EP1003077A2 - Process for making photographic process chemicals in tablet form - Google Patents

Abstract

a) Zerkleinern von wenigstens 50 Gew.-% des anorganischen Anteils der Einsatzmaterialien auf eine mittlere Korngröße von 125µm oder weniger,

b) Direktverpressen der Einsatzmaterialien zu einem Formkörper mit einer Härte von wenigstens 400 N.

The invention relates to a method for producing photographic process chemicals formulated as moldings, comprising the steps:

a) comminution of at least 50% by weight of the inorganic portion of the starting materials to an average grain size of 125 μm or less,

b) direct pressing of the feed materials into a shaped body with a hardness of at least 400 N.

The invention further relates to those obtainable by this method Molded body. The method according to the invention enables without elaborate pretreatments such as fluidized bed granulation of the corresponding proportion of the feed materials Manufacture of hard and abrasion resistant tablets for use in Developer machines.

Description

The invention relates to a method for producing of photographic formulated as tablets (especially tablets) Process chemicals and those obtainable by these processes corresponding moldings.

Exposed silver halide films are made in commercial laboratories developed and processed fully automatically. Color negative films for example, run through a developer bath Bleaching bath, a fixing bath and usually a stabilizing bath or several washing steps. The steps of bleaching and Fixing can be done using a bleach-fixing bath in one single processing step can be combined. The done developed negatives are exposed on color paper, the exposed color paper then also runs through a developing bath, usually a combined bleach-fix bath and final washing steps. The washing steps can be replaced by a stabilizing bath if necessary.

The various processing baths are exhausted in the course of use. While a photo amateur exhausted baths in usually changes, takes place at commercial photo laboratories refreshing used solutions. In the trade are too for this purpose the corresponding process chemicals as liquid concentrates or powder available.

Liquid concentrates need because of their water content Transport and storage relatively much space. The empty ones Concentrate containers represent a considerable volume of waste.

Powdered chemicals are difficult to handle. Since the Precautions must be taken when powder can be dusted during handling to avoid adverse health effects for users to be hit.

It has therefore already been proposed (EP-A 0 678 782) to formulate photographic process chemicals as granules. There are different types of wet granulation (for example fluidized bed granulation).

It is also known, from a granulate and possibly other powdered components to press tablets (EP-A 0 678 782). The photographic processing machines point Supply magazines for such tablets and dose them automatically into the respective baths as required. Common is the provision of the photographic process chemicals in the form of tablets, especially for smaller ones automatic development machines, which are located in so-called minilabs be used. The tablets must be of sufficient hardness and have abrasion resistance, so that the automatic Handling in the magazines does not lead to tablet breakage and operation is not affected by tablet abrasion. These properties of the tablet need to last for a long time Storage must be guaranteed.

The granulation of the process chemicals before pressing one tablet is expensive. The object of the invention is to achieve this based on a simple, inexpensive method of manufacture to create such moldings.

a) Zerkleinern von wenigstens 50 Gew.-% des anorganischen Anteils der Einsatzmaterialien auf eine mittlere Korngröße von 125µm oder weniger,

b) Direktverpressen der Einsatzmaterialien zu einem Formkörper mit einer Härte von wenigstens 400 N.

The invention solves this problem by a method with the following steps:

a) comminution of at least 50% by weight of the inorganic portion of the starting materials to an average grain size of 125 μm or less,

b) direct pressing of the feed materials into a shaped body with a hardness of at least 400 N.

The invention further relates to a shaped body (in particular one tablet) by the aforementioned method is available.

First, let's look at some of the terms used in the context of the invention explained.

A shaped body is any body with a through shaping purposefully manufactured shape. It is preferably around a tablet.

Photographic process chemicals are any chemicals that as part of one or more photographic processes (e.g. developing, fixing, bleach-fixing or the like) Can find application.

The input materials are all those Substances that are part of the molded body. It is about on the one hand about the person or persons in the respective photographic Processing process of active substances (e.g. fixing and / or Bleach-fixing agent, developer) and auxiliary substances, that are photographically inert or conducive to photography. This means that the photographic processing process, in which the molded body is to be used, either by the Presence of the excipient not or at most insignificantly Way is adversely affected or the Excipient itself is a photochemically active, useful component represents the recipe.

All insert materials of the molded body are water-soluble. A tablet produced according to the invention dissolves when setting the usual concentrations of the process chemicals completely in aqueous solution at the usual bath temperatures where the solution process can be slow, if such a tablet, for example, to regenerate a process bath serves. Any auxiliaries must be in such Extent be water soluble that dissolving for adjustment the desired concentration is not hindered.

Auxiliary substances that are photographically beneficial can be buffer substances, for example to set a desired pH, water softener (in particular complexing agents), possibly optical Brighteners, preservatives, antioxidants, antifoggants, Solubilizers, emulsifiers and additives to increase resistance to moisture his. An exemplary disclosure of suitable auxiliaries can be found in DE-A-197 46 879, the disclosure of which Reference to this also expressly in the present application is included. Reference is also made to the disclosure in Ullmann's Encyclopedia Chemicals Industrial Chemistry, 5th edition, vol. A20, chapter "Photography".

Auxiliaries include, for example, photographic inert additives for tableting in question. It can be fillers, Binders, lubricants, flow regulators, lubricants, Act mold release agents and the like. For definition the terms and for an exemplary list suitable additives are referred to Rudolf Voigt, Textbook of Pharmaceutical Technology, 5th ed., Verlag Chemie, Weinheim 1984, page 178 ff. The disclosure content the specified passage is hereby expressly stated also made the subject of the present application.

Q3_i stellt die Massenverteilung, den Mengenanteil einer Kornklasse zur zugehörigen Kornklasse dar.At least 50% of the inorganic portion of the feed materials is crushed to an average grain size of 125 µm or less. The comminution can be carried out by any suitable method, preferably the corresponding proportion of the starting materials is ground. The average grain size χ _m is defined according to DIN 66141 (page 18) by:

Q3 _i represents the mass distribution, the proportion of a grain class to the associated grain class.

It is preferred according to the invention if the corresponding proportion of the feed materials to a grain size of 125 µm or less is crushed, so that no technical significant part of this shredded portion with a Grain size above 125 µm remains.

According to the invention, the feed materials are pressed directly (Direct tabletting) to a shaped body with a Molded hardness of at least 400 N. The term direct pressing or direct tabletting refers to the compression of powdery feedstocks without one over the invention Pre-treatment to a size reduction Molded body. In the context of the invention means "Direct pressing" that in any case that portion of the feed materials that in step a) to the specified grain size is crushed, no further pretreatment, in particular no granulation (e.g. fluidized bed granulation) is subjected. According to the invention should not be excluded be that a remaining portion of the input materials (e.g. possible organic components) of a pretreatment such as Undergoes granulation. It is preferred according to the invention however, if all feed materials are not pretreated undergo, but immediately as a powder of Undergo direct tableting.

The molded article produced according to the invention has a hardness from at least 400 N.

The hardness is measured with a breaking strength tester TBH30 from ERWEKA. The tablet to be tested is between two extendable jaws clamped and with a rising Force applied. The one needed to break the tablet Force is registered (in N) and as a measure of the Tablet hardness specified.

The moldings produced according to the invention preferably have an abrasion of less than 2%, more preferably less than 1%. This abrasion or the abrasion resistance is measured according to that in Example 3 of the present application specified procedures.

The invention has recognized that surprisingly hard and sufficient abrasion-resistant tablets that are suitable for use in automatic feed magazines of commercial development machines are suitable, thanks to the direct compression without any need on a complex pretreatment of at least one essential Manufacture proportion of the ingredients of the tablet to let. This is surprising given the state of the art (Rudolf Voigt, textbook of pharmaceutical technology, Page 154 et seq.) Teaches that direct pressing is more precise Do not manufacture powder tablets of sufficient strength to let. It is expressly stated there that the Direct tabletting, at most, coarse crystalline substances grain sizes between 0.5 and 1 mm are considered optimal designated. In contrast, the invention has recognized that contrary this teaching of the prior art hard and abrasion resistant Tablets can be made by direct compression correspondingly fine powder.

Preferably at least 70% by weight is more preferred at least 80% by weight, more preferably at least 90% by weight of the inorganic portion of the feed materials crushed to the specified grain sizes. According to the invention can be the total inorganic portion of the feed materials can be comminuted accordingly, and any one organic part in whole or in part in this crushing be included.

The moldings can contain binders, but their proportion preferably below 10% by weight, more preferably below 5, is less than 2 or less than 1% by weight. Ggt. can on binder to be completely dispensed with.

At least 50% by weight are preferred, more preferably at least 80% by weight, more preferably at least 90 or 95 % By weight of the input materials of inorganic substances. Prefers it is when the actual photographic chemical is a is inorganic substance. For example, it can be amonioma and or sodium tiosulfate. The tablets according to the invention with these salts as the main component, for example Use in a fixer or bleach-fixer his.

Embodiments of the invention are explained below.

I. Manufacture of tablets for fixing black and white and Color materials example 1

According to the recipe shown in Table 1, 386.5 g of sodium sulfite, 38.7 g of Na ₂ EDTA, 61.8 g of sodium carbonate, 19.3 g of mercaptotriazole and 38.7 g of maltodextrin as a binder were added to a mixing container. This mixture was made three times.

About 15 kg of ammonium thiosulfate 90/10, which is 90% commercially available consists of ammonium thiosulfate and 10% sodium thiosulfate, were in a BAUERMEISTER powder mill with turbo insert ground to a particle size of less than 125 µm.

The 4445.3 g of ammonium thiosulfate listed in the formulation in Table 1 90/10 were in

Comparative Example 1 (not according to the invention)

44.4% pulverized (= 1973.7 g) and 55.6% as unpowdered Raw material (= 2471.6 g) to one of the three mentioned above Mixtures added. The degree of pulverization of the The main component of ammonium thiosulfate 90/10 was 44.4%.

Example 1a

The degree of pulverization was 90%.

Example 1b

The degree of pulverization was 100%, ie the main inorganic component was used completely pulverized.

Finally, the three mixtures were each treated with 9.7 g of sodium N-lauroyl sarcosinate, that as a lubricant and lubricant Tableting is used, added and for 10 min until receipt mixed into a homogeneous mixture.

final blends" wurden mit einer hydraulischen Laborpresse vom Typ ENERPAC zu Tabletten mit einem Durchmesser von 30 mm und einem Gewicht von 10,4 g verpraßt. Die Bruchfestigkeiten (Härten) der Tabletten können der Tabelle 2 entnommen werden, sie wurden wie folgt bestimmt:The so obtained

final blends "were pressed with a hydraulic laboratory press of the ENERPAC type into tablets with a diameter of 30 mm and a weight of 10.4 g. The breaking strengths (hardness) of the tablets can be found in Table 2, they were determined as follows:

Tablet breaking strength : 6 tablets in each case were tested for breaking strength using a TBH 30 tablet breaking strength tester from ERWEKA and the mean value was formed. A hardness of> 400 N is required to avoid damage during transport.

Comparative Example 2 (not according to the invention)

93.6 kg of sodium sulfite, 9.4 kg of Na ₂ EDTA, 15.0 kg of sodium carbonate, 4.7 kg of mercaptotriazole and 468.0 kg of powdered ammonium thiosulfate 90/10 (milled in a commercial GLATT fluidized bed granulator GCPG800 according to the recipe in Table 1 filled in a BAUERMEISTER powder mill with turbo insert to a grain size <125 µm). By spraying a solution of 9.4 kg of maltodextrin in 56.2 liters of water with a two-component nozzle, the powder mixture is granulated in the fluidized bed, then dried at an air temperature of 60 ° C for 8 minutes and finally at an air temperature of 0 ° C within 7 min cooled to 35 ° C. The entire fluidized bed granulation process was complete after 1 h 25 min.

The granules obtained were placed in a mixer and the following raw materials were added: 608.4 kg of ammonium thiosulfate 90/10 (the raw material was not pulverized or pretreated) and 2.3 kg of sodium N-lauroyl sarcosinate. The mixture was mixed for 10 minutes and the final blend obtained was pressed on a rotary tablet press of the FETTE 2090 type to give tablets with a diameter of 30 mm and a weight of 10.4 g. The hardness of the tablets was determined as in Examples 1a - 1c, it is also shown in Table 2. Degree of powdering ammonium thiosulfate 90/10 Tablet hardness Comparative Example 1 44.4% 229 N Example 1a 90.0% 408 N. Example 1b 100% 657 N Comparative Example 2 420 N

From Table 2 it can be seen that with increasing degree of Pulverization (the main component ammonium thiosulfate 90/10) the hardness of the tablet increases and especially when it is more extensive tablets or full pulverization hardness is sufficient to prevent damage during transport to avoid.

Example 2

Sokalan CP45 ( mit Maleinsäure modifizierte Polyacrylsäure)

Luvitec VPI 55 K18P (Copolymer aus Vinylpyrrolidon und N-Vinylimidazol)

Luviskol K90 ( Polyvinylpyrrolidon)

D-Sorbit

D-Mannit

Sorbit/Xylit (cogesprühte Mischung)

As in Example 1, powder mixtures are produced which differ in the degree of pulverization of the ammonium thiosulfate 90/10 (44.4%, 90% and 100%). In addition, the binder maltodextrin was replaced by an equal weight of the following water-soluble and photographically inert binders:

Sokalan CP45 (maleic acid modified polyacrylic acid)

Luvitec VPI 55 K18P (copolymer of vinyl pyrrolidone and N-vinyl imidazole)

Luviskol K90 (polyvinyl pyrrolidone)

D-sorbitol

D-mannitol

Sorbitol / xylitol (co-sprayed mixture)

As in Example 1, the individual powder mixtures were pressed into tablets. The tablets had the breaking strengths given in Table 3: Degree of powdering ammonium thiosulfate 90/10 44.4% (not according to the invention) 90% 100% Tablet hardness [N] Tablet hardness [N] Tablet hardness [N] Maltodextrin 229 408 657 Sokalan CP45 305 474 856 Luvitec VPI 55 K18P 368 607 828 Luviskol K90 346 545 754 D-sorbitol 352 541 806 D-mannitol 305 415 759 Sorbitol / xylitol 351 517 751

As can be seen from Table 3, the choice of binder affects the breaking strength of the tablets. With direct compression with largely or completely ground Ammonium thiosulfate 90/10 can have considerable break resistance be achieved.

Example 3

According to the recipe listed in Table 1, 50 kg final blend, maltodextrin was used as a binding agent chosen. The total amount of ammonium thiosulfate was previously with a BAUERMEISTER powder mill with turbo insert on one Grain size <125 microns have been milled. The final blend received with a rotary tablet press of the type FETTE 2090 to tablets (diameter 30 mm, tablet thickness 9.50 mm and Weight 10.45 g) pressed. Hardness, abrasion and storage stability of the tablets were determined:

Storage stability: For an accelerated storage test, 6 tablets are sealed in a pouch made of aluminum composite film and stored in a warming cabinet at 50 ° C. After a certain number of days, one sachet is removed and after cooling the average values of the tablet hardness and the tablet thickness are determined.

Tablet abrasion : Five tablets are weighed and placed in the plexiglass drum of an ERWEKA TA-10 tablet abrasion and friability tester. After a rotation time of 5 minutes, the tablets are freed of adhering dust and weighed again. The percentage abrasion is calculated from the weight loss in relation to the initial weight.

In the tablets produced in Comparative Example 2 Fluidized bed granules, which are also on a rotary tablet press (Type FETTE 2090) was used for comparison purposes also the hardness and storage stability checked.

The values determined are given in Table 4: Example 3 Average of 6 tablets Comparative Example 2 Average of 6 tablets After 0 days Tablet thickness [mm] 9.50 9.46 Tablet hardness [N] 509 459 Tablet abrasion [%] 0.50 0.20 After 14 days at 50 ° C Tablet thickness [mm] 9.63 9.57 Tablet hardness [N] 639 672 After 28 days at 50 ° C Tablet thickness [mm] 9.57 9.80 Tablet hardness [N] 661 408

As can be seen in Table 4, direct tableting with fully powdered ammonium thiosulfate tablets achieved with sufficient hardness with regard to the storage stability of the tablets from fluidized bed granules are superior (comparative example 2, tablet hardness after 28 days at 50 ° C). The thickness of the tablets in direct tableting is slightly higher than the tablets made of fluidized bed granulate, but increases with longer periods Storage also less. For tablet abrasion only less favorable values are found, however an abrasion is < 2% acceptable for the transport of tablets.

II. Production of tablets for fixing bleaching materials Example 4

In a standard LÖDIGE ploughshare mixer of the type FM130 with double jacket were the raw materials according to Table 5 NaH-Fe-DTPA (58.43 kg) and polyethylene glycol 4000 (6.57 kg). The temperature of the water in the double jacket was set to 75 ° C. With mixer and on The cutter head was melt-granulated until it reached one Product temperature of 59 ° C from the powder mixture a dust-free Granules had arisen. The melt granules obtained was emptied from the mixer and allowed to air cool.

The cooled melt granules were treated with 67.35 kg of ammonium thiosulfate 90/10, which had previously been ground in a BAUERMEISTER powder mill with turbo insert to a particle size of <125 μm, with 5.03 kg of sodium disulfite, 9.25 kg of sodium sulfite, 410 g Maltodextrin and 1.46 kg of sodium N-lauroyl sarcosinate mixed in a mixer for 10 minutes to a homogeneous mass. The final blend obtained was compressed on a rotary tablet press of the FETTE 2090 type to tablets with a diameter of 30 mm and a weight of 10.73 g. [kg] NaH-Fe-DTPA 58.43 Polyethylene glycol 4000 6.57 65.00 Ammonium thiosulfate 90/10 67.35 Sodium disulfite 5.03 Sodium sulfite 9.25 Maltodextrin 0.41 Sodium N-lauroyl sarcosinate 1.46 148.50

Comparative Example 3 (not according to the invention)

549.62 kg of NaH-Fe-DTPA were filled into a commercially available GLATT fluidized bed granulator GCPG800 in accordance with the recipe in Table 5. By spraying a solution of 50.38 kg of polyethylene glycol 4000 in 74.8 liters of water with a two-component nozzle, the powder mixture is granulated in the fluidized bed, then dried at an air temperature of 66 ° C for 5 minutes and finally at an air temperature of 0 ° C within Cooled to 35 ° C for 3 min. The entire fluidized bed granulation process was complete after 2 hours. The fluidized bed granules obtained are referred to as granules A.

After cleaning, 485.38 kg of ammonium thiosulfate, which had previously been ground to a particle size of <125 μm with a BAUERMEISTER powder mill with turbo insert, were then filled into the fluidized bed granulator, 36.26 kg of sodium disulfite and 66.67 kg of sodium sulfite. By spraying a solution of 2.92 kg of maltodextrin and 8.77 kg of polyethylene glycol 4000 in 46.8 liters of water with a two-component nozzle, the powder mixture in the fluidized bed is granulated, then dried at an air temperature of 60 ° C for 11 minutes and finally at an air temperature cooled from 0 ° C to 35 ° C within 4 min. The entire fluidized bed granulation process was complete after 1 h 15 min. The fluidized bed granules obtained are referred to as granules B.

Of the granules A and B obtained, 300.7 kg and 392.5 kg together with 6.9 kg of sodium N-lauroyl sarcosinate in given a mixer and to a homogeneous mass within mixed by 10 min. The final blend was obtained on a Rotary tablet press type FETTE 2090 for tablets with a diameter of 30 mm and a weight of 10.73 g pressed.

The tablet hardness, tablet abrasion and storage stability were investigated for the tablets of Example 4 and Comparative Example 3 which were identical with regard to the ingredients (Table 6). Example 4 Average of 6 tablets Comparative Example 3 Average of 6 tablets After 0 days Tablet thickness [mm] 9.58 10.08 Tablet hardness [N] 489 828 Tablet abrasion [%] 0.45 0.37 After 7 days at 50 ° C Tablet thickness [mm] 9.68 10.10 Tablet hardness [N] 728 868 After 14 days at 50 ° C Tablet thickness [mm] 9.70 10.11 Tablet hardness [N] 740 818

As can be seen from Table 6, they show from the two fluidized bed granules (Granules A and Granules B) Bleach-fixing tablets from Comparative Example 3 are high Initial hardness of the tablet almost in the course of storage remains constant, however, as in Example 4, only the organic one Main component NaH-Fe-DTPA (melt) granulated and the main inorganic component ammonium thiosulfate into one Particle size <125 µm powdered and with the other components added to the final blend is the initial tablet hardness smaller, but increases with longer storage noticeably. With tablet abrasion and the increase in thickness storage shows the double fluidized bed tablet slightly better values, which are also accepted in example 4 can be.

Claims (10)

Process for the production of photographic process chemicals formulated as moldings, with the following steps: a) comminution of at least 50% by weight of the inorganic portion of the starting materials to an average grain size of 125 μm or less, b) direct pressing of the feed materials into a shaped body with a hardness of at least 400 N. A method according to claim 1, characterized in that at least 70% by weight, preferably at least 80% by weight of the inorganic portion of the feed materials to a average grain size of 125 µm or less crushed become. A method according to claim 1 or 2, characterized in that that the feed materials are water-soluble, photographically contain inert and / or photographically beneficial additives. A method according to claim 3, characterized in that the feed materials contain binders. A method according to claim 4, characterized in that the proportion of binder is less than 10% by weight, preferably less than 5% by weight, more preferably less than 2% by weight, more preferably is less than 1% by weight. Method according to one of claims 1 to 5, characterized in that that at least 50% by weight, preferably at least 80% by weight, more preferably at least 90 % By weight, more preferably at least 95% by weight of the starting materials are inorganic substances. Method according to one of claims 1 to 6 for the production a molded body for use in a fixing or Bleach-fixer. Shaped body containing photographic process chemicals and having a hardness of at least 400 N, obtainable by a process with the following steps: a) comminution of at least 50% by weight, preferably at least 70% by weight, further preferably at least 80% by weight, of the inorganic fraction of the starting materials to an average particle size of 125 μm or less, b) direct pressing of the insert materials into a shaped body with a hardness of at least 400 N. Shaped body according to claim 8, characterized in that he used photographic process chemicals to make a Contains fixer or bleach-fixer. Shaped body according to claim 9, characterized in that he ammonium thiosulfate and / or alkali thiosulfate as inorganic Main ingredient contains.