Method for producing pressure-responsive particles, method for producing a printed matter, method for producing a sheet for producing a 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.SOLUTION: A method for producing pressure-responsible particles includes an aggregation step of adding a dispersion containing silica particles and 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, and a fusion step of heating and fusing the aggregated particles, and forming pressure-responsible particles, wherein an amount of the silica particles to be added by the dispersion liquid containing the silica particles is 0.5 mass% or more and 10 mass% or less with respect to the total mass of the composite resin particles, a mass ratio of the styrenic resin to the (meth)acrylate-based resin contained in the pressure-responsible particles is 80:20 to 20:80, and a difference between a lowest glass transition temperature and a highest glass transition temperature in the resin contained in the pressure-responsible particles is 30°C or more.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a releasable sheet capable of releasably adhering overlapping surfaces, which has 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. The pressure-sensitive adhesive layer contains an adhesive base containing 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] Also, Patent Document 2 describes an adhesive material containing a styrene-based resin containing styrene and other vinyl monomers as polymerization components, and a (meth)acrylate-based resin containing at least two (meth)acrylate esters as polymerization components, wherein the mass ratio of the (meth)acrylate ester in the total polymerization components is 90% by mass or more, and the mass ratio of the styrene-based resin to the (meth)acrylate-based resin is 80:20 to 20:80, and having at least two glass transition temperatures, the lowest glass transition temperature being -30°C or lower and the highest glass transition temperature being 30°C or higher.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem of the present invention is to add a dispersion containing silica particles and a flocculant to a dispersion containing composite resin particles containing a styrene resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylate resin containing a (meth)acrylate compound as a polymerization component, and flocculate to obtain flocculated particles, and a fusion step of heating and fusing the flocculated particles to form pressure-responsive particles. The addition amount of silica particles by the dispersion containing silica particles is less than 0.5% by mass or more than 10% by mass based on the total mass of the composite resin particles, or the mass ratio of the styrene resin and the (meth)acrylate resin contained in the pressure-responsive particles is 80 or more: less than 20 to 100:0 or 0:100 to less than 20:80. Compared with the case, it is to provide a method for producing pressure-responsive particles excellent in adhesive force during pressure bonding and storage stability of the dispersion.

Means for Solving the Problems

[0006] Specific means for solving the above problems include the following aspects. <1> A flocculation step of adding a dispersion containing silica particles and a flocculant to a dispersion containing composite resin particles containing a styrene resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylate resin containing a (meth)acrylate compound as a polymerization component, and flocculating to obtain flocculated particles, and a fusion step of heating and fusing the flocculated particles to form pressure-responsive particles. The addition amount of silica particles by the dispersion containing silica particles is 0.5% by mass or more and 10% by mass or less based on the total mass of the composite resin particles, the mass ratio of the styrene resin and the (meth)acrylate resin contained in the pressure-responsive particles is 80:20 to 20:80, and the difference between the lowest glass transition temperature and the highest glass transition temperature in the resin contained in the pressure-responsive particles is 30°C or more. A method for producing pressure-responsive particles. <2> The method for producing pressure-responsive particles according to <1>, wherein the addition amount of silica particles by the dispersion containing silica particles is 2% by mass or more and 8% by mass or less based on the total mass of the composite resin particles. <3> The method for producing pressure-responsive particles according to <1> or <2>, wherein the arithmetic mean particle diameter of the silica particles is 5 nm or more and 100 nm or less. <4> The method for producing pressure-responsive particles according to <3>, wherein the arithmetic mean particle diameter of the silica particles is 7 nm or more and 40 nm or less. <5> The method for producing pressure-responsive particles according to any one of <1> to <3>, further comprising a shell formation step of adding and aggregating a styrene-based resin particle dispersion to the dispersion containing the aggregated particles after the aggregation step and before the fusion step. <6> The method for producing pressure-responsive particles according to <5>, wherein the addition amount of the styrene-based resin particles by the styrene-based resin particle dispersion in the shell formation step is 10% by mass or more and 25% by mass or less based on the total mass of the composite resin particles. <7> The method for producing pressure-responsive particles according to any one of <1> to <6>, wherein the aggregating agent is aluminum sulfate. <8> The method for producing pressure-responsive particles according to any one of <1> to <7>, wherein the glass transition temperature of the styrene-based resin contained in the pressure-responsive particles is 30°C or more. <9> The method for producing pressure-responsive particles according to any one of <1> to <8>, wherein the glass transition temperature of the (meth)acrylate-based resin contained in the pressure-responsive particles is -30°C or less. <10> A method for producing a printed matter, comprising an arranging step of arranging the pressure-responsive particles on a recording medium using the pressure-responsive particles produced by the method for producing pressure-responsive particles according to any one of <1> to <9>, and a pressing step of folding and pressing the recording medium, or pressing the recording medium and another recording medium by overlapping them. <11> A method for producing a sheet for producing a printed matter, comprising an arranging step of arranging the pressure-responsive particles on a substrate using the pressure-responsive particles produced by the method for producing pressure-responsive particles according to any one of <1> to <9>. <12> Pressure-responsive particles produced by the method for producing pressure-responsive particles according to any one of <1> to <9>.

Advantages of the Invention

[0007] According to the invention according to <1>, in a dispersion containing composite resin particles containing a styrene resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylate resin containing a (meth)acrylate compound as a polymerization component, a dispersion containing silica particles and a flocculant are added and flocculated to obtain flocculated particles, and a fusion step of heating and fusing the flocculated particles to form pressure-responsive particles is included. The addition amount of silica particles by the dispersion containing silica particles is less than 0.5% by mass or more than 10% by mass with respect to the total mass of the composite resin particles, or the mass ratio of the styrene resin and the (meth)acrylate resin contained in the pressure-responsive particles is 80 or more: less than 20 to 100:0 or 0:100 to less than 20:80 or more. Compared with the case, a method for producing pressure-responsive particles excellent in adhesive force during pressure bonding and storage stability of the dispersion is provided. According to the invention according to <2>, compared with the case where the addition amount of silica particles by the dispersion containing silica particles is less than 2% by mass or more than 8% by mass with respect to the total mass of the composite resin particles, the adhesive force during pressure bonding and the storage stability of the dispersion are more excellent. A method for producing pressure-responsive particles is provided. According to the invention according to <3>, compared with the case where the arithmetic mean particle diameter of the silica particles is less than 5 nm or more than 100 nm, the adhesive force during pressure bonding and the storage stability of the dispersion are more excellent. A method for producing pressure-responsive particles is provided. According to the invention according to <4>, compared with the case where the arithmetic mean particle diameter of the silica particles is less than 7 nm and more than 40 nm, the adhesive force during pressure bonding and the storage stability of the dispersion are more excellent. A method for producing pressure-responsive particles is provided. According to the invention according to <5>, compared with the case where the shell formation step is not performed, a method for producing pressure-responsive particles excellent in adhesive force during pressure bonding and storage stability of the dispersion is provided. According to the invention according to <6>, compared with the case where the addition amount of styrene resin particles by the styrene resin particle dispersion in the shell formation step is less than 10% by mass or more than 25% by mass with respect to the total mass of the composite resin particles, the adhesive force during pressure bonding and the storage stability of the dispersion are more excellent. A method for producing pressure-responsive particles is provided. According to the invention according to <7>, a method for producing pressure-responsive particles that is superior in adhesion during pressure bonding and storage stability of the dispersion liquid as compared with the case where the flocculant is polyaluminum chloride is provided. According to the invention according to <8>, a method for producing pressure-responsive particles that is superior in adhesion during pressure bonding and storage stability of the dispersion liquid as compared with the case where the glass transition temperature of the styrene-based resin contained in the pressure-responsive particles is less than 30°C is provided. According to the invention according to <9>, a method for producing pressure-responsive particles that is superior in adhesion during pressure bonding and storage stability of the dispersion liquid as compared with the case where the glass transition temperature of the (meth)acrylate-based resin contained in the pressure-responsive particles is more than -30°C is provided. According to the invention according to <10>, <11> or <12>, in a method for producing pressure-responsive particles, a dispersion liquid containing composite resin particles containing a styrene-based resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylate-based resin containing a (meth)acrylate compound as polymerization components, a dispersion liquid containing silica particles and a flocculant are added and aggregated to obtain aggregated particles, and a fusion step of heating and fusing the aggregated particles to form pressure-responsive particles is included. The addition amount of silica particles by the dispersion liquid containing silica particles is less than 0.5% by mass or more than 10% by mass with respect to the total mass of the composite resin particles, or the mass ratio of the styrene-based resin and the (meth)acrylate-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. A method for producing a printed matter, a method for producing a sheet for producing a printed matter, or pressure-responsive particles that are superior in adhesion during pressure bonding and storage stability of the dispersion liquid are provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples are illustrative of the embodiments and do not limit the scope of the embodiments.

[0010] In the present disclosure, a numerical range indicated using "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively.

[0011] In the numerical ranges described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other stepwise descriptions. Also, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

[0012] In the present disclosure, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the intended purpose of the step is achieved.

[0013] When the embodiments are described with reference to the drawings in the present disclosure, the configuration of the embodiments is not limited to the configuration shown in the drawings. Also, the sizes of the members in each figure are conceptual, and the relative relationships of the sizes between the members are not limited thereto.

[0014] In the present disclosure, each component may include a plurality of corresponding substances. When referring to the amount of each component in the composition, in the case where there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the plurality of substances present in the composition.

[0015] In the present disclosure, the particles corresponding to each component may include a plurality of types. When there are a plurality of types of particles corresponding to each component in the composition, the particle diameter of each component means a value for a mixture of the plurality of types of particles present in the composition, unless otherwise specified.

[0016] In the present disclosure, the notation “(meth)acryl” means that it may be either “acryl” or “methacryl”.

[0017] In the present disclosure, the “toner for electrostatic charge image development” is also simply referred to as “toner”, and the “electrostatic charge image developer” is also simply referred to as “developer”.

[0018] In the present disclosure, a printed matter formed by adhering the opposing surfaces of a recording medium folded and opposed to each other, or a printed matter formed by adhering the opposing surfaces of two or more recording media stacked and opposed to each other is referred to as a “thermocompression printed matter”.

[0019] (Method for producing pressure-responsive particles) The method for producing pressure-responsive particles according to the present embodiment includes an aggregation step of adding a dispersion liquid containing silica particles and a flocculant to a dispersion liquid containing composite resin particles containing a styrene-based resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylate-based resin containing a (meth)acrylate compound as a polymerization component, and aggregating to obtain aggregated particles, and a fusion step of heating and fusing the aggregated particles to form pressure-responsive particles. The addition amount of silica particles by the dispersion liquid containing silica particles is 0.5% by mass or more and 10% by mass or less based on the total mass of the composite resin particles. The mass ratio of the styrene-based resin and the (meth)acrylate-based resin contained in the pressure-responsive particles is 80:20 to 20:80, and the difference between the lowest glass transition temperature and the highest glass transition temperature in the resin contained in the pressure-responsive particles is 30°C or more. Also, the pressure-responsive particles according to the present embodiment are pressure-responsive particles produced by the method for producing pressure-responsive particles according to the present embodiment.

[0020] Conventionally, for promotional purposes, ultraviolet curable varnish (UV varnish) has been used for pressure-sensitive postcards, and for exhibition purposes, glue based on natural rubber has been used. In both cases, the glue application process is complicated, and the odor and cleaning of the coating device are troublesome. Therefore, alternative pressure-responsive particles have been studied. As the pressure-responsive material, a resin containing a styrene resin containing styrene and other vinyl monomers as polymerization components and a (meth)acrylate resin, wherein the mass ratio of the styrene resin to the (meth)acrylate resin is 80:20 to 20:80, and the difference between the lowest glass transition temperature and the highest glass transition temperature is 30 °C or more, if the particle size can be adjusted using this resin, the pressure-responsive particles can be taken out as a powder. Therefore, pressure-responsive particles were obtained by controlling the particle size using a flocculant. However, the mixing of the styrene resin and the (meth)acrylate resin was inhibited by the flocculant, and as a result, the adhesive strength, particularly the adhesive strength under low temperature and low humidity, decreased. Also, when pressure-responsive particles are used in a pressure-sensitive adhesive, the adhesive strength of the pressure-responsive particles decreases over time. Therefore, the leading-edge adhesive paper of the pressure-sensitive postcard also has a short shelf life, and its inventory management is troublesome. Conversely, if there is a locally strong adhesive part, paper breakage will occur during peeling after storage in a high-humidity environment. In the method for producing a pressure-responsive particle dispersion according to the present embodiment, a dispersion containing composite resin particles containing a styrene resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylate resin containing a (meth)acrylate compound as polymerization components is added with a dispersion containing silica particles and a flocculant and aggregated to obtain aggregated particles. The aggregation step is included, and the addition amount of the silica particles by the dispersion containing the silica particles is 0.5% by mass or more and 10% by mass or less with respect to the total mass of the composite resin particles. After the aggregation is completed, the silica particles act as a trapping agent for the flocculant, and the flocculant escapes from the pressure-responsive particles together with the silica particles. Therefore, it is estimated that the mixing of the styrene resin and the (meth)acrylate resin during the formation of the pressure-responsive particles is not inhibited, and the storage stability of the dispersion is excellent while maintaining the adhesive strength during pressure bonding.

[0021] The pressure-responsive particles in the present embodiment undergo a phase transition under pressure by exhibiting thermal properties of "having at least two glass transition temperatures, and the difference between the lowest glass transition temperature and the highest glass transition temperature being 30°C or more". In the present embodiment, the pressure-responsive particles that undergo a phase transition under pressure mean pressure-responsive particles that satisfy the following formula (1).

[0022] Formula (1) ··· 10°C ≤ T1 - T2 In Formula (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. The method for obtaining the temperature T1 and the temperature T2 will be described later.

[0023] In the method for producing the pressure-responsive particles according to the present embodiment, the mass ratio of the styrene-based resin and the (meth)acrylate-based resin contained in the pressure-responsive particles is 80:20 to 20:80, and from the viewpoints of the adhesive force during pressure bonding and the storage stability of the dispersion liquid, it is preferably 70:30 to 30:70, and more preferably 60:40 to 40:60. Note that 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 both styrene-based resins added in the shell formation step when the shell formation step is performed.

[0024] In the method for producing the pressure-responsive particles according to the present embodiment, the difference between the lowest glass transition temperature and the highest glass transition temperature in the resin contained in the pressure-responsive particles is 30°C or more, and from the viewpoints of the adhesive force during pressure bonding, the storage stability of the dispersion liquid, and the suppression of paper breakage after storage, it is preferably 40°C or more, more preferably 60°C or more, still 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 the glass transition temperatures is presumed to be the glass transition temperature of the styrene-based resin, and the other is presumed to be the glass transition temperature of the (meth)acrylate-based resin. Further, it is preferable that the lowest glass transition temperature contained in the composite resin particles is the glass transition temperature of the (meth)acrylate resin. Furthermore, it is preferable that the highest glass transition temperature is the glass transition temperature of the styrene 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)acrylate resin contained in the pressure-responsive particles, and the highest glass transition temperature is the glass transition temperature of the styrene resin contained in the pressure-responsive particles. Regarding the lowest glass transition temperature and the highest glass transition temperature, among the resins contained in the pressure-responsive particles, the content thereof is 1% by mass or more based on the total mass of the resins 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 the form having two glass transition temperatures include a form in which the resins contained in the pressure-responsive particles are only a styrene resin and a (meth)acrylate resin; and a form in which the content of other resins that are not a styrene resin and a (meth)acrylate resin is small (for example, the content of other resins is 5% by mass or less based on the entire pressure-responsive particles).

[0027] In the present disclosure, the glass transition temperature of the resin is determined from a differential scanning calorimetry curve (DSC curve) obtained by performing differential scanning calorimetry (DSC). More specifically, it is determined according to the "extrapolated onset temperature of glass transition" described in the method for determining the glass transition temperature in JIS K7121:1987 "Method for Measuring Transition Temperature of Plastics".

[0028] From the viewpoints of the adhesive force during pressure bonding and the storage stability of the dispersion liquid, the content of the flocculant added in the flocculation step of the pressure-responsive particles is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and particularly preferably 1% by mass or less, based on the total mass of the flocculant added in the flocculation step.

[0029] Also, from the viewpoints of the adhesive force during pressure bonding and the storage stability of the dispersion liquid, the content of the silica particles added in the flocculation step of the pressure-responsive particles is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 1% by mass or less, and particularly preferably 0.1% by mass or less, based on the total mass of the silica particles added in the flocculation step.

[0030] From the viewpoint of suppressing the fluidization of the composite resin particles in the unpressurized state, 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, still more preferably 50°C or higher. From the viewpoint of forming composite resin particles that are easily phase-transitioned by pressure, it is preferably 110°C or lower, more preferably 100°C or lower, still more preferably 90°C or lower.

[0031] From the viewpoint of forming pressure-responsive resin particles that are easily phase-transitioned by pressure, the glass transition temperature of the (meth)acrylate-based resin contained in the pressure-responsive particles is preferably 10°C or lower, more preferably 0°C or lower, still more preferably -10°C or lower. From the viewpoint of suppressing the fluidization of the pressure-responsive resin particles in the unpressurized state, it is preferably -90°C or higher, more preferably -80°C or higher, still more preferably -70°C or higher.

[0032] <Flocculation step> The method for producing pressure-responsive particles according to this embodiment includes an aggregation step of adding a dispersion containing silica particles and a flocculant to a dispersion containing composite resin particles including a styrene resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylate resin containing a (meth)acrylate compound as a polymerization component, and aggregating them to obtain aggregated particles. The addition amount of the silica particles by the dispersion containing the silica particles is 0.5% by mass or more and 10% by mass or less with respect to the total mass of the composite resin particles. Details of the styrene resin and the (meth)acrylate resin will be described later.

[0033] The method for producing pressure-responsive particles according to this embodiment obtains pressure-responsive particles by the aggregation and integration method. In the aggregation step, the composite resin particles are aggregated in the dispersion containing the composite resin particles to form aggregated particles having a diameter close to the diameter of the target pressure-responsive particles.

[0034] Specifically, for example, a dispersion containing silica particles and a flocculant are added to the composite resin particle dispersion, the pH of the composite resin particle dispersion is adjusted to acidic (for example, pH 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. Then, it is heated to a temperature close to the glass transition temperature of the styrene resin (specifically, for example, the glass transition temperature of the styrene resin - 30°C or more and the glass transition temperature of the styrene resin - 10°C or less) to aggregate the composite resin particles and form aggregated particles. By adding the dispersion containing silica particles, after the aggregation is completed, the flocculant is trapped by the silica particles, suppressing the remaining of the flocculant in the pressure-responsive particles, not inhibiting the mixing of the styrene resin and the (meth)acrylate resin during the formation of the pressure-responsive particles, and estimating that the storage stability of the dispersion is excellent while maintaining the adhesive force during pressure bonding.

[0035] In the aggregation step, the composite resin particle dispersion may be stirred with a rotary shear homogenizer at room temperature (for example, 25°C), a flocculant may be added, the pH of the composite resin particle dispersion may be adjusted to acidic (for example, pH 2 or more and 5 or less), and a dispersion stabilizer may be added as necessary, and then heating may be performed.

[0036] As the dispersion liquid containing the silica particles, an aqueous medium dispersion liquid containing silica particles is preferable, and an aqueous dispersion liquid containing silica particles is more preferable. Examples of the dispersion medium include aqueous media such as water and alcohols. These may be used alone or in combination of two or more.

[0037] The addition amount of the silica particles in the dispersion liquid containing the silica particles in the aggregation step is 0.5% by mass or more and 10% by mass or less, and from the viewpoints of the adhesive force during pressure bonding and the storage stability of the dispersion liquid, it is preferably 1% by mass or more and 9% by mass or less, and more preferably 2% by mass or more and 8% by mass or less. Moreover, although there is no particular limitation on the solid content of the dispersion liquid containing the silica particles, it is preferably 1% by mass or more and 50% by mass, and preferably 2% by mass or more and 40% by mass or less.

[0038] From the viewpoints of the adhesive force during pressure bonding and the storage stability of the dispersion liquid, the arithmetic average particle diameter 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, still more preferably 7 nm or more and 40 nm or less, and particularly preferably 7 nm or more and 25 nm or less.

[0039] The method for measuring the arithmetic average particle diameter of the silica particles in this embodiment is to observe with a scanning electron microscope (S-4100 manufactured by Hitachi, Ltd.) and take an image. The taken image is imported into an image analyzer (LUZEXIII manufactured by Nireco, Inc.), the area of each particle is obtained by image analysis, and the equivalent circle diameter (nm) is obtained from the area. The arithmetic average of the equivalent circle diameters of 100 or more particles is calculated and taken as the arithmetic average particle diameter.

[0040] Examples of the aggregating agent include surfactants having a reverse polarity to the surfactants contained in the composite resin particle dispersion liquid, inorganic metal salts, and metal complexes of divalent or higher valences. When a metal complex is used as the aggregating agent, the amount of the surfactant used is reduced and the charging characteristics are improved. An additive that forms a complex or a similar bond with the metal ions of the flocculant may be used as needed together with the flocculant. As this additive, a chelating agent is preferably used.

[0041] Examples of the inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide; and the like. Among them, from the viewpoints of flocculability, adhesive force during pressure bonding, and storage stability of the dispersion, an aluminum-based flocculant is preferably used, more preferably aluminum chloride, aluminum sulfate, polyaluminum chloride, or polyaluminum hydroxide, and particularly preferably aluminum sulfate. The addition amount of the flocculant is not particularly limited, but is preferably 0.001 parts by mass or more and 5 parts by mass or less, more preferably 0.005 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the composite resin particles.

[0042] In the flocculation step, a chelating agent may be further added, but it is preferably not added. As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA); and the like. The addition amount of the chelating agent is preferably 0.01 parts by mass or more and 5.0 parts by mass or less, more preferably 0.1 parts by mass or more and less than 3.0 parts by mass, based on 100 parts by mass of the composite resin particles.

[0043] The volume average particle diameter of the composite resin particles is preferably 140 nm or more and 300 nm or less, more preferably 150 nm or more and 280 nm or less, and still more preferably 160 nm or more and 250 nm or less.

[0044] The dispersion containing the composite resin particles in the aggregation step is preferably an aqueous dispersion, more preferably a water 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, more preferably 30% by mass or more and 40% by mass or less.

[0045] <Fusion step> The method for producing pressure-responsive particles according to this embodiment includes a fusion step of heating and fusing the aggregated particles to form pressure-responsive particles. In the fusion step, the aggregated particle dispersion in which the aggregated particles 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 equal to or higher than 30°C to 50°C higher than the glass transition temperature of the styrene resin), and the aggregated particles are fused and united to form pressure-responsive particles.

[0046] <Shell formation step> From the viewpoints of the adhesive force during pressure bonding and the storage stability of the dispersion, the method for producing pressure-responsive particles according to this embodiment preferably further includes a shell formation step of adding and aggregating a styrene-based resin particle dispersion to the dispersion containing the aggregated particles after the aggregation step and before the fusion step.

[0047] Specifically, for example, after the aggregation step, after adding a styrene-based resin particle dispersion to the dispersion containing the aggregated particles, it is heated to a temperature close to the glass transition temperature of the styrene-based resin (specifically, for example, the glass transition temperature of the styrene-based resin - 30°C or higher and the glass transition temperature of the styrene-based resin - 10°C or lower), and the styrene-based resin particles are aggregated on the surface of the aggregated particles to form aggregated particles having the styrene-based resin particles on the surface.

[0048] The addition amount of the styrene-based resin particles by the styrene-based resin particle dispersion in the shell formation step is preferably 5% by mass or more and 30% by mass or less, more preferably 10% by mass or more and 25% by mass or less, and particularly preferably 15% by mass or more and 20% by mass or less, based on the total mass of the composite resin particles used in the aggregation step.

[0049] The pressure-responsive particles of the core-shell structure obtained through the shell formation step and the fusion step have a shell layer containing a styrene resin. Alternatively, a resin particle dispersion in which other types of resin particles are dispersed may be used instead of the styrene resin particle dispersion to form a shell layer containing other types of resin.

[0050] After the fusion step, it is preferable to subject the pressure-responsive particles formed in the dispersion to a known washing step, solid-liquid separation step, and drying step to obtain pressure-responsive particles in a dried state. From the perspective of chargeability, it is advisable to perform sufficient substitution washing with ion-exchanged water in the washing step. From the perspective of productivity, suction filtration, pressure filtration, etc. may be performed in the solid-liquid separation step. From the perspective of productivity, freeze drying, airflow drying, fluidized drying, vibration-type fluidized drying, etc. may be performed in the drying step.

[0051] And the pressure-responsive particles may be produced, for example, by adding and mixing an external additive to the obtained pressure-responsive particles in a dried state. The mixing may be performed, for example, using a V blender, Henschel mixer, Lodige mixer, etc. Further, if necessary, coarse particles of the pressure-responsive particles may be removed using a vibrating sieve, air classifier, etc.

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

[0053] In addition, the method for producing pressure-responsive particles according to the present embodiment preferably further includes a polymerization step A of polymerizing a styrene compound and other vinyl monomers to obtain a styrene-based resin, and a polymerization step B of polymerizing a (meth)acrylate compound 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)acrylate-based resin.

[0054] <Polymerization step A> The method for producing a pressure-responsive particle dispersion according to the present embodiment preferably further includes a polymerization step A of polymerizing a styrene compound and other vinyl monomers to obtain a styrene-based resin. The polymerization in the polymerization step A is not particularly limited, but is preferably emulsion polymerization. In addition, the method for producing the composite resin particle dispersion is preferably carried out by an emulsion polymerization method.

[0055] In addition, the polymerization step A is preferably a step of obtaining styrene-based resin particles, and more preferably a step of obtaining a styrene-based resin particle dispersion. Examples of the method for dispersing the styrene-based resin particles in a dispersion medium include a method of mixing the styrene-based resin and the dispersion medium and stirring and dispersing them using a rotary shear homogenizer, a ball mill having media, a sand mill, a dynomill, or the like. In addition, another method for dispersing the styrene-based resin particles in a dispersion medium is an emulsion polymerization method. Specifically, after mixing the polymerization components of the styrene-based resin with a chain transfer agent or a polymerization initiator, an aqueous medium containing a surfactant is further mixed, stirred to prepare an emulsion, and the styrene-based resin is polymerized in the emulsion. At this time, a thiol compound is preferably used as the chain transfer agent, and dodecanethiol is more preferably used. As the dispersion medium, the above-described aqueous medium is preferably used.

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

[0057] There is no particular limitation on the polymerization initiator, and known photopolymerization initiators and thermal polymerization initiators are used. Among them, thermal polymerization initiators are preferred, peroxides are more preferred, and ammonium persulfate is particularly preferred. There is no particular limitation on the polymerization temperature and polymerization time, and they may be appropriately selected according to the monomers and polymerization initiators used.

[0058] In polymerization step A, the volume average particle diameter 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 still 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 by a laser diffraction particle size distribution measuring device (for example, LA-700 manufactured by Horiba, Ltd.), and the particle diameter at which the cumulative value reaches 50% in the volume-based particle size distribution starting from the smaller diameter side is defined as the volume average particle diameter (D50v).

[0059] The content of the styrene-based resin particles contained 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 the pressure-responsive particle dispersion according to this embodiment preferably further includes a polymerization step B of polymerizing a (meth)acrylic acid ester compound 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] Further, the polymerization step B is preferably a step of obtaining a composite resin particle dispersion. As a method of dispersing the composite resin particles in a dispersion medium, for example, a method of mixing the styrene-based resin and the dispersion medium and stirring and dispersing them using a rotary shear homogenizer, a ball mill having media, a sand mill, a dynomill, etc. can be mentioned. Also, as another method of dispersing the composite resin particles in a dispersion medium, a polymerization component of a (meth)acrylic acid ester-based resin is added to the styrene-based resin particle dispersion, and an aqueous medium is added as necessary. Next, while slowly stirring the dispersion, the temperature of the dispersion is heated to a temperature equal to or higher than the glass transition temperature of the obtained styrene-based resin (for example, a temperature 10°C to 30°C higher than the glass transition temperature of the styrene-based resin). Then, while maintaining the temperature, an aqueous medium containing a polymerization initiator is slowly dropped, and stirring is continued for a long time in the range of 1 hour or more and 15 hours or less. At this time, it is preferable to use ammonium persulfate as the polymerization initiator. As the dispersion medium and the polymerization initiator, those described above are preferably mentioned. Also, a surfactant may be used in the polymerization step B. As the surfactant, those described above are preferably mentioned. The polymerization temperature and the polymerization time are not particularly limited and may be appropriately selected according to the monomers and polymerization initiators used.

[0062] Although the detailed mechanism is not necessarily clear, when the above method is adopted, it is presumed that the monomer and the polymerization initiator are impregnated in the styrene resin particles, and the (meth)acrylate ester polymerizes inside the styrene resin particles. As a result, it is presumed that a (meth)acrylate ester resin is contained inside the styrene resin particles, and composite resin particles are obtained in which the styrene resin and the (meth)acrylate ester resin form a microphase-separated state inside the particles.

[0063] In addition, the method for producing pressure-responsive particles according to the present embodiment may include known steps other than those described above.

[0064] Hereinafter, the styrene resin and the (meth)acrylate ester resin preferably used in the present embodiment will be described in detail.

[0065] <Styrene resin> The styrene resin contained in the pressure-responsive particles contains a styrene compound and other vinyl monomers as polymerization components. The styrene compound used for the polymerization of the styrene resin preferably contains styrene. In addition, from the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state, the mass ratio of styrene in the total polymerization components of the styrene resin is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 75% by mass or more, and from the viewpoint of forming pressure-responsive particles that are likely to undergo a phase transition under pressure, it is preferably 95% by mass or less, more preferably 90% by mass or less, and still more preferably 85% by mass or less.

[0066] Examples of styrene compounds other than styrene used in the polymerization of the styrene resin include vinyl naphthalene; alkyl-substituted styrenes such as α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, etc.; 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, 2,5-difluorostyrene, etc.; nitro-substituted styrenes such as m-nitrostyrene, o-nitrostyrene, p-nitrostyrene, etc. The styrene compound may be used alone or in combination of two or more.

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

[0068] As the acrylic monomer, at least one acrylic monomer selected from the group consisting of (meth)acrylic acid and (meth)acrylic acid ester compounds is preferable. 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, di(meth)acrylic acid ester compounds, etc. 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)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, etc. Examples of the (meth)acrylic acid carboxy-substituted alkyl ester include 2-carboxyethyl (meth)acrylate, etc. 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, 4-hydroxybutyl (meth)acrylate, etc. Examples of the (meth)acrylic acid alkoxy-substituted alkyl ester compound include 2-methoxyethyl (meth)acrylate, etc. 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, decanediol di(meth)acrylate, etc.

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

[0071] Examples of other vinyl monomers used in the polymerization of the styrene 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 are easily phase-transitioned by pressure, the styrene resin preferably contains a (meth)acrylic acid ester compound as a polymerization component, more preferably contains a (meth)acrylic acid alkyl ester compound, still more preferably contains a (meth)acrylic acid alkyl ester compound having an alkyl group with 2 to 10 carbon atoms, still more preferably contains a (meth)acrylic acid alkyl ester compound having an alkyl group with 4 to 8 carbon atoms, and particularly preferably contains at least one of n-butyl acrylate and 2-ethylhexyl acrylate.

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

[0074] From the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state, the mass ratio 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, still more preferably 25% by mass or less. From the viewpoint of facilitating the phase transition of the pressure-responsive particles by pressure, it is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more. As the (meth)acrylic acid ester compound here, a (meth)acrylic acid alkyl ester compound is preferable, a (meth)acrylic acid alkyl ester compound having 2 to 10 carbon atoms in the alkyl group is more preferable, and a (meth)acrylic acid alkyl ester compound having 4 to 8 carbon atoms in the alkyl group is still more preferable.

[0075] It is particularly preferable that the styrene-based resin contains at least one of n-butyl acrylate and 2-ethylhexyl acrylate as polymerization components. From the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state, the total amount of n-butyl acrylate and 2-ethylhexyl acrylate in the total polymerization components of the styrene-based resin is preferably 40% by mass or less, more preferably 30% by mass or less, still more preferably 25% by mass or less. From the viewpoint of forming pressure-responsive particles that are prone to phase transition under pressure, it is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more.

[0076] From the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state, the weight average molecular weight of the styrene-based resin is preferably 10,000 or more, more preferably 20,000 or more, still more preferably 30,000 or more. From the viewpoint of forming pressure-responsive particles that are prone to phase transition under pressure, it is preferably 200,000 or less, more preferably 150,000 or less, still more preferably 100,000 or less.

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

[0078] From the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state, the glass transition temperature of the styrene resin is preferably 30°C or higher, more preferably 40°C or higher, still more preferably 50°C or higher. From the viewpoint of forming pressure-responsive particles that are prone to phase transition under pressure, it is preferably 110°C or lower, more preferably 100°C or lower, still more preferably 90°C or lower.

[0079] <(meth)acrylate resin> The (meth)acrylate resin contained in the pressure-responsive particles contains a (meth)acrylate compound as a polymerization component. Only one kind of the (meth)acrylate compound may be used, or two or more kinds may be used, but it is preferable to contain at least two kinds of (meth)acrylates as polymerization components. Further, the mass ratio of the (meth)acrylate in the total polymerization components of the (meth)acrylate resin is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass or more, and particularly preferably 100% by mass.

[0080] Examples of the (meth)acrylate compound used for the polymerization of the (meth)acrylate resin include (meth)acrylate alkyl ester compounds, (meth)acrylate carboxy-substituted alkyl ester compounds, (meth)acrylate hydroxy-substituted alkyl ester compounds, (meth)acrylate alkoxy-substituted alkyl ester compounds, di(meth)acrylate ester compounds, and the like.

[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)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, and the like. Examples of the (meth)acrylic acid carboxy-substituted alkyl ester compound include 2-carboxyethyl (meth)acrylate and the like. 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, 4-hydroxybutyl (meth)acrylate, and the like. Examples of the (meth)acrylic acid alkoxy-substituted alkyl ester compound include 2-methoxyethyl (meth)acrylate and the like. 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, decanediol di(meth)acrylate, and the like.

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

[0083] As the (meth)acrylic acid ester compound used for the polymerization of the (meth)acrylic acid ester resin, from the viewpoint of forming pressure-responsive particles that are likely to undergo a phase transition under pressure and have excellent adhesiveness, an (meth)acrylic acid alkyl ester compound is preferable. An (meth)acrylic acid alkyl ester compound having 2 to 10 carbon atoms in the alkyl group is more preferable, an (meth)acrylic acid alkyl ester compound having 4 to 8 carbon atoms in the alkyl group is still more preferable, and n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferable. From the viewpoint of forming pressure-responsive particles that are likely to undergo a phase transition under pressure, it is preferable that the styrene resin and the (meth)acrylic acid ester resin contained in the pressure-responsive particles contain the same (meth)acrylic acid ester compound as a polymerization component. That is, from the viewpoint of forming pressure-responsive particles that are likely to undergo a phase transition under pressure, it is preferable that the styrene resin and the (meth)acrylic acid ester resin contained in the pressure-responsive particles each have a structural unit derived from the same (meth)acrylic acid ester compound.

[0084] Among the at least two (meth)acrylic acid ester compounds contained as polymerization components in the (meth)acrylic acid ester resin, it is preferable that the two having the largest mass ratio are (meth)acrylic acid alkyl ester compounds. As the (meth)acrylic acid alkyl ester compound here, an (meth)acrylic acid alkyl ester compound having 2 to 10 carbon atoms in the alkyl group is preferable, and an (meth)acrylic acid alkyl ester compound having 4 to 8 carbon atoms in the alkyl group is more preferable.

[0085] When the two (meth)acrylic acid ester compounds with the highest mass ratios among 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 of the alkyl groups of the two (meth)acrylic acid alkyl ester compounds is preferably from 1 to 4, more preferably from 2 to 4, and still 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 transferred by pressure and have excellent adhesive strength, the (meth)acrylic acid ester resin preferably contains n-butyl acrylate and 2-ethylhexyl acrylate as polymerization components, and it is particularly preferred that the two (meth)acrylic acid ester compounds with the highest mass ratios among at least two (meth)acrylic acid ester compounds contained as polymerization components in the (meth)acrylic acid ester resin are n-butyl acrylate and 2-ethylhexyl acrylate. The total amount of n-butyl acrylate and 2-ethylhexyl acrylate in the total polymerization components of the (meth)acrylic acid ester resin is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass or more, and still more preferably 100% by mass.

[0087] The (meth)acrylic acid ester resin may contain vinyl monomers other than (meth)acrylic acid ester compounds as polymerization components. 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)acrylate resin contains a vinyl monomer other than the (meth)acrylate compound as a polymerization component, as the vinyl monomer other than the (meth)acrylate compound, at least one of acrylic acid and methacrylic acid is preferable, and acrylic acid is more preferable.

[0089] From the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state, the weight average molecular weight of the (meth)acrylate resin is preferably 10,000 or more, more preferably 20,000 or more, and still more preferably 30,000 or more. From the viewpoint of forming pressure-responsive particles that are easily phase-transitioned by pressure, it is preferably 200,000 or less, more preferably 150,000 or less, and still more preferably 100,000 or less.

[0090] From the viewpoint of forming pressure-responsive particles that are easily phase-transitioned by pressure, the glass transition temperature of the (meth)acrylate resin is preferably 10°C or lower, more preferably 0°C or lower, and still more preferably -10°C or lower. From the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state, it is preferably -90°C or higher, more preferably -80°C or higher, and still more preferably -70°C or higher.

[0091] <Other resins> The pressure-responsive particles may contain, for example, polystyrene; non-vinyl resins such as epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, and modified rosin; etc. These resins may be used alone or in combination of two or more.

[0092] <Various additives> The pressure-responsive particles may contain, if necessary, a colorant (e.g., pigment, dye), a release agent (e.g., hydrocarbon wax; natural waxes such as carnauba wax, rice wax, candelilla wax; synthetic or mineral / oil-based waxes such as montan wax; ester waxes such as fatty acid ester, montanic acid ester), a charge control agent, etc.

[0093] When the pressure-responsive particles are transparent pressure-responsive particles, the amount of the colorant in the pressure-responsive particles is preferably 1.0% by mass or less based on the whole pressure-responsive particles, and the less amount is more preferable from the viewpoint of enhancing the transparency of the pressure-responsive particles.

[0094] It is preferable that the other resin and the additive are added to the dispersion liquid containing the composite resin particles in the aggregation step and contained in the pressure-responsive particles.

[0095] <Structure of pressure-responsive particles> The internal structure of the pressure-responsive particles preferably has a sea-island structure. As the sea-island structure, a sea-island structure having a sea phase containing a styrene-based resin and an island phase containing a (meth)acrylate-based resin dispersed in the sea phase is preferable. The specific form of the styrene-based resin contained in the sea phase is as described above. The specific form of the (meth)acrylate-based resin contained in the island phase is as described above. An island phase not containing a (meth)acrylate-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 phase is preferably 200 nm or more and 500 nm or less. When the average diameter of the island phase is 500 nm or less, the pressure-responsive particles are likely to undergo a phase transition by pressure, and when the average diameter of the island phase is 200 nm or more, the mechanical strength required for the pressure-responsive particles (for example, the strength that is difficult to deform when stirred in a developing device) is excellent. From these viewpoints, the average diameter of the island phase is more preferably 220 nm or more and 450 nm or less, and still more preferably 250 nm or more and 400 nm or less.

[0097] As a method for controlling the average diameter of the island phase of the sea-island structure within the above range, for example, in the method for producing pressure-responsive particles described later, the amount of the (meth)acrylate-based resin with respect to the amount of the styrene-based resin is increased or decreased, and the time for maintaining a high temperature in the step of fusing and unifying the aggregated resin particles is increased or decreased, etc. can be mentioned.

[0098] The confirmation of the sea-island structure and the measurement of the average diameter of the island phase are carried out by the following method. The pressure-responsive particles are embedded in an epoxy resin, sections are prepared using a diamond knife or the like, and the prepared sections are stained in a desiccator using osmium tetroxide or ruthenium tetroxide. The stained sections are observed with a scanning electron microscope (SEM). The sea phase and the island phase of the sea-island structure are distinguished by the shade resulting from the degree of staining of the resin by osmium tetroxide or ruthenium tetroxide, and the presence or absence of the sea-island structure is confirmed using this. 100 island phases are randomly selected from the SEM image, the major axis of each island phase is measured, and the average value of the 100 major axes is taken as the average diameter.

[0099] The pressure-responsive particles may be single-layer pressure-responsive particles or core-shell type pressure-responsive particles having a core part and a shell layer covering the core part. From the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state, the pressure-responsive particles are preferably core-shell type pressure-responsive particles.

[0100] When the pressure-responsive particles have a core-shell structure, from the viewpoint of being easily phase-transitioned by pressure, it is preferable that the core part contains a styrene-based resin and a (meth)acrylate-based resin. Further, from the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state, it is preferable that the shell layer contains a styrene-based resin. The specific form of the styrene-based resin is as described above. The specific form of the (meth)acrylate-based resin is as described above.

[0101] When the pressure-responsive particles have a core-shell structure, it is preferable that the core part has a sea phase containing a styrene resin and an island phase containing a (meth)acrylate resin dispersed in the sea phase. The average diameter of the island phase is preferably within the above-mentioned range. Further, in addition to the core part having the above configuration, it is preferable that the shell layer contains a styrene resin. In this case, the sea phase of the core part and the shell layer form a continuous structure, and the pressure-responsive particles are likely to undergo a phase transition under pressure. The specific forms of the styrene resins contained in the sea phase of the core part and the shell layer are as described above. The specific forms of the (meth)acrylate resins contained in the island phase of the core part are as described above.

[0102] Examples of the resin contained in the shell layer include polystyrene; non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosin. These resins may be used alone or in combination of two or more.

[0103] From the viewpoint of suppressing deformation of the pressure-responsive particles, 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 that the pressure-responsive particles are likely to undergo a phase transition under pressure, it is preferably 550 nm or less, more preferably 500 nm or less, and even more preferably 400 nm or less.

[0104] The average thickness of the shell layer is measured by the following method. The pressure-responsive particles are embedded in an epoxy resin, sections are prepared using a diamond knife or the like, and the prepared sections are stained in a desiccator using osmium tetroxide or ruthenium tetroxide. The stained sections are observed with a scanning electron microscope (SEM). Ten cross-sections of the pressure-responsive particles are randomly selected from the SEM image, the thickness of the shell layer is measured at 20 locations for each pressure-responsive particle, and the average value is calculated. The average value of the 10 pressure-responsive particles is taken as the average thickness.

[0105] The volume average particle diameter (D50v) of the pressure-responsive particles is preferably 4 μm or more, more preferably 5 μm or more, still more preferably 6 μm or more, from the viewpoint of ease of handling of the pressure-responsive particles, and preferably 30 μm or less, more preferably 20 μm or less, still more preferably 15 μm or less, from the viewpoint of easy phase transition of the entire pressure-responsive particles by pressure.

[0106] The volume average particle diameter (D50v) of the pressure-responsive particles is measured using a Coulter Multisizer II (manufactured by Beckman Coulter, Inc.) and an aperture with an aperture diameter of 100 μm. 0.5 mg or more and 50 mg or less of the pressure-responsive particles are added to 2 mL of a 5 mass% aqueous solution of sodium alkylbenzenesulfonate and dispersed, and then mixed with 100 mL or more and 150 mL or less of an electrolytic solution (ISOTON-II, manufactured by Beckman Coulter, Inc.), and dispersed for 1 minute with an ultrasonic disperser. The obtained dispersion is used as a sample. The particle diameters of 50,000 particles with a particle diameter of 2 μm or more and 60 μm or less in the sample are measured. The particle diameter at which the cumulative percentage reaches 50% in the volume-based particle size distribution starting from the smaller diameter side is defined as the volume average particle diameter (D50v).

[0107] <External additive> The pressure-responsive particles may contain an external additive as necessary. Examples of the external additive include inorganic particles. Examples of the inorganic particles include SiO2, TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, K2O·(TiO2)n, Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, MgSO4, etc.

[0108] The surface of the inorganic particles as an additive is preferably subjected to a hydrophobization treatment. The hydrophobization treatment is performed, for example, by immersing the inorganic particles in a hydrophobization treatment agent. The hydrophobization treatment agent is not particularly limited, and examples thereof include silane-based coupling agents, silicone oils, titanate-based coupling agents, aluminum-based coupling agents, and the like. These may be used alone or in combination of two or more. The amount of the hydrophobization treatment agent is, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

[0109] Examples of the additive also include resin particles (resin particles such as polystyrene, polymethyl methacrylate, and melamine resin), cleaning agents (for example, metal salts of higher fatty acids typified by zinc stearate, particles of fluorine-based high molecular weight substances), and the like.

[0110] The addition amount of the additive is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.01% by mass or more and 2.0% by mass or less, based on the total mass of the pressure-responsive particles (pressure-responsive base particles) other than the additive.

[0111] <Pressure characteristics of the pressure-responsive particles> The pressure-responsive particles produced by the method for producing pressure-responsive particles according to the present embodiment are pressure-responsive particles that undergo a phase transition under pressure and satisfy the following formula 1. Formula 1 ··· 10°C ≤ T1 - T2 In Formula 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 from the viewpoint of facilitating the phase transition of the pressure-responsive particles under pressure, preferably 15°C or more, more preferably 20°C or more, and preferably 120°C or less, more preferably 100°C or less, still more preferably 80°C or less, from the viewpoint of suppressing the fluidization of the pressure-responsive particles in a non-pressurized state.

[0113] The value of temperature T1 is preferably 140°C or lower, more preferably 130°C or lower, still more preferably 120°C or lower, and even more preferably 115°C or lower. The lower limit of temperature T1 is preferably 80°C or higher, and more preferably 85°C or higher. The value of temperature T2 is preferably 40°C or higher, more preferably 50°C or higher, and still more preferably 60°C or higher. The upper limit of temperature T2 is preferably 85°C or lower.

[0114] As an index indicating that the pressure-responsive particles are likely to undergo a phase transition under pressure, there is the temperature difference (T1 - T3) between the temperature T1 at which the viscosity is 10,000 Pa·s under a pressure of 1 MPa and the temperature T3 at which the viscosity is 10,000 Pa·s under a pressure of 4 MPa. The temperature difference (T1 - T3) is preferably 5°C or more. From the viewpoint that the pressure-responsive particles are likely to undergo a phase transition under pressure, the temperature difference (T1 - T3) is preferably 5°C or more, and more preferably 10°C or more. The temperature difference (T1 - T3) is generally 25°C or lower.

[0115] From the viewpoint that the temperature difference (T1 - T3) of the pressure-responsive particles is 5°C or more, the temperature T3 at which the viscosity is 10,000 Pa·s under a pressure of 4 MPa is preferably 90°C or lower, more preferably 85°C or lower, and still more preferably 80°C or lower. The lower limit of temperature T3 is preferably 60°C or higher.

[0116] The method for obtaining temperature T1, temperature T2, and temperature T3 is as follows. Compress the pressure-responsive particles to prepare a pellet-shaped sample. Set the pellet-shaped sample in a flow tester (manufactured by Shimadzu Corporation, CFT-500), fix the applied pressure at 1 MPa, and measure the viscosity with respect to the temperature at 1 MPa. From the obtained viscosity graph, at an applied pressure of 1 MPa, when the viscosity is 10 4Determine the temperature T1 when it becomes Pa·s. Except for changing the applied pressure from 1 MPa to 10 MPa, determine the temperature T2 in the same manner as the method related to the temperature T1. Except for changing the applied pressure from 1 MPa to 4 MPa, determine the temperature T3 in the same manner as the method related to the temperature T1. Calculate the temperature difference (T1 - T2) from the temperature T1 and the temperature T2. Calculate the temperature difference (T1 - T3) from the temperature T1 and the temperature T3.

[0117] (Cartridge) The cartridge according to the present embodiment is a cartridge that houses pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment and is detachable from a printing material manufacturing apparatus. When the cartridge is attached to the printing material manufacturing apparatus, the cartridge and the arranging means of the printing material manufacturing apparatus for arranging the pressure-responsive particles on the recording medium are connected by a supply pipe. The pressure-responsive particles are supplied from the cartridge to the arranging means, and when the pressure-responsive particles housed in the cartridge decrease, the cartridge is replaced.

[0118] (Printing material manufacturing apparatus, printing material manufacturing method, printing material) The printing material manufacturing apparatus according to the present embodiment houses pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment, and includes arranging means for arranging the pressure-responsive particles on a recording medium, and pressing means for folding and pressing the recording medium, or for overlapping and pressing the recording medium with another recording medium.

[0119] The arranging means may include, for example, an applying device for applying the pressure-responsive particles on the recording medium, and further may include a fixing device for fixing the pressure-responsive particles applied on the recording medium on the recording medium.

[0120] The pressing means includes, for example, a folding device for folding the recording medium on which the pressure-responsive particles are arranged, or an overlapping device for overlapping the recording medium on which the pressure-responsive particles are arranged with another recording medium, and a pressing device for pressing the overlapped recording media.

[0121] The pressing device included in the pressing means applies pressure to a recording medium on which pressure-responsive particles are disposed. As a result, the pressure-responsive particles are fluidized and exhibit adhesiveness on the recording medium.

[0122] By the manufacturing apparatus for a printed matter according to the present embodiment, the manufacturing method for a printed matter according to the present embodiment is implemented. The manufacturing method for a printed matter according to the present embodiment uses pressure-responsive particles manufactured by the manufacturing method for pressure-responsive particles according to the present embodiment, and includes an arranging step of arranging the pressure-responsive particles on a recording medium, and a pressing step of folding and pressing the recording medium, or pressing the recording medium and another recording medium by overlapping them.

[0123] The arranging step includes, for example, a step of applying pressure-responsive particles onto a recording medium, and may further include a step of fixing the pressure-responsive particles applied onto the recording medium on 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 pressing step of pressing the stacked recording media.

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

[0126] The amount of the pressure-responsive particles (preferably transparent pressure-responsive particles) on the recording medium is, for example, 0.5 g / m 2 or more and 50 g / m 2 or less in the arranged area, 1 g / m 2 or more and 40 g / m 2 or less, 1.5 g / m 2 or more and 30 g / m 2The following applies. The layer thickness of the pressure-responsive particles (preferably transparent pressure-responsive particles) on the recording medium is, for example, 0.2 μm or more and 25 μm or less, 0.4 μm or more and 20 μm or less, or 0.6 μm or more and 15 μm or less.

[0127] Examples of the recording medium applicable to the printing apparatus according to the present embodiment include paper, coated paper obtained by coating the surface of paper with resin or the like, cloth, non-woven fabric, resin film, resin sheet, and the like. The recording medium may have images on one side or both sides.

[0128] Hereinafter, an example of the printing apparatus according to the present embodiment will be shown, but the present embodiment is not limited thereto.

[0129] FIG. 1 is a schematic configuration diagram showing an example of the printing apparatus according to the present embodiment. The printing apparatus shown in FIG. 1 includes a placement unit 100 and a pressure bonding unit 200 disposed downstream of the placement unit 100. The arrow indicates the conveyance direction of the recording medium.

[0130] The placement unit 100 is an apparatus that places pressure-responsive particles on the recording medium P using the pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment. An image is formed in advance on one side or both sides of the recording medium P.

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

[0132] The application device 110 applies the pressure-responsive particles M onto the recording medium P. Examples of the application method employed by the application device 110 include 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 electrophotographic method, and the like. 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 are applied by the applying device 110 is conveyed to the fixing device 120.

[0134] The fixing device 120 includes, for example, a heating device that has a heat source and heats the pressure-responsive particles M on the passing recording medium P to fix the pressure-responsive particles M on the recording medium P; a pressing device that includes a pair of pressing members (roll / roll, belt / roll) and presses the passing recording medium P to fix the pressure-responsive particles M on the recording medium P; a pressing and heating device that includes a pair of pressing members (roll / roll, belt / roll) having a heat source inside, presses and heats the passing recording medium P, and fixes the pressure-responsive particles M on the recording medium P; and the like.

[0135] When the fixing device 120 has a heat 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 pressing member, the pressure applied by the pressing member to the recording medium P may be lower than the pressure applied by the pressing device 230 to the recording medium P2.

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

[0138] In the printing apparatus according to the present embodiment, the arranging means 100 and the pressure-bonding means 200 may be in a form close to each other or in a form separated from each other. When the arranging means 100 and the pressure-bonding means 200 are separated, the arranging means 100 and the pressure-bonding means 200 are connected by, for example, a conveying means (for example, a belt conveyor) that conveys the recording medium P1.

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

[0140] The folding device 220 folds the recording medium P1 passing through the device to produce the folded recording medium P2. The way the recording medium P2 is folded can be, for example, in half, into thirds, or into fourths, and a form in which only a part of the recording medium P2 is folded may also be acceptable. The recording medium P2 is in a state where the pressure-responsive particles M are arranged on at least a part of at least one of the two opposing surfaces.

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

[0142] Instead of the folding device 220, the crimping means 200 may include a stacking device that stacks the recording medium P1 and another recording medium. The form of the overlap between the recording medium P1 and another recording medium can be, for example, a form in which one other recording medium overlaps on the recording medium P1, a form in which one other recording medium overlaps at a plurality of locations on the recording medium P1, etc. The other recording medium may be a recording medium with an image previously formed on one or both sides, a recording medium without an image formed, or a pre-produced crimped print.

[0143] The recording medium P2 that exits the folding device 220 (or the stacking device) is conveyed toward the pressing device 230.

[0144] The pressing device 230 includes a pair of pressing members (that is, the pressing rolls 231 and 232). The pressing roll 231 and the pressing roll 232 contact and press against each other on their outer peripheral surfaces, and apply pressure to the passing recording medium P2. The pair of pressing members included in the pressing device 230 is not limited to the combination of a pressing roll and a pressing roll, and may also be a combination of a pressing roll and a pressing belt, or a combination of a pressing belt and a pressing belt.

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

[0146] The pressurizing device 230 may or may not have a heat source (e.g., a halogen heater) inside for heating the recording medium P2. Note that the fact that the pressurizing device 230 does not have a heat source inside does not exclude the possibility that the temperature inside the pressurizing device 230 becomes equal to or higher than the ambient temperature due to heat generation from a motor or the like provided in the pressurizing device 230.

[0147] When the recording medium P2 passes through the pressurizing device 230, the overlapping surfaces are adhered by the pressure-responsive particles M that have been fluidized, and the pressure-bonded printed matter P3 is produced. In the pressure-bonded printed matter P3, two opposing surfaces are partially or entirely adhered.

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

[0149] The first form of the pressure-bonded printed matter P3 is a pressure-bonded printed matter in which the folded recording medium is adhered by the pressure-responsive particles M on the opposing surfaces. The pressure-bonded printed matter P3 of this form is manufactured by a printing matter manufacturing device including a folding device 220.

[0150] The second form of the pressure-bonded printed matter P3 is a pressure-bonded printed matter in which a plurality of overlapping recording media are adhered by the pressure-responsive particles M on the opposing surfaces. The pressure-bonded printed matter P3 of this form is manufactured by a manufacturing device for pressure-bonded printed matter including a stacking device.

[0151] The printing matter manufacturing device according to the present embodiment is not limited to a device in a form that continuously conveys the recording medium P2 from the folding device 220 (or stacking device) to the pressurizing device 230. The printing matter manufacturing device according to the present embodiment may be a device in a form that stores the recording medium P2 that has exited the folding device 220 (or stacking device), and after the storage amount of the recording medium P2 reaches a predetermined amount, conveys the recording medium P2 to the pressurizing device 230.

[0152] In the printing material manufacturing apparatus according to the present embodiment, the folding device 220 (or stacking device) and the pressure bonding and pressing device 230 may be in a form close to each other or in a separated form. When the folding device 220 (or stacking device) and the pressure bonding and pressing device 230 are separated, the folding device 220 (or stacking device) and the pressure bonding and pressing device 230 are connected, for example, by a conveying means (e.g., a belt conveyor) that conveys the recording medium P2.

[0153] The printing material manufacturing apparatus according to the present embodiment may include a cutting means for cutting the recording medium into a predetermined size. The cutting means is, for example, a cutting means disposed between the arranging means 100 and the pressure bonding means 200 and cutting off an area that is a part of the recording medium P1 and where the pressure-responsive particles M are not disposed; a cutting means disposed between the folding device 220 and the pressing device 230 and cutting off an area that is a part of the recording medium P2 and where the pressure-responsive particles M are not disposed; a cutting means disposed downstream of the pressure bonding means 200 and cutting off an area that is a part of the pressure-bonded printed matter P3 and is not adhered by the pressure-responsive particles M; and the like.

[0154] The printing material manufacturing apparatus according to the present embodiment is not limited to a sheet-fed apparatus. The printing material manufacturing apparatus according to the present embodiment may be an apparatus that forms a long pressure-bonded printed matter by performing an arranging process and a pressure bonding process on a long recording medium and then cuts the long pressure-bonded printed matter into a predetermined size.

[0155] The printing material manufacturing apparatus according to the present embodiment may further include a colored image forming means for forming a colored image on the recording medium using a coloring material. Examples of the colored image forming means include a means for forming a colored ink image on the recording medium by an inkjet method using colored ink as the coloring material, a means for forming a colored image on the recording medium by an electrophotographic method using a colored electrostatic charge developer, and the like.

[0156] By the manufacturing apparatus having the above configuration, a manufacturing method of a printed matter according to the present embodiment is implemented, which further includes a colored image forming step of forming a colored image on a recording medium using a coloring material. Specifically, the colored image forming step includes, for example, a step of forming a colored ink image on a recording medium by an inkjet method using colored ink as a coloring material, a step of forming a colored image on a recording medium by an electrophotographic method using a colored electrostatic charge image developer, and the like.

[0157] (Sheet for manufacturing printed matter, manufacturing method of sheet for manufacturing printed matter) The sheet for manufacturing a printed matter according to the present embodiment has a base material and pressure-responsive particles disposed on the base material. The sheet for manufacturing a printed matter according to the present embodiment is manufactured using the pressure-responsive particles manufactured by the manufacturing method of the pressure-responsive particles according to the present embodiment. The pressure-responsive particles on the base material may or may not maintain the particle shape before being disposed on the base material.

[0158] The sheet for manufacturing a printed matter according to the present embodiment is applied to, for example, a masking sheet that is adhered on a 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 a recording medium when adhering recording media to each other; and the like.

[0159] Examples of the base material applied to the sheet for manufacturing a printed matter according to the present embodiment include paper, coated paper obtained by coating the surface of paper with a resin or the like, cloth, non-woven fabric, resin film, resin sheet, and the like. An image may be formed on one side or both sides of the base material.

[0160] In the sheet for manufacturing a printed matter according to the present embodiment, the pressure-responsive particles may be disposed on the entire surface of the base material or may be disposed on a part of the base material. The pressure-responsive particles are disposed in one layer or a plurality of layers on the base material. The layer of the pressure-responsive particles may be a layer continuous in the plane direction of the base material or a layer discontinuous in the plane direction of the base material. The layer of the pressure-responsive particles may be a layer in which the pressure-responsive particles are arranged as particles, or a layer in which adjacent pressure-responsive particles are fused and arranged.

[0161] The amount of pressure-responsive particles on the substrate is, in the arranged region, for example, 0.5 g / m 2 or more and 50 g / m 2 or less, 1 g / m 2 or more and 40 g / m 2 or less, 1.5 g / m 2 or more and 30 g / m 2 or less. The layer thickness of the pressure-responsive particles on the substrate is, for example, 0.2 μm or more and 25 μm or less, 0.4 μm or more and 20 μm or less, 0.6 μm or more and 15 μm or less.

[0162] The sheet for manufacturing a printed matter according to the present embodiment is manufactured, for example, by using pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment and by a manufacturing method including an arranging step of arranging the pressure-responsive particles on a substrate.

[0163] The arranging step includes, 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 onto the substrate.

[0164] The applying step is realized, for example, by an applying method such as 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 laminating method, an electrophotographic method, etc. Depending on the applying method of the applying 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 applying step.

[0165] The fixing step is, for example, a heating step of heating the pressure-responsive particles on the substrate with a heat source to fix the pressure-responsive particles on the substrate; a pressing step of pressing the substrate with the pressure-responsive particles applied thereon with a pair of pressing members (roll / roll, belt / roll) to fix the pressure-responsive particles on the substrate; a pressing and heating step of pressing and heating the substrate with the pressure-responsive particles applied thereon with a pair of pressing members (roll / roll, belt / roll) having a heat source inside to fix the pressure-responsive particles on the substrate; etc.

[0166] (Manufacture of printed matter by electrophotographic method) An embodiment example of applying the pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment to the electrophotographic method will be described. In the electrophotographic method, the pressure-responsive particles are used as toner.

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

[0168] There is no particular limitation on the carrier, and known carriers can be mentioned. Examples of the carrier include: a coated carrier in which a resin is coated on the surface of a core material made of magnetic powder; a magnetic powder-dispersed carrier in which magnetic powder is dispersed and blended in a matrix resin; a resin-impregnated carrier in which porous magnetic powder is impregnated with resin; and the like. The magnetic powder-dispersed carrier and the resin-impregnated carrier may be carriers in which the constituent particles of the carrier are used as the core material and the surface thereof is coated with resin.

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

[0170] Examples of the resin for coating and the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic ester copolymer, straight silicone resin composed of an organosiloxane bond or a modified product thereof, fluororesin, polyester, polycarbonate, phenol resin, epoxy resin, etc. The resin for coating and the matrix resin may contain conductive particles and other additives. Examples of the conductive particles include metals such as gold, silver, and copper, and particles such as 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, methods such as coating with a coating solution formed by dissolving the resin for coating and various additives (used as necessary) in an appropriate solvent can be mentioned. The solvent is not particularly limited and may be selected in consideration of the type of resin used, coating applicability, etc. Specific resin coating methods include an immersion method in which the core material is immersed in the coating solution for forming a coating layer; a spray method in which the coating solution for forming a coating layer is sprayed onto the surface of the core material; a fluidized bed method in which the coating solution for forming a coating layer is sprayed while the core material is suspended by flowing air; a kneader coater method in which the core material of the carrier and the coating solution for forming a coating layer are mixed in a kneader coater and then the solvent is removed; etc.

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

[0173] <Printed matter manufacturing apparatus, printed matter manufacturing method> A manufacturing apparatus for printed matter applying an electrophotographic method accommodates a developer containing pressure-responsive particles manufactured by the manufacturing method of the pressure-responsive particles according to the present embodiment, and disposing means for disposing the pressure-responsive particles on a recording medium by an electrophotographic method, and pressing means for folding and pressing the recording medium, or for overlapping and pressing the recording medium with another recording medium.

[0174] By the manufacturing apparatus for printed matter according to the present embodiment, a manufacturing method for printed matter by an electrophotographic method is implemented. The manufacturing method for printed matter according to the present embodiment includes a disposing step of disposing the pressure-responsive particles on a recording medium by an electrophotographic method using a developer containing pressure-responsive particles manufactured by the manufacturing method of the pressure-responsive particles according to the present embodiment, and a pressing step of folding and pressing the recording medium, or of overlapping and pressing the recording medium with another recording medium.

[0175] The disposing means included in the manufacturing apparatus for printed matter according to the present embodiment is, for example, a photoreceptor, charging means for charging the surface of the photoreceptor, electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged photoreceptor, developing means for accommodating the electrostatic charge image developer according to the present embodiment and developing the electrostatic charge image formed on the surface of the photoreceptor as a pressure-responsive particle imparting portion with the electrostatic charge image developer, transferring means for transferring the pressure-responsive particle imparting portion formed on the surface of the photoreceptor to the surface of the recording medium, and is provided with. The disposing means preferably further includes fixing means for fixing the pressure-responsive particle imparting portion transferred to the surface of the recording medium.

[0176] The disposing step included in the manufacturing method for printed matter according to the present embodiment is, for example, a charging step of charging the surface of the photoreceptor, an electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged photoreceptor, A developing step of developing an electrostatic charge image formed on the surface of the photoreceptor with the electrostatic charge image developer according to the present embodiment as a pressure-responsive particle-imparting portion; A transfer step of transferring the pressure-responsive particle-imparting portion formed on the surface of the photoreceptor to the surface of a recording medium; and includes. The arranging step preferably further includes a fixing step of fixing the pressure-responsive particle-imparting portion transferred to the surface of the recording medium.

[0177] The arranging means is, for example, a direct transfer type device that directly transfers the pressure-responsive particle-imparting portion formed on the surface of the photoreceptor to the recording medium; a pressure-responsive particle-imparting portion formed on the surface of the photoreceptor is first transferred to the surface of an intermediate transfer member, and the pressure-responsive particle-imparting portion transferred to the surface of the intermediate transfer member is secondarily transferred to the surface of the recording medium. An intermediate transfer type device; a device provided with cleaning means for cleaning the surface of the photoreceptor after transfer of the pressure-responsive particle-imparting portion and before charging; a device provided with discharging means for discharging by irradiating the surface of the photoreceptor with discharging light after transfer of the pressure-responsive particle-imparting portion and before charging; and the like. When the arranging means is an intermediate transfer type device, the transfer means includes, for example, an intermediate transfer member to which a pressure-responsive particle-imparting portion is transferred on the surface, and a primary transfer means for primarily transferring the pressure-responsive particle-imparting portion formed on the surface of the photoreceptor to the surface of the intermediate transfer member. And a secondary transfer means for secondarily transferring the pressure-responsive particle-imparting portion transferred to the surface of the intermediate transfer member to the surface of the recording medium.

[0178] The portion of the arranging means including the developing means may have a cartridge structure (so-called process cartridge) that is detachable from the arranging means. As the process cartridge, for example, a process cartridge that houses the electrostatic charge image developer according to the present embodiment and includes developing means is preferably used.

[0179] The pressure-applying means included in the printing material manufacturing apparatus according to this embodiment applies pressure to a recording medium on which pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to this embodiment are arranged. As a result, the pressure-responsive particles are fluidized on the recording medium and exhibit adhesiveness. The pressure applied by the pressure-applying means to the recording medium for the purpose of fluidizing 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 arranged over the entire surface of the recording medium or may be arranged on a part of the recording medium. The pressure-responsive particles are arranged in one layer or multiple layers on the recording medium. The layer of the pressure-responsive particles may be a continuous layer in the plane direction of the recording medium or a discontinuous layer in the plane direction of the recording medium. The layer of the pressure-responsive particles may be a layer in which the pressure-responsive particles are arranged as particles, or may be a layer in which adjacent pressure-responsive particles are fused and arranged.

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

[0182] Examples of the recording medium applicable to the printing material manufacturing apparatus according to this embodiment include paper, coated paper obtained by coating the surface of paper with resin or the like, cloth, non-woven fabric, resin film, resin sheet, and the like. The recording medium may have an image on one side or both sides.

[0183] Hereinafter, an example of a printing apparatus according to the present embodiment to which an electrophotographic method is applied will be shown, but the present embodiment is not limited thereto.

[0184] FIG. 2 is a schematic configuration diagram showing an example of a printing apparatus according to the present embodiment. The printing apparatus shown in FIG. 2 includes an arranging unit 100 and a pressure bonding unit 200 arranged downstream of the arranging unit 100. The arrow indicates the rotation direction of the photoreceptor or the conveyance direction of the recording medium.

[0185] The arranging unit 100 is a direct transfer type apparatus that arranges pressure-responsive particles produced by the method for producing pressure-responsive particles according to the present embodiment on a recording medium P by an electrophotographic method using a developer containing the pressure-responsive particles produced by the method for producing pressure-responsive particles according to the present embodiment. An image is previously formed on one or both sides of the recording medium P.

[0186] The arranging unit 100 has a photoreceptor 101. Around the photoreceptor 101, a charging roll (an example of charging means) 102 for charging the surface of the photoreceptor 101, an exposure device (an example of electrostatic charge image forming means) 103 for exposing the charged surface of the photoreceptor 101 with a laser beam to form an electrostatic charge image, a developing device (an example of developing means) 104 for supplying pressure-responsive particles to the electrostatic charge image to develop the electrostatic charge image, a transfer roll (an example of transfer means) 105 for transferring the developed pressure-responsive particle application portion onto the recording medium P, and a photoreceptor cleaning device (an example of cleaning means) 106 for removing the pressure-responsive particles remaining on the surface of the photoreceptor 101 after transfer are arranged in this order.

[0187] The operation of the arranging unit 100 for arranging the pressure-responsive particles produced by the method for producing pressure-responsive particles according to the present embodiment on the recording medium P will be described. First, the surface of the photoreceptor 101 is charged by the charging roll 102. The exposure device 103 irradiates a laser beam onto the charged surface of the photoreceptor 101 according to image data sent from a control unit (not shown). Thereby, 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 charge image formed on the photoreceptor 101 rotates to the developing position as the photoreceptor 101 travels. Then, at the developing position, the electrostatic charge 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 houses a developer containing at least the pressure-responsive particles and the carrier. The pressure-responsive particles are triboelectrically charged by being agitated with the carrier inside the developing device 104 and are held on the 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 having the pressure-responsive particle application portion formed thereon continues to travel, and the pressure-responsive particle application portion on the photoreceptor 101 is conveyed to the transfer position.

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

[0191] The pressure-responsive particles remaining on the photoreceptor 101 are removed and recovered by the photoreceptor cleaning device 106. The photoreceptor cleaning device 106 is, for example, a cleaning blade, a cleaning brush, or the like. 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 a film shape.

[0192] The recording medium P with the pressure-responsive particle applying unit transferred thereon is conveyed to a fixing device (an example of a fixing means) 107. The fixing device 107 is, for example, a pair of fixing members (roll / roll, belt / roll). The arranging means 100 may not include the fixing device 107, but it is preferably provided with the fixing device 107 from the viewpoint of suppressing the dropping of the pressure-responsive particles from the recording medium P. The pressure applied by the fixing device 107 to the recording medium P may be a low pressure compared to the pressure applied by the pressurizing device 230 to the recording medium P2. Specifically, it is preferably 0.2 MPa or more and 1 MPa or less.

[0193] The fixing device 107 may or may not have a heat source (for example, a halogen heater) for heating the recording medium P inside. When the fixing device 107 has a heat source inside, the surface temperature of the recording medium P when heated by the heat source is preferably 150°C or more and 220°C or less, more preferably 155°C or more and 210°C or less, and still more preferably 160°C or more and 200°C or less. Note that the fact that the fixing device 107 does not have a heat source inside does not exclude the case where the temperature inside the fixing device 107 becomes equal to or higher than the ambient temperature due to heat generation of a motor or the like provided in the arranging means 100.

[0194] The recording medium P becomes the recording medium P1 with the pressure-responsive particles applied on the image by passing through the arranging means 100. The recording medium P1 is conveyed toward the crimping means 200.

[0195] In the printing apparatus according to the present embodiment, the arranging means 100 and the crimping means 200 may be in a form close to each other or in a form separated from each other. When the arranging means 100 and the crimping means 200 are separated, the arranging means 100 and the crimping means 200 are connected by, for example, a conveying means (for example, a belt conveyor) for conveying the recording medium P1.

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

[0197] The folding device 220 folds the recording medium P1 passing through the device to produce the folded recording medium P2. The way the recording medium P2 is folded may be, for example, double-folded, triple-folded, or quadruple-folded, or a form in which only a part of the recording medium P2 is folded. The recording medium P2 is in a state where the pressure-responsive particles are arranged on at least a part of at least one of the two opposing surfaces.

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

[0199] Instead of the folding device 220, the crimping means 200 may include a stacking device that stacks the recording medium P1 and another recording medium. The form of the overlap between the recording medium P1 and another recording medium may be, for example, a form in which another recording medium overlaps on the recording medium P1, or a form in which another recording medium overlaps one by one at a plurality of locations on the recording medium P1. Another recording medium may be a recording medium with an image formed in advance on one or both sides, a recording medium without an image formed, or a pre-produced crimped printed matter.

[0200] The recording medium P2 that exits the folding device 220 (or the stacking device) is conveyed toward the pressing device 230.

[0201] The pressing device 230 includes a pair of pressing members (that is, pressing rolls 231 and 232). The pressing roll 231 and the pressing roll 232 contact and press against each other on their outer peripheral surfaces, and apply pressure to the passing recording medium P2. The pair of pressing members provided in the pressing device 230 is not limited to the combination of a pressing roll and a pressing roll, and may also be a combination of a pressing roll and a pressing belt, or a combination of a pressing belt and a pressing belt.

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

[0203] The pressing device 230 may or may not have a heat source (e.g., a halogen heater) inside for heating the recording medium P2. When the pressing device 230 has a heat source inside, the surface temperature of the recording medium P2 when heated by the heat source is preferably 30°C or more and 120°C or less, more preferably 40°C or more and 100°C or less, and still more preferably 50°C or more and 90°C or less. Note that the fact that the pressing device 230 does not have a heat source inside does not exclude the possibility that the temperature inside the pressing device 230 becomes equal to or higher than the ambient temperature due to heat generation by a motor or the like provided in the pressing device 230.

[0204] As the recording medium P2 passes through the pressing device 230, the overlapping surfaces are adhered by the pressure-responsive particles that have been fluidized, and a pressure-bonded printed matter P3 is produced. In the pressure-bonded printed matter P3, the opposing surfaces are partially or entirely adhered.

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

[0206] The first form of the pressure-bonded printed matter P3 is a pressure-bonded printed matter in which the folded recording media are adhered by the pressure-responsive particles on the opposing surfaces. The pressure-bonded printed matter P3 of this form is manufactured by a printing matter manufacturing device including a folding device 220.

[0207] The second form of the pressure-bonded printed matter P3 is a pressure-bonded printed matter in which a plurality of overlapping recording media are adhered by the pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment on the opposing surfaces. The pressure-bonded printed matter P3 of this form is manufactured by a pressure-bonded printed matter manufacturing device including a stacking device.

[0208] The manufacturing apparatus for printed matter according to the present embodiment is not limited to an apparatus that continuously conveys the recording medium P2 from the folding apparatus 220 (or stacking apparatus) to the pressing apparatus 230. The manufacturing apparatus for printed matter according to the present embodiment may be an apparatus that stores the recording medium P2 that has exited the folding apparatus 220 (or stacking apparatus), and after the storage amount of the recording medium P2 reaches a predetermined amount, conveys the recording medium P2 to the pressing apparatus 230.

[0209] In the manufacturing apparatus for printed matter according to the present embodiment, the folding apparatus 220 (or stacking apparatus) and the pressure-bonding pressing apparatus 230 may be in a form that is close to each other or in a form that is separated from each other. When the folding apparatus 220 (or stacking apparatus) and the pressure-bonding pressing apparatus 230 are separated, the folding apparatus 220 (or stacking apparatus) and the pressure-bonding pressing apparatus 230 are connected by, for example, a conveying means (such as a belt conveyor) that conveys the recording medium P2.

[0210] The manufacturing apparatus for printed matter according to the present embodiment may include a cutting means for cutting the recording medium to a predetermined size. The cutting means is, for example, disposed between the disposing means 100 and the pressure-bonding means 200, and cuts off an area of the recording medium P1 where the pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment are not disposed; disposed between the folding apparatus 220 and the pressing apparatus 230, and cuts off an area of the recording medium P2 where the pressure-responsive particles are not disposed; disposed downstream of the pressure-bonding means 200, and cuts off an area of the pressure-bonded printed matter P3 that is not adhered by the pressure-responsive particles according to the present embodiment; and the like.

[0211] The manufacturing apparatus for printed matter according to the present embodiment is not limited to a sheet-fed apparatus. The manufacturing apparatus for printed matter according to the present embodiment may be an apparatus that forms a long pressure-bonded printed matter by performing a disposing step and a pressure-bonding step on a long recording medium, and then cuts the long pressure-bonded printed matter to a predetermined size.

[0212] The manufacturing apparatus for printed matter according to this embodiment may further include a colored image forming means for forming a colored image on a recording medium by an electrophotographic method using a colored electrostatic charge image developer. The colored image forming means includes, for example, a photoreceptor, a charging means for charging the surface of the photoreceptor, an electrostatic charge image forming means for forming an electrostatic charge image on the charged surface of the photoreceptor, a developing means for accommodating a colored electrostatic charge image developer and developing the electrostatic charge image formed on the surface of the photoreceptor as a colored toner image with the colored electrostatic charge image developer, a transfer means for transferring the colored toner image formed on the surface of the photoreceptor to the surface of the recording medium, and a heat fixing means for heat-fixing the colored toner image transferred to the surface of the recording medium.

[0213] By the manufacturing apparatus having the above configuration, a manufacturing method according to this embodiment, which further includes a colored image forming step of forming a colored image on a recording medium by an electrophotographic method using a colored electrostatic charge image developer, is implemented. Specifically, the colored image forming step includes a charging step of charging the surface of the photoreceptor, an electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the photoreceptor, a developing step of developing the electrostatic charge image formed on the surface of the photoreceptor as a colored toner image with a colored electrostatic charge image developer, a transfer step of transferring the colored toner image formed on the surface of the photoreceptor to the surface of the recording medium, and a heat fixing step of heat-fixing the colored toner image transferred to the surface of the recording medium.

[0214] The colored image forming means included in the printing material manufacturing apparatus according to the present embodiment is, for example, a direct transfer type apparatus that directly transfers a colored toner image formed on the surface of a photoreceptor to a recording medium; an intermediate transfer type apparatus that first transfers a colored toner image formed on the surface of a photoreceptor to the surface of an intermediate transfer body and then secondarily transfers the colored toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium; an apparatus provided with cleaning means for cleaning the surface of the photoreceptor before charging after the transfer of the colored toner image; an apparatus provided with charge elimination means for irradiating the surface of the photoreceptor with charge elimination light for charge elimination before charging after the transfer of the colored toner image; and the like. When the colored image forming means is an intermediate transfer type apparatus, the transfer means includes, for example, an intermediate transfer body on which a colored toner image is transferred to the surface, a primary transfer means for primarily transferring the colored toner image formed on the surface of the photoreceptor to the surface of the intermediate transfer body, and a secondary transfer means for secondarily transferring the colored toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium.

[0215] In the printing material manufacturing apparatus according to the present embodiment, when the arrangement means of the developer containing the pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment and the colored image forming means adopt an intermediate transfer method, the arrangement means and the colored image forming means may share the intermediate transfer body and the secondary transfer means.

[0216] In the printing material manufacturing apparatus according to the present embodiment, the arrangement means of the image developer containing the pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment and the colored image forming means may share the heat fixing means.

[0217] Hereinafter, an example of the printing material manufacturing apparatus according to the present embodiment provided with colored image forming means is shown, but the present embodiment is not limited thereto. In the following description, the main parts shown in the drawings will be described, and the others will be omitted from the description.

[0218] FIG. 3 is a schematic configuration diagram showing an example of a printing apparatus according to the present embodiment to which an electrophotographic method is applied. The printing apparatus shown in FIG. 3 includes a printing unit 300 that collectively performs the arrangement of pressure-responsive particles manufactured by the method for manufacturing pressure-responsive particles according to the present embodiment on a recording medium and the formation of a colored image, and a pressure-bonding unit 200 disposed downstream of the printing unit 300.

[0219] The printing unit 300 is a printing unit of a five-unit tandem type and an intermediate transfer type. The printing unit 300 includes a unit 10T for arranging the pressure-responsive particles (T), and units 10Y, 10M, 10C, and 10K for forming colored images of yellow (Y), magenta (M), cyan (C), and black (K). The unit 10T is an arranging unit that arranges 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 units that form colored images on the recording medium P using developers containing colored toners. The units 10T, 10Y, 10M, 10C, and 10K employ an electrophotographic method.

[0220] The units 10T, 10Y, 10M, 10C, and 10K are arranged side by side at intervals in the horizontal direction. The units 10T, 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the printing unit 300.

[0221] Below the units 10T, 10Y, 10M, 10C, and 10K, an intermediate transfer belt (an example of an intermediate transfer member) 20 extends through each unit. The intermediate transfer belt 20 is provided by being wound around a driving roll 22, a support roll 23, and an opposing roll 24 that are in contact with the inner surface of the intermediate transfer belt 20, and is configured to travel in a direction from the unit 10T toward the unit 10K. On the image holding surface side of the intermediate transfer belt 20, an intermediate transfer member cleaning device 21 is provided opposite to the driving roll 22.

[0222] Units 10T, 10Y, 10M, 10C, and 10K each include developing devices (an example of developing means) 4T, 4Y, 4M, 4C, and 4K. In each of the developing devices 4T, 4Y, 4M, 4C, and 4K, the pressure-responsive particles stored in the pressure-responsive particle cartridge 8T, or the yellow toner, magenta toner, cyan toner, and black toner stored in the toner cartridges 8Y, 8M, 8C, and 8K are supplied.

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

[0224] Unit 10T has a photoreceptor 1T. Around the photoreceptor 1T, a charging roll (an example of charging means) 2T that charges the surface of the photoreceptor 1T, an exposure device (an example of electrostatic charge image forming means) 3T that exposes the charged surface of the photoreceptor 1T with a laser beam to form an electrostatic charge image, a developing device (an example of developing means) 4T that supplies pressure-responsive particles to the electrostatic charge image to develop the electrostatic charge image, a primary transfer roll (an example of 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 cleaning means) 6T that removes the pressure-responsive particles remaining on the surface of the photoreceptor 1T after primary transfer are arranged in order. The primary transfer roll 5T is arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoreceptor 1T.

[0225] Hereinafter, while exemplifying the operation of the unit 10T, the operation of arranging the pressure-responsive particles manufactured by the manufacturing method of the pressure-responsive particles according to the present embodiment on the recording medium P and forming a colored image will be described. First, the surface of the photoreceptor 1T is charged by the charging roll 2T. The charged surface of the photoreceptor 1T is irradiated with a laser beam by the exposure device 3T according to the image data sent from a control unit (not shown). Thereby, 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 charge image formed on the photoreceptor 1T rotates to the developing position as the photoreceptor 1T travels. Then, at the developing position, the electrostatic charge image on the photoreceptor 1T is developed by the developing device 4T and becomes the pressure-responsive particle applying portion.

[0227] In the developing device 4T, a developer containing at least the pressure-responsive particles and the carrier is accommodated. The pressure-responsive particles are triboelectrically charged by being agitated together with the carrier inside the developing device 4T and are held on the 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 on which the pressure-responsive particle applying portion is formed continues to travel, and the pressure-responsive particle applying portion on the photoreceptor 1T is conveyed to the primary transfer position.

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

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

[0230] The intermediate transfer belt 20 onto which the pressure-responsive particle application portion and the toner image are multiply transferred through the units 10T, 10Y, 10M, 10C, and 10K reaches a secondary transfer portion composed of the intermediate transfer belt 20, a counter roll 24 that contacts the inner surface of the intermediate transfer belt, and a secondary transfer roll (an example of secondary transfer means) 26 disposed on the image holding surface side of the intermediate transfer belt 20. On the other hand, the recording medium P is fed into the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact via a supply mechanism, and a secondary transfer bias is applied to the counter roll 24. At this time, the electrostatic force directed from the intermediate transfer belt 20 toward the recording medium P acts on the pressure-responsive particle application portion and the toner image, and the pressure-responsive particle application portion and the toner image 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 portion and the toner image are transferred is conveyed to a heat fixing device (an example of heat fixing means) 28. The heat fixing device 28 includes a heating source such as a halogen heater and heats the recording medium P. The surface temperature of the recording medium P when heated by the heat 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 still more preferably 160°C or higher and 200°C or lower. By passing through the heat fixing device 28, the colored toner image is heat-fixed onto the recording medium P.

[0232] From the viewpoints of suppressing the pressure-responsive particles from falling off the recording medium P and improving the fixability of the colored image onto the recording medium P, the heat fixing device 28 is preferably a device that performs pressurization together with heating. For example, it may be a pair of fixing members (roll / roll, belt / roll) having a heating source inside. When the heat fixing device 28 performs pressurization, the pressure applied by the heat fixing device 28 to the recording medium P may be a lower pressure compared to the pressure applied by the pressurizing device 230 to the recording medium P2. Specifically, it is preferably 0.2 MPa or higher and 1 MPa or lower.

[0233] The recording medium P becomes the recording medium P1 to which the colored image and the pressure-responsive particles are applied by passing through the printing means 300. The recording medium P1 is conveyed 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 descriptions of the configuration and operation of the crimping means 200 are omitted.

[0235] In the printing material manufacturing apparatus according to the present embodiment, the printing means 300 and the crimping means 200 may be in a form close to each other or in a separated form. When the printing means 300 and the crimping means 200 are separated, the printing means 300 and the crimping means 200 are connected by, for example, a conveying means (such as a belt conveyor) that conveys the recording medium P1.

[0236] The printing material manufacturing apparatus according to the present embodiment may include a cutting means for cutting the recording medium into a predetermined size. The cutting means is, for example, a cutting means disposed between the printing means 300 and the crimping means 200 for cutting off a region of a part of the recording medium P1 where the pressure-responsive particles are not disposed; a cutting means disposed between the folding device 220 and the pressing device 230 for cutting off a region of a part of the recording medium P2 where the pressure-responsive particles are not disposed; a cutting means disposed downstream of the crimping means 200 for cutting off a region of a part of the crimped printed matter P3 that is not adhered by the pressure-responsive particles; and the like.

[0237] The printing material manufacturing apparatus according to the present embodiment is not limited to a sheet-fed apparatus. The printing material manufacturing apparatus according to the present embodiment may be an apparatus that forms a long crimped printed matter by performing a colored image forming step, an arranging step, and a crimping step on a long recording medium and then cuts the long crimped printed matter into a predetermined size.

[0238] <Process cartridge> A process cartridge applied to a printing material manufacturing apparatus using an electrophotographic method will be described. The process cartridge according to the present embodiment houses the electrostatic charge image developer according to the present embodiment and includes a developing means for developing an electrostatic charge image formed on the surface of a photoreceptor as a pressure-responsive particle applying portion with the electrostatic charge image developer, and is a process cartridge that is detachable from the printing material manufacturing apparatus.

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

[0240] As an example of an embodiment of the process cartridge, there is a cartridge in which a photosensitive member, a charging roll (an example of a charging unit) provided around the photosensitive member, a developing device (an example of a developing unit), and a photosensitive member cleaning device (an example of a cleaning unit) are integrated by a housing. The housing has an opening for exposure. The housing has mounting rails, and the process cartridge is mounted on a printing apparatus via the mounting rails.

Example

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

[0242] (Example 1) <Preparation of styrene 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. 8 parts of an anionic surfactant (DOWFAX 2A1 manufactured by Dow Chemical Co., Ltd.) 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, charged into a polymerization flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas introduction tube, heated to 73° C. with stirring, and held. 3 parts of ammonium persulfate was dissolved in 21 parts of ion-exchanged water, and the solution was dropped into the polymerization flask through a metering pump over 15 minutes. Then, the emulsion was dropped into the flask through a metering pump over 160 minutes. Next, while continuously stirring slowly, the polymerization flask was maintained at 75 °C for 3 hours and then returned to room temperature (25 °C, the same hereinafter). As a result, a styrene resin particle dispersion St1 with a volume average particle size (D50v) of 220 nm, a weight average molecular weight of 33,000 by GPC (UV detection), a glass transition temperature of 53 °C, and a solid content of 42% was obtained.

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

[0244] <Preparation of pressure-responsive particles> Composite resin particle dispersion SM1: 180 parts (solid content) Silica (arithmetic mean particle size 12 nm) slurry (aqueous dispersion of silica particles): 11 parts (solid content) Anionic surfactant: 1 part The above components were placed in a reaction vessel and mixed, and 0.1 part of aluminum sulfate was added while dispersing with a homogenizer (5,000 rpm) and dispersed for 6 minutes. Then, the temperature was raised to cause aggregation and growth, and when the particle size reached 10 μm, 40 parts (solid content) of a styrene-based resin particle dispersion St1 was added. Thereafter, the temperature was raised to 90 °C for unification, followed by filtration, washing, and drying to obtain pressure-responsive particles (EA1) with a volume-average particle size of 10.5 μm and an average circularity of 0.967.

[0245] (Comparative Example 1) Pressure-responsive resin particles (EA2) were obtained in the same manner as in Example 1, except that the silica slurry was reduced to 1 part (solid content) and charged into the reaction vessel.

[0246] (Examples 2 and 3) Pressure-responsive resin particles were obtained in the same manner as in Example 1, except that the ratio of the amount of the styrene-based resin particle dispersion St1 used to the amounts of the monomers 2-ethylhexyl acrylate and n-butyl acrylate used in the preparation of the composite resin particle dispersion SM1 was changed to the values shown in Table 1.

[0247] (Examples 4 and 5, and Comparative Example 2) Pressure-responsive resin particles were obtained in the same manner as in Example 1, except that the amount of the silica slurry added was changed to the values shown in Table 1.

[0248] (Comparative Examples 3 and 4) Pressure-responsive resin particles were obtained in the same manner as in Example 1, except that the ratio of the amount of the styrene-based resin particle dispersion St1 used to the amounts of the monomers 2-ethylhexyl acrylate and n-butyl acrylate used in the preparation of the composite resin particle dispersion SM1 was changed to the values shown in Table 1.

[0249] (Examples 6 to 19) Pressure-responsive resin particles were obtained in the same manner as in Example 1, except that the total amount of the resin was not changed, but the types and usage ratios of the raw material monomers, the amount of silica particles added in the aggregation step, and the amount of the styrene-based resin particle dispersion used in the shell formation step were changed as described in Table 1.

[0250] <Adhesion evaluation> The obtained pressure-responsive particles were uniformly coated (2.0 g / m 2 ) on a paper on which a character image was printed by an electrophotographic printer using a cake printer, fixed to the paper using a fixing bench of a multifunction machine, folded in half and the images were aligned, then passed through a sealer (Pressle multi2 manufactured by Toppan Forms Co., Ltd.) to apply pressure (Gap 10), placed in a chamber at 10°C and 15% humidity overnight, cut into strips 15 mm wide, and a 90-degree peel test was performed to measure and evaluate the peel force (unit: N / 15 mm). The evaluation criteria are shown below. A: ≧0.8 N / 15 mm B: Exceeding 0.4 N / 15 mm and less than 0.8 N / 15 mm C: ≦0.4 N / 15 mm Evaluation A or B is preferred, and evaluation A is more preferred.

[0251] <Storage stability evaluation of dispersion> In the preparation of the pressure-responsive particles, after heating to 90°C and combining, and then cooling the pressure-responsive particle dispersion before filtration to 30°C, it was stored sealed in a chamber at 30°C for one month, and then the particle size distribution was measured using a LS Coulter. When aggregated particles are generated, the measurement result of the volume average particle size distribution shows a bimodal distribution with a peak on the coarse powder side. Therefore, the evaluation criteria are shown below. A: The same particle size distribution as the initial one, showing a single-peak. B: It becomes a bimodal peak with a peak on the coarse powder side, but returns to a single-peak after re-stirring. C: It becomes a bimodal peak with a peak on the coarse powder side and does not return to a single-peak even after re-stirring. Evaluation A or B is preferred, and evaluation A is more preferred.

[0252] The evaluation results are collectively shown in Table 1.

[0253]

Table 1

[0254] Note that in Comparative Example 2, aggregation did not progress and pressure-responsive particles could not be obtained, so evaluation was not possible. Also, in Table 1, the monomers are described using the following abbreviations. Styrene: St, n-butyl acrylate: BA, 2-ethylhexyl acrylate: 2EHA, ethyl acrylate: EA, 4-hydroxybutyl acrylate: 4HBA, acrylic acid: AA, methacrylic acid: MAA, hexyl acrylate: HA, propyl acrylate: PA

[0255] From the above results, it can be seen that this example is superior in terms of the adhesive force during crimping and the storage stability as a dispersion liquid compared to the comparative examples.

Explanation of symbols

[0256] 100 Arrangement means 110 Application device 120 Fixing device 200 Crimping means 220 Folding device 230 Pressing device 231, 232 Pressing rolls M Pressure-responsive particles P Recording medium P1 Recording medium with pressure-responsive particles applied on the image P2 Folded recording medium P3 Crimped printed matter

[0257] 101 Photoconductor 102 Charging roll (an example of charging means) 103 Exposure device (an example of electrostatic charge image forming means) 104 Developing device (an example of developing means) 105 Transfer roll (an example of transfer means) 106 Photoconductor cleaning device (an example of cleaning means) 107 Fixing device (an example of fixing means)

[0258] 300 Printing means 1T, 1Y, 1M, 1C, 1K Photoconductors 2T, 2Y, 2M, 2C, 2K Charging rolls (an example of charging means) 3T, 3Y, 3M, 3C, 3K Exposure device (an example of electrostatic charge 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 primary transfer means) 6T, 6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of cleaning means) 8T Pressure-responsive particle cartridge 8Y, 8M, 8C, 8K Toner cartridge 10T, 10Y, 10M, 10C, 10K Unit 20 Intermediate transfer belt (an example of intermediate transfer body) 21 Intermediate transfer body cleaning device 22 Driving roll 23 Support roll 24 Opposing roll 26 Secondary transfer roll (an example of secondary transfer means) 28 Heat fixing device (an example of heat fixing means)

Claims

1. A dispersion containing composite resin particles comprising a styrene resin containing a styrene compound and other vinyl monomers as polymerization components and a (meth)acrylate resin containing a (meth)acrylate compound as a polymerization component, a dispersion containing silica particles, and a flocculant are added and flocculated to obtain flocculated particles, and A fusion step of heating and fusing the flocculated particles to form pressure-responsive particles, The amount of silica particles added by the dispersion containing the silica particles is 2% by mass or more and 10% by mass or less based on the total mass of the composite resin particles, The mass ratio of the styrene resin to the (meth)acrylate 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. The method for producing pressure-responsive particles according to claim 1, wherein the amount of silica particles added by the dispersion containing the silica particles is 2% by mass or more and 8% by mass or less based on the total mass of the composite resin particles.

3. The method for producing pressure-responsive particles according to claim 1 or claim 2, wherein the arithmetic mean particle diameter of the silica particles is 5 nm or more and 100 nm or less.

4. The method for producing pressure-responsive particles according to claim 3, wherein the arithmetic mean particle diameter of the silica particles is 7 nm or more and 40 nm or less.

5. The method for producing pressure-responsive particles according to any one of claims 1 to 3, further comprising a shell formation step of adding and flocculating a styrene resin particle dispersion to the dispersion containing the flocculated particles after the flocculation step and before the fusion step.

6. The manufacturing method of the pressure-responsive particles according to claim 5, wherein the addition amount of the styrene-based resin particles by the styrene-based resin particle dispersion liquid in the shell formation step is 10% by mass or more and 25% by mass or less based on the total mass of the composite resin particles.

7. The manufacturing method of the pressure-responsive particles according to any one of claims 1 to 6, wherein the aggregating agent is aluminum sulfate.

8. The manufacturing method of the pressure-responsive particles according to any one of claims 1 to 7, wherein the glass transition temperature of the styrene-based resin contained in the pressure-responsive particles is 30°C or higher.

9. The manufacturing method of the pressure-responsive particles according to any one of claims 1 to 8, wherein the glass transition temperature of the (meth)acrylic acid ester-based resin contained in the pressure-responsive particles is -30°C or lower.

10. An arranging step of arranging the pressure-responsive particles on a recording medium using the pressure-responsive particles manufactured by the manufacturing method of the pressure-responsive particles according to any one of claims 1 to 9, A pressing step of folding and pressing the recording medium, or pressing the recording medium and another recording medium by overlapping them, A manufacturing method of a printed matter including.

11. A manufacturing method of a sheet for manufacturing a printed matter, including an arranging step of arranging the pressure-responsive particles on a substrate using the pressure-responsive particles manufactured by the manufacturing method of the pressure-responsive particles according to any one of claims 1 to 9. A manufacturing method of a sheet for manufacturing a printed matter.

Images