin is equal to or less than about 10,000 centipoise; wherein the distributing of the silica or glass microspheres is achieved with low shear mixing equipment; and, wherein the curing of the mixture takes place at a net pressure of less than about 1 atmosphere.
Claim 51
Independent Claim
152 words
A method of insulating a structure with an ablator composition comprising the steps of: mixing together 100 parts by weight of siloxane resin selected from the group consisting of methyl-phenyl-vinyl polysiloxane, dimethyl polysiloxane and methyl-phenyl siloxane and about 6 parts by volume of silica fibers; distributing uniformly in the resin-fiber mixture 1175 parts by volume silica or glass microspheres sized from 0.0030 to 0.0080 inch; forming the resulting mixture into a predetermined configuration between the structure and a region subject to high temperature exposure; and, curing the mixture for a time and at a temperature sufficient to cure the siloxane resin; wherein the viscosity of the siloxane resin is equal to or less than about 10,000 centipoise; wherein the distributing of the silica or glass microspheres is achieved with low shear mixing equipment; and, wherein the curing of the mixture takes place at a net pressure of less than about 1 atmosphere.
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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) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |