JP2018079687A - Image-forming method image-forming apparatus, image-forming system, method of manufacturing printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image-forming method giving an image not offsetting even when applying pressure, excellent in anti-blocking, and slide friction resistance, and high in glossiness.SOLUTION: The image-forming method includes: a first ink-applying process for forming an unpressurized image by applying ink on a recording medium; and a pressurizing process for forming an image by pressurizing the unpressurized image, where the ink contains water, an organic solvent, and a coloring material, the maximum value of logarithmic decrement at 60°C obtained by measuring an ink film formed using the ink by a rigid body pendulum test is 1.50 or less, and the time for the logarithmic decrement to reach a maximum value is 3,800 sec. or less.SELECTED DRAWING: None

Description

  The present invention relates to an image forming method, an image forming apparatus, an image forming system, and a printed material manufacturing method.

  The ink jet recording method not only has the advantage that the noise of the apparatus to be used is small and the operability is good, but also has the advantage that it can be easily colored and can use plain paper as a recording medium. Widely used as an output machine in offices and homes.

  On the other hand, in industrial applications, it is expected that it will be used as an output device for digital printing due to improvements in inkjet technology. Printing machines that can record on non-absorbing recording media using solvent ink and UV ink are actually available on the market. It has been. However, in recent years, demand for water-based inks has increased due to environmental concerns.

  Ink-jet water-based inks have been developed for a long time as special printing papers such as plain paper and photographic glossy paper. On the other hand, in recent years, the application of the ink jet recording system is expected to be expanded, and the need for printing on coated paper such as coated paper is increasing. However, it is difficult to firmly fix the pigment on a recording medium having low permeability such as coated paper, and there is a problem that the rubbing resistance is deteriorated.

  Therefore, the sliding resistance of the recording medium on which the image is formed can be improved. The displacement amount of the movable member is controlled with good responsiveness to effectively prevent the movable member from being displaced beyond the movable range. There has been proposed a roll paper transport device that can avoid problems such as damage to a movable member due to collision with the inner surface of the body, generation of vibration and abnormal noise, and adhesion of paper stains (see, for example, Patent Document 1). ).

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming method capable of obtaining an image having excellent anti-blocking and rubbing resistance and high gloss without being offset even when pressure is applied.

  The image forming method of the present invention as a means for solving the above problems includes a first ink application step of applying an ink to a recording medium to form an unpressurized image, and applying pressure to the unpressurized image. Logarithmic decay at 60 ° C. measured by a rigid pendulum test of the ink film containing water, an organic solvent, and a coloring material, and an ink film formed using the ink. The maximum value of the rate is 1.50 or less, and the time for the maximum value of the logarithmic decay rate is 3,800 seconds or less.

  According to the present invention, it is possible to provide an image forming method capable of obtaining an image having excellent anti-blocking property and anti-sliding property and high gloss without being offset even when pressure is applied.

FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus using continuous paper. FIG. 2 is a graph showing the relationship between the logarithmic decay rate and the elapsed time. FIG. 3 is a schematic view showing an ink jet recording apparatus which is an example of the image forming apparatus of the present invention. FIG. 4 is an enlarged view of the head unit 304 in FIG. FIG. 5 is a perspective view illustrating an example of continuous paper (roll paper) having an image. FIG. 6 is a side view of continuous paper (roll paper) having the image of FIG.

(Image forming method, image forming apparatus, and image forming system)
The image forming method of the present invention includes a first ink applying step for forming an unpressurized image by applying ink to a recording medium, and a pressurizing step for forming an image by applying pressure to the unpressurized image, The ink contains water, an organic solvent, and a coloring material, and the maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test of an ink film formed using the ink is 1.50 or less And the time to reach the maximum value of the logarithmic decay rate is 3,800 seconds or less, and further includes other steps as necessary.
The image forming method of the present invention is based on the knowledge that the conventional roll paper conveying device has a problem that the blocking resistance is insufficient.

In addition, the present inventors have obtained the following knowledge.
By adding a resin emulsion in the ink, it is possible to improve the fixability, which has been a problem in the past, but the resin that can improve the fixability is highly elastic, and logarithmic decay by adding the resin The maximum value of the rate will increase. By increasing the maximum value of the logarithmic decay rate, the image is offset when pressure is applied to the image area, such as when fixing using a fixing roller after image formation, or when printing on roll paper and then winding it. This is based on the knowledge that it becomes a problem.

In addition, when using an image forming apparatus having a sheet feeding device 1, a recording medium 2, a pretreatment liquid application unit 3, an ink ejection unit head 4, and a drying unit 5 as shown in FIG. In the process of rewinding the continuous paper after image formation into a roll, a large pressure is applied near the center of the roll and the image is offset.
Further, when the continuous paper is tensioned and the image-formed paper is rewound into a roll shape, a large pressure is applied not only near the roll center but also at the outer edge of the roll, and the image can be offset. Further, when such continuous paper is used, after printing and winding once in the first ink application step, printing is performed again on the surface of the recording medium recorded in the first ink application step. There is a case where “reprinting” which is a second ink application process is performed. If the take-up pressure after the first image formation is large, the roll is uniformly wound and the reprinting can be performed cleanly, but the image is offset as described above. On the other hand, if the take-up pressure is low, the roll will bend and become non-uniform, and it is based on the knowledge that problems such as misalignment of recording due to the paper not being conveyed at a constant speed during reprinting. .
The second ink application step is preferably performed on the surface of the recording medium recorded in the first ink application step from the viewpoint that the above problem can be solved, but the recording is performed in the first ink application step. This does not exclude the case where the recording is performed on the surface opposite to the surface of the recording medium.

The image forming apparatus of the present invention forms an image by applying pressure to the unpressurized image, a first ink applying unit that forms an unpressurized image by applying the ink to a recording medium. A maximum of a logarithmic decay rate at 60 ° C. measured by a rigid pendulum test on an ink film formed using the ink, wherein the ink contains water, an organic solvent, and a coloring material. The time when the value is 1.50 or less and the maximum value of the logarithmic decay rate is 3,800 seconds or less.
The image forming system of the present invention forms an image by applying pressure to the non-pressurized image, first ink applying means for forming the non-pressurized image by applying the ink to a recording medium. A maximum of a logarithmic decay rate at 60 ° C. measured by a rigid pendulum test on an ink film formed using the ink, wherein the ink contains water, an organic solvent, and a coloring material. The time when the value is 1.50 or less and the maximum value of the logarithmic decay rate is 3,800 seconds or less.

[Logarithmic decay rate]
The maximum value of the logarithmic decay rate at 60 ° C. measured by the rigid pendulum test of the ink film formed using the ink is 1.50 or less, preferably 0.01 or more and 1.50 or less, 0.7 More preferably, it is 1.50 or less. When the maximum value of the logarithmic decay rate is 1.50 or less, stickiness in ink film formation can be suppressed, and blocking can be prevented from occurring.
The time to reach the maximum value of the logarithmic decay rate is 3,800 seconds or less, preferably 100 seconds or more and 3,800 seconds or less, and more preferably 1,700 seconds or more and 3,800 seconds or less. When the time when the logarithmic decay rate reaches the maximum value is 3,800 seconds or less, the ink film-forming speed can be increased, and the occurrence of blocking can be prevented. The time when the logarithmic decay rate reaches the maximum value means the time from the start of measurement until the logarithmic decay rate reaches the maximum value.
When the maximum value of the logarithmic decay rate is 1.50 or less and the time for which the maximum value of the logarithmic decay rate is 3800 seconds or less, 3.5 kg / cm ² or more after the unpressurized image is formed. Even when a pressure of 0 kg / cm ² or less is applied, blocking does not occur, the rubbing resistance is good, and a glossy image can be obtained. In addition, since the tackiness of the film is unlikely to increase during ink film formation, the backing paper and the ink do not stick to each other, so that the occurrence of blocking can be suppressed. Furthermore, since blocking does not occur, it is possible to wind strongly between papers, thereby improving the fixability, and by winding strongly, the surface can be smoothed and gloss can be improved.

The logarithmic decay rate can be calculated as follows.
As a method for measuring the logarithmic decay rate, a rigid pendulum type physical property tester (device name: RPT-3000W, manufactured by A & D Corporation) is used. 40 μL of ink is dropped on an aluminum substrate, and an ink film with a thickness of 100 μm is applied with a dedicated coating jig (PCT-100) for coating with a thickness of 100 μm. The obtained ink film is quickly installed together with a cooling / heating block (CHB-100), and a cylinder edge (RBP-040) and a pendulum (FRB-100) are set. At this time, two FRB-100 exclusive weights are set at the bottom of the pendulum. The measurement temperature is raised from room temperature (25 ° C.) to 60 ° C. at a rate of 5 ° C./min, and thereafter kept at 60 ° C. The logarithmic decay rate and temperature are plotted against time. The obtained plot is smoothed, the maximum value is calculated, and the maximum value of the logarithmic decay rate is obtained. Note that the maximum value of the logarithmic decay rate can be used as an index of tack force.
The logarithmic decay rate (D ′ (n)) after the smoothing can be obtained as follows when the logarithmic decay rate of the nth plot is defined as D (n).
D ′ (n) = {D (n−2) + D (n−1) + D (n) + D (n + 1) + D (n + 2)} / 5
D ′ (1) = D (1)
D ′ (2) = {D (1) + D (2)} / 2

  FIG. 2 is a graph showing the relationship between the logarithmic decay rate and the elapsed time. As shown in FIG. 2, in Sample A, the maximum value of the logarithmic attenuation rate exceeds 1.50, and the time for the maximum value of the logarithmic attenuation rate exceeds 3,800 seconds. On the other hand, in Sample B, the maximum value of the logarithmic attenuation rate is 1.50 or less, and the time for the maximum value of the logarithmic attenuation rate is 3,800 seconds or less. Like Sample B, the maximum value of the logarithmic attenuation rate is 1.50 or less, and the time for the maximum value of the logarithmic attenuation rate is 3,800 seconds or less, so that blocking resistance, friction resistance, and Glossiness can be improved.

[Pressure applied to the non-pressurized image in the pressurization process]
As the pressure applied to the unpressurized image in the pressing step is preferably 3.5 kg / cm ² or more 8.0 kg / cm ² or less, 3.5 kg / cm ² or more 7.3 kg / cm ² or less being more preferred. When the pressure is 3.5 kg / cm ² or more, sufficient image fixability can be obtained, and the rubbing resistance can be improved. When the pressure is 8.0 kg / cm ² or less, an unpressurized image is obtained. Can be prevented from being offset on the pressure roller, the overlapping non-pressurized image, or paper. In addition, there is no restriction | limiting in particular as a measuring method of the said pressure, A well-known apparatus can be selected suitably according to the objective. Further, even when the pressure in the pressurizing step is generated by winding the continuous paper after applying the ink into a roll, there is no particular limitation, and a known apparatus is appropriately selected according to the purpose. For example, apparatus name: I-SCAN5027 (made by Nitta Corporation) can be used.
The set pressure applied to the pressure roller and the pressure applied to the non-pressurized image are the same.

As the pressure at the pressure roller, without applying tension, if it is simple laminate can be a 3.5 kg / cm ² or more 8.0 kg / cm ² or less.
The pressure when simply laminating without applying tension with the pressure roller is, for example, 3.5 kg / cm ² when the roll thickness is 0.5 m, and the roller thickness is diameter. In the case of 1.5 m, it becomes 8.0 kg / cm ² .

  The pressure applied to the roll-shaped continuous paper can be calculated by referring to the diameter, height, and mass of the roll-shaped continuous paper from, for example, a photograph or information of the roll-shaped continuous paper.

  The pressure in the pressurizing step is preferably generated by winding the continuous paper after application of the ink into a roll when the recording medium is continuous paper.

  The ink film having the maximum value of the logarithmic decay rate and its time within a predetermined range does not cause an offset when a pressure within the predetermined pressure range is applied, and has good anti-blocking properties. In addition, the friction resistance and glossiness of the ink can be improved, and a sufficient winding pressure is applied within the pressure range, so that an additional effect that reprinting can be performed without any problem can be obtained.

<First ink application step and first ink application means>
The first ink application step is a step of forming an unpressurized image by applying ink to a recording medium.
The first ink applying unit is a unit that forms an unpressurized image by applying ink to a recording medium.
The first ink application step can be suitably performed by the first ink application unit.

  The maximum value of the logarithmic decay rate on the surface of the ink film and the time required to reach the maximum value of the logarithmic decay rate are particularly affected by the type of resin in the ink. The type of resin, the amount of addition, and the like as examples that can realize the maximum value of the logarithmic decay rate and the time range within which the logarithmic decay rate becomes the maximum value will be described in detail later.

<Ink>
Hereinafter, the organic solvent, water, color material, resin, additive, and the like used for the ink will be described.

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and a water-soluble organic solvent can be used. Examples thereof include ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.
Specific examples of the water-soluble organic solvent include, for example, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, Glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-he Polyhydric alcohols such as sundiol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, petriol, ethylene glycol mono Polyhydric alcohol alkyl ethers such as ethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monophenyl ether, ethylene glycol mono Polyhydric alcohol aryl ethers such as benzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl- -N-containing heterocyclic compounds such as pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone, formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, Amides such as N-dimethylpropionamide and 3-butoxy-N, N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate, Examples thereof include ethylene carbonate.
In addition to functioning as a wetting agent, it is preferable to use an organic solvent having a boiling point of 250 ° C. or lower because good drying properties can be obtained.

A polyol compound having 8 or more carbon atoms and a glycol ether compound are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and the like.
Specific examples of glycol ether compounds include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether. Polyhydric alcohol alkyl ethers such as polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

  A polyol compound having 8 or more carbon atoms and a glycol ether compound can improve ink permeability when paper is used as a recording medium.

  The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably a glycol ether compound, more preferably a glycol ether compound having no hydroxyl group, represented by the following general formula (1) The glycol ether compounds represented are particularly preferred.

However, the general formula (1), ^{R 1} is a hydrogen atom, or represents a number from 1 to 10 alkyl group carbon, ^{R 2,} and ^{R 3} are each independently alkyl having 1 to 10 carbon atoms Represents a group, and n represents an integer of 1 to 5.

R ¹ in the general formula (1) is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably a hydrogen atom or a methyl group.
R ² in the general formula (1) is an alkyl group having 1 to 10 carbon atoms, preferably a methyl group or an ethyl group.
R ³ in the general formula (1) is an alkyl group having 1 to 10 carbon atoms, preferably a methyl group, an ethyl group, or a butyl group.
In the general formula (1), n is an integer of 1 to 5, preferably 2 or more and 3 or less.

  There is no restriction | limiting in particular as a glycol ether compound represented by the said General formula (1), Although it can select suitably according to the objective, Tripropylene glycol monobutyl ether, Triethylene glycol dimethyl ether, Diethylene glycol diethyl ether, Dipropylene Glycol dimethyl ether and tripropylene glycol dimethyl ether are preferred.

  The content of the organic solvent in the ink is not particularly limited and can be appropriately selected according to the purpose, but is preferably 10% by mass or more and 60% by mass or less from the viewpoint of the drying property and ejection reliability of the ink, 20 mass% or more and 60 mass% or less are more preferable.

<Resin>
The type of resin contained in the ink is not particularly limited and can be appropriately selected according to the purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene type Examples thereof include resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
Resin particles made of these resins may be used. An ink can be obtained by mixing resin particles with a material such as a colorant or an organic solvent in a resin emulsion state in which water is dispersed as a dispersion medium. As said resin particle, what was synthesize | combined suitably may be used and a commercial item may be used. Moreover, these may be used individually by 1 type, or may be used in combination of 2 or more types of resin particles.

  Among the above resin particles, urethane resin particles are preferable from the viewpoint of rubbing resistance.

-Urethane resin particles-
The urethane resin particles are made of polyurethane, and the polyurethane is obtained by urethane bonding of an isocyanate compound having a plurality of isocyanate groups and a polyol compound having a plurality of hydroxyl groups. Each of the isocyanate compound and the polyol compound may itself be a polymer compound.

--Isocyanate compound--
The isocyanate compound having a plurality of isocyanate groups used in the polyurethane is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include bifunctional isocyanate compounds, trifunctional isocyanate compounds, and tetrafunctional isocyanate compounds. . These may be used individually by 1 type and may use 2 or more types together.
Examples of the bifunctional isocyanate compound include isophorone diisocyanate, cyclohexane diisocyanate, 1,6-hexane diisocyanate, 1,4-butane diisocyanate, 1,4-benzene diisocyanate, and diphenylmethane diisocyanate.
Examples of the trifunctional isocyanate compound include 1,3,5-cyclohexane triisocyanate, 1,4,8-octane triisocyanate, and 1,3,5-benzene triisocyanate.
Examples of the tetrafunctional isocyanate compound include 1,2,5,6-cyclohexanetetraisocyanate.
Among these, although there are differences in mechanical strength and weather resistance obtained by synthesizing urethane using these, isophorone diisocyanate and cyclohexane diisocyanate are preferable from the viewpoint of mass production handling, environmental protection, and physical property operation.

--Polyol compound--
The polyol compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol , 1,6-hexanediol); alkylene ether glycol (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diol (1,4-cyclohexanedimethanol) Hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.); alkylene oxides of the above alicyclic diols (ethylene oxide, propylene) Oxide, butylene oxide, etc.) adducts; 4,4′-dihydroxybiphenyls (3,3′-difluoro-4,4′-dihydroxybiphenyl etc.); bis (hydroxyphenyl) alkanes (bis (3-fluoro-4) -Hydroxyphenyl) methane, 1-phenyl-1,1-bis (3-fluoro-4-hydroxyphenyl) ethane, 2,2-bis (3-fluoro-4-hydroxyphenyl) propane, 2,2-bis ( 3,5-difluoro-4-hydroxyphenyl) propane (alias: tetrafluorobisphenol A), 2,2-bis (3-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane); Bis (4-hydroxyphenyl) ethers (such as bis (3-fluoro-4-hydroxyphenyl) ether); Alkylene oxide phenols (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. These may be used individually by 1 type and may use 2 or more types together.

Examples of the polyol compound include carbonate-based polyols, ester-based polyols, and ether-based polyols. These may be used individually by 1 type and may use 2 or more types together. Each of these has two or more hydroxyl groups in the polyol compound.
The polyol compound preferably has a hydroxyl group at both ends of the compound for synthesis.

  The carbonate polyol is preferably a compound represented by the following general formula (A).

  The ester polyol is preferably a compound represented by the following general formula (B).

  The ether polyol is preferably a compound represented by the following general formula (C).

  However, in the general formulas (A) to (C), each R independently includes various skeletons such as a hexamethylene group, a cyclohexane group, a phenylene group, a tetramethylene group, a cyclohexanedimethylene group, and a cyclohexanemonomethylene group. However, the examples are not limited to the examples. Moreover, n is 1-20.

The volume average particle diameter of the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 nm or more and 1,000 nm or less from the viewpoint of obtaining good fixability and high image hardness. It is more preferably 200 nm or less and particularly preferably 10 nm or more and 100 nm or less.
The volume average particle diameter can be measured using, for example, a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

  The resin content is not particularly limited and may be appropriately selected according to the purpose. However, from the viewpoint of fixability and ink storage stability, the content of the resin is 1% by mass or more and 30% by mass or less. Is preferable, and 5 mass% or more and 20 mass% or less are more preferable.

  The particle size of the solid content in the ink is not particularly limited and can be appropriately selected according to the purpose. From the viewpoint of improving the image quality such as ejection stability and image density, the maximum frequency in terms of the maximum number Is preferably 20 nm to 1000 nm, and more preferably 20 nm to 150 nm. The solid content includes resin particles, pigment particles, and the like. The particle size can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

[Mass ratio (glycol ether compound / urethane resin particles)]
The mass ratio (glycol ether compound / urethane resin particles) between the content (mass%) of the urethane resin particles and the content (mass%) of the glycol ether compound is preferably 0.4 or more and 2.4 or less. 0.4 to 1.8 is more preferable, and 1.2 to 1.8 is particularly preferable. When the mass ratio (glycol ether compound / urethane resin particles) is 0.4 or more and 2.4 or less, the maximum value of the logarithmic decay rate is 1.50 or less, and the time for which the logarithmic decay rate is the maximum value is set. It becomes easy to make it 3,800 seconds or less.

<Color material>
The color material is not particularly limited, and pigments and dyes can be used.
As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. A mixed crystal may be used.
Examples of the pigment that can be used include black pigments, yellow pigments, magenta pigments, white pigments, green pigments, orange pigments, glossy pigments such as gold and silver, and metallic pigments.
As the inorganic pigment, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, carbon produced by a known method such as a contact method, a furnace method, or a thermal method. Black can be used.
Examples of the organic pigment include azo pigments, polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments. ), Dye chelates (for example, basic dye chelates, acidic dye chelates, etc.), nitro pigments, nitroso pigments, aniline black, and the like. Of these pigments, those having good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
Specific examples of the pigment include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11). ), Metals such as titanium oxide, and organic pigments such as aniline black (CI Pigment Black 1).
Further, for color use, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like.
The dye is not particularly limited, and an acid dye, a direct dye, a reactive dye, and a basic dye can be used. One kind may be used alone, or two or more kinds may be used in combination. .
Examples of the dye include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52, 80, 82, 249, 254, 289, C.I. I. Acid Black 1, 2, 24, 94, C.I. I. Food Black 1, 2, C.I. I. Direct Yellow 1,12,24,33,50,55,58,86,132,142,144,173, C.I. I. Direct Red 1,4,9,80,81,225,227, C.I. I. Directed Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive black 3, 4, 35 etc. are mentioned.

  The content of the color material in the ink is preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass from the viewpoints of improvement in image density, good fixability and ejection stability. It is as follows.

In order to obtain an ink by dispersing a pigment, a method of introducing a hydrophilic functional group into the pigment to form a self-dispersing pigment, a method of coating the surface of the pigment with a resin and dispersing, a dispersing agent is used. Method, etc.
As a method of introducing a hydrophilic functional group into a pigment to obtain a self-dispersing pigment, for example, a method of making it dispersible in water by adding a functional group such as a sulfone group or a carboxyl group to the pigment (for example, carbon) Is mentioned.
As a method for coating the surface of the pigment with a resin and dispersing it, a method in which the pigment is included in microcapsules and dispersible in water can be mentioned. This can be paraphrased as a resin-coated pigment. In this case, it is not necessary that all pigments blended in the ink are coated with a resin, and within a range where the effects of the present invention are not impaired, uncoated pigments and partially coated pigments are dispersed in the ink. It may be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular type dispersant or high-molecular type dispersant represented by a surfactant.
As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or the like can be used depending on the pigment.
RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and naphthalenesulfonic acid Na formalin condensate can also be suitably used as a dispersant.
A dispersing agent may be used individually by 1 type, or may use 2 or more types together.

<Pigment dispersion>
An ink can be obtained by mixing a material such as water or an organic solvent with a pigment. Further, it is also possible to produce an ink by mixing a pigment, other water, a dispersant, and the like into a pigment dispersion and mixing a material such as water or an organic solvent.
The pigment dispersion is obtained by mixing and dispersing water, a pigment, a pigment dispersant, and other components as necessary, and adjusting the particle size. For dispersion, a disperser is preferably used.
The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency is 20 nm or more in terms of maximum number because the pigment dispersion stability is good and the image quality such as ejection stability and image density is also high. 500 nm or less is preferable and 20 nm or more and 150 nm or less are more preferable. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).
The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good ejection stability and increasing the image density, 0.1% by mass. % To 50% by mass is preferable, and 0.1% to 30% by mass is more preferable.
The pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator or the like, if necessary.

<Water>
The water content in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by mass or more and 90% by mass or less, and 20% by mass from the viewpoint of ink drying property and ejection reliability. % To 60% by mass is more preferable.

  There is no restriction | limiting in particular as said water, According to the objective, it can select suitably, For example, pure water, such as ion-exchange water, ultrafiltration water, reverse osmosis water, distilled water; Ultrapure water etc. are mentioned. . These may be used individually by 1 type and may use 2 or more types together.

<Additives>
If necessary, a surfactant, an antifoaming agent, an antiseptic / antifungal agent, a rust inhibitor, a pH adjuster, and the like may be added to the ink.

<Surfactant>
As the surfactant, any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants and anionic surfactants can be used.
There is no restriction | limiting in particular in silicone type surfactant, According to the objective, it can select suitably. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, and side chain both terminal modified polydimethylsiloxane. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferred because they exhibit good properties as an aqueous surfactant. In addition, as the silicone surfactant, a polyether-modified silicone surfactant can be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the side chain of the Si portion of dimethylsiloxane.
Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. Polyoxyalkylene ether polymer compounds are particularly preferred because of their low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylate. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. As counter ions of salts in these fluorosurfactants, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) ₃ etc. are mentioned.
Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Nonionic surfactants include, for example, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan Examples include fatty acid esters and ethylene oxide adducts of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
These may be used alone or in combination of two or more.

The silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, side Since both ends of the chain are modified with polydimethylsiloxane, a polyether-modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibits good properties as an aqueous surfactant. preferable.
As such a surfactant, an appropriately synthesized product or a commercially available product may be used. Commercially available products can be obtained from, for example, Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd.
There is no restriction | limiting in particular as said polyether modified silicone surfactant, According to the objective, it can select suitably, For example, the polyalkylene oxide structure represented by a general formula (S-1) type | formula is dimethylpolyethylene. Examples thereof include those introduced into the side chain of Si part of siloxane.
Formula (S-1)
(However, in the formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R ′ represents an alkyl group.)
A commercial item can be used as said polyether modified silicone type surfactant, For example, KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Japan Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Bic Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.), etc. are mentioned.

As the fluorine-based surfactant, a fluorine-substituted compound having 2 to 16 carbon atoms is preferable, and a fluorine-substituted compound having 4 to 16 carbon atoms is more preferable.
Examples of the fluorosurfactant include perfluoroalkyl phosphate compounds, perfluoroalkylethylene oxide adducts, and polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain. Among these, polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain are preferred because of their low foaming properties, and are particularly fluorine-based compounds represented by the general formulas (F-1) and (F-2). A surfactant is preferred.
Formula (F-1)
In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10 and n is preferably an integer of 0 to 40 in order to impart water solubility.
Formula (F-2)
_{C n F 2n + 1- CH 2} CH (OH) CH 2 -O- (CH 2 CH 2 O) a -Y
In the compound represented by the general formula (F-2), Y is H, or CnF _{2n + 1} , n is an integer of 1 to 6, or CH ₂ CH (OH) CH ₂ —CnF _{2n + 1,} where n is 4 to 6. An integer, or CpH _{2p + 1} , p is an integer of 1-19. a is an integer of 4-14.
A commercial item may be used as said fluorosurfactant.
As this commercial item, for example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F -1405, F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by Chemours); FT-110, FT-250 FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (Omnova) Manufactured), Unidyne DSN-403N (produced by Daikin Industries, Ltd.) and the like. Among these, good print quality, particularly color developability, penetrability to paper, wettability, and leveling are significantly improved. FS-3100, FS-34, FS-300 manufactured by Chemours, FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos Co., Ltd. Particularly preferred are Fox PF-151N and Unidyne DSN-403N manufactured by Daikin Industries, Ltd.

  There is no restriction | limiting in particular as content of surfactant in an ink, Although it can select suitably according to the objective, From the point which is excellent in wettability and discharge stability, and image quality improves, it is 0.001 mass. % To 5% by mass is preferable, and 0.05% to 5% by mass is more preferable.

<Antifoaming agent>
There is no restriction | limiting in particular as an antifoamer, For example, a silicone type antifoamer, a polyether type | system | group antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned. These may be used alone or in combination of two or more. Among these, a silicone type antifoaming agent is preferable from the viewpoint of excellent foam breaking effect.

<Antiseptic and antifungal agent>
The antiseptic / antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

<Rust preventive>
There is no restriction | limiting in particular as a rust preventive agent, For example, acidic sulfite, sodium thiosulfate, etc. are mentioned.

<PH adjuster>
The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

There is no restriction | limiting in particular as a physical property of an ink, According to the objective, it can select suitably, For example, it is preferable that a viscosity, surface tension, pH, etc. are the following ranges.
The viscosity at 25 ° C. of the ink is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less from the viewpoint of improving the printing density and character quality and obtaining good discharge properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. Measurement conditions are 25 ° C., standard cone rotor (1 ° 34 ′ × R24), sample liquid amount 1.2 mL, rotation speed 50 rpm, and measurement is possible for 3 minutes.
The surface tension of the ink is preferably 35 mN / m or less and more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the ink is suitably leveled on the recording medium and the drying time of the ink is shortened.
The pH of the ink is preferably 7 to 12 and more preferably 8 to 11 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

<Recording medium>
The recording medium is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include plain paper, glossy paper, special paper, cloth, film, OHP sheet, and general-purpose printing paper.
In particular, the recording medium that is effective in the present invention includes a support and a coating layer provided on at least one surface side of the support, and, if necessary, other layers. And a recording medium having

A recording medium having the support and the coating layer is generally called a coated paper and is known as a recording medium having low ink permeability. Although it is difficult to firmly fix a coloring material on a recording medium with low permeability such as coated paper and the rubbing resistance often deteriorates, as described above, the ink film was measured by a rigid pendulum test. If the maximum value of the logarithmic attenuation rate at 60 ° C. is 1.50 or less and the time for the maximum value of the logarithmic attenuation rate is 3,800 seconds or less, 3.5 kg / cm ² after the unpressurized image formation. Even when a pressure of 8.0 kg / cm ² or less is applied, blocking is not caused and an image with better gloss can be obtained.

In the recording medium having the support and the coating layer, the transfer amount of pure water to the recording medium at a contact time of 100 ms measured with a dynamic scanning absorption meter is 2 mL / m ² or more and 35 mL / m ² or less. Is preferably 2 mL / m ² or more and 10 mL / m ² or less.
If the transfer amount of the ink and pure water at the contact time of 100 ms is too small, beading is likely to occur. If it is too large, the ink dot diameter after image formation is too smaller than the desired diameter. Sometimes.
Transfer amount to the recording medium of pure water at the contacting time 400ms measured by a dynamic scanning absorptometer, preferably 3 mL / ^{m 2} or more 40 mL / ^{m 2} or less, 3 mL / ^{m 2} or more 10 mL / ^{m 2} or less More preferred.
When the amount of transfer at the contact time of 400 ms is small, the drying property is insufficient, and thus spur marks are likely to occur. When the amount is too large, the gloss of the image portion after drying is likely to be low. is there. The amount of pure water transferred to the recording medium at the contact time of 100 ms and 400 ms can be measured on the surface of the recording medium having the coated layer.

Here, the dynamic scanning absorptiometer (DSA, Kojipa Gakkai, Vol. 48, May 1994, pp. 88-92, Kuju Shigenori) absorbs liquid in a very short time. It is a device that can measure the amount accurately. The dynamic scanning absorption meter reads the liquid absorption speed directly from the movement of the meniscus in the capillary, makes the sample a disk, and then scans the liquid absorption head in a spiral shape, and the scanning speed according to a preset pattern. Is automatically changed by a method in which the number of necessary points is measured with one sample.
A liquid supply head for a paper sample is connected to a capillary via a Teflon (registered trademark) tube, and the position of the meniscus in the capillary is automatically read by an optical sensor. Specifically, the transfer amount of pure water or ink can be measured using a dynamic scanning absorption meter (K350 series D type, manufactured by Kyowa Seiko Co., Ltd.).
The transfer amount at the contact time of 100 ms and the contact time of 400 ms can be obtained by interpolation from the measured value of the transfer amount at the contact time adjacent to each contact time.

-Support-
The support is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include paper based on wood fibers, and sheet-like materials such as non-woven fabrics mainly composed of wood fibers and synthetic fibers. .

There is no restriction | limiting in particular as said paper, According to the objective, it can select suitably according to the objective, For example, wood pulp, waste paper pulp, etc. are used.
Examples of the wood pulp include hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), NBSP, LBSP, GP, and TMP.

As the raw material of the used paper pulp, the white paper, ruled white, cream white, card, special white, medium white, imitation, fair white, Kent, white, as shown in the used paper standard quality standard table of the used paper recycling promotion center Art, special upper limit, another upper limit, newspaper, magazine, etc. are mentioned.
Specifically, printer paper such as non-coating computer paper, thermal paper, and pressure-sensitive paper as information-related paper; OA waste paper such as PPC paper; coating of art paper, coated paper, finely coated paper, matte paper, etc. Paper: High quality paper, color quality, notebook, notepaper, wrapping paper, fancy paper, medium quality paper, newsprint, reprint paper, super paper, imitation paper, pure white roll paper, uncoated paper such as milk carton, etc. Examples of used paper and paperboard include chemical pulp paper and high-yield pulp-containing paper.
These may be used individually by 1 type and may use 2 or more types together.

The waste paper pulp can be generally produced from a combination of the following four steps.
(1) For disaggregation, waste paper is treated with mechanical force and chemicals with a pulper to loosen it into a fibrous form, and the printing ink is peeled off from the fiber.
(2) Dust removal is to remove foreign matter (plastic etc.) and dust contained in waste paper with a screen, cleaner or the like.
(3) In the deinking, the printing ink peeled off from the fiber using a surfactant is removed from the system by a flotation method or a cleaning method.
(4) Bleaching increases the whiteness of the fiber using an oxidizing action or a reducing action.
When mixing the used paper pulp, the mixing ratio of the used paper pulp in the total pulp is preferably 40% or less from the viewpoint of curling after image formation.

As the internal filler used for the support, for example, a conventionally known pigment is used as a white pigment.
Examples of the white pigment include light calcium carbonate, heavy calcium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, White inorganic pigments such as calcium silicate, magnesium silicate, synthetic silica, aluminum hydroxide, alumina, lithopone, zeolite, magnesium carbonate, magnesium hydroxide; styrene plastic pigment, acrylic plastic pigment, polyethylene, microcapsule, urea resin And organic pigments such as melamine resin. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the internally added sizing agent used for making the support include neutral rosin sizing agents used for neutral papermaking, alkenyl succinic anhydride (ASA), alkyl ketene dimer (AKD), and petroleum resins. System sizing agents and the like. Among these, a neutral rosin sizing agent or alkenyl succinic anhydride is particularly preferable. The alkyl ketene dimer has a small size effect, so the addition amount may be small. However, since the friction coefficient on the surface of the recording paper (recording medium) decreases and becomes slippery, it is not preferable from the viewpoint of transportability during ink jet recording. There is a case.

-Coating layer-
The coating layer contains a pigment and a binder (binder), and further contains a surfactant and other components as necessary. In the present invention, the coating layer only needs to contain a pigment and a binder (binder) as described above, and there is no limitation on the formation method such as whether or not the coating layer is actually applied. Means things.

As the pigment, an inorganic pigment or a combination of an inorganic pigment and an organic pigment can be used.
Examples of the inorganic pigment include kaolin, talc, heavy calcium carbonate, light calcium carbonate, calcium sulfite, amorphous silica, titanium white, magnesium carbonate, titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, Examples thereof include zinc hydroxide and chlorite. Among these, kaolin is particularly preferable because it has excellent glossiness and can be made close to a paper for offset printing.

  The kaolin includes delaminated kaolin, calcined kaolin, engineered kaolin by surface modification, etc. In consideration of gloss expression, the particle size distribution is such that the ratio of the particle size is 2 μm or less is 80% by mass or more. It is preferable that the kaolin which has occupies 50 mass% or more of the whole kaolin.

  The kaolin content is preferably 50 parts by mass or more with respect to 100 parts by mass of the binder. Glossiness can be improved as the said addition amount is 50 mass parts or more. The upper limit of the content is not particularly limited, but is preferably 90 parts by mass or less from the viewpoint of coating suitability in consideration of the fluidity of kaolin, particularly the thickening under high shear force.

Examples of the organic pigment include water-soluble dispersions such as styrene-acrylic copolymer particles, styrene-butadiene copolymer particles, polystyrene particles, and polyethylene particles. Two or more of these organic pigments may be mixed.
The addition amount of the organic pigment is preferably 2 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the total pigment in the coating layer. Since the organic pigment is excellent in gloss expression and its specific gravity is smaller than that of an inorganic pigment, it is possible to obtain a coating layer that is bulky, high gloss, and has good surface coverage. When the content is 2 parts by mass or more, the effect can be improved. When the content is 20 parts by mass or less, the fluidity of the coating liquid is excellent, the coating operability can be improved, and it is economical in terms of cost. is there.

  In the form of the organic pigment, there are a solid type, a hollow type, a donut type, and the like, but the average particle diameter of the organic pigment is in consideration of the balance of gloss development, surface covering property and fluidity of the coating liquid. Is preferably 0.2 μm or more and 3.0 μm or less, and more preferably a hollow type having a porosity of 40% or more.

As the binder, an aqueous resin is preferably used.
As the aqueous resin, at least one of a water-soluble resin and a water-dispersible resin is preferably used.
There is no restriction | limiting in particular as said water-soluble resin, According to the objective, it can select suitably, For example, modified products of polyvinyl alcohol, such as polyvinyl alcohol, anion modified polyvinyl alcohol, cation modified polyvinyl alcohol, acetal modified polyvinyl alcohol; Polyurethane; polyvinylpyrrolidone and polyvinylpyrrolidone and vinyl acetate copolymer, vinylpyrrolidone and dimethylaminoethyl / methacrylic acid copolymer, quaternized vinylpyrrolidone / dimethylaminoethyl / methacrylic acid copolymer, vinylpyrrolidone and Modified products of polyvinylpyrrolidone such as a copolymer of methacrylamidopropyl trimethylammonium chloride; Cellulo such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose Modified products of cellulose such as cationized hydroxyethyl cellulose; Synthetic resins such as polyester, polyacrylic acid (ester), melamine resin, or modified products thereof, polyester and polyurethane copolymer; poly (meth) acrylic acid, Examples include poly (meth) acrylamide, oxidized starch, phosphate esterified starch, self-modified starch, cationized starch, or various modified starches, polyethylene oxide, sodium polyacrylate, and sodium alginate. These may be used individually by 1 type and may use 2 or more types together.
Among these, from the viewpoint of ink absorbability, polyvinyl alcohol, cation-modified polyvinyl alcohol, acetal-modified polyvinyl alcohol, polyester, polyurethane, and a copolymer of polyester and polyurethane are preferable.

The water-dispersible resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyvinyl acetate, ethylene-vinyl acetate copolymer, polystyrene, styrene- (meth) acrylate ester copolymer Polymer, (meth) acrylic acid ester polymer, vinyl acetate- (meth) acrylic acid (ester) copolymer, styrene-butadiene copolymer, ethylene-propylene copolymer, polyvinyl ether, silicone-acrylic copolymer Coalescence, etc. Further, it may contain a crosslinking agent such as methylolated melamine, methylolated urea, methylolated hydroxypropylene urea, or isocyanate, or may be a copolymer containing units such as N-methylolacrylamide and having a self-crosslinking property. A plurality of these water-based resins can be used simultaneously.
The content of the aqueous resin is preferably 2 parts by mass or more and 100 parts by mass or less, and more preferably 3 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the pigment. The content is determined so that the liquid absorption characteristics of the recording medium fall within a desired range.

  A cationic organic compound can be appropriately selected and used depending on the purpose. For example, a primary to tertiary amine, quaternary ammonium salt monomer or oligomer that reacts with a sulfonic acid group, a carboxyl group, an amino group, or the like in a direct dye or acidic dye in water-soluble ink to form an insoluble salt. Examples thereof include polymers. Among these, oligomers and polymers are preferable.

Examples of the cationic organic compound include dimethylamine / epichlorohydrin polycondensate, dimethylamine / ammonia / epichlorohydrin condensate, poly (trimethylaminoethyl methacrylate / methyl sulfate), diallylamine hydrochloride / acrylamide copolymer, (Diallylamine hydrochloride / sulfur dioxide), polyallylamine hydrochloride, poly (allylamine hydrochloride / diallylamine hydrochloride), acrylamide / diallylamine copolymer, polyvinylamine copolymer, dicyandiamide, dicyandiamide / ammonium chloride / urea / formaldehyde condensate , Polyalkylene polyamine dicyandiamide ammonium salt condensate, dimethyl diallyl ammonium chloride, polydiallyl methylamine hydrochloride, poly (diallyl dimethyl ester) Ruammonium chloride), poly (diallyldimethylammonium chloride / sulfur dioxide), poly (diallyldimethylammonium chloride / diallylamine hydrochloride derivative), acrylamide / diallyldimethylammonium chloride copolymer, acrylate / acrylamide / diallylamine hydrochloride copolymer Products, ethyleneimine derivatives such as polyethyleneimine and acrylicamine polymer, and polyethyleneimine alkylene oxide modified products. These may be used individually by 1 type and may use 2 or more types together.
Among these, low molecular weight cationic organic compounds such as dimethylamine / epichlorohydrin polycondensate and polyallylamine hydrochloride and other relatively high molecular weight cationic organic compounds such as poly (diallyldimethylammonium chloride) It is preferable to use in combination. The combined use improves the image density and further reduces feathering compared to the single use.

The cation equivalent of the cationic organic compound by colloid titration method (using polyvinyl potassium sulfate and toluidine blue) is preferably 3 meq / g or more and 8 meq / g or less. If the cation equivalent is within this range, good results can be obtained within the dry adhesion range.
Here, in the measurement of the cation equivalent by the colloid titration method, the cationic organic compound is diluted with distilled water so as to have a solid content of 0.1% by mass, and pH adjustment is not performed.

The dry adhesion amount of the cationic organic compound is preferably 0.3 g / m ² or more and 2.0 g / m ² or less. When the dry adhesion amount of the cationic organic compound is 0.3 g / m ² or more and 2.0 g / m ² or less, the image density can be sufficiently improved and the effect of reducing feathering can be improved.

  The surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant is used. be able to. Among these, nonionic surfactants are particularly preferable. By adding the surfactant, the water resistance of the image is improved, the image density is increased, and bleeding is improved.

  Examples of the nonionic surfactant include higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, higher aliphatic amine ethylene oxide adducts, and fatty acids. Amide ethylene oxide adduct, fat ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, fatty acid ester of glycerol, fatty acid ester of pentaerythritol, fatty acid ester of sorbitol and sorbitan, fatty acid ester of sucrose, alkyl ether of polyhydric alcohol And fatty acid amides of alkanolamines. These may be used individually by 1 type and may use 2 or more types together.

The polyhydric alcohol is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include glycerol, trimethylolpropane, pentaerythritol, sorbitol, and sucrose.
As the ethylene oxide adduct, it is also effective to substitute a part of ethylene oxide with an alkylene oxide such as propylene oxide or butylene oxide as long as water solubility can be maintained. The substitution rate is preferably 50% or less.
The HLB (hydrophilic / lipophilic ratio) of the nonionic surfactant is preferably 4 or more and 15 or less, and more preferably 7 or more and 13 or less.

  The addition amount of the surfactant is preferably 0 parts by mass or more and 10 parts by mass or less, and more preferably 0.1 parts by mass or more and 1.0 parts by mass or less with respect to 100 parts by mass of the cationic organic compound.

  Other components can be added to the coating layer as necessary, as long as the objects and effects of the present invention are not impaired. As said other component, additives, such as an alumina powder, a pH adjuster, antiseptic | preservative, antioxidant, etc. are mentioned.

There is no restriction | limiting in particular as a formation method of the said coating layer, According to the objective, it can select suitably, It can carry out by the method of impregnating or apply | coating a coating layer liquid on the said support body. The impregnation or coating method of the coating layer liquid is not particularly limited and may be appropriately selected depending on the intended purpose. For example, conventional size press, gate roll size press, film transfer size press, blade coater, rod coater It is possible to coat with various coating machines such as air knife coater and curtain coater, but from the viewpoint of cost, conventional size press, gate roll size press, film transfer size press etc. installed in paper machine It may be impregnated or coated and finished on-machine.
The adhesion amount of the coating layer liquid is not particularly limited and may be appropriately selected depending on the purpose, the solid content, 0.5 g / ^{m 2} or more 20 g / ^{m 2} or less is preferable, 1 g / m ² or more and 15 g / m ² or less are more preferable.
After the impregnation or coating, drying may be performed as necessary. In this case, the drying temperature is not particularly limited and may be appropriately selected depending on the intended purpose. Is preferred.

  The recording medium may further have a back layer on the back surface of the support, between the support and the coating layer, or another layer between the support and the back layer, and a protective layer on the coating layer. It can also be provided. Each of these layers may be a single layer or a plurality of layers.

<< Pressurizing step and pressurizing means >>
The pressurizing step is a step of forming an image by applying pressure to the non-pressurized image obtained in the first ink applying step.
The pressurizing unit is a unit that forms an image by applying pressure to the non-pressurized image obtained in the first ink applying unit.
The said pressurization process can be suitably implemented by the said pressurizing means.
By applying pressure to the unpressurized image, it is possible to obtain an image having excellent blocking resistance and rubbing resistance and high gloss.

  The pressure is preferably generated by rolling the continuous paper after application of ink into a roll.

  In addition to the pressure generated by overlapping continuous sheets as described above, when cut sheets are stacked, pressure is applied when cutting continuous sheets or cut sheets, and the fixing property is improved after image formation. For example, a pressure may be applied by installing a roller for applying the post-treatment liquid or a roller for applying the post-treatment liquid. Such a case is also included in the pressure applied to the image in the pressurizing step.

<< Second ink application step and second ink application means >>
The second ink application step is a step of forming an image by applying ink to the continuous paper after the pressurizing step.
The second ink application unit is a unit that forms an image by applying ink to the continuous paper after the pressurizing step.
The second ink application step can be suitably performed by the second ink application means.

(Method for producing printed matter)
The method for producing a printed matter according to the present invention includes a first ink application step for forming an unpressurized image by applying ink to a recording medium, and a pressurizing step for forming an image by applying pressure to the unpressurized image. The ink contains water, an organic solvent, and a coloring material, and the maximum value of the logarithmic decay rate at 60 ° C. measured by the rigid pendulum test of the ink film formed using the ink is 1.50. And the time for the maximum value of the logarithmic decay rate is 3,800 seconds or less.

As the first ink application step, the same step as the first ink application step in the image forming method can be used.
As the pressing step, the same step as the pressing step in the image forming method can be used.

  Hereinafter, an image forming method, an image forming apparatus, an image forming system, and a printed material manufacturing method according to the present invention will be described with reference to the drawings. Note that the image forming system is defined as a concept including the whole of the plurality of apparatuses when the respective units constituting the present invention are distributed over a plurality of apparatuses. For example, it is a concept including the case where the first ink applying unit and the pressurizing unit described below exist in different apparatuses. The continuous paper is a recording medium that is continuous in the transport direction during image formation.

  Examples of the continuous paper include roll paper rolled into a roll and continuous paper folded at predetermined intervals. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

  FIG. 3 is a schematic view showing an ink jet recording apparatus which is an example of the image forming apparatus of the present invention. An ink jet recording apparatus 300 to which the present invention is applied includes a recording medium transport unit 301, a pretreatment process unit 302 that applies a pretreatment liquid to the recording medium 203, and a pretreatment that dries the recording medium 203 to which the pretreatment liquid is applied. Post-drying section 303, image forming process section 304, post-processing process section 305 for applying post-processing liquid to the recording medium after the image forming process, and post-processing post-drying section 306 for drying recording medium 203 to which the post-processing liquid has been applied. It is composed of.

  The recording medium conveyance unit 301 includes a paper feeding device 307, a plurality of conveyance rollers, and a winding device 308. The recording medium 203 is a continuous paper (roll paper) wound in a roll shape. The recording medium 203 is unwound from the paper feeding device by a conveyance roller, conveyed on the platen, and taken up by a winding device.

  The recording medium 203 conveyed from the recording medium conveying unit 301 is applied with a pretreatment liquid in the pretreatment step unit 302 of FIG. In inkjet, when an image is formed on a recording medium other than dedicated inkjet paper, quality problems such as bleeding, density, color tone and show-through, and problems related to image fastness such as water resistance and weather resistance occur. As a means for solving the problem, a technique for improving image quality by applying a pretreatment liquid having a function of aggregating ink before forming an image on a recording medium is performed.

  The pretreatment step may be any coating method in which the above pretreatment liquid is uniformly applied to the surface of the printing paper, and is not particularly limited. Examples of such coating methods include blade coating, gravure coating, gravure offset coating, bar coating, roll coating, knife coating, air knife coating, comma coating, U comma coating, and AKKU coating. , Smoothing coating method, micro gravure coating method, reverse roll coating method, 4 to 5 roll coating method, dip coating method, curtain coating method, slide coating method, die coating method and the like.

  Further, the pretreatment section may be provided with a pretreatment drying section 303 after the coating process. The pre-processing and post-drying unit includes, for example, heat rollers 311 and 312. According to this apparatus, the continuous paper coated with the pretreatment liquid is transported to the heat roller by the transport roller. The heat roller is heated to a high temperature of 50 ° C. or higher and 100 ° C. or lower, and the continuous paper coated with the pretreatment liquid evaporates and dries due to contact heat transfer from the heat roller.

FIG. 4 is an enlarged view of the head unit 304 in FIG. As shown in the figure, a large number of print nozzles 310 are arranged on the nozzle surface 309 of 304 along the longitudinal direction of the head unit 304 to form a nozzle row. In this embodiment, the number of nozzle rows is one, but a plurality of rows can be provided. The other recording heads 304C, 304M, and 304Y have the same configuration, and the four recording heads 304K, 304C, 304M, and 304Y are arranged in the transport direction while maintaining the same pitch. As a result, it is possible to form an image over the entire print area width in a single recording operation.
The post-processing liquid is applied to the recording medium after the image forming process by a post-processing process unit 305. This post-treatment liquid described later contains a component capable of forming a transparent protective layer on the recording medium.

  In the post-processing step in the present embodiment, it is applied only to a specific portion of the image forming area of the recording medium. It is preferable to apply an optimal amount according to the color of the ink forming the image. More preferably, the coating amount and the coating method may be changed according to the type and resolution of the recording medium.

The method for applying the post-treatment liquid is not particularly limited, and various methods are appropriately selected depending on the type of the post-treatment liquid. The same method as the method for applying the pre-treatment liquid or the above inkjet ink is allowed to fly. Any of the methods similar to the method can be preferably used. Among these, a method similar to the method of flying an inkjet ink is particularly preferable from the viewpoint of the apparatus configuration and the storage stability of the post-treatment liquid. In this post-processing step, a protective layer is formed by applying a post-processing solution containing a transparent resin so that the dry adhesion amount is 0.5 g / m ² or more and 10 g / m ² or less on the formed image surface. It is.

  The post-processing post-drying section includes, for example, heat rollers 313 and 314 as shown in FIG. According to this apparatus, the continuous paper coated with the post-treatment liquid is conveyed to the heat roller by the conveyance roller. The heat roller is heated to a high temperature, and the continuous paper coated with the post-treatment liquid is dried due to evaporation of moisture by contact heat transfer from the heat roller. The drying means is not limited to this, and an infrared drying device, a microwave drying device, hot air, etc. can also be applied. Instead of using a single device, for example, a heat roller and a hot air device are combined. May be.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

  “Maximum value of logarithmic decay rate” and “time to reach the maximum value of logarithmic decay rate” used in the following examples and comparative examples were measured as follows.

(Maximum value of logarithmic decay rate and time to reach maximum value of logarithmic decay rate)
The maximum value of the logarithmic decay rate and the time to reach the maximum value of the logarithmic decay rate were measured using a rigid pendulum type physical property tester (device name: RPT-3000W, manufactured by A & D Corporation).
Specifically, 40 μL of ink was dropped on an aluminum substrate, and an ink film with a thickness of 100 μm was applied with a dedicated coating jig (PCT-100) for coating with a thickness of 100 μm. The obtained ink film was quickly installed together with a cold block (CHB-100), and a cylinder edge (RBP-040) and a pendulum (FRB-100) were set. At this time, two FRB-100 exclusive weights were set at the bottom of the pendulum. The measurement temperature was raised from normal temperature (25 ° C.) to 60 ° C. at 5 ° C./min, and thereafter kept at 60 ° C. The logarithmic decay rate and temperature were plotted against time. The obtained plot was smoothed, and the maximum value was calculated as the maximum value of the logarithmic decay rate.
The logarithmic decay rate (D ′ (n)) after the smoothing can be obtained as follows when the logarithmic decay rate of the nth plot is defined as D (n).
D ′ (n) = {D (n−2) + D (n−1) + D (n) + D (n + 1) + D (n + 2)} / 5
D ′ (1) = D (1)
D ′ (2) = {D (1) + D (2)} / 2

(Preparation example 1 of polyurethane resin particle dispersion)
<Preparation of polyurethane resin particle dispersion 1>
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 1,6-hexanediol and 1,6-hexanedioic acid were adjusted to titanium tetraisopropoxide so that OH / COOH = 1.5. (1,000 ppm (1% by mass) with respect to resin component). Then, it heated up to 200 degreeC in about 4 hours. Next, the temperature was raised to 230 ° C. over 2 hours, and the reaction was continued until there was no effluent water. Then, further, it was made to react under reduced pressure of 1,334 Pa-2,000 Pa (10 mmHg-15 mmHg) for 5 hours, and intermediate polyester was obtained.
Next, the intermediate polyester and isophorone diisocyanate are charged at a molar ratio of 2.0 into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, and diluted to 48% by mass with ethyl acetate. Then, it was made to react at 100 degreeC for 5 hours. Thereafter, a large amount of water was added and desolubilization was performed to obtain a polyurethane resin particle dispersion 1 having a solid content concentration of 10% by mass.

(Preparation example 2 of polyurethane resin particle dispersion)
<Preparation of polyurethane resin particle dispersion 2>
In the preparation example 1 of the polyurethane resin particle dispersion, the solid content concentration was 10 mass in the same manner as in the preparation example 1 of the polyurethane resin particle dispersion, except that 1,6-hexanediol was changed to 1,4-butanediol. % Polyurethane resin particle dispersion 2 was obtained.

(Preparation Example 3 of polyurethane resin particle dispersion)
<Preparation of polyurethane resin particle dispersion 3>
The solid content concentration was the same as in Preparation Example 1 of the polyurethane resin particle dispersion, except that 1,6-hexanedioic acid was changed to 1,4-butanedioic acid in Preparation Example 1 of the polyurethane resin particle dispersion. A polyurethane resin particle dispersion 3 of 10% by mass was obtained.

(Ink Preparation Example 1)
<Preparation of ink 1>
Magenta pigment (trade name: Pigment Red 122, manufactured by Dainichi Seika Kogyo Co., Ltd.) 5.0% by mass, tripropylene glycol monobutyl ether (Dow Chemical Japan Co., Ltd.) 4.0% by mass, triethylene glycol dimethyl ether (Dow)・ Chemical Japan Co., Ltd.) 5.0 mass%, 1,2-propanediol (propylene glycol) (Kanto Chemical Co., Ltd.) 25.0 mass%, polyurethane resin particle dispersion 1 (solid content concentration: 10 mass%) ) The remaining amount of ultrapure water was added so that the total amount was 50.0% by mass, and the total amount was 100% by mass, and stirred and mixed to obtain ink 1.

(Ink Preparation Examples 2 to 20)
<Preparation of inks 2 to 20>
Inks 2 to 20 were obtained in the same manner as in Ink Preparation 1 except that the composition was changed to the compositions shown in Tables 1 to 3 below.

In addition, in the said Tables 1-3, it is as follows about the brand name of a component, and a manufacturing company name.
-Magenta pigment: manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: Pigment Red 122
-Yellow pigment: manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: Pigment Yellow 154
・ Tripropylene glycol monobutyl ether: Dow Chemical Japan Ltd. ・ Triethylene glycol dimethyl ether: Dow Chemical Japan Ltd. ・ Diethylene glycol diethyl ether: Dow Chemical Japan Ltd. ・ Dipropylene glycol dimethyl ether: Dow Chemical Japan Ltd. Company-made: Tripropylene glycol dimethyl ether: Dow Chemical Japan Co., Ltd. 1,2-propanediol (propylene glycol): Kanto Chemical Co., Ltd.

(Examples 1-39 and Comparative Examples 1-10)
[Image formation]
Using the obtained inks 1 to 20, images were recorded on both sides of a recording medium by an inkjet printing system (RICOH Pro VC60000, manufactured by Ricoh Co., Ltd.), and the images were evaluated. As the recording medium, as shown in Tables 4 and 5 below, roll paper of LAG90 (manufactured by Stora Enso, paper width 520.7 mm), Magno Plus Silk (manufactured by Sappi Global), or Magno Gloss (manufactured by Sappi Global). And an unpressurized image was recorded at a resolution of 1,200 dpi. As a winding device, Rewinding module RW6 (manufactured by Hunkeler) was used, and at that time, simple lamination was performed to wind up to a pressure as shown in Tables 4 and 5 below, thereby forming an image. Using the formed image, “blocking resistance”, “sliding resistance”, and “glossiness” were evaluated. Next, once the recording is completed, the paper is set again, the first ink is changed to the second ink (black ink), and a solid image is recorded at a resolution of 1,200 dpi. The “positional shift at the time of ink application” was evaluated. In addition, the pressure concerning an unpressurized image was measured using apparatus name: Surface pressure distribution measurement system I-SCAN (made by Nitta Corporation), and I-SCAN # 5027 (made by Nitta Corporation) as a sensor sheet. As shown in FIGS. 5 and 6, a continuous sheet 12 was wound in a roll shape, and a sensor sheet 13 for measuring pressure was installed at a position 20 cm from the outside of the paper tube 11 having the cavity 10. By installing the sensor sheet 13 at three points whose positions were changed in the width direction of the continuous paper 12, three measurement points were provided. Then, the winding of the continuous paper 13 is continued, the pressure at the stage where the 10 cm paper is overlapped when viewed from the three measurement points is measured, and the average value of the three pressures is converted into an unpressurized image. This pressure was taken. The results are shown in Tables 4 and 5 below.
Further, in the LAG90, a contact time of 100 ms measured by a dynamic scanning absorpometer (DSA, Papa Technical Journal, Vol. 48, May 1994, pp. 88 to 92, Kuju Shigenori). The transfer amount of pure water at 2.9 mL / m ² is 2.9 mL / m ² , and the transfer amount of pure water at the contact time of 400 ms is 4.9 mL / m ² .
In the Magno Plus Silk, a contact time of 100 ms as measured by a dynamic scanning absorpometer (DSA, Papa, Japan, 48, May 1994, pp. 88-92, Shigenori Kusaka). The transfer amount of pure water at 2.5 is 2.5 mL / m ² , and the transfer amount of pure water at the contact time of 400 ms is 4.3 mL / m ² .
In the above-mentioned Magno Gloss, contact time measured by a dynamic scanning absorptiometer (DSA, Papa-Pagi Kyodo Journal, Vol. 48, May 1994, pp. 88-92, Shigenori Kusaka) at 100 ms The transfer amount of pure water is 1.8 mL / m ² , and the transfer amount of pure water at the contact time of 400 ms is 3.5 mL / m ² .

(Blocking resistance)
The condition of sticking between recorded images and the state of image transfer (offset) were confirmed by visual observation, and “blocking resistance” was evaluated based on the following evaluation criteria. Rank 7 or higher is good in quality, and rank 10 is particularly good. Moreover, the quality is remarkably deteriorated at rank 3 or lower.
〔Evaluation criteria〕
10: Papers do not stick to each other, and images are not peeled off, resulting in a visually uniform image. 9: Papers do not stick to each other, and there is no image peeling, but there is a minute image dropout of less than 10 μm. 8: Paper does not stick to each other and image peeling does not occur, but there is a minute image dropout of 10 μm or more and less than 20 μm 7: Paper does not stick to each other and image peeling does not occur, but there is a minute image dropout of 20 μm or more to less than 30 μm 6: Paper does not stick to each other, and there is no image peeling, but there is a minute image omission of 30 μm or more and less than 40 μm. 3: Paper is stuck to each other, and the image is extremely missing. 1: Papers are stuck to each other. Is markedly chipped, and the paper is also markedly missing. 0: The papers are sticking together and are united

(Rubbing resistance)
About each obtained image, the image was rubbed 20 times using the paper (LAG90 (made by Stora Enso)) cut into a 1.2 cm square, and the reflection type color spectrophotometric densitometer (made by X-Rite) was used. Then, the ink adhesion stain on the paper was measured, the density obtained by subtracting the background color of the rubbed paper was calculated, and the “rubbing resistance” was evaluated based on the following evaluation criteria.
〔Evaluation criteria〕
○: Transfer density is less than 0.05 Δ: Transfer density is 0.05 or more and less than 0.10 ×: Transfer density is 0.10 or more

(Glossy)
About each obtained image, 60 degree glossiness was measured using the gloss meter (the BYK Gardner company make: Micro-TRI-Gloss 4520), and "glossiness" before and after pressurization was evaluated.

(Position misalignment during second ink application)
The positional deviation from the first ink when the second ink was recorded was visually confirmed, and the “positional deviation at the time of applying the second ink” was evaluated based on the following evaluation criteria.
〔Evaluation criteria〕
○: No misalignment ×: Misalignment

As an aspect of this invention, it is as follows, for example.
<1> a first ink application step of applying an ink to a recording medium to form an unpressurized image;
Pressure is applied to the unpressurized image to form an image, and
The ink contains water, an organic solvent, and a coloring material;
The maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test for the ink film formed using the ink is 1.50 or less, and the time for the maximum value of the logarithmic decay rate is 3,800 seconds. An image forming method is characterized by the following.
<2> The recording medium is continuous paper,
The image forming method according to <1>, wherein the pressing step is a winding step of winding the recording medium into a roll.
<3> the pressure, The image forming method according 3.5 kg / cm ² or more 8.0 kg / cm ² or less is the items <1> or <2>.
<4> The image forming method according to any one of <2> to <3>, further including a second ink applying step of forming an image by applying ink to the continuous paper after the pressing step. .
<5> The recording medium has a support and a coating layer provided on at least one surface side of the support,
The amount of pure water transferred to the recording medium at a contact time of 100 ms measured by a dynamic scanning absorption meter is 2 mL / m ² or more and 35 mL / m ² or less, and the recording medium of the pure water at the contact time of 400 ms is used. The image forming method according to any one of <1> to <4>, wherein the transfer amount to is from 3 mL / m ^{2 to} 40 mL / m ² .
<6> The recording medium is continuous paper,
The pressure in the pressurizing step is generated by winding the continuous paper after applying the ink into a roll,
The recording medium has a support and a coating layer provided on at least one side of the support, and the recording medium of pure water at a contact time of 100 ms measured by a dynamic scanning absorption meter transfer amount to is 2 mL / ^{m 2} or more 35 mL / ^{m 2} or less, and the amount of transferred onto the recording medium of pure water in the contact time 400ms is at 3 mL / ^{m 2} or more 40 mL / ^{m 2} or less wherein The image forming method according to <1>.
<7> The image forming method according to any one of <1> to <6>, wherein the ink further includes urethane resin particles.
<8> The image forming method according to any one of <1> to <7>, wherein the organic solvent includes a glycol ether compound.
<9> The image forming method according to <8>, wherein the glycol ether compound is a glycol ether compound having no hydroxyl group.
<10> The image forming method according to any one of <9>, wherein the glycol ether compound is represented by the following general formula (1).
However, the general formula (1), ^{R 1} is a hydrogen atom, or represents a number from 1 to 10 alkyl group carbon, ^{R 2,} and ^{R 3} are each independently alkyl having 1 to 10 carbon atoms Represents a group, and n represents an integer of 1 to 5.
<11> The mass ratio (glycol ether compound / urethane resin particles) between the content (mass%) of the urethane resin particles and the content (mass%) of the glycol ether compound is 0.4 to 1.8. The image forming method according to any one of <8> to <10>, wherein
<12> The maximum value of the logarithmic decay rate at 60 ° C. measured by the rigid pendulum test of the ink film is 0.01 or more and 1.30 or less, and the time for the maximum value of the logarithmic decay rate is 100 seconds or more 3 The image forming method according to any one of <1> to <11>, wherein the image forming method is 1,000 seconds or less.
<13> The image forming method according to any one of <8> to <12>, wherein the content of the glycol ether compound is 2.0% by mass or more and 8.0% by mass or less based on the total amount of the ink. is there.
<14> ink and
First ink applying means for forming an unpressurized image by applying the ink to a recording medium;
Pressurizing means for forming an image by applying pressure to the unpressurized image,
The ink contains water, an organic solvent, and a coloring material;
The maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test for the ink film formed using the ink is 1.50 or less, and the time for the maximum value of the logarithmic decay rate is 3,800 seconds. An image forming apparatus is characterized by the following.
<15> The image forming apparatus according to <14>, wherein the ink further includes urethane resin particles.
<16> The maximum value of the logarithmic decay rate at 60 ° C. measured by the rigid pendulum test of the ink film is 0.01 or more and 1.30 or less, and the time for the maximum value of the logarithmic decay rate is 100 seconds or more 3 The image forming apparatus according to any one of <14> to <15>, wherein the image forming apparatus is for 1,000 seconds or less.
<17> Ink,
First ink applying means for forming an unpressurized image by applying the ink to a recording medium;
Pressurizing means for forming an image by applying pressure to the unpressurized image,
The ink contains water, an organic solvent, and a coloring material;
The maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test for the ink film formed using the ink is 1.50 or less, and the time for the maximum value of the logarithmic decay rate is 3,800 seconds. An image forming system is characterized by the following.
<18> The maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test of the ink film formed using the ink is 0.01 or more and 1.30 or less, and the maximum value of the logarithmic decay rate is The image forming system according to <17>, wherein the time is from 100 seconds to 3,000 seconds.
<19> a first ink application step of applying an ink to a recording medium to form an unpressurized image;
Pressure is applied to the unpressurized image to form an image, and
The ink contains water, an organic solvent, and a coloring material;
The maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test for the ink film formed using the ink is 1.50 or less, and the time for the maximum value of the logarithmic decay rate is 3,800 seconds. It is the manufacturing method of the printed matter characterized by the following.
<20> The maximum value of the logarithmic decay rate at 60 ° C. measured by the rigid pendulum test of the ink film is 0.01 or more and 1.30 or less, and the time for the maximum value of the logarithmic decay rate is 100 seconds or more 3 It is a manufacturing method of the printed matter as described in said <19> which is 1,000 second or less.

  The image forming method according to any one of <1> to <13>, the image forming apparatus according to any one of <14> to <16>, and any one of <17> to <18>. According to the image forming system and the method for producing a printed material according to any one of <19> to <20>, the conventional problems can be solved and the object of the present invention can be achieved.

JP 2013-248883 A

300 Inkjet recording apparatus (image forming apparatus)
203 recording medium

Claims (16)

A first ink application step of applying an ink to a recording medium to form an unpressurized image;
Pressure is applied to the unpressurized image to form an image, and
The ink contains water, an organic solvent, and a coloring material;
The maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test for the ink film formed using the ink is 1.50 or less, and the time for the maximum value of the logarithmic decay rate is 3,800 seconds. An image forming method comprising: The recording medium is continuous paper;
The image forming method according to claim 1, wherein the pressurizing step is a winding step of winding the recording medium into a roll shape. The pressure is, the image forming method according to any one of claims 1 to 2 is 3.5 kg / cm ² or more 8.0 kg / cm ² or less.   4. The image forming method according to claim 2, further comprising a second ink applying step of forming an image by applying ink to the continuous paper after the pressurizing step. 5. The recording medium has a support and a coating layer provided on at least one surface side of the support,
The amount of pure water transferred to the recording medium at a contact time of 100 ms measured by a dynamic scanning absorption meter is 2 mL / m ² or more and 35 mL / m ² or less, and the recording medium of the pure water at the contact time of 400 ms is used. 5. The image forming method according to claim 1, wherein the amount of transfer to is 3 mL / m ² or more and 40 mL / m ² or less. The recording medium is continuous paper;
The pressure in the pressurizing step is generated by winding the continuous paper after applying the ink into a roll,
The recording medium has a support and a coating layer provided on at least one side of the support, and the recording medium of pure water at a contact time of 100 ms measured by a dynamic scanning absorption meter transfer amount to is 2 mL / ^{m 2} or more 35 mL / ^{m 2} or less, and the amount of transferred onto the recording medium of pure water in the contact time 400ms is at 3 mL / ^{m 2} or more 40 mL / ^{m 2} or less according Item 4. The image forming method according to Item 1.   The image forming method according to claim 1, wherein the ink further contains urethane resin particles.   The image forming method according to claim 1, wherein the organic solvent contains a glycol ether compound.   The image forming method according to claim 8, wherein the glycol ether compound is a glycol ether compound having no hydroxyl group. The image forming method according to claim 9, wherein the glycol ether compound is represented by the following general formula (1).
However, the general formula (1), ^{R 1} is a hydrogen atom, or represents a number from 1 to 10 alkyl group carbon, ^{R 2,} and ^{R 3} are each independently alkyl having 1 to 10 carbon atoms Represents a group, and n represents an integer of 1 to 5.   The mass ratio (glycol ether compound / urethane resin particles) between the content (% by mass) of the urethane resin particles and the content (% by mass) of the glycol ether compound is 0.4 to 1.8. Item 11. The image forming method according to any one of Items 8 to 10.   The maximum value of the logarithmic decay rate at 60 ° C. measured by the rigid pendulum test of the ink film is 0.01 or more and 1.30 or less, and the time when the logarithmic decay rate is the maximum value is 100 seconds or more and 3000 seconds. The image forming method according to claim 1, wherein:   The image forming method according to any one of claims 8 to 12, wherein the content of the glycol ether compound is 2.0% by mass or more and 8.0% by mass or less based on the total amount of the ink. Ink,
First ink applying means for forming an unpressurized image by applying the ink to a recording medium;
Pressurizing means for forming an image by applying pressure to the unpressurized image,
The ink contains water, an organic solvent, and a coloring material;
The maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test for the ink film formed using the ink is 1.50 or less, and the time for the maximum value of the logarithmic decay rate is 3,800 seconds. An image forming apparatus comprising: Ink,
First ink applying means for forming an unpressurized image by applying the ink to a recording medium;
Pressurizing means for forming an image by applying pressure to the unpressurized image,
The ink contains water, an organic solvent, and a coloring material;
The maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test for the ink film formed using the ink is 1.50 or less, and the time for the maximum value of the logarithmic decay rate is 3,800 seconds. An image forming system comprising: A first ink application step of applying an ink to a recording medium to form an unpressurized image;
Pressure is applied to the unpressurized image to form an image, and
The ink contains water, an organic solvent, and a coloring material;
The maximum value of the logarithmic decay rate at 60 ° C. measured by a rigid pendulum test for the ink film formed using the ink is 1.50 or less, and the time for the maximum value of the logarithmic decay rate is 3,800 seconds. A method for producing a printed matter characterized by the following.