JPS58162391A - Lithographic original plate - Google Patents

Abstract

PURPOSE:To enhance the water resistance and printability of a lithographic original plate by providing a modified polyvinyl alcohol layer containing silicon on a supporter. CONSTITUTION:A modified polyvinyl alcohol containing silicon is obtained by a method in which silicon is introduced into a modified polyvinyl acetate with carboxylic or hydroxyl group or a polyvinyl alcohol by using a silylizing agent or subjecting a copolymer of vinyl ester and an olefinic unsaturated monomer containing silicon to saponification. A pigment particle of zinc oxide, cadmium sulfide, titanium oxide, etc., having a photo-conductive layer, is dispersed into the modified polyvinyl alcohol aqueous solution, and the dispersion is laminated on a supporter to obtain an original plate. The original plate is subjected to desensitization treatment in order to keep it in lipophilic state. Thus, the water resistance is raised because oil ink is adhered only to lipophilic sections.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lithographic printing original plate having good water resistance and excellent printability. In more detail, modified polyvinyl alcohol containing silicon in the molecule is PV.
Abbreviated as A. ) is provided on a supporting substrate, and has good water resistance and printability.

Conventionally, the lithographic printing plates used in office printing basically use wet strong paper as a support base.
On top of this is a direct bolt image receiving layer or a photoconductive type iii.
It is produced by forming an image-receiving layer, and furthermore, in order to improve the printing durability of the plate material, an intermediate layer is also formed between the above-mentioned image-receiving layer and the supporting substrate.

The image-receiving layer and intermediate layer in such a lithographic printing original plate generally have enough hydrophilicity to repel ink during printing by more than a dozen printing machines, and at the same time have sufficient hydrophilicity to repel ink, and at the same time, retain moisture that is repeatedly supplied during printing. It is praised for its water resistance, which is strong enough to withstand water.

Conventionally, in order to satisfy the requirements of hydrophilicity and water resistance, the image-receiving layer or intermediate layer has been made of water-soluble polymers such as PVA, Cain, and Tonoe, or water-resistant materials such as these water-soluble polymers and amino resin wire metal fittings. Tomomo is known to apply the crosslinking reaction with a curing agent.

However, when carrying out a crosslinking reaction in these systems, if the reaction is carried out in the state of the paint before it is spread on the support, the paint thickens and gels, making it impossible to perform the crosslinking reaction, or during coating or during coating. If a cross-linking reaction is to be carried out later, curing at high temperatures and over a long period of time is required, and when employed on an industrial scale, productivity and profitability are extremely low.Furthermore, in the above-mentioned system, Depending on the mixing ratio of the water-soluble resin and crosslinking agent, or slight variations in curing conditions, either the hydrophilicity or water resistance of the image-receiving layer or the intermediate layer tends to be insufficient. However, it is difficult to carry out preparations in a manner that satisfies both the characteristics and characteristics at a regular time, and the quality of the lithographic printing original plate product tends to vary.

The present inventors have conducted intensive studies with the aim of overcoming the above-mentioned drawbacks and providing a lithographic printing original plate having an image-receiving layer or an intermediate layer that is excellent in both hydrophilicity and water resistance. When one or both of the intermediate layer contains modified PVA containing silicon in the molecule, special high temperature and long curing conditions are not required, and both wood affinity and water resistance can be achieved under normal manufacturing conditions. The present invention was completed based on the discovery that an excellent lithographic printing original plate can be obtained.

The non-invention will be explained in more detail below.

The modified PVA containing silicon in the molecule used in the present invention may be any one containing silicon in the molecule, but
Silicon contained in the molecule has a reactive direct donor group such as a hydroxyl group, an alkoxyl group, or an alkoxyl group.
Particularly preferably used methods for producing such modified PVA include: (1) introducing silicon into PVA=4- or modified polyvinyl acetate containing a carboxyl group or a hydroxyl group by post-modification using a silylating agent; (2) A method of saponifying a copolymer of a vinyl ester and a silicon-containing olefinic unsaturated monomer. In the method of post-modifying PVA or modified polyvinyl acetate using a silylating agent, for example, the silylating agent is added to an organic solvent that does not react with the silylating agent, such as benzene, toluene, xylene, hexano, heptane, ether or haacetone. Powdered P is dissolved in the solution.
V16 or the above-mentioned modified polyvinyl acetate is made cloudy under stirring, and the silylating agent and PVA'4) or the above-mentioned modified polyvinyl acetate are reacted at a temperature ranging from room temperature to the boiling point of the silylating agent. Furthermore, silicon-containing modified PVA can be obtained by saponifying vinyl acetate units using an alkali catalyst or the like. Silylating agents used in post-modification include trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane,
Organohalogensilanes such as vinyltrichlorosilane, diphenyl-5-dichlorosilane, and triethylfluorosilane; organosilicon esters such as trimethylacetoxysilane/dimethyldiacetoxysilane; organoalkoxysilanes such as trimethylmethoxysilane and dimethyldimethoxysilane; trimethylsilanol; Examples include organosilanols such as diethyl 7landiol, aminoalkylsilanes such as N-7 minoethylaminobrobyl trimethoxysilane, and organosilicon isocyanates such as trimethylsilicon incyanate. The introduction rate of the silylating agent, that is, the modification rate, can be adjusted as desired depending on the amount of the silylating agent used and the reaction time. It can be arbitrarily adjusted by the degree of saponification, the degree of polymerization of the above-mentioned modified polyvinyl acetate, and the saponification reaction.

In the method of saponifying a comonomer of a vinyl ester and a silicon-containing olefinically unsaturated monomer, for example, the vinyl ester and the silicon-containing olefinically unsaturated monomer are radically initiated in alcohol. A silicon-containing modified PVA can be obtained by copolymerizing the copolymer using a copolymer and then saponifying the copolymer by adding an alkali or acid catalyst to an alcohol solution of the copolymer. Vinyl esters used in the above method include vinyl acetate, vinyl propionate, vinyl formate, etc., but vinyl acetate is preferred from an economical standpoint. In addition, the silicon-containing olefinically unsaturated monomer used in the above method has the following formula (
Vinylsilanes represented by 1) and (meth)acrylamidoalkylsilanes represented by (II) are included.

υ (where n is θ~4, m is 0~2, R1 is an alkyl group
Hz is an alkoxyl group, an acyloxyl group (an alkoxyl group or an acyloxyl group refers to an oxygen group, and an alkylene group or a divalent organic residue in which chain carbon atoms are bonded to each other by oxygen or minerals, respectively). .

Specific examples of the vinylsilane represented by formula (1) include vinyltrimethoxysilane, vinyltriethoxysila/, vinyltris-(β-methoxyethoxy)silane, vinyltriacetoxysilane, allyltrimethoxysilane, and allyltriacetoxysilane. , vinylmethyldimethoxysilane.

Vinyldimethylmethoxysilane, vinylmethyljethoxysilane, vinyldimethylethoxysilane, vinylmethyldiacetoxysilane, vinyldimethylacetoxysilane, vinylinbutyldimethoxysilane, vinyltributoxysilane, vinylmethoxysilhexyloxysilane,
Vinyldimethoxyoctyloxysicine, vinylmethoxydioctyloxysilane, vinylmethoxydilauryloxysilane to 8-cyoleyloxysilane, and further general formula % formula % (where 2%m is the same as above, X is 1 to 20 Examples include polyethylene glycolized vinylsilane represented by the following formula. Further, as specific examples of the (meth)acrylamide-alkylsilane represented by formula (1), for example,
3-(meth)acrylamidoglobiltrimethoxycin, disilane in 3-(meth)acrylamidoglobiltrieth.

N -(2-(meth)acryland-ether)-aminopropyltrimethin, 3-(meth)acrylamide-propyltriacetoxysilane% 2-(meth)acrylamide-methyltrimethoxysilane , 3-
Examples include (meth)acrylamitope-vilmethyldimethoxysilane, 3-(meth)acrylamidoprobyldimethylmethoxysilane, and 3-(N-methyl-(meth)acrylamido)-propyltrimethoxysilane.

In addition, when copolymerizing the vinyl ester and the silicon-containing olefinic unsaturated monomer to produce the modified PVA used in the present invention, it is necessary to Other unsaturated monomers capable of copolymerization, such as styrene, alkyl vinyl ethers, hinyl versatate, (meth)acrylamide, ethylene, propylene, α-hexene, α-octene olefins, (meth)acrylic acid, croton acids, (anhydrous) unsaturated acids such as maleic acid, fumaric acid, itaconic acid, and their alkyl esters, alkali salts, 2-acrylamide-2-
Sulfonic acid-containing monomers such as methylpronosulfonic acid and their alkali salts, tri-10-methyl-5-(1-acrylamido-1,1-dimethylpropyl) ammonium chloride, trimethyl-5-(
1-acrylamidopropyl) ammonium chloride,
It is also possible to have a small proportion of cationic monomers such as 1-vinyl-2-methylimidazole and its 4M compound present.Containment of silicon in the silicon-containing modified PVA used in the present invention The amount, saponification, or degree of polymerization is appropriately selected depending on the purpose and is not particularly restricted. The effect of the silicon atom is exhibited even at a relatively small content, and the content is usually in the range of 0.01 to 10 mol. The saponification degree is usually preferably in the range of 70 to 100 moles. Further, the degree of 1 degree is usually selected from the range of 300 to 3000.

Modified PV containing silicon in the molecule used in the present invention
When using AFi, it may be preferable to use it in the form of a vinyl resin emulsion. In such cases, the vinyl resin emulsion includes vinyl acetate, acrylic ester, methacrylic ester, acrylonitrile, styrene, , a polymer emulsion consisting of a vinyl monomer supporting a polymerizable vinyl group such as vinyl chloride, vinylidene chloride, ethylene, bumediene, or at least 1 m of the polymerizable vinyl monomer and acrylic acid, methacrylic M, maleic acid. A copolymer emulsion with at least one monopolymer such as itaconic acid or other ethylenically unbound carbonaceous acid, glycidyl (meth)acrylate, hydroxyethyl (meth)acrylate, or (meth)acrylamide is used. Noto II MW emulsion is emulsion polymerized using a low-molecular nonionic or anionic emulsifier, or contains HPVA, cellulose enzyme conductor, (meth)acrylic acid copolymer, α-olefin-maleic anhydride copolymer, etc. Any emulsion obtained by emulsion using a holding colloid such as an electropolymer can be used, or preferably an emulsion obtained by emulsion polymerization using a modified PvA containing silicon in the molecule as a holding colloid. used. Emulsion polymerization can be carried out by a known separation method.

As mentioned above, the original plate of the present invention has a basic structure in which an image receiving layer or a photoconductive layer is provided on a supporting substrate such as paper or plastic film, which itself has water resistance. It has a structure in which a water-resistant intermediate layer is provided between the photoconductor layer and the photoconductive layer, and a back coat layer is provided on the back surface of the supporting substrate. In the lithographic printing original plate of the present invention, at least one layer among the above layers contains modified PVA containing silicon in the molecule, and in particular, either the image-receiving layer or the water-resistant intermediate layer. It is preferable that the above-mentioned i-type PVA be contained in either or both of them. In this case, the above-mentioned modified PVA or a vinyl resin emulsion containing the modified PVA is used as the wood for forming the SM image-receiving layer or the water-resistant intermediate layer. Pigments such as barium sulfate and delta oxide, dispersants for cough pigments, antifoaming agents, and ordinary water-soluble resins such as unmodified PVA are used. In addition, in forming a layer containing modified PVA13- as used in the present invention, an L tin-based compound,! A hydrolysis catalyst for silicon-bonded alkoxyl groups and acyloxyl groups in the modified PVA, such as lti lead-based -8t+g, can be added as appropriate. l1llIIJ1
! A method for forming a receiving layer or a water-resistant intermediate layer is to apply a mixture of the materials mentioned above as a glue to the surface of a supporting substrate and dry it. The usual method is adopted. The amount of balls at this time is usually 1 to 302 as dry vein solid content.
／It is a male.

Formation of the photoconductive layer in the original plate of the present invention is carried out using zinc oxide, sulfide domicum, and #j11 of titanium bonito having a photoconductive layer.
The heavy particles are separated into a water-molecular solution or a vinyl resin emulsion, or an acrylic resin, a silicone resin, or a vinyl acetate resin containing the above-mentioned modified PVA. This is done by coating the water-resistant intermediate layer with

Further, in the original plate of the present invention, a back coat layer containing an anti-curl agent, a conductive component, or a moisture-absorbing substance may be provided for the purpose of preventing curling and improving conductivity. It goes without saying that water repellency can be imparted to the layer by incorporating modified P''li'A containing silicon in the molecule.

Modified P containing silicon in the molecule formed in the present invention
An image-receiving layer, a water-resistant intermediate layer, or a puncture coat layer consisting only of VA or containing the modified Pvum is wood-friendly and has excellent water resistance. The reason why such remarkable performance is obtained is basically that P
It has hydrophilicity due to the hydroxyl group derived from the modified PV film, and the alkoxyl group bonded to silicon in the modified PV film, the alkoxyl group, or the silanol group which is a hydrolyzate thereof, or a salt thereof forms a film when the PVA aqueous solution is dried. This is thought to be because it easily self-condenses and crosslinks during formation, and also reacts with *the memorial material or the substrate to form a water-insoluble film.

Below, we will briefly explain the actual practice of lithographic printing (offset printing). In the case of lithographic printing, it is necessary to print on the image-receiving layer using Type 2 Iku, etc., or to write by hand using oil-based ink. Therefore, an image is formed by transferring an image created by the xerographic method onto the above-mentioned receiving layer and then thermally fixing it.

On the other hand, in the case of an original plate for electrophotographic lithographic printing, multiple images can be formed by dry or wet development after uniformly corona discharge is applied to the photoconductive layer. The original plate for direct plate printing or the original plate for electrophotographic printing on which an image has been formed in this manner is then desensitized with a desensitizing liquid (etching liquid).

As a result, the non-image areas are rendered oil-insensitive and become hydrophilic, but the image-receiving layer is in a state where the image-receiving layer is covered with oil-based ink, toner, etc., which are themselves oleophilic. This prevents the action of the etchant from reaching the image-receiving layer, and as a result, the image area remains lipophilic. The desensitization process is generally carried out by treating the plate surface with an aqueous solution containing gold components such as sodium ferrocyanide, ammonium phosphate, citric acid, and phytic acid.

When a lithographic printing original plate that has been desensitized in this way is used for offset printing, the desensitized portion wetted by IM water repels oil-based ink and does not adhere to oil-based prints. If the oil-based ink adheres only to the paper, a printed matter can be obtained by transferring it to the intended paper.

EXAMPLES Next, the present invention will be further explained with reference to Examples, but the present invention is not limited thereto. In addition, in the examples, unless otherwise specified, f, ``gb'', and ``part''
represents weight basis.

Example 1 A copolymer of vinyl methoxydiocteroxysilane and vinyl acetate was saponified to contain 0.6 mol of silicon as vinyl silane units, and the degree of saponification of vinyl acetate units was 9.
The viscosity of an 8.5 mol-14 aqueous solution at 20°C is 30
A silicon-containing modified PVA of centiboise (cp) was obtained. Next, the following composition: 101b aqueous solution of the modified PVA 90 parts dibutyltin dilaure 0.18 parts 17- (silicon-bonded alkoxyl group hydrolysis catalyst) 30 parts zinc oxide, 50 parts containing 70% clay Chi water dispersion 8ON water
A dispersion having a composition of 60 parts was applied to the surface of a supporting substrate (90f/11' wet hook reinforced paper) and dried at 130°C for 1 minute to give a dispersion of about 20 parts.
An f/male image-receiving layer was formed.

Next, a dispersion having the following formulation was applied to the face of the supporting substrate and dried at 130°C for 5 minutes to form a back coat layer of about 1Of/wl, which was supercalendered to form a direct seeding lithographic printing original plate. 10 parts of a 50% aqueous dispersion of the fustyrene-butadiene copolymer emulsion prepared (Dow Chemical Co., Ltd. DL636) 45 parts of a 10% aqueous solution of pv (manufactured by Kuraray) 50% aqueous dispersion of clay 800 80 parts melamine formalin fat aqueous dispersion 2.5 parts 18- Ammonium chloride 0.1 part water
7
After printing on the lithographic printing original plate thus obtained using a commercially available typewriter, it was treated with an insensitive oil solution and printed on an offset printing machine.
0 (A clear print without one or more background stains was obtained.

Comparative Example 1 In place of silicon-containing modified PVA, saponified lm18.5 mol-14-aqueous solution with viscosity [30CI] at 20°C (manufactured by Kuraray Co., Ltd., PVA117) was used, and dibutyltin dilaurate was not used, except for Example 9. When a straight-horizontal lithographic printing original plate was prepared in the same manner as in 1 and a printing test was conducted in the same manner, scumming occurred from about the 10th sheet.

Example 2 A copolymer of vinylmethyldimethoxysilane and vinyl acetate was saponified to convert silicon into vinylsilane units to 0.2
A silicon-containing modified PVA having a viscosity of 6.5 cp at 20° C. of an aqueous solution containing 5 moles of vinyl acetate units and saponified vinyl acetate units was obtained.

Then a stirrer, temperature ir1', dropping funnel and reflux -
Into a reaction tank equipped with a cooler, 450 seconds of the above 10-aqueous solution of modified PVA, 10 seconds of acrylic acid ether, and 50 parts of vinyl acetate were charged, and after uniformly emulsifying, 41 parts of 6% ammonium persulfate and 1 Add 60s of 〇- sodium east sulfite, i! in the system! The temperature was raised to 60°C and one batch was started. While continuing polymerization at a temperature of 60° C., a mixture of 90 parts of ethyl acrylate and 450 parts of vinyl acetate and 80 parts of a 2% ammonium persulfate aqueous solution were added dropwise to emulsion for 3 hours. After the dropwise addition was completed, the temperature was raised to 70° C., aged for 30 minutes, and cooled to a temperature of 5.0° C. with a 10% ammonia aqueous solution.

Next, a working liquid having the following composition was prepared.

Emulsion obtained as described above 60 parts clay
Obtained by saponifying a coelectrolyte of 60 parts vinyltriacetoxysilane and vinyl acetate,
Contains more than 0.5 mole of silicon as a vinyl silane unit,
The viscosity of the aqueous solution at 20°C is 6.5CpO silicon-containing submersible PVAC) 10% water bath liquid
Further, 70 parts of the working solution was added to a supporting substrate (PVA
1 20 W/wl original paper with a nice second side) top Kb! ! Coating so that the shape is 3t/d, 14
Blend with iIL at 0℃ for 30 seconds to form a middle layer.

On top of this intermediate layer, a &1ilUl pedestal layer having the following composition was further applied at a concentration of 7 f/ml and dried at 150°C for 1 minute.

Calcium carbonate 35 parts clay
Obtained by saponifying a copolymer of 15 parts vinyl acetoxysilane and vinyl acetate, with 0 silicon as a vinyl silane unit.
．． 101 aqueous solution of silicon-containing modified PVA containing more than 4 moles 45 Tosui

30 copies were printed on the nine planographic printing original plates obtained in this way using a commercially available typewriter, and then the images were treated with an insensitive oil and printed using an offset printing machine.
Even after printing 1,000 sheets, clear printed matter with no background stains was obtained.

Comparative Example 2 A lithographic printing original plate prepared according to Example 2 and PF1 was used, except that an intermediate layer and an image-receiving layer having the following composition were provided in place of the intermediate layer and image-receiving layer of Example 2. When a printing test was carried out, background smearing occurred from about the 600th stitch of printing.

Composition of the composition used when producing the intermediate layer: In the emulsion production conditions in Example 2, the modified PVA used was replaced with a polymerization degree of x7oo and a saponification degree of 8.
Partial saponification of 8 mol)'VA (PV manufactured by Kuraray Co., Ltd.)
Example 2 and fi! except that A-217) is used. ! Emulsion obtained in 1 manner
60 parts amine resin (manufactured by Sumitomo Chemical, 5R-613)
3rd division clay
60 Zhengxia degree 500, saponification degree 99.8 moles PV
70 parts of IO di aqueous solution of VHPVA-105) Composition of the composition used in preparing the image-receiving layer: Calcium carbonate 35 parts 22- Clay 15 parts 1 go 1 tl
700. Ke/(tJt98.50PVA (PVA-117 manufactured by Kuraray Co., Ltd.) 45 parts water

30 parts Example 3 Supporting substrate (100t/+I10 wet reinforcement g)+Z) Jl
A conductive paint having the following composition was applied to the lli at a coating amount of 4 f/l.

Polymerization [1700, saponification [9s, 5opvA (Rinsha Co., Ltd. 2nd PVA-117) 30 parts vinyl acetate resin (Daicel Sepian A-522)
50 parts Quaternary ammonium type conductive agent (ECR-34 manufactured by Dow Chemical) 20s
In addition, a coating liquid having the following composition was applied to the surface of the supporting substrate. L cloth and dried at 130° C. for 3 minutes to form an approximately 10 f/I10 intermediate layer.

Acrylic acid ester emulsion (solid content 46%) C Japan Acrylic Actinic Ray, Primal HA16)
408il clay 4
0 parts vinyl triacetogysilane and vinyl acetate 1 part
10% of modified PVA containing 0.5 mol of silicon obtained by saponifying the coalescence as a vinyl silane unit and having a viscosity of 6.5 Cp in a 4% water bath solution at 20°C.
Water bath liquid 60s
Eleven parts of a coating solution having the following composition were applied onto the above intermediate layer at a rate of 25t/♂ to form a light guiding layer.

Photoconductive zinc oxide 100 parts (Sazetx 2000, manufactured by Sakai Kaji) Silicone resin 30 parts (KR-211, manufactured by Shin-Etsu Kaji) Rose Bengal 0.1 part Toluene 150 parts Next, 50 parts of this
After conditioning the humidity in a dark place under an atmosphere of 1RH and 25° C. for 24 hours, a plate was made using an Itic 175 electronic plate making machine. When this was desensitized with an etchant (manufactured by Itic Co., Ltd.) and printed on an offset printing machine, 5,000 copies were printed. Ta.

Ratio [N3 Modified PV containing 9K bulk used in forming the intermediate layer in Example 3
Acrylic acid ester emulsion (solid content 4
An intermediate layer was formed in the same manner except that 15 parts of 696) and 46 parts of water were used, and a photoconductive layer was further formed to prepare a lithographic printing plate. When a printing test was conducted in the same manner as in Example 3, peeling of the plate surface occurred after printing 700 sheets.

Examples 4 to 9 The following silicon-containing modified PVA was used in place of the silicon-containing modified Pv membrane of Example 1, and the same procedure as in Example 1 was carried out except for #9.
An IJ image-receiving layer was formed and an offset printing test was conducted. In either case, you can get over 1000 clear prints with no background stains.

Nine silicon-containing modified PVA used in Example 4.

0.25 silicon as vinyltrimethoxy Schiff unit
A silicon-containing modified PvA having a saponification degree of 991 mol of vinyl acetate units and a viscosity of a 143G aqueous solution at 20° C. of 25 Cp.

The modified PVA used in Example 5 contained 0.4 mol of silicon as a 3-acrylamidoglobiltriethoxysilane unit, had a saponification degree of vinyl acetate units of 99.6 mol, and was a 4% aqueous solution. Silicon-containing modified PvA0 with a viscosity of 28 Cp at 20°C The silicon-containing modified PV used in Example 6 contains 1 mol of silicon as a vinyltris(β-methoxyethoxy)silane unit, and the degree of saponification of vinyl acetate units is The viscosity of a 99.5molti, 4ti aqueous solution at 0°C is 35
Silicon-containing modified PvA of Cp.

Silicon shoulder-containing modified PVA used in Example 7.

Silicon as vinyl dimethoxycycne unit, 2
A silicon-containing modified PVA having a saponification degree of 99.2 molar vinyl acetate units and a viscosity of 4-aqueous solution at 20°C of 32 Cp.

Modified PVA containing Kyushu wood used in Example 8.

Contains 0.25 mol of silicon as 2-acrylic acid-2-methylglobin 2/unit of viltrimethoxine, saponification f of vinyl acetate unit is 98.5 mol, 4
0.5 mol of silicon-containing modified PVA used in Example 9 and having a viscosity of g6 water [k at 20°C of a o cp as a disilane unit]
Contains, the degree of saponification of vinyl acetate units is 99.5 mol-,
a % A modified PV film containing K-slip having a viscosity of 31 Cp at 020°C.

Example 1O Saponification of a copolymer containing 0.4 mol of vinyl triacetoxycycne units and 99.6 parts % vinyl acetate units obtained by copolymerizing vinyl triacetoxycycline and vinyl acetate. By doing so, 0.4 mol of silicon is contained as a vinyl silane unit, the degree of saponification of vinyl acetate unit is 99.4 mol, 4s water fII'ffi, 020 ° C.
A modified PV material containing silicon ice was obtained with a viscosity of 30 CI).

Next, this modified PVA was dissolved in water containing 2 parts of sodium hydroxide per part of the modified PV to prepare a 10 part aqueous solution of the modified PVA. Next, 90 parts of an aqueous PVAl0ti solution with a galvanic quality and 509 g with a mixing ratio of zinc oxide and clay of 3 = 7.
A dispersion having a composition of 80 parts of aqueous dispersion and 60 parts of water was applied to the surface of a supporting substrate (90 f/wl wet reinforcement paper), and 1
A dry pulse was applied at 30° C. for 1 minute to form an image-receiving layer of about 20 fid.

Next, a bank coat layer was formed by coating the following composition on the & side of the supporting substrate to a dry solid content of 49/d, and forming a TFI drawing type lithographic printing original plate. .

Above 6 Self-denatured PVAI O-chi aqueous solution 45 clay (50-chi aqueous dispersion) 80 parts water
70 copies of the planographic printing master plate thus obtained were used as Rico-P500.
(■Ricoh s I) PC copy paper), desensitized it with etchant, and after death, printed it on an offset printing machine, resulting in more than 2,000 clear prints with no background stains. . As Comparative Example 10, silicon-containing modified PVA was replaced with OPVA with a degree of saponification of 99.9 mol and a 4% aqueous solution with a viscosity of 27 Cp at 20° C. (manufactured by Kuraray Co., Ltd., pvmu-h:c). A direct drawing type lithographic printing original plate was prepared in the same manner as in Example 10, and a printing test was conducted in the same manner.As a result, scumming occurred from about the 20th sheet onwards.

Registered person Rira Shi Co., Ltd. Agent Patent attorney not required Gong 29 - Procedural amendment May 7, 1970 Haruki Miyajimada, Commissioner of the Japan Patent Office 1, Patent Application for Indication of Case No. 1983-46676 2 , Name of the invention Lithographic printing original plate <108) RiRa Co., Ltd. Representative Director Tsuneo Masa 4, Agent Telephone: Tokyo 03 (?77) 3182 5, Subject of amendment 6, Contents of amendment (1)” Specification Amend the claims in a separate sheet.

(2) Specification page 7, line 14 to page 8, line 6 1
Y'- OH5=OH-(OH2)H-Bi-(R2)3'
,,---- respectively shown). ' shall be amended as follows.

r R'm C! H2=CH-(OIh)n-8i-(R2),
m (1) [Here, n is 0 to 4, 1 ml is 0 to 2
, fL' is an alkyl group (such as a lower 7-kyl group with an R prime number of 1 to 5), and R2 is a 7-coxyl group or an acyloxyl group having 1 to 50 carbon atoms (here, the alkoxyl group and acyloxyl group are oxygen-containing substituted groups). may have a group), R
3 is a hydrogen atom or a methyl group 14 is a hydrogen atom or a lower furkyl group (lower alkyl group having 1 to 5 carbon atoms), R
5 is an alkylene group (alkylene group having 1 to 5 carbon atoms, etc.)
or a divalent organic residue in which chain carbon atoms are interconnected by oxygen or nitrogen, respectively. ]” (3) Page 9, lines 4 to 6 “〒2rn CH2=CH8i((OC■2CH2)x-OH),,
(Here, R2 and m are the same as above, and X is the month indicating 1 to 20.
OH) s, -m (where R1, m are the same as above, X
indicates 1 to 20)".

2. Claims (1) Modified polyvinylfluor containing silicon gold in the molecule:'
-1' A lithographic printing original plate comprising a layer containing 1' on a supporting substrate.

(2) The lithographic plate according to claim 1, wherein the modified polyvinyl alcohol containing silicon in the molecule is a saponified product of a copolymer of vinyl acetate and an olefinic unsaturated monomer containing silicon in the molecule. Original version for printing.

(5) The oleuniformly unsaturated monomer containing silicon in the molecule has the following general formula (1) %Formula%KylM%R2 is an alkoxyl group or an acyloxyl group having 1 to 50 carbon atoms (here, an alkoxyl group, The lithographic printing original plate according to claim 1, which is a vinylsilane represented by the following (the acyloxyl group may have an oxygen-containing substituent).

-5:

Claims (1)

[Scope of Claims] (1) A lithographic printing original plate comprising a layer containing modified polyvinyl alcohol containing silicon in the molecule provided on a supporting substrate. (2) The modified polyvinyl alcohol containing silicon in the molecule is a saponified product of a copolymer of vinyl acetate and an ethylenically unsaturated monomer containing silicon in the molecule! F. The lithographic printing original plate according to claim 1. (8) An ethylenically unsaturated monomer containing silicon in the molecule or the following general formula (1) [where n is θ~4, m is 0~2, R1 is an alkyl group]
B2 is a vinylsilane represented by an alkoxyl group or acyloxyl group having 1 to 30 carbon atoms (the alkoxyl group or acyloxyl group may have a substituent containing ψ1 in oxygen F)] A lithographic printing original plate according to claim 1.