WO2020162224A1

WO2020162224A1 - Detergent for printing machines

Info

Publication number: WO2020162224A1
Application number: PCT/JP2020/002498
Authority: WO
Inventors: 加瀬裕貴; 藤丸浩一; 井上武治郎
Original assignee: 東レ株式会社
Priority date: 2019-02-04
Filing date: 2020-01-24
Publication date: 2020-08-13
Also published as: CN113382871B; EP3922464A1; CN113382871A; EP3922464A4; JP7413994B2; JPWO2020162224A1

Abstract

The present invention provides a detergent for printing machines, said detergent containing at least water and a compound that contains an amino group and a carboxyl group, and having a pH of 8.0 to 13.0, inclusive.　With this detergent for printing machines, it is easy to remove ink from the rollers of printing machines and efficiently clean the rollers. The present invention makes it possible to obtain a detergent for printing machines which generates minimal amounts of volatile organic compounds (VOC). This detergent for printing machines is safe and causes minimal environmental pollution. The present invention also provides a method for cleaning active energy beam-curable ink using a detergent for printing machines, said detergent containing at least water and a compound that contains an amino group and a carboxyl group, and having a pH of 8.0 to 13.0, inclusive.　This method for cleaning active energy beam-curable ink facilitates installation to printing equipment, is safe, and causes minimal environmental pollution.

Description

Cleaning agent for printing machine

The present invention relates to a cleaning agent for a printing machine. Furthermore, the present invention relates to a method for cleaning an active energy ray curable ink.

Efforts to significantly reduce the use of volatile petroleum solvents in various printing fields and to reduce the emission of volatile organic compounds (hereinafter referred to as VOCs) in order to prevent environmental deterioration in recent years and improve the working environment. Is in progress. Since a large amount of petroleum-based solvent is used for ink for general printing machines, it is desired to make the ink aqueous and solvent-free. Among them, the active energy ray curable ink that can be instantly cured by irradiating with active energy rays such as ultraviolet rays is easy to install printing equipment, safe, less environmental pollution, and high in productivity. , Is widely used in many fields. Patent Document 1 discloses a lithographic printing detergent composition containing a glycol solvent as a main component, which is capable of washing active energy ray-curable ink. Further, Patent Document 2 discloses a cleaning agent for water-based ink that can be used for gravure and flexographic printing. However, the cleaning agents described in

Patent Documents

1 and 2 contain a solvent having carcinogenicity and flammability, have high volatility, and may deteriorate the global environment, work environment, and safety and health, so improvements are required. Was needed.

JP, 2017-94663, A JP, 2003-301197, A

The object of the present invention is to provide a cleaning agent for a printing press, which has excellent cleaning properties and produces a small amount of VOCs.

Furthermore, an object of the present invention is to provide a method for cleaning active energy ray curable ink that is safe and has little environmental pollution.

In order to solve the above problems, the cleaning agent for a printing machine of the present invention contains at least water and a compound containing an amino group and a carboxyl group, and has a pH of 8.0 or more and 13.0 or less. Is.

Furthermore, the present invention cleans an active energy ray-curable ink using a cleaning agent for a printing machine, which contains at least water and a compound containing an amino group and a carboxyl group and has a pH of 8.0 or more and 13.0 or less. Is the way to do it.

The cleaning agent for a printing machine of the present invention can easily remove ink from the roller of the printing machine, and can efficiently clean the roller. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain a cleaning agent for a printing press that produces a small amount of VOC (volatile organic compound). The cleaning agent for a printing press of the present invention is safe and has little environmental pollution. ‥

According to the method of cleaning the active energy ray-curable ink of the present invention, the installation of printing equipment is easy, it is safe, and there is little environmental pollution.

In the present invention, it is a cross-sectional view of an apparatus for testing the washability of ink.

The present invention will be described in detail below.

The present invention is a cleaning agent for a printing press, which contains at least water and a compound containing an amino group and a carboxyl group and has a pH of 8.0 or more and 13.0 or less.

The cleaning agent for a printing machine of the present invention has a pH of 8.0 or higher, preferably 10.0 or higher. When the pH is 8.0 or higher, the detergency is strong. The cleaning agent for a printing machine of the present invention has a pH of 13.0 or less, preferably 12.0 or less. When the pH is 13.0 or less, it is easy to handle.

As the compound containing an amino group and a carboxyl group contained in the detergent for a printing machine of the present invention, preferably, an amphoteric surfactant or a commonly used amino acid can be used.

Examples of the amphoteric surfactant include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine and the like. Of these, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine is particularly preferable because it can adjust the pH of the cleaning agent to 8.0 or more by itself.

Examples of amino acids include glycine, alanine, valine, leucine, isoleucine, methionine, proline, phenylalanine, tryptophan, serine, threonine, asparagine, glutamine, arginine, histidine, lysine, aspartic acid, glutamic acid, tyrosine, and cysteine. These amino acids can be used in the L-form or D-form, and the hydrochloride salt can also be used. In addition, these amino acids can be used alone or in admixture of two or more. Since the pH of the detergent can be adjusted to 8.0 or more and 13.0 or less, a basic amino acid is preferable as the compound containing an amino group and a carboxyl group. Basic amino acids include arginine, lysine and histidine.

Amino acid has high solubility in water because it contains amino and carboxyl groups. Of these, arginine is preferable because it is easy to adjust the pH independently to 8.0 or more and 13.0 or less. When arginine is contained in the cleaning liquid, it is most preferable because it is more excellent in cleaning property and the amount of VOC generated is small. L-arginine is particularly preferable because it is easily available.

According to US EPA (Environmental Protection Agency) Method 24, the residual mass when heated at 110°C ± 5°C for 1 hour is less than 99%, and the compound containing carbon atoms is VOC (volatile organic compound). Is defined as The cleaning agent for a printing press of the present invention preferably has a weight loss rate of less than 1% when heated at 1 atmosphere of 110° C. for 1 hour, and more preferably 0.5% or less. The smaller the weight reduction rate, the smaller the VOC emissions. Therefore, it is possible to obtain a cleaning agent for a printing machine, which has less influence on the human body and is excellent in global environment, working environment, and safety and health. As a device used for heating the cleaning agent for a printing press, a conventionally known device may be used, and for example, a hot air drying oven SPHH-200 (manufactured by TABAI Co., Ltd.) can be used.

The cleaning agent for a printing press of the present invention can measure the amount of VOC emission by a photoionization detector (PID). The VOC emission amount measured by MiniRAE 3000 (manufactured by Honeywell) of the cleaning agent of the present invention is preferably 100 ppm or less, more preferably 50 ppm or less, most preferably 10 ppm or less. ..

The pH of the cleaning agent for a printing machine of the present invention may be adjusted to pH 8.0 or more and 13.0 or less with only a compound containing an amino group and a carboxyl group, or a compound containing an amino group and a carboxyl group and an inorganic base may be used. In combination, the pH may be adjusted to 8.0 or more and 13.0 or less. In addition, a surfactant other than an amphoteric surfactant may be used in combination with an inorganic base to adjust the pH to 8.0 or more and 13.0 or less.

In the present invention, an inorganic base can be added for the purpose of adjusting the pH of the cleaning agent for a printing machine. An inorganic base is preferably used because it has a high boiling point and does not generate VOC. Specific examples of the inorganic base include lithium carbonate, sodium carbonate, alkali metal carbonates such as potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, alkali metal bicarbonates such as potassium hydrogen carbonate, disodium hydrogen phosphate, and the like. Examples thereof include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, tetramethylammonium hydroxide and tetraethylammonium hydroxide. These may be used alone or in combination of two or more. May be.

From the viewpoint of obtaining sufficient detergency, the content of the compound containing an amino group and a carboxyl group is preferably 0.010 mass% or more, and 1.0 mass% when the total amount of the cleaning agent for a printing machine is 100 mass %. % Or more is more preferable. The content of the compound containing an amino group and a carboxyl group is preferably 20.0% by mass or less and 10.0% by mass or less from the viewpoint of the solubility of the compound containing an amino group and a carboxyl group in water. It is more preferably 5.0% by mass or less.

In the detergent for a printing press according to the present invention, an amino acid is preferably used as a compound containing an amino group and a carboxyl group. From the viewpoint of obtaining sufficient detergency, the content of the amino acid is preferably 0.010% by mass or more, and more preferably 1.0% by mass or more in 100% by mass of the cleaning agent for a printing machine. From the viewpoint of solubility of amino acids in water, the content of amino acids is preferably 20.0% by mass or less, more preferably 10.0% by mass or less, and further preferably 5.0% by mass or less. The amino acid content is more preferably 0.010 mass% or more and 20.0 mass% or less.

The content of a compound containing an amino group and a carboxyl group contained in the cleaning agent for a printing machine can be easily measured by GC-MS. The content of compounds containing amino groups and carboxyl groups contained in the cleaning agent for printing machines was measured by dissolving the sample in water to 1.0 mass% and using it for GC-MS (EI, CI) measurement. can do. Similarly, the amino acid content can be easily measured by GC-MS.

The cleaning agent for a printing press according to the present invention may optionally contain an anionic surfactant or a cationic surfactant. Further, the cleaning agent for a printing press according to the present invention may contain a surfactant other than the amphoteric surfactant. Further, the cleaning agent for a printing machine according to the present invention may contain a nonionic surfactant. By including these surfactants, the wettability to the surface of the doctor blade made of resin is improved and the scraping property of the solution is improved, which is preferable.

Examples of the anionic surfactant include fatty acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkylsulfosuccinates, polyoxyethylene alkylsulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salts, N- Examples thereof include alkylsulfosuccinic acid monoamide disodium salt, polyoxyethylene alkyl ether sulfate ester salt, fatty acid monoglyceride sulfate ester salt, alkyl phosphate ester salt, and polyoxyethylene alkyl ether phosphate ester salt.

Examples of cationic surfactants include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, polyethylene polyamine derivatives and the like.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene polyoxypropylene block Polymers, glycerin fatty acid partial esterification products, sorbitan fatty acid partial esterification products, pentaerythritol fatty acid partial esterification products, propylene glycol monofatty acid esters, sucrose fatty acid partial esterification products, polyoxyethylene sorbitan fatty acid partial esterification products, Polyoxyethylene sorbitol fatty acid partial esterification products, polyethylene glycol fatty acid ester esters, polyglycerin fatty acid partial esterification products, polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esterification products, fatty acid diethanolamides, N, N- Examples thereof include bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters and trialkylamine oxides.

A cleaning liquid containing a nonionic surfactant is preferable because the ink can be easily scraped off by a doctor blade and the amount of VOC generated is small. Among the nonionic surfactants, a cleaning liquid containing polyoxyethylene sorbitan fatty acid partial esterified products is more preferable because the ink can be easily scraped off by a doctor blade and the amount of VOC generated is small.

HLB (hydrophilic-lipophilic balance <Hydrophilic-Lypophilic Balance>) of the nonionic surfactant is preferably 10 or more, more preferably 12 or more, from the viewpoint of solubility in water. It is preferably 13 or more. From the viewpoint of the solubility of the ink, HLB is preferably 20 or less, more preferably 19 or less, and further preferably 18 or less. The HLB of the nonionic surfactant is even more preferably 10 or more and 20 or less. Here, HLB represents the molecular weight of the hydrophilic group portion in the total molecular weight of the surfactant, and for the nonionic surfactant, the following Griffin formula HLB=20×(surfactant (Molecular weight of hydrophilic group in molecule/Molecular weight of surfactant)
Is required by.

In the cleaning agent for a printing machine of the present invention, the hydrophilic group of the nonionic surfactant is preferably an ethylene oxide group from the viewpoint of facilitating removal of the remaining cleaning agent with water after cleaning the ink. .. Further, it is preferable that the nonionic surfactant has an ethylene oxide group. Specifically, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene polyoxypropylene block polymers, polyoxyethylene polyoxypropylene block polymers, Oxyethylene sorbitan fatty acid partial esterification products, polyoxyethylene sorbitol fatty acid partial esterification products, polyethylene glycol fatty acid esters, polyoxyethylene-ized castor oil, polyoxyethylene glycerin fatty acid partial esterification products, polyoxyethylene alkylamines, etc. Can be mentioned. Polyoxyethylene sorbitan monolaurate is most preferable because it has high solubility in ink, high rinseability in water, and does not correspond to GHS described later.

The average added mole number of ethylene oxide groups is preferably 2 or more, more preferably 4 or more, and further preferably 5 or more. From the viewpoint of handleability and prevention of precipitation of the surfactant, the average added mole number of ethylene oxide groups is 50 or less, preferably 40 or less, and more preferably 30 or less.

The content of the nonionic surfactant is preferably 5% by mass or more, and more preferably 10% by mass, from the viewpoint that the ink and the cleaning agent for a printing machine can be easily scraped off by a doctor blade. It is above, and more preferably 15% by mass or more. From the viewpoint of removing the ink with a small amount of detergent, it is preferably 40% by mass or less, more preferably 30% by mass or less, and further preferably 25% by mass or less. The content of the nonionic surfactant is even more preferably 5% by mass or more and 40% by mass or less.

Since printing is performed in the range of 10°C to 30°C during normal offset printing, the cleaning agent for a printing machine of the present invention is preferably liquid at 10°C to 30°C. It is preferable that the surfactant is also a liquid in the range of 10°C to 30°C because it facilitates rinsing and washing with water.

In the cleaning agent for a printing press of the present invention, the content of water is preferably 40% by mass or more, and more preferably 60% by mass or more from the viewpoint of suppressing the amount of VOC generation. From the viewpoint of ink solubility, the water content is preferably 99.99 mass% or less. The cleaning agent for a printing press of the present invention more preferably has a water content of 40 mass% or more and 99.99 mass% or less.

The cleaning agent for a printing machine of the present invention can be used in an automatic roller cleaning machine. Here, the viscosity of the cleaning agent for a printing machine refers to a viscosity measured 1 minute after the start of stirring using a Brookfield type B type digital viscometer at a liquid temperature of 25° C. according to JISK7117-1:1999. The viscosity of the cleaning agent for a printing machine is preferably 1.0 mPa·s or more, and more preferably 5.0 mPa·s or more, from the viewpoint of preventing dripping when using an automatic roller washer. From the viewpoint of facilitating washing with an automatic washing machine, the viscosity of the cleaning agent for a printing machine is preferably 200 mPa·s or less, more preferably 150 mPa·s or less. The cleaning agent for a printing press of the present invention preferably has a viscosity at 25° C. of 1.0 mPa·s to 200 mPa·s.

For the cleaning agent for a printing press of the present invention, it is preferable to use a raw material that does not fall under Globally Hramonized System of Classification and Labeling of Chemicals (hereinafter referred to as “GHS”). Here, GHS is defined as "a globally unified rule in which the contents of classification standards and labels and safety data sheets are harmonized for each hazard (hazard) of a chemical product". The GHS stipulates that "the pictograms that visually show the characteristics of hazards as a means of transmitting information and pictograms regarding incentives when handling are used" are used. From the description, it is possible to determine the non-adequacy of GHS.

ㆍChemical products corresponding to GHS are labeled with hazard classification. Here, the hazard category refers to the category of judgment criteria within each hazard class. Each category is indicated by a number, and the smaller the number, the higher the risk. These categories are relatively classified according to the intensity of hazard within the hazard class.

The cleaning agent for a printing press of the present invention can be used for cleaning the ink adhering to various members of the printing press, and is particularly preferably used for cleaning the blast drying ink and the active energy ray-curing ink.

The cleaning method using the cleaning agent for a printing machine of the present invention is a method in which flexographic printing, a plate and a roller during lithographic printing operation, an ink attached to a blanket, an impression cylinder, and the cleaning agent for a printing machine of the present invention are in contact with each other. The cleaning process is performed. For example, at the time of printing work, the cleaning agent may be soaked directly into a piece of cloth to wipe off the ink adhering to the flexo, plate and printing machine during lithographic printing work, or a dedicated plate cleaning machine or automatic roller cleaning machine. It can also be used as a cleaning agent for automatic blanket cleaning machines. The cleaning method using the cleaning agent for a printing machine of the present invention preferably further includes a step of further cleaning with water thereafter.

The cleaning agent for a printing machine of the present invention is preferably used for cleaning active energy ray-curable ink. It is more preferable to use the cleaning agent for a printing press of the present invention in an active energy ray-curable ink containing a polyfunctional (meth)acrylate having a hydroxyl group. Since the active energy ray-curable ink has a high ink polarity, it has high solubility in the cleaning agent according to the present invention, and good cleaning properties can be obtained.

Specific preferred examples of the polyfunctional (meth)acrylate having a hydroxyl group include poly(meth)acrylates of polyhydric alcohols such as trimethylolpropane, glycerin, pentaerythritol, diglycerin, ditrimethylolpropane and dipentaerythritol, and these. The alkylene oxide adduct of

Further, the cleaning agent for a printing machine of the present invention is preferably used for an active energy ray curable ink containing a resin having a hydrophilic group. Since the ink has high polarity, it has high solubility in the cleaning agent for a printing machine of the present invention, and good cleaning properties can be obtained.

As the hydrophilic group of the resin having a hydrophilic group, polyethylene oxide group, hydroxyl group, carboxyl group, sulfo group, phosphoric acid group and the like can be mentioned. Of these, a carboxyl group is particularly preferable because it has good pigment dispersibility.

Specific examples of the resin having a hydrophilic group include acrylic resin, styrene acrylic resin, styrene maleic acid resin, rosin-modified maleic acid resin, rosin-modified acrylic resin, epoxy resin, polyester resin, polyurethane resin, and phenol resin. However, it is not particularly limited.

The acid value of the resin having a hydrophilic group is preferably 30 mgKOH/g or more and 250 mgKOH/g or less. The acid value of the resin having a hydrophilic group is preferably 30 mgKOH/g or more, more preferably 60 mgKOH/g or more, and 75 mgKOH/g in order to obtain good solubility of the resin in the cleaning agent for a printing machine. It is more preferably g or more. Further, it is preferably 250 mgKOH/g or less, more preferably 230 mgKOH/g or less, and further preferably 210 mgKOH/g or less from the viewpoint of ink handling property. Even more preferably, the acid value of the resin contained in the active energy ray-curable ink is 30 mgKOH/g or more and 250 mgKOH/g or less.

The acid value of the resin having a hydrophilic group is JIS K:0070: 1992 "Test method for acid value, saponification value, ester value, iodine value, hydroxyl value and saponification value of chemical product", "3.1. It can be determined in accordance with the "neutralization titration method". ‥

The cleaning agent for a printing press of the present invention is preferably a cleaning agent for a lithographic printing machine.

The method for washing the active energy ray-curable ink of the present invention uses a cleaning agent for a printing press containing at least water and a compound containing an amino group and a carboxyl group and having a pH of 8.0 or more and 13.0 or less. Then, the active energy ray curable ink is washed. The method for cleaning the active energy ray-curable ink of the present invention preferably uses a cleaning agent for a printing press containing at least water and an amino acid and having a pH of 8.0 or more and 13.0 or less. Wash the energy ray curable ink. The method for cleaning the active energy ray-curable ink of the present invention more preferably uses a cleaning agent for a printing machine, which contains at least water and a basic amino acid and has a pH of 8.0 or more and 13.0 or less. Then, the active energy ray curable ink is washed.

In the method for cleaning the active energy ray-curable ink of the present invention, the cleaning time is more preferably 10 minutes or less. The cleaning time was measured by starting the measurement when the doctor blade came into contact with the roller and visually measuring the time until it was determined that the ink and the cleaning agent for the printing machine could be completely removed.

In lithographic printing roller cleaning, it is preferable to perform cleaning by scraping a solution obtained by dissolving the ink applied on the roller with a cleaning agent using a resin doctor blade.

Since the doctor blade is a consumable item, a doctor blade made of thermoplastic resin that can be manufactured at low cost is preferably used. Further, from the viewpoint of not damaging the roller surface, a doctor blade made of a thermoplastic resin is preferable. As the thermoplastic resin, polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester such as polyethylene naphthalate (PEN), polypropylene (PP), polyamide (PA), polycarbonate (PC), poly Ether imide (PEI), polyether ether ketone (PEEK), polyether ketone (PEK), polyether sulfone (PES), polyimide (PI), polyacetal (POM), polyphenylene sulfide (PPS), polystyrene (PS), Examples include polyurethane (PU). Among these, at least one selected from the group consisting of polyethylene (PE), polyester, and polyacetal (POM) is preferably used from the viewpoints of abrasion resistance and adhesion to the roller in the width direction.

From the viewpoint of facilitating the scraping of the ink and the cleaning agent for a printing machine with a doctor blade, the contact angle of the doctor blade surface with water is preferably 50 degrees or less. When the contact angle is 50 degrees or less, the wettability of the ink cleaning liquid with respect to the blade surface is improved, which facilitates the flow into the cleaning tank on the downstream side of the blade. Further, from the viewpoint that the cleaning time can be shortened, the contact angle of the doctor blade surface with water is preferably 40 degrees or less, and more preferably 20 degrees or less. Examples of the method for setting the contact angle with water to 50 degrees or less include hydrophilic resin coating treatment, ultraviolet irradiation treatment, flame treatment, corona discharge treatment, and plasma treatment. From the viewpoint that the surface treatment can be made uniform, ultraviolet irradiation treatment, corona discharge treatment, and plasma treatment are preferable, and from the viewpoint of durability of the surface treatment, plasma treatment is more preferable.

In the present invention, the contact angle of the doctor blade surface with water is the glass substrate described in Japanese Industrial Standard JIS R3257: 1999 "Substrate glass surface wettability test method". As the gas for plasma treatment, which is the value measured by the static method, a known gas other than fluorine gas can be used. As the gas for plasma treatment, a gas containing oxygen gas can be preferably used. Thereby, a hydrophilic group such as a carboxyl group, a hydroxyl group, and a carbonyl group can be formed on the doctor blade surface. Further, it is more preferable to perform plasma treatment using only oxygen gas. More preferably, after forming fine irregularities on the doctor blade surface using a gas such as argon or helium, plasma treatment is performed with oxygen gas. This makes it possible to obtain a highly hydrophilic doctor blade.

In the method of washing the active energy ray-curable ink of the present invention, more preferably, the number of times the washing liquid is applied in lithographic printing is 10 times or less. In the washability evaluation in planographic printing, the presence or absence of the ink residue adhering to the ink roller was visually judged. 20 ml of the cleaning agent shown in Table 1 was applied on the roller at 1-minute intervals, and the number of times of application of the cleaning agent for a printing machine was once. ‥

In the method for cleaning the active energy ray-curable ink of the present invention, more preferably, in the evaluation of the cleaning property in flexographic printing, the number of times that all ink can be washed off is 2 or less. In the evaluation of detergency in flexographic printing, a waste cloth was impregnated with the detergent for a printing press described in Example, the resin plate was wiped, and the presence or absence of ink residue adhering to the resin plate was visually judged. The time of wiping from one end of the resin plate to the other end was set to one wiping.

Hereinafter, the present invention will be described in more detail with reference to Examples.

<Blow-drying lithographic printing ink production example>
<Resin varnish I>
Styrene maleic acid resin "Alaster" (registered trademark) 700 (manufactured by Arakawa Chemical Industries): 32% by mass
Solvent I Propylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.): 51.85% by mass
Solvent II Glycerin (manufactured by Wako Pure Chemical Industries, Ltd.): 6% by mass
Polyether polyamine I Diethanolamine (manufactured by Wako Pure Chemical Industries, Ltd.): 10% by mass
Polyether polyamine II "Jeffamine" (registered trademark) T403 (manufactured by Hunstman Corporation): 0.15% by mass
By heating and stirring the styrene maleic acid resin, the polyether polyamine I, the polyether polyamine II, the solvent I, and the solvent II, which are weighed in the above proportions, at 130° C. for 2 hours, and after cooling the styrene maleic acid resin, the mixture is cooled to room temperature Resin varnish I was obtained.

<Ink I>
Lionol Blue 7330 (manufactured by Toyo Ink Co., Ltd.): 20 parts by mass Resin varnish I: 75 parts by mass Solvent I Propylene glycol: 4 parts by mass PE wax: 1 part by mass The above mixture is weighed and a three-roll mill “EXAKT” (registered trademark) Using a M-80S (manufactured by EXAKT), the roller gap scale of the apparatus was kneaded 1 times to 3 times to obtain a blast drying type lithographic printing ink.

<Example of production of active energy ray-curable lithographic printing ink>
<Resin composition>
Resin I: 0.4 equivalent of glycidyl methacrylate (GMA) is added to the carboxyl group of a copolymer composed of 25% by mass of methyl methacrylate, 25% by mass of styrene and 50% by mass of methacrylic acid, Resin I having an ethylenically unsaturated group and a hydrophilic group was obtained. The obtained resin I had a weight average molecular weight of 34,000, an acid value of 102 mgKOH/g, and an iodine value of 2.0 mol/kg.

<Resin varnish II>
Resin I: 21.8% by mass
Polyfunctional (meth)acrylate I having a hydroxyl group I "Miramer" (registered trademark) M340 (manufactured by MIWON): 64% by mass
Polyfunctional (meth)acrylate II having a hydroxyl group "Miramer" (registered trademark) M4004 (manufactured by MIWON): 14% by mass
Polymerization inhibitor I p-methoxyphenol (manufactured by Wako Pure Chemical Industries, Ltd.): 0.2% by mass
The resin I and the polymerization inhibitor I were weighed in the above proportions and added to a mixed solvent of a polyfunctional (meth)acrylate I having a hydroxyl group and a polyfunctional (meth)acrylate II having a hydroxyl group, which was heated to 90° C. and stirred. Then, after the resin I was dissolved, the resin varnish II was obtained by cooling to room temperature.

<Ink II>
Seika cyanin blue (manufactured by Dainichiseika Co., Ltd.): 20% by mass
Resin I: 12 mass%
Polyfunctional (meth)acrylate I having a hydroxyl group: 24% by mass
Polyfunctional (meth)acrylate II having a hydroxyl group: 33% by mass
Photopolymerization initiator I: "Irgacure" (registered trademark) 907 (manufactured by BASF): 5% by mass
Sensitizer I: Diethylaminobenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.): 5% by mass
Polymerization inhibitor I: p-methoxyphenol (manufactured by Wako Pure Chemical Industries, Ltd.): 1% by mass
For the active energy ray-curing lithographic printing, the above mixture is weighed and the roller gap scale of the apparatus is kneaded 3 times by using a triple roll mill “EXAKT” (registered trademark) M-80S (manufactured by EXAKT). I got ink.

<Doctor blade>
Polyethylene (Ultra high molecular weight polyethylene, manufactured by Sakushin Kogyo Co., Ltd., Newlite (white) doctor blade)
Polyester ("Plastic Doctor" (registered trademark), HI-PE, manufactured by Fuji Shoko Co., Ltd.)
Polyacetal ("Plastic Doctor" (registered trademark), HI-POM, manufactured by Fuji Shoko Co., Ltd.).

<Hydrophilic treatment of doctor blade>
Hydrophilization treatment was performed by subjecting the doctor blade to plasma treatment under the following conditions.

1. Gas species: oxygen 2. Gas flow rate: 1000 sccm
3. Pressure: 20Pa
4. High frequency applied power: 1500W (frequency 13.56MHz)
5. Processing time: 2 minutes.

<Measurement of contact angle of water on doctor blade surface>
To measure the contact angle of the doctor blade surface with water, 3 μl of pure water at 25° C. and DMo-501 manufactured by Kyowa Interface Science Co., Ltd. were used as an apparatus. The contact angle was measured 30 seconds after pure water contacted the doctor blade surface.

<Measurement of pH>
For pH measurement, a pH meter F-52 (manufactured by Horiba Ltd.) was used, and the pH was measured according to JIS Z 8802:2011 at a liquid temperature of 25°C.

<Cleanability test>
<Flexographic printing>
A photosensitive resin plate (“TORELIEF” (registered trademark) DWF95DIII, manufactured by Toray Industries, Inc.) is mounted on a flexographic printing tester (Flexiproof 100, manufactured by PrintCoat Instruments), and the anilox roll uses 400 lines. did. Ink I was supplied and 500 sheets were printed on a PET (polyethylene terephthalate) film (“Novaclear” (registered trademark), thickness: 100 μm, manufactured by Mitsubishi Chemical Corporation). Thereafter, the waste was impregnated with the cleaning agent for a printing machine described in Example, the cylinder was wiped, and the cleaning property was visually evaluated.

<Lithographic printing>
A waterless planographic printing plate (TAN-E, manufactured by Toray Industries, Inc.) was mounted on an offset printing machine (Oliver 266EPZ, manufactured by Sakurai Graphic System Co., Ltd.). Ink I or Ink II was supplied so that the reflection density of the solid print portion would be 1.6 (indigo), and 500 sheets were printed. After that, 20 ml of the cleaning agent described in the example was applied onto the roller at 1-minute intervals, and the ink was dissolved using a doctor blade (Nulight doctor blade manufactured by Shinoda Shoji Co., Ltd., thickness: 27 mm) and for a printing machine. The cleaning agent was removed.

FIG. 1 shows a sectional view of an apparatus for testing the cleaning property of ink in the present invention. Put the ink in the ink fountain. The ink is transferred to the printing plate of the plate cylinder by the roller. The ink is collected with a doctor blade after being used for printing.

The measurement of the cleaning time was started when the doctor blade came into contact with the roller, and visually measured the time until it was judged that the ink and the cleaning agent for the printing machine could be completely removed. The washing time is preferably 10 minutes or less, and more preferably 5 minutes or less. It was judged that the cleaning agent which requires 20 minutes or more for the cleaning time cannot be cleaned.

<Evaluation of washability: flexographic printing>
The cleanability was judged according to the following criteria.
A: All ink was washed off with one wipe B: All ink was washed off with two wipes C: Ink residue remained after three or more wipes. The resin plate was wiped with a cloth containing the detergent for a printing machine described in the example, and the presence or absence of ink residue adhering to the resin plate was visually judged. The time of wiping from one end of the resin plate to the other end was set to one wiping.

<Evaluation of washability: planographic printing>
The cleanability was judged according to the following criteria.
A: Ink could be removed by applying the cleaning liquid 5 times or less B: Ink could be removed by cleaning liquid 6 times or more 10 times or less C: Cleaning liquid application 11 times or more Ink was able to be removed by 15 times or less. D: Ink residue remained even after applying the cleaning liquid 16 times or more. In the cleaning property evaluation in lithographic printing, the presence or absence of the ink residue adhering to the ink roller was confirmed. It was judged visually. 20 ml of the cleaning agent shown in Table 1 was applied on the roller at 1-minute intervals, and the number of times of application of the cleaning agent for printing machine was once.

<Measurement of VOC generation amount>
When performing the detergency test, the amount of VOCs generated was measured using a MiniRAE 3000 (manufactured by Honeywell) at a position 30 cm above the roller.

<Measurement of viscosity>
For the viscosity measurement, a B-type digital viscometer DV-E (manufactured by Brookfield Co., Ltd.) was used, and 1 minute after the stirring was started according to JISK7117-1:1999 at a liquid temperature of 25°C.

<Evaluation of Method 24>
3 g of a mixture obtained by weighing the other raw materials except the water content contained in the cleaning agent for a printing machine in a predetermined ratio was weighed in an aluminum cup and heated at 110° C. in a hot air drying oven SPHH-200 (manufactured by Tabai Co., Ltd.). The heating residue rate (weight after heating/weight before heating) after heating for 1 hour was measured. If the heating residue rate was 99% or more, it was determined that the cleaning agent for a printing machine was not VOC.

<Presence or absence of GHS mark>
The SDS of each raw material was confirmed, and the presence or absence of the GHS mark was investigated. SDS is an acronym for SAFETY DATA SHEEET "Safety Data Sheet". It is a chemical substance that a business entity delivers when it transfers or provides chemical substances and products containing chemical substances to other businesses. It is a document that describes hazard information. It was judged that raw materials that do not show the GHS mark are superior to the effects on the human body, the global environment, the work environment, and health and safety.

<Cleaning liquid components>
(Basic compound)
・Ethanolamine・Triethanolamine (amino acid)
・L-histidine (Kyowa Hakko Bio Co., Ltd.)
・Glycine (Kyowa Hakko Bio Co., Ltd.)
・L-proline (Kyowa Hakko Bio Co., Ltd.)
・L-alanine (Kyowa Hakko Bio Co., Ltd.)
・L-methionine (Kyowa Hakko Bio Co., Ltd.)
・L-Tyrosine (Kyowa Hakko Bio Co., Ltd.)
・L-Arginine (Kyowa Hakko Bio Co., Ltd.)
(Inorganic base)
・Potassium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.)
(Nonionic surfactant)
The following nonionic surfactants are all liquid in the range of 10°C to 30°C. The number in parentheses represents the average number of moles of ethylene oxide groups added.
・Polyoxyethylene (5) lauryl ether (manufactured by Kao Corporation)
・Polyoxyethylene (9) lauryl ether (manufactured by Kao Corporation)
・Polyoxyethylene (4) oleyl ether (manufactured by Kao Corporation)
・Polyoxyethylene (9) oleyl ether (manufactured by Kao Corporation)
-Polyoxyethylene (5) alkyl (sec-C11-15) ether (manufactured by Kao Corporation)
・Polyoxyethylene (9) alkyl (sec-C11-15) ether (manufactured by Kao Corporation)
・Polyoxyethylene (12) monolaurate (manufactured by Kao Corporation)
-Polyoxyethylene (10) monooleate (manufactured by Kao Corporation)
-Polyoxyethylene (30) sorbitol tetraoleate (manufactured by Kao Corporation)
・Polyoxyethylene (6) sorbitan monolaurate (manufactured by Kao Corporation)
・Polyoxyethylene (20) sorbitan monopalmitate (manufactured by Kao Corporation)
-Polyoxyethylene (20) sorbitan monolaurate (manufactured by Kao Corporation).

(Example 1)
The detergent composition shown in Table 1 was weighed and the mixture was stirred for 10 minutes to obtain a detergent for a printing machine. When pH was measured, a cleaning agent for a printing machine having a pH of 11.2 was obtained. When a cleaning property test was carried out using AkwaConte K (manufactured by Toyo Ink Co., Ltd.) by the flexographic printing method, the ink could be completely removed from the plate by wiping twice. When the VOC generation amount was measured, the generation amount was 50 ppm. When the GHS mark was confirmed from the SDS of each raw material, the following marks were confirmed for potassium hydroxide.
・Skin corrosion and irritation: Hazard category 2
・Serious eye damage/eye irritation: Hazard category 1
・Specific target organ toxicity (single exposure): Hazard category 2 (respiratory system)
When the method 24 was measured, the residual heating rate was 99.6 mass %, so it was judged that the cleaning agent for a printing machine of Example 1 was not VOC. When the viscosity was measured, it was 2 mPa·s, and it was judged that it could be used in an automatic roller washer.

(Examples 2, 3 and Comparative Example 1)
Each cleaning agent was evaluated in the same manner as in Example 1 except that the composition of the cleaning agent was changed to that shown in Table 1. The results are shown in Table 1.

(Example 4)
The detergent composition shown in Table 2 was weighed, and the mixture was stirred for 10 minutes to obtain a detergent for a printing machine. When pH was measured, a cleaning agent for a printing machine having a pH of 11.2 was obtained. When a detergency test was conducted using Ink I by the lithographic printing method, the ink could be completely removed from the roller within 10 minutes from the start of washing. It was 50 ppm when the VOC generation amount was measured. When the GHS mark was confirmed from the SDS of each raw material, the same mark as in Example 1 was confirmed for potassium hydroxide.

When the method 24 measurement was carried out, the heating residue rate was 99.6 mass %, so it was judged that the cleaning agent for the printing machine of Example 4 was not VOC. When the viscosity was measured, it was 2 mPa·s, and it was judged that it could be used in an automatic roller washer.

(Examples 5 to 8 and Comparative Examples 2 and 3)
The cleaning agent for each printing press was evaluated in the same manner as in Example 4 except that the cleaning agent composition was changed to that shown in Table 2. The results are shown in Table 2.

(Example 9)
The detergent composition shown in Table 3 was weighed and the mixture was stirred for 10 minutes to obtain a detergent for a printing machine. When pH was measured, a cleaning agent for a printing machine having a pH of 11.2 was obtained. When a detergency test was conducted using ink by the lithographic printing method, Ink II could be completely removed from the roller in 8 minutes from the start of washing. When the VOC generation amount was measured, the generation amount was less than 10 ppm. When the GHS mark was confirmed from the SDS of each raw material, the same mark as in Example 1 was confirmed for potassium hydroxide. When the method 24 was measured, the residual heating rate was 99.6 mass %, so it was judged that the cleaning agent for a printing machine of Example 9 was not VOC. When the viscosity was measured, it was 2 mPa·s, and it was judged that it could be used in an automatic roller washer.

(Examples 10 to 15 and Comparative Example 4)
Each cleaning agent was evaluated in the same manner as in Example 9 except that the composition of the cleaning agent was changed to that shown in Table 3. The results are shown in Table 3.

(Examples 16 to 20 and Comparative Examples 5 to 7)
Each cleaning agent was evaluated in the same manner as in Example 9 except that the composition of the cleaning agent was changed to that shown in Table 4. The results are shown in Table 4.

(Examples 21 to 33)
Each cleaning agent was evaluated in the same manner as in Example 9 except that the composition of the cleaning agent was changed to that shown in Table 5. The results are shown in Table 5.

(Examples 34 to 38)
Each cleaning agent was evaluated in the same manner as in Example 9 except that the composition of the cleaning agent was changed to that shown in Table 6. The results are shown in Table 6.

(Example 39)
The doctor blade of Example 35 was subjected to hydrophilic treatment under the conditions described in <Hydrophilic treatment of doctor blade> column (Fuji Shoko Co., Ltd., “Plastic Doctor” (registered trademark), HI). An ink cleaning test was performed in the same manner as in Example 9 except that the composition was changed to -PE). The results are shown in Table 7.

(Example 40)
The doctor blade of Example 35 was subjected to hydrophilic treatment under the conditions described in <Hydrophilic treatment of doctor blade> column ("Plastic Doctor" (registered trademark), HI manufactured by Fuji Shoko Co., Ltd.). An ink cleaning test was performed in the same manner as in Example 9 except that the composition was changed to -PE). The results are shown in Table 7.

(Example 41)
The doctor blade of Example 35 was subjected to hydrophilic treatment under the conditions described in <Hydrophilic treatment of doctor blade> column ("Plastic Doctor" (registered trademark), HI manufactured by Fuji Shoko Co., Ltd.). An ink cleaning test was performed in the same manner as in Example 9 except that the ink composition was changed to -POM). The results are shown in Table 7.

(Example 42)
As a treatment for making the doctor blade hydrophilic, a doctor blade of polyacetal (manufactured by Fuji Shoko Co., Ltd., "Plastic Doctor" (registered trademark), HI-POM) was prepared by changing the gas species from oxygen to argon. Using this doctor blade, an ink cleaning test was conducted in the same manner as in Example 9. The results are shown in Table 7.

(Example 43)
In addition to the hydrophilized doctor blade of Example 38, a blade was further prepared in which the gas species was changed to oxygen and the hydrophilization was performed. Using this doctor blade, an ink cleaning test was conducted in the same manner as in Example 9. The results are shown in Table 7.

As can be understood from the results of Tables 1 to 7, the detergent containing a compound containing an amino group and a carboxyl group and having a pH of 8.0 or more and 13.0 or less has excellent detergency and VOC emission in a short time. It was found to show the effect of quantity control.

The cleaning agent for a printing machine of the present invention can easily remove ink from the roller of the printing machine, and can make the roller efficient. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain a cleaning agent for a printing press that produces a small amount of VOC (volatile organic compound). The cleaning agent for a printing press of the present invention is safe and has little environmental pollution.

1. Ink fountain
2. Ink 3. Ink roller (resin or rubber material)
4. Metal roller 5. Plate cylinder 6. Printing edition 7. Cleaning agent application point 8. Doctor blade 9. Recovery ink

Claims

A cleaning agent for a printing press, which contains at least water and a compound containing an amino group and a carboxyl group and has a pH of 8.0 or more and 13.0 or less.
The cleaning agent for a printing press according to claim 1, wherein the compound is an amino acid.
The cleaning agent for a printing press according to claim 2, which contains 0.010% by mass or more and 20.0% by mass or less of an amino acid.
The cleaning agent for a printing press according to claim 2, wherein the amino acid is a basic amino acid.
The cleaning agent for a printing press according to any one of claims 2 to 4, wherein the amino acid is arginine.
The cleaning agent for a printing machine according to claim 1, wherein the cleaning agent for a printing machine has a viscosity at 25° C. of 1.0 mPa·s to 200 mPa·s.
The cleaning agent for a printing press according to any one of claims 1 to 6, further comprising a nonionic surfactant.
The cleaning agent for a printing press according to claim 7, wherein the nonionic surfactant has an HLB of 10 or more and 20 or less.
The cleaning agent for a printing press according to claim 7, wherein the nonionic surfactant has an ethylene oxide group.
The cleaning agent for a printing press according to any one of claims 7 to 9, wherein the content of the nonionic surfactant is 5% by mass or more and 40% by mass or less.
The cleaning agent for a printing press according to any one of claims 1 to 10, wherein a water content is 40% by mass or more and 99.99% by mass or less.
The cleaning agent for a printing machine according to any one of claims 1 to 11, which is used for cleaning an active energy ray-curable ink.
The cleaning agent for a printing machine according to claim 12, wherein the resin contained in the active energy ray-curable ink has an acid value of 30 mgKOH/g or more and 250 mgKOH/g or less.
The cleaning agent for a printing machine according to any one of claims 1 to 13, wherein the cleaning agent for a printing machine is a cleaning agent for a lithographic printing machine.
A method for cleaning an active energy ray-curable ink using the cleaning agent for a printing press according to any one of claims 1 to 14.
The method for cleaning active energy ray-curable ink using the cleaning agent for a printing press according to claim 15, wherein the cleaning time is 10 minutes or less.
The method for cleaning an active energy ray-curable ink according to claim 15 or 16, wherein the number of times the cleaning liquid is applied in lithographic printing is 10 or less.
The method for cleaning an active energy ray-curable ink according to claim 15 or 16, wherein the number of times that all inks can be washed off is 2 or less in the evaluation of cleaning property in flexographic printing.