The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 28, 1986
Filed:
May. 11, 1977
Applicant:
Inventor:
William R Lawton, Orchard Park, NY (US);
Assignee:
Graphic Controls Corporation, Buffalo, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ; C09K / ;
U.S. Cl.
CPC ...
422 57 ; 116216 ; 374163 ; 436-2 ; 2524081 ; 428913 ;
Abstract
Heat-sensitive compositions which rapidly develop color upon heating and rapidly discharge their color upon cooling, comprising an intimate mixture of a 3,3-bis (p-aminophenyl) phthalide and an organic acid. The color-producing and color-discharging cycle may be reproduced many times without noticeable change in response. The novel compositions of the invention are useful as temperature indicators, thermal display media, safety papers and validation devices.