US4946737A
Expired / Lapsed
US
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Gasket composition having expanded microspheres
Assignee: HELLER FINANCIAL Inc AS AGENT
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Filing: 1987-09-03
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Granted: 1990-08-07
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Expires: 2007-09-03
Abstract
Abstract A gasket is described which contains microspheres which expand inside the gasket sheet material after the gasket sheet is formed. Such gaskets are especially useful to provide a seal against fluid leaks at significantly lower pressures due to the presence of the microspheres. Some microspheres can expand during use.
Inventors
- 👤 Charles M. Lindeman
- 👤 Ralph D. Andrew
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:42
CPC Classifications
B; B65; B65D; B65D53/00; B29; B29K; B29K2105/00; B29K2105/04; B29K2105/048; Y; Y10; Y10S; Y10S277/00; Y10S277/935; Y10S277/936; Y10S277/937; Y10S277/938; Y10S277/943; Y10T; Y10T428/00; Y10T428/26; Y10T428/268; Y10T442/00; Y10T442/60; Y10T442/699
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
60 words
A gasket material comprising a wet-laid gasket sheet which has good sealability, good compressive strength and good compression/ recover; further providing that the wet-laid gasket sheet includes fiber, expanded polymeric microspheres and a binder, wherein the fibers and expanded microspheres are held by the binder, and wherein the said expanded microspheres inflated inside the wet-laid sheet after it was formed.
Claim 2
Dependent Claim
60 words
A gasket material comprising a wet-laid gasket sheet which has good sealability, good compressive strength and good compression/ recover; further providing that the wet-laid gasket sheet includes fiber, expanded polymeric microspheres and a binder, wherein the fibers and expanded microspheres are held by the binder, and wherein the said expanded microspheres inflated inside the wet-laid sheet after it was formed.
Claim 3
Dependent Claim
24 words
A gasket material as described in claim 1 wherein the wet-laid gasket sheet also includes a filler, with the fiber, expanded microspheres and binder.
Claim 4
Dependent Claim
35 words
A gasket material as described in claim 1 wherein the microspheres are present at an amount in the range of from about 0.75 to about 0.25% by weight of the total amount of gasket material.
Claim 5
Dependent Claim
78 words
A gasket material as described in claim 1 wherein the fiber is comprised of a material selected from the group consisting of cellulosic, mineral wool, glass, polyaramid, polyacrylate, ceramic, and carbon fibers; and wherein the binder is comprised of a material selected from the group consisting of: butadiene acrylonitrile, carboxylated acrylonitrile butadiene, styrene butadiene, carboxylated styrene butadiene, polychloroprenes, polyvinylidene chloride, polystyrene, polyvinyl chloride, fluornated ethylene propylene, acrylic, tetrafluoroethylene, natural rubber, polyisoprene, polyethylene propylenediene monomer, silicone latex, and polybutadiene.
Claim 6
Dependent Claim
24 words
A gasket material as described in claim 3 wherein the wet-laid gasket sheet also includes a filler with the fiber, expanded microspheres, and binder.
Claim 7
Dependent Claim
56 words
A gasket material as described in claim 3 wherein the fiber is present at an amount in the range of from about 5.0 to about 75% by weight of the total material and the binder is present at an amount in the range of from about 3 to about 60% by weight of the total material.
Claim 8
Dependent Claim
15 words
A gasket material as described in claim 1 wherein the gasket sheet includes cellulosic fibers.
Claim 9
Dependent Claim
18 words
A gasket material as described in claim 1 wherein the wet-laid gasket sheet also includes unexpanded, expandable microspheres.
Claim 10
Dependent Claim
39 words
A gasket material as described in claim 1 wherein after it was formed, the wet-laid gasket sheet was dried, further providing that the microspheres inflated in the presence of heat which was applied after the wet-laid sheet was dried.
Claim 11
Dependent Claim
26 words
A gasket material as described in claim 1 wherein the wet-laid gasket sheet was formed and then dried further providing that the microspheres inflated during drying.
Claim 12
Dependent Claim
28 words
A gasket material as described in claim 9 wherein after drying the wet-laid gasket sheet was pressed, and during pressing the heat was applied to inflate the microspheres.
Claim 13
Dependent Claim
14 words
A gasket material was described in claim 3 wherein the fiber includes cellulosic fibers.
Claim 14
Dependent Claim
64 words
A gasket material comprising: a wet-laid gasket sheet which has good sealability, good compressive strength and good compression/recovery further providing that the wet-laid gasket sheet includes fiber; unexpanded, expandable polymeric microspheres; and a binder, wherein the fibers and microspheres are held by the binder, and wherein the said microspheres will expand in the presence of an effective amount of heat to give internal densification.
Claim 15
Dependent Claim
64 words
A gasket material comprising: a wet-laid gasket sheet which has good sealability, good compressive strength and good compression/recovery further providing that the wet-laid gasket sheet includes fiber; unexpanded, expandable polymeric microspheres; and a binder, wherein the fibers and microspheres are held by the binder, and wherein the said microspheres will expand in the presence of an effective amount of heat to give internal densification.
Claim 16
Dependent Claim
49 words
A gasket material as described in claim 13 where substantially all of the unexpanded, expandable polymeric microspheres have an average diameter in the range of from about 0.5 to about 75 microns, and wherein the said microspheres can, by expansion, provide a microsphere volumetric increase of at least 10%.
Claim 17
Dependent Claim
17 words
A gasket material as described in claim 13 wherein the wet-laid gasket sheet also includes a filter.
Claim 18
Dependent Claim
35 words
A gasket material as described in claim 13 wherein the microspheres are present in an amount in the range of from about 0.075 to about 25% by weight of the total amount of gasket material.
Claim 19
Dependent Claim
35 words
A gasket material as described in claim 13 wherein the microspheres are present in an amount in the range of from about 0.75 to about 25% by weight of the total amount of gasket material.
Claim 20
Dependent Claim
44 words
A gasket comprising a mixture which includes fiber, expanded polymeric microspheres, and a binder, wherein the mixture is a gasket sheet having good sealability, good compression/recovery, and good compressive strength further providing that the polymeric microspheres expanded, in the sheet to cause internal densification.
Claim 21
Dependent Claim
44 words
A gasket comprising a mixture which includes fiber, expanded polymeric microspheres, and a binder, wherein the mixture is a gasket sheet having good sealability, good compression/recovery, and good compressive strength further providing that the polymeric microspheres expanded, in the sheet to cause internal densification.
Claim 22
Dependent Claim
56 words
The gasket of claim 18 wherein the fiber is present in an amount of from about 5 to about 75% by weight, the polymeric microspheres are present in an amount of from about 0.75 to about 25% by weight, and the binder is present in an amount of from about 3 to about 60% by weight.
Claim 23
Dependent Claim
28 words
A gasket as described in claim 19 wherein a filler is present in an amount of from about 10 to about 85 parts per hundred parts of fiber.
Claim 24
Dependent Claim
11 words
A gasket as described in claim 18 which includes a filler.
Claim 25
Dependent Claim
29 words
A gasket as described in claim 21 wherein the filler is selected from the group consisting of: clay, calcium silicate, talc, vermiculite, calcium carbonate, mica, diatomaceous earth and silica.
Claim 26
Dependent Claim
12 words
A gasket as described in claim 18 which is a wet-laid gasket.
Claim 27
Dependent Claim
31 words
A gasket as described in claim 18 wherein the filter is comprised of a material selected from the group consisting of cellulosic, mineral wood, glass, polyaramid, polyacrylate, ceramic and carbon fibers.
Claim 28
Dependent Claim
48 words
A gasket as described in claim 18 wherein the binder is selected from the group consisting of: butadiene acrylonitrile, carboxylated acrylonitrile butadiene, styrene butadiene, carboxylated styrene butadiene, polychloroprenes, polyvinylidene chloride, polystyrene, polyvinyl chloride, fluornated ethylene propylene, acrylic, tetrafluoroethylene, natural rubber, polyisoprene, polyethylene propylenediene monomer, silicone latex and polybutadiene.
Claim 29
Dependent Claim
49 words
A gasket material as described in claim 8 wherein substantially all of the unexpected, expandable polymeric microspheres have an average diameter in the range of from about 0.05 to about 75 microns, and wherein the said microspheres can, by expansion, provide a microsphere volumetric increase of at least 10%.
Claim 30
Dependent Claim
36 words
The gasket material of claim 1 wherein the wet-laid gasket sheet was prepared by adding flocculatn and base to an aqueous suspension which included fibers and the microspheres, adding the binder with agitation, and then dewatering.
Claim 31
Dependent Claim
33 words
The gasket material of claim 10 wherein the microspheres are present at an amount in the range of from about 0.75 to about 25% by weight of the total amount of gasket material.
Claim 32
Dependent Claim
12 words
A gasket material as described in claim 10 which includes a filler.
Claim 33
Dependent Claim
14 words
A gasket material as described in claim 10 wherein the fiber includes cellulosic fibers.
Claim 34
Dependent Claim
35 words
The gasket of claim 23 wherein the wet-laid gasket was prepared by adding flocculant and base to an aqueous suspension that included the fiber and the microspheres, adding the binder with agitation, and then dewatering.
Claim 35
Dependent Claim
9 words
The gasket of claim 23 which includes a filler.
Claim 36
Dependent Claim
32 words
The gasket of claim 23 wherein the microspheres are present at an amount in the range of from about 0.75 to about 25% by weight of the total amount of gasket material.
Claim 37
Dependent Claim
29 words
The gasket of claim 18 wherein the microspheres are present at an amount in the range of from about 0.05 to about 20 parts per hundred parts of fiber.
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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) | 1993-08-06 | 1994-02-05 | 1994-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-06 | 1998-02-05 | 1998-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-06 | 2002-02-05 | 2002-08-07 | $7700.00 | Window Closed / Lapsed |