JPH0316008B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a photographic material, and more particularly to a method for melting a mass of a gel-like photographic material, mixing additives, etc., and transferring the melted mass.

For example, gel-like photographic silver halide emulsions are usually melted in a heated container. For this purpose, the gel-like base emulsion is transferred from the cooling chamber into a relatively small container and introduced into the melting container in the form of blocks each weighing approximately 1 kg. The heat required for melting is applied externally through the walls of the container. The temperature difference between the wall and the emulsion needs to be fairly large in order to avoid unduly long heating times and therefore batch times. This can only be achieved if the temperature of the container walls is significantly higher than the required final temperature of the emulsion. During the melting process, the emulsion is kept in constant motion by a stirrer to increase heat transfer. Despite that,
Approximately 3~ for containers in the 500~1000 liter capacity range
A batch time of 4 hours is common. After melting, the base emulsion is mixed with various photochemical additives. The additives impart properties to the photographic material, such as, for example, the sensitivity required for a particular region of the spectrum, stability during the coating operation, stability during storage as an intermediate or finished product after coating, and antifogging. . These additives generally need to be added in a certain order and at certain intervals to obtain the desired effect. Sample tests are then carried out to control the quality of the photographic material. After a sample test confirms the quality is acceptable, the melt is transferred to the coating process. By this time, approximately 5 hours are required from the start of the process. The capacity of the above container is approximately 500-1000
If it is a liter, the flow rate of the emulsion is about 2.5 liters per minute, and it takes an additional 3 to 6 hours to finish coating the entire emulsion. Thus, for some portions of the emulsion, approximately 10 hours elapse from the time of melting to the time of application. In contrast, an emulsion that is melted last in the melting process and coated first has a residence time of about 2 hours.

The most serious drawbacks of the batch process as described above are summarized as follows. That is,
Since the walls of the melting container reach a high temperature, the emulsion near the walls becomes overheated and the photographic properties deteriorate. Furthermore, variations in photographic properties between individual batches occur, making it difficult to produce uniform photographic materials. Also, the portion of the emulsion outside the gel-like mass of photographic material melts faster than the portion of the emulsion inside the mass of photographic material, resulting in differences in aging properties, especially for extremely sensitive color photographs. In the case of emulsions, the desired design performance cannot be maintained. The finished emulsion mixed with additives is
It remains in a sol state until it gels again after application.
At this time, the photographic properties change drastically, and if left in the sol state for a long time, the performance of the sensitive material will be impaired.For example, if the coater is not operated for a long time, the finished emulsion that has been left unused will become unusable, resulting in serious losses. occurs. Especially in the case of high-speed color emulsions, the so-called dissolution time must be kept as short as possible.
It has also been found that in order to obtain constant quality, the dissolution time should be uniform for all parts of the emulsion. The melting time is the time that elapses from when the emulsion is melted at a temperature of about 40°C until it is coated.

In Japanese Utility Model Publication No. 49-34816, a slit is formed at the bottom of a cylindrical body containing a gel-like substance, and a heating medium is sent to a heater having a conical slope to melt the gel-like substance and to release the gel-like substance from the slit. The molten liquid to be discharged is stored in a tank, the liquid level in the tank is detected by a detector, and the amount of heating medium sent to the heater is adjusted based on a signal from the detector. An apparatus for continuous melting of gel-like materials is disclosed. Although the device and method of the present invention are called continuous melting, considering that the melting is done in tank units, it is only a batch system in which only the melting process is continuous, and the efficiency of the heating melter is also affected by the heat transfer area. Since it is small, the heat transfer efficiency is low, and the melting time described above from 3 to 4 hours can only be shortened to 2 to 3 hours. or,
With the device of this invention, even if the feeding rate of the heating medium is adjusted,
Since the control response characteristics of the heating melter are poor, the controllability is not necessarily good.Furthermore, since there are two tanks of the same capacity, the area occupied by the device is also large.

JP-A No. 51-34713 discloses that in a continuous method for producing photographic materials, a gel-form silver halide emulsion is melted; and the melted emulsion is transferred to a continuous mixing means with a throughput equivalent to the melting speed of the emulsion. directly introducing; mixing the emulsion successively with each introduced additive before the next additive is introduced in the mixing means; and mixing the emulsion ready for casting. A method for producing a photographic material, characterized in that the emulsion is allowed to flow continuously from a means and thereafter immediately applied to a transfer web to be coated, and a cylindrical container, a container for melting the solid emulsion adjacent to the base of the container. a melting means equipped with a heating grid, the emulsion passing through an outlet at the bottom of the melting vessel according to the heat output of the grid such that the flow rate is equivalent to the throughput of the mixing means adjoining the melting means; BACKGROUND ART Continuous photographic material manufacturing apparatuses have been proposed that are equipped with means for controlling the flow rate. This publication states that according to the method and apparatus of the invention, a melting rate of 195 liters/hour is possible; however, the heating grid melting means has a low heat transfer efficiency of about 50%, so the apparatus is It is large-scale and causes various inconveniences in terms of occupied space, maintenance, etc., and also requires a storage section, so there remains a factor in the deterioration of photographic materials over time.

It is an object of the present invention to improve the drawbacks of the prior art and to provide a method for melting photographic materials that has high melting ability and high heat transfer efficiency.

Another object of the present invention is to provide a method for melting photographic materials in which the melt can be supplied to the next process without requiring a storage section, in order to prevent the equipment from increasing in scale due to improvements in melting ability and heat transfer efficiency. The goal is to provide the following.

This object of the present invention is achieved by a method for melting a photographic material, which is characterized in that a mass of gel-like photographic material is pulverized and melted using a heat exchanger while being continuously supplied.

Hereinafter, the present invention will be explained in more detail with reference to the accompanying drawings.

In FIG. 1, a gel-like photographic material 2 is stored in a cylindrical container 1, and while the gel-like photographic material 2 is crushed by a crusher 3 and heat exchanged by a feeder 4, it is transferred to a static mixer 6. and then mix in additives if necessary. In the heat exchange section 5 of the feeder 4, heat exchange is performed by hot water flowing from the hot water supply port 7a to the hot water discharge port 7b, and the crushed photographic material is thermally melted, and a gel-like material is formed. The photographic material is converted into a gel. The static mixer 6 is also provided with a hot water jacket around the hot water supply port 8a.
Supplementary heat exchange or heat retention is performed by hot water flowing from the hot water outlet 8b to the hot water outlet 8b.

As the crusher 3, a type is used in which the gel-like photographic material 2 is sandwiched between two rollers whose cross-sectional circumferences are machined with a blade shape or the like. In particular, a pulverizer constructed with two screw-shaped rollers showed good results. A screw conveyor, a snake conveyor, or the like is used as the feeder 4, and the screw conveyor can particularly prevent destruction of photographic performance due to shear stress. The static mixer 6 has a structure in which a stationary shaft having stirring supply blades of various shapes is provided in a supply pipe, and an additive supply port is provided as necessary.

When a photographic material is melted at a rate of about 3.5 liters per minute by the method of the present invention, the temperature of the hot water fed to the heat exchanger 5 may be 30 DEG C. to 60 DEG C., and the flow rate may be 20 liters to 60 liters per minute. For example, in FIG. 1, the hot water flowing from the hot water supply port 7a to the hot water supply port 7b is set at 50°C, and from the hot water supply port 8a to the hot water discharge port 8.
By setting the temperature of the hot water flowing through b to 40°C, quality deterioration can be prevented and efficient melting can be achieved.

When the gel-like photographic material mass 2 is crushed by the crusher 3, it is preferable that the size at the outlet of the crusher 3 is 10 cm ³ or less. By setting it to 10 cm ³ or less, there will be no trouble in transferring within the feeder 4 and static mixer 6, and the efficiency of heat exchange will be improved.

In the present invention, a flow rate measuring device is provided at the outlet of the static mixer 6, and the rotational speed of the feeder 5 and the static mixer 6 is determined based on the difference signal between the set amount of the setting device provided on the control panel and the measured flow rate. By performing the control, it becomes possible to adjust the melt supply amount with high responsiveness.

In the process of crushing and supplying gel-like photographic material mass according to the method of the present invention, so-called bubbles may be entrained, but as shown in FIG. vacuum chamber 10 connected to
By providing bubbles and performing defoaming, it becomes possible to obtain a bubble-free sol-like photographic material.

Gel-like photographic materials melted by the method of the present invention include, in addition to general photographic emulsions, emulsified dispersions used in the photographic industry, gelatin dispersions such as solid dispersions of dyes, and the like.

Gelatin is advantageously used as a binder or protective colloid in photographic emulsions, but other hydrophilic colloids can also be used.

For example, gelatin derivatives, graft polymers of gelatin and other polymers, proteins such as albumin and casein; cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, and cellulose sulfates; sugar derivatives such as sodium alginate and starch derivatives; polyvinyl alcohol , polyvinyl alcohol partial acetal,
Poly-N-vinylpyrrolidone, polyacrylic acid,
A wide variety of synthetic hydrophilic polymeric materials can be used, such as single or copolymers of polymethacrylic acid, polyacrylamide, polyvinylimidazole, polyvinylpyrazole, and the like.

In addition to lime-treated gelatin, acid-treated gelatin and enzyme-treated gelatin as described in Bull.Soc.Sci.Phot.JaPan.No.16.30 (1966) may be used as the gelatin. or enzymatic decomposition products can also be used. As gelatin derivatives, various compounds such as acid halides, acid anhydrides, isocyanates, bromoacetic acids, alkanesultones, vinyl sulfonamides, maleimide compounds, polyalkylene oxides, and epoxy compounds can be added to gelatin. The product obtained by the reaction is used. A specific example is a US patent
No. 2614928, No. 3132945, No. 3186846, No. 3186846, No. 3132945, No. 3186846, No.
3312553, British Patent No. 861414, British Patent No. 1033189, British Patent No.
It is described in No. 1005784, Special Publication No. 42-26845, etc.

The gelatin graft polymer is a gelatin grafted with a single (homo) or copolymer of vinyl monomers such as acrylic acid, methacrylic acid, derivatives thereof such as esters and amides, acrylonitrile, styrene, etc. can be used. In particular, polymers with some degree of compatibility with gelatin, such as acrylic acid,
Graft polymers with polymers such as methacrylic acid, acrylamide, methacrylamide, hydroxyalkyl methacrylate are preferred. Examples of these are U.S. Pat.
It is described in issues such as No. 2956884.

Typical synthetic hydrophilic polymer substances include West German Patent Application (OLS) No. 2312708 and U.S. Patent No. 3620751.
No. 3879205 and Special Publication No. 7561 of 1973.

According to the present invention, since the gel-like photographic material is pulverized and supplied while being passed through a heat exchanger, the heat transfer efficiency is improved to over 80%, and since the gel-like photographic material is continuously supplied, there is no need for a storage section for melted material. Therefore, it is possible to avoid increasing the scale of the device while improving the melting ability.

Further, according to the present invention, since the amount of melting is adjusted by controlling the rotational speed of the crusher and the feeder, it is possible to melt and feed the photographic material in a quantitative manner with good responsiveness and high accuracy.

Furthermore, according to the present invention, the quantitative melting and supply of the photographic material is realized, so that deterioration of the photographic material over time is prevented and the aging characteristics can be adjusted with high precision.

The present invention is not limited to the drawings of the embodiments, and can be widely applied.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an outline of an apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing another embodiment. 1... Container, 2... Photographic material, 3... Grinder,
4... Feeder, 5... Heat exchanger, 6... Static mixer.

Claims (1)

[Claims] 1 Grind the gel-like photographic material mass using a grinder,
A conveyor-type feeder continuously stirs and feeds the feeder while melting it by a heat exchanger installed downstream of the feeder, and the amount of melting is adjusted by controlling the rotational speed of the crusher and the feeder. A method of melting photographic materials.