US3855376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making structural material having a foamed inner layer
Assignee: Mitsubishi Chemical Corp
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Filing: 1972-12-08
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Granted: 1974-12-17
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Expires: 1992-12-08
Abstract
Abstract A synthetic resin structural material comprising surface layers and an intersticed inner layer having an expansion ratio between 1.3 and 5, which are integrally bonded together through interfused layers thereof. A process for producing the above-described synthetic resin structural material, comprising introducing surface layerconstituting molten resin and an inner layer-constituting molten resin with a blowing agent blended therein into a die from separate entrances respectively, joining the flows of the respective resins within the die in such a manner that the inner layer-constituting resin flow is sandwiched by the surface layerconstituting resin flows and the resins are not mixed with each other, leading the joined resin flows towards an exit of the die while gradually cooling and hardening the surface layerconstituting resins and applying a suitable pressure to the outer surfaces of said resin flows, discharging the joined resin flows from said die, whereupon said pressure is removed allowing, the inner layer-constituting resin to foam into an intersticed structure, and then regulating the thickness of the thus formed structural material by thickness regulating members.
Inventors
- 👤 K Ono
- 👤 T Tsuchiya
- 👤 A Kawamoto
- 👤 J Nakada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:25
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/03; B29C48/09; B29C48/11; B29C44/00; B29C44/20; B29C44/22; B29C48/07; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/305; B29C48/307; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B3/00; B32B3/10; B32B3/12; B29C48/08; B32B2325/00; B32B2327/00; B32B2327/06; B32B2355/00; B32B2355/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
221 words
A process for producing a synthetic structural material having excellent impact resistance consisting essentially of: a. introducing flat surface layers consisting of molten resins and an inner layer consisting of a molten resin having a blowing agent blended therein into a die from separate entrances, respectively; b. joining the flows of the respective resins within the die in such a manner that the inner layer resin is interposed between the surface layers without mixing together; c. leading the joined resin flows toward an exit while gradually lowering the temperatures and thereby increasing the viscosities of the surface layer resins; d. applying a suitable pressure to the outer surfaces of the surface layer resin flows to shape said surfaces smooth and flat; e. upon completion of the shaping, extruding the joint flow from the die whereupon said pressure is removed from said surfaces, thereby allowing the inner layer resin to foam, and f. then regulating the thickness of the resultant extruded material by thickness regulating members; said blowing agent being added to the inner layer resin in such proportions as to produce a foamed inner layer having an expansion ratio of between 1.3 and 5, and wherein the surface layers are integrally bonded to the inner layer through interfused layers formed during the extrusion process, thereby avoiding the use of an adhesive.
Claim 2
Dependent Claim
221 words
A process for producing a synthetic structural material having excellent impact resistance consisting essentially of: a. introducing flat surface layers consisting of molten resins and an inner layer consisting of a molten resin having a blowing agent blended therein into a die from separate entrances, respectively; b. joining the flows of the respective resins within the die in such a manner that the inner layer resin is interposed between the surface layers without mixing together; c. leading the joined resin flows toward an exit while gradually lowering the temperatures and thereby increasing the viscosities of the surface layer resins; d. applying a suitable pressure to the outer surfaces of the surface layer resin flows to shape said surfaces smooth and flat; e. upon completion of the shaping, extruding the joint flow from the die whereupon said pressure is removed from said surfaces, thereby allowing the inner layer resin to foam, and f. then regulating the thickness of the resultant extruded material by thickness regulating members; said blowing agent being added to the inner layer resin in such proportions as to produce a foamed inner layer having an expansion ratio of between 1.3 and 5, and wherein the surface layers are integrally bonded to the inner layer through interfused layers formed during the extrusion process, thereby avoiding the use of an adhesive.
Claim 3
Dependent Claim
34 words
A process according to claim 1 wherein the temperature difference between the molten resins constituting the outer layer and the molten resin constituting the inner layer is less than 10*C in the process steps.
Claim 4
Dependent Claim
21 words
A process according to claim 1 wherein one of the surface layer resins is different in physical characteristics from the other.
Claim 5
Dependent Claim
17 words
A process according to claim 3 wherein one of the surface layer resins is a weather-proof resin.
Claim 6
Dependent Claim
21 words
A process according to claim 1 wherein the outer surface resins and the inner layer resin consists of an acrylonitrile-butadiene-styrene copolymer.
Claim 7
Dependent Claim
31 words
A process according to claim 1 wherein the outer surface resins consist of a copolymer of acrylic rubber, acrylonitrile and styrene and the foamed inner layer consists of an acrylonitrile-butadiiene-styrene copolymer.
Claim 8
Dependent Claim
8 words
THE PRODUCT OF THE PROCESS OF CLAIM 1.
Claim 9
Dependent Claim
8 words
The product of the process of claim 4.
Claim 10
Dependent Claim
8 words
The product of the process of claim 5.
Claim 11
Dependent Claim
8 words
The product of the process of claim 6.
References Cited (Backward Citations)
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US3461197A
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US3331900A
Cited
US3523988A
Cited
US3444036A
Cited
US3764642A
Cited
US3558753A
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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) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |