JP2006058501A - Diffusion transfer film unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color diffusion transfer film unit with low toner concentration in which the progression of transfer is rapid, and the concentration in the unexposed part is low. <P>SOLUTION: The diffusion transfer film unit with low toner concentration comprises: a photosensitive sheet having an image receiving layer, a white light diffusion layer, a light shielding layer and a silver halide emulsion layer combined with a pigment image forming material on a transparent support; a transparent cover sheet having a neutralization layer and a neutralization timing layer on a support; and a carbon black-containing alkali treatment composition developed between the photosensitive sheet and the transparent cover sheet, and is arranged in such a manner that exposure is caused through the transparent cover sheet. The space between the white light diffusion layer and the light shielding layer in the photosensitive sheet is provided with a photoreflective particulate-containing layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a diffusion transfer film unit. More specifically, the present invention relates to an integrated color diffusion transfer film unit. The present invention also relates to a color diffusion transfer film unit having a thin film unit, a rapid transfer progress, and a low density in an unexposed area.

  The color diffusion transfer film unit includes an integral type and a divided type. One typical example of the split type is a so-called peel-apart type, in which the photosensitive element and the dye-receiving element are coated on different supports, and after image exposure, the photosensitive element and the dye-receiving element are separated. The dye image transferred to the dye image-receiving layer is obtained by superimposing and developing the treatment composition between them, and then peeling off the dye-receiving element. The feature of this embodiment is that the dye image can be directly observed instead of observing the image through the support as in the case of the integrated type described later, and shows excellent color reproducibility without deterioration in image quality. However, in this embodiment, there is an inconvenience in operation in which the photosensitive element and the image receiving element are superposed in the camera, and an inconvenience in handling the processed film in which the alkaline processing liquid is sticky and easily adheres to the periphery after peeling. is there.

  In this operation, the one that improves inconvenience in handling is an integrated form. The integrated diffusion transfer film unit is well known in many documents such as Non-Patent Document 1 or Non-Patent Document 2. In the integrated type, a dye image-receiving element, a photosensitive element, and a neutralization timing element are coated between a transparent support and the other support, and the photosensitive element is coated on the same transparent support as the image-receiving element. And a form coated on another support (hereinafter referred to as the latter).

  In the former case, a white light diffusion layer is coated between the image receiving element and the photosensitive element. In the latter case, the image is received by adding a white pigment to the processing composition developed between the image receiving element and the photosensitive element. The dye image transferred to the layer can be observed with reflected light. The present invention relates to the former form, a photosensitive sheet having an image receiving layer, a white light diffusing layer, a light shielding layer, at least one silver halide emulsion layer combined with at least one dye image forming material on a transparent support, transparent A color diffusion comprising a transparent cover sheet having at least a neutralization layer and a neutralization timing layer on a support, and a light-shielding alkaline treatment composition adapted to be developed between the photosensitive sheet and the transparent cover sheet It relates to a transfer film unit.

Here, the roles of the light shielding layer, the light-shielding alkali treatment composition, and the white light diffusion layer will be described in detail. The role of the light-shielding layer and the light-shielding alkaline processing composition is an element necessary for darkening the silver halide emulsion layer after processing. After processing, the film unit released from the film pack will be completely exposed to light. In the absence of a light-shielding layer, light reaches the silver halide emulsion layer after processing, so the unexposed areas are also exposed, developed, and colored when stored after processing. For this reason, it is necessary to make a dark room by sandwiching with a light shielding layer. However, when the silver halide emulsion layer is darkened from the beginning, imagewise exposure cannot be performed. For this purpose, the exposure side is designed to allow light to pass through during exposure, and a light-shielding alkaline processing composition is developed during processing, and the other side is covered to achieve a dark room. A light shielding layer is necessary for darkening, but the light shielding layer must be black in order to shield light of all wavelengths. However, if the film unit is black, the image transferred like an image cannot be confirmed. In order to solve this problem, a white light diffusion layer is necessary. The white light diffusion layer is placed between the image receiving layer and the light shielding layer and covers the black color of the light shielding layer to form a white background. Due to the presence of the white light diffusion layer, a white image can be obtained in the unexposed area.
A fine powder of titanium oxide is used for the white light diffusion layer of the current color diffusion transfer film unit. Titanium oxide fine powder is originally a transparent substance, but diffuses light at the interface with air to form a white color. Titanium oxide has the highest refractive index among the existing materials, and is the most excellent material for forming a white background using light diffusion.
However, even when this titanium oxide is used, an enormous amount of titanium oxide is required to hide the black color of the light shielding layer. This enormous amount of titanium oxide occupies a large portion of the film thickness of the current color diffusion transfer film unit, which causes a delay in transfer progress.
Under such circumstances, it has been desired to develop a technique for reducing the amount of titanium oxide and speeding up the transfer while maintaining sufficient whiteness of the unexposed area.

Research Disclosure, 1976, Volume 151 No. 15162 Photographic Science and Engineering, July 18, 1976, Volume 20, Issue 4

  Accordingly, an object of the present invention is to provide a color diffusion transfer film unit having a thin film unit, a rapid transfer progress, and a low density of an unexposed portion.

The above problems have been achieved by the following.
(1) A photosensitive sheet having a silver halide emulsion layer combined with an image-receiving layer, a white light diffusing layer, a light-shielding layer, and a dye image-forming substance on a transparent support, a neutralization layer and a neutralization timing layer on the support And a diffusion transfer film unit arranged so as to be exposed through the transparent cover sheet, comprising a carbon black-containing alkaline treatment composition developed between the photosensitive sheet and the transparent cover sheet. A diffusion transfer film unit comprising a light reflective fine particle-containing layer between a white light diffusion layer and a light shielding layer in the photosensitive sheet.
(2) The diffusion transfer film unit according to (1), wherein the light reflective fine particles are metal fine particles.
(3) The diffusion transfer film unit according to (1), wherein the light reflective fine particles are a light reflective organic compound.
(4) The diffusion transfer film unit according to (1), wherein the light reflective fine particles are retroreflective light reflection beads.
(5) The diffusion transfer film unit according to (1), wherein the light-reflecting fine particles are a swellable inorganic layered compound.
(6) The diffusion transfer film unit according to any one of (1) to (5), wherein the silver halide emulsion in the diffusion transfer film unit photosensitive sheet is a negative type silver halide emulsion. Diffusion transfer film unit characterized by that.
(7) The diffusion transfer film unit according to any one of (1) to (5), wherein the silver halide emulsion in the diffusion transfer film unit photosensitive sheet has an internal latent image type direct positive halogenation. A diffusion transfer film unit characterized by being a silver emulsion.
(8) The diffusion transfer film unit according to any one of (1) to (7), wherein exposure is performed using an exposure head having different light sources that emit light in a plurality of specific wavelength regions. Diffusion transfer film unit.

The diffusion transfer film unit of the present invention makes it possible to maintain the white color of an unexposed portion with a small amount of white light diffusing agent even when exposed using an exposure head having different light sources that emit light in a plurality of specific wavelength ranges. It is possible to speed up the transfer while maintaining the same white background.
Therefore, the diffusion transfer film unit of the present invention can reduce the density of the unexposed area by reducing the thickness of the film unit, speeding up the transfer process.

The light reflective fine particles used in the diffusion transfer film unit of the present invention will be described in detail below. The light-reflecting fine particles used in the diffusion transfer film unit of the present invention may be any fine particles that have the property of reflecting light, but may be metal fine particles, light-reflective organic compound fine particles, retroreflective light. Reflective beads or swellable inorganic layered compounds are preferred.
The size of the fine particles used in the diffusion transfer film unit of the present invention is preferably 0.001 μm to 50 μm. More preferably, it is 0.01 μm to 20 μm. Particularly preferably, it is 0.02 μm to 10 μm. Here, the size of the fine particles is obtained by taking the diameter of a circle equivalent to the projected area of the particles as the particle size and taking the number average. The shape of the particles may be any shape, for example, a spherical particle shape, a particle shape on a flat plate, a chain-like particle shape, a cubic particle shape, a rectangular parallelepiped particle shape, or the like is preferable.

(Metal fine particles)
The metal fine particles preferably used in the diffusion transfer film unit of the present invention will be described in detail below.
In the present invention, any substance having a metal bond can be used. As the metal fine particles, metal fine particles having a single composition and metal fine particles of a composite metal or alloy of two or more metals can be used. Two or more different metal fine particles can be used in combination.
Metals preferably used in the diffusion transfer film unit of the present invention are aluminum, magnesium, titanium, vanadium, chromium, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, tin, Examples thereof include osmium, iridium, platinum, gold, and lead, and alloys thereof are also preferably used. Examples of the alloy preferably used include stainless steel and brass. Among these, silver or platinum is more preferably used in that it has a white metallic luster.
The size of the metal fine particles used in the present invention is preferably 0.001 μm to 10 μm, more preferably 0.01 μm to 1 μm, and particularly preferably 0.02 μm to 0.5 μm. The shape of the particles may be any shape, but a spherical particle shape, a particle shape on a flat plate, a chain-like particle shape, a cubic particle shape, a rectangular parallelepiped particle shape, or the like is also preferable.
The addition amount of the fine metal particles of the present invention is preferably (mass area versus the photosensitive ^{sheet) 0.01g / m 2 ~50g / m} 2, more preferably ^{0.1g / m 2 ~10g / m 2} , 0.2g / M ^{2 to 5} g / m ² is particularly preferable. When the amount is too small, the black color of the light shielding layer cannot be sufficiently shielded, and when the amount is too large, the object of the present invention of accelerating the transfer cannot be achieved.

  The metal fine particles used in the diffusion transfer film unit of the present invention can be dispersed by adding 5 to 10 weights of metal fine particles to 100 parts by weight of water and using a dispersing machine. As the disperser, various dispersers that disperse by applying mechanical force directly can be used. It is done. Preferred dispersers include a ball mill, a sand grinder mill, a visco mill, a colloid mill, a homogenizer, a dissolver, a polytron, a homomixer, a homoblender, a ketdy mill, a jet agitator, a capillary emulsifier, a liquid siren, an electrostrictive ultrasonic generator, Or an emulsifying device having a Paulman whistle.

(Light-reflective organic compound)
The light reflective organic compound used in the diffusion transfer film unit of the present invention will be described below.
If a substance has an absorption band in the visible region, it will be colored. At that time, there is usually a complementary color relationship between the color of the absorbed light and the color actually seen. However, this is the color indicated by the light passing through the material. The reflectance R of reflected light from a solid (specular reflection at normal incidence) is expressed by the following equation.

ここで、ｎはその物質の屈折率、ｋは吸収係数である。ｋは、ｃをモル濃度、λを光の波長、εをその波長でのモル吸光係数として、ｋ＝２．３０３εｃλで表される値である。したがって、吸収帯が無くｋ＝０であるとき、またはｋが小さく、ｌｏｇε＝２でｋ＝０．１程度のときは、物質の色と吸収帯との関係は補色の関係のままである。しかしｋが大きく、ｌｏｇεが約３またはそれ以上になると、Ｒの値に影響してくる。このように、吸収帯の裾と極大付近ではＲが著しく異なることとなり、波長依存性が出てくるため、吸収する光の色が見えることになる。本発明で用いられる光反射性有機化合物は、この原理に基づき、好ましくはLogεが３以上の有機化合物である。
本発明の拡散転写フイルムユニットに用いられる光反射性有機化合物は上記の原理により光を反射する有機化合物であればいかなる有機化合物でも良いが、以下の一般式（Ｉ）で表される構造を有する有機化合物が好ましく用いられる。

Here, n is the refractive index of the substance, and k is the absorption coefficient. k is a value represented by k = 2.303εcλ, where c is the molar concentration, λ is the wavelength of light, and ε is the molar extinction coefficient at that wavelength. Therefore, when there is no absorption band and k = 0, or when k is small, log ε = 2 and k = about 0.1, the relationship between the color of the substance and the absorption band remains a complementary color relationship. However, when k is large and log ε is about 3 or more, the value of R is affected. In this way, R is remarkably different between the bottom and the maximum of the absorption band, and the wavelength dependence appears, so that the color of the absorbed light can be seen. Based on this principle, the light reflective organic compound used in the present invention is preferably an organic compound having a Log ε of 3 or more.
The light-reflective organic compound used in the diffusion transfer film unit of the present invention may be any organic compound as long as it reflects light based on the above principle, but has a structure represented by the following general formula (I). Organic compounds are preferably used.

(In the formula, A and B each represent an atomic group necessary to complete a conjugated double bond chain, and Y and Z each represent an atomic group necessary to form a carbocyclic or heterocyclic ring. L ¹ , L ² , L ³ , L ⁴ and L ⁵ each represents an optionally substituted methine group, M ^{k +} represents a metal cation, and X and X ′ each represent an oxygen atom, a sulfur atom or —C ( CN) _2. m1 and n1 each represents 0, 1, or 2, x and y each represents 0 or 1. M ^{k +} represents a k-valent metal cation, and k represents an integer of 2 or more. , N represents a number necessary to make the number of positive charges and the number of negative charges in the general formula (I) equal.)

Hereinafter, the compound represented by formula (I) will be described in detail.
In the general formula (I), -C- (A) _x -C (= X)-bonded to Y and -C = (B) _y = C (-X ' ^- )-bonded to Z are respectively It is in a conjugated state. Therefore, a carbocyclic or heterocyclic ring represented by Y and -C- (A) _x -C (= X)-bonded thereto, and Z and -C = (B) _y = C (bonded thereto. Each of the carbocycles or heterocycles represented by -X ' ^- )-is considered as one of the resonance structures. In the following, for convenience, Y and Z and —C— (A) _x —C (═X) — and —C— (B) _y —C (—X ′ ⁻ ) —, which are bonded to each of Y and Z, respectively. The carbocycles and heterocycles represented (hereinafter sometimes referred to as “resonance structure carbocycles” and “resonance structure heterocycles” respectively) will be described together.

  As the carbocycle and heterocycle having a resonance structure, a 4- to 7-membered carbocycle or heterocycle is preferable. Particularly preferred is a 5- or 6-membered carbocyclic or heterocyclic ring. These rings may be further condensed with other rings, and the condensed ring is preferably a 4- to 7-membered ring. In addition, the carbocycle or heterocycle may have a substituent.

  Substituents include halogen atoms, alkyl groups (including cycloalkyl groups and bicycloalkyl groups), alkenyl groups (including cycloalkenyl groups and bicycloalkenyl groups), alkynyl groups, aryl groups, heterocyclic groups, cyano groups, hydroxyl groups Group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy, amino group (including anilino group), acylamino Group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thiol Sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl and heterocyclic azo group, imide group, phosphino group, phosphinyl group, Preferred examples include a phosphinyloxy group, a phosphinylamino group and a silyl group.

  The substituent will be described in more detail. A halogen atom (for example, chlorine atom, bromine atom, iodine atom), an alkyl group (straight chain, branched, cyclic substituted or unsubstituted alkyl group, preferably 1 carbon atom) To 30 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl), cycloalkyl groups (preferably having carbon atoms) A substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, That is, one hydrogen atom is removed from a bicycloalkane having 5 to 30 carbon atoms. And monovalent groups such as bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl, and tricyclo structures having many ring structures are also preferable. . An alkyl group (for example, an alkyl group of an alkylthio group) in the substituents described below also represents an alkyl group having the same concept.

An alkenyl group (a linear, branched, cyclic substituted or unsubstituted alkenyl group, preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, such as vinyl, allyl, prenyl, geranyl, oleyl), A cycloalkenyl group (preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms. 2-cyclopenten-1-yl, 2-cyclohexen-1-yl), bicycloalkenyl groups (substituted or unsubstituted bicycloalkenyl groups, preferably substituted or unsubstituted bicycloalkenyl groups having 5 to 30 carbon atoms, A monovalent group in which one hydrogen atom of a bicycloalkene having one heavy bond is removed (for example, bicyclo [ , 2,1] hept-2-en-1-yl, bicyclo [2,2,2] oct-2-en-4-yl) are preferable.
Further, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms (for example, ethynyl, propargyl, trimethylsilylethynyl group), an aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms such as phenyl P-tolyl, naphthyl, m-chlorophenyl, o-hexadecanoylaminophenyl),

  Heterocyclic group (preferably a monovalent group obtained by removing one hydrogen atom from a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, more preferably 3 carbon atoms. To 30-membered or 6-membered aromatic heterocyclic group such as 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy A group (preferably a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, such as methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy), an aryloxy group (preferably A substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, such as phenoxy, 2-methylphenoxy, 4- -Butylphenoxy, 3-nitrophenoxy, 2-tetradecanoylaminophenoxy), silyloxy groups (preferably silyloxy groups having 3 to 20 carbon atoms, such as trimethylsilyloxy, t-butyldimethylsilyloxy), heterocyclic oxy Group (preferably a substituted or unsubstituted heterocyclic oxy group having 2 to 30 carbon atoms, 1-phenyltetrazole-5-oxy, 2-tetrahydropyranyloxy), acyloxy group (preferably formyloxy group, carbon atom) A substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms, such as formyloxy, acetyloxy, pivaloyloxy, stearoyloxy, benzoyloxy, p- Methoxyfe Le carbonyloxy)

  A carbamoyloxy group (preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms, such as N, N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinocarbonyloxy, N, N-di -N-octylaminocarbonyloxy, Nn-octylcarbamoyloxy), an alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, such as methoxycarbonyloxy, ethoxycarbonyloxy, t-butoxycarbonyloxy, n-octylcarbonyloxy), aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, such as phenoxycarboni Oxy, p-methoxyphenoxycarbonyloxy, pn-hexadecyloxyphenoxycarbonyloxy), amino group (preferably amino group, substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, carbon number 6 -30 substituted or unsubstituted anilino groups such as amino, methylamino, dimethylamino, anilino, N-methyl-anilino, diphenylamino), acylamino groups (preferably formylamino groups, 1-30 carbon atoms) Substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms such as formylamino, acetylamino, pivaloylamino, lauroylamino, benzoylamino, 3,4,5-tri -N-octyloxyphenyl Ruboniruamino),

  Aminocarbonylamino group (preferably substituted or unsubstituted aminocarbonylamino having 1 to 30 carbon atoms, such as carbamoylamino, N, N-dimethylaminocarbonylamino, N, N-diethylaminocarbonylamino, morpholinocarbonylamino) An alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms such as methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, n-octadecyloxycarbonylamino, N-methyl) Rumethoxycarbonylamino), an aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms, such as phenoxycarbonyl Mino, p-chlorophenoxycarbonylamino, mn-octyloxyphenoxycarbonylamino), sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms, such as Famoylamino, N, N-dimethylaminosulfonylamino, Nn-octylaminosulfonylamino),

  Alkyl and arylsulfonylamino groups (preferably substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino having 6 to 30 carbon atoms, such as methylsulfonylamino, butylsulfonylamino) , Phenylsulfonylamino, 2,3,5-trichlorophenylsulfonylamino, p-methylphenylsulfonylamino), mercapto group, alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms such as methylthio , Ethylthio, n-hexadecylthio), arylthio group (preferably substituted or unsubstituted arylthio having 6 to 30 carbon atoms, such as phenylthio, p-chlorophenylthio, m-methoxyphenylthio), heterocyclic A group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, such as 2-benzothiazolylthio, 1-phenyltetrazol-5-ylthio), a sulfamoyl group (preferably having 0 to 0 carbon atoms). 30 substituted or unsubstituted sulfamoyl groups such as N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl, N-acetylsulfamoyl, N-benzoylsulfur Famoyl, N- (N′-phenylcarbamoyl) sulfamoyl), sulfo group, alkyl and arylsulfinyl group (preferably substituted or unsubstituted alkylsulfinyl group having 1 to 30 carbon atoms, substituted or unsubstituted 6 to 30 carbon atoms) Substituted arylsulfinyl groups such as methylsulfinyl, ethyls Finiru, phenylsulfinyl, p- methyl phenylsulfinyl),

  Alkyl and arylsulfonyl groups (preferably substituted or unsubstituted alkylsulfonyl groups having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonyl groups having 6 to 30 carbon atoms such as methylsulfonyl, ethylsulfonyl, phenylsulfonyl, p -Methylphenylsulfonyl), acyl group (preferably formyl group, substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, such as acetyl , Pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl), an aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxy Carbonyl, -Chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, pt-butylphenoxycarbonyl), an alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms such as methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, n-octadecyloxycarbonyl), a carbamoyl group (preferably a substituted or unsubstituted carbamoyl having 1 to 30 carbon atoms, for example, carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-di-n-octylcarbamoyl, N- (methylsulfonyl) carbamoyl),

  Aryl and heterocyclic azo groups (preferably substituted or unsubstituted arylazo groups having 6 to 30 carbon atoms, substituted or unsubstituted heterocyclic azo groups having 3 to 30 carbon atoms, such as phenylazo, p-chlorophenylazo, 5-ethylthio-1,3,4-thiadiazol-2-ylazo), imide group (preferably N-succinimide, N-phthalimide), phosphino group (preferably substituted or unsubstituted having 2 to 30 carbon atoms) Phosphino groups such as dimethylphosphino, diphenylphosphino, methylphenoxyphosphino), phosphinyl groups (preferably substituted or unsubstituted phosphinyl groups having 2 to 30 carbon atoms such as phosphinyl, dioctyloxyphosphinyl, Diethoxyphosphinyl), phosphinyloxy group (preferred Or a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, such as diphenoxyphosphinyloxy, dioctyloxyphosphinyloxy), a phosphinylamino group (preferably having a carbon atom number) 2-30 substituted or unsubstituted phosphinylamino groups, such as dimethoxyphosphinylamino, dimethylaminophosphinylamino, silyl groups (preferably substituted or unsubstituted silyl having 3 to 30 carbon atoms) Groups such as trimethylsilyl, t-butyldimethylsilyl, phenyldimethylsilyl) are preferred.

Among the substituents exemplified above, those having a hydrogen atom may be substituted with the substituents exemplified above after removing the hydrogen atom contained in the substituent. Examples of the substituent containing a hydrogen atom include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group, wherein the hydrogen atom is removed and further substituted with a substituent. Examples of are methylsulfonylaminocarbonyl, p-methylphenylsulfonylaminocarbonyl, acetylaminosulfonyl, and benzoylaminosulfonyl groups. Further, among the substituents exemplified above, those having a dissociable hydrogen atom remove the dissociative hydrogen atom contained in the substituent, and n / k M ^{k +} (for details of n, k and M) May form a salt with the polyvalent cation represented by (4) or other cations, and preferably forms a salt with the polyvalent cation represented by n / k M ^{k +} . Examples of the substituent having a dissociative hydrogen atom include a hydroxyl group, a carboxyl group, an imide group, a sulfo group, and a carbamoyl group (such as an acylcarbamoyl group and a sulfonylcarbamoyl group).

  The heterocycle may contain one type of heteroatom, or may contain two or more different heteroatoms. Preferable heteroatoms that form a heterocyclic ring having a resonance structure are atoms selected from a boron atom, a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. Among these, an atom selected from a nitrogen atom, an oxygen atom, and a sulfur atom is more preferable.

  In the general formula (I), x and y each independently represent 0 or 1, but preferably 0.

In the general formula (I), X and X ′ represent an oxygen atom, a sulfur atom or —C (CN) ₂ . Among these, an oxygen atom is preferable.

  Examples of the carbocycle having the resonance structure include the following carbocycles I-1 to I-4.

  Among these, carbocycles I-1 and I-4 are preferable as the carbocycle having a resonance structure.

  Examples of the heterocyclic ring having the resonance structure include the following heterocyclic rings I-5 to I-41.

  Among these, as the heterocyclic ring having a resonance structure, I-5, I-6, I-7, I-8, I-9, I-18, I-35, I-36 and I-40 are preferable. 5, I-6 and I-7 are more preferred, and I-6 is particularly preferred.

In the carbocycle and heterocycle, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each represents a hydrogen atom or a substituent, and the substituent includes the carbocycle and heterocycle of the resonance structure. Synonymous with ring substituent. Further, any ^{two of} R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ may be linked to form a condensed ring.

In the general formula (I), the methine groups represented by L ¹ , L ² , L ³ , L ⁴ and L ⁵ may be the same or different. The methine group includes an unsubstituted methine group and a methine group having a substituent. The substituent is synonymous with the carbocyclic and heterocyclic substituents of the resonance structure. Among them, preferred substituents are an alkyl group, aryl group, alkoxy group, aryloxy group, acylamino group, alkylthio group, arylthio group, halogen atom, amino group, carbamoyl group or heterocyclic group. Two or more substituents are connected to form a 5- to 7-membered ring (for example, a cyclopentene ring, 1-dimethylaminocyclopentene ring, 1-diphenylaminocyclopentene ring, cyclohexene ring, 1-chlorocyclohexene ring, isophorone ring, 1- Morpholinocyclopentene ring, cycloheptene ring, etc.) may be formed.

  In the general formula (I), m1 and n1 each represents 0, 1 or 2. Among these, the sum of m1 and n1 is preferably 0, 1, 2, or 3, and the sum of m1 and n1 is more preferably 0, 1, or 2.

In the general formula (I), M ^{k +} represents a k-valent metal cation, k represents an integer of 2 or more, and n is for equalizing the number of positive charges and the number of negative charges in the general formula (I). Represents the number required for. The metal cation represented by M ^{k +} may be any metal as long as it can take a divalent or higher state. Any of the typical metal ions of Group 2 and Groups 12 to 15 and the transition metal ions of Groups 3 to 11 can be used. Among these, typical metal ions of Group 2, Group 12, and Group 13 are more preferable, magnesium, calcium, strontium, barium, zinc, and aluminum ions are more preferable, and magnesium, calcium, zinc, and aluminum ions are particularly preferable. .

  k represents an integer of 2 or more, preferably 2 to 6, more preferably 2 to 4, and particularly preferably 2 or 3.

  Among the dyes represented by the general formula (I), a compound represented by the following general formula (I ′) is particularly preferable.

In the general formula (I ′), the definitions and preferred ranges of R ¹ , R ² , L ¹ , L ² , L ³ , L ⁴ , L ⁵ , m 1, n 1, M ^{k +} , k and n are as defined above. The same as in formula (I).

  Specific examples of the compound represented by the general formula (I) are shown below as exemplified compound Nos. Although shown together, these do not limit the present invention.

  The compound represented by the general formula (I) may contain a crystal solvent. The solvent or reagent used at the time of synthesis can be a crystal solvent. An example is water.

The compound represented by the general formula (I) is water and / or an organic solvent (for example, methanol) containing a compound represented by the following general formula (III) and a salt of a divalent or higher metal cation (M ^{k +} ). , Ethanol, isopropanol, dimethylformamide, dimethylacetamide, dimethylsulfoxide, etc.) and can be easily synthesized by a salt exchange reaction. The salt exchange reaction may be performed by, for example, adding a dye powder to an aqueous solution or organic solvent solution containing a salt of a polyvalent metal cation, or a mixed solution of water and an organic solvent, an aqueous dye solution, an organic solvent solution, or water. And a mixed solution of an organic solvent. Conversely, an aqueous solution or organic solvent solution of a dye, or a mixed solution of water and an organic solvent, a salt powder of a polyvalent metal cation, an aqueous solution or salt solution containing a salt of a polyvalent metal cation, or It can also be carried out by adding a mixed solution of water and an organic solvent. Furthermore, the salt exchange reaction can also be performed by mixing the dye and the salt of the polyvalent metal cation in a state where they are not completely dissolved.
When adding a powder of a dye, it is preferable that the dye to be added dissolves to some extent in a solvent containing a polyvalent metal cation. When the dye to be added has low solubility in a solvent containing a polyvalent metal cation, the dye is preferably added in the form of a solution.

In the general formula (III), A, B, Y, Z, L ¹ , L ² , L ³ , L ⁴ , L ⁵ , P, P ′, Q, Q ′, X, X ′, m1, n1, x and y have the same definitions as those already defined in formula (I). M ¹⁺ represents a monovalent organic or inorganic cation (for example, alkali metal ion (for example, lithium ion, sodium ion, potassium ion, etc.), ammonium ion (NH ₄ ⁺ ), triethylammonium ion (Et ₃ NH ⁺ ), Pyridinium ions (C ₆ H ₅ NH ^+, etc.).

  The compound represented by the general formula (III) generally introduces a corresponding active methylene compound ((thio) barbituric acid, pyrazolone, indandione, isoxazolone, etc.) and a methine group or polymethine group into a methine dye. It can be synthesized by a condensation reaction with a methine source used for the above. For details on the synthesis of this type of compound, JP-B-39-22069, JP-A-43-3504, JP-A-52-38056, JP-A-54-38129, JP-A-55-10059, JP-A-58-35544, JP JP-A-49-99620, JP-A-52-92716, JP-A-59-16834, JP-A-63-316853, JP-A-64-40827, and British Patent No. 1337986, US Pat. No. 3,247,127, Reference can be made to the specifications of 4,042,397, 4,181,225, 5,213,956, 5,260,179 and the like.

  Specifically, orthoesters such as ethyl orthoformate and ethyl orthoacetate or N, N-diphenylformamidine hydrochloride can be used for the introduction of the monomethine group, and trimethoxypropene is used for the introduction of the trimethine group. 1,1,3,3-tetramethoxypropane, malondialdehyde dianyl hydrochloride (or a derivative thereof), and the like can be used. Further, glutaconaldehyde dianil hydrochloride, 1- (2,4-dinitrophenyl) -pyridinium chloride, 1- (2-benzthiazolyl) -pyridinium chloride (or a derivative thereof) or the like can be used for introducing a pentamethine group.

The light reflective organic compound used in the diffusion transfer film unit of the present invention is preferably provided with light reflectivity by being introduced into the diffusion transfer film unit in a solid dispersion state.
The solid fine particle dispersion for obtaining the light reflecting organic compound fine particles used in the diffusion transfer film unit of the present invention is a compound represented by the general formula (I) (hereinafter, these compounds are referred to as “compounds of the present invention”). In some cases) is preferably dispersed in a medium. Since the compound represented by the general formula (I) has low solubility in water, it can be used as various colorants by being dispersed in an aqueous medium. When the compound represented by the general formula (I) is dispersed in an aqueous medium, a disperser (eg, ball mill, sand mill, attritor, roll mill, agitator mill, Henschel mixer, colloid mill, ultrasonic homogenizer, pearl mill, jet mill) It is preferable to disperse the compound represented by the general formula (I) in the form of fine particles. It is also possible to prepare a fine particle dispersion by dissolving the compound represented by the general formula (I) in an appropriate organic solvent and then adding the obtained solution to an aqueous medium.
The light reflecting organic compound contained in the light reflecting fine particle-containing layer may be one kind or two or more kinds.

The particle size of the solid dispersion of the light-reflective organic compound used in the diffusion transfer film unit of the present invention is preferably 0.001 μm to 10 μm, more preferably 0.01 μm to 1 μm, and more preferably 0.05 μm to 0.5 μm. Particularly preferred.
The addition amount of the light-reflective organic compound of the present invention is preferably from ^{0.01g / m 2 ~50g / m 2} , more preferably ^{0.1g / m 2 ~10g / m 2} , 2g / m 2 ~5g / m 2 Is particularly preferred. When the amount is too small, the black color of the light shielding layer cannot be sufficiently shielded, and when the amount is too large, the object of the present invention of accelerating the transfer cannot be achieved.

(Swellable inorganic layered compound)
Next, the swellable inorganic layered compound used in the diffusion transfer film unit of the present invention will be described in detail. Examples of the swellable inorganic layered compound used in the diffusion transfer film unit of the present invention include swellable clay minerals such as bentonite, hectonite, and montmorillonite, swellable synthetic mica, and swellable synthetic smectite. These swellable inorganic layered compounds have a laminated structure composed of unit crystal lattice layers having a thickness of 10 to 15 Å, and the metal atom substitution in the lattice is significantly larger than other clay minerals. As a result, the lattice layer is deficient in positive charge. In order to compensate for this, lithium ions (Li ⁺ ), sodium ions (Na ⁺ ), calcium ions (Ca ²⁺ ), magnesium ions (Mg ²⁺ ), etc. Adsorbs cations. The cations present between these layers are called exchangeable cations and exchange with various cations. In particular, when the cation between the layers is lithium ion (Li ⁺ ) or sodium ion (Na ⁺ ), the bond between the layered crystal lattices is weak because the ionic radius is small, and the layer swells greatly with water. If shear is applied in this state, it will easily cleave and form a stable sol in water. Bentonite and swellable synthetic mica have a strong tendency and are preferable for the purpose of the present invention. In particular, swellable synthetic mica is preferably used. Examples of the swellable synthetic mica used in the present invention include sodium tetrasic mica (NaMg _2.5 (Si ₄ O ₁₀ ) F ₂ , sodium or lithium teniolite (NaLi) Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , sodium or lithium Hectorite (NaLi) _1/3 Mg _2/3 Li _1/3 (Si ₄ O ₁₀ ) F ₂ etc. The size of the swellable synthetic mica preferably used in the present invention is 1 to 50 nm in thickness, surface In order to make the swellable inorganic layered compound-added layer of the diffusion transfer film unit thinner, the thinner the swellable inorganic layered compound, the better the plane size is. Therefore, the aspect ratio is preferably 100 or more, more preferably 200 or more, and particularly preferably 400 or more, although there is no particular upper limit, but the available aspect ratio is 1000. The following is practical amount of the swellable inorganic layered compound used in. The present invention is preferably from ^{0.01g / m 2 ~50g / m 2} , more preferably ^{0.1g / m 2 ~10g / m 2} , 0.2g / m ² ~5g / m ² is particularly preferred. If too small can not shield the black sufficiently shielding layer, if too much can not achieve the object of the present invention that increase the transfer progression .
The swellable inorganic layered compound contained in the light-reflecting fine particle-containing layer may be one kind or two or more kinds.

  Next, a method for dispersing the swellable inorganic layered compound used in the diffusion transfer film unit of the present invention will be described. It is possible to add 5 to 10 parts by weight of a swellable inorganic layered compound to 100 parts by weight of water, sufficiently saturate it with water, swell and then disperse it with a disperser. As the disperser to be used, various dispersers that disperse by applying a direct mechanical force can be used. Examples include a high-speed stirring disperser having a large shearing force and a disperser that provides high-intensity ultrasonic energy. It is done. Preferred dispersers include a ball mill, a sand grinder mill, a visco mill, a colloid mill, a homogenizer, a dissolver, a polytron, a homomixer, a homoblender, a ketdy mill, a jet agitator, a capillary emulsifier, a liquid siren, an electrostrictive ultrasonic generator, Or an emulsifying device having a Paulman whistle. The dispersion of 5 to 10% by mass dispersed by the above method is highly viscous or gelled, and the storage stability is very good. When adding to the coating solution, dilute with water and stir well before adding.

(Retro reflective beads)
Next, the retroreflective beads used in the diffusion transfer film unit of the present invention will be described in detail. Retroreflective light reflection is a reflection method in which light is reflected as it is toward a light source, regardless of the direction of light, unlike ordinary reflection.
The beads capable of performing such retroreflection are the retroreflection beads preferably used in the diffusion transfer film unit of the present invention, such as Na ₂ O—CaO—SiO ₂ glass, BaO—SiO _2. -TiO ₂ type glass, BaO-ZnO-TiO ₂ system glass, and the like.
The form of the retroreflective light-reflecting beads of the present invention is substantially spherical, and the preferred particle size range is 0.1 μm to 50 μm, more preferably 0.5 μm to 20 μm, and particularly preferably 1 μm to 10 μm. .
Amount of retro-reflected light beads of the present invention is preferably from ^{0.01g / m 2 ~50g / m 2} , more preferably ^{1g / m2~10g / m 2, 0.2g} / m 2 ~5g / m 2 is Particularly preferred. When the amount is too small, the black color of the light shielding layer cannot be sufficiently shielded, and when the amount is too large, the object of the present invention of accelerating the transfer cannot be achieved.
The retroreflective light-reflecting beads contained in the light-reflecting fine particle-containing layer may be one kind or two or more kinds.

  A method for dispersing the retroreflective light reflecting beads used in the diffusion transfer film unit of the present invention will be described. It is possible to add 5 to 10 weights of retroreflective light-reflecting beads to 100 parts by weight of water and disperse with a disperser. As a disperser to be used, various dispersers that disperse mechanically by applying a contact force can be used. For example, a high-speed stirring disperser having a large shearing force, a disperser that gives high-intensity ultrasonic energy, and the like. Can be mentioned. Preferred dispersers include a ball mill, a sand grinder mill, a visco mill, a colloid mill, a homogenizer, a dissolver, a polytron, a homomixer, a homoblender, a ketdy mill, a jet agitator, a capillary emulsifier, a liquid siren, an electrostrictive ultrasonic generator, Or an emulsifying device having a Paulman whistle.

(Light reflective fine particle content layer)
In the diffusion transfer film unit of the present invention, it is preferred that the layer containing the light-reflecting fine particles can pass the diffusing dye, and for this purpose, it is preferable to disperse in a water-soluble binder. Gelatin is preferably used, and other hydrophilic colloids can also be preferably used. Examples include gelatin derivatives, graft polymers of gelatin and other polymers, proteins such as albumin and casein; cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, cellulose sulfates, sugar derivatives such as sodium alginate and starch derivatives, polyvinyl alcohol A variety of synthetic hydrophilic polymer materials such as mono- or copolymers such as polyvinyl alcohol partial acetal, poly≡N≡vinyl pyrrolidone, polyacrylic acid, polymethacrylic acid, and polyacrylamide can be used.

  As gelatin, besides lime-processed gelatin, acid-processed gelatin may be used, and gelatin hydrolyzate and gelatin enzyme dispersion may also be used. Examples of gelatin derivatives include gelatin, for example, acid halides, acid anhydrides, isocyanates, bromoacetic acid, alkane sultones, vinyl sulfonamides, maleimide compounds, polyalkylene oxides, epoxy compounds, and the like. Those obtained by reacting these compounds are preferably used. The binder amount of the light reflecting fine particles used in the diffusion transfer film unit of the present invention is preferably 1 to 1000 parts by weight, more preferably 5 to 100 parts by weight, particularly preferably 100 parts by weight of the light reflecting fine particles. 10 to 50 parts by weight.

  It is preferable to use a surfactant when dispersing the light-reflecting fine particles of the present invention in a binder. Any surfactant can be used as the surfactant, but nonionic surfactants are preferred.

  Next, the nonionic surfactant used in the present invention will be described. Nonionic surfactants are represented by the following general formulas (W≡II), (W≡III), (W≡IV), (W≡V), (W≡VI) and (W≡VII). Can be used.

R ₂₆ and R ₂₈ are preferably an alkyl group having 1 to 20 carbon atoms, an aryl group such as a phenyl group, p≡chlorophenyl group, ≡OR ₃₅ (where R ₃₅ is an alkyl group having 1 to 20 carbon atoms or an aryl group) An alkoxy group and an aryloxy group, a halogen atom such as a chlorine atom or a bromine atom, and a carbon atom represented by ≡COR _35. An amide group represented by: ≡NR ₃₆ COR ₃₅ (wherein R ₃₆ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; the same shall apply hereinafter), ≡NR ₃₆ SO ₂ R ₃₅ Or a carbamoyl group represented by ≡CON (R ₃₆ ) ₂ or a sulfamoyl group represented by ≡SO ₂ N (R ₃₆ ) ₂ . Of these, R ₂₆ and R ₂₈ are more preferably an alkyl group or a halogen atom, and most preferably a tertiary alkyl group such as a t≡butyl group, a t≡amyl group, or a t≡octyl group. R ₂₂ , R ₂₃ , R ₂₇ and R ₂₉ are preferably hydrogen atoms or the groups listed as preferred for R ₂₆ and R ₂₈ above. Of these, R ₂₇ and R ₂₉ are particularly preferably hydrogen atoms. R ₂₄ and R ₂₅ represent a hydrogen atom, an alkyl group or an aryl group, and these groups include those having a substituent. R ₂₄ and R ₂₅ are particularly preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a phenyl group, a furyl group, or the like. R ₂₄ and R ₂₅ , R ₂₆ and R _27, and R ₂₈ and R ₂₉ may be linked to each other to form a ring, for example, a cyclohexyl ring. In the general formula (W≡VI), the substituent of the phenyl ring may be asymmetrical. R ₃₁ represents a hydrogen atom or an alkyl group, and this alkyl group includes those having a substituent. R ₃₂ represents a hydrogen atom or an alkyl group, alkenyl group, aryl group or aralkyl group having 1 to 30 carbon atoms. Each group represented by R ₃₂ includes those having a substituent. Examples of the substituent include an alkyl group, an aryl group, a halogen atom, an alkoxy group, an aryloxy group, a thioether group, and a polyoxyalkyl ether group. It is done. R ₃₃ represents an alkylene group having 1 to 10 carbon atoms, a polyoxyalkylene group or a divalent aromatic group (for example, a phenylene group), and these include those having a substituent. R ₃₄ represents an alkyl group having 1 to 20 carbon atoms or an aryl group. Each group represented by R ₃₄ includes those having a substituent. Examples of the substituent include an alkyl group, an aryl group, a halogen atom, an alkoxy group, an aryloxy group, a thioether group, and a polyoxyalkylene ether group. Can be mentioned. n11, n12, n13 and n14 are the average number of moles of ethylene oxide added and are 2 to 50, particularly preferably 5 to 30. n13 and n14 may be the same or different. N15 is also the average number of moles of ethylene oxide added and is a number from 1 to 100. m is an integer of 2 to 50, m11 and m12 are each an integer of 0 to 20, and p is an integer of 0 to 30. These compounds are disclosed in U.S. Pat. Nos. 2,982,651, 3,428,456, 3,457,076, 3,454,625, 3,552,972, 3, 655,387, Japanese Patent Publication No. 51≡9610, Japanese Patent Publication No. 53≡29715, Japanese Patent Publication No. 54≡89626, Japanese Patent Application No. 57≡85764, Japanese Patent Application No. 57≡90909, Hiroshi Horiguchi, “New Interface Activator "(Sankyo Publishing, 1975) and the like. Among the nonionic surfactants represented by the general formulas (W≡II) to (W≡VII), those preferably used are sorbitan ester compounds represented by (W≡II) and (W≡III). .
Next, specific examples of the nonionic surfactant preferably used in the present invention will be shown, but the present invention is not limited thereto.

The addition amount of the surfactant is not particularly ^{limited, 1 × 10 -5 g / m} 2 ~1g / m 2 are ^{preferred, 1 × 10 -4 g / m} 2 ~1 × 10 -1 g / m ² is more preferable, and 1 × 10 ⁻³ g / m ² to 1 × 10 ⁻² g / m ² is particularly preferable.

  The light reflective fine particles contained in the light reflective fine particle-containing layer may be one kind or two or more kinds. In addition to the surfactant, a necessary compound or the like can be appropriately added as long as the effect of the light reflecting fine particles is not hindered. Although there is no restriction | limiting in particular in the thickness of a light reflective fine particle content layer, 0.1 micrometer-10 micrometers are preferable.

  Hereinafter, embodiments of each layer constituting the diffusion transfer film unit of the present invention will be described, but the present invention is not limited thereto.

I. Photosensitive sheet

A) White light diffusing layer The white light diffusing layer of the photosensitive sheet in the diffusion transfer film unit of the present invention may form a white background of a color image, but it is usually preferable to contain a white pigment and a hydrophilic binder.
As preferred white pigments for the white light diffusion layer, barium sulfate, zinc oxide, barium stearate, silver flakes, silicates, alumina, zirconium oxide, sodium zirconium sulfate, kaolin, mica, titanium dioxide, and the like are used. Furthermore, non-film-forming polymer particles made of styrene or the like are also used. Moreover, these may be used independently and can also be mixed and used in the range in which the preferable reflectance is obtained. More preferably, it is titanium dioxide.

The whiteness of the white light diffusion layer varies depending on the type of pigment, the mixing ratio of the pigment and the binder, and the coating amount of the pigment, but the light reflectance is preferably 70% or more.
When titanium dioxide is used as the white pigment, it is preferable to apply 5 to 40 g / m ^{2 of} titanium dioxide, more preferably 10 to 25 g / m ² , and light reflectance of 78 to 540 nm. A white light diffusion layer having 85% is preferred. Titanium dioxide can be selected from various commercially available brands.
Among these, it is particularly preferable to use rutile type titanium dioxide. Most of the commercially available products are surface-treated with alumina, silica, zinc oxide or the like, and in order to obtain a high reflectance, a surface treatment amount of 5% or more is preferable. Examples of commercially available titanium dioxide include those described in Research Disclosure Magazine No. 15162 in addition to Ti-pure R931 (trade name) manufactured by DuPont.

As the white light diffusion layer, an alkali-permeable polymer matrix such as gelatin, polyvinyl alcohol, or a cellulose derivative such as hydroxyethyl cellulose or carboxymethyl cellulose can be used. When gelatin is used as the binder, the mass ratio of the white pigment to gelatin is 1/1 to 20/1, preferably 5/1 to 10/1.
In the white light diffusing layer, it is preferable to incorporate an anti-fading agent such as Japanese Patent Publication Nos. 62-30620 and 62-30621.

B) Light Shielding Layer A light shielding layer containing a light shielding agent and a hydrophilic binder is provided between the white light diffusing layer and the following photosensitive layer. As the light shielding agent, any material having a light shielding function is used, but carbon black is preferably used. Further, degradable dyes described in US Pat. No. 4,615,966 may be used. The binder for coating the light-shielding agent may be any one that can disperse carbon black, and is preferably gelatin. As the carbon black raw material, there can be used any production method such as a channel method, a thermal method, and a furnace method as described in Donnel Voet Carbon Black Marcel Dekker, Inc. (1976). The particle size of carbon black is not particularly limited, but is preferably 90 to 1800 angstroms. The addition amount of the black pigment as the light shielding agent may be adjusted according to the sensitivity of the photosensitive material to be shielded from light, but is preferably about 5 to 10 in terms of optical density.
The thickness of the light shielding layer used in the present invention is not particularly limited.

C) Support The support of the photosensitive sheet used in the present invention is any smooth transparent support that is usually used for photographic light-sensitive materials, and cellulose acetate, polystyrene, polyethylene terephthalate, polycarbonate, etc. are used, and an undercoat layer is used. (Undercoat layer) is preferably provided. In general, the support preferably contains a trace amount of a dye or a pigment such as titanium oxide in order to prevent light piping. The thickness of the support of the photosensitive sheet is 25 to 350 μm, preferably 50 to 210 μm, more preferably 70 to 150 μm. If necessary, a layer for curling balance or an oxygen barrier layer described in JP-A-56-78833 can be provided on the back side of the support.

D) Image receiving layer The image receiving layer (dye image receiving layer) of the photosensitive sheet used in the present invention includes a mordant contained in a hydrophilic colloid. This may be a single layer or a multilayer structure in which mordants having different mordant powers are applied in layers. These are described in JP-A-61-252551. As the mordant, a polymer mordant is preferable.
The polymer mordant is a polymer containing secondary and tertiary amino groups, a polymer having a nitrogen-containing heterocyclic moiety, a polymer containing a quaternary cation, etc., having a molecular weight of 5,000 or more, particularly preferably 10,000 or more. Is. The coating amount of the mordant is generally 0.5 to 10 g / m ^2, preferably 1.0 to 5.0 g / m ^2, particularly preferably ² to 4 g / m ² .

As the hydrophilic colloid used for the image receiving layer of the photosensitive sheet, gelatin, polyvinyl alcohol, polyacrylamide, polyvinyl pyrrolidone and the like are used, and gelatin is preferred.
In the image receiving layer, anti-fading agents described in JP-A Nos. 62-30620, 62-30621, and 62-215272 can be incorporated.
The thickness of the image receiving layer used in the present invention is not particularly limited.

E) Photosensitive layer In the present invention, a photosensitive layer comprising at least one silver halide emulsion layer combined with a dye image forming substance (dye image forming compound) is provided adjacent to the light shielding layer. The components will be described below.

(1) Dye Image Forming Compound Specific examples of the dye image forming compound are described in the following documents.
Examples of yellow dyes:
U.S. Pat. Nos. 3,597,200, 3,309,199, 4,013,633, 4,245,028, 4,156,609, 4,139 No. 4,383, No. 4,195,992, No. 4,148,641, No. 4,148,643, No. 4,336,322, JP-A No. 51-114930, No. 56-71072, Research Disclosure 17630 (1978), and 16475 (1977).

Examples of magenta dyes:
U.S. Pat. Nos. 3,453,107, 3,544,545, 3,932,380, 3,931,144, 3,932,308, 3,954 No. 4,476, No. 4,233,237, No. 4,255,509, No. 4,250,246, No. 4,142,891, No. 4,207,104, 4,287,292, JP-A-52-106727, 53-23628, 55-36804, 56-73057, 56-71060, 55-134 , JP-A-7-120901, 8-286343, 8-286344, and 8-292537.

Examples of cyan dyes:
U.S. Pat. Nos. 3,482,972, 3,929,760, 4,013,635, 4,268,625, 4,171,220, 4,242 , 435, 4,142,891, 4,195,994, 4,147,544, 4,148,642; British Patent 1,551,138 Japanese Patent Laid-Open Nos. 54-99431, 52-8827, 53-47823, 53-143323, 54-99431, 56-71061; European Patent (EP) 53,037, 53,040; Research Disclosure 17,630 (1978) and 16,475 (1977).

A dye image forming compound that forms a dye by coupling can also be used. For example, they are described in JP-A-8-286340, JP-A-9-152705, JP-A-8-357190, JP-A-8-357191, JP-A-9-117529, and the like.
A positive type dye image forming compound can also be used. In this case, a negative silver halide emulsion may be used as the silver halide emulsion. Examples thereof include JP-A-4-156542, JP-A-4-155332, JP-A-4-172344, JP-A-4-172450, JP-A-4-318844, JP-A-356046, and JP-A-5-45824. Gazette, 5-45825 gazette, 5-53279 gazette, 5-107710 gazette, 5-241302 gazette, 5-107708 gazette, 5-232659 gazette, and U.S. Pat. No. 192,649.

  These compounds can be dispersed by the method described in JP-A-62-215272, pages 144-146. These dispersions may contain the compounds described in JP-A-62-215272, pages 137 to 144. Specific examples of these dye image forming compounds include the following compounds. Dye in the following compounds represents a dye group, a dye group temporarily shortened in wavelength, or a dye precursor group.

(2) Silver halide emulsion The silver halide emulsion used in the present invention may be, for example, silver chloride, silver bromide, silver iodobromide, silver chlorobromide, silver chloroiodide or silver chloroiodobromide. In particular, a negative type silver halide emulsion that forms a latent image on the surface of silver halide grains, or an internal latent image type direct positive emulsion that forms a latent image inside silver halide grains is preferred.

  The negative type emulsion that forms a latent image on the surface of the silver halide grain may be a so-called core-shell emulsion having a phase different from that of the inside of the grain and the surface of the grain, and silver halides having different compositions are joined by epitaxial joining. May be. The silver halide emulsion may be monodispersed or polydispersed, and a method of adjusting the gradation by mixing monodispersed emulsions as described in JP-A-1-167743 and 4-223463 is also used.

  The crystal habit of silver halide grains has regular crystals such as cubes, octahedrons, tetradecahedrons, spherical crystals, irregular crystal systems such as high aspect ratio flat plates, twins Any of those having a crystal defect such as a plane, a composite system thereof, or the like may be used.

  Specifically, US Pat. No. 4,500,626, column 50, 4,628,021, Research Disclosure Journal (hereinafter abbreviated as RD) No. 17, 029 (1978), ibid. 17, 643 (December 1978) 22-23, the same No. 18, 716 (November 1979) 648, ibid. 307, 105 (November 1989) 863-865, JP-A-62-253159, JP-A-64-13546, JP-A-2-236546, JP-A-3-110555, and Grafkide, "Photograph Physics and Chemistry". Published by Paul Monte (P. Glafkides, Chemie et Pisique Photographique, Paul Montel, 1967), "Photoemulsion Chemistry" by Duffin, published by Focal Press (GF Duffin, Photographic Emulsion Chemistry, Focal Press, 1966), Halogens prepared using the method described in “Production and coating of photographic emulsions” by Zelikman et al., Published by Focal Press (V. L. Zelikman et al., Making and Coating Photographic Emulsion, Focal Press, 1964), etc. Any silver halide emulsion can be used.

  In the process of preparing a photosensitive silver halide emulsion, it is preferable to perform so-called desalting to remove excess salt. As a means for this, a Nudell water washing method in which gelatin is gelled may be used, and inorganic salts (for example, sodium sulfate) composed of polyvalent anions, anionic surfactants, anionic polymers (for example, polystyrene sulfonic acid) Sodium), or a precipitation method using a gelatin derivative (for example, aliphatic acylated gelatin, aromatic acylated gelatin, aromatic carbamoylated gelatin, etc.) may be used. A sedimentation method is preferably used.

The photosensitive silver halide emulsion used in the present invention may contain, for example, heavy metals such as iridium, rhodium, platinum, cadmium, zinc, thallium, lead, iron and osmium for various purposes. These compounds may be used alone or in combination of two or more. The amount added depends on the purpose of use, but is generally about 10 ⁻⁹ to 10 ⁻³ mol per mol of silver halide. Moreover, when making it contain, you may put in a particle | grain uniformly and you may make it local in the inside and surface of particle | grains. Specifically, emulsions described in JP-A-2-236542, 1-116637, and 5-181246 are preferably used.

  In the grain formation stage of a light-sensitive silver halide emulsion, rhodan salts, ammonia, tetrasubstituted thioether compounds, organic thioether derivatives described in JP-B-47-11386 or JP-A-53-144319 are described as silver halide solvents. Sulfur-containing compounds can be used.

  Other conditions are described in the above-mentioned Graffkide, "Photo Physics and Chemistry" published by Paul Monte (P. Glafkides, Chemie et Pisique Photographique, Paul Montel, 1967), Duffin's "Photo Emulsion Chemistry", Focal Press ( GF Duffin, Photographic Emulsion Chemistry, Focal Press, 1966), “Production and Coating of Photographic Emulsions” by Zerikman et al., Published by Focal Press (V. L. Zelikman et al., Making and Coating Photographic Emulsion, Focal Press , 1964). That is, any of an acidic method, a neutral method, and an ammonia method may be used, and any one of a one-side mixing method, a simultaneous mixing method, and a combination thereof may be used as a form for reacting a soluble silver salt and a soluble halogen salt. In order to obtain a monodisperse emulsion, a simultaneous mixing method is preferably used. A backmixing method in which grains are formed in the presence of excess silver ions can also be used. As one type of the simultaneous mixing method, a so-called controlled double jet method in which pAg in a liquid phase in which silver halide is generated is kept constant can be used.

  In order to accelerate grain growth, the addition concentration, addition amount, and addition rate of silver salt and halogen salt to be added may be increased (Japanese Patent Laid-Open Nos. 55-142329, 55-158124, US Pat. No. 3,650,757). etc). Furthermore, the stirring method of the reaction solution may be any conventional stirring method. Further, the temperature and pH of the reaction solution during the formation of silver halide grains may be set in any manner according to the purpose. A preferred pH range is 2.3 to 8.5, more preferably 2.5 to 7.5.

The light-sensitive silver halide emulsion is usually a chemically sensitized silver halide emulsion.
For chemical sensitization of light-sensitive silver halide emulsions, known emulsions for light-sensitive materials include known sulfur sensitizing methods, selenium sensitizing methods, chalcogen sensitizing methods such as tellurium sensitizing methods, gold, platinum, palladium, etc. The noble metal sensitizing method and the reduction sensitizing method to be used can be used alone or in combination (for example, JP-A-3-110555, JP-A-5-241267, etc.). Such chemical sensitization can also be performed in the presence of a nitrogen-containing heterocyclic compound (Japanese Patent Laid-Open No. 62-253159). An antifoggant can be added after the chemical sensitization. Specifically, the methods described in JP-A-5-45833 and JP-A-62-240446 can be used. The antifoggant represented by formula (A) used in the present invention is preferably added at the end of chemical sensitization.

The pH during chemical sensitization is preferably 5.3 to 10.5, more preferably 5.5 to 8.5, and the pAg is preferably 6.0 to 10.5, more preferably 6.8 to 9.0. The coating amount of the photosensitive silver halide used in the present invention is in the range of 1 mg / m ^{2 to} 10 g / m ^{2 in} terms of silver, and preferably 10 mg / m ^{2 to} 10 g / m ² .

  In order to give the photosensitive silver halide used in the present invention green sensitivity, red sensitivity, and blue sensitivity, the photosensitive silver halide emulsion is spectrally sensitized with methine dyes and the like. Moreover, you may give infrared-sensitive spectral sensitization as needed.

  The dyes used include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes. Specific examples include sensitizing dyes described in U.S. Pat. No. 4,617,257, JP-A-59-180,550, JP-A-64-13546, JP-A-5-45828, and JP-A-5-45834. Is mentioned. These sensitizing dyes may be used alone, or a combination thereof may be used, and the combination of sensitizing dyes is often used for the purpose of adjusting the wavelength of supersensitization or spectral sensitization.

In addition to the sensitizing dye, a dye that does not itself have spectral sensitizing action or a compound that does not substantially absorb visible light and exhibits supersensitization may be contained in the emulsion (for example, US Pat. 615,641, JP-A-63-23145, etc.). These sensitizing dyes may be added to the emulsion before or after chemical ripening, or before or after nucleation of silver halide grains according to US Pat. Nos. 4,183,756 and 4,225,666. Good. These sensitizing dyes and supersensitizers may be added in a solution of an organic solvent such as methanol, a dispersion such as gelatin, or a surfactant solution. The amount added is generally about 10 ^-8 to 10 ^-2 mole per mole of silver halide.

  Internal latent image type direct positive emulsions include, for example, so-called “conversion type” emulsions made by utilizing the difference in solubility of silver halide, metal ions doped, chemically sensitized, or both. There is a “core / shell type” emulsion in which at least the photosensitive sites of the inner core (core) grains of the silver halide applied are coated with an outer shell (shell) of silver halide. 592,250, 3,206,313, British Patent 1,027,146, US Patents 3,761,276, 3,935,014, 3,447,927, 2, 297,875, 2,563,785, 3,551,662, 4,395,478, West German Patent 2,728,108, US Pat. No. 4,431,730, etc. ing

  When an internal latent image type direct positive emulsion is used, it is necessary to give surface fog nuclei using light or a nucleating agent after image exposure. As the nucleating agent therefor, hydrazines described in US Pat. Nos. 2,563,785 and 2,588,982, hydrazines and hydrazones described in US Pat. No. 3,227,552, UK Patent 1,283,835, JP-A-52-69613, US Patent 3,615,615, 3,719,494, 3,734,738, 4,094,683, Heterocyclic quaternary salt compounds described in U.S. Pat. No. 4,115,122, and sensitizing dyes having a nucleating substituent described in U.S. Pat. No. 3,718,470 in dye molecules, U.S. Pat. , 030,925, 4,031,127, 4,245,037, 4,255,511, 4,266,013, 4,276,364, British Patent 2, 012,443 etc. Thiourea-linked acylhydrazine compounds and heterocyclic groups such as thioamide rings, triazoles, and tetrazoles described in US Pat. Nos. 4,080,270, 4,278,748, British Patent 2,011,391B, etc. An acyl hydrazine-based compound in which is bonded as an adsorbing group is used.

  In the present invention, a spectral sensitizing dye can be used in combination with these negative emulsion and internal latent image type direct positive emulsion. Specific examples thereof include JP-A-59-180550, JP-A-60-140335, Research Disclosure (RD) 17029, U.S. Pat. No. 1,846,300, JP-A-2,078,233, JP-A-2,089, No. 129, No. 2,165,338, No. 2,231,658, No. 2,917,516, No. 3,352,857, No. 3,411,916, No. 2,295,276 2,481,698, 2,688,545, 2,921,067, 3,282,933, 3,397,060, 3,660,103, 3,335,010, 3,352,680, 3,384,486, 3,623,881, 3,718,470, 4,025,349, etc. ing.

(3) Structure of photosensitive layer The above-described dye image-forming compound which provides a dye having a selective spectral absorption in the same wavelength range as that of the emulsion spectrally sensitized by the spectral sensitizing dye for reproducing a natural color by the subtractive color method And a photosensitive layer comprising at least two of the combinations.
The emulsion and the dye image-forming compound may be applied as separate layers, or may be mixed and applied as a single layer. When the dye image-forming compound is coated and has absorption in the spectral sensitivity range of the emulsion combined therewith, a separate layer is preferred. The emulsion layer may be composed of a plurality of emulsion layers having different sensitivities, and an arbitrary layer may be provided between the emulsion layer and the dye image forming compound layer. For example, a layer containing a nucleation development accelerator described in JP-A-60-173541, a partition layer described in JP-B-60-15267 is provided to increase the color image density, or a reflective layer is formed. The sensitivity of the provided photosensitive element can also be increased.

Such a reflective layer is a layer containing a white pigment and a hydrophilic binder. Preferably, the white pigment is titanium oxide and the hydrophilic binder is gelatin. The coating amount of titanium oxide is preferably from ^{0.1g / m 2 ~8g / m 2} , more preferably from ^{0.2g / m 2 ~4g / m 2} . An example of the reflective layer is described in JP-A-60-91354.

In the multilayer structure of the photosensitive layer in the present invention, it is preferable that the combination unit of the blue-sensitive emulsion, the combination unit of the green-sensitive emulsion, and the combination unit of the red-sensitive emulsion are sequentially arranged from the exposure side. Arbitrary layers can be provided between the respective emulsion layer units as required. In particular, it is preferable to provide an intermediate layer in order to prevent the undesired influence of the development effect of a certain emulsion layer on other emulsion layer units.
In the present invention, an irradiation prevention layer, a UV absorber layer, a protective layer and the like are coated as necessary.
The thickness of the photosensitive layer in the present invention is not particularly limited.

II. Transparent cover sheet In the color diffusion transfer film unit of the present invention, it is preferable to have a neutralizing function on the transparent cover sheet.
F) Support The support of the cover sheet used in the present invention may be any smooth transparent support that is usually used for photographic materials, and cellulose acetate, polystyrene, polyethylene terephthalate, polycarbonate, etc. are used, and an undercoat is used. It is preferred to provide a layer. The support preferably contains a trace amount of dye to prevent light piping.

G) Layer having a neutralization function The layer having a neutralization function (neutralization layer) used in the present invention contains an acidic substance in an amount sufficient to neutralize the alkali introduced from the alkali treatment composition described later. It may be a layer having a multilayer structure composed of layers such as a neutralization rate adjusting layer (neutralization timing layer) and an adhesion reinforcing layer, if necessary.
A preferred acidic substance is a substance containing an acidic group having a pKa of 9 or less (or a precursor group that gives such an acidic group by hydrolysis), more preferably olein described in US Pat. No. 2,983,606. Higher fatty acids such as acids, polymers of acrylic acid, methacrylic acid or maleic acid and their partial esters or acid anhydrides as disclosed in US Pat. No. 3,362,819; French Patent 2,290 Copolymer of acrylic acid and acrylate ester as disclosed in US Pat. No. 4,699; Research Disclosure No. 4,139,383 and Research Disclosure No. Mention may be made of latex-type acidic polymers as disclosed in US Pat. No. 16102 (1977). In addition, U.S. Pat. No. 4,088,493, JP-A-52-153739, 53-1023, 53-4540, 53-4541, 53-4542, etc. Mention may also be made of the disclosed acidic substances.

  Specific examples of the acidic polymer (polymer acid) as the acidic substance include a copolymer of vinyl monomer such as ethylene, vinyl acetate, vinyl methyl ether, and maleic anhydride, and an n-butyl ester, butyl acrylate, and acrylic. Examples thereof include a copolymer with an acid, cellulose, and acetate / hydrodiene phthalate.

The acidic polymer can be used as a mixture with a hydrophilic polymer. Examples of such hydrophilic polymers include polyacrylamide, polymethylpyrrolidone, polyvinyl alcohol (including partially saponified products), carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, polymethyl vinyl ether, and the like. Of these, polyvinyl alcohol is preferred.
Further, a polymer other than the hydrophilic polymer such as cellulose acetate may be mixed with the acidic polymer.

  The coating amount of the polymer acid is adjusted by the amount of alkali in the alkali treatment composition described later. The equivalent ratio of polymer acid to alkali per unit area is preferably 0.9 to 2.0. If the amount of the polymer acid is too small, the hue of the transfer dye changes or stains are produced in the white background, and if it is too much, problems such as a change in hue or a decrease in light resistance occur. A more preferred equivalent ratio is 1.0 to 1.3. If the amount of the hydrophilic polymer to be mixed is too large or too small, the quality of the photograph is deteriorated. The mass ratio of the hydrophilic polymer to the polymer acid is 0.01 to 10, preferably 0.1 to 3.0.

  Additives can be incorporated into the layer having a neutralizing function in the present invention for various purposes. For example, hardeners well known to those skilled in the art to harden this layer, or polyhydric hydroxyl compounds such as polyethylene glycol, polypropylene glycol, glycerin, etc., can be added to improve the brittleness of the film. In addition, an antioxidant, a fluorescent brightening agent, a development inhibitor, and a precursor thereof can be added as necessary.

  In the present invention, the neutralization timing layer used in combination with the neutralization layer is an alkali such as gelatin, polyvinyl alcohol, partially acetalized polyvinyl alcohol, cellulose acetate, partially hydrolyzed polyvinyl acetate, or the like. Polymers that lower the permeability, latex polymers that are made by copolymerizing a small amount of a hydrophilic comonomer such as an acrylic acid monomer and that increase the activation energy of alkali permeation, or polymers having a lactone ring are useful.

  Of these, cellulose acetate disclosed in JP-A-54-136328, U.S. Pat. No. 4,267,262, U.S. Pat. No. 4,009,030, U.S. Pat. Timing layer, JP-A-54-128335, JP-A-56-69629, JP-A-57-6843, U.S. Pat. No. 4,056,394, JP-A-4,061,496, JP-A-4,199, No. 362, No. 4,250,243, No. 4,256,827, No. 4,268,604, etc. are copolymerized with a small amount of a hydrophilic comonomer such as acrylic acid. Latex polymer produced, polymer having monoacrylic acid ester or monomethacrylic acid ester of polyhydric alcohol disclosed in JP-A-11-2890 Polymers having a lactone ring disclosed in US Pat. No. 4,229,516, other JP-A-56-25735, JP-A-56-97346, JP-A-57-6842, European Patent (EP) 31, The polymers disclosed in 957A1, 37,724A1, 48,412A1, etc. are particularly useful.

In addition, those described in the following documents can also be used.
U.S. Pat. Nos. 3,421,893, 3,455,686, 3,575,701, 3,778,265, 3,785,815, 3,847 No. 4,615, No. 4,088,493, No. 4,123,275, No. 4,148,653, No. 4,201,587, No. 4,288,523, No. 4,297,431, West German Patent Application (OLS) No. 1,622,936, No. 2,162,277, Research Disclosure 15162, no. 151 (1976).
The neutralization timing layer using these materials can be used as a single layer or as a combination of two or more layers.

  Further, for example, US Pat. No. 4,009,029, West German Patent Application (OLS) 2,913,164, US Pat. 54-155837, 55-138745, etc., development inhibitors and / or precursors thereof, hydroquinone precursors disclosed in US Pat. No. 4,201,578, and other useful photographs. It is also possible to incorporate additives for use or precursors thereof. Furthermore, providing a neutralizing layer as described in JP-A Nos. 63-168648 and 63-168649 as the layer having the neutralizing function reduces the change in transfer density over time after processing. This is effective.

H) Others The cover sheet in the present invention may have a back layer, a protective layer, a filter dye layer, and the like as a layer having an auxiliary function in addition to the layer having a neutralizing function.
The back layer is provided for adjusting curl and imparting slipperiness. Filter dyes may be added to this layer.
The protective layer is mainly used to prevent adhesion to the cover sheet back surface and adhesion to the photosensitive material protective layer when the photosensitive material and the cover sheet are overlapped. The sensitivity of the photosensitive layer can be adjusted by incorporating a dye into the cover sheet.
The filter dye may be added directly to the support of the cover sheet or the layer having a neutralizing function, and further to the back layer, protective layer, capture mordant layer, etc., or a single layer may be provided. .

III. Alkaline Processing Composition In the present invention, the alkali processing composition is uniformly spread on the photosensitive element after exposure of the photosensitive sheet (photosensitive element), and is (A) the back side of the support or the side opposite to the processing solution in the photosensitive layer. The photosensitive layer is completely shielded from external light, and at the same time, the photosensitive layer is developed with the components contained therein. For this purpose, the composition contains an alkali, a thickener, a light-shielding agent, a developer, a development accelerator for controlling development, a development inhibitor, and an antioxidant for preventing deterioration of the developer. Etc. A light-shielding agent is always included in the composition for light-shielding.

These alkali processing compositions are preferably developed on the photosensitive element with a development thickness (a processing liquid amount per m ² after transferring the processing liquid) of 10 μm to 200 μm. The processing temperature for processing the photosensitive element is preferably 0 to 50 ° C, more preferably 0 to 40 ° C.

  The alkali is sufficient to adjust the pH of the liquid to 12 or more, such as an alkali metal hydroxide (for example, sodium hydroxide, potassium hydroxide, lithium hydroxide), an alkali metal phosphate (for example, potassium phosphate). , Guanidines and hydroxides of quaternary amines (for example, tetramethylammonium hydroxide), among which potassium hydroxide and sodium hydroxide are preferable.

  The thickener is necessary to uniformly develop the processing composition and to maintain adhesion between the photosensitive layer / cover sheet. For example, an alkali metal salt of polyvinyl alcohol, hydroxyethyl cellulose, or carboxymethyl cellulose is used, and preferably hydroxyethyl cellulose or sodium carboxymethyl cellulose is used. As the light-shielding agent, any dye or pigment or a combination thereof may be used as long as it does not diffuse to the dye image-receiving layer and produce stain. A typical example is carbon black.

  As the preferred developer, any developer can be used as long as it cross-oxidizes the dye image-forming compound and does not substantially produce stain even when oxidized. Such developing agents may be used alone or in combination of two or more, or may be used in the form of a precursor. These developing agents may be contained in an appropriate layer of the photosensitive sheet or in the alkaline processing composition. Specific examples of the compound include aminophenols and pyrazolidinones. Among them, pyrazolidinones are particularly preferable because they generate less stain. For example, 1-phenyl-3-pyrazolidinone, 1-p-tolyl-4,4-dihydroxymethyl-3-pyrazolidinone, 1- (3-methyl-phenyl) -4-methyl-4-hydroxymethyl-3-pyrazolidinone, Examples include 1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidinone, 1-p-tolyl-4-methyl-4-hydroxymethyl-3-pyrazolidinone.

A development accelerator described in JP-A-62-215272, pages 72 to 91, a hardener described in pages 146 to 155, or a surfactant described in pages 201 to 210, in any one of a photosensitive sheet, a cover sheet and an alkali processing composition. A fluorine-containing compound described on pages 210-222, a thickener described on pages 225-227, an antistatic agent described on pages 227-230, a polymer latex described on pages 230-239, a matting agent described on page 240, and the like. Can do. Further, tertiary amine latexes described in JP-A-6-273907, JP-A-7-134386, JP-A-7-175193, and JP-A-7-287372 can be included.
The thickness of the diffusion transfer film unit of the present invention is not particularly limited.

  For details of the heat-developable color photographic material (dye fixing element) in which the dye image-forming compound of the present invention is used and the exposure / heating method and apparatus to be applied, see, for example, [0128] to [0159] of JP-A-7-219180. 〕It is described in. A preferred exposure method is a method in which exposure is performed using an exposure head having different light sources that emit light in a plurality of specific wavelength regions.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.
Example 1
1. Preparation of photosensitive sheet First, photosensitive elements (photosensitive sheet-101) having the compositions shown in Tables 1 to 4 below were prepared. The emulsions in the table were prepared by the method shown in Table 5.

  The compounds used for the emulsion preparation are summarized below.

  The compound used for preparation of the photosensitive element (Photosensitive sheet-101) is shown below.

2. Production of Cover Sheet A polyethylene sheet having a thickness of 75 μm was coated on a transparent transparent support of polyethylene terephthalate to form a cover sheet 101 as shown in Table 6.

  The chemical structural formulas and the like of the compounds used in the cover sheet are shown below.

3. Production of Alkali Treatment Composition Next, an alkali treatment composition (treatment liquid 101) having the following composition was produced.
Carbon black (manufactured by Dainichi Seika Co., Ltd.) 224.3g
Additive (23) 12.1 g
Carboxymethylcellulose Na salt 43.0g
Potassium sulfite (anhydrous) 1.90 g
1-phenyl-4-hydroxymethyl-4-methyl-3-pyrazolidone
13.6g
Potassium hydroxide 52.7g
Zinc nitrate 0.60g
Water was added in a total amount of 1 kg. Each treatment liquid having the above composition was filled in 0.3 g at a pressure-breakable container.

  Photosensitive sheets 102 to 105 were prepared in the same manner as the photosensitive sheet 101 except that the third layer (intermediate layer, see Table 4) of the photosensitive sheet 101 was changed to the layer shown in Table 7 below.

* 1 Metal fine particles: Silver ink (water dispersion) manufactured by Sumitomo Electric Industries, Ltd.
(Average particle size 30 nm, coating amount is described in terms of silver)
* 2 Polymer surfactant: manufactured by Kao Corporation * 3 Light-reflective organic compound (solid dispersion with an average particle size of 0.1 μm)
* 4 Swellable inorganic layered compound: ME100 manufactured by Corp Chemical Co.
(Average particle size 5μm, thickness 10nm)
* 5 Retroreflective light-reflecting beads: Union M series (average particle size 10 μm)

  Using the photosensitive sheets 101 to 105, the cover sheet 101, and the processing solution 101, color diffusion transfer photographic units 101 to 105 were produced by the method of JP-A-7-159931. After this color diffusion transfer photographic unit is loaded into the camera, it is exposed from the cover sheet side, developed by a pressure roller adjusted so that the processing liquid has a thickness of 55 μm between both materials, and color diffusion units 101-105. Were exposed and developed. The treatment was performed at 25 ° C., and the reflection density one day after the development treatment was measured with a color densitometer to obtain the highest density and the lowest density.

Samples 102 to 105 were prepared by adjusting the coating amount of the second layer (white light diffusion layer) of the photosensitive sheets 102 to 105 so that the minimum density was the same as that of the color diffusion unit 101 under the processing conditions.
In the same manner as described above, the color diffusion units 102 to 105 were prepared using the prepared photosensitive sheet, the cover sheet 101, and the processing liquid 101 (in green light, which is the region with the highest relative visibility). The concentration was adjusted by measurement). The prepared sample was exposed to white light and processed in the same manner as the above processing method. The yellow density of each unit after processing was measured over time, and the time when the yellow density exceeded 1.6 was examined. Table 8 shows the coating amount of the second layer (white light diffusion layer) 102 to 105 as a ratio with respect to the coating amount of the color diffusion unit 101, and further shows the time when the yellow density exceeds 1.6.

  From Table 8, it was found that the white color of the unexposed area can be maintained with a small amount of titanium dioxide by using the light reflective fine particles of the present invention. Further, it was found that the transfer progress can be accelerated while maintaining the same white background.

(Example 2)
In the color diffusion transfer photographic unit production method of Example 1, the photosensitive element was changed to the photosensitive sheet 201, and a unit in which the developed thickness of the processing liquid was changed was produced, and the effect was evaluated.

  First, photosensitive elements (photosensitive sheet 201) having the compositions shown in Tables 9 to 11 below were prepared.

  The compound used for preparation of the photosensitive element (photosensitive sheet 201) is shown below.

  Three types of silver halide emulsions, surface latent image type emulsions J, K, and L, were prepared by the following preparation method and used. Table 12 summarizes the results.

Emulsion-K:
In 0.7 liter of gelatin aqueous solution containing 1.1 g of low molecular weight gelatin having 0.005 mol of potassium bromide and an average molecular weight of 20,000 or less, 26.5 ml of silver nitrate aqueous solution having a concentration of 0.58 mol / liter and 0.42 mol of potassium bromide 46.4 ml of an aqueous solution containing 1.5% by weight of a low molecular weight gelatin having an average molecular weight of 20,000 or less was mixed at the same time by virtue of the double jet method over 1 minute (first addition). During this time, the gelatin aqueous solution was kept at 35 ° C. After adding 0.5 g of potassium bromide, the temperature was raised to 75 ° C. with a gradient of 1.5 ° C. per minute.
After reaching a temperature of 75 ° C., 0.16 liters of gelatin solution containing 16% by mass of deionized gelatin having a Ca content of 100 ppm or less (first addition) and 5 ml of 4.9% sulfuric acid aqueous solution were added. Subsequently, a double jet of an aqueous silver nitrate solution with a concentration of 1.88 mol / liter and an aqueous potassium bromide solution with a concentration of 1.88 mol / liter at an accelerated flow rate (the flow rate at the end is 3.5 times the flow rate at the start). (The second addition, the amount of silver nitrate aqueous solution used was 366 ml, and the amount of potassium bromide aqueous solution was 375 ml).

  Next, 0.08 liter of gelatin solution containing 14% by mass of deionized gelatin having a Ca content of 100 ppm or less (second addition) and 2 mg of sodium benzenethiosulfate were added. Subsequently, an aqueous solution of silver nitrate with a concentration of 1.88 mol / liter and an aqueous solution of potassium bromide with a concentration of 1.88 mol / liter are double jetted at an accelerated flow rate (the flow rate at the end is 1.2 times the flow rate at the start). (Added for the third time, the amount of silver nitrate aqueous solution used was 157 ml, and the amount of potassium bromide aqueous solution was 163 ml).

After adding 4.6 g of potassium bromide, it was washed with water by a conventional flocculation method, deionized gelatin, 2-phenoxyethanol and methyl p-hydroxybenzoate were added, and then adjusted to pH 5.8 and pAg 8.8. The emulsion was adjusted to contain 1.35 mol of silver and 84 g of gelatin per 1 kg of the emulsion. 0.74 kg of the emulsion thus prepared was dissolved by heating and heated to 55 ° C., then 0.5 g of potassium iodide, 4.2 × 10 ⁻⁴ mol of sensitizing dye (6), and sensitizing dye. 5.4 × 10 ⁻⁴ mol of (7) was added and aging was performed for 30 minutes. Next, 5.0 × 10 ⁻⁴ mol of potassium thiocyanate, 1.4 × 10 ⁻⁵ mol of potassium tetrachloroaurate, and 1.2 × 10 ⁻⁵ mol of sodium thiosulfate were added and aged for 60 minutes. Emulsion preparation was completed by adding 1.0 × 10 ⁻³ mol of Compound E-4 and further adding 3.2 × 10 ⁻⁴ mol of Compound E-5 at the end of ripening.

  The diameter of a circle having an area equal to the projected area when viewed from the main plane direction of each particle is called a circle equivalent diameter. As a result of observation by an electron microscope, the average value of the particle thickness hi (= Σhi × ni / Σni) was 0.135 μm, and the average value of the equivalent circle diameter Di of the particles (= ΣDi × ni / Σni) was 1.15 μm. The average aspect ratio defined by the average value of the equivalent circle diameter Di / the average value of the particle thickness hi was 8.5.

Emulsion-J:
Emulsion-J was prepared by adding 9.2 × 10 ⁻⁴ mol of sensitizing dye (9) instead of sensitizing dye (6) and sensitizing dye (7) in the preparation method of emulsion-K. .

Emulsion-L:
In the preparation method of Emulsion-K, sensitizing dye (1) is 8.4 × 10 ⁻⁴ mol instead of sensitizing dye (6) and sensitizing dye (7), and sensitizing dye (2) is 2.6. Emulsion-L was prepared by adding .times.10.sup.- ⁵ mol and sensitizing dye (3) to 1.7.times.10.sup.- ⁴ mol.

  The compounds used for the emulsion preparation are summarized below.

  Photosensitive sheets 202 to 205 were prepared in the same manner as the photosensitive sheet 201 except that the third layer (intermediate layer, see Table 12) of the photosensitive sheet 201 was changed to the layer shown in Table 7 above.

Using the photosensitive sheets 201 to 205, the cover sheet 101, and the processing solution 101, color diffusion transfer photographic units 201 to 205 were produced by the method of JP-A-7-159931. This color diffusion transfer photographic unit was subjected from exposure to development processing with an exposure development processing machine incorporating a three-color LED exposure machine of blue, green and red. After the color diffusion transfer photographic units 201 to 205 are loaded into the exposure development processor, the LED is exposed from the cover sheet side using the LED as a light source, and developed by a pressure roller adjusted so that the processing liquid has a thickness of 38 μm between both materials. Then, the units 201 to 205 were exposed and developed. The treatment was performed at 25 ° C., and after 5 minutes from the development treatment, the reflection density after 1 day was measured with a color densitometer to obtain the maximum density and the minimum density.
After this color diffusion transfer photographic unit is loaded into the camera, it is exposed from the cover sheet side and developed by a pressure roller adjusted so that the processing liquid has a thickness of 55 μm between both materials. Development was performed. The treatment was performed at 25 ° C., and the reflection density one day after the development treatment was measured with a color densitometer to obtain the highest density and the lowest density.

Samples 202 to 205 were prepared by adjusting the coating amount of the second layer of the photosensitive sheets 202 to 205 so that the minimum density was the same as that of the unit 201 under the processing conditions.
In the same manner as described above, the color diffusion units 202 to 205 were prepared using the prepared photosensitive sheet, the cover sheet 101, and the processing liquid 101 (in green light, which is the region with the highest relative luminous sensitivity). The concentration was adjusted by measurement).
The prepared sample was exposed to white light and processed in the same manner as the above processing method. The yellow density of each unit after processing was measured over time, and the time when the yellow density exceeded 1.6 was examined.
Table 15 shows the coating amount of the second layer of the color diffusion units 202 to 105 as a ratio with respect to the coating amount of 101, and further shows the time when the yellow density exceeds 1.6.

From Table 15, even when the negative type silver halide emulsion is used and exposure is performed using an exposure head having different light sources that emit light in a plurality of specific wavelength ranges, by using the light-reflecting fine particles of the present invention, a small amount of dioxide dioxide can be obtained. It was found that the white amount of the unexposed part can be maintained with the amount of titanium. Further, it was found that the transfer progress can be accelerated while maintaining the same white background.

Claims (8)

  A photosensitive sheet having a silver halide emulsion layer combined with an image receiving layer, a white light diffusing layer, a light shielding layer, and a dye image forming material on a transparent support, and a transparent having a neutralization layer and a neutralization timing layer on the support A diffusion transfer film unit arranged to be exposed through a transparent cover sheet, comprising a cover sheet, and a carbon black-containing alkali treatment composition developed between the photosensitive sheet and the transparent cover sheet. A diffusion transfer film unit comprising a light-reflecting fine particle-containing layer between a white light diffusion layer and a light shielding layer in the photosensitive sheet.   2. The diffusion transfer film unit according to claim 1, wherein the light reflective fine particles are metal fine particles.   2. The diffusion transfer film unit according to claim 1, wherein the light reflective fine particles are a light reflective organic compound.   2. The diffusion transfer film unit according to claim 1, wherein the light reflecting fine particles are retroreflective light reflecting beads.   2. The diffusion transfer film unit according to claim 1, wherein the light-reflecting fine particles are a swellable inorganic layered compound.   The diffusion transfer film unit according to any one of claims 1 to 5, wherein the silver halide emulsion in the diffusion transfer film unit photosensitive sheet is a negative type silver halide emulsion. Diffusion transfer film unit.   The diffusion transfer film unit according to any one of claims 1 to 5, wherein the silver halide emulsion in the diffusion transfer film unit photosensitive sheet is an internal latent image type direct positive silver halide emulsion. Diffusion transfer film unit characterized by 8. The diffusion transfer film unit according to claim 1, wherein the diffusion transfer film unit is exposed using an exposure head having different light sources that emit light in a plurality of specific wavelength regions. unit.