Patent US4299736A successfully refreshed from Google Patents.
US4299736A
Expired / Lapsed
US
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Conductive molding composition and discs therefrom
Assignee: RCA Corp
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Filing: 1980-05-19
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Granted: 1981-11-10
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Expires: 2000-05-19
Abstract
Abstract Polyvinyl chloride base molding compositions containing conductive carbon particles which have been treated with a fatty acid chloride have reduced melt viscosities, improved processabilities, and increased electrical conductivities, as well as improved dispersion of the carbon particles in the molding compositions. High density information discs having improved playback performance can be readily molded from these compositions.
Inventors
- 👤 Pabitra Datta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:31
CPC Classifications
G; G11; G11B; G11B9/00; G11B9/06; G11B9/061; G11B9/063; G11B9/068; C; C08; C08K; C08K9/00; C08K9/04
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
131 words
In a high density information recording medium, adapted for use with a playback stylus to effect recovery of signals occupying a bandwidth of at least several megahertz when relative motion at a desired rate is established between said recording medium and said stylus, said recording medium comprising a disc of molded plastic material containing a sufficient amount of finely divided conductive particles so that the material has a bulk resistivity below about 500 ohm-cm at 900 MHz and having an information track constituted by a surface relief pattern in said track whereby said signals are recovered upon establishment of said motion at said rate, the improvement which comprises employing as said conductive particles carbon black particles the surfaces of which have been treated with a chloride of a long-chain fatty acid.
Claim 2
Dependent Claim
131 words
In a high density information recording medium, adapted for use with a playback stylus to effect recovery of signals occupying a bandwidth of at least several megahertz when relative motion at a desired rate is established between said recording medium and said stylus, said recording medium comprising a disc of molded plastic material containing a sufficient amount of finely divided conductive particles so that the material has a bulk resistivity below about 500 ohm-cm at 900 MHz and having an information track constituted by a surface relief pattern in said track whereby said signals are recovered upon establishment of said motion at said rate, the improvement which comprises employing as said conductive particles carbon black particles the surfaces of which have been treated with a chloride of a long-chain fatty acid.
Claim 3
Dependent Claim
23 words
The recording medium according to claim 1 wherein said carbon black particles have an apparent bulk density of about 140-160 grams per liter.
Claim 4
Dependent Claim
33 words
The recording medium according to claim 1 wherein said disc has a spiral groove on the surface containing said information track with said groove being dimensioned for reception therein of said playback stylus.
Claim 5
Dependent Claim
16 words
The recording medium according to claim 1 wherein said plastic material is a polyvinylchloride molding composition.
Claim 6
Dependent Claim
31 words
The recording medium according to claim 1 wherein said carbon black particles are surface treated with said chloride of a long-chain fatty acid prior to their incorporation into said plastic material.
Claim 7
Dependent Claim
30 words
The recording medium according to claim 1 wherein said carbon black particles are surface treated by being suspended in a solvent solution of said chloride of a long-chain fatty acid.
Claim 8
Dependent Claim
24 words
The recording medium according to claim 1 wherein said chloride of a long-chain fatty acid contains from about 5 to about 20 carbon atoms.
Claim 9
Dependent Claim
28 words
The recording medium according to claim 1 wherein said chloride of a long chain fatty acid is selected from the group consisting of stearoyl chloride and decanoyl chloride.
Claim 10
Dependent Claim
40 words
The recording medium according to claim 1 wherein a layer of methylalkylsiloxane lubricant of the formula: ##STR2## wherein R is an alkyl group of 4 to 20 carbon atoms and x is an integer is disposed over the recording medium.
Claim 11
Dependent Claim
70 words
In a conductive molding composition comprising a polyvinylchloride polymer, a solid mercapto tin stabilizer, an acrylic processing aid, an internal lubricant and a sufficient amount of conductive particles so that the composition has a bulk resistivity below about 500 ohm-cm at 900 MHz, the improvement which comprises employing as said conductive particles carbon black particles the surfaces of which have been treated with a chloride of a long-chain fatty acid.
Claim 12
Dependent Claim
70 words
In a conductive molding composition comprising a polyvinylchloride polymer, a solid mercapto tin stabilizer, an acrylic processing aid, an internal lubricant and a sufficient amount of conductive particles so that the composition has a bulk resistivity below about 500 ohm-cm at 900 MHz, the improvement which comprises employing as said conductive particles carbon black particles the surfaces of which have been treated with a chloride of a long-chain fatty acid.
Claim 13
Dependent Claim
24 words
The conductive molding composition according to claim 10 wherein said carbon black particles have an apparent bulk density of about 140-160 grams per liter.
Claim 14
Dependent Claim
40 words
The conductive molding composition according to claim 10 wherein said internal lubricant is a mixture of at least two lubricants, one an ester wax of monofatty acids and alcohols, and the other an ester wax of polyfunctional acids and alcohols.
Claim 15
Dependent Claim
29 words
The conductive molding composition according to claim 10 wherein said stabilizer is present in an amount from about 1 to about 3 percent by weight of the molding composition.
Claim 16
Dependent Claim
30 words
The conductive molding composition according to claim 10 wherein said processing aid is present in an amount from about 1 to about 3 percent by weight of the molding composition.
Claim 17
Dependent Claim
32 words
The conductive molding composition according to claim 10 wherein said carbon black particles are surface treated with said chloride of a long-chain fatty acid prior to their incorporation into the molding composition.
Claim 18
Dependent Claim
31 words
The conductive molding composition according to claim 10 wherein said carbon black particles are surface treated by being suspended in a solvent solution of said chloride of a long-chain fatty acid.
Claim 19
Dependent Claim
25 words
The conductive molding composition according to claim 10 wherein said chloride of a long-chain fatty acid contains from about 5 to about 20 carbon atoms.
Claim 20
Dependent Claim
29 words
The conductive molding composition according to claim 10 wherein said chloride of a long-chain fatty acid is chloride selected from the group consisting of stearoyl chloride and decanoyl chloride.
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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) | 1984-11-09 | 1985-05-11 | 1985-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-09 | 1989-05-11 | 1989-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-09 | 1993-05-11 | 1993-11-10 | $7700.00 | Window Closed / Lapsed |