JP2023008818A - Active energy ray-curable composition, active energy ray-curable ink composition, active energy ray-curable inkjet ink composition, composition container, image forming device, image forming method, and cured product - Google Patents

Abstract

To provide an active energy ray-curable composition that has high adhesion to various substrates while ensuring the fastness of its cured product.SOLUTION: A second active energy ray-curable composition is applied to a cured product of a first active energy ray-curable composition. The second active energy ray-curable composition contains the following components (A), (B), and (C). The content of the component (B) is 60 mass% or more in the total of the polymerizable compounds. In the component (B), the proportion of polyfunctional monomers modified with the same number of oxyalkylene groups as the number of functional groups is 90 mass% or more, in which the proportion of tri- or higher polyfunctional monomers is 50 mass% or more. (A) Monofunctional monomer. (B) Polyfunctional monomer. (C) Photopolymerization initiator.SELECTED DRAWING: None

Description

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

There are various printing methods, and among them, the inkjet recording method is applied to various printing fields because it can easily and inexpensively produce an image.
In recent years, in the printing industry, it has been proposed to use an ultraviolet curable ink that dries (cures) instantly by light irradiation. Among them, a typical example is an active energy ray-curable composition containing a radical reactive compound (radical monomer) and a photoradical initiator.
Since the active energy ray-curable composition is cured by irradiation with an active energy ray, it is required to have excellent drying properties and adhesion to a wide variety of substrates as compared to solvent-based ink compositions.

Patent Document 1 discloses microencapsulated UV-curable pressure-sensitive ink that has low viscosity and excellent adhesiveness without causing problems such as viscosity increase or curing due to the progress of reaction of photopolymerization components during storage. A UV curable ink containing a photoinitiator is described.

Patent Document 2 describes an ink composition that provides a cured product having excellent stretchability and scratch resistance as well as excellent adhesion to a substrate. monomer) and a monomer B (a trifunctional or higher monomer having a molecular weight/functional group number of ≥ 200), and the total content of the monofunctional monomers in the total amount of the active energy ray-polymerizable monomers is 85.0 mol% or more, and the monomer B content of 0.5 mol % or more and 10.0 mol % or less is described.

Patent Document 3 describes a UV curable resin composition for ink jet printer ink containing a multi-branched monomer reacted with a mercapto group for the purpose of providing adhesiveness, scratch resistance and flexibility of the cured product. It is

In Patent Document 4, as an inkjet recording method capable of printing on various recording media with good quality at high speed and for the purpose of reducing poor curing, a recording pattern is formed on a recording medium with a first ultraviolet curable ink (A). forming an overcoat layer with a second ultraviolet curable ink (B) so as to cover the recording pattern of the ink (A); and further, ultraviolet irradiation. In the method, the first UV-curable ink (A) contains a photobase generator and a base-reactive compound, and the second UV-curable ink (B) contains a photo-radical generator and a radical-reactive compound. An ink jet recording method containing and is described.

When an active energy ray-curable composition attempts to achieve adhesion to a wide variety of substrates, there has been a problem of reduced robustness. Therefore, in some cases, an overcoat is further applied on the printed matter, but the printed matter is poor in fastness, and the overcoat liquid may damage the printed matter. Moreover, if the fastness on the overcoat side is increased too much, the film may become brittle.

An object of the present invention is to provide an active energy ray-curable composition that achieves both adhesion to a wide variety of substrates and robustness of a cured product, which have conventionally been in a trade-off relationship.

The active energy ray-curable composition of the present invention as means for solving the above problems is as described below.
A second active energy ray-curable composition applied on the cured product of the first active energy ray curable composition,
The second active energy ray-curable composition contains the following components (A), (B), and (C),
The content of the following component (B) in all polymerizable compounds is 60% by mass or more,
In the following component (B), the polyfunctional monomer modified with the same number of oxyalkylene groups as the number of functional groups is 90% by mass or more, and the trifunctional or higher polyfunctional monomer is 50% by mass or more. , an active energy ray-curable composition.
(A) monofunctional monomer (B) polyfunctional monomer (C) photopolymerization initiator

ADVANTAGE OF THE INVENTION According to this invention, the above-mentioned conventional problems can be solved and the active-energy-ray-curable composition which has both the adhesiveness to various base materials and the robustness of hardened|cured material 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. 10 is a schematic diagram showing an example of still another image forming apparatus according to the present invention;

The active energy ray-curable composition of the present invention is a second active energy ray-curable composition that is applied onto a cured product of the first active energy ray-curable composition, wherein the second active energy The radiation-curable composition contains the following components (A), (B), and (C).
(A) a monofunctional monomer (B) a multifunctional monomer (C) a photopolymerization initiator And the content of the component (B) in the total polymerizable compound is 60% by mass or more, and in the component (B), Polyfunctional monomers modified with the same number of oxyalkylene groups as the number of functional groups account for 90% by mass or more, of which trifunctional or higher polyfunctional monomers account for 50% by mass or more.
However, in the present invention, when the polyfunctional monomer is modified with oxyalkylene groups, the number of functional groups and the number of oxyalkylene groups are said to be the same. When the polyfunctional monomer is modified with polyoxyalkylene groups, the number of oxyalkylene groups is a multiple of the number of functional groups.

<Second active energy ray-curable composition>
The monofunctional monomers and polyfunctional monomers used in the active energy ray-curable composition (second active energy ray-curable composition) of the present invention will be described.

<Monofunctional monomer>
Conventionally known monofunctional monomers can be used, and may be used singly or in combination of two or more.

<Polyfunctional monomer>
A conventionally well-known polyfunctional monomer can be used, and may be used individually by 1 type, and may be used in combination of 2 or more types.
In addition, conventionally known ones modified with the same number of oxyalkylene groups as the number of functional groups used in the second active energy ray-curable composition can be used, and one type may be used alone, You may use 2 or more types together. Specific examples include, but are not limited to, compounds represented by the following structural formulas (A-1) to (A-7).

In the second active energy ray-curable composition of the present invention, the content of the polyfunctional monomer is 60% by mass or more, and the polyfunctional monomer is modified with the same number of oxyalkylene groups as the number of functional groups. 90% by mass or more, of which 50% by mass or more is trifunctional or higher. If the polyfunctional monomer is not modified with oxyalkylene groups, the film will be too hard and brittle.
If the ratio of the polyfunctional monomer is less than 60% by mass, the strength of the film will be weak.

<First active energy ray-curable composition>
The components of the first active energy ray-curable composition in the present invention are not particularly limited as long as the cured product sufficiently adheres to each substrate. As the polymerizable compound, monofunctional monomers and polyfunctional monomers used in the second active energy ray-curable composition can be used. Further, when the second active energy ray-curable composition is applied, the first active energy ray-curable composition is not affected, so that the components of the first active energy ray-curable composition include cross-linking It is preferable to add a certain amount of a polyfunctional monomer capable of forming a structure. It is preferable that the content of the monofunctional monomer is 60% by mass or more and the amount of the polyfunctional monomer is 5% by mass or more and 20% by mass or less.
In addition, from the viewpoint of enhancing substrate adhesion and coating film strength, the first active energy ray-curable composition contains a polyester resin containing an unsaturated bond, a polymerizable dendritic branching compound, and an allophanate bond-containing compound. is preferred.
The unsaturated bond-containing polyester resin, the polymerizable dendritic branching compound, and the allophanate bond-containing compound, which are the components of the first active energy ray-curable composition, are described below.

<Polyester resin containing unsaturated bond>
The polyester resin containing unsaturated bonds in the present invention preferably contains unsaturated bonds other than those derived from acrylic groups. Examples of unsaturated bonds other than acrylic groups include vinyl groups and allyl groups, but are not limited to these.

The polyester resin preferably has a number average molecular weight of 3,000 or less. If the number average molecular weight exceeds 3,000, the ejection stability by inkjet may deteriorate.
The content of the polyester resin is preferably 5.0% by mass or more and 20.0% by mass or less with respect to the total amount of the composition. If the content is less than 5.0% by mass, sufficient adhesion to the substrate cannot be obtained, and if it exceeds 20.0% by mass, the ejection stability may deteriorate.

Preferably, the unsaturated bond-containing polyester resin contains a polymerizable unsaturated bond-containing polyester resin. When the polyester resin has a polymerizable unsaturated bond, it is presumed that strong adhesion to a substrate can be obtained by copolymerization with a polymerizable compound.

The polyester resin containing polymerizable unsaturated bonds in the present invention preferably contains unsaturated bonds other than those derived from (meth)acryloyl groups. Examples of unsaturated bonds other than (meth)acryloyl groups include, but are not limited to, vinyl groups and allyl groups.
Specific examples of the polyester resin containing the polymerizable unsaturated bond include UVAD-081 (manufactured by Osaka Soda Co., Ltd.) and UVAD-085 (manufactured by Osaka Soda Co., Ltd.).

The polyester resin preferably has a number average molecular weight of 3,000 or less. When the number average molecular weight is 3,000 or less, the ejection stability by inkjet is less likely to deteriorate. The lower limit of the number average molecular weight is, for example, about 500.

The content of the polyester resin is preferably 5.0% by mass or more and 20.0% by mass or less, more preferably 10.0% by mass or more and 15.0% by mass or less, relative to the total amount of the composition. When the content of the polyester resin is 5.0% by mass or more, sufficient adhesion to the substrate can be obtained, and when it is 20.0% by mass or less, the ejection stability is less likely to decrease.

<Polymerizable dendritic branching compound>
A polymerizable compound having a dendrimer structure or a hyperbranched structure is preferably used as the polymerizable dendritic branching compound in the present invention. By using a polymerizable compound having a dendrimer structure or a hyperbranched structure, a three-dimensional structure actively develops due to the unique radial structure of the compound, a cured product with a high crosslink density is obtained, and a high coating strength is obtained. achieved. In addition, the polymerizable compound having a dendrimer structure or hyperbranched structure has a three-dimensional radial structure unique to the material, and by using a compound having an average number of polymerizable functional groups of 6 or more, high cross-linking can be achieved. density is achieved.
In addition, compared to general linear polymerizable compounds, polymerizable compounds having a dendrimer structure or hyperbranched structure can effectively relax external stress or internal stress due to their unique three-dimensional structure. It is possible to reduce the adverse effect on the adhesion to the substrate.

The polymerizable dendritic branching compound is preferably a compound having at least an acryloyloxy group or a methacryloyloxy group at its terminal and having a dendrimer structure or a hyperbranched structure. A radically polymerizable compound having six or more acryloyloxyoxy groups or methacryloyloxyoxy radically polymerizable functional groups and having a dendrimer structure or a hyperbranched structure in the molecule is also preferred.

Here, "hyperbranched structure" means a hyperbranched polymer synthesized by self-condensation of a compound having a total of three or more two types of substituents capable of reacting with each other in one molecule. A “dendrimer structure” means a multibranched polymer having a branched structure in which branched molecular structures serving as basic units are repeatedly linked from a polyfunctional compound serving as the center of the molecular structure called a core molecule.

The content of the polymerizable dendritic compound is preferably 4.0% by mass or more and 25.0% by mass or less with respect to the total amount of the composition. When the content is 4.0% by mass or more, sufficient coating film strength is obtained, and when it is 25.0% by mass or less, curing shrinkage does not increase and adhesion does not decrease. .

As the radically polymerizable compound having a hyperbranched structure or dendrimer structure, an appropriately synthesized one may be used, or a commercially available product may be used. Synthetic methods include the following.
A hyperbranched structure is obtained by self-condensation of an ABx type molecule having a total of 3 or more of two types of substituents in one molecule. For example, a hyperbranched polyester can be obtained by polycondensation using 3,5-dihydroxybenzoic acid as a starting material. In this case, a hydroxyl group is present at the terminal, and a radically polymerizable compound having a hyperbranched structure can be obtained by acting acrylic acid or methacrylic acid on it.

As methods for synthesizing dendrimers, there are known a divergent method in which synthesis proceeds from the core outward, a convergent method in which synthesis proceeds from the terminal functional groups inward, or a combination of these two methods. For example, using the convergent method, in the first step, 2-(4-hydroxyphenoxyethyl)-acrylate and 5-hydroxyisophthalic acid are coupled, and in the second step, trimesic acid is used to form a dendrimer structure. A radically polymerizable compound having

Commercially available products include, but are not limited to, the following compounds.
The dendrimer structure is V#1000 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), and the hyperbranched structure is CN2302 (manufactured by Sartomer), CN2303 (manufactured by Sartomer), CN2304 (manufactured by Sartomer), Etercure 6361-100 (manufactured by Eternal Material Industry Co., Ltd.) and Etercure 6363 (manufactured by Eternal Material Industry Co., Ltd.) can be mentioned. These may be used individually by 1 type, and may use 2 or more types together.
Moreover, the composition of the present invention may contain a polymerizable compound other than the compounds described above. Conventionally known ones can be used as these, and these may be used singly or in combination of two or more.

<Allophanate bond-containing compound>
As the allophanate bond-containing compound in the present invention, it is preferable to use a polymerizable compound having an allophanate bond. By using a polymerizable compound having an allophanate bond, a cured ink product having excellent adhesion to highly polar substrates such as metal and glass can be obtained due to the unique structure of the compound.

In addition, since the hydrogen bond contained in the allophanate bond suppresses thickening due to a general urethane bond, an ink having excellent continuous inkjet ejection properties can be obtained.
The allophanate bond-containing compound is preferably a compound having at least an allophanate bond and further having an acryloyloxy group or a methacryloyloxy group at its end. Radical polymerizable compounds having a radically polymerizable functional group of acryloyloxy group or methacryloyloxy group are also preferred.

The content of the allophanate bond-containing compound is preferably 4.0% by mass or more and 10.0% by mass or less, more preferably 4.8% by mass or more and 8.0% by mass or less, relative to the total amount of the composition. When the content of the allophanate bond-containing compound is 4.0% by mass or more, sufficient coating film strength is obtained, and when it is 10.0% by mass or less, curing shrinkage is suppressed and adhesion becomes more difficult to decrease. .
As the allophanate bond-containing compound, an appropriately synthesized one may be used, or a commercially available product may be used.

Commercially available products include, but are not limited to, the following compounds.
EBECRYL4666 (manufactured by Daicel Allnex Ltd.), EBECRYL4738 (manufactured by Daicel Allnex Ltd.), EBECRYL4740 (manufactured by Daicel Allnex Ltd.). These may be used individually by 1 type, and may use 2 or more types together.

<Curing means>
Examples of means for curing the curable composition of the present invention include heat curing and curing with active energy rays, and among these, curing with active energy rays is preferable.
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 may 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. Moreover, in order to obtain a sufficient curing speed, the polymerization initiator is preferably contained in an amount of 5% by mass or more and 20% by mass or less 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 an organic solvent, especially a volatile organic solvent (VOC (Volatile Organic Compounds) free), the safety of the place where the composition is handled is further increased, and it is also 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 include, but are not particularly limited to, conventionally known surfactants, polymerization inhibitors, leveling agents, antifoaming agents, fluorescent whitening agents, penetration accelerators, humectants (humectants), fixing agents, Viscosity stabilizers, antifungal agents, preservatives, antioxidants, ultraviolet absorbers, chelating agents, pH adjusters, thickeners, and the like.

<Preparation 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 preparation 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. It can be prepared by

<Viscosity>
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 15 mPa·s, particularly preferably 6 to 12 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 setting the temperature of constant temperature circulating water to 20° C. Measurement can be performed by appropriately setting the temperature in 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.

<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.

In the image forming method of the present invention, an active energy ray may be used, or heating may be used.
At least, in order to cure the active energy ray-curable composition of the present invention with an active energy ray, there is an irradiation step of irradiating the active energy ray, and the image forming apparatus of the present invention irradiates the active energy ray. and an accommodating portion for accommodating the active energy ray-curable composition of the present invention, and the container may be accommodated in the accommodating portion. 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, ceramics, glass, 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. Not limited to those used as general recording media, corrugated cardboard, building materials such as wallpaper and flooring, concrete, cloth for clothing such as T-shirts, textiles, leather, and the like can be used as appropriate.
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.

Although the present invention will be described in more detail based on examples below, the technical scope of the present invention is not limited to the following examples.
The abbreviations of the raw material components used in Examples and Comparative Examples are shown in Table 1 below.

(Examples 1 to 7 and Comparative Examples 1 to 3)

<Preparation of active energy ray-curable composition>
Based on the materials and contents (mass parts) shown in Table 2, active energy ray-curable compositions of Examples and Comparative Examples were prepared by a conventional method. In addition, the code|symbol which represents each compound in Table 2 corresponds with the code|symbol of the compound described in Table 1.
For the active energy ray-curable composition of each example and comparative example, a film having a thickness of 10 μm was formed on each substrate such as a PET film (E5100 manufactured by Toyobo Co., Ltd., thickness 100 μm), a slide glass, and a steel plate. was cured with a metal halide lamp (4000 mJ/cm ² ) manufactured by Ushio Inc.
The films formed above were evaluated for "appearance", "adhesion" and "pencil hardness" by the following evaluation methods, and the results are shown in Table 2.

<Appearance>
Whether or not the cured product of the first active energy ray-curable composition is eroded when the second active energy ray-curable composition is applied onto the cured first active energy ray-curable composition was judged by appearance. ○ indicates no effect, × indicates erosion of the cured film.

<Adhesion>
In the adhesion test, the adhesion to the substrate was evaluated according to the cross-cut evaluation method of JIS K5600-5-6 and the evaluation criteria. There are six evaluation criteria from 0 to 5, with 0 indicating the best evaluation result. A case with an evaluation of 2 or more was judged to be practicable. Table 1 shows the results.

<Pencil hardness>
The pencil hardness test was conducted according to JIS K5600-5-4 (scratch hardness: pencil method).
Table 1 shows the results.

<Ink ejection property as inkjet ink>
Three types of inkjet inks composed of the active energy ray-curable compositions of Examples 1 to 3 were evaluated for curability and ink jettability in the following manner.
[Evaluation method]
A nozzle check pattern was printed using ink to check for ink discharge failure (non-discharge or crooked discharge from the nozzle). In each nozzle check pattern, the presence or absence of white spots and ejection disturbance was visually evaluated.
[Evaluation criteria]
A: No ejection disturbance
B: Slightly disturbed ejection C: Disturbed ejection, or some areas where ejection is not performed D: Severe ejection disturbance, or many nozzles that do not eject
As a result, all of the inkjet inks were evaluated as A.

From the results in Table 2, the active energy ray-curable composition of the present invention has a pencil hardness of HB or more, adhesion to PET, glass, and steel, and the second active energy ray-curable composition has a base. It can be seen that it is compatible with not eroding. (If the substrate is eroded, the adhesion and pencil hardness are not evaluated.)

The present invention relates to the active energy ray-curable composition of (1) below, and includes the following (2) to (10) as embodiments.
(1) A second active energy ray-curable composition applied on the cured product of the first active energy ray-curable composition,
The second active energy ray-curable composition contains the following components (A), (B), and (C),
The content of the following component (B) in all polymerizable compounds is 60% by mass or more,
In the following component (B), the polyfunctional monomer modified with the same number of oxyalkylene groups as the number of functional groups is 90% by mass or more, and the trifunctional or higher polyfunctional monomer is 50% by mass or more. , an active energy ray-curable composition.
(A) a monofunctional monomer (B) a multifunctional monomer (C) a photopolymerization initiator (2) the first active energy ray-curable composition contains the following components (A) to (E), The active energy ray-curable composition according to (1) above.
(A) a monofunctional monomer (B) a multifunctional monomer (C) a photopolymerization initiator (D) a polyester resin containing an unsaturated bond (E) a polymerizable dendritic branching compound or/and an allophanate bond-containing compound.
(3) The active energy ray-curable composition according to (2) above, wherein the content of component (A) in all polymerizable compounds in the first active energy ray-curable composition is 85% by mass or more. .
(4) An active energy ray-curable ink composition using the active energy ray-curable composition according to any one of (1) to (3) above.
(5) An active energy ray-curable ink composition for inkjet, characterized by using the active energy ray-curable ink composition described in (4) above.
(6) A composition container containing the composition according to any one of (1) to (5) above.
(7) An image forming apparatus comprising: a container containing the composition according to any one of (1) to (5) above; and irradiation means for irradiating active energy rays.
(8) An image forming method comprising an irradiation step of irradiating the composition according to any one of (1) to (5) above with an active energy ray.
(9) An image forming method comprising the step of applying a second active energy ray-curable composition onto a cured product of the first active energy ray-curable composition, wherein the second active energy ray-curable composition An image forming method, wherein the composition described in any one of (1) to (5) above is used as the composition.
(10) A cured product obtained by irradiating the composition according to any one of the above (1) to (5) with an active energy ray to cure it.

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 medium 23a, 23b, 23c, 23d Printing units 24a, 24b, 24c, 24d Light source 25 Processing unit 26 Print winding roll 30 modeled object ejection head units 31, 32 support member ejection head units 33, 34 ultraviolet ray irradiation means 35 three-dimensional modeled object 36 support laminate 37 modeled object support substrate 38 stage 39 image forming apparatus

JP 2004-115655 Patent No. 6566953 Patent No. 5512970 Patent No. 6103213

Claims (10)

A second active energy ray-curable composition applied on the cured product of the first active energy ray curable composition,
The second active energy ray-curable composition contains the following components (A), (B), and (C),
The content of the following component (B) in all polymerizable compounds is 60% by mass or more,
In the following component (B), the polyfunctional monomer modified with the same number of oxyalkylene groups as the number of functional groups is 90% by mass or more, and the trifunctional or higher polyfunctional monomer is 50% by mass or more. , an active energy ray-curable composition.
(A) monofunctional monomer (B) polyfunctional monomer (C) photopolymerization initiator The active energy ray-curable composition according to claim 1, wherein the first active energy ray-curable composition contains the following components (A) to (E).
(A) a monofunctional monomer (B) a multifunctional monomer (C) a photopolymerization initiator (D) a polyester resin containing an unsaturated bond (E) a polymerizable dendritic compound or/and an allophanate bond-containing compound 3. The active energy ray-curable composition according to claim 2, wherein the content of component (A) in all polymerizable compounds in said first active energy ray-curable composition is 85% by mass or more. An active energy ray-curable ink composition comprising the active energy ray-curable composition according to claim 1 . 5. An active energy ray-curable inkjet ink composition comprising the active energy ray-curable ink composition according to claim 4. A composition container containing the composition according to claim 1. 6. An image forming apparatus comprising: a storage section storing the composition according to claim 1; and an irradiation means for irradiating active energy rays. 6. An image forming method, comprising an irradiation step of irradiating the composition according to any one of claims 1 to 5 with an active energy ray. An image forming method comprising the step of applying a second active energy ray-curable composition onto a cured product of a first active energy ray-curable composition, wherein the second active energy ray-curable composition is 6. An image forming method comprising using the composition according to any one of claims 1 to 5. A cured product obtained by irradiating the composition according to any one of claims 1 to 5 with an active energy ray to cure it.

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