Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Identified backing or protective layer containing
Reexamination Certificate
1999-05-20
2001-08-28
Schilling, Richard L. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Identified backing or protective layer containing
C430S537000, C430S609000, C430S627000, C430S628000, C428S521000, C428S522000
Reexamination Certificate
active
06280917
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an image forming material with improved layer intensity and to a novel latex containing an acetoacetoxy group and a silver halide photographic light-sensitive material containing the same, specifically to the novel latex containing the acetoacetoxy group which can improve storage stability, fogging by pressure and covering power of the silver halide photographic light-sensitive material and the silver halide photographic light-sensitive material employing the same.
BACKGROUND OF THE INVENTION
In an image forming material comprising a necessary layer on a support (for example, a silver halide light-sensitive material, a sheet used in a ink jet, a diffusion transfer image forming material and its receiving sheet, etc.), in recent years, enhancing an endurance has been demanded. Improvement of a layer peeling caused by with passage of time or by addition of strong power has been demanded. A hydrophilic colloidal layer constituting the silver halide photographic light-sensitive material is mainly composed of gelatin. However, when surface of the light-sensitive material is rubbed against foreign matter by virtue of weak force by which the hydrophilic colloidal layer is not destroyed, pressure is given to a silver halide through the gelatin which is binder to result in fog.
Various improvements of fogging by pressure have been proposed. For example, a method for increasing an amount of binder in a silver halide emulsion layer, a method for adding polymer latex to the emulsion layer described in Japanese Patent Publication Open to Public Inspection (hereinafter referred to as JP-A) No. 50-56227, a method for adding high boiling organic solvent to the emulsion layer described in JP-A Nos. 53-13923, 53-85421, a method for adding colloidal silica to the emulsion layer, a method for adding composite latex to the emulsion layer described in JP-A No. 1-177033, and a method for adding polymer latex containing an active methylene group to the emulsion layer described in JP-A Nos. 7-295130, 7-239523, are known. However, since still more toughness has been required in the silver halide photographic light-sensitive material, by these technique mentioned above, sufficient effect can not be obtained, furthermore storage stability and covering power tend to decrease.
A method for increasing intensity of wet gelatin membrane by adding the polymer latex containing the active methylene group to the light-sensitive material has been proposed in Japanese Patent Examined Publication Nos. 45-5819, 46-22507, JP-A Nos. 50-73625, 8-248548, 8-201950. Further, as active methylene latex polymerized in the presence of water soluble polymer, copolymerized latex derived from vinylacetate and monomer containing the active methylene group is described in JP-A 52-22030. However, there is no applied example in which the copolymerized latex derived from vinylacetate and monomer containing the active methylene group is employed in the light-sensitive material.
The inventors of the present invention examined improvement of the silver halide fog occurred by pressure generated by rubbing without decrease of storage stability and covering power, employing latex containing active methylene groups and found that active methylene latex polymerized in the presence of water soluble polymer could improve not only fogging by pressure but also storage stability and covering power.
SUMMARY OF THE INVENTION
An object of the present invention is to decrease fogging by pressure together with enhancement of storage stability and covering power, and provide active methylene latex to realize the above-mentioned object. And other object is to obtain an image forming material with improved layer intensity.
DETAILED DESCRIPTION OF THE INVENTION
Above objects of the invention could be attained by the following method.
(1) A latex comprising a polymer having an ethylenically unsaturated monomer unit containing an active methylene group and an ethylenically unsaturated monomer unit selected from methacrylic acid ester, acrylic acid ester, maleic acid ester and diene derivative, wherein said polymer is produced in the presence of a water soluble polymer through emulsion polymerization.
(2) The latex of item 1, wherein the water soluble polymer is an anionic water soluble polymer, a nonionic water soluble polymer or a natural polymer.
(3) The latex of item 1, wherein the water soluble polymer is an anionic water soluble polymer and said polymer is composed of not less than two kinds of monomer units selected from the ethylenically unsaturated monomer unit and a conjugated diene monomer unit, and content of an anionic monomer unit is not less than 60% in weight ratio.
(4) The latex of item 1, wherein the water soluble polymer is an anionic water soluble polymer and said polymer contains a conjugated diene type sulfonic acid or its alkaline salt.
(5) The latex of item 4, wherein the conjugated diene type sulfonic acid or its alkaline salt is styrenesulfonic acid or its alkaline salt.
(6) The latex of item 1, wherein the water soluble polymer is a nonionic water soluble polymer and said polymer is composed of not less than two kinds of monomer units selected from the ethylenically unsaturated monomer unit and a conjugated diene monomer unit, and content of a nonionic monomer unit is not less than 60% in weight ratio.
(7) The latex of item 1, wherein the water soluble polymer is a natural water soluble polymer which is dextran derivative.
(8) The latex of item 2, wherein the water soluble polymer contains acrylamide derivative or methacrylamide derivative unit.
(9) The latex of item 2, wherein the water soluble polymer contains vinylpyrrolidone unit.
(10) The latex of item 2, wherein glass transition temperature of said polymer is not lower than −20° C.
(11) The latex of item 1, wherein the polymer having the ethylenically unsaturated monomer unit containing the active methylene group and the ethylenically unsaturated monomer unit selected from methacrylic acid ester, acrylic acid ester, maleic acid ester and diene derivative produced in the presence of the water soluble polymer through emulsion polymerization is represented by the following Formula [1],
−(A)x−(B)y−(C)z− Formula [1]
wherein, A represents the ethylenically unsaturated monomer unit containing the active methylene group represented by the following Formula [2], B represents the ethylenically unsaturated monomer unit selected from methacrylic acid ester, acrylic acid ester or maleic acid having glass transition temperature of not higher than 35° C., C represents the ethylenically unsaturated monomer other than A and B; x, y and z represent weight percentage ratio of each component in said polymer, and x, y and z each indicate 0.5≦x≦41, 0>y≦59, and x+y+z=100,
CH
2
═C(R
1
)L—X Formula [2]
wherein R
1
represents a hydrogen atom, an alkyl group having 1 to 4 carbon atom(s) or a halogen atom, L represents a single bond or a divalent linking group, X represents a monovalent group containing an active methylene group.
(12) The latex of item 11, wherein x and y each indicate 2≦x≦20 and 5≦y≦50.
(13) The latex of item 12, wherein X of Formula [2] is R
8
COCH
2
COO—, CNCH
2
COO—, R
8
COCH
2
CO— or R
8
COCH
2
CON(R
5
)—, wherein R
5
represents a hydrogen atom, a substituted or an unsubstituted alkyl group having 1 to 6 carbon atom(s), and R
8
represents an alkyl group having 1 to 12 carbon atom(s), an aryl group, an alkoxy group, a cycloalkyloxy group, an aryloxy group, an amino group, the groups represented as R
8
may have a substituent.
(14) The latex of item 11, wherein B of Formula [1] is alkylacrylate having a branched alkyl chain having not more than two carbon atoms, alkylmethacrylate having a branched alkyl chain having not less than six carbon atoms or diene derivative of which glass transition temperature is not higher than 10° C.
(15) The latex of item 1, wherein the poly
Kubo Nobuo
Kurachi Yasuo
Nagaike Chiaki
Ueda Eiichi
Frishauf, Holtz Goodman, Langer & Chick, P.C.
Konica Corporation
Schilling Richard L.
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