JPH02109043A - Granular color photographic developer and manufacture thereof - Google Patents

Abstract

PURPOSE: To enable a granular color photographic developer to be fed into water without causing fine powder dust and to speed up dissolution by specifying the average grain diameter of the developer and its deviation range. CONSTITUTION: This developer comprises the granular developer (A) and a granular antioxidant and a granular alkali donor and the component (A) is spherical and has an average grain diameter of >=150μm and >=80% of the total grains is in the deviation range of ±100μm, and it is preferred that this component (A) is manufactured by injecting it in the form of solution into a fluidized bed, recovering fine grains carried over together with a waste gas from the fluidized bed, returning them into the bad, controlling a gas speed to obtain the desired grain sizes, sieving the obtained grains, and drying them. The granular developer is manufactured by mixing the obtained developer with the other components granulated by desired methods.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a granular color photographic developer and to a method for producing such a rapidly dissolving developer.

To summarize the invention, the granulated developer material obtained according to the invention is spherical, has an average particle size of ≧150 μL, and 80% of the particles are within ±100 Pi of the desired particle size. A particulate mixture comprising a particulate developer material, a particulate antioxidant and a particulate alkali donor, within a not too large deviation range, can be poured without creating dust.
urable), have indefinite durability in moisture-proof packaging, and dissolve extremely quickly.

Color photographic developers typically contain a number of solid components such as, for example, original developing substances, antioxidants, complexing agents, sodium sulfite, alkali donors, and alkali metals/percent halides. Since these compounds tend to chemically react with each other, they are prepared separately and mixed together just before use. They are suitably manufactured as powders or as liquid concentrates, the latter in particular since some developers contain liquid components, such as benzyl alcohol, which of course cannot be made into powder form. Liquid concentrates have become increasingly widely used over the years.

To produce a ready-to-use developer, the three or four concentrates are mixed with each other in certain proportions, with optional addition of water.

Since such concentrates can only be stored for a limited time and, if they contain water, require high transportation costs, solid colors must meet at least the following conditions: Desires exist for photographic developers: 1. The formulation must contain all solid components of a ready-to-use color photographic developer.

2. Solid formulations must dissolve very quickly.

3. Solid formulations should not produce fines.

German Patent Application Publication flHH Book DH-Ag3,733.
No. 861, black and white development as a rapidly dissolving dry powder by first producing a liquid photographic developer solution, removing the solvent to form a powder, and packaging the powder to prevent contact with the atmosphere. Although it is known to produce agents,
Because freeze-drying or spray-drying is used to remove the solvent, this method cannot be applied to color photographic developers with completely different compositions. Moreover, the time required to dissolve the powder is at least 2 to 4 minutes, depending on the developer, which is still too long.

The developer material is sprayed in the form of a solution into the fluidized bed, the fine particles that fly out of the fluidized bed with the exhaust gas are separated, and they are returned to the fluidized bed as nuclei for the formation of granules, and the sieving gas By controlling the granulation process in the fluidized bed by adjusting the air flow of the sieving gas so that particles with a constant size are obtained by the air flow of the sifting has, all color photographic developers can be It has now been newly discovered that particulate compositions containing solid components can be produced. The resulting granulate was passed through one or more self-flowing gravity mechanical sieves (gravity 5i) inserted into the perforated base of a fluidized bed apparatus.
fter) and the granules are dried in vacuum, mixed with other components of the granular developer in any desired manner and packaged in moisture-proof packaging.

Therefore, the present invention involves spraying the developer material of a color photographic developer in the form of a solution into a fluidized bed, separating out the fine particles that fly away from the fluidized bed with the exhaust gas, and using them as nuclei for the formation of granules. The granulation process in the fluidized bed is controlled by returning the sieving gas to the fluidized bed and adjusting the air flow of the sieving gas so that particles having a constant size are obtained by the air flow of the sieving gas. The present invention relates to a method for producing a granular formulation of solid components of a color photographic developer. The resulting granules are removed by one or more countercurrent gravity mechanical sieves inserted into the perforated base of a fluidized bed apparatus, and the granules are dried in vacuo in any desired manner. The granulated developer is mixed with other components of the developer and packaged in moisture-proof form.

The resulting granular solid component of the color photographic developer is mechanically stable, uniform in particle size, rapidly soluble,
It has indefinite durability, produces no fines, and is pourable. In particular, the granules are spherical.

It is particularly preferred to use aqueous solutions of developer substances having a concentration of 10 to 70% by weight.

The average particle size of the granules of developer material should preferably be ≧150μ clear, especially 150 to 300μ rich. The method according to the invention is suitable for obtaining extremely narrow particle size distributions. Preferably 280% of the grains are within ±10 of the desired grain size.
It is within a range that does not deviate significantly from 0 μyoi. If the developer material is particularly sensitive to oxidation, granulation, drying, mixing and packaging are preferably carried out under a protective gas, such as nitrogen.

Other solid components of the developer, such as antioxidants, alkali donors, water softeners, heavy metal complexing agents, sodium sulfite and alkali metal halides, can be granulated by any method.

One suitable method is, for example, by grinding the material to a particle size of less than 10 microns, then subjecting it to a powder agglomeration process by optionally adding a granulating liquid containing a binder, and drying in vacuo. Become.

Preferably, the antioxidant and the alkali donor are granulated separately. The other components may also be granulated separately, or some with the oxidizing agent and some with the alkali donor.

In particular, the auxiliary agent is granulated to the same average particle size as the developer material, although the deviation of the individual granules from the average particle size may be greater than the deviation of the developer material.

The granular mixtures thus produced are mechanically stable, uniform in particle size, rapidly dissolving, indefinitely durable, free of fines, and pourable.

The color developer compound used may be any developer compound that is capable of reacting in the form of its oxidation product with a color former to produce an azomethine or indophenol dye. Aromatic compounds of the p-7 22-diamine series containing at least one primary amino group, such as N,N-diethyl p-phenylenediamine, I-(N
-ethyl-N-methanesulfonamidoethylthyl-p-7 22-diamine, l-(N-ethyl-N
-hydroxy7ethyl)-3-methyl-p-phenylenediamine, and l-(N-ethyl-N-methoxyethyl)
N,N such as -3-methyl-p-7 22-diamine
-Dialkyl-p-phenylene diamines are suitable color developer compounds. For example, J. ^mer. Che
m. Soc. 7 3 s:3106 (1951
) and G. By HaisL, 1979, John Wile & Sons
Modern 7 Autographic Processing (Mode Y and Sons), published by Niney Embroidery York.
rn Photographic Processin
g) Other suitable color developers are described on pages 545 and below. 1-(N-ethyl-N-methanesulfonamyl-"ethyl)-3-methyl-p-phenylenediamine.3/2HzSO+.H,O (CD3) is a preferred compound.

The invention is further characterized in that the granulated developer material is spherical with an average particle size of 2150 μm, and 80% of the particles are within a deviation of no more than ±100 μm from the desired particle size. A particulate mixture comprising a particulate developer material, a particulate antioxidant, and a particulate alkali donor.

Example developer material CD3 (molecular weight -436.5) granules (
The compound for producing granules A) is used as a 50% by weight aqueous solution.

Granulation is carried out in a glass column with a diameter of 225 m+i by repeatedly spraying an aqueous solution onto the solid cores present in a fluidized bed.

Solid CD3 in an amount of about 1 ki is initially used as a granulation raw material,
German Patent Application Publication DE-A No. 3.

507,376, from the feed hopper into the porous base of a 225 ml+ diameter glass column. Then flow a fluid gas: 9 to 127 ml of nitrogen with a diameter of the inlet cross section of 225 mm and a heating rate of 100°C.
/hour, exhaust gas temperature: 62°C.

A 50% by weight aqueous solution of CD3, kept at room temperature, is sprayed through a two-headed nozzle into a fluidized bed of inert gas. The product is pumped to the nozzle by a hose pump. The solid particles (or granulated material) initially formed from droplets evaporated in the fluidized bed grow into an onion-like shape to a desired size by repeated spraying. The diameter of the individual grains can be adjusted within narrow limits by the speed of the mechanical sieve gas flow.

Diameter 5001 wide attachment on glass column
Serves as a pre-separator for medium particles and in fluidized beds that do not hit their target; to solidify the spray droplets.

Fine particles separated from the exhaust gas stream are returned through a filter attachment. When the filter is being cleaned, the fine material is returned to the fluidized bed as a rain of agglomerated material so that the kernels are once again exposed to the spray jet.

Discharge of the finished granulate through a mechanical sieve begins after 20 minutes and the contents of the fluidized bed are kept at a CD of approximately 1 hg. The granules are collected in a flask that is tightly fitted and acts as an exchangeable receiver.

machine &1. The processing rate of gas through vl is 9.5 at 62°C.
kg/hour.

Properties of the obtained granules = (Grain A): Color of granules:
Shape of granules very pale, almost colorless, not pinkish Spherical apparent density: 730 g/Q; Product flows freely and does not form fines Moisture of granules: Karl Fischer
4.2% by Scher) method Average particle size: 400 μm (approximately 90% of the particles are between 300 and 500 μm) Storage stability: Preparation of indefinite antioxidant granules (granules B) Crystallized sulfur-ugly hydroquine ammonium 0,6 a
m mesh size Alexander (A 1exand
er) Easy grinding, then air jet pulverization a (
Mill in an air jet m111) to an average particle size of <lOμ+x.

This finely pulverized material was processed using a commercially available fluidized bed spray granulator (Bubendorrl/7.
tory, ] apparatus) by spraying a total of 3811 IQ of water onto the material within 7 minutes at room temperature and then drying the granulate for 8 minutes at an air temperature of 63°C. 200
All particles larger than 0 μm are removed by sieving.

The granules are then at tcr-dryed in vacuo at 40° C. for 90 minutes.

Preparation of the granules (granules C and granules D) for the alkaline developer component The following chemicals are mixed together: Mixture C Mixture D a) Disodium salt of l-hydroxyethane-1,1-diphosphonic acid b) Sodium sulfite C) Ethylene diamino-tetraacetic acid d) Potassium carbonate e) Sodium bicarbonate r) Potassium bromide 4y 39g 39g zh 336g336g 15g 15g 15g 15g n Prepare compounds C and D separately as follows: Graining: 1. Homogenization in L5dige mixer.

2. Air jet milling to average particle size <10 pra.

3. Spray granulation in a fluidized bed; as in granulate B, 110 (or 115) mQ of water is sprayed onto the material within 6 minutes (or 7 minutes), then the air temperature is 70 °C and 80 °C. Dry at C for 10 minutes.

4. Undersized and oversized particles (<2000 IIa; >200
Sieve to remove 0μ旙).

5. Post-drying in vacuum as above.

Production of a ready-to-use granular mixture: To produce a ready-to-use granular mixture, the individual granules A, B% C and D are mixed together in a laboratory mixer in the weight ratios indicated below. . In this process, it is essential to block moisture.

Granules A 4.52g Granules 8 2.4g Granules C 21.95g Granules D 21.459 Total weight 50.32g Packaging The granule mixture was placed in a paper bag laminated with plastic and aluminum foil to block moisture ( (under a stream of very dry air) and seal the bag immediately.

Sexual condition 1. The granular mixture is pourable and does not produce fines.

2. Color: Colorless 3. Dissolution rate: 95011i 50.32g of granular mixture at approximately 25°C
Introduce the mixture into the water in Step 2 while stirring gently. All solid particles dissolve within 22 seconds. The color of the solution is yellow and transparent.

The test film was developed in a color negative film developer prepared by dissolving the 44 Photographic Properties particulate mixture. No sensitometric differences were observed between the developed films and films developed with the same type of conventional developer.

5. Storage Stability of Granular Developer The granular mixture has an indefinite durability if moisture is excluded during manufacturing and packaging.

The main features and aspects of the invention are as follows.

■, granulated; the developer material is spherical, ≧150μ;
a particulate developer material, a particulate antioxidant and a particulate alkali donor, characterized in that the particulate developer material has an average particle size of 100%, and 80% of the particles are within a deviation range of no greater than ±100 μm from the desired particle size. Granular mixture containing bodies.

2. The average particle size of the particulate developer material is 150 to 30
00 μm, the granular mixture according to item 1 above.

3. The granular mixture according to item 1 above, packaged in moisture-proof packaging.

4. Spray the developer material of the color photographic developer into the fluidized bed in the form of a solution, separate the fine particles that fly out of the fluidized bed with the exhaust gas, and use them as nuclei for the production of granules in the fluidized bed. and controlling the granulation process in the fluidized bed by adjusting the flow of the sieving gas to obtain particles having a size determined by the flow of the sieving gas, and the resulting granules is removed by one or more counter-current gravity mechanical sieves inserted into the perforated base of the fluidized bed apparatus and dried in vacuum, leaving the rest of the developer granulated in any desired manner. A process for producing a granular formulation of solid components of a color photographic developer, characterized in that the solid components of a color photographic developer are mixed with the components and packaged in moisture-proof packaging.

Claims (1)

[Claims] 1. The granulated developer material is spherical and has a diameter of ≧150 μm.
and 80% of the grains are within ± from the desired grain size.
A granular mixture comprising a granular developer material, a granular antioxidant and a granular alkali donor, characterized in that they are within a deviation range of no greater than 100 μm. 2. Spray the developer material of the color photographic developer into the fluidized bed in the form of a solution, separate the fine particles that fly out of the fluidized bed with the exhaust gas, and use them as nuclei for the production of granules in the fluidized bed. and controlling the granulation process in the fluidized bed by adjusting the flow of the sieving gas to obtain particles having a size determined by the flow of the sieving gas, and the resulting granules is removed by one or more counter-current gravity mechanical sieves inserted into the perforated base of the fluidized bed apparatus and dried in vacuum, leaving the rest of the developer granulated in any desired manner. A process for producing a granular formulation of solid components of a color photographic developer, characterized in that the solid components of a color photographic developer are mixed with the components and packaged in moisture-proof packaging.