Patent US3965350A successfully refreshed from Google Patents.
US3965350A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dye penetrant method for detecting flows
Assignee: Air Products and Chemicals Inc
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Filing: 1974-06-17
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Granted: 1976-06-22
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Expires: 1994-06-17
Abstract
Abstract A dye penetrant composition adapted to enter minute surface defects when applied over a workpiece surface, which consists essentially of an organic dye, preferably a fluorescent dye, in a lactam solvent, particularly N-methyl-2-pyrrolidone, and providing improved clarity and definition when inspected under suitable, e.g. fluorescent, light.
Inventors
- 👤 Orlando G. Molina
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:18
CPC Classifications
C; C09; C09D; C09D5/00; C09D5/22; G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/91
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
105 words
A method for detecting cracks and flaws in the surface of an object which comprises applying to said surface a homogeneous liquid penetrant composition which consists essentially of an N-alkyl-2-pyrrolidone, as vehicle, and a fluorescent dye which is soluble in said pyrrolidone, said pyrrolidone having the general formula ##EQU2## where R is an alkyl group containing from 1 to 4 carbon atoms; removing excess liquid penetrant composition from said surface, a portion of said liquid penetrant remaining in said cracks and flaws therein; and viewing the surface of said body under fluorescigenous light to obtain colored traces from the dye in said cracks and flaws.
Claim 2
Independent Claim
105 words
A method for detecting cracks and flaws in the surface of an object which comprises applying to said surface a homogeneous liquid penetrant composition which consists essentially of an N-alkyl-2-pyrrolidone, as vehicle, and a fluorescent dye which is soluble in said pyrrolidone, said pyrrolidone having the general formula ##EQU2## where R is an alkyl group containing from 1 to 4 carbon atoms; removing excess liquid penetrant composition from said surface, a portion of said liquid penetrant remaining in said cracks and flaws therein; and viewing the surface of said body under fluorescigenous light to obtain colored traces from the dye in said cracks and flaws.
Claim 3
Dependent Claim
11 words
The method as defined in claim 1, said pyrrolidone being N-methyl-2-pyrrolidone.
Claim 4
Dependent Claim
63 words
The method as defined in claim 1, said pyrrolidone being N-methyl-2-pyrrolidone, said fluorescent dye being selected from the group consisting of fluorscent naphthalimide, xanthene and coumarin dyes, the ratio of said dye to said pyrrolidone ranging from about one part of dye to about 25 parts of pyrrolidone, to about 2 parts of said dye to about 1 part of pyrrolidone, by volume.
Claim 5
Dependent Claim
22 words
The method as defined in claim 1, wherein said liquid penetrant composition includes hydrophilic nonionic detergent containing ether-oxygen groups as a surfactant.
Claim 6
Dependent Claim
15 words
The method as defined in claim 1, said liquid penetrant composition including isobutyl heptyl ketone.
Claim 7
Dependent Claim
36 words
The method as defined in claim 4, said surfactant being selected from the group consisting of a nonyl phenyl polyethylene glycol ether, a trimethyl nonyl ether of polyehtylene gly glycol and an alkyl aryl polyether alcohol.
Claim 8
Dependent Claim
26 words
The method as defined in claim 3, wherein said liquid penetrant composition includes hydrophilic nonionic detergent containing ether-oxygen groups as a surfactant and isobutyl heptyl ketone.
Claim 9
Dependent Claim
23 words
The method as defined in claim 3, said liquid penetrant composition containing a nonyl phenyl polyethylene glycol ether surfactant and isobutyl heptyl ketone.
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) | 1979-06-22 | 1979-12-22 | 1980-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-22 | 1983-12-22 | 1984-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-22 | 1987-12-22 | 1988-06-22 | $7700.00 | Window Closed / Lapsed |