Magenta dye-donor element used in thermal dye transfer

- Eastman Kodak Company

A magenta dye-donor element for thermal dye transfer comprises a support having thereon a magenta dye dispersed in a polymeric binder, the magenta dye comprising a substituted 5-arylazoisothiazole.In a preferred embodiment, the magenta dye has the formula ##STR1## wherein R.sup.1 and R.sup.2 may each independently be hydrogen, alkyl, allyl, cycloalkyl or aryl; or R.sup.1 and R.sup.2 may be taken together to form a ring; or R.sup.1 or R.sup.2 may be part of a 5- or 6-membered heterocyclic ring;R.sup.3 may be hydrogen, alkyl, aryl, alkylthio or halogen;J may be alkyl, aryl or NHA, where A is an acyl or sulfonyl radical; andQ may be cyano, thiocyanato, alkylthio or alkoxycarbonyl.

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Description

The following examples are provided to illustrate the invention.

(A) A magenta dye-donor element was prepared by coating the following layers in the order recited on a 6 .mu.m poly(ethylene terephthalate) support:

(1) Dye-barrier layer of gelatin nitrate (gelatin, cellulose, nitrate, and salicyclic acid in approximately 20:5:2 weight ratio in a solvent of acetone, methanol and water) (0.20 g/m.sup.2), and

(2) Dye layer containing a magenta dye as identified in the following Table 1 (0.17-0.22 g/m.sup.2) in cellulose acetate hydrogen phthalate (0.30-0.33 g/m.sup.2) coated from an acetone/2-butanone/cyclohexanone solvent.

On the back side of the element, a slipping layer of poly(vinyl stearate) (0.31 g/m.sup.2) in cellulose acetate butyrate (0.55 g/m.sup.2) was coated from tetrahydrofuran solvent.

                TABLE 1                                                     
     ______________________________________                                    
      ##STR24##                                                                
     Compound                                                                  
     No.          R.sup.1    R.sup.2                                           
     ______________________________________                                    
     1            C.sub.2 H.sub.5                                              
                             CH.sub.2 C.sub.6 H.sub.5                          
     2            C.sub.2 H.sub.5                                              
                              ##STR25##                                        
     3            C.sub.2 H.sub.5                                              
                             CH.sub.2 CH.sub.2 O.sub.2 CCH.sub.3               
     nC.sub.3 H.sub.7                                                          
     n-C.sub.3 H.sub.7                                                         
     Control Compound 1                                                        
      ##STR26##                                                                
     Control Compound 2                                                        
      ##STR27##                                                                
     Control Compound 3                                                        
      ##STR28##                                                                
     ______________________________________

Dye receiving elements were prepared by coating a solution of Makrolon 5705.RTM. (Bayer AG Corporation) polycarbonate resin (2.9 g/m.sup.2) in a methylene chloride and trichloroethylene solvent mixture on an ICI Melinex 990.RTM. white polyester support for density evaluations or on a transparent poly(ethylene terephthalate) film support for spectral absorption evaluations.

The dye side of the dye-donor element strip 0.75 inches (19 mm) wide was placed in contact with the dye image-receiving layer of the dye-receiver element of the same width. The assemblage was fastened in the jaws of a stepper motor driven pulling device. The assemblage was laid on top of a 0.55 (14 ) diameter rubber roller and a Fujitsu Thermal Head (FTP-040MCS001) and was pressed with a spring at a force of 3.5 pounds (1.6 kg) against the dye-donor element side of the assemblage pushing it against the rubber roller.

The imaging electronics were activated causing the pulling device to draw the assemblage between the printing head and roller at 0.123 inches/sec (3.1 mm/sec). Coincidentally, the resistive elements in the thermal print head were heated at 0.5 msec increments from 0 to 4.5 msec to generate a graduated density test pattern. The voltage supplied to the print head was approximately 19 v representing approximately 1.75 watts/dot. Estimated head temperature was 250.degree.-400.degree. C.

The dye-receiving element was separated from the dye-donor element and the Status A green reflection density of the step image was read. The image was then subjected to "HID-fading": 4 days, 50 kLux, 5400 K., 32.degree. C., approximately 25% RH. The density loss at a density near 1.0 was calculated.

The following dye stability data were obtained:

                TABLE 2                                                     
     ______________________________________                                    
     Dye          .DELTA.D (at initial 1.0 density)                            
     ______________________________________                                    
     Compound 1   -0.12                                                        
     Compound 2   -0.12                                                        
     Compound 3   -0.12                                                        
     Compound 4   -0.12                                                        
     Control 1    -0.38                                                        
     Control 2    -0.43                                                        
     Control 3    -0.18                                                        
     ______________________________________

Use of the compounds in accordance with the invention showed superior light stability as compared to a variety of control dyes.

The light absorption spectra from 400 to 700 nm were also obtained after transfer of an area of the dye to the transparent support receiver in the manner indicated above. From a computer normalized 1.0 density curve, the .lambda.-max, and HBW (half-band width=width of the dye absorption envelope at one-half the maximum dye density) were calculated. The following results were obtained.

                TABLE 3                                                     
     ______________________________________                                    
     Dye              .lambda.-max                                             
                              HBW                                              
     ______________________________________                                    
     Compound 1       548     96                                               
     Compound 2       558     83                                               
     Compound 3       546     95                                               
     Compound 4       558     82                                               
     Control 1        538     102                                              
     Control 2        525     81                                               
     Control 3        514     81                                               
     ______________________________________

The dyes of the invention are of good magenta hue and all have .lambda.-max in the desired region of 545 to 560 nm. The control dyes are all too red (too much absorption on the short wavelength side). The control dye 3 with relatively good dye stability was the poorest for hue.

EXAMPLE 2

A magenta dye-donor element was prepared by coating the following layers in the order recited on a 6 .mu.m poly(ethylene terephthalate) support:

(1) Dye-barrier layer of poly(acrylic) acid (0.16 g/m.sup.2) coated from water, and

(2) Dye layer containing a magenta dye as identified in the following Table 4 (0.41 mmoles/m.sup.2) (0.17-0.20 g/m.sup.2), a cellulose acetate binder (40% acetyl) at a weight equal to 1.5.times. that of the dye, and FC-431.RTM. 3M Corp. (2.2 mg/m.sup.2), coated from a 2-butanone/cyclohexanone solvent mixture.

On the back side of the element was coated a slipping layer of the type disclosed in copending U.S. patent application Ser. No. 813,199 of Vanier et al., filed Dec. 24, 1985.

Dye-receiving elements were prepared as in Example 1.

The dye side of the dye-donor element strip 0.75 inches (19 mm) wide was placed in contact with the dye image-receiving layer of the dye-receiver element of the same width. The assemblage was fastened in the jaws of a stepper motor driven pulling device. The assemblage was laid on top of a 0.55 (14 mm) diameter rubber roller and a TDK Thermal Head (No. L-133) and was pressed with a spring at a force of 8.0 pounds (3.6 kg) against the dye-donor element side of the assemblage pushing it against the rubber roller.

The imaging electronics were activated causing the pulling device to draw the assemblage between the printing head and roller at 0.123 inches/sec (3.1 mm/sec). Coincidentally, the resistive elements in the thermal print head were pulse-heated at increments from 0 to 8.3 msec to generate a graduated density test pattern. The voltage supplied to the print head was approximately 22 v representing approximately 1.5 watts/dot (12 mjoules/dot) for maximum power.

The dye-receiving element was separated from the dye-donor element and dye stability and light absorption data were obtained as described in Example 1 except that the dye stability data was calculated as percent density loss from a mid-scale density near 1.0. The following results were obtained.

                TABLE 4                                                     
     ______________________________________                                    
     Dye      Density Loss   .lambda. max                                      
                                     HBW                                       
     Cmpd.    (%)            (nm)    (nm)                                      
     ______________________________________                                    
      1        8             548     96                                        
     14       11             542     93                                        
     15       17             537     93                                        
     16       17             528     93                                        
     17       16             542     91                                        
     18       32             553     94                                        
     19       15             543     91                                        
     20       19             542     92                                        
     21        4             526     135                                       
     22       12             535     106                                       
     23        7             536     104                                       
     24        5             562     86                                        
     25        8             548     93                                        
     26       21             561     90                                        
     27       14             540     86                                        
     28       17             524     95                                        
     29       28             524     88                                        
     30       16             530     105                                       
     Cont. 1  34             538     102                                       
     Cont. 4  34             523     84                                        
     Cont. 5  61             548     84                                        
     Control 4                                                                 
      ##STR29##                                                                
     Control 5                                                                 
      ##STR30##                                                                
     ______________________________________

The dyes of the invention are all of good or acceptable hue and show superior light stability compared to the control dyes having close structural similarity.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

Claims

1. A magenta dye-donor element for thermal dye transfer comprising a support having thereon a dye layer comprising a magenta dye dispersed in a polymeric binder, said magenta dye having the formula: ##STR31## wherein R.sup.1 and R.sup.2 may each independently be hydrogen, substituted or unsubstituted alkyl or allyl of from 1 to about 6 carbon atoms, substituted or unsubstituted cycloalkyl of from about 5 to about 7 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms; or R.sup.1 and R.sup.2 may be taken together to form a ring; or a 5- or 6-membered heterocyclic ring may be formed with R.sup.1 or R.sup.2, the nitrogen to which R.sup.1 or R.sup.2 is attached, and either carbon atom ortho to the carbon attached to said nitrogen atom;

R.sup.3 may be hydrogen, substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms, alkylthio or halogen;
J may be substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms or NHA, where A is an acyl or sulfonyl radical; and
Q may be cyano, thicyanato, alkylthio or alkoxycarbonyl.

2. The element of claim 1 wherein R.sup.3 is methyl and Q is CN.

3. The element of claim 1 wherein J is --NHCOCH.sub.3.

4. The element of claim 1 wherein R.sup.1 is C.sub.2 H.sub.5 and R.sup.2 is CH.sub.2 C.sub.6 H.sub.5, cyclohexyl or CH.sub.2 CH.sub.2 O.sub.2 CCH.sub.3.

5. The element of claim 1 wherein R.sup.1 and R.sup.2 are each n--C.sub.3 H.sub.7 or C.sub.2 H.sub.5.

6. The element of claim 1 wherein a dye-barrier layer is located between said dye layer and said support.

7. The element of claim 1 wherein the side of the support opposite the side bearing said dye layer is coated with a slipping layer comprising a lubricating material.

8. The element of claim 1 wherein said support comprises poly(ethylene terephthalate).

9. The element of claim 1 wherein said dye layer comprises sequential repeating areas of cyan, yellow and said magenta dye.

10. In a process of forming a magenta dye transfer image comprising imagewise-heating a dye-donor element comprising a support bearing a dye layer comprising a magenta dye dispersed in a polymeric binder and transferring a magenta dye image to a dye-receiving element to form said magenta dye transfer image, the improvement wherein said magenta dye comprises a substituted 5-arylazoisothiazole having the formula: ##STR32## wherein R.sup.1 and R.sup.2 may each independently be hydrogen, substituted or unsubstituted alkyl or allyl of from 1 to about 6 carbon atoms, substituted or unsubstituted cycloalkyl of from about 5 to about 7 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms; or R.sup.1 and R.sup.2 may be taken together to form a ring; or a 5- or 6-membered heterocyclic ring may be formed with R.sup.1 or R.sup.2, the nitrogen to which R.sup.1 or R.sup.2 is attached, and either carbon atom ortho to the carbon attached to said nitrogen atom;

R.sup.3 may be hydrogen, substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms, alkylthio or halogen;
J may be substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms or NHA, where A is an acyl or sulfonyl radical; and
Q may be cyano, thiocyanato, alkylthio or alkoxycarbonyl.

11. The process of claim 10 wherein said support is poly(ethylene terephthalate) which is coated with sequential repeating areas of cyan, yellow and said magenta dye, and said process steps are sequentially performed for each color to obtain a three-color dye transfer image.

12. In a thermal dye transfer assemblage comprising:

(a) a magenta dye-donor element comprising a support having thereon a dye layer comprising a magenta dye dispersed in a polymeric binder, and
(b) a dye receiving element comprising a support having thereon a dye image-receiving layer,
R.sup.3 may be hydrogen, substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms, alkylthio or halogen;
J may be substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms or NHA, where A is an acyl or sulfonyl radical; and
Q may be cyano, thiocyanato, alkylthio or alkoxycarbonyl.

13. The assemblage of claim 12 wherein R.sup.3 is methyl and Q is CN.

14. The assemblage of claim 12 wherein J is --NH--COCH.sub.3.

15. The assemblage of claim 12 wherein R.sup.1 is C.sub.2 H.sub.5 and R.sup.2 is CH.sub.2 C.sub.6 H.sub.5, cyclohexyl or CH.sub.2 CH.sub.2 O.sub.2 CCH.sub.3.

16. The assemblage of claim 12 wherein R.sup.1 and R.sup.2 are each n--C.sub.3 H.sub.7 or C.sub.2 H.sub.5.

17. The assemblage of claim 12 wherein said support of the dye-donor element comprises poly(ethylene terephthalate)..Iadd.

18. A thermal transfer printing sheet comprising a support having thereon a dye layer comprising a magenta azo dye dispersed in a polymeric binder, said magenta azo dye having the formula:

A is isothiazol-5-yl substituted in the 3-position by hydrogen, substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms, alkylthio or halogen, and substituted in the 4-position by cyano, thiocyanato, alkylthio or alkoxycarbonyl; and
E is a group of the formula: ##STR34## wherein J may be substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstited aryl of from about 5 to about 10 carbon atoms or NHA, where A is an acyl or sulfonyl radical; and

19. A thermal transfer printing sheet according to claim 18 wherein A is selected from 4-cyanoisothiazol-5-yl and 3-methyl-4-cyanoisothiazol-5-yl..Iaddend..Iadd.20. A transfer printing sheet according to claim 18 wherein the azo dye conforms to the formula: ##STR35## wherein A is selected from 4-cyanoisothiazol-5-yl and 3-methyl-4-cyanoisothiazol-5-yl;

J is selected from unsubstituted alkyl of from 1 to about 6 carbon atoms and NHA, where A is an acyl radical; and
R.sup.1 and R.sup.2 are each independently selected from hydrogen; unsubstituted alkyl of from 1 to about 6 carbon atoms; or alkyl of from 1 to about 6 carbon atoms substituted by a group selected from alkoxy,

acyloxy, cyano and halogen..Iaddend..Iadd.21. A transfer printing process which comprises contacting a transfer sheet coated with a dye according to claim 18 with a receiver sheet, so that the dye is adjacent to the receiver sheet, and selectively heating areas of the transfer sheet to a temperature from 250.degree.-400.degree. C. for a period of from 0.5 to 8.3 msec whereby dye in the heated areas of the transfer sheet may be selectively transferred to the receiver sheet..Iaddend..Iadd.22. A thermal transfer printing sheet comprising a support having thereon a dye layer comprising a magenta azo dye dispersed in a polymeric binder, said magenta azo dye having the formula:

A is isothiazol-5-yl substituted in the 3-position by hydrogen, halogen or substituted alkyl of from 1 to about 6 carbon atoms, and substituted in the 4-position by cyano, thiocyanato or alkoxycarbonyl; and
E is a group of the formula: ##STR36## wherein J may be unsubstituted alkyl of from 1 to about 6 carbon atoms or NHA, where A is an acyl radical; and
R.sup.1 and R.sup.2 may each independently be hydrogen; unsubstituted alkyl of from 1 to about 6 carbon atoms; or alkyl of from 1 to about 6 carbon atoms substituted by a group selected from aryl, halogen, cyano, alkoxy or

acyloxy..Iaddend..Iadd.23. A thermal transfer printing sheet comprising a support having thereon a dye layer comprising a magenta azo dye dispersed in a polymeric binder, said magenta azo dye having the formula:

A is isothiazol-5-yl substituted in the 3-position by hydrogen, halogen or substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, and substituted in the 4-position by cyano, thiocyanato or alkoxycarbonyl; and
E is a group of the formula: ##STR37## wherein J may be unsubstituted alkyl of from 1 to about 6 carbon atoms or NHA, where A is an acyl radical; and
R.sup.1 and R.sup.2 may each independently be hydrogen; unsubstituted alkyl of from 1 to about 6 carbon atoms; or alkyl of from 1 to about 6 carbon atoms substituted by a group selected from aryl, halogen, cyano, alkoxy or

acyloxy..Iaddend..Iadd.24. A thermal transfer printing sheet comprising a support having thereon a dye layer comprising a magenta azo dye dispersed in a polymeric binder, said magenta azo dye having the formula:

A is isothiazol-5-yl substituted in the 3-position by hydrogen, substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms, alkylthio or halogen, and substituted in the 4-position by cyano, thiocyanato, alkylthio or alkoxycarbonyl; and
E is a group of the formula: ##STR38## wherein
J may be substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms or NHA, where A is an acyl or sulfonyl radical; and
R.sup.1 and R.sup.2 may each independently be hydrogen; unsubstituted alkyl or allyl of from 1 to about 6 carbon atoms; alkyl or allyl of from 1 to about 6 carbon atoms substituted by a group selected from hydroxy, acyloxy, alkoxy, aryl, cyano, acylamido, or halogen; substituted or unsubstituted cycloalkyl of from about 5 to about 7 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms; or R.sup.1 and R.sup.2 may be taken together to form a ring; or a 5- or 6-membered heterocyclic ring may be formed with R.sup.1 or R.sup.2, the nitrogen to which R.sup.1 or R.sup.2 is attached, and either carbon atom ortho to the carbon attached to said nitrogen atom..Iaddend.

.Iadd.. A thermal transfer printing sheet comprising a substrate having a coating comprising at least one azo dye of the formula:

A is isothiazol-5-yl substituted in the 3-position by hydrogen, substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms, alkylthio or halogen, and substituted in the 4-position by cyano, thiocyanato, alkylthio or alkoxycarbonyl; and
E is a group of the formula: ##STR39## wherein J may be substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms or NHA, where A is an acyl or sulfonyl radical; and
R.sup.1 and R.sup.2 may each independently be hydrogen; substituted or unsubstituted alkyl or allyl of from 1 to about 6 carbon atoms; substituted or unsubstituted cycloalkyl of from about 5 to about 7 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms; or R.sup.1 and R.sup.2 may be taken together to form a ring; or a 5- or 6-membered heterocyclic ring may be formed with R.sup.1 or R.sup.2, the nitrogen to which R.sup.1 or R.sup.2 is attached to said

nitrogen atom..Iaddend..Iadd.26. A thermal transfer printing sheet according to claim 25 wherein A is selected from 4-cyanoisothiazol-5-yl and 3-methyl-4-cyanoisothiazol-5-yl..Iadd.27. A transfer printing sheet according to claim 25 wherein the azo dye conforms to the formula: ##STR40## wherein is selected from 4-cyanoisothiazol-5-yl and 3-methyl-4-cyanoisothiazol-5-yl;

J is selected from unsubstituted alkyl of from 1 to about 6 carbon atoms and NHA, where A is an acyl radical; and
R.sup.1 and R.sup.2 are each independently selected from hydrogen-unsubstituted alkyl of from 1 to about 6 carbon atoms; or alkyl of from 1 to about 6 carbon atoms substituted by a group selected from

alkoxy, acyloxy, cyano and halogen..Iaddend..Iadd.28. A transfer printing process which comprises contacting a transfer sheet coated with a dye according to claim 25 with a receiver sheet, so that the dye is adjacent to the receiver sheet, and selectively heating areas of the transfer sheet to a temperature from 250.degree.-400.degree. C. for a period of from 0.5 to 8.3 msec whereby dye in the heated areas of the transfer sheet may be selectively transferred to the receiver sheet..Iaddend..Iadd.29. A thermal transfer printing sheet comprising a substrate having a coating comprising at least one azo dye of the formula:

A is isothiazol-5-yl substituted in the 3-position by hydrogen, halogen or substituted alkyl of from 1 to about 6 carbon atoms, and substituted in the 4-position by cyano, thiocyanato or alkoxycarbonyl; and
E is a group of the formula: ##STR41## wherein J may be unsubstituted alkyl of from 1 to about 6 carbon atoms or NHA, where A is an acyl radical; and
R.sup.1 and R.sup.2 may each independently by hydrogen; unsubstituted alkyl of from 1 to about 6 carbon atoms; or alkyl of from 1 to about 6 carbon atoms substituted by a group selected from aryl, halogen, cyano, alkoxy or

acyloxy..Iaddend..Iadd.30. A thermal transfer printing sheet comprising a substrate having a coating comprising at least one azo dye of the formula:

A is isothiazol-5-yl substituted in the 3-position by hydrogen, halogen or substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, and substituted in the 4-position by cyano, thiocyanato or alkoxycarbonyl; and
E is a group of the formula: ##STR42## wherein J may be unsubstituted alkyl of from 1 to about 6 carbon atoms or NHA, where A is an acyl radical; and
R.sup.1 and R.sup.2 may each independently be hydrogen; unsubstituted alkyl of from 1 to about 6 carbon atoms; or alkyl of from 1 to about 6 carbon atoms substituted by a group selected from aryl, halogen, cyano, alkoxy or

acyloxy..Iaddend..Iadd.31. A thermal transfer printing sheet comprising a substrate having a coating comprising at least one azo dye of the formula:

A is isothiazol-5-yl substituted in the 3-position by hydrogen, substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms, alkylthio or halogen, and substituted in the 4-position by cyano, thiocyanato, alkylthio or alkoxycarbonyl; and
E is a group of the formula: ##STR43## wherein J may be substituted or unsubstituted alkyl of from 1 to about 6 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms or NHA, where A is an acyl or sulfonyl radical; and
R.sup.1 and R.sup.2 may each independently be hydrogen; unsubstituted alkyl or allyl of from 1 to about 6 carbon atoms; alkyl or allyl of from 1 to about 6 carbon atoms substituted by a group selected from hydroxy, acyloxy, alkoxy, aryl, cyano, acylamido, or halogen; substituted or unsubstituted cycloalkyl of from about 5 to about 7 carbon atoms, substituted or unsubstituted aryl of from about 5 to about 10 carbon atoms; or R.sup.1 and R.sup.2 may be taken together to form a ring; or a 5-or 6-membered heterocyclic ring may be formed with R.sup.1 or R.sup.2, the nitrogen to which R.sup.1 or R.sup.2 is attached, and either carbon atom ortho to the carbon attached to said nitrogen atom.
Referenced Cited
U.S. Patent Documents
4374767 February 22, 1983 Weaver et al.
4374768 February 22, 1983 Fleischer et al.
Foreign Patent Documents
30028 June 1981 EPX
30695 June 1981 EPX
151287 December 1984 EPX
99378 August 1977 JPX
30394 February 1985 JPX
1379233 January 1975 GBX
1465895 February 1977 GBX
Patent History
Patent number: RE33819
Type: Grant
Filed: Mar 17, 1989
Date of Patent: Feb 11, 1992
Assignee: Eastman Kodak Company (Rochester, NY)
Inventors: William H. Moore (Kingsport, TN), Max A. Weaver (Kingsport, TN), Kin K. Lum (Webster, NY)
Primary Examiner: Bruce H. Hess
Attorney: Harold E. Cole
Application Number: 7/325,173