JP2019018447A - Transfer body, transfer type inkjet recording device, and transfer type inkjet recording method - Google Patents

Abstract

To provide a transfer body that can maintain high-transfer properties even when repeatedly transferring at a high speed and inhibit generation of a crack.SOLUTION: A transfer body for inkjet having at least an outermost surface layer part has a storage elastic modulus of the outermost surface layer part of 20 MPa or more and 100 MPa or less and a loss tangent (tanδ) of 0.100 or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transfer body, a transfer ink jet recording apparatus using the transfer body, and a transfer ink jet recording method.

  As an image recording method using ink, there is known a transfer type ink jet recording method in which an ink image is formed by applying ink to an image forming surface of a transfer body using an ink jet device, and the formed ink image is transferred to a recording medium. It has been. It is preferable that the transfer body used in this image recording method has a property that the ink image is easily peeled off on the surface thereof, that is, a good ink image transfer property. Also, for the purpose of holding the formed ink image, before applying the ink, a liquid (hereinafter referred to as “reaction liquid”) that reduces the fluidity of the ink by contacting the ink is applied on the transfer body. It has also been proposed to do.

  As a transfer body used in such a transfer type ink jet recording method, Patent Document 1 discloses a transfer body having a surface layer formed by a sol-gel method or the like as a surface layer portion. In Patent Document 1, the range of the compressive elastic modulus of the surface layer is defined from the viewpoint of suppressing cracks on the surface of the transfer body caused by contact with the recording medium during repeated transfer.

JP 2012-45923 A

  In recent years, a further increase in printing speed has been demanded, and a transfer type inkjet recording method requires a high-speed transfer process with a short transfer nip time. For this reason, a high-speed transfer process generally requires a higher transfer nip pressure than that at a low speed. In addition, since the transfer body is subjected to dynamic stress that repeats loading and unloading of the nip pressure in a short cycle, there is a concern that damage due to contact with a recording medium or the like during repeated transfer may increase. Furthermore, since the speed of ink image formation is also required along with the speeding up of the entire process, it is necessary to enhance the aggregation action of components contained in ink such as pigments and resin particles using a reaction liquid containing acid or the like. Become. However, in that case, there is a concern about deterioration of the surface layer portion of the transfer body due to the acid in the reaction solution during repeated printing. Furthermore, a high transfer nip pressure may be required to cope with a wide variety of recording media such as paper having a large surface irregularity. For this reason, in the high-speed and high-pressure transfer process as described above, when repeated recording is performed using the transfer body described in Patent Document 1, cracks may occur in the surface layer portion of the transfer body. It was not enough to specify the compression modulus.

  Accordingly, the present invention provides a transfer body capable of maintaining high transferability and suppressing the occurrence of cracks even when transferring repeatedly at high speed, a transfer type ink jet recording apparatus and a transfer type ink jet recording using the transfer body. It aims to provide a method.

  In order to achieve the above object, the present inventors have focused on viscoelasticity as the dynamic behavior of the surface of the transfer body, and have reached the present invention. The present invention is a transfer body for ink jet recording having at least a surface layer portion, wherein the storage elastic modulus of the surface layer portion is 20 MPa or more and 100 MPa or less, and a loss tangent (tan δ) is 0.100 or less. It is a featured transfer body.

  In addition, the present invention is a transfer type ink jet recording apparatus provided with the above transfer body.

  Furthermore, the present invention provides a transfer mold including a step of forming an ink image by applying ink on a transfer body using an inkjet device, and a step of transferring the ink image from the transfer body to a recording medium. An ink jet recording method, wherein the transfer body is the transfer body described above.

  ADVANTAGE OF THE INVENTION According to this invention, even when transferring repeatedly at high speed, the transfer body which can maintain high transferability and can suppress generation | occurrence | production of a crack, the transfer type inkjet recording device using the said transfer body, and transfer type inkjet recording A method can be provided.

It is a schematic diagram which shows the structure of the transfer body for transfer type inkjet recording of this invention. It is a figure which shows the structural example of the transfer body for transfer type inkjet recording of this invention. It is a schematic diagram showing an example of a transfer type ink jet recording apparatus of the present invention.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments. In the present invention, an ink jet recording apparatus provided with a transfer body is hereinafter referred to as a transfer type ink jet recording apparatus for convenience, and an ink jet recording method using the transfer body is hereinafter referred to as a transfer type ink jet recording method for convenience. .
<Transfer>
FIG. 1 shows the configuration of a transfer body for transfer type inkjet recording according to an embodiment of the present invention. The transfer body 1 has a surface layer portion 2, and the image forming surface of the transfer body 1 is the surface of the surface layer portion 2 (the surface of the transfer body). An ink image is formed on the image forming surface by applying ink using an inkjet device. Hereinafter, the ink image formed on the transfer body is also referred to as an intermediate image.

  The transfer body of the present invention may be a single layer or a plurality of layers. When composed of a plurality of layers, the surface layer portion can be provided on the side closest to the image forming surface of the transfer body as a thick layer. Here, FIG. 2 shows a configuration example when the transfer body is composed of a plurality of layers. The transfer body 1 may have an elastic layer 3, a compression layer 4, and a base material 5 in this order under the surface layer portion 2 on the image forming surface side (front surface side). Hereinafter, each layer of the transfer body will be described.

[Surface part]
The surface layer portion in the transfer body of the present invention is a portion including an image forming surface located on the outermost surface of the transfer body on the image forming surface side, and a layer may be formed like a surface layer. The surface layer portion has a surface with good peelability from the intermediate image. The surface layer portion has a storage elastic modulus of 20 MPa or more and 100 MPa or less and a loss tangent of 0.100 or less. By defining the viscoelasticity of the surface layer portion within the above range, it is possible to obtain a transfer body that can maintain high transferability and suppress the occurrence of cracks even when transferring repeatedly at high speed.

  Conventionally, with regard to cracks in the surface layer portion of a transfer body that occur during repeated transfer, it has been generally known that the harder the surface layer portion, the more prominent the occurrence of cracks. Therefore, by reducing the compression elastic modulus (also called Young's modulus) of the surface layer portion, cracks have been suppressed and the durability of the transfer body has been improved. However, according to the study by the present inventors, it has been found that even if the compression elastic modulus of the surface layer portion is sufficiently small, cracks may occur when transfer is performed at high speed and high pressure. In particular, even when there is no great difference in compression modulus, there are cases where differences in the ease of occurrence of cracks during repetitive transfer may be observed, and further studies are required to suppress the occurrence of cracks.

  Therefore, the present inventors focused on the dynamic viscoelasticity of the surface layer portion of the transfer body with respect to the dynamic stress due to repeated loading and unloading of the transfer nip pressure applied during actual transfer. It was found that there is a correlation with the storage elastic modulus and loss tangent of the surface layer portion of the transfer body.

  That is, the storage elastic modulus of the surface layer portion in the transfer body of the present invention is 20 MPa or more and 100 MPa or less with respect to the storage elastic modulus that is the spring elastic modulus component of the viscoelastic body. When the storage elastic modulus exceeds 100 MPa, the surface layer portion is too hard, and cracks are likely to occur during repeated transfer. On the other hand, when the storage elastic modulus is less than 20 MPa, the surface layer portion is too soft, so that the surface layer portion is easily worn by contact with the recording medium during repeated transfer, and as a result, high transferability is maintained. Becomes difficult. The storage elastic modulus of the surface layer part is preferably 20 MPa or more and 50 MPa or less, and in this case, very high durability is obtained.

  In addition, regarding the loss tangent (tan δ = loss elastic modulus / storage elastic modulus) used as an easy to plastic deformation of the viscoelastic body or a brittleness index, the loss tangent of the surface layer portion in the transfer body of the present invention is 0.100. It is as follows. If the loss tangent exceeds 0.100, the brittleness of the surface layer portion becomes large, so that cracks are likely to occur during repeated transfer. The loss tangent of the surface layer portion is preferably 0.050 or less, and in this case, extremely high durability is obtained. Although there is no restriction | limiting in particular about the lower limit of the loss tangent of a surface layer part, For example, it can be set to 0.001 or more.

  In addition, the storage elastic modulus and loss tangent in the present invention are measured with a Berkovich diamond indenter under the conditions of a load of 40 μN, a frequency of 150 Hz, and room temperature (25 ° C.) using a nanoindenter. Value.

  As the material for the surface layer portion that satisfies the above storage elastic modulus and loss tangent, various materials such as resin and ceramic can be used as appropriate. Specific examples include an acrylic resin, an acrylic silicone resin, a fluorine-containing resin, a compound obtained by condensing a hydrolyzable organosilicon compound (condensate of an organosilicon compound), and the like. Among these, a condensate of an organosilicon compound is preferable from the viewpoint of intermediate image formation and transferability. When the condensate of hydrolyzable organosilicon compound is included in the surface layer portion, a good intermediate image is formed because it has appropriate wettability with respect to ink and reaction liquid, and peeling from the intermediate image becomes easy. This is because it has an appropriate surface free energy, and thus good transferability is exhibited.

At this time, depending on the type of organosilicon compound, the ratio of the organosilicon compound used as a monomer in the case of co-condensation using a plurality of types of organosilicon compounds, and the type and amount of other additives, the viscoelasticity of the surface layer portion It is possible to control physical properties such as surface free energy.
For example, when an organosilicon compound having a crosslinkable polymer group such as an epoxy group is co-condensed with another organosilicon compound, if the ratio of the organosilicon compound having a crosslinkable polymer group that is a crosslinkable monomer is reduced, The storage elastic modulus can be reduced. Further, if a compound having a polyalkylene oxide unit such as a polyethylene oxide unit is added as an additive for imparting flexibility, the storage elastic modulus can be similarly reduced. At this time, the addition amount of the additive is preferably 0.1 mol% or more and 20 mol% or less, and more preferably 1 mol% or more and 10 mol% or less with respect to the total amount of the organosilicon compound.
Moreover, if the organosilicon compound which has a fluorinated alkyl group is used, the surface free energy of a surface layer part can be made low. At that time, since the tackiness of the surface layer portion is also lowered, the peelability from the intermediate image is improved, and the transferability can be enhanced.

  The surface layer portion preferably contains 10 to 100 mass% of these resins and ceramics in total, more preferably 50 to 100 mass%, more preferably 70 to 100 mass%. More preferably, the content is less than or equal to mass%.

  The surface layer portion can be formed by a known method. For example, after a solution containing the organosilicon compound monomer and a polymerization initiator are mixed to obtain a coating solution for forming the surface layer portion, the coating solution is applied to form a film, which is then exposed to heat and cured. Can be formed.

  The thickness of the surface layer part is preferably 0.1 μm or more and 30 μm or less. If the thickness of the surface layer portion is 0.1 μm or more, it becomes easy to form the outermost surface layer uniformly on the surface of the transfer body. Moreover, if the thickness of the surface layer portion is 30 μm or less, the internal stress during deformation does not become excessively large, and the effects of the present invention can be sufficiently obtained. The thickness of the surface layer portion is more preferably 1 μm or more and 10 μm or less, and in this range, the followability to the surface shape of the recording medium at the time of transfer is ensured, and better transferability can be obtained.

  In order to improve the wettability of ink and reaction liquid, image quality, transferability, etc., surface treatment may be performed on the surface layer portion. Examples of the surface treatment include flame treatment, corona treatment, plasma treatment, polishing treatment, roughening treatment, active energy ray irradiation treatment, ozone treatment, surfactant treatment, and silane coupling treatment. A plurality of these may be combined. Furthermore, you may provide arbitrary surface shapes in a surface layer part.

[Elastic layer]
The elastic layer is a layer having an elastic body that may be sandwiched between the surface layer portion and the compression layer. By providing the elastic layer, the followability to the concavo-convex shape of the surface of the recording medium on the surface of the surface layer portion of the transfer body at the time of transfer becomes good. Moreover, even when the surface irregularity shape of the compression layer is large, the elastic layer is formed on the compression layer, thereby contributing to smoothing the surface of the transfer body.

  As the material for the elastic layer, various materials such as resin and ceramic can be used as appropriate. The elastic layer may be composed of a plurality of layers made of different materials and compositions. From the viewpoint of processing characteristics and the like, various elastomer materials and rubber materials are preferably used. Specifically, for example, silicone rubber, fluorosilicone rubber, phenyl silicone rubber, fluorine rubber, chloroprene rubber, urethane rubber, nitrile rubber, ethylene propylene rubber, natural rubber, styrene rubber, isoprene rubber, butadiene rubber, ethylene / propylene / diene rubber And nitrile butadiene rubber. Among these, silicone rubber, fluorosilicone rubber, and phenyl silicone rubber are preferable in terms of dimensional stability and durability because they have a small compression set, and also have high heat resistance and a small temperature change in elastic modulus. This is also preferable. In addition, ethylene / propylene / diene rubber has high tear strength and a large elongation at break, and therefore is preferably used from the viewpoint of suppressing cracks in the surface layer portion. The elastic layer preferably contains a total of 10% by mass or more and 100% by mass or less of these resins, ceramics, and rubbers, more preferably 30% by mass or more and 100% by mass or less, and 50% by mass. More preferably, the content is 100% by mass or less.

The thickness of the elastic layer is preferably 0.01 mm or more and 1.0 mm or less, and more preferably 0.05 mm or more and 0.5 mm or less.
Moreover, the hardness of the elastic body used for the elastic layer is preferably 20 degrees or more and 80 degrees or less, more preferably 30 degrees or more and 60 degrees or less in terms of durometer type A (JIS K 6253 compliant) hardness. . By setting the hardness of the elastic body to 20 degrees or more, large deformation of the elastic layer can be suppressed and good followability of the surface layer portion with respect to deformation of the elastic layer can be ensured. In addition, by setting the hardness of the elastic body to 80 degrees or less, local stress applied to the surface layer portion can be sufficiently relaxed by the elastic layer, particularly during high-speed transfer, and the crack resistance and transferability of the transfer body can be reduced. Can be increased.

[Compression layer]
The compressed layer is a layer having a function of absorbing pressure fluctuation. By providing the compression layer, the compression layer absorbs deformation, disperses the fluctuations with respect to local pressure fluctuations, and can maintain good transferability even during high-speed printing.

  Examples of the material for the compression layer include acrylonitrile-butadiene rubber, acrylic rubber, chloroprene rubber, urethane rubber, and silicone rubber. The compression layer may be composed of a plurality of layers made of different materials and compositions. The compression layer preferably contains 10 to 100% by mass of these rubbers in total, more preferably 30 to 100% by mass, and more preferably 50 to 100% by mass. It is more preferable to contain. Further, when molding the rubber material, a predetermined amount of vulcanizing agent, vulcanization accelerator and the like are blended, and further, a foaming agent such as an antifoaming agent, hollow fine particles or salt is blended as necessary to make the porous material. Those are preferred. Thereby, since the bubble part is compressed with a volume change with respect to various pressure fluctuations, deformation in the direction other than the compression direction is small, and more stable transferability and durability can be obtained. The porous rubber material includes a continuous pore structure in which the pores are continuous with each other and an independent pore structure in which the pores are independent from each other. In the present invention, any structure may be used, and these structures may be used in combination.

  The hardness of the rubber used for the compression layer is a durometer type A (JIS K 6253 compliant) hardness, preferably 20 degrees or more and 80 degrees or less, and more preferably 20 degrees or more and 60 degrees or less. If the hardness of the rubber is 20 degrees or more, the restoring property of the transfer body does not deteriorate, and it becomes easy to obtain the pressure necessary for transfer. If the hardness of the rubber is 80 degrees or less, it is possible to prevent the transfer body from being damaged due to scratches or the like when a foreign object is sandwiched or when a recording medium is double fed.

  The thickness of the compressed layer is preferably 0.1 mm or more and 5.0 mm or less, and more preferably 0.2 mm or more and 2.0 mm or less. If the thickness of the compression layer is 0.1 mm or more, sufficient compression characteristics can be obtained even when the transfer pressure is high. Further, when the thickness of the compression layer is 5.0 mm or less, distortion in the shear direction during transfer is not increased, and deterioration in image quality can be suppressed.

[Base material]
The base material is provided in order to increase the strength of the transfer body in the planar direction and to improve the handleability of the transfer body to be mounted on the inkjet recording apparatus. Examples of materials used for the substrate include metal materials such as aluminum, iron, and stainless steel; resin materials such as acetal resin, epoxy resin, polyimide, polyethylene, polyethylene terephthalate, nylon, and polyurethane; woven fabric, nonwoven fabric, felt, and the like Cloth material etc. Moreover, it is also preferable to use these in combination. As the substrate, a film-like substrate can be preferably used according to the form of the recording apparatus to be applied or the transfer mode to the recording medium.

  The thickness of the substrate is preferably from 0.01 mm to 5 mm, and more preferably from 0.05 mm to 3 mm. If the thickness of the substrate is 0.01 mm or more, the strength required for use as a transfer body can be ensured. Moreover, if the thickness of the base material is 5 mm or less, the bendability is also maintained, and the handling property is high in mounting and transportation to the recording apparatus.

  Various adhesives and double-sided tapes for fixing and holding these may be used between the elastic layer and the compression layer, or between the compression layer and the substrate. In addition, a reinforcing layer may be provided by a film, a woven fabric, or the like in order to suppress lateral elongation when the recording apparatus is mounted or to maintain stiffness. The transfer body can also be produced by arbitrarily combining the layers made of the above materials.

  The size of the transfer body can be freely selected according to the target print image size. Examples of the overall shape of the transfer member include a sheet shape, a roller shape, a drum shape, a belt shape, and an endless web shape.

<Transfer type ink jet recording apparatus and transfer type ink jet recording method>
One embodiment of a transfer type ink jet recording apparatus according to the present invention is shown in FIG. This transfer type ink jet recording apparatus includes a transfer body 11 of the present invention having an image forming surface, an ink jet device 15 as an ink application device, a roller type coating device 14 as a reaction liquid application device, and a transfer pressing member ( Transfer pressure roller) 18. The pressure roller 18 and the transfer body 11 constitute an intermediate image (ink image) transfer device. The inkjet device 15 has an inkjet recording head that ejects ink. Further, the transfer type ink jet recording apparatus may have a cleaning member 19 for cleaning the surface of the transfer body 11 after the transfer, if necessary.

  The transfer-type inkjet recording method according to the present invention includes a step of forming an intermediate image (ink image) by applying ink using an inkjet device on the transfer member (intermediate image forming step), and transferring the intermediate image to the transfer member. And transferring to the recording medium (transfer process).

  Specifically, image recording (image formation) by the transfer inkjet recording method according to the present invention can be performed by the following operation using the transfer inkjet recording apparatus. An intermediate image is formed by applying ink using the inkjet device 15 to the image forming surface on the transfer body 11 to which the reaction liquid has been applied by the application roller included in the roller type application device 14. Then, the intermediate image formed on the transfer body is brought into contact with the recording medium 17 while being pressed by the pressing roller 18 to transfer the intermediate image to the recording medium.

The transfer body 11 of the present invention can be installed on the support member 12. The support member 12 is driven to rotate in the direction of the arrow about the rotation shaft 13 of the support member, and each device disposed in the periphery operates in synchronization with the rotation. Specifically, the reaction liquid applying device 14 sequentially applies the reaction liquid and the ink applying device 15 to the moving transfer body 11, and an intermediate image (ink image) is formed on the transfer body. The intermediate image formed on the transfer body 11 is moved to the transfer portion in contact with the recording medium by the movement of the transfer body 11. While the intermediate image is in contact with the recording medium, the pressing member 18 presses the transfer body 11 through the recording medium, whereby the intermediate image is transferred onto the recording medium.
The transfer body 11 is supported on a support member 12. As a method for supporting the transfer body 11, various adhesives and double-sided tapes may be used. Alternatively, the transfer body 11 may be supported on the support member 12 by using an installation member by attaching an installation member made of metal, ceramic, resin, or the like to the transfer body 11.
The support member is required to have a certain degree of structural strength from the viewpoint of conveyance accuracy and durability. As the material of the support member, metal, ceramic, resin, or the like is preferably used. Among them, in addition to rigidity and dimensional accuracy that can withstand pressurization during transfer, in order to reduce inertia during operation and improve control responsiveness, the following are preferably used. For example, metal materials such as aluminum, iron, and stainless steel; resin materials such as acetal resin, epoxy resin, polyimide, polyethylene, polyethylene terephthalate, nylon, and polyurethane; ceramic materials such as silica ceramics and alumina ceramics. Moreover, it is also preferable to use these in combination. As the support member, for example, a roller-like or belt-like member can be preferably used in accordance with the form of the recording apparatus to be applied or a transfer mode to the recording medium. The use of a drum-shaped support member or a belt-shaped endless web structure support member makes it possible to repeatedly use the same transfer body, which is extremely preferable from the viewpoint of productivity.

[Reaction solution application process]
The transfer type inkjet recording method of the present invention preferably further includes a step of applying a reaction liquid onto the transfer body (reaction liquid applying step) in order to form a good ink image. Further, it is preferable to apply a reaction liquid to the transfer body before applying ink. When the reaction liquid comes into contact with the ink, the fluidity of a part of the ink and / or ink composition on the transfer body is lowered, and bleeding and beading during image formation by the ink can be suppressed. . Specifically, a reactant (also referred to as an ink thickening component) contained in the reaction liquid reacts chemically when it comes into contact with a color material or resin that is a part of the composition constituting the ink. Or physically adsorbed. This causes an increase in the viscosity of the ink as a whole, and a local increase in viscosity due to agglomeration of some of the components constituting the ink, such as the color material, resulting in a partial fluidity of the ink and / or ink composition. Can be reduced. As a method for applying the reaction solution, various conventionally known methods can be appropriately used. For example, die coating, blade coating, gravure roller, or a combination of these with an offset roller can be used. Moreover, it is also preferable to use an inkjet device as a method which can provide a reaction liquid at high speed and with high precision.

<Reaction solution>
Hereinafter, each component which comprises the reaction liquid applied to this embodiment is demonstrated in detail.

(Reactant)
The reaction liquid agglomerates a component (resin, self-dispersing pigment, etc.) having an anionic group in the ink by contacting with the ink, and contains a reactive agent. Examples of the reactive agent include cationic components such as polyvalent metal ions and cationic resins, and organic acids.
Examples of the polyvalent metal ion include divalent metal ions such as Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Sr ²⁺ , Ba ²⁺ and Zn ²⁺ , Fe ³⁺ , Cr ³⁺ , Y ³⁺ and Al ^3+. Of the trivalent metal ions. In order to contain a polyvalent metal ion in the reaction solution, a polyvalent metal salt (which may be a hydrate) constituted by combining a polyvalent metal ion and an anion can be used. Examples of the anion include Cl ⁻ , Br ⁻ , I ⁻ , ClO ⁻ , ClO ₂ ⁻ , ClO ₃ ⁻ , ClO ₄ ⁻ , NO ₂ ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ , CO ₃ ²⁻ , HCO _3. ⁻ , PO ₄ ³⁻ , HPO ₄ ²⁻ , and inorganic anions such as H ₂ PO ₄ ⁻ ; HCOO ⁻ , (COO ⁻ ) ₂ , COOH (COO ⁻ ), CH ₃ COO ⁻ , C ₂ H ₄ (COO ⁻ ) ₂ , organic anions such as C ₆ H ₅ COO ⁻ , C ₆ H ₄ (COO ⁻ ) ₂ and CH ₃ SO ₃ ^— . When a polyvalent metal ion is used as the reactant, the content (% by mass) in terms of the polyvalent metal salt in the reaction solution is 1.00% by mass or more and 20.00% by mass or less based on the total mass of the reaction solution. Preferably there is.
The reaction solution containing an organic acid has a buffering ability in an acidic region (pH less than 7.0, preferably pH 2.0 to 5.0), thereby converting an anionic group of a component present in the ink into an acid form. Aggregates. Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, glycolic acid, lactic acid, salicylic acid, pyrrole carboxylic acid, furan carboxylic acid, picolinic acid, nicotinic acid, thiophene carboxylic acid, levulinic acid, and coumarin acid. Monocarboxylic acids and salts thereof; oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, itaconic acid, sebacic acid, phthalic acid, malic acid, tartaric acid, dicarboxylic acids, and the like Examples thereof include salts and hydrogen salts; tricarboxylic acids such as citric acid and trimellitic acid and salts and hydrogen salts thereof; tetracarboxylic acids such as pyromellitic acid and salts and hydrogen salts thereof. The content (% by mass) of the organic acid in the reaction solution is preferably 1.00% by mass or more and 50.00% by mass or less.
Examples of the cationic resin include a resin having a primary to tertiary amine structure and a resin having a quaternary ammonium salt structure. Specific examples include resins having a structure such as vinylamine, allylamine, vinylimidazole, vinylpyridine, dimethylaminoethyl methacrylate, ethyleneimine, and guanidine. In order to enhance the solubility in the reaction solution, a cationic resin and an acidic compound can be used in combination, or a quaternization treatment of the cationic resin can be performed. When a cationic resin is used as the reactant, the content (% by mass) of the cationic resin in the reaction solution may be 1.00% by mass or more and 10.00% by mass or less based on the total mass of the reaction solution. preferable.

(Ingredients other than reactants)
As the components other than the reactants, the same materials as the aqueous medium and other additives mentioned above as those that can be used in the ink can be used.

[Intermediate image forming process]
In this step, ink is applied by the inkjet device 15 to the image forming surface of the transfer body 11 to which the reaction liquid has been applied, and an intermediate image is formed. As an inkjet device, for example, an ink is ejected by forming a bubble by causing film boiling in the ink by an electro-thermal converter, a form in which the ink is ejected by an electro-mechanical converter, and an ink using static electricity. There are discharge forms. In order to perform high-density printing at high speed, a form using an electro-thermal converter is preferably used. There is no restriction | limiting in particular as a form of the whole inkjet device. Line head type head in which ink discharge ports are arranged in the moving direction of the transfer body (axial direction in the case of a drum shape), or shuttle type head that performs recording while scanning the head perpendicular to the moving direction of the transfer body Can also be used.

<Ink>
Hereafter, each component which comprises the ink applied to this embodiment is demonstrated in detail.

(Color material)
As the color material, pigments and dyes can be used. The content of the coloring material in the ink is preferably 0.5% by mass or more and 15.0% by mass or less, and 1.0% by mass or more and 10.0% by mass or less based on the total mass of the ink. Is more preferable.
Specific examples of the pigment include inorganic pigments such as carbon black and titanium oxide; organic pigments such as azo, phthalocyanine, quinacridone, isoindolinone, imidazolone, diketopyrrolopyrrole and dioxazine.
As a dispersion method of the pigment, a resin dispersion pigment using a resin as a dispersant, a self-dispersion pigment in which a hydrophilic group is bonded to the particle surface of the pigment, or the like can be used. Further, a resin-bonded pigment in which an organic group containing a resin is chemically bonded to the pigment particle surface, a microcapsule pigment in which the surface of the pigment particle is coated with a resin, or the like can be used.
As the resin dispersant for dispersing the pigment in the aqueous medium, it is preferable to use a resin dispersant that can disperse the pigment in the aqueous medium by the action of the anionic group. As the resin dispersant, a resin as described later can be preferably used, and a water-soluble resin can be more preferably used. The content (mass%) of the pigment is a mass ratio with respect to the content of the resin dispersant (pigment / resin dispersant), and is preferably 0.3 times or more and 10.0 times or less.
As the self-dispersing pigment, a pigment in which an anionic group such as a carboxylic acid group, a sulfonic acid group, or a phosphonic acid group is bonded to the pigment particle surface directly or through another atomic group (-R-) is used. be able to. The anionic group may be either an acid type or a salt type, and when it is a salt type, it may be either partially dissociated or completely dissociated. Examples of the cation serving as a counter ion when the anionic group is a salt type include alkali metal cations; ammonium; organic ammonium. Specific examples of other atomic groups (—R—) include linear or branched alkylene groups having 1 to 12 carbon atoms; arylene groups such as phenylene groups and naphthylene groups; carbonyl groups; imino groups; amide groups. Sulfonyl group; ester group; ether group and the like. Moreover, it is good also as group which combined these groups.
As the dye, one having an anionic group is preferably used. Specific examples of the dye include dyes such as azo, triphenylmethane, (aza) phthalocyanine, xanthene, and anthrapyridone.

(resin)
The ink can contain a resin. The content (% by mass) of the resin in the ink is preferably 0.1% by mass or more and 20.0% by mass or less, and 0.5% by mass or more and 15.0% by mass or less based on the total mass of the ink. More preferably.
The resin may be added to the ink for the purpose of (i) stabilizing the dispersion state of the pigment, that is, as the above-described resin dispersant and its auxiliary, (ii) improving various characteristics of the recorded image. it can. Examples of the form of the resin include a block copolymer, a random copolymer, a graft copolymer, and combinations thereof. Further, the resin may be in a state of being dissolved as a water-soluble resin in an aqueous medium, or in a state of being dispersed as resin particles in an aqueous medium. The resin particles do not have to include a color material.
In the present invention, that the resin is water-soluble means that, when the resin is neutralized with an alkali equivalent to the acid value, it does not form particles whose particle diameter can be measured by a dynamic light scattering method. To do. Whether or not the resin is water-soluble can be determined according to the following method. First, a liquid (resin solid content: 10% by mass) containing a resin neutralized with an alkali corresponding to an acid value (sodium hydroxide, potassium hydroxide, etc.) is prepared. Next, the prepared liquid is diluted 10 times (volume basis) with pure water to prepare a sample solution. And when the particle diameter of resin in a sample solution is measured by a dynamic light scattering method, when the particle | grains which have a particle diameter are not measured, it can be judged that the resin is water-soluble. The measurement conditions at this time can be set, for example, as SetZero: 30 seconds, the number of measurements: 3 times, and the measurement time: 180 seconds. As the particle size distribution measuring apparatus, a particle size analyzer (for example, trade name “UPA-EX150”, manufactured by Nikkiso) using a dynamic light scattering method can be used. Of course, the particle size distribution measuring apparatus and measurement conditions to be used are not limited to the above.
The acid value of the resin is preferably from 100 mgKOH / g to 250 mgKOH / g in the case of a water-soluble resin, and preferably from 5 mgKOH / g to 100 mgKOH / g in the case of a resin particle. The weight average molecular weight of the resin is preferably 3,000 to 15,000 in the case of a water-soluble resin, and preferably 1,000 to 2,000,000 in the case of a resin particle. The volume average particle diameter of the resin particles measured by a dynamic light scattering method (measurement conditions are the same as described above) is preferably 100 nm or more and 500 nm or less.

Examples of the resin include acrylic resins, urethane resins, and olefin resins. Of these, acrylic resins and urethane resins are preferable.
As acrylic resin, what has a hydrophilic unit and a hydrophobic unit as a structural unit is preferable. Among these, a resin having a hydrophilic unit derived from (meth) acrylic acid and a hydrophobic unit derived from at least one of a monomer having an aromatic ring and a (meth) acrylic acid ester monomer is preferable. In particular, a resin having a hydrophilic unit derived from (meth) acrylic acid and a hydrophobic unit derived from at least one monomer of styrene and α-methylstyrene is preferable. Since these resins are likely to interact with the pigment, they can be suitably used as a resin dispersant for dispersing the pigment.
The hydrophilic unit is a unit having a hydrophilic group such as an anionic group. The hydrophilic unit can be formed, for example, by polymerizing a hydrophilic monomer having a hydrophilic group. Specific examples of hydrophilic monomers having a hydrophilic group include acidic monomers having a carboxylic acid group such as (meth) acrylic acid, itaconic acid, maleic acid and fumaric acid, and anions such as anhydrides and salts of these acidic monomers. And the like monomer. Examples of the cation constituting the salt of the acidic monomer include ions such as lithium, sodium, potassium, ammonium, and organic ammonium. The hydrophobic unit is a unit having no hydrophilic group such as an anionic group. The hydrophobic unit can be formed, for example, by polymerizing a hydrophobic monomer having no hydrophilic group such as an anionic group. Specific examples of the hydrophobic monomer include monomers having an aromatic ring such as styrene, α-methylstyrene, benzyl (meth) acrylate; methyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid 2 -(Meth) acrylic acid ester monomers such as ethylhexyl.
As a urethane-type resin, it can obtain by making polyisocyanate and a polyol react, for example. Further, it may be further reacted with a chain extender. Examples of the olefin resin include polyethylene and polypropylene.

(Aqueous medium)
The ink can contain water or an aqueous medium that is a mixed solvent of water and a water-soluble organic solvent. As water, deionized water or ion exchange water is preferably used. The content (% by mass) of water in the aqueous ink is preferably 50.0% by mass or more and 95.0% by mass or less based on the total mass of the ink. The content (% by mass) of the water-soluble organic solvent in the aqueous ink is preferably 3.0% by mass or more and 50.0% by mass or less based on the total mass of the ink. As the water-soluble organic solvent, any of those usable for ink-jet inks such as alcohols, (poly) alkylene glycols, glycol ethers, nitrogen-containing compounds and sulfur-containing compounds can be used.

(Other additives)
In addition to the above-mentioned components, the ink has various antifoaming agents, surfactants, pH adjusting agents, viscosity adjusting agents, rust preventives, antiseptics, antifungal agents, antioxidants, anti-reducing agents, etc. The additive may be contained.

[Drying process]
The transfer type inkjet recording method according to the present invention may have a drying step for reducing the liquid content from the formed intermediate image. In the transfer type inkjet recording apparatus shown in FIG. 3, the liquid content is reduced from the intermediate image by heating using the heater 16. If the liquid content of the intermediate image is excessive, excess liquid may overflow or overflow in the next transfer process. As a result, the intermediate image may be disturbed or transferability may be deteriorated. As a method for removing the liquid component, any of various commonly used methods can be preferably applied. For example, a method by heating, a method of blowing low-humidity air, a method of reducing pressure, a method of contacting an absorber, and the like can be mentioned. A plurality of these may be combined. Or it is also possible to dry by natural drying.

[Transfer process]
After the drying step, the intermediate image is brought into contact with the recording medium, and a printed matter on which the final image is recorded is obtained by a transfer step in which the intermediate image is transferred from the image forming surface of the transfer body to the recording medium. The recording medium in the present invention includes not only plain paper and glossy paper used in general printing but also widely includes cloth, plastic, film and other printing media. When the intermediate image comes into contact with the recording medium, it is preferable that the intermediate image is efficiently transferred to the recording medium by pressing the recording medium toward the transfer body with the pressing roller 18. It is also preferable to press in multiple stages because good transferability can be obtained.

[Cleaning process]
The transfer body may be used repeatedly and continuously from the viewpoint of productivity. In that case, it is preferable to carry out a cleaning process in which the surface of the transfer body is washed and regenerated with the cleaning roller 19 or the like before the next image formation. As a means for performing cleaning, any of various commonly used methods can be preferably applied. For example, a method of applying a cleaning liquid in a shower form, a method of wiping a wet Molton roller in contact with the surface, a method of contacting the surface of the cleaning liquid, a method of scraping with a wiper blade, a method of applying various energy, and the like. A plurality of these may be combined.

  Examples of the present invention and comparative examples will be described below.

<Synthesis of condensates of organosilicon compounds>
First, the condensate contained in the surface layer part of the transfer body was synthesized using the hydrolyzable organosilicon compound and additives shown in Table 1 below.

(Synthesis of condensate X01)
The following hydrolyzable organosilicon compound, additive and water were mixed, and the resulting mixture was heated to reflux for 24 hours to obtain a solution containing the condensate X01. In addition, the addition amount of BTES-PEO as an additive is 3 mol% with respect to the total amount of GPMDES and DMDES.
・ GPMDES 74.52g
・ DMDES 177.94g
・ BTES-PEO 67.50g
・ Water 64.85g

(Synthesis of condensates X02 to X13)
Similar to the synthesis of the condensate X01, a solution containing the condensates X02 to X13 was obtained using the hydrolyzable organosilicon compound, additives and water shown in Table 2 below.

<Preparation of transfer body>
Then, the transfer body was produced using the solution containing each obtained condensate.

[Production Example 1: Preparation of transfer body Y01]
A solution containing the condensate X02 was diluted to 25% by mass with a mixed solvent of ethanol / methylisobutylketone (mass ratio: 4/1), and CPI-410S (trade name) which is a photocationic polymerization initiator as a photopolymerization initiator. , San Apro Co., Ltd.) was added in an amount of 3% by mass with respect to the solid content to obtain a coating solution for forming the surface layer portion.
Subsequently, an elastic layer having a thickness of 0.2 mm formed of silicone rubber having a rubber hardness (durometer type A hardness) of 40 degrees is formed on a PET (polyethylene terephthalate) film having a thickness of 0.05 mm as a base material. A laminate was prepared. Next, atmospheric pressure plasma treatment was performed on the surface of the elastic layer of the laminate. Then, on the surface of the elastic layer of the laminate subjected to the atmospheric pressure plasma treatment, the coating solution for forming the surface layer part was applied by spin coating to form a film. Thereafter, the coating solution for forming the surface layer portion is exposed by irradiation with a UV lamp (exposure amount: 1.74 J / m ² ), and further heated at 150 ° C. for 2 hours, thereby The coating liquid was cured to obtain a transfer body Y01 having a surface layer portion (surface layer) constituting the image forming surface. The thickness of the surface layer portion of the obtained transfer body Y01 was 3.5 μm.

Next, the dynamic viscoelasticity measurement of the surface layer part of the obtained transfer body Y01 was performed. The measurement sample was produced as follows. On the silicon wafer, the coating liquid used for preparation of the transfer body Y01 was applied by spin coating to form a film. Thereafter, the UV lamp is irradiated for exposure (exposure amount: 1.74 J / m ² ), and the coating liquid is cured by heating at 150 ° C. for 2 hours, and the above-mentioned transfer body is formed on the silicon wafer. A thin film having a thickness of 3.5 μm similar to the surface layer portion was formed. This thin film was used as a measurement sample. The storage modulus and loss tangent were measured using a TI950 TriboIndentor (trade name, manufactured by Hystron) under the conditions of a load of 40 μN, a frequency of 150 Hz, and room temperature (25 ° C.) using a Berkovich diamond indenter. As a result, the storage elastic modulus was 23 MPa, and the loss tangent (tan δ) was 0.038.

[Production Examples 2 to 18: Preparation of transfer bodies Y02 to Y18]
In the same manner as in Production Example 1, transfer bodies Y02 to Y18 were produced using the condensate, photopolymerization initiator, UV exposure amount, and heating temperature shown in Table 3 below. In addition, in transfer body Y08, SP150 which is a photocationic polymerization initiator (trade name, manufactured by ADEKA Corporation) was used as a photopolymerization initiator.
The thickness of the surface layer portion (surface layer) of each obtained transfer member was 3.5 μm. Furthermore, the dynamic viscoelasticity measurement was performed on the surface layer portion of each transfer body in the same manner as the transfer body Y01, and the storage elastic modulus and loss tangent were measured. The results are shown in Table 3.

<Evaluation>
[Examples 1-15, Comparative Examples 1-6]
The following evaluation was performed about each obtained transfer body using the transfer type inkjet recording device shown in FIG. A cylindrical drum made of an aluminum alloy was used as the support member 12 for the transfer body.
First, the reaction liquid was continuously applied to the surface of the transfer body using a roller type coating device. As the reaction solution, the following was used.
Z1: A solution in which a surfactant and an additive are appropriately added to a 50% by mass aqueous solution of citric acid to adjust the surface tension and viscosity. Z2: A 12.0% by mass aqueous solution of calcium chloride (CaCl ₂ .2H ₂ O) A solution in which surface tension and viscosity are adjusted by appropriately adding surfactants and additives.

Subsequently, the ink for image formation was ejected from the ink jet device to the image forming surface of the transfer body to form an intermediate image on the transfer body. As the ink jet device, a device of a type that ejects ink by an on-demand method using an electric-heat converter is used. As the ink, a resin-dispersed pigment ink having the following composition was used.
・ C. I. Pigment Blue 15 3.0 parts by mass-Styrene-acrylic acid-ethyl acrylate copolymer (acid value 240, weight average molecular weight 5000) 1.0 part by mass-Glycerol 10.0 parts by mass-Ethylene glycol 5.0 parts by mass・ Surfactant (trade name: Acetylenol E100, manufactured by Kawaken Fine Chemical Co., Ltd.)
0.5 parts by mass ・ Ion-exchanged water 80.5 parts by mass

High-quality paper (trade name: OK Prince fine quality, manufactured by Oji Paper Co., Ltd., basis weight: 81.4 g / m ² ) is used as a recording medium, and a pressure roller for transfer so that the transfer nip pressure is 5 kg / cm ^2. Was pressed against the transfer medium through the recording medium to transfer the intermediate image on the transfer medium to the recording medium, thereby obtaining a printed material on which the final image was formed on the recording medium. This transfer was performed 30000 times at each transfer speed shown in Table 4, the state of the transferred body and the final image after recording 30000 times was observed, and the crack suppression performance and transferability were evaluated according to the following criteria. The evaluation results are shown in Table 4 together with the storage elastic modulus and loss tangent of the surface layer portion of each transfer body. Here, the transfer speed is a print speed of an ink image printed on a recording medium by transfer, and is the same as the transfer speed of the transfer body. In this evaluation, if the crack suppression performance and the transferability evaluation are both B or more, it is judged that the transfer type inkjet recording transfer body having high durability, which is the object of the present invention, is obtained. did.

(Evaluation of crack suppression performance)
The surface of the transfer body was observed with an optical microscope and evaluated according to the following criteria.
A: Cracks were not confirmed on the surface of the transfer body.
B: A slight crack was confirmed on the surface of the transfer body.
C: Cracks were confirmed on the surface of the transfer body.
D: Many cracks were confirmed on the surface of the transfer body.

(Evaluation of transferability)
The image quality of the ink image on the transfer body after transfer and the final image formed on the recording medium was observed with an optical microscope and evaluated according to the following criteria.
A: The remainder of the ink image was not confirmed on the transfer body, and the final image was well formed.
B: Although the remainder of the ink image was slightly confirmed on the transfer body, the quality of the final image was sufficient.
C: The remainder of the ink image was slightly confirmed on the transfer body, and a part of the final image was not sufficiently transferred.
D: The remainder of the ink image was confirmed on the transfer body, and the final image was not fully transferred as a whole.

As shown in Table 4, in the transfer body of the example in which the storage elastic modulus of the surface layer part is 20 MPa or more and 100 MPa or less and the loss tangent is 0.100 or less, cracks are not observed even after repeated transfer 30000 times. Generation was suppressed, good transferability was maintained even after repeated transfer, and high durability was obtained. On the other hand, when only the specified range of either the storage elastic modulus or loss tangent was satisfied (Comparative Examples 4 and 5), cracks occurred and durability was not sufficient.
In addition, the transfer bodies (Examples 1-4, 8, 14, and 15) having a storage elastic modulus of 20 MPa or more and 50 MPa or less and a loss tangent of 0.050 or less were very high in durability. On the other hand, when the storage elastic modulus was less than 20 MPa as in Comparative Example 1, the surface layer portion after repeated printing was worn and the transferability was lowered.

When the transfer speed of the transfer body Y04 was compared (Examples 3 to 5), the higher the transfer speed, the greater the damage such as cracking, but in the speed range of 0.3 m / s to 1.8 m / s. It was confirmed that high durability was obtained.
Furthermore, when the reaction solution was compared in the transfer body Y15 (Examples 11 and 12), when the reaction solution did not contain an organic acid, the occurrence of cracks after repeated recording was suppressed, and the durability was improved. However, when the reaction solution did not contain an organic acid, the transferability was slightly lowered due to the low cohesive effect of the reaction solution during high-speed printing at 1.0 m / s. Therefore, in order to maintain high transferability even during high-speed printing, it is preferable to use a reaction solution containing an organic acid. In this case, durability deterioration during repetitive recording is likely to occur. However, if the transfer body has high durability according to the present invention, it is possible to suppress damage to the extent that there is no practical problem.

1 Transfer body 2 Surface layer part

Claims (7)

A transfer body for inkjet recording having at least a surface layer part,
The transfer body, wherein the storage elastic modulus of the surface layer portion is 20 MPa or more and 100 MPa or less, and the loss tangent (tan δ) is 0.100 or less.   The transfer body according to claim 1, wherein the surface layer portion contains a condensate of an organosilicon compound.   The transfer body according to claim 1 or 2, wherein the storage elastic modulus of the surface layer portion is 20 MPa or more and 50 MPa or less.   The transfer body according to claim 1, wherein the loss tangent of the surface layer portion is 0.050 or less.   A transfer type inkjet recording apparatus comprising the transfer body according to claim 1. Forming an ink image on the transfer body by applying ink using an inkjet device; and
Transferring the ink image from the transfer body to a recording medium;
An inkjet recording method comprising:
The transfer type inkjet recording method, wherein the transfer body is the transfer body according to any one of claims 1 to 4.   The transfer type inkjet recording method according to claim 6, further comprising a step of applying a reaction liquid to the transfer body.

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