Method of manufacturing recorded material

Abstract

To provide a recording method which improves the peelability of a recording surface and a non-recording surface and can give a recorded matter with a more suppressed change in texture of the resulting recorded matter.SOLUTION: There is provided a method for producing a recorded matter which comprises: a first discharge step of discharging a first ink, which is a radiation-curable inkjet composition, followed by adhering to a recording medium; a first irradiation step of irradiating the first ink adhered to the recording medium with radiation to obtain a cured coating film of the first ink; a second discharge step of discharging a second ink, which is a radiation-curable inkjet composition, to adhere to the cured coating film of the first ink so that the duty is 1% or more and 20% or less: a second irradiation step of irradiating the second ink adhered to the recording medium with radiation to cure the second ink to obtain a recorded matter; and a lamination step of laminating the recorded matter so that a recording surface to which the first ink and the second ink are adhered and a non-recording surface to which the first ink and the second ink are not adhered face each other.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a recorded matter. [Background technology]

[0002] The inkjet recording method is capable of recording high-resolution images using a relatively simple device. Rapid developments are being made in various fields. Among them, the method of forming multiple ink layers for recording is For example, Patent Document 1 describes a method for producing a photosensitive material with excellent image quality and gloss. It provides a good surface condition, has excellent blocking resistance, and forms an image without any tint of the underlying color. In order to provide an ink set for forming a multilayer, a specific radical polymerizable compound is used. and a clear ink composition, An ink set in which the content of a polymerization initiator contained in a rear ink composition is adjusted is disclosed. do. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-067770 Summary of the Invention [Problem to be solved by the invention]

[0004] As described in Patent Document 1, when recording onto a film-based recording medium industrially, After the ink is applied, the recording medium is sometimes wound up into a roll and stored. In the document 1, the clear ink layer is formed on the base including the entire area where the image is formed by the image forming process. However, it is not possible to form a clear ink layer as a base image in this way. When the ink is formed as a photoimage layer, the clear ink layer of the recording medium is not visible when the ink is stored in a roll. The recording surface with the adhesive and the non-recording surface on the other side will stick together. When rewinding the disc for use, the image may peel off easily from the recording surface at the adhesive part, or marks may be left behind. This may result in scratches or damage to the recorded image. [Means for solving the problem]

[0005] The present invention relates to a method for ejecting a first ink, which is a radiation curable ink jet composition, onto a recording medium. a first ejection step of applying radiation to the first ink applied to the recording medium; a first irradiation step of irradiating the first ink with radiation to obtain a cured coating film of the first ink; A second ink having a composition of 1% duty is ejected onto the cured coating film of the first ink. a second discharge step of discharging the ink so that the ink adheres to the recording medium to a concentration of 20% or more; The second ink is irradiated with radiation to cure the second ink, thereby obtaining a recorded product. a recording surface on which the first ink and the second ink are adhered, and The first ink and the second ink are stacked so that the non-recording surface, on which the second ink is not attached, faces each other. and a lamination step. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic diagram of a recording apparatus that can be used in this embodiment. [Figure 2] 1 is a schematic cross-sectional view of a recorded matter according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described with reference to the drawings as necessary. However, the present invention is not limited to this, and the gist of the present invention is not limited to this. Various modifications are possible within the scope of the present invention. In addition, the positional relationship such as up, down, left, and right will not be specified. Insofar as possible, the positional relationship shown in the drawings shall be based on the above. It is not limited to:

[0008] In this specification, "(meth)acryloyl" refers to acryloyl and its corresponding methacryloyl. and "(meth)acrylate" means at least one of acrylate and methacrylate. The term "methacrylate" refers to at least one of the acrylates and the corresponding methacrylates. ) "acrylic" means acrylic and / or its corresponding methacrylic do.

[0009] 1. Manufacturing method of recorded materials The method for producing a recorded material of this embodiment is to use a first ink, which is a radiation-curable ink-jet composition. a first ejection step of ejecting the first ink onto the recording medium and causing the first ink to adhere to the recording medium; In contrast, a first irradiation step of irradiating radiation to obtain a cured coating film of the first ink, and a second irradiation step of curing the radiation-curable ink. The second ink, which is an ink jet composition, is ejected onto the cured coating film of the first ink. a second ejection step of adhering the ink to the recording medium so that the ink is 1% or more and 20% or less; A second irradiation step in which the ink is irradiated with radiation to cure the second ink, thereby obtaining a recorded product. The recording material is then divided into a recording surface on which the first ink and the second ink are adhered and a recording surface on which the first ink and the second ink are adhered. and a laminating step of stacking the laminated sheets so that the non-recording surface, on which no mark is attached, faces the non-recording surface.

[0010] In this embodiment, the second ink to be laminated on the cured coating film of the first ink has a duty of 1. By attaching the material to the recording surface in a ratio of 10% to 20%, the amount of the material that corresponds to the duty is Therefore, the surface on which the ink adheres (hereinafter referred to as the "recording surface") of the recording material can be The surface on which ink is not attached (hereinafter also referred to as the "non-recording surface") is laminated. When the disc is pressed against the recording surface, the contact area is reduced, preventing the recording surface and non-recording surface from coming into tight contact with each other. This improves the peelability between the recording and non-recording surfaces, preventing marks from being left on the recording surface and the non-recording surface. This can prevent a part of the ink layer from adhering to the surface.

[0011] In addition, by adjusting the duty of the second ink within the above range, the effect of unevenness on image quality can be reduced. This makes it possible to reduce the noise and change the texture of the printed matter obtained with the first ink. The steps of the method for producing a printed matter according to this embodiment and the method for producing the printed matter using the ink are as follows: We will explain in detail about ink, etc.

[0012] First, before explaining each step, the following will be described. A recording apparatus that can be used in this embodiment will be described with reference to FIG. A schematic diagram of a recording device that can be used is shown.

[0013] As shown in FIG. 1, the recording apparatus 1 includes a first inkjet head 2 that ejects a first ink. a second inkjet head 3 for ejecting a second ink; and a transport mechanism 5 for the recording medium. The first inkjet head 2 has, for example, a head for each type of ink as shown in the figure. Further, downstream of each of the heads 2a to 2d, a recording medium 6 may be attached. Light sources 4a to 4d are provided for curing the deposited first ink.

[0014] The second inkjet head 3 is, for example, a head 3 for depositing the second ink. A light source 4e for curing the second ink adhered to the recording medium 6 is provided downstream of the light source 4a. can be done.

[0015] The recording medium conveyance mechanism 5 has, for example, a feed roller 51 and a take-up roller 52. The recording medium is fed from the roller 51 in the transport direction F, and the recording medium after recording is wound by the winding roller 52. The recorded surface and the non-recorded surface of the recorded material are wound up into a roll. Contact within.

[0016] 1.1.First discharge process In the first ejection step, the first ink, which is a radiation curable ink jet composition, is ejected. This is a process in which the ink is ejected from the jet head 2 and adhered to the recording medium 6. More specifically, The pressure generating means is driven to apply the composition filled in the pressure generating chamber of the ink jet head. This ejection method is also called an ink jet method.

[0017] Inkjet heads 2 and 3 used in the first ejection step and the second ejection step described later There are two types of heads: a line head that records by a line method and a serial head that records by a serial method. Real head is one example.

[0018] In the line method using a line head, for example, an ink jet head having a width equal to or greater than the recording width of the recording medium is used. The inkjet head is fixed to the recording device. The nozzle of the inkjet head moves in conjunction with this movement. An image is recorded on a recording medium by ejecting ink droplets from the nozzle.

[0019] In the serial method using a serial head, for example, a cap that can move in the width direction of the recording medium is used. The inkjet head is mounted on the carriage. Then, the carriage is moved in the main scanning direction (recording medium The nozzle of the head moves along the body (horizontal and width directions), and the ink is ejected from the nozzle opening of the head in conjunction with this movement. By discharging ink droplets, an image can be recorded on a recording medium.

[0020] Among these, from the viewpoint of winding up the recording medium to which the ink is attached, the first ejection step and the subsequent In the second discharge step described below, it is preferable to use a line system. While the recording medium is continuously fed in the sub-scanning direction, the line head continuously records and irradiates the image. The ink is then sprayed onto the recording medium downstream, and the recording medium with the ink attached is wound up. The installation format is a line system.

[0021] The manner of application of the first ink, such as the duty, in the first ejection step is not particularly limited, and may be determined as desired. This can be adjusted appropriately depending on the image to be displayed.

[0022] In the method for producing a recorded matter of this embodiment, the first ink is a color ink, It is preferable that the second ink is a clear ink. After the ink is applied, the second ink, which is a clear ink, is applied to the 1. The peelability between the recording surface with the image formed by ink and the non-recording surface is improved, and no marks are left on the recording surface. This can prevent the ink layer from remaining on the non-recording surface or from adhering to the non-recording surface.

[0023] Here, "clear ink" corresponds to the color ink used to color the recording medium. Specifically, clear ink is a preferred ink. or the content of coloring material is less than 0.2% by mass, and more preferably, the ink composition does not contain coloring material. On the other hand, color ink is an ink used to color a recording medium, Preferably, the content of the coloring material is 0.2% by mass or more.

[0024] Furthermore, in the method for producing a recorded matter according to the present embodiment, before the first discharging step, another discharging step may be performed. For example, the other ejection step and irradiation step may include a white The ink is applied to the recording material and cured, and the first ejection process is carried out on the white ink layer. This allows the formation of a concealing layer or the like, and the color is developed when viewed from the recording surface side. Therefore, a printed matter with good properties can be obtained.

[0025] In another embodiment, for example, in the other ejection step and irradiation step, colored ink is applied to the recording material. The image is formed by adhering the color ink layer to the ink layer and curing it. Alternatively, a white ink may be applied and cured by the method described above. This allows a hiding layer or the like to be formed. It is possible to obtain a recording material having good color development when the transparent recording medium is viewed from the non-recording side. can be done.

[0026] The recording medium is preferably a non-absorbent recording medium. It is preferable that both the recording surface and the non-recording surface of the recording medium are non-absorbent. By using such a recording medium, it is possible to obtain a recording material suitable for label applications, etc. The non-absorbent nature of the ink allows the hardened ink film to adhere more easily to the non-recording surface, The unevenness created by the ink acts more effectively, and the peelability of the printed matter tends to improve. be.

[0027] The non-absorbent recording medium is not particularly limited, but examples thereof include polyvinyl chloride, polyethylene polyethylene, polypropylene, polyethylene terephthalate (PET), polycarbonate, Films and plates of plastics such as styrene and polyurethane; iron, silver, copper, aluminum Metal plates such as aluminum; or metal plates made by vapor deposition of these various metals or plastic film, stainless steel or brass alloy plate; paper substrate with poly Vinyl chloride, polyethylene, polypropylene, polyethylene terephthalate (PET), Adhesion of plastic films such as polycarbonate, polystyrene, polyurethane, etc. Examples of suitable recording media include those coated with a magnetic material.

[0028] In this embodiment, non-absorbable means that the material is not absorbable by the Bristow method. The amount of water absorbed within 30 msec from the start of contact is 10 mL / m 2 The following also applies: The non-absorbent recording medium refers to a recording medium that has such non-absorbent properties. is the most widely used method for measuring the amount of liquid absorbed in a short time, and is used by Japan Pulp and Paper Co., Ltd. It is also adopted by the Japan TAPPI Technology Association. For details of the test method, please see "JAPA N TAPPI Paper and Pulp Test Methods 2000 Edition, Standard No. 51 "Paper and Paperboard - Liquid Absorption" This is described in "Absorptivity Test Method - Bristow Method".

[0029] 1.2.First irradiation process In the first irradiation step, light is irradiated from the light sources 4a to 4d onto the first ink attached to the recording medium 6. This is a process of irradiating the first ink with light to obtain a cured coating film. In the irradiation step, radiation is applied to the radiation curable ink jet composition adhered to the recording medium. When irradiated with radiation, the polymerization reaction of the monomers begins, causing the composition to harden. If a polymerization initiator is present, radicals, acids, bases, etc. The polymerization reaction of the monomer is promoted by the function of the initiating species. can be.

[0030] Here, examples of radiation include ultraviolet rays, infrared rays, visible light, and X-rays. The radiation source is provided downstream of the inkjet head and irradiates the composition. The radiation source is not particularly limited, but examples thereof include UV-LED. By using such a radiation source, it is possible to reduce the size and cost of the device. UV-LEDs as external radiation sources are small, so they can be installed inside inkjet recording devices. It is possible.

[0031] 1.3.Second discharge process In the second ejection step, the second ink, which is a radiation curable inkjet composition, is ejected. The ink is ejected from the jet head 3 and applied onto the cured coating film of the first ink with a duty within a predetermined range. The duty in the second discharge step is 1% or more and 20% or less. It is preferably 3% or more and 18% or less, and more preferably 6% or more and 15% or less. A duty of 1% or more improves the peelability between the recording surface and non-recording surface, This can prevent marks from being left on the recording surface and prevent part of the ink layer from adhering to the non-recording surface. Duty is 20% or less, which reduces the effect of unevenness on image quality. This makes it possible to further suppress changes in the texture of the printed matter obtained by the first ink. do.

[0032] In this embodiment, "Duty" is a value calculated by the following formula, and corresponds to a pixel. This means the amount of ink adhered to the print head. Here, the duty is between 1% and 20%. This means that the actual number of printed dots is 1 to 20% of the specified pixel (vertical resolution x horizontal resolution). This means that... Duty (%) = Actual print dot count / (vertical resolution x horizontal resolution) x 100 (In the formula, "actual print dot count" is the actual print dot count per unit area, and "vertical resolution" and "Horizontal resolution" and "lateral resolution" are the resolution per unit area.)

[0033] 1.4.Second irradiation process In the second irradiation step, the second ink adhered to the recording medium 6 is irradiated with radiation from the light source 4e. This is the process of irradiating the second ink with light to harden it, thereby obtaining a recorded product. The second ink adhered to the cured coating film can be cured, and the D Regarding the irradiation of radiation, the first irradiation step and the second irradiation step are performed. The same can be said.

[0034] 1.5.Lamination process In the lamination process, the recording material is laminated by laminating the recording surface on which the first ink and the second ink are adhered and the recording surface on which the first ink and the second ink are adhered. This is a process of stacking the first and second ink sheets so that the non-recording surface, on which the second ink is not attached, faces the second ink sheet.

[0035] The stacking method in the stacking step is not particularly limited. For example, In addition to stacking the sheets so that the recording surface and non-recording surface face each other, The recorded material is then wound up in a roll downstream of the recording device. More specifically, the recording surface and the non-recording surface may be stacked facing each other. By winding it up on the take-up roller 52, the recorded material can be made into a roll. In the roll, the recorded material is stacked and wound with the recording surface and the non-recording surface facing each other.

[0036] By winding it up in a roll like this, the recording surface and the non-recording surface are pressed tightly together within the roll. When rolled, they rub against each other. The peelability of the recording surface has been improved, preventing marks from remaining on the recording surface and part of the ink layer from adhering to the non-recording surface. The present invention is particularly useful in that it can suppress the occurrence of such a problem.

[0037] 1.6. First ink and second ink The first ink and the second ink used in this embodiment are both radiation curable inkjet inks. The first ink and the second ink are described in detail below. When there is no need to distinguish between the second ink and the ink, they are collectively referred to simply as "ink" and When referring to the composition of the first ink or the second ink, the subject matter shall be clearly stated.

[0038] The ink is not particularly limited as long as it is a radiation-curable inkjet composition. In the present invention, the radiation-curable inkjet composition is a composition that is cured by irradiation with radiation. Radiation includes ultraviolet rays, electron beams, infrared rays, visible light, and X-rays. Among these, radiation is particularly advantageous because the radiation source is easily available and widely used. , and the availability and widespread use of materials suitable for curing by ultraviolet radiation. Ultraviolet light is preferred.

[0039] The ink is not particularly limited, but may contain, for example, a polymerizable compound, a photopolymerization initiator, a polymerization inhibitor, The first ink may contain a slip agent, a coloring material, a dispersant, etc. Preferably, the first ink is a color ink, and the second ink is a clear ink. This will be explained in detail.

[0040] 1.6.1. Polymerizable compounds The polymerizable compound contains a monofunctional monomer and, if necessary, a polyfunctional monomer. Good too.

[0041] 1.6.1.2. Monofunctional Monomers The monofunctional monomer is not particularly limited, but for example, a monofunctional monomer having an alicyclic group Monofunctional monomers having an aromatic group, and monofunctional monomers having a nitrogen-containing heterocycle are examples of such monomers. Furthermore, a monomer other than these may also be used as the monofunctional monomer.

[0042] By using a monofunctional monomer, adhesion is improved as described above, and the film also has excellent stretchability. On the other hand, there is an advantage that a recording can be obtained using ink with high adhesion. When a recording surface and a non-recording surface are laminated together, the high adhesion makes it easier to peel off the recording surface, and it can cause scratches. Therefore, it is necessary to obtain a printed matter that takes advantage of the characteristics of the monofunctional monomer while preventing peeling. The present invention is particularly useful from the viewpoint of obtaining a printed matter that has excellent releasability and is less likely to leave marks.

[0043] In particular, when the first ink contains a monofunctional monomer, the content of the monofunctional monomer is The content of the polymerizable compound in the first ink is preferably 80% by mass or more, and more preferably The content is preferably 85 to 99% by mass, and more preferably 90 to 98% by mass. By having a content of 80% by mass or more of the mer, adhesion between the ink layer and the recording medium and curing Sexuality tends to improve.

[0044] Furthermore, when the second ink contains a monofunctional monomer, the content of the monofunctional monomer is The content of the polymerizable compound in the second ink is preferably 80% by mass or more, more preferably The content is preferably 85 to 99% by mass, and more preferably 90 to 98% by mass. The content of the mer is 80% by mass or more, so that the coating film of the first ink and the coating film of the second ink The adhesion between the two inks and the curing property tend to be improved. Therefore, when processing and using the stacked recording materials, it is easy to prevent the recording materials from being damaged. become.

[0045] 1.6.1.2.1. Monofunctional Monomers with Alicyclic Groups The monofunctional monomer having an alicyclic group is not particularly limited, but for example, dicyclopentadiene Dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate Dicyclopentanyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate tert-butyl cyclohexanoate, isobornyl (meth)acrylate, tert-butyl cyclohexanoate 2-(meth)acrylic acid-1,4-dioxaspiro[4,5 ] alicyclic group-containing (meth)acrylates such as dec-2-ylmethyl.

[0046] Among these, dicyclopentenyl (meth)acrylate (DCPA) and isobornyl By using such a monomer, The resulting coating tends to have improved adhesion and abrasion resistance.

[0047] The content of the monofunctional monomer having an alicyclic group is preferably is 25 to 55 mass %, more preferably 30 to 50 mass %, and even more preferably The content of the monofunctional monomer having an alicyclic group is within the above range. This tends to further improve the adhesion and abrasion resistance of the resulting coating film.

[0048] 1.6.1.2.2. Monofunctional monomers with aromatic groups The monofunctional monomer having an aromatic group is not particularly limited, but for example, phenoxy ethylene Benzyl (meth)acrylate, benzyl (meth)acrylate, alkoxylated 2-phenoxy Diethyl (meth)acrylate, Ethoxylated nonylphenyl (meth)acrylate, Al Coxylated nonylphenyl (meth)acrylate, p-cumylphenol EO modified (meth) acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate. It can be obtained.

[0049] Among these, phenoxyethyl acrylate (PEA) is preferred. By using a monofunctional monomer containing an aromatic group, the solubility of the photopolymerization initiator is further improved, and the In particular, the curing properties of acylphosphine oxide-based photopolymerization initiators tend to be improved. When using initiators or thioxanthone-based photopolymerization initiators, the solubility tends to be good. .

[0050] The content of the monofunctional monomer having an aromatic group is preferably is 20 to 50% by mass, more preferably 25 to 45% by mass, and even more preferably The content of the aromatic group-containing monofunctional monomer is within the above range. This tends to further improve the adhesion and abrasion resistance of the coating film.

[0051] 1.6.1.2.3. Nitrogen-containing monofunctional monomers The nitrogen-containing monofunctional monomer is not particularly limited, but for example, N-vinylcaprolactone acetamide, N-vinylformamide, N-vinylcarbazole, N-vinylacetamide and nitrogen-containing monofunctional vinyl monomers such as N-vinylpyrrolidone; acryloylmorpholin Nitrogen-containing monofunctional acrylate monomers such as (meth)acrylamide, N-hydroxy Methyl (meth)acrylamide, Diacetone acrylamide, N,N-dimethyl (meth)acrylamide acrylamide, dimethylaminoethyl acrylate benzyl chloride quaternary salt, etc. p) Nitrogen-containing monofunctional acrylamide monomers such as acrylamide.

[0052] Among these, N-vinylcaprolactam, N-vinylcarbazole, N-vinylpyrrolidone Monomers with nitrogen-containing heterocyclic structures such as morpholino or acryloylmorpholine are more preferred. It is preferable that the compound contains acryloylmorpholine (ACMO). By using such a nitrogen-containing monofunctional monomer, the abrasion resistance of the coating film tends to be further improved. Furthermore, nitrogen-containing monofunctional acrylates having a nitrogen-containing heterocyclic structure such as acryloylmorpholine are also suitable. Acrylate monomers tend to improve the extensibility and adhesion of the coating film.

[0053] The content of the nitrogen-containing monofunctional monomer is preferably 10 to 100% by weight based on the total amount of the polymerizable compounds. 25% by mass, more preferably 12.5 to 22.5% by mass, and even more preferably The content of the nitrogen-containing monofunctional monomer is 15 to 20 mass %. This tends to further improve the abrasion resistance and adhesion of the coating film.

[0054] 1.6.1.3. Polyfunctional Monomers The polyfunctional monomer is not particularly limited, but examples thereof include vinyl group-containing (meth)acrylic acrylates and polyfunctional (meth)acrylates.

[0055] 1.6.1.3.1. Vinyl group-containing (meth)acrylates The vinyl group-containing (meth)acrylate is not particularly limited, but may be, for example, a compound represented by the formula (1): Examples of the compound include compounds represented by the following formula: H2C=CR 1 -CO-OR 2 -O-CH=CH-R 3 ··· (1) (In the formula, R 1 is a hydrogen atom or a methyl group, and R 2 is a divalent organic residue having 2 to 20 carbon atoms. R 3 is a hydrogen atom or a monovalent organic residue having 1 to 11 carbon atoms.

[0056] In the above formula (1), R 2 As a divalent organic residue having 2 to 20 carbon atoms, A linear, branched or cyclic alkylene group having 2 to 20 prime numbers, which may be substituted; optionally substituted, having an oxygen atom via an ether bond and / or an ester bond an alkylene group having 2 to 20 carbon atoms, a divalent aromatic group having 6 to 11 carbon atoms which may be substituted, Examples include groups.

[0057] Among these, ethylene group, n-propylene group, isopropylene group, and butylene group alkylene groups having 2 to 6 carbon atoms, such as oxyethylene groups, oxy-n-propylene groups, oxyethylene groups, Oxygen atoms in the structure of dimethylisopropylene and oxybutylene groups due to ether bonds Furthermore, the viscosity of the composition can be further reduced, and In addition, from the viewpoint of further improving the curability of the composition, R 2 However, oxyethylene group, oxy The structure contains aryl groups such as n-propylene, oxyisopropylene, and oxybutylene groups. Glycol, which is an alkylene group with 2 to 9 carbon atoms and an oxygen atom via a ter bond Compounds having an ether chain are more preferred.

[0058] In the above formula (1), R 3 As the monovalent organic residue having 1 to 11 carbon atoms, A linear, branched or cyclic alkyl group having 1 to 10 prime numbers, which may be substituted, and having 6 carbon atoms Optionally substituted aromatic groups of up to 11 are preferred.

[0059] Among these, alkyl groups having 1 to 2 carbon atoms, such as methyl groups or ethyl groups, and phenyl groups are preferred. Aromatic groups having 6 to 8 carbon atoms, such as a benzyl group, are preferably used.

[0060] Specific examples of the compound of formula (1) include, but are not limited to, (meth)acrylic 2-(2-vinyloxyethoxy)ethyl acrylate, Ethoxy)ethyl (VEEA) is preferred.

[0061] In particular, the second ink contains a vinyl group-containing polyfunctional monomer represented by the above formula (1): It is preferable that the second ink contains (meth)acrylate. This improves the curing properties of the second ink. It tends to be upward.

[0062] The content of the vinyl group-containing (meth)acrylate is preferably It is preferably 1 to 25% by mass, more preferably 2 to 20% by mass, and even more preferably 3% by mass. The content of the nitrogen-containing monofunctional monomer is in the above range, so that The viscosity of the ink decreases, and ejection stability tends to be improved.

[0063] 1.6.1.3.2 Multifunctional (meth)acrylates The polyfunctional (meth)acrylate is not particularly limited, but for example, dipropylene glycol Lithium di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate Bifunctional (meth)acrylates such as ethylene glycol di(meth)acrylate; trimethyl Trimethylolpropane tri(meth)acrylate, EO modified trimethylolpropane tri(meth)acrylate ) acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol and polyfunctional (meth)acrylates having three or more functional groups, such as tetra(meth)acrylate. do.

[0064] Among these, dipropylene glycol diacrylate (DPGDA) is preferred. By using such a polyfunctional (meth)acrylate, the curing property and abrasion resistance of the ink can be improved. It tends to be more improved.

[0065] The content of the polyfunctional (meth)acrylate is preferably 1:1 based on the total amount of the polymerizable compounds. It is preferably 0.0 to 10% by mass or more, more preferably 2.0 to 8.0% by mass, and even more preferably The content of the polyfunctional (meth)acrylate is within the above range, or 3.0 to 7.0 mass %. This tends to further improve the curability and abrasion resistance of the ink.

[0066] 1.6.2. Photoinitiators The photopolymerization initiator may be any one that generates active species upon irradiation with radiation. Although not limited thereto, for example, acylphosphine oxide-based photopolymerization initiators, alkylphenanthroline Known polymerization initiators such as non-based polymerization initiators, titanocene-based polymerization initiators, and thioxanthone-based photopolymerization initiators Among these, acylphosphine oxide photopolymerization initiators are preferred. By using such a photopolymerization initiator, the curing property of the ink is further improved. In particular, the curing process using UV-LED light tends to improve curing properties. The photopolymerization initiator may be used alone or in combination of two or more.

[0067] The acylphosphine oxide photopolymerization initiator is not particularly limited, but examples thereof include , 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4 ,6-trimethylbenzoyl)-phenylphosphine oxide, bis-(2,6-di methoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, etc. It can be obtained.

[0068] Commercially available products of such acylphosphine oxide photopolymerization initiators include, for example, IRGACURE 819 (Bis(2,4,6-trimethylbenzoyl)-phenylphosphine Sphingloxacin, IRGACURE 1800 (bis-(2,6-dimethoxybenzoyl) 2,4,4-trimethylpentyl phosphine oxide and 1-hydroxy -cyclohexyl-phenyl ketone (mixture of 25:75 by mass), IRGACURE TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) ( (All manufactured by BASF)

[0069] The content of the photopolymerization initiator is preferably 3.0 to 15% by mass relative to the total amount of the ink. It is more preferably 5.0 to 13.5 mass %, and even more preferably 8.0 to 12 mass %. By having the content of the photopolymerization initiator within the above range, the curing property and photosensitivity of the ink are improved. The solubility of the polymerization initiator tends to be further improved.

[0070] 1.6.3. Polymerization inhibitors Examples of the polymerization inhibitor include, but are not limited to, p-methoxyphenol, hydroxybenzoate, and the like. Quinone monomethyl ether (MEHQ), 4-hydroxy-2,2,6,6-tetramethyl Tylpiperidine-N-oxyl, hydroquinone, cresol, t-butylcatechol, 3 ,5-di-t-butyl-4-hydroxytoluene, 2,2'-methylenebis(4-methyl -6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-butylphenol) phenol), and 4,4'-thiobis(3-methyl-6-t-butylphenol), hindered The polymerization inhibitor may be used alone or in combination of two or more. may be used in combination.

[0071] The content of the polymerization inhibitor is preferably 0.05 to 1.0% by mass relative to the total amount of the ink. The content is more preferably 0.05 to 0.5 mass %.

[0072] 1.6.4. Slip agents As the slip agent, a silicone surfactant is preferred, and a polyester-modified silicone is preferred. Polyester-modified silicone or polyether-modified silicone is more preferred. Cones include BYK-347, 348, BYK-UV3500, 3510, and 3530 (All manufactured by BYK Additives & Instruments) and polyether-modified silicone. Examples of suitable surfactants include BYK-3570 (manufactured by BYK Additives & Instruments). The topping agent may be used alone or in combination of two or more.

[0073] The content of the slip agent is preferably 0.01 to 2.0% by mass relative to the total amount of ink. The content is more preferably 0.05 to 1.0 mass %.

[0074] 1.6.5.Colorants The coloring material may be at least one of a pigment and a dye.

[0075] In the case of color ink, the total content of coloring materials is preferably is 0.2 to 20 mass%, more preferably 0.5 to 15 mass%, and even more preferably In the case of clear ink, as described above, the coloring material is It is preferable that it is not contained, and even if it is unavoidably contained, it is less than 0.2 mass %.

[0076] Dispersants The dispersant is not particularly limited, but for example, a polymer dispersant is used to prepare a pigment dispersion. Specific examples of dispersants include polyoxyalkylene Polyalkylene polyamines, vinyl polymers and copolymers, acrylic polymers and Copolymers, polyesters, polyamides, polyimides, polyurethanes, amino-based polymers , silicon-containing polymer, sulfur-containing polymer, fluorine-containing polymer, and epoxy resin. The dispersant may be used alone or in combination of two or more. They may also be used in combination.

[0077] Commercially available polymer dispersants include the Ajisper series manufactured by Ajinomoto Fine-Techno Co., Ltd. and Abe Solsperse series available from Avecia and Noveon (Solsperse 36000, etc.), BYK Additives & Instru Examples include the Disperbic series manufactured by ments and the Disparlon series manufactured by Kusumoto Chemicals. It can be obtained.

[0078] The content of the dispersant is preferably 0.1 to 2.0% by mass relative to the total amount of the ink, It is more preferably 0.1 to 1.0 mass%, and even more preferably 0.1 to 0.5 mass%. be.

[0079] 2. Recorded materials FIG. 2 shows a schematic cross-sectional view of a recorded matter 5 in this embodiment. The recorded matter 7 has a recording surface 61 on which the first ink 71 and the second ink 72 are adhered, and a recording medium 6 having a non-recording surface 62 on which the first ink 71 and the second ink 72 are not attached; The first ink 71 is applied to the recording surface 61 of the recording medium 6, and the first ink 71 The second ink 72 is applied on top at a relatively low duty.

[0080] For example, after the first ink 71, which is a color ink, is applied as a solid image, By applying the second ink 72, which is a clear ink, at a low duty, The recording surface 61 having the image formed thereon and the non-recording surface 62 are easily separated by the recording surface 61. 1, or part of the first ink 71 or the second ink 72 adheres to the non-recording surface 62. This can prevent the risk of this happening.

[0081] The recording medium 6 used in the recording material 7 in this embodiment is a long one as shown in FIG. It is preferable that the recorded matter 7 is stored as a roll wound on a roller. By storing the recorded matter 7 in such a state, the recorded surface 61 and the non-recorded surface 62 of the recorded matter 7 come into contact with each other. The contact area between the recording surface 61 and the non-recording surface 62 is reduced by the ink 72. When the object 7 is used as a label or the like, even if it is unwound from the roll, marks remain on the recording surface 61, and non-uniformity occurs. It is possible to prevent a part of the first ink 71 or the second ink 72 from adhering to the recording surface 62. Cut.

[0082] In particular, the image layer formed by the first ink 71 has improved adhesion to the recording medium 6 and has good followability. From the viewpoint of improving the recording performance, when a large amount of monofunctional monomers is used in the first ink 71, The adhesion between the recording surface 61 and the non-recording surface 62 is also improved, and problems such as marks and peeling are likely to occur. In the case of the recorded matter 7 of this embodiment, the second ink 72 separates the recorded surface 61 and the non-recorded surface 62. Since it is possible to reduce the adhesion of 62, it is possible to suppress the occurrence of marks and peeling. [Example]

[0083] The present invention will be described in more detail below using examples and comparative examples. The examples are not intended to be limiting in any way.

[0084] 1. Preparation of Inkjet Composition First, weigh out a portion of the colorant, dispersant, and each monomer and place them in a tank for pigment dispersion. By adding a ceramic bead mill with a diameter of 1 mm to the mixture and stirring, the colorant was dissolved in the monomer. A pigment dispersion was obtained in which the pigment was dispersed in the above-mentioned solution.

[0085] Next, the mixture was poured into a stainless steel container, a mixing tank, so as to obtain the composition shown in Table 1. The remaining monomers, polymerization initiator and polymerization inhibitor are added and mixed and stirred until completely dissolved. The pigment dispersion obtained above was added and further mixed and stirred at room temperature for 1 hour, and then a 5 μm particle size was obtained. The radiation-curable inkjet composition of each example was filtered through a membrane filter. The numerical values ​​of each component shown in each example in the tables represent mass % unless otherwise specified.

[0086] [Table 1]

[0087] <Monofunctional monomer> ACMO (Acryloylmorpholine, manufactured by KJ Chemicals Co., Ltd.) PEA (product name "Viscoat #192", manufactured by Osaka Organic Chemical Industry Co., Ltd.) (Acrylate) DCPA (Hitachi Chemical Co., Ltd., dicyclopentenyl acrylate) IBXA (Osaka Organic Chemical Industry, Ltd., isobornyl acrylate) <Polyfunctional Monomer> VEEA (2-(2-vinyloxyethoxy)ethyl acrylate, manufactured by Nippon Shokubai Co., Ltd.) DPGDA (product name "SR508", manufactured by Sartomer Corporation, dipropylene glycol) diacrylate) <Polymerization initiator> 819 (product name "IRGACURE 819" manufactured by BASF, bis(2,4,6-trimethylsilyl) Methylbenzoyl)-phenylphosphine oxide) TPO (product name "IRGACURE TPO", manufactured by BASF, 2,4,6-trimethyl (benzoyldiphenylphosphine oxide) <Polymerization inhibitor> MEHQ (product name "p-methoxyphenol", manufactured by Kanto Chemical Co., Ltd.) (methyl ether) <Slip agent> BYK-UV3500 (BYK Additives & Instruments) Polyether-modified polydimethylsiloxane with acryloyl groups) <Coloring materials (pigments)> PB15:3 (product name "CI Pigment Blue 15:3", manufactured by DIC, phthalocyanine Anin Blue) PW6 (product name "CI Pigment White 6", manufactured by Tika, titanium dioxide) <Dispersant> Solsperse 36000 (Lubrizol polymer dispersant)

[0088] In Table 1, "content of monofunctional monomer relative to the total amount of polymerizable compound" is the amount of the polymerizable compound. The ratio (mass %) of the content of the monofunctional monomer to the total amount is shown.

[0089] 2. Evaluation Method 2.1.Adhesion Printer equipped with LED (model number PX-G5000 modified machine, Seiko Epson Corporation Each radiation-curable inkjet composition listed in Table 1 was applied to a vinyl chloride film using a (JT5829R, MACtac) 20ng / dot, 600dpi x 600 The resulting coating was extruded at 1000 dpi and cured to obtain a coating film with a thickness of 10 μm. Apply transparent adhesive tape to the cut area and press the tape firmly with your fingers so that the paint film is visible through the tape. Then, within 5 minutes of applying the tape, rub the surface at an angle close to 60° for 0.5 to 1.0 seconds. The tape was then peeled off the coating film. Based on the results of the test, the adhesion was evaluated according to the following evaluation criteria. (Evaluation criteria) A: No peeling was observed. B: Partial peeling was observed. C: All peeled off.

[0090] 2.2. Curability Printer equipped with LED (model number PX-G5000 modified machine, Seiko Epson Corporation The coating thickness was measured on a vinyl chloride film (JT5829R, manufactured by MACtac) using a coating material. Each of the radiation-curable ink jet compositions listed in Table 1 was applied so that the thickness was 10 μm. The inkjet composition was then irradiated at a central wavelength of 395 nm and 1000 mW / cm 2 in After irradiating the surface with ultraviolet light for a specified time, the surface of the coating is rubbed with a cotton swab. The irradiation energy at which the cotton swab does not become colored is measured. The curability was evaluated based on the irradiation energy [mJ / cm 2 ] is the irradiation intensity [mW / c m 2 The evaluation criteria are as follows: (Evaluation criteria) A: Irradiation energy is 200mJ / cm 2 below B: Irradiation energy is 200 mJ / cm 2 Excess 300mJ / cm 2 below C: Irradiation energy is 300 mJ / cm 2 excess

[0091] 2.3. Traces Printer equipped with LED (model number PX-G5000 modified machine, Seiko Epson Corporation Each radiation-curable inkjet composition was prepared using a combination of vinyl chloride and vinyl chloride copolymers shown in Table 2. The film was attached to a Nilfilm (JT5829R, manufactured by MACtac). The first ink is 20ng / dot, 600dpi x 600dpi, Duty 100% After the first ink was applied, the irradiation energy was 400 mJ / cm 2 So that ultraviolet The second ink, which is the upper layer, is applied to the first ink coating. The deposition conditions were 20 ng / dot, 600 dpi x 600 dpi, and The conditions for ty were as shown in Table 2. For the second ink, the irradiation energy was Energy is 400mJ / cm 2 The printed matter was obtained by irradiating ultraviolet light so that the Only in Example 1, the second ink as the upper layer was not attached, and the evaluation described below was carried out.

[0092] The recording surface of the recorded matter obtained as described above to which the first ink and the second ink are attached is Then, place another vinyl chloride film on top of it without any recording on it and apply a 1 kg load on top of it. After that, the recorded material was peeled off from the other vinyl chloride film, and the recorded surface was The transfer of traces of other vinyl chloride films was visually confirmed. The evaluation criteria were as follows: This is the case. (Evaluation criteria) A: No transfer marks on the recording surface B: There are very slight transfer marks on the recording surface C: There are noticeable transfer marks on the recording surface D: There are noticeable transfer marks on the recording surface, and color transfer to the back of other vinyl chloride films.

[0093] 2.4.Glossiness In the same manner as in the case of the above-mentioned traces, a recorded matter was obtained. The reflection of the fluorescent light on the obtained printed matter was observed on the coating film. The evaluation criteria were as follows: This is the case. (Evaluation criteria) A:Can be seen from a distance of more than 50cm B: If it is between 30cm and 50cm, it can be confirmed. C: If it was less than 30cm, it could be confirmed.

[0094] [Table 2]

[0095] 3. Evaluation Results Table 2 shows the conditions for the recording method using each radiation-curable inkjet composition and the evaluation results. From Table 2, it can be seen that applying the second ink at a specified duty reduces the amount of residue. It was found that the image quality (glossiness) of the first ink was maintained.

Claims

1. a first ejection step of ejecting a first ink, which is a radiation curable inkjet composition, onto a recording medium; a first irradiation step of irradiating the first ink adhered to the recording medium with radiation to form a cured coating film of the first ink; a second ejection step of ejecting a second ink, which is a radiation curable inkjet composition, onto the cured coating film of the first ink so that the duty is 5% or more and 20% or less; a second irradiation step of irradiating the second ink adhered to the recording medium with radiation to cure the second ink, thereby obtaining a recorded matter; a lamination step of stacking the recorded matter so that a recording surface on which the first ink and the second ink are adhered faces a non-recording surface on which the first ink and the second ink are not adhered, the second ink contains acryloylmorpholine; the content of the acryloylmorpholine is 10 to 25 mass % with respect to the total amount of the polymerizable compounds in the second ink; A method for producing recorded materials.

2. The first ink is a color ink. A method for producing the recorded matter according to claim 1.

3. the second ink is a clear ink; A method for producing the recorded matter according to claim 1 or 2.

4. In the stacking step, the recorded matter is wound into a roll so that the recorded surface and the non-recorded surface face each other. A method for producing the recorded matter according to any one of claims 1 to 3.

5. The recording surface and the non-recording surface of the recording medium are both non-absorbent. A method for producing the recorded matter according to any one of claims 1 to 4.

6. the first ink contains a polymerizable compound containing a monofunctional monomer, the content of the monofunctional monomer is 80% by mass or more based on the total amount of the polymerizable compound; A method for producing the recorded matter according to any one of claims 1 to 5.

7. the second ink contains a polymerizable compound containing a polyfunctional monomer, The polyfunctional monomer includes a vinyl group-containing (meth)acrylate represented by the following formula (1): H 2 C=CR 1 -CO-OR 2 -O-CH=CH-R 3 ・・・ (1) (In the formula, R 1 is a hydrogen atom or a methyl group, and R 2 is a divalent organic residue having 2 to 20 carbon atoms, and R 3 is a hydrogen atom or a monovalent organic residue having 1 to 11 carbon atoms. A method for producing the recorded matter according to any one of claims 1 to 6.

8. the polymerizable compound contained in the second ink contains a monofunctional monomer, the content of the monofunctional monomer is 80% by mass or more based on the total amount of the polymerizable compound; A method for producing the recorded matter according to claim 7.

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