US4650816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expanded polypropylene and articles thereof
Assignee: MONTEFINA SA FELUY BELGIUM A CORP OF BELGIUM
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Filing: 1985-09-30
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Granted: 1987-03-17
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Expires: 2005-09-30
Abstract
Abstract Disclosed are rigid materials such as sheets, boards or tubes made of expanded polypropylene, which have a uniform specific gravity d of from about 4.1×10 -6 to about 8.1×10 -6 Newton/mm 3 , a crystallization temperature of from about 115° C. to about 135° C. and a flexural modulus Mf expressed in Newton/mm 3 such that the ratio Mf:d is from about 1.5×10 8 to about 1.7×10 8 mm.
Inventors
- 👤 Jean-Noel M. Bertrand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:37
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/0014; C08J2323/00; C08J2323/02; C08J2323/10; C08J2323/12; Y; Y10; Y10S; Y10S521/00; Y10S521/908
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
64 words
Rigid materials made of expanded polypropylene characterized by having (i) a uniform specific gravity d of from about 4.1×10 -6 to about 8.1×10 -6 Newton/mm 3 , (ii) a crystallization temperature of from about 115° C. to about 135° C., and (iii) a flexural modulus Mf expressed in Newton/mm 2 such that the ratio MF:d is from about 1.50×10 8 and 1.70×10 8 mm.
Claim 2
Dependent Claim
64 words
Rigid materials made of expanded polypropylene characterized by having (i) a uniform specific gravity d of from about 4.1×10 -6 to about 8.1×10 -6 Newton/mm 3 , (ii) a crystallization temperature of from about 115° C. to about 135° C., and (iii) a flexural modulus Mf expressed in Newton/mm 2 such that the ratio MF:d is from about 1.50×10 8 and 1.70×10 8 mm.
Claim 3
Dependent Claim
21 words
Rigid materials according to claim 1, characterized by having a crystallization temperature of from about 115° C. to about 130° C.
Claim 4
Dependent Claim
20 words
Rigid materials according to claim 1, having a ratio Mf/d of from about 1.52×10 8 to about 1.68×10 8 mm.
Claim 5
Dependent Claim
33 words
Expanded polypropylene sheets of claim 1 obtained by extruding a polymeric composition comprising: (a) isotactic polypropylene; (b) an agent for increasing the crystallization speed of said polymeric composition; and (c) a blowing agent.
Claim 6
Dependent Claim
14 words
The sheets of claim 4 wherein said polymeric composition further comprises a nucleating agent.
Claim 7
Dependent Claim
60 words
The sheets of claim 4 wherein the agent for increasing the crystalliztaion speed is selected from the group consisting of dibenzilidene sorbitol, sodium bis(4-tert-butyl-phenol)phosphate, sodium benzoate, a mixture comprising a monocarboxylic aromatic acid or a polycarboxylic aliphatic acid and a silicate or an alumino-silicate of a metal of Group I or II of the Periodic System, and any mixture thereof.
Claim 8
Dependent Claim
28 words
The sheets of claim 6 wherein said agent is present in an amount of from about 500 ppm to about 5000 ppm based on the weight of polypropylene.
Claim 9
Dependent Claim
42 words
The sheets of claim 4 wherein the isotactic polypropylene is selected from the group consisting of propylene homopolymer, a copolymer of propylene and not greater that 10 wt. % of an alpha-olefin having up to 6 carbon atoms, and any mixture thereof.
Claim 10
Dependent Claim
16 words
The sheets of claim 4 characterized by having a variation in density of less than 5%.
Claim 11
Dependent Claim
32 words
The sheets of claim 4 wherein said blowing agent is present in sufficient amounts to give the sheets a density of from about 4.1×10 -6 to about 8.1×10 -6 Newton/mm 3 .
Claim 12
Dependent Claim
33 words
Expanded polypropylene tubes of claim 1 obtained by extruding a polymeric composition comprising: (a) isotactic polypropylene; (b) an agent for increasing the crystallization speed of said polymeric composition; and (c) a blowing agent.
Claim 13
Dependent Claim
14 words
The tubes of claim 11 wherein said polymeric composition further comprises a nucleating agent.
Claim 14
Dependent Claim
60 words
The tubes of claim 11 wherein the agent for increasing the crystalliztaion speed is selected from the group consisting of dibenzilidene sorbitol, sodium bis(4-tert-butyl-phenol)phosphate, sodium benzoate, a mixture comprising a monocarboxylic aromatic acid or a polycarboxylic aliphatic acid and a silicate or an alumino-silicate of a metal of Group I or II of the Periodic System, or any mixture thereof.
Claim 15
Dependent Claim
28 words
The tubes of claim 13 wherein said agent is present in an amount of from about 500 ppm to about 5000 ppm based on the weight of polypropylene.
Claim 16
Dependent Claim
42 words
The tubes of claim 11 wherein the isotactic polypropylene is selected from the group consisting of propylene homopolymer, a copolymer of propylene and not greater than 10 wt % of an alpha-olefin having up to 6 carbon atoms, or any mixture thereof.
Claim 17
Dependent Claim
16 words
The tubes of claim 11 characterized by having a variation in density of less than 5%.
Claim 18
Dependent Claim
32 words
The tubes of claim 11 wherein said blowing agent is present in sufficient amounts to give the sheets a density of from about 4.1×10 -6 to about 8.1×10 -6 Newton/mm 3 .
References Cited (Backward Citations)
US3207739A
Cited
US3268499A
Cited
US3808300A
Cited
US3839238A
Cited
US3725317A
Cited
US3962154A
Cited
US4407768A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-16 | 1990-09-15 | 1991-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-16 | 1994-09-15 | 1995-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-16 | 1998-09-15 | 1999-03-17 | $7700.00 | Window Closed / Lapsed |