Liquid for maintaining an ink coating apparatus, and method for maintaining an ink coating apparatus

Abstract

To provide an ink applicator maintenance fluid and an ink applicator maintenance method which can suppress the performance degradation of a rubber member in an ink channel even when ensuring adequate fluidity in the ink channel.SOLUTION: An ink applicator maintenance fluid for use in the maintenance of an ink applicator contains at least one compound selected from compounds represented by the general formulae (1) and (2): R1-(CO)x-(OR3)n-O-(CO)x-R2 (1) and R1OCO-R4-COOR1 (2). In the general formulae (1) and (2), R1 represents a C7-11 hydrocarbon group, R2 represents a hydrogen atom or a C7-11 hydrocarbon group, R3 represents a C3-6 hydrocarbon group, R4 represents a C2-4 hydrocarbon group, n represents an integer of 1-3, and x represents an integer of 0 or 1.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a liquid for maintaining an ink coating apparatus and a method for maintaining an ink coating apparatus.

Background Art

[0002] In recent years, for example, with the improvement of the image quality of printed matter, ink coating apparatuses tend to become more precise. In a highly precise ink coating apparatus, for example, the risk of failures caused by foreign substances such as aggregates generated in the ink mixing into the ink flow path is increasing. In order to maintain the cleanliness of the ink flow path in such an ink coating apparatus, a liquid for maintaining an ink coating apparatus is used. By performing maintenance such as cleaning the ink flow path using the liquid for maintaining an ink coating apparatus, it becomes possible to use the ink coating apparatus in a normal state. As components of the liquid for maintaining an ink coating apparatus, as disclosed in Patent Documents 1 to 4, polymerizable monomers, aromatic solvents, aliphatic hydrocarbon solvents, ester solvents, etc. are used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the ink coating apparatus maintenance liquid, by ensuring the fluidity in the ink flow path by blending low-viscosity components, for example, the cleanability of the ink flow path can be enhanced. However, in the ink coating apparatus maintenance liquid with ensured fluidity, the aggressiveness against the rubber members used in the ink flow path increases, which may reduce the performance of the rubber members. When the performance of the rubber members thus deteriorates, for example, there is a risk of causing a decrease in the sealing property of the ink flow path.

Means for Solving the Problems

[0005] In order to solve the above problems, in one aspect of the present invention, there is provided an ink coating apparatus maintenance liquid used for the maintenance of an ink coating apparatus, containing at least one compound selected from the compounds represented by the following general formulas (1) and (2).

[0006] R 1 -(CO) x -(OR 3 ) n -O-(CO) x -R 2 ···(1) R 1 OCO-R 4 -COOR 1 ···(2) In general formulas (1) and (2), R 1 represents a hydrocarbon group having 7 to 11 carbon atoms, R 2 represents a hydrogen atom or a hydrocarbon group having 7 to 11 carbon atoms, R 3 represents a hydrocarbon group having 3 to 6 carbon atoms, R 4 represents a hydrocarbon group having 2 to 4 carbon atoms, n represents an integer of 1 to 3, and x represents an integer of 0 or 1.

Advantages of the Invention

[0007] The present invention exhibits the effect of being able to suppress a decrease in the performance of the rubber members used in the ink flow path even when the fluidity in the ink flow path is ensured.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, an embodiment of a liquid for maintaining an ink coating apparatus and a method for maintaining an ink coating apparatus will be described. In the following, the liquid for maintaining an ink coating apparatus may be simply referred to as "maintenance liquid".

[0009] <Use of the Liquid for Maintaining an Ink Coating Apparatus> The liquid for maintaining an ink coating apparatus is used for maintaining an ink coating apparatus. The maintenance liquid is used for purposes such as cleaning an ink flow path and maintaining the constancy of the ink flow path. The maintenance liquid may flow through the ink flow path in the ink coating apparatus and its auxiliary equipment, or may be filled in the ink flow path for a certain period of time.

[0010] The ink coating apparatus has an ink flow path including each part of a storage part of ink, an application part of ink, a discharge part of ink, a connection part connecting the application part and the storage part, and a connection part connecting the application part and the discharge part. The storage part of ink may be arranged outside the ink coating apparatus. Further, the storage part of ink may have a connection part connected to the discharge part without passing through the application part. Further, the ink discharge part may be arranged outside the ink coating apparatus. The liquid for maintaining an ink coating apparatus may be used for cleaning a storage part arranged outside the ink coating apparatus and a connection part connecting this storage part and the ink coating apparatus. Further, the liquid for maintaining an ink coating apparatus may be used for cleaning a discharge part arranged outside the ink coating apparatus and a connection part connecting this discharge part and the ink coating apparatus.

[0011] Examples of the members constituting the ink flow path include a supply pipe, a supply pipe connection member, an ink cartridge, an ink reservoir tank, a waste liquid tray, a tank of a waste liquid storage part, a connection member to the tank, a valve sealing material, a tube pump (peristaltic pump), a diaphragm pump, a print head, a printing plate cylinder, an ink roller, a printing blanket, an ink chamber, an anilox roller, and the like.

[0012] The members constituting the ink flow path include rubber members. The type of the rubber member is not particularly limited. Examples of the rubber member include at least a part of the members constituting the ink flow path. The rubber member may be a seal member constituting the ink flow path. Examples of the seal member include gaskets, packings, O-rings, and the like. The rubber member may be an inner layer or an outer layer of the members constituting the ink flow path.

[0013] The rubber of the rubber member is a material having rubber elasticity or rubber-like elasticity at normal temperature, and is defined by, for example, JIS 6200(2008), JIS 6200(2019), etc. More specifically, the rubber refers to a substance that can be modified or is already in a state of being essentially insoluble (able to swell) in boiling solvents such as benzene, methyl ethyl ketone, or ethanol / toluene azeotropic mixture. The rubber, in the state of being modified and not containing a diluent, can double its length at room temperature (18°C to 29°C), and even if it is held for 1 minute before relaxation, it will contract to less than 1.5 times its original length within 1 minute. Also, the rubber has the property that it cannot be easily reshaped into a permanent shape even when heated and pressure are applied in the state of the modified rubber.

[0014] Examples of the rubber include natural rubber, isoprene rubber, chloroprene rubber, isobutylene isoprene rubber, nitrile butadiene rubber (nitrile rubber), ethylene propylene rubber, ethylene propylene diene rubber, styrene butadiene rubber, chlorosulfonated ethylene rubber, urethane rubber, polyester urethane rubber, polyether urethane rubber, silicone rubber, fluororubber, tetrafluoroethylene propylene rubber, perfluororubber, and the like.

[0015] Examples of the ink coating method of the ink coating device include an inkjet method, an offset method, a roll coater method, a flexo method, a gravure method, a silk screen method, a pad method, spray coating, and the like. The liquid for maintaining the ink coating device of the present embodiment can be suitably used for an inkjet type ink coating device.

[0016] <Components of the Ink Coating Apparatus Maintenance Liquid> The ink coating apparatus maintenance liquid contains at least one compound selected from the compounds represented by the following general formulas (1) and (2). The ink coating apparatus maintenance liquid preferably further contains at least one compound selected from the compounds represented by the following general formulas (3) and (4). The ink coating apparatus maintenance liquid preferably further contains a stabilizer.

[0017] <Compounds Represented by General Formulas (1) to (4)> The compounds represented by general formulas (1) and (2) are cleaning components. The maintenance liquid containing the cleaning components is filled into the ink flow path. By discharging the maintenance liquid filled in the ink flow path from the ink flow path, ink components, aggregates of ink components, volatile substances present in the ink flow path, etc. can be removed from the ink flow path.

[0018] R 1 -(CO) x -(OR 3 ) n -O-(CO) x -R 2 ···(1) R 1 OCO-R 4 -COOR 1 ···(2) In general formulas (1) and (2), R 1 represents a hydrocarbon group having 7 to 11 carbon atoms. This hydrocarbon group may be any of a linear, branched, and cyclic hydrocarbon group. The carbon number of R 1 is preferably 8 to 11, more preferably 8 to 10. When the carbon number of R 1 is 7 or more, the aggressiveness to the rubber member can be suppressed. When the carbon number of R 1 is 11 or less, the fluidity of the maintenance liquid can be enhanced. From the viewpoint of further suppressing the aggressiveness to the rubber member, R 1 preferably does not contain an unsaturated bond.

[0019] In general formula (1), R2 represents a hydrogen atom or a hydrocarbon group having 7 to 11 carbon atoms. This hydrocarbon group may be any of a linear, branched, and cyclic hydrocarbon group. R 2 Preferably has 8 to 10 carbon atoms, and more preferably 8 or 9 carbon atoms. R 2 By having 7 or more carbon atoms, the aggressiveness against the rubber member can be suppressed. R 2 By having 11 or less carbon atoms, the fluidity of the preservation liquid can be enhanced. R 2 Preferably does not contain an unsaturated bond from the viewpoint of further suppressing the aggressiveness against the rubber member.

[0020] In the general formula (1), R 3 represents a hydrocarbon group having 3 to 6 carbon atoms. R 3 By having 3 or more carbon atoms, the stability when the preservation liquid is mixed with the ink can be enhanced. Specifically, even when the preservation liquid is mixed with the ink at an arbitrary ratio in the ink flow path and left standing, the generation of gelation of the mixed liquid and turbidity caused by the generation of foreign substances can be suppressed. As a result, the cleanliness of the ink flow path is improved, and the constancy of the ink coating apparatus can be enhanced. R 3 By having 6 or less carbon atoms, the fluidity of the preservation liquid can be enhanced. R 3 The hydrocarbon group preferably does not contain an unsaturated bond from the viewpoint of further suppressing the aggressiveness against the rubber member, and more preferably is a linear or branched type that does not contain an unsaturated bond.

[0021] In the general formula (2), R 4 represents a hydrocarbon group having 2 to 4 carbon atoms. This hydrocarbon group is preferably linear or branched. R 4 Preferably does not contain an unsaturated bond from the viewpoint of further suppressing the aggressiveness against the rubber member.

[0022] In the general formula (1), n represents an integer of 1 to 3. In this case, the fluidity of the preservation liquid can be enhanced. In the general formula (1), x represents an integer of 0 or 1. In this case, the fluidity of the preservation liquid can be enhanced.

[0023] The compound represented by the general formula (1) can be used singly or in combination of two or more. The compound represented by the general formula (2) can be used singly or in combination of two or more. Examples of the compounds represented by the general formulas (1) and (2) include propylene glycol mono-2-ethylhexyl ether, dipropylene glycol mono-2-ethylhexyl ether, propylene glycol mono-2-ethylhexanoate, 3-(2-ethylhexyloxy)propionic acid, bis(2-ethylhexyl) succinate, diisononyl succinate, diisodecyl succinate, bis(2-ethylhexyl) glutarate, diisononyl glutarate, diisodecyl glutarate, diheptyl adipate, bis(2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, etc.

[0024] The content of the compounds represented by the general formulas (1) and (2) in the preservation liquid is preferably 30% by mass or more, more preferably 32.5% by mass or more, and still more preferably 35% by mass or more. By increasing the content of the compounds represented by the general formulas (1) and (2) in the preservation liquid, it becomes possible to further suppress the aggressiveness to the rubber member. The upper limit of the content of the compounds represented by the general formulas (1) and (2) in the preservation liquid is not particularly limited.

[0025] The compounds represented by the general formulas (3) and (4) are also the above-described cleaning components, similar to the compounds represented by the general formulas (1) and (2). When the compounds represented by the general formulas (3) and (4) are used as the first cleaning component, the compounds represented by the general formulas (3) and (4) become the second cleaning component.

[0026] R 6 -(OR 5 ) m -OR 7 ···(3) R 7 -(CO) y -(OR 5 ) p -OCOR6 ···(4) In general formulas (3) and (4), R 5 represents a hydrocarbon group having 3 to 6 carbon atoms. This hydrocarbon group may be any of a linear, branched, and cyclic hydrocarbon group. Since R 5 has 3 or more carbon atoms, in the mixed solution mixed with the ink, it is possible to suppress the occurrence of turbidity caused by gelation or the generation of foreign matters. Thereby, the cleanliness can be improved. Since R 5 has 6 or less carbon atoms, the fluidity of the preservation liquid can be enhanced. R 5 preferably does not contain an unsaturated bond from the viewpoint of further suppressing the aggressiveness against the rubber member.

[0027] In general formulas (3) and (4), R 6 represents a hydrocarbon group having 1 to 6 carbon atoms. This hydrocarbon group may be any of a linear, branched, and cyclic hydrocarbon group. Since R 6 has 1 or more carbon atoms, the aggressiveness against the rubber member can be further suppressed. Since R 6 has 6 or less carbon atoms, the fluidity of the preservation liquid can be enhanced. R 6 preferably does not contain an unsaturated bond from the viewpoint of further suppressing the aggressiveness against the rubber member.

[0028] In general formulas (3) and (4), R 7 represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. This hydrocarbon group may be any of a linear, branched, and cyclic hydrocarbon group. Since R 7 has 1 or more carbon atoms, the aggressiveness against the rubber member can be further suppressed. Since R 7 has 6 or less carbon atoms, the fluidity of the preservation liquid can be enhanced. R 7 preferably does not contain an unsaturated bond from the viewpoint of further suppressing the aggressiveness against the rubber member.

[0029] In general formula (3), m represents an integer of 2 or 3. In this case, the fluidity of the preservation liquid can be increased while the volatility can be suppressed. In general formula (4), p represents an integer of 1 or 2. In this case, the fluidity of the preservation liquid can be increased. In general formula (4), y represents an integer of 0 or 1. In this case, the fluidity of the preservation liquid can be increased while the volatility can be suppressed.

[0030] As the compound represented by general formula (3), one type or two or more types can be used. As the compound represented by general formula (4), one type or two or more types can be used. Examples of the compounds represented by general formulas (3) and (4) include dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol-mono-n-butyl ether, dipropylene glycol methyl ether acetate, propylene glycol diacetate, dipropylene glycol methyl-n-butyl ether-3-methoxy-3-methyl-1-butyl acetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, 1,6-hexanediol diacetate, and the like.

[0031] The total content of the compounds represented by general formulas (3) and (4) in the preservation liquid is preferably 70% by mass or less, more preferably less than 70% by mass, still more preferably 69% by mass or less, and most preferably 60% by mass or less.

[0032] The total content of the compounds represented by general formulas (1) to (4) in the preservation liquid is preferably 65% by mass or more, more preferably 68% by mass or more, and still more preferably 70% by mass or more. By increasing the total content of the compounds represented by general formulas (1) to (4) in the preservation liquid, it becomes possible to further suppress the aggressiveness to the rubber member.

[0033] In addition, as compounds other than the compounds represented by the above general formulas (1) to (4) in the preservation liquid, it is also possible to contain ethylene glycol ether solvents and diethylene glycol ether solvents. However, from the viewpoint of enhancing the stability in the state where the preservation liquid is mixed with the ink, the content of the ethylene glycol ether solvent and the diethylene glycol ether solvent in the preservation liquid is preferably, for example, 10% by mass or less, more preferably 5% by mass or less, and still more preferably 1% by mass or less. Most preferably, the preservation liquid does not contain an ethylene glycol ether solvent and a diethylene glycol ether solvent.

[0034] Examples of the ethylene glycol ether solvent and the diethylene glycol ether solvent include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monobenzyl ether, and the like.

[0035] <Stabilizer> The components in the preservation liquid and the ink components in the ink flow path may deteriorate due to, for example, active energy rays (such as ultraviolet rays) contained in lighting, outdoor light, etc., or heat applied during storage or use of the preservation liquid. Specifically, the components in the preservation liquid and the ink components in the ink flow path may undergo deterioration reactions such as oxidation, solidification, thickening, and discoloration due to active energy rays or heat. Such deterioration reactions lead to a decrease in the cleanliness of the ink flow path, so it is preferable to contain a stabilizer in the preservation liquid to suppress the deterioration reaction.

[0036] As the stabilizer, a compound that suppresses the above-mentioned deterioration reaction, for example, a compound having an antioxidant function, a polymerization suppression function, etc. can be used. From the viewpoint of efficiently suppressing the above-mentioned deterioration reaction, the stabilizer preferably contains at least one selected from a compound containing a (meth)acrylate group and a phenothiazine-based compound.

[0037] The compound containing a (meth)acrylate group has a mechanism in the molecule to suppress deterioration reactions such as oxidation-reduction reactions and polymerization reactions of the ink components. (Meth)acrylate indicates acrylate or methacrylate. Examples of the compound containing a (meth)acrylate group include a hindered amine containing a (meth)acrylate group, a hindered phenol containing a (meth)acrylate group, a compound containing a phenyl(meth)acrylate group represented by the following general formula (5), glyceryl propoxytri(meth)acrylate, bisphenol A diglycidyl di(meth)acrylate, and the like.

[0038]

Chemical formula

[0039] More specific compounds containing a (meth)acrylate group include, for example, 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentaphenyl acrylate, tetramethylpiperidyl methacrylate, pentamethylpiperidyl methacrylate, and the like.

[0040] One kind or two or more kinds of compounds containing a (meth)acrylate group can be used. The content of the compound containing a (meth)acrylate group in the preservation liquid is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and still more preferably 0.1% by mass or more. By increasing the content of the compound containing a (meth)acrylate group in the preservation liquid, it is easier to ensure the stability of the mixed liquid even when the preservation liquid and the ink are mixed during operation stop.

[0041] The content of the compound containing a (meth)acrylate group in the preservation liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 2.5% by mass or less. By reducing the content of the compound containing a (meth)acrylate group in the preservation liquid, it is difficult to inhibit the curability of the ink even when the preservation liquid is mixed into the ink during operation.

[0042] Examples of the phenothiazine-based compounds include phenothiazine, 2-methoxyphenothiazine, 2-cyanophenothiazine, bis(α-methylbenzyl)phenothiazine, 3,7-dioctylphenothiazine, and bis(α,α-dimethylbenzine)phenothiazine, etc.

[0043] One kind or two or more kinds of the phenothiazine-based compounds can be used. The content of the phenothiazine-based compound in the preservation liquid is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and still more preferably 0.01% by mass or more. By increasing the content of the phenothiazine-based compound in the preservation liquid, even when a mixed liquid of the preservation liquid and the ink is present in the ink flow path at the time of operation stop, the stability of the mixed liquid is easily ensured.

[0044] The content of the phenothiazine-based compound in the preservation liquid is preferably 1% by mass or less, more preferably 0.8% by mass or less, and still more preferably 0.5% by mass or less. By reducing the content of the phenothiazine-based compound in the preservation liquid, even when the preservation liquid is mixed into the ink during operation, it is difficult to inhibit the curability of the ink.

[0045] Examples of the stabilizers other than the compound containing the (meth)acrylate group and the phenothiazine-based compound include hindered phenol-based compounds having no (meth)acrylate group, nitrosoamine-based compounds, hindered amine-based compounds having no (meth)acrylate group, phosphorus-based compounds, etc.

[0046] <Components other than the above> For example, cyclic carbonates, polybasic acid esters, acyl glycerols, polymerizable compounds, etc. can also be contained in the preservation liquid.

[0047] Examples of the cyclic carbonate include ethylene carbonate, propylene carbonate, butylene carbonate and the like. Examples of the polybasic acid ester include dimethyl glutarate, diethyl glutarate, dimethyl succinate, diethyl succinate, dimethyl adipate, diethyl adipate, diisopropyl adipate, diethyl sebacate, tributyl acetylcitrate and the like. Examples of the acyl glycerol include triacetin, tripropionin and the like. Examples of the polymerizable compound include (meth)acrylate compounds, vinyl ether compounds, oxetane compounds and the like.

[0048] The preservation liquid may contain water and a surface tension modifier as necessary. The surface tension modifier is a compound capable of adjusting the surface tension of the preservation liquid within a predetermined range. Examples of the surface tension modifier include ionic surfactants, nonionic surfactants, modified silicone oils and the like.

[0049] Examples of the anionic surfactant of the ionic surfactant include fatty acid salts, alkyl sulfate esters, benzenesulfonates, naphthalenesulfonates, sulfosuccinate esters, polyoxyethylene sulfate esters, and phosphate esters.

[0050] Examples of the fatty acid salts include sodium stearate, potassium oleate, and sodium semi-hardened tallow fatty acid. Examples of the alkyl sulfate esters include sodium dodecyl sulfate, tri(2-hydroxyethyl)ammonium dodecyl sulfate, and sodium octadecyl sulfate.

[0051] Examples of the benzenesulfonates include sodium nonylbenzenesulfonate, sodium dodecylbenzenesulfonate, sodium octadecylbenzenesulfonate, and sodium dodecyldiphenyl ether disulfonate.

[0052] Examples of naphthalene sulfonates include sodium dodecyl naphthalene sulfonate and naphthalene sulfonic acid formalin condensate. Examples of sulfosuccinate esters include sodium didodecyl sulfosuccinate and sodium dioctadecyl sulfosuccinate.

[0053] Examples of polyoxyethylene sulfate esters include sodium polyoxyethylene dodecyl ether sulfate, tri(2-hydroxyethyl)ammonium polyoxyethylene dodecyl ether sulfate, sodium polyoxyethylene octadecyl ether sulfate, and sodium polyoxyethylene dodecyl phenyl ether sulfate.

[0054] Examples of phosphate esters include potassium dodecyl phosphate and sodium octadecyl phosphate. Examples of cationic surfactants among ionic surfactants include quaternary ammonium salts. Examples of quaternary ammonium salts include octadecylammonium acetate, alkylamine salts such as coconut oil amine acetate, dodecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, dioctadecyldimethylammonium chloride, and dodecylbenzyldimethylammonium chloride.

[0055] Examples of zwitterionic surfactants among ionic surfactants include alkyl betaines and amine oxides. Examples of alkyl betaines include dodecyl betaine and octadecyl betaine. Examples of amine oxides include dodecyldimethylamine oxide.

[0056] Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene phenyl ethers, sorbitan fatty acid esters, sorbitol fatty acid esters, and glycerin fatty acid esters.

[0057] Examples of polyoxyethylene alkyl ethers include polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene octadecyl ether, and polyoxyethylene (9-octadecenyl) ether.

[0058] Examples of polyoxyethylene phenyl ethers include polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether. Examples of sorbitan fatty acid esters include sorbitan dodecanoate, sorbitan hexadecanoate, sorbitan octadecanoate, sorbitan (9-octadecenoate), sorbitan (9-octadecenoate) triester, polyoxyethylene sorbitan dodecanoate, polyoxyethylene sorbitan hexadecanoate, polyoxyethylene sorbitan octadecanoate, polyoxyethylene sorbitan octadecanoate triester, polyoxyethylene sorbitan (9-octadecenoate), and polyoxyethylene sorbitan (9-octadecenoate) triester.

[0059] Examples of sorbitol fatty acid esters include polyoxyethylene sorbitol (9-octadecenoate) tetraester. Examples of glycerin fatty acid esters include glycerin octadecanoate and glycerin (9-octadecenoate).

[0060] Examples of modified silicone oils include polyether-modified silicone oil, methylstyrene-modified silicone oil, olefin-modified silicone oil, alcohol-modified silicone oil, and alkyl-modified silicone oil.

[0061] The preservation liquid may contain a dispersant as needed. The dispersant is a component that suppresses the aggregation of particulate components such as coloring components and fillers that are dispersed in the ink when the ink and the preservation liquid are mixed. Examples of the dispersant include a polymer type dispersant and a low molecular weight type dispersant.

[0062] <Viscosity of the preservation liquid> The viscosity of the preservation liquid is preferably 30 mPa·s or less at 25°C, more preferably 20 mPa·s or less, and even more preferably 15 mPa·s or less. By keeping the viscosity of the preservation liquid low, for example, it becomes possible to easily supply the preservation liquid to the ink flow path. Also, by keeping the viscosity of the preservation liquid low, for example, the miscibility with the ink can be enhanced. The lower limit of the viscosity of the preservation liquid is not particularly limited, but at 25°C, for example, it is 0.5 mPa·s or more.

[0063] <Preparation of the preservation liquid and method for maintaining an ink coating apparatus> The preservation liquid containing a plurality of compounds is prepared by mixing using a mixer as necessary. The preservation liquid may be used after degassing. By using the degassed preservation liquid, it becomes possible to dissolve the bubbles present in the ink flow path into the preservation liquid. As a result, it becomes possible to easily remove the bubbles mixed in the ink flow path. The degree of degassing of the preservation liquid can be managed using the amount of dissolved oxygen. The amount of dissolved oxygen in the preservation liquid is preferably 9.0 mg / L or less, more preferably 6.0 mg / L or less, and still more preferably 4.0 mg / L or less. Further, the preservation liquid is preferably filtered from the viewpoint of reducing the risk of foreign matter contamination. The method for preparing the preservation liquid preferably includes at least one of a filtration step and a degassing step. The filtration step and the degassing step can be performed according to conventional methods. Note that the filtration step and the degassing step can also be performed using the ink flow path. That is, for example, by using a filtration device and a degassing device equipped in the ink flow path, the filtration step and the degassing step of the preservation liquid can be performed when the preservation liquid is used. When the ink application method of the ink application device is an inkjet method, it is preferable to perform the filtration step and the degassing step of the preservation liquid.

[0064] Examples of the method for maintaining the ink flow path of the ink application device include a method of cleaning the inside of the ink flow path using a preservation liquid and a method of maintaining the constancy of the ink flow path using a preservation liquid. Examples of the method of cleaning the inside of the ink flow path using a preservation liquid include a method of supplying the preservation liquid manually or automatically to the ink flow path and discharging it from the ink flow path to remove ink components and foreign substances. Such a cleaning step may be repeated a plurality of times. Further, the preservation liquid may be circulated in the ink flow path.

[0065] As a method for maintaining the constancy of the ink flow path using a preservation liquid, the preservation liquid is filled into the ink flow path. By filling the preservation liquid during the manufacture of the ink coating device, for example, the entry of air bubbles into the ink flow path can be suppressed. Further, by filling the preservation liquid after the operation of the ink coating device and when temporarily or permanently stopping the ink coating device, drying of ink residues, solidification or aggregation based on reaction can be suppressed, or the entry of air bubbles into the ink flow path can be suppressed.

[0066] After discharging the preservation liquid from the ink flow path, the preservation liquid adhering to the coating section of the ink coating device may be removed. Examples of methods for removing the preservation liquid include wiping or absorption using fibers, porous materials, etc., scraping using a wiping blade, and removal using an air blow.

[0067] The preservation liquid has good compatibility with components such as (meth)acrylate compounds used in, for example, active energy ray curable compositions. Therefore, it is preferably used in an ink coating device using an active energy ray curable composition. Examples of applications of the active energy ray curable composition include applications for the purpose of coloring to represent characters, photographs, illustrations, figures, or symbols. The application of the active energy ray curable composition may also be applications not for the purpose of coloring such as overcoat agents, undercoat agents, spot coating agents, adhesives, primers, etc. The ink referred to in this specification also includes compositions used for applications not for the purpose of coloring.

[0068] <Actions and Effects of the Present Embodiment> Next, the actions and effects of the present embodiment will be described. (1) The ink application apparatus preservation liquid used for the preservation of an ink application apparatus contains at least one compound selected from the compounds represented by the above general formulas (1) and (2). According to this configuration, even when ensuring the fluidity in the ink flow path, it exhibits the effect of suppressing the deterioration of the performance of the rubber members used in the ink flow path. When the fluidity in the ink flow path is ensured, the preservation liquid can easily flow through the ink flow path. For example, it becomes possible to easily discharge the preservation liquid from the ink flow path. As a result, it becomes possible to efficiently discharge foreign matters and bubbles in the ink flow path. Also, since the deterioration of the performance of the rubber members used in the ink flow path can be suppressed, the deterioration of the sealing property of the ink flow path or the outflow of components in the rubber members can be suppressed. Therefore, it can be suitably used for cleaning the ink flow path and maintaining the constancy of the ink flow path.

[0069] In addition, since the compounds represented by the above general formulas (1) and (2) have long-chain hydrocarbon groups at their terminals, it is presumed that the penetration between rubber molecular chains is suppressed by steric hindrance. Thereby, it is presumed that swelling of the rubber member, decomposition of the rubber member, or outflow of components in the rubber member can be suppressed.

[0070] (2) The total content of the compounds represented by the general formulas (1) and (2) in the preservation liquid is preferably 30% by mass or more. In this case, it becomes possible to further suppress the aggressiveness against the rubber member.

[0071] (3) The preservation liquid preferably further contains at least one compound selected from the compounds represented by the above general formulas (3) and (4). In this case, for example, since it becomes possible to keep the viscosity of the preservation liquid low, the fluidity of the preservation liquid can be easily ensured.

[0072] (4) The total content of the compounds represented by the above general formulas (1) to (4) in the preservation liquid is preferably 65% by mass or more. In this case, it becomes possible to further suppress the aggressiveness against the rubber member.

[0073] (5) Preferably, the total content of the compounds represented by the general formulas (3) and (4) in the preservation liquid is 70% by mass or less. In this case, by ensuring the content of the compounds represented by the general formulas (1) and (2), it becomes possible to further suppress the aggressiveness against the rubber member.

[0074] (6) Preferably, the viscosity of the preservation liquid at 25 ° C is 30 mPa·s or less. In this case, for example, it becomes possible to easily supply the preservation liquid to the ink flow path. Further, by suppressing the viscosity of the preservation liquid to a low level, the miscibility with the ink can be enhanced. For example, the cleaning property of the ink flow path becomes good.

[0075] (7) Preferably, the preservation liquid does not contain an ethylene glycol ether-based solvent and a diethylene glycol ether-based solvent. In this case, for example, it becomes possible to enhance the stability in a state where the preservation liquid and the ink are mixed. In particular, when the ink is an active energy ray-curable composition, it is preferable not to contain an ethylene glycol ether-based solvent and a diethylene glycol ether-based solvent.

[0076] (8) Preferably, the preservation liquid further contains a stabilizer containing a compound having at least one of an antioxidant function and a polymerization inhibition function. In this case, it becomes possible to suppress the deterioration reaction of the components in the preservation liquid and the ink components in the ink flow path. Thereby, it is possible to suppress the decrease in the cleanliness of the ink flow path. More preferably, the stabilizer contains at least one selected from a compound containing a (meth) acrylate group and a phenothiazine-based compound.

[0077] (9) Preferably, the ink application method of the ink application device is an inkjet method. The above preservation liquid can be suitably used for the preservation of a more precise ink flow path such as the inkjet method.

[0078] (10) The amount of dissolved oxygen in the preservation liquid is preferably 9.0 mg / L or less. In this case, the air bubbles present in the ink flow path can be dissolved in the preservation liquid. As a result, the air bubbles mixed in the ink flow path can be easily removed.

Examples

[0079] Next, examples and comparative examples will be described. Examples 1, 4, and 9 below are reference examples shown as references for the invention according to the claims. (Examples 1 to 16 and Comparative Examples 1 to 5) In Examples 1 to 16 and Comparative Examples 1 to 5, each raw material was put into a container so as to have the compositions shown in Tables 1 to 3, stirred at room temperature until the solids disappeared, and then filtered using a glass fiber filter paper (manufactured by Advantec Toyo Co., Ltd., trade name: GS-25) to prepare a preservation liquid.

[0080] The viscosity of the prepared preservation liquid and the preservation liquid - test ink mixture described later was measured at a measurement temperature of 25°C using a viscometer (manufactured by Toki Sangyo Co., Ltd., trade name: RE85L). In Table 1, the unit of the numerical values indicating the composition is mass%. Also, the abbreviations in Table 1 are as follows.

[0081] “Compound A11” is a compound represented by the general formula (2) and is bis(2-ethylhexyl) adipate (manufactured by J. Plus Co., Ltd., trade name: DOA). “Compound A12” is a compound represented by the general formula (2) and is diisodecyl adipate (manufactured by J. Plus Co., Ltd., trade name: DIDA).

[0082] “Compound A13” is a compound represented by the general formula (1) and is propylene glycol mono-2-ethylhexanoate (manufactured by Yokkaichi Gosei Co., Ltd., trade name: Wisinol EHP-01).

[0083] “Compound A21” is a compound represented by the general formula (3) and is dipropylene glycol monopropyl ether (manufactured by Nippon Emulsion Co., Ltd., trade name: Propyl Propylene Diglycol).

[0084] "Compound A22" is a compound represented by general formula (4), and is 1,6 - hexanediol diacetate (manufactured by Daicel Corporation, trade name: 1,6 - HDDA). "Compound A3" is a compound other than the compounds represented by the above general formulas (1) to (4), and is a mixture of dimethyl succinate, dimethyl glutarate, and dimethyl adipate (manufactured by Taoka Chemical Co., Ltd., trade name: No. 23 Ester).

[0085] "Compound A4" is a compound other than the compounds represented by the above general formulas (1) to (4), and is tributyl acetylcitrate (manufactured by J Plus Co., Ltd., trade name: ATBC). "Compound A5" is a compound other than the compounds represented by the above general formulas (1) to (4), and is ethylene glycol monohexyl ether (manufactured by Nippon Emulsion Co., Ltd., trade name: Hexyl Glycol).

[0086] "Compound A6" is a compound other than the compounds represented by the above general formulas (1) to (4), and is ethylene glycol monobenzyl ether (manufactured by Nippon Emulsion Co., Ltd., trade name: Benzyl Glycol).

[0087] "Compound A7" is a compound other than the compounds represented by the above general formulas (1) to (4), and is diethylene glycol monobutyl ether (manufactured by Nippon Emulsion Co., Ltd., trade name: Butyl Diglycol).

[0088] "Compound B11" is a compound containing a (meth)acrylate group, and is tetramethylpiperidinyl methacrylate (manufactured by Showa Denko Materials Co., Ltd., trade name: FA - 712HM).

[0089] "Compound B12" is a compound containing a (meth)acrylate group, and is a mixture of glyceryl propoxytriacrylate and bisphenol A diglycidyl diacrylate (manufactured by RAHN, trade name: GENORAD16).

[0090] "Compound B13" is a compound containing a (meth)acrylate group and is 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM(F)).

[0091] "Compound B21" is a phenothiazine-based compound and is phenothiazine (manufactured by Seiko Chemical Co., Ltd.). (Evaluation of Compatibility of Rubber Components) As the rubber components used for evaluation, an O-ring (manufactured by Air Water Mach Co., Ltd., thickness: 1.9 mm, inner diameter: 8.8 mm) was prepared. The materials of the O-ring were five types of the following Materials 1 to 5 defined in JIS B2401-1 (2012).

[0092] Material 1: NBR-70-1 (nitrile rubber, trade name: N7-438) Material 2: NBR-70-2 (nitrile rubber, trade name: N7-995) Material 3: EPDM-70 (ethylene propylene rubber, trade name: E7-512) Material 4: VMQ-70 (silicone rubber, trade name: S7-947) Material 5: FKM-70 (fluororubber, trade name: F7-135) The following storage tests were conducted on each of the O-rings of the above Materials 1 to 5.

[0093] First, the mass of each O-ring before storage was measured with an analytical balance to the unit of mg. Let the mass of each O-ring before storage be m0 [mg]. Next, each O-ring was separately placed in a 20 mL brown bottle, and 5 g of the preservation liquid of Example 1 was injected into each brown bottle. After each brown bottle was sealed, it was stored at a temperature of 60 °C for 4 weeks.

[0094] After taking out the O-ring from each brown bottle after storage, the preservation liquid adhering to the surface of each O-ring was wiped off. After each O-ring was left at room temperature for 1 day, the mass of each O-ring was measured again. Let the mass of each O-ring after storage be mi [mg].

[0095] The mass change rate of each O-ring before and after the storage test was calculated according to the following formula. Mass change rate [%] = (mi [mg] - m0 [mg]) / m0 [mg] × 100 The compatibility of the rubber components was evaluated based on the following criteria from the calculated mass change rate.

[0096] When the mass change rate was within the range of 0.0% or more and 10.0% or less: It was evaluated that the aggressiveness to the rubber component was very low and the compatibility of the rubber component was excellent (○○). When the mass change rate was within the range of 10.1% or more and 20.0% or less: It was evaluated that the aggressiveness to the rubber component was low and the compatibility of the rubber component was good (○).

[0097] When the mass change rate was within the range of -3.0% or more and less than 0.0%: It was evaluated that the aggressiveness to the rubber component was slightly high and the compatibility of the rubber component was slightly inferior (△-). When the mass change rate was within the range of 20.1% or more and 30.0% or less: It was evaluated that the aggressiveness to the rubber component was slightly high and the compatibility of the rubber component was slightly inferior (△+).

[0098] When the mass change rate was -3.1% or less: It was evaluated that the aggressiveness to the rubber component was high and the compatibility of the rubber component was inferior (×-). When the mass change rate was 30.1% or more: It was evaluated that the aggressiveness to the rubber component was high and the compatibility of the rubber component was inferior (×+).

[0099] For the preservation liquids of Examples 2 to 16 and Comparative Examples 1 to 5, the compatibility of the rubber components was evaluated in the same manner as the preservation liquid of Example 1. The evaluation results of the compatibility of the rubber components are shown in Tables 2 to 4. (Evaluation of Mixing Stability with Ink) Samples for evaluating the mixing stability were prepared by mixing the preservation liquid of Example 1 and the test ink at a predetermined mass ratio. Seven types of samples, Samples 1 to 7 with different mass ratios, were prepared.

[0100] Sample 1: Mass of preservation liquid / Mass of test ink = 1 / 99 Sample 2: Mass of preservation liquid / Mass of test ink = 5 / 95 Sample 3: Mass of preservation liquid / Mass of test ink = 20 / 80 Sample 4: Mass of preservation liquid / Mass of test ink = 50 / 50 Sample 5: Mass of preservation liquid / Mass of test ink = 80 / 20 Sample 6: Mass of preservation liquid / Mass of test ink = 95 / 5 Sample 7: Mass of preservation liquid / Mass of test ink = 99 / 1 The test ink was prepared by putting each raw material into a container so as to have the composition shown in Table 1, stirring in a water bath at 40 to 50 °C until no solid matter remained, and then filtering using a glass fiber filter paper (manufactured by Advantec Toyo Co., Ltd., product name: GS-25).

[0101] The raw materials (product names) of the test ink in Table 1 are as follows. “VEEA” is 2-(2-vinyloxyethoxy)ethyl acrylate (manufactured by Nippon Shokubai Co., Ltd., product name: VEEA).

[0102] “SR9087” is phenoxy polyethylene glycol acrylate (manufactured by Sartomer Co., Ltd., product name: SR9087). “SR508” is dipropylene glycol diacrylate (manufactured by Sartomer Co., Ltd., product name: SR508NS).

[0103] “OMNIRAD TPO” is 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by IGM Resins). “OMNIRAD 184” is 1-hydroxycyclohexyl phenyl ketone (manufactured by IGM Resins).

[0104] “ITX” is 2-isopropylthioxanthone (manufactured by DKSH Japan Co., Ltd., product name: Lunacure 2-ITX). "VARIPLUS AP" is a ketone aldehyde condensation resin (manufactured by EVONIK Industries AG, trade name: VARIPLUS AP).

[0105] "TEGO GLIDE 440" is a polyether-modified siloxane copolymer (manufactured by EVONIK Industries AG, trade name: TEGO GLIDE 440).

[0106] "Irganox 1010" is pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (manufactured by BASF, trade name: Irganox 1010).

[0107] Samples 1 to 7 above were degassed using a vacuum degassing device until the dissolved oxygen content reached 2.0 ± 0.1 ppm. The dissolved oxygen content of each sample was measured using an oxygen sensor (membrane-type galvanic cell oxygen sensor, manufactured by Iijima Electronics Industry Co., Ltd., trade name: B-506). Each degassed sample was filled into a sealed container that had been purged of air in advance.

[0108] Each sample was stored in an atmosphere of 60°C for 4 weeks. The viscosity change rate was determined according to the following formula from the viscosity of each sample measured in advance and the viscosity of each sample after storage for 4 weeks. The viscosity of each sample measured in advance is V0 [mPa·s], and the viscosity of each sample after storage is indicated as Vi [mPa·s].

[0109] Viscosity change rate [%] = Vi [mPa·s] / V0 [mPa·s] × 100 The mixing stability with the ink was evaluated according to the following evaluation criteria from the calculated viscosity change rate and the appearance of the sample after storage.

[0110] When the viscosity change rate is within the range of ±10.0% for all of Samples 1 to 7, and no abnormal appearance such as turbidity of the liquid due to the generation of foreign matter, generation of foreign matter such as sol-like substances, or gelation is observed in each sample: It was evaluated as excellent (○○) in mixing stability with the ink.

[0111] In all of Samples 1 to 7, the above appearance abnormalities were not observed. However, when the viscosity change rate was in the range of 10.1% or more and 20.0% or less, or -20.0% or more and -10.1% or less in at least one sample: it was evaluated that the mixing stability with the ink was good (○).

[0112] In all of Samples 1 to 7, the above appearance abnormalities were not observed. However, when the viscosity change rate was in the range of 20.1% or more or -20.1% or less in at least one sample: it was evaluated that the mixing stability with the ink was poor (△).

[0113] When the above appearance abnormalities were observed in at least one of Samples 1 to 7: it was evaluated that the mixing stability with the ink was very poor (×). Regarding the preservation liquids of Examples 2 to 16 and Comparative Examples 1 to 5 as well, the mixing stability with the ink was evaluated in the same manner as the preservation liquid of Example 1. The evaluation results of the mixing stability with the ink are shown in Tables 2 to 4.

[0114] [Table 1]

[0115] [Table 2]

[0116] [Table 3]

[0117] [Table 4] As shown in Tables 2 and 3, in the preservation liquids of each example, since the viscosity at 25°C was kept low, it can be seen that the fluidity in the ink flow path can be ensured.

[0118] In addition, it can be seen that in the preservation liquids of the respective examples, excellent or good evaluation results are obtained regarding the compatibility of the rubber members of the above materials 1 to 5. In addition, it can be seen that in Examples 1 to 15, excellent results are obtained regarding the mixing stability with the ink.

[0119] As shown in Table 4, in the preservation liquids of the respective comparative examples, regarding the compatibility of at least one of the rubber members of the above materials 1 to 5, somewhat inferior or inferior evaluation results were obtained. <Supplementary Note> The technical idea that can be grasped from the above embodiments and modification examples will be described.

[0120] (Supplementary Note 1) An ink coating apparatus preservation liquid used for the purpose of preserving an ink coating apparatus, An ink coating apparatus preservation liquid containing at least one compound selected from the compounds represented by the above general formulas (1) and (2).

[0121] (Supplementary Note 2) The total content of the compounds represented by the above general formulas (1) and (2) in the ink coating apparatus preservation liquid is 30% by mass or more. The ink coating apparatus preservation liquid according to (Supplementary Note 1).

[0122] (Supplementary Note 3) Further containing at least one compound selected from the compounds represented by the above general formulas (3) and (4). The ink coating apparatus preservation liquid according to (Supplementary Note 1) or (Supplementary Note 2).

[0123] (Supplementary Note 4) The total content of the compounds represented by the above general formulas (1) to (4) in the ink coating apparatus preservation liquid is 65% by mass or more. The ink coating apparatus preservation liquid according to (Supplementary Note 3).

[0124] (Supplementary Note 5) The total content of the compounds represented by the above general formulas (3) and (4) in the ink coating apparatus preservation liquid is 70% by mass or less. The ink coating apparatus preservation liquid according to (Supplementary Note 3) or (Supplementary Note 4).

[0125] (Appendix 6) The viscosity at 25°C is 30 mPa·s or less, and it is a liquid for maintaining an ink coating apparatus as described in any one of (Appendix 1) to (Appendix 5). (Appendix 7) A liquid for maintaining an ink coating apparatus as described in any one of (Appendix 1) to (Appendix 6), which does not contain an ethylene glycol ether solvent and a diethylene glycol ether solvent.

[0126] (Appendix 8) A liquid for maintaining an ink coating apparatus as described in any one of (Appendix 1) to (Appendix 7), which further contains a stabilizer containing a compound having at least one of an antioxidant function and a polymerization inhibition function.

[0127] (Appendix 9) The liquid for maintaining an ink coating apparatus as described in (Appendix 8), wherein the stabilizer contains at least one selected from a compound containing a (meth)acrylate group and a phenothiazine compound.

[0128] (Appendix 10) The liquid for maintaining an ink coating apparatus as described in any one of (Appendix 1) to (Appendix 9), wherein the ink coating method of the ink coating apparatus is an inkjet method. (Appendix 11) The liquid for maintaining an ink coating apparatus as described in any one of (Appendix 1) to (Appendix 10), wherein the amount of dissolved oxygen in the liquid for maintaining an ink coating apparatus is 9.0 mg / L or less.

[0129] (Appendix 12) A method for maintaining an ink coating apparatus, which maintains the ink coating apparatus using the liquid for maintaining an ink coating apparatus as described in any one of (Appendix 1) to (Appendix 11).

Claims

An ink coating apparatus preservation liquid used for the preservation of an inkjet type ink coating apparatus, comprising: At least one first compound selected from 3-(2-ethylhexyloxy)propionic acid, bis(2-ethylhexyl) succinate, diisononyl succinate, diisodecyl succinate, bis(2-ethylhexyl) glutarate, diisononyl glutarate, diisodecyl glutarate, diheptyl adipate, bis(2-ethylhexyl) adipate, diisononyl adipate, and diisodecyl adipate; At least one second compound selected from dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, and dipropylene glycol mono-n-butyl ether, and The total content of the first compound in the ink coating apparatus preservation liquid is 30% by mass or more, and the total content of the first compound and the second compound in the ink coating apparatus preservation liquid is 65% by mass or more. An ink coating apparatus preservation liquid.

2. The ink coating apparatus preservation liquid according to claim 1, which does not contain water.

3. The ink coating apparatus preservation liquid according to claim 1 or claim 2, wherein the total content of the second compound in the ink coating apparatus preservation liquid is 70% by mass or less.

4. The ink coating apparatus preservation liquid according to claim 1 or claim 2, having a viscosity at 25°C of 30 mPa·s or less.

5. The ink coating apparatus preservation liquid according to claim 1 or claim 2, which does not contain ethylene glycol ether solvents and diethylene glycol ether solvents.

6. The ink coating apparatus preservation liquid according to claim 1 or claim 2, further comprising a stabilizer containing a compound having at least one of an antioxidant function and a polymerization inhibition function.

7. The ink coating apparatus preservation liquid according to claim 6, wherein the stabilizer contains at least one selected from compounds containing a (meth)acrylate group and phenothiazine compounds.

8. The ink coating apparatus preservation liquid according to claim 1 or claim 2, wherein the amount of dissolved oxygen in the ink coating apparatus preservation liquid is 4.0 mg / L or less.

9. It is used in an ink flow path in the inkjet type ink coating apparatus, The ink coating apparatus preservation liquid according to claim 1 or claim 2, wherein the ink flow path has a rubber member.

10. A method for preserving an ink coating apparatus, which preserves the inkjet type ink coating apparatus using the ink coating apparatus preservation liquid according to claim 1 or claim 2.

11. The method for preserving an ink coating apparatus according to claim 10, which performs a deaeration step of reducing the amount of dissolved oxygen in the ink coating apparatus preservation liquid.

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