Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Structurally defined
Reexamination Certificate
2001-10-16
2002-07-02
Schilling, Richard L. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Structurally defined
C430S533000, C430S619000, C430S950000
Reexamination Certificate
active
06413705
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a heat-developable recording material.
BACKGROUND OF THE INVENTION
In recent years, reduction of waste solutions in processing has strongly been desired in the field of photographic films for medical diagnosis and in the field of photographic films for phototype process from the viewpoints of environmental protection and space saving. Accordingly, techniques regarding heat-developable photosensitive materials have been needed for medical diagnosis films and for phototype process films which are able to be efficiently exposed with a laser image-setter or a laser imager and to form a clear black image of high resolution and sharpness. These heat-developable photosensitive materials make it possible to provide customers with a simpler and environmentally benign heat development processing system without using any solution type processing chemicals.
The similar requirements exist in the field of general image-forming materials. However, the image for medical diagnosis use is especially characterized in that a cold tone image is preferred from the viewpoint of facilitating medical diagnosis. Besides, a high image quality in sharpness and graininess is necessary, because fine details of the image are required for medical diagnosis. Currently, various hard copy systems utilizing pigments or dyes like inkjet printers and apparatus for electrophotography are prevailing to be general image-forming systems. However, there is no system satisfactory as a medical image-output system.
On the other hand, thermal image-forming systems utilizing an organic silver salt are described, for example, in U.S. Pat. Nos. 3,152,904 and 3,457,075, and D. Klosterboer, “Thermally Processed Silver Systems”,
Imaging Processes and Materials,
Neblette 8th edition compiled by J. Sturge, V. Walworth and A. Shepp, Chapter 9, pp. 279, 1989. Generally, a heat-developable heat-sensitive material has a heat-sensitive layer in which a reducible silver salt (e.g., an organic silver salt), a reducing agent, and according to necessity a toner to control color tone of silver are dispersed in the matrix of binder. In contrast, a heat-developable photosensitive material generally has a photosensitive layer in which a photocatalyst (e.g., a silver halide) in a catalytically active amount, a reducing agent, a reducible silver salt (e.g., an organic silver salt), and according to necessity a toner to control color tone of silver are dispersed in the matrix of binder. The heat-developable photosensitive material is imagewise exposed to light, and then heated to a high temperature (e.g., 80° C. or more) to form a black silver image by a redox reaction between a reducible silver salt (acts as an oxidant) and the reducing agent. The redox reaction is accelerated by catalytic action of a latent image generated in a silver halide by exposure. Therefore, the black silver image is formed in an exposed area.
Regarding a support for these heat-developable recording material, supports having an undercoat layer containing a polyester resin are described in Japanese Patent Laid-Open No. 84574/1999. However, with supports having such an undercoat layer, it was found that problems occurred such as insufficient adhesion between a support and an image-forming layer, unevenness resulted in a coated surface condition or stripes generated in coating, and further repelling marks generated in coating of the image-forming layer. As a matter of course, the material having such a repelling mark forms an image badly influenced. Accordingly, it has been desired to develop a support having an undercoat layer resulting in high productivity and without problems described in the above.
SUMMARY OF THE INVENTION
In consideration of these problems, the present invention has set an aim to provide a heat-developable recording material having an undercoat layer with which adhesion between the support and the image-forming layer is sufficient, unevenness in the coated surface condition in coating has been prevented, coating stripes have been improved, and further the problem of repelling marks generated in coating of the image-forming layer has been solved.
In the result of diligent investigations, the inventors have found that the coating stripes were caused by aggregates occurred in a coating process (in a coating die part) to make the surface condition worse. Further, the inventors have found that the repelling marks in coating a photosensitive layer were caused by foreign matters adhered to the surface of undercoat layer. When a photosensitive layer was coated on the surface where foreign matters had adhered, the photosensitive layer resulted in forming the repelling marks. Based on these analyzed factors, the inventors have discovered that a heat-developable recording material improved in the adhesive property and the coating property can be provided by using an undercoat layer having a specific composition to achieve the invention.
Namely, the invention provides a heat-developable recording material comprising a support, at least one undercoat layer and at least one image-forming layer, in this order,
wherein the undercoat layer comprises:
polyester resins containing at least two kinds of water-soluble and water-dispersible polyester resins, each of which has a different glass transition temperature (Tg); and fine particles having an average particle diameter (k) of from 0.1 &mgr;m to 2.0 &mgr;m, and
the undercoat layer has an average film thickness (d) of from 0.05 &mgr;m to 1.0 &mgr;m, and (k)/(d) is in the range from 2.0 to 10.0.
All of the polyester resins in the undercoat layer used in the invention are preferably a polyester resin without an acrylic-modification.
All of the polyester resins in the undercoat layer used in the invention preferably have a Tg of from 30° C. to 100° C.
Further, it is preferable that at least one of the polyester resins to be used in the invention is a polyester resin which fulfils Condition A:
the polyester resin has a Tg of from 40° C. to 100° C.;
an acid component of the polyester resin comprises: at least one of a terephthalic acid and isophthalic acid in a total amount of from 40 mol % to 90 mol %; and an isophthalic acid having a sulfonyloxy group below in an amount of from 10 mol % to 60 mol %: —(SO
3
)
n
M, wherein M represents a hydrogen atom, an alkali or alkali-earth metal, or a tertiary ammonium group; and
an alcohol component of the polyester resin comprises a diethylene glycol in an amount of from 40 mol % to 90 mol % and a cyclohexane dimethanol in an amount of from 10 mol % to 60 mol %.
It is preferable that the polyester resins in the udercoat layer comprise: the polyester resin which satisfies Condition A in an amount of from 60 wt % to 90 wt %; and a polyester resin having a higher Tg than the polyester resin that satisfies Condition A in an amount of from 10 wt % to 40 wt %.
It is preferable that the undercoat layer contains the fine particles in an amount of from 0.1 wt % to 10 wt % in proportion to the amount of the polyester resin.
It is preferable that the image-forming layer in the invention comprises at least one kind of photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for a silver ion and a binder.
DETAILED DESCRIPTION OF THE INVENTION
Detailed explanation regarding the heat-developable recording materials of the invention will be described hereinafter.
The heat-developable recording material of the invention comprises a support, at least one undercoat layer and at least one image-forming layer, in this order.
The heat-developable recording material of the invention preferably comprises a support, at least one undercoat layer on at least one surface side of the support and at least one image-forming layer on the undercoat layer.
The undercoat layer in the invention is characterized by containing polyester resins and fine particles, wherein the polyester resins are a mixture comprising two or more kinds of water-soluble or water-dispersible polyester resins having a different glass transition temperatu
Fujikura Sadao
Haraoka Hiroshi
Birch & Stewart Kolasch & Birch, LLP
Fuji Photo Film Co. , Ltd.
Schilling Richard L.
LandOfFree
Heat-developable recording material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Heat-developable recording material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Heat-developable recording material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2913908