JPH0456968B2 - - Google Patents

Description

[Detailed description of the invention]

(A) Industrial Application Field The present invention relates to a photosensitive material for silver complex diffusion transfer. In particular, the present invention relates to a light-sensitive material for silver complex diffusion transfer having a panchromatically color-sensitized silver halide emulsion layer. (B) Prior art and its problems The principle of silver complex diffusion transfer method (hereinafter referred to as DTR method) is described in US Pat. No. 2,352,014 and is well known. In the DTR method, an imagewise exposed silver halide emulsion layer is superimposed in contact with an image-receiving layer in the presence of a developing agent and a silver halide complexing agent. In the exposed parts of the silver halide emulsion layer, the silver halide is developed to silver (chemical development) and therefore it cannot be dissolved any further;
Can't spread. In the unexposed areas, the silver halides are converted to soluble silver complexes, which are transferred to the image-receiving layer, where they form a silver image, usually in the presence of physical phenomenon nuclei. In recent years, this type of DTR method has been widely used in graphic
It has been applied in the arts field and is increasingly being used in the block production process. In other words, it is possible to enlarge or reduce the size of an original manuscript using a simple plate-making camera called a graphics camera and a simple processor, or an integrated bright room camera processor, or to enlarge or reduce a photographic manuscript using a screen. It is used in the process of creating a block, such as obtaining a halftone image. The DTR material consists of a donor coated with photosensitive silver halide (also called negative), a receiver (also called positive) consisting of a non-photosensitive image-receiving layer, and a processing solution containing silver halide solution. be done. Donors with various functions are commercially available, such as high-sensitivity hard-tone negatives for camera photography, high-sensitivity reversal for camera photography, low-sensitivity negatives for close-contact use, and soft-tone negatives for continuous tone. Most of these materials have a green-sensitive spectral sensitivity, and therefore, when a color original is used as an original, they do not have photosensitivity to red images.
For example, when obtaining a black-and-white halftone image from a color photo original, red is reproduced as black, which does not suit the human sense that red is a bright neutral color. This is because it does not have the spectral sensitivity of red sensitivity.As a way to solve this problem, a panchromatically color-sensitized silver halide emulsion containing blue-, green-, and red-sensitive sensitizing dyes is used. It can be easily inferred that a coated light-sensitive material for diffusion transfer (donor) is used. As a result, there has been an increasing demand for high-sensitivity panchromatic negatives for applications such as screen photography from color photographic originals. Conventionally, silver chloride-based emulsions with an average grain size of 0.35 μm or less have often been used in light-sensitive materials for diffusion transfer in the DTR field. When blue-, green-, and red-sensitive sensitizing dyes are added to such an emulsion, the color tone becomes reddish and sepia-like, compared to when only green-sensitive sensitizing dyes are added, and the receiver film becomes This results in a disadvantage that the transmission density of This seems to be the result of an increase in the total amount of sensitizing dye, but if the total amount of sensitizing dye is reduced, the value as a high-sensitivity panchromatic negative will decrease. Even high-sensitivity panchromatic negatives currently on the market have these drawbacks. (C) Object and Structure of the Invention The inventors of the present invention have repeatedly conducted various studies in order to improve the color tone of halftone images and also improve the transmission density, and have found a method for improving these. That is, in a panchromatically color-sensitized silver halide emulsion containing blue-sensitive, green-sensitive and red-sensitive sensitizing dyes, the silver halide emulsion contains 95 mol%.
consisting of the above chloride, and the average size of the silver halide grains is in the range of 0.38μ or more and 0.6μ or less,
and more than 90% by weight of all particles are within ± of the average particle size.
The method is to use a light-sensitive material for diffusion transfer having a silver halide emulsion layer containing 40% or less of silver halide. Preferably, the silver halide emulsion is prepared by simultaneously mixing a silver salt aqueous solution and a halide aqueous solution in a hydrophilic colloid aqueous solution at the time of preparation, and the EAg value at the time of mixing is
The method is to use the above-mentioned light-sensitive material for diffusion transfer which is prepared with a value smaller than 130 mV. One object of the present invention is to provide a photosensitive material for high-sensitivity panchromatic diffusion transfer that provides a printing plate with good tone. Another object of the present invention is to provide a photosensitive material for highly sensitive panchromatic diffusion transfer that provides a printing plate with high transmission density. Other objects of the invention will become apparent from the following description. The silver halide grains used in the present invention have an average grain size in the range of 0.38 μm or more and 0.6 μm or less, and 90% by weight or more of the total grains are within ±40% of the average size. In the DTR treatment process, unexposed silver halide grains are
When contacted with a silver halide complexing agent, it is dissolved and diffusely transferred to the image-receiving layer, and it is generally believed that the rate of dissolution depends on the grain size and is generally faster as the grain size becomes smaller. This dissolution rate is also a factor that determines the color tone.The silver halide grains used in the present invention have an average grain size in the range of 0.38μ or more and 0.6μ or less, and have a narrow particle size distribution, and are blue. When combined with sensitive, green-sensitive and red-sensitive sensitizing dyes, favorable color tones were obtained. The silver halide emulsion used in the present invention is preferably a silver chloride, silver chlorobromide, silver chloroiodide, or silver chloroiodobromide emulsion containing 95 moles or more of chloride.
Emulsions mainly composed of silver chloride tend to have a fast chemical reaction rate and dissolution rate, and have poor color tone and transmission density.
Preferably, silver halide emulsions containing 95 mol % or less of chloride tend to have sepia color tone and low transmission density. The silver halide emulsion used in the present invention is prepared by simultaneously mixing an aqueous silver salt solution and an aqueous halide solution in an aqueous hydrophilic colloid solution, and the EAg value at the time of mixing is
More preferably, the voltage is adjusted to a value smaller than 130 mV. By combining the silver halide emulsion prepared under these conditions with blue-, green-, and red-sensitive sensitizing dyes, a highly sensitive material for panchromatic diffusion transfer with good color tone and high transmission density can be obtained. The blue-sensitive, green-sensitive and red-sensitive sensitizing dyes used in the present invention are known merocyanine dyes, cyanine dyes, or other sensitizing dyes. Preferred are those described in Japanese Patent Application No. 132278/1982. That is, at least one sensitizing dye represented by the following general formula [], at least one sensitizing dye represented by the general formula [], and at least one sensitizing dye represented by the general formula [] are combined. It is preferable. EAg measurement in this case is performed using a silver electrode or a silver sulfide electrode, and a silver chloride electrode as a reference electrode. Therefore, the EAg value is a value using a silver chloride electrode as a reference electrode. A saturating force Romel electrode can also be used as a reference electrode, in which case the EAg value will be as low as about 55 mV. General formula [] In formula [], Z ₁ has a substituent (-CH ₃ , CH ₃ O-, C, Br, I, CN,

〔Example〕

The present invention will be explained below using examples. Example 1 An aqueous solution of inert gelatin containing 2% bromide was prepared by simultaneously adding an aqueous solution of sodium chloride and potassium bromide and an aqueous silver nitrate solution at a rate of 4 ml/min while stirring vigorously while maintaining the aqueous solution of inert gelatin at 60°C. ,
Three types of silver chlorobromide monodisperse emulsions were prepared. The mixture was prepared while maintaining the EAg at 115 mV. These emulsion grains have average grain sizes of 0.3, 0.45,
The particle size was 0.65μ, the crystal habit was cubic, and more than 90% by weight of all the three types of particles were contained within ±40% of the average particle size. After these emulsions were precipitated, washed with water and redissolved, they were subjected to sulfur sensitization and gold sensitization using sodium thiosulfate and potassium chloroaurate. Next, 100 mg of the above-mentioned sensitizing dye (-2)/
mole Ag, (-9) 500mg/mole Ag, and
(-2) 300 mg/mole Ag was added, an antifoggant was added, a surfactant and a hardening agent were added to make it up. A 110 g/ ^m2 paper support coated on both sides with polyethylene was coated with 0.3 g/m2 on one side to prevent halation.
g/m ² carbon black, 1.0 g/m ² hydroquinone and 0.2 g/m ² 1-phenyl-4.4
- Gelatin 4 containing dimethyl-3-pyrazolidone
A subbing layer of 1.5 g/m ² of gelatin is applied above which an emulsion layer (gelatin 1.5 g/m ² ) having three average grain sizes according to Table 1 is applied. Both the undercoat layer and emulsion layer are adjusted to pH=4.0. A gelatin layer necessary for curl control is provided on the back side of the support, and the pH of this layer is set to 4.5. These samples were cut, exposed through a step wedge with a density of 0.05, and exposed to light using Mitsubishi Paper Mills One Step OS-PC100 (receiver film) and
In close contact with OS-IP (receiver paper), Mitsubishi Paper Mills One-Step Activator OS-AC
It was passed through a commercially available processor for DTR containing (processing liquid) and peeled off after 60 seconds. The treatment temperature was 23°C. The results are shown in Table 1.

[Table] As is clear from Table 1, sample 2 according to the present invention
had a high transmission density at PC100 and a good color tone at IP, but samples with a small average particle size and sample 3 with a large average particle size had a slightly lower transmission density at PC100 and a good color tone at IP. It wasn't good.
These results reveal that the light-sensitive material for diffusion transfer of the present invention provides a printing plate with high transmission density and good color tone. Example 2 For comparison, using the single jet method, the average particle size was 0.45μ, but
A silver chlorobromide emulsion (2 mole % bromide) was prepared in which 20% by weight of the total grains were not within ±40% of the average grain size. A coating sample was prepared using this emulsion in the same manner as in Example 1. (Sample 4) On the other hand, a similar sample was prepared according to Table 2 using the 0.45μ silver chlorobromide monodisperse emulsion of Example 1 (Sample 5), and the processing temperature was set to 30°C. The same treatment as above was carried out, and the results shown in Table 2 were obtained.

[Table] As is clear from Table 2-1, Sample 5 according to the present invention had a higher transmission density at PC100 and a more favorable color tone than Sample 4. These results reveal that the light-sensitive material for diffusion transfer of the present invention provides a printing plate with high transmission density and good color tone. Example 3 An aqueous solution of inert gelatin containing 2% bromide was prepared by simultaneously adding an aqueous solution of sodium chloride and potassium bromide and an aqueous silver nitrate solution at a rate of 4 ml/min while stirring vigorously while maintaining the aqueous solution of inert gelatin at 60°C. ,
Three types of silver chlorobromide monodispersed emulsions were prepared. These were prepared while maintaining the EAg value at the time of mixing according to Table 3. The average size of these emulsion grains is as shown in Table 3, and they are almost the same, the crystal habit is cubic, and more than 90% by weight of all the three types of grains are within ±40% of the average grain size. It was Hereinafter, an emulsion was prepared in the same manner as in Example 1, and a coated silver amount of 1.28 g/m ² was applied on a paper support provided with the same undercoat layer and backing layer as in Example 1. The results shown in Table 3 were obtained by applying the same coating as in Example 1 and carrying out the same treatment as in Example 1.

[Table] As is clear from Table 3, Samples 7 and 8, which correspond to preferred embodiments of the present invention, had high transmission density at PC100 and favorable color tone. On the other hand, sample 6
Compared to Samples 7 and 8, the transmission density at PC100 was slightly lower and the color tone was also slightly inferior.
Therefore, more favorable results were obtained by adjusting the EAg value during mixing to a value smaller than 130 mV.

Claims (1)

[Scope of Claims] 1. A panchromatically color-sensitized silver halide emulsion containing blue-sensitive, green-sensitive and red-sensitive sensitizing dyes, wherein the silver halide emulsion consists of 95 mol% or more of chloride. , the average size of the silver halide grains is in the range of 0.38μ or more and 0.6μ or less, and 90% by weight or more of all grains are ±40% of the average grain size.
A light-sensitive material for diffusion transfer having a silver halide emulsion layer contained within. 2. The silver halide emulsion is prepared by simultaneously mixing a silver salt aqueous solution and a halide aqueous solution in a hydrophilic colloid aqueous solution at the time of preparation, and the EAg value at the time of mixing is set to a value smaller than 130 mV, The light-sensitive material for diffusion transfer according to claim 1, which is prepared by: