US4499036A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave curing of latex-based compositions
Assignee: WR Grace and Co Conn
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Filing: 1984-07-20
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Granted: 1985-02-12
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Expires: 2004-07-20
Abstract
Abstract A method of providing cured latex-based compositions is disclosed which permits in situ curing of latexes disposed in plastic container closures or other heat sensitive receptacles without adverse effect on the closure or receptacle. The method comprises heating a fluid latex composition to gel the latex and effect removal of at least a portion of the water initially contained therein and subjecting the resultant composition to modulated microwave energy to effect curing thereof. Modulation of the microwave energy is achieved by applying same in an intermittent or pulsed fashion. The method is of particular interest for the in situ formation of cured latex-based gaskets in polyalkylene container closures.
Inventors
- 👤 J. Barry Hawkes, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:21
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; B; B29; B29C; B29C35/00; B29C35/02; B29C35/08; B29C44/00; B29C44/02; B29C44/12; B29C35/0805; B29C2035/0855; B29K; B29K2021/00; B29K2105/00; B29K2105/0058; B29K2105/0064; B29K2105/04; B29L; B29L2031/00; B29L2031/26; B29L2031/265; B29L2031/56; B29L2031/565; C08J2321/00; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S521/00; Y10S521/915
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
80 words
A process of forming a cured latex-based foam composition comprising the steps of heating a fluid rubber latex containing a gelling agent, a curing agent and a blowing agent to effect gelling and foaming thereof and removal of a major proportion of the water initially contained therein and subjecting the resultant gelled and foamed composition to microwave radiation to effect curing thereof, said microwave radiation being modulated to provide substantially uniform and complete curing of said gelled and foamed composition.
Claim 2
Dependent Claim
80 words
A process of forming a cured latex-based foam composition comprising the steps of heating a fluid rubber latex containing a gelling agent, a curing agent and a blowing agent to effect gelling and foaming thereof and removal of a major proportion of the water initially contained therein and subjecting the resultant gelled and foamed composition to microwave radiation to effect curing thereof, said microwave radiation being modulated to provide substantially uniform and complete curing of said gelled and foamed composition.
Claim 3
Dependent Claim
18 words
A process of claim 1 wherein said microwave energy is modulated by being applied in a pulsed fashion.
Claim 4
Dependent Claim
33 words
A process of claim 2 wherein the pulses of microwave radiation are about 5 to 40 seconds in duration and are applied at equally spaced intervals ranging from about 5 to 40 seconds.
Claim 5
Dependent Claim
19 words
A process of claim 3 wherein the pulses are of equal duration and are applied at equally spaced intervals.
Claim 6
Dependent Claim
20 words
A process of claim 4 wherein the pulse duration and interval time are equal and are at least 10 seconds.
Claim 7
Dependent Claim
19 words
A process of claim 1 wherein said fluid latex is heated to a temperature of at least 150° F.
Claim 8
Dependent Claim
30 words
A process of claim 6 wherein said fluid latex is heated to a temperature in the range of about 160° F. to 180° F. for about 15 to 30 minutes.
Claim 9
Dependent Claim
28 words
A process of claim 1 wherein a sufficient amount of said water is removed to permit a substantially uniform cellular structure to be formed in said foam composition.
Claim 10
Dependent Claim
11 words
A process of claim 8 wherein said water is completely removed.
Claim 11
Dependent Claim
15 words
A process of claim 1 wherein said fluid latex is deposited on a polyalkylene substrate.
Claim 12
Dependent Claim
14 words
A process of claim 1 wherein said fluid latex is a styrene-butadiene rubber latex.
Claim 13
Dependent Claim
13 words
A process of claim 1 wherein said fluid latex comprises a naphthenic oil.
Claim 14
Dependent Claim
19 words
A process of claim 1 wherein said foam composition possesses a thickness or diameter of at least 1/8 inch.
Claim 15
Dependent Claim
97 words
A process of forming a cured rubber latex-based gasket in a container closure comprising the steps of applying a fluid rubber latex composition containing a gelling agent, a curing agent and a blowing agent about the periphery of said closure, heating said closure and latex composition to effect gelling and foaming thereof and removal of a major proportion of the water initially contained therein, and subjecting the resultant gelled and foamed composition to microwave radiation to effect curing thereof, said microwave radiation being modulated to provide substantially uniform and complete curing of said gelled and foamed composition.
Claim 16
Dependent Claim
97 words
A process of forming a cured rubber latex-based gasket in a container closure comprising the steps of applying a fluid rubber latex composition containing a gelling agent, a curing agent and a blowing agent about the periphery of said closure, heating said closure and latex composition to effect gelling and foaming thereof and removal of a major proportion of the water initially contained therein, and subjecting the resultant gelled and foamed composition to microwave radiation to effect curing thereof, said microwave radiation being modulated to provide substantially uniform and complete curing of said gelled and foamed composition.
Claim 17
Dependent Claim
18 words
A process of claim 14 wherein said microwave energy is modulated by being applied in a pulsed fashion.
Claim 18
Dependent Claim
33 words
A process of claim 15 wherein the pulses of microwave radiation are about 5 to 40 seconds in duration and are applied at equally spaced intervals ranging from about 5 to 40 seconds.
Claim 19
Dependent Claim
19 words
A process of claim 16 wherein the pulses are of equal duration and are applied at equally spaced intervals.
Claim 20
Dependent Claim
20 words
A process of claim 17 wherein the pulse duration and interval time are equal and are at least 10 seconds.
Claim 21
Dependent Claim
19 words
A process of claim 14 wherein said fluid latex is heated to a temperature of at least 150° F.
Claim 22
Dependent Claim
30 words
A process of claim 19 wherein said fluid latex is heated to a temperature in the range of about 160° F. to 180° F. for about 15 to 30 minutes.
Claim 23
Dependent Claim
27 words
A process of claim 14 wherein a sufficient amount of said water is removed to permit a substantially uniform cellular structure to be formed in said gasket.
Claim 24
Dependent Claim
11 words
A process of claim 21 wherein said water is completely removed.
Claim 25
Dependent Claim
15 words
A process of claim 14 wherein said closure is comprised of a molded polyalkylene polymer.
Claim 26
Dependent Claim
11 words
A process of claim 23 wherein said polyalkylene polymer is polypropylene.
Claim 27
Dependent Claim
14 words
A process of claim 14 wherein said fluid latex is a styrene-butadiene rubber latex.
Claim 28
Dependent Claim
13 words
A process of claim 14 wherein said fluid latex comprises a naphthenic oil.
Claim 29
Dependent Claim
18 words
A process of claim 14 wherein said gasket possesses a thickness or diameter of at least 1/8 inch.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |