DE1266641B - Process for developing diazotype copies - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

G 03 c

German KL: 57 b - »/ es · 44

Number: 1266 641

File number: J 28094IX a / 57 b

Filing date: May 8, 1965

Open date: April 18, 1968

There are already processes for developing photosensitive diazo compounds coated Papers known in which the papers are exposed to ammonia vapor in a developing chamber will. The ammonia vapor is generated by heating ammonia water. This diazotype process are z. B. in the introduction to the German patent 820,373 described. These procedures however, require a relatively long development time that the copying speeds required today has not grown anymore. In addition, the known development processes lead to an unsatisfactory resolution of the Diazo compounds result, which is a consequence of the diazo diffusion during the slow development process is.

In the above-mentioned patent, it is mentioned in lines 19 to 29 of column 2 that at Use of highly concentrated ammonia solutions to create an overpressure in the development chamber can arise. However, this overpressure is described as undesirable.

The blueprint machine used commercially today contains a chamber in which a Container that can be heated. At a concentration of around 20 to 25%, the ammonia becomes water dripped into the heated container where almost all of the ammonia along with a large Part of the water is evaporated. Diazo paper or Diazo film is brought into contact with the hot, damp ammonia fumes. With regard to the development of paper, experience has shown that a certain degree of moisture is very essential for the proper development of diazo paper. The development Ammonia-containing films and papers are also accelerated by heating.

When films and papers are developed at room temperature, the development is extreme slowly, and the results are unsatisfactory. While modern blueprint machines are diazo papers can expose at a speed of more than 30 m / min are the development devices not up to this speed. In such cases there is a second or multiple pass through the ammonia chamber required in most cases to ensure that the has converted all of the unexposed diazo compound to form azo dye. This fact that cannot be developed at blueprint speed, of course, greatly reduces the value of high-speed exposure devices and the use of very light-sensitive diazo paper.

Process for developing diazotype copies

Applicant:

International Business Machines Corporation,

Armonk, N.Y. (V. St. A.)

Representative:

Dipl.-Ing. G. Brügel, patent attorney,

7030 Boeblingen, Sindelfinger Str. 49

Named as inventor:

John Wallace Boone, Saratoga, Calif .;

Henry Swan Todd, Los Gatos, Calif. (V. St. A.)

Claimed priority:

V. St. ν. America May 25, 1964 (369 861) - -

A number of other difficulties are associated with the currently employed development process, using hot vapors from ammonia water for development. For example, many diazo products contain several couplers and / or various diazo compounds. In practice it has been found that the colorations obtained depend to a large extent on the development conditions. For example, a "hot, dry" environment produces slightly blue copies, while a "cool, dry" humid environment often produces yellow-brown shades.

In addition, a certain moisture content is essential for the development of diazo paper; the The speed of development depends to a large extent on the amount of water present. So too little water causes poor development and discoloration while Too much water results in soaked prints, bleeding colors, warping and color defects.

The difficulties related to paper products listed here are compounded even in the case of the "dry development" of diazo films. These diazo films generally exist made of a transparent, tough carrier, a polyester film that is stable in its dimensions, with which a synthetic resin layer for diazo sensitization is bonded. Cellulose acetate is a well known one layer that can be used for this purpose. In view of

809 539/373

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the water-repellent properties of such a diazo rate would be expected, an increase

Layers occur when using ammonia- the rate of development is achieved

water difficulties. In addition to some hundreds of times faster than those with

Development difficulties that were already achieved in the case of ammonia under the same conditions

Paper mentioned, further problems show up, 5 was. EHe development takes place almost instantaneously

such as the tendency of the film to lent itself under so that along with the relatively low

certain humidity and heat conditions temperatures that are used practically none

to discolor and glaze, and a noticeable diffusion of the diazo compounds occurs before the

Reduction of the development speed, since the compound becomes resistant to diffusion due to color formation,

rapid penetration of the ammonia water. In addition, an essentially constant temperature

is made more difficult by the layer. In addition, a temperature is possible so that the relative coupling

corrugation of the material caused by water, the speeds remain constant,

one of the main difficulties in using films and papers made according to the method

of paper, with certain types of film, the invention is being developed, show one so far

Drive out of control. 15 unmatched fidelity. Since the speed

Ultimately, one of the greatest difficulties the new process makes possible arises Capabilities in Current Developing Processes Apparatus for developing with constant density construct a lack of resolution due to the winding time instead of variierba diffusion of the diazo compound during the relatively ren development period, that of "synchronized" Malang seeds Development process. Since technology is indispensable, stelnik become blurred of the photographic materials does not approximate the stage of development, spots and warpage in the films To resolve 1000 lines / mm, it is greatly reduced or completely avoided. the Meaning that the latent image during the after-sensitivity and color fidelity and the extra Process stages is retained. In the case of decent speed of development Diazo film process, it is essential that the 25 lent continuous cooperation with mo development process It is geared towards the fact that the data-processing machines. Diffusion of the diazo compound to a minimum In the process according to the invention what is kept will, d. H. that the diazo compound by serfree, pure ammonia gas with a pressure ver-color formation turns diffusion-proof as quickly as possible, which is sufficiently high that a condensation becomes. It is known that the diffusion rate of the gas in the molecular pores of lightness increases at a higher temperature, so that a sensitive layer can be expected. the Low temperature development is desirable. Coupling reaction can therefore in the presence of fluids it is necessary that there is sufficient ammonia in place of ammonia water Enter the amount of developer as quickly as possible.

penetrates into the synthetic resin layer that carries the diazo image. 35 It is known that in liquid ammonia it carries. The ammonia evolution process, rates of many reactions are essentially obviously unsuitable in this regard, and are higher than in water. A preferred possibility of a strong deterioration in the image resolution in order to carry out the development with the consequence of diazodifusion is shown in development processes according to the invention is that processes in which heat is applied to a piece of film or paper between two surfaces during development Development is introduced to achieve a satisfactory image with _a small distance, so that only development is essential. very little free space is left. Then the

The ammonia water development technology is extracted from air so that the diffusion of the development of the properties described cannot cope with today's application gas due to the presence of air requirements. This defect _{45 is} hindered. Subsequently, ammonia gas will be crucial in film systems in which supplied with a pressure that is slightly above the high demands on the resolution. Saturation pressure is (about 6 to 8 kp / cm ² ) and one

It is the object of the invention to provide a new duration of fractions of a second (e.g. about

to specify the development process, which is much faster o, l seconds). Immediately afterwards the ammo

ler expires and a stronger resolving power _5o niakspuren on the film or paper by suction

who allows diazorypie copies. or by placing in a vessel with an am-

The inventive method for developing monia absorbent removed.

of diazotype copies is characterized in that the method according to the invention is so efficient

the development with anhydrous ammonia at kungsvoll that almost no excess ammonia

a pressure greater than 3.5 kp / cm ² and a temperature remains so that the gas evacuation or removal

temperature between 4 and 100 ° C is carried out. _is very easy with other means. The entire development

The invention is based on the drawings in the winding process therefore requires at room temperature

individually explained. It only shows temperature for about 0.2 seconds. One stands for it

F i g. 1 the dependence of the development time on the development time of several minutes compared to

Pressure of the ammonia gas and 60 in the known devices, the ammonia "

Fig. 2 shows a comparison of the development water used at the same temperature.

times when applying the procedure according to which are.

Invention and the known method. The inventive method can also

The invention allows the development of diazo to use in non-sucked air. Is preferred Film and diazo papers at room temperature in a 65 developing chamber with a relatively low-level location the high temperatures used so far. ammonia introduced under pressure to the volume of air. Despite the use of low temperatures, it has been found that this is a complete solution in itself a reduction in development pacifying development even with existing

being of air is possible. The only major difference between the development at before Evacuation and the presence of air is due to the fact that developing in the latter If the pressure the ammonia has to be increased by about the level of the atmospheric pressure, in order to be able to carry out the development in the same time as with the method with the previous one Evacuation can be achieved.

It is known that the speed of a chemical process by increasing the concentration a catalyst or the concentration of one of the reacting constituents will. It should be noted, however, that apart from the other advantages, the increase in the Development speed, as it is guaranteed by the process, is decidedly greater, than was to be expected from an increase in pressure. It is assumed that the specified Pressure conditions the coupling reaction takes place in liquid ammonia.

The following examples show the improved development times brought about by the new process compared to other commercially available diazo developing machines. In all Examples tested three different types of commercially available diazo films. The movies are denoted by A, B and C.

Example I.

Apparatus similar to that used in U.S. Patent 2,948,208 was used to obtain the to test three different diazo films. This apparatus contains a central cylinder around which the film samples to be developed are laid. This cylinder is surrounded by an outer cylinder, which forms the developing chamber; in addition, heating devices are provided to maintain the developing chamber at an elevated temperature of about 47 ° C. A measured one Amount (115 g) of 28% ammonia was poured into the bottom of the cylinder and the indicated Temperature set. Samples of each of the three types of diazo film were placed around the heated central Cylinder placed. The development time was measured with a stop watch. Different patterns of each type of film were treated in this way, each individual pattern being different for one has been exposed to ammonia vapors for a long time. At the end of the set for each pattern During development time, the clock was stopped and the sample was removed from the development chamber.

The degree of development of each pattern was determined by photographic density measurement, and the results are shown in Table I as a percentage of contrast developed. “Complete Development «was defined as follows:

"« / 0 \ L> _max i-> mln) ' ^tJ min

or 90% of the possible maximum contrast, where D _{max is} the maximum or the greatest possible density of the film and D _{mln is} the density of the film before development.

In the table under "% Contrast" the percentage of complete development is given was achieved for the film in question in the specified development time.

Table I.

A. Develop Vo B. »/ O Kon C. o / o con lungs time contrast Develop touch Develop touch in lungs time lungs time Seconds 3.1 in 1.2 in 4.8 5 3.6 Seconds 1.8 Seconds 7.2 10 6.7 5 2.3 5 11.2 15th 12.9 10 3.5 10 15.2 20th 17.0 15th 11.7 15th 22.8 30th 30.0 20th 22.8 20th 40.8 40 43.8 30th 35.6 30th 57.6 50 46.4 40 43.4 40 72.0 60 65.4 50 49.1 . 50 87.3 75 75.8 60 62.0 60 95.2 90 83.5 75 74.3 75 105 92.8 90 84.3 90 120 105 120

Example II

Samples of each of the listed diazo films were then placed on a blueprint machine. This machine uses ammonia water at a higher temperature. These film samples were developed at different belt speeds for different development times apply. The data obtained with this machine are shown in Table II.

Table II

A. Develop ° / o B. ° / o Kon C. %> lungs time contrast Develop touch Develop contrast in lungs time lungs time Seconds in in 54.5 34.5 Seconds 16.5 Seconds 1.04 59.0 1.04 95 1.15 58.0 1.04 1.30: 63.0 50.0 1.50 i 70.0 1.50 1.73 74.0 56.0 28.0 2.10 80.0 2.10 65.5 2.60 83.0 2.10 80.0 2.10 44.5 3.5 91.0 3.5 85.0 52.0 4.2 92.5 3.5 62.0 5.2 98.0 5.2 97.0 4.2 70.0 6.5 "100.0" 5.2 81.0 7.4 6.5 87.0 7.4 91.0 10.4 »100.0« ö, / 95.0 10.4 96.0 11.5 99.0 13.0 14.9

Example III

Samples of each of the listed types of diazo film were developed in a diazo film processor, in which warm ammonia water is used at a temperature of around 47 ° C. the Data obtained on this machine are summarized in Table III.

Table ΠΙ

A. % Con Develop B. ° / o C. ° / o Kon Develop touch lungs time contrast Develop touch lungs time in lungs time in 32.1 Seconds 37.5 in 47.3 Seconds 37.8 5 49.2 Seconds 52.2 2 44.5 10 57.5 5 59.5 3 58.5 15th 68.8 7th 66.0 5 64.2 20th 78.5 10 76.6 7th 71.5 30th 87.8 12th 82.2 10 76.8, 40 93.0 15th 87.3 12th 84.0 50 97.0 20th 97.0 15th 91.2 60 97.8 25th 20th 96.4 75 "100.0" 30th 25th 90 30th

Example IV

A sample of each of the various films listed above was kept in an apparatus developed according to the method according to the invention. The apparatus has a device that an almost instantaneous addition of ammonia gas to a chamber at a pressure that is slightly below the saturation pressure of liquid ammonia at room temperature (20 ° C). This chamber has a very small volume; by inserting the pattern between two closely fitting ones There is little empty space left on surfaces. After evacuating the air in the chamber, ammonia was added to the chamber with the aid of fast-acting mechanical valves, through which the ammonia gas remains in the Development chamber of about 0.05 seconds were allowed.

The ammonia development chamber was then emptied, air was let in and the sample was taken taken. Various ammonia pressures were used and the development times observed are in Fig. 1 shown as a function of development pressure.

From Fig. 1, it is found that complete development is carried out in a very short time and that when the developing pressure is as low as 7 kgf / cm ^2, the most photosensitive film was fully developed in 0.1 seconds.

When developing in the presence of air, it is only necessary to increase the pressure of the developing ammonia by the level of atmospheric pressure in order to achieve complete development in the same time as developing without air. Under these circumstances, the diagrams of FIG. 1 also apply to the development in the presence of air, with the one exception that the pressure values are to be increased ^{by 1 kg / cm 2.}

The results of the investigations described above are shown in the diagrams in FIG. 2 summarized, in which the data of Examples I to IV according to contrast in percent as a function of the Development time in seconds are shown.

The graphs of Fig. 2 clearly show the superiority of the present invention in terms of development time. It can be seen that even the fastest running machines known in the art (Example II) took about 3.4 seconds with the most photosensitive film to achieve 90% contrast while going through the process according to the invention, at a pressure of 8.5 kp / cm ^{2, the} same film pattern achieves a contrast of 90% in a time of 0.07 seconds; this corresponds to an improvement factor in the development time of almost 50. A contrast of 90% could be achieved in 0.35 seconds even with the least sensitive film. This corresponds to an improvement factor in development speed of about 10 over the fastest operating machine known from the prior art (Example II) with the most sensitive film.

F i g. Figure 2 also shows that the other two known machines (Examples I and II) are essential work more slowly than in the method according to the invention. The improvement factor over these Machines is 330 or 1100.

Different copies show noticeable differences in color when used in the known apparatus had been developed according to Examples I or II. When developing according to the process according to the invention a very uniform density was found.

It is believed that when pressure is applied, the coupling takes place in a liquid ammonia environment within the molecular pores of the resin layer. The optimal pH range is between 4.5 and 9.5. Above a pH value of 9.5, the coupling rate is reduced because of the conversion of the diazonium ion into the diazotate in an aqueous medium (see R. Wi st ar and PD Bartlett in "Kinetics and Mechanism of the Coupling of Diazonium Salts with Aromatic Amines in Buffer Solution ", Journal of American Chemical Society, Vol. 63, pp. 413 to 417, [1941]). In the development process of the invention, it is believed that the ammonia permeation of the film in a substantially non-aqueous environment would be highly alkaline conditions which would allow a high rate of coupling without the formation of diazotate.
The ammonia pressure range that can be used according to the invention is quite large. The curves in FIG. 1 show that at a pressure of about 6 kgf / cm ² the development time for all film samples was less than one second at room temperature. Even an absolute pressure of 3.5 kp / cm ² made this possible

go development of all film samples in times that were lower than or equal to those for the fastest working known device (Example II) are required.

The upper pressure limit of our invention is similarly determined by a number of practical factors, such as condensation of ammonia on the surface of the film at very high ammonia pressure. The maximum ammonia pressure upon development in accordance with the present invention preferably does not exceed the saturation pressure of the Ammonia at the temperature used to cause condensation of ammonia on the film avoid. The applicable temperature range for the ammonia is from 4 to 100 ° C, whereby Room temperature has proven to be particularly favorable. If ammonia temperatures are used, which are above room temperature, it is advantageous to have the development chamber with the diazo

material to about the same temperature as the ammonia to avoid condensation.

When using ammonia under pressure, it is necessary to precisely control the development time in order to achieve complete development of the film without undesired chemical reactions of the film due to excessive exposure to the ammonia at these pressures. The calculations showed that at a temperature of 100 ° C. with a corresponding ammonia ^{pressure of 64 kp / cm 2} absolute, 90% development of a diazo film would occur in 0.35 milliseconds. Such pressures can be used to limit the contact time of the diazo film with the ammonia to this short range. In a single development system the mechanical problems are e.g. With respect to valves, to achieve such a short development time, considerable. However, if the diazo material is in strip form and it is passed through the development station at a corresponding speed, development times of this magnitude can be achieved.

In all experiments carried out according to the method according to the invention, was anhydrous ammonia gas is used.

Claims (4)

Patent claims: 1. A method for developing diazotype copies, characterized in that the development with anhydrous ammonia at a pressure greater than 3.5 kp / cm ² and a temperature between 4 and 100 ° C is carried out. 2. The method according to claim 1, characterized in that the development in a development chamber is carried out after suctioning off the air. 3. The method according to claim 1, characterized in that the development takes place in the presence of air and that the total pressure is higher than 4.5 kp / cm ² . 4. The method according to any one of claims 1 to 3, characterized in that the development is carried out at a pressure of the ammonia of 6 to 9 kp / cm ² and at a temperature of about 20 ° C. Considered publications:
German patent specification No. 820 373. 1 sheet of drawings 809 539/373 4.68 © Bundesdruckerei Berlin