US5728311A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tire cure bladders containing polytetrafluoroethylene powder and use thereof
Assignee: Goodyear Tire and Rubber Co
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Filing: 1996-01-16
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Granted: 1998-03-17
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Expires: 2016-01-16
Abstract
Abstract Expandable bladders for use in curing presses for hydrocarbon rubbers, such as pneumatic tires, are a crosslinked elastomer composition comprising isobutylene repeat units and including a fluorinated ethylene polymer added in particulate form and thereafter dispersed throughout the bladder. These fluorinated ethylene polymer may or may not form fibers. The bladders may further comprise graphite. A preferred isobutylene elastomer is a brominated copolymer of from 80 to 99 weight percent isobutylene and from 1 to 20 weight percent paramethylstyrene. The bladders have enhanced lubricity, reduced adhesion to cured tire innerliners, better resistance to cracking during flexing, and have lower tension set than similar compositions without fluorinated ethylene polymers. The above enhancements allow hydrocarbon rubbers such as tires to be molded with fewer defects caused by abraded or deformed bladders. They also enhance the useful life of the bladder reducing the cost of tire curing.
Inventors
- 👤 George Philemon Patitsas
- 👤 Paul Harry Sandstrom
- 👤 Samson Samuel Apticar
- 👤 Bharat Kanchanlal Kansupada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:49
CPC Classifications
C; C08; C08L; C08L27/00; C08L27/02; C08L27/12; C08L27/18; B; B29; B29D; B29D30/00; B29D30/06; B29D30/0601; B29D30/0654; B29C; B29C33/00; B29C33/44; B29C33/48; B29C33/50; B29C33/505; B29C33/56; B29C33/60; B29C33/62; B60; B60C; B60C1/00; B60C1/0025; C08K; C08K3/00; C08K3/02; C08K3/04; C08L23/00; C08L23/02; C08L23/18; C08L23/20; C08L23/22; C08L23/26; C08L23/28; C08L23/283; C08L9/00; B29C35/00; B29C35/02; B29C35/04; B29C35/049; B29D2030/0655; B29K; B29K2021/00; B29K2027/00; B29K2027/12; B29K2027/18; B29L; B29L2022/00; B29L2022/02; B29L2022/025; B29L2030/00
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
156 words
In a curing press for a hydrocarbon rubber composition which uses an expandable bladder molded from a formulated rubber bladder compound to assist in shaping and curing said rubber composition the improvement wherein said bladder comprises from about 0.5 to about 10 parts by weight of at least one fluorinated ethylene polymer, optionally from about 0.1 to about 20 parts by weight of graphite, where said fluorinated ethylene polymer and said optional graphite when present are added in a particulate form to and dispersed within said formulated rubber bladder compound, said formulated rubber bladder compound comprising at least one rubbery polymer which comprises at least one isobutylene polymer; wherein said parts by weight are based on 100 parts by weight of said at least one rubbery polymer, and wherein said formulated rubber compound after curing and aging for 24 hours at 177° C. has an elongation at break (ASTM D412) from about 300 to about 500%.
Claim 2
Dependent Claim
156 words
In a curing press for a hydrocarbon rubber composition which uses an expandable bladder molded from a formulated rubber bladder compound to assist in shaping and curing said rubber composition the improvement wherein said bladder comprises from about 0.5 to about 10 parts by weight of at least one fluorinated ethylene polymer, optionally from about 0.1 to about 20 parts by weight of graphite, where said fluorinated ethylene polymer and said optional graphite when present are added in a particulate form to and dispersed within said formulated rubber bladder compound, said formulated rubber bladder compound comprising at least one rubbery polymer which comprises at least one isobutylene polymer; wherein said parts by weight are based on 100 parts by weight of said at least one rubbery polymer, and wherein said formulated rubber compound after curing and aging for 24 hours at 177° C. has an elongation at break (ASTM D412) from about 300 to about 500%.
Claim 3
Dependent Claim
65 words
In a curing press according to claim 1, wherein said at least one isobutylene polymer comprises from about 80 to about 99 weight percent repeat units from isobutylene and from about 1 to about 20 weight percent repeat units from paramethylstyrene and said at least one fluorinated ethylene polymer having at least one fluorine atom in at least 75 mole percent of its repeat units.
Claim 4
Dependent Claim
77 words
In a curing press according to claim 1, wherein said at least one rubbery polymer comprises at least 50 phr of at least one polymer of 95 to 99 weight percent repeat units from isobutylene and from 1 to 5 weight percent repeat units from one or more conjugated dienes and wherein said at least one fluorinated ethylene polymer of said bladder compound has one or more fluorine atoms in at least 75% of its repeat units.
Claim 5
Dependent Claim
22 words
In a curing press according to claim 2, wherein said at least one fluorinated ethylene polymer consists essentially of tetrafluoroethylene repeat units.
Claim 6
Dependent Claim
22 words
In a curing press according to claim 3, wherein said at least one fluorinated ethylene polymer consists essentially of tetrafluoroethylene repeat units.
Claim 7
Dependent Claim
46 words
In a curing press according to claim 2, wherein said at least one isobutylene polymer comprises at least 85 weight percent of said at least one rubbery polymer of said bladder and wherein said bladder includes from about 0.5 to about 10 parts by weight graphite.
Claim 8
Dependent Claim
45 words
In a curing press according to claim 3, wherein said at least one isobutylene polymer comprises at least 85 weight percent of said at least one rubbery polymer of said bladder and wherein said bladder includes about 0.5 to about 10 parts by weight graphite.
Claim 9
Dependent Claim
39 words
In a curing press according to claim 2 wherein said isobutylene polymer comprised of paramethylstyrene and isobutylene is brominated and is from about 10 to about 60 weight percent of said at least one rubbery polymer of said bladder.
Claim 10
Dependent Claim
30 words
In a curing press according to claim 6, wherein said at least one fluorinated ethylene polymer comprises a dispersed polymer essentially of tetrafluoroethylene at least partially in a fibrous form.
Claim 11
Dependent Claim
30 words
In a curing press according to claim 7, wherein said at least one fluorinated ethylene polymer comprises a dispersed polymer essentially of tetrafluoroethylene at least partially in a fibrous form.
Claim 12
Dependent Claim
142 words
An expandable curing bladder comprising from about 0.5 to about 10 parts by weight of at least one fluorinated ethylene polymer, optionally, from about 0.1 to about 20 parts by weight of graphite, at least one rubbery polymer comprising at least one isobutylene polymer having at least 50 weight percent repeat units from isobutylene, and one or more curatives reacted with said at least one rubbery polymer, wherein said parts by weight are based upon 100 parts by weight of said at least one rubbery polymer, wherein said at least one fluorinated ethylene polymer, and said optional graphite are added in particulate form and dispersed in said at least one rubbery polymer, and wherein a composition of said bladder after curing and aging at 177° C. for 24 hours has an elongation at break (ASTM D412) from about 300 to about 500%.
Claim 13
Dependent Claim
142 words
An expandable curing bladder comprising from about 0.5 to about 10 parts by weight of at least one fluorinated ethylene polymer, optionally, from about 0.1 to about 20 parts by weight of graphite, at least one rubbery polymer comprising at least one isobutylene polymer having at least 50 weight percent repeat units from isobutylene, and one or more curatives reacted with said at least one rubbery polymer, wherein said parts by weight are based upon 100 parts by weight of said at least one rubbery polymer, wherein said at least one fluorinated ethylene polymer, and said optional graphite are added in particulate form and dispersed in said at least one rubbery polymer, and wherein a composition of said bladder after curing and aging at 177° C. for 24 hours has an elongation at break (ASTM D412) from about 300 to about 500%.
Claim 14
Dependent Claim
95 words
An expandable curing bladder according to claim 11, wherein said at least one isobutylene polymer comprises at least one polymer of from 80 to 99 weight percent repeat units from isobutylene and from 1 to 20 weight percent repeat units from paramethylstyrene and said at least one fluorinated ethylene polymer has at least one fluorine atom on at least 75 mole percent of its repeat units, said at least one isobutylene polymer of repeat units from isobutylene and paramethylstyrene is at least 50 weight percent of said at least one rubbery polymer of said bladder.
Claim 15
Dependent Claim
88 words
An expandable curing bladder according to claim 11, wherein said at least isobutylene polymer comprises a copolymer of from 95 to 99 weight percent repeat units from isobutylene and from 1 to 5 weight percent repeat units from one or more conjugated dienes and wherein said one or more particulate fluorinated ethylene polymers have one or more fluorine atoms in at least 75% of their repeat units and said copolymers of isobutylene and conjugated dienes are at least 50 weight percent of the rubbers of said curing bladder.
Claim 16
Dependent Claim
25 words
An expandable curing bladder according to claim 11, wherein said one or more fluorinated ethylene polymer comprises a dispersed polymer essentially of tetrafluoroethylene repeat units.
Claim 17
Dependent Claim
21 words
An expandable curing bladder according to claim 14, wherein said polymer essentially of tetrafluorethylene is at least partially in fibrous form.
Claim 18
Dependent Claim
55 words
An expandable curing bladder according to claim 12, wherein said polymer comprised of repeat units from isobutylene and paramethylstyrene is brominated, said at least one fluorinated ethylene polymer comprises a dispersed polymer essentially of repeat units from tetrafluorethylene, and said bladder includes from about 0.5 to about 10 parts by weight of graphite dispersed therein.
Claim 19
Dependent Claim
22 words
An expandable curing bladder according to claim 16, wherein said polymer essentially of tetrafluorethylene units is at least partially in fibrous form.
Claim 20
Independent Claim
236 words
A method of using an expandable rubber bladder to shape and cure a hydrocarbon rubber, said method comprising: a) inserting an uncured rubber composition into a curing mold having an expandable rubber bladder positioned therein and at least one other mold surface, said expandable bladder comprising: 1) at least 50 parts by weight of at least one isobutylene polymer having at least 50 weight percent repeat units from isobutylene, 2) optionally at least one other rubbery polymer, 3) from about 0.5 to about 10 parts by weight of at least one fluorinated ethylene polymer, added in particulate form and dispersed through said at least one isobutylene polymer, and 4) at least one curative for curing said at least one isobutylene polymer, and wherein said parts by weight are based upon 100 parts by weight of said at least one isobutylene polymer and said optional at least one rubbery polymer in said bladder and wherein said bladder after aging for 24 hours at 177° C. has an elongation to break (ASTM D412) of from about 300 to about 500%, b) closing the mold and expanding said rubber bladder outwardly against the inner surface of the uncured hydrocarbon rubber to force said uncured hydrocarbon rubber against the at least one other mold surface, c) curing the hydrocarbon rubber under heat and pressure, d) deflating said expandable bladder, and e) removing the cured hydrocarbon material from said curing mold.
Claim 21
Independent Claim
236 words
A method of using an expandable rubber bladder to shape and cure a hydrocarbon rubber, said method comprising: a) inserting an uncured rubber composition into a curing mold having an expandable rubber bladder positioned therein and at least one other mold surface, said expandable bladder comprising: 1) at least 50 parts by weight of at least one isobutylene polymer having at least 50 weight percent repeat units from isobutylene, 2) optionally at least one other rubbery polymer, 3) from about 0.5 to about 10 parts by weight of at least one fluorinated ethylene polymer, added in particulate form and dispersed through said at least one isobutylene polymer, and 4) at least one curative for curing said at least one isobutylene polymer, and wherein said parts by weight are based upon 100 parts by weight of said at least one isobutylene polymer and said optional at least one rubbery polymer in said bladder and wherein said bladder after aging for 24 hours at 177° C. has an elongation to break (ASTM D412) of from about 300 to about 500%, b) closing the mold and expanding said rubber bladder outwardly against the inner surface of the uncured hydrocarbon rubber to force said uncured hydrocarbon rubber against the at least one other mold surface, c) curing the hydrocarbon rubber under heat and pressure, d) deflating said expandable bladder, and e) removing the cured hydrocarbon material from said curing mold.
Claim 22
Dependent Claim
22 words
A method according to claim 18, wherein said at least one fluorinated ethylene polymer comprises a polymer of essentially tetrafluoroethylene repeat units.
Claim 23
Dependent Claim
50 words
A method according to claim 19, wherein said at least one isobutylene polymer is at least 80 parts by weight and is comprised of a polymer being 80 to 99 weight percent repeat units from isobutylene and 1 to 20 weight percent repeat units from paramethylstyrene, said polymer being brominated.
Claim 24
Dependent Claim
51 words
A method according to claim 19, wherein said at least one isobutylene polymer is at least 80 parts by weight and is comprised of a polymer being 95 to 99 weight percent repeat units from isobutylene and from 1 to 5 weight percent repeat units from one or more conjugated dienes.
Claim 25
Dependent Claim
22 words
A method according to claim 20, wherein said expandable bladder includes from 0.5 to 20 parts by weight of graphite dispersed therein.
Claim 26
Dependent Claim
150 words
In a curing press for a hydrocarbon rubber composition which uses a monolayer expandable bladder optionally with a surface lubricant to assist in shaping and curing said rubber composition, the improvement wherein said monolayer expandable bladder comprises a) from about 0.5 to 10 parts by weight of at least one fluorinated ethylene polymer added in particulate form and dispersed within b) a formulated rubber bladder compound, and c) optionally from about 0.1 to about 20 parts by weight of graphite dispersed in said b); wherein said b) formulated rubber compound comprises at least one rubbery polymer which comprises at least one isobutylene polymer, wherein said parts by weight are based upon 100 parts by weight of said at least one rubbery polymer, and wherein said formulated rubber bladder compound after curing and aging for 24 hours at 177° C. has an elongation at break (ASTM D412) from 300 to 500%.
Claim 27
Dependent Claim
150 words
In a curing press for a hydrocarbon rubber composition which uses a monolayer expandable bladder optionally with a surface lubricant to assist in shaping and curing said rubber composition, the improvement wherein said monolayer expandable bladder comprises a) from about 0.5 to 10 parts by weight of at least one fluorinated ethylene polymer added in particulate form and dispersed within b) a formulated rubber bladder compound, and c) optionally from about 0.1 to about 20 parts by weight of graphite dispersed in said b); wherein said b) formulated rubber compound comprises at least one rubbery polymer which comprises at least one isobutylene polymer, wherein said parts by weight are based upon 100 parts by weight of said at least one rubbery polymer, and wherein said formulated rubber bladder compound after curing and aging for 24 hours at 177° C. has an elongation at break (ASTM D412) from 300 to 500%.
Claim 28
Dependent Claim
24 words
In a curing press according to claim 23, wherein said expandable bladder includes from 0.5 to 10 parts by weight of graphite dispersed therein.
References Cited (Backward Citations)
US3002938A
Cited
US3223676A
Cited
US3600309A
Cited
US3940455A
Cited
US3853809A
Cited
US3967968A
Cited
US3932088A
Cited
US4215178A
Cited
US4310427A
Cited
US4333977A
Cited
US4407988A
Cited
US4863650A
Cited
EP0344021A2
Cited
US5063268A
Cited
US5238991A
Cited
US5162409A
Cited
US5162409B1
Cited
US5538218A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-03-16 | 2001-09-15 | 2002-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-03-16 | 2005-09-15 | 2006-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-03-16 | 2009-09-15 | 2010-03-17 | $7700.00 | Window Closed / Lapsed |