David Wayne Weigel

US Patent:

49237926, May 8, 1990

Filed:

Jun 20, 1989

Appl. No.:

7/368566

Inventors:

Duncan M. A. Grieve - Walden, GB
Stephen S. C. Poon - Harlow, GB
Tran V. Thien - Harlow, GB
Kumars Sakizadeh - Woodbury MN
David C. Weigel - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - St. Paul MN

International Classification:

G03C 108

US Classification:

430559

Abstract:

A photothermographic element comprising: (A) a coating comprising a support bearing a photothermographic medium, the medium comprising a light sensitive silver halide in reactive association with a silver salt of an organic acid and a color generating reducing agent which is a leuco compound which is oxidizable by silver ions into a colored dye of the general formula: ##STR1## in which: n=0, 1 or 2, R. sup. 1 represents H, CN, lower alkyl of 1 to 5 carbon atoms, aryl or COOR. sup. 6 in which R. sup. 6 is lower alkyl of 1 to 5 carbon atoms or aryl, R. sup. 2 and R. sup. 3 independently represent CN, NO. sub. 2, COOR. sup. 6, SO. sub. 2 R. sup. 6, CONHR. sup. 6 in which R. sup. 6 is as defined above or R. sup. 2 and R. sup. 3 together represent the necessary atoms to form a 5- or 6-membered carbocyclic or heterocyclic ring having ring atoms selected from C, N, O and S atoms, whch carbocyclic or heterocyclic rings possess at least one conjugated electron withdrawing substituent, R. sup. 4 and R. sup.

US Patent:

48837474, Nov 28, 1989

Filed:

May 31, 1988

Appl. No.:

7/200665

Inventors:

Duncan M. A. Grieve - Walden, GB3
Stephen S. C. Poon - Harlow, GB3
Tran V. Thien - Harlow, GB3
Kumars Sakizadeh - Woodbury MN
David C. Weigel - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - St. Paul MN

International Classification:

G03C 114

US Classification:

430542

Abstract:

A photothermographic element comprising a support bearing a photothermographic medium, the medium comprising a light sensitive silver halide in reactive association with a silver salt of an organic acid and a color generating reducing agent which is a leuco compound which is oxidisable by silver ions into a colored dye of the general formula: ##STR1## in which: n=0, 1 or 2, R. sup. 1 represents H, CN, lower alkyl of 1 to 5 carbon atoms, aryl or COOR. sup. 6 in which R. sup. 6 is lower alkyl of 1 to 5 carbon atoms or aryl, R. sup. 2 and R. sup. 3 independently represent CN, NO. sub. 2, COOR. sup. 6, SO. sub. 2 R. sup. 6, CONHR. sup. 6 in which R. sup. 6 is as defined above or R. sup. 2 and R. sup. 3 together represent the necessary atoms to form a 5- or 6-membered carbocyclic or heterocyclic ring having ring atoms selected from C, N, O and S atoms, which carbocyclic or heterocyclic rings possess at least one conjugated electron withdrawing substituent, R. sup. 4 and R. sup. 5 independently represent H, CN or lower alkyl of 1 to 5 carbon atoms or together represent the necessary atoms to complete a 5- or 6-membered carbocyclic ring, and Ar represents: (a) a thienyl group which may be substituted with one or more lower alkyl groups of 1 to 5 carbon atoms, (b) a furyl group which may be substituted with one or more lower alkyl groups of 1 to 5 carbon atoms or (c) a phenyl group which may be substituted with one or more groups selected from halogen, hydroxy, lower alkyl of 1 to 5 carbon atoms, lower alkoxy of 1 to 5 carbon atoms, NR. sup. 7 R. sup.

US Patent:

55760740, Nov 19, 1996

Filed:

Aug 23, 1995

Appl. No.:

8/518547

Inventors:

David C. Weigel - White Bear Lake MN
David A. Morgan - Stillwater MN

Assignee:

Minnesota Mining and Manufacturing Company - St. Paul MN

International Classification:

B05D 306
B05D 302

US Classification:

427559

Abstract:

A process is described for providing a conductive metal circuit using a coherent radiation source. The circuit pattern is directly written onto a laser addressable element having a supercooling material layer. A conductive metal toner is then applied to the light struck areas and fired in a furnace to provide a conductive metal circuit.

US Patent:

45857342, Apr 29, 1986

Filed:

Feb 1, 1985

Appl. No.:

6/697342

Inventors:

David C. Weigel - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - St. Paul MN

International Classification:

G03C 102

US Classification:

430619

Abstract:

Certain effective toning systems for silver halide/silver salt/reducing agent photothermographic imaging materials tend to bleach the final image. The presently disclosed toning system of phthalazine and an active-hydrogen containing heterocyclic compound is more stable than some previous toners.

US Patent:

45872112, May 6, 1986

Filed:

Feb 1, 1985

Appl. No.:

6/697279

Inventors:

Takuzo Ishida - Woodbury MN
David C. Weigel - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - St. Paul MN

International Classification:

G03C 102

US Classification:

430619

Abstract:

Certain effective leuco dyes for silver halide/silver salt/reducing agent photothermographic color imaging materials tend to bleach in the final image. The presently disclosed system of a syringaldazine and a stabilizing binder resin is more stable.

US Patent:

52759326, Jan 4, 1994

Filed:

Jul 22, 1992

Appl. No.:

7/918555

Inventors:

David C. Weigel - White Bear Lake MN
Oanh V. Pham - Maplewood MN

Assignee:

Minnesota Mining and Manufacturing Company - Saint Paul MN

International Classification:

G03C 1494

US Classification:

430617

Abstract:

Thermal recording material containing a suitable substrate coated with an image forming layer. The image forming layer contains a thermally reducible source of silver, a 3-indazolinone or urea compound; a polymeric binder; and optionally, an auxiliary reducing agent and toner. Preferably, an anti-stick layer is coated on top of the imaging layer. The 3-indazolinone and urea compounds have been found to enhance the thermal image forming capability of thermal recording material.

US Patent:

51852314, Feb 9, 1993

Filed:

Aug 26, 1991

Appl. No.:

7/749573

Inventors:

David C. Weigel - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - Saint Paul MN

International Classification:

G03C 554
G03C 726

US Classification:

430203

Abstract:

Certain fluoran dyes have been found to be effective reducing agents for silver ion in dry silver constructions. The fluoran dyes have the following structure: ##STR1## wherein: R. sup. 1 represents methyl or n-butyl; R. sup. 2 represents n-butyl or cyclohexyl; R. sup. 3 represents hydrogen, methyl, or methoxy; and R. sup. 4 represents ##STR2## where X represents halogen (preferably chlorine); and a binder.

US Patent:

43281818, May 4, 1982

Filed:

Jul 6, 1979

Appl. No.:

6/055146

Inventors:

Leon W. Anders - Woodbury MN
David C. Weigel - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Co. - St. Paul MN

International Classification:

G01N 2178
G01N 3122

US Classification:

422 56

Abstract:

Indicator material for monitoring personal exposure to hazardous substances in ambient air comprising a pigment material, a binder and a sensitizer coated upon a transparent support member as a porous coating which permits gaseous diffusion throughout the coating is disclosed. Detection or monitoring is effected when the indicator material undergoes a visually observable reaction with hazardous material in the atmosphere at room temperature.