Laminated printed matter

Abstract

To provide a pressure-bonded printed matter in which peeling history of a pressure-bonded surface can be visually confirmed.SOLUTION: A pressure-bonded printed matter comprises: a recording medium pressure-bonded by overlapping a pair of pressure-bonded surfaces; an image layer provided on one or both of the pair of pressure-bonded surfaces of the recording medium; a first pressure-bonded layer provided on one or both of the pair of pressure-bonded surfaces of the recording medium to pressure-bond the pair of pressure-bonded surfaces; and a second pressure-bonded layer provided on one or both of the pair of pressure-bonded surfaces of the recording medium to pressure-bond the pair of pressure-bonded surfaces, and provided at a position pressure-bonded by facing the first pressure-bonded layer. A track of a shape of the second pressure-bonded layer is visually recognized in the first pressure-bonded layer pressure-bonded by facing the second pressure-bonded layer when the pair of pressure-bonded surfaces of the recording medium are peeled off to observe the pair of pressure-bonded surface in a developed matter obtained by developing the recording medium in plan view.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pressure-bonded printed matter. [Background technology]

[0002] Patent Document 1 discloses a "method for producing a pressure-bonded printed matter, characterized in that when an adhesive is applied to the adhesive surface of a paper sheet to be folded, an information pattern is formed using the adhesive."

[0003] Patent Document 2 discloses an information carrier medium comprising: a base sheet on which a crease has been formed in advance for the purpose of deformation into a folded state; two carrier areas formed on both sides of the crease on one surface of the base sheet, each carrying visually decodable encrypted cryptographic information; a release layer formed on one of the two carrier areas, which fixes the carried cryptographic information in a state that allows it to be peeled off from the base sheet; and an adhesive layer formed on at least one of the two carrier areas, which covers the cryptographic information, and which is separated after the two carrier areas are adhered to each other as the base sheet is folded, thereby enabling the cryptographic information to be transferred from one carrier area to the other carrier area upon peeling from the release layer.

[0004] Patent document 3 discloses a "method for applying powder adhesive to postcards to be pressed, characterized in that powder adhesive is applied in a striped pattern with a predetermined direction to the two surfaces of the postcards to be pressed." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-155518 [Patent Document 2] Patent No. 5912334 specification [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-073972 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a pressure-bonded printed matter in which the peeling history of the pressure-bonded surface can be visually confirmed. [Means for solving the problem]

[0007] Specific means for solving the above problems include the following aspects. <1> a recording medium in which a pair of pressure-bonding surfaces are superimposed and pressure-bonded together; an image layer provided on one or both of the pair of pressure-contact surfaces of the recording medium; a first pressure-bonding layer provided on one or both of a pair of pressure-bonding surfaces of the recording medium, the first pressure-bonding layer pressing the pair of pressure-bonding surfaces together; A second pressure-bonding layer is provided on one or both of the pair of pressure-bonding surfaces of the recording medium and presses the pair of pressure-bonding surfaces together, the second pressure-bonding layer being provided at a position where it is in face-to-face pressure contact with the first pressure-bonding layer; Equipped with When a pair of pressure-bonded surfaces of the recording medium are peeled from each other and the pair of pressure-bonded surfaces in the unfolded product of the recording medium are observed in a planar view, a trace of the shape of the second pressure-bonded layer can be seen on the first pressure-bonded layer that was face-to-face pressed against the second pressure-bonded layer. <2> When the pair of pressure-bonded surfaces in the development are observed in a plan view, the trace of the shape of the second pressure-bonded layer visible on the first pressure-bonded layer that was face-to-face pressed with the second pressure-bonded layer is visible due to the difference in gloss between the area where the second pressure-bonded layer was face-to-face pressed in the first pressure-bonded layer and the periphery of that area. <1> The laminated printed matter described in 1. <3> The height of the second pressure-sensitive adhesive layer from the pressure-sensitive adhesive surface is greater than the heights of the image layer and the first pressure-sensitive adhesive layer from the pressure-sensitive adhesive surface. <1> or <2> The laminated printed matter described in 1. <4> The height of the image layer and the first pressure-sensitive adhesive layer from the pressure-sensitive adhesive surface is 80% or less of the height of the second pressure-sensitive adhesive layer from the pressure-sensitive adhesive surface. <2> The laminated printed matter described in 1. <5> The height of the second pressure-bonding layer from the pressure-bonding surface is 0.5 μm or more and 12 μm or less. <3> or <4> The laminated printed matter described in 1. <6> the second pressure-bonding layer is provided on both of the pair of pressure-bonding surfaces of the recording medium, The second pressure-bonding layers provided on both of the pair of pressure-bonding surfaces of the recording medium are partially overlapped with each other to press the pair of pressure-bonding surfaces together. <1> ~ <5> The laminated printed matter according to any one of claims 1 to 4. <7> The shape of the second pressure-bonding layer includes a linear shape. <1> ~ <6> The laminated printed matter according to any one of claims 1 to 4. <8> The line width of the linear shape is 0.2 mm or more and 3 mm or less. <7> The laminated printed matter described in 1. <9> The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are each composed of a styrene-based resin containing styrene and other vinyl monomers as polymerization components, and a (meth)acrylic acid ester-based resin containing at least two types of (meth)acrylic acid esters as polymerization components, with the mass ratio of the (meth)acrylic acid esters in the total polymerization components being 90 mass% or more, and a pressure-sensitive phase transition resin having at least two glass transition temperatures, with the difference between the lowest glass transition temperature and the highest glass transition temperature being 30°C or more. <1> ~ <8> The laminated printed matter according to any one of claims 1 to 4. [Effects of the Invention]

[0008] <1> , <2> , or <3> According to the invention, a pressure-bonded printed matter is provided in which the peeling history of the pressure-bonded surface can be visually confirmed.

[0009] <4> According to the invention, a pressure-bonded printed matter is provided in which the peeling history of the pressure-bonded surface is easier to visually confirm than when the height of the image layer and first pressure-bonded layer from the pressure-bonded surface is more than 80% of the height of the second pressure-bonded layer from the pressure-bonded surface. <5> According to the invention, a pressure-bonded printed matter is provided in which the peel history of the pressure-bonded surfaces is easier to visually check than when the height of the second pressure-bonding layer from the pair of pressure-bonded surfaces is less than 0.5 μm. <6> According to the invention, a pressure-bonded printed matter is provided in which the peeling history of the pressure-bonded surface is easier to visually confirm than when the second pressure-bonded layer is provided on only one of the pair of pressure-bonded surfaces of the recording medium. <7> According to the invention, a pressure-bonded printed matter is provided in which the peel history of the pressure-bonded surface can be more easily visually confirmed than when the shape of the second pressure-bonded layer does not include a linear shape. <8> According to the invention, a pressure-bonded printed matter is provided in which the peel history of the pressure-bonded surface can be more easily confirmed visually than when the line width of the linear shape is less than 0.2 mm or more than 3 mm.

[0010] <9> According to the invention, a pressure-bonded printed matter is provided in which the first pressure-bonded layer and the second pressure-bonded layer are made of a pressure-induced phase transition resin containing a styrene-based resin and a (meth)acrylic ester-based resin, and the (meth)acrylic ester-based resin contains a pressure-induced phase transition resin that is a homopolymer of (meth)acrylic ester, and in which the first pressure-bonded layer and the second pressure-bonded layer have superior adhesiveness compared to when the (meth)acrylic ester-based resin contains a pressure-induced phase transition resin that is a homopolymer of (meth)acrylic ester. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic plan view showing an example of a medium before being pressed to produce a pressure-bonded printed matter according to an embodiment of the present invention. FIG. [Figure 2] 2 is a schematic partial cross-sectional view showing an example of a medium before being pressed for producing a pressure-bonded printed matter according to the present embodiment, taken along line AA in FIG. 1. FIG. [Figure 3] 1 is a schematic plan view showing an example of a development of a pressure-bonded printed product according to the present embodiment, in which a pair of pressure-bonded surfaces of a recording medium are peeled off. FIG. [Figure 4] 10 is a schematic plan view showing an example of a development in which a pair of pressure-bonded surfaces of a recording medium of a pressure-bonded printed product according to the present embodiment are peeled off, and then pressure-bonded and peeled off again. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described. These descriptions and examples are for illustrating the embodiment, and are not intended to limit the scope of the embodiment.

[0013] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively.

[0014] In the present specification, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. In addition, in the present specification, the upper or lower limit of a numerical range may be replaced with a value shown in the examples.

[0015] In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0016] When embodiments are described herein with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the size of components in each drawing is conceptual, and the relative size relationships between components are not limited to these. Furthermore, components having substantially the same function are given the same reference numerals throughout the drawings, and redundant descriptions may be omitted as appropriate.

[0017] In this specification, each component may contain multiple corresponding substances. When referring to the amount of each component in a composition in this specification, if multiple substances corresponding to each component are present in the composition, the total amount of the multiple substances present in the composition is meant unless otherwise specified.

[0018] In this specification, the particles corresponding to each component may include multiple types. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0019] In this specification, the expression "(meth)acrylic" means either "acrylic" or "methacrylic".

[0020] <Compression printed matter> The pressure-bonded printed matter according to this embodiment is a recording medium in which a pair of pressure-bonding surfaces are superimposed and pressure-bonded together; an image layer provided on one or both of the pair of pressure-contact surfaces of the recording medium; a first pressure-bonding layer provided on one or both of a pair of pressure-bonding surfaces of the recording medium, the first pressure-bonding layer pressing the pair of pressure-bonding surfaces together; A second pressure-bonding layer is provided on one or both of the pair of pressure-bonding surfaces of the recording medium and presses the pair of pressure-bonding surfaces together, the second pressure-bonding layer being provided at a position where it is in face-to-face pressure contact with the first pressure-bonding layer; Equipped with. Then, when the pair of pressure-bonded surfaces of the recording medium are peeled away from each other and the pair of pressure-bonded surfaces in the unfolded product of the recording medium are observed in a planar view, traces of the shape of the second pressure-bonded layer can be seen on the first pressure-bonded layer that was face-to-face pressed against the second pressure-bonded layer.

[0021] Here, "laminated printed matter" refers to a printed matter in which one recording medium is folded and laminated, for example, by V-folding, Z-folding, gatefolding, etc., or a printed matter that has at least a laminate in which two recording media are laminated and laminated.

[0022] "A pair of pressure-bonding surfaces of a recording medium" refers to the surfaces of the recording medium that face each other when pressed together, and on one or both of which an image layer, a first pressure-bonding layer, and a second pressure-bonding layer are formed, respectively. Specifically, in the case of a V-folded press-bonded printed material, the "pair of press-bonded surfaces of the recording medium" refers to the surfaces that face each other and overlap due to the valley fold, with the valley fold line as the boundary. In this case, the recording medium has a pair of press-bonded surfaces on only one side. In addition, in the case of a press-bonded print in which the recording medium is folded in a Z-shape, the "pair of press-bonded surfaces of the recording medium" refers to the surfaces that face each other due to the valley fold and the surfaces that face each other due to the mountain fold, with the valley fold and the mountain fold being the boundaries. In this case, the recording medium has a pair of press-bonded surfaces on both sides. In addition, in the case of a press-bonded printed product in which two recording media are superimposed, the "pair of press-bonded surfaces of the recording media" refers to the surfaces of the two recording media that face each other. In this case, the press-bonded surfaces on only one side of the recording media are considered to be the pair of press-bonded surfaces. The image layer, the first pressure-sensitive adhesive layer, and the second pressure-sensitive adhesive layer may be provided directly on the pressure-sensitive adhesive surface, or may be provided via another layer.

[0023] The "pressure layer (first pressure layer and second pressure layer)" is preferably a transparent or semi-transparent layer from the viewpoint of suppressing the obstruction of visibility of the image layer. However, if the pressure layer is not provided on the image layer, it may be non-transparent. The term "transparent or translucent" means that the visible light transmittance measured according to JIS K 7361-1:1997 (or ISO 13468-1:1996) is 50% or more and 100% or less (preferably 80% or more and 100% or less, more preferably 90% or more and 100% or less).

[0024] With the above-described configuration, the pressure-bonded printed matter according to this embodiment allows the peeling history of the pressure-bonded surface (that is, the opening history of the pressure-bonded printed matter) to be visually confirmed for the following reasons.

[0025] Conventionally, for example, in order to conceal information formed in an image layer, a pressure-bonded printed matter (e.g., a pressure-bonded postcard) has been known, which is made of a recording medium in which a pair of pressure-bonded surfaces are laminated together, with at least the surface of the area in which the image layer to be concealed is provided as a pressure-bonded surface.

[0026] However, if a pair of pressure-bonded surfaces of a recording medium (i.e., a pair of pressure-bonded surfaces of a pressure-bonded printed material) is peeled off once and then re-pressed, the past peeling history (i.e., opening history) is not known, and, for example, leakage of information contained in the image layer goes unnoticed.

[0027] Therefore, in the laminated printed matter of this embodiment, in addition to the conventional laminated layer (corresponding to the "first laminated layer" in this embodiment) that laminates a pair of laminated surfaces of a recording medium, it also has a second laminated layer that laminates the pair of laminated surfaces together, and is positioned so that it is face-to-face laminated to the first laminated layer. When the pair of pressure-bonded surfaces of the second pressure-bonded layer are peeled off and the pair of pressure-bonded surfaces in the developed product in which the recording medium is developed are observed in a plan view, a trace of the shape of the first pressure-bonded layer that was face-to-face pressed to the second pressure-bonded layer is visible. In other words, the shape of the second pressure-bonded layer is visible because the trace of face-to-face pressing to the second pressure-bonded layer remains on the first pressure-bonded layer.

[0028] Therefore, even when the pair of pressure-bonded surfaces of the recording medium are peeled off once and then pressed and peeled off again, traces of the shape of the second pressure-bonded layer are visible on the first pressure-bonded layer that has been face-to-face pressed to the second pressure-bonded layer by the second pressure-bonding. At this time, the traces of the shape of the second pressure-bonded layer visible on the first pressure-bonded layer after the second pressure-bonding and peeling are visually shifted from the traces of the shape of the second pressure-bonded layer visible on the first pressure-bonded layer after the initial pressure-bonding and peeling. This is because even if one tries to precisely repeat the crimping so that the pair of crimped surfaces are crimped in the same positional relationship as in the initial crimping, it is difficult to reproduce this, and when the crimping is repeated, the areas where the first and second crimped layers are crimped face-to-face are shifted compared to the initial crimping.

[0029] That is, after the first bonding and peeling, one trace of the shape of the second bonding layer is visible on the first bonding layer. On the other hand, after once bonding and peeling and then again bonding and peeling, two shifted traces of the shape of the second bonding layer are visible on the first bonding layer. This makes it possible to visually determine whether the bonded surface of the pressure-bonded printed matter has been peeled off once.

[0030] As described above, in the pressure-bonded printed matter according to this embodiment, the peeling history of the pressure-bonded surface (i.e., the opening history of the pressure-bonded printed matter) can be visually confirmed, which makes it possible to detect, for example, the leakage of information including the image layer.

[0031] In the laminated printed matter of this embodiment, when a pair of laminated surfaces in the developed product are observed in a planar view, it is preferable that the visible trace of the shape of the second laminated layer on the first laminated layer that was face-to-face laminated to the second laminated layer is visible due to the difference in gloss between the area on the first laminated layer where the second laminated layer was face-to-face laminated and the surrounding area. The difference in gloss level allows the trace of the shape of the second pressure-sensitive adhesive layer to be visible on the first pressure-sensitive adhesive layer, so that when the first pressure-sensitive adhesive layer is provided on the image layer, the visibility of the image layer is not impaired.

[0032] The difference in gloss (absolute value) between the area of ​​the first pressure-bonded layer where the second pressure-bonded layer was face-to-face pressed and the surrounding area of ​​that area is preferably 1 or more and 8 or less (preferably 2 or more and 5 or less) from the viewpoint of improving the visibility of the trace of the shape of the second pressure-bonded layer.

[0033] Here, the glossiness indicates the glossiness obtained by measurement at a measurement angle of 60° in accordance with JIS Z 8741:1997.

[0034] In the pressure-bonded printed matter according to this embodiment, an example of a state in which a trace of the shape of the second pressure-bonded layer is visible on the first pressure-bonded layer due to a difference in glossiness is when the height of the second pressure-bonded layer from the pressure-bonded surface is greater than the height of the image layer and the first pressure-bonded layer from the pressure-bonded surface.

[0035] If the height from the pressure-bonding surface of the second pressure-bonding layer is increased relative to the height from the pressure-bonding surface of the image layer and the first pressure-bonding layer, when a pair of pressure-bonding surfaces of the recording medium are pressed together, the pressure applied to the area of ​​the first pressure-bonding layer that is face-to-face pressed together with the second pressure-bonding layer becomes greater than the pressure applied to the surrounding area of ​​that area (i.e., the area other than that area). Therefore, when the pair of pressure-bonded surfaces of the recording medium are peeled off, the surface properties (specifically, surface roughness) will differ between the area of ​​the first pressure-bonded layer that is face-to-face bonded to the second pressure-bonded layer and the area surrounding that area. Therefore, the difference in glossiness causes the trace of the shape of the second pressure-bonded layer formed on the first pressure-bonded layer to be visible. When the pressure-bonded printed matter is opened, the "shift" of the traces of the shape of the two second pressure-bonded layers formed on the first pressure-bonded layer after the pair of pressure-bonded surfaces are pressed and peeled again is visible. As a result, the peeling history of the pressure-bonded surfaces (i.e., the opening history of the pressure-bonded printed matter) can be visually confirmed.

[0036] An example of a pressure-bonded printed matter according to this embodiment will be described below with reference to the drawings.

[0037] (Pre-press medium for producing press-printed items) The medium before being pressed to produce the pressure-bonded printed matter according to this embodiment will be described below. FIG. 1 is a schematic plan view showing an example of a medium before being pressed to produce a pressure-bonded printed matter according to this embodiment. Hereinafter, the "medium before compression bonding" will also be referred to as the "medium before compression bonding."

[0038] 1 includes, for example, a recording medium 10 having a pair of pressure-bonding surfaces 12 on one side thereof. An image layer 14, a first pressure-bonding layer 16, and a second pressure-bonding layer 18 are provided on both of the pair of pressure-bonding surfaces 12 of the recording medium 10. The pre-press medium 101 is a medium for producing a pressed printed matter, for example, by V-folding the recording medium 10 along the valley fold line shown by the dotted line in Figure 1, and then overlapping and pressing a pair of pressing surfaces 12 on one side.

[0039] The recording medium 10 may be, for example, paper, coated paper in which the surface of paper is coated with resin or the like, cloth, nonwoven fabric, resin film, resin sheet, or the like.

[0040] The image layer 14 is provided directly on both of the pair of pressure-contact surfaces 12 of the recording medium 10 . However, the image layer 14 may be provided directly on one of the pair of pressure-sensitive adhesive surfaces 12 of the recording medium 10. The image layer 14 may also be provided directly on the first pressure-sensitive adhesive layer 16.

[0041] Examples of the image layer 14 include a fixing layer for a toner image formed by an electrophotographic method, and an ink image layer formed by an inkjet method. The image layer 14 forms characters, symbols, figures (barcodes, QR codes (registered trademark), etc.), etc.

[0042] The first pressure-bonding layer 16 is a pressure-bonding layer that presses together the pair of pressure-bonding surfaces 12 of the recording medium 10 . The first bonding layer 16 is provided, for example, on both of the pair of bonding surfaces 12 . The first pressure-sensitive adhesive layer 16 is provided, for example, directly on the image layer 14 and directly on the recording medium 10. However, the first pressure-sensitive adhesive layer 16 may also be provided directly on the image layer 14 or directly on the recording medium 10.

[0043] The first pressure-bonding layer 16 is, for example, provided solidly on the entire surfaces of the pair of pressure-bonding surfaces 12. However, the first pressure-bonding layer 16 may also be provided in a pattern on a portion of the pair of pressure-bonding surfaces 12. For example, on each of a pair of pressure-bonding surfaces 12, linear or strip-shaped pressure-bonding layers may be arranged in a row as the first pressure-bonding layer 16, or dot-shaped (circular, polygonal, etc.) pressure-bonding layers may be arranged in a row as the first pressure-bonding layer 16. For example, the first bonding layer 16 may be provided on each of the outer edges of the pair of bonding surfaces 12 .

[0044] The second pressure-bonding layer 18 is a pressure-bonding layer that presses the pair of pressure-bonding surfaces 12 of the recording medium 10 together. The second pressure-bonding layer 18 is provided, for example, on both of the pair of pressure-bonding surfaces 12. However, the second pressure-bonding layer 18 may be provided on one of the pair of pressure-bonding surfaces 12.

[0045] The second pressure-sensitive adhesive layer 18 is provided, for example, directly on the first pressure-sensitive adhesive layer 16. However, the second pressure-sensitive adhesive layer 18 may also be provided directly on one or both of the image layer 14 and the recording medium 10. In addition, when the second pressure-sensitive adhesive layer 18 is provided directly on the first pressure-sensitive adhesive layer 16 and the first pressure-sensitive adhesive layer 16 and the second pressure-sensitive adhesive layer 18 are made of the same material, the second pressure-sensitive adhesive layer 18 is considered to be provided directly on the recording medium 10.

[0046] The second pressure-bonding layer 18 is provided at a position where it is in face-to-face pressure-bonding contact with the first pressure-bonding layer 16 when the pair of pressure-bonding surfaces 12 of the recording medium 10 are overlapped and pressure-bonded together.

[0047] The second pressure-bonding layers 18 are provided, for example, on parts of the pair of pressure-bonding surfaces 12, respectively, by patterning. Specifically, when a pair of pressure-bonding surfaces 12 of the recording medium 10 are overlapped and pressed together, the second pressure-bonding layer 18 provided on one pressure-bonding surface 12 and the second pressure-bonding layer 18 provided on the other pressure-bonding surface 12 are partially overlapped with each other and are positioned to press the pair of pressure-bonding surfaces 12 together. More specifically, for example, linear pressure-sensitive layers are arranged on each of the pair of pressure-sensitive surfaces 12 as the second pressure-sensitive layer 18. Then, for example, when the pair of pressure-sensitive surfaces 12 of the recording medium 10 are overlapped and pressure-bonded together, the linear pressure-sensitive layer provided on one pressure-sensitive surface 12 intersects with the linear pressure-sensitive layer provided on the other pressure-sensitive surface 12 (preferably at an acute angle of 25° to 90°, more preferably at an acute angle of 45° to 90°).

[0048] When the second pressure-sensitive adhesive layer 18 is provided on both of the pair of pressure-sensitive adhesive surfaces 12 of the recording medium 10 in this positional relationship, the visibility of the "misalignment" of the traces 20 of the shapes of the two second pressure-sensitive adhesive layers 18 formed on the first pressure-sensitive adhesive layer 16 after the pair of pressure-sensitive adhesive surfaces 12 are again pressed and peeled off after opening in the pressure-sensitive adhesive printed matter produced from the pre-press medium 101 is improved. This makes it easier to visually determine whether the pressure-sensitive adhesive surfaces 12 in the pressure-sensitive adhesive printed matter have been peeled off once, further improving the visibility of the peeling history.

[0049] The shape of the second pressure-bonding layer 18 is not limited to a linear shape, but may be a character shape, a strip shape, a dot shape (circular shape, polygonal shape), or other geometric patterns. For example, the second pressure-bonding layer 18 is not limited to an arrangement of linear second pressure-bonding layers, but may be an arrangement of character shapes, strip shapes, dot shapes, or other geometric patterns.

[0050] However, if the shape of the second pressure-bonded layer 18 includes a linear shape, the visibility of the "misalignment" of the traces 20 of the shapes of the two second pressure-bonded layers 18 formed on the first pressure-bonded layer 16 after the pair of pressure-bonded surfaces 12 are again pressed and peeled off after opening in the pressure-bonded printed matter produced from the pre-press medium 101 is improved. This makes it easier to visually determine whether the pressure-bonded surfaces 12 in the pressure-bonded printed matter have been peeled off once, further improving the visibility of the peeling history. In particular, if the line width of the linear shape is, for example, 0.2 mm or more and 3 mm or less (preferably 0.25 mm or more and 2 mm or less, more preferably 0.3 mm), the visibility of the ``misalignment'' of the traces 20 of the shapes of the two second pressure-sensitive layers 18 formed on the first pressure-sensitive layer 16 is improved. This makes it easier to visually determine whether or not the pair of pressure-bonded surfaces 12 in the pressure-bonded printed matter have been peeled off once, and makes it easier to visually confirm the peeling history.

[0051] Here, the shape of the second pressure-sensitive adhesive layer 18 is the shape when a pair of pressure-sensitive adhesive surfaces 12 of the recording medium 10 (or, in a pressure-sensitive printed matter, the pair of pressure-sensitive adhesive surfaces 12 are peeled off from each other and the recording medium 10 is unfolded) is observed in a planar view.

[0052] The height TA2 of the second pressure-bonding layer 18 from the pressure-bonding surface 12 is greater than, for example, the heights TG1 and TA1 of the image layer 14 and the first pressure-bonding layer 16 from the pressure-bonding surface 12 (see FIG. 2). If the height TA2 from the bonding surface 12 of the second pressure-sensitive adhesive layer 18 and the heights TG1 and TA1 from the bonding surface 12 of the image layer 14 and the first pressure-sensitive adhesive layer 16 are increased, when the pair of pressure-sensitive adhesive surfaces 12 of the recording medium 10 are pressed together, the pressure applied to the area of ​​the first pressure-sensitive adhesive layer 16 that is face-to-face pressed against the second pressure-sensitive adhesive layer 18 becomes greater than the pressure applied to the surrounding area of ​​that area (i.e., the area other than that area), and traces of the shape of the second pressure-sensitive adhesive layer formed on the first pressure-sensitive adhesive layer due to the difference in glossiness become visible.

[0053] In particular, if the heights TG1 and TA1 of the image layer 14 and the first pressure-sensitive adhesive layer 16 from the pressure-sensitive adhesive surface 12 are, for example, 80% or less (preferably 10% or more and 80% or less, more preferably 10% or more and 60% or less) of the height TA2 of the second pressure-sensitive adhesive layer 18 from the pressure-sensitive adhesive surface 12, the pressure applied to the area of ​​the first pressure-sensitive adhesive layer 16 that is face-to-face pressure-bonded to the second pressure-sensitive adhesive layer 18 will be greater than the pressure applied to the surrounding area of ​​that area (i.e., areas other than that area). In addition, from the viewpoint of improving the visibility of the traces of the shape of the second pressure-sensitive adhesive layer 18, the height TA2 of the second pressure-sensitive adhesive layer 18 from the pressure-sensitive adhesive surface 12 is, for example, 0.5 μm or more and 12 μm or less (preferably 2 μm or more and 8 μm or less, more preferably 6 μm or less).

[0054] As a result, in a laminated printed material made from a pre-laminated medium 101, after opening and again laminating and peeling a pair of laminating surfaces 12, the traces of the shapes of the two second laminating layers 18 formed on the first laminating layer 16 are more easily visible, making it easier to visually confirm the peeling history.

[0055] The height TA2 from the bonding surface 12 of the second pressure-sensitive adhesive layer 18, and the heights TG1 and TA1 from the bonding surface 12 of the image layer 14 and the first pressure-sensitive adhesive layer 16 are the heights when observing a cross section of the recording medium 10 (i.e., the developed objects 102, 103) cut in the thickness direction of the recording medium 10 (i.e., the developed objects 102, 103) by peeling off a pair of pressure-sensitive adhesive surfaces 12 from each other and developing the recording medium 10 in a pressure-bonded printed matter). Each height TG1, TA1, and TA2 is the arithmetic mean value of the height measured at three points in the area excluding the boundary portions of the layers when the image layer 14, the first pressure-sensitive adhesive layer 16, and the second pressure-sensitive adhesive layer 18 are viewed in a plane.

[0056] (Expanded version of the pressure-sensitive printed material) Next, a development of the pressure-bonded printed matter according to this embodiment, in which the pair of pressure-bonded surfaces of the recording medium are peeled off, will be described. FIG. 3 is a schematic plan view showing an example of a development of the pressure-bonded printed product according to this embodiment, in which the pair of pressure-bonded surfaces of the recording medium are peeled off.

[0057] The unfolded object 102 shown in Figure 3 is an unfolded object in which the pair of bonded surfaces 12 of the recording medium 10 in the pre-bonded medium 101 shown in Figure 1 is peeled off from each other to unfold the recording medium 10 in a bonded printed matter produced by bonding the pair of bonded surfaces 12 of the recording medium 10.

[0058] In the deployed object 102 shown in Figure 3, when the pair of pressure-bonded surfaces 12 are observed in a planar view, a trace 20 of the shape of the second pressure-bonded layer is formed and visible on the first pressure-bonded layer that was face-to-face pressure-bonded to the second pressure-bonded layer 18. Other aspects of the development 102 shown in FIG. 3 are the same as those of the pre-compression medium 101 shown in FIG.

[0059] (The laminated printed material was peeled off, then laminated and peeled off again.) Next, after the pair of pressure-bonded surfaces of the recording medium of the pressure-bonded printed product according to this embodiment are peeled off, the developed product that is pressure-bonded and peeled off will be described again. FIG. 4 shows a developed product obtained by peeling off the pair of pressure-bonded surfaces of the recording medium of the pressure-bonded printed matter according to this embodiment, and then pressing and peeling them again.

[0060] The deployed object 103 shown in FIG. 4 is a deployed object in which the pair of crimped surfaces 12 of the deployed object 102 shown in FIG. 3 are crimped and peeled again.

[0061] In the developed object 103 shown in Fig. 4, when the pair of pressure-bonded surfaces 12 are observed in a plan view, in addition to the trace 20 of the shape of the second pressure-bonded layer formed in the developed object 102 shown in Fig. 3 on the first pressure-bonded layer that was face-to-face pressure-bonded to the second pressure-bonded layer 18, a trace 20 of the shape of the second pressure-bonded layer is formed and visible at a position shifted from the trace 20 of the shape of the second pressure-bonded layer. In Fig. 3, 20A indicates the trace of the shape of the second pressure-bonded layer formed at the shifted position. Other aspects of the developed material 103 shown in FIG. 4 are the same as those of the developed material 102 shown in FIG. 3 (that is, the pre-compression medium 101 shown in FIG. 1).

[0062] As described above, in the pressure-bonded printed matter according to this embodiment, after the first bonding and peeling, a trace of the shape of one second pressure-bonded layer 18 is visible on the first pressure-bonded layer 16. On the other hand, after the pressure-bonded and peeled once and then the pressure-bonded and peeled again, shifted traces 20 of the shapes of two second pressure-bonded layers 18 are visible on the first pressure-bonded layer 16. This makes it possible to visually determine whether the pressure-bonded surface of the pressure-bonded printed matter has been peeled off once. Therefore, in the pressure-bonded printed product according to this embodiment, the peeling history of the pressure-bonded surface (i.e., the opening history of the pressure-bonded printed product) can be visually confirmed, which makes it possible to notice, for example, the leakage of information including the image layer.

[0063] (Materials of the pressure-bonding layer) Next, the materials constituting each pressure-bonded layer of the pressure-bonded printed matter according to this embodiment will be described. In the pressure-bonded printed matter according to this embodiment, the first pressure-bonding layer 16 and the second pressure-bonding layer 18 preferably contain a pressure-induced phase transition resin, from the viewpoint of improving the adhesiveness of the pair of pressure-bonding surfaces. Specifically, the pressure phase transition resin preferably includes a styrene-based resin containing styrene and other vinyl monomers as polymerization components, and a (meth)acrylic acid ester-based resin containing at least two types of (meth)acrylic acid esters as polymerization components, with the mass proportion of the (meth)acrylic acid esters in the total polymerization components being 90 mass% or more, and has at least two glass transition temperatures, with the difference between the lowest and highest glass transition temperatures being 30°C or more. More specifically, the first pressure-sensitive adhesive layer 16 and the second pressure-sensitive adhesive layer 18 are preferably pressure-sensitive adhesive layers formed by an electrophotographic method using a pressure-sensitive phase-transition toner containing a pressure-sensitive phase-transition resin.

[0064] However, the first pressure-sensitive layer 16 may also be composed of a well-known pressure-sensitive adhesive (natural rubber, modified natural rubber, (poly)isoprene rubber, butadiene rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, ethylene-propylene copolymer rubber, butyl rubber, chloroprene rubber, acrylic rubber, and other synthetic rubbers, aqueous emulsion-type pressure-sensitive adhesives containing a mixture of these as the largest amount of the main component, etc.).

[0065] Next, the pressure phase transition toner containing the pressure phase transition resin will be described in detail. The structure and properties of the pressure phase transition resin correspond to the structure and properties of the binder resin of the pressure phase transition toner.

[0066] The pressure phase transition toner is a styrene-based resin containing styrene and other vinyl monomers as polymerization components; a (meth)acrylic acid ester-based resin containing at least two kinds of (meth)acrylic acid esters as polymerization components, in which the mass ratio of the (meth)acrylic acid esters to the total polymerization components is 90 mass % or more; It is preferable that the resin has at least two glass transition temperatures, with the difference between the lowest and highest glass transition temperatures being 30° C. or more.

[0067] Pressure-induced phase change toner undergoes a phase transition due to pressure by exhibiting the thermal characteristic of "having at least two glass transition temperatures, with the difference between the lowest and highest glass transition temperatures being 30°C or more." In this disclosure, pressure-induced phase change toner that undergoes a phase transition due to pressure means a pressure-induced phase change toner that satisfies the following formula 1:

[0068] Formula 1...10℃≦T1-T2 In Equation 1, T1 is the temperature at which the viscosity is 10,000 Pa s under a pressure of 1 MPa, and T2 is the temperature at which the viscosity is 10,000 Pa s under a pressure of 10 MPa. How to determine temperatures T1 and T2 will be described later.

[0069] Pressure-induced phase transition toners are characterized by their ease of phase transition under pressure and excellent adhesiveness, due to the inclusion of a "styrene-based resin containing styrene and other vinyl monomers as polymerization components" and a "(meth)acrylic acid ester-based resin containing at least two types of (meth)acrylic acid esters as polymerization components, with the (meth)acrylic acid esters accounting for 90% by mass or more of the total polymerization components." As a result, the adhesiveness of the adhesive joints is enhanced. The following mechanism is presumed to be the cause.

[0070] Generally, styrene-based resins and (meth)acrylate-based resins have low compatibility with each other, so it is believed that the two resins are contained in a phase-separated state in the pressurized phase-transition toner particles. Furthermore, when pressurized phase-transition toner particles are pressurized, the (meth)acrylate-based resin, which has a relatively low glass transition temperature, first becomes fluid, and this fluidization spreads to the styrene-based resin, causing both resins to become fluid. Furthermore, it is believed that the two resins in the pressurized phase-transition toner particles, once fluidized by pressure and then solidified by reduced pressure to form a resin layer, again form a phase-separated state due to their low compatibility. It is presumed that a (meth)acrylic acid ester-based resin containing at least two types of (meth)acrylic acid esters as polymerization components has at least two types of ester groups bonded to the main chain, and therefore has a lower degree of molecular alignment in the solid state than a (meth)acrylic acid ester homopolymer, and therefore is more likely to fluidize under pressure. Furthermore, when the mass ratio of (meth)acrylic acid esters to the total polymerization components is 90 mass% or more, at least two types of ester groups are present at high density, and therefore the degree of molecular alignment in the solid state is lower, and therefore it is presumed that it is more likely to fluidize under pressure. Therefore, it is presumed that the pressure-induced phase transition toner according to this embodiment is more likely to fluidize under pressure, i.e., to undergo phase transition under pressure, than a pressure-induced phase transition toner in which the (meth)acrylic acid ester-based resin is a (meth)acrylic acid ester homopolymer. Furthermore, a (meth)acrylic acid ester-based resin containing at least two types of (meth)acrylic acid esters as polymerization components, with the mass ratio of the (meth)acrylic acid esters to the total polymerization components being 90 mass % or more, exhibits low molecular alignment even when solidified, and is therefore presumed to undergo minute phase separation with the styrene-based resin. The finer the phase separation between the styrene-based resin and the (meth)acrylic acid ester-based resin, the more uniform the state of the adhesion surface to the adherend, resulting in superior adhesiveness. Therefore, the pressure phase transition toner according to this embodiment is presumed to have superior adhesiveness compared to a pressure phase transition toner in which the (meth)acrylic acid ester-based resin is a homopolymer of (meth)acrylic acid ester.

[0071] The components, structure, and properties of the pressure-sensitive phase transition toner will be described in detail below. In the following description, unless otherwise specified, "styrene resin" means "styrene resin containing styrene and other vinyl monomers as polymerization components," and "(meth)acrylic acid ester resin" means "(meth)acrylic acid ester resin containing at least two types of (meth)acrylic acid esters as polymerization components, in which the mass ratio of (meth)acrylic acid esters to the total polymerization components is 90 mass% or more."

[0072] The pressure phase transition toner contains at least pressure phase transition toner particles, and optionally contains an external additive.

[0073] (Pressure Phase Change Toner Particles) The pressure phase transition toner particles contain at least a styrene resin and a (meth)acrylic acid ester resin as binder resins. The pressure phase transition toner particles may also contain a colorant, a release agent, and other additives.

[0074] In order to maintain adhesiveness, the pressure-sensitive phase transition toner particles preferably contain a styrene resin in an amount greater than the amount of the (meth)acrylic ester resin. The amount of the styrene 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, based on the total amount of the styrene resin and the (meth)acrylic ester resin.

[0075] -Styrene-based resin- The pressure phase transition toner particles constituting the pressure phase transition toner contain a styrene-based resin containing styrene and other vinyl monomers as polymerization components.

[0076] The mass proportion of styrene in all the polymer components of the styrene-based resin is preferably 60 mass% or more, more preferably 70 mass% or more, and even more preferably 75 mass% or more, from the viewpoint of suppressing fluidization of the pressure-sensitive phase transition toner in an unpressurized state, and is preferably 95 mass% or less, more preferably 90 mass% or less, and even more preferably 85 mass% or less, from the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure.

[0077] Examples of vinyl monomers other than styrene that constitute the styrene-based resin include styrene-based monomers other than styrene and acrylic monomers.

[0078] Examples of styrene-based monomers other than styrene include alkyl-substituted styrenes, aryl-substituted styrenes, alkoxy-substituted styrenes, halogen-substituted styrenes, nitro-substituted styrenes, etc. One type of styrene-based monomer may be used alone, or two or more types may be used in combination.

[0079] The acrylic monomer is preferably at least one acrylic monomer selected from the group consisting of (meth)acrylic acid and (meth)acrylic acid esters. Examples of the (meth)acrylic acid esters include (meth)acrylic acid alkyl esters, (meth)acrylic acid carboxy-substituted alkyl esters, (meth)acrylic acid hydroxy-substituted alkyl esters, (meth)acrylic acid alkoxy-substituted alkyl esters, and di(meth)acrylic acid esters. The acrylic monomers may be used alone or in combination of two or more.

[0080] Examples of other vinyl monomers constituting the styrene-based resin include, in addition to styrene-based monomers and acrylic-based monomers, (meth)acrylonitrile; vinyl ether; vinyl ketone; and olefin.

[0081] From the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure, the styrene-based resin preferably contains a (meth)acrylic acid ester as a polymerization component, more preferably a (meth)acrylic acid alkyl ester, even more preferably a (meth)acrylic acid alkyl ester having an alkyl group with 2 to 10 carbon atoms, still more preferably a (meth)acrylic acid alkyl ester having an alkyl group with 4 to 8 carbon atoms, and particularly preferably at least one of n-butyl acrylate and 2-ethylhexyl acrylate. From the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure, the styrene-based resin and the (meth)acrylic acid ester-based resin preferably contain the same type of (meth)acrylic acid ester as a polymerization component.

[0082] The mass proportion of the (meth)acrylic acid ester in the total polymerization components of the 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 viewpoint of suppressing fluidization of the pressure-sensitive phase transition toner in an unpressurized state, and is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, from the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure. The (meth)acrylic acid ester here is preferably a (meth)acrylic acid alkyl ester, more preferably a (meth)acrylic acid alkyl ester having 2 to 10 carbon atoms in the alkyl group, and even more preferably a (meth)acrylic acid alkyl ester having 4 to 8 carbon atoms in the alkyl group.

[0083] It is particularly preferable that the styrene resin contains at least one of n-butyl acrylate and 2-ethylhexyl acrylate as a polymerization component, and the total amount of n-butyl acrylate and 2-ethylhexyl acrylate in all polymerization components of the styrene 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 viewpoint of suppressing fluidization of the pressure-sensitive phase transition toner in an unpressurized state, and is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, from the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure.

[0084] The weight average molecular weight of the styrene resin is preferably 3,000 or more, more preferably 4,000 or more, and even more preferably 5,000 or more, from the viewpoint of preventing the pressure-sensitive phase transition toner from fluidizing when no pressure is applied, and is preferably 60,000 or less, more preferably 55,000 or less, and even more preferably 50,000 or less, from the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition when subjected to pressure.

[0085] The weight-average molecular weight of the resin is measured by gel permeation chromatography (GPC). Molecular weight measurement by GPC is performed using a Tosoh HLC-8120GPC as the GPC device, a Tosoh TSKgel SuperHM-M (15 cm) as the column, and tetrahydrofuran as the solvent. The weight-average molecular weight of the resin is calculated using a molecular weight calibration curve prepared using monodisperse polystyrene standard samples.

[0086] The glass transition temperature of the styrene resin is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher, from the viewpoint of preventing the pressure-sensitive phase transition toner from fluidizing when not pressurized. From the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition when subjected to pressure, the glass transition temperature is preferably 110°C or lower, more preferably 100°C or lower, and even more preferably 90°C or lower.

[0087] The glass transition temperature of a resin is determined from a differential scanning calorimetry (DSC) curve obtained by DSC measurement. More specifically, it is determined according to the "extrapolated glass transition onset temperature" described in JIS K7121:1987 "Method for measuring transition temperatures of plastics."

[0088] The glass transition temperature of a resin can be controlled by the type and polymerization ratio of the polymerization components. The glass transition temperature tends to be lower as the density of flexible units such as methylene groups, ethylene groups, and oxyethylene groups contained in the main chain increases, and tends to be higher as the density of rigid units such as aromatic rings and cyclohexane rings contained in the main chain increases. In addition, the glass transition temperature tends to be lower as the density of aliphatic groups in the side chain increases.

[0089] The mass proportion of the styrene resin in the entire pressure phase transition toner particles 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 viewpoint of suppressing fluidization of the pressure phase transition toner in an unpressurized state, and is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less, from the viewpoint of forming a pressure phase transition toner that easily undergoes phase transition under pressure.

[0090] -(Meth)acrylic ester resin- The pressure phase transition toner particles constituting the pressure phase transition toner contain a (meth)acrylic acid ester-based resin containing at least two types of (meth)acrylic acid esters as polymerization components, with the mass ratio of the (meth)acrylic acid esters to the total polymerization components being 90 mass% or more.

[0091] The mass proportion of (meth)acrylic acid ester in all the polymerizable components of the (meth)acrylic acid ester resin is 90 mass % or more, more preferably 95 mass % or more, even more preferably 98 mass % or more, and still more preferably 100 mass %.

[0092] Examples of the (meth)acrylic acid ester include (meth)acrylic acid alkyl ester, (meth)acrylic acid carboxy-substituted alkyl ester, (meth)acrylic acid hydroxy-substituted alkyl ester, (meth)acrylic acid alkoxy-substituted alkyl ester, and di(meth)acrylic acid ester. The (meth)acrylic acid ester may be used alone or in combination of two or more kinds.

[0093] As the (meth)acrylic acid ester, from the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure and has excellent adhesiveness, a (meth)acrylic acid alkyl ester is preferred, a (meth)acrylic acid alkyl ester having an alkyl group with 2 to 10 carbon atoms is more preferred, a (meth)acrylic acid alkyl ester having an alkyl group with 4 to 8 carbon atoms is even more preferred, and n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferred. From the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure, it is preferred that the styrene-based resin and the (meth)acrylic acid ester-based resin contain the same type of (meth)acrylic acid ester as a polymerization component.

[0094] The mass proportion of the (meth)acrylic acid alkyl ester in all the polymerization components of the (meth)acrylic acid ester-based resin is preferably 90 mass % or more, more preferably 95 mass % or more, even more preferably 98 mass % or more, and still more preferably 100 mass % from the viewpoint of forming a pressure phase transition toner that easily undergoes phase transition under pressure and has excellent adhesiveness. Here, the (meth)acrylic acid alkyl ester is preferably a (meth)acrylic acid alkyl ester having an alkyl group with 2 to 10 carbon atoms, and more preferably a (meth)acrylic acid alkyl ester having an alkyl group with 4 to 8 carbon atoms.

[0095] The mass ratio of the two (meth)acrylic acid esters having the largest mass proportions among the at least two (meth)acrylic acid esters contained as polymerization components in the (meth)acrylic acid ester-based resin is preferably 80:20 to 20:80, more preferably 70:30 to 30:70, and even more preferably 60:40 to 40:60, from the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure and has excellent adhesiveness.

[0096] Of the at least two (meth)acrylic acid esters contained as polymerization components in the (meth)acrylic acid ester-based resin, the two with the largest mass proportions are preferably (meth)acrylic acid alkyl esters. The (meth)acrylic acid alkyl esters herein are preferably (meth)acrylic acid alkyl esters having an alkyl group with 2 to 10 carbon atoms, and more preferably (meth)acrylic acid alkyl esters having an alkyl group with 4 to 8 carbon atoms.

[0097] When the two (meth)acrylic acid alkyl esters having the largest mass proportions among the at least two (meth)acrylic acid esters contained as polymerization components in the (meth)acrylic acid ester-based resin are (meth)acrylic acid alkyl esters, the difference in the number of carbon atoms in the alkyl groups of the two (meth)acrylic acid alkyl esters is preferably 1 to 4, more preferably 2 to 4, and even more preferably 3 or 4, from the viewpoint of forming a pressure-induced phase transition toner that is easily transitioned by pressure and has excellent adhesiveness.

[0098] From the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure and has excellent adhesiveness, the (meth)acrylic acid ester resin preferably contains n-butyl acrylate and 2-ethylhexyl acrylate as polymerization components, and it is particularly preferred that the two (meth)acrylic acid esters having the largest mass proportions among the at least two types of (meth)acrylic acid esters contained as polymerization components in the (meth)acrylic acid ester resin are n-butyl acrylate and 2-ethylhexyl acrylate. The total amount of n-butyl acrylate and 2-ethylhexyl acrylate in the total polymerization components of the (meth)acrylic acid ester resin is preferably 90 mass% or more, more preferably 95 mass% or more, even more preferably 98 mass% or more, and even more preferably 100 mass%.

[0099] The (meth)acrylic acid ester resin may contain a vinyl monomer other than (meth)acrylic acid ester as a polymerization component. Examples of vinyl monomers other than (meth)acrylic acid ester include (meth)acrylic acid; styrene; styrene-based 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 may be used alone or in combination of two or more.

[0100] When the (meth)acrylic acid ester-based resin contains a vinyl monomer other than a (meth)acrylic acid ester as a polymerization component, the vinyl monomer other than a (meth)acrylic acid ester is preferably at least one of acrylic acid and methacrylic acid, and more preferably acrylic acid.

[0101] The weight average molecular weight of the (meth)acrylic acid ester resin is preferably 50,000 or more, more preferably 100,000 or more, even more preferably 120,000 or more, and even more preferably 150,000 or more, from the viewpoint of preventing the pressure-sensitive phase transition toner from fluidizing when no pressure is applied, and is preferably 250,000 or less, more preferably 220,000 or less, and even more preferably 200,000 or less, from the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition when subjected to pressure.

[0102] The glass transition temperature of the (meth)acrylic acid ester resin is preferably 10°C or lower, more preferably 0°C or lower, and even more preferably -10°C or lower, from the viewpoint of forming a pressure-sensitive phase transition toner that easily undergoes phase transition under pressure, and is preferably -90°C or higher, more preferably -80°C or higher, and even more preferably -70°C or higher, from the viewpoint of preventing the pressure-sensitive phase transition toner from fluidizing when no pressure is applied.

[0103] The mass proportion of the (meth)acrylic acid ester resin in the entire pressure phase transition toner particles is preferably 20 mass % or more, more preferably 25 mass % or more, and even more preferably 30 mass % or more, from the viewpoint of forming a pressure phase transition toner that easily undergoes phase transition under pressure, and is preferably 45 mass % or less, more preferably 40 mass % or less, and even more preferably 35 mass % or less, from the viewpoint of preventing the pressure phase transition toner from fluidizing when not pressurized.

[0104] The total amount of the styrene-based resin and (meth)acrylic acid ester-based resin contained in the pressure phase transition toner particles is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass, based on the total amount of the pressure phase transition toner particles.

[0105] -Other resins- The pressurized phase change toner particles are made of, for example, polystyrene; epoxy resin; polyester resin; It may contain non-vinyl resins such as urethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins. These resins may be used alone or in combination of two or more.

[0106] -Various additives- The pressurized phase change toner particles may contain, as necessary, a colorant (e.g., pigment, dye), a release agent (e.g., hydrocarbon wax; natural wax such as carnauba wax, rice wax, candelilla wax; synthetic or mineral / petroleum wax such as montan wax; ester wax such as fatty acid ester, montan acid ester), a charge control agent, etc.

[0107] When the pressure-sensitive phase transition toner is to be a transparent pressure-sensitive phase transition toner, the amount of colorant in the pressure-sensitive phase transition toner particles is preferably 1.0% by mass or less relative to the total amount of the pressure-sensitive phase transition toner particles. From the viewpoint of increasing the transparency of the pressure-sensitive phase transition toner, the smaller the amount, the better.

[0108] -Structure of pressure-induced phase transition toner particles- The internal structure of the pressure phase transition toner particles is preferably a sea-island structure, and the sea-island structure preferably has a sea phase containing a styrene-based resin and an island phase containing a (meth)acrylic ester-based resin dispersed in the sea phase. The specific form of the styrene-based resin contained in the sea phase is as described above. The specific form of the (meth)acrylic ester-based resin contained in the island phase is as described above. Island phases not containing a (meth)acrylic ester-based resin may be dispersed in the sea phase.

[0109] When the pressure-sensitive phase transition toner particles have a sea-island structure, the average diameter of the island phases is preferably 200 nm to 500 nm. When the average diameter of the island phases is 500 nm or less, the pressure-sensitive phase transition toner particles are easily phase-transitioned by pressure. When the average diameter of the island phases is 200 nm or more, the pressure-sensitive phase transition toner particles have excellent mechanical strength (for example, strength to resist deformation when stirred in a developing device). From these viewpoints, the average diameter of the island phases is more preferably 220 nm to 450 nm, and even more preferably 250 nm to 400 nm.

[0110] Examples of methods for controlling the average diameter of the island phases of the sea-island structure within the above range include increasing or decreasing the amount of (meth)acrylic ester-based resin relative to the amount of styrene-based resin in the method for producing pressurized phase transition toner particles described below, and increasing or decreasing the time for which the temperature is maintained at a high temperature in the process of fusing and coalescing aggregated resin particles.

[0111] The sea-island structure is confirmed and the average diameter of the island phase is measured by the following method. The pressurized phase transition toner is embedded in epoxy resin, sliced ​​using a diamond knife or similar, and stained with osmium tetroxide or ruthenium tetroxide in a desiccator. The stained slices are then observed using a scanning electron microscope (SEM). The sea and island phases of the sea-island structure are distinguished by the degree of staining of the resin with osmium tetroxide or ruthenium tetroxide, and this is used to confirm the presence or absence of the sea-island structure. 100 island phases are randomly selected from the SEM image, and the longest diameter of each island phase is measured. The average of the longest diameters of the 100 island phases is used as the average diameter.

[0112] The pressure-sensitive phase change toner particles may be pressure-sensitive phase change toner particles having a single layer structure, or pressure-sensitive phase change toner particles having a core-shell structure having a core and a shell layer covering the core. From the viewpoint of preventing the pressure-sensitive phase change toner from fluidizing in an unpressurized state, the pressure-sensitive phase change toner particles preferably have a core-shell structure.

[0113] When the pressure-sensitive phase transition toner particles have a core-shell structure, it is preferable that the core contains a styrene-based resin and a (meth)acrylic acid ester-based resin, from the viewpoint of facilitating a phase transition under pressure. Furthermore, it is preferable to suppress the pressure-sensitive phase transition toner from fluidizing when no pressure is applied. From this viewpoint, it is preferable that the shell layer contains a styrene-based resin. Specific embodiments of the styrene-based resin are as described above. Specific embodiments of the (meth)acrylic acid ester-based resin are as described above.

[0114] When the pressure phase transition toner particles have a core-shell structure, it is preferable that the core portion has a sea phase containing a styrene-based resin and an island phase containing a (meth)acrylic ester-based resin dispersed in the sea phase. The average diameter of the island phase is preferably within the above-mentioned range. Furthermore, in addition to the core portion having the above-mentioned structure, it is preferable that the shell layer contains a styrene-based resin. In this case, the sea phase of the core portion and the shell layer have a continuous structure, and the pressure phase transition toner particles are likely to undergo phase transition under pressure. The specific form of the styrene-based resin contained in the sea phase and shell layer of the core portion is as described above. The specific form of the (meth)acrylic ester-based resin contained in the island phase of the core portion is as described above.

[0115] Examples of resins contained in the shell layer include polystyrene, and non-vinyl resins such as epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, and modified rosin. These resins may be used alone or in combination of two or more.

[0116] The average thickness of the shell layer is preferably 120 nm or more, more preferably 130 nm or more, and even more preferably 140 nm or more, from the viewpoint of suppressing deformation of the pressure-sensitive phase transition toner particles, and is preferably 550 nm or less, more preferably 500 nm or less, and even more preferably 400 nm or less, from the viewpoint of facilitating phase transition of the pressure-sensitive phase transition toner particles due to pressure.

[0117] The average thickness of the shell layer is measured by the following method. The pressurized phase change toner is embedded in epoxy resin and sliced ​​using a diamond knife or similar tool. The slices are then stained with osmium tetroxide or ruthenium tetroxide in a desiccator. The stained slices are then observed using a scanning electron microscope (SEM). Ten cross sections of pressurized phase change toner particles are randomly selected from the SEM images, and the shell layer thickness is measured at 20 points per pressurized phase change toner particle, the average value calculated, and the average thickness of the 10 pressurized phase change toner particles is used as the average thickness.

[0118] The volume average particle size (D50v) of the pressurized phase transition toner particles is preferably 4 μm or more, more preferably 5 μm or more, and even more preferably 6 μm or more, from the viewpoint of ease of handling of the pressurized phase transition toner particles, and is preferably 12 μm or less, more preferably 10 μm or less, and even more preferably 9 μm or less, from the viewpoint of ease of phase transition of the entire pressurized phase transition toner particles due to pressure.

[0119] The volume-average particle size (D50v) of pressurized phase transition toner particles is measured using a Coulter Multisizer II (Beckman Coulter, Inc.) with a 100 μm aperture. 0.5 mg to 50 mg of pressurized phase transition toner particles are dispersed in 2 mL of a 5% by weight aqueous solution of sodium alkylbenzene sulfonate. This is then mixed with 100 mL to 150 mL of electrolyte (ISOTON-II, Beckman Coulter, Inc.) and dispersed for 1 minute using an ultrasonic disperser. The resulting dispersion is used as the sample. The particle sizes of 50,000 particles with diameters between 2 μm and 60 μm in the sample are measured. The volume-average particle size (D50v) is defined as the particle size at which the cumulative 50% of the particle size distribution, calculated from the smallest diameter, is reached.

[0120] [External additives] Examples of external additives include inorganic particles, such as SiO2, TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, KO, Na2O, ZrO2, CaO·SiO2, KO·(TiO2)n, Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, and MgSO4.

[0121] The surfaces of inorganic particles as external additives are preferably subjected to a hydrophobic treatment. The hydrophobic treatment is carried out, for example, by immersing the inorganic particles in a hydrophobic treatment agent. The hydrophobic treatment agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used alone or in combination of two or more. The amount of the hydrophobic treatment agent is, for example, 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic particles.

[0122] Examples of external additives include resin particles (resin particles such as polystyrene, polymethyl methacrylate, and melamine resin), cleaning agents (for example, metal salts of higher fatty acids such as zinc stearate, and particles of fluorine-based polymers).

[0123] The amount of the external additive added is preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 2.0% by mass or less, based on the pressure phase transition toner particles.

[0124] (Characteristics of pressure phase transition toner) The pressure phase transition toner has at least two glass transition temperatures, one of which is presumed to be the glass transition temperature of a styrene-based resin and the other is presumed to be the glass transition temperature of a (meth)acrylic acid ester-based resin.

[0125] The pressure phase transition toner may have three or more glass transition temperatures, but preferably has two glass transition temperatures. The pressure phase transition toner having two glass transition temperatures may have a configuration in which the resins contained in the pressure phase transition toner are only a styrene resin and a (meth)acrylic acid ester resin, or a configuration in which the content of other resins other than a styrene resin and a (meth)acrylic acid ester resin is small (for example, a configuration in which the content of other resins is 5% by mass or less of the total pressure phase transition toner).

[0126] The pressure phase transition toner has at least two glass transition temperatures, and the difference between the lowest and highest glass transition temperatures is 30° C. or more. From the viewpoint of facilitating phase transition of the pressure phase transition toner under pressure, the difference between the lowest and highest glass transition temperatures is more preferably 40° C. or more, even more 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.

[0127] The lowest glass transition temperature of the pressure-sensitive phase transition toner is preferably 10°C or lower, more preferably 0°C or lower, and even more preferably -10°C or lower, from the viewpoint of facilitating phase transition of the pressure-sensitive phase transition toner under pressure, and is preferably -90°C or higher, more preferably -80°C or higher, and even more preferably -70°C or higher, from the viewpoint of preventing the pressure-sensitive phase transition toner from fluidizing when not under pressure.

[0128] The highest glass transition temperature of the pressurized phase transition toner is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher, from the viewpoint of preventing the pressurized phase transition toner from fluidizing when not pressurized; and is preferably 70°C or lower, more preferably 65°C or lower, and even more preferably 60°C or lower, from the viewpoint of facilitating phase transition of the pressurized phase transition toner under pressure.

[0129] The glass transition temperature of the pressure phase transition toner is determined from the differential scanning calorimetry (DSC) curve obtained by performing differential scanning calorimetry (DSC). More specifically, it is determined in accordance with the "extrapolated glass transition onset temperature" described in the method for determining glass transition temperature in JIS K7121:1987 "Method for measuring transition temperature of plastics."

[0130] The pressure phase transition toner is a pressure phase transition toner that undergoes a phase transition due to pressure, and satisfies the following formula 1. Formula 1...10℃≦T1-T2 In Equation 1, T1 is the temperature at which the viscosity is 10,000 Pa·s under a pressure of 1 MPa, and T2 is the temperature at which the viscosity is 10,000 Pa·s under a pressure of 10 MPa.

[0131] The temperature difference (T1-T2) is preferably 10°C or more, more preferably 15°C or more, and even more preferably 20°C or more, from the viewpoint of facilitating phase transition of the pressurized phase transition toner under pressure, and is preferably 120°C or less, more preferably 100°C or less, and even more preferably 80°C or less, from the viewpoint of preventing the pressurized phase transition toner from fluidizing when no pressure is applied.

[0132] The value of the temperature T1 is preferably 140° C. or less, more preferably 130° C. or less, even more preferably 120° C. or less, and still more preferably 115° C. or less. The lower limit of the temperature T1 is preferably 80° C. or more, more preferably 85° C. or more. The value of the temperature 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 the temperature T2 is preferably 85° C. or lower.

[0133] An index showing that a pressure-induced phase transition toner easily undergoes phase transition is the temperature difference (T1-T3) between the temperature T1 at which the toner exhibits a viscosity of 10,000 Pa·s under a pressure of 1 MPa and the temperature T3 at which the toner exhibits a viscosity of 10,000 Pa·s under a pressure of 4 MPa, and the temperature difference (T1-T3) is preferably 5°C or greater. From the viewpoint of ease of pressure-induced phase transition, the pressure-induced phase transition toner according to this embodiment preferably has a temperature difference (T1-T3) of 5°C or greater, and more preferably 10°C or greater. The temperature difference (T1-T3) is generally less than 25°C.

[0134] In order to ensure that the temperature difference (T1-T3) of the pressure phase transition toner is 5°C or more, the temperature T3 at which the toner exhibits a viscosity of 10,000 Pa s under 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 the temperature T3 is preferably 60°C or more.

[0135] The temperature T1, the temperature T2, and the temperature T3 are determined as follows. The pressurized phase transition toner is compressed to prepare a pellet-shaped sample. The pellet-shaped sample is placed in a flow tester (Shimadzu Corporation, CFT-500), and the applied pressure is fixed at 1 MPa. The viscosity at 1 MPa is measured against the temperature. From the resulting viscosity graph, the temperature T1 at which the viscosity becomes 104 Pa·s at an applied pressure of 1 MPa is determined. The temperature T2 is determined in the same manner as for the temperature T1, except that the applied pressure of 1 MPa is changed to 10 MPa. The temperature T3 is determined in the same manner as for the temperature T1, except that the applied pressure of 1 MPa is changed to 4 MPa. The temperature difference (T1-T2) is calculated from the temperatures T1 and T2. The temperature difference (T1-T3) is calculated from the temperatures T1 and T3.

[0136] (Method for producing pressure phase transition toner) The pressure phase transition toner can be obtained by producing pressure phase transition toner particles and then externally adding an external additive to the pressure phase transition toner particles.

[0137] The pressure phase transition toner may be produced by either a dry production method (e.g., a kneading and pulverization method) or a wet production method (e.g., an aggregation and coalescence method, a suspension polymerization method, a dissolution and suspension method). There are no particular limitations on these production methods, and any known production method may be used. Among these, it is preferable to obtain pressure phase transition toner particles by the aggregation and coalescence method.

[0138] (Test Example A) Below, test examples will be shown that demonstrate that the pressure-induced phase transition toner described above is easy to undergo phase transition under pressure and has excellent adhesiveness. In the following description, unless otherwise specified, "parts" and "%" are based on mass.

[0139] <Preparation of Dispersion Containing Styrene-Based Resin Particles> [Preparation of styrene-based resin particle dispersion (St1)] Styrene: 390 parts n-Butyl acrylate: 100 parts Acrylic acid: 10 parts Dodecanethiol: 7.5 parts The above materials were mixed and dissolved to prepare a monomer solution. Eight parts of an anionic surfactant (Dowfax2A1, manufactured by The Dow Chemical Company) was dissolved in 205 parts of ion-exchanged water, and the monomer solution was added thereto, dispersed and emulsified to obtain an emulsion. 2.2 parts of anionic surfactant (Dowfax 2A1, manufactured by The Dow Chemical Company) was dissolved in 462 parts of ion-exchanged water, and the solution was charged into a polymerization flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube. The mixture was heated to 73°C with stirring and maintained at that temperature. 3 parts of ammonium persulfate was dissolved in 21 parts of ion-exchanged water and added dropwise to the polymerization flask via a metering pump over 15 minutes, and then the emulsion was added dropwise via a metering pump over 160 minutes. The polymerization flask was then maintained at 75°C for 3 hours with slow stirring, and then allowed to cool to room temperature. This resulted in a styrene-based resin particle dispersion (St1) containing styrene-based resin particles, with a volume average particle size (D50v) of 174 nm, a weight average molecular weight measured by GPC (UV detection) of 49,000, a glass transition temperature of 54°C, and a solid content of 42%.

[0140] The styrene resin particle dispersion (St1) was dried to extract the styrene resin particles, and their thermal behavior was analyzed in the temperature range of -100°C to 100°C using a differential scanning calorimeter (Shimadzu Corporation, DSC-60A). One glass transition temperature was observed. Table 1 shows the glass transition temperatures.

[0141] [Preparation of styrene-based resin particle dispersions (St2) to (St3)] Styrene-based resin particle dispersions (St2) to (St13) were prepared in the same manner as in the preparation of the styrene-based resin particle dispersion (St1), except that the monomers were changed as shown in Table 1.

[0142] The composition and physical properties of the styrene-based resin particle dispersion (St1) and the like are shown in Table 1. In Table 1, the monomers are abbreviated as follows. 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

[0143] [Table 1]

[0144] <Preparation of dispersion containing composite resin particles> [Preparation of Composite Resin Particle Dispersion (M1)] Styrene-based resin particle dispersion (St1): 1,190 parts (solids: 500 parts) 2-Ethylhexyl acrylate: 250 parts n-Butyl acrylate: 250 parts Ion-exchanged water: 982 parts The above materials were charged into a polymerization flask, stirred at 25°C for 1 hour, and then heated to 70°C. 2.5 parts of ammonium persulfate was dissolved in 75 parts of ion-exchanged water, and the resulting solution was placed in the polymerization flask. The solution was added dropwise via a volumetric pump over 60 minutes. The polymerization flask was then maintained at 70°C for 3 hours with slow stirring, and then allowed to cool to room temperature. This resulted in a composite resin particle dispersion (M1) containing composite resin particles with a volume average particle size (D50v) of 219 nm, a weight average molecular weight measured by GPC (UV detection) of 219,000, and a solid content of 32%.

[0145] The composite resin particle dispersion (M1) was dried, and the composite resin particles were extracted. Their thermal behavior was analyzed in the temperature range of -150°C to 100°C using a differential scanning calorimeter (Shimadzu Corporation, DSC-60A). Two glass transition temperatures were observed. Table 2 shows the glass transition temperatures.

[0146] [Preparation of Composite Resin Particle Dispersions (M2) to (M3)] Composite resin particle dispersions (M2) to (M3) were prepared in the same manner as in the preparation of composite resin particle dispersion (M1), except that the styrene-based resin particle dispersion (St1) was changed as shown in Table 2, or the polymerization components of the (meth)acrylic acid ester-based resin were changed as shown in Table 2.

[0147] [Preparation of Composite Resin Particle Dispersions (M4) to (M5)] Composite resin particle dispersions (M4) to (M5) were prepared in the same manner as in the preparation of composite resin particle dispersion (M1), except that the amounts of 2-ethylhexyl acrylate and n-butyl acrylate used were adjusted.

[0148] The composition and physical properties of the composite resin particle dispersion (M1) and the like are shown in Table 2. In Table 2, the monomers are abbreviated as follows. Styrene: St, n-butyl acrylate: BA, 2-ethylhexyl acrylate: 2EHA, acrylic acid: AA

[0149] [Table 2]

[0150] <Preparation of Pressure-Sensitive Phase-Transition Toner> [Preparation of Pressure-Sensitive Phase-Transfer Toner (1)] ·Composite resin particle dispersion (M1): 504 parts Ion-exchanged water: 710 parts Anionic surfactant (Dow Chemical Company, Dowfax2A1): 1 part

[0151] The above materials were placed in a reaction vessel equipped with a thermometer and pH meter, and the pH was adjusted to 3.0 by adding 1.0% aqueous nitric acid solution at 25°C. Then, 23 parts of a 2.0% aqueous aluminum sulfate solution were added while dispersing using a homogenizer (Ultra Turrax T50, manufactured by IKA) at 5,000 rpm. Next, a stirrer and a mantle heater were installed in the reaction vessel, and the temperature was increased at a rate of 0.2°C / min up to 40°C, and then at a rate of 0.05°C / min after exceeding 40°C. The particle size was measured every 10 minutes using a Multisizer II (aperture diameter 50 μm, manufactured by Beckman Coulter). When 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 the addition, the mixture was maintained at 50°C for 30 minutes, and then a 1.0% aqueous sodium hydroxide solution was added to adjust the pH of the slurry to 6.0. Next, the temperature was raised to 90°C at a rate of 1°C / min while adjusting the pH to 6.0 every 5°C, and then maintained at 90°C. When the particle shape and surface properties were observed using an optical microscope and a field emission scanning electron microscope (FE-SEM), coalescence of the particles was confirmed after 10 hours, so the container was cooled to 30°C over 5 minutes with cooling water.

[0152] The cooled slurry was passed through a nylon mesh with 15 μm openings to remove coarse particles, and the slurry that passed through the mesh was filtered under reduced pressure using an aspirator. The solids remaining on the filter paper were crushed as finely as possible by hand and added to ion-exchanged water (temperature 30°C) in an amount 10 times the solid content and stirred for 30 minutes. The mixture was then filtered under reduced pressure using an aspirator. The solids remaining on the filter paper were crushed as finely as possible by hand and added to ion-exchanged water (temperature 30°C) in an amount 10 times the solid content, stirred for 30 minutes, and then filtered under reduced pressure again using an aspirator. The electrical conductivity of the filtrate was measured. This procedure was repeated until the electrical conductivity of the filtrate reached 10 μS / cm or less, and the solids were washed.

[0153] The washed solids were crushed into fine powder using a wet-dry granulator (Comil) and vacuum-dried in an oven at 25°C for 36 hours to obtain pressurized phase transition toner particles (1). The pressurized phase transition toner particles (1) had a volume average particle size of 8.0 μm.

[0154] 100 parts of the pressurized phase transition toner particles (1) and 1.5 parts of hydrophobic silica (RY50, manufactured by Nippon Aerosil Co., Ltd.) were mixed and mixed for 30 seconds at a rotation speed of 13,000 rpm using a sample mill. The mixture was sieved using a vibrating sieve with 45 μm openings to obtain pressurized phase transition toner (1).

[0155] The thermal behavior of the pressurized phase transition toner (1) was analyzed in the temperature range of -150°C to 100°C using a differential scanning calorimeter (Shimadzu Corporation, DSC-60A). Two glass transition temperatures were observed. The glass transition temperatures are shown in Table 3.

[0156] The temperatures T1 and T2 of the pressurized phase transition toner (1) were determined by the above-mentioned measurement method, and it was found that the pressurized phase transition toner (1) satisfied the formula 1 "10°C≦T1−T2".

[0157] When the cross section of the pressurized phase change toner (1) was observed with a scanning electron microscope (SEM), a sea-island structure was observed. The pressurized phase change toner (1) had a core portion containing island phases and a shell layer containing no island phases. The sea phase contained a styrene-based resin, and the island phase contained a (meth)acrylic ester-based resin. The average diameter of the island phases was determined using the measurement method described above. Table 3 shows the average diameter of the island phases.

[0158] [Preparation of Pressure-Sensitive Phase-Transfer Toners (2) to (5)] Pressurized phase transition toners (2) to (5) were prepared in the same manner as in the preparation of pressurized phase transition toner (1), except that the composite resin particle dispersion and the styrene-based resin particle dispersion were changed as shown in Table 3.

[0159] The temperatures T1 and T2 of the pressurized phase transition toners (2) to (5) were determined by the above-mentioned measurement method, and all of the pressurized phase transition toners (2) to (5) satisfied the formula 1 "10°C≦T1-T2".

[0160] [Evaluation of pressure-responsive phase transition] The temperature difference (T1-T3), which is an index showing the ease with which pressure-sensitive phase transition toners undergo phase transition under pressure, was determined. Each pressure-sensitive phase transition toner was used as a sample, and temperatures T1 and T3 were measured using a flow tester (Shimadzu Corporation, CFT-500), and the temperature difference (T1-T3) was calculated. The temperature difference (T1-T3) is shown in Table 3.

[0161] [Adhesion evaluation] Postcard paper V424 manufactured by FUJIFILM Business Innovation Co., Ltd. was prepared as the recording medium. An image layer was formed by transferring and fixing a toner image with an area density of 30% containing a mixture of black text and a full-color photographic image onto one side of the postcard paper that would become a pair of pressure-bonding surfaces (hereinafter simply referred to as the "pair of pressure-bonding surfaces") using an image forming apparatus DocuCentre C7550I manufactured by FUJIFILM Business Innovation Co., Ltd. and commercially available yellow toner, magenta toner, cyan toner, and black toner manufactured by FUJIFILM Business Innovation Co., Ltd.

[0162] Next, each of the prepared pressurized phase transition toners was applied to the entire pair of pressed surfaces of the postcard paper in an amount of 3 g / m. 2 The postcard paper was passed through a belt roll fixing machine to fix the pressurized phase transition toner to the pair of pressure-bonded surfaces of the postcard paper, forming a pressure-bonded layer consisting of a fixed layer of the pressurized phase transition toner, thereby obtaining a pre-pressurized medium.

[0163] Next, using a PRESSLE multiII sealer manufactured by Toppan Forms Co., Ltd., the postcard paper was folded in a V shape so that the pair of bonding surfaces faced each other, and a pressure of 90 MPa was applied to the V-folded postcard paper to bond the pair of bonding surfaces together, resulting in a bonded postcard as a bonded printed product. Ten bonded postcards were produced in succession using the above equipment and conditions.

[0164] Next, the tenth compressed postcard was cut in the long direction to a width of 15 mm to create a rectangular test piece, and a 90-degree peel test was performed to peel off the pair of compressed surfaces of the compressed postcard. The peel speed for the 90-degree peel test was 20 mm / min, and the load (N) was sampled at 0.4 mm intervals from 10 mm to 50 mm after the start of the measurement, and the average was calculated. The load (N) for three test pieces was also averaged. The load (N) required for peeling was classified as follows. The results are shown in Table 3.

[0165] A: 0.8N or more B: 0.6N or more, less than 0.8N C: 0.4N or more, less than 0.6N D: 0.2N or more, less than 0.4N E: Less than 0.2N

[0166] [Table 3]

[0167] From the above, it can be seen that the pressure phase transition toner of the test example easily undergoes phase transition under pressure and has excellent adhesiveness.

[0168] (Test Example B) A pre-press medium shown in Fig. 1 was prepared, and a press-bonded print was produced from the prepared pre-press medium, and the following evaluations were carried out. Specifically, the evaluations were as follows.

[0169] Postcard paper V424 manufactured by FUJIFILM Business Innovation Co., Ltd. was prepared as the recording medium. A toner image with an area density of 30% containing a mixture of black text and a full-color photographic image was formed and fixed on one side of the postcard paper that would become a pair of pressure-sensitive adhesive surfaces (hereinafter simply referred to as the "pair of pressure-sensitive adhesive surfaces") using an image forming apparatus DocuCentre C7550I manufactured by FUJIFILM Business Innovation Co., Ltd. and commercially available yellow toner, magenta toner, cyan toner, and black toner manufactured by FUJIFILM Business Innovation Co., Ltd., to form an image layer.

[0170] Next, a modified image forming apparatus DocuCentre C7550I manufactured by Fujifilm Business Innovation Co., Ltd. (a modified apparatus capable of forming a pressure-bonding layer consisting of a fixing layer of pressure-bonding phase transition toner) was used to apply a pressure-bonding phase transition toner image at an amount of 3 g / m to the area that would become the first pressure-bonding layer on the entire pair of pressure-bonding surfaces of the postcard paper. 2 At the same time, a pressure-sensitive phase transition toner image was applied in an amount of 7.5 g / m to the area that would become the second pressure-sensitive layer. 2 After transfer, each toner image was fixed. As a result, a first pressure-sensitive adhesive layer consisting of a fixing layer for a pressurized phase-transition toner image and a second pressure-sensitive adhesive layer (a second pressure-sensitive adhesive layer with an arrangement of linear pressure-sensitive adhesive layers) consisting of a fixing layer for a pressurized phase-transition toner image were formed on a pair of pressure-sensitive adhesive surfaces of the postcard paper, together with an image layer, and the pre-pressurized medium shown in Figure 1 was obtained. Here, the pressure phase transition toner used was the pressure phase transition toner (1) prepared in "Test Example 1" of Test Example A. The heights TG1 and TA1 from the pressure-bonding surface of the image layer and the first pressure-bonding layer are as shown in Table 4. However, the height from the pressure-bonding surface of the first pressure-bonding layer indicates the height from the pressure-bonding surface of the first pressure-bonding layer formed on the image layer. The length, line width, and height TA2 from the pressure-bonded surface of the linear shape of the second pressure-bonded layer were as shown in Table 4. In Comparative Example 101, the second pressure-bonding layer was not provided, and the first pressure-bonding layer was formed in the region where the second pressure-bonding layer was to be formed.

[0171] Next, using a sealer PRESSLE multiII manufactured by Toppan Forms Co., Ltd., the postcard paper as the pre-lamination medium shown in Figure 1 was folded in a V shape so that a pair of lamination surfaces faced each other, and a pressure of 90 MPa was applied to the V-folded postcard paper to laminate the pair of lamination surfaces together, resulting in a lamination postcard as a lamination printed matter.

[0172] Next, the pair of pressed surfaces of the postcard paper was peeled off from the obtained pressed postcard, and the pressed postcard was opened (see the developed product shown in FIG. 3). Next, using the unfolded unsealed postcard, the postcard paper was again folded in a V shape under the same conditions as above so that a pair of pressure-bonded surfaces faced each other, and a pressure of 90 MPa was applied to the V-folded postcard paper to press the pair of pressure-bonded surfaces together, resulting in a pressure-bonded postcard as a pressure-bonded printed matter.

[0173] Next, the pair of pressed surfaces of the postcard paper was peeled off again from the obtained pressed postcard, and the pressed postcard was opened (see the developed product shown in FIG. 4). Then, a pair of pressure-bonded surfaces in the unfolded unsealed postcard obtained were observed in a planar view, and the visibility of the trace of the shape of the second pressure-bonded layer and the visibility of the "shift" of the trace of the shape of the second pressure-bonded layer were evaluated using the following evaluation criteria.

[0174] -Evaluation criteria for visibility of traces of the shape of the second pressure-bonded layer- A: The difference in gloss (absolute value) between the area of ​​the first adhesive layer where the second adhesive layer is face-to-face bonded and the surrounding area is 5.0 or more. B: The difference in gloss (absolute value) between the area of ​​the first pressure-sensitive adhesive layer where the second pressure-sensitive adhesive layer was face-to-face pressed and the surrounding area of ​​that area is 3.0 or more and less than 5.0 C: The difference in gloss (absolute value) between the area of ​​the first pressure-sensitive adhesive layer where the second pressure-sensitive adhesive layer is face-to-face pressed and the surrounding area of ​​that area is 1.0 or more but less than 3.0 D: The difference in gloss (absolute value) between the area of ​​the first pressure-sensitive adhesive layer where the second pressure-sensitive adhesive layer is face-to-face pressed and the surrounding area of ​​that area is 0 or more and less than 1.0

[0175] -Evaluation criteria for visibility of "misalignment" of traces of the shape of the second pressure-bonded layer- A: There is a clear misalignment of the two bonded layers, which can be seen immediately after peeling. B: The "misalignment" of the traces of the shape of the two bonded layers can be seen upon close observation. C: It is difficult to visually recognize the "misalignment" of the traces of the shape of the two bonded layers, or the "misalignment" is not visible.

[0176] [Table 4]

[0177] From the above results, it can be seen that in the test example in which the second pressure-sensitive adhesive layer was provided, unlike the comparative example in which the second pressure-sensitive adhesive layer was not provided, traces of the shape of the second pressure-sensitive adhesive layer and its "shift" were visible, and the peeling history of the pressure-sensitive adhesive surface could be visually confirmed. Furthermore, it can be seen that when the height from the pressure-bonded surface and the line width of the linear shape of the second pressure-bonded layer are set within a specific range, the visibility of the trace of the shape of the second pressure-bonded layer and its "shift" is improved. [Explanation of symbols]

[0178] 10 Recording media 12 Crimping surface 14 Image Layer 16 First bonding layer 18 Second bonding layer 20 Evidence of the shape of the second bonded layer 101 Pre-pressing medium 102 Developments 103 Developments

Claims

1. a recording medium in which a pair of pressure-bonding surfaces are superimposed and pressure-bonded together; an image layer provided on one or both of the pair of pressure-contact surfaces of the recording medium; a first pressure-bonding layer provided on one or both of a pair of pressure-bonding surfaces of the recording medium, the first pressure-bonding layer pressing the pair of pressure-bonding surfaces together; A second pressure-bonding layer is provided on one or both of the pair of pressure-bonding surfaces of the recording medium and presses the pair of pressure-bonding surfaces together, the second pressure-bonding layer being provided at a position where it is in face-to-face pressure contact with the first pressure-bonding layer; Equipped with When the pair of pressure-bonded surfaces of the recording medium are peeled off from each other and the pair of pressure-bonded surfaces in the developed product in which the recording medium is developed are observed in a planar view, the first pressure-bonded layer that has been face-to-face pressed against the second pressure-bonded layer is observed as a trace of the shape of the second pressure-bonded layer. A difference in gloss between the area where the second pressure-bonded layer in the first pressure-bonded layer was face-to-face pressed and the periphery of the area is visually recognized. A pressure-bonded printed matter, wherein the height of the second pressure-bonding layer from the pressure-bonding surface is greater than the height of the image layer and the first pressure-bonding layer from the pressure-bonding surface.

2. The pressure-bonded printed matter according to claim 1 , wherein the height of the image layer and the first pressure-bonding layer from the pressure-bonding surface is 80% or less of the height of the second pressure-bonding layer from the pressure-bonding surface.

3. The pressure-bonded printed matter according to claim 1 or 2, wherein the height of the second pressure-bonding layer from the pressure-bonding surface is 0.5 μm or more and 12 μm or less.

4. the second pressure-bonding layer is provided on both of the pair of pressure-bonding surfaces of the recording medium, The second pressure-sensitive adhesive layer provided on both of a pair of pressure-sensitive adhesive surfaces of the recording medium is partially overlapped with each other to press the pair of pressure-sensitive adhesive surfaces together. A pressure-sensitive adhesive printed matter described in any one of claims 1 to 3.

5. The pressure-bonded printed matter according to any one of claims 1 to 4, wherein the shape of the second pressure-bonding layer includes a linear shape.

6. The pressure-bonded printed matter according to claim 5 , wherein the line width of the linear shape is 0.2 mm or more and 3 mm or less.

7. The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are a styrene-based resin containing styrene and other vinyl monomers as polymerization components, and at least two (meth)acrylic acid esters as polymerization components. The mass ratio of the (meth)acrylic acid ester to the total polymerization components is 90 mass% or more. The pressure-sensitive adhesive printed matter according to any one of claims 1 to 6 contains a (meth)acrylic acid ester-based resin, and has at least two glass transition temperatures, and the difference between the lowest glass transition temperature and the highest glass transition temperature is 30 ° C. or more.

Images