DE7323369U - HIGH-IMPACT POLYSTYRENE FILM FOR COLOR DEVELOPMENT SHEETS - Google Patents

Description

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HENKEL, KERN, FEILER & HÄNZEL ^

BAVARIAN MORTGAGE AND

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OJI Paper Co., Ltd.

Tokyo, Japan

2 3 DEC. 1975

/ High impact polystyrene film for color development

leaves

The invention relates to a high-impact polystyrene film for the development of color images that are extremely erasable and extremely resistant to sunlight and water.

It is generally known that colorless color formers which are reactive with acids, e.g. crystal violet lactone, Leuco auramine compounds, leucomethylene blue compounds and leuco fluoran compounds, by contacting Let develop into dyes with an acidic color developer.

Such colorless color formers which are reactive with acids as well Suure color developers get used in the manufacture of Reproductions and hard copies are used.

As a rule, there are the usual pressure-sensitive, carbon-free ones Copy paper made of a top layer, on one surface of which there is a layer of a colorless one Color former containing microcapsules is located, and a base, on one surface of which is a layer of a

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Color developer suitable for removing the color from the colorless color former is applied. The color developer layer of the Backing points towards the microcapsule layer of the top layer.

The microcapsules consist of fine particles of a solution of the colorless color former in a non-volatile solvent and a thin shell covering the fine particles. The thin shell usually consists of one film-forming material such as gelatin.

When on top of the top layer by writing on with hand or typewriter as desired When pressure is applied, the pressurized microcapsules break, the solution being colorless Color former out of the broken microcapsules with the color developer layer of the lower layer in Comes into contact, so that color images are formed on the base v / ground.

The backing of the pressure-sensitive copier paper can be used as a printing film for printing with the colorless color former containing printing ink can be used. That is, if the formed by the colorless printing ink on the printing plate colorless images with the color developer layer are brought into contact with the printing film, the colorless printing color images are transferred to the surface of the color developer layer transferred to the printing film, on which color images are created.

The colorless color formers that can be developed by acid are electron donors, the acidic color developers are electron acceptors. If consequently the colorless color formers with the color developer !! come into contact, an elec-

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tron of the colorless color former molecule on the color developer molecule over, whereby the colorless color former changes into a (colored) dye.

Colorless color formers representing electron donors include colorless triphenylmethane compounds, e.g. crystal violet lactone, which is excellent in coming into contact with the electron accepting color developer Has color-forming ability, the colorless triphenylmethane compound quickly turns into a light bluish-purple dye. The triphenylmethane dyes possess however, when developed on conventional color developer sheets have the following disadvantages:

1. The triphenylmethane dyes are extremely low Resistance to light, i.e. if it is only exposed to or exposed to direct sunlight for a few hours Exposure to UV light will ground the colored triphenylmethane dye images bleached and then disappear completely.

2. The triphenylmethane dye images disappear when moistened with water temporarily.

Because of the disadvantages outlined, the individual use of colorless triphenylmethane color formers is a duplication s or printing dye unsatisfactory. In order to counter the disadvantages described, the colorless Triphenylmethane color former is expediently mixed with a colorless leucomethylene blue color former and the resulting Mixture used as duplicating or printing dye. As a rule, they have methylene blue dyes high lightfastness. However, it is also known that the methylene blue dyes only have a very low

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ge color depth and discolouring with prolonged storage tend. Even if the color images are made from a mixture of triphenylmethane and methylene blue dyes are formed, this can be attributed to the bleaching of the triphenylmethane dye Color image from methylene blue dye remaining due to solar radiation is lower because of this Very difficult to read color depth. In addition, such color images change their hue on prolonged storage because of the tendency of the methylene blue dye to discolour.

On the other hand, the usual color developer sheets for forming color images (thereon) are of a series of large sizes Disadvantages. The color developers to be applied to the surface of the color developer layer are electron acceptors. For example, an acidic inorganic material, e.g. attapulgite, bentonite, Kaolin, zeolite and acid clay can be used. These solid acidic materials have the most disadvantageous ones Tendency to decompose by staying bsi longer than about one month's storage in the atmosphere their ability to develop the acid-developable colorless color former lose. The reason for this decomposition of such solid acidic materials is not yet fully understood, however, it is believed that they absorb water or with the carbon dioxide contained in the atmosphere react. For the reasons mentioned, it goes without saying that such inorganic acidic solid materials Color developing layers which do not act as color developers become completely useless after prolonged storage.

It is also known that phenol, phenol derivatives and condensation products of phenol can be used as a color developer for acid developable colorless color formers.

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However, a disadvantage of phenolic compounds is that they are high Have evaporation or sublimation properties, are rapidly decomposed when exposed to UV rays and a have a strong tendency to corrode the paper substrate of the color ^ i.j.

It is therefore a matter of course that conventional color developer layers are located Do not store with phenolic compounds on them for a long time without impairment permit.

It is also known that conventional color developer layers are used on the surface The color images formed are very poorly erasable and water-resistant.

The invention was now based on the object of creating a color developer layer which could be stored for a long time, inside it with the use of acid developable, colorless color formers to a high degree erasable, sun and Have water-resistant color images produced with a brilliant depth of color. There should also be a training method such images are created inside these color developing sheets.

The invention was based on the knowledge that the task at hand using at least one of the Can dissolve modified polystyrene sheets or films containing reactants.

The subject matter of the invention is thus a high-impact polystyrene sheet for color development, which is characterized in that it consists of one of at least one in unidirectional stretched polystyrene film of high impact resistance existing document, which is on one or both sides (one)

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by treating the relevant surface (s) of the high-impact polystyrene film with an organic liquid capable of swelling or dissolving polystyrene, paper-like, rough surface (η) with numerous micropores contained therein, and one contained in the micropores, for developing an acid-developable one colorless color former capable of acidic color developer.

It is known from US Pat. No. 3,515,567 and DT-OS 2,058,573 that a high-impact polystyrene film a plastic film with a paper-like, rough surface, which is written on with colored printing ink, reproduced and can be printed, can be produced. Such a high-impact polystyrene sheet or film can be as in produce the following in detail.

As a rule, the starting point is a polystyrene / rubber mixture in which uniformly fine particles of a natural rubber and / or an artificial rubber, e.g. a polybutadiene optionally grafted with styrene, a styrene / butadiene or acrylonitrile / butadiene / styrene rubber, existing organic elastomers are dispersed. As a rule, the high-impact polystyrene film consists of 80 to 98, preferably 92 to 96 % by weight of polystyrene and 2 to 20, preferably 4 to 8% by weight of one of the aforementioned chewing components. The fine rubber particles dispersed in the polystyrene should preferably have an average size of about 1 to 7 η . The polystyrene / rubber mixture is shaped into a film or a sheet in a conventionally known manner, whereupon the film or sheet is stretched in one or two directions. During stretching, the numerous particles of the rubber component dispersed in the polystyrene become grounded in one

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or two direction (s) extended and extended in this Shape by the polystyrene component surrounding the rubber particles fixed. As a result, the elongated and fixed rubber particles have a high shrinkage potential.

When at least one surface of the stretched high impact Polystyrene film is treated with an organic liquid capable of dissolving or swelling the polystyrene, the rubber particles are released from fixation and extension, shrinking rapidly. The quick one Shrinkage of the rubber particles leads to the formation of micropores in the treated part of the film or sheet. The formation of the micropores in turn leads to the unhappy Film part to form a rough surface. Contain the micropores formed in the process described the organic liquid. The organic liquid contained in the micropores then becomes more common in a known manner, for example by evaporation, by displacement by a non-solvent or by washing out removed.

The high-impact polystyrene layer or film treated in this way has one or two opaque or translucent, rough surface (s) with numerous micropores contained therein. The micropores preferably have a medium one Size from about 3 to 20 u.

The opaque or translucent, rough surface layer is capable of writing ink, duplicating ink or printing ink easily absorbed. Consequently, the high impact polystyrene sheet thus treated has at least one A rough surface layer with numerous micropores for color development and a non-treated one

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treated substrate layer. The untreated sub-step layer should preferably have an average thickness of about 50% of the thickness of the original high-impact polystyrene film. The treated high-impact polystyrene film can be used as a writing, duplicating or printing film.

Suitable for treating high-impact polystyrene Organic liquids must (only) be able to dissolve or swell the polystyrene. Suitable organic liquids are for example aliphatic hydrocarbons, such as η-hexane, n-heptane, and n-octane, aromatic hydrocarbons, such as benzene, toluene and xylene, halogenated hydrocarbons such as carbon tetrachloride, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and ethers such as 1,4-dioxane.

As already stated, contains in the solvent treatment The rough surface layer formed by the high-impact polystyrene film has numerous micropores. In the case of the invention The micropores in the rough surface layer contain high-impact polystyrene layers for color development an acidic color developer suitable for developing acid-developable, colorless color formers. The acidic color developer is in the micropores of the high-impact polystyrene sheet according to the invention in one

Amount of, based on 1 m of support surface, contain 0.5 to 3 g and is practically (completely) enclosed in the micropores.

In the following the invention is explained in more detail with reference to the drawing. Show in detail:

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Fig. 1 is a photographic representation of one according to the invention Polystyrene sheet for color development in cross-section and

2 to 5, respectively, reproduction foils or stencils together with a polystyrene layer according to the invention for color development _β

In the case of the polystyrene layer 1 according to the invention, shown in cross section in FIG. 1, for color development, there is on both A rough surface layer 3 is formed on the sides of a substrate layer 2. Find in the rough surface layer 3 There are numerous micropores 4 of a complicated and unspecified shape. These micropores contain the acidic Color developer.

The acidic color developer to be selected in each case according to the invention must take into account the (by it) to be developed colorless color former can be selected. Colorless color formers which can be developed by acid are generally colorless Triphenylmethane color former, especially crystal violet lactone, is used. Consequently, one must be a color developer choose a compound that serves as an electron acceptor for the colorless color former mentioned and the latter thereby able to develop into a dye. For example, a dye developer can optionally use a or more than one group (s) other than the carboxyl group-containing monocarboxylic acid, e.g. p-aminobenzoic acid, p-hydroxybenzoic acid or acetic acid, optionally containing one or more radicals other than the carboxyl radical Polycarboxylic acid, e.g. succinic acid, maleic acid, citraconic acid, chloromaleic acid, itaconic acid, aconitic acid or Phthalic acid, a homopolymer of an ethylenically unsaturated Carboxylic acid, e.g. poly (acrylic acid) or poly (methacrylic acid), a mixed polymer of an ethylenically unsaturated

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acidic anhydride, e.g. of maleic, chloromaleic, citraconic, itaconic or aconitic anhydride, with ethylene and / or styrene, a phenolic compound, e.g. p-cumylphenol, p-phenylphenol, p-tert-butylphenol, p-octylphenol or p-nonylphenol, a polyphenolic compound, e.g. gallic acid, Bisphenol A, bisphenol B or pyrocathecin, a novolak condensation product of a phenolic compound, e.g. a novolak condensation product of phenol, p-phenylphenol, p-cumylphenol, p-tert-butylphenol, p-octylphenol or p-nonylphenol, with formaldehyde, preferably with a maximum of 3 phenol units, or a phenol / acetylene polymer be used.

Because the acidic dye develops in the micropores of the rough Surface layer is enclosed, it is practically completely sealed off from the atmosphere and can consequently against destruction through the action of moisture (atmospheric moisture) or exposure to sunlight be preserved.

A high-impact polystyrene sheet for color development according to the present invention can, as will be described later in detail will be produced.

Here, a high-impact polystyrene film is first applied in one or two directions, preferably in two directions, stretched. The stretched film is made with a solution of the acidic color developer in one to dissolve the same and treated organic liquid suitable for dissolving or swelling the polystyrene.

An aliphatic hydrocarbon, such as η-hexane, n-heptane, for example, can be used as a suitable organic liquid and n-octane, an aromatic hydrocarbon such as toluene

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and xylene, a halogenated hydrocarbon such as carbon tetrachloride, Trichlorethylene or tetrachlorethylene, a ketone such as acetone, ethyl ethyl ketone and methyl isobutyl ketone, or an ether such as a 1,4-dioxane can be used. One of the compounds mentioned can be used as the acidic color developer.

The acidic color developer can also be dissolved directly in the organic solvent. Furthermore, the acid Color developer initially in a different solvent than that used to dissolve or swell the polystyrene, e.g. in a Alcohol such as ethanol, n-3utanol, an ether such as tetrahydrofuran and 1,4-dioxane, an aliphatic hydrocarbon, such as n-heptane, an aromatic hydrocarbon such as toluene or xylene, an ether alcohol such as ß-hydroxymethylethyl ether and ß-hydroxyethyl ether, a ketone such as acetone or methyl isobutyl ketone, a halogenated hydrocarbon, such as chloroform or tetrachloroethane, an unsaturated one Hydrocarbon, v / ie styrene or 6-methylstyrene, a carboxylic acid, v / ie acetic acid or methacrylic acid, a natural fat or oil, v / ie linseed oil, or an ester such as methyl formate or ethyl acetate, and the resulting solution is then dissolved in a solvent or sources of the polystyrene mixed in. Consequently, the solvent for the polystyrene must be acidic Color developer and the first solvent are able to dissolve. When the high-impact polystyrene filra on his The surface is treated with the solution containing the acidic color developer in the organic liquid, numerous micro-pores are formed in it. The micropores v / earth impregnated with the solution. The organic solvent is then removed to form the acidic color developer to be deposited inside the micropores. After full

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Removal of the organic solvent, the acidic color developer is practically (completely) in the micropores locked in.

The method described has the advantage that the inventive High-impact polystyrene layer in just a single step made from the high-impact polystyrene film can be produced.

However, the high impact polystyrene sheet for color development of the present invention can also be produced as follows will:

The stretched high-impact polystyrene film is coated on its surface with a to dissolve or swell the polystyrene treated with a suitable solvent, resulting in a highly impact-resistant polystyrene layer with a rough surface layer (en) and numerous micropores located therein. This is followed by the rough surface layer allowed to act a solution of the color developer in a solvent. This solvent can for example from an aliphatic hydrocarbon such as ^ .- heptane or n-octane, an aromatic hydrocarbon such as toluene or xylene, an ether such as ethyl ether or 1,4-diorane, an ether alcohol, such as ß-hydroxyethyl methyl ether or ß-hydroxyethyl ether, a carboxylic acid such as acetic acid or methacrylic acid, a ketone such as acetone or methyl isobutyl ketone, a ^ ster, such as ethyl acetate or methyl formate, a halogenated hydrocarbon, such as tetrachloroethane, an alcohol such as methanol or ethanol, or a mixture thereof. When the solution of the acidic color developer is applied to the rough surface of the layer, it penetrates the micropores and fills them. Removing the solvent removes the acidic color

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curlers deposited in the micropores and remains after complete Removal of the solvent is practically (completely) included. This process variant has the advantage that a pre-formed, high-impact polystyrene layer is used to produce the color developer layer with a rough surface layer can be used and that the color developer is applied to one of the surface layers can be applied at any time.

When prepared according to the two process variants according to the invention high-impact polystyrene sheets for color development, the micropores should preferably be medium Size from about 3 to 20 microns and the untreated Substrate layer have an average thickness of about 50% of the original film. To develop the acid-developable colorless film former on the developer layer, the colorless color former should match the image or pattern be transferred to the rough surface layer of the developer layer.

In the context of the process according to the invention, an acid-developable colorless color former is used in the interior the high-impact polystyrene sheet according to the invention (for color development) developed color images. During execution of the method according to the invention is a solution or printing ink with an acid developable colorless Color former, consisting of a Leukotriphenylmethanver ~ bond or a leuco-fluoran compound, in accordance with the image or pattern, onto the rough surface of the color developer layer transfer.

The colorless color formers are usually in an organic solvent, consisting of a non-volatile

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gene liquid, for example a vegetable oil such as olive oil, castor oil, cottonseed oil, or peanut oil, a mineral oil, for example any paraffin oil, a synthetic oil such as a chlorinated diphenyl, an alkyldiphenyl, an alkylnaphthalene, an arylalkane, a chlorinated paraffin, dioctyl phthalate, tricresyl phosphate or a mixture thereof, dissolved. These solvents can sufficiently wet and dissolve or swell the polystyrene forming the color developer layer. Consequently, when the solution of the colorless color former is applied to the rough surface layer of the color developer layer, the solution is able to penetrate rapidly into the micropores containing the acidic color developer while at the same time dissolving or swelling the polystyrene. Here, the dissolved colorless color former is brought into contact with the acidic color developer in the micropores, creating colored images. The escape disgusted the dye-containing solution penetrates to the bottom of the rough surface layer ^or, in some ^cases even Aellen to the substrate layer prior to and is fixed there in such a way that the dye formed is mixed with the solvent dissolved in the polystyrene we d.

As already stated, the color images formed in this way are in the strong hydrophobic properties, high-impact polystyrene layer embedded. As a result, the color images are highly water-resistant. Self when the high-impact polystyrene layer carrying the colored image is wetted with water, it does not occur to a blurring (or flowing out) or to a disappearance of the color image. Furthermore, the color image possesses high resistance to erasure. Finally, the color image also has a high level of lightfastness, as the The polystyrene layer covering the color image absorbs the incident light

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reflects and / or absorbs and in this way protects the color image from exposure to radiation. So own even color images consisting of triphenylmethane dyes, which inherently have a very low lightfastness have, as a result of the embedding in the high-impact polystyrene layer, an unexpectedly high light resistance.

The high-impact polystyrene sheet according to the invention for color development can be used as a base for a pressure-sensitive, carbon-free duplicating sheet can be used.

A carbon-free duplicating sheet 21 shown in FIG. 2 consists of an upper layer 22 and a lower layer Layer 23. The upper layer 22 consists of a base 24 made of paper and a microcapsule layer 25 on the underside of the base 24. The microcapsule layer 25 consists of numerous microcapsules and one the microcapsules in the form of a single layer of fixing binder. The lower layer 23 consists of one according to the invention high-impact polystyrene sheet (for color development), which in turn consists of a substrate layer 26 and one on the Microcapsule layer 25 aligned, the color development causing rough surface layer 27 is formed.

When the carbonless duplicating sheet 21 is pressed onto the surface of the topsheet 22 in an image or pattern matching manner is, the microcapsules of the top layer 22 break as a result of the pressure exerted in an image or pattern. the The replication liquid flowing out of the broken microcapsules penetrates into the one causing the color development rough surface layer of the lower layer 23, the polystyrene base material being dissolved or swollen and

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contact with the color developer in the micropores is brought about. As a result, the rough surface layer 27 of the lower layer 23 from color images of the desired pattern.

A carbon-free duplicating sheet 30 shown in FIG. 3 consists of a top layer 31, an intermediate layer 32 and a lower layer 33

The upper layer 31 consists of a base 34 made of paper and one provided on the underside of the base 34 Microcapsule layer 35. The intermediate layer 32 consists of a high-impact polystyrene layer according to the invention (for color development) with a substrate layer 36, a rough one causing color development and aligned with the microcapsule layer 35 of the top sheet 31 Surface layer 37a on top of substrate layer 36 and one on the lower side of the substrate layer provided microcapsule layer 38. The lower layer 33 consists of a highly impact-resistant polystyrene layer according to the invention (for color development) with a substrate layer 39 and one on the microcapsule layer 38 of the intermediate layer 32 aligned, color development causing rough surface layer 37b on top of the substrate layer 39.

When the duplicating sheet 30 is pressed onto the surface of the topsheet 31 in an imagewise or pattern, form Color images appear in the rough surface layers 37a and 37b of the intermediate layer 32 and the lower layer 33, respectively.

As shown, the duplicating sheet may have two or more interleaves. The lower layer and the intermediate

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-e?

The next layer with the color images are from the top layer separately and used as outdoor sample sheets, labels, and long-life copies.

A pressure-sensitive, carbonless duplicating sheet 41 shown in Figure 4 consists of a top layer and a lower layer 43.

The upper layer 42 consists of a base 44 made of paper or a plastic and one on the underside of the substrate 44 provided microcapsule layer 45. The lower layer 43 consists of an adhesive duplicating sheet 46 and a release liner 47 separable from the adhesive duplicating sheet 46. The adhesive duplicating sheet 46 consists of a high-impact polystyrene layer according to the invention (for color development) 48 with a substrate layer 49, one on top of the microcapsule layer

45 of the upper layer 42 aligned, the color development causing the rough surface layer 50 and one on the The adhesive layer 51 provided on the underside of the polystyrene ply 48. The release sheet 47 consists of a base 52 Paper or a plastic film and one aligned with the adhesive layer 51 of the duplicating sheet 46 Layer 53 of a release material. The layer 53 is so weak that the release sheet 47 is easily removed from the duplicating sheet 46 can be deducted.

After the patterned color images have been formed in the rough surface layer 50 of the duplicating sheet

46, the release sheet 47 is peeled from the duplication sheet 46, whereupon the duplication sheet 46 with the desired color images via the adhesive layer 51 on the desired object or on the desired material is glued on.

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A carbon-free duplicating sheet 60 shown in FIG. 5 consists of a top layer 61, a Intermediate layer 62 and a pad 63. The top layer

61 consists of a base 64 made of paper or a Plastic film and a microcapsule layer 65 provided on the underside of the base 64. The intermediate layer

62 consists of an adhesive duplication sheet 66 and a release sheet 67. The adhesive duplication sheet 66 consists of a high-impact polystyrene layer according to the invention (for color development) 68 with a Substrate layer 69, one on top of microcapsule layer 65 the color development causing rough surface layer 70 aligned with the upper layer 61 and one on the Underside of the high-impact polystyrene sheet 68 provided adhesive layer 71. The release sheet 67 consists of a base 72 made of paper or a plastic film, a layer provided on the upper side of the base 72 73 made of a separating material and a microcapsule layer 74 provided on the underside of the support 72. The Layer 73 of a release material adheres so weakly to adhesive layer 71 of duplicating sheet 66 that it can be easily peeled off from the adhesive layer 71. The lower layer 63 consists of one according to the invention high impact polystyrene sheet (for color development) with a substrate layer 75 and one on top of the microcapsule layer 74 of the intermediate layer 62 aligned, the color development causing the rough surface layer 76.

After the replication, the replication sheet 66 of the intermediate layer 62 is separated from the release sheet 67 and adhered to a desired object or to a desired material, the lower layer 63 as a recording medium serves. It doesn't need to be specifically emphasized

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that, as in FIG. 5, two or more intermediate layers are inserted between the upper and lower layers can.

The high-impact polystyrene sheets according to the invention (for color development) have the following advantages:

1. Even if a colorless color former has a low water resistance and poor light resistance such as a colorless triphenylmethane derivative is used Color images formed on the color developer sheet according to the invention have excellent light and water resistance. Hence, the colorless triphenylmethane derivative does not need to match a colorless methylene blue derivative mixed to ground in order, as usual, to improve the lightfastness of the triphenylmethane dye images formed to improve. In this way, the production costs of the color images can be reduced and those on the Avoid discoloration due to the presence of methylene blue dyes during storage.

When a colorless methylene blue derivative is used in the form of a mixture with the colorless triphenylmethane derivative because of poor solubility of the colorless methylene blue derivative, it is necessary to use this in a strong, non-volatile solvent, e.g. a highly toxic, polychlorinated benzene to solve. However, since in the production of the color developer layers according to the invention on mixtures of the colorless Methylene blue derivative and the colorless triphenylmethane derivative can be dispensed with, one can look into advantageously use to dissolve the colorless color former of a non-toxic solvent.

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2. Even if a color developer sheet according to the invention is stored for a long time, the activity changes of the color developer in the surface layer of the ply practically not, since the color developer in the closed Micropores from exposure to atmospheric moisture is preserved. In comparison, the usual color developer papers change for one to several months Storage their quality, with the color development activity decreases or is completely lost. Hence, a color developer sheet according to the invention possesses far more advantageous practical usability than ordinary color developing paper.

3. Even when moistened or when exposed to sun or UV rays, a color developer layer occurs according to the invention does not result in a change in the activity of the color developer contained therein.

4. Since the color developer is practically completely in "the closed." Enclosed micropores, it can consist of a volatile or sublimable solid or consist of a liquid.

5. A color developer sheet according to the invention can serve as a recording medium for a long time, since the color image developed on it has excellent light and water resistance and is extremely erasable is.

6. A color developer sheet according to the invention can be used as an outdoor address, packing slip or note used for deliveries without having to be covered. In comparison, the usual Color developer layers produced colored addresses or

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Notes should be covered with clear film, as the color images have poor light and water resistance exhibit.

7. Since the color developer is contained in the micropores, the strength of the layer as such does not increase by incorporating the color developer. With the usual Color developer layers have their own color developer layer adhered to the surface of the paper substrate, as a result of which the strength of the situation as such is increased.

According to the invention, a very thin color developer layer is obtained with which - even if there are several such layers superimposed for joint reproduction - produce several sharp color images at the same time permit.

8, When a color developing sheet according to the invention is used as Printing stencil for common printing processes, e.g. letterpress, lithographic or intaglio printing processes, is used, the prints will not adhere to each other as the printing ink penetrates into the interior of the sheet. Furthermore, since the color images are formed in the interior of the sheet, the color images formed are particularly resistant to abrasion.

The following examples are intended to illustrate the invention in more detail. Unless otherwise stated, all "parts" and "percentages" mean parts by weight or Weight percent.

example 1

Following the procedure described below was initially

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produced a carbonless duplicating sheet with a top and a bottom layer.

A) Making the top layer

A mixture of 2 g of gelatin and 2 g of gum arabic was dissolved in 1 liter of pure water, whereupon the resulting solution was adjusted to a pH of 10.0 by adding a 10% aqueous sodium hydroxide solution. Thereafter, the solution was washed with 20 g of a solution prepared by dissolving 6 parts of crystal violet lactone in 100 parts hexylnaphthalene added, and the resulting mixture was emulsified at a temperature of 50 ⁰ C using a homogenizer. The emulsion obtained was then adjusted to a pH of 4.0 by adding 10 acetic acid. After the emulsion had cooled to a temperature of 10 ^° C., 2 g of an aqueous solution of at least 37% formaldehyde were added. The mixture was then adjusted to a pH of 10.0 by adding 10% aqueous sodium hydroxide solution. Finally, the obtained emulsion was allowed to stand for 24 hours and then concentrated. After the end of the concentration, numerous microcapsules with a leuco dye solution had formed. 100 parts of the obtained microcapsules were mixed with an aqueous solution containing 10 parts of starch as a binder, and the mixture was applied to a paper surface and dried to make the upper layer.

B) Production of the lower layer

250 g of a commercially available 2,2'-methylenebis (4-chlorophenol) were dissolved with heating in a uniform mixture of 4.9 1 n-heptane and 0.1 1 ß-hydroxyethyl ether. the

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solution was maintained at a temperature of 5O ⁰ C. In the 5O ⁰ C warm solution was immersed u 2 see long a stretched high impact polystyrene film having a thickness of 100th After pulling out, the film was air dried. A polystyrene sheet with an upper and a lower rough surface was obtained. The thickness of the layer obtained was 120 µ.

The rough surfaces had numerous micropores with enclosed 2,2'-methylenebis (4-chlorophenol) as a color developer and an average size of about 5 η .

C) Making a pressure-sensitive, carbon-free duplicating sheet

The upper layer produced in the manner described became the lower layer produced in the manner described Layer placed in such a way that the microcapsule layer of the upper layer is aligned with the rough surface of the lower layer was. A carbon-free duplicating set was obtained.

D) reproduction

On top of the carbon-free duplicating set produced as described above were with the Hand applied the desired images or patterns. On the lower layer there were brilliant violet-blue Received pictures.

E) Examination of the color images obtained

The rough surface of the lower layer bearing the color images was exposed to direct sunlight for 8 hours.

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sets what the percentage ratio of the color depth of the images after exposure to the color depth of the Eilder before the exposure was determined. This ratio is a measure of the lightfastness of the color images.

A rough surface of the lower layer was made prior to duplication exposed to direct sunlight for 4 hours, before the reproduction on the irradiated rough surface of the lower layer took place. Here, too, the percentage ratio of the color depth of the exposed Surface layer generated color images for the depth of color of the non-exposed surface layer of the lower layer generated color images determined. This ratio is a measure of the lightfastness of the color developer in the lower tier.

For comparison purposes, two common bottom plies made from (1) paper and acid clay and (2) paper and a novolak phenolic resin were used manufactured.

The lightfastness of the color images and the color developer in the lower layer of a polystyrene color developer sheet According to the invention and two common documents (1) and (2) are summarized in the following Table I;

Table I.

Lower Layer Lower La- Lower Layer Lower Layer

ge, according to (1) according to (2) according to

Example 1 the state of the state

manufactured technique of technique

Lightfastness

of the color image (JS) 95 15 30

Lightfastness
of the color developer
in the lower layer (JO 90 40 53

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It is clear from Table I that the Color image and the color developer in the lower layer of a polystyrene developer sheet according to the invention considerably have higher lightfastness than the color image and the color developer in conventional documents (1) and (2) prior art color developer sheets.

The color images formed on the lower layer of the polystyrene color developer sheet according to the invention are self-floating when immersed in water not apart or completely gone.

Furthermore, the rough surface of the lower layer bearing color images was moistened and processed with an eraser. There was no bleeding of the color images. In comparison, the color images float on the usual lower layer (1) quickly apart. With the moistener the usual lower layers (1) and (2) of the known duplicating sheets and subsequent erasure occurred bleeding and blurring of the color images.

Example 2

The measures outlined in Example 1 were repeated as follows:

A) manufacture; a color developer

A flask equipped with a reflux condenser with a mixture of 170 parts of p-phenylphenol, 65 parts a 37% aqueous formaldehyde solution, 1 part oxalic anhydride and 50 parts of a 7? ° aqueous hydrochloric acid solution charged, whereupon the contents of the flask

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was heated to the boiling point for reaction. After 4 to 6 hours, heating was discontinued and the water contained in the reaction mixture was removed. The product obtained had a molecular weight of 270 to 400. The pressure in the flask was then reduced by means of a suction device, whereupon the reaction product was distilled ^{at a temperature of 100 ° C. under reduced pressure.} The distillate obtained had a melting point of 80 ° to 100 ⁰ C.

B) Production of the lower layer

100 g of the reaction product (color developer) prepared in the manner described in 1 1 ß-hydroxyethylether was uniformly mixed with 4 1 of n-0ctan was increased and the temperature of the mixture to 50 ⁰ C and maintained at this value. In the resulting mixture, a bi-directionally stretched high impact polystyrene film having a thickness of 100 µ m was immersed for 5 seconds. Immediately after taking it out, the polystyrene film was air-dried to remove the solvent. A polystyrene sheet with an upper and a lower rough surface layer was obtained. The polystyrene sheet contained the dye developer consisting of a condensation product of p-phenylphenol and formaldehyde in the micropores formed in the rough surface layers and could consequently be used as the lower layer of the pressure-sensitive, carbon-free duplicating sheet. The thickness of the polystyrene sheet obtained was 140 µ.

C) Production of a duplication sheet

The lower layer produced in the described method was covered with the upper layer produced according to Example 1, whereby a pressure-sensitive carbonless duplicating sheet was obtained.

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duplication

Letters were typewritten on the top of the duplicating sheet. In the rough surface layer of the lower layer aligned with the microcapsule layer of the upper layer, brilliant violet-blue images (of the original typewriter letters) were created.

Examination of the color images

The lightfastness of the color images in the lower layer was determined in the manner described in Example 1.

The light resistance of the color developer in the lower The position was determined, irradiated for 5 hours in a bleaching device by means of a xenon larape and then irradiated in the manner described in Example 1 to duplication points was used. For comparison purposes, the same tests were carried out with those in Example 1 used usual documents (1) and (2) carried out from known duplicating sheets. The The results are summarized in the following table II:

Lower layer

Table II

Lower layer, produced according to Example 2

Lower layer (1) according to
the state
of the technique

Lower layer (2) according to the prior art

Lightfastness

of the color picture (Jo) 98

Light resistance of the color developer in the lower layer (SO 95

30th

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It is clear from Table II that the color images and the color developer in the lower layer of the polystyrene color developer sheet according to the invention have a considerably higher light resistance than the color images and color developer in the usual lower layers of the known duplicating sheets.

It was also found that those formed in the lower layer of the polystyrene color developer sheet according to the invention Color pictures had considerably higher water resistance and erasure resistance than those of the usual ones color images formed in the lower layers of the known duplicating sheets.

Example 3

Example 1 was repeated as follows:

A) Color developer

Commercially available p-aminobenzoic acid was used as the color developer.

B) Production of the lower layer

A stretched in two directions high-impact polystyrene film having a thickness of 10Ou was lake at a temperature of 50 ⁰ C 30 immersed in n-heptane and then dried to remove the n-heptane immediately to the atmosphere. A paper-like polystyrene sheet with an upper and a lower rough surface layer was obtained. The thickness of the layer obtained was about 145 U. 100 g of p-aminobenzoic acid were then dissolved in 1 liter of β-hydroxymethyl ethyl ether and 0.1 liter of the solution obtained

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7323389 or above 06.76

Xylene mixed. The resulting mixed solution was applied to one side of the polystyrene sheet produced as described above applied. The obtained polystyrene sheet had a surface layer with numerous, the color developer containing micropores and was therefore suitable as the bottom layer of a carbonless duplicating sheet.

C) Manufacture of the duplication sheet

The upper layer produced according to Example 1 was placed on the lower layer produced in the described manner, whereby a pressure-sensitive carbonless duplicating sheet was obtained.

D) reproduction

Letters were handwritten on the upper side of the copying sheet obtained, the rough being in the On the surface layer of the lower layer, brilliant purple-blue images (of the written letters) were obtained.

E) Examination of the color images

The light resistance of the color images formed in the lower layer was determined as described in Example 1. The light resistance of the color developer contained in the lower layer was also determined as in Example 1. For comparison purposes, the same usual lower layers (1) and (2) from known duplicating sheets were used as in example 1 tested together with the upper layers of example 1 under corresponding conditions.

The results of these investigations are summarized in the following table III:

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35

Table III

Lower layer

Lower layer, produced according to Example 3

Lower tier Lower tier

(1) according to (2) according to

the state of the state

of technology of technology

Lightfastness

of the color image (50 93

Light resistance of the color developer in the lower layer (90 81

15th

30th

53

Table III clearly shows that the color images and the color developer in the lower layer of the polystyrene color developer sheet according to the invention have a considerably higher lightfastness than that Color images and the color developer in the lower layers of the comparative duplicating sheets.

Furthermore, it was found that those formed in the lower layer of the polystyrene color developer sheet according to the invention Color images had significantly higher water resistance and erasure resistance than the color images in the usual documents of the comparative duplication sheets.

Example 4

In the manner described in Example 1, the same lower sheet for use as a printing stencil was produced. Pictures were printed on the rough surface of the 25 cm × 40 cm printing stencil using a test printing press with the aid of a colorless printing ink consisting of 5% rhodamine-B-lactam, 40% by volume pigment, 30 % varnish and 25% diarylethane. The colorless printing ink is drar.

7373369 06/03/76

quickly penetrated the rough layer, immediately forming brilliant red images. Even after 7 days When the prints were placed on top of one another with a weight of 10 kg / cm, the individual prints did not stick to one another.

The color images formed had excellent light- and water resistance and were erasable.

Example 5

In the manner described in Example 2, the same base was used as a printing stencil in an offset printing press manufactured.

Using the colorless printing ink according to Example 4 were in a rotary offset printing press at a speed of 120 sheets / min at a pressure of about 12 kg / cm 500 printing stencils printed.

The printing ink was immediately absorbed through the rough surface layer of the printing stencil, creating brilliant blue images in it. Blocking of the prints obtained could not be ascertained. The lightfastness of the color images was determined by exposing them to artificial light in a bleaching device for 24 hours. The color images only faded by 5% .

For comparison purposes, 500 were common, 25 cm × 40 cm in size Printing sheets produced. For this purpose, 100 parts of the color developer used were finely ground in a ball mill in a homogenizer evenly with 40 parts of acid clay, 20 parts of a latex one

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Styrene / butadiene rubber and some dispersing agent mixed, whereupon the mixture obtained in an amount of 6 g / m 2 support surface on a paper surface applied and dried.

The comparison print sheets are under double pressure the same printing forms applied. When the same fading test was carried out, it was found that the obtained Fade color images by 70 / S.

This comparison clearly shows that the in erfindungsgeraäß trained printing templates or printing sheets color images produced have excellent lightfastness.

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Claims (11)

Protection claims 1. High impact polystyrene film for color development, characterized in that it consists of one of at least one in one direction stretched polystyrene film of high impact strength existing underlay, the one or on both sides (a) paper-like, rough surface (s) with has numerous micropores contained therein, and one contained in the micropores for developing a acid developable colorless color former capable of acidic color developer. 2. Polystyrene film according to claim 1, characterized in that that they are used as an acidic color developer a monocarboxylic acid, polycarboxylic acid, a homo- or mixed polymer ethylenically unsaturated carboxylic acid, a phenolic compound, a polyphenolic compound, a condensation product of a phenolic compound and formaldehyde Phenol / acetylene polymer, a p-hydroxystyrene polymer, contains an organic sulfonic acid or a polymer thereof and / or boric acid. 3. Polystyrene film according to one of claims 1 and 2, characterized characterized in that they are used as monocarboxylic acid color developers p-aminobenzoic acid, p-hydroxybenzoic acid and / or Contains acetic acid. 4 · Polystyrene film according to one of Claims 1 and 2, characterized characterized in that they are used as polycarboxylic acid color developers, succinic acid, maleic acid, citraconic acid, chloromaleic acid, Contains itaconic acid, aconitic acid and / or phthalic acid. - 34 - 7323369 06/03/76 5. Polystyrene film according to one of claims 1 and 2, characterized in that it is made from a homopolymer an ethylenically unsaturated carboxylic acid Color developer poly (acrylic acid) and / or poly (methacrylic acid) contains. β. Polystyrene film according to one of Claims 1 and 2, characterized characterized in that they consist of a copolymer of an ethylenically unsaturated carboxylic acid Color developer a mixed polymer of maleic acid, chloromaleic acid, citraconic acid, itaconic acid and / or Contains aconitic anhydride and ethylene and / or styrene. 7. Polystyrene film according to one of claims 1 and 2, characterized characterized that they are phenol, p-cumylphenol, p-phenylphenol, p-tert-butylphenol, Contains p-octylphenol and / or p-nonylphenol. 8. Polystyrene film according to one of claims 1 and 2, characterized characterized in that they are used as polyphenol color developer gallic acid, bisphenol A, bisphenol B and / or cathechin contains. 9 · Polystyrene film according to one of Claims 1 and 2, characterized characterized as being a color developer consisting of a phenol / formaldehyde condensation product (novolak resin) a condensation product of phenol, p-phenylphenol, p-cumylphenol, p-tert-butylphenol, p-octylphenol and / or contains p-nonylphenol with formaldehyde each with 3 or fewer phenolic components. 10. polystyrene film according to one or more of the preceding claims, characterized in that the polystyrene film of high impact strength from 80 to 98 wt -.% - 35 - 73? 3369 6/3/76 consists of polystyrene and from 2 to 20% by weight of a polybutadiene optionally grafted with styrene, a styrene / butadiene rubber, an acrylonitrile / butadiene-styrene oil rubber and / or natural rubber. 11. Pclystyrene film according to one or more of the preceding Claims, characterized in that the amount aes ρ
acidic color developer per m 2 support area is 0.5 to 3 g. 73P3369 6/3/76