Patent US4071490A successfully refreshed from Google Patents.
US4071490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plastics foil for the manufacture of audio-visual information carriers
Assignee: Hoechst AG
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Filing: 1976-09-08
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Granted: 1978-01-31
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Expires: 1996-09-08
Abstract
Abstract A rigid polyvinyl chloride foil with modified impact resistance and free from plasticizer especially suitable for the manufacture of audio-visual information carriers with stamped spiral grooves from which the information is played back by pressure scanning. The foil is characterized by a special combination of properties such as flow, reduction in length, toughness, surface resistance, elasticity, peak-to-valley height and surface deposit.
Inventors
- 👤 Hans-Joachim Andrascheck
- 👤 Rainer Mucke
- 👤 Werner Lorz
- 👤 Heinz Borchard
- 👤 Jurgen Buck
- 👤 Herbert Knothe
- 👤 Bruno Rybka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:59
CPC Classifications
G; G11; G11B; G11B3/00; G11B3/68; G11B3/70; G11B3/705; G11B3/707
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
148 words
Rigid polyvinyl chloride foil free from plasticizer and having modified impact resistance, suitable for the manufacture of audio-visual information carriers with stamped in spiral grooves carrying the information reproducible by pressure scanning characterized by the following properties: a. a flow corresponding to a melt viscosity in the range of from 20 to 72 g/10 minutes, b. a reduction in length of at most 20 % at 160° C, c. a toughness corresponding to a factor of at least (25% . mm 2 )/newtons in longitudinal and transverse directions d. a surface resistance of at most 10 10 ohms, e. an elasticity corresponding to an elastic modulus in the range of from 2,500 to 5,000 newtons/mm 2 , f. a peak-to-valley height corresponding to a Perth-O-Meter value of less than 0.4 μm, and g. a surface deposit corresponding to a foil extraction residue of less than 0.012% by weight.
Claim 2
Dependent Claim
148 words
Rigid polyvinyl chloride foil free from plasticizer and having modified impact resistance, suitable for the manufacture of audio-visual information carriers with stamped in spiral grooves carrying the information reproducible by pressure scanning characterized by the following properties: a. a flow corresponding to a melt viscosity in the range of from 20 to 72 g/10 minutes, b. a reduction in length of at most 20 % at 160° C, c. a toughness corresponding to a factor of at least (25% . mm 2 )/newtons in longitudinal and transverse directions d. a surface resistance of at most 10 10 ohms, e. an elasticity corresponding to an elastic modulus in the range of from 2,500 to 5,000 newtons/mm 2 , f. a peak-to-valley height corresponding to a Perth-O-Meter value of less than 0.4 μm, and g. a surface deposit corresponding to a foil extraction residue of less than 0.012% by weight.
Claim 3
Dependent Claim
27 words
Rigid polyvinyl chloride foil as claimed in claim 1, having a flow corresponding to a melt viscosity in the range of from 35 to 55 g/10 minutes.
Claim 4
Dependent Claim
24 words
Rigid polyvinyl chloride foil as claimed in claim 1, having an elastic modulus in the range of from 2,700 to 3,200 newtons/mm 2 .
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) | 1981-01-30 | 1981-08-01 | 1982-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-30 | 1985-08-01 | 1986-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-30 | 1989-08-01 | 1990-01-31 | $7700.00 | Window Closed / Lapsed |