US4762891A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scorch-resistant, curable fluorinated elastomer
Assignee: Dyneon LLC
•
Filing: 1987-02-13
•
Granted: 1988-08-09
•
Expires: 2007-02-13
Abstract
Abstract A scorch-resistant, curable, fluorinated elastomer gum composition is provided. A free-radically curable, fluorinated elastomer gum is compounded with an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo moieties contains a β,γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound. The diorganosulfur compound reduces the tendency of the compounded fluorinated elastomer gum to scorch, i.e. begin curing prematurely, in the presence of a free-radical curing agent during compounding and shaping of the gum at elevated temperatures below the intended cure temperature. Specific examples of said compounds include 2,5-dihydrothiophene-1,1-dioxide, 2,5-dihydrothiophene-1-oxide, and diallylsulfide. Methods of compounding a fluorinated elastomer gum composition and of shaping and curing such a composition to obtain a fluorinated elastomeric article are also provided.
Inventors
- 👤 Loren D. Albin
- 👤 Robert E. Kolb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:19
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/36; C08K5/41; C08K5/37; C08K5/372; C08K5/45
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
58 words
A fluorinated elastomer composition comprising a free-radically curable, fluorinated elastomer gum and an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo groups contains a β,γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound.
Claim 2
Dependent Claim
58 words
A fluorinated elastomer composition comprising a free-radically curable, fluorinated elastomer gum and an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo groups contains a β,γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound.
Claim 3
Dependent Claim
86 words
A composition of claim 1 wherein said diorganosulfur compound has the formula R 1 --S(O) n --R 2 wherein n is 0, 1 or 2 and R 1 and R 2 are organic groups at least one of which contains a β,γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to the S atom, and R 1 and R 2 can be covalently bonded to each other to form a heterocyclic ring.
Claim 4
Dependent Claim
14 words
A composition of claim 2 wherein said diorganosulfur compound is an aliphatic diorganosulfur compound.
Claim 5
Dependent Claim
13 words
A composition of claim 2 wherein said diorganosulfur compound is an aliphatic diorganosulfide.
Claim 6
Dependent Claim
15 words
A composition of claim 2 wherein said diorganosulfur compound is an aliphatic diorganosulfoxide or diorganosulfone.
Claim 7
Dependent Claim
63 words
A composition of claim 2 wherein said diorganosulfur compound has the structural formula: ##STR2## wherein n is 0, 1, or 2, p is 0 or 1, and each R in said structural formula is independently selected from the group consisting of hydrogen or alkyl, at least one of R 3 , R 4 , R 5 or R 6 is a hydrogen atom.
Claim 8
Dependent Claim
20 words
A composition of claim 2 wherein said diorganosulfur compound is selected from the group consisting of 2,5-dihydrothiophene-1,1-dioxide, 3-methyl-2,5-dihydrothiophene-1,1-dioxide and 3-ethyl-2,5-dihydrothiophene-1,1-dioxide.
Claim 9
Dependent Claim
11 words
A composition of claim 2 wherein said diorganosulfur compound is diallylsulfide.
Claim 10
Dependent Claim
25 words
A composition of claim 1 wherein said diorganosulfur compound is present in an amount sufficient to inhibit the scorch of the composition at elevated temperatures.
Claim 11
Dependent Claim
25 words
A composition of claim 1 wherein said diorganosulfur compound is present in the amount of 0.05 to 10 percent by weight of said elastomer gum.
Claim 12
Dependent Claim
19 words
A curable, fluorinated elastomer comprising a mixture of the composition of claim 1 and a thermally-activatable free-radical curing system.
Claim 13
Dependent Claim
13 words
A composition of claim 10 wherein said curing system comprises an organic peroxide.
Claim 14
Dependent Claim
26 words
A composition of claim 1 wherein said fluorinated elastomer is a copolymer of fluorinated olefins and a cure-site monomer having a covalently-bonded bromine or iodine atom.
Claim 15
Dependent Claim
35 words
A composition of claim 1 wherein said fluorinated elastomer gum is a polymer comprised of repeating units derived from vinylidene fluoride and at least one compound selected from the group consisting of hexafluoropropylene and tetrafluoroethylene.
Claim 16
Dependent Claim
25 words
A composition of claim 14 wherein said polymer is further comprised of units derived from a cure-site monomer having a covalently-bonded bromine or iodine atom.
Claim 17
Dependent Claim
12 words
A composition of claim 15 wherein said covalently bonded atom is bromine.
Claim 18
Dependent Claim
29 words
A composition of claim 14 wherein said polymer is comprised of units derived from vinylidene fluoride, hexafluoropropylene and a copolymerizable cure-site monomer having a covalently-bonded bromine or iodine atom.
Claim 19
Dependent Claim
14 words
A composition of claim 16 wherein said polymer further comprises units derived from tetrafluoroethylene.
Claim 20
Dependent Claim
67 words
A curable composition comprising a free-radically curable fluorinated elastomer gum, a thermally-activatable organic peroxide curing system, and as a scorch inhibitor an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo moieties contains a β,γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound.
Claim 21
Dependent Claim
67 words
A curable composition comprising a free-radically curable fluorinated elastomer gum, a thermally-activatable organic peroxide curing system, and as a scorch inhibitor an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo moieties contains a β,γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound.
Claim 22
Dependent Claim
21 words
A composition of claim 19 wherein said diorganosulfur oxide compound is selected from the group consisting of 2,5-dihydrothiophene-1,1-dioxide, 3-methyl-2,5-dihydrothiophene-1,1-dioxide, and 3-ethyl-2,5-dihydrothiophene-1,1-dioxide.
Claim 23
Dependent Claim
29 words
A composition of claim 20 wherein said fluorinated elastomer gum is a polymer comprised of units derived from vinylidene fluoride, hexafluoropropylene, and a bromo- or iodo-containing copolymerizable cure-site monomer.
Claim 24
Independent Claim
66 words
A method of compounding a curable fluorinated elastomer gum composition comprising mixing a free-radically curable fluorinated elastomer gum and an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo moieties contains a β, γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound.
Claim 25
Independent Claim
66 words
A method of compounding a curable fluorinated elastomer gum composition comprising mixing a free-radically curable fluorinated elastomer gum and an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo moieties contains a β, γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound.
Claim 26
Independent Claim
102 words
A method of forming a cured fluorinated elastomeric article comprising: (a) compounding a fluorinated elastomer gum with at least (i) a thermally-activatable free-radical curing system and (ii) a scorch inhibitor comprising an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo moieties contains a β, γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound, (b) shaping said composition at an elevated temperature into the form of an article, and (c) heating the formed composition to cure said composition.
Claim 27
Independent Claim
102 words
A method of forming a cured fluorinated elastomeric article comprising: (a) compounding a fluorinated elastomer gum with at least (i) a thermally-activatable free-radical curing system and (ii) a scorch inhibitor comprising an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo moieties contains a β, γ-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the α carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound, (b) shaping said composition at an elevated temperature into the form of an article, and (c) heating the formed composition to cure said composition.
Claim 28
Dependent Claim
10 words
A method of claim 23 wherein said shaping is molding.
Claim 29
Dependent Claim
10 words
A method of claim 23 wherein said shaping is extruding.
References Cited (Backward Citations)
US3318854A
Cited
US3051677A
Cited
US2968649A
Cited
US2968549A
Cited
US3538028A
Cited
US4287320A
Cited
US4214060A
Cited
US4035565A
Cited
US4243770A
Cited
US4263414A
Cited
US4450263A
Cited
US4595720A
Cited
US4564662A
Cited
US4550132A
Cited
US4501866A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-09 | 1992-02-08 | 1992-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-09 | 1996-02-08 | 1996-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-09 | 2000-02-08 | 2000-08-09 | $7700.00 | Window Closed / Lapsed |