Gidrofilizatory the basis of printed forms for flat printing and receipt

B41N3/03 - Chemical or electrical pretreatment

 

(57) Abstract:

The invention relates to the field of flat printing and provides a method of producing a substrate of the printing form for flat printing, which includes casting base, for example, aluminum or plastics in contact with liquid having a pH of 9 or higher and containing a solution of a silicate such as sodium silicate, in which the dispersed material in the form of particles, such as aluminum oxide or titanium oxide. During curing the liquid forms a hydrophilic layer on this basis. Also described substrate itself. 2 c. and 35 C.p. f-crystals.

This invention relates to the field of flat printing and provides a method of producing a substrate of the printing element for flat printing, the printed substrate element for flat printing, and a printing element for flat printing. This invention particularly, though not exclusively, relates to the field of lithography.

The lithographic process includes the creation of the surface carrying the image (the print), and surfaces of the carrier image (napechatala), on the substrate, essentially in a common plane. When using such processes in the printing industry surface, levelname. In the printing ink oil-based repelled from surfaces which are not bearing the image, after bringing the substrate into contact with water.

The surface of the bearing and not bearing the image can be created using processes that include the stage of radiation exposure on the recording material on the surface of the substrate. Radiation exposure leads to different solubility of the recording material corresponding to the surfaces of the bearing and not bearing the image. In the process of manifestation of the more soluble portion of the surface is removed, leaving on the substrate topography corresponding to the image.

Preparation of the substrate for applying a layer of the recording material must ensure the connection of the recording material with the substrate. However, it should provide the ability to release soluble material image in the development process.

One of the most common substrates used in lithography, includes a base layer of aluminum, which is processed in such a way as to make it suitable for use. Typically, the aluminum layer includes high-quality aluminum, for example alloy 1050, having a purity of at maniam, with further processing by chemical methods, for example by treatment with a water solution of a phosphate or silicate salt or polycarboxylic acid.

Printing plates for lithography, which uses treated electrotherapies and/or anodized and/or chemically treated aluminum, for example described in patent application UK 1439127, U.S. patents 3181461, 3963594, 4052275, 4072589, 4131518, in European patent application 0110417 and Japanese publication 20/3956.

One of the problems associated with the known processes is that they consume a significant amount of electrical energy during electrosurgery and anodizing. In addition, these stages provide waste chemical substances that should be eliminated. Besides these processes, as a rule, you can go only with a relatively low speed.

Have been proposed many solutions to the above problems; however, few of these proposals have received an industrial application.

For example, in PCT publication W0 91/12140 described printing plate for lithography of aluminum metal, which is deposited oxide layer, obtained from a Sol of zirconium oxide.

In U.S. patent 4457971 described peteski layer, containing non-metallic inorganic particles and a water-repellent phase or phases of the product of dehydration of at least one monobasic phosphate.

U.S. patent 4420549 describes a printing plate for lithography containing aluminium or coated with aluminium, which is applied to a ceramic coating containing a polymeric form of aluminum phosphate or mixture of phosphates of aluminum, the coating essentially does not contain the dispersed substances.

In U.S. patent 4542089 described a method of obtaining a photosensitive substrate, comprising applying a hydrophilic ceramic aluminum or coated aluminum surface of the base by applying a suspension of at least one monobasic phosphate and inorganic non-metallic particles at least on one surface of a substrate of aluminum or coated aluminum and firing the slurry at a temperature of at least 230oC for a sufficiently long time to ensure substantially complete dehydration of the ceramic layer with the formation of hydrophilic ceramic coating.

Italian patent application N A000448 describes printing plates for lithography, made of titanium, on the aluminum base. The polymerization of the fluorosilicate is carried out at 225-300oC for 50-180 C.

One of the problems associated with the above processes, is a consequence of the relatively high temperature required for otvetit and/or polymerizate coating on the aluminum. It was found that high temperatures lead to annealing of the aluminum base and reduce its tensile strength. In addition, high temperatures can warp the plate and give it a wavy structure. Both of these effects can cause problems when plates operate on a printing press.

Another solution to the problem of electrosurgery and/or annealing is described in patent application PCT GB 93/01910. This document describes the manufacture of printing plates for lithography by plasma spraying a powder of Al2O3on a sheet of aluminum alloy.

As an alternative to aluminum as the base, you can use plastics, such as polyesters. Coatings on such materials is also described in many cases.

For example, in U.S. patent 4330605 described receiving the image sheet for photolithography, which can be applied to the image using diffluence of silicon oxide and a dry powder of silicon oxide.

In EP 0619524, EP 0619525 and EP 0620502 also describes the various coating film made of polyethylene terephthalate.

The objective of the invention is to solve the problems associated with known printed forms for flat printing, their parts and methods for their preparation.

According to this invention, a method for preparing the substrate of the printing element for flat printing, including the stage of formation of the hydrophilic layer by contact of the substrate with a liquid comprising a solution of a silicate, in which the dispersed material in the form of particles.

Preferably the specified print element for flat printing is the printing form.

This solution of the silicate may contain a solution of any soluble silicate, including connections, often called liquid glass, metasilicate, orthosilicate and sesquioleate. The specified silicate solution may include a solution of the modified silicate, such as borosilicate or phosphosilicate.

This solution of the silicate may include one or more, preferably only one silicate of a metal or nonmetal. Silicate of the metal may be an alkali metal silicate. Silicate nonmetal can bgde the ratio of the number of moles of silicon-containing particles, for example SiO2to the number of moles of cationic particles, such as particles of metal, is in the range from 0.25 to 10, preferably in the range of from 0.25 to about 6, more preferably in the range from 0.5 to 4.

The specified silicate preferably is a silicate of an alkali metal. In this case, the ratio of the number of moles of SiO2to the number of moles M2O in the specified silicate, where M represents the alkali metal may be at least 0,25, valid at least 0.5, and preferably at least 1, more preferably at least 1.5 times. Especially preferred is the case when the aforementioned ratio is at least a 2.5. This ratio can be less than 6, preferably less than 5 and more preferably less than 4.

Preferred alkali metal silicates include silicates of lithium, sodium and potassium, and particularly preferred silicates of lithium and/or sodium. The most preferred silicate solution containing only sodium silicate.

This fluid may contain from 2 to 30 wt%. silicate (i.e., dissolved solids sodium silicate), preferably from 5 to 20 wt. -%, more preferably from 8 to 16% of the mass. The liquid can prigmore silicate, which contains from 30 to 40% of the mass. silicate.

This fluid may contain from 5 to 60 wt%. material in the form of particles. Preferably the liquid comprises from 10 to 50 wt%. more preferably from 15 to 45 wt. -%, especially from 20 to 40% of the mass. material in the form of particles.

The mass ratio of silicate to the mass of material in the form of particles in the liquid is preferably in the range from 0.1 to 2, and more preferably in the range from 0.1 to 1. Especially preferred is the case when this ratio is in the range from 0.2 to 0.6.

The liquid may include more than 20 wt. -%, preferably more than 30 wt. -%, more preferably more than 40 wt. -%, especially more than 45% of the mass. water (including water provided in the specified solution of silicate). This fluid may contain less than 80 wt. -%, preferably less than 70 wt. -%, more preferably less than 65% of the mass. especially less than about 60% of the mass. water.

The specified material in the form of particles may be organic or inorganic material. Organic materials in the form of particles can be represented by latex. Inorganic materials in the form of particles can be selected from the oxide of the measures kaolin, lithopone and titanium oxide.

The specified material in the form of particles may contain the first material may have a hardness higher than 8 units on the modified Mohs scale (a scale from 0 to 15), preferably greater than 9, and more preferably more than 10 units on the modified Mohs scale.

Said first material may consist mainly of spherical particles. In another embodiment, this material may contain the flattened particles or plates.

The first material may have an average particle size of at least 0.1 micron, and preferably at least 0.5 micron.

The first material may have an average particle size less than 45 μm, preferably less than 20 μm, more preferably less than 10 microns.

The distribution of particle sizes for 95% of the particles of the first material may be in the range of from 0.01 to 150 μm, preferably in the range from 0.05 to 75 μm, more preferably in the range from 0.05 to 30 μm.

The first material preferably comprises an inorganic material. The first material preferably comprises aluminum oxide (this term includes Al2O3and its hydrates, for the

The specified material in the form of particles in the specified fluid may include at least 20 wt. -%, preferably at least 30% of the mass. and more preferably at least 40% of the mass. specified the first material. The fluid can include from 5 to 40 wt. -%, preferably from 5 to 30 wt. -%, more preferably from 7 to 25 wt. -%, especially from 10 to 20% of the mass. the specified first material.

The specified material in the form of particles may contain a second material. The specified second material can have an average particle size of at least about 0.001 μm, preferably at least 0.01 µm. The specified second material can have an average particle size less than 10 microns, preferably less than 5 microns and more preferably less than 1 micron.

The average particle sizes of these first and second materials, respectively, relate to the initial particle sizes of these materials.

The specified material in the form of particles in the specified fluid may include at least 20 wt. -%, preferably at least 30% of the mass. and more preferably at least 40% of the mass. the specified second material. The fluid can include from 5 to 40 wt. -%, preferably from 5 to 30% by weight of asandy the second material is preferably a pigment. The specified second material is preferably inorganic. The specified second material is preferably titanium dioxide.

These first and second materials preferably provide multimodal, e.g. bimodal distribution of particle sizes. If the liquid contains silicate and the specified material in the form of particles includes, as described, the first and second materials, the ratio of the % of the mass. silicate (e.g., dissolved solids sodium silicate) and % wt. specified the first material may be in the range from 0.25 to 4, preferably in the range from 0.5 to 1.5 and more preferably about 1. Similarly, the ratio of wt%. silicate and % mass. the specified second material may be in the range from 0.25 to 4, preferably in the range from 0.5 to 1.5 and more preferably about 1. The ratio of the % of the mass. the first material and % of the mass. the second material may be in the range from 0.5 to 2, preferably in the range from 0.75 to 1.5, more preferably about 1: 1.

The specified material in the form of particles may include a third material, which preferably is used to reduce the pH of the silicate solution. Specified third material can and this is the preferred aluminum phosphate. If there is a third material, the percentage specified of the third material in the specified material in the form of particles is preferably less than 30 wt. -%, more preferably less than 20 wt. -%, and especially less than 10 wt. -%

The pH value of the specified fluid may be higher at 9.0, preferably above 9.5, more preferably above 10.0. Especially preferred is when the pH is above 10.5V. The pH value, respectively, are controlled so that the silicate remained in solution and did not form a gel. Typically, the gel is formed when the pH of the silicate solution falls below pH 9. The pH value of the specified liquid is preferably lower than 14, more preferably below 13. It is clear that the pH of the liquid affects the adhesion of the hydrophilic layer to the base. It was found that the use of a liquid having the above pH value, can lead to good adhesion.

This fluid may include other components for the regulation of its properties. For example, the liquid may include one or more surfactants. The fluid can include from 0 to 1% of the mass. surfactants (substances). A suitable class of surfactants are anionic sulfates or sulfonates. Recostructed from 0 to 10 wt. -%, preferably from 0 to 5% of the mass. substance (s) that increases the viscosity. In addition, the liquid may include dispersing agents for the distribution of inorganic material in the form of particles in the liquid. This fluid may contain from 0 to 2% of the mass. dispersing agent (agents). Suitable dispersing agent may be sodium hexametaphosphate.

Were proposed hydrophilic layers of printed forms for flat printing, which include organic polymers, such as thermoplastic polymers, to increase the strength and/or hardness of the hydrophilic layer. The liquid used in the method according to this invention preferably contains a thermoplastic organic polymer material such as polyvinylidene fluoride or the like.

This liquid may have a viscosity less than 100 CPS (at 20oC and a shear stress of about 200-1when using a viscometer Mettier Rheomat 180 having a measuring circuit with a double gap. Preferably the viscosity should be less than 50 JV, more preferably less than 30 JV in the measurement, as mentioned above. Especially preferred is the case when the viscosity is less than 20 SP.

This liquid can be applied on both sides of the specified groundwork to form a hydrophilic layer on both sides. The basis of such a layer on both sides can be used for the manufacture of double-sided lithographic printing plates. In that case, if this framework is used for single-sided shape, the side plates, which do not cause the image layer can be protected hydrophilic layer. Specified fluid preferably is applied only on one surface of the specified framework.

This liquid can be deposited on a specified basis, to form a hydrophilic layer having an average thickness after drying is less than 20 μm, preferably less than 10 μm, and more preferably less than 5 microns. Especially preferred is the case where the average thickness is less than 3 microns.

The thickness of the hydrophilic layer can be more than 0.1 μm, preferably more than 0.3 μm and more preferably more than 0.5 μm.

The specified material in the form of particles determines the specified hydrophilic layer formation, which make the layer is not flat, and are located so that when applying the image layer on top of wabeno to as described in the patent application great Britain GB 2277282, the contents of which are incorporated herein by reference.

This method preferably includes the steps of creating the appropriate conditions to remove water from the liquid after applying liquid Foundation. These conditions may include passive or active removal of water and can be to create air flow over and/or in the regulation of the humidity of the air surrounding the base. Preferably, this method includes a step of placing the base in a heated environment. This basis can be placed in such conditions that the temperature did not exceed 230oC, preferably not to exceed 200oC, and more preferably not to exceed 175oC. Particularly preferred is a case where the temperature does not exceed 150oC.

The core can be located in this heated environment for a period of less than 180, preferably less than 120 seconds, and more preferably less than 100 C.

The core can include aluminum or its alloy. In this case, found that it is useful to place the base in an environment where the temperature is below 230oC, as described above, since at this temperature annealing framework neseta tensile strength of aluminum, measured using a bursting machine Hounsfield, may be at least 100 MPa, preferably at least 110 MPa, and more preferably at least 120 MPa. Especially preferred is the case where the tensile strength is at least 140 MPa.

The above-described liquid conveniently put on the plastic, such as polyester, to provide therein a hydrophilic layer, given the fact that this liquid only requires curing at a relatively low temperature within a short period of time. As will be appreciated hereinafter, the curing at a relatively high temperature for a long period of time can, on the other hand, adversely affect the properties of the plastic.

It is assumed that the removal of water from the liquid deposited on the base, causing the polymerization of silicate and retention of inorganic material in the form of particles in a certain position.

Thus, it should be understood that one advantage of the method of the present invention may be able to use on a wide range of core materials. For example, if the base material is aluminum is used for lithographic printing plates. Additionally and/or alternatively, use a metal which is more resistant against, for example, the reagents of the developer. In addition, this method can be used for applying a hydrophilic layer on other types of core materials, such as other metals, foil paper and plastic.

The base material before applying the specified hydrophilic layer can be pushed. If the substrate is aluminum or aluminum alloy, can be pre-processed one or more conventional methods used for surface treatment of aluminum, for example cleaning, alkaline etching, acid etching, graining brush, mechanical or suspension graining, sandblasting, abrasive cleaning, electroacusticas, degreasing solvents, ultrasonic cleaning, alkaline cleaning without etching primer, by shot peening with blasting metal grit or shot and electrotherapies. The details of these methods is given in the book "Processing and cleaning of the surface of aluminum and its alloys" by S. Wernick, R. Pinner and P. G. Sheasby, published Finishing Publication Ltd., ASM International, 5th edition, 1987.

If the base material pre-obree surface properties of the substrate material, for example, those that include cleaning, graining, etc., If the surface of the substrate are coated, the coating is preferably applied in liquid form.

Preferably specified liquid containing a solution of silicate, as described above, are essentially on a dry surface the specified framework.

Preferably specified liquid applied directly to the material of the specified framework.

Preferably the base material is cleaned and/or etched before bringing into contact with the specified fluid. Cleaning and/or etching can be achieved using an alkaline liquid, for example, sodium hydroxide, possibly with additives such as sodium gluconate and/or sorbitol.

You can also expose the base material cleaned from pickling sludge, possibly with the use of nitric acid. After this treatment, the base material should be washed and/or dried before bringing into contact with the specified fluid.

The method of preparation of the substrate preferably includes a step of regulating the pH of the surface of the hydrophilic layer, formed on the basis of the contact of this surface with aluminium sulphate to this hydrof the building of the image layer it is possible directly on the specified hydrophilic layer so that the hydrophilic layer was located between the image layer and the base.

The concept of "image layer includes a layer that can subsequently be partially removed to define a surface that will be printed, and includes a layer that is already marked surface that will be printed.

The image layer can be obtained on the entire surface of the specified hydrophilic layer. It may include any known photosensitive material located so as to form a positive or negative form. Examples of photosensitive materials include materials on the basis of diatone/dyazide, polymers that undergo depolymerization or more photopolymerization, and compositions on the basis of silver halide and gelatin. Examples of suitable materials are described in GB 1592281, GB 2031442, GB 2069164, GB 2080964, GB 2109573, EP 0377589, US 4268609 and US 4567131. Preferably the light-sensitive material is a quinone-designy material.

In another case, the image layer in the form of a desired image for use in flat printing can be applied over a specified Hydra is relevane. An example of the latter is described in US 5171650.

The above image layer is preferably applied over the specified hydrophilic layer so that its surface were obtained education, appropriate formations formed in the above-mentioned hydrophilic layer of the particles. These formations can be located so as to form channels between the photosensitive layer and the mask, so that between this layer and the mask could go the air to reduce the use of a mask on this layer before the exposure of the printing form.

This invention extends to the substrate of the printing element for flat printing, which can be made in the described manner.

It was found that the substrate prepared in this way, includes a hydrophilic layer, a well adjacent to the base. If the base is aluminum or alloy, suggest that this is due to the formation of aluminium silicate (or at least aluminosilicate links) on the substrate surface. Thus, the present invention proposed the substrate, in which the formation of chemical bonds between the substrate and the hydrophilic layer, located on MaterialName with the wear resistance of conventional substrates, treated electrocompaniet or anodizing.

The substrate is a printed form for flat printing preferably includes a base and a hydrophilic layer which contains a binder material obtained (or which can be obtained from the solution of a silicate and a material in the form of particles.

This solution of the silicate may be such as described in any of the listed options.

Assume that the material of the binder obtained from a solution of silicate of the type described, contains extremely small three-dimensional ion polymer silicate, carrying a negative charge. Removing water from the system, as described above, causes the condensation of silanol groups with the formation of polymer structures, including group-Si-O-Si-. Accordingly, the invention extends to the substrate of the printing element for flat printing, comprising a binder material containing a polymeric structure including a group-Si-O-Si-containing material in particulate form.

The specified material in the form of particles may be such as described in any of these statements.

The specified hydrophilic layer is ASS="ptx2">

The specified material in particulate form preferably includes a first material as described in any of these statements.

The first material preferably has a hardness higher than 8 units on the modified Mohs scale (a scale from 0 to 15), preferably greater than 9, and more preferably above 10 units by a modified Mohs scale.

The first material in the specified hydrophilic layer may have an average particle size and/or distribution of particle sizes as described above for the specified first material located at the specified fluid.

The specified material in the form of particles on the substrate may include at least 20 wt. -%, preferably at least 30% of the mass. more preferably at least 40% of the mass. the specified first material.

The specified material in particulate form preferably comprises a second material as described in any of these statements.

The specified second material in the specified hydrophilic layer may have an average particle size and/or distribution of particle sizes as described above for the specified second material in at the least 20 wt. -%, preferably at least 30% of the mass. more preferably at least 40% of the mass. the specified second material.

In this layer, the ratio in weight percent of the first material and the mass percentage of the second material may be in the range from 0.5 to 2, preferably in the range from 0.75 to 1.5, more preferably about 1: 1.

The specified material in the form of particles may include a third material as described in any of these statements.

The specified hydrophilic layer preferably does not include a thermoplastic organic polymeric material, such as polyvinylidene fluoride, etc.

The specified hydrophilic layer preferably has an average thickness less than 20 microns, preferably less than 10 μm, and more preferably less than 5 microns.

The specified hydrophilic layer preferably has an average thickness of more than 0.1 μm, preferably more than 0.3 μm, more preferably more than 0.5 μm.

The specified hydrophilic layer may have Ra, measured by the measuring instrument with a sharp object (Hommelmeter T2000) with the measuring head LV-50, in the range of from 0.1 to 2 μm, it is possible in the range from 0.2 to 2 μm, preferably in S="ptx2">

The specified hydrophilic layer may include from 1 to 20 grams of material per square meter of substrate. Preferably, the layer contains from 5 to 15 g, more preferably from 8 to 12 grams of material per square meter of substrate. Most preferably, the layer contains about 10 grams of material per square meter.

This base may be any type of foundations that are commonly used for printed items. For example, it may be a metal, such as aluminum, steel, tin or their alloys; paper, coated metal (e.g. aluminum foil); plastic, such as polyester, or plastic coated metal. Preferably the base is aluminum or its alloy.

The method according to this invention can be used to optimize the tensile strength of aluminum by reducing/eliminating annealing of the metal during solidification of the hydrophilic layer. So, based on this invention has a tensile strength of at least 100 MPa, preferably at least 110 MPa, and more preferably at least 120 MPa. Especially preferred is the case where the tensile strength is at least 140 MPa.

In addition to twci. For example, it was found that when using the described method for aluminum bases maximum wave height may be only about 2 mm, and the maximum number of waves per meter can be 3.

This invention extends to a printing element for flat printing, comprising a substrate, as described above, and the image layer on top of the hydrophilic layer of the substrate.

Preferably the material is in the form of particles in the hydrophilic layer is located between the base surface and the image layer so that in the result of the presence of material in the form of particles below this layer were obtained education in the surface layer of the image.

The specified image layer preferably includes a photosensitive material, and is preferred quinone-designy material.

Any feature of any aspect of any of the invention described here can be combined with any feature of any other of the invention described here.

Hereinafter the invention will be described using examples.

The production of printing plates for lithography.

Example 1

Operation 1

Preparation of aluminum

Sheet aluminate sheet loaded face up in the sodium hydroxide solution, dissolved in distilled water (100 g/l) at room temperature for 60 s, and then thoroughly washed with water.

Step 2

Preparation of coating composition

This operation used the following reagents:

The solution of sodium silicate having a ratio of SiO2: Na2O in the interval from 3,17 up to 3.45 (on average about 3.3), the following composition: 27,1 - 28,1% of the mass. SiO2, 8.4 to 8.8% of the mass. Na2O, the rest is water, the density is about 75 degrees Tudela (oTw), which is equivalent to 39.5 degrees Baume (oVe), with a specific gravity 1,375. -

- Deionized water with a resistivity of 5 MOsm.

Powder Al2O3containing alumina (99.6 percent) in the form of hexagonal plates. The average particle size is 3 μm. This powder has a hardness of 9 units on the Mohs scale (when the hardness scale of 0 to 10).

- Titanium dioxide (rutile), with an inorganic coating of Al2O3, ZnO and ZnPO4. The average size of the crystals is 0.23 μm.

Deionized water (48 g, 24% wt.) and sodium silicate solution (80 g, 40 wt%. ) were placed in a 250 ml chemical beaker and was stirred solution using a high speed mixer Silverson operating at maximum RMSE is the end of the addition, the liquid was stirred for a further two minutes. Then added alumina powder (36 g, 18% of the mass.) portions of approximately 2 g every ten C. after the addition was finished, the liquid was stirred for another two minutes. The viscosity of the liquid was about 10 CPS (at 20oC and shear stress 200-1when using a viscometer Mettler Rheomat 180 with the scheme of measurement, including the double gap.

Operation 3

Applying a coating composition

The coating composition prepared for operation 2, was deposited on the aluminum sheet prepared in the step 1, using a rotating rod device Meier coater (model C), the result that was obtained by the film thickness in the wet state 6 microns.

Operation 4

Drying composition

The sheet with the coating prepared at operation 3, was placed in a drying Cabinet at 130oC to 80 C. Then the plate was removed from the oven and cooled to room temperature.

Operation 5

Processing after drying

The dried sheet prepared in stage 4 was immersed in aluminum sulfate (0.1 M) for thirty seconds. Then, this sheet was washed by spraying for about twenty seconds with the use of tap water is toulene printing form from a sheet, received at operation 5, by coating of a photosensitive material such as quinone-diazide/Novolac resin using core devices Meyer; the dry weight coverage of 2 g/m2. The photosensitive material was dried at 130oC for 80 sec.

It was found that the printing form obtained at operation 6, has a performance comparable to commercial printed forms. However, the advantage is that it can be obtained with less effort.

Example 2

In General, the process is repeated the procedure described in example 1, except that operations 2 used a different coating composition. This composition was obtained by adding the following components to deionized water (40% wt.) in the specified sequence. After each addition the composition was subjected to intensive mixing.

COMPONENT wt. -%

Hombitan LW (trade mark) - TiO2(anatase) (average primary particle size of 0.2 μm) - 14,2

Microgrit C3 (trademark) alumina powder (average primary particle size of 3 μm) - 14,2

A solution of sodium silicate as in example 1 to 31.2

It was found that the operational characteristics of the floor is procedure of example 2, except that in stage 2 the following components were mixed in the order shown below.

COMPONENT wt. -%

Deionized water - 21,51

Hombitan LW (trade mark), as in example 2 - 14,15

The alumina powder, as in example 2 - 14,15

A solution of sodium polysilicate having a ratio of SiO2:Na2O = 5,2:1 and containing 22,78% solids - 50,19

It was found that the operating characteristics of the obtained printing plate is comparable to the form obtained in example 1.

Example 4

Used the procedure of example 2, where in stage 2 was mixed with the following components in the following sequence.

COMPONENT wt. -%

Deionized water - 33,29

Hombitan LW (trade mark), as in example 2 - 11,83

The alumina powder, as in example 2 - 11,83

Bindzil 15/500 (trade mark) is colloidal silica having an average particle size of 7 nm - 1,1

The sodium polysilicate, as in example 3 - 41,95

It was found that the obtained printing plate has performance characteristics comparable to the form obtained in example 1, except slightly coloured spots on the hydrophilic layer.

Example 5

Ispolzo.

COMPONENT wt. -%

Deionized water - 40

Hobitan LW, as in example 2 - 14,23

Powder of aluminum oxide, as in example 2 - 13,23

Fabutit 748 (trade mark) - phosphate of aluminium sodium Silicate as in example 1 - 31,5

It was found that the obtained printing plate has performance characteristics comparable to the form obtained in example 1.

The reader's attention is drawn to all articles and documents associated with this application, which was registered in parallel with the description or before him, and that this description be open to public inspection, and content of all these articles and documents cited here as reference.

All the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all transactions of any method or process disclosed in this way can be combined in any combination, except combinations, when at least some of these signs and/or operations are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by Kim way unless explicitly stating otherwise, any open sign is just one example of the total series of equivalent or similar features.

This invention is not limited to the details above performance (performances). This invention applies to any new feature or any novel combination of characteristics disclosed in the description (including any accompanying claims, abstract and drawings), or to any new operation, or any novel combination of operations, any method or process disclosed in this way.

1. A method of producing a substrate of the printing element for flat printing, including the formation of the hydrophilic layer on the substrate by bringing the substrate into contact with a liquid comprising a solution of a silicate, in which the dispersed material in the form of particles, characterized in that the silicate solution contains an alkali metal silicate, the ratio of the number of moles of SiO2to the number of moles M2About in the specified alkali metal silicate is at least 2.5, the liquid contains 5 to 20 wt.% dissolved solid alkali metal silicate.

2. The method according to p. 1, characterized in that the ratio CI">

3. The method according to p. 1 or 2, characterized in that the alkali metal silicate is sodium silicate.

4. The method according to any of the preceding paragraphs, characterized in that said fluid contains 8 to 16 wt.% dissolved solid alkali metal silicate.

5. The method according to any of the preceding paragraphs, characterized in that the ratio of the mass of the silicate to the mass of material in the form of particles in the liquid is in the range of 0.1 - 2.

6. The method according to any of the preceding paragraphs, characterized in that the ratio of the mass of the silicate to the mass of material in the form of particles in the liquid is in the range of 0.2 to 0.6.

7. The method according to any of the preceding paragraphs, characterized in that said fluid contains more than 45 wt.% water.

8. The method according to any of the preceding paragraphs, characterized in that the specified material in the form of particles includes a first material having a hardness higher than 8 units on the modified Mohs scale ( a scale from 0 to 15).

9. The method according to p. 8, wherein said first material has an average particle size of at least 0.5 micron and less than 10 μm.

10. The method according to p. 8 or 9, characterized in that the specified material is tx2">

11. The method according to any of paragraphs.8 to 10, characterized in that the specified material in the form of particles in the specified fluid includes at least 40 wt.% the specified first material.

12. The method according to any of paragraphs.8 to 11, characterized in that the liquid comprises 5 to 40 wt.% the specified first material.

13. The method according to any of paragraphs.8 to 12, characterized in that the liquid comprises 10 to 20 wt.% the specified first material.

14. The method according to any of paragraphs.8 to 13, characterized in that said first material includes aluminum oxide.

15. The method according to any of paragraphs.8 to 14, characterized in that the ratio of wt. percent dissolved alkali metal silicate and wt.% specified the first material is in the range of 0.5 - 1.5.

16. The method according to any of the preceding paragraphs, characterized in that the specified material in the form of particles comprises a second material.

17. The method according to p. 16, characterized in that the second material has an average particle size of at least about 0.001 μm and less than 10 μm.

18. The method according to p. 16 or 17, characterized in that the material in the form of particles in the specified fluid includes at least 20 wt.% the specified second material.

20. The method according to any of paragraphs.16 to 19, characterized in that the liquid comprises 5 to 40 wt.% the specified second material.

21. The method according to any of paragraphs.16 to 20, characterized in that the liquid comprises 10 to 20 wt.% the specified second material.

22. The method according to any of paragraphs.16 to 21, characterized in that the second material is a pigment.

23. The method according to any of paragraphs.16 to 22, characterized in that the second material is titanium dioxide.

24. The method according to any of paragraphs.16 to 23, characterized in that the ratio of wt. percent dissolved alkali metal silicate and wt.% the specified second material is in the range of 0.5 - 1.5.

25. The method according to any of the preceding paragraphs, characterized in that the pH of the specified fluid above 9,0.

26. The method according to any of the preceding paragraphs, characterized in that said liquid has a viscosity less than 100 centipoise.

27. The method according to any of the preceding paragraphs, characterized in that said fluid contains substances that increase the viscosity dispersing agents and/or one or more surface-active substance.

28. The method according to any of the preceding paragraphs, characterized in that the specified fluid.

29. The method according to any of the preceding paragraphs, characterized in that the specified liquid is applied on the specified substrate for forming a hydrophilic layer having an average thickness after drying of less than 20 microns.

30. The method according to any of the preceding paragraphs, characterized in that the substrate includes aluminum, or alloy, or plastic.

31. The method according to any of the preceding paragraphs, characterized in that the substrate comprises aluminum.

32. The method according to any of the preceding paragraphs, characterized in that said print element for flat printing is a printing form for flat printing.

33. The substrate of the printing element for flat printing, comprising a base and a hydrophilic layer which contains a binder comprising a polymer structure consisting essentially of groups-Si-O-Si-containing material in the form of particles, wherein the binder material is obtained from a silicate of an alkali metal, where the ratio of the number of moles of SiO2to the number of moles M2Of the alkali metal silicate is at least 2,5.

34. The substrate for p. 33, characterized in that the hydrophilic layer iminy layer has an Ra in the range of 0.1 to 2 microns.

36. Substrate according to any one of paragraphs.33 to 35, characterized in that the hydrophilic layer contains 1 to 20 g of material at 1 m2of the substrate.

37. Substrate according to any one of paragraphs.33 to 36, characterized in that it is designed for printing plates for flat printing.

 

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