Printed matter and method for manufacturing printed matter

Abstract

The present invention relates to a printed matter and a method for manufacturing the printed matter. In the printed matter, a surface on which an image portion and a pressure phase change layer are formed is used as a pressure bonding surface, and a recording medium is folded and pressure-bonded, or a surface on which an image portion and a pressure phase change layer are formed is used as a pressure bonding surface, and a recording medium is pressure-bonded to another recording medium, and the average thickness of the pressure phase change layer formed on the image portion is greater than the average thickness of the pressure phase change layer formed on a non-image portion on the pressure bonding surface of the recording medium.

Description

Technical Field

[0001] This invention relates to printed matter and a method for manufacturing printed matter. Background Technology

[0002] Japanese Patent Application Publication No. 2008-170659 discloses "a powder fixer, characterized in that it is configured to be coated onto paper by a process of developing, transferring and fixing based on an electrophotographic method, having a cyclic polyolefin resin as the basic structure, containing more than 40% of the cyclic polyolefin resin, and containing less than 30% of a thermoplastic elastomer."

[0003] Japanese Patent Application Publication No. 2008-173831 discloses "an apparatus for producing laminated printed matter, which laminates the bonding surfaces of a sheet-like printing medium on which variable information is printed using a toner to complete the laminated printed matter, characterized in that the apparatus has the following mechanisms: a fixer coating mechanism that applies a powder fixer to at least a specific surface of the sheet-like printing medium on which the variable information is printed using the toner; and a printing area setting mechanism that sets the area so that the printing area on which the variable information is printed is smaller than the coating area of ​​the powder fixer applied by the fixer coating mechanism." Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide printed materials, etc., in which the deviation of the pressing force of the pressing surface is reduced compared to the following situations: in printed materials formed by folding and pressing a recording medium with the surface where the image part and the pressure phase change layer are formed as the pressing surface, or by overlapping and pressing a recording medium with other recording media with the surface where the image part and the pressure phase change layer are formed as the pressing surface, the average thickness of the pressure phase change layer formed on the image part of the pressing surface of the recording medium is the same as the average thickness of the pressure phase change layer formed on the non-image part.

[0005] According to a first aspect of the present invention, a printed article is provided, wherein a recording medium is folded and pressed together with the surface on which an image portion and a pressure phase change layer are formed, or a recording medium is overlapped and pressed together with other recording media with the surface on which an image portion and a pressure phase change layer are formed, wherein the average thickness of the pressure phase change layer formed on the image portion on the pressing surface of the recording medium is greater than the average thickness of the pressure phase change layer formed on the non-image portion.

[0006] According to the second aspect of the present invention, the thicker the image portion, the thicker the pressure phase change layer formed on the image portion.

[0007] According to the third aspect of the present invention, the average thickness of the pressure phase change layer formed on the image portion is 0.5 μm or more and 5.0 μm or less, the average thickness of the image portion is greater than 0 μm and 5.0 μm or less, and when the thickness BR of the image portion is 0.5 μm or less, the following equations (1) to (3) are satisfied.

[0008] Equation (1): AR = X1 × BR + Y1

[0009] Equation (2): 2≦X1≦10

[0010] Equation (3): 0.5≦Y1≦2

[0011] (In Equation (1), AR represents the thickness (μm) of the pressure phase change layer formed on the image portion, and BR represents the thickness (μm) of the image portion. The thicknesses represented by AR and BR are the thickness of the pressure phase change layer directly above the image portion and the thickness of the image portion directly below the pressure phase change layer whose thickness has been determined.)

[0012] According to the fourth aspect of the present invention, the coverage of the pressure phase change layer formed on the above-mentioned image portion is 60% or more and 100% or less.

[0013] According to the fifth aspect of the present invention, the coverage of the pressure phase change layer formed in the non-image portion is 10% or more and 60% or less.

[0014] According to the sixth aspect of the present invention, the above-mentioned image section is a toner image section.

[0015] According to a seventh aspect of the present invention, the pressure phase change layer comprises: a styrene-based resin containing styrene and other vinyl monomers in its polymer composition; and a (meth)acrylate-based resin containing at least two (meth)acrylates in its polymer composition, wherein the (meth)acrylates account for 90% or more of the total polymer composition by mass. The pressure phase change layer has at least two glass transition temperatures, wherein the difference between the lowest and highest glass transition temperatures exhibited by the pressure phase change layer is 30°C or more.

[0016] According to the eighth aspect of the present invention, the mass percentage of styrene in all the polymer components of the above-mentioned styrene-based resin is 60% by mass or more and 95% by mass or less.

[0017] According to the ninth aspect of the present invention, among the at least two kinds of (meth)acrylates contained in the above-mentioned (meth)acrylate resin as a polymerizing component, the mass ratio of the two kinds with the highest mass proportion is 80:20 to 20:80.

[0018] According to a tenth aspect of the present invention, a method for manufacturing the above-mentioned printed matter is provided, comprising the following steps: a pressure phase change particle imparting step, imparting pressure phase change particles to a recording medium on which an image portion is formed; a fixing step, fixing at least the pressure phase change particles onto the recording medium to form a pressure phase change layer; and a pressing step, using the surface on which the image portion and the pressure phase change layer are formed as a pressing surface, folding and pressing the recording medium, or using the surface on which the image portion and the pressure phase change layer are formed as a pressing surface, overlapping and pressing the recording medium with other recording media, such that the amount of pressure phase change particles imparted to the image portion is greater than the amount of pressure phase change particles imparted to the non-image portion.

[0019] The effects of the invention

[0020] According to the first scheme described above, the pressure force deviation of the pressing surface is reduced compared to the following situation: in printed materials formed by folding and pressing the recording medium with the surface where the image part and the pressure phase change layer are formed as the pressing surface, or by overlapping and pressing the recording medium with other recording media with the surface where the image part and the pressure phase change layer are formed as the pressing surface, the average thickness of the pressure phase change layer formed on the image part of the pressing surface of the recording medium is the same as the average thickness of the pressure phase change layer formed on the non-image part.

[0021] According to the second embodiment described above, a printed matter is provided in which the pressure force deviation of the pressing surface is reduced compared to the case where the thickness of the pressure phase change layer formed on the image portion does not change with the thickness of the image portion.

[0022] According to the third scheme above, a printed matter is provided in which the pressure deviation of the pressing surface is reduced compared with the case where equations (1) to (3) are not satisfied.

[0023] According to the fourth embodiment above, a printed matter is provided in which the pressure force deviation of the pressing surface is reduced compared to the case where the coverage of the pressure phase change layer formed on the image section is less than 60%.

[0024] According to the fifth embodiment above, a printed matter is provided in which the pressure force deviation of the pressing surface is reduced compared to cases where the coverage of the pressure phase change layer formed on the non-image area is less than 10% or greater than 60%.

[0025] According to the sixth embodiment described above, a printed article is provided in which, even if the image portion is a toner image portion, the pressure deviation of the pressing surface is reduced compared to the following situation: in a printed article formed by folding and pressing a recording medium with the surface where the image portion and pressure phase change layer are formed as the pressing surface, or by overlapping and pressing a recording medium with other recording media with the surface where the image portion and pressure phase change layer are formed as the pressing surface, the average thickness of the pressure phase change layer formed on the image portion of the pressing surface of the recording medium is the same as the average thickness of the pressure phase change layer formed on the non-image portion.

[0026] According to the seventh embodiment above, a printed matter is provided that has a high bonding force compared to the following cases, where the comparison is made when: the pressure phase change layer contains a styrene-based resin that includes styrene and other vinyl monomers in the polymer composition and a (meth)acrylate-based resin that includes at least two (meth)acrylates in the polymer composition and the (meth)acrylates account for less than 90% by mass of the total polymer composition; or it has at least two glass transition temperatures and the difference between the lowest and highest glass transition temperatures among the glass transition temperatures exhibited by the pressure phase change particles is less than 30°C.

[0027] According to the eighth embodiment above, a printed matter is provided that has high bonding strength compared to cases where the mass proportion of styrene in the total polymer components of the styrene-based resin is less than 60% by mass or greater than 95% by mass.

[0028] According to the ninth embodiment above, a printed article is provided that has high pressing force compared to cases where the mass ratio of the two (meth)acrylates contained as polymerizing components in a (meth)acrylate resin is less than 80:20 or greater than 20:80.

[0029] According to the 10th embodiment above, a method for manufacturing printed matter is provided, wherein the pressure force deviation of the pressing surface is reduced compared to the following situation: in a method for manufacturing printed matter in which the surface on which the image portion and the pressure phase change layer are formed is used as the pressing surface and the recording medium is folded and pressed, or the surface on which the image portion and the pressure phase change layer are formed is used as the pressing surface and the recording medium is overlapped and pressed with other recording media, the average thickness of the pressure phase change layer formed on the image portion of the pressing surface of the recording medium is the same as the average thickness of the pressure phase change layer formed on the non-image portion. Attached Figure Description

[0030] Figure 1 This is a schematic partial cross-sectional view showing an example of a recording medium before lamination for producing printed matter according to this embodiment.

[0031] Figure 2This is a schematic diagram illustrating an example of a printing manufacturing system according to this embodiment.

[0032] Figure 3 This is a schematic diagram illustrating another example of a printing manufacturing system according to this embodiment. Detailed Implementation

[0033] The following describes embodiments of the present invention. These descriptions and examples are illustrative and do not limit the scope of the embodiments.

[0034] In the numerical ranges described in this specification, the upper or lower limit of a numerical range can be replaced with the upper or lower limit of other numerical ranges described in the specification. Furthermore, the upper or lower limit of the numerical ranges described in this specification can be replaced with the values ​​shown in the embodiments.

[0035] In this specification, the term "step" includes not only independent steps, but also steps that achieve the desired purpose, even if they cannot be clearly distinguished from other steps.

[0036] In this specification, while embodiments are described with reference to the accompanying drawings, the configuration of these embodiments is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in the figures are schematic, and the relative sizes of the components are not limited thereto.

[0037] Each component in this specification may contain two or more corresponding substances. In this specification, when referring to the amount of each component in the composition, if there are two or more corresponding substances in the composition, it refers to the total amount of those two or more substances present in the composition, unless otherwise stated.

[0038] In this specification, the particles corresponding to each component may comprise two or more types. In the case where two or more particles corresponding to each component are present in the composition, unless otherwise stated, the particle size of each component refers to the value for a mixture of the two or more particles present in the composition.

[0039] In this specification, the term "(meth)acrylic acid" can refer to either "acrylic acid" or "methacrylic acid".

[0040] In this specification, "peel strength" is an indicator of the degree of peeling between the opposing surfaces (i.e., the pressing surfaces) of the recording medium, and has essentially the same meaning as "crimping strength," which indicates the degree of pressing. It should be noted that, in the following text, when simply referred to as "peel strength," it refers to the peel strength between the opposing surfaces (i.e., the pressing surfaces) of the recording medium; conversely, when simply referred to as "crimping strength," it refers to the crimping strength between the opposing surfaces (i.e., the pressing surfaces) of the recording medium.

[0041] [printed matter]

[0042] In the printed matter of this embodiment, the surface on which the image portion and the pressure phase change layer are formed is used as the pressing surface and the recording medium is folded and pressed, or the surface on which the image portion and the pressure phase change layer are formed is used as the pressing surface and the recording medium is overlapped and pressed with other recording media. The average thickness of the pressure phase change layer formed on the image portion of the pressing surface of the recording medium is greater than the average thickness of the pressure phase change layer formed on the non-image portion.

[0043] Here, "other recording media" refers to recording media that use the surface where the image part and the pressure phase change layer are formed as the bonding surface.

[0044] Printed materials made by folding and pressing recording media together, as well as printed materials made by overlapping and pressing recording media with other recording media together, are also called "pressed printed materials".

[0045] The printed material of this embodiment, with the above-described configuration, reduces the deviation of the pressing force on the pressing surface. The reason for this is presumably as follows.

[0046] The following printed materials are well known: printed materials made by folding and pressing a recording medium with a surface coated with UV varnish or water-based varnish as the bonding surface; or printed materials made by overlapping and pressing a recording medium with other recording media with a surface coated with UV varnish or water-based varnish as the bonding surface.

[0047] In addition, the following types of printed matter are also known: printed matter formed by folding and pressing a recording medium with the surface having an image portion and a pressure phase change layer as the pressing surface; or printed matter formed by overlapping and pressing a recording medium with other recording media with the surface having an image portion and a pressure phase change layer as the pressing surface.

[0048] However, in these printed materials, deviations in the bonding force of the bonding surfaces can occur, potentially leading to localized damage or peeling. This is believed to be caused by a decrease in the bonding force on the image area of ​​the bonding surface.

[0049] Therefore, in the printed matter of this embodiment, the average thickness of the pressure phase change layer formed on the image portion of the pressing surface of the recording medium is greater than the average thickness of the pressure phase change layer formed on the non-image portion. This suppresses the reduction of the pressing force on the image portion of the pressing surface, thus suppressing deviations in the pressing force of the pressing surface.

[0050] Based on the above, it can be inferred that the printed matter of this embodiment, through the above-described configuration, can reduce the pressure deviation of the pressing surface.

[0051] Here, printed materials made by pressing together three folds such as Z-folds and two folds such as V-folds have the advantage of increased information content. However, since the pressing surface has four sides, the deviation of the pressing force on the pressing surface has a significant impact, and it is particularly easy to cause local damage or peeling.

[0052] However, even if the printed matter of this embodiment is a printed matter formed by pressing with three folds such as Z-folds, the pressure deviation of the pressing surface can be reduced, thereby suppressing local damage or peeling.

[0053] The details of the printed matter according to this embodiment will be described below.

[0054] (Image section, pressure phase change layer, and recording medium)

[0055] Examples of image units include toner image units formed using electrophotography on a recording medium and ink image units formed using inkjet printing. In particular, the presence of a toner image unit reduces the bonding force and easily leads to bonding force deviation on the bonding surface. However, in this embodiment, bonding force deviation on the bonding surface can be suppressed.

[0056] Pressure phase change layers can be exemplified by layers formed by applying pressure phase change particles to a recording medium and then fixing it.

[0057] Recording media can include, for example, paper, coated paper with resin coating, cloth, non-woven fabric, resin film, resin sheet, etc.

[0058] It should be noted that details regarding the image section and the pressure phase change layer will be explained in detail in the printing method described later.

[0059] (Thickness of the pressure phase change layer)

[0060] In the printed matter of this embodiment, the average thickness of the pressure phase change layer formed on the image portion of the pressing surface of the recording medium is greater than the average thickness of the pressure phase change layer formed on the non-image portion (see reference). Figure 1 ).

[0061] Figure 1In the diagram, G10 represents the image section, PL10 represents the pressure phase change layer formed on the non-image section, PL12 represents the pressure phase change layer formed on the image section, T10 represents the thickness of the pressure phase change layer formed on the non-image section, and T12 represents the thickness of the pressure phase change layer formed on the image section.

[0062] It should be noted that, Figure 1 A schematic partial cross-sectional view is shown, illustrating an example of a recording medium before crimping for producing printed matter via Z-folding.

[0063] Specifically, from the perspective of suppressing the deviation of the pressing force on the pressing surface, it is preferable that the thickness of the pressure phase change layer formed on the image section increases as the thickness of the image section increases. This is because the greater the thickness of the image section, the lower the pressing force tends to be.

[0064] More specifically, it is preferable that the average thickness of the pressure phase change layer formed on the image section is 0.5 μm or more and 5.0 μm or less, the average thickness of the image section is greater than 0 μm and 5.0 μm or less, and the thickness BR of the image section is 0.5 μm or less, satisfying the following equations (1) to (3).

[0065] Equation (1): AR = X1 × BR + Y1

[0066] Equation (2): 2≦X1≦10

[0067] Equation (3): 0.5≦Y1≦2

[0068] (In Equation (1), AR represents the thickness (μm) of the pressure phase change layer formed on the image section, and BR represents the thickness (μm) of the image section. The thicknesses represented by AR and BR are the thickness of the pressure phase change layer directly above the image section and the thickness of the image section directly below the pressure phase change layer whose thickness has been calculated.)

[0069] When the average thickness of the pressure phase change layer formed on the image section and the average thickness of the image section are within the above range and the thickness BR of the image section is 0.5 μm or less, the reduction of the pressure force on the image section can be suppressed by satisfying equations (1) to (3).

[0070] When the thickness of the image section is greater than 0.5 μm, the increase in pressure reaches saturation, so the thickness of the pressure phase change layer can remain unchanged.

[0071] Here, from the perspective of suppressing the deviation of the pressing force on the pressing surface, in formula (2), the value of X1 is preferably 2.5 or more and 7 or less, and more preferably 3 or more and 5 or less.

[0072] From the same perspective, in equation (3), the value of Y1 is preferably 0.7 or more and 1.4 or less, and more preferably 0.8 or more and 1.3 or less.

[0073] The thickness of the pressure phase change layer and the thickness of the image section were measured as follows.

[0074] Release the pressure and unfold the printed material (that is, peel the pressed surfaces of the printed material from each other), and take a sample from the unfolded material with the cross-section as the observation surface.

[0075] Using a specimen, cut it in such a way that the image portion, which serves as the cross-sectional observation area, is located at the end, and observe the cross-section using a laser microscope.

[0076] Furthermore, the thickness of the pressure phase change layer at five locations was measured, and the average value was taken as the "thickness of the pressure phase change layer formed on the non-image area".

[0077] The thickness of the image region was measured at 5 locations, and the average value was taken as the "average thickness of the image region".

[0078] In addition, the following method is used to determine whether equation (1) is satisfied: the thickness of the image part and the pressure phase change layer formed on the image part are measured at three locations with different thicknesses. The thickness of the pressure phase change layer is plotted on the vertical axis and the thickness of the image part is plotted on the horizontal axis. A curve is drawn to determine whether equation (1) is satisfied.

[0079] (Covering ratio of the pressure phase change layer)

[0080] The coverage of the pressure phase change layer formed on the image section is preferably 60% or more and 100% or less.

[0081] By ensuring the coverage ratio of the pressure phase change layer formed on the image section is within the aforementioned range, the pressure phase change layer can adequately cover the paper surface. Therefore, it is easier to suppress pressure deviation on the pressing surface.

[0082] The coverage of the pressure phase change layer formed on the non-image section is preferably 10% to 60%, more preferably 15% to 55%, and even more preferably 20% to 50%.

[0083] By ensuring the coverage ratio of the pressure phase change layer formed on the non-image area is within the aforementioned range, the pressure phase change layer can adequately cover the paper surface. Therefore, it is easier to suppress pressure deviation on the pressing surface.

[0084] The coverage of the pressure phase change layer was determined as follows.

[0085] Samples were taken from the areas where the pressure phase change layer was formed, and images of the state were obtained using a SEM microscope or similar device, magnified 1000 times. The pressure phase change layer was extracted by binarizing the obtained images, and its proportion in the overall structure was determined. This measurement was performed at three points, and the average value of the three points was taken as the coverage rate.

[0086] (Printed materials)

[0087] Examples of printed materials in this embodiment include: printed materials formed by folding and pressing a recording medium with the surface having an image portion and a pressure phase change layer as the pressing surface (printed materials formed by pressing three folds such as Z-folds, printed materials formed by pressing two folds such as V-folds), and printed materials formed by overlapping and pressing a recording medium with other recording media with the surface having an image portion and a pressure phase change layer as the pressing surface.

[0088] As a type of printed material in this embodiment, a crimped postcard can be representatively shown.

[0089] [Methods and systems for manufacturing printed materials]

[0090] The method for manufacturing printed matter according to this embodiment includes the following steps:

[0091] The pressure phase change particle application step involves applying pressure phase change particles to a recording medium on which an image section is formed; the fixing step involves fixing at least the pressure phase change particles onto the recording medium to form a pressure phase change layer; and

[0092] In the pressing step, the surface on which the image section and the pressure phase change layer are formed is used as the pressing surface and the recording medium is folded and pressed, or the surface on which the image section and the pressure phase change layer are formed is used as the pressing surface and the recording medium is overlapped and pressed with other recording media.

[0093] In the method for manufacturing printed matter according to this embodiment, in order to manufacture the printed matter of this embodiment, the amount of pressure phase change particles applied to the image area is greater than the amount of pressure phase change particles applied to the non-image area.

[0094] The method for manufacturing printed matter according to this embodiment is carried out using the printing matter manufacturing system of this embodiment shown below.

[0095] The printed matter manufacturing system of this embodiment includes:

[0096] The pressure phase change particle imparting unit stores pressure phase change particles and imparts pressure phase change particles to a recording medium on which an image unit is formed.

[0097] The fixing section fixes at least pressure phase change particles onto the recording medium to form a pressure phase change layer; and

[0098] The pressing section uses the surface where the image section and the pressure phase change layer are formed as the pressing surface to fold and press the recording medium; or it uses the surface where the image section and the pressure phase change layer are formed as the pressing surface to overlap and press the recording medium with other recording media.

[0099] It should be noted that the image section is the area where a color image is formed, and there is no particular limitation as long as the image contains pigments. Examples of image sections include images where the average transmittance of light in the visible region (400 nm to 700 nm) is less than 90%. The average transmittance of the aforementioned light in the color image is preferably less than 50%, more preferably less than 10%. The aforementioned average transmittance is measured using a spectrophotometer V700 (manufactured by Nippon Spectrophotometer Co., Ltd.).

[0100] "Pressure phase change layer" and "pressure phase change particle" refer to layers and particles that undergo phase change due to pressure. Specifically, they refer to layers and particles that satisfy Equation 1 below.

[0101] Equation 1···10℃≦T1-T2

[0102] In Equation 1, T1 is the temperature at which the viscosity is 10000 Pa·s under a pressure of 1 MPa, and T2 is the temperature at which the viscosity is 10000 Pa·s under a pressure of 10 MPa. The methods for determining temperatures T1 and T2 are described below.

[0103] The "pressure phase change layer" and "pressure phase change particles" contain the following resins: a styrene-based resin containing styrene and other vinyl monomers in its polymer composition, and a (meth)acrylate-based resin containing at least two (meth)acrylates in its polymer composition, wherein the (meth)acrylates account for 90% or more of the total polymer composition by mass; and the "pressure phase change layer" and "pressure phase change particles" have at least two glass transition temperatures, wherein the difference between the lowest and highest glass transition temperatures exhibited by the "pressure phase change layer" and "pressure phase change particles" is preferably 30°C or more. The reasons are as follows.

[0104] Typically, styrene-based resins and (meth)acrylate-based resins have low compatibility, so they can be considered to be contained in the particles in a phase-separated state. Furthermore, it is known that when pressure is applied to the layers and particles, the (meth)acrylate-based resin, which has a lower glass transition temperature, first fluidizes, and this fluidization extends to the styrene-based resin, causing both resins to become fluidized. It is also known that when the two resins in the layers and particles are fluidized under pressure and then solidify under reduced pressure, phase separation occurs again due to their low compatibility.

[0105] In methacrylate-based resins containing at least two types of methacrylates in their polymer composition, at least two types of ester groups are bonded to the main chain. Therefore, compared to homopolymers of methacrylates, the molecular arrangement (order) in the solid state is lower, suggesting that they are more prone to fluidization under pressure. Furthermore, when the mass percentage of methacrylates in the total polymer composition is 90% or more, the high density of at least two ester groups further reduces the molecular arrangement in the solid state, thus suggesting even greater efficiency in fluidization under pressure.

[0106] Therefore, it is speculated that the aforementioned "pressure phase change layer" and "pressure phase change particles" are prone to fluidization due to pressure, that is, they are prone to phase change due to pressure.

[0107] Furthermore, methacrylate-based resins containing at least two types of methacrylates in their polymer composition, with the methacrylates accounting for more than 90% by mass of the total polymer composition, exhibit low molecular arrangement even upon re-curing. Therefore, it is speculated that the phase separation between the methacrylate-based resin and the styrene-based resin is minimal. It is further speculated that the smaller the phase separation between the styrene-based resin and the methacrylate-based resin, the higher the uniformity of the fixing surface on the substrate, and the better the compressibility resulting from pressing.

[0108] Therefore, it is speculated that the "pressure phase change layer" and "pressure phase change particles" have excellent compressibility due to compression bonding.

[0109] In the following text, the steps of the printing method of this embodiment will be described together with the mechanisms of the printing manufacturing system of this embodiment.

[0110] <Pressure phase change particle application steps and pressure phase change particle application section>

[0111] In the application step, pressure phase change particles are applied to the recording medium on which the image section is formed in the pressure phase change particle application section (hereinafter also referred to as the "application section").

[0112] There are no particular restrictions on the pressure phase change particle delivery mechanism in the delivery section, as long as it is a mechanism that can deliver pressure phase change particles to the target delivery position at the target delivery amount on the surface of the recording medium.

[0113] Specifically, pressure phase change particle imparting mechanisms include blowing methods that use pressure phase change particles, coating methods that apply pressure phase change particles, and electrophotographic methods that use pressure phase change particles as toners.

[0114] (Assigning position to pressure-dependent phase change particles)

[0115] The pressure phase change particles can be assigned to the entire surface of the recording medium or a portion thereof.

[0116] Regarding the placement of pressure phase change particles on the recording medium, the pressure phase change particles are placed in the image and non-image portions of the pressure-contact surface of the recording medium.

[0117] Here, as described below, the pressure phase change particles are preferably transparent.

[0118] By making the pressure phase change particles transparent, the visibility of the image section can be ensured even when the pressure phase change particles are applied to the image section of the recording medium to form a pressure phase change layer.

[0119] It should be noted that "transparent" means that the average transmittance of the region to which the pressure-transformed phase-change particles are applied is 10% or more, preferably 50% or more, more preferably 80% or more, and even more preferably 90% or more.

[0120] The average transmittance mentioned above was measured using a V700 spectrophotometer (manufactured by Japan Spectrophotometer Co., Ltd.).

[0121] (The state imparted by pressure-induced phase change particles)

[0122] The state in which pressure phase change particles are given can be either a state in which the particle shape is retained or a state in which the pressure phase change particles are aggregated to form a layer. From the perspective of obtaining sufficient peel strength (or compressibility generated by compression), a layered state is preferred.

[0123] The layer produced by pressure-phase-change particles can be a continuous layer or a discontinuous layer.

[0124] The amount of pressure-sensitive phase-change particles imparted is preferably 0.5 g / m³, from the perspective of obtaining compressibility resulting from sufficient compressibility. 2 Above 8.0g / m 2 The following, or more preferably, is 0.8 g / m 2 Above 6.0g / m 2 The following, and more preferably, is 1.0 g / m 2 The above 4.5g / m 2 the following.

[0125] In this case, the amount of pressure phase change particles imparted to the image section is greater than the amount of pressure phase change particles imparted to the non-image section.

[0126] (Imparting pressure-dependent phase change particles)

[0127] As mentioned above, there are no particular limitations on the mechanism for applying pressure phase change particles (PPPs) as long as the PPPs can be applied to the target application location. Specifically, this includes methods such as blowing PPPs, coating PPPs, and electrophotographic methods using PPPs as toners. PPPs can be applied directly onto the recording medium or by roller coating. There are no particular limitations on the method of applying PPPs as long as they can be applied to the recording medium.

[0128] As an example of a part that imparts pressure phase change particles to a recording medium, as described above, examples include a part for blowing pressure phase change particles, a part for coating pressure phase change particles, and a part for electrophotographic methods that use pressure phase change particles as toners.

[0129] The imparting steps based on the blowing method include, for example, the step of preparing a dispersion in which pressure phase change particles are dispersed; the step of blowing the dispersion onto a recording medium; and the step of drying the dispersion blown onto the recording medium.

[0130] In addition, the delivery unit based on the blowing method includes, for example, a blowing mechanism for blowing a dispersion containing pressure phase change particles to a recording medium, and a drying mechanism for drying the dispersion blown onto the recording medium.

[0131] As a blowing mechanism, a sprayer can be cited as an example. As a drying mechanism, a hot air supply device, a near-infrared heater, or a laser irradiation device can be cited as an example.

[0132] The application steps based on the coating method may include, for example, the step of coating pressure phase change particles onto a recording medium. In this coating method, a coating liquid in which pressure phase change particles are dispersed can be used. The application steps based on a coating method using a coating liquid may include, for example, the steps of: preparing a coating liquid in which pressure phase change particles are dispersed; applying the coating liquid onto the recording medium; and drying the coating liquid applied to the recording medium.

[0133] Additionally, the application unit based on the coating method may include, for example, a coating mechanism for coating pressure phase change particles onto the recording medium. The application unit based on a coating method using a coating liquid may include, for example, a coating mechanism for coating the coating liquid onto the recording medium, and a drying mechanism for drying the coating liquid applied to the recording medium.

[0134] As a coating mechanism, a roller can be used, for example.

[0135] The electrophotographic method includes, for example, a charging step for charging the surface of an image holder; an electrostatic image forming step for forming an electrostatic image on the charged surface of the image holder; a developing step for developing the electrostatic image formed on the surface of the image holder into a pressure phase change particle region using an electrostatic image developer containing pressure phase change particles; and a transfer step for transferring the pressure phase change particle region formed on the surface of the image holder to the surface of a recording medium.

[0136] Additionally, the electrophotographic-based imprinting unit includes, for example: an image holder; a charging mechanism for charging the surface of the image holder; an electrostatic image forming mechanism for forming an electrostatic image on the charged surface of the image holder; a developing mechanism for storing an electrostatic image developer containing pressure phase change particles and developing the electrostatic image formed on the surface of the image holder into a pressure phase change particle region using the electrostatic image developer; and a transfer mechanism for transferring the pressure phase change particle region formed on the surface of the image holder to the surface of the recording medium.

[0137] The portion of the electrophotographic applicator that includes the developing mechanism can be a cartridge structure (so-called a processing cartridge) that is loaded and unloaded from the particle loading device. For example, a processing cartridge is suitable for use that includes a developing mechanism for storing an electrostatic image developer containing pressure phase-change particles, and is loaded and unloaded from the particle loading device.

[0138] Both the electrophotographic method and the electrophotographic unit can use an electrophotographic image forming method and an image forming apparatus, and can use known steps and mechanisms employed in the electrophotographic image forming method and image forming apparatus.

[0139] Alternatively, the electrophotographic method and the application unit can employ an intermediate transfer method. In the intermediate transfer method, for example, the pressure-phase-change particle region formed on the surface of the image holder is temporarily transferred to the surface of an intermediate transfer body, and then finally transferred from the surface of the intermediate transfer body to the surface of the recording medium.

[0140] Furthermore, the electrophotographic method and the applying unit may include, for example, a step and mechanism for cleaning the surface of the image holder, and a device having a de-electrostatic mechanism for removing electricity by irradiating the surface of the image holder with de-electrostatic light, and other mechanisms and steps other than those mentioned above.

[0141] When using a recording medium having an image portion formed thereon, pressure phase change particles can be applied to the recording medium having the image portion formed thereon, and the image formation step and the application step of forming the image portion on the recording medium can be performed continuously.

[0142] As a method for continuously performing the image forming step and the assignment step, examples include performing the assignment step after the image forming step using an inkjet recording method, and performing the image forming step and the assignment step using an electrophotographic method. Specifically, for example, a method can be used to form a composite image portion on the surface of a recording medium using both the image forming pigment (preferably colored ink) from the image forming step and the pressure phase change particles from the assignment step.

[0143] <Fixing Steps and Fixing Section>

[0144] In the fixing step, at least pressure phase change particles are fixed onto the recording medium to form a pressure phase change layer.

[0145] Specifically, in the fixing step, for example, the pressure-bearing phase change particles applied to the recording medium are heated in the fixing section.

[0146] It should be noted that when an unfixed toner image portion is formed on the recording medium as the image portion, the fixing step can be a step of fixing the unfixed toner image portion together with the pressure phase change particles.

[0147] There are no particular restrictions on the mechanism for heating pressure phase change particles (hereinafter also referred to as "particle heating mechanism"), as long as it is a mechanism capable of heating pressure phase change particles applied to the recording medium.

[0148] As a mechanism for heating pressure-phase change particles (particle heating mechanism), it can be either a contact method or a non-contact method.

[0149] Contact-type particle heating mechanisms include methods that heat components such as rollers, belts, and pads and then bring these heated components into contact with pressure-phase-change particles.

[0150] Examples of non-contact particle heating mechanisms include: a method in which a recording medium having formed a color image and being imparted with pressure phase change particles passes through an area heated by a heater, oven, or the like; and a method in which pressure phase change particles are heated by irradiation light from a halogen lamp, xenon lamp, or the like.

[0151] In terms of being able to heat the pressure phase change particles while suppressing their movement and shedding, the fixing step preferably uses a particle heating mechanism with a contact method.

[0152] That is, the particle heating mechanism is preferably a contact-type particle heating mechanism.

[0153] (Heating of pressure-induced phase change particles using contact method)

[0154] When heating pressure phase change particles by contact, the set temperature of the component in contact with the pressure phase change particles (also called the contact component) can be such that the pressure phase change particles can be plasticized. Considering the heating efficiency of the pressure phase change particles, for example, it is preferably 120°C to 250°C, more preferably 130°C to 200°C, and even more preferably 150°C to 180°C.

[0155] Here, the set temperature of the contact component refers to the target value of the surface temperature of the contact component in contact with the pressure phase change particles.

[0156] As a contact component, there are no particular limitations as long as it is a component with a surface that can be heated to the aforementioned set temperature; for example, rollers, belts, pads, etc. can be cited.

[0157] The fixing step is preferably a step of heating and pressurizing the pressure phase change particles.

[0158] By heating and pressurizing the pressure phase change particles, the surface of the pressure phase change particles (e.g., the surface of the pressure phase change layer) can be made smooth.

[0159] The pressure applied to the phase change particles during the fixing step can be exemplified by the pressure applied by a fixing mechanism based on an electrophotographic method.

[0160] Examples of mechanisms (also known as heating and pressurizing components) for heating and pressurizing phase change particles can be found below.

[0161] Examples include: heated and pressurized roller pairs, which are two roller pairs in contact, with at least one roller being heated so that a recording medium with a color image and pressure-bearing phase change particles is inserted between the roller pairs and subjected to heat and pressure; heated and pressurized components, which are components with rollers and belts in contact, with at least one of the rollers and belts being heated so that a recording medium with a color image and pressure-bearing phase change particles is inserted between these components and subjected to heat and pressure; heated and pressurized belt pairs, which are two belt pairs in contact, with at least one belt being heated so that a recording medium with a color image and pressure-bearing phase change particles is inserted between the belt pairs and subjected to heat and pressure; and so on.

[0162] <Crimping steps and crimping parts>

[0163] In the lamination step, the surface where the image portion and the pressure phase change layer are formed is used as the lamination surface, and the recording medium is folded and laminationd; or the surface where the image portion and the pressure phase change layer are formed is used as the lamination surface, and the recording medium is overlapped and laminationd with other recording media. It should be noted that, in the following text, the recording medium where the image portion and the pressure phase change layer are formed will also be referred to as the "post-lamination recording medium".

[0164] Specifically, in the pressing step, pressure is applied along the thickness direction to the following laminates: a laminate formed by folding a recording medium (i.e., a post-application recording medium) with an image portion and a pressure phase change layer formed in between, with the pressure phase change layer sandwiched in between; or a laminate formed by overlapping a post-application recording medium with an image portion and a pressure phase change layer formed in between with other recording media sandwiched in between, with the pressure phase change layer sandwiched in between.

[0165] The folding shape of the recording medium after application can be, for example, folded in half, three-folded, four-folded, or only partially folded. It should be noted that, in this case, a pressure phase change layer for fixing using a fixing step is disposed on two opposing surfaces of the recording medium after application.

[0166] Regarding the overlapping configuration of the applied recording medium with other recording media, there are configurations such as overlapping one other recording medium onto the applied recording medium, or overlapping one other recording medium at each of multiple locations on the applied recording medium. Here, the other recording medium can be a recording medium with an image pre-formed on one or both sides, a recording medium without an image, or a pre-made laminated print. It should be noted that this achieves a state where pressure-modified phase-change particles, fixed by the fixing step, are arranged on two opposing surfaces of the applied recording medium and the other recording medium.

[0167] There are no particular restrictions on the mechanism for pressurizing the laminate (laminate pressurizing mechanism), as long as it is a mechanism that can press the laminate along the thickness direction. It can be a mechanism that inserts the laminate between separate roller pairs, or a mechanism that uses a press to press the laminate.

[0168] In the pressing step, it is preferable to insert the laminate between pairs of rollers separated by a gap C and press the laminate along the thickness direction.

[0169] That is, the laminate pressing mechanism is preferably a mechanism that inserts the laminate between roller pairs separated by a distance C and presses the laminate along the thickness direction.

[0170] Here, the interval C can be determined as appropriate from the perspective of obtaining the target peel strength (or the compressibility generated by the pressing) based on the thickness of the pressurized laminate. For example, it is preferably 0.01 mm or more and 0.40 mm or less, more preferably 0.05 mm or more and 0.30 mm or less, and even more preferably 0.10 mm or more and 0.25 mm or less.

[0171] (Conditions for pressurization)

[0172] The pressure applied along the thickness direction of the laminate (hereinafter also referred to as "pressing pressure") is preferably 48 MPa or more and 120 MPa or less, more preferably 60 MPa or more and 110 MPa or less, and even more preferably 80 MPa or more and 100 MPa or less, measured by the maximum pressure gauge.

[0173] By applying a crimping pressure of 48 MPa or higher, it is easy to obtain the crimping properties resulting from sufficient crimping. Furthermore, by applying a crimping pressure of 120 MPa or lower, it is easier to suppress damage and deformation of the recording medium during pressurization.

[0174] The crimping pressure is measured using a commercially available pressure measuring membrane. Specifically, a suitable pressure measuring membrane is the Prescale pressure measuring film manufactured by Fuji Film Co., Ltd. It should be noted that the maximum pressure mentioned above represents the maximum value of the pressure change during the period when pressure is applied to the laminate using a laminate pressurization mechanism.

[0175] Commercially available devices can be used as pressurization mechanisms for laminated bodies. Specifically, examples include PRESSLE LEADA, PRESSLE CORE, and PRESSLE Bee manufactured by ToppanForms Co., Ltd., and PS-500H, PS-500, EX-4100WI, EX-4100W, EX-4100 / 4150, and PS-100 manufactured by DUPLO SEIKO Co., Ltd.

[0176] The crimping process can be performed without heating or while heating is in progress.

[0177] That is, the lamination pressurization mechanism may not have a heating mechanism and pressurize the lamination without heating, or it may have a heating mechanism and pressurize the lamination while heating.

[0178] In addition to the imposition step, fixing step, and lamination step, the printing method of this embodiment may also include other steps.

[0179] Other steps include forming an image portion on a recording medium before applying pressure phase-change particles, and trimming a recording medium after fixing or a laminate after lamination to a target size.

[0180] <An Example of a Manufacturing System and Manufacturing Method>

[0181] The following describes an example of the printing manufacturing system of this embodiment to illustrate the printing manufacturing method of this embodiment, but this embodiment is not limited thereto.

[0182] Figure 2This is a schematic diagram illustrating an example of a printing manufacturing system according to this embodiment. Figure 2 The printed matter manufacturing system shown includes: a printing unit 500, which simultaneously forms an image portion and applies pressure-sensitive phase-change particles to a recording medium using an inkjet method; and a pressing unit 200 disposed downstream of the printing unit 500. Arrows indicate the direction of transport of the recording medium.

[0183] In the printing unit 500, as an example of an image forming unit, an inkjet recording head 520 is provided to form an image by ejecting ink droplets onto a recording medium P.

[0184] As observed from the inkjet recording head 520, a particle application device 518 is arranged downstream of the recording medium P in the transport direction (arrow direction in the figure) to apply pressure phase change particles 516 to the surface of the recording medium P. This is an example of applying pressure phase change particles to the application section of the recording medium by coating.

[0185] In addition, the printing mechanism 500 includes: a recording medium storage section (not shown) for storing a recording medium P; a transport section (not shown) for transporting the recording medium P stored in the recording medium storage section; a fixing device 564 for fixing ink droplets and pressure phase change particles 516 applied to the recording medium P onto the recording medium P; and a recording medium discharge section (not shown) for discharging the recording medium P with ink droplets and pressure phase change particles 516 fixed by the fixing device 564.

[0186] The fixing device 564 includes a heating roller 564A with a built-in heating source and a pressure roller 564B disposed opposite to the heating roller 564A.

[0187] The particle delivery device 518 is a device for supplying pressure phase change particles 516 to the surface of the recording medium P and forming a pressure phase change particle region 516A on the surface of the recording medium P.

[0188] In the particle application device 518, a supply roller 518A is provided in the part opposite to the recording medium P, which applies pressure phase change particles 516 to the corresponding coating area.

[0189] In the particle feeding device 518, pressure phase change particles 516 are supplied to the supply roller 518A (conductive roller), and the amount of pressure phase change particles 516 supplied to the recording medium P (i.e., the layer thickness of the pressure phase change particle region 516A supplied in layers on the recording medium P) is adjusted.

[0190] The inkjet recording head 520 comprises: an inkjet recording head 520Y that ejects yellow ink droplets from its nozzles, an inkjet recording head 520M that ejects magenta ink droplets from its nozzles, an inkjet recording head 520C that ejects cyan ink droplets from its nozzles, and an inkjet recording head 520K that ejects black ink droplets from its nozzles. These inkjet recording heads 520 are driven by piezoelectric methods, thermal sensing methods, or the like.

[0191] The inkjet recording head 520 can be a recording head whose recording width is set above the recording area and which ejects droplets onto the recording medium P to record an image without moving in a direction intersecting the transport direction of the recording medium P. Alternatively, it can be a recording head that ejects droplets onto the recording medium P to record an image while moving in a direction intersecting the transport direction of the recording medium P.

[0192] Furthermore, regarding the ink ejected by the inkjet recorder 520, both water-based and oil-based inks can be used; from an environmental perspective, water-based inks are more suitable. Water-based inks, in addition to recording materials such as pigments, also contain ink solvents (such as water and water-soluble organic solvents). Other additives may also be included as needed.

[0193] In the printing unit 500, the recording medium P is first transported from the recording medium storage unit via a transport unit. When it reaches the position of the inkjet recording head 520, the inkjet recording head 520 applies droplets of ink of various colors onto the recording medium P to form an image section. Next, when the recording medium P with the image section formed is transported via the transport unit and reaches the position of the particle application device 518, the particle application device 518 applies pressure phase change particles 516 onto the recording medium P to form a pressure phase change particle region 516A.

[0194] The recording medium P, having formed the image section and the pressure phase change particle region 516A, is then conveyed to the fixing device 564 (an example of a fixing unit). The pressure applied to the recording medium P by the fixing device 564 can be lower than the pressure applied to the recording medium P by the pressurizing device 230, specifically, preferably 0.2 MPa or more and 1 MPa or less. The surface temperature of the recording medium P when heated by the heating roller 564A of the fixing device 564 is preferably 150°C or more and 220°C or less, more preferably 155°C or more and 210°C or less, and even more preferably 160°C or more and 200°C or less.

[0195] As described above, by passing the recording medium P through the printing mechanism 500, it becomes a post-recording medium P1 with an image section formed and pressure-transformed particles imparted to it.

[0196] Next, the recording medium P1 is transferred to the crimping mechanism 200.

[0197] In the printing manufacturing system of this embodiment, the printing mechanism 500 and the pressing mechanism 200 can be close together or separated.

[0198] When the printing mechanism 500 is separated from the pressing mechanism 200, the printing mechanism 500 and the pressing mechanism 200 can be connected, for example, by a transport mechanism (e.g., a belt conveyor) that transports the recording medium P1 after it is applied.

[0199] The crimping mechanism 200 includes a folding device 220 and a pressing device 230, and is a mechanism for folding and crimping the recording medium P1 after it has been applied.

[0200] The folding device 220 folds the recording medium P1 after it has been applied by the device to create the folded recording medium, i.e., the laminate P2.

[0201] It should be noted that in the folded recording medium (i.e., the laminate), at least a portion of at least one of the two opposing surfaces of the recording medium is provided with pressure-transformed particles imparted by the printing mechanism 500.

[0202] The crimping mechanism 200 may also have an overlapping device to overlap the applied recording medium with other recording media instead of the folding device 220.

[0203] In a recording medium, i.e. a laminate, obtained by using an overlay device, at least a portion of at least one of two opposing surfaces of the recording medium and other recording media after application is provided with pressure-induced phase-change particles applied by a printing mechanism 500.

[0204] The laminate P2, which leaves the folding device 220 (or overlapping device), is conveyed toward the pressurizing device 230.

[0205] The pressurizing device 230 includes, for example, a pair of pressurizing components (i.e., pressurizing rollers 231 and 232). Pressurizing rollers 231 and 232 are separated, for example, by a distance C, and pressure is applied along the thickness direction of the laminate P2 by passing the laminate P2 between the rollers. The pair of pressurizing components in the pressurizing device 230 is not limited to a combination of pressurizing rollers, but can also be a combination of pressurizing rollers and a pressurizing belt, or a combination of pressurizing belts.

[0206] The pressurizing device 230 may or may not have a heating source (e.g., a halogen heater) for heating the laminate P2. When the pressurizing device 230 has a heating source, the surface temperature of the laminate P2 when heated by the heating source is preferably 30°C to 120°C, more preferably 40°C to 100°C, and even more preferably 50°C to 90°C. It should be noted that when the pressurizing device 230 does not have a heating source, it is possible that the temperature inside the pressurizing device 230 may reach or exceed the ambient temperature due to heat dissipation from the motor or other components of the pressurizing device 230.

[0207] When pressure is applied to the laminate P2 through the pressurizing device 230, the folded surfaces are fixed by fluidized pressure phase change particles to produce a press-printed material P3.

[0208] In the produced overprinted material P3, the opposing surfaces are partially or completely fixed.

[0209] The completed press-printed material P3 is delivered from the pressurizing device 230.

[0210] The first method of press-printed P3 is to press-print a folded recording medium by fixing the opposite surfaces with pressure phase-change particles.

[0211] The press-printed material P3 is manufactured by a printing manufacturing system equipped with a folding device 220.

[0212] The second method of lamination printing P3 is lamination printing produced by fixing two or more overlapping recording media on opposite surfaces with pressure phase change particles.

[0213] The overprinted print P3 is manufactured using an overprinted print manufacturing system equipped with an overlay device.

[0214] The printing manufacturing system of this embodiment is not limited to a device that continuously conveys the laminate P2 from the folding device 220 (or overlapping device) to the pressurizing device 230.

[0215] The printing manufacturing system of this embodiment can also be an apparatus in the following manner: storing the laminate P2 that has left the folding device 220 (or overlapping device), and after the storage amount of the laminate P2 reaches a preset amount, transferring the laminate P2 to the pressurizing device 230.

[0216] In the printing manufacturing system of this embodiment, the folding device 220 (or overlapping device) and the pressurizing device 230 can be close together or separated. When the folding device 220 (or overlapping device) and the pressurizing device 230 are separated, the folding device 220 (or overlapping device) and the pressurizing device 230 are connected, for example, through a conveying mechanism (e.g., a belt conveyor) that conveys the laminate P2.

[0217] Furthermore, the printing manufacturing system of this embodiment may include a cutting mechanism for cutting the recording medium to a preset size. The cutting mechanism may be, for example, the following: a cutting mechanism disposed between the printing mechanism 500 and the pressing mechanism 200 that cuts off areas that are part of the applied recording medium P1 and are not provided with pressure phase change particles; a cutting mechanism disposed between the folding device 220 and the pressing device 230 that cuts off areas that are part of the laminate P2 and are not provided with pressure phase change particles; a cutting mechanism disposed downstream of the pressing mechanism 200 that cuts off areas that are part of the pressed printed material P3 and are not fixed by pressure phase change particles; and so on.

[0218] It should be noted that, depending on the cutting mechanism, a portion of the area containing pressure phase change particles can also be cut off.

[0219] The printing system of this embodiment is not limited to a single-page device. The printing system of this embodiment can also be a device that forms a strip-shaped laminated printed product by performing a configuration step and a lamination step on a strip-shaped recording medium, and then cuts the strip-shaped laminated printed product to a preset size.

[0220] Figure 3 This is a schematic diagram illustrating an example of a printing manufacturing system according to this embodiment. Figure 3 The printed matter manufacturing system shown includes: a printing mechanism 300 that simultaneously forms an image portion on a recording medium and imparts pressure-phase-change particles; and a pressing mechanism 200 disposed downstream of the printing mechanism 300.

[0221] The printing mechanism 300 is a five-drum series printing mechanism with intermediate transfer printing.

[0222] The printing unit 300 includes: a unit 10T for imparting pressure phase change particles (T); and units 10Y, 10M, 10C, and 10K for forming images of yellow (Y), magenta (M), cyan (C), and black (K). Unit 10T is a particle imparting mechanism (i.e., imparting section) that imparts pressure phase change particles to a recording medium P using a developer containing pressure phase change particles. Units 10Y, 10M, 10C, and 10K are mechanisms for forming colored images (i.e., image sections) on the recording medium P using a developer containing color toners. Units 10T, 10Y, 10M, 10C, and 10K employ electrophotography.

[0223] Units 10T, 10Y, 10M, 10C, and 10K are arranged side-by-side, spaced apart from each other in the horizontal direction. Units 10T, 10Y, 10M, 10C, and 10K can be processing boxes that are loaded and unloaded in the printing unit 300.

[0224] Below units 10T, 10Y, 10M, 10C, and 10K, an intermediate transfer belt (an example of an intermediate transfer body) 20 extends through each unit. The intermediate transfer belt 20 is wound around a drive roller 22, a support roller 23, and a counter roller 24 that are in contact with the inner surface of the intermediate transfer belt 20, and moves in the direction from unit 10T toward unit 10K. On the image holding side of the intermediate transfer belt 20, an intermediate transfer body cleaning device 21 is provided opposite to the drive roller 22.

[0225] Units 10T, 10Y, 10M, 10C, and 10K are equipped with developing devices (an example of a developing mechanism) 4T, 4Y, 4M, 4C, and 4K, respectively. Pressure phase change particles, yellow toner, magenta toner, cyan toner, and black toner, which are contained in cartridges 8T, 8Y, 8M, 8C, and 8K, are supplied to the developing devices 4T, 4Y, 4M, 4C, and 4K, respectively.

[0226] Units 10T, 10Y, 10M, 10C, and 10K have the same structure and operation; therefore, unit 10T, which imparts pressure phase change particles to the recording medium, will be used as an example for explanation.

[0227] Unit 10T includes a photoreceptor (an example of an image holder) 1T. Around the photoreceptor 1T are arranged in sequence: a charging roller (an example of a charging mechanism) 2T, which charges the surface of the photoreceptor 1T; an exposure device (an example of an electrostatic image forming mechanism) 3T, which exposes the charged surface of the photoreceptor 1T using a laser line to form an electrostatic image; a developing device (an example of a developing mechanism) 4T, which supplies pressure phase change particles to the electrostatic image and develops the electrostatic image to form a pressure phase change particle region; a primary transfer roller (an example of a primary transfer mechanism) 5T, which transfers the pressure phase change particle region formed by development onto an intermediate transfer belt 20; and a photoreceptor cleaning device (an example of a cleaning mechanism) 6T, which removes pressure phase change particles remaining on the surface of the photoreceptor 1T after the primary transfer. The primary transfer roller 5T is disposed inside the intermediate transfer belt 20 and is positioned opposite the photoreceptor 1T.

[0228] The operation of unit 10T is illustrated below, and the operation of imparting pressure phase change particles and forming an image section on the recording medium P is also explained.

[0229] First, the surface of the photoreceptor 1T is charged using the charging roller 2T. The exposure apparatus 3T then irradiates the charged surface of the photoreceptor 1T with laser lines based on image data sent from a control unit (not shown). This forms an electrostatic image on the surface of the photoreceptor 1T, representing the area where pressure-dependent phase-change particles are applied.

[0230] The electrostatic image formed on the photoreceptor 1T rotates to the developing position as the photoreceptor 1T rotates. At the developing position, the electrostatic image on the photoreceptor 1T is developed by the developing apparatus 4T, forming a pressure phase change particle region.

[0231] The developing apparatus 4T stores a developer containing at least pressure phase change particles and a carrier. The pressure phase change particles are agitated together with the carrier inside the developing apparatus 4T, thereby generating triboelectric charge and being held on the developer rollers. The surface of the photoreceptor 1T passes through the developing apparatus 4T, thereby electrostatically attaching the pressure phase change particles to an electrostatic image on the surface of the photoreceptor 1T. The electrostatic image is developed using the pressure phase change particles, thus forming a pressure phase change particle region. The photoreceptor 1T, having formed the pressure phase change particle region, continues to operate, conveying the pressure phase change particle region formed on the photoreceptor 1T to a primary transfer position.

[0232] When the pressure phase change particle region on the photoreceptor 1T is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roller 5T. An electrostatic force from the photoreceptor 1T toward the primary transfer roller 5T acts on the pressure phase change particle region, transferring it onto the intermediate transfer belt 20. The pressure phase change particles remaining on the photoreceptor 1T are removed and recovered by the photoreceptor cleaning device 6T. The photoreceptor cleaning device 6T is, for example, a cleaning scraper or a cleaning brush, preferably a cleaning brush.

[0233] In units 10Y, 10M, 10C, and 10K, the same operation as in unit 10T is performed using a developer containing colored toners. In unit 10T, the intermediate transfer belt 20, which contains pressure phase change particle regions, passes sequentially through units 10Y, 10M, 10C, and 10K, transferring the toner images of each color multiple times onto the intermediate transfer belt 20.

[0234] The intermediate transfer belt 20, which has undergone multiple transfers of the pressure phase change particle region and the toner image via units 10T, 10Y, 10M, 10C, and 10K, arrives at the secondary transfer section. This secondary transfer section consists of the intermediate transfer belt 20, an opposing roller 24 in contact with the inner surface of the intermediate transfer belt, and a secondary transfer roller 26 (an example of a secondary transfer mechanism) disposed on the image holding side of the intermediate transfer belt 20. Meanwhile, the recording medium P is fed to the gap between the secondary transfer roller 26 and the intermediate transfer belt 20 by a supply member, and a secondary transfer bias is applied to the opposing roller 24. At this time, an electrostatic force from the intermediate transfer belt 20 toward the recording medium P acts on the pressure phase change particle region and the toner image, and the pressure phase change particle region and toner image on the intermediate transfer belt 20 are transferred to the recording medium P.

[0235] A recording medium P, on which a pressure phase change particle area and a toner image are transferred, is conveyed to a heating device (an example of a particle heating mechanism) 28, which is an example of a fixing unit. By heating with the heating device 28, the colored toner image is thermally fixed onto the recording medium P, and the pressure phase change particle area is heated, promoting the plasticization of the pressure phase change particles.

[0236] From the perspective of suppressing the shedding of pressure phase change particles from the recording medium P, improving the fixing properties of the colored toner on the recording medium P, and further from the perspective of promoting the plasticization of pressure phase change particles, the heating device 28 is preferably a device that heats and pressurizes simultaneously (also called a heating and pressurizing device).

[0237] When the heating device 28 is a heating and pressurizing device, it is preferably equipped with a heating source such as a halogen heater, and includes a pair of rollers that contact the pressure phase change particle region and the toner image on the recording medium P to heat the pressure phase change particle region and the toner image. By passing the recording medium having the pressure phase change particle region and the toner image between the rollers, the colored toner image is thermally fixed on the recording medium P, and the pressure phase change particle region is heated, promoting the plasticization of the pressure phase change particles.

[0238] As described above, the recording medium P passes through the printing mechanism 300, thereby becoming a post-recording medium P4 with an image section formed and pressure-transformed particles imparted to it.

[0239] Then, the recording medium P4 is transferred toward the crimping mechanism 200.

[0240] In the printing manufacturing system of this embodiment, the printing mechanism 300 and the pressing mechanism 200 can be close together or separated.

[0241] When the printing mechanism 300 is separated from the pressing mechanism 200, the printing mechanism 300 and the pressing mechanism 200 are connected, for example, through a transport mechanism (e.g., a belt conveyor) that transmits the recording medium P4.

[0242] Figure 3 The crimping mechanism 200 shown is Figure 2 The crimping mechanism 200 shown is similarly equipped with a folding device 220 and a pressing device 230, and is used to crimp a laminate P5 obtained by folding the recording medium P4 to obtain a crimped printed matter P6.

[0243] As Figure 3 The crimping mechanism 200 in the printing manufacturing system shown is used with Figure 2 The same crimping mechanism 200 is shown in the printing manufacturing system.

[0244] <Pressure phase change layer and pressure phase change particles>

[0245] The following is a detailed description of the pressure phase change layer and pressure phase change particles in this embodiment.

[0246] It should be noted that the pressure phase change layer in this embodiment is a layer formed by the pressure phase change particles of this embodiment, therefore, the following description only focuses on the pressure phase change particles of this embodiment.

[0247] The pressure phase change particles of this embodiment include at least master particles and, if necessary, additives.

[0248] The parent particles contained in the pressure phase change particles can be particles with at least two glass transition points and a difference of more than 30°C between the lowest and highest glass transition temperatures.

[0249] [Master Particles]

[0250] (Adhesive resin)

[0251] The masterbatch preferably contains, as an adhesive resin, a styrene-based resin that includes styrene and other vinyl monomers in the polymer composition, and a (meth)acrylate-based resin that includes at least two (meth)acrylates in the polymer composition and the (meth)acrylates account for more than 90% by mass of the total polymer composition.

[0252] In the following text, "styrene-based resins containing styrene and other vinyl monomers in the polymer composition" will be referred to as "specific styrene-based resins", and "(meth)acrylate-based resins containing at least two (meth)acrylates in the polymer composition and whose (meth)acrylates account for more than 90% by mass of all polymer compositions" will be referred to as "specific (meth)acrylate-based resins".

[0253] In the masterbatch, from the perspective of maintaining the compressibility generated by compression bonding, it is preferable that the content of a specific styrene-based resin is greater than the content of a specific (meth)acrylate-based resin. The content of the specific styrene-based resin relative to the total content of the specific styrene-based resin and the specific (meth)acrylate-based resin is preferably 55% by mass or more and 80% by mass or less, more preferably 60% by mass or more and 75% by mass or less, and even more preferably 65% ​​by mass or more and 70% by mass or less.

[0254] -Specific styrene-based resins-

[0255] The master particles constituting the pressure phase change particles contain a specific styrene-based resin in which styrene and other vinyl monomers are included in the polymerization composition.

[0256] From the perspective of suppressing the fluidization of pressure phase change particles under unpressurized conditions, the mass percentage of styrene in the total polymer components of a specific styrene-based resin is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 75% by mass or more.

[0257] From the perspective of forming pressure-phase-change particles that are prone to phase change due to pressure, the mass percentage of styrene in the total polymeric components of a specific styrene-based resin is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

[0258] That is, in the total polymer components of a specific styrene-based resin, the mass percentage of styrene is preferably 60% to 95% by mass.

[0259] Other vinyl monomers (hereinafter also referred to as other vinyl monomers) included in the polymerization components of a specific styrene-based resin, such as styrene-based monomers and acrylic monomers, can be listed as examples.

[0260] Examples of styrene monomers among other vinyl monomers include vinylnaphthalene; alkyl-substituted styrene such as α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, and p-n-dodecylstyrene; aryl-substituted styrene such as p-phenylstyrene; alkoxy-substituted styrene such as p-methoxystyrene; halogen-substituted styrene such as p-chlorostyrene, 3,4-dichlorostyrene, p-fluorostyrene, and 2,5-difluorostyrene; nitro-substituted styrene such as m-nitrostyrene, o-nitrostyrene, and p-nitrostyrene; and so on.

[0261] These styrene monomers can be used individually or in combination of two or more.

[0262] As an acrylic monomer among other vinyl monomers, at least one acrylic monomer selected from the group consisting of (meth)acrylic acid and (meth)acrylates is preferred. Examples of (meth)acrylates include alkyl (meth)acrylates, carboxyl-substituted alkyl (meth)acrylates, hydroxyl-substituted alkyl (meth)acrylates, alkoxy-substituted alkyl (meth)acrylates, and di(meth)acrylates.

[0263] These acrylic monomers can be used alone or in combination of two or more.

[0264] Examples of alkyl methacrylates include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, dicyclopentyl methacrylate, and isobornyl methacrylate.

[0265] Examples of carboxyl-substituted alkyl esters of (meth)acrylic acid include (meth)acrylic acid-2-carboxyethyl ester.

[0266] Examples of hydroxylated alkyl esters of (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

[0267] Examples of alkoxy-substituted alkyl esters of (meth)acrylate include 2-methoxyethyl ester of (meth)acrylate.

[0268] Examples of di(meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, pentanediol di(meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, and decanediol di(meth)acrylate.

[0269] Other examples of (meth)acrylates include 2-(diethylamino)ethyl (meth)acrylate, benzyl (meth)acrylate, and methoxy polyethylene glycol (meth)acrylate.

[0270] Other vinyl monomers included in the polymerization composition of a particular styrene-based resin, besides styrene monomers and acrylic monomers, include, for example, (meth)acrylonitrile; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, and vinyl isopropenyl ketone; and olefins such as isoprene, butene, and butadiene.

[0271] In certain styrene-based resins, from the perspective of forming pressure-phase-change particles that are prone to phase change due to pressure, other vinyl monomers included as polymerization components preferably include (meth)acrylates, more preferably include (meth)acrylate alkyl esters, even more preferably include (meth)acrylate alkyl esters containing alkyl groups with 2 to 10 carbon atoms, and even more preferably include (meth)acrylate alkyl esters containing alkyl groups with 4 to 8 carbon atoms.

[0272] In certain styrene-based resins, from the viewpoint of forming pressure-phase-change particles that are prone to phase change due to pressure, other vinyl monomers included as polymerizing components are particularly preferably at least one of n-butyl acrylate and 2-ethylhexyl acrylate.

[0273] From the perspective of forming pressure-phase-change particles that are prone to phase change due to pressure, certain styrene-based resins and certain (meth)acrylate-based resins described later preferably contain the same type of (meth)acrylate as a polymerization component.

[0274] From the perspective of suppressing the fluidization of pressure phase change particles under unpressurized conditions, the mass percentage of (meth)acrylate in the total polymeric components of a specific styrene-based resin is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less. From the perspective of forming pressure phase change particles that are prone to phase change due to pressure, this mass percentage is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. The (meth)acrylate used here is preferably an alkyl (meth)acrylate, more preferably an alkyl (meth)acrylate with 2 to 10 carbon atoms in the alkyl group, and even more preferably an alkyl (meth)acrylate with 4 to 8 carbon atoms in the alkyl group.

[0275] In certain styrene-based resins, it is particularly preferred that at least one of n-butyl acrylate and 2-ethylhexyl acrylate is included as a polymerization component. From the viewpoint of suppressing the fluidization of pressure phase change particles under unpressurized conditions, the total amount of n-butyl acrylate and 2-ethylhexyl acrylate is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less in the total polymerization components of the styrene-based resin. From the viewpoint of forming pressure phase change particles that are prone to phase change due to pressure, the total amount of n-butyl acrylate and 2-ethylhexyl acrylate is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more in the total polymerization components of the styrene-based resin.

[0276] Regarding the weight-average molecular weight of a specific styrene-based resin, from the perspective of suppressing the fluidization of pressure phase change particles under unpressurized conditions, it is preferably 3000 or more, more preferably 4000 or more, and even more preferably 5000 or more. From the perspective of forming pressure phase change particles that are prone to phase change due to pressure, it is preferably 60000 or less, more preferably 55000 or less, and even more preferably 50000 or less.

[0277] The weight-average molecular weight of the resin was determined by gel permeation chromatography (GPC). For the GPC molecular weight determination, a Tosoh HLC-8120 GPC was used as the GPC apparatus, a Tosoh TSKgelSuperHM-M (15 cm) column was used as the column, and tetrahydrofuran was used as the solvent. The weight-average molecular weight of the resin was calculated using a molecular weight calibration curve prepared using monodisperse polystyrene standard samples.

[0278] Regarding the glass transition temperature of a specific styrene-based resin, from the perspective of suppressing the fluidization of pressure phase change particles under unpressurized conditions, it is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher. From the perspective of forming pressure phase change particles that are prone to phase change due to pressure, it is preferably 110°C or lower, more preferably 100°C or lower, and even more preferably 90°C or lower.

[0279] The glass transition temperature of the resin is determined by differential scanning calorimetry (DSC) curves. More specifically, it is determined by extrapolating the glass transition onset temperature as described in the method for determining the glass transition temperature in JIS K7121:1987 "Method for determination of transition temperature of plastics".

[0280] The glass transition temperature of a resin is controlled by the type and ratio of polymerizing components. The glass transition temperature tends to decrease as follows: a higher density of flexible units such as methylene, ethylene, and ethylene oxide in the main chain tends to result in a lower glass transition temperature; conversely, a higher density of rigid units such as aromatic rings and cyclohexane rings in the main chain tends to result in a higher glass transition temperature. Furthermore, a higher density of aliphatic groups in the side chains tends to result in a lower glass transition temperature.

[0281] Regarding the mass percentage of a specific styrene-based resin in the total masterbatch, from the perspective of suppressing the fluidization of pressure phase change particles under unpressurized conditions, it is preferably 55% by mass or more, more preferably 60% by mass or more, and even more preferably 65% ​​by mass or more. From the perspective of forming pressure phase change particles that are prone to phase change due to pressure, it is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less.

[0282] -Specific (meth)acrylate resins-

[0283] The master particles constituting the pressure phase change particles preferably contain a (meth)acrylate resin in which at least two (meth)acrylates are included in the polymer composition and the (meth)acrylates account for more than 90% by mass of the total polymer composition.

[0284] In the total polymer components of the (meth)acrylate resin, the mass percentage of (meth)acrylate is 90% or more by mass, more preferably 95% or more by mass, further preferably 98% or more by mass, and even more preferably 100% by mass.

[0285] Examples of (meth)acrylates include alkyl (meth)acrylates, carboxyl-substituted alkyl (meth)acrylates, hydroxyl-substituted alkyl (meth)acrylates, alkoxy-substituted alkyl (meth)acrylates, and di(meth)acrylates.

[0286] Examples of alkyl methacrylates include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, dicyclopentyl methacrylate, and isobornyl methacrylate.

[0287] Examples of carboxyl-substituted alkyl esters of (meth)acrylic acid include (meth)acrylic acid-2-carboxyethyl ester.

[0288] Examples of hydroxylated alkyl esters of (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

[0289] Examples of alkoxy-substituted alkyl esters of (meth)acrylate include 2-methoxyethyl ester of (meth)acrylate.

[0290] Examples of di(meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, pentanediol di(meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, and decanediol di(meth)acrylate.

[0291] Other examples of (meth)acrylates include 2-(diethylamino)ethyl (meth)acrylate, benzyl (meth)acrylate, and methoxy polyethylene glycol (meth)acrylate.

[0292] (Meth)acrylates can be used alone or in combination with two or more types.

[0293] From the perspective of forming pressure-phase-change particles that are easy to undergo phase change due to pressure and have excellent compressibility when produced by compression, alkyl methacrylates are preferred as (meth)acrylates, alkyl methacrylates with 2 to 10 carbon atoms in the alkyl group are more preferred, alkyl methacrylates with 4 to 8 carbon atoms in the alkyl group are even more preferred, and n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferred.

[0294] As mentioned above, from the perspective of forming pressure phase change particles that are prone to phase change due to pressure, certain (meth)acrylate resins and certain styrene resins preferably contain the same type of (meth)acrylate as a polymerization component.

[0295] From the perspective of forming pressure-phase-change particles that are prone to phase change due to pressure and exhibit excellent compressibility due to compression bonding, the specific alkyl methacrylate ester accounts for a mass percentage of 90% or more, more preferably 95% or more, further preferably 98% or more, and even more preferably 100% by mass in the total polymeric components of the methacrylate-based resin. As the alkyl methacrylate ester here, it is preferable to have an alkyl methacrylate ester with 2 or more but less than 10 carbon atoms in the alkyl group, and more preferably to have an alkyl methacrylate ester with 4 or more but less than 8 carbon atoms in the alkyl group.

[0296] From the perspective of forming pressure-phase-change particles that are easy to undergo phase change due to pressure and have excellent compressibility due to compression, the mass ratio of the two (meth)acrylates included as polymerizing components in a specific (meth)acrylate resin that have the highest mass proportion is preferably 80:20 to 20:80, more preferably 70:30 to 30:70, and even more preferably 60:40 to 40:60.

[0297] In a specific (meth)acrylate resin, the two (meth)acrylates comprising at least two types of (meth)acrylates in the polymer composition with the highest mass proportion are preferably alkyl (meth)acrylates. As the alkyl (meth)acrylates here, it is preferable that the alkyl group has 2 or more but less than 10 carbon atoms, and more preferably that the alkyl group has 4 or more but less than 8 carbon atoms.

[0298] When the two (meth)acrylates contained as polymerizing components in a specific (meth)acrylate resin are alkyl (meth)acrylates with the highest mass proportion among the at least two (meth)acrylates, from the viewpoint of forming pressure phase change particles that are easy to undergo phase change due to pressure and have excellent compressibility when compressed, the difference in the number of carbon atoms of the alkyl groups of the two (meth)acrylates is preferably 1 or more and 4 or less, more preferably 2 or more and 4 or less, and even more preferably 3 or 4.

[0299] In certain (meth)acrylate resins, from the perspective of forming pressure-phase-change particles that readily undergo phase change under pressure and exhibit excellent compressibility when pressed, it is preferable to include n-butyl acrylate and 2-ethylhexyl acrylate as polymerizing components. Particularly preferred are n-butyl acrylate and 2-ethylhexyl acrylate, which constitute the largest mass proportion of at least two (meth)acrylates included as polymerizing components in the (meth)acrylate resin. The total amount of n-butyl acrylate and 2-ethylhexyl acrylate preferably accounts for 90% or more by mass, more preferably 95% or more by mass, further preferably 98% or more by mass, and even more preferably 100% by mass of the total polymerizing components of the (meth)acrylate resin.

[0300] Certain (meth)acrylate resins may contain vinyl monomers other than (meth)acrylates in their polymerization composition.

[0301] Examples of vinyl monomers other than (meth)acrylates include (meth)acrylic acid; styrene; styrene monomers other than styrene; (meth)acrylonitrile; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, and vinyl isopropenyl ketone; and olefins such as isoprene, butene, and butadiene. These vinyl monomers can be used individually or in combination of two or more.

[0302] When a particular (meth)acrylate resin contains vinyl monomers other than (meth)acrylates in its polymerization composition, acrylic acid and methacrylic acid are preferred as vinyl monomers other than (meth)acrylates, and acrylic acid is more preferred.

[0303] Regarding the weight-average molecular weight of the specific (meth)acrylate resin, from the perspective of suppressing the fluidization of pressure phase change particles under unpressurized conditions, it is preferably 100,000 or more, more preferably 120,000 or more, and even more preferably 150,000 or more. From the perspective of forming pressure phase change particles that are prone to phase change due to pressure, it is preferably 250,000 or less, more preferably 220,000 or less, and even more preferably 200,000 or less.

[0304] Regarding the glass transition temperature of a specific (meth)acrylate resin, from the perspective of forming pressure phase change particles that are prone to phase change due to pressure, it is preferably 10°C or less, more preferably 0°C or less, and even more preferably -10°C or less. From the perspective of suppressing the fluidization of pressure phase change particles in an unpressurized state, it is preferably -90°C or more, more preferably -80°C or more, and even more preferably -70°C or more.

[0305] Regarding the mass percentage of a specific (meth)acrylate resin in the total masterbatch, from the perspective of forming pressure phase change particles that are prone to phase change due to pressure, it is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more. From the perspective of suppressing the fluidization of pressure phase change particles in an unpressurized state, it is preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less.

[0306] In this embodiment, the total amount of the specific styrene-based resin and the specific (meth)acrylate-based resin contained in the masterbatch is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass relative to the total masterbatch.

[0307] The masterbatch may contain, as needed, non-vinyl resins such as polystyrene, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, modified rosin, etc.

[0308] These resins can be used alone or in combination of two or more.

[0309] (Other ingredients)

[0310] The masterbatch can contain other ingredients as needed.

[0311] Other components include colorants (such as pigments and dyes), release agents (such as hydrocarbon waxes; natural waxes such as carnauba wax, rice bran wax, and candelilla wax; synthetic or mineral / petroleum-based waxes such as lignite wax; ester-based waxes such as fatty acid esters and lignite esters), and charge control agents.

[0312] Pressure-dependent phase-change particles can contain colorants within a range that does not compromise the visibility of the image.

[0313] From the perspective of improving the transparency of pressure phase change particles, the lower the content of colorant in the master particles, the better. Specifically, the content of colorant relative to the total master particles is preferably 1.0% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.01% by mass or less, and particularly preferably does not contain any colorant.

[0314] It should be noted that pressure-induced phase change particles can be transparent.

[0315] In this embodiment, "transparent" means that the average transmittance of the region to which the pressure-transformed phase-change particles are applied is 10% or more, preferably 50% or more, more preferably 80% or more, and even more preferably 90% or more.

[0316] The average transmittance mentioned above was measured using a V700 spectrophotometer (manufactured by Japan Spectrophotometer Co., Ltd.).

[0317] (Structure of the parent particle)

[0318] The internal structure of the master particle is preferably an island structure.

[0319] As an island structure, a preferred island structure is one having a marine phase and an island phase, wherein the marine phase contains one of two or more binding resins, and the island phase contains another resin dispersed in the marine phase. More specifically, from the perspective of ease of phase transformation due to pressure, a preferred island structure is one having a marine phase containing a specific styrene-based resin and an island phase containing a specific (meth)acrylate-based resin dispersed in the marine phase. Details of the specific styrene-based resin contained in the marine phase and the (meth)acrylate-based resin contained in the island phase are as described above. It should be noted that an island phase not containing a (meth)acrylate-based resin may also be dispersed in the marine phase.

[0320] When the master particles have an island structure, the average diameter of the island phase is preferably 200 nm or more and 500 nm or less. When the average diameter of the island phase is 500 nm or less, the master particles are more prone to phase transition due to pressure; when the average diameter of the island phase is 200 nm or more, the required mechanical strength of the master particles (e.g., the strength to resist deformation when stirred in a developer) is excellent. From these aspects, the average diameter of the island phase is more preferably 220 nm or more and 450 nm or less, and even more preferably 250 nm or more and 400 nm or less.

[0321] As a method to control the average diameter of the island phase in the island structure within the aforementioned range, examples include increasing or decreasing the amount of a specific (meth)acrylate resin relative to the amount of a specific styrene resin in the method for manufacturing master particles described later, and increasing or decreasing the time spent maintaining the aggregated resin particles at high temperature in the step of fusing / merging the aggregated resin particles.

[0322] The confirmation of island structure and the determination of the average diameter of island facies were carried out by the following methods.

[0323] Pressure-modified phase-change particles were embedded in epoxy resin, and sections were prepared using a diamond scalpel. The prepared sections were then stained with osmium tetroxide or ruthenium tetroxide in a desiccator. The stained sections were observed using a scanning electron microscope (SEM). The presence or absence of island structures was determined by the intensity of the osmium tetroxide or ruthenium tetroxide staining on the resin, thus confirming the presence of island structures. One hundred island phases were randomly selected from the SEM images, and the major axis of each island phase was measured. The average of the 100 major axes was taken as the mean diameter.

[0324] The parent particle can be a single-layer structure or a core / shell structure with a core and a shell covering the core. From the perspective of suppressing the fluidization of pressure-phase-change particles under unpressurized conditions, the parent particle is preferably a core / shell structure.

[0325] When the parent particles have a core / shell structure, from the perspective of ease with which a phase change occurs due to pressure, it is preferable that the core contains a specific styrene-based resin and a specific (meth)acrylate-based resin. Furthermore, from the perspective of suppressing the fluidization of pressure-phase-change particles under unpressurized conditions, it is preferable that the shell contains a specific styrene-based resin.

[0326] When the parent material has a core / shell structure, it is preferable that the core has a marine phase containing a specific styrene-based resin and an island phase containing a specific (meth)acrylate-based resin dispersed within the marine phase. The average diameter of the island phase is preferably within the range described above. Furthermore, in addition to the core having the above-described configuration, it is also preferable that the shell layer contains a specific styrene-based resin. In this case, the marine phase in the core and the shell layer form a continuous structure, and the parent material is prone to phase transition due to pressure.

[0327] Examples of resins included in the shell include polystyrene; epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, modified rosin, and other non-vinyl resins; and so on.

[0328] These resins can be used alone or in combination of two or more.

[0329] Regarding the average thickness of the shell, from the perspective of suppressing the deformation of the parent particles, it is preferably 120 nm or more, more preferably 130 nm or more, and even more preferably 140 nm or more. From the perspective of the parent particles being prone to phase transition due to pressure, it is preferably 550 nm or less, more preferably 500 nm or less, and even more preferably 400 nm or less.

[0330] The average thickness of the shell was determined by the following method.

[0331] The particles were embedded in epoxy resin, and sections were prepared using a diamond scalpel. The prepared sections were then stained with osmium tetroxide or ruthenium tetroxide in a desiccator. The stained sections were observed using a scanning electron microscope (SEM). Ten cross-sections of the parent particle were randomly selected from the SEM images. For each parent particle, the shell thickness was measured at 20 locations, and the average value was calculated. The average value of the ten parent particles was taken as the average thickness.

[0332] Regarding the volume average particle size (D50v) of the masterbatch, from the perspective of ease of processing, it is preferably 4 μm or more, more preferably 5 μm or more, and even more preferably 6 μm or more. Furthermore, the volume average particle size of the masterbatch is preferably 15 μm or less, more preferably 12 μm or less, and even more preferably 10 μm or less.

[0333] The volume average particle size (D50v) of the masterbatch was determined using a Coulter Multisizer II (Beckman Coulter) with a pore size of 100 μm. Masterbatch particles of 0.5 mg to 50 mg were added to 2 mL of a 5% (w / w) aqueous solution of sodium alkylbenzene sulfonate and dispersed. This was then mixed with 100 mL to 150 mL of electrolyte (ISOTON-II, Beckman Coulter) and dispersed using an ultrasonic disperser for 1 minute. The resulting dispersion was used as the sample. The particle size of 50,000 particles with a diameter of 2 μm to 60 μm in the sample was measured. The particle size of the cumulative 50% point in the volumetric reference particle size distribution, measured from the smallest diameter side, was taken as the volume average particle size (D50v).

[0334] [Additives]

[0335] Examples of additives include inorganic particles. Examples of inorganic particles include SiO2, TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, K2O·(TiO2)n, Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, and MgSO4.

[0336] The surface of the inorganic particles used as an additive can be hydrophobically treated. This hydrophobic treatment can be performed, for example, by impregnating the inorganic particles in a hydrophobic treatment agent. There are no particular limitations on the hydrophobic treatment agent; examples include silane-based coupling agents, silicone oils, titanate-based coupling agents, and aluminum-based coupling agents. These agents can be used alone or in combination of two or more. The amount of the hydrophobic treatment agent is, for example, between 1 and 10 parts by mass relative to 100 parts by mass of the inorganic particles.

[0337] Other examples of additives include resin particles (such as polystyrene, polymethyl methacrylate, and melamine resin particles) and cleaning and activating agents (such as metal salts of higher fatty acids, such as zinc stearate, and particles of fluorine-based high molecular weight substances).

[0338] The amount of additive added relative to the masterbatch is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.01% by mass or more and 2.0% by mass or less.

[0339] [Properties of pressure-dependent phase change particles]

[0340] When pressure-sensitive phase-change particles have at least two glass transition temperatures, one of the glass transition temperatures is presumed to be the glass transition temperature of one of the two or more binding resins, and the other glass transition temperature is presumed to be the glass transition temperature of another of the two or more binding resins. As mentioned above, when the binding resin comprises a specific styrene-based resin and a specific (meth)acrylate-based resin, one of the glass transition temperatures is presumed to be the glass transition temperature of the specific styrene-based resin, and the other is presumed to be the glass transition temperature of the specific (meth)acrylate-based resin.

[0341] Pressure-sensitive phase change particles may also have three or more glass transition temperatures, but it is preferable that they have two glass transition temperatures. As for the form with two glass transition temperatures, there are the following forms: forms in which the resin contained in the pressure-sensitive phase change particles consists only of a specific styrene-based resin and a specific (meth)acrylate-based resin; and forms in which the content of other resins that are neither a specific styrene-based resin nor a specific (meth)acrylate-based resin is low (e.g., the content of other resins is 5% by mass or less relative to the total weight of the pressure-sensitive phase change particles).

[0342] The pressure-dependent phase transition particles have at least two glass transition temperatures, with the difference between the lowest and highest glass transition temperatures being 30°C or more. From the perspective of the pressure-dependent phase transition particles readily undergoing a phase transition due to pressure, the difference between the lowest and highest glass transition temperatures is more preferably 40°C or more, further preferably 50°C or more, and even more preferably 60°C or more. The upper limit of the difference between the lowest and highest glass transition temperatures is, for example, 140°C or less, 130°C or less, or 120°C or less.

[0343] Regarding the minimum glass transition temperature exhibited by the pressure phase change particles, from the perspective that the pressure phase change particles are prone to phase change due to pressure, it is preferably below 10°C, more preferably below 0°C, and even more preferably below -10°C. From the perspective of suppressing the fluidization of the pressure phase change particles in the unpressurized state, it is preferably above -90°C, more preferably above -80°C, and even more preferably above -70°C.

[0344] Regarding the highest glass transition temperature exhibited by the pressure phase change particles, from the perspective of suppressing the fluidization of the pressure phase change particles in the unpressurized state, it is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher. From the perspective of the pressure phase change particles being prone to phase change due to pressure, it is preferably 70°C or lower, more preferably 65°C or lower, and even more preferably 60°C or lower.

[0345] Regarding the glass transition temperature of pressure-induced phase change particles, the plate-shaped sample prepared by compressing the pressure-induced phase change particles is determined by differential scanning calorimetry (DSC) to obtain the differential scanning calorimetry curve (DSC curve). More specifically, it is determined by extrapolating the glass transition onset temperature as described in the method for determining the glass transition temperature of JIS K7121:1987 "Method for determination of transition temperature of plastics".

[0346] Pressure-dependent phase change particles are particles that undergo a phase change due to pressure, and they satisfy the following equation 1.

[0347] Equation 1···10℃≦T1-T2

[0348] In Equation 1, T1 is the temperature at which the viscosity reaches 10000 Pa·s under a pressure of 1 MPa, and T2 is the temperature at which the viscosity reaches 10000 Pa·s under a pressure of 10 MPa. The methods for determining T1 and T2 are described below.

[0349] From the perspective that pressure-sensitive phase change particles are prone to phase change due to pressure, the temperature difference (T1-T2) is 10°C or more, preferably 15°C or more, and more preferably 20°C or more. From the perspective of suppressing the fluidization of pressure-sensitive phase change particles in an unpressurized state, the temperature difference (T1-T2) is preferably 120°C or less, more preferably 100°C or less, and even more preferably 80°C or less.

[0350] The value of T1 is preferably below 140°C, more preferably below 130°C, even more preferably below 120°C, and even more preferably below 115°C. The lower limit of temperature T1 is preferably above 80°C, more preferably above 85°C.

[0351] The value of T2 is preferably 40°C or higher, more preferably 50°C or higher, and even more preferably 60°C or higher. The upper limit of temperature T2 is preferably 85°C or lower.

[0352] As an indicator of the susceptibility of pressure-sensitive phase-change particles to undergo phase change under pressure, the temperature difference (T1-T3) between temperature T1, which exhibits a viscosity of 10000 Pa·s at a pressure of 1 MPa, and temperature T3, which exhibits a viscosity of 10000 Pa·s at a pressure of 4 MPa, can be used. The temperature difference (T1-T3) is preferably 5°C or more. Typically, the temperature difference (T1-T3) is 25°C or less.

[0353] In pressure-sensitive phase change particles, from the perspective of easy phase change due to pressure, the temperature difference (T1-T3) is preferably 5°C or more, and more preferably 10°C or more.

[0354] It should be noted that the upper limit of the temperature difference (T1-T3) is usually below 25℃.

[0355] In pressure-sensitive phase change particles, from the perspective of achieving a temperature difference (T1-T3) of 5°C or more, the temperature T3 exhibiting a viscosity of 10000 Pa·s at a pressure of 4 MPa is preferably 90°C or less, more preferably 85°C or less, and even more preferably 80°C or less. The lower limit of temperature T3 is preferably 60°C or more.

[0356] The method for determining temperatures T1, T2, and T3 is as follows.

[0357] Particles of the phase change polymer were compressed to prepare granular samples. These samples were then placed in a flow testing apparatus (Shimadzu CFT-500), and the applied pressure was fixed at 1 MPa. Viscosities were measured at different temperatures under this pressure. The resulting viscosity curves determined that a viscosity of 10 was achieved at an applied pressure of 1 MPa. 4 Temperature T1 is determined at a pressure of 1 MPa to 10 MPa. Temperature T2 is determined using the same method as for temperature T1, except that the applied pressure is changed from 1 MPa to 4 MPa. Temperature T3 is determined using the same method as for temperature T1. The temperature difference (T1-T2) is calculated from temperatures T1 and T2. The temperature difference (T1-T3) is calculated from temperatures T1 and T3.

[0358] [Method for manufacturing pressure-dependent phase change particles]

[0359] Pressure phase change particles are obtained by adding additives to the master particles after they have been manufactured.

[0360] Masterbatch can be manufactured using any of the following methods: dry manufacturing (e.g., mixing and pulverizing) or wet manufacturing (e.g., agglomeration and aggregation (agglomeration-1), suspension polymerization, dissolution suspension, etc.). There are no particular limitations on these methods, and well-known methods can be used. Among these, agglomeration and aggregation is preferred for obtaining masterbatch.

[0361] The following is an example of a method for manufacturing master particles using the agglomeration and merging method.

[0362] In the case of manufacturing master particles by agglomeration and merging, the master particles are manufactured, for example, through the following steps:

[0363] Steps for preparing a styrene-based resin particle dispersion containing styrene-based resin particles with a specific styrene-based resin (styrene-based resin particle dispersion preparation steps).

[0364] The step of polymerizing a specific (meth)acrylate resin in a styrene-based resin particle dispersion to form composite resin particles containing a specific styrene-based resin and a specific (meth)acrylate resin (composite resin particle formation step).

[0365] The step of agglomerating the composite resin particles in a composite resin particle dispersion to form agglomerated particles (agglomerated particle formation step); and

[0366] The step of heating the dispersion of agglomerated particles to fuse / merge the agglomerated particles and form mother particles (fusion / merging step).

[0367] The following details each step.

[0368] The following description outlines a method for obtaining masterbatch free of release agent. Release agents and other additives may be used as needed.

[0369] In cases where the master particles contain colorants and / or release agents, the colorant particle dispersion and / or release agent particle dispersion can be mixed together with the composite resin particle dispersion in the agglomerated particle forming step, so that the composite resin particles and colorants and / or release agents agglomerate to form agglomerated particles.

[0370] Colorant particle dispersions and release agent particle dispersions can be prepared, for example, by mixing the colorant or release agent with a dispersion medium and then dispersing it using a known disperser.

[0371] -Preparation steps for styrene-based resin particle dispersion-

[0372] In the preparation step of the styrene-based resin particle dispersion, a styrene-based resin particle dispersion containing styrene-based resin particles of a specific styrene-based resin is prepared.

[0373] Styrene-based resin particle dispersions are, for example, dispersions formed by dispersing styrene-based resin particles in a dispersion medium using a surfactant.

[0374] Examples of dispersion media include aqueous media such as water and alcohols. These components can be used individually or in combination of two or more.

[0375] Examples of surfactants include anionic surfactants such as sulfate esters, sulfonates, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyols. Nonionic surfactants can also be used in combination with anionic or cationic surfactants. Among these, anionic surfactants are preferred. Surfactants can be used alone or in combination of two or more.

[0376] As a method for dispersing styrene-based resin particles in a dispersion medium, examples include: mixing a specific styrene-based resin with a dispersion medium and then dispersing it by stirring using a rotary shear homogenizer or a ball mill, sand mill, bead mill, or similar device with a medium.

[0377] Another method for dispersing styrene-based resin particles in a dispersion medium is emulsion polymerization. Specifically, the polymerization component of a specific styrene-based resin is mixed with a chain transfer agent or polymerization initiator, and then further mixed with an aqueous medium containing a surfactant. The mixture is stirred to create an emulsion, in which the styrene-based resin is polymerized. In this case, dodecyl mercaptan is preferably used as the chain transfer agent.

[0378] The volume average particle size of the styrene-based resin particles dispersed in the styrene-based resin particle dispersion is preferably 100 nm or more and 250 nm or less, more preferably 120 nm or more and 220 nm or less, and even more preferably 150 nm or more and 200 nm or less.

[0379] Regarding the volume average particle size of the resin particles contained in the resin particle dispersion, the particle size is measured using a laser diffraction particle size distribution measuring device (e.g., the LA-700 manufactured by Horiba Corporation), and the particle size of the cumulative 50% point in the volume reference particle size distribution measured from the small diameter side is taken as the volume average particle size (D50v).

[0380] The content of styrene-based resin particles in the styrene-based resin particle dispersion is preferably 30% to 60% by mass, more preferably 40% to 50% by mass, relative to the total mass of the styrene-based resin particle dispersion.

[0381] -Composite resin particle formation steps-

[0382] In the composite resin particle formation step, a specific (meth)acrylate resin is polymerized in a styrene-based resin particle dispersion to form composite resin particles containing a specific styrene-based resin and a specific (meth)acrylate resin.

[0383] In the composite resin particle formation step, a styrene-based resin particle dispersion is mixed with a polymerizing component of a specific (meth)acrylate resin, and the specific (meth)acrylate resin is polymerized in the styrene-based resin particle dispersion to form composite resin particles containing the specific styrene-based resin and the specific (meth)acrylate resin.

[0384] The composite resin particles are preferably resin particles comprising a specific styrene-based resin and a specific (meth)acrylate-based resin in a microphase-separated state. These resin particles are manufactured, for example, by the method described below.

[0385] Add the polymerization component of a specific (meth)acrylate resin (containing at least two (meth)acrylate monomer groups) to a styrene-based resin particle dispersion, and add an aqueous medium as needed. Then, while slowly stirring the dispersion, heat the dispersion to above the glass transition temperature of the specific styrene-based resin (e.g., a temperature 10°C to 30°C higher than the glass transition temperature of the specific styrene-based resin). Next, while maintaining the temperature, slowly add the aqueous medium containing the polymerization initiator, and continue stirring for an extended period of 1 hour to 15 hours. Ammonium persulfate is preferably used as the polymerization initiator at this time.

[0386] Although the detailed mechanism may not be clear, it is speculated that, using the above method, monomers and polymerization initiators infiltrate into styrene-based resin particles, and a specific (meth)acrylate resin polymerizes inside the styrene-based resin particles. It is speculated that this can yield composite resin particles that contain a specific (meth)acrylate resin inside the styrene-based resin particles, with the specific styrene-based resin and the specific (meth)acrylate resin forming a microphase-separated state within the particles.

[0387] The volume average particle size of the composite resin particles dispersed in the composite resin particle dispersion is preferably 140 nm or more and 300 nm or less, more preferably 150 nm or more and 280 nm or less, and even more preferably 160 nm or more and 250 nm or less.

[0388] The content of composite resin particles in the composite resin particle dispersion is preferably 20% to 50% by mass, more preferably 30% to 40% by mass, relative to the total mass of the composite resin particle dispersion.

[0389] -Steps in the formation of aggregated particles-

[0390] In the aggregated particle formation step, the composite resin particles in the composite resin particle dispersion containing the composite resin particles are aggregated to form aggregated particles.

[0391] Here, in the agglomerated particle formation step, the composite resin particles are agglomerated to form agglomerated particles with a diameter similar to that of the target master particle.

[0392] Regarding the steps for forming aggregated particles, specifically, for example, a coagulant is added to the composite resin particle dispersion, and the pH of the composite resin particle dispersion is adjusted to acidic (e.g., pH 2 or higher than pH 5). After adding a dispersing stabilizer as needed, the mixture is heated to a temperature close to the glass transition temperature of a specific styrene-based resin (specifically, for example, a glass transition temperature of -30°C or higher than -10°C for a specific styrene-based resin), causing the composite resin particles to aggregate and form aggregated particles.

[0393] In the step of forming aggregated particles, a coagulant can be added to the composite resin particle dispersion at room temperature (e.g., 25°C) while stirring with a rotary shear homogenizer, the pH of the composite resin particle dispersion can be adjusted to acidic (e.g., pH 2 or higher than 5), and a dispersant stabilizer can be added as needed before heating.

[0394] Examples of flocculants include surfactants with polarity opposite to that of the surfactant contained in the composite resin particle dispersion, inorganic metal salts, and metal complexes with a polarity of two or higher. When metal complexes are used as flocculants, the amount of surfactant required is reduced, and the charging characteristics are improved.

[0395] Additives that form complexes or similar bonds with the metal ions of the flocculant can be used as needed. Chelating agents are suitable as such additives.

[0396] Examples of inorganic metal salts include calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide; and so on.

[0397] Water-soluble chelating agents can be used as chelating agents. Examples of chelating agents include hydroxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA); and so on.

[0398] The amount of chelating agent added relative to 100 parts by weight of resin particles is preferably 0.01 parts by weight or more and 5.0 parts by weight or less, more preferably 0.1 parts by weight or more and less than 3.0 parts by weight.

[0399] -Merge / merge steps-

[0400] In the fusion / merging step, the dispersion of agglomerated particles containing agglomerated particles is heated to fuse / merge the agglomerated particles and form mother particles.

[0401] In the fusion / merging step, the dispersion of agglomerated particles containing the agglomerated particles is heated to, for example, above the glass transition temperature of a specific styrene-based resin (e.g., a temperature 10°C to 30°C higher than the glass transition temperature of a specific styrene-based resin) to fuse / merge the agglomerated particles and form master particles.

[0402] The master particles obtained through the above steps typically have an island structure, which consists of a marine phase containing a specific styrene-based resin and an island phase containing a specific (meth)acrylate-based resin dispersed within the marine phase. It is speculated that in composite resin particles, when the specific styrene-based resin and the specific (meth)acrylate-based resin are in a microphase-separated state, during the fusion / merging step, the specific styrene-based resin aggregates to form the marine phase, and the specific (meth)acrylate-based resin aggregates to form the island phase.

[0403] The average diameter of the island phase in the island structure can be controlled, for example, by increasing or decreasing the amount of styrene-based resin particle dispersion or the amount of at least two (meth)acrylates used in the composite resin particle formation step, or by increasing or decreasing the time maintained at high temperature in the fusion / merging step.

[0404] Core / shell structured master particles are manufactured, for example, through the following steps:

[0405] After obtaining the aggregated particle dispersion (hereinafter also referred to as the first aggregated particle dispersion containing the first aggregated particles) in the above-mentioned aggregated particle forming step, the aggregated particle dispersion and the styrene-based resin particle dispersion are further mixed, and aggregated in such a way that styrene-based resin particles are further attached to the surface of the aggregated particles to form the second aggregated particles (the second aggregated particle forming step); and

[0406] The step of heating the dispersion of the second aggregated particles containing the second aggregated particles to fuse / merge the second aggregated particles and form a core / shell structured parent particle (core / shell structure formation step).

[0407] The core / shell structured master particles obtained through the above steps have a shell containing a specific styrene-based resin.

[0408] Alternatively, a resin particle dispersion containing other types of resin particles can be used instead of a styrene-based resin particle dispersion to form a shell containing other types of resin.

[0409] After the fusion / merging step is completed, the mother particles formed in the solution are subjected to a known washing step, a solid-liquid separation step, and a drying step to obtain dried mother particles.

[0410] Regarding the cleaning process, from a rechargeability perspective, displacement cleaning using ion-exchange water can be fully implemented. Regarding the solid-liquid separation process, from a productivity perspective, methods such as vacuum filtration and pressure filtration can be implemented. Regarding the drying process, from a productivity perspective, methods such as freeze drying, airflow drying, fluidized bed drying, and vibrating fluidized bed drying can be implemented.

[0411] Then, for example, an additive is added to the obtained dry masterbatch and mixed to produce pressure phase change particles.

[0412] Mixing can be done using a V-type mixer, Henschel mixer, Rhodiola mixer, etc.

[0413] Furthermore, vibrating screens, pneumatic screens, and other equipment can be used as needed to remove coarse particles from the granules.

[0414] Pressure phase change particles can be used directly as coatings or as electrostatic image developers. These electrostatic image developers can be single-component developers containing only pressure phase change particles, or two-component developers composed of pressure phase change particles and a carrier.

[0415] There are no particular limitations on the carrier, and known carriers can be cited as examples. Examples of carriers include: a coated carrier in which resin is coated onto the surface of a core material formed of magnetic powder; a magnetic powder dispersion carrier in which magnetic powder is dispersed and mixed in a matrix resin; a resin-impregnated carrier formed by impregnating porous magnetic powder with resin; and so on. Magnetic powder dispersion carriers and resin-impregnated carriers can also be carriers in which the constituent particles of the carrier are used as the core material and their surfaces are coated with resin.

[0416] Examples of magnetic powders include: magnetic metals such as iron, nickel, and cobalt; magnetic oxides such as ferrite and magnetite; and so on.

[0417] Examples of resins used for coating and matrix resins include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylate copolymer, pure silicone resins or their modifications comprising organosiloxane bonds, fluoropolymers, polyesters, polycarbonates, phenolic resins, epoxy resins, etc. The coating resin and matrix resin may contain other additives such as conductive particles. Examples of conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium dioxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, potassium titanate, etc.

[0418] When using resin to coat the surface of a core material, methods such as coating with a coating layer forming solution made by dissolving the resin to be coated and various additives (used as needed) in a suitable solvent can be employed. There are no particular limitations on the solvent; it can be selected considering the type of resin used and its coating suitability.

[0419] Specific resin coating methods include: impregnation, in which the core material is impregnated in a coating layer forming solution; spraying, in which the coating layer forming solution is sprayed onto the surface of the core material; fluidized bed method, in which the coating layer forming solution is sprayed while the core material is suspended by flowing air; kneading coating machine method, in which the core material of the carrier is mixed with the coating layer forming solution in a kneading coating machine, and then the solvent is removed; and so on.

[0420] The mixing ratio (mass ratio) of pressure phase change particles and carrier in the two-component developer is preferably particles:carrier = 1:100 to 30:100, more preferably 3:100 to 20:100.

[0421] [Example]

[0422] The following examples illustrate the implementation of the invention in detail, but the implementation of the invention is not limited to these examples. In the following description, unless otherwise stated, "parts" and "%" are based on mass.

[0423] Example A

[0424] <Preparation of Pressure-Induced Phase Change Particles>

[0425] [Preparation of styrene-based resin particle dispersion (A1) and composite resin particle dispersion (A1)]

[0426] Styrene: 450 parts

[0427] • n-Butyl acrylate: 140 parts

[0428] Acrylic acid: 20 parts

[0429] • Dodecanthiol: 10 parts

[0430] The above components are mixed and dissolved to prepare a monomer solution.

[0431] Ten parts of anionic surfactant (manufactured by Dow Chemical Company, DOWFAX2A1) were dissolved in 250 parts of ion-exchanged water, and the above monomer solution was added to disperse and emulsify in a flask to obtain an emulsion.

[0432] One part of anionic surfactant (manufactured by Dow Chemical Company, DOWFAX2A1) was dissolved in 555 parts of ion-exchanged water and added to a polymerization flask equipped with a stirrer, thermometer, reflux cooling tube and nitrogen inlet tube. Nitrogen gas was injected and the polymerization flask was heated to 75°C in a water bath with slow stirring and maintained.

[0433] Nine parts of ammonium persulfate were dissolved in 43 parts of ion-exchanged water and added dropwise to a polymerization flask over 20 minutes using a metering pump. Then, the emulsion was added dropwise over 200 minutes using a metering pump.

[0434] Subsequently, the polymerization flask was kept at 75°C for 3 hours with continuous stirring, and then returned to room temperature (25°C) to end the first stage of polymerization.

[0435] Thus, a styrene-based resin particle dispersion (A1) was obtained, which contains styrene-based resin particles, the volume average particle size (D50v) of the resin particles is 195 nm, the glass transition temperature of the styrene-based resin is 53 °C, and the weight average molecular weight is 32,000 as determined by GPC (UV detection).

[0436] Next, 240 parts of 2-ethylhexyl acrylate, 160 parts of n-butyl acrylate, and 1200 parts of deionized water were added to a polymerization flask containing a styrene-based resin particle dispersion (A1) cooled to room temperature (25°C), and the mixture was slowly stirred for 2 hours.

[0437] Subsequently, the temperature was raised to 70°C with continuous stirring, and 4.5 parts of ammonium persulfate and 100 parts of deionized water were added dropwise over 20 minutes via a metering pump. The polymerization was then maintained for 3 hours with continuous stirring to complete the polymerization.

[0438] The above steps yielded the following composite resin particle dispersion (A1): the volume average particle size (D50v) of the composite resin particles was 240 nm, the weight average molecular weight of the composite resin determined by GPC (UV detection) was 133,000, the number average molecular weight was 18,000, and the solid content after adding ion-exchanged water was 30% by mass.

[0439] The obtained composite resin particle dispersion (A1) was dried, and the dried composite resin particles were embedded in epoxy resin to prepare a sample. The sample was then cut with a diamond scalpel to prepare a cross-sectional section of the composite resin particles. The cross-section of the sample was then stained in ruthenium tetroxide vapor and observed using a transmission electron microscope for confirmation. Subsequent cross-sectional observation of the composite resin particles confirmed that the structure of the composite resin particles consisted of multiple low-Tg (meth)acrylate resin microregions dispersed within a high-Tg styrene resin matrix.

[0440] Furthermore, when analyzing the glass transition temperature (Tg) behavior of dried composite resin particles using a differential scanning calorimeter (DSC) manufactured by Shimadzu Corporation, starting from -150°C, a glass transition caused by low-Tg (meth)acrylate resin was observed at -60°C. Additionally, a glass transition caused by high-Tg styrene resin was observed at 53°C (glass transition temperature difference: 113°C).

[0441] [Preparation of styrene-based resin particle dispersion (B1)]

[0442] Styrene: 450 parts

[0443] • n-Butyl acrylate: 135 parts

[0444] Acrylic acid: 12 parts

[0445] • Dodecanethiol: 9 parts

[0446] The above components are mixed and dissolved to prepare a monomer solution.

[0447] In addition, 10 parts of anionic surfactant (manufactured by Dow Chemical Company, DOWFAX2A1) were dissolved in 250 parts of ion-exchanged water, and the above monomer solution was added. The mixture was then dispersed and emulsified in a flask to obtain an emulsion.

[0448] One part of anionic surfactant (manufactured by Dow Chemical Company, DOWFAX2A1) was dissolved in 555 parts of ion-exchange water and placed into a polymerization flask equipped with a stirrer, thermometer, reflux cooling tube and nitrogen inlet tube. Nitrogen gas was injected and the polymerization flask was heated to 75°C in a water bath with slow stirring and maintained.

[0449] Nine parts of ammonium persulfate were dissolved in 43 parts of ion-exchanged water and added dropwise to a polymerization flask over 20 minutes using a metering pump. Then, the emulsion was added dropwise over 200 minutes using a metering pump.

[0450] The polymerization flask was then kept at 75°C for 3 hours with continuous stirring, and then returned to room temperature (25°C) to end the first stage of polymerization.

[0451] Thus, a styrene-based resin particle dispersion (B1) was obtained, which contains styrene-based resin particles, the volume average particle size (D50v) of the resin particles is 190 nm, the glass transition temperature of the styrene-based resin is 53 °C, the weight average molecular weight determined by GPC (UV detection) is 33,000, and the solid content after adding ion-exchanged water is 40% by mass.

[0452] [Preparation of release agent dispersion (A1)]

[0453] Fischer-Tropsch wax: 270 pieces

[0454] (Manufactured by Nippon Seiro Co., Ltd., Trade name: FNP-0090, Melting temperature = 90°C)

[0455] • Anionic surfactant: 1.0 part

[0456] (Manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., NEOGEN RK)

[0457] • Ion-exchanged water: 400 parts

[0458] The above components were mixed, heated to 95°C, dispersed using a homogenizer (IKA, ULTRA-TURRAX T50), and then dispersed for 360 minutes using a Manton Gaulin high-pressure homogenizer (Gaulin) to prepare a release agent dispersion (A1) containing a release agent with a volume average particle size of 0.23 μm (solid component concentration: 20% by mass).

[0459] [Preparation of pressure phase change particles (A1) and developer (A1)]

[0460] • Composite resin particle dispersion (A1): 600 parts

[0461] • Release agent dispersion (A1): 8 parts

[0462] Colloidal silica aqueous solution: 13 parts

[0463] (Manufactured by Nissan Chemical Co., Ltd., Snowtex OS)

[0464] • Ion-exchanged water: 1000 parts

[0465] • Anionic surfactant: 1 part

[0466] (Made by Dow Chemical Co., Ltd., Dowfax2A1)

[0467] The above components were placed into a 3-liter reaction vessel equipped with a thermometer, pH meter and stirrer. A 1.0% by mass nitric acid aqueous solution was added at 25°C to make the pH 3.0. Then, while dispersing using a homogenizer (ULTRA-TURRAXT T50 manufactured by IKA Japan Co., Ltd.) at 5,000 rpm, 4 parts of the prepared 10% by mass polyaluminum chloride aqueous solution were added and dispersed for 6 minutes.

[0468] A heating mantle was then installed on the reaction vessel, and the stirrer speed was adjusted to ensure thorough mixing of the slurry. Simultaneously, the temperature was increased to 40°C at a rate of 0.2°C / min. Once above 40°C, the temperature was increased at a rate of 0.05°C / min. Particle size was measured every 10 minutes using a Multisizer II (50μm pore size, Coulter). The temperature was maintained when the volume average particle size reached 7.5μm, and 115 parts of the styrene-based resin particle dispersion (B1) were added over 5 minutes. After addition, the mixture was maintained for 30 minutes, and then the pH of the slurry was adjusted to 6.0 using a 1.0% (w / w) sodium hydroxide aqueous solution. Subsequently, the pH was adjusted to 6.0 every 5°C, while the temperature was increased to 96°C at a rate of 1°C / min and maintained at 96°C. The particle shape and surface properties were observed using an optical microscope and a field emission scanning electron microscope (FE-SEM). The results showed that particle aggregation was confirmed at 2.0 hours. Therefore, the container was cooled to 30°C using cooling water for 5 minutes.

[0469] The cooled slurry was passed through a nylon mesh with a 30 μm opening to remove coarse particles. The slurry that had passed through the mesh was then filtered under reduced pressure using a suction device. The solids remaining on the filter paper were crushed as finely as possible by hand and added to ion-exchange water at 30°C (10 times the volume of the solids). The mixture was stirred and mixed for 30 minutes. Then, the slurry was filtered under reduced pressure again using a suction device. The remaining solids on the filter paper were crushed as finely as possible by hand and added to ion-exchange water at 30°C (10 times the volume of the solids). The mixture was stirred and mixed for 30 minutes. The filtrate was then filtered under reduced pressure again using a suction device, and the conductivity of the filtrate was measured. This process was repeated until the conductivity of the filtrate reached below 10 μS / cm, at which point the solids were washed away.

[0470] The cleaned solid components were finely crushed using a wet-dry granulator (wet granulation machine), and then vacuum dried at 25°C for 36 hours to obtain master particles (A1). The obtained master particles (A1) had a volume average particle size of 8.1 μm, a weight average molecular weight of 126,000, and a number average molecular weight of 17,000.

[0471] Next, 1.5 parts of hydrophobic silica (manufactured by NIPPON AEROSIL Co., Ltd., RY50) were added to 100 parts of the obtained master particles (A1), and the mixture was stirred in a sample mill at a rotation speed of 13,000 rpm for 30 seconds. The mixture was then sieved using a vibrating sieve with a mesh size of 45 μm to prepare pressure phase change particles (A1). The volume average particle size of the obtained pressure phase change particles (A1) was 8.4 μm.

[0472] Using pressure-sensitive phase change particles (A1) as samples, the thermal behavior of the particles in the temperature range of -150°C to 100°C was analyzed using a differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-60A). The results showed that glass transition temperatures were observed at -60°C and 53°C.

[0473] The temperatures T1 and T2 of the pressure phase change particles (A1) were determined using the above measurement method. The results showed that the pressure phase change particles (A1) satisfied Equation 1, "10℃≦T1-T2".

[0474] Cross-sections of the pressure phase change particles (A1) were observed using scanning electron microscopy (SEM), revealing an island structure. The pressure phase change particles (A1) possess a core containing island phases and a shell without island phases. The island phases consisted of styrene-based resins, while the island phases consisted of (meth)acrylate-based resins. The average diameter of the island phases was determined using the aforementioned measurement method, and was found to be 250 nm.

[0475] For pressure-sensitive phase change particles (A1), the temperature difference (T1-T3) was determined as an indicator of how easily the particles undergo a phase change due to pressure. Specifically, temperature T1 and temperature T3 were measured using a flow testing instrument (Shimadzu CFT-500). The results showed that temperature T3 was 76°C and temperature difference (T1-T3) was 17°C.

[0476] Eight parts of pressure phase change particles (A1) and 100 parts of the resin-coated carrier were loaded into a V-type mixer and stirred for 20 minutes. Then, the mixture was sieved using a vibrating screen with a mesh size of 212 μm to obtain the developer (A1).

[0477] 14 parts of toluene, 2 parts of styrene-methyl methacrylate copolymer (mass ratio: 80 / 20, weight average molecular weight: 70,000), and 0.6 parts of MZ500 (zinc oxide, titanium industry) were mixed and stirred for 10 minutes to prepare a coating layer forming solution with dispersed zinc oxide. Next, this coating layer forming solution and 100 parts of ferrite particles (volume average particle size: 38 μm) were loaded into a vacuum degassing kneader and stirred at 60°C for 30 minutes. Then, the mixture was further degassed under reduced pressure under heating and dried to produce a resin-coated carrier.

[0478] <Preparation of toners and developers for image formation>

[0479] [Crystall Polyester Resin Dispersion (A2)]

[0480] Add a monomeric component consisting of 100 mol% dimethyl sebacate and 100 mol% nonanediol, along with 0.3 parts dibutyltin oxide as a catalyst (relative to 100 parts of the monomeric component), to a heated and dried three-necked flask. Then, create an inert atmosphere in the container using nitrogen by reducing the pressure. Stir and reflux at 180°C for 4 hours using mechanical stirring.

[0481] The mixture was then slowly heated to 230°C under reduced pressure and stirred for 2 hours until it reached a viscous state. Afterward, it was air-cooled to stop the reaction, thus synthesizing a crystalline polyester resin (A2). Based on molecular weight determination using gel permeation chromatography (converted to polystyrene), the obtained crystalline polyester resin (A2) had a weight-average molecular weight (Mw) of 15300, a number-average molecular weight (Mn) of 3800, and an acid value of 13.5 mg KOH / g.

[0482] In addition, the melting point (Tm) of the crystalline polyester resin (A2) was determined using a differential scanning calorimeter (DSC), and the results showed a clear endothermic peak at a temperature of 77.2 °C.

[0483] Next, using crystalline polyester resin (A2), a resin particle dispersion was prepared as follows.

[0484] • Crystalline polyester resin (A2): 90 parts

[0485] • Ionic surfactant (NEOGEN RK, Daiichi Kogyo Pharmaceutical): 1.8 parts

[0486] • Ion-exchanged water: 210 parts

[0487] The above components were mixed and heated to 100°C. After dispersion using a homogenizer (ULTRA-TURRAX T50 manufactured by IKA), the mixture was further dispersed by heating to 110°C for 1 hour using a pressure-dispensing Gaulin Homogenizer to obtain a crystalline polyester resin dispersion (A2) with a volume average particle size of 210 nm and a solid content of 30% by mass.

[0488] [Amorphous polyester resin dispersion (A2)]

[0489] Bisphenol A propylene oxide adduct: 80 mol%

[0490] • Bisphenol A ethylene oxide 2-molar adduct: 20 mol%

[0491] ·Terephthalic acid: 60 mol%

[0492] Fumaric acid: 20 mol%

[0493] • Dodecenyl succinic anhydride: 20 mol%

[0494] The monomer components in the above proportions were added to a 5-liter flask equipped with a stirrer, nitrogen inlet pipe, temperature sensor, and distillation column. The temperature was raised to 190°C over 1 hour. After confirming that the reaction system was uniformly stirred, 1.2 parts of dibutyltin oxide were added, relative to 100 parts of the monomer components. Further, while distilling off the generated water, the temperature was raised from that temperature to 240°C over 6 hours. A dehydration condensation reaction was then carried out at 240°C for another 2 hours to obtain an amorphous polyester resin (A2) with a glass transition temperature of 63°C, an acid value of 10.5 mg KOH / g, a weight-average molecular weight of 17000, and a number-average molecular weight of 4200.

[0495] Next, using the obtained amorphous polyester resin (A2), a resin particle dispersion was prepared as follows.

[0496] • Amorphous polyester resin (A2): 100 parts

[0497] Ethyl acetate: 50 parts

[0498] Ethyl acetate was added to a 5-liter detachable flask, followed by the slow addition of the aforementioned resin components. Stirring was performed using a three-one motor until the resin was completely dissolved, yielding an oil phase. A 10% (w / w) ammonia solution was slowly added dropwise to this stirred oil phase in a total of 2 parts using a dropper. Then, 230 parts of deionized water were slowly added dropwise at a rate of 10 ml / min to induce phase inversion emulsification. The solvent was further removed using an evaporator under reduced pressure, yielding an amorphous polyester resin dispersion (A2). The amorphous polyester resin particles in this dispersion had a volume average particle size of 120 nm and a solids concentration of 30% (w / w).

[0499] [Colorant Particle Dispersion (A1)]

[0500] • Carbon black (manufactured by Cabot, Legal 330): 50 parts

[0501] • Anionic surfactant (manufactured by Nippon Oil Co., Ltd., New Rex R): 2 parts

[0502] • Ion-exchanged water: 198 samples

[0503] The above components were mixed and pre-dispersed for 10 minutes using a homogenizer (manufactured by IKA Corporation, ULTRA-TURRAX). Then, they were dispersed for 15 minutes using an Ultimaizer (head-on collision type wet pulverizer, manufactured by Sugino Machine) at a pressure of 245 MPa to obtain a colorant particle dispersion (A1) with a volume average particle size of 354 nm and a solid content of 20.0% by mass.

[0504] [Colorant Particle Dispersion (A2)]

[0505] • Blue pigment (copper phthalocyanine, CIPigment blue 15:3, manufactured by Dainnishi Chemical): 50 parts

[0506] • Ionic surfactants (NEOGEN RK, Daiichi Kogyo Pharmaceutical): 5 parts

[0507] • Ion-exchanged water: 195 parts

[0508] The above components were mixed and dispersed for 10 minutes using a homogenizer (manufactured by IKA Corporation, ULTRA-TURRAX). Then, the dispersion was carried out for 15 minutes using an Ultimaizer (head-on collision type wet pulverizer, manufactured by Sugino Machine) at a pressure of 245 MPa to obtain a colorant particle dispersion (A2) with a volume average particle size of 462 nm and a solid content of 20.0% by mass.

[0509] [Colorant Particle Dispersion (A3)]

[0510] • Magenta pigment (CI Pigment Red 122): 80 parts

[0511] • Anionic surfactant (NEOGEN SC, Daiichi Kogyo Pharmaceutical): 8 parts

[0512] • Ion-exchanged water: 200 parts

[0513] The above components were mixed and dissolved, and dispersed for 10 minutes using a homogenizer (ULTRA-TURRAX T50, manufactured by IKA). Then, the mixture was irradiated with 28kHz ultrasound for 10 minutes using an ultrasonic disperser to obtain a colorant particle dispersion (A3) with a volume average particle size of 132nm and a solid content of 29.0% by mass.

[0514] [Colorant Particle Dispersion (A4)]

[0515] • Yellow pigment (5g x 03, made by Clariant): 80 parts

[0516] • Anionic surfactant (NEOGEN SC, Daiichi Kogyo Pharmaceutical): 8 parts

[0517] • Ion-exchanged water: 200 parts

[0518] The above components were mixed and dissolved, and dispersed for 10 minutes using a homogenizer (ULTRA-TURRAX T50, manufactured by IKA). Then, the mixture was irradiated with ultrasonic waves at 28 kHz for 20 minutes using an ultrasonic disperser to obtain a colorant particle dispersion (A4) with a volume average particle size of 108 nm and a solid content of 29.0% by mass.

[0519] [Release agent particulate dispersion (A2)]

[0520] • Olefin wax (melting point: 88℃): 90 parts

[0521] • Ionic surfactant (NEOGEN RK, Daiichi Kogyo Pharmaceutical): 1.8 parts

[0522] • Ion-exchanged water: 210 parts

[0523] The above components were mixed and heated to 100°C. After dispersion using a homogenizer (ULTRA-TURRAX T50 manufactured by IKA), the mixture was further dispersed by heating to 110°C for 1 hour using a pressure-dispensing Gaulin Homogenizer to obtain a release agent particle dispersion (A2) with a volume average particle size of 180 nm and a solid content of 30% by mass.

[0524] [Preparation of Black Toner Granules (A1)]

[0525] • Amorphous polyester resin dispersion (A2): 166 parts

[0526] • Crystalline polyester resin dispersion (A2): 50 parts

[0527] • Colorant particle dispersion (A1): 25 parts

[0528] • Release agent particle dispersion (A2): 40 parts

[0529] The above components were mixed and dispersed in a round stainless steel flask using a homogenizer (ULTRA-TURRAX T50). Then, 0.20 parts of polyaluminum chloride were added, and dispersion was continued using the ULTRA-TURRAX T50. The flask was heated to 48°C with stirring in an oil bath. After maintaining this temperature at 48°C for 60 minutes, 60 parts of the amorphous polyester resin dispersion (A2) were added gradually. Subsequently, the pH of the system was adjusted to 8.0 using a 0.5 mol / L sodium hydroxide aqueous solution. The stainless steel flask was then sealed, and the mixture was heated to 90°C with continuous stirring using a magnetic seal, and maintained for 3 hours.

[0530] After the reaction, the solution was cooled, filtered, and washed with deion-exchanged water. Solid-liquid separation was then achieved using a Buchner funnel filtration system. The solution was further redispersed in 1 liter of deion-exchanged water at 40°C, with stirring and washing at 300 rpm for 15 minutes. This process was repeated five times. At a filtrate pH of 7.5 and a conductivity of 7.0 μS / cm, solid-liquid separation was performed using No. 5A filter paper via a Buchner funnel filtration system. Vacuum drying was then carried out for 12 hours to obtain black colorant particles (A1).

[0531] The particle size of the black toner particles (A1) was determined using Multisizer II, and the results showed that the volume average particle size D50 was 6.4 μm and the volume particle size distribution index GSDv was 1.21.

[0532] [Making of Black Toning Agent (A1)]

[0533] 100 parts of black colorant particles (A1), 0.8 parts of decylsilane-treated hydrophobic titanium dioxide with an average particle size of 15 nm, and 1.3 parts of hydrophobic silica (NY50, manufactured by NIPPON AEROSIL) with an average particle size of 30 nm were mixed. The mixture was then mixed for 10 minutes at a circumferential speed of 32 m / s using a Henschel mixer. After mixing, coarse particles were removed using a sieve with a mesh size of 45 μm to obtain black colorant (A1).

[0534] [Preparation of developer (C1)]

[0535] Ferritic particles (volume average particle size: 50 μm, volume resistivity: 108 Ωcm): 100 parts

[0536] Toluene: 14 parts

[0537] • Ethyl perfluorooctyl acrylate / methyl methacrylate copolymer (copolymer ratio 40 / 60, Mw: 50,000): 1.6 parts

[0538] • Carbon black (VXC-72, manufactured by Cabot): 0.12 parts

[0539] • Cross-linked melamine resin particles (number average particle size: 0.3 μm): 0.3 parts

[0540] Mix the components other than the ferrite particles in the above composition and disperse them for 10 minutes using a stirrer to prepare a coating forming solution. Add the coating forming solution and ferrite particles to a vacuum degassing kneader, stir at 60°C for 30 minutes, and then reduce the pressure to remove toluene by distillation, forming a resin coating on the surface of the ferrite particles to manufacture the carrier (A2).

[0541] 94 parts of carrier (A2) and 6 parts of black toning agent (A1) were mixed and stirred at 40 rpm for 20 minutes using a V-type mixer. The mixture was then sieved using a sieve with a mesh size of 177 μm to prepare developer (C1).

[0542] [Preparation of Cyan Toner Particles (A2), Cyan Toner (A2), and Developer (C2)]

[0543] In the preparation of black toner particles (A1), 20 parts of colorant particle dispersion (A2) were used instead of colorant particle dispersion (A1). Otherwise, cyan toner particles (A2) were obtained in accordance with the preparation of black toner particles (A1). The obtained toner particles had a volume average particle size D50 of 7.2 μm and a volume particle size distribution index of 1.19.

[0544] A cyan toner (A2) is obtained in the same way as the black toner (A1), except that cyan toner particles (A2) are used instead of black toner particles (A1).

[0545] Except that a cyan toner (A2) is used instead of a black toner (A1), the developer (C2) is obtained in the same way as the developer (C1).

[0546] [Preparation of magenta toner particles (A3), magenta toner (A3), and developer (C3)]

[0547] In the preparation of black toner particles (A1), 25 parts of colorant particle dispersion (A3) were used instead of colorant particle dispersion (A1). Otherwise, magenta toner particles (A3) were obtained according to the preparation method of black toner particles (A1). The obtained toner particles had a volume average particle size D50 of 6.8 μm and a volume particle size distribution index of 1.22.

[0548] Except that magenta toner particles (A3) are used instead of black toner particles (A1), magenta toner (A3) is obtained in the same way as black toner (A1).

[0549] The developer (C3) is obtained in the same way as the developer (C1), except that a magenta toner (A3) is used instead of a black toner (A1).

[0550] [Preparation of yellow tone particles (A4), yellow tone agent (A4), and developer (C4)]

[0551] In the preparation of black toner particles (A1), 25 parts of colorant particle dispersion (A4) were used instead of colorant particle dispersion (A1). Otherwise, yellow toner particles (A4) were obtained in accordance with the preparation method of black toner particles (A1). The obtained toner particles had a volume average particle size D50 of 7.4 μm and a volume particle size distribution index of 1.19.

[0552] A yellow toner (A4) is obtained in the same way as the black toner (A1), except that yellow toner particles (A4) are used instead of black toner particles (A1).

[0553] The developer (C4) is obtained in the same way as the developer (C1), except that a yellow toner (A4) is used instead of a black toner (A1).

[0554] <Production of Overprinted Printed Materials>

[0555] [Crimped Printed Matter (A1)]

[0556] A developer (A1) containing pressure phase change particles is supplied to the developer of the Color1000 Press modified machine manufactured by Fuji Xerox Corporation. The developer is filled with black, cyan, magenta and yellow image-forming developers (C1) to (C4).

[0557] The recording paper (OK Prince fiberless paper, manufactured by Oji Paper Co., Ltd.) used as the recording medium is produced in a manner that allows for the production of printed materials (pressed postcards) by Z-folding and overlapping. The pressing surface is the side on which the image area and the pressure phase change layer are formed on both sides.

[0558] A developer (A1) containing pressure phase change particles is stored in a pressure phase change layer developing machine located on the outermost surface of the image. An electrophotographic image forming apparatus, which stores developers (C1) to (C4) in individual color developing machines, simultaneously outputs the image section and the pressure phase change layer. The pressure phase change layer is output to the laminating surface of the laminating postcard, while only the toner for image formation is output to the areas constituting the recipient's name side and the back side.

[0559] It should be noted that the thickness of the pressure phase change layer formed on the image section is adjusted so that the relationship between the thickness of the pressure phase change layer and the thickness of the image section satisfies Equation 1 using the X1 and Y1 values ​​shown in Table 1.

[0560] Next, the surface with the image section and the pressure phase change layer is used as the pressing surface. The recording paper is folded in a Z-fold and pressed using a modified PRESSLE LEADA (Toppan Forms Co., Ltd.) pressing and sealing machine to produce a pressed printed product (A1).

[0561] [Crimped Printed Matter (A2~(A19))]

[0562] Except for the conditions shown in Table 1, press-printed products (A2) to (A19) are made in the same manner as press-printed products (A1).

[0563] <Evaluation>

[0564] The following is an evaluation of the difference in pressing force between the front and back pressing surfaces of each printed material obtained by Z-folding.

[0565] 〇: Pressure difference less than 0.5, no damage occurred.

[0566] ×: Damage occurs when the pressure difference is above 0.5.

[0567]

[0568] As can be seen from the above results, compared with the comparative example, in this embodiment, the difference in pressing force between the front and back pressing surfaces of each printed product obtained by pressing with Z-fold is small, and the pressing force deviation of the pressing surfaces is reduced.

[0569] Example B

[0570] Preparation of dispersions containing styrene-based resin particles

[0571] [Preparation of styrene-based resin particle dispersion (St1)]

[0572] Styrene: 390 portions

[0573] • n-Butyl acrylate: 100 parts

[0574] Acrylic acid: 10 parts

[0575] • Dodecanthiol: 7.5 parts

[0576] The above materials are mixed and dissolved to prepare a monomer solution.

[0577] Eight parts of anionic surfactant (manufax2A1 manufactured by Dow Chemical Company) were dissolved in 205 parts of ion-exchanged water, and the above monomer solution was added for dispersion and emulsification to obtain an emulsion.

[0578] 2.2 parts of anionic surfactant (Dowfax2A1 manufactured by Dow Chemical Company) were dissolved in 462 parts of ion-exchanged water and added to a polymerization flask equipped with a stirrer, thermometer, reflux cooling tube and nitrogen inlet tube. The mixture was heated to 73°C with stirring and maintained.

[0579] Dissolve 3 parts of ammonium persulfate in 21 parts of ion-exchanged water and add it dropwise to the polymerization flask over 15 minutes using a metering pump. Then add the emulsion dropwise over 160 minutes using a metering pump.

[0580] Then, while stirring slowly and continuously, the polymerization flask was kept at 75°C for 3 hours, and then returned to room temperature (25°C).

[0581] Thus, a styrene-based resin particle dispersion (St1) was obtained, which contains styrene-based resin particles, the volume average particle size (D50v) of the resin particles is 174 nm, the weight average molecular weight determined by GPC (UV detection) is 49 kJ, the glass transition temperature of the styrene-based resin is 54 °C, and the solid content is 42% by mass.

[0582] The styrene-based resin particle dispersion (St1) was dried, and the styrene-based resin particles were removed. The thermal behavior of the particles in the temperature range of -100°C to 100°C was analyzed using a differential scanning calorimeter (Shimadzu DSC-60A). One glass transition temperature was observed. The glass transition temperatures are shown in Table 2.

[0583] [Preparation of styrene-based resin particle dispersions (St2) to (St13)]

[0584] As shown in Table 2, the monomers were changed. In addition, styrene-based resin particle dispersions (St2) to (St13) were prepared in the same manner as the preparation of styrene-based resin particle dispersion (St1).

[0585] In Table 2, the individual units are recorded using the following abbreviations.

[0586] Styrene: St, n-Butyl acrylate: BA, 2-Ethylhexyl acrylate: 2EHA, Ethyl acrylate: EA, 4-Hydroxybutyl acrylate: 4HBA, Acrylic acid: AA, Methacrylic acid: MAA, 2-Carboxyethyl acrylate: CEA

[0587] [Table 2]

[0588]

[0589] Preparation of dispersions containing composite resin particles

[0590] [Preparation of composite resin particle dispersion (M1)]

[0591] • Styrene-based resin particle dispersion (St1): 1190 parts (500 parts solids)

[0592] · 2-Ethylhexyl acrylate: 250 parts

[0593] • n-Butyl acrylate: 250 parts

[0594] • Ion-exchanged water: 982 samples

[0595] The above materials were added to a polymerization flask, stirred at 25°C for 1 hour, and then heated to 70°C.

[0596] Dissolve 2.5 parts of ammonium persulfate in 75 parts of ion-exchanged water and add it dropwise to the polymerization flask over 60 minutes using a metering pump.

[0597] Next, while stirring slowly and continuously, the polymerization flask was kept at 70°C for 3 hours, and then returned to room temperature (25°C).

[0598] Thus, a composite resin particle dispersion (M1) is obtained, which contains composite resin particles, the volume average particle size (D50v) of the resin particles is 219 nm, the weight average molecular weight of the composite resin is 219 kJ as determined by GPC (UV detection), and the solid content is 32 g / L.

[0599] The composite resin particle dispersion (M1) was dried, and the composite resin particles were removed. The thermal behavior in the temperature range of -150℃ to 100℃ was analyzed using a differential scanning calorimeter (Shimadzu DSC-60A). Two glass transition temperatures were observed. The glass transition temperatures are shown in Table 3.

[0600] [Preparation of composite resin particle dispersions (M2) to (M21)]

[0601] As described in Table 3, the styrene-based resin particle dispersion (St1) was modified, or the polymerization composition of the (meth)acrylate-based resin was modified as described in Table 3. In addition, composite resin particle dispersions (M2) to (M21) were prepared in the same manner as the preparation of composite resin particle dispersion (M1).

[0602] [Preparation of composite resin particle dispersions (M22) to (M27)]

[0603] Adjust the amounts of 2-ethylhexyl acrylate and n-butyl acrylate, and prepare composite resin particle dispersions (M22) to (M27) in the same manner as the preparation of composite resin particle dispersion (M1).

[0604] In Table 3, the following abbreviations are used to represent individual units.

[0605] Styrene: St, n-Butyl acrylate: BA, 2-Ethylhexyl acrylate: 2EHA, Ethyl acrylate: EA, 4-Hydroxybutyl acrylate: 4HBA, Acrylic acid: AA, Methacrylic acid: MAA, 2-Carboxyethyl acrylate: CEA, Hexyl acrylate: HA, Propylene acrylate: PA

[0606] [Table 3]

[0607]

[0608] <Preparation of Pressure-Induced Phase Change Particles>

[0609] [Preparation of pressure phase change particles (1) and developer (1)]

[0610] • Composite resin particle dispersion (M1): 504 parts

[0611] • Ion-exchanged water: 710 parts

[0612] • Anionic surfactant (manufactured by Dow Chemical Company, Dowfax 2A1): 1 part

[0613] The above materials were added to a reaction vessel equipped with a thermometer and a pH meter. A 1.0% (w / w) nitric acid aqueous solution was added at 25°C to adjust the pH to 3.0. While dispersing using a homogenizer (IKA, ULTRA-TURRAX T50) at 5000 rpm, 23 parts of a 2.0% (w / w) aluminum sulfate aqueous solution were added. Next, a stirrer and heating mantle were placed in the reaction vessel, and the temperature was increased to 40°C at a rate of 0.2°C / min. After exceeding 40°C, the temperature was increased at a rate of 0.05°C / min. Particle size was measured every 10 minutes using a Multisizer II (50 μm pore size, Beckman Coulter). Once the volume average particle size reached 5.0 μm, the temperature was maintained, and 170 parts of a styrene-based resin particle dispersion (St1) were added over 5 minutes. After addition, the mixture was maintained at 50°C for 30 minutes, and then a 1.0% (w / w) sodium hydroxide aqueous solution was added to adjust the pH of the slurry to 6.0. Next, the pH was adjusted to 6.0 every 5°C, while the temperature was increased to 90°C at a rate of 1°C / min and maintained at 90°C. The particle shape and surface properties were observed using an optical microscope and a field emission scanning electron microscope (FE-SEM). The results confirmed particle aggregation at the 10th hour, so the container was cooled to 30°C with cooling water for 5 minutes.

[0614] The cooled slurry was passed through a 15μm mesh nylon screen to remove coarse particles. The slurry that had passed through the screen was then filtered under reduced pressure using a suction device. The remaining solids on the filter paper were crushed as finely as possible by hand and added to 10 times the volume of the solids in ion-exchanged water (30°C), and stirred for 30 minutes. Then, reduced pressure filtration was performed again using a suction device, and the remaining solids on the filter paper were crushed as finely as possible by hand and added to 10 times the volume of the solids in ion-exchanged water (30°C), and stirred for 30 minutes. The filtrate was then filtered under reduced pressure again using a suction device, and the conductivity of the filtrate was measured. This process was repeated until the conductivity of the filtrate reached below 10 μS / cm, at which point the solids were washed away.

[0615] The cleaned solid components were finely crushed using a wet-dry granulator (wet granulator) and then vacuum dried in an oven at 25°C for 36 hours to obtain master particles (1). The volume average particle size of master particles (1) was 8.0 μm.

[0616] 100 parts of master particles (1) were mixed with 1.5 parts of hydrophobic silica (manufactured by NIPPON AEROSIL Co., Ltd., RY50) and mixed for 30 seconds at a rotation speed of 13,000 rpm using a sample mill. The mixture was then sieved using a vibrating sieve with a mesh size of 45 μm to obtain pressure phase change particles (1).

[0617] Using pressure-dependent phase change particles (1) as samples, the thermal behavior in the temperature range of -150°C to 100°C was analyzed using a differential scanning calorimeter (Shimadzu DSC-60A). Two glass transition temperatures were observed. The glass transition temperatures are shown in Table 4.

[0618] The temperatures T1 and T2 of the pressure phase change particles (1) were determined using the above measurement method. The results showed that the pressure phase change particles (1) satisfied Equation 1, “10℃≦T1-T2”.

[0619] The cross-section of the pressure phase change particles (1) was observed using a scanning electron microscope (SEM), revealing an island structure. The pressure phase change particles (1) have a core containing island phases and a shell without island phases. The island phases consist of styrene-based resins, and the island phases consist of (meth)acrylate-based resins. The average diameter of the island phases was determined using the methods described above. The average diameter of the island phases is shown in Table 4.

[0620] Ten parts of pressure phase change particles (1) and 100 parts of the resin-coated carrier were added to a V-type mixer and stirred for 20 minutes. Then, the mixture was sieved using a vibrating screen with a mesh size of 212 μm to obtain developer (1).

[0621] • Mn-Mg-Sr ferrite particles (average particle size 40 μm): 100 parts

[0622] Toluene: 14 parts

[0623] • Polymethyl methacrylate: 2 parts

[0624] • Carbon black (VXC72: made from Cabot): 0.12 parts

[0625] The above-mentioned materials, excluding ferrite particles, were mixed with glass beads (1 mm in diameter, in equal amounts to toluene) and stirred for 30 minutes at 1200 rpm using a sand mill manufactured by Kansai Paint Co., Ltd., to obtain a dispersion. This dispersion and ferrite particles were then added to a vacuum degassing kneader and dried under reduced pressure with stirring to obtain a resin-coated carrier.

[0626] [Preparation of pressure phase change particles (2) to (27) and developer (2) to (27)]

[0627] As shown in Table 4, the composite resin particle dispersion and the styrene-based resin particle dispersion were changed. Pressure phase change particles (2) to (27) and developer (2) to (27) were prepared in the same way as the preparation of pressure phase change particles (1).

[0628] The temperatures T1 and T2 of the pressure phase change particles (2) to (27) were determined using the above measurement method. The results showed that all the pressure phase change particles (2) to (27) satisfied Equation 1 "10℃≦T1-T2".

[0629] [Evaluation of pressure-responsive phase transitions]

[0630] The temperature difference (T1-T3) was determined as an indicator of how easily particles undergo a phase transition due to pressure. Each particle was used as a sample, and temperatures T1 and T3 were measured using a flow testing instrument (Shimadzu CFT-500). The temperature difference (T1-T3) was then calculated. Table 4 shows the temperature difference (T1-T3).

[0631] [Evaluation of crimpability]

[0632] As a manufacturing device for printed materials, preparation Figure 3 The apparatus shown is a printing manufacturing apparatus that includes a printing mechanism and a pressing mechanism with a folding device and a pressing device. The printing mechanism is a five-drum series printing mechanism that simultaneously forms the image on the recording medium and imparts pressure phase-change particles, and is an intermediate transfer printing mechanism.

[0633] The printing unit has five developers, each containing pressure phase change particles (or comparative particles), yellow toner, magenta toner, cyan toner, and black toner. The yellow toner, magenta toner, cyan toner, and black toner are commercially available products manufactured by Fuji Xerox.

[0634] As a recording medium, we prepared postcard paper V424 manufactured by Fuji Xerox.

[0635] The image formed on the postcard paper is an image with an area density of 30% that contains both black text and full-color photographic images, formed on one side of the postcard paper.

[0636] The amount of pressure-sensitive phase change particles (or particles for comparison) imparted in the image-forming area of ​​the postcard paper is 3 g / m². 2 .

[0637] The folding device is a device for folding postcard paper in half with the image section forming surface facing inwards.

[0638] The pressurization device was set to a pressure of 90 MPa.

[0639] Under the above-described apparatus and conditions, 10 postcards are produced consecutively by folding them in half with the image forming surfaces facing inwards and fixing the image forming surfaces together.

[0640] The 10th postcard was cut along its long side to a width of 15mm to create a rectangular test piece, which was then subjected to a 90-degree peel test. The peeling speed for the 90-degree peel test was 20mm / min. Regarding the sample tensile amount (distance) at the time of measurement, loads (N) were collected at 0.4mm intervals from 10mm to 50mm after the start of the test, and the average value was calculated. The loads (N) of the three test pieces were then averaged. The required peel loads (N) were graded according to the following criteria. The results are shown in Table 4.

[0641] A: 0.8N or more

[0642] B: Above 0.6N and less than 0.8N

[0643] C: Above 0.4N, less than 0.6N

[0644] D: Above 0.2N and less than 0.4N

[0645] E: less than 0.2N

[0646] [Table 4]

[0647]

Claims

1. A printed matter, wherein, The recording medium can be folded and pressed together using the surface where the image element and pressure phase change layer are formed as the pressing surface, or the recording medium can be overlapped and pressed together with other recording media using the surface where the image element and pressure phase change layer are formed as the pressing surface. The average thickness of the pressure phase change layer formed on the image portion of the pressing surface of the recording medium is greater than the average thickness of the pressure phase change layer formed on the non-image portion. The thicker the image portion, the thicker the pressure phase change layer formed on the image portion.

2. The printed matter as claimed in claim 1, wherein, The average thickness of the pressure phase change layer formed on the aforementioned image portion is 0.5 μm or more and 5.0 μm or less. The average thickness of the aforementioned image portion is greater than 0 μm and less than 5.0 μm. Furthermore, when the thickness BR of the aforementioned image portion is 0.5 μm or less, the following equations (1) to (3) are satisfied. Equation (1): AR = X1 × BR + Y1 Equation (2): 2≦X1≦10 Equation (3): 0.5≦Y1≦2 In equation (1), AR represents the thickness (μm) of the pressure phase change layer formed on the image portion, and BR represents the thickness (μm) of the image portion; wherein, the thicknesses represented by AR and BR are the thickness of the pressure phase change layer directly above the image portion and the thickness of the image portion directly below the pressure phase change layer whose thickness has been determined.

3. The printed matter as described in claim 1, wherein, The coverage of the pressure phase change layer formed on the above-mentioned image section is 60% to 100%.

4. The printed matter as described in claim 3, wherein, The coverage rate of the pressure phase change layer formed in the non-image section is 10% to 60%.

5. The printed matter as claimed in claim 1, wherein, The image section mentioned above is the toner image section.

6. The printed matter as claimed in claim 1, wherein, The aforementioned pressure phase change layer includes: Styrene-based resins contain styrene and other vinyl monomers in their polymer composition; and (Meth)acrylate resins contain at least two types of (meth)acrylates in their polymer composition, and the (meth)acrylates account for more than 90% by mass of the total polymer composition. The pressure phase change layer has at least two glass transition temperatures, and the difference between the lowest and highest glass transition temperatures is more than 30°C.

7. The printed matter as claimed in claim 6, wherein, In all the polymer components of the above-mentioned styrene-based resins, styrene accounts for more than 60% by mass and less than 95% by mass.

8. The printed matter as claimed in claim 6, wherein, Among the at least two types of (meth)acrylates included as polymerizing components in the above-mentioned (meth)acrylate resins, the mass ratio of the two types with the highest mass proportion is 80:20 to 20:

80.

9. A method for manufacturing printed matter, as described in claim 1, comprising the following steps: The pressure phase change particle application step involves applying pressure phase change particles to a recording medium on which an image section is formed. The fixing step involves fixing at least the aforementioned pressure phase change particles onto the aforementioned recording medium to form a pressure phase change layer; and In the pressing step, the recording medium is folded and pressed together using the surface where the image portion and the pressure phase change layer are formed as the pressing surface, or the recording medium is overlapped and pressed together with other recording media using the surface where the image portion and the pressure phase change layer are formed as the pressing surface. The average thickness of the pressure phase change layer formed on the image portion of the pressing surface of the recording medium is greater than the average thickness of the pressure phase change layer formed on the non-image portion, so that the amount of pressure phase change particles imparted on the image portion is greater than the amount of pressure phase change particles imparted on the non-image portion. The thicker the image portion, the thicker the pressure phase change layer formed on the image portion.

Images