US4889669A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing foamed thermoplastic resin articles
Assignee: Mitsubishi Chemical Corp
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Filing: 1988-03-18
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Granted: 1989-12-26
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Expires: 2008-03-18
Abstract
Abstract A process for producing a foamed thermoplastic resin article is disclosed, comprising separately melt kneading the first thermoplastic resin composition comprising a first thermoplastic resin and 10 to 400 parts by weight per 100 parts by weight of the first thermoplastic resin of a filler and constituting an unfoamed layer at the time of extrusion molding, and the second thermoplastic resin composition comprising a second thermoplastic resin and a foaming agent and constituting a foamed layer at the time of extrusion molding, by the use of extruders, and extruding the two resin compositions in the form of laminate through a T die.
Inventors
- 👤 Yasuyosi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:28
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/20; B29C44/22; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C48/00; B29C48/03; B29C48/07; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/305; B29C48/307; B29K; B29K2105/00; B29K2105/06; B29K2105/16; B29L; B29L2009/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
101 words
A process for producing a foamed thermoplastic resin article which comprises separately melt kneading the first thermoplastic resin composition comprising a first thermoplastic resin and 10 to 400 parts by weight per 100 parts by weight of the first thermoplastic resin of a filler and constituting an unfoamed layer at the time of extrusion molding, and the second thermoplastic resin composition comprising a second thermoplastic resin and a foaming agent and constituting a foamed layer at the time of extrusion molding, by the use of extruders, and coextruding the two resin compositions in the form of laminate through a T die.
Claim 2
Dependent Claim
101 words
A process for producing a foamed thermoplastic resin article which comprises separately melt kneading the first thermoplastic resin composition comprising a first thermoplastic resin and 10 to 400 parts by weight per 100 parts by weight of the first thermoplastic resin of a filler and constituting an unfoamed layer at the time of extrusion molding, and the second thermoplastic resin composition comprising a second thermoplastic resin and a foaming agent and constituting a foamed layer at the time of extrusion molding, by the use of extruders, and coextruding the two resin compositions in the form of laminate through a T die.
Claim 3
Dependent Claim
21 words
The process as claimed in claim 1, wherein the structure of the laminate is an unfoamed layer/a foamed layer/an unfoamed layer.
Claim 4
Dependent Claim
24 words
The process as claimed in claim 1, wherein the thickness ratio of the unfoamed layer is 0.05/1 to 0.7/1 based on the total thickness.
Claim 5
Dependent Claim
20 words
The process as claimed in claim 1, wherein the expansion ratio of the foamed layer is up to 10 times.
Claim 6
Dependent Claim
21 words
The process as claimed in claim 1, wherein the first and second thermoplastic resin compositions are laminated in a T die.
Claim 7
Dependent Claim
24 words
The process as claimed in claim 1, wherein the first and second thermoplastic resin compositions are laminated prior to introduction into the T die.
Claim 8
Dependent Claim
19 words
The process as claimed in claim 1, wherein the first and second thermoplastic resins are each a polyolefin resin.
Claim 9
Dependent Claim
25 words
The process as claimed in claim 7, wherein the first and second thermoplastic resins are each a polypropylene resin or a high density polyethylene resin.
Claim 10
Dependent Claim
19 words
The process as claimed in claim 1, wherein the first and second thermoplastic resins are each a styrene-series resin.
Claim 11
Dependent Claim
23 words
The process as claimed in claim 9, wherein the first and second thermoplastic resins are each a polystyrene resin or an ABS resin.
Claim 12
Dependent Claim
16 words
The process as claimed in claim 1, wherein the filler is talc, mica or calcium carbonate.
Claim 13
Dependent Claim
28 words
The process as claimed in claim 1, wherein the foaming agent is an alkali metal citrate, a mixture of an alkali metal citrate and sodium hydrogencarbonate, or azodicarbonamide.
Claim 14
Dependent Claim
19 words
The process as claimed in claim 1, wherein the second thermoplastic resin composition does not substantially contain a filler.
References Cited (Backward Citations)
US3331900A
Cited
US3411981A
Cited
DE1779874A1
Cited
US3668288A
Cited
CA948820A
Cited
US3855376A
Cited
US4107247A
Cited
US4101050A
Cited
US4221624A
Cited
EP0084360B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |