Radiation imagery chemistry: process – composition – or product th – Post imaging processing – Including post developing step
Reexamination Certificate
1998-11-20
2002-02-05
Schilling, Richard L. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Post imaging processing
Including post developing step
C430S496000, C430S510000, C430S533000, C430S534000, C430S536000, C430S531000
Reexamination Certificate
active
06344310
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to photographic materials. In a preferred form it relates to photographic reflective images.
BACKGROUND OF THE INVENTION
In the formation of color paper it is known that the base paper has applied thereto a layer of polymer, typically polyethylene. This layer serves to provide waterproofing to the paper, as well as providing a smooth surface on which the photosensitive layers are formed. The formation of a suitably smooth surface is difficult, requiring great care and expense to ensure proper laydown and cooling of the polyethylene layers. The formation of a suitably smooth surface would also improve image quality, as the display material would have more apparent blackness as the reflective properties of the improved base are more specular than the prior materials. As the whites are whiter and the blacks are blacker, there is more range in between and, therefore, contrast is enhanced. It would be desirable if a more reliable and improved surface could be formed at less expense.
Prior art photographic reflective papers comprise a melt extruded polyethylene layer which also serves as a carrier layer for optical brightener and other whitener materials, as well as tint materials. It would be desirable if the optical brightener, whitener materials, and tints, rather than being dispersed in a single melt extruded layer of polyethylene, could be concentrated nearer the surface where they would be more effective optically.
Prior art photographic reflective materials typically contain cellulose fiber paper to provide support for the imaging layers. While paper is an acceptable support for the imaging layers, providing a perceptually preferred feel and look to the photograph, paper does present a number of manufacturing problems which reduce the efficiency at which photographic paper can be manufactured. Problems include those such as processing chemistry penetration into the edges of the paper, paper dust as photographic paper is slit, punched and chopped, and as loss of emulsion hardening efficiency because of the moisture gradient that exists between the photographic emulsion and the paper. It would be desirable if a reflective image could be formed without the use of cellulose paper.
In reflective photographic papers there is a need to protect the imaging layers from scratches, fingerprints, and stains. Current photographic reflective papers use a gelatin overcoat to protect the imaging layers. While the gelatin does provide some level of protection, it can easily be scratched reducing the quality of the image. Further, fingerprints or stains caused by common household liquids such as coffee, water, or fruit juice can easily stain and distort images. Wiping the images while wet causes undesirable distortion to the gelatin overcoat. Post photographic processing equipment exists that provides a protective coating to the imaging layers. Typically consumer images are individually coated or laminated with a polymer to provide protection to the image layers. A common example is photographic identification badges which are typically laminated with a clear polymer sheet to provide protection to the image on the identification badge. Post processing application of a protective layer is expensive, as it requires an additional step in the preparation of the reflective print and additional materials to provide the overcoat. It would be desirable if a reflective photographic image could be formed with a protective coating over the developed image layers that could be efficiently applied.
Typically, photographic reflective imaging layers are coated on a polyethylene coated cellulose paper. While polyethylene coated cellulose paper does provide an acceptable support for the imaging layers, there is a need for alternate support materials such as polyester or fabric. The problem with alternate, nonpaper supports is the lack of robustness in photographic processing equipment to mechanical property changes in supports. The photographic processing equipment will not run photographic materials that have significantly different mechanical properties than prior art photographic materials. It would be desirable if a reflective photographic image could be efficiently formed on alternate supports.
PROBLEM TO BE SOLVED BY THE INVENTION
There is a continuing need for photographic elements that are more durable in use and lighter weight for handling during the formation, imaging, and development process.
SUMMARY OF THE INVENTION
It is an object of the invention to overcome disadvantages of prior art and practices.
It is another object to provide photographic elements that are lightweight and thin for ease of handling during formation of the element and its imaging and development.
It is a further object to provide photographic elements that may be easily provided in finished form with a variety of substrates.
These and other objects of the invention are accomplished by a photographic element consisting essentially of a transparent biaxially oriented polymer sheet, at least one emulsion adhering layer, and at least one light sensitive silver halide grain containing emulsion layer adhered to said emulsion adhering layer, wherein said polymer sheet is less than 76 &mgr;m in thickness.
ADVANTAGEOUS EFFECT OF THE INVENTION
The invention provides a photographic element that is light in weight for ease of formation, imaging, and development, and may be easily adhered to a variety of substrates.
DETAILED DESCRIPTION OF THE INVENTION
The invention has numerous advantages over prior photographic elements. The elements of the invention are lighter in weight and thickness so that a roll of the photographic element of the same diameter will contain many more linear feet resulting in many more images per roll. The imaging element of the invention after development may be easily adhered to a variety of substrates, thereby allowing customized use of the images. It may be desirable for images that will be mailed to be adhered to a lightweight substrate, whereas images to be displayed can easily be adhered to a heavy substrate after their development. The invention further provides a wear resistant surface on the photographic element that will not be easily damaged during handling or use of the image. The wear resistant surface provides protection from fingerprinting, spills of liquids, and other environmental deleterious exposures. The paper that is utilized in mounting of the photographic images of the invention may be lower in cost, as it is not present during development of the image and not subjected to the development chemicals. The problem of dusting during slitting and chopping of photographic elements is greater minimized, as slitting and chopping takes place when there is no paper substrate present. The paper substrate is the primary source of dusting during slitting and chopping operations. The photographic elements of the invention also are less susceptible to curl, as the gelatin containing layers are sealed from humidity contamination to a great degree. Further, the biaxially oriented film provides a barrier to oxygen, as well as water vapor at the top of the print. These and other advantages will be apparent from the detailed description below.
The term as used herein, “transparent” means the ability to pass radiation without significant deviation or absorption. For this invention, “transparent” material is defined as a material that has a spectral transmission greater than 90%. For a photographic element, spectral transmission is the ratio of the transmitted power to the incident power and is expressed as a percentage as follows: T
RGB
=10
−D
*100 where D is the average of the red, green, and blue Status A transmission density response measured by an X-Rite model 310 (or comparable) photographic transmission densitometer. For this invention, “reflective” print material is defined as a print material that has a spectral transmission of 15% or less.
For the photographic element of this invention, the light sensitive emulsion layers are coated onto thin bia
Aylward Peter T.
Bourdelais Robert P.
Camp Alphonse D.
Gula Thaddeus S.
Eastman Kodak Company
Leipold Paul A.
Schilling Richard L.
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