JP2020033391A - Active energy ray-curable inkjet ink composition - Google Patents

Abstract

To provide an active energy ray-curable inkjet ink composition having a low viscosity that is enough for the ink to be discharged as an inkjet ink, and capable of showing sufficient adhesion to a plastic substrate having a low surface free energy.SOLUTION: The active energy ray-curable inkjet ink composition comprises a polyester resin (A). The polyester resin (A) is constituted by a structural unit (a-1) derived from a polybasic acid, a structural unit (a-2) derived from a polyhydric alcohol, and a urethane structural unit (a-3) derived from an isocyanate compound, and the polyester resin (A) has a urethane bond equivalent of 100 to 2000.SELECTED DRAWING: None

Description

  The present invention relates to an active energy ray-curable inkjet ink composition and printed matter.

  Active energy ray or ultraviolet curable ink-jet ink compositions are broadly classified into radical curing systems and ionic (anion / cation) curing systems depending on the curing system. In adjusting the drying speed and the physical properties of the coating film, the radical curing system is superior in that there are various composition options, and is widely used.

  The composition of the ultraviolet-curable inkjet ink includes an ultraviolet-curable monomer, an ultraviolet-curable oligomer, an ultraviolet-curable polymer, a polymerization initiator, a colorant, and various additives. In some cases, the ink-jet ink does not contain a polymer component due to viscosity restrictions. In some cases, the polymer component is an inert polymer that is not an ultraviolet curable type.

  Substrates to which the ultraviolet-curable inkjet ink is applied include paper, plastic, metal, and inorganic substances (such as glass). Of these, there are various types of plastics, including soft and hard, but polyethylene and polypropylene having particularly low surface free energy often cause insufficient adhesion, which may cause troubles in peeling of the coating film.

  As a method of solving the adhesion to the low surface free energy base material, a specific functional resin may be added. For example, Patent Literature 1 solves the problem by adding a polymer. However, the cured coating film of the composition containing the resin may have cracks or chips in the cured coating film due to the rigid resin molecular structure.

  In Patent Document 2, cracking of a cured coating film is improved by adjusting the composition of the composition. However, since the composition of the monomer alone does not contain the resin component, the curing shrinkage rate is high, and there are cases where problems such as substrate warpage occur. At this time, if a general resin is added, the viscosity of the ink becomes large and ink jetting cannot be performed.

Patent No. 5540862 JP 2017-149825

  An object of the present invention is to provide an active energy-curable ink-jet ink composition which has a viscosity low enough to be ejected as an ink-jet ink and does not cause warping, peeling, cracking, etc. on a plastic substrate having a low surface free energy.

As a means for solving the above-mentioned problems, the inventors of the present application have conducted intensive studies,
It has been found that an active energy ray-curable ink composition containing a polyester resin having a urethane structural unit derived from an isocyanate compound in the resin has excellent adhesion to a plastic substrate while maintaining a low viscosity.

That is, the present invention can be described as follows.
An active energy ray-curable inkjet ink composition containing a polyester resin (A),
The polyester resin (A) includes a structural unit (a-1) derived from a polybasic acid, a structural unit (a-2) derived from a polyhydric alcohol, and a urethane structural unit (a-3) derived from an isocyanate compound. Consisting of
By using a composition characterized in that the urethane bond equivalent of the polyester resin (A) is from 100 to 2,000, a plastic substrate having a low surface free energy while maintaining a low viscosity required for an inkjet ink ( For example, it has been found that a composition excellent in sufficient adhesion to a substrate composed of, for example, polypropylene or polyethylene terephthalate) can be obtained, and the present invention has been completed.

  A printed material obtained by printing on a plastic substrate using the active energy ray-curable inkjet ink of the present invention exhibits high adhesion to the plastic substrate (particularly, cross-cut resistance). Further, even if the polyester resin of the present invention is blended, the composition can maintain a low viscosity, so that it can be used for an ultraviolet-curable inkjet ink.

  Hereinafter, the active energy ray-curable inkjet ink composition will be described in detail.

Active energy ray-curable inkjet ink composition In the active energy ray-curable inkjet ink composition of the present invention, the polyester resin (A) is derived from a structural unit (a-1) derived from a polybasic acid and a polyhydric alcohol. (A-2) and a urethane structural unit (a-3) derived from an isocyanate compound, wherein the polyester resin (A) has a urethane bond equivalent of 100 to 2,000. And, if necessary, it contains a (meth) acrylate monomer (B) and a polymerization initiator (C).
In the case of a colored ink, a coloring agent is added here. In the case of a colorless ink (top coating agent, varnish, etc.), no coloring agent is added. The properties of the ink may be adjusted with various additives.

Polyester resin composition (A)
The polyester resin (A) of the present invention comprises a structural unit (a-1) derived from a polybasic acid, a structural unit (a-2) derived from a polyhydric alcohol, and a urethane structural unit (a) derived from an isocyanate compound. -3). Further, the urethane bond equivalent of the polyester resin (A) is from 100 to 2,000. The polyester resin (A) has a number average molecular weight of 500 to 5,000 and an acid value of 20 to 140.

  The polyester resin (A) of the present invention is a reaction product obtained by reacting a dibasic or higher polybasic acid with a dihydric or higher polyhydric alcohol. The polybasic acid may be an acid anhydride thereof, or may be used alone or in combination of two or more.

Structural unit (a-1) derived from polybasic acid
As an example of the structural unit (a-1) derived from the polybasic acid used in the present invention, either an unsaturated polybasic acid or a saturated polybasic acid may be used.

  The unsaturated polybasic acid is not particularly limited, and a known one can be used. Examples of unsaturated polybasic acids include maleic anhydride, fumaric acid, citraconic acid, itaconic acid and the like. These can be used alone or in combination of two or more.

It does not specifically limit as a saturated polybasic acid, A well-known thing can be used. Examples of saturated polybasic acids include fumaric acid, succinic acid, glutaric acid, maleic acid, maleic anhydride, chloromaleic acid, itaconic acid, citraconic acid, mesaconic acid, adipic acid, dodecane diacid, hexahydrophthalic anhydride, tetrahydro The constituent carbon derived from phthalic anhydride, orthophthalic acid, isophthalic acid, and terephthalic acid is mentioned.
Among them, structural units derived from hexahydrophthalic anhydride, tetrahydrophthalic anhydride, orthophthalic acid, isophthalic acid, and terephthalic acid are preferable, and structural units derived from hexahydrophthalic anhydride and tetrahydrophthalic anhydride are more preferable.

Structural unit derived from polyhydric alcohol (a-2)
The structural unit (a-2) derived from the polyhydric alcohol in the present invention is not particularly limited, and a known unit can be used. For example, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 4-butanediol, 1,5-pentaneddiol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,9-nonanediol, -Methyloctanediol, 1,10-decanediol, bisphenol A, bisphenol F, hydrogenated bisphenol A, structural units derived from hydrogenated bisphenol F, and the like. Among them, structural units derived from hydrogenated bisphenol A and hydrogenated bisphenol F are preferable, and structural units derived from hydrogenated bisphenol A are more preferable. It is also possible to use two or more of the above-mentioned polyhydric alcohols in combination.

Urethane structural units (a-3) derived from isocyanate compounds
The urethane structural unit (a-3) derived from the isocyanate compound in the present invention is not particularly limited, and a known unit can be used. Examples of the isocyanate compound include a monoisocyanate and a diisocyanate.

The monoisocyanate may or may not have a functional group other than the isocyanate group.Specifically, propyl isocyanate, butyl isocyanate, pentyl isocyanate, hexyl isocyanate, heptyl isocyanate, isocyanic acid Octyl, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, allyl isocyanate, 6-chlorohexyl isocyanate, cyclohexyl isocyanate, 2-ethylhexyl isocyanate, 2,3,4-methylcyclohexyl isocyanate, 3,3,5 -Trimethylcyclohexyl isocyanate, 2-norbornyl-methyl isocyanate, decyl isocyanate, dodecyl isocyanate, tetradecyl isocyanate, hexadecyl isocyanate Octadecyl isocyanate, 3-butoxypropyl isocyanate, 3- (2-ethylhexyloxy) -propyl isocyanate, phenyl isocyanate, tolyl isocyanate, chlorophenyl isocyanate (2,3,4-isomer), dichlorophenyl isocyanate, 4-nitrophenyl isocyanate, Examples include 3-trifluoromethyl-phenyl isocyanate, benzyl isocyanate, dimethylphenyl isocyanate (commercial mixtures and individual isomers), 4-dodecylphenyl isocyanate, 4-cyclohexyl-phenyl isocyanate, 1-naphthyl isocyanate, and the like. it can.
Among them, propyl isocyanate, butyl isocyanate, pentyl isocyanate, hexyl isocyanate, heptyl isocyanate, octyl isocyanate, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, and allyl isocyanate are preferred.

As diisocyanates, cyclohexane diisocyanate, methyl cyclohexane diisocyanate, ethyl cyclohexane diisocyanate, propyl cyclohexane diisocyanate, methyl diethyl cyclohexane diisocyanate, propane diisocyanate, butane diisocyanate, pentane diisocyanate, hexane diisocyanate, heptane diisocyanate, octane diisocyanate, nonane diisocyanate, 4-isocyanatomethyl -1,8-octane diisocyanate (TIN), decane diisocyanate and decane triisocyanate, undecane diisocyanate and undecane triisocyanate, dodecane diisocyanate and dodecane triisocyanate, 4-methyl-cyclohexane-1, -Diisocyanate, 2-butyl-2-ethylpentamethylene-diisocyanate, 3 (4) -isocyanatomethyl-1-methylcyclohexyl isocyanate, 2-isocyanatopropylcyclohexyl-isocyanate, 2,4'-methylenebis (cyclohexyl) diisocyanate and / Or 1,4-diisocyanato-4-methylpentane, isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), 2,2'-dicyclohexylmethane diisocyanate (2,2'-H12MDI), 2,4'-dicyclohexylmethane Diisocyanate (2,4'-H12MDI), 4,4'-dicyclohexylmethane diisocyanate (4,4'-H12MDI), 2-methylpentane diisocyanate (MPDI), pen Diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (2,2,4-TMDI), 2,4,4-trimethylhexamethylene diisocyanate (2,4,4-TMDI), norbornane diisocyanate (NBDI), methylene Examples thereof include diphenyl diisocyanate (MDI), toluidine diisocyanate (TDI), tetramethyl xylylene diisocyanate (TMXDI), xylylene diisocyanate (MXDI), methylene diphenyl 4,4′-diisocyanate, and toluene diisocyanate.
Among them, hexamethylene diisocyanate (HDI), methylene diphenyl 4,4′-diisocyanate, and toluene diisocyanate are preferred.

The polyester resin (A) of the present invention contains a urethane structural unit (a-3) derived from an isocyanate compound, and the urethane bond equivalent of the polyester resin (A) may be in the range of 100 to 2,000, preferably 200 to 2,000. It is in the range of 1500, more preferably in the range of 300 to 1100.
In addition, the urethane bond equivalent is a value obtained by dividing the number average molecular weight of the polyester resin (A) by one molecule of the polyester resin, and can be obtained from the following equation (1).
Urethane bond equivalent = number average molecular weight of polyester resin / number of urethane bonds per molecule (1)

When the value of the urethane bond equivalent of the polyester resin is less than 100, when a coating film is formed, flexibility is obtained and cracking of the coating film can be suppressed, but the adhesion of the coating film to the plastic substrate is deteriorated. . On the other hand, if the value of the urethane bond equivalent is more than 2,000, the resulting coating film lacks flexibility and causes cracking and chipping.

  The number average molecular weight (Mn) of the polyester resin is preferably from 500 to 5,000, more preferably from 700 to 3,000. The weight average molecular weight (Mw) of the polyester resin is not particularly limited, but is preferably from 500 to 5,000, more preferably from 700 to 3,000. If the molecular weight is small, the ink after the addition of the resin does not adhere to the plastic, and if the molecular weight is large, the viscosity of the ink after the addition of the resin becomes high and the ink jet cannot be ejected. In the present specification, “number average molecular weight” and “weight average molecular weight” are measured at 40 ° C. using gel permeation chromatography (Prominence-i, LC-2030 manufactured by Shimadzu Corporation), and standard polystyrene calibration is performed. It was obtained using a line. The acid value of the polyester resin can be measured by a commonly used method, and may be from 5 to 300, preferably from 10 to 200, more preferably from 20 to 140.

  The reaction for obtaining the polyester resin (A) can be synthesized by a known method using the above-mentioned raw materials. Various conditions in this synthesis need to be appropriately set according to the raw materials used and the amounts thereof. In this reaction, a catalyst can be used if necessary. Examples of the catalyst include known catalysts such as manganese acetate, dibutyltin oxide, stannous oxalate, zinc acetate, and cobalt acetate. These can be used alone or in combination of two or more. The reaction temperature is preferably in the range of 150 to 220 ° C, and more preferably in the range of 170 to 200 ° C, for obtaining the optimum reaction rate and yield.

  The reaction is preferably performed under an atmosphere of an inert gas such as nitrogen or argon. The reaction pressure may be either atmospheric pressure or elevated pressure, but it is preferable to carry out the reaction at atmospheric pressure in view of the simplicity of the operation. The reaction can be carried out by charging the raw materials once or separately in a reactor equipped with stirring blades and then reacting at the above-mentioned predetermined temperature.

  In the reaction for obtaining the polyester resin, the order of adding the raw materials may be appropriately selected.For example, first, a structural unit derived from a polybasic acid and a structural unit derived from a polyhydric alcohol are reacted to obtain a reaction intermediate. After that, a reaction intermediate (eg, an intermediate having a terminal hydroxyl group structure) is reacted with a urethane structural unit derived from an isocyanate compound (eg, monoisocyanate), or a urethane structural derived from an isocyanate compound. After reacting a unit (eg, diisocyanate) with a constituent unit derived from a polyhydric alcohol to obtain a reaction intermediate (intermediate having a terminal hydroxyl group structure), the reaction intermediate is derived from a polybasic acid. To react while alternately adding a structural unit to be formed and a structural unit derived from a polyhydric alcohol, and furthermore, a reaction intermediate (terminal hydroxyl group structure). Against intermediate) can be exemplified a method in which is further reacted urethane constituent units derived from the isocyanate compound (monoisocyanate).

  In the polyester resin (A) of the present invention, a structural unit (a-1) derived from a polybasic acid, a structural unit (a-2) derived from a polyhydric alcohol, and a structural unit (a-3) derived from an isocyanate compound ) May be in the range of 20 mol% to 30 mol%: 40 mol% to 60 mol%: 10 mol% to 40 mol%.

  The content of the polyester resin (A) in the active energy ray-curable inkjet ink composition may be in the range of 1 to 20% by weight, and is preferably in the range of 5 to 15% by weight. If it is 1% or less, sufficient adhesion to the substrate cannot be obtained, and if it is 20% or more, the viscosity increases, and it becomes impossible to discharge as an ink jet ink.

(Meth) acrylate monomer (B)
The active energy ray-curable inkjet ink composition of the present invention contains a (meth) acrylate monomer (B).

  The (meth) acrylate monomer is not particularly limited as long as it can be ejected as an inkjet ink, but needs to have low viscosity. As a guide, those exhibiting about 10 to 20 mPa · s at 25 ° C. are good, and generally are monofunctional or bifunctional (meth) acrylate monomers. If added in such a small amount that the viscosity can be kept low, a polyfunctional (meth) acrylate can be used as needed.

  Examples of (meth) acrylate monomers include isobonyl acrylate, 4-hydroxybutyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate, phenoxyethyl acrylate, isooctyl acrylate, stearyl acrylate, cyclohexyl acrylate, 2-ethoxyethyl acrylate, and benzyl Acrylate, 1H, 1H, 5H-octafluoropentyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobutyl acrylate, t-butyl acrylate, tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, 2,2,2-tri Fluoroethyl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, methoxytrie Len glycol acrylate, PO-modified nonylphenol acrylate, EO-modified nonylphenol acrylate, EO-modified 2-ethylhexyl acrylate, phenylglycidyl ether acrylate, phenoxydiethylene glycol acrylate, EO-modified phenol acrylate, EO-modified cresol acrylate, methoxy polyethylene glycol acrylate, dipropylene glycol acrylate, Cyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 2-n-butyl-2-ethyl-1,3-propanediol diacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, 1,9-nonanediol diacrylate , 1,4-butanediol diacryle Bisphenol A EO-modified diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol 200 diacrylate, neopentyl glycol hydroxypivalate diacrylate, 2-ethyl-2-butyl-propanediol diacrylate, polypropylene glycol diacrylate , PO modified bisphenol A diacrylate, EO modified hydrogenated bisphenol A diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, trimethylolpropane EO modified triacrylate, glycerin PO addition Triacrylate, trisacryloyloxyethyl phosphate, pentaerythr Tall tetraacrylate, PO-modified trimethylolpropane triacrylate, γ-butyrolactone acrylate, pentamethylpiperidyl acrylate, tetramethylpiperidyl acrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, lactone acrylate mevalonate, Dimethylol tricyclodecane diacrylate, 2- (2-vinyloxyethoxy) ethyl acrylate, 1-adamantyl methyl acrylate, 1-adamantyl acrylate, 2-acryloyloxyethyl phthalate, isobornyl acrylate, 3-acryloyloxy Propyl acrylate, dicyclopentanyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, diethylene glycol diethyl Ruether, N-vinylcaprolactam and N-vinylpyrrolidone.

  The content of the (meth) acrylate monomer (B) in the active energy ray-curable inkjet ink composition of the present invention is 50 to 1500 parts by weight of the (meth) acrylate monomer (B) based on 100 parts by weight of the polyester resin (A). Parts by weight, more preferably 50 to 1,300 parts by weight, and particularly preferably 50 to 1200 parts by weight.

Polymerization initiator (C)
The active energy ray-curable inkjet ink composition of the present invention contains a polymerization initiator. In the present invention, a polymerization initiator can be used without limitation. It is particularly preferable to contain a photopolymerization initiator.

  The compounding amount of the polymerization initiator in the active energy ray-curable inkjet ink composition of the present invention is 0.1 to 20 parts by weight based on 100 parts by weight of the total of the (meth) acrylic monomer (B) and the polyester resin (A). Parts by weight, more preferably 1 to 15 parts by weight, and particularly preferably 5 to 10 parts by weight.

  Examples of the photopolymerization initiator are not particularly limited, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin such as benzoin n-butyl ether, benzoin alkyl ethers, benzophenone, Benzophenones such as p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy- 2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] Acetophenones such as 2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, N, N-dimethylaminoacetophenone, 2,4-dimethylthioxanthone, Thioxanthones such as 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone, anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, Anthraquinones such as 2-amylanthraquinone and 2-aminoanthraquinone, ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal, 1.2-octanedione, 1- [4- (phenylene) Thio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (0-acetyloxime) Oxime esters such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, acylphosphines such as bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, phenyldisulfide 2-nitrofluorene, butyroin, anisoin Examples thereof include ethyl ether and azobisisobutyronitrile. Particularly, acetophenones, acylphosphine oxides, oxyphenyls, and oxime ester benzoins are preferable, and acetophenones are more preferable. These photopolymerization initiators may be used alone or in combination of two or more.

  As the photopolymerization initiator, metal soaps, metal chelates and amines may be used in combination as an accelerator. Examples include metal chelates such as cobalt naphthenate, cobalt octylate, zinc octylate, vanadium octylate, copper naphthenate, barium naphthenate, vanadium acetyl acetate, cobalt acetyl acetate, iron acetylacetonate, N , N-substituted-p-toluidine, and amines such as 4- (N, N-substituted amino) benzaldehyde. Further, a sensitizer may be used in combination with the photopolymerization initiator.

  Examples of the sensitizer include anthracene, phenothiazene, perylene, thioxanthone, and benzophenone thioxanthone.

  The active energy rays used for curing the active energy ray-curable inkjet ink composition of the present invention include, in addition to ultraviolet rays, polymerization in the composition such as electron rays, α rays, β rays, γ rays, and X rays. The material is not particularly limited as long as it can provide energy necessary for promoting the polymerization reaction of the acidic component (for example, the (meth) acrylate monomer). In particular, when a high energy light source is used, the polymerization reaction can proceed without using a polymerization initiator. In the case of ultraviolet irradiation, mercury-free is strongly desired from the viewpoint of environmental protection, and replacement with a GaN-based semiconductor ultraviolet light emitting device is very useful industrially and environmentally. Furthermore, ultraviolet light emitting diodes (UV-LEDs) and ultraviolet laser diodes (UV-LDs) are compact, have a long life, are highly efficient, and are low in cost, and are preferred as ultraviolet light sources.

  The active energy ray-curable inkjet ink composition of the present invention includes various additives, for example, a stabilizer (for example, a polymerization inhibitor such as hydroquinone, methoquinone, and methylhydroquinone), and a pigment (for example, cyanine blue, disazo yellow). , Carmine 6b, lake C, carbon black, titanium white), and various additives such as fillers and viscosity modifiers, depending on the purpose.

Preparation of Active Energy Ray-Curable Inkjet Ink Composition The active energy ray-curable inkjet ink composition of the present invention can be produced using the above-mentioned various components, and the preparation means and conditions are not particularly limited, but, for example, , A pigment, a dispersant, and the like are charged into a dispersing machine such as a ball mill, a chity mill, a disc mill, a pin mill, a dyno mill, and dispersed to prepare a pigment dispersion, and the (meth) acrylate monomer is further added to the pigment dispersion to initiate polymerization. It can be prepared by mixing an agent, a polymerization inhibitor, a surfactant and the like.

  The viscosity of the active energy ray-curable inkjet ink composition of the present invention may be appropriately adjusted depending on the application and application means, and is not particularly limited. For example, a discharge means for discharging the composition from a nozzle may be used. When applied, the viscosity in the range of 20 ° C to 65 ° C, preferably the viscosity at 25 ° C is from 1 mPa · s to 20 mPa · s, and preferably from 5 mPa · s to 15 mPa · s. Further, the viscosity may be adjusted by adding an organic solvent or the like to the viscosity range. The viscosity can be measured by using a MARSIII rheometer manufactured by Thermo Scientific, setting the rotation speed at 10 rpm and the temperature of the constant temperature circulating water in the range of 20 ° C to 65 ° C as appropriate.

The use of the active energy ray-curable inkjet ink composition of the present invention is not particularly limited as long as the active energy ray-curable material is generally used in the field, and can be appropriately selected depending on the purpose. , Molding resins, paints, adhesives, insulating materials, release agents, coating materials, sealing materials, various resists, various optical materials, and the like.
Furthermore, the active energy ray-curable inkjet ink composition of the present invention can be used as an ink to form not only two-dimensional characters and images, and design coating films on various substrates, but also three-dimensional solid images (stereolithography). ) Can also be used as a material for three-dimensional modeling for forming the object.

  As a three-dimensional modeling device for modeling a three-dimensional molded product using the active energy ray-curable inkjet ink composition of the present invention, a known three-dimensional modeling device can be used, and is not particularly limited. One provided with a storage means, a supply means, a discharge means, an active energy ray irradiation means, and the like.

  The present invention also includes a cured product obtained by curing the active energy ray-curable inkjet ink composition and a molded product obtained by processing a structure in which the cured product is formed on a substrate. The molded product is obtained by subjecting a cured product or a structure formed into a sheet or a film, for example, to a molding process such as a heat drawing or a punching process. -It is suitably used for applications that require molding after decorating the surface, such as instruments such as electronic devices and cameras, and panels for operation units.

  The substrate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, and composite materials thereof. From the viewpoint of processability, a plastic substrate (for example, polypropylene (PP), polyethylene (PE), polycarbonate (PC), polyvinyl chloride (PVC), polyethylene terephthalate (PET), etc.) is preferable.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples.

  Materials used in Examples and Comparative Examples described below are described below.

Polyester resin A polymer is prepared from the following raw materials.
Tetrahydrophthalic anhydride (hereinafter referred to as THPA, Shin Nippon Rika Ricacid TH)
Hydrogenated bisphenol A (HBPA, manufactured by Maruzen Petrochemical)
Butyl isocyanate (ICAB, manufactured by Wako Pure Chemical Industries)
2-isocyanatoethyl methacrylate (hereinafter MOI, Karenz MOI manufactured by Showa Denko)
Methylene diphenyl 4,4'-diisocyanate (MDI, manufactured by Wako Pure Chemical Industries, Ltd.)
Toluene diisocyanate (hereinafter TDI, TCI)
Hexamethylene diisocyanate (hereinafter HDI, manufactured by TCI)
Dibutyltin dilaurate (Wako Pure Chemical Industries)

Polymerization Example 1 Synthesis of Polyester Resin 1 65 g of THPA was charged into a 500 ml cylindrical round bottom flask, heated to 100 ° C. and melted. While the temperature was raised to 120 ° C., and nitrogen was rotated at 200 ml / min and 100 rpm, 206 g of HBPA powder was charged in four times. After visually confirming that the powder is dissolved, raise the heater temperature to 200 ° C., wait for water distilling while rotating at 150 rpm, and after confirming the liquid drop, sample every 30 minutes and sample the number average molecular weight and acid value. The reaction was stopped when the target number average molecular weight and acid value were reached, and the number average molecular weight was 1280, the acid value was 40, and 100 mol% of HBPA in the polyhydric alcohol was measured. 301 g of polyester resin 1 was obtained. This polyester resin does not contain a urethane structural unit derived from an isocyanate compound. The obtained polyester resin 1 was used in Comparative Example 2.

Polymerization Example 2: Synthesis of Polyester Resin 2 65 g of THPA was charged into a 500 ml cylindrical round bottom flask, heated to 100 ° C. and melted. While the temperature was raised to 120 ° C., and nitrogen was rotated at 200 ml / min and 100 rpm, 206 g of HBPA powder was charged in four times. After visually confirming that the powder was dissolved, the temperature of the heater was increased to 200 ° C., and the mixture was stirred for 3 hours while rotating the stirrer at 150 rpm. 40 g of this intermediate was put into 100 g of tetrahydrofuran in a 500-ml cylindrical round-bottom flask, and 0.08 g of dibutyltin dilaurate was also added thereto. And the mixture was stirred for 20 hours. The reaction was transferred to a tray and dried at 40 ° C. under air to complete the operation. 45 g of a polyester resin 2 having a number average molecular weight of 790, an acid value of 23, and a urethane bond equivalent of 395 was obtained. The obtained polyester resin 2 was used in Example 1.

Polymerization Example 3: Synthesis of polyester resin 3 65 g of THPA was charged into a 500-ml cylindrical round-bottom flask, heated to 100 ° C. and melted. While the temperature was raised to 120 ° C., and nitrogen was rotated at 200 ml / min and 100 rpm, 206 g of HBPA powder was charged in four times. After visually confirming that the powder was dissolved, the temperature of the heater was increased to 200 ° C., and the mixture was stirred for 3 hours while rotating the stirrer at 150 rpm. 40 g of this intermediate was put into 100 g of tetrahydrofuran in a 500 ml cylindrical round bottom flask, and 0.12 g of dibutyltin dilaurate was also added thereto. At a rotation of a stirrer at 50 ° C. and 300 rpm, a MOI of 15 g was 0.2 mg / h. And the mixture was stirred for 20 hours. The reaction was transferred to a tray and dried at 40 ° C. under air to complete the operation. 50 g of a polyester resin 3 having a number average molecular weight of 856, an acid value of 23, and a urethane bond equivalent of 428 was obtained. The obtained polyester resin 3 was used in Example 2.

Polymerization Example 4: Synthesis of polyester resin 4 65 g of THPA was charged into a 500 ml cylindrical round bottom flask, heated to 100 ° C. and melted. While the temperature was raised to 120 ° C., and nitrogen was rotated at 200 ml / min and 100 rpm, 206 g of HBPA powder was charged in four times. After visually confirming that the powder was dissolved, the temperature of the heater was increased to 200 ° C., and the mixture was stirred for 3 hours while rotating the stirrer at 150 rpm. 40 g of this intermediate was put into 200 g of tetrahydrofuran in a 500 ml cylindrical round-bottom flask, and 0.03 g of dibutyltin dilaurate was also added thereto. And the mixture was stirred for 20 hours. The reaction was transferred to a tray and dried at 40 ° C. under air to complete the operation. 42 g of a polyester resin 4 having a number average molecular weight of 1385, an acid value of 29, and a urethane bond equivalent of 639 was obtained. The obtained polyester resin 4 was used in Example 3.

Polymerization Example 5 Synthesis of Polyester Resin 5 65 g of THPA was charged into a 500 ml cylindrical round bottom flask, heated to 100 ° C. and melted. While the temperature was raised to 120 ° C., and nitrogen was rotated at 200 ml / min and 100 rpm, 206 g of HBPA powder was charged in four times. After visually confirming that the powder was dissolved, the temperature of the heater was increased to 200 ° C., and the mixture was stirred for 3 hours while rotating the stirrer at 150 rpm. 80 g of this intermediate was put into 200 g of tetrahydrofuran in a 500 ml cylindrical round bottom flask, 0.04 g of dibutyltin dilaurate was also added thereto, and 6 g of TDI was added at 0.4 mg / h while rotating a stirrer at 50 ° C. and 400 rpm. And the mixture was stirred for 20 hours. The reaction was transferred to a tray and dried at 40 ° C. under air to complete the operation. 84 g of a polyester resin 5 having a number average molecular weight of 20,96, an acid value of 29, and a urethane bond equivalent of 1,048 was obtained. The obtained polyester resin 5 was used in Example 4.

Polymerization Example 6: Synthesis of Polyester Resin 6 65 g of THPA was charged into a 500 ml cylindrical round bottom flask, heated to 100 ° C. and melted. While the temperature was raised to 120 ° C., and nitrogen was rotated at 200 ml / min and 100 rpm, 206 g of HBPA powder was charged in four times. After visually confirming that the powder was dissolved, the temperature of the heater was increased to 200 ° C., and the mixture was stirred for 3 hours while rotating the stirrer at 150 rpm. 80 g of this intermediate was put into 200 g of tetrahydrofuran in a 500 ml cylindrical round bottom flask, 0.04 g of dibutyltin dilaurate was also added thereto, and 6 g of TDI was added at 0.4 mg / h while rotating a stirrer at 50 ° C. and 400 rpm. And the mixture was stirred for 20 hours. The reaction was transferred to a tray and dried at 40 ° C. under air to complete the operation. 84 g of a polyester resin 6 having a number average molecular weight of 2025, an acid value of 29, and a urethane bond equivalent of 1012 was obtained. The obtained polyester resin 6 was used in Example 5.

The synthesized polyester resin was used as an indicator of the end of the reaction by the fact that the isocyanate group absorption of the isocyanate raw material did not appear at 2260 cm-1 in FT-IR. The measurement was performed by an ATR method using Nicolet iG50 manufactured by Thermo Scientific.

The physical property values of the synthesized polyester resin were measured according to the following methods.

(1) GPC Measurement Conditions Under the following conditions, the weight average molecular weight and the number average molecular weight were measured by a GPC method using a standard polystyrene calibration curve.
Apparatus: Prominence-i, LC-2030 manufactured by Shimadzu Corporation
Column: Shodex LF-804 × 2, guard column S
Phase change: THF
Flow rate: 1.0 ml / min
Injection volume 50μl
Column temperature 40 ° C

(2) Measurement of Acid Value 1.5 g of a solid or liquid polyester resin was weighed in an Erlenmeyer flask, and dissolved by adding about 10 ml of a solvent (toluene / methanol = 7/3 (volume ratio)). Next, 3 drops of an indicator (1% phenolphthalein / ethyl alcohol solution) were added, and titration was performed with a 0.1 N aqueous potassium hydroxide solution.
Acid value (mgKOH / g) = A × F / S
F: coefficient of 0.1 N aqueous potassium hydroxide solution (f × 5.61), f = 1
V: Titration of 0.1 N aqueous potassium hydroxide solution (ml)
W: Sample weight (g)

  For evaluation as an active energy curable inkjet ink composition, 90 parts by weight of dipropylene glycol diacrylate as a (meth) acrylate monomer and 1-hydroxy-cyclohexyl-phenyl-ketone (IGM Resins BV. A varnish composition was prepared by dissolving 10 parts by weight of the polyester resins 1 to 6 prepared in 10 parts by weight of a mixture (Irgacure 184, manufactured by Irgacure 184). In each dissolution, the mixture was charged into a container equipped with a disperser and stirred while being heated at 40 ° C. until it became visually transparent.

(3) Calculation of Urethane Bond Equivalent of Polyester Resin The urethane bond equivalent of the polyester resin was calculated from the formula (1) described in “0023”.

  The measurement of the varnish composition was performed according to the following method.

(1) Viscosity The viscosity of the varnish composition at 25 ° C. was measured using a MARSIII rheometer manufactured by Thermo Scientific. The cone plate angle was 2 °, and the reading of the viscosity value was at 10 rpm. Table 2 shows the results.

(2) Substrate warpage Polypropylene substrate (Toyobo P2161, biaxially-stretched polypropylene, corona-treated) A coating film of 6 ± 1 μm thickness is prepared with a bar coater on the entire surface of a 100 mm square, and irradiated with a metal halide light source of 200 mJ / cm 2. To prepare an ultraviolet-cured coating film. At this time, when the substrate warpage was visually confirmed, x was evaluated, and when it was not confirmed, ○ was evaluated. Table 2 shows the results.

(3) Tape peeling test A 6 ± 1 μm thick coating film was prepared with a bar coater on a polypropylene base material (Toyobo P2161, biaxially oriented polypropylene, corona treated), and cured by irradiation with a metal halide light source of 200 mJ / cm 2. A coating was prepared. The state when a cellophane tape made of Nichiban was applied thereto and strongly rubbed off with a finger was evaluated according to the following three grades. Table 2 shows the results.
3: No peeling when the tape is peeled 2: 50% peeling when the tape is peeled 1: Complete peeling when the tape is peeled

(4) Cross cut tape peeling test A coating film having a thickness of 6 ± 1 μm was prepared on a polypropylene base material (Toyobo P2161, biaxially oriented polypropylene, corona treated) with a bar coater, and irradiated with a metal halide light source of 200 mJ / cm 2. An ultraviolet-cured coating film was prepared. A grid-shaped cut was made on this coating film with a Cote-1 CCI-1 cross cutter, and a Nichiban cellophane tape was applied to the coating, followed by vigorous rubbing with a finger, followed by peeling. The number was counted. Table 2 shows the results.

Table 1 shows the compositions of the varnish compositions used in the examples and comparative examples. The numerical units of the composition in the table are parts by weight.

  Comparative Example 1 is a composition containing no polyester resin, and since no resin is present, curing shrinkage increases and substrate warpage increases. Comparative Example 2 contains polyester resin 1, curing shrinkage is suppressed, there is no substrate warpage, and substrate adhesion is excellent, but polyester resin 1 does not contain urethane structural units derived from isocyanate compounds, and the coating film is rigid. Therefore, when the cross cutter was inserted, cracks or chips occurred on the end face of the coating film, and the results did not endure the cross-cut tape peeling test.

In Examples 1 and 2, the molecular terminals were an alkyl group and a methacrylate group, respectively, and a polyester resin having no functional group and a functional group was used, but the cross-cut tape peeling test resistance both showed good results.
Examples 3, 4, and 5 all have a urethane structural unit near the center of the polyester resin molecule and have a relatively high urethane bond equivalent, but show good results in the resistance to the cross-cut tape peeling test.

  The active energy ray-curable inkjet ink composition of the present invention can be used as an inkjet ink in various inks, coating agents, paints, and the like.

Claims (5)

An active energy ray-curable inkjet ink composition containing a polyester resin (A),
The polyester resin (A) includes a structural unit (a-1) derived from a polybasic acid, a structural unit (a-2) derived from a polyhydric alcohol, and a urethane structural unit (a-3) derived from an isocyanate compound. Consisting of
The urethane bond equivalent of the polyester resin (A) is 100 to 2,000.   The active energy ray-curable inkjet ink composition according to claim 1, wherein the polyester resin (A) has a number average molecular weight of 500 to 5,000 and an acid value of 20 to 140.   The active energy ray-curable inkjet ink composition according to claim 1, further comprising a (meth) acrylate monomer (B).   The active energy ray-curable inkjet ink composition according to any one of claims 1 to 3, further comprising a polymerization initiator (C).   A printed matter obtained by printing the active energy ray-curable inkjet ink composition according to claim 1 and irradiating the active energy ray.