JP2022097872A - Method for manufacturing laminate - Google Patents

Abstract

To provide a method for manufacturing a laminate which achieves both adhesion and coated film fastness and has good productivity.SOLUTION: There is provided a method for manufacturing a laminate that forms a first ink layer composed of first active energy ray-curable inkjet ink on a base material, forms a second ink layer composed of second active energy ray-curable inkjet ink on the first ink layer, then irradiates the first ink layer and the second ink layer with active energy rays, and forms a first curable layer and a second curable layer, in which static surface tension γ1 of the first active energy ray-curable inkjet ink is larger than static surface tension γ2 of the second active energy ray-curable inkjet ink, and the second active energy ray-curable inkjet ink contains 10 mass% or more and 40 mass% or less of a polyfunctional polymerizable compound having a weight average molecular weight (Mw) of 500 or more, and contains 1 mass% or more and 30 mass% or less of inorganic particles.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a laminate.

Conventionally, active energy ray-curable inks that are cured using active energy rays such as ultraviolet rays (UV) and electron beams (EB) have been supplied and used for offsets, silk screens, topcoat agents, etc., but are dried. In recent years, the amount used has been increasing due to merits such as cost reduction by simplifying the process and reduction of the volatilization amount of the solvent as an environmental measure. Recently, as industrial applications, due to its on-demand properties, applications such as decorative printing and coating using inkjet are increasing. However, in terms of inkjet suitability, there is generally a trade-off relationship between the robustness of the coating film and the adhesion, and the inkjet ink coating film alone often cannot meet the market demand. Therefore, it is necessary to separately coat or laminate, but if a separate process is provided, the productivity will decrease.

Patent Document 1 proposes a method of improving the adhesion to a non-penetrating substrate by forming a multilayer coating film on the substrate using inks having different contact angles. By using this method, it is possible to achieve both the robustness of the coating film and the adhesion.
Patent Document 2 proposes a method of ejecting an ultraviolet curable material onto the liquid surface of an ultraviolet curable resin liquid by an inkjet method to form an image (layer).
Patent Document 3 proposes a method for forming a multilayer coating film wet-on-wet in an active ray-curable inkjet ink containing a gelling agent and a white pigment. By using this method, it is possible to prevent color mixing between different inks depending on the gelling agent.

Since the method of Patent Document 1 employs a step of printing each layer of the other layer coating film one layer at a time, the productivity is lowered. Although the method of Patent Document 2 is formed, it is intended to spread the image pattern thinly on the surface, and it is difficult to impart the function of robustness because the film thickness of the upper layer is thin.
An object of the present invention is to provide a method for producing a laminate having both adhesiveness and robustness of a coating film and having good productivity.

The present invention as a means for solving the above-mentioned problems relates to a method for producing a laminated body as described below.
A step of ejecting a first active energy ray-curable inkjet ink onto a substrate to form a first ink layer,
A step of ejecting a second active energy ray-curable inkjet ink onto the first ink layer to form a second ink layer,
The first ink layer and the second ink layer are irradiated with active energy rays to cure the first ink layer to form a first cured layer and to cure the second ink layer. And the process of forming the second hardened layer
A method for producing a laminate having the first cured layer and the second cured layer.
The static surface tension of the first active energy ray-curable inkjet ink was γ1 (mN / m), and the static surface tension of the second active energy ray-curable inkjet ink was γ2 (mN / m). Occasionally, γ1 and γ2 satisfy the relationship of the following equation (1), and
γ1> γ2 (1)
The second active energy ray-curable inkjet ink contains 10% by mass or more and 40% by mass or less of a polyfunctional polymerizable compound having a weight average molecular weight (Mw) of 500 or more, and contains 1% by mass or more and 30% by mass of inorganic particles. % Or less,
A method for manufacturing a laminated body, which is characterized by the above.

According to the present invention, it is possible to provide a method for producing a laminate having both adhesiveness and coating film fastness and having good productivity.

It is a schematic diagram which shows an example of the apparatus which carries out the manufacturing method of the laminated body of this invention.

Hereinafter, the method for producing the laminate of the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to the embodiments shown below, and can be modified within the range conceivable by those skilled in the art, such as other embodiments, additions, modifications, and deletions. However, as long as the action and effect of the present invention are exhibited, it is included in the scope of the present invention.

In the method for producing a laminate of the present invention, a first active energy ray-curable inkjet ink and a second active energy ray-curable inkjet ink are used.
The method for producing a laminate of the present invention includes the following steps.
-A step of ejecting a first active energy ray-curable inkjet ink onto a substrate to form a first ink layer-A second active energy ray-curable inkjet ink is ejected onto the first ink layer. Step of Forming Second Ink Layer-The first ink layer and the second ink layer are irradiated with active energy rays to cure the first ink layer to form a first cured layer. A step of curing the second ink layer to form a second cured layer, and setting the static surface tension of the first active energy ray-curable inkjet ink to γ1 (mN / m). When the static surface tension of the active energy ray-curable inkjet ink of No. 2 is γ2 (mN / m), γ1 and γ2 satisfy the relationship of the following formula (1).
γ1> γ2 (1)
The second active energy ray-curable inkjet ink contains 10% by mass or more and 40% by mass or less of a polyfunctional polymerizable compound having a weight average molecular weight (Mw) of 500 or more, and contains 1% by mass or more of inorganic particles. Contains 30% by mass or less,

As described above, in the method for producing a laminated body of the present invention, the laminated body is formed by a first ink jet ink and a second inkjet ink to form a laminated structure composed of a first ink layer and a second ink layer. Productivity can be improved by irradiating the first ink layer and the second ink layer with active energy rays to cure the first ink layer and the second ink layer at the same time.

Further, by making the static surface tension (γ1 [mN / m]) of the inkjet ink larger than the static surface tension (γ2 [mN / m]) of the second active energy ray-curable inkjet ink, the first It is possible to prevent the second inkjet ink from entering the inkjet ink layer.

Further, the second active energy ray-curable inkjet ink contains 10% by mass or more and 40% by mass or less of a polyfunctional polymerizable compound having a weight average molecular weight (Mw) of 500 or more in the total amount thereof, so that the ink adheres. High hardness can be developed without impairing the properties.

Further, when the second inkjet ink contains 1% by mass or more and 30% by mass or less of inorganic particles in the total amount thereof, the inorganic particles are oriented at high density on the surface of the coating film, thereby achieving both adhesion and fastness. be able to. This is because when the droplets of the second inkjet ink land on the liquid layer of the first inkjet ink, the monofunctional monomer having a small molecular weight contained in the second inkjet ink is the liquid layer of the first inkjet ink. By diffusing inward, the density of the inorganic particles in the droplets of the second inkjet ink is increased, and the density of the inorganic particles in the layer of the second inkjet ink is increased, so that the hardness of the coating film is improved. This is also because the adhesion is improved by the effect of suppressing the peeling of the surface layer.

<Inkjet ink>
The inkjet ink in the present invention uses at least a first active energy ray-curable inkjet ink and a second active energy ray-curable inkjet ink in combination. Each inkjet ink has different physical characteristics.

The material composition of the inkjet ink is not particularly limited. Since the monomer and the surfactant have a great influence on the physical properties of the obtained cured product, it is preferable to select an appropriate one according to the physical properties of the desired cured product. Inkjet ink contains, if necessary, a polymerization initiator, a coloring material, a polymerization inhibitor, a diluting solvent, other known components, and the like, in addition to the monomer and the surfactant.
Hereinafter, the first active energy ray-curable inkjet ink may be referred to as a “first inkjet ink”, and the second active energy ray-curable inkjet ink may be referred to as a “second inkjet ink”.

<Laminated body>
The laminate of the present invention includes at least a first cured layer made of a cured product of the first inkjet ink and a second cured layer made of a cured product of the second inkjet ink.
Since the first cured layer is located under the laminated body, it is preferable that the first cured layer has an adhesive function. Since the second cured layer is located on the upper layer of the laminated body, it is preferable that the second cured layer has a function of coating film fastness.

<Monomer>
The monomer is a compound that undergoes a polymerization reaction by an active energy ray (ultraviolet rays, electron beams, etc.) or an active species generated by the active energy ray and is cured, and is a polyfunctional monomer or a monofunctional monomer depending on the number of functional groups. Monomers can be mentioned. The monomer may have a polymerizable property and may contain a polymerizable oligomer or a polymerizable polymer (macromonomer).
There are no restrictions on the type of monomer for each inkjet ink, but since the first inkjet ink is located in the lower layer of the laminate, it is preferable to impart an adhesion function, and it contains a large amount of monofunctional monomers. It is preferable that the monofunctional monomer is contained in an amount of 50% by mass or more.

Since the second inkjet ink is located on the upper layer of the laminate, it is preferable to impart the function of coating film fastness, and the monofunctional monomer is 45% by mass or more and the polyfunctional monomer having Mw of 500 or more is 10% by mass. It is preferably contained in an amount of% or more and 40% by mass or less, and more preferably 15% by mass or more and 30% by mass or less. When a layer is formed in a liquid state by the first inkjet ink and the second inkjet ink, the components contained in the second inkjet ink diffuse into the layer made of the first inkjet ink, so that the substrate adhesion is achieved. May decrease. The layer in which the monofunctional monomer is composed of the first inkjet ink by containing 45% by mass or more of the monofunctional monomer and 10% by mass or more and 40% by mass or less of the polyfunctional monomer having Mw of 500 or more in the second inkjet ink. High adhesion to the substrate can be maintained even if it diffuses into the ink, and the polyfunctional monomer has a certain molecular weight, which makes it difficult to diffuse, and stays in the layer made of the second inkjet ink to provide high adhesion. It is possible to achieve both the fastness of the coating film. If the polyfunctional monomer is contained in an amount of more than 40% by mass, the adhesion to the substrate cannot be maintained.
The content of the polyfunctional monomer in the inkjet ink preferably satisfies the relationship [content of the polyfunctional monomer in the first inkjet ink <content of the polyfunctional monomer in the second inkjet ink]. If the polyfunctional monomer is excessively contained in the first inkjet ink, the adhesion is lowered due to the influence of curing shrinkage, and if the content of the polyfunctional monomer is small in the second inkjet ink, sufficient hardness is not developed.

As the polyfunctional monomer, it is preferable to use a bifunctional monomer, a trifunctional monomer, or a (meth) acrylate monomer having a higher number of functional groups.
The polyfunctional monomer is not particularly limited as long as the weight average molecular weight (Mw) is 500 or more, and can be appropriately selected depending on the intended purpose.
The weight average molecular weight (Mw) can be measured by using gel permeation chromatography manufactured by Shimadzu Corporation.
Examples of the polyfunctional monomer include neopentyl glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, and tetraethylene glycol di (meth). ) Aacrylate, (poly) propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, (poly) tetramethylene glycol di (meth) acrylate, bisphenol A propylene oxide (PO) adduct di (meth) acrylate. , Eethoxylated neopentyl glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, ethylene oxide (EO) adduct di (meth) acrylate of bisphenol A, EO-modified pentaerythritol trimethylolpropane (meth) acrylate, PO Modified pentaerythritol trimethylolpropane (meth) acrylate, EO-modified pentaerythritol tetra (meth) acrylate, PO-modified pentaerythritol tetra (meth) acrylate, EO-modified dipentaerythritol tetra (meth) acrylate, PO-modified dipentaerythritol tetra (meth) acrylate , EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO-modified tetramethylolmethanetetra (meth) acrylate, PO-modified tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) ) Acrylic, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, trimethylolethanetri (meth) acrylate, trimethylolpropane Tri (meth) acrylate, bis (4- (meth) acryloxypolyethoxyphenyl) propane, diallylphthalate, triallyltrimethylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di ( Meta) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate hydroxypivalate, tetramethylolmethanetri (meth) acrylate, di Methyloltricyclodecanedi (meth) acrylate, modified glycerintri (meth) acrylate, bisphenol A diglycidyl ether (meth) acrylic acid adduct, modified bisphenol A di (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate. , Dipentaerythritol hexa (meth) acrylate, pentaerythritol tri (meth) acrylate tolylene urethane prepolymer, pentaerythritol tri (meth) acrylate hexamethylene diisocyanate urethane prepolymer, ditrimethylolpropanetetra (meth) acrylate, pentaerythritol tri Examples thereof include (meth) acrylate hexamethylene diisocyanate urethane prepolymer, urethane acrylate oligomer, epoxy acrylate oligomer, polyester acrylate oligomer, polyether acrylate oligomer, silicone acrylate oligomer and the like. These may be used alone or in combination of two or more.

The monofunctional monomer is a monomer having one functional group.
The monofunctional monomer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, hydroxyethyl (meth) acrylamide, (meth) acryloylmorpholine, dimethylaminopropylacrylamide, isobornyl (meth) acrylate, and adamantyl (meth). ) Acrylate, 2-methyl-2-adamantyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 3,3,5-trimethylcyclohexane (Meta) acrylate, t-butyl methacrylate, tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2- Examples thereof include hydroxybutyl acrylate, isobutyl acrylate, t-butyl acrylate, phenoxyethyl acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate, and cyclic trimethylolpropaneformal acrylate. These may be used alone or in combination of two or more.

<Surfactant>
The surfactant has an effect of suppressing mixing of the compositions with each other when the first inkjet ink and the second inkjet ink form a layer with a liquid.
It is preferable that each inkjet ink contains a trace amount of a surfactant as needed, and it is preferable that at least the second inkjet ink contains a surfactant, and the surfactant is 0.01% by mass or more and 1% by mass or less. It is preferable to contain it. This is because if an excessive amount of surfactant is added, the antifouling property and the ejection stability in inkjet are impaired. Further, when the blending amount of the surfactant is small or not contained, when the first inkjet ink and the second inkjet ink form a layer with a liquid, the inks are mixed with each other, and the adhesion and the coating film are formed. It causes the incompatibility of robustness. As the surfactant, one type may be used alone, or two or more types may be used in combination.

<Inorganic particles>
By adding the inorganic particles to the second inkjet ink, the inorganic particles are oriented at a high density on the surface of the coating film, and both robustness and adhesion can be achieved at the same time. This is because when the droplets of the second inkjet ink land on the liquid layer of the first inkjet ink, the monofunctional monomer having a small molecular weight diffuses into the liquid layer of the first inkjet ink. This is due to the increase in the density of inorganic particles in the droplets of the inkjet ink of 2. By increasing the density of the inorganic particles in the layer of the second inkjet ink, the hardness of the coating film is improved, and the adhesion is also improved by the effect of suppressing the peeling of the surface layer.

The inorganic particles are not particularly limited and may be appropriately selected depending on the intended purpose. The inorganic particles are preferably silica. This is because silica is particularly likely to be oriented on the surface of the coating film and its hardness is likely to be developed.
The average primary particle diameter of the inorganic particles is preferably 30 nm or more and 1 μm or less, and more preferably 100 nm or more. This is because the hardness of the coating film improves as the average primary particle diameter of the inorganic particles increases. By setting the average primary particle diameter of the inorganic particles to 1 μm or less, it is possible to suppress a decrease in ejection stability.

The blending ratio of the inorganic particles is preferably 1% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less. This is because if the amount of the inorganic particles blended is small, the effect of the above-mentioned inorganic particles cannot be sufficiently obtained, and if the inorganic particles are blended excessively, the inorganic particles are likely to settle in the inkjet head, and the ejection stability is improved. This is because it is damaged. As the inorganic particles, one type may be used alone, or two or more types may be used in combination.

<Curing means>
Examples of the means for curing the curable inkjet ink of the present invention include heat curing or curing with active energy rays, and among these, curing with active energy rays is preferable.
The active energy rays used for curing the active energy ray-curable inkjet ink of the present invention include polymerizable components in the composition such as electron beams, α rays, β rays, γ rays, and X rays in addition to ultraviolet rays. It is not particularly limited as long as it can impart the energy required for advancing the polymerization reaction of the above. In particular, when a high-energy light source is used, the polymerization reaction can proceed without using a polymerization initiator. Further, 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. Further, the ultraviolet light emitting diode (UV-LED) and the ultraviolet laser diode (UV-LD) are compact, have a long life, have high efficiency, and are low in cost, and are preferable as an ultraviolet light source.

<Polymer initiator>
The active energy ray-curable inkjet ink of the present invention may contain a polymerization initiator. The polymerization initiator may be any one capable of generating active species such as radicals and cations by the energy of the active energy ray and initiating the polymerization of the polymerizable compound (monomer or oligomer). As such a polymerization initiator, known radical polymerization initiators, cationic polymerization initiators, base generators and the like can be used alone or in combination of two or more, and among them, a radical polymerization initiator is used. Is preferable. Further, 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 inkjet ink in order to obtain a sufficient curing rate.
Examples of the radical polymerization initiator include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds, and the like. Examples thereof include a ketooxime ester compound, a borate compound, an azinium compound, a metallocene compound, an active ester compound, a compound having a carbon halogen bond, and an alkylamine compound.
Further, in addition to the above-mentioned polymerization initiator, a polymerization accelerator (sensitizer) can also be used in combination. The polymerization accelerator is not particularly limited, and is, for example, trimethylamine, methyldimethylamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, p-dimethylaminobenzoic acid-2-ethylhexyl, N, Amine compounds such as N-dimethylbenzylamine and 4,4'-bis (diethylamino) benzophenone are preferable, and the content thereof may be appropriately set according to the polymerization initiator used and the amount thereof.

<Color material>
The active energy ray-curable inkjet ink 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, glossy colors such as gold and silver, etc., depending on the purpose and required characteristics of the inkjet ink in the present invention. Can be used. The content of the coloring material may be appropriately determined in consideration of a desired color density, dispersibility in the inkjet ink, and the like, and is not particularly limited, but is 0. It is preferably 1 to 20% by mass. The active energy ray-curable inkjet ink of the present invention may be colorless and transparent without containing a coloring material, and in that case, for example, it is suitable as an overcoat layer for protecting an image.
The addition of a coloring material to the combination of the inkjet inks of the present invention is optional, but in particular, the second inkjet ink that is landed at the end makes it easy to arrange the dots of the droplets in high definition, and the drawing containing the coloring material. It is preferable to use a color ink for use or a clear ink that does not contain a coloring material. The first inkjet ink used as a base is preferably white ink or clear ink.
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.
As the inorganic pigment, for example, carbon black (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, iron oxide, and titanium oxide can be used.
Examples of organic pigments include azo pigments such as insoluble azo pigments, condensed azo pigments, azolakes and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments and quinophthalones. Polycyclic pigments such as pigments, dye chelate (for example, basic dye type chelate, acidic dye type chelate, etc.), dyeing rake (basic dye type rake, acidic dye type rake), nitro pigment, nitroso pigment, aniline black, Daylight fluorescent pigments can be mentioned.
Further, in order to improve the dispersibility of the pigment, a dispersant may be further contained. The dispersant is not particularly limited, and examples thereof include dispersants commonly used for preparing pigment dispersions such as polymer dispersants.
As the dye, for example, an acid dye, a direct dye, a reactive dye, and a basic dye can be used, and one type may be used alone or two or more types may be used in combination.

<Organic solvent>
The active energy ray-curable inkjet ink of the present invention may contain an organic solvent, but it is preferable not to contain it if possible. If the composition does not contain an organic solvent, particularly a volatile organic solvent (VOC (Volatile Organic Compounds) free), the safety of the place where the composition is handled is further enhanced, and it is possible to prevent environmental pollution. .. The "organic solvent" means a general non-reactive organic solvent such as ether, ketone, xylene, ethyl acetate, cyclohexanone, and toluene, and should be distinguished from the reactive monomer. be. Further, "not containing" the organic solvent means that it is substantially free of the organic solvent, and it is preferably less than 0.1% by mass.

<Other ingredients>
The active energy ray-curable inkjet ink of the present invention may contain other known components, if necessary. The other components are not particularly limited, but are, for example, conventionally known polymerization inhibitors, leveling agents, antifoaming agents, fluorescent whitening agents, penetration promoters, wetting agents (moisturizing agents), fixing agents, and viscosity stabilizing agents. Examples include agents, fungicides, preservatives, antioxidants, UV absorbers, chelating agents, pH regulators, thickeners and the like.

<Preparation of active energy ray-curable composition>
The active energy ray-curable inkjet ink of the present invention can be produced by using the above-mentioned various components, and the preparation means and conditions thereof are not particularly limited. For example, a polymerizable monomer, a pigment, a dispersant and the like are used in a ball mill. It is put into a disperser such as a kitty mill, a disc mill, a pin mill, and a dyno mill, and dispersed to prepare a pigment dispersion, and the pigment dispersion is further mixed with a polymerizable monomer, an initiator, a polymerization inhibitor, a surfactant, and the like. It can be prepared by letting it.

<Viscosity>
The viscosity of the active energy ray-curable inkjet ink of the present invention may be appropriately adjusted according to the intended use and application means, and is not particularly limited. For example, when a ejection means for ejecting the composition from a nozzle is applied. The viscosity in the range of 20 ° C. to 65 ° C., preferably 3 to 40 mPa · s, more preferably 5 to 15 mPa · s, and particularly preferably 6 to 12 mPa · s at 25 ° C. Further, it is particularly preferable that the viscosity range is satisfied without containing the organic solvent. For the above viscosity, a cone rotor (1 ° 34'× R24) was used with a cone plate type rotational viscometer VISCOMETER TVE-22L manufactured by Toki Sangyo Co., Ltd., the rotation speed was 50 rpm, and the temperature of constant temperature circulating water was 20 ° C. It can be appropriately set and measured in the range of about 65 ° C. VISCOMATE VM-150III can be used to adjust the temperature of the circulating water.

<Use>
The application of the active energy ray-curable inkjet ink of the present invention is not particularly limited as long as it is in a field where an active energy ray-curable material is generally used, and can be appropriately selected depending on the intended purpose, for example, for molding. Examples thereof include resins, paints, adhesives, insulating materials, mold release agents, coating materials, sealing materials, various resists, and various optical materials.
The present invention also includes a cured product obtained by curing an active energy ray-curable inkjet ink and a molded product obtained by processing a structure in which the cured product is formed on a substrate. The molded product is, for example, a cured product or structure formed in a sheet shape or a film shape that has been subjected to molding processing such as heat stretching or punching, and is, for example, an automobile, an OA device, or electricity. -Suitably used for applications that require molding after decorating the surface, such as electronic devices, meters for cameras, and panels for operation units.
The base material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, or a composite material thereof and the like. From the viewpoint of processability, a plastic base material is preferable.

<Composition container>
The inkjet ink container of the present invention means a container in which an active energy ray-curable inkjet ink is stored, and is suitable for use in the above-mentioned applications. For example, when the active energy ray-curable composition of the present invention is used for ink, the container containing the ink can be used as an ink cartridge or an ink bottle, whereby ink transfer, ink replacement, etc. It is not necessary to touch the ink directly in the work, and it is possible to prevent the fingers and clothes from getting dirty. In addition, it is possible to prevent foreign substances such as dust from being mixed into the ink. Further, the shape, size, material, etc. of the container itself may be suitable for the intended use and usage, and is not particularly limited, but the material is a light-shielding material that does not transmit light, or the container blocks light. It is desirable that it is covered with a sex sheet or the like.

<Image formation method, forming device>
As the method for forming an image of the present invention, active energy rays may be used, or heating or the like may be mentioned.
In order to cure the curable inkjet ink of the present invention with active energy rays, an irradiation step of irradiating the active energy rays is provided, and the image forming apparatus of the present invention is an irradiation means for irradiating the active energy rays. , The accommodating portion for accommodating the active energy ray-curable inkjet ink of the present invention may be provided, and the container may be accommodated in the accommodating portion. Further, it may have a ejection step and ejection means for ejecting the active energy ray-curable inkjet ink. The method of discharging is not particularly limited, and examples thereof include a continuous injection type and an on-demand type. Examples of the on-demand type include a piezo method, a thermal method, and an electrostatic method.
FIG. 1 is a schematic view showing an example of an image forming apparatus provided with an inkjet ejection means according to the present invention. Using the head unit (movable in the AB direction) in which the inkjet heads are arranged, the head unit 25 to the first inkjet ink 22 and the head unit 26 to the second inkjet ink 23 having a composition different from that of the first inkjet ink. Each of these inkjet inks is ejected and laminated while being cured by an adjacent active energy ray irradiating device 27. The head units 25 and 26 may be provided with a heating mechanism so that the ink is liquefied at the ink ejection portion. Further, if necessary, a mechanism for cooling the base material 21 to about room temperature by contact or non-contact may be provided. Further, as the inkjet recording method, a serial method in which the head is moved to eject ink onto the recording medium or a recording medium is continuously moved with respect to a recording medium that moves intermittently according to the ejection head width. Any of the line methods of ejecting ink onto the recording medium from the head held at a fixed position can be applied.
The base material 21 is not particularly limited, and examples thereof include paper, film, ceramics, glass, metal, and composite materials thereof, and may be in the form of a sheet. Further, the configuration may be such that only single-sided printing is possible or double-sided printing is possible. Not limited to those used as general recording media, cardboard, building materials such as wallpaper and floor materials, cloth for clothing such as concrete and T-shirts, textiles, leather and the like can be appropriately used.
The recorded materials recorded by the ink of the present invention include not only those printed on a smooth surface such as ordinary paper or resin film, but also those printed on a surface to be printed having irregularities, metal, ceramics, and the like. It also includes those printed on the printed surface made of various materials. Further, by stacking two-dimensional images, it is possible to form a partially three-dimensional image (an image composed of two-dimensional and three-dimensional) or a three-dimensional object.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.
In the following examples, "part" means "part by mass" and "%" means "% by mass".

<Preparation of inorganic particle dispersion>
(Preparation of Inorganic Particle Dispersion A)
Add 56 parts of AEROSIL 50 (manufactured by Aerosil Japan), 40 parts of monofunctional monomer TMCHA (manufactured by Osaka Organic Chemical Industry Co., Ltd.), and 4 parts of SOLSERSE32000 (manufactured by Lubrizol), and stir for 24 hours with a bead mill. Dispersion A] was prepared.

(Preparation of Inorganic Particle Dispersion B)
Add 56 parts of X-24-9600A (manufactured by Shin-Etsu Chemical Co., Ltd.), 40 parts of monofunctional monomer TMCHA (manufactured by Osaka Organic Chemical Industry Co., Ltd.), and 4 parts of SOLSERSE32000 (manufactured by Lubrizol), and stir for 24 hours with a bead mill. Then, [Inorganic Particle Dispersion B] was prepared.

(Preparation of Inorganic Particle Dispersion C)
Add 56 parts of Sicastar (manufactured by Corefront Co., Ltd.), 40 parts of monofunctional monomer TMCHA (manufactured by Osaka Organic Chemical Industry Co., Ltd.), and 4 parts of SOLSERSE32000 (manufactured by Lubrizol), and stir for 24 hours with a bead mill. Dispersion C] was prepared.

(Preparation of Inorganic Particle Dispersion D)
Add 56 parts of titanium oxide (coloring material for white ink) (manufactured by Dainippon Printing Co., Ltd.), 40 parts of monofunctional monomer TMCHA (manufactured by Osaka Organic Chemical Industry Co., Ltd.), and 4 parts of SOLSERSE32000 (manufactured by Lubrizol), and use a bead mill to 24 parts. After stirring for hours, [Inorganic Particle Dispersion D] was prepared.

<Preparation of active energy ray-curable inkjet ink>
(Preparation of the first inkjet ink)
Based on the materials and contents (parts by mass) shown in Table 1-1, active energy ray-curable inkjet inks of inks 1 to 3, which are the first inkjet inks, were prepared by a conventional method.

(Preparation of second inkjet ink)
Based on the materials and contents (parts by mass) shown in Table 1-1 and Table 1-2, active energy ray-curable inkjet inks of inks 4 to 19, which are the second inkjet inks, were prepared by a conventional method.

The compositions and physical properties of the inks 1 to 19 are shown in Table 1-1 and Table 1-2.
Further, in Tables 1-1 and 1-2, "inorganic particles" are shown as compounding components, but Table 2 shows the compositions and physical properties of inks 4 to 19 when "inorganic particle dispersion" is shown as a compounding component. show. In Table 2, since the inorganic particle dispersion contains the monofunctional monomer TMCHA, the numerical values shown in the section of the monofunctional monomer TMCHA in Table 1-1 and Table 1-2 and the simple elements in Table 2 are used. It is different from the numerical value shown in the section of the functional monomer TMCHA.

The trade names and manufacturing company names of the compounds shown in Table 1-1, Table 1-2 and Table 2 indicate the following contents.

<Monomer>
(Monofunctional monomer)
・ ACMO: Acryloylmorpholine-KJ Chemicals Co., Ltd. ・ NVC: N-vinylcaprolactam-Tokyo Chemical Industry Co., Ltd. ・ PEA: Phenoxyethyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.)
・ TMCHA: 3,5,5, trimethylcyclohexylacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.)
(Polyfunctional monomer)
-DPGDA: Dipropylene glycol diacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) Molecular weight 242
-DPHA: Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.) Molecular weight 524
-CN963: Aliphatic urethane acrylate (manufactured by Sartmer)
-Viscort # 1000: Tripentaerythritol acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) Molecular weight 2000

<Polymer initiator>
-TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by BASF)

<Surfactant>
・ TEGO GRIDE432 (manufactured by EVONIK)
・ TEGO WET500 (manufactured by EVONIK)
・ Mega Fuck RS-76NS (manufactured by DIC Corporation)

<Inorganic particles>
・ AEROSIL 50 (manufactured by Aerosil Japan)
・ X-24-9600A (manufactured by Shin-Etsu Chemical Co., Ltd.)
・ Sicastar (manufactured by Core Front Co., Ltd.)
-TiO ₂ : Titanium oxide (coloring material for white ink) (manufactured by Dai Nippon Printing Co., Ltd.)

<Inorganic particle dispersant>
・ SOLSERSE32000 (manufactured by Lubrizol)

<Color material>
-TiO ₂ : Titanium oxide (coloring material for white ink) (manufactured by Dai Nippon Printing Co., Ltd.)
-Magenta pigment: PR122 (coloring material for magenta ink) (manufactured by Dai Nippon Printing Co., Ltd.)

Further, a method for measuring the physical characteristics of each ink is shown below.
<Static surface tension>
It was measured at 25 ° C. using an automatic surface tensiometer (DY-300, manufactured by Kyowa Surface Chemistry Co., Ltd.) and a platinum plate by the plate method.

<Viscosity at 25 ° C>
Measured with a cone plate type rotational viscometer VISCOMETER TVE-22L manufactured by Toki Sangyo Co., Ltd. using a cone rotor (1 ° 34'x R24) at a rotation speed of 50 rpm and a constant temperature circulating water temperature of 25 ° C. ..

<Average primary particle size of inorganic particles>
The primary particle size of the inorganic particles in the inorganic particle dispersion was measured by diluting the inorganic particles 100-fold with PEA (manufactured by Osaka Organic Chemical Industry Co., Ltd.) using Microtrac UPA150 manufactured by Nikkiso Co., Ltd.

[Examples 1 to 12, Comparative Examples 1 to 6]
For an inkjet ejection device in which a plurality of inkjet heads and a UV light source are mounted on a series of carriages as shown in FIG. 1, MH5421 (manufactured by Ricoh Co., Ltd.) is used as an inkjet head, and a UV-LED light source having a wavelength of 395 nm is used as an active energy ray irradiation device. Inkjet ink was set in the combination shown in Table 3.
With this inkjet ejection device, an ink set composed of first and second inkjet inks is ejected on a polycarbonate substrate (manufactured by Mitsubishi Gas Chemical Company, Iupiron NF-2000, thickness 0.5 mm, length 100 mm, width 100 mm). A laminated body was prepared from the step of performing UV irradiation. The output of the UV-LED light source with a wavelength of 395 nm is 4.5 W / cm ² , the moving speed of the carriage is 840 mm / sec, the distance from the head to the UV irradiator is 30 cm, and the amount of drops per drop is 12 μg. , The dot density was set to be 600 dpi × 600 dpi.

-Evaluation method-
For the laminated bodies of each Example and Comparative Example, the pencil hardness, the adhesion, and the ejection stability of the second inkjet ink were measured by the following evaluation methods.
The measurement results are shown in Table 3.
<Pencil hardness>
According to JIS K 5600 5-4, a scratch hardness (pencil method) test was carried out using a Cortec model KT-VF2391 at a load of 750 g.

<Adhesion>
Eleven cuts were made vertically and horizontally at 1 mm intervals on the obtained laminate using a cutter guide to make 100 grids. Nichiban Cellotape (registered trademark) No. The 405 was strongly pressure-bonded to the grid portion, and the exposure frequency of the base material when it was peeled off at once was confirmed.
(Evaluation criteria)
〇: Base material exposure is less than 5% △: Base material exposure is 5% or more and less than 35% ×: Base material exposure is 35% or more

<Discharge stability>
The second inkjet ink is ejected continuously for 5 minutes from 320 nozzles in a row by an inkjet ejection device equipped with MH5421 (manufactured by Ricoh), and the number of nozzles with missing nozzles is calculated. The discharge stability was evaluated based on. In the inkjet ejection device, the drive frequency was set to 10 kHz, and the amount of ink ejected at one time was set to 12 μg.
(Evaluation criteria)
〇: 2 nozzles or less △: 3 nozzles or more and 5 nozzles or less ×: 6 nozzles or more

The present invention relates to the method for producing the laminate according to the following (1), and includes the following (2) to (7) as embodiments.
(1) A step of ejecting a first active energy ray-curable inkjet ink onto a substrate to form a first ink layer,
A step of ejecting a second active energy ray-curable inkjet ink onto the first ink layer to form a second ink layer,
The first ink layer and the second ink layer are irradiated with active energy rays to cure the first ink layer to form a first cured layer and to cure the second ink layer. And the process of forming the second hardened layer
A method for producing a laminate having the first cured layer and the second cured layer.
The static surface tension of the first active energy ray-curable inkjet ink was γ1 (mN / m), and the static surface tension of the second active energy ray-curable inkjet ink was γ2 (mN / m). Occasionally, γ1 and γ2 satisfy the relationship of the following equation (1), and
γ1> γ2 (1)
The second active energy ray-curable inkjet ink contains 10% by mass or more and 40% by mass or less of a polyfunctional polymerizable compound having a weight average molecular weight (Mw) of 500 or more, and contains 1% by mass or more and 30% by mass of inorganic particles. % Or less,
A method for manufacturing a laminated body, which is characterized by the above.
(2) The method for producing a laminate according to (1) above, wherein the second active energy ray-curable inkjet ink contains 5% by mass or more and 20% by mass or less of inorganic particles.
(3) The method for producing a laminate according to (1) or (2) above, wherein the primary particle diameter of the inorganic particles contained in the second active energy ray-curable inkjet ink is 100 nm or more and 1 μm or less.
(4) The method for producing a laminate according to any one of (1) to (3) above, wherein the inorganic particles contained in the second active energy ray-curable inkjet ink are silica particles.
(5) The item according to any one of (1) to (4) above, wherein the content of the polyfunctional monomer contained in the second active energy ray-curable inkjet ink is 15% by mass or more and 30% by mass or less. Method of manufacturing a laminate of.
(6) The laminate according to any one of (1) to (5) above, wherein the content of the monofunctional monomer contained in the first active energy ray-curable inkjet ink is 50% by mass or more. Production method.
(7) The first active energy ray-curable inkjet ink is a clear ink, and the second active energy ray-curable inkjet ink is a color ink, or the first active energy ray-curable inkjet ink. The method for producing a laminate according to any one of (1) to (6) above, wherein the ink is white ink and the second active energy ray-curable inkjet ink is clear ink.

21 Base material 22 First inkjet ink 23 Second inkjet ink 25, 26 Head unit 27 Active energy ray irradiation device 30 Active energy ray

Japanese Patent No. 5568857 Japanese Patent No. 5990868 International Publication No. 2016/098678

Claims (7)

A step of ejecting a first active energy ray-curable inkjet ink onto a substrate to form a first ink layer,
A step of ejecting a second active energy ray-curable inkjet ink onto the first ink layer to form a second ink layer,
The first ink layer and the second ink layer are irradiated with active energy rays to cure the first ink layer to form a first cured layer and to cure the second ink layer. And the process of forming the second hardened layer
A method for producing a laminate having the first cured layer and the second cured layer.
The static surface tension of the first active energy ray-curable inkjet ink was γ1 (mN / m), and the static surface tension of the second active energy ray-curable inkjet ink was γ2 (mN / m). Occasionally, γ1 and γ2 satisfy the relationship of the following equation (1), and
γ1> γ2 (1)
The second active energy ray-curable inkjet ink contains 10% by mass or more and 40% by mass or less of a polyfunctional polymerizable compound having a weight average molecular weight (Mw) of 500 or more, and contains 1% by mass or more and 30% by mass of inorganic particles. % Or less,
A method for manufacturing a laminated body, which is characterized by the above. The method for producing a laminate according to claim 1, wherein the second active energy ray-curable inkjet ink contains 5% by mass or more and 20% by mass or less of inorganic particles. The method for producing a laminate according to claim 1 or 2, wherein the primary particle diameter of the inorganic particles contained in the second active energy ray-curable inkjet ink is 100 nm or more and 1 μm or less. The method for producing a laminate according to any one of claims 1 to 3, wherein the inorganic particles contained in the second active energy ray-curable inkjet ink are silica particles. The method for producing a laminate according to any one of claims 1 to 4, wherein the content of the polyfunctional monomer contained in the second active energy ray-curable inkjet ink is 15% by mass or more and 30% by mass or less. .. The method for producing a laminate according to any one of claims 1 to 5, wherein the content of the monofunctional monomer contained in the first active energy ray-curable inkjet ink is 50% by mass or more. The first active energy ray-curable inkjet ink is a clear ink and the second active energy ray-curable inkjet ink is a color ink, or the first active energy ray-curable inkjet ink is white. The method for producing a laminate according to any one of claims 1 to 6, wherein the ink is an ink and the second active energy ray-curable inkjet ink is a clear ink.

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