JPS63253351A - Production of photographic material - Google Patents

Abstract

PURPOSE:To prevent generation of a coagulated product in a coating soln., and to prevent occurrence of tailing in the stage of coating multiple layers at the same time by a slide-hopper process by using a coating soln. contg. both gelatin having <=about 1,000ppm Ca concn. and at least one specified amphoteric compd. CONSTITUTION:Suitable gelatin to be used is one having <=about 1,000ppm Ca concn. and suitable amphoteric compd. to be used is one having an oleophilic atomic group comprising a >=5C alkyl group, aryl group, or aralkyl group in a moiety and a hydrophilic atomic group in another moiety of the molecule. Better result is obtained when the Ca concn. of the gelatin is low, and such gelatin having <=about 500ppm Ca concn. is preferred. By this constitution, generation of coagulated product is prevented, and occurrence of tailing in the stage of coating multiple layers at a same time by the slide-hopper process is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to a method for producing photographic materials, and also relates to a method for producing a coating solution that has excellent stability over time and that does not cause abnormalities during the coating process. It is something.

CB) Prior art and problems In recent years, as a coating method, simultaneous multi-layer coating technology using a slide hopper method has improved its efficiency and high speed coating.
It is making remarkable progress. In particular, the development of simultaneous coating technology for three or more layers is also remarkable. however,
It still has many problems.

One of the problems is the occurrence of Ashikaga. This is because when the coating liquid flows out in piles from the outflow part called the E-bar and adheres to the web, a difference in flow velocity occurs between each layer.
Shear stress occurs. At this time, if foreign matter or air bubbles are present in the layer, the distribution of the coating liquid will be disturbed, resulting in minute streaks called ashikaga. Where Ashikaga occurs, the uniformity of the material is impaired, resulting in unevenness, which naturally causes problems in practical use.
It becomes a big problem.

The present inventors have conducted various studies on the causes of Ashikaga. As a result, one of the causes of tail side generation is agglomerated products of gelatin or silver halide emulsion to form a layer (hereinafter simply referred to as "agglomerates") for those that are present in the coating solution. ) was found to be causing the core.

For the detailed mechanism of aggregate generation, please refer to
Although it is still under investigation, it is possible that aggregates are clearly observed to have already formed during the preparation of the coating solution, and in that case, Ashikaga formation can generally be seen even during application immediately after the preparation of the coating solution. . In addition, even if the coating is in good condition with no ashikaga occurring during application immediately after preparation, in many cases, the aggregates formed immediately after the preparation of the coating solution are so small that they have little influence on ashikaga at that point. However, as the coating liquid progresses over time in the coating process, the number and size of aggregates increase, causing a negative impact on Ashikaga.
The force also became large, and it was found that Ashikaga finally occurred and continued to increase.

Generally, gelatin is manufactured by solubilizing collagen, the main component of animal skin and bones, in hot water, but it is difficult to extract the raw material immediately into hot water, so it is manufactured using industrial methods. In this method, collagen is partially hydrolyzed in advance by pre-treatment of immersing the raw material in milk of lime for 3 months in one layer, ie, a long-term pre-treatment called liming. In the case of beef bones, most of the inorganic components that occupy one layer or more of the raw material are calcium phosphate. When this is converted into soluble calcium dihydrogen phosphate using dilute hydrochloric acid and eluted, ossein whose main component is insoluble collagen remains. Since ossein is partially hydrolyzed by acid and lost, hydrochloric acid treatment is carried out under efficient conditions, and long-term treatment to remove calcium phosphate promotes the necessary hydrolysis of ossein, so this is the best option. processing is being carried out. Even in this case, the gelatin extracted after lime treatment has a fairly high concentration of calcium and other inorganic salts. For example, focusing on calcium, commercially available photographic gelatin usually contains 3,000 ppm to 5,000 ppm of calcium.

It is a fact that when at least one coating layer other than the bottom layer adjacent to the support is coated with a coating liquid prepared using photographic gelatin, which is extremely commonly used as described above, it is easy to cause rashes. The inventor's experiments have revealed this fact.

(C) Purpose of the Present Invention The purpose of the present invention is to prevent the occurrence of footing during multilayer simultaneous coating using a slide hopper method.

Another object of the present invention is to prevent the generation of agglomerated products that cause foot ulcers.

Other objects of the invention will become apparent from the following description.

CD) Structure of the Invention In order to compensate for the above-mentioned drawbacks, the inventors of the present invention have made extensive research and found that at least one layer, excluding the bottom layer adjacent to the support, is selected from gelatin with a calcium concentration of about 11,000 pp or less and an amphoteric compound described below. By using a coating liquid that coexists with at least one of The object of the present invention, which is to provide a manufacturing method that can produce photographic materials in a good and stable manner, has been achieved.

The gelatin used in the present invention has a calcium concentration of about 11,000 pp or less.

Furthermore, better results are obtained with lower calcium concentrations. For example, gelatin at about 500 ppm or less is preferred.

These gelatins can be purchased as commercially available products, and are usually available in the range of 3,000 to soo.

It can also be obtained by desalting gelatin with a calcium concentration of ppm.

Although it is preferred to use gelatin alone as a binder with a calcium concentration of about 11,000 pp or less, as long as the calcium concentration of the coating is less than about 11,000 pp.
It can be used in combination with ordinary gelatin, and hydrophilic synthetic resins such as polyvinyl alcohol, partially saponified polyvinyl alcohol, maleic anhydride copolymers (such as styrene-maleic anhydride copolymer, ethylene-maleic anhydride) can be used in combination with ordinary gelatin. copolymers, inbutylene-maleic anhydride copolymers, vinyl methyl ether/maleic anhydride copolymers, vinyl acetate-maleic anhydride copolymers, etc.), and combinations of these maleic anhydride copolymers with polyvinyl alcohol. Heated processed products, polyacrylamide, polyacrylic acid,
Poly-N-vinylpyrrolidone, emulsion polymerized synthetic resins (e.g., polyacrylic ester, polyacrylic acid, polymethacrylic acid, polymethacrylic ester,
(single or copolymer of polystyrene, polybutadiene, etc.)
Furthermore, it can be used in combination with carboxylmethyl cellulose, hydroxylethyl cellulose, sodium alginate, dextran, gum arabic, agar, starch and its conductor.

The amphoteric compound used in the present invention has a lipophilic atomic group consisting of an alkyl group, an aryl group, or an aralkyl group having 5 or more carbon atoms in the molecule, and a hydrophilic atomic group on one side. Specific examples are given below, but the present invention is not limited to these specific examples.

CH.

(CHI)I H3 The compound according to the present invention is an amphoteric compound having at least one alkyl group, aryl group, or aralkyl group having 5 or more carbon atoms in its lipophilic atomic group.

The alkyl group includes substituted alkyl groups such as fluorinated alkyl groups.

In order to incorporate the amphoteric compound used in the present invention into the coating liquid, it may be added as a solution in water or an organic solvent such as methanol, ethanol, acetone, etc. that is optionally miscible with water. A range of 0°01 to about 20t, preferably 0.05 to 10F is suitable. It may be added at any time before coating on a support or the like.

In the slide hopper coating according to the present invention, there is no particular limit to the flow rate ratio between each layer, but the following conditions are preferable. That is, (1) Take one layer interface of each layer to be coated and make sure that the ratio of the total flow rate from that interface to the upper layer/total flow rate from that interface to the lower layer is about 3/4 or less,
The flow rate ratio at each interface in the flow cross section of the coating liquid on the E bar should be approximately 4/3 or more.
It is preferable that the above conditions are met.

Furthermore, there is no particular range of viscosity between each layer. Now, the pseudo-Reynolds number Rtel is defined as shown in the following equation.

Rrel = Vmov/7 (1) V here
mov is the coating liquid flow rate, and is the viscosity.

Although it is preferable that the pseudo-Reynolds number of the G layer decreases from the lower layer to the upper layer, there is no simple relationship with this factor, and it is thought that a moderate number of cases will hold true.

The at least two layers other than the bottom layer adjacent to the support may be any layer, such as an anti-e-Noragelon layer,
If the silver halide emulsion layer is one filter layer, no silver halide (t[uJffi, intermediate layer and overlayer, for example) silver halide emulsion layer, the preparation method e.g. acidic method, neutral method, ammonia method, etc., halogen composition such as silver chloride, silver bromide, silver chlorobromide, and silver iodide as well as silver iodide, silver
In addition, it is a general negative emulsion or a US patent is, s
O1,305, 3.501,306, 3
．． No. 501,307, No. 3,531,290, etc., there are no particular restrictions on whether the emulsion is a direct positive emulsion or not. Additionally, if necessary, e.g.
Stabilizers, development accelerators, hardeners, thickeners, matting agents, and the like can be included in the coating liquid. Furthermore, even if those layers are, for example, anti-harassment training or over-jL, they can include machining in accordance with the function of the layer, and are not subject to any limitations.

There are no further restrictions on the bottom layer, and it may be any layer.

The present invention will be explained below with reference to examples.
It is not limited to these.

CB) Examples Example 1 (Emulsifier): Using lime-treated gelatin (gelatin A) with a calcium concentration of 4100 ppm, the gelatin concentration was 1%.
, silver to gelatin ratio 8:1 calculated as silver nitrate, silver chloride 95
A gelatin emulsion of Morch's silver chlorobromide having a cubic shape and an average particle size of 0.35 microns was prepared by a double jet method, coagulated and precipitated, and then washed with water. Furthermore, a gelatin solution was added, redissolved, and chemically ripened.

Gelatin A is desalinated to have a calcium concentration of 18 o
ppm c gelatin B), 740 ppm (gelatin C)
, 270 ppm (gelatin yD) was used in the same manner as above, except that emulsion B, emulsion C, and emulsion were prepared, respectively.

Next, each of these was divided into 5 parts, and the following surfactant and exemplified compound according to the present invention were added to each part, and a hardening agent was added to each part, so that the gelatin concentration was about 5.8 cm, and I'H
A finishing emulsion of 5.5 was prepared.

An undercoating solution was prepared with a gelatin concentration of 5.0 cm and P)I of 5.5, containing titanium oxide, a black pigment, a hardening agent, and the following surfactant.

Gelatin concentration 4 using gelatin B or gelatin C
．． The gelatin solutions Over B and Over C to which a hardening agent had been added were each divided into two, and the following surfactants and exemplified compounds were added to each of the gelatin solutions to obtain an over solution.

Each of the coating solutions prepared in this way was kept warm at 35° C. for 6 hours, and then coated using a slide-hopper type coater in the following combinations. Undercoat liquid 80%, emulsion 36%
It was applied in three skin configurations with a flow rate of 12 q/cm overflow.

Activator (a) Sodium hebutyl-a-sulfolarate activator ←) Nonadecane-10-sulfate compound (a) Exemplary compound (1) I (b) I (2) # (C) I (20) Coating liquid Are the amounts added to the coating liquid IKf? ) 31° The combinations of gelatin and activator or compound and emulsion layer and overlayer are shown below. In addition, the results of observing the coated surface of the photographic material obtained by coating were shown to determine whether or not the appearance of scabies occurred. The evaluation criteria for Ashikaga outbreak is that the heat generated is Ol, and if it occurs regardless of the degree, it is marked as ×.

(Left below) Table 1 From the results in Table 1, the calcium concentration of either the emulsion coating liquid or the overcoating liquid, or both, is approximately 1000 ppm.
When the coating liquid contained the following gelatin and the amphoteric compound according to the present invention, there was no sagging, and the photographic material was coated uniformly.

Example 2 An undercoat liquid was prepared in the same manner as in Example 1 except that gelatin C was used, and a surfactant (c) was added to prepare a coating liquid.

Activator (c) A cubic silver chlorobromide (silver chloride 95 mol%) gelatin emulsion with an average particle size of 0.3 microns was prepared by a sodium dodecylbenzenesulfonate double jet method, coagulated and precipitated, and then washed with water. did.

After redissolving this emulsion and adding gelatin, 0.2 caps of thiourea dioxide per mole of silver was added to give a pH of 7.0.6.
The mixture is aged at 0° C. for 60 minutes, then fi41q of potassium chloroaurate per mole of silver is added, and the mixture is aged for a further 60 minutes. The temperature was lowered to about 40° C., and 1 mole of silver was added to the above emulsion, which was adjusted to a pig of 7.8 with NaCl and the pH was lowered to 5.0.
Pinacryptol Yellow 400q and dye 3001q below were added. The gelatin used for emulsion preparation was A. Further, a hardening agent and compound (C) were added to prepare an emulsion coating solution having a gelatin concentration of about 5.4 and a pH of 5.5.

An over-solution was prepared in the same manner as in Example 1, except that gelatin A and gelatin D were used, and the following activators or compounds were added to prepare a coating solution.

The flow rate is 70 coats of undercoating liquid, 25 coats of emulsion, and 12 coats of overcoating liquid.
M fabrics were prepared in the same manner as in Example 1, except that the ratio was set to d/m'', and caudal development was evaluated. The combinations and results are shown in Table 2.

Compound (d) Exemplary compound (3)z (e)
z (4) 1 (f) I
(1B) From the results in Table 2, it can be seen that the photographic material coated with the over coating liquid containing gelatin D with a low calcium concentration and the amphoteric compound according to the present invention has no tail side occurrence and unevenness. It was an excellent direct positive silver halide photographic material with no oxidation.

Furthermore, after aging these coating solutions at 35°C for 6 hours (!il
When coating was carried out again in the same manner (12 hours after production), the photographic material prepared with the overcoating liquid containing gelatin D and the amphoteric compound according to the present invention still showed no occurrence of horse prickling. However, samples with other combinations showed an increased degree of horse bite.

Claims (1)

[Claims] In a method for producing a photographic material in which at least three layers of coating liquid are applied simultaneously by a slide hopper method, at least one layer adjacent to the support except for the bottom layer contains gelatin having a calcium concentration of about 1000 ppm or less and a carbon number in the molecule. 5
A method for producing a photographic material, comprising a lipophilic atomic group consisting of the above alkyl group, aryl group, or aralkyl group, and at least one amphoteric compound having a hydrophilic atomic group.