DE1772381C - Process for the production of a magnetophotographic recording material - Google Patents

Description

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color or toner and the degree to which they are smeared. For copying documents, halftone originals and the like according to the invention, the spacing between periodic units of the pattern of the netic material should be 39.37 to 590.55 lines / cm, or 118.11 to 295 , 3 lines / cm, for a total of 0.0025 to 0.025, preferably 0.0076 to pnjid mm.
Ipie engraved base from which the embossed plastic films are formed as a carrier, be a flat plate or cylindrical and have any shape in order to produce the carrier sheet in the desired shape. In certain applications, the recording materials must consist of endless strips, ζ 3. Ribbons, in some cases the engraved base can be made in the form of a ⁷ "inch, which represents a roller pair of rollers. The tape that should be in front but has a surface that is below. is flowable, is then by & .i rollers ge-ί For some applications it can be appropriate Us recording material in the form of a cy-

be, -! as recording material in the form of a cylindrical Manufacture pipe. In this case, the g ivierte pad on the inside of a cylindrical Hollow form and the plastic rope nde material on the surface in the form of a Liquid can be applied, which is then allowed to harden before being removed from the inside of the hollow cylindrical master disk is stripped.

T he engraved pad can be made of any suitable material compatible with the desired degree of detail and fineness η can be shaped. Metals are used because of the lightness with which they can be brought into the desired shape, and because of their: durability particularly preferred. It is obvious that numerous impressions in the form of the embossed plastic sheets from a single engraved base can be made. The engraved base can be cut into it of the desired pattern, e.g. B. grooves or notches on the surface, using a lathe for the cylindrical shape or a drawing machine ff "flat shapes can be made. Dot pattern can be made using a diamond tip cut into the surface of the metal mold is pushed in. It is also possible to make engraved metal bases through electrical machining to produce on the surface of softer materials, e.g. B. on a photo-mechanically machined Plastic plate or a pressure-sensitive plastic, even with the help of suitable tools has been coined.

The film-forming plastic is applied to the master cylinder, while at least its surface is in a liquid state. The liquid can be a solution of a preformed plastic in a suitable solvent. The liquid material can also be a monomer or a mixture of monomers be together with catalysts that form the polymer in situ. Prepolymers used in Monomers and optionally other solvents are dissolved, for. B. the known casting compounds based on M ^ hylmethacrylatpolymeren, can can also be used. In the liquid casting compound can hardeners, dyes to change the Permeability seals of the substrate and the like. can also be incorporated.

The plastic sheet forming materials should have the following desirable properties:

1. Dimensional stability: The plastic must not stretch during normal use.

2. Sufficient flexibility and strength to allow the To enable stripping from the engraved base.

3. Adhesion to the binder of the following written Art.

4th Sufficient permeability for radiation, ζ. Β. visible light Optical clarity is desirable, but not essential. Usually you can use translucent materials, especially

, in thin foils, can be used.

5. Sufficient thermal resistance when used as a magnetophotographic material.

According to one embodiment of the invention verao is used as plastics forming material a binder solution, preferably a polyvinyl chloride, Polycarbonate, cellulose acetate or polyether urethane solution. These materials can be particularly easy to use and easy to

> 5 passable.

The invention enables the production of a magnetophotographic recording material in a simple manner allows that with perfect transparency at the same time a high flow strength of the magnetic material ensures and the recovery of excellent copies of high Density and maximum resolution allowed.

Suitable polymer solutions for covering are for example solutions of polymethyl methacrylate in acetone, solutions of styrene polymers in benzene and solutions of polyvinyl chloride in tetrahydrofuran.

Coating compounds, for example, are also suitable as monomers which polymerize to form plastics 4 »Based on polyurethane resins and epoxy compounds mixed with certain hardeners and the like, methyl methacrylate prepolymers, which are dissolved in methyl methacrylate monomers can also be used will.

It is not necessary that the entire plastic film serving as a layer support initially in the form of a liquid mass is present.

According to one embodiment of the invention, a plastic film forming material can be used Use heat softened plastic film. According to a further embodiment is used as Plastic film forming material a plastic film softened on a surface with a solvent. Particularly favorable results are obtained when a cellulose acetate film softened with acetone or a polycarbonate sheet softened with methylene chloride will use. In the embodiments listed, moderate pressure may be advantageous, to soften the film surface until it is flowable. The advantage of these ways of working lies in the fact that a complete liquefaction of the film material is omitted and that for drying and curing takes less time and energy.

Composites, layered films, in which a solid polymer layer with a liquid plastic-forming Mass or with a plastic that softens to a flowable state through heat or solvents

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are also suitable. Prevent or block the carrier film. more details

Hard magnetic materials can be found in a for the substrate by stretching or rolling

Increasing the strength of the molecular orien- "Hard Magnetic Materials" by B. P. Wohlf orth,

tieruhg are subject to. Bei'Vielen Crystalline Advances in Physics, Supplement to Philosophical

Polymeren has the molecular orientation by 5 Magazines, 8 (April 1959), pp. 87 to 224, and in that Rolls the further advantage that the optical clarity book by R. M. Bozo r t h on »Ferromagnetism« »

is improved, edited by D. van Nostrand and Company,

The thickness of the substrate is not critical. Princeton, New Jersey, 1951, especially in the ab-]

important; The Mirtdestdicke depends on the depth of the cut over fine particles, p. 828 to 834. »Soft-

embossed pattern. The thickness of "magnetic materials" that are too magnetic are also largely determined

tizing layers of magnetizable material discussed in the literature, e.g. B. by E. W. L e e;

lind binder depends on the depth of the embossing pattern and R. L. L y η c h, Advances in Physics, supplement j

away. For maximum resolution, i. H. True to the original for Philosophical Magazine, 8 (July 1959), p. 292 to:

Rendering, this layer should have a thickness of 0.25 348. j

to 130μ, preferably from 5 to 25μ. The 15 CrO ₂ can alone, ie in practically pure form, j

The flexible substrate generally has a thickness of or modified with one or more reactive j

Range from 2.5 to 635 μ. Most commonly, capable elements is used. will. The her- j

a thickness in the range from 5 to 500 μ, and a positioning process as well as the products with the required]

Thickness from 0.013 to 0.28 mm will be particularly pre- ferred properties are in the following USA.- j

«Igt. »0 patent specifications described: 2923o83, 2 923 684,!

The magnetizable material must be magnetized 2 923 685, 2 956 955, 3 034 988, 3 068 176, 3 074 778,

can be that it is an energy product {BH) _max 3 078 147, 3 117 093, 3 278 263.

from 0.08 to 8.0 Gauss-Oersted · 10 ⁴ , a remanence As materials for the purposes of the invention, the \ Br from 500 to 21,500 Gauss, a coercive force H _e to magnetize the hard magnetic state can be found j from 40 to 6000 then to demagnetize Oe and a Curie temperature of as selectively to 0 ⁰ K suitable to 1? no ° C, preferably from 25 to 500 ° C, has. Except for CrO _2, all known hard magnetic materials should also be used. In the case of materials with relatively high saturation magnetization B, in the case of high Curie temperatures, the choice must of course be made with the abovementioned range of the binding agent, ie the investment material, in which they have the desired properties. 3 <> must be dispersed, as well as the support, as magnetic compounds for the purpose of which the magnetizable slide is applied. Many substances are suitable for this invention. These materials are made with appropriate caution,
should not only have hard magnetic properties, a representative magnetic materials that are low Curie temperature, high remanence and high for the purposes of the invention, the ferrites, coercive force, but also physically 35 hard magnetic ternary alloys of Al, Ni and after Customary methods to process relatively fine, Co, ternary alloys of Cu, Ni and Fe, preferably acicular, particles Mn, _ie FeTi _0iS O ₄ , MnFe ₁ O ₄ , Fe ₃ O ₄ , CoFe ₁ O ₄ , NiFe ₁ O ₄ , the dimensions of which are single district _{ab- and Li 0> e} Fe 2f6 O ₄ . Hard magnetic measurements are also suitable. ternary alloys of Cu, Ni and Co, chromium steel, a number of factors contribute to the designation 40 cobalt steel, Fe, Co, Ni and the elongated magnetic iron magnets consisting of a material called "hard magnetic" or "soft single-district particles". Many magnetic materials, the rialien (usually produced in powder form and usually referred to as "soft", show increased coercive force according to the usual methods of metal-ceramic when worked as fine particles) as well as Fe ₈ Al, FeBe ₁ , FeBe ₅ , Fe ₁ B, Fe ₃ C. Geometric factors 45 Fe ₂ Ce, Fe ₄ N, Fe ₄ P, FeS, 5 / -Fe ₁ O ₃ , Fe ₂ P, Fe ₃ Si, Co ₁ B, including size and shape of the particle are important. In the case of CoS ₁ , CoZn, Co ₄ Zr, Ni ₁ Mg, Ni ₃ Mn, MnAs, MnB, iron is normally considered to be »soft- MnBi, Mn ₄ N, MnP, MnSb, Mn ₂ Sb, Mn ₁ Sn. Cr ₆ S "magnetic" material with a coercive force of Mn ₃ As ₁ , CrPe, Fe ₃ O ₃ S, AIFe ₂ O ₄ , CoFe ₁ O ₄ , MgFe ₂ O ₄ . Fraction of an oersted. In the case of small iron particles, MnFe ₁ O ₄ , NiFe ₂ O ₄ , Fe ₅ C, or Fe ₂₀ C ₈ (they are made up of individual districts of great length in the carbide), Co ₁ P, Co-substituted y-Fe ^ O ,, (FcCo),?, Exist in the same way as the diameter, but with YCo ₁ , Bs ₀₁₄ Ie ₁ O ,, PtCo and Comodified Fe ₁ O ₄ . Coercive force in the order of magnitude from 10 * to the hard magnet isefcei) state magnetically writable 10 ⁴ Oe to Tcchnen. In this case the high Koer material in the new thermomagnetic Aufzitivkraft is due to form anisotropic. In the case of drawing materials, it is useful to have a subset of other materials, e.g. B. Manganese dismutide or SS size of 1 μ and below, although the particles, such as Kobah, can have high coercive force for single regions- this in most magnetically sterile materials is the consequence of magnet-crystalline anisotropy of this type of FaB, which is by its nature aggios being They tend to incline from the tekhten alignment of the magnetization, so that the individual dimensioning along a certain crystal direction often gives an agglomeration of each magnetizable surface. Even fine nickel particles must have merates with a uniaxial 60, which may show high coercive forces in the area up to stress. Many lie to 0.25 mm. In the case of computation and copying normal “soft magnetic” materials, which both dissolve and close in the form of tiinzdbeairken, the packing factor can be given directly depending on the particle-high coercive force, depending on the size of the respective work component.
For example, a bit cannot be effectively exposed to cold working or similar treatments. which the work component, which is to be recorded 'Zwctk habMi, movements of B: rek; hswämkn zu. Accordingly, the smaller and the better, the better

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more uniformly the particle size of the component to be magnetized is an amine, ζ. B. hexamethylene

material is. Preferably these should be diamine, can.

Particles a size in the range from 0.01 to 5 μ, except for those mentioned above, to a large extent particular from 0.1 to 2.0 μ have. only organic binders and embedding for the application to the embossed carrier film 5 can use suitable inorganic binders wkc the magnetic material can be used in a liquid and investment, namely under BindeniiUelmas.se dispersed, which become an art- the only requirement that they are used for the substance is curable. The main pre-illumination certain radiation are permeable. Laws for these binders are. suitable are, for example, the silicones, aqueous colloidal

lo dale silica sols, aluminum oxide films, titanate films,

1. You are allowed to use the magnetic filler, i. H. which are dispersed and hardened by heat or on the Component of work, do not respond. can be steamed.

2. You need to briefly (milliseconds) up to the magnetic material that is in a sufficient j 'acceptable temperatures of, for example, 200 amount of the binder is dispersed so that the

up to 400 ° C thermally stable and against the »5 particles adhere to each other and to the base, exposed to radiation. can be applied to the embossed substrate with a squeegee 3..They must preferably be flexible and in each wipe od. The like. Be applied so that the upper case according to conventional methods, e.g. B. by surface of the magnetic material with the raised solution, processing on the mixing mill, part of the embossing pattern in the carrier film in one plane Calendering and extrusion, easily processed ao lies.

be workable. Preferably shape anisotropy or magnet-4. They should preferably be poor conductors of crystalline anisotropy in making the image, Plates or foils exploited according to the invention! a preferred orientation of the magnetic Suitable binders of this type are the various particles either in the coating direction or those commercially available acrylate and metha- perpendicular to the surface of the film. ' Sinker acrylate polymers as well as functionally substituted acrylic right orientation can be achieved by If - and methacrylate polymers, the different the magnetizable material and the binder in Vinyl and vinylidene polymers and copolymers, e.g. B. dry in a vertically applied magnetic field and / Vinyl chloride-Vinyiatciai-Cupöijüicrc, Vinyüdenchlo- 3 ° or can be hardened or in the case of thermoplastic binderide-vinyl acetate copolymers and vinyl chloride-vinyl agents operate at such a high temperature that fluoride copolymers, the various olefin polymers are flowable, but with the temperature still mers and copolymers, e.g. polyethylene and poly- below the Curie temperature of any magnetized mapropylene, Ethylene-vinyl acetate copolymers and Ethy- terials lies, and in the perpendicularly applied magnetic field len vinyl chloride copolymers. 35 lets cool to room temperature. Likewise, the Natural, modified natural and synthetic applied from solution or from the melt Materials can also be used as a binder or coating for parallel orientation, i.e. H. in the Investment materials are used, provided that the coating direction is unmistakable before solidification they are drawn the basically required physical over the pole pieces of a magnet that does so Have properties, d. H. by magnetic 4 »is aligned that the field axes in the flow line Force fields are not influenced, the tape movement is not heat-sensitive.

The copying material, ie the magnetic layer, is compatible with the respective magnetic material. Examples of such materials are, and the associated carrier, must have limited percentages of natural investment materials, e.g. B. Tung or Chinese wood have permeability properties. With the actinic radiation used for and linseed oil, all known printing inks and lithographic 45 exposure, graphene varnishes, the natural resins such as copal resin, were already permeable to the varnish and damar resin, the drying oils, with a permeability of only 2 ⁰ I _{0 IgCn} Exposing radiation successfully copied, with a known coating composition based on alkyd resins demagnetization of up to about 60% was achieved. In the case of and drying oils, derivatives of natural poly- these extremely low permeability ranges, z. B. regenerated cellulose, ie rayon, 50 but carries the energy density that is necessary to achieve cellulose acetate, cellulose acetate propionate, cellulose- this percentage demagnetization, propior.at, cellulose acetate butyrate, the synthetic about 270 millijoules / cm *. Of course, in the case of the condensation polymers, e.g. B. the known nylon higher percentage ranges of permeability types, z. B. polycaprolactam, polyhexamethylene adipine of the copying material for the acid amide used for exposure. Polyurethanes, for example the polyurethane from SS actinic radiation found that permeabilities ethylene glycol, adipic acid and toluylene diisocyanate, up to 99 ⁹ I _{0 can be used} successfully for copying and the polyurethanes based on proportionally, provided that the magnetic high molecular weight Addittonsglykolen, z. B. the poly layer has a sufficiently high coercive force and reurethane of a Polytetraniethylenätherglykols obtained manenz.

by ring opening of tetrahydrofuran / adipic acid / 60 The percentage permeability of the copying material

Toluylene hexamethylene diisocyanate, optionally with the associated magnetic layer and / or

a "finishing" diamine, e.g. B. hexamethylenediamine, the optionally used binder for the

or similar mixed ester-amides and radiation exposing therefrom is normally in the range

derived synthetic condensation polymers, from 10 to 90 ° / ₀ . The best results will however

z. B. Potyhydroxymethylpolyhexamethylenadipinsäu- 65 with copier materials and exposure radiation

reatnid, thermosetting resins or investment materials, e.g. B. hold if the permeability percentage of the

Polyurea-maldehyde resin and modified poly copier material for radiation in the range of SO

Lyurea-formaldehyde resins, in which the modi to 80 ° / ₀ is. Afs further photography of the percentage

ΟΙ 772 381 ^Γ

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Permeability of the copy material and the reflex exposure necessary to use a plate that

Intensity of the exposing radiation for copying both lines and points of the same or different

these different (inevitably dependent) dimensions are either in the same

Factors chosen so that the intensity of the existed or with essentially the same distance

having luminous radiation depending on the pro- 5. The determining factor remains whether the

percent transmittance at the lowest possible value Reflex engraving underlay the percent light transmittance

lies, which with the achievement of a demagnetized permeability has within the above-mentioned limits

Image of good contrast is consistent. In and at the same time a magnetic component of

Ideally, the copy material will contain sufficient strength to produce a good magnetic

compiled to get its percentage permeability io signal, as in the previous package

for the exposing radiation is such that a strong limit is described.

Demagnetization of the magnetized layer of the magnetophotographic copying described here, for example 80 to 100 ° / ₀ , preferably from 90 to drawing materials are particularly suitable for 100%, with energy density values on the magnetophotographic copying of documents to be copied, the surface of not more than 250 millijoules / cm \ are legible with the eye, ie of documents which selectively reflect visible light preferably in the range of not more than 200 to 240 visible light. It is. however, millijoules / cm ¹ , is achievable. obviously that the copier materials with suitable

This result can also be achieved by setting the neter modification for the substrate and the Ratio of the surface area of the magnetic binder materials used according to the beMaterials the surface size of the transparent parts »0 also knew the properties of these materials of the copy material. Application of electromagnetic radiation outside

Some modifications of the copy materials, those of the visible part of the spectrum or with

Particulate radiation produced by the method according to the invention are useful, which the ferro-

are shown in the drawings. able to heat magnetic material and from

Furthermore, the various stages of the process «5 document is selectively reflected.

shown in the form of a box scheme. All of the following examples relate to the

Figures are not to scale, identical parts are quantitative data on the weight.

each denoted by the same reference numerals. «. . . .

F i g. 1 shows a top view of a recording ^sp

material, which consists of a carrier film 20, in the 30 flat, parallel grooves were in a polished,

"Lines" 21 on magnetic material in grooves square brass block from IMcm edge

(22 in Fig. 2) are in the band. length and 0.64 cm thick so that 1000

F i g. 2 shows a reduced section along the grooves 0.013 mm wide and 0.005 mm deep

Line 2-2 of FIG. 1 and illustrates the lines at a distance of 0.013 mm from center to center

21, which are introduced into grooves 22 in the carrier film 20. 35 were holding. The one covered with 393.7 lines / cm

F i g. Fig. 3 shows a plan view of a recording surface of the block (or master) forming the

material in which "dots" 24 of magnetic indentation contained strichtexi became horizontal

material are inserted into holes in the carrier film 20; Layer wetted with excess tetrahydrofuran,

F i g. Fig. 4 is a view similar to Fig. 4. 3, whereupon an excess of a 12.5 ⁰ Z ₀ IjCn solution of

however, shows another arrangement of the points 24; 40 high molecular weight polyvinyl chloride (PVC) in tetra

F i g. 5 shows a reduced section along the hydrofuran on the center of the surface used

Line 5-5 of FIG. 4 the holes 23 in which the points were applied. After drying and

24 are inserted; The strip became a bubble-free, clear, transparent one

F i g. 6 is a section through a multilayer PVC film obtained on one side with an inverted one

Drawing material, with the C ' carrier film 31, the 45 relief image of the grooved metal surface carried. the

The points 32 and 33 of different depths of foil had a thickness of about 0.2 to 0.25 mm.

contains magnetic material, with an adhesive- A 15 ^e / o solution, which consists of 50.4 parts of poly-

Layer 34 firmly connected to a carrier film 35 is methyl methacrylate of medium molecular weight

(see example 6); consisted in 285.6 parts of toluene, was 174 hours

F i g. 7,8 and 9 beef enlarged sections through the so with 50.4 parts of chromium dioxide, which is based on the in the USA.

TtSgerfoHe 40 and show the various formulas described in patent specification 3,278,263 prepared way

4Ί, 42 and 43, oüe the wells for the admission had been made, and 41TdIeIIi isooctylphenoxy poly-

of points (holes) or lines (grooves) made of magnetic ethoxyethanol (a commercially available non-

ash may have material in cross-section; ionic dispersant) in a ball mill.

Pig.IC is a top view of a foil 55 that 55 grinds. The chromium dioxide had the following properties

however, both lines46 and points 47 expose: i7 / _e = 401 Oe, σ, = 80 electromagnetic

magnetic »material carries; Units / gram measured at 4400Oe. The CrOr

Fi g. Figure 11 is a box diagram showing the on-one suspension was used to create the 0.005mm deep

different sequence of process stages illustrated. Grooves in the relief image with 39.7 lines / cm

The pictures show a line plate to be filled in with reget- 60 on the foil. Excess material

moderately arranged, uniformly ^wide; The same was removed by replacing the filled film with

Spaced magnetic lines and glued paper that would be wiped off with toluene Point plate with regularly arranged η points was slightly moistened to ensure that the Sähet) and columns evenly spaced the entire surface of the filled sheet evenly

with the same diameter as in FIG. 4 shown, H and was flat.

However, this great regularity is not necessarily. The filled in slide was dried in

necessary, over-desired In the context of the invention, a magnetic field of an average of 1500Gaeß

It is thus possible as a reflex engraving base for magnetized and with the filled side against one

1 ι

Bureau of Standards grid board, which contained printed numbers and a series of black bars. A flash unit with a capacity of 3000 μ.Ρ was charged to 500 V and discharged through the back of the magnetized film. The film was removed from the grid and then briefly immersed in a suspension of fine iron powder in a hydrocarbon solvent and air dried. It was found that the iron particles _{adhered to the parts of the CrO a} -containing film which corresponded to the image areas of the original black line pictures and printed numbers. The iron powder pattern was then transferred to a pressure-sensitive adhesive sheet by applying slight pressure, a right-sided positive copy of the original board being obtained on the adhesive side of the adhesive sheet. This copy showed faithful reproduction, good resolution and good "contrast".

Example 2

A brass cylinder ¹ .r, two inches in diameter by three inches in length, was cut on a lathe. The surface of the cylinder was polished to a mirror finish. A spiral groove 5 µm deep and 13 µm wide with a center-to-center spacing between adjacent annular grooves 13 µm was cut in the surface of the cylinder to give 393.7 grooves / cm. A very thin hard chrome plating was electrolytically applied to the surface of the grooved cylinder with an estimated thickness of 1.3μ.

The grooved and plated cylinder was mounted horizontally so that it was axial about its major dimension could be rotated. The end of a cllulose acetate film, which was 7.62-15.24 cm in size and 0.076 mm thick was treated with a Adhesive tape attached to the surface of the cylinder in the axial direction. A jet of acetone from a The wash bottle was directed into the space between the foil and the cylinder while the foil passed through Rotating the cylinder has been wrapped around the cylinder. The other end of the slide was attached with adhesive tape Cylinder attached, whereupon the enclosed acetone layer was allowed to evaporate through the foil. the dried film after removal from the cylinder showed an accurate embedded in its surface opposite relief image of 393.7 lines / cm on the surface of the cylinder at a depth of 5 μ each.

A solution was prepared from 75 parts of polyvinyl alcohol (PVA), which contained some unhydrolyzed acetate groups, and 175 parts of methyl sulfoxide (DMSO). This solution was made with 112 parts of chromium dioxide (i // _e = 594 Oe, a _t = 82 electromagnetic units / gram , a $ = 41 electromagnetic units / gram) and 3 parts of isooctylphenoxypolyethoxyethanol passed through a paint mill six times, using dimethyl sulfoxide to maintain the desired grinding viscosity. The paste obtained was applied with a squeegee into the grooves of the 7.62 × 15.24 cm film carrying the relief image, the squeegee being held essentially parallel to the grooves. The surface was cleaned of material that had adhered to the narrow areas between the filled-in grooves to ensure a uniform, even surface, and the film was then allowed to dry.

The filled sheet was applied to the one in Example 1

magnetized, exposed with the flash lamp, developed and used for printing, but the printed image was not as intense as the image obtained in Example 1 because the grooves were somewhat S were less sharp and flat overall.

Example 3

A copper plate with 295.3 grooves / cm was photomechanically fabricated as follows: A thin layer

ίο a commercially available, water-soluble, when exposed to light Insoluble copier coating on a smooth copper plate was replaced by a Negative containing 295.3 lines / cm exposed. The uncured copier in the unexposed Areas that corresponded to the black lines of the negative were peeled off with water, whereupon grooves were etched to a controlled depth of 7.6 to 13μ. Finally, the remaining hardened copy layer material removed. A

ao Rdief image was made of the etched surface, by rinsing them in a horizontal position with acetone and placing a 0.076 mm thick cellulose acetate sheet pressed onto the wetted surface and allowed to dry while with the etched plate

“5 was in close contact. After separation, the dry film, which was a relief image of the etched surface, was _{filled with the magnetic paste of CrO 2} , PVA and DMSO described in Example 2, using a parallel block held at an angle of 45 ° to the doctor blade . The film was used to print a correct-sided positive image by reflex thermomagnetography in the manner described in Example 1.

B e i s ρ i e 1 4

A photopolymer printing plate with 295.3 depressions / cm (each about 7.6 μ deep) in each direction dt. ' Two-dimensional surface was made from a dot negative with 295.3 lines / cm. An opposite Relief image of this printing plate was made using a liquid, exposed to air Room temperature curable silicone resin made. An opposite relief image of the silicone surface was then made using a room temperature curing mixture of commercially available liquid epoxy resins. The relief image obtained in this way in the hardened epoxy resin was sprayed with silver and plated with nickel in a nickel sulfamate electrochemical bath until the Nickel deposit had a thickness of about 0.79 mm. The surface of the nickel posed a similar one Relief image (intaglio) of the original printing plate. By applying a 0.076 mm thick Cellulose acetate film on the surface of the nickel plate wetted with acetone in intimate contact with Surface to surface and allowed to dry, a relief image of the nickel plate was obtained, the one exact opposite of the original

Printing plate was.

The regularly arranged depressions in the cellulose acetate image were compared with that in Example 2 described magnetic paste made of CrOj, PVA and DMSO filled in. The excess paste was

from the area between the filled in ridges without Difficulty wiped off.

The dried filled FoHe was magnetized in a field averaging 1500 Gauss,

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grooves were left face down on a printed surface. the

Rastertafel (Bureau of Standards) laid and the curing of the epoxy binder was completed by The back of the filled film was held at 50 ° C. for 16 hours with a xenon flash lamp in the “no ball”

reflector that has been charged to 900V by one.

140μΡ-Κοηαεη83ΐοΐ ^ ηΐρρβ was fed, exposed. 5 The dried filled sheet was in a

The output energy of the lamp is magnetized at the applied field of an average of 1500 Gauss,

The distance of 10.16 cm was 0.15 joules / cm * of with the filled surface against a printed one

the filled in foil top. The exposed, laid with Rastertafei (Bureau of Standards) and through

CrOj-filled slide was in suspension from the back with a xenon flash lamp in the above Expose carbonyl iron powder in the manner described in 1,1,2-trichlorotrifluorethane. The latent magnetic

wraps. The developed image was transferred by spreading a picture in an aqueous dispersion of an image

it developed against an adhesive-coated white toner made up of particles 5 to 10 μ in size

was pressed, with a laterally correct imprint that of a 70:30 mixture of Fe ^ O «with a thermo-

Grid board with good accuracy, resolution and plastic polyamide was made and made of n-propyl alcohol

good contrast was obtained. 15 had been spray-dried. That developed

Image was made using heat and pressure B is ρ ie I 5 transferred to ^the "paper, with a cleaner, darker,

laterally correct imprint of the grid table with good

A whitewashed copper plate measuring 15.24 x 15.24 cm that maintains accuracy, resolution and good contrast a recessed dot pattern of 295.3 lines / cm was created.

Example 7 was made in the manner described in Example 3
manufactured. The plate was in a soft lead plate

pressed, with a total pressure of 1219.2 t. A thin layer of an adhesive based on a was applied. From this lead plate, amorphous polyester was applied to a 0.127 mm thick, 0.076 mm thick cellulose acetate film as a polyester film with a flame. A solution de original on the copper plate to the examples in a nylon 66/610/6 PoWamidharzes in 88 ° / _o sodium spiet manner described 3 was prepared. One of these as ethanol was poured onto the subbed polyester film and left to dry. The film obtained was filled with the 0.2 to 0.025 mm thick nylon surface of the composite _{CrO 2} -PVA-DMSO paste described in Example 2. Excess 3 <> film was easily wiped off with the paste with the line pattern of 295.3 from the flat area between the lines / cm onto the depressions filled in in Example 6. The manner described at 140'C and a pressure of filled film was embossed for developing and printing 70.3 kg / cm * 3 minutes,
of a thermomagnetic image after reflective The obtained composite embossed film was filled by the method in the manner described in Example 4 using magnetic paste described in Example 6. A certain difficulty arose when cleaning the surface of the film from the over-

liquid paste. The filled film was cured

A 0.076 mm thick polyester film was used with and for copying the printed grid board onto the thin layer of a solution of an adhesive in the manner described in Example 6.
Basis of a thermoplastic amorphous polyester in

Coated with methyl ethyl ketone. While the adhesive example 8
layer was still damp, a cellulose acetate

A film 0.076 mm thick was rolled over it, whereupon a solution of 15 parts of high molecular weight ethyl was allowed to dry the layered film. A plate made by electrical 45 cellulose, 203 parts of tetrachlorethylene and 100 parts of metal removal, which had a line pattern of 4-methyl-2-pentanone was written on the in Example 7 with 295.3 lines / cm as a relief of 7.6 μ height Cast polyester film, which was pressed into the cellulose acetate side of the laminate with a thin layer of an adhesive based on an amorphous 125 ° C in a Carver press, with a print covered polyester, and left to dry, of 70.3 kg / cm * Applied for 2 minutes and a pattern was obtained with a pattern. As an alternative, the nickel plate was left in which the cellulose acetate film with the polyester lines / cm had been incorporated into which the cellulose acetate film had been incorporated by means of an electrochemical treatment adhesive layer on the polyester film to dry and electroforming the manner described above 55 game 6 described manner at 125 ° C and 42.2 kg / cm ¹ carried out embossing. 3 minutes embossed. The foil was embossed with

The layered film, which consists of solid acetate film and the polyester magnetic paste film described in the examples, the surface of which had been filled and, after partial curing at room temperature, 295.3 grooves / cm had been pressed in, was wiped clean with and finally overnight in a paint mill produced paste filled, 60 50 ⁰ C hardened. The cured, filled film was made from 70 parts of chrotene dioxide (i7 / _e = 594; σ, = 82; for thermomagnetic reflex copying of the raster a, = 41, see Example 2) and 30 parts of epoxy resin under the panel on the in Example 6 described way verZusatz of enough 2-butoxyethanol produced applies.

to obtain the desired mill viscosity. B e i ■ $ η i e 1 9

After partial curing at room temperature 65 ^p

using tetraethylene pentamine (TEPA) A solution of 30 parts of a commercially available

as a hardening catalyst was excess. Paste of polycarbonate resin in 216 parts of 1,1,2-trichloroethane

removed from the top of the film, the up to was poured onto a 0.127 mm thick polyester film,

15 16

which was previously filled with a thin film of an adhesive on the table paste made from 70 parts of chromium-based amorphous polyester mixed with dioxide (iH _t - 424 Oe; a _t = 80.3 electromagnetic units / gram coated with a modified diisocyanate; a _T = 36.7 electromagnetic Einwar and left to dry. The obtained, approximately units / Gratnm) and 30 parts of a commercial, 0.02 to 0.25 mm thick polycarbonate surface consisted of 5 epoxy resin catalyzed with TEPA. The composite film was embossed on the surface of the film described in Example 6 after partial curing at 180 ^° C. and 42.2 kg / cm · 3 minutes with an excess plate in the air at room temperature, which was embossed on the plate described in Example 6 black paste cleaned, after which curing was completed by way electrochemical treatment with a by passing the film has been provided overnight at 40 dot pattern of 196.8 lines / cm to kept to 50 ° C.

was. The tiny depressions, which had an equal The cured filled film was to the thermal distance, were filled with a paste ground on the color mill using a magnetic reflex copying of the grid, which was used in the manner described in Example 6
70 parts CrO, (iff _c = 417 Oe; σ, = 79 electromagnetic units / gram; a, = 38 electromagnetic 15 B is ρ ie 1 12
Units / gram) in an alkyd resin, then partially in air at room temperature. A CeDulose acetate film 11.4 x 12.7 cm was cured, wiped off and air dried. The filled film which had been hardened with the solvent in Example 3 was provided with the imprint of the line pattern grid board in the manner described in Example 6 for copying in the manner written at 196.8 lines / cm. The grooves used in the. Film were measured using the straight edge B ice T he 1 10 ^{c 'ner} ^ ^a ^ ^{e' with e 'ner} dispersion of 6.1 parts of ^P ₁ of CrO Step Example "11,1,5 parts epoxy resin, 2.9 parts of A plate filled with butyl cellosolve and 0.2 parts of TEPA by electrochemical treatment. The film coated with a dot pattern of 176.8 lines / cm was then viewed between the two and a relief of about 7.6 μm - brought the pulling poles of an electromagnet, which pointed, was in a horizontal position with methylene had a magnetic field of 4000 Gauss, with warm air chloride humidified, whereupon a 0.127 mm thick poly carbonate sheet was pressed onto the plate by a hand fan for about 5 minutes and the poly - was blown. The film was then taken from the magnetic carbonate film itself with a thin polyester field, 2 days at room temperature and the film was covered, which was then held flat with a metal plate for final curing for 16 hours. After 10 minutes, the upper 50 ^° C. was kept. Excess coating mass on the metal plate and the polyester film removed, whereupon the surface of the film was removed by wiping with one the methylene chloride through the polycarbonate film soft tissue paper. The vertical orien evaporated. After complete drying, the magnetized CrO, particles were 92%, and the polycarbonate film was removed from the engraved base as determined by X-ray reflection diffractometry. It was found that in its surface a reef image which is opposite to the degree of the preferred alignment of the e-axis shows the electrochemical perpendicular to the plane of the film. Exposure and treatment of the pattern applied to the plate. Development was imprinted in the manner described in Example 5. 40 with an exposure time of 3 seconds resulted in a weak copy density evenly spaced. Longer development times depressions of the relief image on the polycarbonate film up to nine seconds resulted in a fairly dense copy were a '.n paint mill ground and a significant resolution of the transferred image. Paste filled in, made up of 70 parts of chromium dioxide and

30 parts of a liquid alkyd resin as a binder 45 Example 13
existed (see Example 9). After partial hardening on

the air at room temperature was the excess A horizontally oriented Fc ^; ie was based on the im

Paste removed. Each well was made up to the top edge of Example 12 using the manner described

filled in while there was no paste on the flat difference that the freshly coated film six times

Places between the wells. The end 50 between the opposite poles of two hoof-

valid ₆ e curing in air was accelerated, iron magnets were carried out, which a magnetic

by keeping the film at 45 to 50 ^° C. overnight, had a field of 4000 Gauss. The horizontal orientation

would. The ratio of the CrOj particles was 91.3%, determined

The cured film was used for copying by X-ray diffractometry with translucent Typewriter writing on white paper on the 55 radiation showing the extent of the preferred alignment

used in the manner described in Example 6, the direction of the c-axis of the particles parallel to the longitudinal

the labeled paper instead of the grid shows what the foil is doing. Exposure and development

would apply. in the manner described in Example 12 gave a

Example 11 8 " ^1β black development with fairly good consistency

60 solution.

The plate described in Example 10 on which the orientation of the magnetic material in the

by electrochemical treatment of a line pattern of reflective copy films according to the invention improves the

from 196.8 lines / cm had been applied, the magnetic properties of the reflective films were completely

5 minutes at 180 ° C under a pressure of 1756 kg / considerable. When orienting the magnetic

cm ^a into the carrierless 65 particles described in Example 10, e.g. B. CrO _g , in the separate surface

0.25 mm pressed polycarbonate sheet. The slide that areas, e.g. B. grooves, become magnetic

was provided with the inverted relief image, remanence values were obtained which were more square

with a magne- hysteresis loop ground in a dye mill, which leads to a higher

Magnetic output power for the reflex oiled iH _t = 260Oe, 1 part of a commercially available film is required. This increases the attraction for fatty alkyd resin varnish (linseed oil), which has an acid number of toner particles during development. The orien- from 6 to 10 had, and 3 parts of Stoddard solution kaaa were done in two directions: One in medium with 300 passes in a mechanical longitudinal direction of the copying material, ie in its 5 ore mill was ground. The thick printing plane obtained, referred to as the horizontal orientation, and color was used to reproduce the commercially available polycarbonate sheet written in Example 10, the other perpendicular to the plane of the film, as a vertical, commercially available polycarbonate base, which denotes an orientation. Had a size of 161.3 cm * and like ω the previous two

Both types of orientation require an example to be filled with a line pattern of 196.8 lines / cm of the correct viscosity range of the magnetic masses to which was provided. The filled sheet was dried in which the particles of the magnetic material were allowed to dry for 2 days under room conditions, whereupon they could move freely and along the direction of the applied surface, the surface was cleaned and aligned with a fine abrasive magnetic field. For products was the medium polished on the basis of aluminum oxide, the type described above on the basis of Cr ₈ O Finally, the polished film was 15 dertem pressure at 55 ^C C verminzeigte found that a viscosity of 4000OcP (measured with a Brookfield dried The obtained Viscometer with a spindle reflex master die was magnetized by No. 7 at 50 rpm and 22 °) the maximum value of the viscosity over the edge of a strongly magnetized steel plate, which allows orientation. Preferred was drawn.

becomes a Vi! osity range from 30,000 to 40,000 ocP. The obtained magnetized master die was.

Below about lOOOOcP, agglomeration _ao with the pattern side against a 0.127 mm thick pole,

take place instead of an orientation. Ethylene terephthalate film placed on which a squint · ..

Vertical orientation is achieved by using Cr ₂ O in polyvinylidene chloride as a binder

the freshly coated l-olic was attached between the two. The CrO ₁ had a ///, - value

pulling poles of an electromagnet, where 314 Oe. The two slides were under a pressure

higher degrees of orientation in the same direction a ₅ of 90.7 kg between square, smooth aluminum

can be achieved with a higher strength of the magnetic field. nium plates in a Carver press for 2 minutes

A field of 4000 Gauss has a 85- to 92 ° / "ige, 130 ⁰ C heated, whereupon it quickly with cold water

vertical orientation as a result, determined by being cooled. This pressing temperature is above the

the X-ray diffraction pattern, the ski. from the reflection Curie temperature of the CrOj, and from cooling

the plane 002 results in 1 needle-shaped CrO, particles. _3O by the Curie temperature in the contract with the das

Horizontal orientation is achieved by using a y-Fe ₂ O _{3 line} pattern-bearing reflex master matrix

the freshly coated film between the opposite was a corresponding magnetic line image in

lying poles of two: horseshoe magnets formed by the CrOj layer.

which has a range from 3000 to 8000 Gauss per The plate bearing the CrOg line pattern was magnetized according to the distance between the two magnets _3g was projected through a positive Iran and the width of the gap in the middle for the orien- parent, which contains both a line - as well as a halftone titration. An orientation of 90 to 92% copy contained at 80 ° C using a could be achieved if the film was magnetized six times in a xenon exposure lamp at 1000 V selectively in a field of 4000 to 6000 Gauss. The CrO, exposed in this way became. Both types of orientation are un- ₄₀ Foil was developed by blowing a dilute magnetic alkyd oil-water emulum in hot air while stirring in indirectly after the orientation to evaporate the solvent so that the ion printing ink was dipped. After a development time of 20 seconds in the preferred direction of magnetization, the CrO, foil was kept on. The degree of horizontal orientation of an air brush passed around the printing ink is determined by X-ray diffractometry 45 to remove from the non-image areas. The radiation penetrating in this way, the degree of the wrapped CrO, film being measured with the aid of a belt, the preferred alignment of the c- axis parallel to the length roll with the layer side against a transmission of the reflective film. paper (common sized paper) pressed, whereby

Tests carried out on the foils in the machine produced an imprint of the text of the original projection transmission with the various orientations mentioned above, which had good resolution and showed that the horizontally oriented particles had much accuracy both in the letter areas and better image forming properties in both the in the halftone areas showed. Essentially had the dot patterns as well as the line patterns. The same results were obtained when a positive transparency turned upside down was used to produce a copy that was much better in terms of copy density, 55 right-sided copy or that developed, while the vertically oriented films only produced a magnetic image on an offset rubber blanket Reflectance density. These tests were taken and then carried out on the receiving sheet with a development time of 3 seconds as was transferred in offset printing. When the development time prolongs the magnetic ink on Basil the verwurden gave the vertically oriented film has a s ₀ thinned alkyd oil-in-water emulsion containing a einbessere resolution of the images, however, were obtained with the encapsulated pigment was prepared dürcr horizontal oriented foils even more dense mixing of 5 parts carbonyl iron powder, 5 parts copies are obtained. a commercially available fatty alkyd resin paint ?! Example 14 ^for printing inks, 2 parts of an aliphatic mineral

65 oil », the 0.2 part of a commercially available carbon black:

A printing ink based on iron oxide (99.0% for printing inks contained, 6 parts of one in the Mühh Jz-Fe ₂ O ₃ ) was prepared by adding a mixture of prepared mixture containing 3 parts of one in your hands

4 parts of a fine commercial iron oxide containing available octahedral Fe ₃ O ₄ , and 3 parts

a commercially available dispersant (sorbitan monolaurate). This oil phase was rapidly stirred with a single blade stirrer, adding to the slurry a solution was added containing 60 parts of water and 2 parts of a commercially available polyoxyethylene sorbitan monolaurate contained. First a thick, pasty water-in-oil emulsion was formed. The reversal to an oil-in-water emulsion took place after 50 parts of solution were added had been. This suspension contained oil alkyd droplets from 3 to 12 μ in diameter, in which the pigment was included. For the development the concentrated suspension was diluted with 320 parts of water while stirring vigorously.

Example 15

A commercially available conversion film with an opaque, porous, fusible.! Or opaque coating of 0.01 i. M thick on a 0.127 mm thick oriented carrier film made of • ethylene nephthalate was carefully cleaned and • It was wound in a metal mandrel that had a 10.16 cm penetration, was provided with holes for sucking the film on the edges and was clamped in a pre- / sions lathe. The mandrel was evacuated, sucking the test polyester film onto its surface. A rotary tool \ viirde used to form a narrow groove in the soft, by ^Druckeinw: rkuiig transparent becoming f herzug up to the interface with the Polyesterträgerfoüe depress. The rotating tool had a cutting edge that was hand honed from a 0.6μ thick tool steel blue and tapered at the tip to an edge 0.008μ wide. This rotating tool was fed through the lead screw on the lathe in such a way that 189 lines per centimeter were cut into the opaque, pressure-clear film (OPC film), using ethanol as the cutting fluid and working under a dust cover.

Using an iir. Commercially available chemical copper plating systems, a copper layer was then deposited on the surface of the conversion foil that was scratched in this way. The incised film was first placed with the soft layer side up for 1 minute in a flat dish containing a commercially available acidic solution for sensitizing non-metallic and non-conductive substrates and then carefully rinsed with distilled water. It was then treated with a commercially available activator solution for further pretreatment of the substrate for the subsequent non-electrolytic application of the copper layer for 3 minutes and rinsed again with distilled water. The copper layer was then applied by treating the foil for 15 minutes in a commercially available chemical copper plating bath, from which a dense, fine-grain copper coating 6 micro centimeters thick was deposited on the foil by chemical reduction. The copper-plated foil on these wines was further plated in a technical nickel plating bath for 18 hours at 43 ° C. and 1.50 V, a nickel deposit of 0,> 5 mm thick being formed.
The incised conversion film was taken from the

The copper layer is stripped off and then the copper layer is removed from the nickel deposit with a dilute aqueous solution of chromic acid (118.3 ml / 3.781) and sulfuric acid 01.25 mi / 1) removed.

A 38.1 x 16 cm piece of commercially available flame retarded polyester terephthalate film was used to prevent curling with a 0.4μ thick backing made from a commercially available one Polyether urethane varnish provided. This varnish existed

ίο from a 54 weight percent solids containing Solution of 1.0 mol of polypropylene glycol with a molecular weight of 1025, 1.22 mol of trimethylolpropane, 5121 moles of a mixture of 2,4- and 2,6-tolylene diisocyanate and 0.3 percent by weight dimethyldode-

"5 cylamine as a catalyst in 3 parts of toluene, 2 parts of xylene and 1 part of Cellosolveacc.tat and was made from a solution of 1 part by weight of acetone and 5 parts by weight of a solution of a Polyätheruretban" in special solvents (4 ^Λ percent by weight Fcst-

* o fabric) from a 25.4 cm wide Trjchter-Süeichmaschine, which had a 0.32 cm wide slot, which was covered with filter paper Whatman No. 1 and a close-meshed nylon filter cloth. The backing layer was left out in the air overnight.

»5 cure while preventing the final film from rolling up, but this is not necessary. The other side of the film backed in this way was then coated with the same polyether urethane varnish, which had a solids content of 45 ° / ", with a doctor blade setting of 0.38 mm. The layer was allowed to cure for 16.5 hours at room temperature until it was tack-free. Its thickness was about 76 μ. The Nickejstrichplatte described above was used to determine the 76 μ thick coating of the Poiyätherurethanlack 5 minutes at 125 ⁰ C nut a pressure of 43.9 kg / cm ² to emboss. The following day, the embossed film was filled with a thick paste that had been prepared by adding 80 parts of CrOj and 20 parts of a commercially available hardening agent.

The alkyd resin binder was milled 40 passes on a three-roll mill. During milling and coating, the CrO, alkyd dispersion was diluted with Stoddard solvent so that the viscosity during coating was about 60,000 cP. The embossed sheet was then taped to a clean, smooth work surface (a 6.35 mm thick rubber pad covered with 0.13 mm thick polyester terephthalate sheet) to fill in. The filling was carried out as follows: A bead of the thick paste described above was placed in front of a steel doctor blade which had a radius of 3.18 mm. The doctor blade was held at an angle of 30 to 35 and drawn once over the surface to be coated without interruption. As the Stoddard solvent evaporated, the squeegee was drawn across the surface several times in rapid succession. This took about JO seconds. To remove most of the excess dispersion from the surface, a sharp knife edge was finally drawn over the surface. The alkyd binder was allowed to cure overnight at room temperature. Excess CrO ₂ and alkyd resin were removed from the surface by careful grinding with a dispersion of 0.3 μ-aluminum oxide particles in water.

The foil filled with CrO ₂ was then covered on the top with an approximately 0.4 μ thick coating

■ ms.

from the above-described polyether urethane lacquer coated in exactly the same way as described above for the original backing layer. The finished filled sheet contained about 3.27 g of CrO ₁ and alkyd resin as a binder per square centimeter.

This film was used for reflective exposures that were carried out with aqueous toner dispersions on the in the in the way described in the previous examples. Excellent copies of the Received originals.

1 sheet of drawings

Claims (6)

or toners containing magnetic particles by S claims: electromagnetic reproduction, developed by magnetic-optical apparatus or other means 1. Method of making a magneto-be. From U.S. Pat. No. 2,799,609, is photographic recording material with a 5 production of a magnetophotographic recorder overmomagnetic Layer in which a layer of voltage material is known, in which a magnetic formed on a base, cured and supported by the pigment-containing layer on a base is peeled off, thereby formed, hardened and peeled off from the base indicates that a is a plastic film. Constructive material comprising at least one major class of documents the surface is in a flowable state to a level that is legible with the eye, i. H. visible fourth pad laid, hardened and selectively reflecting from the electromagnetic radiation. Document is peeled off, so that the wells In order to make true copies of such documents obtained the relief image obtained with a suspension, a copying material is used which for ferromagnetic particles in a solution of a 15 the radiation is essentially transparent, and a curable binder filled and - given- radiation pulse is used to generate the magnetic otherwise the ferromagnetic particles used by a picture The copying materials, (He for this Magnetic field to be oriented - and that the purpose are required, thus must have two self-binding means. is hardened. shafts: a high flow strength of the ma- 2. The method of claim 1, marked by * o-magnetic material and transparency. This intrinsic characteristic, that as plastic film-forming plastic films are inherently contradicting one another, materially a binder solution, preferably one because the ferromagnetic particles, the substantial amounts of polyvinyl chloride, polycarbonate, cellulose acetate required to develop the flow strength, or a polyether urethane solution is used. are opaque to radiation. 3. The method according to claim 1, characterized in that »5 there was therefore the object of providing a method for draws that as a plastic film forming Ma- production of such a magnetophotographic Aufterial to deliver one on a surface with a solution drawing material that is permeable softened plastic film is used. Free transparency with high river strength at the same time 4. The method according to claim 3, characterized in that the magnetic material is characterized. draws that a cellulose softened with acetone 3 ° A solution to this problem is that acetate foil or a ferromagnetic material softened with methylene chloride in one essentially Polycarbonate sheet is used. periodic pattern on the substrate, ζ. Β. as 5. The method according to Ansprut.i 1, characterized by points or lines to be arranged, whereby the Strah shows that as a plastic film forming painting through the transparent substrate between material a plastic film 35 softened by heat is allowed to pass through the magnetic elements,
is used. The invention is based on a method for 6. The method according to claim 1, characterized marked production of a magnetofo'oetrafischen records, that as ferromagnetic particles needling material with a thermomagnetic layer, shaped particles, preferably made of CrO «, in which a layer is formed on a base, turned will. 40 hardens and is removed from the base. It is characteristic that a plastic film forming Material that is in a flowable state on at least one surface on an engraved base laid, hardened and peeled off from the base The invention relates to a method for producing with a suspension of ferromagnetic particles Positioning of a magnetophotographic recording material in a solution of a hardenable binder with a thermomagnetic layer, with fills and - optionally the ferromagnetic which a layer is formed on a base, hardened particles are oriented by a magnetic field - and is removed from the base. 5 »and the binder is hardened. The Belgian patent specification 672017 describes a. According to a preferred embodiment of the Erneues magnetophotographic Refflexaufnahmver- the ferromagnetic particles are needle thread, in which a magnetic image of a document is shaped and consist in particular of CrO ₁ . That can be obtained. Here one puts the document advantage of the use of CrO ₁ lies in its three against a copy material, which from; a layer support 55 has mutually dependent properties, namely, which on the side facing the document with a relatively high coercive force, a film made of hard magnetic material has high remanence at room temperature and before easily, and emits an 'achievable' through the copy material Curie temperature.
Pulse of radiation on the document. The preferred distance between adjacent, temperature of the ferromagnetic elements in the copier periodic structures depends on the different material is in this way due to the most radiation factors. The distance must be small in proportion to the impulse uniformly over its surface up to the characters or other images on the document to be copied at the Curie temperature and by selective reflection in order to resolve the detail of the document in and through the Curie range . When the image is applied with a magnetic pressure so that the ferromagnetic element is selectively developed in color or a magnetic toner, partially or completely to form an image which is then transferred to another substrate, e.g. B. paper, to demagnetize the document. The magnetic production of the copy is transferred, the image can then partly depend on the fineness of the particles by treatment with printing ink solution