NL8001085A - PHOTOSENSITIVE MATERIALS AND OBJECTS. - Google Patents

Description

Photosensitive materials and objects.

Field of the invention

The invention relates to polymerizable materials and in particular to photo-reactive materials. These materials are useful as imaging layers for photo-5 printing systems and as imaging layers in printing plates. These materials can also be developed with water and can be processed without the use of organic solvents.

Background of the Invention Most negative-working printing plate materials operate in the following manner. A photo-reactive material is applied to a substrate. The coated substrate is imaged by radiation (eg visible light, infrared radiation, ultraviolet radiation, etc.), heat or electron radiation. When the radiation or other imaging effect has hit the photosensitive coating material, the photoreactive material polymerizes. This polymerization in imaged areas makes these areas of the composition less soluble in solvents. When a developer solution is applied to the exposed surface of the coated substrate, the unexposed material is removed more easily and faster than the exposed material. Removal of the unexposed material leaves an ink recording image in the exposed areas. When used as a printing plate, these coated substrates therefore act as negative-working plates.

These imaging systems act on a change in solubility, and the unexposed region 80 0 1 0 85 2 should dissolve or release more easily from the substrate, while the exposed region should not be disturbed by the solvent. As the unpolymerized material is more easily removed by the developer solutions, the polymerized material becomes more resistant and the better the system.

Most polymerizable systems require organic solvent developer systems and non-aqueous developer systems since it is easier to formulate organic solvent printing materials that are soluble before polymerization and insoluble after polymerization. Organic solvent systems are less desirable than aqueous systems because of the potential for contamination and the higher cost of the organic solvents. However, it has been very difficult to prepare aqueous developer systems at an appropriate imaging rate; which, when not exposed, are easily removed; which, when exposed, are insoluble and have a long service life as a printing plate. Water-soluble materials are described, for example, in U.S. Pat. Nos. 3,837,858, 3,899,332, 3,933.1 * 99, 1 * .092,170 and 1 * .01 * 2,386 and British Patent 1,1 * 1 * 7,11 * 2.

Those systems, referred to in the art as water-developable, are not readily water-developable and often require the use of other additives, such as surfactants. Some of these known systems, such as those according to U.S. Patent 1,101,01072, rely on diazo resins as the photopolymerizable material in the material and have a short life on the press. Other known systems, for example that according to U.S. Pat. No. 3,036,915, utilize various polyethylenically unsaturated materials as the photopolymerizable component in the material. These systems are very sensitive to moisture and are not stable when stored. The active material detaches from the surface of the plate, can be easily sanded off the 80 0 1 0 85 3 * * plate and has a reduced resolution when stored under humid conditions.

Summary of the Invention The invention relates to polymerizable materials which can be used as printing plate materials. The invention further relates to printing plates having these compositions thereon, wherein the compositions develop solvent or water.

The materials suitable for use in a pressure plate system include a homogeneous mixture of an organic solvent-soluble photo-reactive oligomeric resin, an organic solvent-soluble film-forming resin with oleophilic binder properties, a free radical photoinitiator system , a polyfunctionally unsaturated monomer or oligomer and a water-softenable polymer.

The plates of the invention are pre-sensitized and contain an oleophobic substrate, a water-soluble photo-reactive resin on at least one surface of the substrate, and a coating on one of the materials of the invention over that resin.

The broadest ranges of components used in the invention are the following: A. 1-75% by weight organic solvent soluble film-forming resin B. 10-65% by weight free-radical polymerizable polyethylenically unsaturated compounds with at least two ethylenically unsaturated groups, C. 0.5-15% by weight of a free radical photoinitiator system, 30D · 5-1 * 0% by weight of a water-soluble, organic solvent-soluble polymer in E 1-20 wt% of an organic solvent-soluble diazo resin.

Preferably, the sum of the water-softenable and organic film-forming resins is equal to at least 80 0 10 85 k 10% by weight of the material.

Detailed Description of the Invention The photo-reactive, solvent-soluble oligomeric resin component used in the invention is a diazo resin. These resins must be soluble in organic solvent, but may also be slightly water-soluble and are known, as shown in U.S. Pat. Nos. MO0,072,3,933,399, 3,837,858 and 3,899,332. Examples of diazos useful in the formation of such resins, which are well known, are: U-diazo-diphenylamine, 1-diazo-UN, N-dimethylamino-benzene, 1-diazo-Λ-Ν, N -diethylamino-benzene, 1-diazo-UN-ethyl-N-hydroxyethylamino-benzene, 15 1-diazo-N-methyl-N-hydroxyethylamino-benzene, 1-diazo-2,5-diethoxy-U-benzoylamino -benzene, 1-diazo-UN-benzylamino-benzene, 1-diazo-Λ-Ν, N-dimethylamino-benzene, 1-diazo-U-morpholino-benzene, 20 1-diazo-2,5-dimethoxy - ^ - p-tolyl mercaptobenzene, 1-diazo-2-ethoxy - N - N-dimethylaminobenzene, p-diazo-dimethyl aniline, 1-diazo-2,5-dibutoxy-U-morpholino-benzene, 1-diazo-2,5 diethoxy-H-morpholino-benzene, 1-diazo-2,5-dimethoxy-l-morpholino-benzene, 1-diazo-2,5-diethoxy-1-morpholino-benzene, 1-diazo-2, 5-diethoxy-kp-tolyl-mercapto-benzene, 1-diazo-3-ethoxy-N-methyl-N-benzylamino-benzene, 1-diazo-3-chloro-1-N, N-diethylamino-benzene, 30 1 -diazo-3-methyl-U-pyrrolidino-benzene, 1-diazo-2-chloro-ii-N, N-dimethylamino-5-methox --benzene, and 1-diazo-3-methoxy-pyrrolidino-benzene These diazos are soluble in organic solvent when a suitable anion is selected, for example, 80 0 1 0 85 f * 5 from the known one, such as tetrafluoroborate , triisopropylnaphthalene sulfonate, p-toluene sulfonate, lauryl sulfate, hexafluorophosphate, 2-naphthalene sulfonate, etc. These resins listed in the above table are organic solvent soluble, slightly sensitive, negatively explored aromatic diazo resins. The diazo resins are generally useful as 1-20% by weight of the active ingredients in the printing material. Preferably they are present as 3-3% by weight of the material. The preparation of these resins is generally described in U.S. Patent 2,771,066. It is noted that the diazo resins used in the invention are not synonymous with or including known diazonium salts. Diazo resins have more than one diazonium group in the molecule, diazo resins contain a number of salts, at least 2, covalently bonded together. A useful diazo-15 resin can be represented, for example, by the formula 1 of the formula sheet, wherein n is about 1 or 5.

It is important to note that polymerization does not necessarily take place by formation of a Lewis acid. The anion shown in the formula does not form or develop a Lewis acid when the diazo resin is photoinitiated. Levis acids can be developed in other diazo resins, but non-Lewis acid developing resins are useful in the invention.

The binder resin coraponent, which is an organic 23 solvent-soluble film-forming resin, is well known.

It is preferably selected from epoxy resins, polyesters, polyallyl orthophthalate prepolymers, polyallyl isophthalate prepolymers, polyvinyl formals, polyurethanes, polyvinyl butyrals, polyoxyethylene oxides, polyvinyl hydrogen phthalates, polyacrylates, polymethacrylates, cellulose acetate esters. Some of these resins are described as useful in sheet materials in U.S. Patent Nos. 4,104,072, 3,899,332, 3,837,858, and 3,933. These binder resins may or may not participate in the polymerization that takes place when exposed to radiation. Prepolymers 80 0 1 0 85 6 or fully polymerized materials can be useful as long as they are capable of forming a film with sufficient structural integrity to be self-supporting. These resins are generally useful as 15-75 parts of the printing material, excluding solvents and other non-functional additives. Preferably 30-50 wt% solid ingredients are binder resin. A minimum molecular weight of at least 1000, preferably 2000, and most preferably 3500, is desired. No upper limit on molecular weight is required. Molecular weights of 2,000,000 or 3,000,000 are known and useful. The use of binders with a molecular weight of less than 200,000 and preferably less than 100,000 has been found to make the materials easier to develop. It is preferred that these resins be more oleophilic than hetero-1. be fiel. When the binder resin is selected to be a prepolymer capable of independent cross-linking or polymerization upon heating (which is readily identifiable outside the materials of the invention), the plate on which the material is coated may postheated (i.e., after development) to check the dot size of the image on the plate and also to enhance the integrity of the image. This improves the press life. Because the dots are given more structural integrity by postheating, underexposure during imaging can be used for fine resolution dot shapes. These dots are usually removed during development or on the press, but reheating with these particular types of binder resins causes the dots to adhere to the printing plate. This is believed to be unique in nega-2Q active water developable plates. It is preferred that this cross-linking or polymerization can be initiated at a temperature of at least 100 ° C. Higher polymerization temperatures are also advantageous. Examples of this class of binders are polyallyl isophthalate and polyallyl orthophthalate prepolymers, such as those of the formula sheet.

The polyfunctional unsaturated monomer or oligomer component useful in the present invention is a free radically polymerizable, poly-ethylenically unsaturated compound. These compounds can be true monomers or dimers, trimers, oligomers or polymers with at least 2, preferably 2 to 12, most preferably 2 to 5 ethylenically unsaturated groups, such as acrylate, methacrylate, vinyl, acrylamide and allyl. Preference is given to compounds having multiple acrylate and methacrylate groups, such as acrylic and methacrylic acid esters of polyols. Examples of these materials are trimethylol propane triacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, pentaerythritol 15 tetramethacrylate, diallyl phthalate, diallyl-substituted succinate, unsaturated ethylene oxide, etc. are alkylene or polyalkylene glycol diacrylates, for example diethylene glycol diacrylate, glycerol diacrylate, glycerol triacrylate, 1,3-propanediol dimethacrylate, 1,3-propanediol dimethacrylate, 1,2-butanedriol trimethacrylate, 1,1-cyclohexanediol diacrylate; bis / "1- (3-acryloxy-2-hydroxy) 7p-ethoxy-phenyl-dimethyl-methane, tris-hydroxyethylisocyanurate trimethacrylate, the bis-acrylates and bis-methacrylates of polyethylene glycols with a molecular weight of 200-500 and the like unsaturated amides, for example methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bisacrylamide, diethylene triamine trisacryl amide, B-methacrylaminoethyl methacrylate, vinyl esters such as divinyl succinate, divinyl adipate and divinyl phthalate, as well as mixtures of these esters mixtures of these compounds with alkyl esters of acrylic acid and methacrylic acid, including esters such as methyl acrylate, methyl methacrylate, ethyl acrylate, isopropyl methacrylate, n-hexyl acrylate, stearyl acrylate, allyl acrylate, styrene, diallyl phthalate and the like.

800 1 0 85 8

These compounds are well known, for example, from U.K. Pat. No. 1,882,953 and U.S. Pat. Nos. 3,995 + 75 and 3,905,815. The polyunsaturated materials are generally useful as 10-60 wt.% Active ingredients in 5 the printing material. Preferably they are present as 20-1 + 0 wt% of the material.

The free radical photoinitiator systems of the invention are well known. These are the compounds that absorb radiation, generally actinic radiation, and are activated to become agents that extract hydrogen atoms from hydrogen donors. There may also or may be need for sensitizers to be present to photo-activate the compounds. Examples of these materials are the benzoins, acetophenones, naphthoquinones and benzophenones 15 (as described in British patent specification 1.1 + 82.953), vinyl substituted halomethyl-s-triazine compounds (as described in U.S. Patent 3,951 + ^ 75) and aromatic onium compounds ( as described in U.S. Pat. Nos. 1 + .058.1 + 00 and K.058.1 + 01). Other desirable photoinitiator systems are well known, such as from U.S. Pat. Nos. 3,775,113, 3,887.1 + 50, 3,895.9 ^ 9 and 1 + .01 + 3,819.

The photoinitiator systems are generally useful as 0.5-15% by weight of active ingredients in the printing material. Preferably they are present as 1-6% by weight of the material. If necessary, usually spectral sensitizers are included in an amount of about 10 to 70% by weight of the photoinitiator.

The water-softenable polymer according to the invention is a water-soluble or at least water-softenable polymer, which is also soluble in organic solvent systems. By "water-softenable" is meant here that the Young's modulus of the polymer drops in the presence of water. This modulus can be measured on commercially available devices, such as the "Rheovibron" model D-DV-II-C, manufactured by Toyo Baldwin Co., Ltd. A polymer, which forms a molecular suspension in water, would be an example 80 0 1 0 85 9 of an insoluble (water) polymer that is water-softenable. Another example of a water-softenable polymer is a polymer, in which some of the bonds inside or outside (eg hydrogen bonds) the polymers are broken in the presence of water. Specific examples of these polymers are polyvinylpyrrolidone, partially hydrolysed polyvinyl acetate, hydroxyalkyl cellulose resins (e.g. hydroxypropylellulose) and organic solvent soluble polyvinyl alcohol derivatives or copolymers.

These materials are well known. British Patent 1,482,953 describes the use of photopolymer materials suitable for the manufacture of relief plates, which are developable with water and contain amino-substituted hydroxyalkyl cellulose resins, which would also be useful and are a species of hydroxyalkyl cellulose resins. The term "water-softenable" as used herein includes water-soluble resins unless otherwise stated. The water-softenable resins are generally useful as 10-40% by weight solid ingredients in the printing material. Preferably they are present as 12-15% by weight of the material.

The substrates of the invention can be any substrate, including metal, polymer and paper surfaces. Only when the coated article is to be used as a printing plate must the substrates be oleophobic on the surfaces. They are usually hydrophilic at the same time, but this is not essential. The substrate for a printing plate can be of any material coated on at least one surface to provide this oleophobic property. The substrates normally used for lithographic plates, such as those according to US patents 556,380, 2,100,003, 2,251,181, 3,181,461, 2,373,357 and 4,116,695 are useful in the invention. Preference is given to polymeric or metal substrates.

Aluminum and zinc substrates are particularly desirable. Most preferred are aluminum substrates, which have a permanent hydrophilic coating, which is reacted on its surface by reaction of an aqueous solution of a soluble silicate, as in U.S. Patent 2,771,066. This form of aluminum or zinc substrate is referred to as flake, grained or grained and anodized.

A variety of alloys can be used with the aluminum, as is known, for example, from U.S. Patent No. 1,116,695. When the term aluminum substrate or aluminum sheet is used, it means that the material is mainly, but not necessarily exclusively, IQ aluminum. is.

Typically, another coating is applied over this substrate, which contains a water-soluble photosensitive diazo resin, which may be the same as some of the above-described resins as part of the photo-reactive material. These resins are known and are also described in U.S. Pat. Nos. 2,771,066 and 3,905,815.

In a preferred embodiment of the invention, a sixth component can be added. This component is an oleophilic polymer which is added to the material to improve ink uptake thereby. If the printing plates operate to provide an image with areas of ink recording (oleophilic areas) and non-ink recording (oleophobic areas) in a subtractive developing process, an increased ink recording in the image areas where the material is retained on the plate 25 is desired. Some of the previously destroyed binder resins are also oleophilic and resins in this list, which are oleophilic, may be added to the material to contain more than one organic solvent soluble resin. The oleophilic resin need not be a film-forming resin, since structural integrity is provided by other components, but it is preferred that the oleophilic resin be a film-forming polymer. Any compatible film-forming oleophilic resin is useful, and cellulose acetate esters, such as cellulose acetate butyrate and cellulose acetate propionate, have been found to be particularly desirable. This ingredient shows useful 80 0 1 0 85 11 effects in weight percentages of 0.5 to 75% of the material (the maximum is when it also forms the binder resin).

There are many other additives that it may be desirable to use on these materials.

It is generally desirable to have a solvent system in the materials when applied to the substrate. These solvents naturally tend to evaporate from the material after it has been coated. These solvent systems can contain one or more solvents to keep all ingredients compatible. The solvents are usually organic polar solvents, but a minor amount (e.g. up to about 25% by weight) of non-polar solvents can be included. Particularly desirable solvents are methyl ethyl ketone (and other ketones such as cyclohexanone and acetone), amides (such as dimethyl formamide), chlorinated hydrocarbons (such as ethylene dichloride), 2-nitropropane, diacetone alcohol and short chain (e.g. 1 to 5 carbon atoms) aliphatic alcohols. Many of these materials are described in British Patent Specification No. 20.1 ^ 7.1 ^ 2. These are the types of organic solvents from which all materials previously referred to as inorganic solvent soluble may contain a solvent system of one or more solvents.

Dyes or pigments can also be used in the printing materials. Sharp dyes are also useful in the composition of the invention. Many of these materials are described in British Patent Specification 1.M * 7.1 ^ 2 for printing materials.

With the aim of preventing premature polymerization and reducing any polymerization in unimaged areas by scattered light, the incorporation of stabilizers, such as phenolic stabilizers, may be useful.

These materials are known and examples are di-t-butyl-p-cresol, hydroquinone, quinone, hydroquinone monomethyl ether, amylquinone, n-butylphenol etc. These stabilizers are usually present in amounts from 0.0002 to 1 wt% of the solids in the material.

The materials can also contain inert particulate filler, which is transmissive or transparent to actinic light. The particles can also be so small that they do not interfere with light transmission. Organophilic silicas, bentonites and powdered glass are examples of these substances. All should be less than 10 microns, preferably less than 1 micron, and most preferably less than 0.1 micron.

Flow control agents, viscosity modifiers and surfactants may also be useful in the subject materials.

As noted above, many additional materials can be added to the compositions of the invention. Some are, of course, more or less desirable than others. Epoxy polymerizable materials are among those ingredients which are less preferred or undesirable unless present in amounts less than 10% by weight solids in the materials. Preferably no epoxy polymerizable materials are present. The presence of the epoxy resins in amounts of 9 wt% or more, as described in U.S. Patent Application Serial No. 15,535, filed February 27, 1979 in the name of C. Podsiadly and J. Holmes, was found to give only limited water developability, smaller amounts of epoxy polymerizable materials have been found to provide surprisingly improved properties, even when both ethylenically unsaturated materials and epoxy polymerizable materials were present in that system.

In view of the requirement for that minimum amount of epoxy polymerizable components in that system, this was a surprising discovery. An epoxy polymerizable material is defined as any material (monomer, oligomer, prepolymer, or polymer) that has polymerizable epoxy groups, especially those materials having an epoxy equivalent weight between 90 and 10,000.

80 0 1 0 85 t ψ 13

The following examples demonstrate some additional aspects of the invention. All percentages are weight percentages unless otherwise stated. All plates were treated with commercially available diazo desensitizing materials after development.

Example I

A photoactive material according to the invention was prepared by successively mixing the following ingredients: diallyl orthophthalate prepolymer 10 (with the above structure) as a 25% solution in methyl ethyl ketone 363 g of polyvinylpyrrolidone as a 7% solution in ethylene glycol mono-methyl ether 590 g pentaerythritol tetraacrylate 68.75 g cellulose acetate butyrate 1.75 g polyurethane resins as a 10% solution in dimethylformamide 279 g 20 2 (p-methoxystyryl) 4,6-bis (trichloromethyl) - s-triazine 5.5 g fluoroborate salt of the condensation product of paraformaldehyde and p-diazo diphenylamine 16.5 g 25 in oil soluble dye 2. U g dispersion of 18% Microlith Blue dye in methyl ethyl ketone (a copper phthalocyanine pigment) 168 g

After homogeneous mixing of these materials, the final solution was reduced to 8% solids by adding 250 g of methyl ethyl ketone, 500 g of dimethylformamide and 1293 g of ethylene glycol monomethyl ether. The polyurethane resin used in this and the other examples was a thermoplastic polyurethane with recurring units of the formula 3 of the formula sheet, which had a Shore hardness of 78A, a tensile strength of 80 0 1 0 85

1U

2 Λ of 623 kg / cm and a 300% modulus at 10.3 kg / cm '.

The pigment dispersion in this and the other examples was 60% pigment in 1 + 0% vinyl copolymer, which contained 86% units derived from vinyl chloride and k% units derived from vinyl acetate.

A lithographic support plate structure for use in the examples was prepared according to the example in U.S. Pat. No. 2,771I + .066. A smooth surface aluminum sheet was washed with trisodium 10 phosphate, then treated with a nitric acid solution and rinsed in water. The plate was then treated with an aqueous silicate solution and washed clean of any remaining water-soluble material. An initially water-soluble photosensitive resin, p-diazodiphenylamine formaldehyde resin as a 2.5% aqueous solution, was then coated over the silicate-treated surface. A dry coating weight of 120-11 + 0 rag / ft of the above-described photo-reactive material was then applied and air dried at 71-88 ° C.

Part of this printing plate was exposed to a carbon arc source of ultraviolet radiation for 100 sec. load 1.37 meters. The development took place with tap water and rubbing gently with a soft cloth for a few seconds.

After the coating in the unexposed areas was removed, the entire surface of the plate was treated with an aqueous desensitizer and gum solution. The plate was rubbed dry, mounted on a lithographic printing plate, and tested with the thick pads for more than 1 + 000 prints without loss of detail. With normal underlayings, one would expect 50,000 prints when using fine quality halftone negatives. These plates can reliably reproduce 176-line grids containing 3% highlight dots and 97% shadows. The water-developed plate required only 35 to 5 paper copies to pass through the press before all 80 0 1 0 85 15 ink-exposed areas took up ink, and were fully converted from a generally hydrophilic surface to a hydrophobic oleophilic surface. . This compares favorably with plates developed with organic solvent.

Example II

A conventional granulated and anodized substrate, generally manufactured according to the teachings of U.S. Pat. Nos. 3,181,661 and 3,865,700, was first coated with an initially water-soluble photosensitive p-diazodiphenylamine formaldehyde resin as a 0.5 $ - aqueous solution and then coated with the following material to a dry coating weight of 170-200 mg / ft: wt. diallyl orthophthalate prepolymer (with the above structure) as a 25 # solution in methyl ethyl ketone 30 g polyvinylpyrrolidone as a 7 # solution in ethylene glycol monomethyl ether 16 g pentaerythritol tetraacrylate 2.0 g cellulose acetate butyrate 2.0 g polyurethane resin as a 10% solution in dimethyl formamide 5.5 g 2- (p-methoxystyry1) b, 6- bis (trichloromethyl) -s-triazine 2.0 g of 25 fluoroborate salt of the condensation product of paraformaldehyde and p-diazodiphenylamine 8.0 g of yellow oil-soluble dye 0.5 g of dispersion of 18% Microlith Blue bean dye in methyl ethyl ketone 12.0 g. After exposure and development as in Example 1, press testing under accelerated conditions showed an expected durability of about 100,000 impressions under normal conditions. Rolling the plate required only 5 copies and the image quality was found to be sufficient for developing and holding a 176-line raster with 3-97% dots.

80 0 1 0 85 16

Example III

This example shows the utility of the plates according to the invention for underexposure and post-heating.

A plate prepared as in Example 1 was exposed by a raster negative such that different sections of the plate had 1/2 / 3 A full exposure as in Example I. This plate was then as in Example I developed with tap water and treated with gum desensitizer. This plate was then placed in an oven at about 230 ° C for 6 minutes, thereby promoting cross-linking of underexposed portions of the plate and maintaining the sharp point structure of the image.

When mounted on a press along with a commercially available solvent-developed plate, which has had a normal full exposure, the underexposed portions of the water-developed plates produced prints with a sharper dot structure and nevertheless, the life of the section, which had only received a quarter of the normal exposure time, the same life as the control solvent-developed plate.

Example IV

The coating material of Example I, without the pentaerythritol tetraacrylate, was coated, bi-light, developed and desensitized as in Example I.

The record showed good point quality and resolution.

However, the plate exhibited very poor resistance to contact with solvents such as those which may be present in printing press chambers and in some conventional inks. This result confirms the necessity of the polyethylenically unsaturated component in the material and plates of the invention.

30 Example V

When the material of Example 1, without the inorganic solvent-soluble diazo resin, was coated onto grained and anodized aluminum, no visible image was obtained after exposure, although the development was good. However, the adhesion of the coating was poor, since the 80 0 1 0 85 ϊ φ 17 gray layer could be rubbed almost entirely with water only. This shows the independent criticality of the diazo resin for the material. It is believed that one of the significant aspects of the invention is the combination of the ethylenically unsaturated component and the inorganic solvent soluble diazo resin in a material. The combination of these two different imaging materials provides a composition of non-quality and performance as a water-developable composition.

Examples VI-XI

A master batch of photo-reactive material without the inorganic solvent-soluble film-forming resin was composed as follows: diallylphthalate prepolymer of Example I 38% polyvinylpyrrolidone 20% pentacrythritol triacrylate 20 "cellulose acetate butyrate 5% 2- (p-methoxystyryl) -4,6- bis (tri-chloromethyl) -2-triazine 3% fluoroborate salt of example I 6% yellow oil-soluble dye 0.5%

To parts of this material, one of the following resins was added in an amount of 7.5% to form six different materials, which were coated onto grained and anodized aluminum up to the weight stated in brackets: 6. No additional film-forming resin.

o 7. polyvinyl formal (167 mg / ft) 8. diglycidyl ether of bisphenol A (mol. wt.

1750-2050) (173 mg / ft2) 9. Terpolymer of vinyl chloride (86%), vinyl acetate (13%) and maleic acid (1%) (183 mg / ft2) 10. The polymer of Example VIII, methacrylates by mixing of 500 g of the polymer with 8.6 g of methacrylic acid, 0.4 g of triphenyl antimony and 0.065 g of triphenyl phosphorus and heating 80 0 1 0 85 18 for 2 hours at 100 ° C (183 mg / ft2) 11. (poly) 8 methacryloxypropyltrimethoxysilane (198 mg / ft2).

These solutions were coated with 8% solids using a wire bond

Meyer rod on a smooth and primed aluminum base, both pre-coated with a 1% solution of the water-soluble diazo resin, used as a coating in Example I. Ha exposure, development and mounting on a press, the life of all samples was 10 larger than of the same material without polymer addition. The polyvinyl formal and terpolymer have been found to be the most durable materials of these resins.

Examples XII and XIII

The material of Example I was replicated once without any cellulose acetate butyrate and once with an equal weight amount of cellulose acetate propionate replacing the butyrate. The film containing the cellulose acetate propionate behaved in the same manner as the material of claim 1 when exposed, developed and placed on a press.

Both materials with the cellulose acetate esters retained portions of the ink charge on developed plates applied by the ink roller more efficiently than the plates without these esters.

This property allows a 3-speed roll-up and a quick deposit in the application of the presses.

Examples XIV-XVIII

A material without a photoinitiator system was prepared with the following ingredients: diallyl orthophthalate prepolymer of Example I as a 10% solution in methyl ethyl ketone 13.1% polyvinylpyrrolidone (as a 7 solution in ethylene glycol monomethyl ether 2% triacrylate of tris (2 -hydroxyethyl) 35 isocyanurate (as a 50% solution in methyl ethyl ketone) 30.3% 800 1 0 85 19 cellulose acetate butyrate (10% in dimethylformamide) 1.2% polyurethane of Example I (10% in dimethylformamide) 6.1 1 5 Fluoroborate salt of Example I · 7.2% yellow oil-soluble dye 0.4% pigment dispersion of Example I (32.5 g) l7 »0%

To this were added 152 g of ethylene glycol monomethyl ether, 485 g of methyl ethyl ketone and 768 g of dimethylformamide. Five 105 g portions of each of this material were taken and one of the following photoinitiators was added: 1. 2- (p-methoxystyryl) -4,6-bis- (trichloromethyl) -s-triazine 0.4 g 2. 2-chloro-thioxanthone 0.1 g 15 3. diphenyliodoniuo hexafluorophosphate (0.4 g) and 4,4-bis (dimethylamino) benzophenone 0.4 g 4. isopropyl benzoin ether (0.4 g) and 4 1 * '-b is (dimethylamino) benzophenone 0.2 g. The fifth portion did not contain a photoinitiator system. The first portion showed good resistance to organic solvent, indicating good cross-linking.

The second and third portions showed fairly good solvent resistance, which could be improved by higher intensity exposure. The fourth and fifth portions showed no solvent resistance. In the case of the ether, the glass window of the illumination frame may have acted as a special peak sensitivity range filter for that particular known free radical photoinitiator.

30 Examples XIX - XX

Servings of a material with all ingredients of Example I, except the polyvinylpyrrolidone and with the following composition: prepolymer 31%, tetraacrylate 31%> triazine photoinitiator 3% * diazo resin 3 cellulose acetate butyrate 3%, yellow oil dye 1% 9 pigment dispersion 9% and dimethyl-800 1 0 85 20 formamide in an amount equal to about 31 times the combined weight of the initiator, diazo resin, butyrate and yellow oil dye were added the following polymers in an amount equal to 19% of the total solid substances of a material (as 10% solutions in dimethylformamide): 1. low molecular weight hydroxypropyl cellulose wt.

2. copolymer (50/50 tapolyvinyl acetate and polyvinyl alcohol.

Both materials were coated to an amount of 20% on a smooth aluminum base with a coating of water-soluble diazo resin. In all cases, the pre-dispersed pigment tended to settle out of the solution. After exposure through a grid slide and development with tap water, it was noted that the copolymer material developed more easily and the image obtained was more tough than that of the material with the cellulose. The first material developed easily and the image areas absorbed ink easily. The use of high molecular weight hydroxypropyl cellulose resins caused the material to develop more difficult, but it developed with tap water and the images took up the ink after desensitizing with conventional lithographic process.

Examples XXI and XXII

Four portions of the material of Example I 25 were duplicated, except that the prepolymer was replaced by equal amounts of two diglycidyl ethers of bisphenol A with high (molecular weight 875-1025) and low (molecular weight 1 * 50-550) molecular weights, polymethacrylated diglycidyl ether of bisphenol A and polyacrylated polycaprolactone-30 2,1 * -toluene diisocyanate-hexane diol oligomer, described in Example II of U.S. Patent Application Serial No.

901.1 * 80, filed May 1978.

The materials without the acrylate groups either had poor solvent and abrasion resistance or developed poorly. Both materials containing the ethylenically 80 0 1 0 85 21 unsaturated materials had good performance compared to the material of Example 1. The diglycidyl ether prepolymers had the structure k of the formula sheet wherein n in the low molecular weight prepolymer is about 2 , 5 and n in the 5 high molecular weight prepolymer is about 6.

Examples XXIII - XXV

In these examples, the extreme limits for the ranges of certain ingredients are explored. All materials were formed from the same components: 1) monomer: trishydroxyethylisocyanurate triacrylate 2) water-softenable binder; polyvinylpyrrolidone (as a 7 # solution in ethylene glycol monomethyl ether) 15 3) film-forming binders: a) the polyallyl orthophthalate prepolymer, the structural formula of which is given above, b) an eopolymer of vinyl acetate and vinyl chloride (1U / B6 ), and c) cellulose acetate butyrate, 4) solvent-soluble diazo resin; the tetrafluoroborate salt of the condensation product of paraform aldehyde and p-diazodiphenylamine, 5) photoinitiator system: 2- (p-methoxystyry -) - U, U-bis- (trichloromethyl) -s-triazine, 6) pigment: Microlith Blue UGK in methyl ethyl -25 ketone (18% dispersion).

The materials tested are shown in percentages by weight in the following table 30 80 0 1 0 85 22

Example XXIII xxiv xxv monoreer 50 65 65 water softenable 30 10 5 binder film-forming binder 5.0a 3.2b 8a, 3.2b 2c 9a, 3.2b diazo 5 55 photoinitiators 2 22 pigment 4.8 4.8 4.8 80 0 1 0 85 23

Each of the materials was mixed homogeneously and coated to a weight of 120-1 * 10 mg / ft on separate lithographic support plate structures as indicated in Example I. The plates were then exposed and developed in tap water according to the methods of Example I. All plates could be developed with water and held ink well. The plate of Example XV was more difficult to develop (required more rubbing with water), but gave a useful plate. The larger amounts of monomer made the 10 plates more tacky, but all behaved reasonably well.

In fact, the water-softenable binder imparts some coherent film-forming properties to the material and printing plate in a manner similar to the inorganic solvent-soluble film-forming binder. The primary requirement for the presence of at least 1% by weight of the latter is to promote ink uptake.

80 0 1 0 85

Claims (21)

2k 1. Photo-reactive material, containing a homogeneous mixture of A. 15-75% by weight of an inorganic solvent 5 soluble film-forming resin, B. 10-60% by weight of free-radical polymerizable polyethylenically unsaturated compounds with at least two ethylenically unsaturated groups . C. 0.5-15 wt.% Of a free radical photoinitiator system, D. 10-10 wt.% Of a water-softenable, inorganic solvent-soluble polymer and, E. 1-20 wt.% Of an inorganic solvent soluble diazo resin. An imaging system comprising a substrate with a coating of the photo-reactive material of claim 1 on at least one surface. Imaging system according to claim 2, characterized in that the substrate contains aluminum, the surface of which is coated with the photo-reactive material is oleophilic. k. Imaging system according to claim 3, characterized in that a coating of water-soluble diazo resin is present on the aluminum surface under the coating of the photo-reactive material. The material according to claim 1, characterized in that at least two of the ethylenically unsaturated groups in the ethylenically unsaturated compounds are acrylate or methacrylate groups. Material according to claim 5, characterized in that the ethylenically unsaturated compounds have 2 to 5 acrylate or methacrylate groups. The material according to any one of claims 1 to 5, characterized in that the water-softenable polymer is selected from the group consisting of polyvinylpyrrolidone, 80 0 1 0 85 partially hydrolyzed polyvinyl acetate, hydroxyalkyl cellulose resins and inorganic solvent-soluble polyvinyl alcohol derivatives. 8. A material according to claim 5, characterized in that the water-softenable resin contains polyvinylpyrrolidone. Material according to claim 6, characterized in that the water-softenable resin contains polyvinylpyrrolidone. 10. A material according to claim 1 or 5, characterized in that at least 0.5 wt% of a second film-forming resin which is oleophilic is present. Material according to claim 8, characterized in that at least 0.5 wt.% Oleophilic film-forming resin is present. 12. A material according to claim 11, characterized in that the oleophilic film of the resin is selected from the group consisting of cellulose acetate butyrate and cellulose acetate propionate. 13. The material according to claim 5, characterized in that the group consists of epoxy resins, polyesters, polyallyl orthophthalate prepolymers, polyallyl isophthalate prepolymers, polyvinyl formal, polyurethanes, polyvinyl butyral, polyoxyethylene oxides, polyvinyl hydrogen phthalates, polyethacrylates, polyethacrylates, cellulose acrylics, cellulose polymers of at least 1000. 1U. Material according to claim 5 »25, characterized in that the group consists of epoxy resins, polyesters, polyallyl orthophthalate prepolymers, polyallyl isophthalate prepolymers, polyvinyl formal, polyurethanes, polyvinyl butyral, polyoxyethylene oxides, polyvinyl hydrogen phthalates, polyethacrylates with polyethylene chloride, cellulose acetate. at least 1000. The material according to claim 5, characterized in that the group consists of epoxy resins, polyesters, polyallyl orthophthalate prepolymers, polyallyl isophthalate prepolymers, polyvinyl formal, polyurethanes, polyvinyl butyral, polyoxyethylene oxides, polyvinyl hydrogen phthalates, polyacrylates, 80 0 1 0 85 polyethylacetacryl. a molecular weight of at least 1000. Material according to claim 5, characterized in that the group consists of epoxy resins, polyesters, polyallyl-5 orthophthalate prepolymers, polyallyl isophthalate prepolymers, polyvinyl formal, polyurethanes, polyvinyl butyral, polyoxyethylene oxides, polyvinyl hydrogen phthalates, polyethacrylates, polyethacrylates, cellulose acrylates, cellulose acrylics at least 1000. 10 1 · Imaging system, characterized in that it comprises a grained and anodized aluminum substrate, of water-soluble diazo resin on one surface thereof and the photo-reactive material according to any one of claims 5 * 6, 8, 9, 11, 12 , 13, 1H, 15 or 16 as a coating over the water-soluble diazo resin. 18. Photo-reactive material, characterized in that it contains, homogeneously mixed, a diazo resin, a free-radical polymerizable polyethylenically unsaturated compound and a free-radical photoinitiator system. The material according to claim 6, characterized in that the solvent-soluble film-forming resin contains a resin which can cross-link or polymerize on its own when heated to a temperature of at least 100 ° C. 20. Imaging system, characterized in that it comprises a grained and anodized aluminum substrate, a water-soluble diazo resin on one surface thereof, and a photoreactive material according to claim 7 coated on the water-soluble diazo resin. 21. Imaging system, characterized. 30 comprising a grained and anodized substrate, a water-soluble diazo resin on one surface thereof and the photo-reactive material of claim 10 coated on the water-soluble diazo resin. 22. Photo-reactive material, characterized in that it contains a homogeneous mixture of 800 1 0 85 A. 1-75% by weight of inorganic solvent soluble film-forming resin, B. 10-65% by weight of free-radical polymerizable polyethylenic unsaturated compounds having at least 5 two ethylenically unsaturated groups, C. 0.5 to 15% by weight of a free-radical photoinitiator system, D. 5-1 * 0% by weight of a water-softenable, inorganic solvent-soluble polymer, and 10 E. 1-20 wt% of an inorganic solvent soluble diazo resin. 23. Photo-reactive material, characterized in that it contains a homogeneous mixture according to claim 22, wherein the sum of the water-softenable and the organic film-forming resins is equal to at least 10% by weight of the material. 80 0 1 0 85