Method for producing pressure-responsive particles, method for producing printed matter, method for producing sheet for producing printed matter, and pressure-responsive particles

Abstract

To provide a method for producing pressure-responsible particles which is excellent in adhesive force in crimping and storage property of a dispersion liquid, and suppresses occurrence of an aggregate and a fusion material.SOLUTION: A method for producing pressure-responsible particles includes an aggregation step of adding an aggregating agent to a dispersion containing composite resin particles containing a styrenic resin and a (meth)acrylate-based resin, aggregating the mixture, and obtaining aggregated particles A, a shell formation step of adding styrenic resin particles and an aggregating agent to the dispersion liquid containing the aggregated particles A, aggregating the mixture, and obtaining aggregated particles B, and a fusion step of heating and fusing the aggregated particles B, and forming pressure-responsible particles, wherein an amount of the styrenic resin particles to be added in the shell formation step is 5 mass% or more and 40 mass% or less with respect to the total mass of the composite resin particles, and an amount of the aggregating agent to be added in the shell formation step is 0.1 mass% or more and 1.0 mass% or less with respect to the total mass of the composite resin particles.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing pressure-responsive particles, a method for producing printed matter, a method for producing a sheet for producing printed matter, and pressure-responsive particles. [Background technology]

[0002] Patent Document 1 discloses a removable sheet that can be used to removably bond overlapping surfaces together, the removable sheet having a base sheet, a pressure-sensitive adhesive layer provided on at least one surface of the base sheet, and a surface layer provided on the surface of the pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer contains an adhesive base including a natural rubber-based material, and the surface layer contains one or more selected from the group consisting of cellulose nanofibers, chitin nanofibers, and chitosan nanofibers.

[0003] Patent Document 2 also describes an adhesive material containing 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 to the total polymerization components being 90 mass % or more, wherein the mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin is 80:20 to 20:80, and the resin particles have at least two glass transition temperatures, the lowest of which is −30° C. or lower and the highest of which is 30° C. or higher. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-053220 [Patent Document 2] Patent Publication No. 2021-017465 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention addresses the problem of providing a method for producing pressure-responsive particles, the method comprising: an aggregation step of adding an aggregating agent to a dispersion containing composite resin particles, the dispersion containing a styrene-based resin containing a styrene compound and other vinyl monomers as polymerization components, and a (meth)acrylic acid ester-based resin containing a (meth)acrylic acid ester compound as polymerization components, to form aggregated particles A; a shell formation step of adding an aggregating agent to a dispersion containing the aggregated particles A to form aggregated particles B, the dispersion containing the aggregated particles A, to form aggregated particles B; and a fusion step of heating and fusing the aggregated particles B to form pressure-responsive particles, the method comprising: a method for producing pressure-responsive particles, the method comprising: a method for producing pressure-responsive particles, the method comprising: adding an aggregating agent to a dispersion containing composite resin particles, the dispersion containing composite resin particles containing a styrene compound and other vinyl monomers as polymerization components, and aggregating the composite resin particles to form aggregated particles B; and a fusion step of heating and fusing the aggregated particles B to form pressure-responsive particles, the method exhibiting superior adhesive strength during compression and superior storage stability of the dispersion, and producing less aggregates and fused products, compared to a method in which the amount of aggregating agent added in the shell formation step is less than 0.01 mass% or more than 1.0 mass% relative to the total mass of the composite resin particles, or a method in which the mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin contained in the pressure-responsive particles is greater than 80:less than 20 to 100:0 or 0:100 to less than 20:more than 80. [Means for solving the problem]

[0006] Specific means for solving the above problems include the following aspects. <1> The method includes an aggregation step of adding an aggregating agent to a dispersion containing composite resin particles including a styrene-based resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylic acid ester-based resin containing a (meth)acrylic acid ester compound as polymerization components, and aggregating the particles to obtain aggregated particles A; a shell formation step of adding an aggregating agent to a dispersion containing the aggregated particles A and styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components, and aggregating the particles to obtain aggregated particles B; and a fusion step of heating and fusing the aggregated particles B to form pressure-responsive particles, and the shell A method for producing pressure-responsive particles, wherein the amount of styrene-based resin particles added in the forming step is 5% by mass or more and 40% by mass or less relative to the total mass of the composite resin particles, the amount of aggregating agent added in the shell forming step is 0.1% by mass or more and 1.0% by mass or less relative to the total mass of the composite resin particles, the mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin contained in the pressure-responsive particles is 80:20 to 20:80, and the difference between the lowest and highest glass transition temperatures of the resins contained in the pressure-responsive particles is 30°C or more. <2> In the shell formation step, the temperature of the dispersion containing the aggregated particles A is lowered after the aggregation step, and then styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components and an aggregating agent are added. <1> A method for producing the pressure-responsive particles described in 1. <3> In the shell formation step, the liquid temperature is lowered to 5°C or more before adding the styrene-based resin particles and the flocculant. <2> A method for producing the pressure-responsive particles described in 1. <4> The flocculant used in the flocculation step and the shell formation step is an aluminum-based flocculant. <1> ~ <3> 10. A method for producing pressure-responsive particles according to any one of the above. <5> The flocculant in the flocculation step is aluminum sulfate. <4> A method for producing the pressure-responsive particles described in 1. <6> In the aggregation step, silica particles are added. <1> ~ <5> 10. A method for producing pressure-responsive particles according to any one of the above. <7> The amount of silica particles added in the aggregation step is 2% by mass or more and 8% by mass or less with respect to the total mass of the composite resin particles. <6> A method for producing the pressure-responsive particles described in 1. <8> The silica particles have an arithmetic mean particle size of 7 nm or more and 40 nm or less. <6> or < 7 >A method for producing pressure-responsive particles described in <9> The glass transition temperature of the styrene resin contained in the pressure-responsive particles is 30°C or higher. <1> ~ <7> 10. A method for producing pressure-responsive particles according to any one of the above. <10> The glass transition temperature of the (meth)acrylic acid ester resin contained in the pressure-responsive particles is −30° C. or lower. <1> ~ <8> 10. A method for producing pressure-responsive particles according to any one of the above. <11> <1> ~ <10> a pressure-responsive particle manufacturing method according to any one of the preceding claims, wherein the pressure-responsive particle is disposed on a recording medium; and a pressure-bonding step of folding and pressing the recording medium, or of folding and pressing the recording medium and another recording medium together. <12> <1> ~ <10> A method for producing a sheet for producing printed matter, comprising a step of arranging pressure-responsive particles on a substrate using pressure-responsive particles produced by the method for producing pressure-responsive particles described in any one of the above. <13> <1> ~ <10> 2. Pressure-responsive particles produced by the method for producing pressure-responsive particles according to any one of the above. [Effects of the Invention]

[0007] <1> or <13> According to the invention, a method for producing pressure-responsive particles is provided, which includes an aggregation step of adding an aggregating agent to a dispersion containing composite resin particles, the dispersion containing a styrene-based resin containing a styrene compound and other vinyl monomers as polymerization components, and a (meth)acrylic acid ester-based resin containing a (meth)acrylic acid ester compound as polymerization components, and aggregating the particles to obtain aggregated particles A; a shell formation step of adding styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components and an aggregating agent to the dispersion containing the aggregated particles A, and aggregating the particles to obtain aggregated particles B; and a fusion step of heating and fusing the aggregated particles B to form pressure-responsive particles, wherein the amount of aggregating agent added in the shell formation step is less than 0.1 mass% or more than 1.0 mass% relative to the total mass of the composite resin particles, or the mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin contained in the pressure-responsive particles is more than 80:less than 20 to 100:0 or 0:100 to less than 20:more than 80, and the method provides a method for producing pressure-responsive particles which has excellent adhesive strength during compression and good storability of the dispersion, and which produces less aggregates and fused products, compared to when the amount of aggregating agent added in the shell formation step is less than 0.1 mass% or more than 1.0 mass% relative to the total mass of the composite resin particles, or when the mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin contained in the pressure-responsive particles is more than 80:less than 20 to 100:0 or 0:100 to less than 20:more than 80. <2> According to the invention, a method for producing pressure-responsive particles is provided in which, in the shell formation step, the adhesive strength during compression and the storage properties of the dispersion are superior, and less aggregates and fused materials are generated, compared to when styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components and an aggregating agent are added without lowering the liquid temperature of the dispersion containing aggregated particles A after the aggregation step. <3> According to the present invention, a method for producing pressure-responsive particles is provided which, in the shell formation process, has better adhesive strength during compression and better storage stability of the dispersion liquid, and produces less aggregates and fused materials, compared to when the liquid temperature is lowered to less than 5°C before adding the styrene-based resin particles and the aggregating agent. <4> According to the invention, a method for producing pressure-responsive particles is provided which has better adhesive strength during compression and better storage properties of the dispersion liquid, and produces less aggregates and fused materials, compared to when the aggregating agent in the aggregation process and the shell formation process is a magnesium-based aggregating agent. <5> According to the present invention, a method for producing pressure-responsive particles is provided which has better adhesive strength during compression and better storage stability of the dispersion, and which produces less aggregates and fused materials, compared to when the aggregating agent in the aggregation process and the shell formation process is polyaluminum chloride. <6> According to the present invention, a method for producing pressure-responsive particles is provided which has better adhesive strength during compression and storage stability of the dispersion liquid, and produces less aggregates and fused materials, compared to when silica particles are not added in the aggregation process. <7> According to the present invention, a method for producing pressure-responsive particles is provided which has superior adhesive strength during compression and storage stability of the dispersion liquid compared to when the amount of silica particles added in the aggregation process is less than 2 mass% or more than 8 mass% relative to the total mass of the composite resin particles. <8> According to the present invention, a method for producing pressure-responsive particles is provided which has better adhesive strength during compression and better storage stability of the dispersion, and produces less aggregates and fused particles, compared to when the arithmetic mean particle size of the silica particles is less than 7 nm or more than 40 nm. <9> According to the present invention, a method for producing pressure-responsive particles is provided which has better adhesive strength during compression and storage stability of the dispersion, and produces less aggregates and fused materials, compared to when the glass transition temperature of the styrene-based resin contained in the pressure-responsive particles is less than 30°C. <10> According to the present invention, a method for producing pressure-responsive particles is provided which has superior adhesive strength during compression and storage stability of the dispersion, and produces less aggregates and fused materials, compared to when the glass transition temperature of the (meth)acrylic acid ester resin contained in the pressure-responsive particles is higher than -30°C. <11> or <12> According to the invention, a method for producing pressure-responsive particles includes an aggregation step of adding an aggregating agent to a dispersion containing composite resin particles including a styrene-based resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylic ester-based resin containing a (meth)acrylic ester compound as polymerization components, and aggregating the particles to obtain aggregated particles A; a shell formation step of adding styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components and aggregating the particles to the dispersion containing the aggregated particles A, and aggregating the particles to obtain aggregated particles B; and a shell formation step of heating and fusing the aggregated particles B to obtain pressure-responsive particles. The present invention provides a method for producing a printed item using pressure-responsive particles, or a method for producing a sheet for producing a printed item, which includes a fusion step of forming pressure-responsive particles, and which has excellent adhesive strength during compression and storage stability of the dispersion, and produces less aggregates and fused material, compared to when the amount of aggregating agent added in the shell formation step is less than 0.01 mass% or more than 1.0 mass% relative to the total mass of the composite resin particles, or when the mass ratio of styrene-based resin to (meth)acrylic acid ester-based resin contained in the pressure-responsive particles is more than 80:less than 20 to 100:0 or 0:100 to less than 20:more than 80. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating an example of a printed matter manufacturing apparatus according to an embodiment of the present invention. [Figure 2] FIG. 10 is a schematic diagram illustrating another example of a printed matter manufacturing apparatus according to the present embodiment. [Figure 3] FIG. 10 is a schematic diagram illustrating another example of a printed matter manufacturing apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0023] The following describes embodiments of the present disclosure. These descriptions and examples are intended to illustrate the embodiments and are not intended to limit the scope of the embodiments.

[0010] In the present disclosure, 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.

[0011] In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples.

[0012] In the present disclosure, 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.

[0013] When embodiments of the present disclosure are described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited to these.

[0014] In the present disclosure, each component may contain multiple corresponding substances. When referring to the amount of each component in a composition in the present disclosure, 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.

[0015] In the present disclosure, the composition may contain multiple types of particles corresponding to each component. 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.

[0016] In the present disclosure, the term "(meth)acrylic" means either "acrylic" or "methacrylic."

[0017] In the present disclosure, "toner for developing electrostatic images" is also referred to simply as "toner," and "electrostatic image developer" is also referred to simply as "developer."

[0018] In this disclosure, a printed matter formed by folding a recording medium and adhering the opposing surfaces together, or a printed matter formed by overlapping two or more recording media and adhering the opposing surfaces together, is referred to as a "press-bonded printed matter."

[0019] (Method for producing pressure-responsive particles) The method for producing pressure-responsive particles according to this embodiment includes an aggregation step of adding an aggregating agent to a dispersion containing composite resin particles including a styrene-based resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylic acid ester-based resin containing a (meth)acrylic acid ester compound as polymerization components, and aggregating the particles to obtain aggregated particles A; a shell formation step of adding styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components and aggregating the particles to the dispersion containing the aggregated particles A, and aggregating the particles to obtain aggregated particles B; and a shell formation step of heating and fusing the aggregated particles B to obtain pressure-responsive particles. The method includes a fusion process of forming a shell, wherein the amount of styrene-based resin particles added in the shell formation process is 5% by mass or more and 40% by mass or less relative to the total mass of the composite resin particles, the amount of aggregating agent added in the shell formation process is 0.1% by mass or more and 1.0% by mass or less relative to the total mass of the composite resin particles, the mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin contained in the pressure-responsive particles is 80:20 to 20:80, and the difference between the lowest and highest glass transition temperatures of the resins contained in the pressure-responsive particles is 30°C or more. The pressure-responsive particles according to this embodiment are pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment.

[0020] Conventionally, adhesive postcards use ultraviolet-curable varnish (UV varnish) for promotional purposes and natural rubber-based glue for confidential use. Both methods require a complicated glue application process, which can lead to odors and the need to clean the application equipment. Therefore, pressure-responsive particles have been investigated as an alternative. Pressure-responsive materials include a styrene-based resin containing styrene and other vinyl monomers as polymerization components, and a (meth)acrylate resin. The mass ratio of the styrene-based resin to the (meth)acrylate resin is 80:20 to 20:80, and the difference between the lowest and highest glass transition temperatures is 30°C or more. If the particle size is adjusted using a resin, and surface exposure of the (meth)acrylate resin can be suppressed, pressure-responsive particles can be extracted as a powder. Furthermore, when pressure-responsive particles are used in pressure-sensitive adhesives, the adhesive strength of the pressure-responsive particles decreases over time, making the adhesive paper for pressure-sensitive postcards have a short shelf life and inventory management difficult. Conversely, if there are areas with strong adhesive strength, the paper will tear when peeled off after storage in a high-humidity environment. Furthermore, if the resulting pressure-responsive particles have even a small amount of exposed core, the pressure-responsive particles may aggregate and fuse to components during the process of electrostatically applying the pressure-responsive particles to paper. The method for producing pressure-responsive particles according to this embodiment includes a shell formation process in which styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components are added with an aggregating agent and aggregating to obtain aggregated particles B. It is estimated that by adding an amount of aggregating agent in the shell formation process of 0.1% by mass or more and 1.0% by mass or less relative to the total mass of the composite resin particles, after aggregation is complete, the core and shell in the pressure-responsive particles are firmly attached to each other and the exposed core portion is reduced, thereby maintaining adhesive strength during compression while providing pressure-responsive particles with excellent storage stability in the dispersion and with little generation of aggregates and fused materials.

[0021] The pressure-responsive particles of this embodiment undergo a phase transition in response 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 embodiment, the pressure-responsive particles that undergo a phase transition in response to pressure refer to pressure-responsive particles that satisfy the following formula 1:

[0022] 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 calculate temperatures T1 and T2 will be described later.

[0023] In the method for producing pressure-responsive particles according to this embodiment, the mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin contained in the pressure-responsive particles is 80:20 to 20:80, and from the viewpoints of adhesive strength during compression bonding, storage properties of the dispersion, and suppression of the occurrence of aggregates and fused materials, it is preferably 70:30 to 30:70, and more preferably 60:40 to 40:60. The styrene-based resin contained in the pressure-responsive particles includes not only the styrene-based resin contained in the composite resin particles, but also the styrene-based resin added in the shell formation process if a shell formation process is performed.

[0024] In the method for producing pressure-responsive particles according to this embodiment, the difference between the lowest and highest glass transition temperatures of the resin contained in the pressure-responsive particles is 30°C or more, and from the viewpoints of adhesive strength during compression, storage properties of the dispersion, and suppression of the occurrence of aggregates and fused materials, it is preferably 40°C or more, more preferably 60°C or more, even more preferably 60°C or more and 200°C or less, and particularly preferably 80°C or more and 150°C or less.

[0025] The pressure-responsive particles have 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 of which is presumed to be the glass transition temperature of a (meth)acrylic acid ester-based resin. The lowest glass transition temperature of the composite resin particles is preferably the glass transition temperature of the (meth)acrylic acid ester resin. Furthermore, it is preferable that the highest glass transition temperature is the glass transition temperature of the styrene-based resin contained in the pressure-responsive particles, and it is more preferable that the lowest glass transition temperature is the glass transition temperature of the (meth)acrylic acid ester-based resin contained in the pressure-responsive particles, and that the highest glass transition temperature is the glass transition temperature of the styrene-based resin contained in the pressure-responsive particles. Furthermore, the lowest glass transition temperature and the highest glass transition temperature are such that the content of the resin contained in the pressure-responsive particles is 1 mass % or more relative to the total mass of the resin contained in the pressure-responsive particles.

[0026] The pressure-responsive particles may have three or more glass transition temperatures, but preferably have two glass transition temperatures. Examples of a form having two glass transition temperatures include a form in which the resins contained in the pressure-responsive particles are only styrene-based resin and (meth)acrylic acid ester-based resin, and a form in which the content of other resins other than styrene-based resin and (meth)acrylic acid ester-based resin is low (for example, a form in which the content of other resins is 5% by mass or less of the entire pressure-responsive particles).

[0027] In the present disclosure, 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."

[0028] The glass transition temperature of the styrene-based resin contained in the pressure-responsive particles 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 composite resin particles from fluidizing when no pressure is applied; and is preferably 110°C or lower, more preferably 100°C or lower, and even more preferably 90°C or lower, from the viewpoint of forming composite resin particles that are prone to phase transition when pressure is applied.

[0029] The glass transition temperature of the (meth)acrylic acid ester resin contained in the pressure-responsive particles 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 pressure-responsive resin particles that are prone to phase transition when subjected to 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-responsive resin particles from fluidizing when no pressure is applied.

[0030] <Agglomeration process> The method for producing pressure-responsive particles according to this embodiment includes an aggregation step in which an aggregating agent is added to a dispersion containing composite resin particles comprising a styrene-based resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylic acid ester-based resin containing a (meth)acrylic acid ester compound as polymerization components, and the particles are aggregated to obtain aggregated particles A. The styrene-based resin and the (meth)acrylic acid ester-based resin will be described in detail later.

[0031] In the method for producing pressure-responsive particles according to this embodiment, pressure-responsive particles are obtained by an aggregation-coalescence method. In the aggregating step, the composite resin particles are aggregated in a dispersion containing the composite resin particles to form aggregated particles A having a diameter close to that of the target pressure-responsive particles.

[0032] Specifically, for example, an aggregating agent is added to the composite resin particle dispersion, and the pH of the composite resin particle dispersion is adjusted to be acidic (for example, pH 2 or higher and 5 or lower), and a dispersion stabilizer is added as necessary. After that, the dispersion is heated to a temperature close to the glass transition temperature of the styrene-based resin (for example, from −10° C. to +15° C. above the glass transition temperature of the styrene-based resin), causing the composite resin particles to aggregate and forming aggregated particles. In the aggregation process, the composite resin particle dispersion is stirred with a rotary shear homogenizer, an aggregating agent is added at room temperature (e.g., 25°C), the pH of the composite resin particle dispersion is adjusted to an acidic value (e.g., pH 2 or more and 5 or less), a dispersion stabilizer is added as needed, and then heating may be performed.

[0033] Examples of the flocculant include a surfactant having an opposite polarity to that of the surfactant contained in the composite resin particle dispersion, an inorganic metal salt, and a divalent or higher metal complex. When a metal complex is used as the flocculant, the amount of surfactant used can be reduced, and charging properties can be improved.

[0034] Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; and inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Among these, from the viewpoints of coagulation properties, adhesive strength during compression, storage properties of the dispersion, and suppression of the generation of aggregates and fused products, aluminum-based coagulants are preferred, aluminum chloride, aluminum sulfate, polyaluminum chloride, or polyaluminum hydroxide is more preferred, and aluminum sulfate is particularly preferred. The amount of the flocculant to be added is not particularly limited, but is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 2 parts by mass, per 100 parts by mass of the composite resin particles.

[0035] The volume average particle size of the composite resin particles is preferably 140 nm or more and 350 nm or less, more preferably 180 nm or more and 320 nm or less, and even more preferably 200 nm or more and 300 nm or less.

[0036] The dispersion containing the composite resin particles in the aggregation step is preferably an aqueous dispersion, and more preferably an aqueous dispersion. The content of the composite resin particles contained in the dispersion containing the composite resin particles is preferably 20% by mass or more and 50% by mass or less, and more preferably 30% by mass or more and 40% by mass or less.

[0037] In the aggregation step, it is preferable to further add silica particles from the viewpoints of adhesive strength during pressure bonding and storage stability of the dispersion. It is believed that by adding a dispersion containing silica particles, the silica particles trap the flocculant after the aggregation in the shell formation process is completed, preventing the flocculant from remaining in the pressure-responsive particles, not inhibiting the mixing of the styrene-based resin and the (meth)acrylic acid ester-based resin during pressure-responsive particle formation, maintaining adhesive strength during compression bonding, and improving the storage stability of the dispersion. In particular, the addition of the flocculant in the shell formation process is effective in removing excess flocculant.

[0038] The silica particles are preferably added in the form of a dispersion containing silica particles. The dispersion containing silica particles is preferably a dispersion in an aqueous medium containing silica particles, and more preferably a water dispersion containing silica particles. Examples of the dispersion medium include aqueous media such as water, alcohols, etc. These may be used alone or in combination of two or more.

[0039] From the viewpoints of adhesive strength during compression bonding and storage stability of the dispersion, the amount of silica particles added in the aggregation process is preferably 0.5% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 9% by mass or less, and particularly preferably 2% by mass or more and 8% by mass or less, relative to the total mass of the composite resin particles. The solid content of the dispersion containing the silica particles is not particularly limited, but is preferably 1% by mass or more and 50% by mass or less, and more preferably 2% by mass or more and 40% by mass or less.

[0040] From the viewpoints of adhesive strength during compression bonding and storage stability of the dispersion, the arithmetic mean particle size of the silica particles is preferably 5 nm or more and 100 nm or less, more preferably 6 nm or more and 80 nm or less, even more preferably 7 nm or more and 40 nm or less, and particularly preferably 7 nm or more and 25 nm or less.

[0041] In this embodiment, the arithmetic mean particle size of silica particles is measured by observing the particles with a scanning electron microscope (S-4100, manufactured by Hitachi, Ltd.) and taking an image. The image is then imported into an image analyzer (LUZEX III, manufactured by Nireco Corporation), and the area of ​​each particle is determined by image analysis. The equivalent circle diameter (nm) is then calculated from the area. The arithmetic mean of the equivalent circle diameters of 100 or more particles is then calculated as the arithmetic mean particle size.

[0042] <Shell formation process> The method for producing pressure-responsive particles according to this embodiment includes a shell formation step in which styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components and an aggregating agent are added to a dispersion containing aggregated particles A obtained by the aggregation step, and aggregated to obtain aggregated particles B, wherein the amount of styrene-based resin particles added in the shell formation step is 5% by mass or more and 40% by mass or less relative to the total mass of the composite resin particles, and the amount of aggregating agent added in the shell formation step is 0.1% by mass or more and 1.0% by mass or less relative to the total mass of the composite resin particles.

[0043] Specifically, for example, after the aggregation step, a styrene-based resin particle dispersion and an aggregating agent are added to a dispersion containing the aggregated particles A, and then the mixture is heated to a temperature close to the glass transition temperature of the styrene-based resin (specifically, for example, from the glass transition temperature of the styrene-based resin −10°C to the glass transition temperature +15°C), causing the styrene-based resin particles to aggregate on the surfaces of the aggregated particles A, thereby forming aggregated particles B having the styrene-based resin particles on their surfaces.

[0044] The styrene-based resin particles are preferably added in the shell-forming step from a styrene-based resin particle dispersion liquid, and the preferred embodiments of the styrene-based resin particle dispersion liquid in the shell-forming step are the same as the preferred embodiments of the styrene-based resin particle dispersion liquid in the aggregation step. The amount of styrene-based resin particles added in the shell formation process is 5% by mass or more and 40% by mass or less, based on the total mass of the composite resin particles used in the aggregation process. From the viewpoints of adhesive strength during compression bonding, storage stability of the dispersion, and suppression of the occurrence of aggregates and fused materials, the amount is preferably 10% by mass or more and 30% by mass or less, more preferably 12% by mass or more and 25% by mass or less, and particularly preferably 15% by mass or more and 20% by mass or less.

[0045] The amount of the aggregating agent added in the shell formation process is 0.01% by mass or more and 1.0% by mass or less relative to the total mass of the composite resin particles used in the aggregation process. From the viewpoints of adhesive strength during pressing, storage stability of the dispersion, and suppression of the occurrence of aggregates and fused materials, the amount is preferably 0.01% by mass or more and 0.5% by mass or less, more preferably 0.02% by mass or more and 0.2% by mass or less, and particularly preferably 0.02% by mass or more and 0.1% by mass or less.

[0046] In the shell formation step, from the viewpoints of adhesive strength during compression bonding, storability of the dispersion, and suppression of the generation of aggregates and fused products, it is preferable to lower the liquid temperature of the dispersion containing aggregated particles A after the aggregation step before adding the styrene-based resin particles and the aggregating agent, and more preferably to lower the liquid temperature by 5°C or more.

[0047] The preferred embodiments of the flocculant used in the shell-forming step are the same as the preferred embodiments of the flocculant used in the flocculation step. The flocculant used in the shell-forming step and the flocculant used in the flocculation step may be the same or different, but are preferably different.

[0048] The pressure-responsive particles having a core-shell structure obtained through the shell formation step and the fusion step have a shell layer containing a styrene-based resin. In addition to the styrene-based resin particle dispersion, a resin particle dispersion in which other types of resin particles are dispersed may be used to form a shell layer containing other types of resin.

[0049] <Fusion process> The method for producing pressure-responsive particles according to this embodiment includes a fusion step of heating and fusing the aggregated particles B to form pressure-responsive particles. In the fusion step, the aggregated particle dispersion in which aggregated particles B are dispersed is heated, for example, to a temperature equal to or higher than the glass transition temperature of the styrene resin particles (for example, a temperature 30°C to 50°C higher than the glass transition temperature of the styrene resin), to fuse and coalesce the aggregated particles and form pressure-responsive particles.

[0050] After the fusion step, the pressure-responsive particles formed in the dispersion are preferably subjected to a known washing step, solid-liquid separation step, and drying step to obtain dried pressure-responsive particles. From the viewpoint of chargeability, the washing step preferably involves thorough substitution washing with ion-exchanged water. From the viewpoint of productivity, the solid-liquid separation step preferably involves suction filtration, pressure filtration, or the like. From the viewpoint of productivity, the drying step preferably involves freeze drying, flash drying, fluidized bed drying, vibration-type fluidized bed drying, or the like.

[0051] The pressure-responsive particles may be produced by, for example, adding an external additive to the obtained dry pressure-responsive particles and mixing them. The mixing may be performed using, for example, a V-blender, a Henschel mixer, a Loedige mixer, or the like. Furthermore, if necessary, coarse particles may be removed from the pressure-responsive particles using a vibrating sieve, an air sieve, or the like.

[0052] The pressure-responsive particles may also contain a colorant, a release agent, and other additives as necessary. When the pressure-responsive particles contain a colorant and a release agent, the composite resin particle dispersion, the colorant particle dispersion, and the release agent particle dispersion are mixed together, and the aggregation step is performed, followed by the fusion step. The colorant particle dispersion and the release agent particle dispersion can be prepared, for example, by mixing the materials and then performing a dispersion process using a known disperser.

[0053] Furthermore, it is preferable that the method for producing pressure-responsive particles according to this embodiment further includes a polymerization step A in which a styrene compound and other vinyl monomers are polymerized to obtain a styrene-based resin, and a polymerization step B in which a (meth)acrylic acid ester compound is polymerized in the presence of the styrene-based resin obtained in the polymerization step A to obtain composite resin particles containing the styrene-based resin and the (meth)acrylic acid ester-based resin.

[0054] <Polymerization step A> The method for producing a pressure-responsive particle dispersion liquid according to this embodiment preferably further includes a polymerization step A in which a styrene compound and other vinyl monomers are polymerized to obtain a styrene-based resin. The polymerization in the polymerization step A is not particularly limited, but is preferably emulsion polymerization. The composite resin particle dispersion is preferably produced by emulsion polymerization.

[0055] The polymerization step A is preferably a step for obtaining styrene-based resin particles, and more preferably a step for obtaining a styrene-based resin particle dispersion. Examples of a method for dispersing styrene-based resin particles in a dispersion medium include a method in which the styrene-based resin and the dispersion medium are mixed and stirred using a rotary shear homogenizer, a ball mill with media, a sand mill, a dyno mill, or the like to disperse the mixture. In addition, as another method for dispersing styrene-based resin particles in a dispersion medium, emulsion polymerization method can be mentioned.Specifically, after mixing the polymerization components of styrene-based resin with a chain transfer agent or a polymerization initiator, further mix with an aqueous medium containing a surfactant, and stir to prepare an emulsion, and polymerize the styrene-based resin in the emulsion.In this case, it is preferable to use a thiol compound as the chain transfer agent, and it is more preferable to use dodecanethiol. Suitable examples of the dispersion medium include the aqueous media described above.

[0056] Examples of surfactants include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Nonionic surfactants may be used in combination with anionic surfactants or cationic surfactants. Among these, anionic surfactants are preferred. The surfactants may be used alone or in combination of two or more.

[0057] The polymerization initiator is not particularly limited, and known photopolymerization initiators and thermal polymerization initiators can be used. Among these, thermal polymerization initiators are preferred, peroxides are more preferred, and ammonium persulfate is particularly preferred. The polymerization temperature and polymerization time are not particularly limited and may be appropriately selected depending on the monomers and polymerization initiators used.

[0058] In the polymerization step A, the volume average particle size of the styrene-based resin particles dispersed in the styrene-based resin particle dispersion is preferably 100 nm or more and 250 nm or less, more preferably 120 nm or more and 220 nm or less, and even more preferably 150 nm or more and 200 nm or less. The volume average particle diameter of the resin particles contained in the resin particle dispersion is measured using a laser diffraction particle size distribution measuring device (e.g., LA-700 manufactured by Horiba, Ltd.), and the particle diameter at the cumulative 50% in the volume-based particle size distribution calculated from the smallest diameter side is defined as the volume average particle diameter (D50v).

[0059] The content of the styrene-based resin particles in the styrene-based resin particle dispersion is not particularly limited, but is preferably 30% by mass or more and 60% by mass or less, and more preferably 40% by mass or more and 50% by mass or less.

[0060] <Polymerization step B> The method for producing a pressure-responsive particle dispersion liquid according to this embodiment preferably further includes a polymerization step B in which a (meth)acrylic acid ester compound is polymerized in the presence of the styrene-based resin obtained in the polymerization step A to obtain composite resin particles containing the styrene-based resin and the (meth)acrylic acid ester-based resin.

[0061] The polymerization step B is preferably a step for obtaining a composite resin particle dispersion. Examples of a method for dispersing the composite resin particles in a dispersion medium include mixing the styrene resin with the dispersion medium and stirring and dispersing the mixture using a rotary shear homogenizer, a ball mill with media, a sand mill, a dyno mill, or the like. Another method for dispersing composite resin particles in a dispersion medium involves adding a polymerization component of a (meth)acrylic ester resin to a styrene-based resin particle dispersion, and optionally adding an aqueous medium. The dispersion is then heated to a temperature equal to or higher than the glass transition temperature of the resulting styrene-based resin (e.g., a temperature 10°C to 30°C higher than the glass transition temperature of the styrene-based resin) while slowly stirring. Next, while maintaining the temperature, an aqueous medium containing a polymerization initiator is slowly added dropwise, and stirring is continued for a further long period of time, ranging from 1 hour to 15 hours. In this case, ammonium persulfate is preferably used as the polymerization initiator. Suitable examples of the dispersion medium and polymerization initiator include those described above. A surfactant may be used in the polymerization step B. Suitable examples of the surfactant include those mentioned above. The polymerization temperature and polymerization time are not particularly limited and may be appropriately selected depending on the monomers and polymerization initiators used.

[0062] Although the detailed mechanism is not entirely clear, it is speculated that when the above-mentioned method is adopted, the styrene-based resin particles are impregnated with the monomer and the polymerization initiator, and the (meth)acrylic acid ester is polymerized inside the styrene-based resin particles. As a result, it is speculated that composite resin particles are obtained in which the (meth)acrylic acid ester resin is contained inside the styrene-based resin particles, and the styrene-based resin and the (meth)acrylic acid ester resin form a microphase-separated state inside the particles.

[0063] The method for producing pressure-responsive particles according to this embodiment may also include known steps other than those described above.

[0064] The styrene-based resin and (meth)acrylic acid ester-based resin that are preferably used in this embodiment will be described in detail below.

[0065] <Styrene-based resin> The styrene-based resin contained in the pressure-responsive particles contains a styrene compound and other vinyl monomers as polymerization components. The styrene compound used in the polymerization of the styrene-based resin preferably contains styrene. Furthermore, 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-responsive particles 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 pressure-responsive particles that are prone to phase transition due to pressure.

[0066] Examples of styrene compounds other than styrene that can be used in the polymerization of the styrene-based resin include vinylnaphthalene; alkyl-substituted styrenes such as α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, and pn-dodecylstyrene; aryl-substituted styrenes such as p-phenylstyrene; alkoxy-substituted styrenes such as p-methoxystyrene; halogen-substituted styrenes such as p-chlorostyrene, 3,4-dichlorostyrene, p-fluorostyrene, and 2,5-difluorostyrene; and nitro-substituted styrenes such as m-nitrostyrene, o-nitrostyrene, and p-nitrostyrene. One type of styrene compound may be used alone, or two or more types may be used in combination.

[0067] Examples of vinyl monomers other than the styrene compound that can be used in the polymerization of the styrene resin include acrylic monomers.

[0068] The acrylic monomer is preferably at least one acrylic monomer selected from the group consisting of (meth)acrylic acid and (meth)acrylic acid ester compounds. Examples of the (meth)acrylic acid ester compound include (meth)acrylic acid alkyl ester compounds, (meth)acrylic acid carboxy-substituted alkyl ester compounds, (meth)acrylic acid hydroxy-substituted alkyl ester compounds, (meth)acrylic acid alkoxy-substituted alkyl ester compounds, and di(meth)acrylic acid ester compounds. The acrylic monomer may be used alone or in combination of two or more.

[0069] Examples of the (meth)acrylic acid alkyl ester compound include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)methacrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and isobornyl (meth)acrylate. Examples of the carboxy-substituted alkyl (meth)acrylate include 2-carboxyethyl (meth)acrylate. Examples of the (meth)acrylic acid hydroxy-substituted alkyl ester compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of the alkoxy-substituted alkyl (meth)acrylate ester compound include 2-methoxyethyl (meth)acrylate. Examples of the di(meth)acrylic acid ester compound include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, pentanediol di(meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, and decanediol di(meth)acrylate.

[0070] Examples of the (meth)acrylic acid ester compound include 2-(diethylamino)ethyl (meth)acrylate, benzyl (meth)acrylate, and methoxypolyethylene glycol (meth)acrylate.

[0071] Examples of other vinyl monomers that can be used in the polymerization of the styrene-based resin include (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.

[0072] From the viewpoint of forming pressure-responsive particles that easily undergo a phase transition due to pressure, the styrene-based resin preferably contains a (meth)acrylic acid ester compound as a polymerization component, more preferably a (meth)acrylic acid alkyl ester compound, even more preferably a (meth)acrylic acid alkyl ester compound having an alkyl group with 2 to 10 carbon atoms, even more preferably a (meth)acrylic acid alkyl ester compound having an alkyl group with 4 to 8 carbon atoms, and particularly preferably at least one of n-butyl acrylate and 2-ethylhexyl acrylate.

[0073] Among the vinyl monomers other than styrene, the vinyl monomer that accounts for the largest mass proportion in the styrene-based resin is preferably a (meth)acrylic acid ester, more preferably a (meth)acrylic acid alkyl ester compound, even more preferably a (meth)acrylic acid alkyl ester compound having an alkyl group with 2 to 10 carbon atoms, and even more preferably n-butyl acrylate or 2-ethylhexyl acrylate, from the viewpoint of forming pressure-responsive particles that easily undergo phase transition due to pressure.

[0074] The mass proportion of the (meth)acrylic acid ester compound 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-responsive particles 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 facilitating phase transition of the pressure-responsive particles under pressure. The (meth)acrylic acid ester compound here is preferably a (meth)acrylic acid alkyl ester compound, more preferably a (meth)acrylic acid alkyl ester compound having an alkyl group with 2 to 10 carbon atoms, and even more preferably a (meth)acrylic acid alkyl ester compound having an alkyl group with 4 to 8 carbon atoms.

[0075] It is particularly preferable that the styrene-based 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-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 pressure-responsive particles 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 pressure-responsive particles that are prone to phase transition when pressure is applied.

[0076] The weight average molecular weight of the styrene-based resin is preferably 10,000 or more, more preferably 20,000 or more, and even more preferably 30,000 or more, from the viewpoint of preventing the pressure-responsive particles from fluidizing when no pressure is applied, and is preferably 200,000 or less, more preferably 150,000 or less, and even more preferably 100,000 or less, from the viewpoint of forming pressure-responsive particles that are prone to phase transition when subjected to pressure.

[0077] In this disclosure, the weight-average molecular weight of a resin is measured by gel permeation chromatography (GPC). Molecular weight measurement by GPC is performed using a Tosoh HLC-8120GPC GPC apparatus, a Tosoh TSKgel SuperHM-M (15 cm) column, and tetrahydrofuran as a solvent. The weight-average molecular weight of the resin is calculated using a molecular weight calibration curve prepared using monodisperse polystyrene standard samples.

[0078] The glass transition temperature of the styrene-based 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-responsive particles from fluidizing when no pressure is applied; and is preferably 110°C or lower, more preferably 100°C or lower, and even more preferably 90°C or lower, from the viewpoint of forming pressure-responsive particles that are prone to undergo a phase transition when pressure is applied.

[0079] <(Meth)acrylic acid ester resin> The (meth)acrylic acid ester resin contained in the pressure-responsive particles contains a (meth)acrylic acid ester compound as a polymerization component. The (meth)acrylic acid ester compound may be used alone or in combination of two or more kinds, but it is preferable that at least two kinds of (meth)acrylic acid esters are contained in the polymerization components. Furthermore, the mass proportion of the (meth)acrylic acid 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 particularly preferably 100 mass%.

[0080] Examples of the (meth)acrylic acid ester compound used in the polymerization of the (meth)acrylic acid ester-based resin include (meth)acrylic acid alkyl ester compounds, (meth)acrylic acid carboxy-substituted alkyl ester compounds, (meth)acrylic acid hydroxy-substituted alkyl ester compounds, (meth)acrylic acid alkoxy-substituted alkyl ester compounds, and di(meth)acrylic acid ester compounds.

[0081] Examples of the (meth)acrylic acid alkyl ester compound include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)methacrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and isobornyl (meth)acrylate. Examples of the (meth)acrylic acid carboxy-substituted alkyl ester compound include 2-carboxyethyl (meth)acrylate. Examples of the (meth)acrylic acid hydroxy-substituted alkyl ester compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of the alkoxy-substituted alkyl (meth)acrylate ester compound include 2-methoxyethyl (meth)acrylate. Examples of the di(meth)acrylic acid ester compound include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, pentanediol di(meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, and decanediol di(meth)acrylate.

[0082] In addition, examples of the (meth)acrylic acid ester compound include 2-(diethylamino)ethyl (meth)acrylate, benzyl (meth)acrylate, and methoxypolyethylene glycol (meth)acrylate.

[0083] As the (meth)acrylic acid ester compound used in the polymerization of the (meth)acrylic acid ester-based resin, from the viewpoint of forming pressure-responsive particles that easily undergo phase transition under pressure and have excellent adhesiveness, a (meth)acrylic acid alkyl ester compound is preferred, a (meth)acrylic acid alkyl ester compound having an alkyl group with 2 to 10 carbon atoms is more preferred, a (meth)acrylic acid alkyl ester compound 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 pressure-responsive particles that readily undergo a phase transition upon pressure, the styrene-based resin and the (meth)acrylic ester-based resin contained in the pressure-responsive particles preferably contain the same (meth)acrylic ester compound as polymerization components. That is, from the viewpoint of forming pressure-responsive particles that readily undergo a phase transition upon pressure, the styrene-based resin and the (meth)acrylic ester-based resin contained in the pressure-responsive particles preferably each have a constituent unit derived from the same (meth)acrylic ester compound.

[0084] Of the at least two (meth)acrylic acid ester compounds 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 ester compounds. The (meth)acrylic acid alkyl ester compounds here are preferably (meth)acrylic acid alkyl ester compounds having an alkyl group with 2 to 10 carbon atoms, and more preferably (meth)acrylic acid alkyl ester compounds having an alkyl group with 4 to 8 carbon atoms.

[0085] When the two (meth)acrylic acid ester compounds having the largest mass proportions among the at least two (meth)acrylic acid ester compounds contained as polymerization components in the (meth)acrylic acid ester resin are (meth)acrylic acid alkyl ester compounds, the difference in the number of carbon atoms in the alkyl groups of the two (meth)acrylic acid alkyl ester compounds is preferably 1 or more and 4 or less, more preferably 2 or more and 4 or less, and even more preferably 3 or 4, from the viewpoint of forming pressure-responsive particles that are easily transferred by pressure and have excellent adhesive strength.

[0086] From the viewpoint of forming pressure-responsive particles that are easily transitioned by pressure and have excellent adhesive strength, the (meth)acrylic ester resin preferably contains n-butyl acrylate and 2-ethylhexyl acrylate as polymerization components, and it is particularly preferred that the two (meth)acrylic ester compounds having the largest mass proportions among the at least two (meth)acrylic ester compounds contained in the (meth)acrylic ester resin as polymerization components 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 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%.

[0087] The (meth)acrylic acid ester resin may contain a vinyl monomer other than a (meth)acrylic acid ester compound as a polymerization component. Examples of vinyl monomers other than (meth)acrylic acid esters 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.

[0088] When the (meth)acrylic acid ester resin contains a vinyl monomer other than a (meth)acrylic acid ester compound as a polymerization component, the vinyl monomer other than a (meth)acrylic acid ester compound is preferably at least one of acrylic acid and methacrylic acid, and more preferably acrylic acid.

[0089] The weight average molecular weight of the (meth)acrylic acid ester resin is preferably 10,000 or more, more preferably 20,000 or more, and even more preferably 30,000 or more, from the viewpoint of preventing the pressure-responsive particles from fluidizing when no pressure is applied, and is preferably 200,000 or less, more preferably 150,000 or less, and even more preferably 100,000 or less, from the viewpoint of forming pressure-responsive particles that easily undergo phase transition when subjected to pressure.

[0090] 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 pressure-responsive particles that easily undergo phase transition when subjected to 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-responsive particles from fluidizing when no pressure is applied.

[0091] <Other resins> The pressure-responsive particles may contain, for example, polystyrene, or 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.

[0092] <Various additives> The pressure-responsive particles may contain, as necessary, colorants (e.g., pigments, dyes), release agents (e.g., hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, candelilla wax, etc.; synthetic or mineral / petroleum waxes such as montan wax; ester waxes such as fatty acid esters, montan acid esters), charge control agents, etc.

[0093] When the pressure-responsive particles are transparent, the amount of colorant in the pressure-responsive particles is preferably 1.0 mass % or less relative to the entire pressure-responsive particles, and the smaller the amount, the better from the viewpoint of increasing the transparency of the pressure-responsive particles.

[0094] In the aggregation step, the other resin and the additive are preferably added to a dispersion containing the composite resin particles, and are contained in the pressure-responsive particles.

[0095] <Structure of pressure-responsive particles> The internal structure of the pressure-responsive 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.

[0096] When the pressure-responsive particles have a sea-island structure, the average diameter of the island phases is preferably 200 nm or more and 500 nm or less. When the average diameter of the island phases is 500 nm or less, the pressure-responsive particles are likely to undergo phase transition due to pressure, and when the average diameter of the island phases is 200 nm or more, the pressure-responsive particles have excellent mechanical strength (for example, strength that makes them resistant to deformation when stirred in a developing device). From these perspectives, the average diameter of the island phases is more preferably 220 nm or more and 450 nm or less, and even more preferably 250 nm or more and 400 nm or less.

[0097] Methods for controlling the average diameter of the island phases in the sea-island structure within the above range include, for example, increasing or decreasing the amount of (meth)acrylic acid ester-based resin relative to the amount of styrene-based resin in the method for producing pressure-responsive particles described below, or increasing or decreasing the time for which the temperature is maintained at a high temperature in the step of fusing and coalescing the aggregated resin particles.

[0098] The sea-island structure is confirmed and the average diameter of the island phase is measured by the following method. The pressure-responsive particles are embedded in epoxy resin, sliced ​​using a diamond knife or similar, and stained with osmium tetroxide or ruthenium tetroxide in a desiccator. The stained sections are then observed under 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 by osmium tetroxide or ruthenium tetroxide, and this is used to confirm the presence or absence of a 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 islands is used as the average diameter.

[0099] The pressure-responsive particles may be pressure-responsive particles having a single layer structure, or may be core-shell pressure-responsive particles having a core and a shell layer covering the core. From the viewpoint of preventing the pressure-responsive particles from fluidizing in an unpressurized state, the pressure-responsive particles are preferably core-shell pressure-responsive particles.

[0100] When the pressure-responsive particles have a core-shell structure, the core preferably contains a styrene-based resin and a (meth)acrylic ester-based resin, from the viewpoint of facilitating phase transition under pressure. Furthermore, the shell layer preferably contains a styrene-based resin, from the viewpoint of suppressing fluidization of the pressure-responsive particles in an unpressurized state. Specific forms of the styrene-based resin are as described above. Specific forms of the (meth)acrylic ester-based resin are as described above.

[0101] When the pressure-responsive 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 acid ester-based resin dispersed in the sea phase. The average diameter of the island phase is preferably within the range described above. 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 and shell layer of the core portion have a continuous structure, making it easy for the pressure-responsive particles to undergo phase transition due to 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 acid ester-based resin contained in the island phase of the core portion is as described above.

[0102] 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.

[0103] 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-responsive 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-responsive particles due to pressure.

[0104] The average thickness of the shell layer is measured by the following method. The pressure-responsive particles are embedded in epoxy resin, sliced ​​using a diamond knife or similar, and stained with osmium tetroxide or ruthenium tetroxide in a desiccator. The stained sections are then observed under a scanning electron microscope (SEM). Ten pressure-responsive particle cross sections are randomly selected from the SEM images, and the shell layer thickness is measured at 20 points per pressure-responsive particle, the average value is calculated, and the average of the 10 pressure-responsive particles is used as the average thickness.

[0105] The volume average particle size (D50v) of the pressure-responsive 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 the pressure-responsive particles, and is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less, from the viewpoint of ease of phase transition of the entire pressure-responsive particles due to pressure.

[0106] The volume-average particle size (D50v) of pressure-responsive particles was measured using a Coulter Multisizer II (Beckman Coulter) with a 100 μm aperture. Pressure-responsive particles were dispersed in 2 mL of a 5% by mass aqueous solution of sodium alkylbenzene sulfonate (0.5 mg to 50 mg), then mixed with 100 mL to 150 mL of electrolyte (ISOTON-II, Beckman Coulter), and dispersed for 1 minute using an ultrasonic disperser. The resulting dispersion was used as the sample. The particle sizes of 50,000 particles with diameters between 2 μm and 60 μm in the sample were measured. The volume-average particle size (D50v) was determined as the particle size at 50% of the cumulative particle size distribution, calculated from the smallest diameter.

[0107] <External additives> The pressure-responsive particles may contain an external additive, if necessary. 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.

[0108] 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.

[0109] 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).

[0110] The amount of external additive added is preferably 0.01% by mass to 5% by mass, more preferably 0.01% by mass to 2.0% by mass, based on the total mass of the pressure-responsive particles (pressure-responsive base particles) excluding the external additive.

[0111] <Pressure characteristics of pressure-responsive particles> The pressure-responsive particles produced by the method for producing pressure-responsive particles according to this embodiment are pressure-responsive particles that undergo a phase transition in response to pressure, and satisfy 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.

[0112] The temperature difference (T1-T2) is 10°C or more, preferably 15°C or more, and more preferably 20°C or more, from the viewpoint of facilitating phase transition of the pressure-responsive particles due to 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 pressure-responsive particles from fluidizing when no pressure is applied.

[0113] 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.

[0114] An index showing that pressure-responsive particles are susceptible to pressure-induced phase transition is the temperature difference (T1-T3) between the temperature T1 at which they exhibit a viscosity of 10,000 Pa s under a pressure of 1 MPa and the temperature T3 at which they exhibit 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 perspective of the susceptibility of pressure-induced phase transition of the pressure-responsive particles, the temperature difference (T1-T3) is preferably 5°C or greater, and more preferably 10°C or greater. The temperature difference (T1-T3) is generally less than 25°C.

[0115] From the viewpoint of ensuring that the temperature difference (T1-T3) is 5°C or more, the temperature T3 at which the pressure-responsive particles exhibit 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.

[0116] The temperature T1, the temperature T2, and the temperature T3 are determined as follows. The pressure-responsive particles are compressed to prepare a pellet-shaped sample. The pellet-shaped sample is set in a flow tester (Shimadzu Corporation, CFT-500), and the applied pressure is fixed at 1 MPa, and the viscosity at 1 MPa versus temperature is measured. From the obtained viscosity graph, it is found that the viscosity is 10 4Determine the temperature T1 when the pressure becomes Pa·s. Determine the temperature T2 in the same way as for temperature T1, except that the applied pressure is changed from 1 MPa to 10 MPa. Determine the temperature T3 in the same way as for temperature T1, except that the applied pressure is changed from 1 MPa to 4 MPa. Calculate the temperature difference (T1-T2) from temperatures T1 and T2. Calculate the temperature difference (T1-T3) from temperatures T1 and T3.

[0117] (cartridge) The cartridge according to this embodiment contains pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment, and is detachably attached to a printed matter manufacturing device. When the cartridge is attached to the printed matter manufacturing device, a supply pipe connects the cartridge to a placement means of the printed matter manufacturing device that places the pressure-responsive particles on a recording medium. The pressure-responsive particles are supplied from the cartridge to the placement means, and when the pressure-responsive particles contained in the cartridge become scarce, the cartridge is replaced.

[0118] (Printed matter manufacturing equipment, printed matter manufacturing method, printed matter) The printed matter manufacturing apparatus of this embodiment includes a placement means that stores pressure-responsive particles manufactured by the pressure-responsive particle manufacturing method of this embodiment and places the pressure-responsive particles on a recording medium, and a pressing means that folds and presses the recording medium, or that stacks and presses the recording medium and another recording medium together.

[0119] The placement means may include, for example, an application device that applies pressure-responsive particles onto the recording medium, and may further include a fixing device that fixes the pressure-responsive particles applied onto the recording medium onto the recording medium.

[0120] The pressing means includes, for example, a folding device that folds the recording medium on which pressure-responsive particles are arranged, or a stacking device that stacks the recording medium on which pressure-responsive particles are arranged with another recording medium, and a pressure device that applies pressure to the stacked recording media.

[0121] The pressure device provided in the pressure bonding means applies pressure to the recording medium on which the pressure-responsive particles are arranged, causing the pressure-responsive particles to flow on the recording medium and exert adhesive properties.

[0122] The apparatus for producing a printed matter according to the present embodiment implements the method for producing a printed matter according to the present embodiment. The method for producing a printed matter according to the present embodiment uses pressure-responsive particles produced by the method for producing pressure-responsive particles according to the present embodiment, and includes an arrangement step of arranging the pressure-responsive particles on a recording medium, and a compression step of folding and pressing the recording medium or folding and pressing the recording medium and another recording medium together.

[0123] The disposing step may include, for example, a step of applying pressure-responsive particles onto the recording medium, and may further include a step of fixing the pressure-responsive particles applied onto the recording medium onto the recording medium.

[0124] The pressing step includes, for example, a folding step of folding the recording medium or a stacking step of stacking the recording medium and another recording medium, and a pressurizing step of applying pressure to the stacked recording media.

[0125] The pressure-responsive particles may be disposed over the entire surface of the recording medium, or may be disposed on a portion of the recording medium. The pressure-responsive particles may be disposed in one layer or multiple layers on the recording medium. The layer of pressure-responsive particles may be a continuous layer in the surface direction of the recording medium, or a discontinuous layer in the surface direction of the recording medium. The layer of pressure-responsive particles may be a layer in which the pressure-responsive particles are aligned as particles, or a layer in which adjacent pressure-responsive particles are fused and aligned.

[0126] The amount of pressure-responsive particles (preferably transparent pressure-responsive particles) on the recording medium is, for example, 0.5 g / m 2 in the area where they are disposed. 2 More than 50g / m 2 less than 1 g / m 2 More than 40g / m 2 less than or equal to 1.5 g / m 2 More than 30g / m 2The layer thickness of the pressure-responsive particles (preferably transparent pressure-responsive particles) on the recording medium is, for example, 0.2 μm to 25 μm, 0.4 μm to 20 μm, or 0.6 μm to 15 μm.

[0127] Examples of recording media that can be used with the printed matter production device according to this embodiment include paper, coated paper in which the surface of paper is coated with a resin or the like, cloth, nonwoven fabric, resin film, resin sheet, etc. The recording media may have an image on one or both sides.

[0128] An example of a printed matter production apparatus according to this embodiment will be described below, but this embodiment is not limited to this.

[0129] Fig. 1 is a schematic diagram showing an example of a printed matter production apparatus according to the present embodiment. The printed matter production apparatus shown in Fig. 1 includes a placement means 100 and a pressing means 200 arranged downstream of the placement means 100. The arrow indicates the transport direction of the recording medium.

[0130] The placement means 100 is a device that uses pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment to place the pressure-responsive particles on a recording medium P. An image has been formed in advance on one or both sides of the recording medium P.

[0131] The placement means 100 includes an application device 110 and a fixing device 120 arranged downstream of the application device 110 .

[0132] The application device 110 applies the pressure-responsive particles M onto the recording medium P. Examples of application methods that the application device 110 employs include spraying, bar coating, die coating, knife coating, roll coating, reverse roll coating, gravure coating, screen printing, inkjet printing, lamination, and electrophotography. Depending on the application method, the pressure-responsive particles M may be dispersed in a dispersion medium to prepare a liquid composition, and the liquid composition may be applied to the application device 110.

[0133] The recording medium P to which the pressure-responsive particles M have been applied by the application device 110 is transported to the fixing device 120.

[0134] The fixing device 120 may be, for example, a heating device that has a heat source and heats the pressure-responsive particles M on the recording medium P as it passes, thereby fixing the pressure-responsive particles M on the recording medium P; a pressure device that has a pair of pressure members (roll / roll, belt / roll) and pressurizes the recording medium P as it passes, thereby fixing the pressure-responsive particles M on the recording medium P; or a pressure / heating device that has a pair of pressure members (roll / roll, belt / roll) with a heat source inside, and pressurizes and heats the recording medium P as it passes, thereby fixing the pressure-responsive particles M on the recording medium P.

[0135] When the fixing device 120 has a heating source, the surface temperature of the recording medium P when heated by the fixing device 120 is preferably 10°C or higher and 80°C or lower, more preferably 20°C or higher and 60°C or lower, and even more preferably 30°C or higher and 50°C or lower.

[0136] When the fixing device 120 has a pressure member, the pressure applied by the pressure member to the recording medium P may be lower than the pressure applied by the pressure device 230 to the recording medium P2.

[0137] The recording medium P becomes a recording medium P1 having pressure-responsive particles M applied onto the image by passing through the arranging means 100. The recording medium P1 is transported toward the pressure bonding means 200.

[0138] In the printed matter manufacturing apparatus according to this embodiment, the placement means 100 and the pressing means 200 may be located close to each other or may be located apart from each other. When the placement means 100 and the pressing means 200 are located apart from each other, the placement means 100 and the pressing means 200 are connected by, for example, a conveying means (for example, a belt conveyor) that conveys the recording medium P1.

[0139] The pressing means 200 includes a folding device 220 and a pressure device 230, and is a means for folding and pressing the recording medium P1.

[0140] The folding device 220 folds the recording medium P1 that passes through the device to produce a folded recording medium P2. The recording medium P2 may be folded, for example, in half, in thirds, or in fourths, and may be folded only partially. The recording medium P2 has pressure-responsive particles M arranged on at least a portion of at least one of two opposing surfaces.

[0141] The folding device 220 may have a pair of pressure members (for example, roll / roll, belt / roll) that apply pressure to the recording medium P2. The pressure applied by the pressure members of the folding device 220 to the recording medium P2 may be lower than the pressure applied by the pressure device 230 to the recording medium P2.

[0142] The pressing means 200 may be provided with a stacking device that stacks the recording medium P1 and another recording medium instead of the folding device 220. The recording medium P1 and the other recording medium may be stacked, for example, in a form in which one sheet of the other recording medium is stacked on the recording medium P1, or in a form in which one sheet of the other recording medium is stacked at each of multiple locations on the recording medium P1. The other recording medium may be a recording medium with an image formed on one or both sides, a recording medium without an image formed on it, or a pre-prepared press-bonded printed material.

[0143] The recording medium P2 that has left the folding device 220 (or the overlapping device) is conveyed toward the pressure device 230.

[0144] The pressure device 230 includes a pair of pressure members (i.e., pressure rolls 231 and 232). The pressure rolls 231 and 232 come into contact with each other at their outer circumferential surfaces and press against each other, applying pressure to the recording medium P2 passing through. The pair of pressure members included in the pressure device 230 is not limited to a combination of pressure rolls, but may also be a combination of a pressure roll and a pressure belt, or a combination of a pressure belt and a pressure belt.

[0145] When pressure is applied to the recording medium P2 passing through the pressure device 230, the pressure-responsive particles M on the recording medium P2 become fluidized by the pressure and exhibit adhesiveness.

[0146] The pressure applying device 230 may or may not have an internal heat source (e.g., a halogen heater) for heating the recording medium P2. However, the fact that the pressure applying device 230 does not have an internal heat source does not exclude the possibility that the temperature inside the pressure applying device 230 may become equal to or higher than the ambient temperature due to heat generated by a motor or the like provided in the pressure applying device 230.

[0147] As the recording medium P2 passes through the pressure device 230, the overlapping surfaces are bonded together by the fluidized pressure-responsive particles M, producing a pressure-bonded printed matter P3. In the pressure-bonded printed matter P3, two opposing surfaces are partially or entirely bonded together.

[0148] The completed pressure-bonded printed matter P3 is carried out from the pressure device 230.

[0149] The first form of the laminated printed matter P3 is a laminated printed matter in which two folded recording media are adhered on their opposing surfaces by pressure-responsive particles M. The laminated printed matter P3 of this form is produced by a printed matter production apparatus equipped with a folding device 220.

[0150] A second form of the laminated printed matter P3 is a laminated printed matter in which a plurality of overlapping recording media are bonded on their opposing surfaces by pressure-responsive particles M. The laminated printed matter P3 of this form is manufactured by a manufacturing apparatus for a laminated printed matter that is equipped with a layering device.

[0151] The printed matter production device according to this embodiment is not limited to a device that continuously transports the recording medium P2 from the folding device 220 (or the overlapping device) to the pressure device 230. The printed matter production device according to this embodiment may also be a device that stores the recording medium P2 that has left the folding device 220 (or the overlapping device), and transports the recording medium P2 to the pressure device 230 after the amount of stored recording medium P2 reaches a predetermined amount.

[0152] In the printed matter manufacturing apparatus according to this embodiment, the folding device 220 (or overlapping device) and the pressing and pressuring device 230 may be located close to each other or may be located apart from each other. When the folding device 220 (or overlapping device) and the pressing and pressuring device 230 are located apart from each other, the folding device 220 (or overlapping device) and the pressing and pressuring device 230 are connected by, for example, a conveying means (for example, a belt conveyor) that conveys the recording medium P2.

[0153] The printed matter manufacturing apparatus according to this embodiment may include a cutting means for cutting the recording medium to predetermined dimensions. The cutting means may be, for example, a cutting means disposed between the arrangement means 100 and the pressing means 200, which cuts off a portion of the recording medium P1 where the pressure-responsive particles M are not disposed; a cutting means disposed between the folding device 220 and the pressure device 230, which cuts off a portion of the recording medium P2 where the pressure-responsive particles M are not disposed; or a cutting means disposed downstream of the pressing means 200, which cuts off a portion of the pressed printed matter P3 where the pressure-responsive particles M are not adhered.

[0154] The printed matter manufacturing apparatus according to the present embodiment is not limited to a sheet-fed type apparatus, but may be an apparatus that performs a placement process and a pressing process on a long recording medium to form a long, pressed-on printed matter, and then cuts the long, pressed-on printed matter to predetermined dimensions.

[0155] The apparatus for producing a printed matter according to the present embodiment may further include a color image forming unit that forms a color image on a recording medium using a coloring material. Examples of the color image forming unit include a unit that forms a color ink image on a recording medium by an inkjet method using colored ink as a coloring material, and a unit that forms a color image on a recording medium by an electrophotographic method using a colored electrostatic image developer.

[0156] The manufacturing apparatus having the above-described configuration is used to carry out the method for manufacturing a printed matter according to the present embodiment, which further includes a color image forming step of forming a color image on a recording medium using a coloring material. Specific examples of the color image forming step include a step of forming a color ink image on a recording medium by an inkjet method using colored ink as a coloring material, and a step of forming a color image on a recording medium by an electrophotographic method using a colored electrostatic image developer.

[0157] (Sheet for producing printed matter, method for manufacturing sheet for producing printed matter) The sheet for producing printed matter according to this embodiment has a substrate and pressure-responsive particles arranged on the substrate. The sheet for producing printed matter according to this embodiment is produced using pressure-responsive particles produced by the method for producing pressure-responsive particles according to this embodiment. The pressure-responsive particles on the substrate may or may not retain the particle shape they had before being arranged on the substrate.

[0158] The sheet for producing printed matter according to this embodiment is used, for example, as a masking sheet that is placed on top of a recording medium and adhered to the recording medium when it is desired to conceal information recorded on the recording medium; a release sheet that is used to provide an adhesive layer on the recording medium when recording media are placed on top of each other and adhered to each other; and the like.

[0159] Examples of substrates that can be used in the sheet for producing printed matter according to this embodiment include paper, coated paper in which the surface of paper is coated with a resin or the like, cloth, nonwoven fabric, resin film, resin sheet, etc. An image may be formed on one or both sides of the substrate.

[0160] In the sheet for producing printed matter according to this embodiment, the pressure-responsive particles may be disposed over the entire surface of the substrate, or may be disposed on a portion of the substrate. The pressure-responsive particles are disposed in one layer or multiple layers on the substrate. The layer of pressure-responsive particles may be a layer that is continuous in the surface direction of the substrate, or may be a layer that is discontinuous in the surface direction of the substrate. The layer of pressure-responsive particles may be a layer in which the pressure-responsive particles are aligned as particles, or a layer in which adjacent pressure-responsive particles are fused together and aligned.

[0161] The amount of pressure-responsive particles on the substrate is, for example, 0.5 g / m2 in the area where they are disposed. 2 More than 50g / m 2 less than 1 g / m 2 More than 40g / m 2 less than or equal to 1.5 g / m 2 More than 30g / m 2 The layer thickness of the pressure-responsive particles on the substrate is, for example, 0.2 μm to 25 μm, 0.4 μm to 20 μm, or 0.6 μm to 15 μm.

[0162] The sheet for producing printed matter according to this embodiment is manufactured, for example, by a manufacturing method that uses pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment and includes an arrangement step of arranging the pressure-responsive particles on a substrate.

[0163] The disposing step may include, for example, an applying step of applying pressure-responsive particles onto a substrate, and may further include a fixing step of fixing the pressure-responsive particles applied onto the substrate.

[0164] The application step is realized by an application method such as, for example, a spray method, a bar coating method, a die coating method, a knife coating method, a roll coating method, a reverse roll coating method, a gravure coating method, a screen printing method, an inkjet method, a lamination method, an electrophotography method, etc. Depending on the application method in the application step, the pressure-responsive particles may be dispersed in a dispersion medium to prepare a liquid composition, and the liquid composition may be applied to the application step.

[0165] The fixing process includes, for example, a heating process in which the pressure-responsive particles on the substrate are heated with a heat source to fix the pressure-responsive particles on the substrate; a pressurizing process in which the substrate to which the pressure-responsive particles have been applied is pressed with a pair of pressure members (roll / roll, belt / roll) to fix the pressure-responsive particles on the substrate; and a pressurizing and heating process in which the substrate to which the pressure-responsive particles have been applied is pressed and heated with a pair of pressure members (roll / roll, belt / roll) equipped with a heat source inside to fix the pressure-responsive particles on the substrate.

[0166] (Electrophotographic printing) An embodiment in which pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment are applied to an electrophotographic system will be described below. In the electrophotographic system, the pressure-responsive particles are used as toner.

[0167] <Electrostatic image developer> The electrostatic image developer according to this embodiment contains at least pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment. The electrostatic image developer according to this embodiment may be a one-component developer containing only the pressure-responsive particles, or may be a two-component developer containing the pressure-responsive particles and a carrier.

[0168] The carrier is not particularly limited, and known carriers can be used. Examples of the carrier include a coated carrier in which the surface of a core material made of magnetic powder is coated with a resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and mixed in a matrix resin; and a resin impregnated type carrier in which porous magnetic powder is impregnated with a resin. The magnetic powder dispersion type carrier and the resin impregnated type carrier may be a carrier in which the constituent particles of the carrier are used as a core material and the surface of this is coated with a resin.

[0169] Examples of magnetic powder include magnetic metals such as iron, nickel, and cobalt; and magnetic oxides such as ferrite and magnetite.

[0170] Examples of coating resins and matrix resins include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid ester copolymer, straight silicone resins containing organosiloxane bonds or modified products thereof, fluororesin, polyester, polycarbonate, phenolic resin, and epoxy resin. The coating resin and matrix resin may contain other additives such as conductive particles. Examples of conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

[0171] To coat the surface of the core material with a resin, a method of coating with a coating layer-forming solution prepared by dissolving the coating resin and various additives (used as needed) in an appropriate solvent can be used. The solvent is not particularly limited and may be selected taking into consideration the type of resin used, its suitability for application, etc. Specific resin coating methods include an immersion method in which the core material is immersed in a solution for forming a coating layer; a spray method in which the solution for forming a coating layer is sprayed onto the surface of the core material; a fluidized bed method in which the solution for forming a coating layer is sprayed onto the core material while it is suspended in flowing air; and a kneader coater method in which the core material of the carrier and the solution for forming a coating layer are mixed in a kneader coater and then the solvent is removed.

[0172] The mixing ratio (mass ratio) of pressure responsive particles to carrier in the two-component developer is preferably pressure responsive particles:carrier=1:100 to 30:100, more preferably 3:100 to 20:100.

[0173] <Printed material manufacturing device and printed material manufacturing method> The apparatus for producing printed matter using an electrophotographic method includes a placement means for storing a developer containing pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment and for placing the pressure-responsive particles on a recording medium using an electrophotographic method, and a pressing means for folding and pressing the recording medium, or for stacking and pressing the recording medium and another recording medium together.

[0174] The apparatus for producing a printed matter according to the present embodiment is used to carry out a method for producing a printed matter by electrophotography. The method for producing a printed matter according to the present embodiment includes a placement step of electrophotographically arranging pressure-responsive particles on a recording medium using a developer containing the pressure-responsive particles produced by the method for producing pressure-responsive particles according to the present embodiment, and a pressing step of folding and pressing the recording medium or placing and pressing the recording medium and another recording medium together.

[0175] The arrangement unit included in the printed matter manufacturing device according to the present embodiment includes, for example, A photoreceptor; a charging means for charging the surface of the photoreceptor; an electrostatic image forming means for forming an electrostatic image on the charged surface of the photoreceptor; a developing unit that contains the electrostatic image developer according to the present embodiment and develops the electrostatic image formed on the surface of the photoreceptor with the electrostatic image developer as a pressure-responsive particle application portion; a transfer means for transferring the pressure responsive particle application portion formed on the surface of the photoreceptor onto a recording medium; Equipped with. It is preferable that the positioning means further comprises fixing means for fixing the pressure responsive particle application portion transferred to the surface of the recording medium.

[0176] The arrangement step included in the method for producing a printed matter according to the present embodiment includes, for example, a charging step of charging the surface of the photoreceptor; an electrostatic image forming step of forming an electrostatic image on the charged surface of the photoreceptor; a developing step of developing the electrostatic image formed on the surface of the photoreceptor as a pressure-responsive particle-applied portion using the electrostatic image developer according to the present embodiment; a transfer step of transferring the pressure responsive particle application portion formed on the surface of the photoreceptor onto a recording medium; Includes. It is preferable that the arranging step further includes a fixing step of fixing the pressure responsive particle application portion transferred to the surface of the recording medium.

[0177] The arrangement means may be, for example, a direct transfer type device that directly transfers pressure-responsive particle-applied sections formed on the surface of a photoreceptor to a recording medium; an intermediate transfer type device that primarily transfers pressure-responsive particle-applied sections formed on the surface of a photoreceptor to the surface of an intermediate transfer body and then secondarily transfers the pressure-responsive particle-applied sections transferred to the surface of the intermediate transfer body to the surface of a recording medium; a device equipped with a cleaning means that cleans the surface of the photoreceptor after the pressure-responsive particle-applied sections have been transferred and before charging; or a static elimination means that irradiates the surface of the photoreceptor with static elimination light to eliminate static electricity after the pressure-responsive particle-applied sections have been transferred and before charging. When the arrangement means is an intermediate transfer type device, the transfer means may include, for example, an intermediate transfer body onto whose surface the pressure-responsive particle-applied sections are transferred, a primary transfer means that primarily transfers the pressure-responsive particle-applied sections formed on the surface of the photoreceptor to the surface of the intermediate transfer body, and a secondary transfer means that secondarily transfers the pressure-responsive particle-applied sections transferred to the surface of the intermediate transfer body to the surface of a recording medium.

[0178] The arrangement means may have a cartridge structure (so-called process cartridge) in which a portion including the developing means is detachably attached to the arrangement means. As the process cartridge, for example, a process cartridge that contains the electrostatic image developer according to the present embodiment and is equipped with the developing means is preferably used.

[0179] The pressure-bonding means included in the apparatus for producing printed matter according to this embodiment applies pressure to a recording medium on which pressure-responsive particles produced by the method for producing pressure-responsive particles according to this embodiment are arranged. This causes the pressure-responsive particles to fluidize on the recording medium and exhibit adhesive properties. The pressure applied by the pressure-bonding means to the recording medium in order to fluidize the pressure-responsive particles is preferably 3 MPa or more and 300 MPa or less, more preferably 10 MPa or more and 200 MPa or less, and even more preferably 30 MPa or more and 150 MPa or less.

[0180] The pressure-responsive particles may be disposed over the entire surface of the recording medium, or may be disposed on a portion of the recording medium. The pressure-responsive particles may be disposed in one layer or multiple layers on the recording medium. The layer of pressure-responsive particles may be a continuous layer in the surface direction of the recording medium, or may be a discontinuous layer in the surface direction of the recording medium. The layer of pressure-responsive particles may be a layer in which the pressure-responsive particles are aligned as particles, or a layer in which adjacent pressure-responsive particles are fused and aligned.

[0181] The amount of the pressure-responsive particles (preferably transparent pressure-responsive particles) on the recording medium is, for example, 0.5 g / m in the area where they are disposed. 2 More than 50g / m 2 less than 1 g / m 2 More than 40g / m 2 less than or equal to 1.5 g / m 2 More than 30g / m 2 The layer thickness of the pressure-responsive particles (preferably transparent pressure-responsive particles) on the recording medium is, for example, 0.2 μm to 25 μm, 0.4 μm to 20 μm, or 0.6 μm to 15 μm.

[0182] Examples of recording media that can be used with the printed matter production device according to this embodiment include paper, coated paper in which the surface of paper is coated with a resin or the like, cloth, nonwoven fabric, resin film, resin sheet, etc. The recording media may have an image on one or both sides.

[0183] An example of a printed matter production apparatus according to this embodiment that employs an electrophotographic method will be described below, but this embodiment is not limited to this.

[0184] Fig. 2 is a schematic diagram showing an example of a printed matter production apparatus according to the present embodiment. The printed matter production apparatus shown in Fig. 2 includes a placement unit 100 and a pressing unit 200 disposed downstream of the placement unit 100. The arrows indicate the rotation direction of the photosensitive member or the transport direction of the recording medium.

[0185] The placement means 100 is a direct transfer type device that uses a developer containing pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment to electrophotographically place the pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment onto a recording medium P. An image has been formed in advance on one or both sides of the recording medium P.

[0186] The arrangement means 100 has a photoreceptor 101. Around the photoreceptor 101, there are arranged in this order: a charging roll (an example of a charging means) 102 that charges the surface of the photoreceptor 101; an exposure device (an example of an electrostatic image forming means) 103 that exposes the surface of the charged photoreceptor 101 to a laser beam to form an electrostatic image; a development device (an example of a developing means) 104 that supplies pressure-responsive particles to the electrostatic image to develop it; a transfer roll (an example of a transfer means) 105 that transfers the developed pressure-responsive particle-applied portion onto a recording medium P; and a photoreceptor cleaning device (an example of a cleaning means) 106 that removes pressure-responsive particles remaining on the surface of the photoreceptor 101 after transfer.

[0187] The operation of the arranging means 100 for arranging the pressure responsive particles manufactured by the method for manufacturing pressure responsive particles according to this embodiment on the recording medium P will be described. First, the surface of the photoreceptor 101 is charged by the charging roll 102. The exposed surface of the photoreceptor 101 is irradiated with a laser beam by the exposure device 103 in accordance with image data sent from a control unit (not shown). As a result, an electrostatic charge image of the arrangement pattern of the pressure-responsive particles is formed on the surface of the photoreceptor 101.

[0188] The electrostatic image formed on the photoreceptor 101 rotates to the development position as the photoreceptor 101 travels. At the development position, the electrostatic image on the photoreceptor 101 is developed by the developing device 104 and becomes a pressure-responsive particle application portion.

[0189] The developing device 104 contains a developer containing at least the pressure-responsive particles and a carrier. The pressure-responsive particles are triboelectrically charged by being stirred together with the carrier inside the developing device 104, and are held on a developer roll. As the surface of the photoreceptor 101 passes through the developing device 104, the pressure-responsive particles electrostatically adhere to the electrostatic charge image on the surface of the photoreceptor 101, and the electrostatic charge image is developed by the pressure-responsive particles. The photoreceptor 101, on which the pressure-responsive particle-applied portion has been formed, continues to travel, and the pressure-responsive particle-applied portion on the photoreceptor 101 is transported to the transfer position.

[0190] When the pressure-responsive particle application portion on the photosensitive member 101 is transported to the transfer position, a transfer bias is applied to the transfer roll 105, and an electrostatic force from the photosensitive member 101 toward the transfer roll 105 acts on the pressure-responsive particle application portion, causing the pressure-responsive particle application portion on the photosensitive member 101 to be transferred onto the recording medium P.

[0191] The pressure-responsive particles remaining on the photoreceptor 101 are removed and collected by the photoreceptor cleaning device 106. The photoreceptor cleaning device 106 is, for example, a cleaning blade or a cleaning brush. The photoreceptor cleaning device 106 is preferably a cleaning brush, from the viewpoint of suppressing the phenomenon in which the pressure-responsive particles remaining on the surface of the photoreceptor are fluidized by pressure and adhere to the surface of the photoreceptor in the form of a film.

[0192] The recording medium P onto which the pressure-responsive particle application portion has been transferred is transported to a fixing device 107 (an example of a fixing means). The fixing device 107 is, for example, a pair of fixing members (roll / roll, belt / roll). The arrangement means 100 does not necessarily have to include the fixing device 107, but it is preferable that the fixing device 107 be included from the viewpoint of preventing the pressure-responsive particles from falling off from the recording medium P. The pressure applied to the recording medium P by the fixing device 107 may be lower than the pressure applied to the recording medium P2 by the pressure device 230, and specifically, it is preferable that the pressure be 0.2 MPa or more and 1 MPa or less.

[0193] The fixing device 107 may or may not have an internal heat source (e.g., a halogen heater) for heating the recording medium P. If the fixing device 107 has an internal heat source, the surface temperature of the recording medium P when heated by the heat source is preferably 150°C or higher and 220°C or lower, more preferably 155°C or higher and 210°C or lower, and even more preferably 160°C or higher and 200°C or lower. Note that the fact that the fixing device 107 does not have an internal heat source does not exclude the possibility that the temperature inside the fixing device 107 will become equal to or higher than the ambient temperature due to heat generated by a motor or the like provided in the placement means 100.

[0194] The recording medium P becomes a recording medium P1 having the pressure-responsive particles applied onto the image by passing through the placement means 100. The recording medium P1 is transported toward the pressure bonding means 200.

[0195] In the printed matter manufacturing apparatus according to this embodiment, the placement means 100 and the pressing means 200 may be located close to each other or may be located apart from each other. When the placement means 100 and the pressing means 200 are located apart from each other, the placement means 100 and the pressing means 200 are connected by, for example, a conveying means (for example, a belt conveyor) that conveys the recording medium P1.

[0196] The pressing means 200 includes a folding device 220 and a pressure device 230, and is a means for folding and pressing the recording medium P1.

[0197] The folding device 220 folds the recording medium P1 that passes through the device to produce a folded recording medium P2. The recording medium P2 may be folded, for example, in half, in thirds, or in fourths, and may be folded only partially. The recording medium P2 has the pressure-responsive particles disposed on at least a portion of at least one of two opposing surfaces.

[0198] The folding device 220 may have a pair of pressure members (for example, roll / roll, belt / roll) that apply pressure to the recording medium P2. The pressure applied by the pressure members of the folding device 220 to the recording medium P2 may be lower than the pressure applied by the pressure device 230 to the recording medium P2, and specifically, is preferably 1 MPa or more and 10 MPa or less.

[0199] The pressing means 200 may be provided with a stacking device that stacks the recording medium P1 and another recording medium instead of the folding device 220. The recording medium P1 and the other recording medium may be stacked, for example, in a form in which one sheet of the other recording medium is stacked on the recording medium P1, or in a form in which one sheet of the other recording medium is stacked at each of multiple locations on the recording medium P1. The other recording medium may be a recording medium with an image formed on one or both sides, a recording medium without an image formed on it, or a pre-prepared press-bonded printed material.

[0200] The recording medium P2 that has left the folding device 220 (or the overlapping device) is conveyed toward the pressure device 230.

[0201] The pressure device 230 includes a pair of pressure members (i.e., pressure rolls 231 and 232). The pressure rolls 231 and 232 come into contact with each other at their outer circumferential surfaces and press against each other, applying pressure to the recording medium P2 passing through. The pair of pressure members included in the pressure device 230 is not limited to a combination of pressure rolls, but may also be a combination of a pressure roll and a pressure belt, or a combination of a pressure belt and a pressure belt.

[0202] When pressure is applied to the recording medium P2 passing through the pressure device 230, the pressure-responsive particles are fluidized on the recording medium P2 by the pressure and exhibit adhesiveness. The pressure applied to the recording medium P2 by the pressure device 230 is preferably 3 MPa or more and 300 MPa or less, more preferably 10 MPa or more and 200 MPa or less, and even more preferably 30 MPa or more and 150 MPa or less.

[0203] The pressure applying device 230 may or may not have an internal heat source (e.g., a halogen heater) for heating the recording medium P2. If the pressure applying device 230 has an internal heat source, the surface temperature of the recording medium P2 when heated by the heat source is preferably 30°C or higher and 120°C or lower, more preferably 40°C or higher and 100°C or lower, and even more preferably 50°C or higher and 90°C or lower. Note that the fact that the pressure applying device 230 does not have an internal heat source does not exclude the possibility that the temperature inside the pressure applying device 230 will become higher than the ambient temperature due to heat generated by a motor or the like provided in the pressure applying device 230.

[0204] As the recording medium P2 passes through the pressure device 230, the overlapping surfaces are bonded together by the fluidized pressure-responsive particles, producing a pressure-bonded printed matter P3. In the pressure-bonded printed matter P3, the opposing surfaces are partially or entirely bonded together.

[0205] The completed pressure-bonded printed matter P3 is carried out from the pressure device 230.

[0206] The first form of the laminated printed matter P3 is a laminated printed matter in which two folded recording media are bonded on their opposing surfaces by the pressure-responsive particles. The laminated printed matter P3 of this form is produced by a printed matter production apparatus equipped with a folding device 220.

[0207] The second form of the laminated printed matter P3 is a laminated printed matter in which a plurality of overlapping recording media are bonded on opposing surfaces by pressure-responsive particles manufactured by the pressure-responsive particle manufacturing method according to this embodiment. The laminated printed matter P3 of this form is manufactured by a laminated printed matter manufacturing apparatus equipped with a layering device.

[0208] The printed matter production device according to this embodiment is not limited to a device that continuously transports the recording medium P2 from the folding device 220 (or the overlapping device) to the pressure device 230. The printed matter production device according to this embodiment may also be a device that stores the recording medium P2 that has left the folding device 220 (or the overlapping device), and transports the recording medium P2 to the pressure device 230 after the amount of stored recording medium P2 reaches a predetermined amount.

[0209] In the printed matter manufacturing apparatus according to this embodiment, the folding device 220 (or overlapping device) and the pressing and pressuring device 230 may be located close to each other or may be located apart from each other. When the folding device 220 (or overlapping device) and the pressing and pressuring device 230 are located apart from each other, the folding device 220 (or overlapping device) and the pressing and pressuring device 230 are connected by, for example, a conveying means (for example, a belt conveyor) that conveys the recording medium P2.

[0210] The apparatus for producing a printed matter according to this embodiment may include a cutting means for cutting the recording medium to predetermined dimensions. The cutting means may be, for example, a cutting means disposed between the arrangement means 100 and the pressure-bonding means 200, which cuts off a portion of the recording medium P1 where the pressure-responsive particles produced by the pressure-responsive particle production method according to this embodiment are not disposed; a cutting means disposed between the folding device 220 and the pressure-bonding device 230, which cuts off a portion of the recording medium P2 where the pressure-responsive particles are not disposed; or a cutting means disposed downstream of the pressure-bonding means 200, which cuts off a portion of the pressure-bonded printed matter P3 where the pressure-responsive particles according to this embodiment are not bonded.

[0211] The printed matter manufacturing apparatus according to the present embodiment is not limited to a sheet-fed type apparatus, but may be an apparatus that performs a placement process and a pressing process on a long recording medium to form a long, pressed-on printed matter, and then cuts the long, pressed-on printed matter to predetermined dimensions.

[0212] The apparatus for producing a printed matter according to the present embodiment may further include a color image forming unit that forms a color image on a recording medium by an electrophotographic method using a color electrostatic image developer. A photoreceptor; a charging means for charging the surface of the photoreceptor; an electrostatic image forming means for forming an electrostatic image on the charged surface of the photoreceptor; a developing means containing a color electrostatic image developer and developing the electrostatic image formed on the surface of the photoreceptor into a color toner image by using the color electrostatic image developer; a transfer means for transferring the color toner image formed on the surface of the photoreceptor to the surface of a recording medium; and a thermal fixing means for thermally fixing the color toner image transferred onto the surface of the recording medium.

[0213] The manufacturing apparatus having the above-described configuration is used to carry out a method for manufacturing a printed matter according to the present embodiment, which further includes a color image forming step of forming a color image on a recording medium by an electrophotographic method using a color electrostatic image developer. a charging step of charging the surface of the photoreceptor; an electrostatic image forming step of forming an electrostatic image on the charged surface of the photoreceptor; a developing step of developing the electrostatic image formed on the surface of the photoreceptor into a color toner image using a color electrostatic image developer; a transfer step of transferring the color toner image formed on the surface of the photoreceptor to the surface of a recording medium; and a heat fixing step of heat fixing the color toner image transferred onto the surface of the recording medium.

[0214] The color image forming means included in the printed matter production apparatus according to this embodiment may be, for example, a direct transfer type device that directly transfers a color toner image formed on the surface of a photoreceptor to a recording medium; an intermediate transfer type device that primarily transfers a color toner image formed on the surface of a photoreceptor to the surface of an intermediate transfer body and then secondarily transfers the color toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium; a device equipped with a cleaning unit that cleans the surface of the photoreceptor after the transfer of the color toner image and before charging; or a device equipped with a charge eliminating unit that irradiates the surface of the photoreceptor with charge eliminating light to eliminate charge after the transfer of the color toner image and before charging. When the color image forming means is an intermediate transfer type device, the transfer unit may include, for example, an intermediate transfer body onto whose surface the color toner image is transferred, a primary transfer unit that primarily transfers the color toner image formed on the surface of the photoreceptor to the surface of the intermediate transfer body, and a secondary transfer unit that secondarily transfers the color toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium.

[0215] In the printed matter manufacturing apparatus of this embodiment, if the developer placement means containing pressure-responsive particles manufactured by the pressure-responsive particle manufacturing method of this embodiment and the color image forming means adopt an intermediate transfer method, the placement means and the color image forming means may share the intermediate transfer body and secondary transfer means.

[0216] In the printed matter manufacturing apparatus of this embodiment, the image developer placement means containing pressure-responsive particles manufactured by the pressure-responsive particle manufacturing method of this embodiment and the color image forming means may share a thermal fixing means.

[0217] An example of a printed matter production apparatus according to the present embodiment, which is equipped with a color image forming unit, will be described below, but the present embodiment is not limited to this. In the following description, the main parts shown in the drawings will be described, and descriptions of the rest will be omitted.

[0218] Fig. 3 is a schematic diagram showing an example of an electrophotographically applied printed matter production apparatus according to the present embodiment. The printed matter production apparatus shown in Fig. 3 includes a printing unit 300 that simultaneously performs the arrangement of pressure-responsive particles produced by the method for producing pressure-responsive particles according to the present embodiment on a recording medium and the formation of a color image, and a pressing unit 200 that is disposed downstream of the printing unit 300.

[0219] The printing means 300 is a five-tandem type intermediate transfer type printing means. The printing means 300 includes a unit 10T that deposits the pressure-responsive particles (T), and units 10Y, 10M, 10C, and 10K that form images of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K). The unit 10T is a depositing means that deposits the pressure-responsive particles on the recording medium P using a developer containing the pressure-responsive particles. The units 10Y, 10M, 10C, and 10K are means that form color images on the recording medium P using developers containing color toners, respectively. The units 10T, 10Y, 10M, 10C, and 10K employ an electrophotographic system.

[0220] The units 10T, 10Y, 10M, 10C, and 10K are arranged side by side and spaced apart from one another in the horizontal direction. The units 10T, 10Y, 10M, 10C, and 10K may be process cartridges that are detachably attached to the printing means 300.

[0221] An intermediate transfer belt (an example of an intermediate transfer body) 20 is provided below units 10T, 10Y, 10M, 10C, and 10K and extends through each unit. The intermediate transfer belt 20 is provided wrapped around a drive roll 22, a support roll 23, and an opposing roll 24, which are in contact with the inner surface of the intermediate transfer belt 20, and runs in a direction from unit 10T to unit 10K. An intermediate transfer body cleaning device 21 is provided on the image bearing surface side of the intermediate transfer belt 20, facing the drive roll 22.

[0222] Units 10T, 10Y, 10M, 10C, and 10K are equipped with developing devices (examples of developing means) 4T, 4Y, 4M, 4C, and 4K, respectively. Developing devices 4T, 4Y, 4M, 4C, and 4K are supplied with the pressure-responsive particles contained in a pressure-responsive particle cartridge 8T, or yellow toner, magenta toner, cyan toner, and black toner contained in toner cartridges 8Y, 8M, 8C, and 8K, respectively.

[0223] Since units 10T, 10Y, 10M, 10C and 10K have the same configuration and operation, unit 10T, which arranges the pressure-responsive particles on the recording medium, will be described as a representative.

[0224] The unit 10T has a photoreceptor 1T. Around the photoreceptor 1T, there are arranged in this order: a charging roll (an example of a charging means) 2T that charges the surface of the photoreceptor 1T; an exposure device (an example of an electrostatic image forming means) 3T that exposes the surface of the charged photoreceptor 1T to a laser beam to form an electrostatic image; a developing device (an example of a developing means) 4T that supplies pressure-responsive particles to the electrostatic image to develop it; a primary transfer roll (an example of a primary transfer means) 5T that transfers the developed pressure-responsive particle application portion onto the intermediate transfer belt 20; and a photoreceptor cleaning device (an example of a cleaning means) 6T that removes pressure-responsive particles remaining on the surface of the photoreceptor 1T after the primary transfer. The primary transfer roll 5T is arranged inside the intermediate transfer belt 20, facing the photoreceptor 1T.

[0225] Hereinafter, the arrangement of pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment on the recording medium P and the operation of forming a color image will be described, while illustrating the operation of the unit 10T. First, the surface of the photoreceptor 1T is charged by the charging roll 2T. The exposed surface of the photoreceptor 1T is irradiated with a laser beam by the exposure device 3T in accordance with image data sent from a control unit (not shown). As a result, an electrostatic charge image of the arrangement pattern of the pressure-responsive particles is formed on the surface of the photoreceptor 1T.

[0226] The electrostatic image formed on the photoreceptor 1T rotates to the development position as the photoreceptor 1T moves. At the development position, the electrostatic image on the photoreceptor 1T is developed by the developing device 4T and becomes a pressure-responsive particle application portion.

[0227] The developing device 4T contains a developer containing at least the pressure-responsive particles and a carrier. The pressure-responsive particles are triboelectrically charged by being stirred with the carrier inside the developing device 4T and are held on a developer roll. As the surface of the photoreceptor 1T passes through the developing device 4T, the pressure-responsive particles electrostatically adhere to the electrostatic charge image on the surface of the photoreceptor 1T, and the electrostatic charge image is developed by the pressure-responsive particles. The photoreceptor 1T with the pressure-responsive particle application portion formed thereon continues to travel, and the pressure-responsive particle application portion on the photoreceptor 1T is transported to the primary transfer position.

[0228] When the pressure-responsive particle-applied portion on the photoreceptor 1T is transported to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5T, and an electrostatic force from the photoreceptor 1T toward the primary transfer roll 5T acts on the pressure-responsive particle-applied portion, causing the pressure-responsive particle-applied portion on the photoreceptor 1T to be transferred onto the intermediate transfer belt 20. The pressure-responsive particles remaining on the photoreceptor 1T are removed and collected by the photoreceptor cleaning device 6T. The photoreceptor cleaning device 6T is, for example, a cleaning blade or a cleaning brush, and is preferably a cleaning brush.

[0229] In units 10Y, 10M, 10C, and 10K, the same operation as in unit 10T is performed using a developer containing color toner. The intermediate transfer belt 20, onto which the pressure-responsive particle application portion has been transferred in unit 10T, passes through units 10Y, 10M, 10C, and 10K in sequence, and toner images of each color are transferred onto the intermediate transfer belt 20 in multiple layers.

[0230] The intermediate transfer belt 20, onto which the pressure-responsive particle application portions and toner images have been multiplex-transferred through units 10T, 10Y, 10M, 10C, and 10K, reaches a secondary transfer portion composed of the intermediate transfer belt 20, an opposing roll 24 in contact with the inner surface of the intermediate transfer belt, and a secondary transfer roll (an example of a secondary transfer means) 26 arranged on the image bearing surface side of the intermediate transfer belt 20. Meanwhile, a recording medium P is fed via a supply mechanism into the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact, and a secondary transfer bias is applied to the opposing roll 24. At this time, an electrostatic force from the intermediate transfer belt 20 toward the recording medium P acts on the pressure-responsive particle application portions and the toner images, and the pressure-responsive particle application portions and the toner images on the intermediate transfer belt 20 are transferred onto the recording medium P.

[0231] The recording medium P onto which the pressure-responsive particle application unit and the toner image have been transferred is transported to a thermal fixing device (an example of a thermal fixing means) 28. The thermal fixing device 28 is equipped with a heat source such as a halogen heater and heats the recording medium P. The surface temperature of the recording medium P when heated by the thermal fixing device 28 is preferably 150°C or higher and 220°C or lower, more preferably 155°C or higher and 210°C or lower, and even more preferably 160°C or higher and 200°C or lower. By passing through the thermal fixing device 28, the colored toner image is thermally fixed onto the recording medium P.

[0232] From the viewpoint of preventing the pressure-responsive particles from falling off the recording medium P and improving the fixability of the color image to the recording medium P, the thermal fixing device 28 is preferably a device that applies pressure as well as heat, and may be, for example, a pair of fixing members (roll / roll, belt / roll) equipped with an internal heat source. When the thermal fixing device 28 applies pressure, the pressure that the thermal fixing device 28 applies to the recording medium P may be lower than the pressure that the pressure device 230 applies to the recording medium P2, and specifically, is preferably 0.2 MPa or more and 1 MPa or less.

[0233] The recording medium P becomes a recording medium P1 to which a colored image and the pressure-responsive particles are applied by passing through the printing means 300. The recording medium P1 is transported toward the pressure bonding means 200.

[0234] The configuration of the crimping means 200 in FIG. 3 may be the same as that of the crimping means 200 in FIG. 2, and detailed description of the configuration and operation of the crimping means 200 will be omitted.

[0235] In the printed matter manufacturing apparatus according to this embodiment, the printing means 300 and the pressing means 200 may be located close to each other or may be located apart from each other. When the printing means 300 and the pressing means 200 are located apart from each other, the printing means 300 and the pressing means 200 are connected by, for example, a conveying means (for example, a belt conveyor) that conveys the recording medium P1.

[0236] The printed matter manufacturing apparatus according to this embodiment may include a cutting means for cutting the recording medium to predetermined dimensions. The cutting means may be, for example, a cutting means disposed between the printing means 300 and the bonding means 200, which cuts off a portion of the recording medium P1 where the pressure-responsive particles are not disposed; a cutting means disposed between the folding device 220 and the pressure device 230, which cuts off a portion of the recording medium P2 where the pressure-responsive particles are not disposed; or a cutting means disposed downstream of the bonding means 200, which cuts off a portion of the bonded printed matter P3 where the pressure-responsive particles are not adhered.

[0237] The printed matter manufacturing apparatus according to the present embodiment is not limited to a sheet-fed type apparatus, but may be an apparatus that performs a color image forming process, a positioning process, and a pressing process on a long recording medium to form a long, pressed-on printed matter, and then cuts the long, pressed-on printed matter to predetermined dimensions.

[0238] <Process cartridge> A process cartridge applied to an electrophotographic printing device will be described. The process cartridge according to this embodiment contains the electrostatic image developer according to this embodiment, and is equipped with a developing means that uses the electrostatic image developer to develop an electrostatic image formed on the surface of a photosensitive element as a pressure-responsive particle application section, and is a process cartridge that is detachably attached to a printed matter manufacturing device.

[0239] The process cartridge according to this embodiment may be configured to include a developing unit, and, if necessary, at least one selected from a photosensitive member, a charging unit, an electrostatic image forming unit, a transfer unit, and the like.

[0240] An example of an embodiment of a process cartridge is a cartridge in which a photosensitive member, a charging roll (an example of a charging means) provided around the photosensitive member, a developing device (an example of a developing means), and a photosensitive member cleaning device (an example of a cleaning means) are integrated into a housing. The housing has an opening for exposure. The housing has mounting rails, and the process cartridge is attached to a printing product production device via the mounting rails. [Example]

[0241] Hereinafter, embodiments of the present invention will be described in detail with reference to examples, but the embodiments of the present invention are not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are by mass.

[0242] Example 1 <Preparation of styrene-based resin particle dispersion St1> Styrene (St): 370 parts n-Butyl acrylate (BA): 115 parts Acrylic acid (AA): 15 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 and dispersed to obtain an emulsion. 2.2 parts of the anionic surfactant 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, and 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. Next, the polymerization flask was maintained at 75°C for 3 hours while continuing to slowly stir, and then returned to room temperature (25°C, the same applies below). This yielded a styrene-based resin particle dispersion St1 having a volume average particle size (D50v) of 220 nm, a weight average molecular weight of 33,000 as determined by GPC (UV detection), a glass transition temperature of 53° C., and a solid content of 42%.

[0243] <Preparation of Composite Resin Particle Dispersion SM1> Styrene-based resin particle dispersion St1: 400 parts (solids) 2-Ethylhexyl acrylate (2EHA): 250 parts n-Butyl acrylate (BA): 150 parts Ion-exchanged water: 982 parts The above materials were charged into a polymerization flask and stirred at 25°C for 1 hour, then heated to 70°C. 2.5 parts of ammonium persulfate was dissolved in 75 parts of ion-exchanged water, and the solution was added dropwise to the polymerization flask over 60 minutes using a metering pump. The polymerization flask was then maintained at 70°C for 3 hours with slow stirring, and then returned to room temperature. This resulted in a composite resin particle dispersion SM1 having a volume average particle size (D50v) of 219 nm, a weight average molecular weight of 220,000 as determined by GPC (UV detection) of the resin in the composite resin particles, and a solid content of 32%.

[0244] <Preparation of pressure-responsive particles> Composite resin particle dispersion SM1: 180 parts (solid content) Anionic surfactant: 1 part The above components were mixed in a reaction vessel, and while dispersing with a homogenizer (5,000 rpm), 1.2 parts of 17% aluminum sulfate was added and dispersed for 6 minutes. The temperature was then raised to allow aggregation and growth. When the particle size reached 10 μm (liquid temperature: 57°C), the mixture was cooled to 49°C. 40 parts (solids) of styrene-based resin particle dispersion St1 and 1.3 parts of polyaluminum chloride were added, the mixture was heated to 55°C, maintained at 55°C for 30 minutes, and then heated to 90°C to allow coalescence. The mixture was then filtered, washed, and dried to obtain pressure-responsive particles (EA1) with a volume-average particle size of 10.5 μm and an average circularity of 0.967.

[0245] (Examples 2 to 5) <Preparation of Composite Resin Particle Dispersions SM2 to SM5> Composite resin particle dispersions SM2 to SM5 were obtained in the same manner as the composite resin particle dispersion SM1, except that the acrylic acid-based monomer was changed to the composition shown in Table 1. Pressure-responsive particles (EA2 to EA5) were obtained in the same manner as in Example 1, except that composite resin particle dispersions SM2 to SM5 were used instead of composite resin particle dispersions SM1.

[0246] Examples 6 to 9 <Preparation of Styrene-Based Resin Particle Dispersions St2 to St5> Styrene-based resin particle dispersions St2 to St5 were obtained in the same manner as for the styrene-based resin particle dispersion St1, except that the styrene-based monomer was changed to the composition shown in Table 1.

[0247] <Preparation of Composite Resin Particle Dispersions SM6 to SM9> Composite resin particle dispersions SM6 to SM9 were obtained in the same manner as the composite resin particle dispersion SM1, except that styrene resin particle dispersions St2 to St5 were used instead of the styrene resin particle dispersion St1. Pressure-responsive particles (EA6 to EA9) were obtained in the same manner as in Example 1, except that composite resin particle dispersions SM6 to SM9 were used instead of composite resin particle dispersion SM1.

[0248] Examples 10 and 11 <Preparation of Composite Resin Particle Dispersions SM10 and SM11> Composite resin particle dispersions SM10 and SM11 were obtained in the same manner as composite resin particle dispersion SM1, except that the amount of acrylic acid-based monomer was changed so that the mass ratio of the (meth)acrylic acid ester-based resin (Ac) to the styrene-based resin (St) was the same as in Table 1. Pressure-responsive particles (EA10 and 11) were obtained in the same manner as in Example 1, except that composite resin particle dispersions SM10 and SM11 were used instead of composite resin particle dispersion SM1.

[0249] Example 12 Pressure-responsive particles (EA12) were obtained in the same manner as in Example 1, except that in the shell process, the styrene-based resin particle dispersion St1 was used in an amount of 11.5 parts (solid content) and the amount of polyaluminum chloride added was changed to the amount of flocculant added in Table 1.

[0250] Example 13 Pressure-responsive particles (EA13) were obtained in the same manner as in Example 1, except that in the shell process, the styrene-based resin particle dispersion St1 was used at 110 parts (solid content) and the amount of polyaluminum chloride added was changed to the amount of flocculant added in Table 1.

[0251] Example 14 Pressure-responsive particles (EA14) were obtained in the same manner as in Example 1, except that in the shell step, 0.77 parts of aluminum sulfate was added instead of polyaluminum chloride.

[0252] Example 15 Pressure-responsive particles (EA15) were obtained in the same manner as in Example 1, except that in the shell step, the styrene-based resin particle dispersion liquid was added without cooling the liquid.

[0253] Example 16 Pressure-responsive particles (EA16) were obtained in the same manner as in Example 1, except that in the preparation of pressure-responsive particles, 13.2 parts (solid content) of silica dispersion (solid content: 21 mass %, particle size 12 nm) was added together with the composite resin particle dispersion SM1 and the anionic surfactant.

[0254] Example 17 Pressure-responsive particles (EA17) were obtained in exactly the same manner as in Example 2, except that in the preparation of pressure-responsive resin particles, 4.4 parts (solid content) of silica dispersion (solid content: 21% by mass, particle size 7 nm) was added together with the composite resin particle dispersion SM1 and the anionic surfactant.

[0255] Example 18 Pressure-responsive particles (EA18) were obtained in the same manner as in Example 3, except that in preparing the pressure-responsive resin particles, 17.6 parts (solid content) of silica dispersion (solid content: 21% by mass, particle size: 40 nm) was added together with the composite resin particle dispersion SM1 and the anionic surfactant.

[0256] (Comparative Example 1) Pressure-responsive resin particles (EA19) were obtained in the same manner as in Example 1, except that the amount of polyaluminum chloride added was changed from 1.3 parts to 0.04 parts.

[0257] (Comparative Example 2) Pressure-responsive resin particles (EA20) were obtained in the same manner as in Example 1, except that the amount of polyaluminum chloride added was changed to the value shown in Table 1.

[0258] (Comparative Examples 3 and 4) Pressure-responsive resin particles (EA21 and 22) were obtained in the same manner as in Example 1, except that the ratio of the amount of styrene-based resin particle dispersion St1 used in the preparation of composite resin particle dispersion SM1 to the amount of 2-ethylhexyl acrylate and n-butyl acrylate monomers used was changed to the values ​​shown in Table 1.

[0259] <Adhesion strength evaluation> On paper on which a character image was printed using an electrophotographic printer, pressure-responsive resin particles were sprinkled on a 50 μm mesh using a cake printer, and a voltage of 100 V was applied to set the coating amount of pressure-responsive particles at 2.0 g / m. 2 , 1.5g / m 2The two levels were uniformly applied, fixed to the paper using the fixing bench of the multifunction printer, folded in half to align the images, and then passed through a sealer (Pressle multi2, manufactured by Toppan Forms Co., Ltd.) to apply pressure (Gap 10). After leaving it overnight, the paper was cut to a width of 15 mm and subjected to a 90-degree peel test to measure and evaluate the peel force (unit: N / 15 mm). The evaluation criteria are shown below. S: 1.5g / m 2 For samples, ≧0.8N / 15mm A: 2.0 g / m 2 For samples, ≧0.8N / 15mm B: 2.0 g / m 2 In the sample, it is more than 0.4N / 15mm and less than 0.8N / 15mm C:2.0g / m 2 For samples, ≦0.4N / 15mm A rating of S, A or B is preferred, a rating of S or A is more preferred, and a rating of S is particularly preferred.

[0260] <Evaluation of storage stability of dispersion liquid> In preparing the pressure-responsive particles, the pressure-responsive particle dispersion liquid, after being heated to 90°C to coalesce and before being filtered, is cooled to 30°C and then sealed and stored in a chamber at 30°C for one month, after which the particle size distribution is measured using an LS Coulter. If agglomerated particles occur, the measurement result for the volume-average particle size distribution will show a two-peak distribution with a peak on the coarse powder side, and the evaluation criteria are as follows: A: The particle size distribution is the same as the initial one, showing one peak. B: Two peaks with a peak on the coarse powder side appear, but after re-mixing, the peak returns to a single peak. C: Two peaks with a peak on the coarse powder side appear, and the peak does not return to a single peak even after re-mixing. A rating of A or B is preferred, and a rating of A is more preferred.

[0261] <Adhesion of aggregates and fusions> In the adhesive strength evaluation, the pressure-responsive particles were applied to 200 sheets of paper using a cake printer, and the adhesive strength was evaluated according to the following evaluation criteria based on the state of application and the state of the mesh when the application was performed. A: It was possible to apply the coating continuously without any problems. B: The mesh clogged a little, but I was able to apply it by blowing the mesh halfway through. C: Pressure-responsive particles clogged the mesh, making it impossible to apply the coating even with blowing.

[0262] The evaluation results are summarized in Table 1.

[0263] [Table 1]

[0264] From the above results, it can be seen that the present example is superior in adhesive strength when pressed and storage stability as a dispersion liquid, and produces fewer aggregates and fused products, compared to the comparative example. [Explanation of symbols]

[0265] 100 Placement means 110 Applicator 120 Fixation device 200 Crimping means 220 Folding device 230 Pressure Device 231, 232 Pressure roll M Pressure-responsive particles P Recording medium P1: Recording medium with pressure-responsive particles applied to the image P2 Folded recording media P3 Pressed Printed Material

[0266] 101 Photoreceptor 102 Charging roll (an example of charging means) 103 Exposure device (an example of electrostatic image forming means) 104 Developing device (an example of developing means) 105 Transfer roll (an example of transfer means) 106 Photosensitive member cleaning device (an example of cleaning means) 107 Fixing device (an example of fixing means)

[0267] 300 Printing means 1T, 1Y, 1M, 1C, 1K photoconductor 2T, 2Y, 2M, 2C, 2K Charging roll (an example of charging means) 3T, 3Y, 3M, 3C, 3K exposure equipment (an example of electrostatic image forming means) 4T, 4Y, 4M, 4C, 4K developing device (an example of developing means) 5T, 5Y, 5M, 5C, 5K Primary transfer roll (an example of a primary transfer means) 6T, 6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of a cleaning means) 8T Pressure-Responsive Particle Cartridge 8Y, 8M, 8C, 8K toner cartridges 10T, 10Y, 10M, 10C, 10K units 20 Intermediate transfer belt (an example of an intermediate transfer body) 21 Intermediate transfer body cleaning device 22 Drive Roll 23 Support Roll 24 opposing roll 26 Secondary transfer roll (an example of a secondary transfer means) 28 Thermal fixing device (an example of thermal fixing means)

Claims

1. an aggregation step of adding an aggregating agent to a dispersion containing composite resin particles including a styrene-based resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylic ester-based resin containing a (meth)acrylic ester compound as polymerization components, and aggregating the composite resin particles to obtain aggregated particles A; a shell-forming step of adding styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components and an aggregating agent to the dispersion containing the aggregated particles A, thereby forming aggregated particles B; and a fusion step of heating and fusing the aggregated particles B to form pressure-responsive particles, the amount of the styrene-based resin particles added in the shell-forming step is 5% by mass or more and 40% by mass or less with respect to the total mass of the composite resin particles; the amount of the aggregating agent added in the shell-forming step is 0.1% by mass or more and 1.0% by mass or less with respect to the total mass of the composite resin particles, the mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin contained in the pressure-responsive particles is 80:20 to 20:80; The difference between the lowest glass transition temperature and the highest glass transition temperature of the resin contained in the pressure-responsive particles is 30° C. or more. A method for producing pressure-responsive particles.

2. 2. The method for producing pressure-responsive particles according to claim 1, wherein in the shell formation process, the liquid temperature of the dispersion containing aggregated particles A is lowered after the aggregation process, and then styrene-based resin particles containing a styrene compound and other vinyl monomers as polymerization components and an aggregating agent are added.

3. 3. The method for producing pressure-responsive particles according to claim 2, wherein in the shell-forming step, the temperature of the liquid is lowered to 5[deg.] C. or higher before the styrene-based resin particles and the flocculant are added.

4. The method for producing pressure-responsive particles according to claim 1 , wherein the aggregating agent used in the aggregating step and the shell-forming step is an aluminum-based aggregating agent.

5. The method for producing pressure-responsive particles according to claim 4 , wherein the flocculant used in the flocculation step is aluminum sulfate.

6. The method for producing pressure-responsive particles according to claim 1 , wherein silica particles are added in the aggregating step.

7. The method for producing pressure-responsive particles according to claim 6 , wherein the amount of silica particles added in the aggregation step is 2% by mass or more and 8% by mass or less with respect to the total mass of the pressure-responsive particles.

8. The method for producing pressure-responsive particles according to claim 6 or 7, wherein the silica particles have an arithmetic mean particle size of 7 nm or more and 40 nm or less.

9. 8. The method for producing pressure-responsive particles according to claim 1, wherein the styrene-based resin contained in the pressure-responsive particles has a glass transition temperature of 30[deg.] C. or higher.

10. 9. The method for producing pressure-responsive particles according to claim 1, wherein the (meth)acrylic acid ester resin contained in the pressure-responsive particles has a glass transition temperature of −30° C. or lower.

11. The method for producing pressure-responsive particles according to any one of claims 1 to 10, a step of arranging the pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles on a recording medium; a crimping step of folding the recording medium and crimping it, or of crimping the recording medium and another recording medium together; A method for producing a printed matter, comprising:

12. The method for producing pressure-responsive particles according to any one of claims 1 to 10, a step of disposing the pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles on a substrate; A method for manufacturing a sheet for producing printed matter.

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