Patent US4444832A successfully refreshed from Google Patents.
US4444832A
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US
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Process for obtaining reinforced cellular materials based on unsaturated polyester resins
Assignee: SNIA VISCOSA SpA - NAZIONALE INDUSTRIA APPLICAZIONI VISCOSA Soc
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Filing: 1982-05-20
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Granted: 1984-04-24
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Expires: 2002-05-20
Abstract
Abstract A process for obtaining cellular materials from unsaturated polyester resins reinforced with fillers having a density below 0.7 kg/lt by injecting a liquid foam, made from the resins by mechanical introduction of a gas therein into a closed mold, is described. The liquid foam, obtained from polyester resins including additives and optionally a reinforcement of synthetic, artificial, vegetable or mineral fibres having a length lower than 5 mm, and optionally containing a low boiling foaming agent, is injected voluminized and cross-linked in the hot or in the cold in a closed mold containing a reinforcing agent of synthetic, artificial, vegetable or mineral fibers as a monofilament mat, a cut fibre mat, a mono or bidirectional roving woven mat, rovings, fabrics.
Inventors
- 👤 Massimo Mazzola
- 👤 Aldo Cipriani
- 👤 Giancarlo Carignani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:05
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/02; B29C44/12; B29K; B29K2067/00; B29K2105/00; B29K2105/06; B29K2105/12; B29K2105/128; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249962
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
110 words
A method of producing reinforced cellular materials based on unsaturated polyester resins, said method comprising (1) injecting a fully mechanically preformed liquid foam of said polyester resin, obtained essentially by mechanical introduction of gas into said resin, into a closed mold containing reinforcing fibres, said fibers being voluminized to such an extent as to have in the mold not more than about 0.2 g of reinforcing fibers per cm 3 of mold volume, the distance between the individual fibers being at least about 0.045 cm; and (2) subsequently cross-linking said foam in the mold, whereby a reinforced cellular material having a density of less than about 0.7 kg/l is obtained.
Claim 2
Independent Claim
110 words
A method of producing reinforced cellular materials based on unsaturated polyester resins, said method comprising (1) injecting a fully mechanically preformed liquid foam of said polyester resin, obtained essentially by mechanical introduction of gas into said resin, into a closed mold containing reinforcing fibres, said fibers being voluminized to such an extent as to have in the mold not more than about 0.2 g of reinforcing fibers per cm 3 of mold volume, the distance between the individual fibers being at least about 0.045 cm; and (2) subsequently cross-linking said foam in the mold, whereby a reinforced cellular material having a density of less than about 0.7 kg/l is obtained.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein said reinforcing fibers are either synthetic, vegetable, or mineral fibers.
Claim 4
Dependent Claim
37 words
A method according to claim 2, wherein said synthetic, vegetable, or mineral fibers are in the form of either a monofilament mat, a cut fiber mat, a monodirectional roving mat, a bidirectional roving mat, rovings, or fabrics.
Claim 5
Dependent Claim
13 words
A method according to claim 1, wherein said preformed foam contains reinforcing materials.
Claim 6
Dependent Claim
17 words
A method according to claim 4, wherein said reinforcing material is either synthetic, vegetable, or mineral fibers.
Claim 7
Dependent Claim
19 words
A method according to claim 5, wherein said reinforcing material has a length of less than about 3 mm.
Claim 8
Dependent Claim
19 words
A method according to claim 5, wherein said reinforcing material has a length of less than about 1.5 mm.
Claim 9
Dependent Claim
26 words
A method according to claim 1, wherein said cross-linking is carried out in the mold at a temperature from about 20° C. to about 80° C.
Claim 10
Dependent Claim
34 words
A method according to either claim 1 or 4, wherein said reinforcing material is present in an amount of from about 5 to 50 percent by weight with respect to the unsaturated polyester resin.
Claim 11
Dependent Claim
26 words
A method according to claim 1, wherein glass fibers having a diameter less than about 16 microns are employed as said reinforcing material in the mold.
Claim 12
Dependent Claim
33 words
A process according to claim 1, wherein said preformed liquid foam is introduced into a pressure vessel and thereafter injected into said closed mold by means of the pressure within said pressure vessel.
Claim 13
Dependent Claim
16 words
A cellular reinforced material of unsaturated polyester resin, produced by the process according to claim 1.
Claim 14
Dependent Claim
22 words
The reinforced cellular material according to claim 12, wherein said reinforced cellular material has a percentage of closed cells above 80 percent.
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) | 1987-04-24 | 1987-10-24 | 1988-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-24 | 1991-10-24 | 1992-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-24 | 1995-10-24 | 1996-04-24 | $7700.00 | Window Closed / Lapsed |