Patent US3960807A successfully refreshed from Google Patents.
US3960807A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermoformed polyester articles having impact resistance and high temperature dimensional stability
Assignee: 3M Co
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Filing: 1974-09-30
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Granted: 1976-06-01
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Expires: 1994-09-30
Abstract
Abstract Shaped, thinwalled, thermoformed, heat-set polyester articles having a composition comprising polyester, 2-16% polymeric crack stopping agent, and at least 0.01% nucleating agent, exhibit relatively high temperature dimensional stability and impact resistance.
Inventors
- 👤 Larry S. McTaggart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:23
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/18; C08K3/20; C08K3/22; C08L; C08L23/00; C08L67/00; C08L67/02; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1397
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
63 words
A shaped, thin-walled, thermoformed, heat-set polyester article the composition of which comprises: A. a thermoplastic, crystallizable, polyester having a glass transition temperature of at least 50°C and a melting point of at least 149°C and an intrinsic viscosity of at least 0.75, B. from 2-16% of a polymeric crack stopping agent, and C. from 0.01% to 20% by weight of a nucleating agent.
Claim 2
Dependent Claim
63 words
A shaped, thin-walled, thermoformed, heat-set polyester article the composition of which comprises: A. a thermoplastic, crystallizable, polyester having a glass transition temperature of at least 50°C and a melting point of at least 149°C and an intrinsic viscosity of at least 0.75, B. from 2-16% of a polymeric crack stopping agent, and C. from 0.01% to 20% by weight of a nucleating agent.
Claim 3
Dependent Claim
12 words
The polyester article of claim 1 wherein the polyester is polyethylene terephthalate.
Claim 4
Dependent Claim
15 words
The polyester article of claim 2 wherein the crack stopping agent is a polyolefinic material.
Claim 5
Dependent Claim
13 words
The polyester article of claim 2 wherein the crack stopping agent comprises poly-4-methylpentene-1.
Claim 6
Dependent Claim
25 words
The polyester article of claim 4 wherein the nucleating agent is titanium dioxide in a concentration of 0.01% to 5% by weight of the composition.
Claim 7
Dependent Claim
21 words
The polyester article of claim 1 having the shape of a tray with a generally flat central portion and raised edges.
Claim 8
Dependent Claim
21 words
The polyester article of claim 5 having the shape of a tray with a generally flat central portion and raised edges.
Claim 9
Dependent Claim
37 words
A method of producing the article of claim 1 which comprises blending components A, B, and C, forming a sheet from the blended components, and thermoforming the sheet into its desired shaped, and heat-setting the formed product.
Claim 10
Dependent Claim
12 words
The polyester article of claim 1 having a thickness of 10-40 mils.
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) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |