The heat-sensitive composition and method of its use for the manufacture of lithographic printing plates

 

(57) Abstract:

The heat-sensitive composition and method of use intended for the manufacture of matrices positive working lithographic printing plates and allow to raise quality of production matrices. The coating on the lithographic substrate consists of a phenolic resin that is not soluble in the developer, and a compound that forms a heat-sensitive complex with phenolic resin. This complex is less soluble in a solution of developer than not associated complex phenolic resin. However, when heated, corresponding to the image, this complex decomposes, releasing phenolic resin, which is dissolved in a solution of developer. The difference of solubility between heated and unheated areas of phenolic resin increases, if the phenolic resin bound complex. On the lithographic substrate preferably also the presence of the material absorbing the laser radiation. Revealed a large number of compounds, which form a heat-sensitive complexes with phenolic resin. Examples of such compounds are compounds of quinoline, benzothiazole, pyridine and imidazole. 4 C. and 37 C.p. f-crystals, 12 tab.

This sobrie compositions, providing images and applied to the specified form.

Technology of lithographic printing is based on necesitamos oil and water, with the oily material or ink is preferably retained in the image area and the water or fountain solution is preferentially retained in free image area. If the surface is prepared properly, moisten with water, and then apply the paint, the background or the free zone of the image will retain water, and the area of the image will accept ink and repel water. Then the paint is applied in the area of the image, is transferred onto the surface of the material on which the reproduced image, in particular, on paper, cloth, etc., Usually the paint is first transferred onto the surface of the intermediate material called intermediate form, and then transferred to the surface of the material on which the reproduced image.

In General, the blank lithographic printing plate has a light-sensitive coating applied to the aluminum base. Billet negative lithographic printing plates are light sensitive coating, which cures when eksponiraju is otoki positive lithographic printing plates, on the contrary, have a coating that after exposure with light of an appropriate wavelength becomes more soluble in the developer in the exposed areas than in unexposed. This difference in solubility caused by light is called photocolorimetry. A large number produced on an industrial scale blanks positive working printing plates with a coating of financiation with phenolic resin to provide an image obtained by photocolorimetry. In both cases, the image areas of the printing form is receptive to ink, or oleophilic, and the free zone of the image, or the background is susceptible to water or hydrophilic.

The difference between the image area and the free zone of the image formed during exposure, when the blank printing plate is applied film with vacuum suction to ensure good contact. After this, the blank printing plate is irradiated with light, which partly consists of ultraviolet radiation. In the case of applying a preset positive printing form the plot of a film on the workpiece printing form corresponding to the image is opaque and does not transmit light on the workpiece printed zlecenie on the floor, which becomes more soluble and is removed.

Later developments in the field blanks lithographic printing plates obtained photosensitive compositions which can be used for casting printing plates with direct laser addressable. The image of the printing form can be obtained with the use of digital information without the help of the original, in particular, phototransport.

Known for a wide range of thermosolubility compositions, useful as a thermographic recording materials previously described in UK patent 1245924, issued September 15, 1971, which States that the solubility of any given parcel layer, providing images in this solvent can be increased by heating the specified layer with indirect exposure under short-term exposure to intense visible light and/or infrared radiation transmitted through or reflected from the background areas of a graphic original located in contact with the recording material. The patent suggests that the coating film consisting of such resins will have enhanced solubility when heating is blue 27). These materials additionally paint the image when used as the recording medium. However, the level of differentiation in solubility of the compounds described in UK patent 1245924 is very low compared with those of industrial structures, which are used for billets positive working lithographic printing plates. Very little latitude manifestations makes the compositions described in the patent GB 1245924 unacceptable for industrial billets lithographic printing plates.

Another example of blank printed forms with laser addressing, which can be used as a direct positive working system described in U.S. patent 5372907, issued December 13, 1994, and in U.S. patent 5491046, issued February 13, 1996. These two patents describe the decomposition of the latent acid Bronsted caused by radiation, with the aim of increasing the solubility of the matrix of the resin in the exposure. However, these blank printed forms very sensitive to ultraviolet radiation due to the fact that they use materials that produce acid.

Known oleophilic heat-sensitive composition comprising a polymeric substance soluble in water SHA 4708925, issued November 24, 1987. This patent describes the preparation of a positive printing form, in which the layer providing the image contains a phenolic resin and a photosensitive Onyewu salt. As shown in the patent, the interaction of phenolic resin and oneway salt leads to the formation of insoluble alkali compounds, which restores the alkali solubility after photolytic decomposition oneway salt. Blank printed forms can be used as positive or negative by introducing additional process steps between exposure and manifestation, as described in UK patent 2082339. Preparation of printed forms, described in U.S. patent 4708925, principally sensitive to ultraviolet radiation and can be further sensitized to visible and infrared radiation.

The above-described known preparation of printed forms that can be used as blanks positive working printing plates of the live image, do not possess one or more desirable qualities. Neither one of these blanks printed forms cannot be used widely without taking into account the lighting conditions in the work area. DL the th lighting, which prevents unwanted exposure to UV light. Preparation of printed forms can be used only for a limited period when illuminated with white light, and the duration of the working period depends on the output spectrum of the white light source. It would be desirable to use the equipment for image digitization and preparation of printed forms on these sites in terms of lighting with white light without any restrictions, to ensure the continuity of the process stream, so the sensitivity of these areas to ultraviolet radiation is a disadvantage. Moreover, when white light would improve conditions in the traditional preparatory areas of extrusion, where currently you have to follow a strict lighting measures.

In addition, both systems blanks printed forms have limitations in respect of the components, creating difficulties in the optimization of the properties of shapes for optimum performance in a wide range of required operating parameters lithographic forms, including the solubility of the developer, the susceptibility to the paint, the length of the passage and adhesion.

In the systems described in patent the presence niewyk salts, not tolerated in the form of modifications dilacerations resin or in the form of additional components, since these groups would cause a decrease in solubility after exposure.

From EP 0631189, G 03 F 7/021, 1994, is known for stocking a positive working lithographic printing plate having a coating on a substrate with a hydrophilic surface, and the method of obtaining lithographic printing plates, including direct exposure of radiation to the workpiece, having a heat-sensitive composition. Also known printing form obtained by direct radiation exposure of the blank printing plate having a coating on a substrate with a hydrophilic surface.

Known for the preparation, printing form and method of reception also possess the above disadvantages (sensitivity workpiece to UV radiation, the need for protective lighting, limited shelf-life, etc).

The task of the invention to provide a heat-sensitive composition suitable for use as a heat-sensitive workpiece positive printing plate to obtain an image when heated, and also the appropriate blanks and forms, n is called the corresponding radiation should lead to increased solubility of the exposed areas in an aqueous developer.

This task is solved in that the oleophilic heat-sensitive composition comprising a polymeric substance soluble in an aqueous developer, and a compound which reduces the solubility of the polymeric substance in an aqueous developer, characterized in that the solubility of the composition in aqueous developer increases when heated and does not increase from the incident ultraviolet radiation.

Thus, one aspect of the present invention to provide an oleophilic heat-sensitive composition which contains a polymeric substance soluble in an aqueous developer and hereinafter referred to as "active polymer, and a compound which reduces the solubility of the polymeric substance in an aqueous solvent and is called hereinafter "compound, reversible decrease solubility, and the solubility of the composition in aqueous developer increases when heated and does not increase from the incident ultraviolet radiation.

Indicating in the description of the invention that the solubility of the composition in aqueous developer is increased, the authors have in mind its essential oolicv aqueous developer does not increase under the action of incident ultraviolet radiation, the authors mean its insignificant increase, i.e., the value of which does not require the adoption of measures of protection against ultraviolet radiation. Thus, within the present invention may be permitted insignificant increase solubility under the action of ultraviolet radiation.

The printed form is preferably a lithographic form, which will be called so forth.

Thus, in all preferred embodiments of the present invention, the positive-working lithographic printing plate obtained after thermal manifestations and treatment. The solubility of the coating composition in an aqueous developer is significantly lower than the solubility of one of the active polymer. Subsequent exposure under the appropriate radiation of the heated parts of the song become more soluble in a solution of manifestation. Thus, when the exposure occurs differentiation of the solubility of the exposed and unexposed areas of the composition. Consequently, the exposed areas of the composition are dissolved, revealing the lower hydrophilic surface of the form.

thermal image on the form with the coating according to intensivelly, transmitted or reflected from the lower areas of the graphic original located in contact with the material of the recording image.

In another preferred embodiment of the invention a thermal image on a form can be created using the heated body. For example, the reverse side of the form or, preferably, the heat-sensitive composition can have contact with the heated needle.

In another preferred embodiment of the invention the form of exhibit directly using a laser to heat the coating. Most preferably, the laser has an emission wavelength greater than 600 nm.

Although applicants do not wish to impose restrictions associated with theoretical explanation of the principle of their invention, it is assumed that between the active polymer and the compound reversibly lowering the solubility of the formed thermally unstable complex. The formation of this complex, apparently, is reversible, and it can be destroyed by heating to recover the solubility of the composition in aqueous developer. It is assumed that the polymer material suitable for use in the present sobratema connection which reduces the solubility of the polymeric substance in an aqueous developer, poor electrons. If you do not assume the necessity of decomposition components in the composition or the presence of any significant decomposition was carried out up to the present time experiments.

Polymeric substance soluble in an aqueous developer may contain one or more functional groups selected from the series comprising hydroxyl, carboxyl, amino, amide and maleimido group.

Polymeric substance soluble in an aqueous developer can be selected from a polymer or copolymer hydroxystyrene, polymer or copolymer of acrylic acid, a polymer or copolymer of methacrylic acid polymer or copolymer maleimide, polymer or copolymer of maleic anhydride, hydrocellulose, carboxycellulose and phenolic resins.

Examples of functional groups of these active polymers suitable for use in this invention include hydroxyl, carboxyl, amino, amide and maleimide functional groups. For use in the present invention is suitable to a wide range of polymeric materials, examples of which include feelin the minimum level (meth)acrylic acid, for example, with styrene, copolymers of maleimide, for example, styrene, hydroxy - or carboxycellulose, copolymers of maleic anhydride, for example, styrene, partially hydrolyzed polymers of maleic anhydride.

Polymeric substance soluble in an aqueous developer can be a phenolic resin. The most preferred active polymer is a phenolic resin. Especially useful for this invention are condensates, which is obtained by the interaction of phenol, alkyl substituted phenols (such as Cresols, p-tert-butylphenol), diphenols (for example, bisphenol-A) and aldehydes (e.g. formaldehyde). Depending on the condensation scheme can achieve a number of phenolic materials with different structures and properties. Especially useful for this invention are Novolac resins, rezol resin and a mixture of Novolac and rezol resins. Examples of suitable Novolac resins have the following General structure.

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An aqueous solution of the developer may be an aqueous solution of alkali.

The composition of the developer depends on the nature of the polymer substance. Common components of water lithographic developers are surface-active vedeseta, organic solvents, in particular, benzyl alcohol, and alkaline components, in particular, inorganic metasilicates, organic metasilicates, hydroxides or bicarbonates.

Preferably the aqueous developer is an alkaline developer, which contains inorganic or organic metasilicate, if the polymer substance is a phenolic resin.

A large number of compounds, which lower the solubility in water is suitable polymeric substances tested for use as compounds, reversible decrease solubility.

A useful class of compounds, reversible decrease the solubility represents a nitrogen-containing compound, in which at least one nitrogen atom or a Quaternary, or incorporated into a heterocyclic ring, or a Quaternary and a built-in a heterocyclic ring.

The connection of lowering the solubility of the polymeric substance in an aqueous developer can be a compound containing at least one Quaternary nitrogen atom.

The connection of lowering the solubility of the polymeric substance in an aqueous developer may be coroboree the preferred connection, reversible reduce the solubility is a nitrogen-containing heterocyclic compound.

The connection of lowering the solubility of the polymeric substance in an aqueous developer can be selected from quinoline and triazole.

The connection of lowering the solubility of the polymeric substance in an aqueous developer can be a compound containing at least one Quaternary nitrogen atom embedded in a heterocyclic ring.

The connection of lowering the solubility of the polymeric substance in an aqueous developer can be selected from the imidazoline compounds, quinoline compounds, benzothiazole compounds and compounds of pyridine.

Examples of suitable nitrogen-containing heterocyclic compounds are quinoline and triazoles, in particular 1,2,4 - triazole.

The preferred connection, reversible decrease the solubility of a Quaternary heterocyclic compound.

Examples of suitable Quaternary heterocyclic compounds are compounds imidazoline, in particular, Monacolin With, Monacolin About, Monacolin CY and Monacolin T, which produces the company Mona Industries, quinoline compounds, in particular, 1-ethyl-2-METHYLPHENOL the unity of pyridine, in particular, cetylpyridinium, italialogistica.it and pereregistratsiu.

Connection quinoline may be a cyanine dye.

The connection of the benzothiazole may be a cyanine dye.

Useful compounds quinoline or benzothiazole are cationic cyanine dyes, in particular, dye, quinoline blue, and 3-ethyl-2-[3-(3-ethyl-2(3H)benzothiazolone)-2-methyl-1 - propenyl]benzothiazoline.

Dye AND

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The connection of lowering the solubility of the polymeric substance in an aqueous developer can be a connection triarylmethane.

Examples of useful compounds containing Quaternary nitrogen, are triarylmethane dyes, in particular, crystal violet (Cl basic violet 3) and utilily and tetraalkylammonium connection, in particular, cetrimide.

The connection of lowering the solubility of the polymeric substance in an aqueous developer can be a compound containing a carbonyl functional group.

Examples of suitable compounds containing carbonyl, are naphtoflavone-naphtoflavone, 2,3-diphenyl-1-indention, Flavon, flavanone, xanthone, benzophenone, N-(4-bromobutyl)phthalimide and phenethyl to be selected from compounds of flavone.

The connection of lowering the solubility of the polymeric substance in an aqueous developer can be selected from flavanone, xanthone, benzophenone, N-(4-bromobutyl)phthalimide, 2,3-diphenyl-1-engineone and phenanthrenequinone.

The connection of lowering the solubility of the polymeric substance in an aqueous developer can be a compound with the General formula:

Q1- S(O)n-Q2,

where Q1- arbitrarily substituted phenyl or an alkyl group,

n is 0, 1 or 2 and Q2is a halogen atom or CNS group.

Preferably Q1represents a C1-4alkylphenyl group, for example, taillow group, or C1-4alkyl group. Preferably n is 1 or better 2. Q2preferably represents a chlorine atom or a C1-4CNS group, particularly preferably ethoxyline group.

The connection of lowering the solubility of the polymeric substance in an aqueous developer may be selected from ethyl-p-toluensulfonate and p-toluensulfonate.

The connection of lowering the solubility of the polymeric substance in an aqueous developer can be dye acridine main orange (Cl orange solvent 15).

This task is solved by the fact that the workpiece is the positive working lithographic printing plate has a coating containing composition from the specified active polymer and the specified connection, reversible down-solubility, which is deposited on a substrate with a hydrophilic surface.

The said coating may be well adapted to the preferred radiation absorption and conversion of the specified radiation into heat.

This composition may contain a radiation absorber capable of absorbing incident radiation and turn it into heat.

The said coating may contain additional layer located under composition, and this additional layer may contain a radiation absorber capable of absorbing incident radiation and turn it into heat.

In one of the preferred variants of the invention may be used an additional layer containing the absorber of radiation. Such a multilayer structure can provide high sensitivity, because it allows you to use the increased amount of paglat, the which has a strong absorption in the desired wavelength range, can be introduced or applied in the form of a homogeneous coating. Dyes, metals and pigments (including metal oxides) can be used in the form of layers, the resulting steam precipitation. The technology of production and application of such films are well known and described, for example, in patent EP 0652483. Preferred components for the present invention are those which form a uniform coating of the hydrophilic or can be processed to obtain a hydrophilic surface, for example, through the use of the hydrophilic layer.

The preferred absorber of infrared light is such an absorber, which has a significant absorption spectrum in the region of the output wavelength of the laser used in the method according to the present invention. Useful application for this purpose organic pigment or dye, in particular, phthalocyaninato pigment. It may also be a dye or pigment classes squarely, merocyanine, cyanine, indolizine, perilya or metallization. Examples of such compounds are:

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and the dye IN

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and dye C, supplied by Riedel de Haen UK, e of the radiation absorber is not less than 1%, preferably at least 2%, preferably up to 25%, more preferably up to 15% of the total weight of the composition. Thus, the preferred content of the radiation absorber can be expressed as 2-15% by weight of the total composition. It is also possible presence of multiple sinks of radiation. Indicate the concentration of such compounds are related to their General content.

A large number of compounds or combinations thereof can be used as absorbers of radiation in the preferred embodiments of the present invention.

In preferred embodiments of the radiation absorber absorbs infrared radiation. However, there may be used and other materials that absorb radiation of different wavelengths (excluding wavelengths of ultraviolet radiation), for example, the radiation of an Ar-ion laser source with a wavelength of 488 nm, and convert the radiation into heat.

The compound which reduces the solubility in an aqueous developer polymer material composition may also be a radiation absorber capable of absorbing incident radiation and turn it into heat.

As an absorber of radiation is useful angle is Yong green, manufactured by BASF, or nigrosine primary NGl produced NH Laboratories Inc. or milori blue (Cl. pigment blue 27), supplied by Aldrich.

The radiation absorber may be gas soot.

The radiation absorber may be a pigment. The pigment may be an organic pigment.

The pigment may be phtalocyanine pigment.

The specified pigment may be an inorganic pigment.

The specified pigment may be selected from the Prussian green, heliogen green or nigrosine.

The radiation absorber may be a dye selected from the following set of classes: squarely, merocyanin, cyanin, indolizine, Pirelli or dithiolan metal.

A separate layer absorbing radiation, may be a thin layer of dye or pigment.

A separate layer absorbing radiation, may be a thin layer of metal or metal oxide.

The compound which reduces the solubility of the polymeric substance in an aqueous developer, and is an absorber of radiation, may be a cyanine dye, which contains a group of quinoline.

Such compounds are preferably cyanine dyes, and more prepact the x compounds include:

2-[3-chloro-5-(1-ethyl-2(1H)-hyalinized)-1,3-pentadienyl] - 1-acylhomoserine

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1-ethyl-2-[5-(1-ethyl-2(1H)-hyalinized)-1,3 - pentadienyl]hyalinized

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4-[3-chloro-5-(1-ethyl-4(1H)-hyalinized)-1,3-pentadienyl] -1 - ethylpirimidin

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Dye D, 1-ethyl-4-[5-(1-ethyl-4(1H)-hyalinized)-1,3-pentadienyl] hyalinized

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Acceptable content of a compound that reversibly reduces the solubility, and is an absorber of radiation is at least 1%, preferably at least 2%, preferably up to 25%, more preferably up to 15% of the total weight of the composition. Thus, the preferred content of the compound that reversibly reduces the solubility, and is an absorber of radiation, can be expressed as 2-15% by weight of the total composition.

The radiation absorber may absorb radiation in excess of 600 nm.

This task is solved in that in the method of obtaining lithographic printing plates, including direct radiation exposure of the workpiece, using the above-described preparation proposed in this invention.

In a preferred method according to the invention covered by the uniform exhibit their laser radiation absorber dye, absorbing infrared light.

The radiation source may be a laser. Examples of lasers that can be used in the method according to the present invention include semiconductor diode lasers with wavelength from 600 nm to 1100 nm. One example is the Nd YAG laser with 1064 nm radiation, but can be used any laser with sufficient power imaging (radiation which is absorbed by the composition).

The emission of laser radiation may exceed 600 nm.

Heat may be supplied from a heated body.

This task is solved by the fact that the printing form is obtained by applying the described method to the described blank printed forms.

In addition to the active polymer, which is described by way interacts with the connection, reversible decrease the solubility, the composition may contain a polymeric substance which is not involved in this interaction. It should be noted that in such a composition containing a mixture of polymeric substances, active polymer can be represented in a lower amount by weight of one or more polymer additives. An acceptable concentration of active polymer alset, present in the composition. However, the most preferred option is the active presence of the polymer at the exclusion of all polymeric substances, which cannot engage in this interaction.

The main part of the composition is preferably one or more polymeric substances, including active polymer, and possibly additional polymeric substance which is not involved in this interaction. Preferably an additional part of the composition consists of a connection, reversible decrease solubility.

Above the main part is acceptable is at least 50%, preferably at least 65% and most preferably at least 80% by weight of the total composition.

The above additional portion of eligible less than 50%, preferably up to 20% and most preferably up to 15% of the total weight of the composition.

Connection, reversible decrease the solubility is at least 1%, preferably at least 2%, preferably up to 25%, more preferably up to 15% of the total weight of the composition. Thus, the preferred content by weight of compounds reversibly lowering the solubility can be expressed as USA with the specified connection. Shown here indicate the concentration of such substances are related to their General content. It is also possible presence of several compounds, reversible decreasing solubility. Indicate their concentrations refer to the total content of such substances.

Six simple tests (tests 1 - 6) can be performed to determine suitability for use with this invention, compositions containing the active polymer, and connection reversible down-solubility, as well as the corresponding aqueous developer.

Test 1. The composition comprising the active polymer in the absence of matter, reversible down-solubility, put on a hydrophilic base and dried. Then cover the surface of the paint. If the ink coverage is uniform, the composition when applied gives the oleophilic layer.

Test 2. Hydrophilic base, covered with a composition comprising the active polymer in the absence of matter, reversible down-solubility, process suitable aqueous developer at room temperature for the appropriate time, which can be determined by trial and error and that is usually from 30 to 60 seconds, then rinsed, dried, and p is e 3. The composition comprising the active polymer and the substance, reversible lowering the solubility, put on a hydrophilic base, dried and covered with paint. If the ink coverage is uniform, the composition when applied gives the oleophilic layer.

Test 4. Hydrophilic base, covered with a composition comprising the active polymer and the substance, reversible lowering the solubility, treated with a suitable aqueous developer at room temperature for the appropriate time, which can be determined by trial and error and that is usually from 30 to 60 seconds, then rinsed, dried and covered with paint. If the paint gives a uniform coating, the composition is not substantially in manifesting the solution.

Test 5. Hydrophilic base, covered with a composition comprising the active polymer and the substance, reversible lowering solubility, is heated in a furnace so that the composition has reached the desired temperature for the appropriate time. Then it is treated with a suitable aqueous developer within a reasonable period of time at room temperature.

After that, the surface is dried and covered with paint. If the paint does not cover, then heated the onenow compositions and their relationships. Appropriate conditions can be determined by simple experiments by trial and error. If such experiments do not allow to set the conditions of passing this test, you should conclude that the composition does not stand this test.

For typical compositions preferably, the composition comprising the active polymer and the compound reversibly lowering the solubility, was heated in a furnace so that the composition has reached a temperature from 50oC to 160oC for 5 to 20 seconds. Then it is treated with a suitable aqueous developer at room temperature for the appropriate time, which can be determined by trial and error and which is usually 30 to 120 seconds.

Most preferably, the composition comprising the active polymer and the compound reversibly lowering the solubility, was heated in a furnace so that the composition has reached a temperature from 50oC to 120oC for 10 -15 seconds. Then it is treated with a suitable aqueous developer at room temperature for 30 to 90 seconds.

Test 6. Hydrophilic base, covered with a composition comprising the active polymer and the substance, set is and which can be determined by trial and error and which is usually 30 seconds. Then it is treated with a suitable aqueous developer at room temperature for the appropriate time, which can be determined by trial and error and which is usually 30 - 60 seconds. After that, the surface is dried and covered with paint. If the paint remains on the floor, it means that ultraviolet radiation does not cause dissolution of the composition and, therefore, such a composition has sufficient resilience to normal working lighting conditions.

If the composition can pass all six tests, it is suitable for use according to the present invention.

Base, which can be used as the substrate, is preferably aluminum plate held normal anodizing, graining and subsequent processing, technology, well known in lithography, with the aim of creating a surface intended for application sensitive to radiation composition and acting when the print function of the background.

Another material that can be used in the method according to the present invention, a base is useful as a material for a plastic base is polyethylene terephthalate with a sublayer, providing a hydrophilic surface. You can also apply the so-called paper coated with resin, which is treated in a corona discharge.

Compositions according to the invention can contain other ingredients, in particular, stabilizing additives, inert dyes, additional inert polymeric binder that is present in many songs lithographic forms.

Preferably heat-sensitive composition according to the present invention do not contain components that are sensitive to ultraviolet radiation. However, there may be sensitive to UV components that are not activated UV due to the presence of other components, in particular, inert dyes that absorb UV, or top layer, UV absorbing.

Any sign of each aspect of the present invention or example of its implementation, described herein, can be combined with any sign of any other task of any described herein of the invention or the reference implementation.

The following examples are more clear illustration of the various aspects of the present invention described above.

The following ssy is it.

Resin In: R17620 - phenol rezol resin, manufactured by C. P. Chemicals Ltd, Sally, Wales.

Resin WITH: SMD995 - alkylphenolethoxylate rezol resin manufactured by the company Schnectady Midland Ltd, Wolverhampton, England.

Resin D: Maruka Lyncur M(S-2) - poly(hydroxystyrene) resin, manufactured by Maruzen Petrochemical Co. Ltd, Tokyo, Japan.

Resin E: Ronacoat 300 - polymer-based dimethylacetamide manufactured by the company Rohner Ltd, Pratteln, Switzerland.

Resin F: Gantrez An 119 - copolymer metilfenidato ether and maleic anhydride, manufactured by Gaf Chemicals Co., Guildford, England.

Resin G: SMA R - polyether strolling anhydride, produced by the company Elf Atochem UK Ltd., Newbury, England.

Resin H: acetate-propionate, cellulose (mol. weight 75 000, contains 2.5% acetate and 45-49% propionate), manufactured by Eastman Fine Chemicals, Rochester, USA.

Testing method at exposure

A substrate with a coating, which is needed to get the image, carved in the shape of a circle with a diameter of 105 mm and was placed on the disc that could be rotated at a constant speed in the range from 100 to 2500 rpm. Near a rotating disk on the movable table was R the freight, when this movable table radial offset of the laser beam relative to a rotating disk in a linear fashion.

Used laser consisted of a diode laser to a single mode having a wavelength of 830 nm, 20 mW, and was focused on the resolution of 10 microns. Laser power supply has been stabilized constant current source.

The resulting image was in the form of a spiral, the image in the center of the spiral corresponded to the low-speed scanning of the laser and the time of exposure, and the outer part of the spiral - high speed scanning and small-time exposure. Energy image acquisition was determined by measuring the diameter, on which was formed the image.

The minimum energy that can be obtained with this system, the exposure was 150 MJ/cm2at 2500 rpm

Comparative examples C1-C5, and examples 1-9 (see tables 1 and 2).

The coatings used in all the examples were prepared as solutions in 1-methoxypropan-2-Ola, with the exception of examples 4, 5 and 8, which used a solution of 1-methoxypropan-2 - OLE/dimethylformamide 40:60 (by volume), and example 7, gdist of aluminum with a thickness of 0.3 mm, held electrolytic etching, anodizing and subsequent treatment with an aqueous solution of inorganic phosphate. The coating solutions was applied on a substrate by using a core with a winding. The concentration of the solution was chosen in order to obtain these compounds in the form of a dry film weight of the coating 1.3 grams per square meter after thorough drying in an oven at 100oC for 3 minutes.

Forms tested problemmost by immersing in an aqueous solution developer for 30 seconds using an appropriate aqueous solution of developer, as described below.

Developer A: 14% solution of metasedimentary sodium in water.

Developer: 7% solution of metasedimentary sodium in water.

The results of simple tests problemmost presented in table 3.

The composition described in comparative examples that do not have resistance to the effects of the developer. The compositions described in examples 1-9 illustrate the effect of reducing the solubility of the polymer in the developer due to the use of the substances described in this invention.

Other forms exhibited by using the above-described laser in the 30 seconds using an appropriate aqueous developer, as explained above. Then we determined the sensitivity of forms.

The results are presented in table 4.

Printing form produced according to the example in table 4, was tested on industrial output setting Trendsetter production company Creo Products Vancouver, Canada. Form secured not less than 10,000 good prints on a lithographic printing press.

Example 10 (see table 5)

Prepared in a solution containing 8,15 g 1-methoxypropan-2-ol, 2,40 g of 40 % by weight solution of resin And 1-methoxypropan-2-Ola, 0.12 g of dye A and 0.24 g of a dispersion of gas soot in water with a concentration of 50% (by weight), and struck in the form of a coating, as described in examples 1-9.

The resulting form exhibited using a diode laser with a power of 200 mW with a wavelength of 830 nm using the above-described device display. Then the form showed in the developer In 30 seconds. The energy density required to obtain the appropriate image was 150 MJ/cm2.

Printing form produced according to example 10 was also tested on industrial output setting Trendsetter production company Creo Products Vancouver, Canada. The form provided is in printed form with the composition, listed below in table 6, were prepared as described in example 4.

The resulting form exhibited using a diode laser with a power of 200 mW with a wavelength of 830 nm using the above-described device display. Then the form showed in the developer In 30 seconds. The energy density required to obtain the appropriate image was 150 MJ/cm2.

Printing form produced according to example 11, was also tested on industrial output setting Trendsetter production company Creo Products Vancouver, Canada. Form secured not less than 10,000 good prints on a lithographic printing press.

Examples 12-18 (see table 7).

Coating formulations used in the examples were prepared as described above, in the form of solutions in 1-methoxypropan-2-Ola, with the exception of example 16, in which he used a solution of 1-methoxypropan-2-OLE/dimethylformamide 80:20 (by volume).

Sample forms exhibited by using the above-described laser device with a wavelength of 830 nm. After that, the exposed discs were treated by immersion for a time in an aqueous solution of the corresponding developer, kvitel With: 15% -naphthylacetate, 5% benzyl alcohol, 2% trinational salt nitrilotriacetic acid, 78% of water.

The developer D: 3% of naphthylacetate, 1% benzyl alcohol, 2% trinational salt nitrilotriacetic acid, 94% of water.

Developer E: 1,5% -naphthylacetate and 0.5% benzyl alcohol, 1% trinational salt nitrilotriacetic acid, 97% of the water.

Examples 19-30 (see table 9)

Coating formulations were prepared as described above, in the form of solutions in 1-methoxypropan-2-Ola with the exception of example 26, in which he used a solution of 1-methoxypropan-2 - OLE/dimethylformamide 50:50 (by volume).

The compositions were applied in the form of a coating, as described in examples 1-9, to obtain a dry film of the composition as indicated in table 9.

Sample forms exhibited by using the above-described laser device with a wavelength of 830 nm. After that, the exposed discs were treated by immersion for a time in an aqueous solution of the corresponding developer, as described above. Then we determined the sensitivity of forms. The results are presented in table 10.

Example 31 (see table 11)

Coating formulations were prepared as described above, in the form of solutions in 1-methoxypropan-2-Ola. From table 11.

Sample forms were heated with a soldering iron Weller EC 2100 M to 311oC. the Speed of movement of the soldering iron on the surface of the forms listed in the following table 12. Then the samples exposed forms were processed by immersing in developer And 60 seconds. The results are presented in the following table 12.

In various places in the description we refer to ultraviolet radiation. Specialists in this area familiar with the typical wavelength range of ultraviolet radiation. However, for the avoidance of doubt we specify that the typical wavelength range of ultraviolet radiation ranges from 190 nm to 400 nm.

All the features described in this description, including the accompanying claims, abstract and drawings figures) and/or all operations described methods or processes may be combined in any combination, except combinations where at least some of such features and/or operations are mutually excluded.

Each feature described in this specification including the accompanying claims, abstract and the figures in the drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless odnosno example of a series of equivalent or similar features.

The invention is not limited to the details described above variants of realization. The invention includes all new features or new combinations of characteristics described in this specification including the accompanying claims, abstract and drawings figures), as well as all new operations or new combinations of operations of any of the described method or process.

1. The oleophilic heat-sensitive composition comprising a polymeric substance soluble in an aqueous developer, and a compound which reduces the solubility of the polymeric substance in an aqueous developer, characterized in that the solubility of the composition in aqueous developer increases when heated and does not increase from the incident ultraviolet radiation.

2. Composition under item 1, in which the polymeric substance soluble in an aqueous developer contains one or more functional groups selected from the series comprising hydroxyl, carboxyl, amino, amide and maleimido group.

3. Composition under item 1, in which the polymeric substance soluble in an aqueous developer, selected from a polymer or copolymer hydroxystyrene, polymer or copolymer of acrylic acid, a polymer or copolymer of meticuloulsy, carboxycellulose and phenolic resins.

4. Composition under item 1, in which the polymeric substance soluble in an aqueous developer is a phenolic resin.

5. The composition according to p. 4, in which the aqueous developer is an aqueous solution of alkali.

6. Composition under item 1, in which the connection of lowering the solubility of the polymeric substance in an aqueous developer is a compound containing at least one Quaternary nitrogen atom.

7. Composition under item 1, in which the connection of lowering the solubility of the polymeric substance in an aqueous developer is a compound containing at least one nitrogen atom embedded in a heterocyclic ring.

8. The composition according to p. 7, in which the connection of lowering the solubility of the polymeric substance in an aqueous developer, selected from quinoline and triazole.

9. Composition under item 1, in which the connection of lowering the solubility of the polymeric substance in an aqueous solution, is a compound containing at least one Quaternary nitrogen atom embedded in a heterocyclic ring.

10. The composition according to p. 9, in which the connection of lowering the solubility of polim is satiate and compounds of pyridine.

11. The composition according to p. 10, in which connection quinoline is a cyanine dye.

12. The composition according to p. 10, in which the benzothiazole compound is a cyanine dye.

13. Composition under item 1, in which the connection of lowering the solubility of the polymeric substance in an aqueous developer, is a compound triarylmethane.

14. Composition under item 1, in which the connection of lowering the solubility of the polymeric substance in an aqueous developer is a connection. containing a carbonyl functional group.

15. The composition according to p. 14, in which the connection of lowering the solubility of the polymeric substance in an aqueous developer, selected from compounds of flavone.

16. The composition according to p. 14, in which the connection of lowering the solubility of the polymeric substance in an aqueous developer, choose from flavanone, xanthone, benzophenone, N-(4-bromobutyl)phthalimide, 2,3-diphenyl-1-engineone and phenanthrenequinone.

17. Composition under item 1, in which the connection of lowering the solubility of the polymeric substance in an aqueous developer, is a compound with the General formula

Q1- S(O)n- Q2,

where Q1- arbitrarily substituted phenyl or alkylen the p. 1, in which connection, lowering the solubility of the polymeric substance in an aqueous developer, selected from ethyl-p-toluensulfonate and p-toluensulfonate.

19. Composition under item 1, in which the connection of lowering the solubility of the polymeric substance in an aqueous developer, is a dye acridine main orange (C1 orange solvent 15).

20. Composition under item 1, in which the compound which reduces the solubility of the polymeric substance in an aqueous developer is ferrocenyl connection.

21. Harvesting a positive working lithographic printing plate having a coating which contains a composition according to PP.1 - 20 and deposited on a substrate with a hydrophilic surface.

22. Blank lithographic printing plate according to p. 21, in which the said coating is well adapted for the preferred radiation absorption and conversion of the specified radiation into heat.

23. Blank lithographic printing plate according to p. 22, in which the composition comprises a radiation absorber capable of absorbing incident radiation and turn it into heat.

24. Blank lithographic printing plate according to p. 22, which specified pokrytii absorber of radiation, capable of absorbing incident radiation and turn it into heat.

25. Blank lithographic printing plate according to p. 22, in which the compound which reduces the solubility in an aqueous developer polymeric substances of the composition under item 1, is also a radiation absorber capable of absorbing incident radiation and turn it into heat.

26. Blank lithographic printing plate according to PP.23 and 24, in which the radiation absorber is gas soot.

27. Blank lithographic printing plate according to PP.23 and 24, in which the radiation absorber is a pigment.

28. Blank lithographic printing plate according to p. 27, in which the specified pigment is an organic pigment.

29. Blank lithographic printing plates by p. 28, in which the specified pigment is phtalocyanine pigment.

30. Blank lithographic printing plate according to p. 27, in which the specified pigment is an inorganic pigment.

31. Blank lithographic printing plate according to p. 27, in which the specified pigment selected from the Prussian green, heliogen green or nigrosine.

32. Blank lithographic printing plate according to PP.23 and 24, the anin, cyanin, indolizine, Pirelli or dithiolan metal.

33. Blank lithographic printing plate according to p. 24, in which a separate layer absorbing radiation, is a thin layer of dye or pigment.

34. Blank lithographic printing plate according to p. 24, in which a separate layer absorbing radiation, is a thin layer of metal or metal oxide.

35. Blank lithographic printing plates by p. 25 in which the compound which reduces the solubility of the polymeric substance in an aqueous developer, and is an absorber of radiation, is a cyanine dye that contains a group of quinoline.

36. Blank lithographic printing plate according to PP.27, 32 and 35, in which the radiation absorber absorbs the study, exceeding 600 nm.

37. The method of obtaining lithographic printing plates, including direct radiation exposure of the workpiece described in any of paragraphs.21 - 36.

38. The method according to p. 37, in which the radiation source is a laser.

39. The method according to p. 38, in which the emission of laser radiation above 600 nm.

40. The method according to p. 27, in which heat flows from a hot body.

41. Printed forma points:

23.04.96 - PP.1, 4, 5 - 7, 9, 11, 21, 22, 23, 25 - 30, 32, 35 - 39, 41;

22.04.97 - PP.2, 3, 13 - 19, 24, 31, 33, 34;

17.01.97 - PP.8, 20;

12.07.96 - PP.10, 40;

13.08.96 on p. 12.

 

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