JP2015189195A - Non-aqueous photocurable inkjet composition storage body and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-aqueous photocurable inkjet composition storage body which can prevent a decrease in curing properties and ensure visibility of contents, and a recording method using the storage body.SOLUTION: The non-aqueous photocurable inkjet composition storage body includes: a non-aqueous photocurable inkjet composition which contains a polymerizable compound of which a moisture absorption rate at a temperature of 60 degrees C and relative humidity of 90% is equal to or greater than 1.5 mass%/24 hours; and a container which accommodates the non-aqueous photocurable inkjet composition and is formed of a member having a metal oxide layer, or a package which accommodates at least a container accommodating the non-aqueous photocurable inkjet composition and is formed of a member having a metal oxide layer.

Description

  The present invention relates to a non-aqueous photocurable inkjet composition container and a recording method.

  The ink jet recording method is capable of recording high-definition images with a relatively simple device, and has been rapidly developed in various fields. Among them, various studies have been made on a container for storing an ink composition. For example, Patent Document 1 discloses a storage that suppresses a curing reaction of a radical polymerizable compound during storage of an ink composition, suppresses an increase in viscosity, and does not inhibit a curing reaction during use of the ink composition. A storage container containing a photocurable ink composition that does not contain a free thermal polymerization inhibitor for the purpose of providing a container and a storage method, and suppresses a curing reaction of a radical polymerizable compound therein A storage container for a photocurable ink composition, in which a solid containing a substance is disposed, is disclosed.

JP 2007-131330 A

  However, ink compositions with excellent curability and adhesion often contain relatively hydrophilic components and tend to absorb moisture when stored in conventional containers. Further, moisture absorption of the ink composition during storage or the like causes a decrease in curability. On the other hand, in order to suppress moisture absorption, it may be possible to form a metal vapor deposition layer on the surface of the container. The problem arises.

  The present invention has been made to solve at least a part of the above-described problems, and can suppress a decrease in curability and ensure the visibility of contents, and a non-aqueous photocurable inkjet composition container and the container It is an object of the present invention to provide a recording method using a container.

  The present inventors diligently studied to solve the above problems. As a result, the inventors have found that the above problem can be solved by using a container having a predetermined configuration, and completed the present invention.

That is, the present invention is as follows.
[1]
A non-aqueous photocurable inkjet composition containing a polymerizable compound having a moisture absorption rate of 1.5% by mass / 24 hours or more at a temperature of 60 ° C. and a relative humidity of 90%;
A member containing the non-aqueous photocurable inkjet composition and made of a member having a metal oxide layer, or a member containing at least a container containing the non-aqueous photocurable inkjet composition and having a metal oxide layer A package comprising:
A non-aqueous photocurable inkjet composition container.
[2]
The non-polymerizable product according to [1], wherein the polymerizable compound has one or more selected from the group consisting of an oxygen atom bonded to two acyclic hydrocarbon groups, a heterocyclic group containing an oxygen atom, and a hydroxyl group. A water-based photocurable inkjet composition container.
[3]
The content of the polymerizable compound is 20% by mass or more based on the total amount of the non-aqueous photocurable inkjet composition, and contains the non-aqueous photocurable inkjet composition according to [1] or [2] above. body.
[4]
The non-aqueous system according to any one of [1] to [3], wherein the metal oxide layer includes one or more oxides selected from the group consisting of silica, alumina, titania, zirconia, and ceria. Photocurable inkjet composition container.
[5]
The non-aqueous photocurable inkjet composition container according to any one of [1] to [4], wherein the non-aqueous photocurable inkjet composition further includes an acylphosphine oxide compound.
[6]
The non-aqueous photocurable inkjet composition container according to any one of [1] to [5], wherein the polymerizable compound includes a radical polymerizable compound.
[7]
The non-aqueous photocurable inkjet composition container according to any one of [1] to [6], wherein the non-aqueous photocurable inkjet composition further includes a pigment and a pigment dispersant.
[8]
The non-aqueous photocurable inkjet composition container according to any one of [1] to [7], wherein the container or the package has visible light permeability.
[9]
The non-aqueous photocurable inkjet composition container according to any one of [1] to [8] above, wherein the container or the package has a moisture permeability of 20 g / m ² · 24 hours or less.
[10]
From the non-aqueous photocurable inkjet composition container according to any one of [1] to [9] above, the non-aqueous photocurable inkjet composition is fed to a discharge nozzle through an ink channel. A liquid feeding process for liquid,
A discharge step of discharging the non-aqueous photocurable inkjet composition from the discharge nozzle onto a recording medium.
[11]
The non-aqueous photo-curable ink jet composition is irradiated with ultraviolet light having an emission peak wavelength of 350 to 420 nm using a light emitting diode to the non-aqueous photo-curable ink jet composition attached to the recording medium. The recording method according to [10] above, further comprising a curing step for curing the product.

It is a disassembled perspective view which shows an example of the non-aqueous photocurable inkjet composition container of this embodiment.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to this, Various modifications are possible without departing from the scope of the invention. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, positional relationships such as up, down, left and right are based on the positional relationships shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

[Non-aqueous photocurable inkjet composition container]
The non-aqueous photocurable inkjet composition container of the present embodiment (hereinafter also referred to as “container”) has a moisture absorption rate of 1.5 mass% / 24 hours or more at a temperature of 60 ° C. and a relative humidity of 90%. A non-aqueous photocurable inkjet composition containing a polymerizable compound (hereinafter also referred to as “ink composition”) and a container containing the non-aqueous photocurable inkjet composition and having a metal oxide layer; Or the package which consists of the member which accommodates the container which accommodates the said non-aqueous photocurable inkjet composition at least, and has a metal oxide layer is provided.

  In this specification, “container” refers to a container that directly contains an ink composition. Further, the “packaging body” refers to a container that stores at least a container that directly stores an ink composition, that is, a container that indirectly stores an ink composition. The package may be anything that accommodates at least the container, and may be an item that accommodates the entire container. The “container” is a concept that includes a container and a case that protects a container to be used as necessary, and refers to a container that accommodates an ink composition directly or indirectly. The container is used for storing and transporting the ink composition before using the ink composition in the recording apparatus, and supplies the ink composition stored in the container to the recording apparatus when used. It is. The container which consists only of a container, ie, the container in which a container is a container as it is, may be sufficient.

  Examples of the container include, but are not limited to, an ink cartridge, a pack, a bottle, a tank, a bottle, and a can. Among these, an ink cartridge, a pack, a bottle, and a tank are preferable, and a pack is more preferable from the viewpoint of being widely used and easily controlling water permeability and oxygen permeability described later to desired values.

  In FIG. 1, the disassembled perspective view which shows an example of the non-aqueous photocurable inkjet composition container of this embodiment is shown. The ink cartridge 40 includes an ink pack 70 filled with ink, and a cartridge case 72 including a main body case 76 and a lid portion 78 that house and protect the ink pack 70. The ink pack 70 includes an ink supply port 74. The main body case 76 includes a notch portion 80 and a groove portion 86, and the lid portion 78 includes a pressing portion 82 and a flange portion 84. In the ink cartridge 40, the ink pack 70 is housed in the main body case 76 and the lid portion 84. At this time, the ink supply port 74 is fitted in the notch portion 80, and then the presser portion 82 and the notch portion 80 are inserted. It is fixed by being pinched. Further, the main body case 76 and the lid portion 84 are sealed by fitting the flange portion 84 into the groove portion 86. The ink pack 70 corresponds to the “container” of the present embodiment, and the entire cartridge including the cartridge case 72 corresponds to the container. Although not illustrated, the “packaging body” may be a bag that accommodates the entire cartridge, or may be a bag that accommodates the ink pack 70 in the cartridge and is accommodated in the cartridge case 72. Alternatively, the cartridge case 72 may also serve as a package. The entire cartridge including the package may be defined as “container”.

  The usage mode of the container is not particularly limited. For example, a container that is separate from the recording apparatus is mounted on the recording apparatus, and the ink composition is supplied from the container to the recording apparatus in the mounted state. Aspect (B) such as a bottle that supplies an ink composition to an ink tank or the like of a recording apparatus from an accommodating body that is separate from the recording apparatus and the aspect (A) such as a cartridge; The aspect (C) provided as a part is mentioned. In the case of the aspect (A) and the aspect (C), the ink composition is supplied from the attached container or the provided container to the head of the recording apparatus through a connection portion such as an ink tube. Recording can be done. In the aspect (B), after the ink composition is transferred from the container to the ink tank or the like of the recording apparatus, the ink composition is supplied from the ink tank to the head of the recording apparatus through a connection portion such as an ink tube. Recording can be done.

[Metal oxide layer]
A container that contains a non-aqueous photocurable inkjet composition or a package that contains at least a container that contains a non-aqueous photocurable inkjet composition is composed of a member having a metal oxide layer. The metal oxide layer is provided on at least one of the outer surface, the inner surface, and the inside of the member constituting the container or the package. It is preferable to provide the entire surface including the composition of the member. By having the metal oxide layer, the container or package of this embodiment has a lower water permeability and excellent visibility. Furthermore, since the moisture permeability is low, it is possible to suppress the generation of foreign substances derived from the moisture absorption of the ink composition. Moreover, since it is excellent in visibility, the discovery of the foreign material which generate | occur | produced in the container or the package becomes easy.

  Although it does not specifically limit as a metal oxide contained in a metal oxide layer, For example, the oxide of 1 or more metals chosen from the group which consists of a silica, an alumina, a titania, a zirconia, and a ceria is preferable. By including such a metal oxide, the moisture permeability of the container or the package is further lowered, and the curability and adhesion of the ink composition to be accommodated tend to be maintained. The metal oxide contained in a metal oxide layer may be used individually by 1 type, or may use 2 or more types together. Further, the metal oxide layer may be a single layer or may be composed of two or more layers.

  The thickness of the metal oxide layer is preferably 10 to 500 nm, more preferably 10 to 100 nm, and further preferably 20 to 80 nm. When the thickness of the metal oxide layer is 10 nm or more, the moisture permeability of the container or the package is further lowered, and the curability and adhesion of the ink composition to be accommodated tend to be maintained. Moreover, it exists in the tendency which visibility and a softness | flexibility improve more because the thickness of a metal oxide layer is 500 nm or less.

  Although it does not specifically limit as a formation method of a metal oxide layer, For example, the method of vapor-depositing a metal oxide on the resin molded object or inorganic molded object surface which comprises a container or a package, Resin which comprises a container or a package The method of apply | coating and drying the liquid composition containing a metal oxide on the surface of a molded object or an inorganic molded object is mentioned. Further, the container or package of the present embodiment may be a layer in which the metal oxide layer mainly constitutes the container or package.

[Other component materials]
A container or a packaging body consists of a member which has a metal oxide layer. As a structure other than the metal oxide layer of the member, a molded body made of a resin material (resin molded body) or a molded body made of an inorganic material (inorganic molded body) can be used, and metal oxide is formed on the surface or inside thereof. It can have a physical layer. Although it does not specifically limit as a constituent material which comprises a resin molding or an inorganic molded object, For example, a polyethylene terephthalate (PET), a polypropylene, polyethylene, a polyamide-type fiber, an ethylene vinyl acetate copolymer, an ethylene vinyl alcohol copolymer ( EVOH), resins such as polystyrene; or inorganic materials such as glass. In addition, the said structural material may be mix | blended and used by a suitable ratio, or may be used in multiple types.

  The member can be configured as a film, a member having a three-dimensional shape such as a box or a bottle, and the film is preferable from the viewpoint of light weight of the container. Among the above-described constituent materials, a film material having good durability when used as a film is not particularly limited. For example, polyethylene terephthalate (PET), polyethylene, polypropylene, polyamide-based fiber, ethylene vinyl acetate copolymer, ethylene Examples thereof include plastic films such as vinyl alcohol copolymer and polystyrene. Among these, high density, low density, or linear low density polyethylene, polypropylene, polyamide fiber, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer, and polystyrene are preferable. The film material may be a laminated film or a stretched film. Examples of the inorganic molded body include glass and metal. In addition, the member should just be a thing which has a metal oxide layer at least, The member which has a metal oxide layer as a main component may be sufficient, for example, the member which consists only of a metal oxide layer may be sufficient as it.

The oxygen permeability of the member having the metal oxide layer of the container or package is preferably 5.0 cc · 20 μm / (m ² · day · atm) or less, more preferably 2.0 cc · 20 μm / (m ² · Day · atm) or less, and more preferably 1.0 cc · 20 µm / (m ² · day · atm) or less. When the oxygen permeability is within the above range, the amount of dissolved oxygen in the ink composition being stored tends to hardly change. The oxygen permeability can be measured by a method defined in JIS K 7126 (ISO 15105).

  In order to improve the oxygen permeability, the container or the package may have a gas barrier layer. The gas barrier layer is not particularly limited, and examples thereof include a metal layer such as an aluminum layer, an organic layer such as an ethylene vinyl alcohol copolymer layer, and a polyvinyl alcohol layer.

  The total thickness of the container or package member is preferably 50 μm or more, more preferably 70 μm or more, and even more preferably 100 μm or more. When the total thickness of the container or the package is 100 μm or more, the water content and dissolved oxygen content of the ink composition to be accommodated hardly change, and the strength of the container or the package tends to be obtained. Further, the total thickness of the container or the package is preferably 300 μm or less, more preferably 200 μm or less, and further preferably 150 μm or less. When the total thickness of the container or the package is 200 μm or less, the flexibility tends to be further improved.

  The capacity of the ink composition that can be accommodated in the container or the package is preferably 100 to 5,000 mL, more preferably 100 to 4,000 mL, still more preferably 300 to 3,000 mL, and even more preferably. Is 500-2500 mL. When the capacity of the container or package is within the above range, the ink composition can be used up while the dissolved oxygen amount of the ink in the container or package remains almost unchanged after the start of use of the container or package. In addition, there are advantageous effects such as that the dissolved oxygen amount of the ink composition during storage is hardly changed.

  The container or package preferably has visible light permeability. “Visible light” refers to light having a wavelength of 400 to 800 nm. The visible light transmittance is preferably 40% or more, more preferably 50% or more, and further preferably 60% or more, as an average transmittance in the above wavelength range. When the visible light transmittance is 40% or more, the visibility tends to be further improved. The upper limit of the visible light transmittance is not particularly limited, but is preferably 100% or less. The visible light transmittance is reduced by increasing the thickness of the molded body (member) made of the metal oxide layer and other constituent materials, and the visible light transmittance of the molded body (member) made of the metal oxide layer and other constituent materials is reduced. Increasing by reducing the thickness. The visible light transmittance can be measured by the method described in the examples.

The moisture permeability of the container or package is preferably 20 g / m ² · 24 hours or less, more preferably 10 g / m ² · 24 hours or less, and even more preferably 5.0 g / m ² · 24 hours or less. It is. When the moisture permeability is 20 g / m ² · 24 hours or less, the curability and adhesion of the ink composition to be accommodated can be maintained, and the generation of foreign matters tends to be suppressed. The moisture permeability of the container or package is preferably 0.10 g / m ² · 24 hours or more, more preferably 0.20 g / m ² · 24 hours or more, and further preferably 1.0 g / m ^2. m ² · 24 hours or more, more preferably 2.0 g / m ² · 24 hours or more. When the moisture permeability is 0.10 g / m ² · 24 hours or less, the storage stability of the composition tends to be further improved. For example, the moisture permeability increases by reducing the thickness of the member, and decreases by increasing the thickness. The moisture permeability can be measured by the method described in the examples.

[Non-aqueous photo-curable inkjet composition]
The non-aqueous photocurable inkjet composition contains a polymerizable compound having a moisture absorption rate of 1.5% by mass / 24 hours or more at a temperature of 60 ° C. and a relative humidity of 90%. In the present embodiment, such a polymerizable compound is also referred to as a hydrophilic polymerizable compound.

[Hydrophilic polymerizable compound]
Among the polymerizable compounds, those having a moisture absorption rate of 1.5% by mass / 24 hours or more at a temperature of 60 ° C. and a relative humidity of 90% are included. Preferably it is 1.75-11 mass% / 24 hours, More preferably, it is 1.90-10 mass% / 24 hours. When the moisture absorption rate of the above compound is 1.5% by mass / 24 hours or more, the curability is excellent and advantageous. Moreover, it exists in the tendency which can suppress generation | occurrence | production of the foreign material etc. which originate in moisture absorption because the moisture absorption rate of the said compound is 11 mass% / 24 hours or less. The moisture absorption rate can be measured by the method described in the examples.

  The polymerizable compound having a moisture absorption rate of 1.5% by mass / 24 hours or more at a temperature of 60 ° C. and a relative humidity of 90% is not particularly limited. For example, acryloylmorpholine, 4-hydroxybutyl acrylate, tetrahydrofurfuryl acrylate And monofunctional monomers such as 2-hydroxy-3-phenoxypropyl acrylate; bifunctional monomers such as 2- (2-vinyloxyethoxy) ethyl acrylate and dipropylene glycol diacrylate.

  Among the above, an oxygen atom bonded to two acyclic hydrocarbon groups (hereinafter also referred to as “acyclic hydrocarbon group containing an oxygen atom”), a heterocyclic group containing an oxygen atom, and a hydroxyl group A polymerizable compound having one or more selected is preferable. These are also referred to as hydrophilic groups. Since such a polymerizable compound has a hydrophilic group having relatively high water absorption, the present invention is particularly advantageous. An acyclic hydrocarbon group containing an oxygen atom is a group in which an acyclic hydrocarbon group is bonded to two bonds of an oxygen atom. The two acyclic hydrocarbon groups may be the same or different, and each is a monovalent or divalent saturated or unsaturated acyclic hydrocarbon group, and the number of carbon atoms per acyclic hydrocarbon group Is preferably 1-8. The heterocyclic group containing an oxygen atom has an oxygen atom as an atom constituting the heterocyclic ring. The heterocycle is preferably a 3- to 8-membered ring. A hydroxyl group is a hydroxyl group in the molecule of the polymerizable compound. Examples of the polymerizable compound having an acyclic hydrocarbon group containing an oxygen atom include 2- (2-vinyloxyethoxy) ethyl acrylate and dipropylene glycol diacrylate, and a heterocyclic group containing an oxygen atom Examples of the polymerizable compound having acryloylmorpholine and tetrahydrofurfuryl acrylate include, and examples of the polymerizable compound having a hydroxyl group include 4-hydroxybutyl acrylate and 2-hydroxy-3-phenoxypropyl acrylate. . Examples of the acyclic hydrocarbon group containing an oxygen atom include an ether bond. The polymerizable compound having a hydrophilic group tends to have a moisture absorption rate of 1.5% by mass / 24 hours or more at a temperature of 60 ° C. and a relative humidity of 90%, but the moisture absorption rate is other than the hydrophilic group in the molecule. Therefore, for example, a polymerizable compound having the above hydrophilic group may be prepared and the moisture absorption rate may be confirmed by the method described in the examples.

  The polymerizable compound preferably includes a radical polymerizable compound, and more preferably includes a hydrophilic radical polymerizable compound. When the polymerizable compound contains a radically polymerizable compound, the curability tends to be further improved.

  The HLB (Hydrophile-Lipophile Balance) value of the polymerizable compound is preferably 8 or more, preferably 9 or more, and preferably 10 or more. Since the polymerizable compound having an HLB value of 8 or more has a relatively high water absorption, the present invention is particularly advantageous. The upper limit of the HLB value of the polymerizable compound is not particularly limited, but is preferably 13 or less. In addition, the HLB value in this specification is defined by the Griffin method.

  The ratio of the number of hydrophilic groups to the molecular weight (molecular weight / number of hydrophilic groups) per molecule of the polymerizable compound is preferably 30 or more, more preferably 50 or more, and even more preferably 100 or more. When the molecular weight / number of hydrophilic groups of the polymerizable compound is 30 or more, the adhesion to the substrate tends to be further improved. Further, the molecular weight / number of hydrophilic groups of the polymerizable compound is preferably 250 or less, more preferably 200 or less, and still more preferably 100 or less. Since the polymerizable compound having a molecular weight / hydrophilic group number of 250 or less has a relatively high water absorption, the present invention is particularly advantageous. The hydrophilic group is not particularly limited, and examples thereof include an oxygen atom bonded to two acyclic hydrocarbon groups, a heterocyclic group containing an oxygen atom, and a hydroxyl group.

  The ratio of the number of carbon atoms to the number of hydrophilic groups (number of carbon atoms / number of hydrophilic groups) per molecule of the polymerizable compound is preferably 3 or more, more preferably 4 or more, and even more preferably 7 or more. is there. When the number of carbon atoms / the number of hydrophilic groups of the polymerizable compound is 3 or more, the adhesion to the substrate tends to be further improved. Further, the number of carbon atoms / the number of hydrophilic groups of the polymerizable compound is preferably 13 or less, more preferably 12 or less, still more preferably 10 or less, and still more preferably 8 or less. Since the polymerizable compound having a carbon number / hydrophilic group number of 13 or less has a relatively high water absorption, the present invention is particularly advantageous.

  The content of the polymerizable compound is preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 45% by mass or more, and still more preferably based on the total amount of the ink composition. Is 50% by mass or more, particularly preferably 60% by mass or more. When the content of the polymerizable compound is 20% by mass or more, curability and adhesion tend to be further improved. Further, the content of the polymerizable compound is preferably 98% by mass or less, more preferably 95% by mass or less, still more preferably 90% by mass or less, and still more preferably based on the total amount of the ink composition. Is 80% by mass or less, and particularly preferably 70% by mass or less. When the content of the polymerizable compound is 98% by mass or less, foreign matter tends to be less likely to occur.

  The non-aqueous photocurable inkjet composition may contain other polymerizable compounds other than the above-mentioned hydrophilic polymerizable compound that are monofunctional, bifunctional, and trifunctional or higher. Examples of other polymerizable compounds include, but are not limited to, monofunctional monomers such as phenoxyethyl acrylate and isobornyl acrylate, and 2 such as 1,6-hexanediol diacrylate and dimethylol-tricyclodecane diacrylate. Functional monomer; a trifunctional monomer such as pentaerythritol triacrylate may be mentioned.

  A polymeric compound may be used individually by 1 type, or may use 2 or more types together. The content of all polymerizable compounds contained in the ink composition is preferably 70% by mass or more based on the total amount of the ink composition.

(Photopolymerization initiator)
The ink composition may further contain a photopolymerization initiator. Although it does not specifically limit as a photoinitiator, For example, an acyl phosphine oxide type compound and a thioxanthone type compound are mentioned. Of these, acylphosphine oxide compounds are preferred. By including an acylphosphine oxide compound, curability tends to be further improved.

(Acylphosphine oxide compounds)
Acylphosphine oxide compounds are susceptible to oxygen inhibition, but on the other hand, the use of acylphosphine oxide compounds tends to improve the curability when LEDs are used. In addition, the combination of the acylphosphine oxide compound and the thioxanthone compound tends to be excellent in the curing process using UV-LED, and the curability and adhesion of the ink composition tend to be further improved.

  Although it does not specifically limit as an acyl phosphine oxide type compound, For example, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and bis- (2 , 6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide.

  Although it does not specifically limit as a commercial item of an acyl phosphine oxide type compound, For example, IRGACURE 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide), DAROCUR TPO (2,4,6-trimethylbenzoyl- Diphenyl-phosphine oxide).

  The content of the acylphosphine oxide compound is preferably 5.0 to 15.0 mass%, more preferably 6.0 to 14.0 mass%, and still more preferably based on the total mass of the ink composition. Is 7.0-10.0 mass%. When the content of the acylphosphine oxide compound is 5.0% by mass or more, the curability tends to be more excellent. Further, when the content of the acylphosphine oxide compound is 15.0% by mass or less, there is little generation of undissolved or precipitated photopolymerization initiator, and the coloring of the ink or coating film by the photopolymerization initiator itself is reduced. There is a tendency to reduce yellowing.

(Thioxanthone compounds)
By including a thioxanthone compound, surface tackiness can be reduced, and in particular, in the case of a thin film that is susceptible to oxygen inhibition, the ink surface tends to be hardened to prevent color mixing and bleeding between dots.

  Although it does not specifically limit as a thioxanthone type compound, For example, it is preferable that 1 or more types selected from the group which consists of thioxanthone, diethyl thioxanthone, isopropyl thioxanthone, and chloro thioxanthone is included. Although not particularly limited, 2,4-diethylthioxanthone is preferable as diethylthioxanthone, 2-isopropylthioxanthone is preferable as isopropylthioxanthone, and 2-chlorothioxanthone is preferable as chlorothioxanthone. An ink composition containing such a thioxanthone compound tends to be more excellent in curability, storage stability, and ejection stability. Of these, thioxanthone compounds containing diethylthioxanthone are preferable. By including diethylthioxanthone, there is a tendency that a wide range of ultraviolet light (UV light) can be converted into active species more efficiently.

  Although it does not specifically limit as a commercial item of a thioxanthone type compound, For example, Speedcure DETX (2,4-diethylthioxanthone), Speedcure ITX (2-isopropylthioxanthone) (above, Lambson make), KAYACURE DETX-S (2, 4-diethylthioxanthone) (manufactured by Nippon Kayaku Co., Ltd.).

  The total content of the photopolymerization initiator is preferably 5.0 to 20% by mass, more preferably 5.0 to 15% by mass, and further preferably 7 to 13% with respect to the total mass of the ink composition. % By mass. When the total content of the polymerization initiator is 5.0% by mass or more, the surface tackiness can be further reduced, and the ink surface is cured in a thin film that is susceptible to oxygen inhibition, thereby preventing color mixing and bleeding between dots. Tend to be able to. Further, when the total content of the polymerization initiator is 20% by mass or less, there is little coloration of the ink by the initiator itself, there is little yellowing of the hue, and there is a tendency that there is little undissolved or precipitated initiator.

[Pigments and pigment dispersants]
The ink composition may contain a pigment, and may further contain a pigment dispersant together with the pigment. Since the pigment and the pigment dispersant are liable to cause foreign matters due to moisture absorption, the ink composition contains them, so that the present invention is particularly advantageous.

(Pigment)
Although it does not specifically limit as a pigment used for black ink, For example, it is No. 2300, no. 900, MCF88, No. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, no. 2200B (Mitsubishi Chemical Corporation), Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700, etc. Rega1 330R, Rega1 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. (Cabot Corp. CA Kol. , Color Black FW2, olor Black FW2V, Color Black FW18, Color Black FW200, Color B1ack S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 (manufactured by Degussa).

  Although it does not specifically limit as a pigment used for white ink, For example, C.I. I. Pigment white 6, 18, 21, titanium oxide, zinc oxide, zinc sulfide, antimony oxide, zirconium oxide, white hollow resin particles and polymer particles.

  Although it does not specifically limit as a pigment used for yellow ink, For example, C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 167, 172, 180.

  Although it does not specifically limit as a pigment used for a magenta ink, For example, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, or C.I. I. Pigment violet 19, 23, 32, 33, 36, 38, 43, 50.

  Although it does not specifically limit as a pigment used for cyan ink, For example, C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15:34, 15: 4, 16, 18, 22, 25, 60, 65, 66, C.I. I. Bat Blue 4, 60.

  The pigments other than those described above are not particularly limited. I. Pigment green 7,10, C.I. I. Pigment brown 3, 5, 25, 26, C.I. I. Pigment orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, 63.

(Pigment dispersant)
The above pigment may be a dispersible pigment. Examples of the pigment dispersion method include a method of dispersing using a pigment dispersant.

  Although it does not specifically limit as a pigment dispersant, For example, polyvinyl alcohols; polyvinyl pyrrolidones; polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic acid ester Acrylic resins such as copolymers and acrylic acid-acrylic acid alkyl ester copolymers; styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-alkyl acrylate copolymers, styrene -Styrene-acrylic resins such as α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-alkyl acrylate copolymer; styrene-maleic acid copolymer; styrene-maleic anhydride copolymer Polymer: Vinyl naphthalene-acrylic Acid copolymer; vinyl naphthalene-maleic acid copolymer; vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer , Vinyl acetate copolymers such as vinyl acetate-acrylic acid copolymers, or salts thereof; proteins such as glue, gelatin, casein, and albumin; natural rubbers such as gum arabic and tragacanth; glucosides such as saponin Alginate derivatives such as alginic acid and propylene glycol alginate, triethanolamine alginate, ammonium alginate; cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, ethylhydroxycellulose, and the like. A pigment dispersant may be used individually by 1 type, or may use 2 or more types together.

[Polymerization inhibitor]
The ink composition of this embodiment may contain a polymerization inhibitor. Although it does not specifically limit as a polymerization inhibitor, For example, hydroquinones represented by hydroquinone, hydroquinone monomethyl ether (MEHQ), 1-o-2,3,5-trimethylhydroquinone, 2-tert-butylhydroquinone; Catechols typified by 4-methylcatechol and 4-tert-butylcatechol; phenol, butylhydroxytoluene, butylhydroxyanisole, p-methoxyphenol, cresol, pyrogallol, 3,5-di-t-butyl-4-hydroxy Toluene, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-butylphenol), and 4,4′-thiobis (3-methyl-6- Phenol represented by t-butylphenol) A compound having a 2,2,6,6-tetramethylpiperidine-N-oxyl skeleton represented by 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxyl, 2,2 , 6,6-Tetramethylpiperidine skeleton compound, 2,2,6,6-tetramethylpiperidine-N-alkyl skeleton compound, and 2,2,6,6-tetramethylpiperidine-N-acyl skeleton Hindered amines represented by the compound having In addition, a polymerization inhibitor may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the polymerization inhibitor is preferably 0.05 to 1.0% by mass, more preferably 0.10 to 0.50% by mass, and still more preferably 0, with respect to the total mass of the ink composition. .10 to 0.30 mass%. When the content of the polymerization inhibitor is 0.05% by mass or more, the storage stability tends to be further improved. Moreover, it exists in the tendency for sclerosis | hardenability to improve more because content of a polymerization inhibitor is 1.0 mass% or less.

[Non-aqueous]
The ink composition of the present embodiment is non-aqueous. Specifically, the water content is preferably 0 to 1.0% by mass, more preferably 0 to 0.50% by mass, and still more preferably 0 to 0.30% by mass. Alternatively, the ink composition is substantially free of water.

〔Recording method〕
In the recording method of the present embodiment, a non-aqueous photocurable inkjet composition containing a polymerizable compound having a moisture absorption rate of 1.5 mass% / 24 hours or more at a temperature of 60 ° C. and a relative humidity of 90% is used for the non-aqueous light. A liquid feeding step of feeding liquid from a curable inkjet composition container to an ejection nozzle via an ink flow path, and ejecting the non-aqueous photocurable inkjet composition to a recording medium from the ejection nozzle. A discharging step.

[Liquid feeding process]
The liquid feeding step is a step of feeding the non-aqueous photocurable inkjet composition from the non-aqueous photocurable inkjet composition container to the discharge nozzle via the ink flow path. Here, the “ink flow path” refers to a flow path for distributing ink in the ink jet recording apparatus. As the ink flow path, for example, an ink supply path for supplying ink from an ink container that stores ink to the ink jet recording head, or a flow path for distributing ink to the nozzle opening in the ink jet recording head Is mentioned. Moreover, as a liquid feeding method, a conventionally known method can be used.

[Discharge process]
The ejection step is a step of ejecting the non-aqueous photocurable inkjet composition from the ejection nozzle to the recording medium.

[Curing process]
The recording method of this embodiment may further include a curing step. In the curing step, the non-aqueous photocurable inkjet composition attached to the recording medium is irradiated with ultraviolet light having an emission peak wavelength of 350 to 420 nm using a light emitting diode (LED), and the non-photosensitive inkjet composition is irradiated with the non-photosensitive ink composition. This is a step of curing the water-based photocurable inkjet composition. By using the LED, it is possible to reduce the size and life of the ink jet recording apparatus and to increase the efficiency and cost of the ink jet recording method as compared with the case of using a metal halide light source or a mercury lamp.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited in any way by the following examples.

[Material for ink composition]
The main materials for the ink compositions used in the following examples and comparative examples are as follows.
(Polymerizable compound)
(Trifunctional monomer)
SR444 (pentaerythritol triacrylate, manufactured by Sartomer)
(Bifunctional monomer)
VEEA (2- (2-vinyloxyethoxy) ethyl acrylate, manufactured by Nippon Shokubai Co., Ltd.)
SR508 (dipropylene glycol diacrylate, manufactured by Sartomer)
V # 230 (1,6-hexanediol diacrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
KAYARAD R-684 (dimethylol-tricyclodecane diacrylate, manufactured by Nippon Kayaku Co., Ltd.)
(Monofunctional monomer)
ACMO (acryloyl morpholine, manufactured by Kojin Film & Chemicals)
4HBA (4-hydroxybutyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
V # 150 (tetrahydrofurfuryl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
DA141 (2-hydroxy-3-phenoxypropyl acrylate, manufactured by Nagase ChemteX Corporation)
V # 192 (phenoxyethyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
IBXA (Isobornyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
[Surfactant]
BYK3500 (silicone surfactant, manufactured by BASF)
[Polymerization inhibitor]
MEHQ (p-methoxyphenol, manufactured by Kanto Chemical Co., Inc.)
LA7RD (4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxyl, manufactured by ADEKA)
(Polymerization initiator)
Hostalux KCB (manufactured by Clariant)
Irgacure 819 (BASF)
Speedcure TPO (made by LAMBSON)
Speedcure DETX (manufactured by LAMBSON)
[Pigment]
PR122 (CI Pigment Red 122)
Titanium oxide (pigment dispersant)
BYK180 (manufactured by BYK) for white pigments Solsperse 36000 (manufactured by Lubrizol) for magenta pigments

[Preparation of ink composition]
Each material was mixed with the composition shown in Table 1 below and stirred sufficiently to obtain ink compositions 1 to 9. In Table 1 below, the numerical unit is mass%, and the total is 100.0 mass%.

[Method of measuring moisture absorption rate of polymerizable compound]
Place the sample bottle (13.5 mL) containing 7 mL of the polymerizable compound in a disposable cup (200 mL) containing 50 cc of water with the lid uncovered, and top the disposable cup with Saran Wrap (registered trademark). Sealed. The disposable cup was left in a constant temperature bath at 60 ° C. for 24 hours to prepare a moisture absorption sample. After moisture absorption, the sample bottle was sealed, and the amount of water contained in the polymerizable compound was measured using a Karl Fischer moisture meter (manufactured by Hiranuma Sangyo Co., Ltd., trace moisture measuring device, AQ-2200). The increase in the amount of water before and after the moisture absorption test was calculated by the following formula to determine the moisture absorption rate.
Moisture absorption rate = (water content after moisture absorption−water content before moisture absorption) / mass of polymerizable compound before moisture absorption × 100

[Production of container]
A low-density polyethylene film having a thickness of 80 μm was used as the substrate. One side of this PET film was pretreated by reactive ion etching using a plasma processor. At this time, a high frequency power source was used for the electrodes, and the atmosphere was an argon / oxygen mixed gas atmosphere. Then, the film which vapor-deposited the silica with a thickness of 50 nm was obtained in-line on the pre-processing surface by reactive ion etching with the vacuum evaporation apparatus by an electron beam heating system. Then, the container 1 for accommodating an ink composition was produced using the obtained film.

  A container 2 for containing the ink composition was prepared in the same manner as the preparation of the container 1 except that aluminum oxide having a thickness of 50 nm was deposited. A container 3 for containing the ink composition was prepared in the same manner as in the preparation of the container 1 except that a biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm having no metal oxide layer was used as a base material. Was made. Further, a container 4 for containing the ink composition was prepared in the same manner as the preparation of the container 1 except that aluminum having a thickness of 50 nm was deposited.

[Moisture permeability]
The water permeability of the containers 1 to 4 was measured by a method for determining water vapor permeability (gas chromatographic method) according to JIS K 7129 plastic film and sheet. First, the low humidity chamber and the high humidity chamber were isolated by a test piece. In the gas chromatographic method, a low-humidity chamber is evacuated with a vacuum pump, a gas controlled to a constant relative humidity is flowed into a high-humidity chamber, the water vapor that has passed through the test piece is collected in a measuring tube for a certain period of time, and the collected water vapor amount is collected in a gas chromatograph. The water vapor permeability was calculated using a graph.

[Oxygen permeability]
The oxygen permeability of containers 1 to 4 was measured by a JIS K 7126 plastic film and sheet gas permeability test method (gas chromatograph method). One (low pressure side) separated by the test piece is kept in vacuum, the test gas is introduced into the other (high pressure side), and the amount of gas that has passed through the test piece and permeated to the low pressure side is measured by gas chromatography. The degree was calculated.

[Foreign matter evaluation]
The ink composition was sealed in each of the containers prepared as described above, and the containers were stored at a temperature of 60 ° C. and a relative humidity of 90% for 7 days. The container after storage was accommodated in an ink cartridge as a package, and the cartridge was attached to a printer (PX-G5000, manufactured by Seiko Epson Corporation). Thereafter, the ink composition in the container was continuously ejected from a head having 360 nozzles for 10 minutes. At this time, the ink temperature was adjusted in the head so that the viscosity of the ink composition was 10 mPa · s. After discharge, the nozzles were inspected and the number of non-discharge nozzles was counted. Based on the number of non-ejection nozzles, the occurrence of foreign matter due to storage was evaluated according to the following evaluation criteria. In the case of evaluation B, when the ink composition in the container was filtered with a filter paper, a residue that was seen as a foreign substance was observed.
A: The number of non-ejection nozzles was 1 or less.
B: There were two or more non-ejection nozzles.

[Curing property]
The ink composition was sealed in each of the containers prepared as described above, and the containers were stored at a temperature of 60 ° C. and a relative humidity of 90% for 7 days. The container after storage was accommodated in an ink cartridge as a package, and the cartridge was attached to a printer (PX-G5000, manufactured by Seiko Epson Corporation). Thereafter, the ink composition in the container was ejected from a head having 360 nozzles and adhered to the recording medium. Thereafter, the ink composition on the recording medium was irradiated with ultraviolet light at an accumulated energy of 200 mJ / cm ² to obtain a coating film having a thickness of 10 μm.

The coating film of the ink composition after ultraviolet light irradiation was rubbed with a cotton swab to confirm the presence or absence of scratches or the presence or absence of dirt on the swab. Based on the presence or absence of scratches or the presence or absence of dirt on the cotton swabs, the curability was evaluated according to the following evaluation criteria.
AA: At an integrated energy of 150 mJ / cm ² , the presence or absence of scratches or the contamination of the swab was not observed.
A: When the accumulated energy was 200 mJ / cm ² , the presence of scratches or the swab was not observed, but when the accumulated energy was 150 mJ / cm ² , the presence or absence of the scratch or the stain of the swab was recognized.
B: Scratches or cotton swabs were found even after irradiation with an integrated energy of 200 mJ / cm ² .

[Adhesion]
The ink composition was sealed in each of the containers prepared as described above, and the containers were stored at a temperature of 60 ° C. and a relative humidity of 90% for 7 days. The container after storage was accommodated in an ink cartridge as a package, and the cartridge was attached to a printer (PX-G5000, manufactured by Seiko Epson Corporation). Thereafter, the ink composition in the container was ejected from a head having 360 nozzles and adhered to the recording medium. Thereafter, the ink composition on the recording medium was irradiated with ultraviolet light at an accumulated energy of 200 mJ / cm ² to obtain a coating film having a thickness of 10 μm.

As a cutting tool, a single blade cutting tool (a cutter that is generally commercially available) and a guide for cutting at equal intervals using a single blade cutting tool were prepared. First, the blade of the cutting tool was applied so as to be perpendicular to the coating film, and six cuts parallel to each other were made in the recorded matter. After making these six cuts, the direction of 90 ° was changed, and another six cuts were made so as to be orthogonal to the cuts already made. In this way, a coating film having a lattice cut was obtained. Next, take out the transparent adhesive tape (width 25 ± 1mm) so that the length is about 75mm, put the tape on the grid-like cut in the coating film, and with your fingers enough to see through the coating film Rubbed the tape. Next, within 5 minutes after the tape was attached, the film was surely peeled off from the coating film at an angle close to 60 ° in 0.5 to 1.0 seconds. The adhesion was evaluated according to the following evaluation criteria based on the presence or absence of peeling of the coating film from the recording medium.
A: No peeling was observed.
B: Peeling was recognized.

〔Visibility〕
The average transmittance in the visible light region of 400 to 800 nm of the container produced as described above was measured with a spectrophotometer (manufactured by Hitachi, Ltd., product name U-3300 spectrophotometer). Visibility was evaluated based on the obtained transmittance.
A: The transmittance was 40% or more.
B: The transmittance was less than 40%.

〔viscosity〕
The viscosity at 20 ° C. of each ink composition after preparation was measured with a viscometer (product name MCR-300, manufactured by Physica), and the viscosity was evaluated according to the following criteria. A cone (diameter 75 mm, angle 1 °) was used, and the shear rate was 200 s ⁻¹ .
AA: The viscosity was 15 mPa · s or less.
A: The viscosity was higher than 15 mPa · s and lower than 20 mPa · s.
B: The viscosity was 20 mPa · s or more.

(Examples 1-9, Comparative Examples 1-6)
Any one of the ink compositions 1 to 9 was accommodated in any of the containers (packs) 1 to 4 and sealed to obtain a container in which the ink composition was sealed in the container. Table 2 shows the combinations of the ink composition and the container.

  In Comparative Examples 1 to 3 and 6, since the container did not have a metal oxide layer, the curability decreased due to moisture absorption, and generation of foreign matters was further confirmed for Comparative Example 1. Moreover, although the comparative example 2 was an ink composition with comparatively low hygroscopicity, since the container did not have a metal oxide layer, sclerosis | hardenability fell. Since the comparative example 4 had a metal layer instead of a metal oxide layer, the visibility was inferior. Further, in Comparative Example 5, although the container had a metal oxide layer, the curability was lowered because it was a relatively hydrophobic ink composition. In Comparative Example 6, it was shown that the content of the acylphosphine oxide compound in the ink composition was higher than that in Comparative Example 1, and the curability was improved. However, the residue originated from the acylphosphine oxide compound as a residue. Foreign objects were also observed. From this, it was found that the present invention is useful in that the generation of foreign matters derived from the acylphosphine oxide compound can be reduced while the composition is further improved in curability using the acylphosphine oxide compound.

  40 ... ink cartridge, 70 ... ink pack, 72 ... cartridge case, 74 ... ink supply port, 76 ... main body case, 78 ... lid.

Claims (11)

A non-aqueous photocurable inkjet composition containing a polymerizable compound having a moisture absorption rate of 1.5% by mass / 24 hours or more at a temperature of 60 ° C. and a relative humidity of 90%;
A member containing the non-aqueous photocurable inkjet composition and made of a member having a metal oxide layer, or a member containing at least a container containing the non-aqueous photocurable inkjet composition and having a metal oxide layer A package comprising:
A non-aqueous photocurable inkjet composition container.   The non-aqueous system according to claim 1, wherein the polymerizable compound has one or more selected from the group consisting of an oxygen atom bonded to two acyclic hydrocarbon groups, a heterocyclic group containing an oxygen atom, and a hydroxyl group. Photocurable inkjet composition container.   The non-aqueous photocurable inkjet composition container according to claim 1 or 2, wherein a content of the polymerizable compound is 20% by mass or more based on a total amount of the non-aqueous photocurable inkjet composition.   The non-aqueous photocurable type according to any one of claims 1 to 3, wherein the metal oxide layer contains one or more oxides selected from the group consisting of silica, alumina, titania, zirconia, and ceria. Inkjet composition container.   The non-aqueous photocurable inkjet composition container according to any one of claims 1 to 4, wherein the non-aqueous photocurable inkjet composition further comprises an acylphosphine oxide compound.   The non-aqueous photocurable inkjet composition container according to claim 1, wherein the polymerizable compound includes a radical polymerizable compound.   The nonaqueous photocurable inkjet composition container according to any one of claims 1 to 6, wherein the nonaqueous photocurable inkjet composition further comprises a pigment and a pigment dispersant.   The non-aqueous photocurable inkjet composition container according to any one of claims 1 to 7, wherein the container or the package has visible light permeability. The non-aqueous photocurable inkjet composition container according to any one of claims 1 to 8, wherein the container or the package has a moisture permeability of 20 g / m ² · 24 hours or less. The non-aqueous photocurable inkjet composition container according to any one of claims 1 to 9, wherein the nonaqueous photocurable inkjet composition is fed to an ejection nozzle through an ink flow path. Liquid process;
A discharge step of discharging the non-aqueous photocurable inkjet composition from the discharge nozzle onto a recording medium.   The non-aqueous photo-curable ink jet composition is irradiated with ultraviolet light having an emission peak wavelength of 350 to 420 nm using a light emitting diode to the non-aqueous photo-curable ink jet composition attached to the recording medium. The recording method according to claim 10, further comprising a curing step for curing the object.

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