DE3106775A1 - Portion container with colour developer concentrate - Google Patents

Abstract

A colour film developer which is preferably intended for use by amateurs and is discarded after a single development process, is, in accordance with the invention, supplied in only a single portion pack for easier handling and in order to avoid confusion and, due to its novel composition, can be concentrated and has a long shelf life.

Description

Patent application:

Concentrated Color Developer The present invention relates to a developer as specified in the preamble of claim 1.

For the development of color films, developers are used, such as they e.g. in the British Journal of Photography Annual 1979 on pages 204 - 206 are described. In 1 liter of developer solution you can use one after the other or at the same time 6 or more films are developed. For mass development are in particular Developer known, depending on the number of processed films with an additional solution can be regenerated and thus the development of even larger amounts of film in a single Allow approach.

For developing individual films at longer intervals However, such developers are not suitable as used developer solution only can be kept for a few weeks. On the other hand, e.g. from the publication: "Notes on Present Day Monochrome Emulsions and their Development by G. W. Crawley in the British Journal of Photography, Jan. 6, 1961 pp. 9-12, a process for development known from black and white negative films, after which the film in a heavily thinned Developer, which is prepared by diluting a concentrate immediately before use is being developed.

The amount of developer substance is so small that A loss of activity sets in during the development of a film. After development, the developer is thrown away. This procedure is not only economical, but also brings quality advantages with regard to the development result.

The film speed is better used, the contrasts compensated for by the symptoms of exhaustion in heavily exposed parts of the image, and the sharpness of the contours is increased by neighboring effects as a result of exhaustion.

However, this method is not limited to black and white films.

In the book: Willi Beutler "Meine Dunkelkammerpraxis" W. Knapp Verlag, 6th edition 1978 pp. 96-101, is a recipe for a color film developer according to indicated the dilution principle. Such a developer combines an enhanced one Image quality with spoilage advantages that are crucial for small consumers.

This developer consists of two components that are separated in form filled concentrates of 50 ml each are stirred into 500 ml of water one after the other Need to become. The concentrates must be hermetically sealed during storage be. The concentration, i.e. the ratio of the amount of the intended diluted developer to the total concentration amount is 6: 1.

For the user, however, it is cumbersome; Mix concentrates. In addition, there is a risk of confusion, as there are usually several portion containers the one, as well as the other component are stored.

The low concentration of 6: 1 requires a correspondingly large amount of storage space and because of the correspondingly large surface area of the container, it makes it difficult to seal off air. However, these disadvantages are accepted, since according to the current state of the art technology is considered impossible to produce durable individual concentrates of color developers to manufacture. With black and white developers, however, such concentrates have been around since known for a long time. A well-known example is the one under the name "Rodinal" since 1891 traded developers of the company

Agfa.

According to the prior art, it is common for color developers to use the Development substance and other auxiliary substances in an acidic concentrate. (pH # 3) good shelf life and which are indispensable for a color developer necessary alkalis and possibly other auxiliary substances in a separate Store concentrate. Sometimes even three or four concentrates are needed, as there are substances like sodium sulfite and hydroxylamines that act as preservatives are known for the color developing substance, among themselves and in the presence of some water softeners based on the action of ethylene diamine tetraacetic acid are based, mutually decompose.

An important requirement of the concentrates is that they should be diluted Dissolve immediately in the water without separation of foreign phases and that the resulting Solution is ready to use immediately.

For the sake of completeness it should be mentioned that there is also the possibility of to summarize all substances, except the developer substance, in one concentrate. This concentrate and the developer substance are diluted for the working solution is added in powder form. As in the British Journal of Photography Annual 1979 p. 205, however, such a developer only works after 6 hours of maturation with constant result.

Regardless of the decomposition problem, there is a problem that alkaline Do not concentrate solutions of the usual developer substances more than in a ratio of 4: 1 because the bases of these substances have only a low solubility in water.

In this context, there is a special problem facing color developers according to the dilution principle. Due to the high degree of dilution of the developer the simultaneous increase in density of the three color layers is not necessarily to the same extent guaranteed, as is the case with common developers. This circumstance will in the case of state-of-the-art dilution developers, that the alkali concentration in contrast to the concentration of the other components compared to usual developers is only reduced to the extent that it is for reasons the associated color shift is considered justifiable. The high necessary Alkali amount of approx. 30g / liter of working solution stands however a reduction of the Concentrate volume opposite.

It is the object of the present invention, the composition of a Specify a color developer intended for single use, which makes it possible to concentrate the ingredients in a single liquid solution. The concentration should be able to achieve values around 10: 1, the duration of the shelf life of the concentrate should be stored in airtight containers for at least a few years and the color rendering should be neutral.

This task becomes for a concentrated color developer after Preamble of claim 1 with the features of the core character of this claim solved. Further refinements and developments of the invention can be found in FIGS Subclaims.

The present invention is based inter alia on the consideration that the Some of the base of the developer substance is insoluble in an aqueous alkaline medium is soluble in organic solvents.

This organic solvent must have high solubility for the Have developer substance, be compatible with all substances of the developer. and have no significant influence on the development process. Furthermore must the solvent be miscible with water in any amount.

The addition of organic solvents to developer concentrates is commonly used in other contexts.

In U.S. Patent 3,574,619 the composition is a developer component claimed that of water, benzyl alcohol, a paraphenylenediamine derivative, a Sulphite, as well as an organic solvent in the form of a liquid glycol.

However, this glycol addition does not solve the problem on which the invention is based Task. First, the patent is an acidic concentrate, in which no base is to be brought into solution, secondly are the ones used Glycol amounts are high compared to the amounts required in the present invention too low. The object of the glycol in US Patent 3,574-619 and in the multitude A similarly composed developer is to convert the benzyl alcohol into a water-miscible Transfer form.

However, benzyl alcohol is not used in developers according to the present invention used.

According to the invention, about 15 times as much solvent is used by weight as needed by developer. Suitable solvents include polyvalent ones Alcohols such as dioxane, glycerine and, in particular, ethylene glycol and those derived therefrom Polyoxy-CHO H. For n = 1, ethylene glycols of the formula HO 4 HO) H are obtained. For n = 1 results in ethylenealycol, n = 2 di-ethylene glycol41, nn = 3 di-ethylene glycol Also different Ether and formamide compounds are suitable as solvents for the purposes of the invention.

With this feature of the characterizing part of the 1st claim, it is true the concentrability of the one-component developer facilitates, but not achieved to the desired extent. The shelf life of the concentrate is unsatisfactory. To increase the concentratability, the amount of carbonate can, as mentioned, at a cost neutral color rendering. In a series of studies was initially tried to change the resulting color change by varying the pH value using NaHC03 and to correct NaOH. However, it has been shown that in a pH value between pH = 9.5 to 11.6 essentially only changes the rapidity of the developer, not but the color change.

However, through systematic searching, I found that adding of boric acid or corresponding borates such as sodium metaborate (Na2B204 ~ 4H20) or di-sodium tetraborate (Na2B407.10H20) the cyan contrast can be increased, which leads to a desired correction of the color gradient.

The results of the corresponding measurements are given in connection with the description of an embodiment is given.

The amount of potassium carbonate can easily be 15 ... 20g / liter "Gc # irauchsl be reduced if approx. 5g of a borate are added.

The main advantage in the context of the invention is the greater ability to concentrate as a result of the lower need for K2CO3. Surprisingly, it has also been shown that the shelf life of the concentrates is considerably increased by the addition of borates will. It is known to those skilled in the art that borates with polyhydric alcohols and others Use organic solvents complex compounds.

It is also known from black and white developers that borates in some Development substances increase the shelf life.

The solution of the base of a developing substance in an organi-weeks Solvents in the presence of boron-oxygen compounds has been unusual result in long-lasting individual concentrates.

Further developer additives such as complexing agents against lime deposits, Antifoggants such as potassium bromide or 5 (6) -nitrobenzimidazole nitrate, antioxidants such as sodium sulfite, hydroxylamine salts, ascorbic acid or small amounts of Black and white developer substances can be used within the scope of the invention in a known manner and can be used with the same effect.

The following is a complete embodiment of the invention described.

60 ml of diethylene glycol are added to 300 ml of water. Afterwards send are those known per se for a different kind of developer, in Britsh Journal of Photography Annual 79 on page 206 under "Color Developer" Chemicals stirred in. Instead of Calgon it was beneficially used to improve Shelf life the same amount of diethylentriaminepentaacetic acid used. For the purpose of Hydroxylaminonium sulfate (H0NH3) 2S04 was replaced by the more soluble Hydroxylammonium chloride HONH3C1 replaced in the same number of moles, as well as the sodium bicarbonate or potassium or sodium hydrogen sulfate according to the invention by means of 209 di-sodium tetraborate replaced and the amount of potassium carbonate increased by SOg to 809. Which increased to 49 Amount of developer substance tN5-ethyl-N5- (2'-hydroxyethyl) -toluene-25-diammonium sulfate (Monohydrate) # was added after the sulfite instead of at the end. It surrendered 400ml concentrate for 4 ... 4.5 liters of developer.

The concentrate was filled into glass bottles of about 24 ml each and closed with a screw cap. The closure contained one with Teflon # coated sealing washer or a silicone rubber washer.

These bottles were kept for 3 months at + 50 ° C, then 6 months at + 30 ° C and stored for a further 12 months at + 20 ° C, as well as for 24 hours at temperatures kept at -200C. There were no changes in the pale yellowish color, no cloudiness, no crystallization and also no evolution of gas. To further Control was a development comparison with one from a freshly prepared Developer concentrate of the same composition prepared developer made.

Both developer concentrates with a volume of 24 ml were each 260 ml Ready-to-use solution (1: 10.8) and a 35mm film in each of the two solutions Developed at 350C for 7 minutes in one tilting dispenser each. Then the Films rinsed with water for 1 minute and then in one for 10 minutes bleach-fix bath (blixer) known from positive technology, bleach-fixed for 10 minutes. Within processing and measurement technology-related Tolerances from D = +0.05 there was no decrease in the activity of the stored compared to the fresh Developer can be proven.

Measurement of the color neutrality showed that Kodacolor II films as well as 3M-Colorprint-400-Films the deviations of the densities of the three basic colors red, green and blue in the density range D = 0.1 ... D = 2.5 were less than D = 0.1.

79 shows the corresponding measurement results on one Kodacolor II film each exposed to daylight in 8 steps, each developed to a contrast of t = 0.65. One film (dotted line) was in the developer according to the invention developed, the other in a developer otherwise of the same composition, however without borates. The pH values of both developers were adjusted to the same value (pH = 10.4). The dotted lines (711), (721) for the developer according to the invention indicate the slight deviations in the yellow density (711) and the purple density (721) of the negative compared to its cyan density again with increasing exposure. The corresponding Deviations in the borate-free thinning developer for yellow (71) and purple (72) are many times larger. Such negatives would turn out to be common calibrated printers result in paper images with a strong color cast.

With individual filtering, the lights are tilted towards green the result in reddish shadows.

The extremely good shelf life of the specified concentrate relates especially on the self-decomposition of the constituents. For one-part concentrates So far, even with airtight packaging, decomposition due to incompatibility has been observed of the substances or as a result of the amounts of oxygen trapped during manufacture held to be inevitable.

This concentrate also occurs in partially filled bottles if the bottle is opened several times in the meantime, a gain after a few weeks the yellowish color of the concentrate and a slight loss of effectiveness of the assigned developer. Airtight packaging is therefore a prerequisite for using the invention.

Fused ampoules are suitable as airtight packaging Glass or thick plastic (Fig. 1).

To make it easier to open, screw locks (3) can be removed Plastic or metal coated with plastic (31) can be provided (Fig. 2). The plastic layer (31) is on the one facing the liquid Page.

A particularly light and material-saving packaging is obtained if you weld the developer in portions in foil bags (Fig. 3!), the from a layer sequence (from inside to outside): thermoplastic plastic (401), Aluminum (402) and, if necessary, other plastic or protective varnish exist is in connection with the invention the oxygen-impermeable aluminum layer (402) (5pm ... 50pm thick). Instead of the foil bag, cups can also be welded on Lids made of such plastic-aluminum layers are used (Fi.SR).

Further details of the packaging can be seen from the figures.

FIG. 1 shows a sealed ampoule with walls (4) made of glass or thick-walled plastic that contains the developer concentrate (1), as well as a certain Contains gas volume (2). The neck (5) can be broken off or cut off.

FIG. 2 shows a bottle that contains the developer concentrate (1), as well as contains a certain volume of gas (2). With the screw cap (3) the sealing Washer or coating (31) pressed onto the threaded neck of the bottle.

FIG. 3 shows one at, for example, three edges, each with a weld seam (6) Sealed foil pouch made of a special material according to FIG. 6.

FIG. 4 shows the bag from FIG. 5 in cross section, the layer structure of the film material forming the walls (4) is explained in FIG.

FIG. 5 shows a bowl (42) filled with the developer concentrate (1), closed by a weld seam (6) with the cover (41). Bowl and lid consist of special material according to Figure 6.

FIG. 6 shows the layer structure of the material for foil bags, bowls and lid. The layer (401) is facing the content (concentrate) (1) made of thermoplastic plastic, followed by the gas-tight aluminum layer (402). Another layer (403) made of plastic or a Paint is made.

FIG. 7 shows the results of a sensitometric measurement of developed negative films. The curves (711) and (721) show the deviations of the Y or M density from the cyan density as a function of the exposure for devi cklun in dilution developer according to the invention. Curves (71) and (2) show the corresponding results for an equally concentrated developer without added borate.

Attachment: 10 claims 7 figures

Claims (10)

Claims: Concentrated Color Developer 1. Air-tight sealed liquid developer concentrate, intended for dilution with water and to be used for a one-time development of one or simultaneous development of several color negative films, on the basis of a development substance in the form of a para-phenylenediamine derivative, of an alkali in the form of a carbonate, the amount of which is at least 10 times the amount corresponds to the developing substance, further auxiliary and protective substances and water as a solvent, characterized in that the developer concentrate apart from water also contains a water-miscible organic solvent in an amount which is more than 10 times the weight of the developing agent; the existence Borate is included as a further alkali and that all substances become a single one liquid solution are combined, which are sealed in an airtight Portion container is located. 2. developer concentrate according to claim 1, characterized in that the water-miscible organic solvent is an ethical alcohol, or a polyoxyethylene glycol of the formulas HO (C2H4O) nH, n-1,2 ... or a mixture of several such substances is. 3. developer concentrate according to claim 2, characterized in that the solvent ethylene glycol or di-ethylene glycol in an amount of 10-20 times Weight of developer substance is. 4. developer concentrate according to any one of claims5 1-3 in that the developing substance [N-ethyl-N5- (2'-hydroxyethyl) -toluene-2,5-diammonium sulfate (Monohydrate)]. 5. developer concentrate according to any one of claims 1-4, characterized in that the alkali in the form of a carbonate is potassium carbonate, its amount is dimensioned so that for one liter of developer diluted as intended, 10-25 Potash um carbonate commerl. 6. developer concentrate according to any one of claims 1-5, characterized in that the borate ummetaborat as another alkali of boron trioxide, boric acid, sodium Di-sodium tetraborate or mixtures of these substances is formed and that on 1 mole of potassium carbonate 0.1 to 0.5 mole of boron is omitted in the corresponding compounds. 7. developer concentrate according to any one of claims 4-6, characterized in that the developer concentrate is provided for about 10-fold dilution and that 100 ml concentrate about 1 g developer substance about 209 potassium carbonate about Contains 15 ml of ikthylene glycol or diethylene glycol, for the exact amounts a margin of + 30% is permitted. 8. developer concentrate according to any one of claims 1-7, characterized in that the airtight portion container is closed on all sides Ampoule made of glass or thick-walled plastic (Fig-. 1). 9. developer concentrate according to any one of claims 1-7, characterized in that the airtight portion container is a bottle made of glass or plastic with screw connection (3) and 20 to 200ml content (Fig. 2). 10. developer concentrate according to any one of claims 1-7, characterized in that the airtight portion container is made of thin-walled, at least two layers of material (42), in which the, the content facing Inner sides consist of a thermoplastic plastic material (401), which on the side facing away from the content is coated over the whole area with an aluminum foil (402) is.