JP2002221764A - Photographic element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film support for a photosensitive image forming element in which adhesion with respect to other layers is improved when annealed. SOLUTION: A photographic element is formed by including a polyester support, an antistatic layer, a cellulose-based binder, a strong magnetic particulate, a transparent magnetic layer containing blocked isocyanate, and an image forming layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates generally to photosensitive imaging elements and, more particularly, to a film support having improved adhesion to other layers upon annealing.

[0002]

2. Description of the Related Art Due to curl and core-set specifications,
Advanced Photo System (APS) films use a polyethylene naphthalate-based support that must be annealed before coating the emulsion layer. The film support can be manufactured by purchasing a stretched PEN base, annealing the base, and then applying an adhesive layer (undercoat layer) and a backing layer to form the structure described below. . Gel base coat layer Adhesive layer PEN support Adhesive layer Antistatic agent / binder Magnetic layer Lubricant

[0003] In order to reduce manufacturing costs, it may be desirable to manufacture a PEN support and apply the same number of support coatings in parallel with base manufacture before annealing in a roll. The current magnetic material-coated support deteriorates during annealing and the adhesion of the magnetic layer becomes insufficient. One method of improving adhesion is to add a crosslinker to the magnetic layer, such as an isocyanate, which is known to be a skin and respiratory sensitizer. Because of the health and safety concerns of handling isocyanates, it is desirable to use another crosslinking agent. The present inventors have found that good adhesion can be achieved by using a heat-activated blocked isocyanate in the magnetic layer. These materials cause the coating to crosslink during the annealing stage of the manufacturing, which is heated for an extended period. An additional advantage of these materials is that they do not react at room temperature, thus extending the life of the coating solution and making it easier to clean.

US Pat. No. 4,225,665 describes an antistatic layer containing a carboxylic acid functionalized polymer crosslinked with aziridine. U.S. Patent No. 5,198,499
No., is an antistatic layer cross-linked with melamine,
Those exhibiting good abrasion resistance, adhesion and antistatic properties are described. U.S. Pat. No. 5,427,900 describes a photographic film having a magnetic layer on the back side. A preferred binder for the magnetic layer is cellulose diacetate, which can be crosslinked with isocyanate, aziridine or melamine. U.S. Pat. No. 5,432,050 describes a magnetic layer containing filler particles that can be crosslinked with isocyanates, aziridine or melamine.

[0005]

If the magnetic package is applied before the annealing process, the adhesion of the backing is degraded due to the annealing process. As many back layers as possible
It may be advantageous to apply the coating in an in-line manner before annealing.

[0006]

SUMMARY OF THE INVENTION The present invention discloses that the adhesion of a package is improved by adding a blocked isocyanate to a magnetic layer and then annealing the magnetic layer. This allows the production of polyester supports to be applied in-line with several backing layers. That is, the present invention provides a polyester support,
The photographic element comprises a transparent magnetic layer containing an antistatic layer, a cellulose-based binder, ferromagnetic particles, and blocked isocyanate, and an image forming layer.

The present invention has many advantages. The use of a blocked isocyanate for an annealable backing package results in good adhesion to a suitable antistatic or non-blocking protective layer. Since the blocked isocyanate does not react at room temperature,
Significant manufacturing and environmental advantages are obtained over conventional isocyanate-based crosslinkers. Specifically, the use of blocked isocyanates extends the life of coating solutions,
It can facilitate cleaning and reduce the risk of personnel being exposed to reactive agents. Heretofore, the only method known to provide an annealable magnetic backing having a vanadium oxide based antistatic layer and a cellulose diacetate based magnetic layer has been to crosslink the magnetic layer.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The image-forming support of the present invention comprises, for example, a photographic element, an electrostatographic element, a photothermographic element, a migration element, an electrothermographic element, a dielectric recording element and a thermal dye transfer type imaging element. It is suitable for various image forming elements including the above. The composition and function of a wide variety of imaging elements are described in detail in U.S. Pat. No. 5,719,016. The imaging elements that can be provided with the support according to the invention can vary widely in structure and composition. For example, there may be differences regarding the type of support, the number and composition of image forming layers, and the number and type of auxiliary layers included in the element.
The imaging layer of a typical photographic imaging element comprises a radiation-sensitive agent (eg, silver halide) dispersed within a hydrophilic water-permeable colloid. Suitable hydrophilic colloids include proteins such as gelatin, gelatin derivatives, cellulose derivatives, polysaccharides such as dextran, gum arabic,
And synthetic polymers such as water-soluble polyvinyl compounds, for example, poly (vinylpyrrolidone), acrylamide polymers, and the like. A general example of the image-forming photographic layer is a gelatin / silver halide emulsion layer. Specifically, the photographic element can be a still film, a motion picture film, an X-ray film, a graphic arts film or a microfish. The photographic element can be a black and white element, a negative / positive color element or a reversal color element.

The polymer film supports useful in the present invention include 1,4-cyclohexane dimethylene terephthalate, polyethylene, 1,2-diphenoxyethane-4,4'-dicarboxylate, polybutylene terephthalate and polyethylene naphthalate. As well as blends or laminates thereof. Particularly preferred are polyethylene naphthalate and blends of polyethylene naphthalate and polyethylene terephthalate. Still other suitable polyester-based supports, polyester copolymers and polyester blends are described in detail in US Pat. No. 5,580,707.

[0010] One or both sides of the film support may be subjected to corona discharge, glow discharge,
LTV exposure, flame treatment, electron beam treatment, or dichloroacetic acid, trichloroacetic acid, phenol derivatives, for example,
Surface treatment can be performed by various treatments including treatment with an adhesion promoter such as resorcinol and p-chloro-m-cresol, and solvent washing before overcoating the undercoat layer of the present invention. In addition to surface treatment or treatment with an adhesion promoter, a vinylidene chloride-containing copolymer,
Butadiene-based copolymer, glycidyl acrylate or methacrylate-containing copolymer, maleic anhydride-containing copolymer, condensation-based polymer, for example, polyester,
Further adhesion promoting primer or tie layers containing polymers such as polyamides, polyurethanes, polycarbonates, mixtures and blends thereof, etc. may be applied to the polyester support. Particularly suitable primer or tie layers include a chlorine-containing latex or a solvent-applicable chlorine-containing polymer layer. As the primer or undercoat layer of the present invention, vinyl chloride-containing polymers and vinylidene chloride-containing polymers are preferred.

The primer or primer composition can be applied to the polyester base in an in-line process during base manufacture or in an off-line process.
When applied in an in-line process, the layer can be applied to the polyester base before stretching, after stretching, or after biaxial stretching after uniaxial stretching. The described primer compositions are typically prepared in US Pat. No. 2,627,0.
No. 88 and 3,143,421. As detailed in U.S. Pat. No. 2,779,684, the coating composition is coated on an amorphous support material, dried, and the resulting film is subjected to a stretching step and other steps such as heat setting. It is oriented by applying. Therefore, the particular support film used, the procedure and equipment for coating it, and the orientation of the film are not requirements of the present invention.
For processing of the film product of the present invention, any of the usual coating apparatuses and processing steps employed in the art can be used.

On the image forming side of the support, a hydrophilic subbing layer containing gelatin is applied to the polyester film base before heat treatment. The subbing layer can be applied to a surface-treated polyester support or can be overlaid on any suitable primer layer. A suitable subbing layer for the imaging side of the support is described in US patent application Ser.
No. 7,306, which is incorporated herein by reference. Typical amount of gelatin subbing layer is 0.25 ~
5% by weight, the preferred amount used is in the range of 0.5 to 1% by weight. The undercoat layer contains additives such as dispersants, surfactants, plasticizers, coagulation aids, solvents, co-binders, soluble dyes, solid particulate dyes, haze inhibitors, adhesion promoters, hardeners, and antistatic agents. , A matting agent, and the like. It is customary in the art to use surfactants (coating aids) or to include water-miscible solvents in aqueous dispersions to modify coatability and drying properties. Suitable solvents include ketones such as acetone or methyl ethyl ketone, and alcohols such as ethanol, methanol, isopropanol, n-propanol and butanol. The lower undercoat layer, primer layer or tie layer may be surface-treated by, for example, corona discharge treatment to improve the wetting by the gelatin undercoat composition.

The support coated according to the present invention is subjected to a long-term heat treatment or annealing step after the conventional heat treatment for producing a support film in order to reduce the tendency of the support to core-set curl. Such a "post-production" heat treatment or annealing step involves heating the coated film support at a temperature 50-50C below the glass transition temperature of the support for 6 hours or more. A heat treatment or annealing step to reduce this tendency of core-set curl is a typical support in that it is performed after the support has been wound into rolls, rather than as part of the primary step of manufacturing the support. A distinction is made from heat treatment for body production. In a preferred embodiment of the present invention, the image-forming support comprises a polyethylene-2,6-naphthalate film base coated with a vinylidene chloride-based primer layer. A gelatin subbing layer is applied on one side of the support. In the case of polyethylene-2,6-naphthalate, Tg is about 140
° C, and the heat treatment temperature is 90 ° C to 120 ° C, preferably 100 ° C to 115 ° C, more preferably 105 ° C to
The range is 115 ° C.

The photographic element according to a preferred embodiment of the present invention may be a single color element or a multicolor element. Multicolor elements contain a plurality of image dye-forming units sensitive to each of the three primary regions of the spectrum. Each unit can contain a single emulsion layer or multiple emulsion layers sensitive to a particular region of the spectrum. The layers of the element, including the layers of the image-forming units, can be arranged in various orders as known in the art. In another format, multiple emulsions sensitive to each of the three primary gamuts of the spectrum can be arranged as a single, partitioned layer.

[0015] A typical multicolor photographic element comprises, on a support, a cyan dye image-forming unit comprising one or more red-sensitive silver halide emulsion layers combined with one or more cyan dye-forming couplers; A magenta dye image forming unit in which one or more magenta dye-forming couplers are combined in a light-sensitive silver halide emulsion layer, and a yellow dye image in which one or more yellow dye-forming couplers are combined with one or more blue-sensitive silver halide emulsion layers It has a configuration that carries a forming unit. The element includes a filter layer, an intermediate layer, an antihalation layer, an overcoat layer, an undercoat layer,
Additional layers may be included, such as.

[0016]

The present invention is illustrated by the following examples. However, the scope of the present invention is not limited to these examples. Example 1 For the following examples, polyethylene naphthalate (PE
The thick sheet of N) was melt extruded and a poly (acrylonitrile-co-vinylidene chloride-co-acrylic acid) adhesion promoting layer was applied to both sides of the support. Next, the support is stretched and tentered to obtain a thickness 9 including an adhesive layer having a thickness of about 60 nm.
A 5 μm PEN film was formed. On one side of the support was applied a gelatin subbing layer of about 0.09 g / m ² . On the side opposite the gelatin subbing layer, an antistatic layer was applied from water. As an example, the antistatic layer (referred to as A1) is formed by mixing poly (acrylonitrile-co-vinylidene chloride-co-acrylic acid): vanadium pentoxide: Tx-100 in a mass ratio of 1:
A first layer containing 1: 1 (dry coverage 0.015 g / m ² );
Hydroxypropyl methylcellulose (E3, Dow Chem
ical) and polyurethane Witcobond W236 (Witco)
And a second layer (a dry coating amount of 0.22 g / m ² ) which is a mixture containing 25/75 by weight. As another example, the antistatic layer (referred to as A2) was a single layer (dry coverage 0.605 g / m ² ) containing a mixture of zinc antimonate and gelatin (weight ratio 90/10).

The magnetic layers shown in Table 1 were applied on the antistatic layer. This layer is composed of dichloromethane / acetone /
Wet coverage 44.1c from solvent mixture of methyl acetoacetate
Coated at c / m ² and dried. Before coating, the coating solution is added to a blocked isocyanate BL-3175A (Bayer Ch.
em.) in the amounts shown in Table 2 (% based on total solids in the coating).

[0018]

[Table 1]

[0019]

[Table 2]

The coating is 15.24 cm (6 inches)
And placed in a 100 ° C. oven for 3 days and then at 100 ° C. for 2 days. In order to evaluate the adhesion, a wet test and a dry test were performed, and the results are shown in Table 2 before and after annealing. Dry: 610 Scotch tape test The coating is scored with a razor blade in a grid pattern (5 lines of 25.4 mm length at 5.08 mm intervals, then further at an angle of 45 degrees to these lines) 5 lines). A 610 Scotch tape was applied over the cut area and the tape was peeled off by hand. This operation is repeated 10 times with a new tape. Thereafter, the peeled amount is evaluated, and is expressed in units of peel%. Wet: AO abrasion A 35 mm piece of coating is immersed in a 37.8 ° C. developer bath for 3 minutes and 15 seconds. The coated piece is then scored with a razor blade, placed in a small trough and a weighted rubber pad is placed on top. The pad is moved back and forth 100 times while in contact with the coating strip. afterwards,
The peeled amount is evaluated and expressed in units of peel%. The results in Table 2 show that the adhesion of the layers was significantly improved after the annealing step.

Example 2 In this example, the amount and type of the blocked isocyanate contained in the magnetic layer were changed. The support was prepared in the same manner as in the above example, except that a layer containing a mixture of zinc antimonate and gelatin (mass ratio 80/20) (dry coverage 0.605 g / m ² ) was used for the antistatic layer. This was designated as A3. The magnetic layer was prepared and tested as described in Example 1, but the amounts and types of blocked isocyanate crosslinkers were varied as described in Table 3. The amount of the crosslinking agent added was expressed as% based on the total solids contained in the coating solution.

[0022]

[Table 3] * Blocked isocyanate from Bayer Chem. ** Blocked isocyanate from Huls Chemical ++ Isocyanate cross-linking agent from Bayer Chem. + Melamine-formaldehyde cross-linking agent from Cytec

These results show that blocked isocyanates are as effective as fast-reacting crosslinkers (isocyanates and melamine-formaldehydes) in improving adhesion after the annealing step. I have.

The preferred embodiments of the present invention will be described below. [1] A photographic element comprising a polyester support, an antistatic layer, and a transparent magnetic layer containing a cellulosic binder, ferromagnetic particles, and blocked isocyanate. [2] A photographic element comprising a polyester support, an antistatic layer, a transparent magnetic layer containing a cellulosic binder, ferromagnetic particles, and blocked isocyanate, and an image forming layer. [3] The photographic element of [2], wherein the image forming layer contains silver halide. [4] The photographic element of [1] or [2], wherein the polyester support comprises polyethylene naphthalate, polyethylene terephthalate or a blend thereof.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Dennis Jay. ECoast United States, Kansas 66215, Lenexa, West One Hundred Fourteenth Street 14260 F-term (reference) 2H023 FC00 HA04

Claims (2)

[Claims] 1. A photographic element comprising a polyester support, an antistatic layer, a transparent magnetic layer containing a cellulosic binder, ferromagnetic particles, and blocked isocyanate, and an image forming layer. 2. The image forming layer contains a silver halide.
A photographic element according to claim 1.