US4600602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low resistance resistor compositions
Assignee: Vibrantz Corp
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Filing: 1984-07-18
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Granted: 1986-07-15
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Expires: 2004-07-18
Abstract
Abstract This invention provides unique resistor compositions. These compositions contain solid long chain phenolic resin, liquid short chain phenolic resin and a mixture of carbon black and graphite particles dispersed therein. The combination of these elements allows for resistor compositions that are capable of withstanding high humidity conditions without significant changes in resistivity and which are capable of low ohmic values in the absence of metals. Also provided is a method of producing these compositions.
Inventors
- 👤 Frank W. Martin
- 👤 Samson Shahbazi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:32
CPC Classifications
C; C08; C08L; C08L61/00; C08L61/04; C08L61/06; H; H01; H01C; H01C7/00; H01C7/003; H01C7/005; C08K; C08K3/00; C08K3/02; C08K3/04; H01C17/00; H01C17/06; H01C17/065; H01C17/06506; H01C17/06513; H01C17/0652; H01C17/06573; H01C17/06586
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
100 words
A resistor composition capable of withstanding high humidity conditions comprising: (A) a resin system comprising (i) liquid short chain phenolic resin having a number average molecular weight of from about 300 to about 400; (ii) solid long chain phenolic resin having a number average molecular weight from about 400 to about 500; and (B) a mixture of (i) carbon black having a surface area of from about 500 m 2 /g to about 1500 m 2 /g; and (ii) graphite particles dispersed in said resin system, said composition having an electrical resistance of from about 18 to about 150 ohms/sq./mil.
Claim 2
Dependent Claim
100 words
A resistor composition capable of withstanding high humidity conditions comprising: (A) a resin system comprising (i) liquid short chain phenolic resin having a number average molecular weight of from about 300 to about 400; (ii) solid long chain phenolic resin having a number average molecular weight from about 400 to about 500; and (B) a mixture of (i) carbon black having a surface area of from about 500 m 2 /g to about 1500 m 2 /g; and (ii) graphite particles dispersed in said resin system, said composition having an electrical resistance of from about 18 to about 150 ohms/sq./mil.
Claim 3
Dependent Claim
19 words
The composition of claim 1 wherein the ratio of (A) to (B) is from about 85:15 to about 50:50.
Claim 4
Dependent Claim
20 words
The composition of claim 1 wherein the ratio of carbon black to graphite is from about 10:90 to about 50:50.
Claim 5
Dependent Claim
27 words
The composition of claim 1 wherein the ratio of liquid short chain phenolic resin to solid long chain phenolic resin is from about 1:1 to about 100:1.
Claim 6
Dependent Claim
21 words
The composition of claim 1 wherein the carbon black has a particle size of from about 10 millimicrons to 100 millimicrons.
Claim 7
Dependent Claim
21 words
The composition of claim 1 wherein the graphite has a particle size of from about 1 micron to about 10 microns.
Claim 8
Dependent Claim
24 words
The composition of claim 1 wherein the average particle size of the carbon black-graphite mixture is from about 1 micron to about 10 microns.
Claim 9
Dependent Claim
25 words
The composition of claim 1 wherein the surface area of the graphite is from about 1 m 2 /g to about 2 m 2 /g.
Claim 10
Dependent Claim
24 words
The composition of claim 1 wherein the ratio of the surface area of carbon black to graphite is from about 500:1 to about 1500:1.
Claim 11
Dependent Claim
18 words
The composition of claim 1 wherein the resin system is a one step heat reactive phenolic resin system.
Claim 12
Dependent Claim
19 words
The composition of claim 1 wherein the fineness of grind is between about 1 micron to about 7 microns.
Claim 13
Dependent Claim
17 words
The composition of claim 1 wherein the ohmic value varies less than ±1.0% at 85% relative humidity.
Claim 14
Dependent Claim
62 words
A method of making a resistor composition of claim 1 comprising: (i) dissolving solid long chain phenolic resin in solvent to form a solution; (ii) mixing said solution with liquid short chain phenolic resin; (iii) dispersing a mixture of carbon black and graphite particles in the solution to form a mixture; (iv) applying the mixture to a substrate; (v) curing the mixture.
Claim 15
Dependent Claim
28 words
The method of claim 13 wherein the mixture is cured at a temperature of from about 150° C. to 165° C. from about 60 to about 120 minutes.
Claim 16
Dependent Claim
16 words
The method of claim 13 wherein the mixture is applied to a substrate by silk screening.
Claim 17
Dependent Claim
28 words
The composition of claim 1 wherein the resistance value varies less than about ±1.0% when the relative humidity varies from about 80% to about 90% at 85° C.
References Cited (Backward Citations)
US3686139A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-07-14 | 1990-01-13 | 1990-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-14 | 1994-01-13 | 1994-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-14 | 1998-01-13 | 1998-07-15 | $7700.00 | Window Closed / Lapsed |