Stock material or miscellaneous articles – Composite – Of polyamidoester
Reexamination Certificate
2001-05-14
2002-09-17
Chen, Vivian (Department: 1773)
Stock material or miscellaneous articles
Composite
Of polyamidoester
C428S475200, C428S478200, C428S480000, C428S481000, C430S523000, C430S527000, C430S531000, C430S533000, C430S539000
Reexamination Certificate
active
06451431
ABSTRACT:
FIELD OF THE INVENTION
Gelatin based subbing layers for improving the adhesion of photographic emulsion to a polyester support upon thermal annealing films support having an auxiliary layer over an antistat layer that avoids blocking and adhesion problems.
BACKGROUND OF THE INVENTION
Because of curl and core-set specifications, an advanced photo system (APS) film uses a polyethylene naphthalate (PEN) based support that must be annealed before applying the emulsion layers. It is known to prepare the film support using a commonly available oriented PEN base, annealing the base, and then applying the adhesive (subbing) and backing layers to form the following structure:
Gel based sub
adhesion layer
PEN support
adhesive layer
antistat/binder
magnetics layer
lubricant
To reduce manufacturing costs it is desirable to manufacture the PEN support and apply as many of the support coatings in line with the base manufacturing before annealing in a wound roll format.
Because the magnetics and lubricant layers are typically coated from organic solvents they generally need to be coated with a separate manufacturing step from the other layers. Because the manegetics layer can degrade is anneal with all the layers it desirable to anneal the package before the application of the magenitics and lubricant layers. If the antistat layer is annealed against the gel sub (when in the rolled format), the antistat will stick to or block with the gel, making it difficult to unwind the roll without tearing or removal of layers.
To prevent blocking, it is possible to apply a water coatable layer on top of the antistat to avoid blocking with the gel sub. Although many materials will not block, an additional problem is getting the magnetics layer (which typically contains a cellulose ester based binder) to adequately adhere to the new layer.
U.S. Pat. No. 4,225,665 describes an antistat layer that contains a carboxylic acid functionalized polymer which is crosslinked with aziridine.
U.S. Pat. No. 5,198,499 describes an antistat layer that is crosslinked with a melamine which provides good abrasion resistance, adhesion and antistatic properties.
U.S. Pat. No. 5,427,900 describes a photographic film with a magnetics layer on the backside. The preferred binder for the magnetics layer is cellulose diacetate that may be crosslinked with isocyanates, aziridines or melamines.
U.S. Pat. No. 5,432,050 describes a magnetics layer with filler particles that may be crosslinked with isocyanates, aziridines or melamines.
JP 7219122A describes a blend of a hydrophillic colloid with a methyl cellulose that provides good blocking resistance when wound on a spool.
U.S. Pat. No. 4,542,093 (JP 60026944) describes a gel/methyl cellulose blend on top of a subbing layer that does not block to the subbing layer on the other side of the support and provides good adhesion with emulsion layers.
SUMMARY OF THE INVENTION
The present application solves the problems discussed above by using a coated layer that contains between 20 and 80 wt% hydroxypropyl methylcellulose on top of the antistat layer in combination with a magnetics layer that contains a crosslinking agent on top of this coating. Such an element solves both the blocking and adhesion problems discussed above. Hence, the present invention discloses:
A photographic support comprising:
a polyester base having a first and a second side;
an antistatic layer superposed on the first side of the base;
a gelatin layer superposed on the second side of the base; and
an auxiliary layer overlying said antistatic layer comprising 20 to 80 percent by weight hydroxypropyl methyl cellulose and a second binder.
The advantages of the invention are many. The auxiliary layer is an aqueous coatable layer which can be applied in manufacturing prior to annealing which allows a reduction in UMC and improved product flow. The present invention would require no change by industries using the current antistatic technologies and although adding an additional layer to the package does not require an extra pass since aqueous coating stations are usually available. Annealing a support with an antistatic layer has been cited by manufacturers a advantageous for the physical qualities of supports.
The combination of a magnetic layer with a crosslinking agent overlying an auxiliary, protective layer containing between 20 and 80 percent by weight hydroxyl propyl methylcellulose provides a backing package that can be annealed without blocking and provides good adhesion. This combination allows the use of current antistatic layers that, when overcoated with an auxiliary, protective coating, can be annealed against a gelatin subbing layer with blocking. Furthermore, after annealing the support having an antistatic layer and a gelatin subbing layer, excellent adhesion of a magnetic layer can be achieved.
DETAILED DESCRIPTION OF THE INVENTION
Any methyl cellulose material may be used to improve the non-blocking characteristics with hydroxypropyl derivatives preferred. The other component in the non-blocking layer can be any material that is compatible with the methylcellulose and forms a film on drying. Preferred materials are polymers and preferably polymers that provide good adhesion with the magnetics layer. Most preferred are polyurethanes which are aliphatic in nature, have an anionic particle charge and are characterized by an ultimate elongation prior to breaking of at least about 350 percent. Several suitable aliphatic, anionic polyurethanes for use in accordance with the invention are commercially available, from Witco Chemical Co., Greenwich, Conn., including Witcobond W-290H (ultimate elongation 600%), W-293 (725%), W-506 (550%), W-236 (450%) and W-234 (350%).
The crosslinking agent may be any compound as described in U.S. Pat. No. 5,427,900 including isocyanates, aziridines, or melamine resins with melamine-formaldehyde resins preferred.
The imaging support of this invention is suitable for use in various imaging elements including, for example, photographic, electrostatographic, photothermographic, migration, electrothermographic, dielectric recording, and thermal dye transfer imaging elements. Details with respect to the composition and function of this wide variety of imaging elements are provided in U.S. Pat. No. 5,719,016. Imaging elements that can be provided with a support in accordance with this invention can differ widely in structure and composition. For example, they can vary in regard to the type of support, the number and composition of the image forming layers, and the number and kinds of auxiliary layers included in the elements. The image forming layer(s) of a typical photographic imaging element includes a radiation sensitive agent (e.g., silver halide) dispersed in a hydrophilic water-permeable colloid. Suitable hydrophilic colloids include both naturally-occurring substances such as proteins, for example, gelatin, gelatin derivatives, cellulose derivatives, polysaccharides such as dextran, gum arabic, and the like; as well as synthetic polymers, for example, water-soluble polyvinyl compounds such as poly(vinylpyrrolidone), acrylamide polymers, and the like. A common example of an image-forming photographic layer is a gelatin-silver halide emulsion layer. In particular, the photographic elements can be still films, motion picture films, x-ray films, graphic arts films or microfiche. They can be black-and-white elements, color elements adapted for use in negative-positive process or color elements adapted for use in a reversal process.
Polymer film supports which are useful for the present invention include polyester supports such as-1,4-cyclohexanedimethylene tereplithalate, polyethylene 1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene tereplithalate, and polyethylene naphthalate and the like; and blends or laminates thereof Particularly preferred are polyethylene naphthalate and blends of polyethylene naphthalate with polyethylene tereplithalate. Additional suitable polyester supports, polyester copolymers and polyester blends are disclosed in detail in U.S. Pat. No. 5,580,7
Bauer Charles L.
Brady Brian K.
Coltrain Bradley K.
Eichorst Dennis J.
Chen Vivian
Eastman Kodak Company
Wells Doreen M.
LandOfFree
Film support with annealable layer and improved adhesion does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Film support with annealable layer and improved adhesion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Film support with annealable layer and improved adhesion will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2855185