Patent US3959793A successfully refreshed from Google Patents.
US4301411A
Expired / Lapsed
US
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NMR Test method for dispersion of solids in elastomer compositions
Assignee: Trinity College Dublin
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Filing: 1980-01-31
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Granted: 1981-11-17
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Expires: 2000-01-31
Abstract
Abstract An NMR test method is provided for determining the homogeneity of dispersion of a filler substance such as carbon black in an elastomer composition such as a rubber, either on an arbitrary scale or by reference to a standard dispersion of optimum homogeneity which is given the value 1.0 on a linear scale. The method involves measuring the intensity of the short component and the total intensity of the proton free induction decay, of a sample of the dispersion deriving the ratio P t of said intensities, and optionally deriving a second similar ratio P s from the standard dispersion to permit a value P t /P s on said linear scale to be derived.
Inventors
- 👤 Gerald E. Wardell
- 👤 Vincent J. McBrierty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:45
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/46; G01R33/4625
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
81 words
A method for measuring the homogeneity of a dispersion of a filler substance in an elastomer composition, which method comprises: measuring, in an NMR pulse spectrometer, the intensity of a short component and a total intensity, of the proton free induction decay, of a sample of the dispersion under investigation, and deriving the ratio of the short component intensity and the total intensity obtained, said ratio (P t ) representing an empirical measure of the homogeneity of the dispersion under investigation.
Claim 2
Independent Claim
81 words
A method for measuring the homogeneity of a dispersion of a filler substance in an elastomer composition, which method comprises: measuring, in an NMR pulse spectrometer, the intensity of a short component and a total intensity, of the proton free induction decay, of a sample of the dispersion under investigation, and deriving the ratio of the short component intensity and the total intensity obtained, said ratio (P t ) representing an empirical measure of the homogeneity of the dispersion under investigation.
Claim 3
Dependent Claim
77 words
A method as claimed in claim 1, which comprises additionally carrying out the said measurements on a sample of a standard dispersion of a filler substance in an elastomer composition, said standard dispersion having arbitrarily defined optimum homogeneity, to derive a second or standard ratio (P s ), and deriving the ratio P t /P s to represent the homogeneity of the dispersion under investigation on a linear scale wherein the standard dispersion has the value 1.0.
Claim 4
Dependent Claim
79 words
A method as claimed in claim 2, which comprises preparing the standard dispersion by intimately mixing a quantity of a dispersion selected from the group consisting of the dispersion under investigation and a substantially similar dispersion, until the ratio P t thereof, determined as set out in claim 1, has reached a maximum whereby said ratio is not appreciably increased when re-determined after further mixing, and whereby said ratio P t is redesignated P s , the standard ratio.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 1, wherein the sample size used in the NMR spectrometer exceeds 0.5 g.
Claim 6
Dependent Claim
26 words
A method as claimed in claim 1, wherein the sample size is such that the free induction decay signal-to-noise ratio is greater than 5 to 1.
Claim 7
Dependent Claim
25 words
A method as claimed in claim 1, wherein the elastomer composition is a rubber composition, comprising natural or synthetic rubber or a blend of both.
Claim 8
Dependent Claim
13 words
A method as claimed in claim 1, wherein the filler is carbon black.
References Cited (Backward Citations)
US3525036A
Cited
US3284700A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-16 | 1985-05-18 | 1985-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-16 | 1989-05-18 | 1989-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-16 | 1993-05-18 | 1993-11-17 | $7700.00 | Window Closed / Lapsed |