US4371632A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compositions, processes, and writing elements employing resins of the thermosetting type
Assignee: EMPIER ENTERPRISES Inc A CORP OF
•
Filing: 1981-04-24
•
Granted: 1983-02-01
•
Expires: 2001-04-24
Abstract
Abstract A "cold-processed" thermoset plastic pencil lead is produced by extruding a composition formed by blending a mixture of a marking material, a phenolic novolac resin, a hardening agent, a plasticizer, and a lubricant. Blending, billeting, and extruding operations are performed at material temperatures that, in general, do not exceed about 200° F. The extrudate is cured at higher temperatures of, for example, 260° F. to 325° F.
Inventors
- 👤 Harold Grossman
- 👤 Richard E. Merrill
- 👤 Paul B. Monaghan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:29
CPC Classifications
C; C09; C09D; C09D13/00
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
66 words
A composition for the manufacture of a cured extruded pencil core, comprising a blended extrudable mixture of a marking material, a phenolic novolac resin, a resin hardener, a plasticizer, and a lubricant, and wherein the ingredients of the composition have the following approximate proportions, by weight: ______________________________________
Ingredient Percentage
______________________________________
Marking Material 55- 75%
Resin (including hardener)
10- 28%
Plasticizer 2- 12%
Lubricant 4- 22%
______________________________________
Claim 2
Dependent Claim
66 words
A composition for the manufacture of a cured extruded pencil core, comprising a blended extrudable mixture of a marking material, a phenolic novolac resin, a resin hardener, a plasticizer, and a lubricant, and wherein the ingredients of the composition have the following approximate proportions, by weight: ______________________________________
Ingredient Percentage
______________________________________
Marking Material 55- 75%
Resin (including hardener)
10- 28%
Plasticizer 2- 12%
Lubricant 4- 22%
______________________________________
Claim 3
Dependent Claim
23 words
A composition in accordance with claim 1, wherein the mixture has been blended at a temperature that does not exceed about 170° F.
Claim 4
Dependent Claim
17 words
A composition in accordance with claim 2, wherein the plasticizer is a liquid at the blending temperature.
Claim 5
Dependent Claim
22 words
A composition in accordance with claim 3, wherein at least one component of the lubricant is a liquid at the blending temperature.
Claim 6
Dependent Claim
22 words
A composition in accordance with claim 1, wherein the mixture has been blended by high-intensity mixing without the addition of external heat.
Claim 7
Dependent Claim
12 words
A composition in accordance with claim 1, wherein the mixture is non-volatile.
Claim 8
Dependent Claim
30 words
A composition in accordance with claim 1, wherein the mixture is capable of being extruded at a temperature less than about 220° F. and cures at a substantially higher temperature.
Claim 9
Dependent Claim
13 words
A composition in accordance with claim 1, wherein the marking material comprises graphite.
Claim 10
Dependent Claim
21 words
A composition in accordance with claim 1, wherein the marking material is selected from the group consisting of dyes and pigments.
Claim 11
Dependent Claim
24 words
A composition in accordance with claim 8 or 9, wherein the plasticizer comprises a dibenzoate and the lubricant comprises a stearate and/or stearic acid.
Claim 12
Dependent Claim
57 words
A pencil core comprising a cured extrudate of a blended mixture of a marking material, a phenolic novolac resin, a resin hardener, a plasticizer, and a lubricant, and wherein the ingredients of the mixture have the following approximate proportions, by weight: ______________________________________
Ingredient Percentage
______________________________________
Marking Material 55-75%
Resin (including hardener)
10-28%
Plasticizer 2-12%
Lubricant 4-22%.
______________________________________
Claim 13
Dependent Claim
57 words
A pencil core comprising a cured extrudate of a blended mixture of a marking material, a phenolic novolac resin, a resin hardener, a plasticizer, and a lubricant, and wherein the ingredients of the mixture have the following approximate proportions, by weight: ______________________________________
Ingredient Percentage
______________________________________
Marking Material 55-75%
Resin (including hardener)
10-28%
Plasticizer 2-12%
Lubricant 4-22%.
______________________________________
Claim 14
Dependent Claim
23 words
A pencil core in accordance with claim 11, wherein the mixture was blended at a temperature that does not exceed about 170° F.
Claim 15
Dependent Claim
18 words
A pencil core in accordance with claim 12, wherein the plasticizer is a liquid at the blending temperature.
Claim 16
Dependent Claim
23 words
A pencil core in accordance with claim 13, wherein at least one compound of the lubricant is a liquid at the blending temperature.
Claim 17
Dependent Claim
22 words
A pencil core in accordance with claim 11, wherein the mixture was blended by high-intensity mixing without the addition of external heat.
Claim 18
Dependent Claim
14 words
A pencil core in accordance with claim 11, wherein the mixture extruded was non-volatile.
Claim 19
Dependent Claim
14 words
A pencil core in accordance with claim 11, wherein the marking material comprises graphite.
Claim 20
Dependent Claim
18 words
A pencil core in accordance with claim 11, wherein the marking material comprises a dye and/or a pigment.
Claim 21
Dependent Claim
25 words
A pencil core in accordance with claim 17 or 18, wherein the plasticizer comprises a dibenzoate and the lubricant comprises a stearate and/or stearic acid.
Claim 22
Independent Claim
72 words
A method of making a pencil core, comprising blending a mixture of a marking material, a resin that may be cured to an infusible state, a plasticizer, and a lubricant, to provide an extrudable composition, extruding the composition into the form of a pencil core, and curing the extrudate, and wherein the composition consists essentially of, by weight: ______________________________________
Ingredient Percentage
______________________________________
Marking Material 55-75%
Resin 10-28%
Plasticizer 2-12%
Lubricant 4-22%.
______________________________________
Claim 23
Independent Claim
72 words
A method of making a pencil core, comprising blending a mixture of a marking material, a resin that may be cured to an infusible state, a plasticizer, and a lubricant, to provide an extrudable composition, extruding the composition into the form of a pencil core, and curing the extrudate, and wherein the composition consists essentially of, by weight: ______________________________________
Ingredient Percentage
______________________________________
Marking Material 55-75%
Resin 10-28%
Plasticizer 2-12%
Lubricant 4-22%.
______________________________________
Claim 24
Dependent Claim
37 words
A method in accordance with claim 20, wherein the blending and extruding are conducted at material temperatures less than about 220° F. and the curing is conducted at material temperatures that are substantially higher than 220° F.
Claim 25
Dependent Claim
48 words
A method in accordance with claim 20, wherein the temperature of the mixture during blending does not exceed about 160° F., the temperature of the composition during extrusion does not exceed about 200° F., and the temperature of the extrudate during curing is at least about 260° F.
Claim 26
Dependent Claim
23 words
A method in accordance with claim 20, wherein the blended mixture is cooled and billeted and the billets are heated prior to extrusion.
Claim 27
Dependent Claim
13 words
A method in accordance with claim 23, wherein the billeted material is non-volatile.
Claim 28
Dependent Claim
21 words
A method in accordance with claim 24, wherein the billets are heated and extruded without the addition of a volatile solvent.
Claim 29
Dependent Claim
17 words
A method in accordance with claim 20, wherein the plasticizer is a liquid at the blending temperature.
Claim 30
Dependent Claim
23 words
A method in accordance with claim 26, wherein the lubricant has at least one component that is a liquid at the blending temperature.
Claim 31
Dependent Claim
26 words
A method in accordance with claim 20, wherein the resin is a thermosetting phenolic novolac resin and is cured by application of heat to the extrudate.
Claim 32
Dependent Claim
13 words
A method in accordance with claim 28, wherein the marking material comprises graphite.
Claim 33
Dependent Claim
22 words
A method in accordance with claim 29, wherein the plasticizer comprises a dibenzoate and the lubricant comprises a stearate and/or stearic acid.
Claim 34
Dependent Claim
20 words
A method in accordance with claim 20, wherein the resin, plasticizer, and lubricant form a solution at the blending temperature.
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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) | 1986-01-31 | 1986-08-02 | 1987-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-31 | 1990-08-02 | 1991-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-31 | 1994-08-02 | 1995-02-01 | $7700.00 | Window Closed / Lapsed |