JP2019081366A - Ink package and method for producing the same - Google Patents

Abstract

To provide an ink package which is less in deformation of a container even in long-term storage.SOLUTION: An ink package 10 includes a container 1, and inkjet ink 2 and gas 3 that are sealed in the container, in which the inkjet ink contains a polyalkylene glycol alkyl ether solvent and a binder resin containing at least one of an acrylic resin (A) and a copolymer (B), an oxygen partial pressure of the gas is less than 0.2 atmospheric pressure, and the container changes its appearance when an inner pressure in the sealed state is 0.8 atmospheric pressure or more, and does not change its appearance by pressure reduction for an oxygen partial pressure.SELECTED DRAWING: Figure 1

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an ink package with little deformation of a container even during long-term storage.

  In recent years, small-lot, large-lot production of printed materials has been promoted, and as a substitute for conventional printing such as offset printing, ink-jet printing, which is on-demand printing that can easily cope with small-lot multi-class, is attracting attention. In addition, inkjet printing is simpler than conventional offset printing, and has merits such as economy and energy saving.

Inkjet printing is a printing method in which microdroplets of ink ejected from a printer head land on a recording medium and then penetrate and fix to form dots, and a large number of these dots are collected to form an image. Inks for ink jet printing are required to have various properties such as ink jet aptitudes such as ejection stability from a printer head and intermittent ejection stability in addition to physical properties such as image quality and weatherability of printed matter.
As such an ink for ink jet printing, one containing a colorant such as a pigment, a binder resin for improving the fixability to a substrate, and a solvent is generally used.
In addition, it is known that these ink components cause deterioration due to moisture absorption and the like to generate precipitates and the like in the ink.
For this reason, as a container used for storage and conveyance of ink, a container etc. which are comprised with material of a predetermined film thickness, and whose water vapor transmission rate is low are used (for example, patent documents 1).

WO 2009/101708

By the way, when the ink package in which the container is filled with the ink is stored for a long time, there is a problem that the container is deformed.
In addition, when a container filled with ink is used as an ink cartridge of a recording apparatus, there is a possibility that the container may not be attached to the recording apparatus or the ink may leak from the container due to deformation of the container. is there.

  The present invention has been made in view of the above problems, and has as its main object to provide an ink package with little deformation of the container even during long-term storage.

  As a result of repeating researches to solve the above problems, long-term storage of ink containing a polyalkylene glycol alkyl ether solvent as a solvent and an acrylic resin or a vinyl chloride-vinyl acetate copolymer resin as a binder resin in a container for a long time If there is a high tendency of the container to deform in addition, and if the gas remaining in the deformed container void is examined, the oxygen partial pressure is low, it is necessary to use the specific solvent and binder resin as described above. When the ink containing the ink is stored for a long time, as a result of oxygen in the container being absorbed by these ink components, the inside of the container is decompressed, and it is found that the container is deformed, and the present invention is completed. .

  That is, the present invention is an ink package comprising a container, an inkjet ink sealed in the container, and a gas, wherein the inkjet ink comprises a polyalkylene glycol alkyl ether solvent, an acrylic resin (A A binder resin containing at least one of a copolymer (B) having a structural unit represented by the following general formula (I) and a structural unit represented by the following general formula (II), The partial pressure of oxygen is less than 0.2 atm, and the container has a change in appearance when the internal pressure in a sealed state is 0.8 atm or higher, and the oxygen partial pressure Provided is an ink package characterized in that the pressure does not change the appearance.

(In the general formula (I) and the general formula (II), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, R ³ represents an alkyl group having 1 to 3 carbon atoms, and X represents Represents a halogen atom)

  According to the present invention, the above-mentioned specific solvent and binder resin can be obtained by using a gas having an oxygen partial pressure within the above range and a container whose appearance does not change within the range of reduced pressure corresponding to the oxygen partial pressure. Even if the ink package is sealed in a container whose appearance changes when the internal pressure in the sealed state of the ink-jet ink containing the ink is 0.8 atmospheric pressure or more, the container is deformed even during long-term storage Can be reduced.

  In the present invention, the gas preferably contains an inert gas. By replacing the oxygen present in the void portion of the container with the inert gas, it is possible to easily obtain an ink package in which a gas having an oxygen partial pressure of less than 0.2 atm is sealed in the container. .

  In the present invention, the content of the polyalkylene glycol alkyl ether-based solvent is preferably 50 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the inkjet ink. Even when the content of the solvent is within the above range, oxygen in the gas is dissolved, and consumption of oxygen by the binder resin is likely to proceed, the ink package can be obtained by using the gas and the container. Can be reduced in deformation of the container. Accordingly, the effects of the present invention can be exhibited more effectively.

  In the present invention, the container is preferably an inner surface coated metal container having a metal container and a resin layer covering the inner surface of the metal container, or a resin container. By being the above-mentioned container, it is possible to easily form a container having a strength that does not change in appearance within the range of the oxygen partial pressure. Moreover, it is because the said container is simple in structure and it is easy to achieve cost reduction.

  The present invention is the method for producing an ink package as described above, wherein an ink filling step of filling the ink jet ink so as to provide a void in the container, filling the container with an inert gas, and And D. a substitution step of filling the gas with an oxygen partial pressure of less than 0.2 atm.

According to the present invention, the oxygen partial pressure of the gas can be easily made less than 0.2 atm by having the substitution step.
For this reason, even if the container is sealed even if the container has a change in appearance when the internal pressure is 0.8 atmospheric pressure or more when the ink jet ink containing the specific solvent and the binder resin is sealed, deformation of the container The above-described ink package can be easily obtained.

In the present invention, it is preferable to have an inspection step of inspecting that the oxygen partial pressure of the gas is less than 0.2 atm during or after the substitution step.
By having the inspection step, it can be confirmed that the oxygen partial pressure of the gas is less than 0.2 atm, and an ink package having the oxygen partial pressure of less than 0.2 atm can be stably obtained. It is from.

  The present invention has the effect of being able to provide an ink package with little deformation of the container even during long-term storage.

It is a schematic sectional drawing which shows an example of the ink package of this invention. It is an explanatory view explaining the volume of the container in the present invention. It is process drawing which shows an example of the manufacturing method of the ink package of this invention.

The present invention relates to an ink package and a method of manufacturing the same.
Hereinafter, the method for producing the ink package and the ink package of the present invention will be described.

A. Ink Package First, the ink package of the present invention will be described.
The ink package of the present invention comprises a container, an inkjet ink and a gas sealed in the container, and the inkjet ink comprises a polyalkylene glycol alkyl ether solvent and an acrylic resin (A A binder resin containing at least one of a copolymer (B) having a structural unit represented by the following general formula (I) and a structural unit represented by the following general formula (II), The partial pressure of oxygen is less than 0.2 atm, and the container has a change in appearance when the internal pressure in a sealed state is 0.8 atm or higher, and the oxygen partial pressure It is characterized in that there is no change in appearance due to pressure reduction.

(In the general formula (I) and the general formula (II), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, R ³ represents an alkyl group having 1 to 3 carbon atoms, and X represents Represents a halogen atom)

Such an ink package of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the ink package of the present invention. The ink package 10 of the present invention comprises the container 1 and the inkjet ink 2 and the gas 3 sealed in the container 1.
Here, the inkjet ink 2 contains a polyalkylene glycol alkyl ether solvent and a binder resin containing at least one of an acrylic resin (A) and a copolymer (B). The oxygen partial pressure of the gas is less than 0.2 atm. The container 1 has a change in appearance when the internal pressure in a sealed state is 0.8 atmosphere or more, and does not change in appearance due to the reduction of the oxygen partial pressure.
Moreover, in this example, it is formed as a separate body from the container 1 and has a lid 4 for sealing the container 1. The ink package 10 further includes a seal member 5 disposed between the container 1 and the lid 4.

According to the present invention, by using a gas having an oxygen partial pressure in the above-mentioned range and a container whose appearance does not change in the range of the oxygen partial pressure, an inkjet including the above-mentioned specific solvent and binder resin Even when the ink is sealed in a container that changes appearance in appearance when the internal pressure in a sealed state is 0.8 atmosphere or more, the ink package has little deformation even when stored for a long period of time It can be done.
Here, the reason why the container is deformed as a result of absorption of oxygen in the container when the above-described specific solvent and binder resin are contained as an inkjet ink is not clear, but it is presumed as follows.

That is, the polyalkylene glycol alkyl ether solvent can dissolve oxygen in the container because the solubility of oxygen is relatively high, but the above solvent alone can not dissolve all the oxygen in the container. it is conceivable that.
However, in the above acrylic resin (A) and copolymer (B), the hydrocarbon moiety is decomposed, and the generated radicals react with oxygen to form a carboxy group, and are dissolved in the solvent. Since oxygen can be consumed by being oxidatively degraded by oxygen, oxygen in the container will be absorbed into the inkjet ink over time.
Therefore, when the gas filled in the container is the atmosphere at 1 atm, oxygen in the gas, that is, about 0.2 atm, is consumed by the binder resin through the solvent, and as a result, oxygen The internal pressure of the container is reduced to the partial pressure, that is, to 0.8 atm, which is reduced by 0.2 atm.
For this reason, when a container whose appearance is changed when the internal pressure in a sealed state is 0.8 atmosphere or more is used, the container is deformed due to long-term storage of the ink package.
That is, the deformation of the container involves a solvent capable of dissolving oxygen (hereinafter, may be simply referred to as an oxygen-soluble solvent) and a resin capable of consuming oxygen (hereinafter, simply referred to as an oxygen-consuming resin). There is a case where it is the first time that the combination of

On the other hand, according to the present invention, using a gas whose oxygen partial pressure is within the above range and a container whose appearance does not change within the range of the oxygen partial pressure, that is, after the ink is filled By using a gas in which the partial pressure of oxygen present in the void is adjusted to be lower than the atmosphere, and a container whose appearance does not change even when all the oxygen contained in the gas after adjustment is consumed The ink jet ink containing the above-mentioned specific solvent which is a soluble solvent and the above-mentioned specific binder resin which is an oxygen consuming resin is sealed in a container which changes appearance when the internal pressure in a sealed state is 0.8 atmosphere or more Even in the case where the ink package is used, it is possible to reduce the deformation of the container even during long-term storage.
Further, as a result, even when the ink package is stored for a long period of time, since the container is excellent in shape stability, the ink package can be stably attached as an ink cartridge of a recording apparatus. can do. Further, the ink package can be made less likely to leak ink due to breakage of the container.

In addition, by using a container that changes in appearance when the internal pressure in a sealed state is 0.8 atmospheric pressure or more (hereinafter, the container may be a specific container), the internal pressure is 0.8 atmospheric pressure or less The ink package can be easily stored and transported as compared with the case of using a container made of a hard material that does not deform even when the
For example, although it is possible to use hard materials, such as high strength metal and glass, as a hard material, the said specific container can be made lightweight compared with a hard material container. In addition, the specific container is less deteriorated in ink quality due to the reaction with the ink component as occurs when the hard material is the metal, and the container is broken compared to the container when the hard material is glass or the like. Can be less likely to occur.
In addition, although it is conceivable to use a thick resin material as the hard material, the specific container can be made smaller in size and lighter in weight than such a thick film container.
From such a thing, by being the said specific container, an ink package can be made easy of storage and conveyance.

The ink package of the present invention comprises a container, an inkjet ink and a gas.
Hereinafter, each configuration of the ink package of the present invention will be described in detail.

1. Container The container in the present invention seals the inkjet ink and the gas.
The container has a change in appearance when the internal pressure in a sealed state is 0.8 atmosphere or more, and the change in the partial pressure of the oxygen does not change the appearance.
That is, the container means that the maximum internal pressure causing the appearance change is 0.8 atmosphere or more and less than the internal pressure after the reduction of the oxygen partial pressure.

In the present invention, sealing the ink-jet ink and the gas means that there is no leakage of the ink-jet ink and that there is substantially no permeation of the gas.
Moreover, it can be confirmed using the sealing strength test based on JIS Z 0238 that gas permeation is substantially non-existent.
More specifically, after a container is prepared and sealed, a sealing strength test applies a constant internal pressure by sealing a gas so that the internal pressure becomes 0.04 MPa higher than the external pressure using a tester. There is no change in pressure for 30 seconds, and one that can hold 0.04 MPa can be substantially free of gas permeation.
Moreover, FKT-100-J by San Chemical Co., Ltd. can be used as a testing machine.

The maximum internal pressure causing the appearance change is the largest internal pressure among the internal pressure causing the appearance change, that is, the internal pressure at which the internal / external pressure difference is the smallest.
The method of measuring the maximum internal pressure is not particularly limited as long as the method can accurately measure the maximum internal pressure.
The above measurement method is, for example, filling the container with 80% by volume of pure water of the internal volume of the container (filling rate 80%) and setting the pressure of nitrogen to 1 atm in the void portion of the container The container is sealed and then the internal pressure in the container is lowered by discharging nitrogen in the container, and a change in appearance is observed after one week at 25 ° C. A method of checking the internal pressure can be used.
Moreover, the said measurement can be measured on the conditions of 25 degreeC and 1 atmosphere of external pressure.

Here, that there is a change in appearance means that a change in a recess or the like can be confirmed visually.
More specifically, the above-mentioned change in appearance means that the volume of the container is measured when the atmosphere is sealed in the container at 25 ° C. and the internal pressure is 1 atm, and the internal / external pressure difference is 0 atm ( Hereinafter, a volume change of 8% by volume or more may be seen with respect to the reference volume.
Further, no change in appearance means that a change in volume of less than 8% by volume or no change in volume is observed with respect to the reference volume.
The method of measuring the volume is not particularly limited as long as it can accurately measure the volume. For example, a general volume measuring method such as a method of immersing the container in a water tank or the like in a closed state Can be used. In addition, the change in appearance is measured in a 25 ° C. environment.
Also, the volume in appearance change refers to the volume enclosed by the outer surface of the container. Further, the volume of the container does not include a lid or the like formed separately from the container. For example, the volume of the container of FIG. 1 already described is that shown in bold and dashed in FIG.

  In the present invention, when the internal pressure in the sealed state is at least 0.8 atm, the internal pressure of the container is at least 0.8 atm when the external pressure of the container is 1 atm under an environment of a temperature of 25 ° C. It means that the difference of the internal pressure to the external pressure is within 0.2 atm.

The internal pressure causing a change in the appearance of the container, that is, the lower limit of the maximum internal pressure (hereinafter sometimes simply referred to as the maximum strength) is 0.8 atmospheric pressure or more. That is, when the internal pressure is lower than 0.8 atm, the container naturally changes in appearance.
Here, under atmospheric pressure (1 atm), the partial pressure of oxygen in the atmosphere is usually 0.2 atm.
Therefore, in the case where the gas sealed in the container is the atmosphere and the oxygen contained in the gas is all dissolved in the ink and consumed in the binder resin because the container has the maximum strength of 0.8 atmosphere or more. In addition, it is possible to use a container having a strength that causes a change in appearance.
As a result, when the gas sealed in the container is the atmosphere, all the oxygen contained in the gas is consumed, and a container using a material that does not change in appearance even when the internal pressure reaches 0.8 atm. For example, the use of a container made of a high strength metal such as a thick steel can and a container made of a hard material such as a glass container, and a container made of a thick resin and the like can be omitted. It can be small.
The maximum strength may be 0.8 atm or more, preferably 0.82 atm or more, particularly preferably 0.85 atm or more, and particularly preferably 0.87 atm or more. Is preferred. The film thickness of the material which comprises a container can be made thin by the said largest intensity | strength being in the above-mentioned range, and container size and mass can be made small. Therefore, the ink package can be easily stored and transported.
In addition, 1 atmospheric pressure is atmospheric pressure, and means that it is 101325 Pa.

In the present invention, the absence of a change in appearance due to the partial pressure reduction of the oxygen partial pressure means the appearance of the container when all the oxygen in the gas sealed in the container is dissolved in the ink or consumed by the binder resin. It is said to have a strength that does not change.
In addition, the said oxygen partial pressure means the oxygen partial pressure in case the said gas is 1 atmosphere. Therefore, when the internal pressure of the container is reduced from 1 atm to less than 1 atm by storing the ink package for a long period of time, the oxygen partial pressure is the reduced amount of the internal pressure by the reduced amount of oxygen. It is required on the assumption that it exists. For example, when the internal pressure is reduced from 1 atm to 0.9 atm and the oxygen partial pressure of the container after pressure reduction is 0.1 atm, the oxygen partial pressure when the internal pressure of the container is 1 atm is 0 .2 atm pressure.

The internal pressure causing a change in the appearance of the container, that is, the upper limit of the maximum internal pressure (hereinafter, may be simply referred to as the minimum strength) is the internal pressure after all the oxygen partial pressure has been consumed. It may be less than the internal pressure obtained by subtracting the oxygen partial pressure from 1 atm (hereinafter sometimes simply referred to as the internal pressure after total consumption), but after the total consumption it is 0.03 internal pressure lower than the internal pressure or less Among them, the internal pressure as low as 0.05 atm is preferable, and the internal pressure as low as 0.07 atm is particularly preferable. When the above-mentioned minimum strength is in the above-mentioned range, it is possible to stably change the appearance without any change by reducing the oxygen partial pressure.
For example, when the oxygen partial pressure of gas is 0.05 atm, the minimum strength of the container may be less than 0.95. If the oxygen partial pressure of the gas is 0.05 atm and the minimum strength is an internal pressure that is 0.05 atm lower than the internal pressure after all consumption, the container will have an internal pressure of 0.95 atm after the entire consumption. .05 atm pressure It deforms in appearance at 0.90 atm or less which is an internal pressure lower than 05 atm, and it means that it does not change in appearance at an internal pressure greater than 0.90 atm.

The above container is a box-like container having no change in appearance regardless of the amount of ink filled in the container.
Here, “no change in appearance regardless of the amount of ink to be filled” means, for example, 50% by volume and 90% by volume of the ink container volume under the condition that a pressure of 1 atmospheric pressure is applied to the surface of the ink jet ink It means that there is no change in the appearance of the container even when the amount of ink is different as in the case where the amount of ink is filled.
More specifically, such a container can be a container whose external appearance does not change when the internal pressure in the sealed state is in the range of 0.97 atm to 1 atm.

The container is not particularly limited as long as it is used for storing and transporting ink and has the strength as described above, and a container made of a single layer material formed using a single material It may be a container made of multiple layers of materials in which multiple materials are stacked.
Such a container is preferably an inner surface coated metal container having a metal container and a resin layer covering the inner surface of the metal container, or a resin container.
It is because the container which has the above-mentioned intensity | strength can be easily formed by being the said container. In addition, the structure is simple and it is easy to reduce the cost.

  The metal material constituting the metal container is not particularly limited as long as it can form the container having the above strength, but, for example, steel, tin, iron, aluminum, tin-free steel, stainless steel plate, etc. Among them, steel, tin-free steel and the like can be preferably used in the present invention. This is because the metal material exhibits sufficient strength at a relatively thin film thickness. Moreover, it is because it is easy to make the said container a thing with a low moisture permeability.

The film thickness of the body portion of the metal material constituting the metal container is not particularly limited as long as the container having the above strength can be formed, but for example, the range of 0.1 mm to 3.0 mm In particular, it is preferably in the range of 0.2 mm to 2.0 mm, and particularly preferably in the range of 0.3 mm to 1.5 mm. It is because it is easy to set it as the above-mentioned intensity because the above-mentioned film thickness is in the above-mentioned range.
The above film thickness refers to the film thickness at the thinnest portion of the body of the container.
In addition, the body portion is generally provided substantially perpendicularly to the bottom surface portion of the container, and is a portion that holds the inkjet ink together with the bottom surface portion.
Specifically, it is a portion indicated by A in FIG. 1 described above.

  The resin material constituting the resin layer is not particularly limited as long as it can form a container having the above strength. For example, epoxy, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (polyethylene terephthalate (polyethylene terephthalate) PET), vinyl chloride, polystyrene, acryl, polycarbonate and the like can be mentioned. Among them, polyethylene, polypropylene and the like can be preferably used in the present invention. This is because the resin material has low reactivity with each component in the inkjet ink, and the container can be made excellent in the storage stability of the ink.

  The film thickness of the resin layer is not particularly limited as long as it can form a container having the above strength, and is different depending on the constituent material and film thickness of the metal container, for example, 0 It is preferable to be in the range of 0.1 mm to 1.0 mm, and in particular, to be in the range of 0.02 mm to 0.5 mm, and in particular to be in the range of 0.05 mm to 0.1 mm preferable. It is because it is easy to set it as the above-mentioned intensity because the above-mentioned film thickness is in the above-mentioned range.

  The resin material of the resin container is not particularly limited as long as it can form the container having the strength. For example, the resin material of the resin layer may be the same. it can.

  The film thickness of the body portion of the resin material constituting the resin container is not particularly limited as long as the container having the above strength can be formed, but, for example, 0.2 mm to 3.0 mm It is preferably in the range of 0.5 mm to 2.5 mm, and particularly preferably in the range of 1.0 mm to 2.0 mm. It is because it is easy to set it as the above-mentioned intensity because the above-mentioned film thickness is in the above-mentioned range.

  The shape of the container is not particularly limited as long as it can form a container having the above strength, but it may be a general container shape used for storage of inkjet ink. Specifically, the shape can be a cylindrical shape, a rectangular solid shape, or the like.

The internal volume of the above container is not particularly limited as long as it can form a container having the above strength, and is different depending on the application etc., but within the range of 0.1 L to 200.0 L In particular, it is preferable to be in the range of 0.3 L to 5.0 L, and in particular, it is particularly preferable to be in the range of 0.5 L to It is preferable to be in the range of 1.2L. This is because the ink package can be easily stored and transported by the internal volume.
In addition, the internal volume of the said container means the internal volume measured when a container is sealed in the state of internal-external pressure difference of 0 atmosphere.

2. Gas The gas in the present invention is sealed in the container.
Moreover, the oxygen partial pressure of the said gas is less than 0.2 atmospheres.

  As mentioned above, under atmospheric pressure (1 atm), the partial pressure of oxygen in the atmosphere is usually 0.2 atm. Therefore, that the oxygen partial pressure is a gas less than 0.2 atm means that oxygen in the atmosphere is artificially replaced with a gas other than oxygen.

The oxygen partial pressure may be less than 0.2 atm, but is preferably 0.15 atm or less, more preferably 0.1 atm or less, and particularly preferably 0.05 atm or less Is preferred. When the oxygen partial pressure is within the above range, it is possible to stably suppress the change in the appearance of the container.
The lower limit of the oxygen partial pressure is preferably as low as possible, preferably 0 atmosphere. For example, a gas heavier than the atmosphere, such as argon, is preferably used and filled in a box filled with the gas. It can be 0 atm. Further, from the viewpoint of easy replacement of oxygen in the gas, the pressure is preferably 0.03 atmosphere or more.
In addition, the said oxygen partial pressure means the oxygen partial pressure in case the said gas is 1 atmosphere, and, specifically, can be made to be the same as the content as described in the term of said "1. container". .

  The internal pressure of the gas in the container is not particularly limited as long as the oxygen partial pressure is in the above-mentioned range, but may be 1 atm immediately after the container is sealed.

The component contained in the gas is not particularly limited as long as it can reduce the oxygen partial pressure to less than 0.2 atm, but preferably contains an inert gas. By replacing the oxygen present in the void portion of the container with the inert gas, it is possible to easily obtain an ink package in which a gas having an oxygen partial pressure of less than 0.2 atm is sealed in the container. .
The inert gas in the present invention is not particularly limited as long as it has lower absorptivity by the binder resin than oxygen.
Specific examples of the inert gas include rare gases such as argon, xenon and krypton; nitrogen, carbon dioxide and the like.
In the present invention, the inert gas is preferably argon or nitrogen, and more preferably nitrogen. By using the above-mentioned inert gas, the absorptivity with the binder resin is low, and the cost can be reduced.
The gas in the present invention may contain one kind of inert gas, but may contain two or more kinds of inert gases.

  The ratio of the gas to the internal volume of the container is appropriately set according to the application of the ink package, but for example, is in the range of 2% to 20% by volume of the internal volume of the container In particular, it is preferably in the range of 5% by volume to 15% by volume. When the ratio is within the above range, for example, it is possible to reduce ink leakage during transportation.

3. Ink Jet Ink The ink jet ink in the present invention is sealed in the container.
Further, the inkjet ink comprises a polyalkylene glycol alkyl ether solvent, an acrylic resin (A), a structural unit represented by the following general formula (I), and a structural unit represented by the following general formula (II) And Binder resin containing at least one of the copolymer (B).

(In the general formula (I) and the general formula (II), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, R ³ represents an alkyl group having 1 to 3 carbon atoms, and X represents Represents a halogen atom)

(1) Binder Resin The binder resin in the present invention contains at least one of an acrylic resin (A) and a copolymer (B).
Further, the binder resin has a decomposable site such as a hydrocarbon site, and radicals generated by the decomposition react with oxygen to form a carboxyl group, and the oxygen dissolved in the solvent Oxygen can be consumed by undergoing oxidative degradation.

(A) Acrylic resin (A)
The acrylic resin (A) in the present invention refers to a polymer compound including a polymer using at least one selected from (meth) acrylic acid and derivatives thereof as at least a monomer. However, the acrylic resin (A) is different from the copolymer (B) described later, and the acrylic resin (A) does not include the copolymer (B) described later.
According to the present invention, by using the acrylic resin (A) as the binder resin, the adhesiveness after printing is suppressed, and it is possible to reduce the back-off and sticking after winding and drying.

The acrylic resin (A) is suitably selected from the group consisting of alkyl (meth) acrylate, aralkyl (meth) acrylate, alkoxyalkyl (meth) acrylate, hydroxyalkyl (meth) acrylate, and (meth) acrylic acid. It can be obtained from free radically polymerizable monomers. It has at least one radically polymerizable ethylenic double bond in the molecule, preferably one radically polymerizable ethylenic double bond in the molecule, and can be polymerized in the presence of a radical polymerization initiator in a solvent If it is a radically polymerizable monomer, various monomers can be further used. For example, vinyl compounds and maleimides may be included as radically polymerizable monomers.
The acrylic resin (A) may be a homopolymer of one type of radically polymerizable monomer, or may be any copolymer selected from two or more types of radically polymerizable monomers.

As a radically polymerizable monomer used for acrylic resin (A), (meth) acrylic acid;
Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, benzyl (meth) acrylate, phenethyl (meth) acrylate, methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate (Meth) acrylates such as 2-methylcyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and trifluoroethyl (meth) acrylate;
(Meth) acrylamides such as (meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, dibutyl (meth) acrylamide, phenyl (meth) acrylamide, benzyl (meth) acrylamide and the like;
Styrene, α-, o-, m-, p-alkyl, nitro, cyano, amide, ester derivative of styrene, (meth) acrylic acid anilide, (meth) acryloyl nitrile, acrolein, vinyl chloride, vinylidene chloride, vinyl fluoride Vinyl compounds such as vinylidene fluoride, N-vinyl pyrrolidone, vinyl pyridine, N-vinyl carbazole, vinyl imidazole, vinyl acetate;
Monomaleimides such as N-benzyl maleimide, N-phenyl maleimide, N-cyclohexyl maleimide, N-laurin maleimide, N- (4-hydroxyphenyl) maleimide and the like;
Mention may be made of phthalimides such as N- (meth) acryloyl phthalimide.
In the present invention, it is preferable to use a monomer having no hydroxyl group among the above monomers from the viewpoint of excellent ejection stability of the ink jet ink and excellent drying property of the ink on the recording medium, and having no hydroxyl group and amino group. It is more preferred to use a monomer.

  The content of (meth) acrylic acid and derivatives thereof as monomers in the acrylic resin (A) is excellent in the ejection stability of the inkjet ink and the drying property of the ink on the recording medium. The amount is preferably 70 parts by mass or more, more preferably 80 parts by mass or more, and still more preferably 90 parts by mass or more based on 100 parts by mass of the monomers constituting the resin (A).

  Particularly preferred acrylic resin (A) is a polymer of methyl (meth) acrylate alone, or methyl (meth) acrylate and butyl (meth) acrylate, ethoxyethyl (meth) acrylate, and benzyl (meth) acrylate And a copolymer of methyl (meth) acrylate alone, or a copolymer of methyl (meth) acrylate and butyl (meth) acrylate, among others. It is more preferable that In the above copolymer, a total of at least one or more compounds selected from the group consisting of butyl (meth) acrylate, ethoxyethyl (meth) acrylate and benzyl (meth) acrylate relative to 100 parts by mass of methyl (meth) acrylate The amount is preferably 0.01 parts by mass to 15 parts by mass, more preferably 0.1 parts by mass to 15 parts by mass, and still more preferably 0.5 parts by mass to 12 parts by mass. Such acrylic resin (A) is excellent in ejection stability and drying property, and can be an inkjet ink suitable for high speed printing.

The acrylic resin (A) has a weight average molecular weight in the range of 5,000 to 150,000, from the viewpoint of excellent discharge stability of the inkjet ink and excellent drying property of the ink on the recording medium. Is more preferable, and in particular, it is still more preferable that it is 10,000 or more and 70,000 or less.
In the present invention, the mass average molecular weight Mw is a value measured by GPC (gel permeation chromatography), and the elution solvent is 0.01 mol using a high-speed GPC apparatus (HLC-8120 GPC, manufactured by Tosoh Corp.). / Liter lithium bromide added N-methylpyrrolidone, and polystyrene standards for calibration curve are Mw 377400, 210500, 96000, 50400, 206500, 10850, 5460, 2930, 1300, 580 (Easi PS-, manufactured by Polymer Laboratories, Inc. 2) and Mw of 10 90000 (manufactured by Tosoh Corp.), and the measurement column is measured as TSK-GEL ALPHA-M × 2 (manufactured by Tosoh Corp.).

The acrylic resin (A) is excellent in the ejection stability of the inkjet ink, and the drying property of the ink on the recording medium, so that the glass transition temperature (Tg) of the acrylic resin (A) is 40 ° C. It is preferable that it is the above, and it is more preferable that a glass transition temperature (Tg) is 70 degreeC or more.
In the present invention, the glass transition temperature (Tg) is a value measured by a differential scanning calorimeter (DSC) (for example, a differential scanning calorimeter “DSC-50” manufactured by Shimadzu Corp.). Although a plurality of glass transition temperatures may be observed, in the present invention, a main transition temperature having a larger heat absorption amount is adopted.
The acid value of the above acrylic resin (A) is not particularly limited, but the acid value of the above resin is 10 mg KOH / g or less because it is excellent in the ejection stability of the inkjet ink and the drying property of the ink on the recording medium. Is preferable, and more preferably 5 mg KOH / g or less.
In the present invention, the acid value means the mass (mg) of potassium hydroxide required to neutralize the acidic component contained in 1 g of the sample (solid content of resin), and the method described in JIS K 0070 It is a value measured by an equivalent method.

The amine value of the acrylic resin (A) is not particularly limited, but is preferably 10 mg KOH / g or less from the viewpoint of excellent ejection stability of the inkjet ink and excellent drying of the ink on the recording medium. It is more preferably 5 mg KOH / g or less, still more preferably 2 mg KOH / g or less.
In the present invention, the term “amine value” refers to the mass (mg) of potassium hydroxide equivalent to the amount of hydrochloric acid necessary to neutralize 1 g of solid content of resin, and the method described in JIS K 7237 It is a value measured by an equivalent method.

The hydroxyl value of the acrylic resin (A) is not particularly limited, but is preferably 10 mg KOH / g or less from the viewpoint of excellent ink jet ink discharge stability and excellent ink drying property on a recording medium. Is preferable, 5 mg KOH / g or less is more preferable, and 2 mg KOH / g or less is even more preferable.
In the present invention, the hydroxyl value is the number of mg of potassium hydroxide required to acetylate the OH group contained in 1 g of the solid content of the resin, and acetic anhydride according to the method described in JIS K 0070 Is used to acetylate the OH group in the sample and to titrate unused acetic acid with potassium hydroxide solution.
In addition, an acid value, an amine value, and a hydroxyl value can be suitably adjusted with the kind and content of a monomer which comprise resin.

Organic peroxide is preferable as the radical polymerization initiator used when manufacturing the said acrylic resin (A), and hydroperoxide type, dialkyl peroxide type, peroxy ester type, diacyl peroxide type, peroxy carbonate And peroxyketal-based and ketone peroxide-based organic peroxides. Among them, dialkyl peroxide-based, peroxy ester-based and diacyl peroxide-based organic peroxides are preferable.
Preferred specific examples of the above radical polymerization initiator include, but are not limited to, t-butylperoxy-2-ethylhexanoate, t-butyl hydroperoxide, di-t-hexyl peroxide and the like is not.

The polymer and copolymer used as acrylic resin (A) can be used individually by 1 type or in combination of 2 or more types.
Moreover, as a commercially available acrylic resin (A), for example, "Paraloid B99N" (methyl methacrylate-butyl methacrylate copolymer) Tg 82 ° C, weight average molecular weight 15,000 of Rohm and Haas Co., "Paraloid B60" (Methyl methacrylate-butyl methacrylate copolymer) Tg 75 ° C., weight average molecular weight 50,000, and the like are exemplified.

(B) Copolymer (B)
The copolymer (B) in the present invention is a copolymer having the structural unit represented by the above general formula (I) and the structural unit represented by the above general formula (II).

As a halogen atom in X in General formula (I), a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, It is preferable that it is a chlorine atom or a bromine atom, and it is more preferable that it is a chlorine atom.
Specific examples of the monomer forming the constitutional unit represented by the general formula (I) include vinyl chloride, vinyl bromide, isopropenyl chloride, isopropenyl bromide and the like, and the ejection stability of the inkjet ink is excellent. Among these, vinyl chloride or isopropenyl chloride is preferable, and vinyl chloride is preferable because it can improve the spreadability of the ink on the recording medium, and can obtain a print having high optical density and excellent stretchability. More preferable.

Moreover, as an alkyl group in R ³ in the general formula (II), a methyl group, an ethyl group, an n-propyl group, an isopropyl group may be mentioned, and a methyl group or an ethyl group is preferable, and a methyl group Is more preferred.
Specific examples of the monomer forming the constitutional unit represented by the general formula (II) include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, isopropenyl acetate, isopropenyl propionate, isopropenyl butyrate, isobutyrate Isopropenyl can be mentioned, which is excellent in the ejection stability of the ink jet ink, and also improves the wetting and spreading properties of the ink on the recording medium, and can obtain a print having high optical density and excellent stretchability. Among them, vinyl acetate or isopropenyl acetate is preferable, and vinyl acetate is more preferable.

As another monomer which comprises a copolymer (B), it can select suitably from conventionally well-known monomers, and can use it. For example, a (meth) acrylate monomer having no functional group exemplified as a monomer of the above-mentioned acrylic resin (A), and other monomers can be suitably used.
In the present invention, among them, it is preferable to include hydroxyalkyl (meth) acrylate. By containing hydroxyalkyl (meth) acrylate as the above other monomer, the ejection stability of the ink-jet ink is excellent, and the wettability of the ink on the recording medium is improved, the optical density is high, and the stretchability is also improved. It is because an excellent printed matter can be obtained.

  The hydroxyalkyl (meth) acrylate may be appropriately selected from conventionally known hydroxyalkyl (meth) acrylates. Among them, 2-hydroxy, because it is excellent in the ejection stability of the ink-jet ink, and the wet spreadability of the ink on the recording medium is improved, and a print having a high optical density and an excellent stretchability can be obtained. Ethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,2-propanediol 2- (meth) acrylate, methyl α- (hydroxymethyl) (meth) acrylate, ethyl α- (hydroxymethyl) (meth) Acrylate, n-butyl α- (hydroxymethyl) (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, or 4-hydroxybutyl (meth) acrylate is preferred, among which 2-hydroxypropyl (meth ) Acrylate or 1,2-propanediol 2- (Meta) Acrylate are preferred. Hydroxyalkyl (meth) acrylate can be used individually by 1 type or in combination of 2 or more types.

In the present invention, in the copolymer (B), the constituent unit represented by the general formula (I) is preferably the main component. Among them, the ejection stability of the ink-jet ink is excellent, the wettability of the ink on the recording medium is improved, the optical density is high, the adhesion to the recording medium is excellent, and the alcohol resistance and the stretchability are also excellent. Ratio of the structural unit represented by the general formula (I) in the copolymer (B) is preferably 70% by mass or more and 95% by mass or less, from the viewpoint that the printed matter can be obtained. It is more preferable that it is 90 mass% or less.
The proportion of the constituent unit represented by the general formula (II) in the copolymer (B) is preferably 4% by mass to 10% by mass, and more preferably 5% by mass to 8% by mass. preferable.
Moreover, it is preferable that it is 1 to 20 mass%, and, as for the ratio of the structural unit derived from the hydroxyalkyl (meth) acrylate in a copolymer (B), it is 5 to 17 mass%. More preferable. This is because blocking at the time of winding after printing can be suppressed.
In the present invention, the main component refers to the entire constituent unit constituting the copolymer (B),
It refers to a structural unit that occupies 50% by mass or more.

  In addition, the ejection stability of the ink-jet ink is excellent, the wettability of the ink on the recording medium is improved, the optical density is high, the adhesion to the recording medium is excellent, and the alcohol resistance and the stretchability are also excellent. From the viewpoint of obtaining the printed matter, the structural unit represented by the general formula (I) in the copolymer (B) and the general unit with respect to the total of all the structural units constituting the copolymer (B) The total proportion with the structural unit represented by the formula (II) is preferably 80% by mass or more, more preferably 90% by mass or more, and further substantially 100% by mass. preferable.

The molecular weight of the copolymer (B) used in the present invention may be appropriately selected, and is not particularly limited. However, the ejection stability of the inkjet ink is excellent, and the wettability of the ink on the recording medium is improved. The number average molecular weight is preferably 10,000 or more, and is preferably in the range of 10,000 or more and 50,000 or less, from the viewpoint that printed matter having high optical density and excellent stretchability can be obtained. Among these, more preferably 10,000 or more and 30,000 or less.
In the present invention, the number average molecular weight Mn is measured by GPC under the same conditions as the above-mentioned measurement of the weight average molecular weight.

  Further, in the present invention, it is possible to obtain a printed material which is excellent in the ejection stability of the ink jet ink, improves the wettability of the ink on the recording medium, and has high optical density and excellent stretchability. Therefore, it is preferable that the glass transition temperature (Tg) of a copolymer (B) is 40 degreeC or more, and it is more preferable that a glass transition temperature (Tg) is 50 degreeC or more.

  As a commercially available copolymer (B), for example, “Solvain TA3” (vinyl chloride 83 mass%, vinyl acetate 4 mass%, hydroxyalkyl acrylate 13 mass% copolymer manufactured by Nisshin Chemical Industry Co., Ltd., Tg 65 ° C., Number average molecular weight 24,000) etc. are mentioned.

(C) Binder resin The binder resin in the present invention contains at least one of the above-mentioned acrylic resin (A) and copolymer (B).

  The binder resin contains at least one of the acrylic resin (A) and the copolymer (B), but preferably contains both the acrylic resin (A) and the copolymer (B). By including both the acrylic resin (A) and the copolymer (B), the binder resin is excellent in ejection stability and intermittent ejection even when applied to high-speed printing, and it is possible to use the ink on the recording medium It is because it can be excellent in wet spreading property, excellent in drying property of the obtained coating film, and high in optical density and high quality of the obtained printed matter, and also excellent in alcohol resistance and stretchability. .

  In the binder resin, the content ratio of the acrylic resin (A) and the copolymer (B) is combined in the range of (A) / (B) = 40/60 to 70/30 on a mass basis. By using it, it is excellent in discharge stability and intermittent dischargeability even when applied to high speed printing, and excellent in the wettability of the ink on the recording medium, and excellent in the drying property of the obtained coating, and the obtained printed matter Is high in optical density and high in quality, and also excellent in alcohol resistance and stretchability. Among them, it is preferable to use the content ratio of the acrylic resin (A) and the copolymer (B) in combination in the range of (A) / (B) = 40/60 or more and 60/40 or less on a mass basis. .

The binder resin may further contain another resin as long as the effects of the present invention are not impaired. As other resin, the conventionally well-known vinyl chloride-vinyl acetate copolymer etc. are mentioned as a suitable thing, for example.
Such other resins are excellent in ejection stability and intermittent ejection even when applied to high-speed printing, and excellent in the wetting and spreading properties of the ink on the recording medium, and the drying properties of the obtained coating film, From the viewpoint that the obtained printed matter has high optical density and high quality, and is excellent in alcohol resistance and stretchability, it is preferably 20 parts by mass or less, and 10 parts by mass with respect to 100 parts by mass of the binder resin in total. It is more preferable that

The total content of the binder resin may be appropriately adjusted, but in particular, the total content of the binder resin is 4.9 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the entire inkjet ink. It is preferably from 5 to 30 parts by mass, and more preferably from 6 to 25 parts by mass.
When the content is in the above-mentioned range, the ink is excellent in ejection stability and intermittent ejection even when applied to high speed printing, and the obtained coating film is excellent in the wetting and spreading properties of the ink on the recording medium. The resulting printed matter has high optical density and high quality, and can also be excellent in alcohol resistance and stretchability.

(2) Polyalkylene Glycol Alkyl Ether-Based Solvent The polyalkylene glycol alkyl ether-based solvent in the present invention is contained as a main solvent of an inkjet ink, and is capable of dissolving oxygen.
In addition, containing as a main solvent means that 60 mass% or more of all the solvents is contained. In the present invention, the content is preferably 70% by mass or more of the total solvent, and particularly preferably 80% by mass or more. With the above content, the high-speed printing can be performed with low odor while maintaining the quality of the printed matter.

As such a polyalkylene glycol alkyl ether solvent, a polyalkylene glycol monoalkyl ether solvent and a polyalkylene glycol dialkyl ether solvent can be used.
In the present invention, among them, polyalkylene glycol dialkyl ether solvents can be preferably used. This is because low odor and high speed printing are possible.

(A) Polyalkylene Glycol Monoalkyl Ether Solvent As the above polyalkylene glycol monoalkyl ether solvent, it is possible to appropriately select and use one from among those known as a solvent.
For example, what is represented by the following general formula (III) can be mentioned. By using a compound represented by the following general formula (III), it is possible to obtain excellent printed matter with excellent intermittent discharge property and improved wet-spreading property of the ink on the recording medium. .

(In the general formula (III), R ⁴ is an alkyl group having 1 to 4 carbon atoms, R ⁵ is a hydrogen atom or a methyl group, R ⁶ is a methylene group or an ethylene group, and m is 2 to 4) And R ⁵ and R ⁶ may be the same or different.)

The alkyl group of R ⁴ and the number of carbon atoms in R ⁵ is 1-4, methyl group, ethyl group, propyl group, and butyl group, and among them, preferably a methyl group or an ethyl group.
m is an integer of 2 to 4, and preferably m is an integer of 2 to 3.

Among polyalkylene glycol monoalkyl ether solvents represented by the general formula (III), among them, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, triethylene glycol monomethyl ether, or triethylene glycol monobutyl ether However, it is preferable in that it is excellent in intermittent discharge performance, improves the wetting and spreading properties of the ink on the recording medium, and can obtain high-quality printed matter with high optical density.
The polyalkylene glycol monoalkyl ether solvents represented by the general formula (III) can be used singly or in combination of two or more.

(B) Polyalkylene Glycol Dialkyl Ether-Based Solvent The above-mentioned polyalkylene glycol dialkyl ether-based solvent can be appropriately selected and used from those known as a solvent.

  The polyalkylene glycol dialkyl ether-based solvent is preferably a solvent represented by the following general formula (IV) from the viewpoint of high-speed printing while maintaining the quality of printed matter.

(In general formula (IV), R ⁷ and R ⁸ each independently represent an alkyl group having 1 to 4 carbon atoms, R ⁹ represents a hydrogen atom or a methyl group, and R ¹⁰ represents a methylene group or an ethylene group. And n are integers of 2 to 4. A plurality of R ⁹ and R ¹⁰ may be the same or different.)

The alkyl group of indicated number of carbon atoms in R ⁷ and R ⁸ is 1 to 4, a methyl group, an ethyl group, a propyl group, and butyl group, and among them, preferably a methyl group or an ethyl group.
n is an integer of 2 to 4, and preferably n is an integer of 2 to 3, and more preferably 2.

Specific examples of polyalkylene glycol dialkyl ether solvents represented by the general formula (IV) include diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether and the like. Among them, diethylene glycol diethyl ether or diethylene glycol methyl ethyl ether is preferable from the viewpoint of low odor and high speed printing while maintaining the quality of printed matter.
The polyalkylene glycol dialkyl ether may be used alone or in combination of two or more.

(C) Polyalkylene Glycol Alkyl Ether Solvent: As the polyalkylene glycol alkyl ether solvent, polyalkylene glycol monoalkyl ether solvents and polyalkylene glycol dialkyl ether solvents can be used.
In the present invention, any solvent containing at least one of a polyalkylene glycol monoalkyl ether solvent and a polyalkylene glycol dialkyl ether solvent may be used, and both may be contained.

The content of the polyalkylene glycol alkyl ether-based solvent may be appropriately adjusted according to the viscosity of the inkjet ink and the like, and is not particularly limited, but 50 parts by mass or more and 95 parts by mass or less per 100 parts by mass of the inkjet ink. Among them, it is preferably 60 parts by mass or more and 90 parts by mass or less, and particularly preferably 70 parts by mass or more and 85 parts by mass or less. When the content of the solvent is within the above range, the oxygen in the gas is dissolved and the consumption of the oxygen by the binder resin progresses while maintaining the quality of the printed matter, while making the ink jet ink capable of high-speed printing with low odor. Even in the case where it is easy to use, the ink package can be made to have less deformation of the container by using the gas and the container. Accordingly, the effects of the present invention can be exhibited more effectively.
Further, from the viewpoint of suppressing the change in appearance, the content of the above-mentioned polyalkylene glycol alkyl ether-based solvent is preferably 50 parts by mass or more and 65 parts by mass or less per 100 parts by mass of the inkjet ink. It is preferable that it is mass part or more and 60 mass parts or less.

(3) Other Components The inkjet ink in the present invention contains the above-mentioned binder resin and polyalkylene glycol alkyl ether solvent, but usually contains a coloring material.
In addition, the above-mentioned ink jet ink may contain other solvents, various additives and the like as needed.

(A) Coloring Material The coloring material in the present invention can be appropriately selected from known coloring materials used in the inkjet ink, and includes known dyes, organic pigments, inorganic pigments and the like. Among the above-mentioned coloring materials, it is preferable to use a pigment from the viewpoint of color developability and weather resistance.

Examples of organic pigments include insoluble azo pigments, soluble azo pigments, derivatives from dyes, phthalocyanine organic pigments, quinacridone organic pigments, perylene organic pigments, dioxazine organic pigments, nickel azo pigments, isoindolinone organic pigments Pyranthrone organic pigments, thioindigo organic pigments, condensed azo organic pigments, benzimidazolone organic pigments, quinophthalone organic pigments, isoindoline organic pigments, quinacridone solid solution pigments, organic solid solution pigments such as perylene solid solution pigments, Other pigments include carbon black and the like.
When organic pigments are exemplified by color index (C.I.) numbers, C.I. I. Pigment yellow 1, 2, 3, 12, 13, 14, 16, 17, 20, 24, 73, 74, 75, 83, 95, 97, 98, 109, 110, 114, 117, 120, 125, 128, 129, 130, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185, 213, 214; I. Pigment red 5, 7, 9, 12, 48, 49, 52, 53, 57, 97, 112, 122, 123, 147, 168, 177, 180, 184, 192, 202, 206, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 242, 254; I. Pigment orange 16, 36, 43, 51, 55, 59, 61, 64, 71; C.I. I. Pigment violet 19, 23, 29, 30, 37, 40, 50; C.I. I. Pigment blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64; I. Pigment green 7, 36, 58, 59; C.I. I. Pigment browns 23, 25, 26 and the like.

  Specific examples of the above-mentioned inorganic pigments are barium sulfate, iron oxide, zinc oxide, barium carbonate, barium sulfate, silica, clay, talc, titanium oxide, calcium carbonate, synthetic mica, alumina, zinc flower, lead sulfate, yellow lead, Zinc yellow, red iron oxide (red iron oxide (III)), cadmium red, ultramarine blue, bitumen, chromium oxide green, cobalt green, amber, titanium black, synthetic iron black, inorganic solid solution pigments and the like can be mentioned.

In the present invention, the pigment is C.I. I. Pigment blue 15: 3, 15: 4 etc., cyan pigments, C.I. I. Green pigments such as C.I. pigment green 7, 36, 58, 59, etc .; I. Magenta pigments such as C.I. pigment red 122, 202, C.I. Pigment Yellow 150, 155, 180, etc., and black pigments such as carbon black are preferable. By including the pigment, absorption of oxygen by the inkjet ink tends to be promoted. Therefore, the effect of suppressing the deformation of the container of the present invention can be more effectively exhibited.
In the present invention, among them, the pigment is preferably a cyan pigment, a green pigment, a black pigment and a magenta pigment, and particularly preferably a cyan pigment, a green pigment and a black pigment. Among them, particularly preferred are cyan pigments and green pigments. The pigments tend to be in the order of cyan pigments, black pigments, magenta pigments and yellow pigments, if the absorption of oxygen is promoted and the containers are arranged in order from those which are likely to cause a change in appearance. In addition, since the green pigment is similar in structure to the cyan pigment, it tends to cause changes in the appearance almost the same as the cyan pigment. For this reason, it is because the effect of suppressing a deformation | transformation of the container of this invention can be exhibited more effectively by including the above-mentioned pigment as said pigment.
Although the reason why the absorption of oxygen is promoted by such a pigment is not clear, it is considered to be because it acts as a catalyst for the consumption of oxygen by the binder resin.

The average dispersed particle size of the pigment is not particularly limited as long as it is capable of desired color development, and varies depending on the type of pigment to be used, but the dispersion stability of the pigment is good and sufficient coloring power can be obtained. From the viewpoint of obtaining, the thickness is preferably in the range of 5 nm to 400 nm, and more preferably in the range of 30 nm to 300 nm. If the above-mentioned average dispersion particle size is below the above-mentioned upper limit value, it is hard to cause clogging of the nozzle of an ink jet head, a highly reproducible homogeneous image can be obtained, and the obtained printed matter can be made high quality. It is from. In the case of below the above-mentioned lower limit value, it is because light resistance may fall.
The average dispersed particle size of the pigment is obtained by preparing a measurement sample obtained by diluting the ink with ethyldiglycol acetate by about 50 times, and measuring it by the dynamic scattering method. Specifically, measurement can be performed using a laser diffraction / scattering particle size analyzer microtrack particle size analyzer UPA 150 (manufactured by Nikkiso Co., Ltd.) at a measurement temperature of 25 ° C.

  The content of the pigment is not particularly limited as long as a desired image can be formed, and is appropriately adjusted. Specifically, although the content varies depending on the type of pigment, it is preferably in the range of 0.05 parts by mass to 25 parts by mass with respect to 100 parts by mass of the inkjet ink in total. More preferably, it is in the range of 20 parts by mass to 20 parts by mass. When the content is within the above range, the balance between the dispersion stability of the pigment and the coloring power can be excellent.

In the present invention, in order to disperse the pigment, it is preferable to use a combination of dispersants.
In addition, the use of the above-mentioned dispersant tends to promote the absorption of oxygen by the inkjet ink. Therefore, the effect of suppressing the deformation of the container of the present invention can be more effectively exhibited.
Although the reason why the absorption of oxygen is promoted by such a dispersant is not clear, it is considered to be because it acts as a catalyst for the consumption of oxygen by the binder resin.

As said dispersing agent, it can select suitably from what is conventionally used as a dispersing agent, and can be used.
As the above-mentioned dispersant, for example, surfactants of cationic type, anionic type, nonionic type, amphoteric type, silicone type and fluorine type can be used. Among the surfactants, polymer surfactants (polymer dispersants) are preferable in that they can be dispersed uniformly and finely.

  Examples of the polymer dispersant include (co) polymers of unsaturated carboxylic acid ester such as polyacrylic acid ester; (partial) amine salt of (co) polymer of unsaturated carboxylic acid such as polyacrylic acid (Partially) ammonium salts and (partially) alkylamine salts; (co) polymers of hydroxyl group-containing unsaturated carboxylic acid esters such as hydroxyl group-containing polyacrylic acid esters and their modified products; polyurethanes; unsaturated polyamides; Siloxanes; Long-chain polyamino amide phosphates; Polyethylenimine derivatives (amides obtained by reaction of poly (lower alkyleneimine) with free carboxyl group-containing polyesters and their bases); Polyallylamine derivatives (polyallylamine and free) Polyester, polyamide or ester and amide having a carboxyl group Compound reaction product obtained by the reaction of one or more compounds selected from the three compounds of (polyester amide)) and the like, is preferably used among others polyester dispersant.

When the pigment is dispersed using the above-mentioned dispersant, the content of the above-mentioned dispersant is preferably 10 parts by mass or more and 150 parts by mass or less, and 20 parts by mass or more with respect to 100 parts by mass of the pigment. More preferably, it is 120 parts by mass or less. If the content is in the above-mentioned range, an ink jet ink excellent in dispersibility and dispersion stability can be obtained.
In addition, by being within the above range, absorption of oxygen by the inkjet ink is promoted, and the effect of suppressing the deformation of the container of the present invention can be more effectively exhibited.

(B) Other Solvents Other solvents in the present invention are solvents other than the above polyalkylene glycol alkyl ether solvents.
Such other solvents are not particularly limited as long as they do not react with the components in the ink jet ink and do not inhibit the effects of the present invention, and those generally used in the ink jet ink are used. can do.
Examples of the other solvent include cyclic esters, ethylene glycol alkyl ether acetate, polyethylene glycol alkyl ether acetate, propylene glycol alkyl ether acetate, and polypropylene glycol alkyl ether acetate.

The above-mentioned cyclic ester refers to one having a cyclic structure formed by dehydration condensation of a hydroxyl group and a carboxyl group in the same molecule.
By containing the above-mentioned cyclic ester as a solvent, the solubility of the binder resin can be improved, and an inkjet ink excellent in intermittent discharge performance and discharge stability can be obtained.

In the present invention, the cyclic ester can be appropriately selected and used from those known as a solvent. Among the above cyclic esters, cyclic esters having a 4 to 7-membered ring structure are preferable, and cyclic esters having a 5 to 7-membered ring structure are more preferable, from the viewpoint of excellent intermittent discharge properties.
Specific examples of the cyclic ester include β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone and the like.
Cyclic ester can be used individually by 1 type or in combination of 2 or more types.

The content of the cyclic ester may be appropriately adjusted according to the viscosity of the inkjet ink and the like, and can be in the range of 3 parts by mass to 10 parts by mass with respect to 100 parts by mass of the inkjet ink.
By being within the above range, the solubility of the binder resin can be improved, and an ink excellent in intermittent discharge performance and discharge stability can be obtained. In addition, it is possible to obtain a high-quality printed material having a high optical density by improving the wettability and spreading property of the ink on the recording medium as well as having low odor and excellent drying property.
In the present invention, the content of the cyclic ester is preferably 3.5 parts by mass or more and 9.5 parts by mass or less, and more preferably 4 parts by mass or more and 9 parts by mass or less with respect to 100 parts by mass of the inkjet ink. preferable.
In particular, in order to obtain high-quality printed matter by high-speed printing, when importance is given to the drying property of ink, wet spreading property, and high optical density, the content of cyclic ester is based on 100 parts by mass of inkjet ink. Is preferably 3 to 6 parts by mass, more preferably 3.5 to 5.5 parts by mass, still more preferably 4 to 5 parts by mass .
On the other hand, when emphasis is placed on the improvement of intermittent ejection performance and ejection stability in order to make the ink more suitable for the inkjet method, the content of the cyclic ester is at least 6 parts by mass with respect to 100 parts by mass of the inkjet ink. The amount is preferably 10 parts by mass or less, more preferably 6.5 parts by mass or more and 9.5 parts by mass or less, and still more preferably 7 parts by mass or more and 9 parts by mass or less.

  By containing the ethylene glycol alkyl ether acetate as a solvent, the solubility of the binder resin can be improved, and an inkjet ink excellent in intermittent discharge performance and discharge stability can be obtained.

  Examples of the ethylene glycol alkyl ether acetate include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate and ethylene glycol monobutyl ether acetate.

The content of the ethylene glycol alkyl ether acetate may be appropriately adjusted according to the viscosity of the inkjet ink and the like, and may be 5 parts by mass or less with respect to 100 parts by mass of the inkjet ink. If the content is in the above-mentioned range, low odor can be ensured even at high speed printing. By containing ethylene glycol alkyl ether acetate, it is also possible to improve the solubility of the binder resin or to improve the intermittent discharge performance.
On the other hand, the content of ethylene glycol alkyl ether acetate is preferably 3 parts by mass or less, and 1 part by mass or less, based on 100 parts by mass of the inkjet ink, from the viewpoint of reducing odor when drying the coating of the inkjet ink. Is more preferable, and it is even more preferable not to contain substantially.

  By containing the above polyethylene glycol alkyl ether acetate, propylene glycol alkyl ether acetate, and polypropylene glycol alkyl ether acetate as a solvent, the solubility of the binder resin is improved, and an inkjet ink excellent in intermittent discharge performance and discharge stability. It can be done.

Examples of the polyethylene glycol alkyl ether acetate include diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, triethylene glycol methyl ether acetate, triethylene glycol ethyl ether acetate and triethylene glycol butyl ether acetate.
Specific examples of propylene glycol alkyl ether acetate include propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate.
Further, specific examples of polypropylene glycol alkyl ether acetate include dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, dipropylene glycol butyl ether acetate, tripropylene glycol methyl ether acetate, tripropylene glycol ethyl ether acetate, tripropylene glycol Butyl ether acetate is mentioned.

The content of the polyethylene glycol alkyl ether acetate is preferably 2 parts by mass or less, and more preferably 1 part by mass or less, based on 100 parts by mass of the inkjet ink, from the viewpoint of reducing odor when the coating is dried. It is even more preferable to be substantially free.
The content of the propylene glycol alkyl ether acetate is preferably 5 parts by mass or less, and more preferably 3 parts by mass or less, based on 100 parts by mass of the inkjet ink, from the viewpoint of reducing odor when the coating is dried. It is even more preferable to be substantially free.
In addition, the content of the polypropylene glycol alkyl ether acetate is preferably 2 parts by mass or less, and 1 part by mass or less, based on 100 parts by mass of the inkjet ink, from the viewpoint of reducing odor when the coating is dried. More preferably, it is even more preferable not to contain substantially.

(C) Additives Additives include antioxidants, surfactants, antifoaming agents, pH adjusters, viscosity modifiers and the like.
Moreover, it is preferable that the said additive is what contains resin stabilizers, such as antioxidant. By containing such a resin stabilizer, consumption of oxygen by the inkjet ink can be suppressed. For this reason, it is because a deformation | transformation of a container can be suppressed more stably.

(4) Method of Producing Ink-Jet Ink The method of producing the above-mentioned ink-jet ink is not particularly limited, and can be appropriately selected and used from conventionally known methods. In the above production method, for example, a polyalkylene glycol alkyl ether solvent, a coloring material, and, if necessary, a dispersant are added to prepare a pigment dispersion, and the pigment dispersion and the binder resin are necessary. Depending on the method, there may be mentioned a method of obtaining an inkjet ink by adding and stirring an optional additive component.

4. Ink Package The ink package of the present invention comprises a container, an inkjet ink and a gas, but may have other configurations as needed.
Such other configurations may include a lid for sealing the container.
The lid is not particularly limited as long as it can seal the container, and is appropriately selected according to the shape of the container opening and the like.
Also, the above other configuration can include a seal member disposed between the container and the lid. As the sealing member, any known member can be used as long as it has a sealing property, and for example, it has a polyolefin foam layer / aluminum layer / sealant layer and seals the container by high frequency induction overheating or the like. What can be used can be used. As the sealant layer, for example, resins such as polyethylene terephthalate, polypropylene and polyethylene can be used.
The sealing member is not limited to the one used together with the lid, but may be used alone to seal the container. As an example of using the sealing member alone, for example, a mode of using as a tape-like one for closing the opening of the container, or a sealing member is included in all or part of the material constituting the container and can be sealed by heat pressure bonding It can be set as a mode used as a heat seal part.

B. Method of Manufacturing Ink Package Next, a method of manufacturing the ink package will be described.
The method for producing an ink package according to the present invention is the method for producing an ink package as described above, wherein the step of filling the inkjet ink is performed so as to provide a void in the container; And filling the container with the gas having an oxygen partial pressure of less than 0.2 atm.

A method of manufacturing such an ink package of the present invention will be described with reference to the drawings. FIG. 3 is a process chart showing an example of the method for producing an ink package of the present invention. In the method for producing an ink package according to the present invention, as illustrated in FIG. 3A, after filling the inkjet ink 2 so as to provide the void 1a in the container 1, the void 1a is filled with an inert gas. The partial pressure of oxygen in the space 1a in the container 1 is reduced by replacing the oxygen in the gas 3a before substitution existing in the space 1a with the inert gas g by supplying g to be sprayed. The ink package 10 is obtained by filling the gas 3 with a pressure of less than 0.2 atm (FIG. 3 (b)) and then sealing the container 1 with the lid 4 (FIG. 3 (c)).
Moreover, in this example, as shown to Fig.3 (a), the oxygen partial pressure of the gas which exists in the cavity 1a is installed in the cavity 1a, installing the oximeter 11 and supplying the inert gas g. Is measured to confirm that the oxygen partial pressure of the gas is less than 0.2 atm.
3 (a) is the ink filling process, FIG. 3 (b) is the replacement process and the inspection process, and FIG. 3 (c) is the sealing process.

According to the present invention, the oxygen partial pressure of the gas can be easily made less than 0.2 atm by having the substitution step.
For this reason, even if the ink jet ink containing the above-mentioned specific solvent and binder resin is sealed in a container whose appearance is changed when the internal pressure in the sealed state is 0.8 atmospheric pressure or more, the container The above-described ink package with little deformation can be easily obtained.

The method for producing an ink package of the present invention includes the above-described ink filling step and the replacement step.
Hereinafter, each process of the manufacturing method of the ink package of this invention is demonstrated.

1. Ink Filling Step The ink filling step in the present invention is a step of filling the inkjet ink so as to provide a void in the container.

The container and the inkjet ink used in this step are the same as the contents described in the section “A. Ink package”, and thus the description thereof is omitted here.
Further, the void portion is a space in the container which is not filled with the inkjet ink, and refers to a space capable of storing the gas. Therefore, the volume of the void is the volume of the gas sealed in the container (25 ° C., 1 atm pressure condition), and the ratio of the void to the internal volume of the container is “A. It can be made to be the same as the ratio to the internal volume of the above-mentioned container of the above-mentioned gas of "2.
Moreover, filling so as to provide a void means filling the container with an inkjet ink of a volume obtained by subtracting the volume of the void from the entire volume of the container.

In this step, the method for filling the container with the inkjet ink can be the same as the general method for filling the inkjet ink.
In the present step, when the replacement step is performed before the present step, that is, when the present step is performed after the inside of the container is filled with the gas, the method for filling the container with the inkjet ink is as follows: It is preferable that the method is a method of filling the inkjet ink at a filling rate that does not replace the gas filling the container.

2. Substitution Step The substitution step in the present invention is a step of filling the above container with an inert gas and filling the inside of the container with the above gas having an oxygen partial pressure of less than 0.2 atm.

  The container and the inert gas used in this step are the same as the contents described in the section “A. Ink package”, and therefore the description thereof is omitted here.

The filling method for filling the container with the inert gas in the present step is not particularly limited as long as the inside of the container can be filled with the gas having an oxygen partial pressure of less than 0.2 atm, The general filling method of the gas in a container can be used.
The above-mentioned filling method, for example, arranges the nozzle tip in the container, supplies inert gas from the nozzle, arranges the whole container in the box, and makes the whole inside of the box under the inert gas environment. It is possible to cite a method of supplying an inert gas into the container.
Moreover, it is preferable that the internal pressure in the container after this process is 1 atmosphere. This is because it is easy to fill the inside of the container with an inert gas and to fill the inside of the container with the above gas having an oxygen partial pressure of less than 0.2 atm.

The execution timing of this process may be any timing before the ink filling process, during the ink filling process, and after the ink filling process.
Here, when the execution timing is before the ink filling step, this step is to fill the inert container into the empty container which is not filled with the inkjet ink. In addition, when the execution timing is after the ink filling step, the void portion in the container provided by the ink filling step is filled with the inert gas.

  About the gas filled so that the inside of a container may be filled by this process, since it is the same as the content as described in the term of said "A. ink package", description here is abbreviate | omitted.

3. Method of Producing Ink Package Although the method of producing an ink package of the present invention has the above-mentioned substitution step, it may have other steps as required.
As such another process, it is preferable to have an inspection process for inspecting that the oxygen partial pressure of the gas is less than 0.2 atm during or after the substitution process.
By having the inspection step, it can be confirmed that the oxygen partial pressure of the gas is less than 0.2 atm, and an ink package having the oxygen partial pressure of less than 0.2 atm can be stably obtained. It is from.

(1) Inspection Step The inspection step in the present invention is a step of inspecting that the oxygen partial pressure of the gas is less than 0.2 atm during or after the substitution step.

The method of confirming the oxygen partial pressure of the gas in this step is not particularly limited as long as it can accurately measure the oxygen partial pressure in the gas present in the container, and measurement is performed using an oximeter Methods can be used.
The oximeter is not particularly limited as long as it can accurately measure the oxygen concentration of gas, but, for example, a trace oxygen analyzer RO-102-SDP manufactured by Iijima Electronics Co., Ltd. is used. be able to.

The term "during the substitution step" means to measure the oxygen partial pressure of the gas in the container in parallel with the filling of the inert gas in the container, and the oxygen partial pressure is in a predetermined range according to this step. It is confirmed that the above-mentioned replacement process is completed.
On the other hand, "after completion of the substitution step" means to carry out after completion of the substitution step, that is, after stopping the substitution of the inert gas.

The execution timing of this process may be either during the above-mentioned substitution process or after the completion of the above-mentioned substitution process.
When the above execution timing is in the substitution process, the substitution process can be ended when the oxygen partial pressure becomes a specified numerical value, so that there is an advantage that the end of the substitution process can be grasped timely.
In addition, when the above execution timing is after the above replacement step, there is an advantage that it is not necessary to perform both steps in parallel simultaneously, and the steps are not complicated.

(2) Others As a process other than the above-mentioned inspection process in the present invention, a sealing process which seals the above-mentioned container after the above-mentioned substitution process can be mentioned.
In addition, such other processes can use the method generally used for the manufacturing method of an ink package.

  The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and it has substantially the same configuration as the technical idea described in the claims of the present invention, and any one having the same function and effect can be used. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be more specifically described by way of examples.

[Ink preparation example 1]
It was set as the following composition as an organic solvent.
Diethylene glycol diethyl ether (DEDG): 75.01 parts by mass Diethylene glycol methyl ethyl ether (MEDG): 4.31 parts by mass γ-butyrolactone (GBL): 6.90 parts by mass

3.0 parts by mass of phthalocyanine blue (Pigment Blue 15: 4) which is a cyan pigment as Pigment 1 in a part of the solvent having the above composition, 3.0 parts by mass of a dispersant (polyester polymer compound, manufactured by Takeo Fine Chemical Co., Ltd.) Hinoacto KF1-M ") (1.10 parts by mass) was added and stirred with a dissolver at 3,000 rpm for 1 hour, and then predispersed with a beads mill filled with zirconia beads (2 mm). The average particle diameter of the obtained colorant particles was 5 μm or less. Furthermore, main dispersion was performed with a nanomill filled with zirconia beads (0.3 mm) to obtain a color material dispersion. The average particle diameter of the colorant particles obtained by this main dispersion was 60 nm.
Then, while stirring the obtained color material dispersion at 4,000 rpm, 5.91 parts by mass of binder resin 1 ("Paraloid B60" manufactured by Rohm & Haas Co., Ltd.) which is an acrylic resin (A), and a copolymer 3.78 parts by mass of binder resin 2 ("Solvain TA3" manufactured by Nisshin Chemical Industry Co., Ltd.) which is (B) and the remainder of the produced organic solvent were added to prepare an inkjet ink (Ink A).

[Ink preparation examples 2 to 16]
An inkjet ink (inks B to P) was prepared in the same manner as in Ink Preparation Example 1 except that the composition of each component was changed as shown in Tables 1 and 2 below.
In Tables 1 and 2, the pigments 2 to 4 are respectively yellow azo pigments such as nickel azo yellow (pigment yellow 150), magenta pigments such as quinacridone magenta (pigment red 122), and black pigments such as carbon black Is an indicator of
Moreover, the binder resin 3 described as binder resin shows "Solvain CLL" by Nisshin Chemical Industry Co., Ltd. which is a copolymer (B).
Also, in Tables 1 and 2, BGAc and MEDG described as solvents indicate butyl glycol acetate and diethylene glycol methyl ethyl ether.

[Oxygen solubility evaluation of solvent]
With respect to the solvent used in the ink preparation example, the solubility of oxygen was evaluated by the following method.

(Method for evaluating oxygen solubility)
Under the condition of 25 ° C, put 50cc of solvent in the syringe, take 50cc of oxygen in another syringe, connect the 2 syringes, push the piston of the syringe containing oxygen, and the syringe until the change in volume does not occur Shake well. Thereafter, the volume of oxygen was measured, and the volume reduced from 50 cc was taken as the solubility of oxygen. The results are shown in Table 3 below.

  From Table 3, it was confirmed that the polyalkylene glycol alkyl ether solvent had high oxygen solubility.

Example 1
A container made of 1 L HDPE was prepared as a container, and the ink A was filled in 1 L HDPE so as to have an ink filling rate of 87% by volume.
Thereafter, while measuring the oxygen concentration in the gas in the void portion of the container with an oximeter, nitrogen is supplied to the void portion, and after confirming that the oxygen partial pressure has reached 0.05 atm, the nitrogen supply is performed. It stopped and the container was sealed using the lid. Thus, an ink package was produced.

(1L HDPE)
-Material: High density polyethylene-Film thickness: 1.5 mm
Diameter: 89.2 mm
・ Height: 228.1 mm
· Shape: cylindrical shape · Internal volume: 1 L
・ The internal pressure in the sealed state is 0.8 atm and the appearance is changed, and when the internal pressure is 0.9 atm, the appearance is not changed.

[Examples 2 to 22 and Comparative Examples 1 to 4]
As containers, using the following 1 L poly container, 200 LHDPE container, inner surface resin coated petroleum can, ink filling rate, oxygen partial pressure after substitution, substitution gas and ink are changed as shown in Tables 4 to 6 below. An ink package was produced in the same manner as in Example 1.

(1 L poly)
-Material: Polyethylene-Film thickness: 0.7 mm
・ Diameter: 91.5 mm
・ Height: 217 mm
· Shape: cylindrical shape · Internal volume: 1 L
-In the closed state, the internal pressure changes at an appearance 0.8 at atmospheric pressure, and when the internal pressure is at 0.9 atmosphere, the appearance does not change.

(200L HDPE)
-Material: High density polyethylene-Film thickness: 3.0 mm
-Diameter: 588 mm
・ Height: 905 mm
· Shape: cylindrical shape · Internal volume: 200 L
-In the closed state, the internal pressure changes at an appearance 0.8 at atmospheric pressure, and when the internal pressure is at 0.9 atmosphere, the appearance does not change.

(HB can (inner resin coated oil can))
· Material: Tin-free styrene (metal material) and polyolefin-based multilayer film (resin material)
・ Film thickness: 0.32 mm of metal material, 0.07 mm of resin material
・ Width and depth: 238 mm × 238 mm
・ Height: 349.5 mm
・ Shape: Rectangular shape ・ Inside volume: 19.25L
-In the closed state, the internal pressure changes at an appearance 0.8 at atmospheric pressure, and when the internal pressure is at 0.9 atmosphere, the appearance does not change.

[Evaluation]
The following evaluations were made as to the presence or absence of change in appearance, discharge stability, coating film drying property, ethanol resistance and odor.

(1) Evaluation of the Presence of Changes in Appearance After storing the ink packages of the Examples and Comparative Examples for 2 weeks at 60 ° C., the presence or absence of changes in appearance was evaluated. In addition, evaluation of the container was performed by visual confirmation and volume change of the container before and after storage. The results are shown in Tables 4 to 6 below.

(Evaluation criteria for visual appearance change by visual observation)
:: no change ○: very slight deformation observed (deformation with no problem in practical use)
X: remarkable deformation

(Method of measuring volume change)
The sealed container was immersed in a water bath before ink filling and after storage for 2 weeks at 60 ° C., and the volume change was confirmed.

(2) Evaluation of Discharge Stability The ink jet recording head of each of Examples and Comparative Examples was measured using an inkjet head KM 512 MHX (Konica, Inc., of the piezo drive type under an environment of room temperature 25 ± 3 (° C.) and humidity 45 ± 5% RH). Using a discharge evaluation tester equipped with Minolta Co., Ltd., the applied voltage was increased continuously by raising the applied voltage by raising the applied voltage, and the maximum speed capable of stably discharging without disturbance was measured. The results are shown in Tables 4 to 6 below.

(Discharge stability evaluation criteria)
○: The maximum speed was 10 m / s or more.
Δ: The maximum speed was 8 m / s or more and less than 10 m / s.
X: The maximum speed was less than 8 m / s.
If the ejection stability evaluation is ○ or Δ, the ejection stability at high speed printing is excellent, and it is evaluated that it can be used without any problem in practical use.

(3) Evaluation of Drying of Coating Film The inkjet ink for inkjet recording of the example and the comparative example was subjected to the inkjet head KM 512 MHX of the piezo drive system under the environment of room temperature 25 ± 3 (° C.) and humidity 45 ± 5% RH A solid film was printed at 720 dpi on a recording medium (PVC sheet JT5829R manufactured by Mactack Co., Ltd.) using a discharge evaluation tester equipped with the above to form a coating film. The recording medium on which the coating film was formed was heated on a hot plate at 45 ° C., and the time when no tack was detected by finger touch was measured. The results are shown in Tables 4 to 6 below.

(Dryability evaluation criteria)
○: dried within 2 minutes.
Fair: 2 minutes or more and dried within 5 minutes.
X: It did not dry after 5 minutes.
If the drying evaluation is ○ or 優 れ, the drying property is excellent and it is evaluated that it can be used without any problem in practical use.

(4) Evaluation of Ethanol Resistance of Coating Film After forming a coating film in the same manner as in the above evaluation of drying property, it was dried in an oven at 60 ° C. for 5 minutes and further dried at room temperature for 12 hours or more to obtain a dried coating film. The coated surface was wiped with a cloth impregnated with an aqueous solution of ethanol (Bentcotton, manufactured by Asahi Kasei Co., Ltd.) to observe whether the recording medium could be seen. The same test was performed by changing the concentration of the aqueous ethanol solution, and the maximum concentration of ethanol to which the recording medium was not exposed was measured. The results are shown in Tables 4 to 6 below.

(Ethanol resistance evaluation criteria)
Good: The recording medium was not exposed even if 50% or more ethanol aqueous solution was used.
B: The recording medium was exposed to an aqueous ethanol solution of 30% or more and less than 50%.
X: The recording medium was exposed with an aqueous ethanol solution of less than 30%.
If the ethanol resistance evaluation is ○ or △, the ethanol resistance is excellent, and it is evaluated that it can be used without any problem in practical use.

(5) Odor Test 0.5 g of each of the inkjet recording inkjet inks of Examples and Comparative Examples was placed in a petri dish and allowed to stand on a hot plate at 45 ° C. for 2 minutes, after which a sensory test of odor was conducted. The results are shown in Tables 4 to 6 below.

(Odor test evaluation criteria)
○: Almost no odor was observed.
Δ: Some odor was observed.
X: An unpleasant odor was observed.
If the odor test evaluation is ○ or, the odor is low, and the odor is evaluated as low even at high speed printing.

[Summary]
According to Tables 4 to 6, a specific solvent and a binder resin are contained by using a gas whose oxygen partial pressure is in the above-mentioned range and a container whose appearance does not change in the range of the oxygen partial pressure. Even when the ink-jet ink is sealed in a container in which the internal pressure is not less than 0.8 atmospheric pressure and the appearance is changed in a sealed state, the above-mentioned ink package is to be less deformed in the container even during long-term storage I was able to confirm that I could do it.
In addition, it was confirmed that the pigment was likely to change in appearance in the order of pigment 1 (cyan pigment), pigment 4 (black pigment), pigment 3 (magenta pigment) and pigment 2 (yellow pigment) .

DESCRIPTION OF SYMBOLS 1 ... Container 1a ... Void part 2 ... Ink-jet ink 3 ... Gas 4 ... Lid 5 ... Seal member 10 ... Ink package body

Claims (6)

A container,
Inkjet ink and gas sealed in the container;
An ink package comprising
The inkjet ink comprises a copolyalkylene glycol alkyl ether-based solvent, an acrylic resin (A), a structural unit represented by the following general formula (I), and a structural unit represented by the following general formula (II) A binder resin containing at least one of the polymers (B),
The partial pressure of oxygen in the gas is less than 0.2 atm.
The container has an appearance change when the internal pressure in a sealed state is 0.8 atmosphere or more, and the appearance does not change due to the reduction of the oxygen partial pressure,
An ink package, wherein a maximum internal pressure causing appearance change of the container is 0.8 atmosphere or more and an internal pressure after pressure reduction of the oxygen partial pressure.

(In the general formula (I) and the general formula (II), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, R ³ represents an alkyl group having 1 to 3 carbon atoms, and X represents Represents a halogen atom)   The ink package according to claim 1, wherein the gas comprises an inert gas.   The ink package according to claim 1 or 2, wherein a content of the polyalkylene glycol alkyl ether solvent is 50 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the inkjet ink.   The said container is an inner surface coated metal container which has a metal container and a resin layer which coats the inner surface of the said metal container, or a resin-made container, The resin container is characterized by the above-mentioned. The ink package as described in. A method of manufacturing an ink package according to any one of claims 1 to 4, wherein
An ink filling step of filling the inkjet ink so as to provide a void in the container;
Filling the container with an inert gas, and filling the container with the gas having an oxygen partial pressure of less than 0.2 atm;
A method of manufacturing an ink package, comprising:   The method for producing an ink package according to claim 5, further comprising an inspection step of inspecting that the oxygen partial pressure of the gas is less than 0.2 atm during or after the substitution step. .

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