DE882998C - Planographic printing film and process for its manufacture - Google Patents

Description

The invention relates to planographic printing films based on coated paper and a. Method of manufacture * such foils.

Paper-based planographic printing foils are used in place of lithographic stones or metal plates used, which are generally used in lithographic printing. When using such Planographic printing films, such as B. when using lithography stones and metal plates, this is ίο to be reproduced, d. H. the printed image, namely a drawing, handwriting or print, by means of a substance, usually of a fatty nature,

z. B. recorded with a pencil, pen and ink or a typewriter on the surface. If water is now applied to the surface of such a plate, resist because of their greasy surface, the parts of the surface that represent the printed image Moistening by water, and when printing ink is applied to the plate, it is only from the parts that represent the printed image are accepted, but not the parts that are moistened with water. In other words, the water is only accepted by those outside the print image

lying surfaces ^, but not of those who do this Show print image. The result is a printing surface that uses the printing ink in a pattern picks up and transfers this to another surface, although all parts of the printing surface are flat, d. H. neither elevated nor deepened.

In order to achieve satisfactory performance, the non-printing or free areas must ίο the plate will have a continuous, aqueous film, and the amount of that on the surface of the non-printing areas retained aqueous liquid may from beginning to Do not waver at the end of a print job. During the printing process, the plate is using A roller dampened the water or etching solution or wiping water on the non-printing Surfaces, and then through another roller that applies the printing ink to the ao print image or the! printing areas applies, moistened with the 'printing ink. Accordingly, the Color, which is applied to the printed image areas, when an untrimmed sheet against the plate provided with printing ink is pressed, transferred to the paper, while the areas that come into contact with the parts of the plate that do not have a printed image, remain empty, since these Flat the plate are only moistened with water and have no printing ink. If the transfer is in the manner described on an empty Sheet is done, the print appears as a mirror image and is, if it is text or print acts, not easily readable; accordingly, it is common to use offset printing machines too use, in which the print image is first transferred to a cloth, which the print as a mirror image, whereupon the 'cloth is brought into contact with an empty sheet, which takes up the print image in its original form.

In order to properly understand the invention, one must realize the many problems involved with whom those grappled with in the past who have already tried to produce flat printing films with paper backing. These difficulties and their reasons will now be discussed.

If ordinary, cheap paper, such as. B. soda paper, is taken as a base occurs Swelling and change in dimensions when the water or wiping solution hits the surface penetrates and softens the substrate. Distortion of the printed image and imperfect Record are the consequences.

When the aqueous wiping solution penetrates into the film body, the surface of the film becomes less completely! moistened, since the water is from the surface is peeled off into the film. The surface can then no longer receive the printing ink repel, and surface parts that should be completely empty turn dark and tone.

When there is a colloidal coating as the surface and water penetrates this surface and makes them soluble under the greased parts of the printed image, the printed image no longer adheres to the Foil and has a tendency to fall off or wander off the printing surface. If on the other hand If the surface does not accept the fat, the substance representing the printed image will not stick properly, and there is then the same disadvantage. The substance representing the printed image must adhere tenaciously to the film and must neither completely nor partially fall off or gradually penetrate Gradual transfer of the printing ink from the printed image areas will be destroyed.

These difficulties are particularly considerable in the case of films which are used for long runs Find use and are therefore exposed to frequent wetting with water and printing ink. One has Attempts have already been made to counter these difficulties by placing one between the paper backing and the surface has laid a resinous, water-repellent separating layer, but prevented it this does not mean that the water from the surface into the coating layers above the release layer penetrated. The use of a release coating also incurs special costs for such a coating Parting layer, so this way out is neither practical nor satisfactory, especially with cheap ones Foils.

Various other difficulties also arise. Unless both sides of the slide are covered with a water-impermeable separating layer, can be used during storage, when wetting or after printing a throwing of the foil will occur because both sides of the foil are not even are damp '. Fingerprints and accidental color stains on the film can only be difficult, if at all, to be removed and reproduced onto the blank sheet. On the Foil can, no etchings are made, or if such are done, this must be done with a liquid. The films show signs of aging within a short time. The printing ink often tends to emulsify and lose its sharpness and clarity. Complicated procedures are required in processing and handling. Before the Bringing to the press may require some processing and a few copies can be matt in the beginning, until the wiping water and the inking rollers have rubbed the foil several times have happened, resulting in a waste of paper and time. Special typewriter ribbons or pencils are required.

Many of the difficulties encountered in the past with paper-backed planographic printing films result from · the fact that surfaces, the grease and printing ink in more satisfactory Assume wise to be easily penetrated by water or the wiping fluid and as a result quickly lose the ability to reproduce images (tinting), so that the slide is only a short one Has a lifetime and unsatisfactory printing properties having. In order to work satisfactorily, the film surface must be such that it

completely and evenly wetted with water or wiping solution, but not may penetrate into the film to a greater extent during the life of the film. Simultaneously the film must have the ability to hold on to the greasy material that represents the printed image, however, the printing ink that is removed from the rollers must not come from the image-free ones Areas are retained or penetrate into ίο these.

Accordingly, it is the primary purpose of the present invention to provide a coated planographic printing sheet to be provided with paper backing with which a sufficient number of clear and sharp prints can be obtained that are cheap and economical according to those in the paper mills conventional processes can be produced that do not tint during use, their printed images during use does not fall off, which makes it possible to remove fingerprints, paint stains and the like, allows the etchings to be used without liquids and without the etching being visible, which do not throw themselves, which are stored in an archive without any loss of utility value and can therefore be used again after storage, which is also before input into the printing press requires no pre-treatment and provides usable copies immediately after use.

Another object of the invention is to provide new and improved methods of making these new To provide flat printing foils.

It is also the purpose of the invention to enable the interposed release coating can be omitted, the earlier to prevent the penetration of water into the paper backing was used, and thereby to give the possibility to produce a FoJie, which by order a single overlay of certain material on the paper backing serves many purposes. The invention relates to the treatment of the hydrophilic planographic printing surface, which is used to receive the Print image is suitable, as described below, with a solution of a water-soluble, salt of a divalent metal which is stable in water or other incorporation of such a salt in such a way that suitable films are produced without relying on a resin-containing, use a water-repellent separating layer or, if such a layer is used, foils to produce that have a particularly long service life and other significant improvements. the The invention therefore makes it possible to produce foils for short, medium-long or long printing, in which there is practically no difference in production or composition. One Long run film according to the present invention can produce over 12,000 copies, while short-cycle transparencies can be used for over 300 prints.

Using the invention results in a paper sheet with a printing surface which is finely divided Contains mineral particles and a hydrophilic, print image-receiving material, which with a treated with a water-soluble salt of a divalent metal which is stable in aqueous solution or 6s this contains.

The water-soluble, water-stable salt of a divalent metal can be made as such an aqueous solution of the salt, which does not contain any substance that chemically reacts with the salt or with the metal compound (s) that when evaporating an aqueous Solution in which the salt has been reacted with ammonium hydroxide remain.

The exact essence of the action of the water-soluble metal salts »on the printing surface is not entirely clear, but it is certain that; it increases the ability of the surface, by water or Mopping water to be wetted, while at the same time allowing the penetrability of the printing surface by washing water or grease and does not affect the surface's ability to Taking up and holding back the substance that represents the printed image. This is probably because of this hence that the water-soluble and water-resistant metal salt tends to get into the interstices to enter, fill and stop, d. H. so the capillary pores and spaces in or between the finely divided mineral particles, which colloidally incorporated into the coating are, especially when a wetting solution is needed that reacts with the metal salt in such a way that a bulky precipitate is formed.

The metal salt increases the netiz ability for aqueous solutions on the film surface, which should take up the print image, and even for printing is determined while at the same time providing resistance to water ingress increased after application of the usual network solution and continues to produce a surface that is sufficient Has fatigue strength.

In any event, it was found that the water-soluble and water-stable salt of a divalent Metal as part of the printing surface of the flat printing foils with coated paper backing, which have been produced according to the present invention, the printing surface of which is so affected, that the new planographic printing films have the aforementioned desirable properties and Possess characteristics including remarkably higher resistance to penetration of both fat and water, as they compare! flat printing foils with coated paper backing manufactured earlier are own. It is therefore necessary no commitment to any explanation of the appearance, whether it is chemical or physical or partly chemical or partly physical in nature.

After so in general the properties of the planographic printing films, with paper backing, which after The invention are made, and their advantages have been set forth, is now an accurate Description of the manufacturing methods of the new foils are given. That for making the Printing film for a so-called medium printing

The process used, which is intended to produce approximately 1,000 prints, should be sent to first Place described. Thereupon -will be a description 4 Albanian changes to the general procedure follow that apply and are necessary to the process on the manufacture of to convert a short run transparency suitable to make approximately 200 copies. It a description of the modifications then follows of the general procedure required to convert the process to the manufacture of a film for long print run that is intended to produce 5000 or more copies Hey far.

Foil for medium-length printing example 1

Operation ι: During each sheet of paper that possesses sufficient wet strength to withstand manufacture and use when Basis used in the production of the planographic printing films according to the present invention becomes a specifically suitable sheet of paper for use in the manufacture of the new foils made as follows.

A waterproof paper web, weighing approximately 31.5 kg, equivalent to 500 sheets, which in 63.5 X 96.5 cm, can be made from a paper stock composition the soda pulp and sulphate or bleached soda pulp treated in the Holländer, Contains rosin glue, melamine-formaldehyde resin, and alum. The web produced is then mostly, but not necessarily, on the surface with an aqueous solution ammonia casein, to which an aqueous formaldehyde solution is added .. 0.450 to 0.900 kg (dry weight) of the casein paste should be absorbed per 500 sheets. the Web can then be dried and calendered on the machine. Instead of a * part or the Whole sulphate pulp can use sulphite pulp and clay or other suitable ones Fillers, although not particularly desirable, can be added to the pulp.

Instead of the materials that have been used to make the one made after this first step To give paper sheets wet strength, so instead of the melamine-formaldehyde resin and of the surface glue from ammoniacal casein-formaldehyde solution, other known ones can also be used Materials! can be used to impart wetness to the paper, including Urea-formaldehyde resins, formaldehyde glue, viscose and other materials.

While using melamine-formaldehyde resin alone in the paper stock composition or the sole use of the mentioned casein / formaldehyde wiping liquid Sheet is obtained which has sufficiently good wet strength and as a basis for the production of flat printing foils for medium-length printing Can be used in the present invention, a very good sheet is obtained for the new planographic printing foils for medium-length printing by the fact that melamine-formaldehyde resin in the paper stock composition and then casein-formaldehyde solution is used.

Operation 2: A sheet of paper or a paper web, which is produced according to the aforementioned first step can be used on both sides 3.6 to 6.3 kg, preferably 5.4 kg per 500 sheets (dry weight) of a mixture are coated, which has the composition shown in Recipe 1 below to provide a pigmented hydrophilic To achieve a base coat of the printing surface of the foils for medium-length printing.

Recipe 1

Pigment (clay) (finely divided) 100.0 parts by weight hydrophilic adhesive base (casein) (in an aqueous

Ammonia solution) 17.5 - ^S 5

Dimethylolurea (around the

To make casein insoluble) 1.75

The sheet or the paper web on which the pigmented hydrophilic adhesive coating is located can be placed on it according to recipe 1 above, dried in a suitable manner, e.g. 10 for up to 15 minutes at a temperature of 50 to 60 °. Calendering follows, although not necessarily necessary is.

Operation 3: The coated and calendered paper sheet can then be applied to the one side can be treated with a hydrophilic, planographic image accepting Material in the form of a solution of a hydrophilic colloidal coating essentially the same as in the composition shown in recipe 2 below, so as to form the body of the outer coating to be delivered, which is applied to the printing surface of the new planographic printing foils.

Recipe 2

hydrophilic material that accepts a planographic image (Na-

trium alginate) 1 part by weight

Water ... .. 95 parts by weight

Butanol 4 -

The butanol used here will reduce the foaming of the mixture and make it easier to penetrate of the hydrophilic colloid (sodium alginate) into the capillary spaces, these are the spaces in between or pores between the finely divided mineral particles of the clay pigment in the pigmented, hydrophilic adhesive or the clay-casein-based coating.

Operation 4: The surface of the sheet of paper that has been painted over in this way is then at room temperature Treated with a mixture, which is composed mainly according to the following recipe is.

Recipe 3

(Water-soluble, water-stable salt of a divalent Metal :)

Zinc acetate Zn (C ₂ H ₃ Oo) ₂

2 H ₂ O (commercially available) 25 parts by weight

Water 72

Butanol 3

If desired, although less convenient, the order in which the planographic image accepting material according to recipe 2 (sodium alginate) and the metal salt solution according to Recipe 3 (zinc acetate) is applied, reversed and the metal salt solution applied directly to the The base spread is applied and the hydrophilic material (sodium alginate) is then applied to the first layer to be brought.

Operation 5: The thus coated and treated sheet is then dried and the top then rubbed the printing surface with rotating brushes. While in the process present invention this operation of rubbing or brushing the printing surface of the is not essential or indispensable to new planographic printing foils, it increases the The lifespan of the transparencies is improved in terms of their ability to reproduce the printed image the quality of the printed images reproduced by the transparencies treated in this way. About that addition, the treatment is by rubbing or brushing the top of the printing surface of the new Planographic printing foils are suitable for any excess metal salt that is underneath the surface of the foil Circumstances crystallized, remove; it increases the resistance to a large extent the so treated printing surface of the new printing foils against fingerprints and printing ink stains. It also makes it easy to remove such fingerprints and ink stains by means of an aqueous etching or moistening solution used in planographic printing or by means of an aqueous, repellent wiping solution for planographic purposes from the printing surface of the Foils while at the same time increasing the resilience of the printing surface of the new planographic printing foils increased against the ingress of fat and water.

The one mentioned in Recipe 3. Butanol is used to carry out the mixture present invention is not essential, but facilitates and promotes penetration the metal salt solution (zinc acetate) into the capillary spaces created by the pores or Gaps between the finely divided mineral particles be formed in the clay-casein-based coating of the printing surface of the new Paper-backed planographic printing films have the advantages and desirable characteristics described above confers. Instead of butanol, equivalent volatile, water-miscible Solvents, such as ethanol, methanol, propanol and the like, in appropriate proportions Find use.

It is possible to use the sodium alginate solution in the context of the present connection from Recipe 2 and the zinc acetate solution from Recipe 3 in a single solution, but they are both. Substances incompatible with each other if the solution is not strongly ammoniacal. It is therefore better to separate the two solutions and in two separate phases when carrying out the apply the present method with painting in two steps, as described here will. In this method, the preferred concentration of this sodium alginate is in the Solution according to recipe 2 about 0.25 to 2 percent by weight of the solution, and the best concentration The zinc acetate in the solution of Recipe 3 is about 5 to ι ο * percent by weight of the mixture, preferably about 20%, where zinc acetate is calculated as anhydrous zinc acetate.

The clay-casein ratio in the recipe 1 The aforementioned clay-casein-based coating can largely contain from about 12 to 100 parts of casein per 100 parts of clay and the weight of the clay-casein coating from about 2.7 to 13.6 kg each 500 sheets and paper side can be varied.

Instead of the clay-casein-based coating mentioned in recipe 1, which was used during the implementation the present invention can be applied according to the aforementioned example 1, can be used as other suitable pigmented hydrophilic coatings based on adhesives in the Carrying out the present invention according to the two-pass painting phase, those in the previous. Example 1 was set out, as well as the painting phase with one operation, set forth in Example 2, the following hydrophilic adhesive-based materials are used be: glue, gelatin, soybean protein, zein, insolubilized starch, polyvinyl alcohol, Gum arabic or any other equivalent, glue-based, hydrophilic substance that p ^ gments and made highly resistant without impairing their hydrophilic character can be against · the penetration of fat and water by means of a water-soluble, in water stable salt of a divalent. Metal incorporated into the printing surface of the planographic printing film is.

In addition, the clay or pigment component of the pigmented, hydrophilic coating can Glue or clay-casein base included in recipe. 1 is mentioned, in whole or in part, by others suitable, finely divided mineral pigments are replaced, such as. B. barium sulfate, calcined clay, Talc, satin white, titanium dioxide and other equivalent, finely divided mineral pigments.

Other water-soluble, hydrophilic colloids that are used in place of sodium alginate as an external hydrophilic Coating material for the recording of the planographic image and instead of the one in the above recipe 2 used sodium alginate can be used and which are intended to be used with the zinc

Acetate solution of the recipe 3 of the Druckaberfläche the To give new printing film »the above-mentioned and desired properties are the in the following table ι listed water-soluble, hydrophilic, colloidal substances.

.Table ι. '

i. Types of rubber.

2. Proteins

3. Synthetic hydrophilic colloidal
Substances ......

4. Other suitable
hydrocolloidal
Substances ......

Arabica, mesquite, karaya, pod bean (Robinia pseudoacacia), guar (and Mannogalactans, similar to guar gum), ammonium alginate

Casein, soybean protein, zein, glue (animal), gelatin, Egg albumin, blood albumin

Carboxymethyl cellulose, sodium polyacrylate, a carboxy derivative of by addition a suitable alkali, such as. B. caustic soda, solubilized Polystyrene, methyl cellulose, oxethyl celhilose, polyvinyl alcohol

Starch, dextrin, pectins and their derivatives including fibrous sodium pectate

This can be used in the manufacture of planographic printing foils according to the present invention, and this was actually done, that in prescription 2 sodium alginate mentioned above by each of the following. Substances in the specified percentage to be replaced with enough water and butanol in the ratio given in Recipe 2 ι oö'Parts of the solution to produce.

Gum arabic 1 to 10 parts by weight

Mesquite rubber ...... 10

Karaya gum. 0.5

Pod thorn

bean gumtni 0.2 -

Guar gum 0.2 -

■ Ammonium alginate 0.5 -

Casein 1 -

Soybean Protein .... 1

Zein ι -

Glue (animal) 0.5 -

gelatin

Egg albumen

Carboxymethyl cellulose ..

Sodium polyacrylate

a cariboxy derivative of
by adding a suitable alkali, such as
z. B. caustic soda, soluble
made of polystyrene

0.5-

5 -0.5-0.5-

i ι 2

IO

5 5 2 2

IO

Methyl cellulose 0.5-2 parts by weight

Oxethyl cellulose 0.5-5 "

Polyvinyl alcohol 5 -

Strength 1 -10

Dextrin I - 10

Sodium pectate (fibrous). 0.2 - i »5 '~ ■

If desired, mixtures of the mutually compatible hydrophilic, colloidal substances mentioned in the above and Table 1 can be used will.

When using the above-mentioned hydrophilic colloidal substances as an outer spread on the printing surface of the new planographic printing films, the outer surface was of each of the thus smeared sheet having a I5 ^o / o solution of zinc acetate in water, and butanol in virtually the same ratio as in Recipe 3 above, indicated, after which each of the webs was then dried and treated with rotating brushes as in operation 5 of the previous example i.

Instead of zinc acetate as a water-soluble, water-stable salt of a divalent one Metals can be each of the use water-soluble metal salts for the same purpose and in the specified concentrations, which are listed in Table 2 below. All of the following water-soluble metal salts are sufficiently stable in aqueous solution to be used in the practice of the present invention To be able to find use, the ratio of water and butanol to one another in the Solutions is roughly the same as in recipe 3 above.

Table 2

Barium acetate 5 to 20 parts by weight

Barium Nitrate ..... 5-20 - ^

Cadmium Acetate 5-20

Calcium acetate 5 - 20

Calcium chloride ......... 5 - 25

Calcium formate 5-15 ~

Calcium nitrate .......... 5 - 25

Cobaltoacetate 5-20

Cobalt chloride ......... "S- - 25

Cobalt nitrate. ... 5 - 25

Cupric acetate 5-15 - no

Cuprinitrate 5 - 25

Cupric sulfate 5-20

Ferrous sulfate at 5-20

Lead acetate 5-20

Lead nitrate. 5-25 -

Magnesium acetate 5-20 -

Magnesium chloride. 5 - - 25 -

Manganoacetate ......... 5-20

Manganese nitrate 5-20

Manganese sulfate 5-20 -

Mercury chloride 5-20

Nickel acetate 5-15

Nickel sulfate 5-20

Strontium acetate 5-20

Strontium nitrate ......... 5-20 ■ -

Zinc chloride ............ 5 - 25 -

While all of the water-soluble metal salts given in Table 2 above in aqueous solution do so are stable in that they act as a modifying agent in and for the printing surface of the new planographic printing foils Can be used is the use of the acetates of the divalent metals in place of the others Salts listed in Table 2 are preferred, since the acetates are readily dissolved in water are soluble, sufficiently stable in water and their ίο application under the usual manufacturing conditions is easily possible.

If desired, mixtures of the metal salts mentioned in Table 2, which with one another are compatible.

While all of the water-soluble metal salts listed in Table 2 above were used in the execution Some of them tend to find use of the present invention, namely the manganese salts, ferrous sulfate and mercury chloride, to give somewhat unstable aqueous solutions, especially if they are kept for long periods of time; they are therefore less suitable for use in the practice of the present invention than the other water soluble ones Metal salts, which are listed in Table 2 and have sufficient stability in aqueous solution, so that they are used in the practical implementation of the manufacture of the new planographic printing films can be.

In this regard, it should be noted that the most appropriate percentage for the water-soluble metal salt, which is to be used for the solution according to recipe 3 above, in part from the special coating method and the one used in the manufacture of the new planographic printing foils Apparatus is dependent and something can be changed depending on the situation of the case. if z. B. is applied by spraying, is a slightly higher concentration of the metal salt in its aqueous solution is recommended than is necessary when using an ordinary brush applicator Is used.

When using the metal salt solution of Recipe 3 or any of the other salts one divalent metal according to Table 2 or their mixtures, regardless of whether they are before or After application of the hydrophilic colloid is applied from the metal salt solution best taken from 2 to 19 liters per 500 sheets. So, z. B. achieves good results, when about 7.5 l of the metal salt solution is applied to such an amount of the coated paper when cut to size to make 500 63.5 X 96.5 cm sheets.

In addition, it is important in practicing the present invention that the concentration of the metal salt in aqueous solution practically constant under the production conditions and the drying cycle used in the preparation of the treated with the metal salt solution new planographic printing foils is used, it is adjusted so that the metal salt

can penetrate well into the printing surface of the foils before the aforementioned metal salt solution dries, since 65 otherwise easily too high a concentration: or even crystallization of the metal salt solution on the Outer parts of the printing surface of the printing foils can arise, as a result of which faulty printed images This can result in 70 i when using the foils.

The temperature at which the water-butanol solution of the zinc acetate according to recipe 3 can be used, as well as the temperature, in which a corresponding aqueous solution of another metal salt according to Table 2 at the Production of the printing films used according to the present invention depend partly on the method of application used, although generally an aqueous solution of each these metal salts at normal temperatures, d. H. at ambient temperature can.

With regard to Table 2 it should be pointed out that it comprises the most important water-soluble, water-stable salts of divalent metals selected from Group 1, 2, 4, 7 and 8 of the Periodic Table. In Group 6 of the Periodic Table there is chromium, which is divalent salts such as B. forms chromium chloride; However, this group of chromium salts is not stable insofar as they easily oxidize in the presence of air to form chromium salts and chromic acid with the intermediate formation of unstable compounds. It. it was found that all water-soluble salts of divalent metals selected from group 1, 2, 4, 7 and 8 of the periodic table and are sufficiently stable in aqueous solution, incidentally, it does not matter in which of the mentioned groups of the periodic table the metal component of the salt may be classified, can be used as a modifying agent in the printing surface of the planographic printing films with coated paper backing, produced according to the present invention, while such salts of divalent metals, such as e.g. B. chromosalts, which are soluble in aqueous solution, but are unstable in aqueous solution and tend to oxidize or in various ways to decompose, are unsuitable for the method according to the present invention. It has also been found that water-soluble salts of trivalent metals which are stable in aqueous solution, such as. B. some of the salts of the metals selected from Group 3 of the Periodic Table, such as e.g. B. aluminum, for which aluminum chloride (AlCl ₃ ) should be mentioned as an example, are unsatisfactory, especially insofar as' the printing surfaces of the planographic printing foils, in which any of these water-soluble salts of trivalent metals is incorporated, too little stability during aging and when stored for a long time before Has use. It was also found that the water-soluble, water-resistant salts of monovalent metals do not have the desired modifying effect on the printing surface of flat

have printing inks with a paper backing, which the claimed salts of divalent metals have. With the various possibilities of replacing the sodium alginate of recipe 2 according to table 1 and with the selection of a suitable metal salt from table 2, which is to be used in recipe 3 instead of the zinc acetate mentioned therein, it is expedient to use a hydrophilic colloid or another hydrophilic one Substance for the recording of the elach print image as well as; to choose a water-soluble, water-stable metal salt, which are compatible with one another in all proportions, without the need for any additional substance. However, if in some cases and with certain mixing ratios a certain degree of obvious incompatibility occurs between the selected hydrophilic colloid or other hydrophilic substance that accepts the planographic printing image and the selected metal salt, this incompatibility can be overcome by adding a solubilizing agent suitable for the selected combination is bound long, is applied to the hydrophilic colloid or other hydrophilic coating mix and the metal salt solution on the pigmented hydrophilic adhesive coating and ^{getrocknet.sind:} wherein the Mietallion the salt temporarily be so. If, for example, one of the metal salts from Table 2 is mixed with sodium alginate from recipe 2 or with ammonium alginate or with one of the proteins (casein, soybean, zein, glue, gelatin and albumin), with carboxymethyl cellulose or sodium polyacrylate from Table 1, a certain amount of gelation occurs one, but this can be remedied and the substances made compatible with one another by adding enough ammonia to make the mixture ammoniacal. However, these are the only possibilities in which incompatibility can occur, as was found in the preparation of the various combinations in Tables 1 and 2, which, however, as indicated, can be remedied by adding ammonia. It may be added that the use of ammonia is particularly effective when a water-soluble, water-stable, copper or zinc salt is used with the hydrophilic colloid or other hydrophilic planographic image-receiving substance. A suitable further sprinkling mix for use in the two-phase process can be prepared as follows.

Pectate paper pulp was prepared according to the following recipe:
Recipe 4

Pectate paper pulp (dry) ............ 20 g

Sodium carbonate 2 g

Water (boiling) 440 g

When producing the pectate paper pulp or the sodium pectate according to recipe 4, dry sodium carbonate was uniformly mixed with dry pectate paper pulp. The mixture was then added to the boiling water and boiled for 10 minutes. The dispersion thus formed was then allowed to stand for 6 g overnight, and gelation was then shown. After warming and dilution with cold water to a concentration of i ⁰ / "the insoluble part was removed by passage through a filter cloth. The approximately 10% sodium pectate solution thus prepared was then applied to a suitable sheet having a clay-casein-based spread prepared according to Recipe 1, whereupon the treated sheet was dried at 85 "for 5 minutes. The sheet was then washed with a 16% solution of zinc acetate ¹ (calculated as anhydrous zinc acetate), then dried and rubbed be achieved.

Other examples of pectins and pectates that can be used in place of the recipe 4 above Manufactured sodium pectate can be used are in the American patent 2,287,849.

"" Example 2

Instead of applying the outer coating of a hydrophilic, planographic printing image-receiving material to the pigmented, hydrophilic coating based on adhesive and metal salt solution in two separate, successive phases according to Example 1, the coating and the metal salt treatment can also be carried out in a single spreading mixture and in one phase will. This method has certain advantages over the two-phase method of example i, e.g. B. the fact that it allows better control in production and eliminates the need to force the metal salt solution to penetrate the previously applied and underlying coating of a hydrophilic colloid or a similar hydrophilic substance receiving the planographic image, as necessary using the procedure of Example 1 in which the metal salt solution is applied after the hydrophilic colloid or similar material. ■>' no

A suitable sheet of paper, which can be of the same type as that in Example 1, is first prepared provided with a suitable pigmented, hydrophilic, adhesive-based coating, the clay-casein-based one can be built up according to recipe 1 "5 or another equivalent, pigmented, can be an adhesive-based hydrophilic coating material; the coating is then for example at a temperature of 50 to 60 ° 1.0 to 15 minutes long dried. An outer coating is then applied to this dried coating, which is a hydrophilic colloid or other equivalent, hydrophilic, planographic image receiving Contains material as selected from the appropriate materials listed below can be, and at the same time a water

soluble salt of a divalent metal, stable in water, derived from the preceding Table 2 can be selected.

For example, a suitable coating mixture of hydrophilic colloid and metal salt can be used for the single-phase process can be made according to the following recipe:

Recipe 5

hydrophilic colloid (1.25 " _½ guar gum in water, corresponding to 0.22" ι, dry guar gum in the total amount) 8.95 parts by weight

aqueous formaldehyde solution

(40% HCHO) 1.75

aqueous silicon dioxide cl

(i5 ^u / "aqueous dispersion. 1.33

(0.2 parts dry weight) aqueous solution of zinc acetate

(25% Zn (C ₂ H ₃ Oo) ₂ ) 33.40 parts by weight

(7 parts anhydrous zinc acetate)

Butanol 1.50 parts by weight

Dye (aqueous solution of

Viktoriagrün - 0.22 ⁰ Z ₀ ) 3.65

50.58 parts by weight

When applying the coating mixture according to recipe 5, consisting of hydrophilic colloid and Metal salt, or any other coating mixture used in the single phase coating process of Example 2. Is this coating mixture is expediently applied in an amount of 2 to 19 liters and to a sufficient one Amount of coated paper applied so that after cutting 500 sheets of 63.5 X 96.5 cm develop. Good results are obtained if 7.5 1 coating mixture per 500 sheets, as indicated, Find use. A typical coating mixture contains 0.25% guar gum, 15% Zinc acetate (calculated as anhydrous zinc acetate) and 0.4% aqueous silica sol. This coating mixture " has a specific weight of 1.1. The coating mixture of hydrophilic colloid and metal salt according to recipe 5 above can be used in a single operation at room temperature applied to the pigmented, hydrophilic base coat using any suitable coating device will. It is then allowed to dry, whereupon the printing surface of the so coated. Arch functional, but not necessarily rubbed with rotating brushes. The merits of this Rubbing treatment has already been explained in example 1 (operation 5) »

In the manufacture of the new planographic printing foils with paper backing using the outer Coating mixture for the single phase process according to Recipe 5 above or any of the equivalents For the external coating mixes for the single phase process mentioned below, it is important that the drying rate of the applied coating mix is adjusted so that a proper one Penetration of the coating in the base coat is achieved because, when the applied coat does not have enough time to penetrate into the base coat before drying, in the case of the metal salt there may be a tendency to crystallize out of the solution and an undesirable increase in the concentration of the metal salt on the printing surface of the foil to cause the rapid wear and tear of the greasy planographic image on the finished film in normal use. For the same reason it is important to ensure that the concentration of the various components of the coating mixture is kept practically constant during the coating process.

The hydrophilic colloid mentioned in the foregoing Recipe 5, namely guar gum, is a Vegetable gum originating from India, now available on the American market is. It's likely a mannogalactan. The concentration of this used in Recipe 5 above Materials can be between 0.05 to 1.25 percent by weight of the dry inclusive Spread mix, calculated on dry guar gum, vary.

The aqueous silica sol mentioned in Recipe 5 above is in US Pat U.S. Patent 2,375,738. This component of the mixture according to recipe 5 above can be used from 0.05 up to and including 2% dry weight of the mixture. The use of silica sol in the mixture facilitates the removal of fingerprints and ink stains of the printing area of the planographic printing foils produced and thus increases, although an additive does not This desirable property of the new printing foils is essential.

When preparing the coating mixture of hydrophilic colloid and metal salt mentioned in recipe 5, the hydrophilic colloid, the aqueous formaldehyde solution and the silicon dioxide sol must be mixed thoroughly with one another. The zinc acetate, butanol and dye solutions are prepared separately. The two solutions prepared separately in this way are then mixed with one another. The zinc acetate component of the coating mixture of the preceding Recipe 5 can vary from 5 to 25 percent by weight of the complete coating mixture, inclusive, the zinc acetate being _{calculated as anhydrous zinc acetate Zn (CoH 3} O ₂ ). However, as mentioned earlier, the concentration of the Zinc acetate, depending on the particular coating method and the equipment used, may vary somewhat.

The amounts and concentrations used in Recipes 3 and 5 and Tables 2 and 4 Metal salt each result in an excess of metal salt over the amount with the hydrophilic adhesive material (casein) in the base coat or with the hydrophilic, organic Material such as B. the sodium alginate in recipe 2, or with certain other hydrophilic, organic substances in Tables 1, 3 and 4 can react. No reaction can be seen

between the metal salt and certain other hydrophilic materials, e.g. B. guar gum from recipe 5, methyl cellulose, oxethyl cellulose or polyvinyl alcohol from Table 3. But the Amounts and concentrations of the metal salt mentioned allow every possible reaction and deliver in each case an excess of metal salt over the Amount that can react in each case. It can be assumed that this excess of metal salt with one or more constituents of the network solutions, z. B. Monoatnmoniumphosphat, reacts and everywhere forms a bulky precipitate, where the metal salt has penetrated into the base and that this process is of superior quality

* 5 of those made according to the present invention Flat printing foils explained.

Although the butanol in the spread mix of hydrophilic colloid and metal salt for the Single-phase procedure according to Recipe 5 is not absolutely necessary, so it nevertheless facilitates penetration the coating mixture into the capillary spaces, d. H. into the pores or spaces of the Clay-casein-based coating. Instead of Butanol, other equivalent volatile substances can be taken in appropriate amounts, including ethanol, methanol and propanol.

The water soluble one mentioned in recipe 5 above

Green dye can of course be replaced by any other appropriate water-soluble dyes can be substituted if a colored planographic printing sheet is desired.

It is also possible to dispense with the use of the dye, a white printing film being obtained.

Instead of the hydrophilic colloid found in the

Spread mixture according to recipe 5 is used, namely guar gum, other suitable ones can be used hydrophilic colloids as well as other suitable hydrophilic non-colloidal substances which are used to contain the Flat printing image are suitable, including those listed in Table 3 below Fabrics.

Tables

Types of rubber ...... Arabic, mesquite, karaya, S. Pod bean (and an Mannitol, Sorbitol Sucrose, 45 their mannogalactans, similar Invert sugar, corn syrup, Lich guar gum) Mannose Other suitable hy drophile colloidal Fabrics .... Starch, dextrin, pectins and 50 their derivatives including fibrous sodium respect Synthetic -hydro SC phile colloidal Fabrics Methyl cellulose, oxethyl cellulose loose, polyvinyl alcohol Hydrophilic, no colloidal matter 60 alien (coalhy drate)

So z. B. certain hydrophilic, the planographic printing image-receiving substances of Table 3 above in place of that given in recipe 5 hydrophilic colloids occur in the concentrations given in Table 4 below and further with such variations in the concentration of the metal salt component (zinc acetate) of the mixture, as they are also listed in the following table, in the zinc acetate billed as anhydrous salt.

Tables _{7 pounds} .

Gum arabic 4 parts by weight

and

Zinc acetate 15 -

Mesquite rubber 4 -

and "

Zinc acetate 15

Karaya gum 0.5

and

Zinc acetate 15

Bean Gum .... 1 -

and

Zinc acetate. 15th

Strength 5

and

Zinc acetate 15 -

Dextrin 5

and

Zinc acetate. . 15th

Sodium pectate ^ (fibrous) 1

and ==

Zinc acetate 16

Methyl cellulose 1

and

Zinc acetate 15 - ■

Oxethyl cellulose,. 0.75 -

and

Zinc acetate 15

Polyvinyl alcohol ............ 5

and
Zinc acetate ........... ....... 15 - i ° 5

Mannitol S

and

Zinc acetate 15

Sorbitol 5

and

Zinc acetate 15

Sucrose 5

and

Zinc acetate 15 -

Glucose 5 -

and

Zinc acetate. 15th

Invert sugar. 5

and

Zinc acetate 15 -

May syrup 5

and

Zinc acetate 15

Mannose 5

and

Zinc acetate ........ _t .... 15

Although the carbohydrates mentioned in Tables 3 and 4 or types of sugar, namely mannitol, sorbitol, sucrose, glucose, invert sugar, corn syrup and mannose, not colloidal in nature, have been found to be when used with one of the aforementioned metal salts as the basis of the mixture for the one-phase process manufacturable outer coating are used, the flat printing films with paper backing, which the the resulting hydrophilic surface that receives the planographic printing image, the latter modified by the metal salt component of the mixture, the desirable aforementioned Have properties and characteristics.

Any of the water-soluble, water-stable salts of divalent metals of Table 2 or Mixtures of mutually compatible salts from Table 2 can be used in the aforementioned recipe 5 take the place of the zinc acetate listed here or in place of the together with the different hydrophilic substances of Table 4 used zinc acetate, the hydrophilic Substances all take the place of the hydrophilic colloid mentioned in Recipe 5, namely guar gum can. If desired, mixtures of mutually compatible can be used in the same way Hydrophilic substances in Table 4 replace the guar gum mentioned in Recipe 5. With these different substitutions, however, it is advisable to use a hydrophilic colloid or a other hydrophilic substance that accepts the print image and a metal salt or mixtures Select these substances that are compatible with each other in any amount without the need for an additional material must be taken. However, if in some cases under certain conditions the Mixtures, some degree of incompatibility between the selected hydrophilic Colloid or another hydrophilic, the planographic printing image-receiving substance and the selected Metal salt results, this incompatibility can be remedied by adding a suitable solvent for the chosen combination can be fixed, thereby binding the metal ion of the salt for so long until the said mixture for the top spread to be applied by the single-phase method applied to the pigmented, hydrophilic adhesive-based layer and dried. if z. B. Karaya gum and zinc acetate in a mixture for a single phase process to be prepared spread, comparable to the above recipe 5, are used together, so occurs no gelation; but there may be separation on standing if the mix does not is stirred. However, this can be remedied by making the mixture ammoniacal will. However, the combination of karaya gum and zinc acetate can be used to make the mixture of the outer spread to be applied according to the single-phase process, which are therefore comparable can be used with recipe 5, with or without added ammonia.

Although it is the mixture for the outer spread to be produced by the single-phase process from · hydrophilic colloid and metal salt of the above Recipe 5 can be applied at room temperature, will in some cases give better results achieved when the said mixture is applied to the coating based on clay-casein or an equivalent, pigmented, hydrophilic glue is applied as a hot solution as this process the penetration of the metal salt component of said mixture for the single-phase process to be produced outer coating in the capillary spaces facilitated by the pores or Interstices in the coating based on clay-casein or an equivalent pigmented one Adhesives are formed and so the resistance of this clay-casein-based coating or another pigmented, hydrophilic adhesive against the penetration of fat and water reinforced.

Foil for short printing

Suitable flat printing foils with paper backing for the so-called short printing cycle, which is necessary for the production of approximately 200 copies can suffice within the scope of the present invention according to the method of Example 1 for producing the outer coating by the two-phase process go and by the procedure of Example 2 to produce an outer coating by the single phase method as well as using the substances listed therein, wherein Changes that are still desirable and necessary can be made, the production costs of the film for a short printing cycle in relation to those for the production a medium print film.

So when making foils for short Printing cycle according to the present invention a sheet of paper according to operation 1, example 1, made are, however, a relatively cheaper paper fiber is used and also the Substances to produce the wet strength are omitted, so as to reduce the production costs of the film to reduce. In this way, the operation can be omitted when producing the foils for a short print run through which the casein-formaldehyde glue is applied to the surface of the paper-based Sheet is applied, and also the incorporation of the melamine-formaldehyde resin in the paper stock composition according to operation i, example 1, are omitted.

When producing the film for a short print run, the casein content of the spread can be increased Clay casein base in recipe 1, example 1, on 20 up to 25 parts of casein per 100 parts of clay are increased to make the clay-casein-based coating to confer an increased resistance to the ingress of water in terms of then it is desirable that the sheet should not be treated with casein formaldehyde for short press runs as was done with the sheet for the medium-speed film.

Film for long printing

Flat printing foils with paper backing for long printing, for the production of 5000 and If more copies are used, according to the present invention, practically the same can be achieved Procedure and using the same materials as used in the Production 'of the foils for medium printing use, either after the Method for an external spread according to the two-phase method according to Example ι or according to the procedure for the external spread according to the Single-phase process according to Example 2 with such variations as are necessary for such Foils for a long print run are the ones required for this to give increased resistance to penetrating water. The slides for long printing process must be provided with a water-separating layer or a water-repellent coating which can be made according to the following recipe;

Recipe 6

i. Resin emulsion 15 parts by weight

consisting of: a) 100 parts ^ polyvin ylbutyral, b) 40 parts ^ utpriclnolSaTX plasticizer) and cj 5 parts soap (emulsifier)

2nd tone 15

3. Water 215

The resin emulsion and the clay were calculated based on their dry weights in the above formula.

The listed in the above recipe 6 Water release coating is applied to the paper sheet in an amount such that the coating has a sufficient thickness, which is achieved by using 2.215 ^>^{'ls 1} S ^% of the mixture according to Rezeptöpro 50oBlatt paper of the format given above with an optimum of 3.6 kg per 500 sheets.
Instead of the water release coating according to Recipe 6, other suitable mixtures can be used for their preparation. These include urea-formaldehyde resin, polyvinyl chloride, polymerized vinylidene chloride, polystyrene, various acrylates and numerous elastomeric type resins and mixtures thereof.

The effectiveness of Ammonia to promote the compatibility between salts of divalent metals and hydrophilic, organic substances pointed out, which makes it possible that in a single aqueous Solution two otherwise incompatible components can be mixed together, whereby an otherwise necessary special operation in the process is eliminated. Such ammoniacal aqueous solutions of metal salts can also be successfully converted into the aqueous solution Mixtures for 'the pigment adhesive coating are included. A suitable coating mixture contains 1. a pigment or filler material, such as B. Ton or Blanc-fixe, 2. an organic one Glue, such as B. casein or glue, and 3. a solution of a metal salt and in particular one ammoniacal solution of a metal salt, which is first precipitated by ammonia and then by excess ammonia is brought back into solution, di. H. a dissolved ammonia complex compound of the metal. The coating differs from the previous coatings in that are used as relatively large amounts of metal salt, d. H. it will be much more Salt used than can react with the glue. A comparison of the following Examples 3 and 4 shows.-Den beneficial effect of the inclusion of ammoniacal cupric chloride in a clay-casein coating mixture is achieved.

B-ei game 3

Cupric chloride was dissolved in water to a solution of 22 parts by weight of CuCl ₂ in a total of approximately "60 parts by weight. Concentrated ammonia water was slowly added with stirring This solution was then stirred into an ammoniacal casein solution containing 22 parts by weight of casein for a total of 90 parts by weight. This in turn was added to 100 parts of Georgia coating clay in water so that the final mixture had a content of 35 ^g / o The amount of copper salt used was just over 15% of the total solids present in the coating and was consistent with the weight of the adhesive used. This coating mixture was 63.5 X 96 at 5.85 kg dry weight per 500 sheets , 5 cm in usual Way painted on one side of the above mentioned material. The paper coated in this way was dried and calendered.

The sheet thus obtained was typed on using a suitable ink ribbon described. The sheet was then transferred to a plate cylinder on an offset reproduction machine placed, in the usual way with an aqueous solution of glycerol and acid phosphate washed. It was then used in the usual manner as with a lithographic printing plate. The print quality achieved was excellent. After ι obo prints, the print was still from perfect condition; In addition, the bow was not soaked in water, which is showed that the coating worked as a printing surface and as an effective water release layer.

B e i s ρ i e 1 4

The procedure of Example 3 was repeated, but omitting the ammoniacal Copper solution. In this case it was the whole

Plate on first contact with the ink rollers completely black and the sheet was unusable as a printing plate. This example shows, as a contrast to Example 3, the importance and the effect of the metal salt.

Instead of the clay pigment and casein glue used in Example 3, any other of the aforementioned pigments or fillers or any of the other hydrophilic adhesives mentioned above can be used in whole or in part. If desired, a mixture of adhesives can be used or another hydrophilic colloid can be added in a small amount to improve the hydrophilic properties of the coating. A sufficient amount of adhesive should be used to hold the cover firmly in place on the backing. The absolute minimum to be used can be determined by experiment. As is known in practice, this minimum depends on the amount of force inherent in the adhesive to be used, on the filler material used, on the quality of the carrier material used and the weight of the coating applied. In general, the amount of the adhesive used is not less than 10 parts per 100 parts of filler, but is preferably not less than 15 parts per 100 parts of filler. Far more than the required adhesive due to its adhesive force minimum \ ^ir can be applied orteilhaft. However, an excess of glue causes difficulties such as warping, buckling, etc. Consequently, 75 parts glue per 100 parts filler material can be regarded as the usable upper limit, while it is appropriate not to use more than 50 parts per 100 parts filler material.

The weight of the applied coating can be between about 0.5 to about 3.5 kg per 90 square meters or between approximately 1.3 and approximately 3 kg per 500 sheets (63.5X96.5 cm) vary. The surface is expediently calendered, but this is not absolutely necessary.

It goes without saying that that in the

The metal salt used in ammoniacal solution must be a salt of a metal that is in excess Ammonia is soluble. The most effective metal salts are those that when they are made alkaline by ammonia water, first a precipitation of the hydroxide of the metal form, peptize or dissolve with further addition of ammonia water. These include copper, Zinc, cadmium, nickel and cobalto salts. If such ammoniacal metal salt solutions either used in a pigment adhesive coating mixture or as a wiping liquid on the surface of the coated sheet of paper are applied, there is a likelihood that at the drying or evaporation of part of the metal salt with the glue, e.g. B. Casein, connects, while a greater part of it is undoubtedly in the surface coating than the metal hydroxide and another perhaps present as a metal ammonium salt.

In any case, a much larger amount of the ammoniacal solution of the metal salt must be used be used to take effect according to the invention than with the glue or a other organic, hydrophilic substance present is able to react. This is shown in the following example 5 shown.

Example 5

The procedure of Example 3 was repeated, with the difference that instead of the ammoniacal copper solution, an ammoniacal solution of zinc chloride equivalent to 66 parts of ZnCl ₂ was used. The zinc hydroxide that was precipitated first is brought back into solution with additional ammonia water. The results obtained were practically identical to those of Example 3. It should be noted that in this case the amount of anhydrous zinc salt used represented 35% of the total solids present in the coating and corresponded by weight to 300% of the weight of the casein used.

In this example 5, the theoretical amount of zinc chloride that can react with the casein glue was at most 1.5 parts, while 66 parts of zinc chloride dissolved in ammonia were actually used in the mixture. An experiment showed that. Mixtures according to Example 5, except for the amount of ammoniacal zinc chloride, 11 parts of zinc salt, calculated as anhydrous ZnCl ₂ , were too small to show sufficient effect. However, satisfactory results were obtained when the zinc salt used, calculated as anhydrous ZnCl ₂ , was present in an amount of approximately 15 to 42% of the total solids present in the coating mixture.

Other examples are given below that make the application of solutions easier and more ammoniacal Show salts of divalent metals on coated paper surfaces.

Example 6

A sheet of wet strength paper was coated on one side with a coating containing 100 parts of clay and 18 parts of casein dissolved with ammonia. Approximately 6.75 kg dry weight of coating was applied per 500 63.5 by 96.5 cm sheets. The coating was dried, calendered and then washed with a strongly ammoniacal solution to which 16 percent by weight of Zn Cl _{2 had been} added. The sheet was dried and then used as an offset plate. 1000 impressions -_._ prints were made without any objection to moisture penetration of the plate. The print quality was good.

Example 7

Example 6 was repeated, but with the difference that the ammoniacal zinc chloride mixed solution was replaced by a 20% lead

acetate solution. The results were practically that same as in example 6.

Example 8 5

One sheet of wet strength material was used on one side per 500 sheets. 1.5751 kg dry weight of a mixture of 100 parts of clay, 35 parts ammonium caseinate and 10 parts mesquite gum coated. The bow was calendered and then rinsed with a S% aqueous solution of zinc acetate. After drying this film was very resistant to penetration when used as an offset film voii water and made good prints. The usage of the very hydrophilic mesquite gum was very favorable in this case.

From the preceding examples it can be seen that the amount of metal salt used, regardless of whether it is in the form of the simple salt or an ammonium complex, must be in a certain ratio to the amount of glue (casein or the like) contained in the coating, and it is true that the amount of metal salt must always be higher than that which reacts with the glue, so that unbound salt is present. It also follows that, when the lower and upper limit of the already indicated range, ie, are ⁰ to 42 Zo, exceeded 15, the results are unibefriedigend. It is also advantageous that when applying aqueous solutions of the metal salts to a coated paper surface, it is only necessary to apply an amount of the metal salt which is greater than that which reacts with the adhesive content of the surface of the coating, since only the surface of the pigment coating and not all of its depth is affected by the applied metal salt. Therefore, if a small amount of the metal salt applied to the surface of the pigment adhesive coating did not penetrate, it would exceed the amount required to react with the adhesive in or on the surface of the coating. The actual salinity of this part of the coating has not yet been determined; but from the description already given it appears that the salt content obtained by surface treatment of the coating with salt solution is between 15 and 42%.

Labeled inert filler, pigment and similar expressions used in the following Claims are used to mean finely divided inert substances, in particular finely divided Mineral fillers such as B. the aforementioned clay and similar substances that are well known and in the art of papermaking and the Paper coatings are used as fillers or pigments and are now also used in the coating on the hydrophilic adhesive base of the new flat paper printing films are incorporated as finely divided fillers or mineral particles dispersed therein, although these substances in carrying out the present Connection cannot be used to color the new printing foils.

By the term printing surface is meant the dried product that comes from the coating is formed, which consists of a hydrophilic adhesive in which finely divided mineral particles are dispersed, and / or the outer coating of a hydrophilic material, the Printing surface either the evaporation residue of a water-soluble salt of a divalent one Contains metal that is stable in aqueous solution, or the evaporation residue an aqueous ammoniacal solution of a complex compound of ammonia and bivalent Metal and is modified by these.

From the preceding description it can be seen that according to the present invention new and improved planographic printing films with paper backing can be produced having the advantages and desired advantages set forth above and still other Have characteristics.

It can also be seen from the above that the present invention is new and improved Offers mixtures and processes with which the new planographic printing foils can be produced.

Claims (6)

PATENT CLAIMS: i. Flat printing film with paper backing, characterized in that the paper backing a coating of hydrophilic adhesive material, e.g. B. from casein, with therein finely divided mineral pigments has, whose capillary pores at least on its surface the evaporation residue the aqueous solution of a salt of a divalent metal stable in water or an ammonia complex compound of such a metal, with a larger amount of metal salt or compound present than is able to react with the hydrophilic adhesive material. 2. Planographic printing film according to claim 1, characterized in that it is a wet-strength paper support contains. 3. Planographic printing film according to claim 1 or 2, characterized in that an acetate or an ammonia complex compound of 'zinc, copper, cadmium, nickel or cobalt is used as the metal salt. 4. planographic printing film according to claim 1 to 3, characterized in that it is on the hydrophilic Coating with mineral particles dispersed in this finely dispersed additive Contains coating made of hydrophilic, organic material. 5. A method for producing a planographic printing film with a paper backing according to claim ι to 4, characterized in that a sheet of paper with a mixture a hydrophilic adhesive material and finely divided mineral pigment coated and after drying, a water-soluble, water-stable salt of a divalent metal or an ammonia complex compound one such a salt in the surface in a larger amount incorporated as to react with the hydrophilic adhesive material \ ^r EMAG. 6. The method according to claim 5, characterized in that the metal salt or the Metal compound in aqueous solution directly on the pigment-containing, hydrophilic coating after it has dried or on a layer initially applied to this coating a hydrophilic, organic substance or together with this hydrophilic, organic Applies fabric. © 5258 7.