US4551390A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of molding multi-ply polymeric composites
Assignee: Owens Corning Fiberglas Technology Inc
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Filing: 1983-05-09
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Granted: 1985-11-05
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Expires: 2003-05-09
Abstract
Abstract This invention pertains to a method to permit the molding of a plurality of plies of polymeric compositions into an integral molded object having a minimum number of internal flaws and, therefore, improved properties. The plies are positioned in contiguous relationship, and the initiation of the polymerization reactions is controlled by selecting catalyst systems which substantially simultaneously initiate polymerization in each of the plies to prevent the development of curing seams at the points of contact between the plies.
Inventors
- 👤 John L. Canning
- 👤 John F. Kay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:29
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/24; C08J3/243; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/252; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2964; Y10T428/31504; Y10T428/31551; Y10T428/31616; Y10T428/3162; Y10T428/31786; Y10T428/31794
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
139 words
An article comprising a plurality of plies including at least an inner ply and a pair of outer plies positioned in contacting contiguous relationship over a desired portion of their surfaces, wherein said inner and pair of outer plies each include an unsaturated, crosslinkable polyester, a monomer and a polymerization catalyst system, the catalyst system in said inner ply exhibiting a lower initiation temperature as compared to initiation temperatures of the catalyst system in each said pair of outer plies, wherein the catalyst system in each of the plies substantially simultaneously reach their respective polymerization initiation temperatures to crosslink the polyesters within each ply when the plies are molded at elevated temperatures and pressures; wherein said catalyst systems are selected from the group consisting of aliphatic diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, aromatic diacyl peroxides, peroxyesters and "azo" catalyst.
Claim 2
Dependent Claim
139 words
An article comprising a plurality of plies including at least an inner ply and a pair of outer plies positioned in contacting contiguous relationship over a desired portion of their surfaces, wherein said inner and pair of outer plies each include an unsaturated, crosslinkable polyester, a monomer and a polymerization catalyst system, the catalyst system in said inner ply exhibiting a lower initiation temperature as compared to initiation temperatures of the catalyst system in each said pair of outer plies, wherein the catalyst system in each of the plies substantially simultaneously reach their respective polymerization initiation temperatures to crosslink the polyesters within each ply when the plies are molded at elevated temperatures and pressures; wherein said catalyst systems are selected from the group consisting of aliphatic diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, aromatic diacyl peroxides, peroxyesters and "azo" catalyst.
Claim 3
Dependent Claim
17 words
The article of claim 1 in which at least one of said plies further comprises glass fibers.
Claim 4
Dependent Claim
15 words
The article of claim 1 wherein said plies further comprise polymerization promoters, fillers and colorants.
Claim 5
Dependent Claim
38 words
The article of claim 1 in which the polymerization initiation temperature of the catalyst system of said inner ply is about 10° F. less than the initiation temperatures of each catalyst system of said pair of outer plies.
Claim 6
Dependent Claim
14 words
The article of claim 1 in which each ply comprises a plurality of layers.
Claim 7
Dependent Claim
23 words
The article of claim 1 wherein the polymeric composition of said plies further comprise different catalyst systems or different quantities of catalyst systems.
References Cited (Backward Citations)
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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) | 1988-11-04 | 1989-05-06 | 1989-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-04 | 1993-05-06 | 1993-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-04 | 1997-05-06 | 1997-11-05 | $7700.00 | Window Closed / Lapsed |