Photographic products and processes employing lamellar pigments

Claim 2

An integral negative-positive film unit which comprises a photosensitive system having at least one silver halide emulsion layer associated with a dye image-providing material, an image-receiving layer adapted to receive a dye image after photoexposure and processing of the photosensitive system and a substantially while layer or means to provide a substantially white layer against which a color transfer image formed in the image-receiving layer can be viewed, said substantially white layer comprising a lamellar pigment dispersed in a matrix material said lamellar pigment having at least one layer with a geometric thickness of a value within the expression: T=λ/4n (or an odd multiple thereof) where T is the geometric thickness of the layer, λ represents a wavelength or wavelength range of radiation in the visible region of the spectrum and n is the refractive index of the lamellar pigment material and is at least 1.7; any layer adjacent said one layer having a geometric thickness of a value also within said expression but comprising a layer material having a refractive index different from the refractive index of said one layer.

Claim 3

A film unit of claim 1 wherein λ of said expression represents a wavelength or wavelength range of radiation between about 4500 A to about 6000 A.

Claim 4

A film unit of claim 1 where λ of said expression represents a wavelength or wavelength range of radiation between about 5000 A to about 5500 A.

Claim 5

A film unit of claim 1 where n of said one layer is between about 2.0 to about 2.8.

Claim 6

A film unit of claim 4 wherein the geometric thickness of said one layer is within the range of from about 450 A to about 700 A.

Claim 7

A film unit of claim 1 where λ of said expression represents a wavelength or wavelength range of radiation between about 5000 A to about 5500 A and n of said one layer is between about 2.0 to about 2.8.

Claim 8

A film unit of claim 1 where said one layer is a layer of titanium dioxide.

Claim 9

A film unit of claim 1 where said one layer is a layer of zirconium dioxide.

Claim 10

A film unit of claim 1 where n of said adjacent layer is lower than n of said one layer.

Claim 11

A film unit of claim 1 where n of said one layer is between about 2.0 to about 2.8 and n of said adjacent layer is less than n of said one layer by at least about 0.3.

Claim 12

A film unit of claim 1 where n of said one layer is between about 2.0 to about 2.8 and n of said adjacent layer is below about 1.5.

Claim 13

A film unit of claim 1 where said pigment comprises three or more layers.

Claim 14

A film unit of claim 1 where said pigment comprises three or more layers and the number of said one layer(s) exceeds the number of said adjacent layer(s).

Claim 15

A film unit of claim 1 where said one layer is a layer of titanium dioxide and said adjacent layer is a layer of strontium fluoride or magnesium fluoride.

Claim 16

A film unit of claim 1 where said one layer is a layer of zirconium dioxide and said adjacent layer is a layer of strontium fluoride or magnesium fluoride.

Claim 17

A film unit of claim 1 which comprises: a first sheet-like element comprising an opaque support carrying a plurality of layers including at least one photosensitive silver halide layer associated with a diffusion transfer process dye image-providing material; a second sheet-like element comprising a transparent support carrying a dye image-receiving layer; a rupturable container releasably holding are aqueous alkaline, opaque processing composition including said lamellar pigment and a matrix material so that after distribution of said processing composition a substantially white layer will be provided; said first and second sheet-like elements being held in superposed, fixed relationship, with said supports outermost, during photoexposure and processing, said photosensitive silver halide emulsion layer(s) being exposable through said transparent support; said rupturable container being positioned transverse said one end of said film unit so as to release said processing composition for distribution between said sheet-like elements after photoexposure to provide said substantially white layer comprising said lamellar pigment and against which a color transfer image formed in said image-receiving layer may be viewed through said transparent support without separation of said superposed first and second sheet-like elements.

Claim 18

A film unit of claim 16 where said opaque processing composition includes at least one optical filter agent which is colored at a pH above the pKa of the filter agent, the concentration of filter agent being effective in combination with said lamellar pigment to provide a layer exhibiting optical transmission density of at least about 6.0 density units with respect to incident light actinic to the silver halide emulsion layer and said film unit comprises means for reducing the pH of the unit below the pKa of the optical filter agent so that said agent is substantially colorless after substantial formation of said color image in said image-receiving layer.

Claim 19

A film unit of claim 16 wherein n of said one layer is between about 2.0 to about 2.8 and the geometric thickness of said one layer is within the range of from about 450 A to about 700 A.

Claim 20

A film unit of claim 16 where said second support carries the following layers in order: a polymeric acid layer, a timing layer and the image-receiving layer.

Claim 21

A film unit of claim 1 which comprises: a first sheet-like element comprising a first transparent support; a second sheet-like element comprising a second transparent support carrying, in sequence, a dye image-receiving layer, a substantially white layer comprising said lamellar pigment and at least one photosensitive silver halide layer associated with a diffusion transfer process dye image-providing material; a rupturable container releasably holding an aqueous, alkaline, opaque processing composition; said first and second sheet-like elements being held in superposed, fixed relationship, with said supports outermost, during photoexposure and processing, said photosensitive silver halide layer.

Claim 22

A film unit of claim 20 where said opaque processing composition includes at least one optical filter agent which is colored at a pH about the pKa of the filter agent, the concentration of filter agent being effective in combination with said lamellar pigment to provide a layer exhibiting optical transmission density of at least about 6.0 density units with respect to incident light actinic to the silver halide emulsion layer and said film unit comprises means for reducing the pH of the unit below the pKa of the optical filter agent so that said agent is substantially colorless after substantial formation of said color image in said image-receiving layer.

Claim 23

A film unit of claim 20 further including a light transmissive layer comprising said lamellar pigment positioned between said image-receiving layer and the emulsion layer positioned closest to the image-receiving layer.

Claim 24

A film unit of claim 20 further including an anti-reflection coating on the outer surface of said transparent support.

Claim 25

A film unit of claim 20 where said lamellar pigment substantially stable and substantially insoluble in a diffusion transfer aqueous alkaline processing composition.

Claim 26

A film unit of claim 20 where λ of said expression represents a wavelength or wavelength range of radiation between about 4500 A to about 5400 A.

Claim 27

A film unit of claim 20 where of said expression represents a wavelength or wavelength range of radiation between about 5000 A to about 5500 A.

Claim 28

A film unit of claim 20 where n of said one layer is between about 2.0 to about 2.8.

Claim 29

A film unit of claim 20 where λ of said expression represents a wavelength or wavelength range of radiation between about 5000 A to about 5500 A and n of said one layer is between about 2.0 to about 2.8.

Claim 30

A film unit of claim 20 where said one layer is a layer of titanium dioxide.

Claim 31

A film unit of claim 20 where said one layer is a layer of zirconium dioxide.

Claim 32

A film unit of claim 20 where n of said adjacent layer is lower than n of said one layer.

Claim 33

A film unit of claim 20 where n of said one layer is between about 2.0 to about 2.8 and n of said adjacent layer is less than n of said one layer by at least about 0.3.

Claim 34

A film unit of claim 20 where n of said one layer is between about 2.0 to about 2.8 and n of said adjacent layer is below about 1.5.

Claim 35

A film unit of claim 20 where said pigment comprises three or more layers.

Claim 36

A film unit of claim 20 where said pigment comprises three or more layers and the number of said one layer(s) exceeds the number of said adjacent layer(s).

Claim 37

A film unit of claim 20 where said one layer is a layer of titanium dioxide and said adjacent layer is a layer of strontium fluoride or magnesium fluoride.

Claim 38

A film unit of claim 20 where said one layer is a layer of zirconium dioxide and said adjacent layer is a layer of strontium fluoride or magnesium fluoride.

Claim 39

A film unit of claim 27 wherein the geometric thickness of said one layer is within the range of from about 450 A to about 700 A.

Claim 42

A method of claim 39 where said image-receiving layer and said silver halide emulsion form a permanent laminate including said substantially white layer comprising the lamellar pigment positioned between the image-receiving layer and said silver halide emulsion.

Claim 43

A method of claim 39 where said flake is substantially stable and substantially insoluble in a diffusion transfer aqueous alkaline processing composition.

Claim 44

A method of claim 39 where λ of said expression represents a wavelength or wavelength range of radiation between about 4500 A to about 6500 A.

Claim 45

A method of claim 39 where λ of said expression represents a wavelength or wavelength range of radiation between about 5000 A to about 5500 A.

Claim 46

A method of claim 39 where n of said one layer is between about 2.0 to about 2.8.

Claim 47

A method of claim 44 wherein the geometric thickness of said one layer is within the range of from about 450 A to about 700 A.

Claim 48

A method of claim 39 where λ of said expression represents a wavelength or wavelength range of radiation between about 5000 A to about 5500 A and n of said one layer is between about 2.0 to about 2.8.

Claim 49

A method of claim 39 where said one layer is a layer of titanium dioxide.

Claim 50

A method of claim 39 where said one layer is a layer of zirconium dioxide.

Claim 51

A method of claim 39 where n of said adjacent layer is lower than n of said one layer.

Claim 52

A method of claim 39 where n of said one layer is between about 2.0 to about 2.8 and n of said adjacent layer is less than n of said one layer by at least about 0.3.

Claim 53

A method of claim 39 where n of said one layer is between about 2.0 to about 2.8 and n of said adjacent layer is below about 1.5.

Claim 54

A method of claim 39 where said pigment comprises three or more layers.

Claim 55

A method of claim 39 where said pigment comprises three or more layers and the number of said one layer(s) exceeds the number of said adjacent layer(s).

Claim 56

A method of claim 39 where said one layer is a layer of titanium dioxide and said adjacent layer is a layer of strontium fluoride or magnesium fluoride.

Claim 57

A method of claim 39 where said one layer is a layer of zirconium and said adjacent layer is a layer of strontium fluoride or magnesium fluoride.