DE482165C - Method for cleaning gelatine surfaces - Google Patents

Description

Procedure for cleaning gelatin surfaces During the manufacture of colored cinema films, as is well known, the transition of the dye from the developed ones Split a die film onto the blank film by touching the two directly Surfaces and subsequent absorption of the dye caused by the blank film.

The Manicealfilffi can either be developed according to the complete image to be transferred to the blank film, as is the case with monochrome films, or only certain parts of the image can be developed according to one color for the purpose of multi-color printing. In each case the developed template film is wetted with the dye and the excess is removed if necessary. The liquid is selectively ab.sorbiert from the developed parts or adsorbed, and ACCORDING any although greater or lesser amounts to the level of development given part. Development here is not necessarily understood to mean the dissolution or removal of a, part - of the template surface, but some physical or chemical change in the template surface, whereby its adsorbing property is increased above that of the normally smooth surface that such films usually present .

While some dyes are now transferred from the die to the blank film in the omit essential completely, there are others for which this is not the case which leave a significant amount of the dye on the die. The amount of dye left can be increased by increasing the contact time between die and blank film can be reduced considerably or through use a more absorbent blank film # so that g ge usually. practically a complete one transition of all the dye located on the surface takes place.

In some cases a permanently adsorbed or adhering part of the dye can remain on the template. This phenomenon is called permanent coloring (croceination), and those parts or properties of the coloring matter which lead to this phenomenon are called permanent coloring. Such a property-en show overall know dye solutions (especially the Crocein saffron Farhen, daher- above name) and may be either an incomplete original resolution of the dye it or be recycled to a subsequent excretion of certain dye portions, so that in this ] Your particles are suspended, which have a greater density or concentration than the rest of the dye and therefore impair the even distribution of the same over the die surface.

The residue can only be a small amount with a single coloring turn off; however, it will accumulate in a series of printing operations. on in any case it is desirable and necessary to him to remove, and although without. Adjustment or even slight changes to the film surface, see above that # the matrix can be used continuously with satisfactory results.

The method according to the invention comprises thorough wetting, for example by dipping the surface to be cleaned with an excess of the solution of an inert base (preferably an organic amine) which does not whiten the gelatin, followed by rinsing, if necessary, with fresh amounts of the solution and the drinking with or without recovery of the liquid, as this is desired or feasible.

It has been found that compounds containing an amino group # z. B. the organic amines, which are inert to the surface to be bent, especially are useful and effective for the complete removal of residual dye. A # s Diethylamine has proven to be particularly suitable. It was also found that the more expensive Aminoverbialdungen expediently and economically by a treatment can be replaced with mixtures of their effective individual wheels.

For example, instead of diethylamine, the much cheaper mixture can be used of ethyl alcohol and ammonia, have been used with essentially equal success.

Even though numerous other possible uses of the invention are conceivable, it will only be described with regard to its ability to remove fax material residues from matrix films. - For this one purpose, either an aniin solution is used or an equivalent mixture of its components, e.g. B. Either diethylamine or an EthyWkohaUösuilg of ammonia. Lefttere is in concentrations of 2% (95%) alcohol or less and 2% ammonia or preferably itself less effective, the latter being without influence on gellatin substance against both the developed and unchanged smooth areas of the matrix surface.

The matrix skin, which is caused by the accumulation of residual tissue. If it is soiled, it is first placed in a bath of the alcohol-ammonia solution before it is dried immersed, the solution preferably kept in unidirectional motion is then removed and passed through drying ovens or the like to make the solution to evaporate quickly.

The ammonia or the basic component of the solution has a similar effect like the corresponding diet liykmin and is probably used primarily for Neutralization of the acids.

The alcohol also serves to promote rapid drying, which is desirable in view of the length and volume of the film. It also has the effect of retaining the solute in the bath if the ammonia content is reduced due to evaporation. The whole mixture is rapidly and completely evaporated and thus removed from the matrix surface, which remains free and clean and essentially in a changed condition. If the die is very dirty, or if a large amount is to be cleansed of Matrizenfilmen, it is desirable to provide a größexen over the cleaning liquid in the bathroom to use, and also a number of au # successive washes instead of a single - to be provided. In this case, the later washes are carried out with less soiled solutions in accordance with the known countercurrent principle.

-When handling large amounts of film, it may be desirable to use the evaporated solvents for the purpose of reuse back: to condense and condense, especially when these are expensive or difficult to obtain.

Claims (3)

PATENT CLAIMS: i. A method for cleaning gelatine surfaces, characterized in that they are treated with a volatile solution of a base which does not affect the gelatine and then dried. 2. Procedure according to Auspmch i, characterized in that an o. Organic amine, especially diethylamine, is used. 3. The method according to claim i, characterized in - that an alcohol-containing ammonia solution with no longer gIS 2 0/0 ammonia is used.