JPH06155959A - Paste printing plate washing agent for planographic printing - Google Patents

Abstract

PURPOSE:To provide a washing agent having a high viscosity and thixotropic properties. CONSTITUTION:In a compsn. prepared by emulsifying an oil phase containing an org. solvent and an aqueous phase containing a water-soluble org. high- molecular compd. and an acid by a surfactant, a fine powder with an average particle size of 0.01-15mum hating thixotropicity is compounded.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a paste plate surface cleaning agent for lithographic printing.

[0002]

2. Description of the Related Art Lithographic printing is a printing system that utilizes the properties of water and oil, which are essentially immiscible, and creates a printing plate surface consisting of a water-receiving area and an oil-receiving area. We are using.

Therefore, when the balance between water and oil is lost and, for example, the hydrophilicity of the non-image area is deteriorated due to some physical or chemical change (scratching, abrasion, corrosion, etc.), ink is often attached to the area and the background It becomes dirty. Further, when the lipophilicity of the image part is desensitized by desensitized rubber, physical abrasion, etc. and the lipophilicity of the image part surface is deteriorated, water often adheres to the area first, making it difficult for ink to ride, Poor ink receptivity.

There are many causes of such background stains and ink inking defects, but as a typical case, the background stains are treated in order to make the lithographic printing plate have high printing durability, or lithographic printing. It may also occur when the plate is left in the air without being protected by the desensitized rubber, and when the plate is left unattended due to troubles of the printing machine, breaks, reprinting, or the like. Therefore, it is customary to perform surface treatment with desensitized rubber, a burning treatment liquid, a plate-forming treatment chemical, etc. If it has not been treated with desensitized rubber, plate processing chemicals, etc., that portion is sensitized and causes scumming. For example, a trace such as a fingerprint appears on the printed matter, which is a similar cause. Furthermore,
Moisture causes air oxidation of the aluminum surface, resulting in dirt.

In addition, defective ink replenishment is changed by heat, humidity, etc. while the plate is placed with the desensitizing rubber attached, or when a long period of time has passed, the rubber sticks to the image surface or becomes desensitized. Often occurs when the surface becomes hydrophilic due to overshooting.

The lithographic printing plate having the above-described background stains and defective ink replenishment has a hydrophilic property containing an acid, a salt and a water-soluble resin after the ink on the plate surface is removed with an ink-soluble solvent such as kerosene. Chemical treatment liquid (plate cleaning agent, plate cleaner)
Or, the normal printing can be performed by treating with or by emulsifying the oil phase and water phase with a surfactant (emulsion type plate surface cleaner, emulsion type plate cleaner) It is customary to wash the plate so that it can.

As such a plate surface cleaning agent, conventionally, a composition comprising phosphoric acid or a water-soluble salt thereof and a surfactant (Japanese Patent Laid-Open No. 261095/1986) and further this composition are provided with ink removing ability. And a solubilizing and emulsifying type composition containing a solvent having an ink-dissolving action (JP-A-53-2
No. 102) is known.

However, these plate surface cleaning agents have various drawbacks shown in the following (1) to (5).

(1) The conventional plate surface cleaning agent has a surface-cleaning action only by a chemical effect, and has a problem in stubborn stain removal.

(2) Conventional plate surface cleaning agents have a formulation having a stronger medicinal effect in order to obtain a rapid effect, and a photosensitive lithographic printing plate developed by aqueous alkaline development, such as O.
A positive photosensitive lithographic printing plate having a photosensitive layer made of a quinonediazide compound (Japanese Patent Publication No. 43-28403, US Pat. No. 3,046,120, etc.) or a negative having a photosensitive layer made of a diazo resin and a binder having an acidic group. Type photosensitive lithographic printing plate (JP-A-54-98613,
US Pat. No. 1,350,521) and the like, when used for a lithographic printing plate produced by the method, the processing time is too long, a part of the image area is violated when the post-washing is insufficient, and the ink is not attached. become worse.

(3) When a conventional plate surface cleaning agent is used, etching is excessive in the non-image area, the hydrophilic layer is excessively attacked, and it becomes rather easy to stain.

(4) Since the conventional plate surface cleaning agent has a strong effect of etching a metal support, a conventional photosensitive lithographic printing plate (referred to as a PS plate) having an aluminum plate as a support is used.
Since the hydrophilic layer applied to the surface of the support is easily destroyed and stains are likely to occur, it is necessary to pay close attention to the metal support.

(5) The conventional plate surface cleaning agent has a viscosity of 5 to 3
Since it is a relatively fluid liquid of about 00 cps,
In the cleaning treatment of the planographic printing plate surface, it is common to incline a bottle on a printing machine to impregnate it with sponge and spread it on the plate surface for processing. Therefore, it is complicated in operation such as opening and closing the mouth of the bottle at the time of use, and when impregnating sponge etc. and tilting the bottle to drop the plate surface cleaning agent, it is mistaken for the printing machine and the plate surface. Directly into the
There is a risk of causing defects.

[0014]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors to develop a plate surface cleaner for lithographic printing plates which does not have the above-mentioned disadvantages (1) to (5), the conventional plate surface cleaner Average particle size 0.01 to 15μ with thixotropic properties
It has been found that the desired plate surface cleaning agent in which the above-mentioned drawbacks are alleviated can be obtained by blending the fine powder of (1). The present invention has been completed based on such knowledge.

That is, the present invention provides a composition obtained by emulsifying an oil phase containing an organic solvent and an aqueous phase containing a water-soluble organic polymer compound and an acid with a surfactant, and having an average thixotropic property. The present invention relates to a paste plate surface cleaning agent for lithographic printing, characterized in that a fine powder having a particle size of 0.01 to 15 µ is mixed.

The plate surface cleaning agent of the present invention is obtained by emulsifying an oil phase and an aqueous phase with a surfactant. As the organic solvent to be mixed in the oil phase, conventionally known ones can be widely used. For example, phthalic acid diesters such as petroleum fraction, xylene, toluene, n-heptane, dibutyl phthalate, diheptyl phthalate and dioctyl phthalate, dioctyl. Aliphatic dibasic acid esters such as adipate, butyl glycol adipate, dibutyl sebacate, di (2-ethylhexyl) sebacate, paraffins having 6 to 18 carbon atoms such as octane, nonane, decane, propylbenzene, butylbenzene, etc. Benzene having an alkyl group having 1 to 30 carbon atoms, epoxidized triglyceride such as epoxidized soybean oil, fatty acid ester such as ethyl stearate, isopropyl stearate, ethyl cetylate, isopropyl cetylate group, acetic acid of stearyl alcohol ester Fatty alcohol esters, tricresyl phosphate, phosphoric acid esters such as trioctyl phosphate, and the like. Further, ketones such as cyclohexanone, ethylene glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monophenyl ether, and ethylene glycol monobutyl ether may be used together with these solvents. These organic solvents may be added to the composition of the present invention in an amount of about 1 to 40% by weight (hereinafter simply referred to as "%"), preferably about 5 to 35%.

The water phase contains a water-soluble organic polymer compound and an acid. As the water-soluble organic polymer compound, conventionally known compounds can be widely used, and examples thereof include cellulose derivatives such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, phosphorylated methyl cellulose, cultivated starch, pregelatinized starch, dextrin, phosphorylated starch. , Starch derivatives such as dialdehyde starch, carboxylated starch, alginic acid and its salts, natural or semi-synthetic polymer compounds such as locust bean gum, tractane, pullulan, etc. or their derivatives, polyvinyl alcohol, phosphorylated polyvinyl alcohol, polyvinylpyrrolidone, poly Examples thereof include synthetic polymer compounds such as acrylic acid, polyacrylamide, polyvinyl methyl ether, polyethylene glycol, vinyl methyl ether and maleic anhydride copolymer, and the like. These alone or 2
Used as a mixture of two or more species. Further, gum arabic, glue, polyacrylic acid derivative and the like can be used together with these. These water-soluble organic polymer compounds are contained in the composition of the present invention in an amount of about 2 to 25%, preferably 4 to 20%.
It is good to mix it to some extent.

As the acid, conventionally known ones can be widely used, and examples thereof include inorganic acids such as phosphoric acid, sulfuric acid and nitric acid, organic phosphoric acid, phosphoric acid-based modified compounds, organic acids such as phytic acid and organic carboxylic acids. Can be mentioned. Such an acid is contained in the composition of the present invention in an amount of about 0.5 to 30%, preferably 2 to 2%.
It is recommended to add about 5%.

In the present invention, the surfactant is used as an emulsion stabilizer for the oil phase and the water phase and as a washing accelerator. As the surface active agent, conventionally known ones can be widely used, and for example, one or more kinds of anionic surface active agents, nonionic surface active agents, cationic surface active agents and the like can be used. Examples of the anion activator include fatty acid salts, alkyl sulfates, alkylbenzenesulfonates, alkylnaphthalenesulfonates, dialkylsulfosuccinic acid ester salts, alkylphosphoric acid ester salts, naphthalenesulfonic acid formalin condensates, and polyoxyethylene alkyls. Examples thereof include sulfuric acid ester salts, polyoxyethylene phenyl sulfuric acid ester salts, polyoxyethylene alkyl phosphoric acid ester salts, polyoxyethylene phenyl phosphoric acid ester salts, and the like. Examples of the nonionic activator include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxypropylene alkyl ethers, polyoxypropylene alkylphenyl ethers, polyoxypropylene fatty acid esters. , Sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, glycerin fatty acid esters, etc.,
Examples thereof include an activator in which a polyoxyethylene-polyoxypropylene copolymer is alkyl etherified, alkyl phenyl etherified, fatty acid esterified, or sorbitan fatty acid esterified. Examples of the cationic activator include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, alkylisoquinolium salts and the like. Among these various activators, polyoxyethylene alkyl ethers,
Polyoxyethylene alkyl phenyl ethers and dialkyl sulfosuccinates are preferred. These surfactants are preferably added in the composition of the present invention in an amount of about 0.5 to 15%, preferably about 1 to 10%.

It is important that the composition of the present invention contains fine powder having a thixotropic property and an average particle diameter of 0.01 to 15 μm. Examples of such fine powder include fine powder silica and its modified compounds, montmorillonite and its derivatives, bentonite and its derivatives, gelling powder of polyacrylic acid ester, and fine powder of insoluble polymer compounds. When finely divided silica or a modified compound thereof is used, those having an average particle size of 1 to 15 μ are preferable, and 2 to 15
μ is particularly preferable. When montmorillonite or its derivative, bentonite or its derivative, gelled powder of polyacrylic acid ester and fine powder of insoluble polymer compound are used, those having an average particle diameter of 0.01 to 10 µ are preferable, and 0.05 to Particularly preferred is 7μ. Such a fine powder is a solvent that removes oily stains such as ink, and an action that further enhances the cleaning action of an acid having an etching property for removing a thin film of oxidation stains, scratch stains, and oily stains on the aluminum plate surface. Further, it has a function of physically rubbing the aluminum surface without damaging an image, and a function of removing persistent stains, which was difficult only by the cleaning action by the conventional chemical etching. These fine powders may be added to the composition of the present invention in an amount of about 2-40%, preferably about 5-30%.

In the present invention, it is desirable to add an abrasive together with the fine powder having the thixotropic property. By using the abrasive together, the effect of using the fine powder having the thixotropic property can be further enhanced. Examples of such an abrasive include mica, talc, diatomaceous earth, clay, silicic acid compounds, insoluble polymer compound powders, and the like. Among these, mica and diatomaceous earth are preferable. The average particle size of these abrasives is 1 to 70.
About μ is preferable, and about 5 to 50 μ is more preferable. The fine powder may be added to the composition of the present invention in an amount of about 1-40%, preferably about 5-30%.

In the present invention, the oil phase may contain a lipophilic resin. The lipophilic resin contributes to improving the stability of the paste and improving the oil sensitivity of the image area (enhancing the ink receptivity). Examples of the lipophilic resin include novolac type phenol resin such as phenol formaldehyde resin and t-butylphenol formaldehyde resin,
Xylene resin in which phenol and xylene are condensed with formaldehyde, resin in which phenol and mesitylene are condensed with formaldehyde, polyhydroxystyrene, brominated polyhydroxystyrene, cashew resin, copolymer of styrene and maleic anhydride, melamine resin, alkyd Examples thereof include resins, polyester resins, epoxy resins, rosin and its derivatives, and petroleum resins such as Gilsonite.
Among these lipophilic resins, novolac type phenolic resin,
Rosin and petroleum resin are preferred. Further, in place of these lipophilic resins, an organic carboxylic acid having 6 to 25 carbon atoms such as oleic acid, lauric acid and nonyl acid may be blended. The lipophilic resin may be added to the composition of the present invention in an amount of about 1 to 10%, preferably about 2 to 5%.

In the present invention, the aqueous phase may contain salts, moisturizers, preservatives and the like. Examples of the salt include alkali salts of acids mixed in the aqueous phase. Specific examples of the alkali salt include Na salt, K salt, NH ₃ salt, and Mg.
Examples include salts, Al salts, Va salts, Ti salts and the like. Such a salt is preferably added in the composition of the present invention in an amount of about 0.5 to 30%, preferably about 2 to 25%.

The moisturizing agent can impart to the composition of the present invention the property of appropriately spreading to the non-image area of the lithographic printing plate even though the aqueous phase of the detergent of the present invention is hard to dry and has high viscosity. . As the moisturizing agent, for example, polyhydric alcohol is usually used. Specific examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butylene glycol, pentanediol, hexylene glycol, tetraethylene glycol, polyethylene glycol, glycerin and sorbitol. , Pentaerythritol, and the like. Among these, ethylene glycol, propylene glycol, butylene glycol and glycerin are particularly preferable. These moisturizers can be incorporated into the composition of the present invention at
It is advisable to mix them so that the content is about 40%, preferably about 5% to 35%.

Examples of preservatives include benzoic acid and its derivatives, phenols and their derivatives such as phenol and cresol, formalin and its derivatives, sodium dihydroacetate, hydroxychlorobenzene and its derivatives, and iodinated benzene compounds. Examples include various thiol-based and amine-based compounds. These preservatives are preferably added to the composition of the present invention in an amount of about 0.001 to 3%.

The composition of the present invention may further contain commonly used colorants, fragrances, viscosity modifiers, stabilizers, antioxidants and the like, if necessary.

The plate surface cleaning agent of the present invention is in the form of a highly viscous paste, and the viscosity is usually in the range of 20 to 1000 poise.

There are no particular restrictions on the production of the plate surface cleaning agent of the present invention, and the plate surface cleaning agent can be manufactured in the same manner as in the conventional plate surface cleaning agent. For example, an oil component is mixed with an aqueous phase prepared by heating and dissolving at 30 to 60 ° C., and an oil phase heated and dissolved at 50 to 90 ° C. is gradually added dropwise to prepare a dispersion liquid, and a homomixer, a homogenizer or the like is used. After forming a milky white emulsion, fine silica powder or the like may be added and kneaded with a kneader, a blade, or a stirrer with a stirring rod.

The plate surface cleaning agent of the present invention is not particularly limited and may be used in the same manner as a conventional plate surface cleaning agent. For example, place the lithographic printing plate on which scumming and ink inking defects have occurred on a flat table, or while it is still attached to the printing machine, take a sufficient amount of the cleaning agent of the present invention with a sponge or the like washed with water, and Lightly rub the sponge with the cleaning agent on the areas where stains and ink adhesion defects have occurred to remove the ink, and at the same time, desensitize the non-image areas, and wash excess cleaning agent and used cleaning agent with water. Wipe it off with a clean sponge.

[0030]

【The invention's effect】

(A) The plate surface cleaning agent of the present invention has not only a surface-cleaning action by chemical etching but also a physical rubbing / polishing action. Due to these synergistic effects, excellent stain removing ability and stain-preventing effect are obtained. Express. Therefore, stubborn stains can be easily removed by using the plate surface cleaning agent of the present invention.

(B) In the conventional plate surface cleaning agent, a strong acid or a chemical agent that violates the photosensitive agent coating film of the image area is blended in order to remove stains on the plate surface only by the surface cleaning operation by chemical etching. In the plate surface cleaning agent of the present invention, in addition to the cleaning action,
Since it also has a physical abrasion effect, it is not necessary to add a strong acid or the like, and it is sufficient to add an acid (for example, pH 2 to 4.5) having a surface-adjusting effect by gentle etching. It can be suitably applied to both photosensitive and negative photosensitive lithographic printing plates.

(C) The plate surface cleaning agent of the present invention comprises the above (b).
As described above, since it has a surface-adjusting action by gentle etching, it not only damages the lipophilic layer surface of the image area and the hydrophilic layer surface of the non-image area, but also the oxidation that occurs in the non-image area. It is also excellent in the effect of preventing stains due to the above, stains that occur over time, the effect of retaining the recovered hydrophilicity, and the effect of recovering or maintaining the lipophilicity of the image area.

(D) The plate surface cleaning agent of the present invention has a mild action of etching a metal support, and therefore can be suitably applied to PS plates.

(E) The plate surface cleaning agent of the present invention is in the form of a highly viscous paste and further has thixotropic properties (non-Newtonian fluidity). Therefore, it is not necessary to fill the bottle with the plate surface cleaning agent like a conventional plate surface cleaning agent, and it can be filled in a wide-mouthed container such as a tube or a wax container, and the cleaning agent can be easily taken out and handled. Become. Further, since the plate surface cleaning agent of the present invention is in the form of a paste, there is no risk of accidentally dropping it on the printing machine or the plate surface due to dripping during sorting into a sponge, and the work can be carried out easily.

(F) The plate surface cleaning agent of the present invention is extremely excellent in emulsion stability and temporal stability.

[0036]

EXAMPLES The present invention will be further clarified with reference to the following examples. In the following, simply "part" means "part by weight"
"%" Means "% by weight", respectively.

Example 1 To 345 parts of pure water, 30 parts of phosphoric acid, 40 parts of diammonium phosphate and 30 parts of citric acid were added with stirring and dissolved. Further, 50 parts of cream dextrin # 5 [thickening / emulsion stabilizer for water-soluble polymer, manufactured by Matsutani Chemical Co., Ltd.] was added with stirring to dissolve. Then, 90 parts of a 1: 1 mixture of glycerin and 1,2-butylene glycol was added as a wetting agent to prepare an aqueous phase.

Hysol 150 [boiling point 181 to 201 ° C.
Hydrocarbon solvent, manufactured by Nippon Petrochemical Co., Ltd.] 250 parts Ionet S-85 [Sorbitan trioleate, manufactured by Sanyo Kasei Co., Ltd.] as an emulsifier, Nicole BC30T
X [polyethylene oxide cetyl ether, Nikko Chemical Co., Ltd.] 12 parts and Perex OT-P [sodium dialkylsulfosuccinate, Kao Atlas Co., Ltd.] 5
Parts were dissolved to prepare an oil phase.

Next, the aqueous phase prepared above was stirred and heated to 4
The oil phase was adjusted to 0 ° C., and the oil phase heated to 80 ° C. was gradually added dropwise thereto, and the mixture was emulsified and stirred with a homomixer to obtain a milky white viscous liquid. Further, while stirring with a feather stirrer, diatomaceous earth [Celi
te, Manville Sales corp. Made)
200 parts and 80 parts of Tokseal N [synthetic amorphous silica, average particle size 7 μm, manufactured by Tokuyama Soda Co., Ltd.] were added to obtain a paste plate surface cleaning agent of the present invention having a viscosity of 80 poise.

Example 2 Water phase Pure water 345 parts Phosphoric acid 30 parts Diammonium phosphate 40 parts Citric acid 30 parts Cream dextrin # 5 50 parts Glycerin 45 parts 1,2-Butylene glycol 45 parts Oil phase Hysol 150 250 parts Ionette S-85 20 parts Nicole BC30TX 12 parts Perex OT-P 5 parts In the same manner as in Example 1, an aqueous phase and an oil phase having the above formulations were prepared. Next, after emulsifying the aqueous phase and the oil phase with a homomixer, 200 parts of diatomaceous earth and 80 parts of Tokseal N were added while stirring the feathers to obtain a plate surface cleaning agent of the present invention having a viscosity of 80 poise.

Use Example 1 A positive PS plate [FPS plate, naphthoquinone diazide type, manufactured by Fuji Photo Film Co., Ltd.] was exposed using a halftone dot positive film, and a positive plate developer DP-4 [Fuji Photo Film Co., Ltd.] was used. )) Was developed with an 8-fold diluted aqueous solution, and then washed with water,
Dried. The plate surface is divided into four equal parts, and the following (a) to (d)
By carrying out the treatment shown in (1), a test plate having background stains and defective ink deposition was obtained.

(B) Without application of gum, it was left to stand in a dryer at 100 ° C. for a whole day and night to examine air-oxidation stains.

(B) Rubberized puff dry, and then 100
The scratches were scratched with an iron brush applied with g, 200 g, and 300 g, and left in the atmosphere for 5 days to check for scratch marks.

(C) 1 g of a mixture of stearic acid and oleic acid was dissolved in 10 g of kerosene, dipped in a waste cloth, puff dried, and allowed to stand for 2 days to examine oil stains.

(D) For comparison, ordinary gum coating and puff drying were carried out after plate making.

The test plate thus obtained was treated with the plate surface cleaning agent obtained in Example 1, and the stain removability and the recoverability of ink inking defects were examined. That is, print 50 test plates with a Heidel KORD type printing machine, stop the printing machine once, wash the plate surface cleaning agent of Example 1 with water, attach it to a squeezed sponge and rub the plate surface with ink. Then 30
Surface treatment was performed for a second. Then, the plate surface was wiped with a cleanly washed sponge to clean and reprint. As a result, a normal printed matter can be obtained after 5 to 6 sheets,
Background stains and defective ink inking were resolved. Then, printing was performed on 30,000 sheets, but no stain was found, and defective ink inking did not occur, and a normal printed matter could be obtained. In addition, the halftone dots in the image area on the plate surface were compared, but the size of the halftone dots and the degree of abrasion did not differ from those of the normal plate (comparative plate) that was not treated with the detergent.

Use Example 2 A negative PS plate [FNS plate, a mixture of paraformaldehyde condensate of p-diazodiphenylamine and an acrylate copolymer containing a hydroxyethyl group, manufactured by Fuji Photo Film Co., Ltd.] was used as a halftone negative film. It was exposed to light, developed with a 2-fold diluted aqueous solution of an aqueous developer [DN-3C, manufactured by Fuji Photo Film Co., Ltd.], washed with water and dried. The surface of the plate was divided into four equal parts, and the treatments described in (a) to (d) above were carried out to obtain a test plate having background stains and defective ink deposition.

The test plate thus obtained was treated with the plate surface cleaning agent obtained in Example 2 to examine the stain removability and the recoverability of ink inking defects. That is, print 50 test plates with a Heidel KORD type printing machine, stop the printing machine once, wash the plate surface cleaning agent of Example 1 with water, attach it to a squeezed sponge and rub the plate surface with ink. Then 30
Surface treatment was performed for a second. Then, the plate surface was wiped with a cleanly washed sponge to clean and reprint. As a result, a normal printed matter was obtained 8 to 9 sheets after the start.
Background stains and defective ink inking were resolved. Then, printing was performed on 30,000 sheets, but no stain was found, and defective ink inking did not occur, and a normal printed matter could be obtained. In addition, the halftone dots in the image area on the plate surface were compared, but the size of the halftone dots and the degree of abrasion did not differ from those of the normal plate (comparative plate) that was not treated with the detergent.

Example 3 Aqueous phase Pure water 345 parts Phosphoric acid 25 parts Ammonium citrate 35 parts Pine dextrin # 2 [degraded dextrin, manufactured by Matsutani Chemical Co., Ltd.] 70 parts Arabic gum 10 parts Ethylene glycol 80 parts Oil phase shell SOL # 71 [boiling point 170-207 ° C, manufactured by Shell Petrochemical Co., Ltd.] 220 parts Ionet S-85 25 parts Nonipol 100 [polyethylene glycol nonyl phenyl ether, manufactured by Sanyo Kasei Co., Ltd.] 18 parts Lapizole B80 [dioctylsulfo amber Acid soda, manufactured by NOF CORPORATION] 12 parts In the same manner as in Example 1, an aqueous phase and an oil phase having the above formulations were prepared. Next, after emulsifying the aqueous phase and the oil phase with a homomixer, laponite RD [synthetic hectorite, synthetic clay-based thixotropic gelling agent, Nihon Silica Industry Co., Ltd., with stirring the feathers.
90 parts and Suzolite Mica 325-HK [average particle size 65 μ, Marietta Resource, USA]
s International Co., Ltd.] 80 parts to obtain a plate surface cleaning agent of the present invention having a viscosity of 120 poise.

Example 4 Water phase Pure water 345 parts Dequest [Aminotrimethylene phosphonic acid, manufactured by Nippon Monsanto Co., Ltd.] 35 parts Potassium nitrate 30 parts Metroze SM-15 [water-soluble methyl cellulose, manufactured by Shin-Etsu Chemical Co., Ltd.] ] 30 parts Pine Dextrin # 2 40 parts Arabic gum 20 parts Sorbitol 80 parts Oil phase LA solvent [boiling point 150-210 ° C, manufactured by Nippon Oil Co., Ltd.] 200 parts Paru 2520 [polyethylene oxide stearyl ether, Marubishi Yuka Kogyo Co., Ltd.] Co., Ltd.] 25 parts Ionet S-85 25 parts Tamanor 510 [alkylphenol resin, Arakawa Chemical Co., Ltd.] 15 parts In the same manner as in Example 1, an aqueous phase and an oil phase having the above formulations were prepared. Next, after emulsifying the water phase and the oil phase with a homomixer, 130 parts of diatomaceous earth and Fineseal T-32 were stirred with the feathers.
[Synthetic amorphous silica, average particle size of about 4μ, Tokuyama Soda Co., Ltd.
[Production] 110 parts was added to obtain a plate surface cleaning agent of the present invention having a viscosity of 80 poise.

Example 5 Water phase Pure water 345 parts Polyphosphoric acid 20 parts Concentrated sulfuric acid 15 parts Sodium borate 30 parts PVA GL05 [Polyvinyl alcohol, manufactured by Kuraray Co., Ltd.] 30 parts 30% Arabic gum 50 parts Butylene glycol 80 parts Oil phase Isopropylbenzene 80 parts EXSOL D 100 [manufactured by Exxon Chemical Co., Ltd.] 120 parts Emazole L-130 [polyethylene oxide sorbitan monolaurate, manufactured by Kao Atlas Co., Ltd.] 15 parts Ionet S-85 25 parts Styrene resin [formaldehyde condensate] 15 parts As in Example 1, an aqueous phase and an oil phase having the above formulations were prepared. Next, the aqueous phase and the oil phase were emulsified with a homomixer, and then 200 parts of Tokseal N was added while stirring the feathers to obtain a plate surface cleaning agent of the present invention having a viscosity of 40 poise.

Example 6 Water Phase Pure Water 345 parts Monopotassium Phosphate 30 parts Diammonium Phosphate 20 parts Cream Dextrin # 5 40 parts Sodium Alginate 25 parts 30% Gum Arabic 50 parts Ethylene Glycol 80 parts Oil Phase No. 3 Solvent [ Boiling point 255-287 ° C, petroleum solvent, manufactured by Nippon Oil Co., Ltd.] 200 parts Dioctyl phthalate 15 parts Stearic acid 10 parts Noniolite S-100 [polyethylene glycol stearate, manufactured by Kyoeisha Oil and Fat Chemical Co., Ltd.] 15 parts Ionette S- 85 27 parts Solvalite S-80 [sodium dialkylmaleate sulfonate, manufactured by Kyoeisha Oil and Fat Chemical Co., Ltd.] 5 parts In the same manner as in Example 1, an aqueous phase and an oil phase having the above-described formulations were prepared. Next, after emulsifying the aqueous phase and the oil phase with a homomixer, 200 parts of Tokseal N and 150 parts of diatomaceous earth were added while stirring the feathers to obtain a plate surface cleaning agent of the present invention having a viscosity of 110 poise.

Example 7 Aqueous phase Pure water 300 parts Polyphosphoric acid 20 parts Phosphoric acid 10 parts Sodium borate 30 parts PVA GL0 25% aqueous solution [polyvinyl alcohol, Kuraray Co., Ltd.] 60 parts Butylene glycol 80 parts Oil phase isopropylbenzene 100 parts EXSOL D 100 100 parts Emazole L-130 15 parts Ionet S-85 25 parts Styrene resin [formaldehyde condensate] 15 parts In the same manner as in Example 1, an aqueous phase and an oil phase having the above formulations were prepared. Next, the aqueous phase and the oil phase were emulsified with a homomixer, and then 200 parts of Tokseal N was added while stirring the feathers to obtain a plate surface cleaning agent of the present invention having a viscosity of 50 poise.

Example 8 Water phase Pure water 345 parts Monopotassium phosphate 30 parts Phosphoric acid 15 parts Cream Dextrin # 5 40 parts Sodium alginate 5% aqueous solution 25 parts Tripropylene glycol 60 parts Oil phase Solvesso 150 [boiling point 180-217 ° C] Exxon Chemical Co., Ltd.] 100 parts Alkylbenzene 100 parts Dibutyl phthalate 20 parts Isopropyl stearate 10 parts Polyhydroxystyrene 20 parts Ionet S-85 25 parts BHT Swanox [2,6-di-t-butyl-4-methylphenol] Manufactured by Seiko Chemical Co., Ltd.] 4 parts In the same manner as in Example 1, an aqueous phase and an oil phase having the above formulations were prepared. Next, the aqueous phase and the oil phase were emulsified with a homomixer, and 250 parts of Tokusil N was added while stirring the blades to obtain a plate surface cleaning agent of the present invention having a viscosity of 90 poise.

Comparative Example Water phase Pure water 665 parts Gum arabic [14 ° Baume aqueous solution] 150 parts Potassium nitrate 10 parts Phosphoric acid 15 parts Sodium hexametaphosphate 20 parts Oil phase EXSOL D 100 160 parts Emulgen # 404 [polyoxyethylene oleyl ether, Kao Atlas Co., Ltd.] 10 parts Emulgen # 911 [polyoxyethylene nonyl phenyl ether, Kao Atlas Co., Ltd.] 30 parts Oleic acid monoglyceride 5 parts Hercoline D [hydrogenated rosin ester, Arakawa Chemical Co., Ltd.] 3 Parts While mixing the oil phase which was heated and dissolved at 80 ° C. into the aqueous phase of the above formulation and mixing and emulsifying with a homomixer, a plate surface cleaning agent was obtained.

Test Example 1 The present invention product in which a plate or a wide-mouth container was filled with the plate surface cleaning agent of Examples 1 to 8 and a comparative product in which a plate surface cleaning agent of Comparative Example was filled in a bottle were mounted on a printing machine. On the plate, a washing treatment operation was performed using a sponge that had been washed once with water, and the operability was examined.

(1) Frequency of opening / closing container cap In the products of the present invention of Examples 1 to 8, they were only opened once in the morning and then closed at the end of the work. However, in the comparison product, there is a risk of spilling. From morning, it was necessary to open and close each time the plate was processed.

(2) Detachability of Detergent In the products (tubes) of the present invention of Examples 1 to 8, by extruding from the tube, the entire amount could be reliably separated with a sponge. In the products of the present invention (wide-mouthed containers) of Examples 1 to 8, the required amount could be reliably collected by pressing the sponge against the detergent from above. On the other hand, in the comparative product, while tilting the bottle carefully to hang it on the sponge to take the required amount,
If care is not taken, there will be inconvenience that more than necessary amount will be dripped and overflow from the sponge and be spilled around the printing machine or on the plate.

Test Example 2 After applying the plate surface cleaning agents of Examples 1 to 8 and the comparative plate surface cleaning agent onto the sponge, the sponge surface was turned over,
The degree of sagging of the cleaning agent was examined with the sponge surface with the cleaning agent facing downward. Although the plate surface cleaning agents of Examples 1 to 8 were completely adhered to the sponge, the plate surface cleaning agent of the comparative example dropped and soiled the periphery of the printing machine and the plate.

Claims (3)

[Claims] 1. A composition obtained by emulsifying an oil phase containing an organic solvent and an aqueous phase containing a water-soluble organic polymer compound and an acid with a surfactant, and having a thixotropic average particle size of 0. A lithographic printing paste plate surface cleaning agent, characterized in that a fine powder of 01 to 15 µ is blended. 2. The cleaning agent according to claim 1, further comprising an insoluble powder having polishing ability. 3. The cleaning agent according to claim 1, having a viscosity in the range of 20 to 1,000 poise.