JP2023038690A - Active energy ray-curable composition, active energy ray-curable ink composition, inkjet ink composition and image forming apparatus - Google Patents

Abstract

To provide an active energy ray-curable composition having excellent adhesion to a base material and blocking resistance and further having excellent inkjet dischargeability.SOLUTION: There is provided an active energy ray-curable composition which comprises a polymerization initiator and a polymerizable compound, wherein the polymerization compound includes a compound (A) having a glass transition temperature of a homopolymer of 90°C or more and a ring structure, an amine-modified acrylate oligomer (B) and a compound (C) having a glass transition temperature of a homopolymer of -30°C or less, the content of the compound (A) is 45 mass% or more based on the total amount of the active energy ray-curable composition, the content of the compound (C) is 10 mass% or less based on the total amount of the active energy ray-curable composition and the relation of the content of the amine-modified acrylate oligomer (B)≥the content of the compound (C) is satisfied.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an active energy ray-curable composition, an active energy ray-curable ink composition, an inkjet ink composition, and an image forming apparatus.

The active energy ray-curable composition has the ability to be cured by irradiation with an active energy ray.

Inkjet printers are increasingly being used in industrial applications such as printing large advertisements. Examples of ink compositions used in inkjet printers include water-based inkjet ink compositions, oil-based inkjet ink compositions, and active energy ray-curable inkjet ink compositions.

Since the active energy ray-curable composition is cured by irradiating the active energy ray, it is excellent in drying property even on impermeable substrates such as acrylic plates.

On the other hand, when the printed matter is stored, the surface to which the ink composition is applied and the surface of the substrate may be in contact with each other, or the surfaces to which the ink composition is applied may be in contact with each other. Desired.

Although the active energy ray-curable composition has excellent drying properties, when the composition is cured by irradiation with active energy rays, blocking may occur due to the composition remaining in an unreacted state. be.

In addition, since the active energy ray-curable composition generates internal stress during curing, the substrate cannot follow the shape change of the cured product due to the internal stress in the case of a rigid substrate such as an acrylic plate. , in particular, may be inferior in adhesion.

Therefore, for example, in Patent Document 1, 44 to 80% by mass of a photopolymerizable monofunctional monomer, 15 to 50% by mass of a photopolymerizable polyfunctional monomer, and 5 to 15% by mass of an acylphosphine photopolymerization initiator. A clear ink composition for UV-LED curable inkjet printing containing Patent Document 2 proposes an active energy ray-curable primer ink composition containing at least a polymerizable compound and a polymerization initiator, wherein the polymerizable compound contains at least an amine-modified epoxy (meth)acrylate.

However, the UV-LED curable clear ink composition for inkjet printing described in Patent Document 1 may have poor adhesion when printed on a rigid substrate such as an acrylic plate. In addition, the active energy ray-curable primer ink composition described in Patent Document 2 may be inferior in blocking resistance.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an active energy ray-curable composition which is excellent in adhesiveness to a substrate and anti-blocking property, and which is also excellent in jettability by inkjet.

The above problem is solved by the following configuration 1).
1) An active energy ray-curable composition containing a polymerization initiator and a polymerizable compound,
As the polymerizable compound, the homopolymer has a glass transition temperature of 90°C or higher, and the compound (A) having a ring structure, the amine-modified acrylate oligomer (B), and the homopolymer have a glass transition temperature of -30°C or lower. containing compound (C),
The content of the compound (A) is 45% by mass or more relative to the total amount of the active energy ray-curable composition, and the content of the compound (C) is 10% relative to the total amount of the active energy ray-curable composition. % by mass or less, and an active energy ray-curable composition satisfying the relationship of the content of the amine-modified acrylate oligomer (B)≧the content of the compound (C).

ADVANTAGE OF THE INVENTION According to this invention, the active-energy-ray-curable composition which is excellent in adhesiveness with respect to a base material, anti-blocking property, and also the ejection property by an inkjet can be provided.

1 is a schematic diagram showing an example of an image forming apparatus according to the present invention; FIG. FIG. 3 is a schematic diagram showing an example of another image forming apparatus according to the present invention; FIG. 3 is a schematic diagram showing an example of still another image forming apparatus according to the present invention;

Hereinafter, embodiments of the present invention will be described in detail.

(Active energy ray-curable composition)
The active energy ray-curable composition of the present invention comprises a polymerization initiator and a polymerizable compound, the polymerizable compound having a homopolymer glass transition temperature of 90° C. or higher and having a ring structure (A); It contains an amine-modified acrylate oligomer (B) and a compound (C) whose homopolymer has a glass transition temperature of −30° C. or lower, and the content of the compound (A) is relative to the total amount of the active energy ray-curable composition. is 45% by mass or more, the content of the compound (C) is 10% by mass or less with respect to the total amount of the active energy ray-curable composition, and the content of the amine-modified acrylate oligomer (B) ≥ the above It is characterized by satisfying the content relationship of the compound (C).

As a result of intensive studies by the present inventors, in the active energy ray-curable composition of the present invention, the glass transition temperature of the homopolymer is 90 ° C. or higher, and by containing the compound (A) having a ring structure, blocking resistance It was found that a cured product having excellent properties and adhesion to a substrate can be obtained.

However, when the compound (A) alone is contained, especially when the surfaces to which the active energy ray-curable composition is applied are brought into contact with each other, blocking resistance may be insufficient. Although the reason for this is not clear, the following may be considered. By containing the compound (A), it is believed that a cured product having a high Tg and a rigid structure with a ring structure is formed, thereby improving blocking resistance. However, due to the bulkiness of the structure, the reactivity during curing may be poor, and a small amount of unreacted substances may remain, especially when the surfaces to which the active energy ray-curable composition is applied are brought into contact. It is thought that the amount of the residue will eventually increase and blocking will occur.

Accordingly, the present inventors conducted intensive studies and found that the inclusion of the amine-modified acrylate oligomer (B) can further improve the reactivity of the compound (A), and in particular, an active energy ray-curable composition is imparted. It was found that a cured product having excellent blocking resistance can be obtained when the surfaces are brought into contact with each other.

Presumably, the presence of the amine-modified acrylate oligomer (B) reduces the influence of oxygen inhibition during the curing reaction, allowing the compound (A) to react more efficiently.

Furthermore, by containing the compound (C) whose homopolymer has a glass transition temperature of -30°C or lower, flexibility can be imparted to the cured product, and a cured product with excellent adhesion can be obtained.

<Compound (A)>
As the compound (A), any compound having a homopolymer glass transition temperature of 90° C. or higher and having a ring structure can be used without particular limitation.
Examples include isobornyl (meth)acrylate, tribromophenyl (meth)acrylate, acryloylmorpholine, vinylcaprolactam and the like.
Compound (A) may be used alone or in combination of two or more.

The content of the compound (A) is preferably 45% by mass or more, more preferably 50% by mass or more, relative to the total amount of the active energy ray-curable composition. This makes it possible to obtain a cured product with excellent adhesion to the substrate and excellent blocking resistance.
Moreover, the upper limit of the content of the compound (A) is preferably 70% by mass or less, more preferably 60% by mass or less, relative to the total amount of the active energy ray-curable composition.
In the compound (A), the homopolymer preferably has a glass transition temperature of 90 to 150°C.

<Amine-modified acrylate oligomer (B)>
As the amine-modified acrylate oligomer (B), any amine-modified acrylate oligomer can be used without any particular limitation. The term "oligomer" as used in the present invention means a polymer having a weight average molecular weight of 1,000 or more and 30,000 or less. The polymerization average molecular weight can be measured, for example, by gel permeation chromatography (GPC).
Commercially available amine-modified acrylate oligomers (B) can be used, for example, GENOMER 5275 manufactured by Rahn AG, CN371, CN550, CN551 manufactured by Sartomer, and the like.
The amine-modified acrylate oligomer (B) may be used alone or in combination of two or more.

The content of the amine-modified acrylate oligomer (B) is, for example, 1% by mass or more and 10% by mass or less, and may be 1% by mass or more and 7.5% by mass or less with respect to the total amount of the active energy ray-curable composition. It is preferably 1% by mass or more and 5% by mass or less, and particularly preferably 3% by mass or more and 5% by mass or less.
This makes it possible to obtain a composition that is excellent in blocking resistance and also excellent in ink-jet ejection properties.

<Compound (C)>
As the compound (C), any homopolymer having a glass transition temperature of -30°C or lower can be used without any particular limitation.
For example, 4-hydroxybutyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, 3-methoxybutyl (meth)acrylate acrylates, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, isoamyl (meth)acrylate, butyl (meth)acrylate, 2-acryloyloxyethyl-succinic acid, isodecyl (meth)acrylate, tridecyl (meth)acrylate, Caprolactone (meth)acrylate, methoxypolyethylene glycol (350) mono(meth)acrylate, methoxypolyethylene glycol (550) mono(meth)acrylate, EBECRYL230, EBECRYL4491, EBECRYL8413 manufactured by Daicel-Ornex Co., Ltd., and the like. Among them, from the viewpoint of improving the effects of the present invention, the compound (C) is preferably a polymerizable compound having a molecular weight of 200 or less.

Compound (C) may be used alone or in combination of two or more.

The content of the compound (C) is 10% by mass or less relative to the total amount of the active energy ray-curable composition, for example, preferably 1% by mass or more and 10% by mass or less, and 1% by mass or more and 7.5% by mass. It is more preferably not more than 3% by mass, more preferably 3% by mass or more and 5% by mass or less.
Thereby, it is possible to obtain a composition having excellent blocking resistance and good adhesion to a substrate.

Moreover, the active energy ray-curable composition of the present invention preferably satisfies the relationship of the content of the amine-modified acrylate oligomer (B)≧the content of the compound (C) on a mass basis. This makes it possible to obtain a composition that is excellent in both blocking resistance and substrate adhesion. In addition, in the active energy ray-curable composition, the content of the amine-modified acrylate oligomer (B) is preferably 2 to 10% by mass relative to the total amount of the active energy ray-curable composition.
In the compound (C), the homopolymer preferably has a glass transition temperature of -70 to -30°C.

<Other polymerizable compounds>
The active energy ray-curable composition of the present invention may contain a polymerizable compound other than the compound (A), the amine-modified acrylate oligomer (B), and the compound (C). Other polymerizable compounds are not particularly limited and can be used as appropriate.
For example, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, ethyl acrylate, 2-hydroxypropyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclic trimethylolpropane formal monoacrylate, imide acrylate, 2,2,2 -trifluoroethyl acrylate, N-vinylformamide, cyclohexyl acrylate, benzyl acrylate, 4-t-butylcyclohexyl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, ethoxylated tribromophenyl acrylate, phenoxydiethylene glycol acrylate, vinylpyrrolidone, 2-hydroxy- 3-phenoxypropyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, stearyl acrylate, lauryl acrylate, 3,3,5-trimethylcyclohexyl acrylate, ethoxylated nonylphenyl acrylate, alkoxylated 2-phenoxyethyl acrylate, phenoxypolyethylene glycol acrylate , dimethylacrylamide, hydroxyethylacrylamide, isopropylacrylamide, diethylacrylamide, dimethylaminopropylacrylamide, monofunctional polymerizable compounds such as pentaerythritol tri(meth)acrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, pentaerythritol tetra (meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol (meth)hexaacrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethanetetra(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, 3-methyl-1,5 pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,3 -butylene glycol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, tetramethylolmethane tri(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate ) Acrylate, Modified Glycerin Di(meth)acrylate, bisphenol A diglycidyl ether (meth)acrylic acid adduct, modified bisphenol A di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, neopentylglycol hydroxypivalate (meth)acrylic acid adduct , 2-hydroxy-3-acryloyloxypropyl methacrylate, urethane acrylate oligomer, pentaerythritol tri(meth)acrylate hexamethylene diisocyanate urethane prepolymer, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate hexamethylene diisocyanate Examples include polyfunctional polymerizable compounds such as urethane prepolymers.

Other polymerizable compounds may be used alone or in combination of two or more.

The active energy ray-curable composition of the present invention preferably contains a urethane acrylate oligomer as another polymerizable compound, and preferably contains a urethane acrylate oligomer having two or more polymerizable functional groups. It is more preferable to contain a urethane acrylate oligomer having a group number of 3 or more, and it is particularly preferable to contain a urethane acrylate oligomer having a polymerizable functional group number of 3.
Thereby, it is possible to obtain a composition having excellent blocking resistance while maintaining adhesion.

When a urethane acrylate oligomer is used, the amount added is preferably 1 to 7% by mass, more preferably 2 to 5% by mass, relative to the total amount of the active energy ray-curable composition.

In addition, (meth)acrylic acid adduct represents acrylic acid adduct or methacrylic acid adduct, and (meth)acrylate represents acrylate or methacrylate.

<Glass transition temperature of homopolymer>
The glass transition temperature (Tg) of the homopolymer referred to in the present invention refers to the glass transition temperature (Tg) of the cured homopolymer of the polymerizable compound. The Tg can be obtained by referring to the catalog value, if any, or by measuring the Tg of the cured homopolymer by a differential scanning calorimetry (DSC) method.

<Active energy ray>
Examples of the active energy ray used for curing the active energy ray-curable composition of the present invention include ultraviolet rays, electron beams, α rays, β rays, γ rays, X rays, and other polymerizable components in the composition. It is not particularly limited as long as it can impart the energy necessary for proceeding with the polymerization reaction. Especially when using a high-energy light source, the polymerization reaction can proceed without using a polymerization initiator. Further, in the case of ultraviolet irradiation, there is a strong desire to eliminate mercury from the viewpoint of environmental protection, and replacement with GaN-based semiconductor ultraviolet light emitting devices is very useful both 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.

<Polymerization initiator>
The active energy ray-curable composition of the present invention can contain a polymerization initiator. Any polymerization initiator may be used as long as it can generate active species such as radicals and cations by the energy of active energy rays to initiate polymerization of polymerizable compounds (monomers and oligomers). As such polymerization initiators, known radical polymerization initiators, cationic polymerization initiators, base generators and the like can be used singly or in combination of two or more. Among them, radical polymerization initiators are used. is preferred. Also, in order to obtain a sufficient curing speed, the polymerization initiator is preferably contained in an amount of 5 to 20% by mass with respect to the total mass (100% by mass) of the composition.
Examples of radical polymerization initiators include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds, Examples include ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds.
Moreover, in addition to the polymerization initiator, a polymerization accelerator (sensitizer) can be used in combination. Examples of the polymerization accelerator include, but are not limited to, trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, 2-ethylhexyl p-dimethylaminobenzoate, N, Amine compounds such as N-dimethylbenzylamine and 4,4'-bis(diethylamino)benzophenone are preferred, and the content thereof may be appropriately set according to the polymerization initiator to be used and its amount.

<Color material>
The active energy ray-curable composition of the present invention may contain a coloring material. As the coloring material, various pigments and dyes that impart black, white, magenta, cyan, yellow, green, orange, lustrous colors such as gold and silver, etc., depending on the purpose and required properties of the composition in the present invention. can be used. The content of the coloring material may be appropriately determined in consideration of the desired color density, dispersibility in the composition, etc., and is not particularly limited. It is preferably 1 to 20% by mass. In addition, the active energy ray-curable composition of the present invention may be colorless and transparent without containing a coloring material, and in that case, it is suitable as an overcoat layer for protecting images, for example.
As the pigment, an inorganic pigment or an organic pigment can be used, and one kind may be used alone, or two or more kinds may be used in combination.
Examples of inorganic pigments that can be used include carbon black (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, iron oxide, and titanium oxide.
Examples of organic pigments include azo pigments such as insoluble azo pigments, condensed azo pigments, azo lakes, and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone. Polycyclic pigments such as pigments, dye chelates (for example, basic dye chelates, acid dye chelates, etc.), dyeing lakes (basic dye lakes, acid dye lakes), nitro pigments, nitroso pigments, aniline black, Daylight fluorescent pigments may be mentioned.
In addition, a dispersant may be further included in order to improve the dispersibility of the pigment. The dispersant is not particularly limited, but includes, for example, dispersants commonly used for preparing pigment dispersions such as polymeric dispersants.
As dyes, for example, acid dyes, direct dyes, reactive dyes, and basic dyes can be used, and they may be used singly or in combination of two or more.

<Organic solvent>
Although the active energy ray-curable composition of the present invention may contain an organic solvent, it is preferable not to contain it if possible. If the composition does not contain organic solvents, especially volatile organic solvents (VOC (Volatile Organic Compounds) free), the safety of the place where the composition is handled is further increased, and it is possible to prevent environmental pollution. . The term "organic solvent" means general non-reactive organic solvents such as ether, ketone, xylene, ethyl acetate, cyclohexanone, and toluene, and should be distinguished from reactive monomers. be. In addition, "not including" an organic solvent means not including substantially an organic solvent, and it is preferably less than 0.1% by mass.

<Other ingredients>
The active energy ray-curable composition of the present invention may optionally contain other known components. Other components are not particularly limited, but include, for example, conventionally known surfactants, polymerization inhibitors, leveling agents, antifoaming agents, fluorescent whitening agents, penetration accelerators, humectants (moisturizing agents), and fixing agents. agents, viscosity stabilizers, antifungal agents, preservatives, antioxidants, ultraviolet absorbers, chelating agents, pH adjusters, and thickeners.

<Adjustment of active energy ray-curable composition>
The active energy ray-curable composition of the present invention can be produced using the various components described above, and the adjustment means and conditions are not particularly limited. Put into a dispersing machine such as kitty mill, disc mill, pin mill, dyno mill, etc., disperse to prepare pigment dispersion liquid, and further mix polymerizable monomer, initiator, polymerization inhibitor, surfactant, etc. into the pigment dispersion liquid. can be adjusted by

The viscosity of the active energy ray-curable composition of the present invention may be appropriately adjusted according to the application and application means, and is not particularly limited. For example, when applying a discharge means for discharging the composition from a nozzle. is preferably 3 to 40 mPa·s, more preferably 5 to 30 mPa·s, particularly preferably 6 to 25 mPa·s, in the range of 20°C to 65°C, preferably 25°C. Moreover, it is particularly preferable that the viscosity range is satisfied without including the organic solvent. The above viscosity was measured using a cone-plate rotary viscometer VISCOMETER TVE-22L manufactured by Toki Sangyo Co., Ltd., using a cone rotor (1°34′×R24), rotating at 50 rpm, and constant temperature circulating water at 20°C. Measurement can be performed by appropriately setting the temperature within the range of ~65°C. VISCOMATE VM-150III can be used to adjust the temperature of the circulating water.

<Application>
The application of the active energy ray-curable composition of the present invention is not particularly limited as long as it is a field where active energy ray-curable materials are generally used, and can be appropriately selected according to the purpose. Examples include resins, paints, adhesives, insulating materials, release agents, coating materials, sealing materials, various resists, and various optical materials.
Furthermore, the active energy ray-curable composition of the present invention can be used not only as an ink to form two-dimensional characters and images, and to form a design coating film on various substrates, but also to form three-dimensional images (three-dimensional objects). It can also be used as a three-dimensional modeling material for forming. This three-dimensional modeling material may be used, for example, as a binder between powder particles used in a powder lamination method in which three-dimensional modeling is performed by repeating curing and lamination of powder layers. It may be used as a three-dimensional configuration material (model material) or a support member (support material) used in such a layered manufacturing method (stereolithography method). In addition, FIG. 2 shows a method of discharging the active energy ray-curable composition of the present invention to a predetermined region, irradiating the active energy ray and curing it, and sequentially laminating the solidified product to form a three-dimensional shape (details will be described later). 3, a storage pool (receiving portion) 1 of the active energy ray-curable composition 5 of the present invention is irradiated with an active energy ray 4 to form a cured layer 6 having a predetermined shape on a movable stage 3, and this is This is a method for three-dimensional modeling by successively layering layers.
As a stereolithography apparatus for molding a three-dimensional object using the active energy ray-curable composition of the present invention, a known apparatus can be used, and is not particularly limited. For example, means for containing the composition , a supply means, a discharge means, an active energy ray irradiation means, and the like.
The present invention also includes a molded article obtained by processing a cured product obtained by curing an active energy ray-curable composition and a structure in which the cured product is formed on a substrate. The molded article is, for example, a sheet-shaped or film-shaped cured product or structure subjected to molding such as heat stretching or punching.・It is suitable for applications that require molding after surface decoration, such as electronic equipment, meters for cameras, and operation panels.
The base material is not particularly limited and can be appropriately selected according to the purpose. Examples include paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, composite materials thereof, and the like. and a plastic substrate is preferable from the viewpoint of workability.

When the active energy ray-curable composition of the present invention is used as an ink, it may be used as an ink containing a coloring material, or as an ink containing substantially no coloring material. The term "substantially free of coloring material" means that the content of coloring material in the composition is less than 0.1% by mass.

<Composition storage container>
The composition storage container of the present invention means a container in which the active energy ray-curable composition is stored, and is suitable for the above uses. For example, when the active energy ray-curable composition of the present invention is used as an ink, the container containing the ink can be used as an ink cartridge or an ink bottle. In the work, it is no longer necessary to touch the ink directly, and it is possible to prevent stains on fingers and clothes. In addition, it is possible to prevent foreign matter such as dust from entering the ink. The shape, size, material, etc. of the container itself are not particularly limited as long as they are suitable for the application and usage. should be covered with a protective sheet or the like.

<Image Forming Method and Forming Apparatus>
The image forming method of the present invention has at least an irradiation step of irradiating an active energy ray for curing the active energy ray-curable composition of the present invention, and the image forming apparatus of the present invention comprises an active energy ray An irradiation means for irradiating radiation and a container for containing the active energy ray-curable composition of the present invention may be provided, and the container may be contained in the container. Furthermore, it may have a discharge step and discharge means for discharging the active energy ray-curable composition. The method of discharging is not particularly limited, but examples include a continuous injection type, an on-demand type, and the like. The on-demand type includes a piezo system, a thermal system, an electrostatic system, and the like.
FIG. 1 shows an example of an image forming apparatus equipped with an inkjet ejection means. Ink is ejected onto the recording medium 22 supplied from the supply roll 21 by the respective color printing units 23a, 23b, 23c, and 23d, which are provided with ink cartridges and ejection heads for active energy ray-curable inks of yellow, magenta, cyan, and black. be done. After that, the light sources 24a, 24b, 24c, and 24d for curing the ink are irradiated with active energy rays to cure the ink, thereby forming a color image. After that, the recording medium 22 is conveyed to the processing unit 25 and the print take-up roll 26 . A heating mechanism may be provided in each of the printing units 23a, 23b, 23c, and 23d so that the ink is liquefied at the ink discharge section. Further, if necessary, a mechanism may be provided for cooling the recording medium to about room temperature by contact or non-contact. Inkjet recording methods include a serial method in which a head is moved to eject ink onto a recording medium that moves intermittently according to the width of an ejection head, and a serial method in which ink is ejected onto a recording medium by moving the recording medium continuously. Any line system in which ink is ejected onto a recording medium from a head held at a fixed position can be applied.
The recording medium 22 is not particularly limited, but includes paper, film, metal, composite materials thereof, and the like, and may be in the form of a sheet. Further, the configuration may be such that only single-sided printing is possible, or that double-sided printing is also possible.
Furthermore, the active energy ray irradiation from the light sources 24a, 24b, and 24c may be weakened or omitted, and after printing a plurality of colors, the active energy ray may be irradiated from the light source 24d. Thereby, energy saving and cost reduction can be achieved.
The recorded matter to be recorded with the ink of the present invention includes not only those printed on smooth surfaces such as ordinary paper and resin films, but also those printed on uneven surfaces to be printed, and those printed on metals, ceramics, and the like. It also includes those printed on a printing surface made of various materials. In addition, by layering two-dimensional images, it is possible to form an image (an image consisting of two-dimensional and three-dimensional images) or a three-dimensional object with a partial three-dimensional effect.
FIG. 2 is a schematic diagram showing an example of another image forming apparatus (three-dimensional stereoscopic image forming apparatus) according to the present invention. The image forming apparatus 39 in FIG. 2 uses a head unit (movable in the AB direction) in which inkjet heads are arranged, and ejects the first active energy ray-curable composition from the ejection head unit 30 for a modeled object. A second active energy ray-curable composition having a composition different from that of the first active energy ray-curable composition is ejected from the head units 31 and 32, and these compositions are cured by adjacent ultraviolet irradiation means 33 and 34. It is laminated while doing so. More specifically, for example, the second active energy ray-curable composition is ejected from the support ejection head units 31 and 32 onto the shaped object support substrate 37, and is irradiated with an active energy ray to be solidified. After forming the first support layer having a reservoir, the first active energy ray-curable composition is discharged from the discharge head unit 30 for a modeled object into the reservoir, and is irradiated with an active energy ray to be solidified. By repeating the step of forming the first model layer by pressing the support layer and the model layer a plurality of times while lowering the vertically movable stage 38 according to the number of layers, the support layer and the model layer are laminated to form the three-dimensional model 35 . to manufacture. After that, the support laminate 36 is removed as needed. In FIG. 2, only one ejection head unit 30 for a modeled object is provided, but two or more may be provided.

(cured product)
The cured product of the present invention is formed by curing by irradiating at least one of the active energy ray-curable composition and the active energy ray-curable ink composition of the present invention with an active energy ray.

Examples of the present invention are shown below, but the scope of the present invention is not limited by these examples.

<Preparation of active energy ray-curable composition>
According to the materials and contents (% by mass) shown in Tables 1 to 3, active energy ray-curable compositions of Examples and Comparative Examples were prepared by a conventional method.
The Tg value in the table indicates the Tg of the cured homopolymer of each polymerizable compound.

<Blocking resistance evaluation>
Each active energy ray-curable composition was filled in an inkjet printer having a GEN5 head manufactured by Ricoh Co., Ltd., and the gap between the head and the substrate surface was 1 mm, and the coating amount was 1.7 mg/cm ² onto the acrylic substrate. A solid image was printed.
The active energy ray-curable composition deposited on the substrate was cured with an LED lamp (peak wavelength: 395 nm, 3000 mJ/cm ² ) manufactured by Ushio Inc.
Overlap the acrylic substrate so that the cured composition surfaces are in contact with each other, and after leaving it at room temperature for 24 hours with a load of 3 kg per A4 size from above, check for sticking and visual change in the cured film. The degree was evaluated according to the following criteria.
The results are listed in Tables 1-3.
[Evaluation criteria]
◎: No sticking, no change in the cured film 〇: Sticking, but no change in the cured film △: Sticking, change in part of the cured film ×: Sticking ⊚, ∘, and Δ evaluations in which there is sticking and changes are observed over the entire cured film are acceptable.

<Adhesion evaluation>
Each active energy ray-curable composition was filled in an inkjet printer having a GEN5 head manufactured by Ricoh Co., Ltd., and the gap between the head and the substrate surface was 1 mm, and the coating amount was 1.7 mg/cm ² onto the acrylic substrate. A solid image was printed.
The active energy ray-curable composition deposited on the substrate was cured with an LED lamp (peak wavelength: 395 nm, 3000 mJ/cm ² ) manufactured by Ushio Inc.
Adhesion Test Evaluation was made according to the following criteria according to the evaluation method of the cross-cut method of JIS K5600-5-6.
◎: No peeling ○: Peeling is seen along the cut of the cutter, but the squares are not peeled △: Less than half of the squares are peeled ×: More than half of the squares are peeled ◎, 〇 Evaluation is pass.

<Evaluation of dischargeability>
Each active energy ray-curable composition was filled in an inkjet printer having a GEN5 head manufactured by Ricoh Co., Ltd., and the gap between the head and the substrate surface was 1 mm, and the coating amount was 1.7 mg/cm ² onto the acrylic substrate. A solid image was printed.
The active energy ray-curable composition deposited on the substrate was cured with an LED lamp (peak wavelength: 395 nm, 3000 mJ/cm ² ) manufactured by Ushio Inc.
The image edge portion on the head scanning direction side was observed and evaluated according to the following criteria.
◯: Almost no ink adhesion is observed in the non-printed portion near the edge of the image △: Slight adhesion of ink is observed in the non-printed portion near the image edge ×: Ink adhesion is observed in the non-printed portion near the image edge ◯ and △ evaluations are acceptable.

From the results in Tables 1 to 3, the compositions of each example are excellent in adhesion to substrates and anti-blocking properties, and are also excellent in ejection properties by inkjet.
On the other hand, in Comparative Examples 1 to 7, the blending amounts of compound (A), amine-modified acrylate oligomer (B) and compound (C) did not satisfy the conditions specified in the present invention, so adhesion to the substrate and resistance to Both the blocking property and the jetting property by inkjet could not be satisfied.

1 storage pool (accommodation part)
3 Movable stage 4 Active energy ray 5 Active energy ray-curable composition 6 Curing layer 21 Supply roll 22 Recording media 23a, 23b, 23c, 23d Color printing units 24a, 24b, 24c, 24d Light source 25 Processing unit 26 Print winding roll 30 ejecting head units 31, 32 for the support body ejection head units 33, 34 ultraviolet irradiation means 35 three-dimensionally shaped article 36 supporting body lamination section 37 shaped article support substrate 38 stage 39 image forming apparatus

JP 2016-20457 A JP 2019-94405 A

Claims (10)

An active energy ray-curable composition containing a polymerization initiator and a polymerizable compound,
As the polymerizable compound, the homopolymer has a glass transition temperature of 90°C or higher, and the compound (A) having a ring structure, the amine-modified acrylate oligomer (B), and the homopolymer have a glass transition temperature of -30°C or lower. containing compound (C),
The content of the compound (A) is 45% by mass or more relative to the total amount of the active energy ray-curable composition, and the content of the compound (C) is 10% relative to the total amount of the active energy ray-curable composition. % by mass or less, and an active energy ray-curable composition satisfying the relationship of the content of the amine-modified acrylate oligomer (B)≧the content of the compound (C). 2. The active energy ray-curable composition according to claim 1, wherein the content of said amine-modified acrylate oligomer (B) is 1% by mass or more and 5% by mass or less relative to the total amount of said active energy ray-curable composition. 3. The active energy ray-curable composition according to claim 1, wherein the content of said compound (A) is 50% by mass or more relative to the total amount of said active energy ray-curable composition. 4. Any one of claims 1 to 3, wherein the compound (A), the amine-modified acrylate oligomer (B) and the polymerizable compound other than the compound (C) include a urethane acrylate oligomer having a functional group of 2 or more. The active energy ray-curable composition according to 1. 5. The active energy ray-curable composition according to claim 4, wherein said urethane acrylate oligomer is a trifunctional urethane acrylate oligomer. 6. The active energy ray-curable composition according to any one of claims 1 to 5, wherein the compound (C) is a polymerizable compound having a molecular weight of 200 or less. An active energy ray-curable ink composition comprising the active energy ray-curable composition according to any one of claims 1 to 6. 8. The active energy ray-curable ink composition according to claim 7, which contains substantially no coloring material. An inkjet ink composition comprising the active energy ray-curable ink composition according to claim 7 or 8. The active energy ray-curable composition according to any one of claims 1 to 6, the active energy ray-curable ink composition according to claim 7 or 8, or the inkjet ink composition according to claim 9. A two-dimensional or three-dimensional image forming apparatus having an accommodating section in which either one is accommodated and an irradiation means for irradiating active energy rays.

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