Kao Corporation

Kyocera Mita Corporation

Hiroshi Mizuhata

Yukinori Nakayama

Shoichi Murata

Kouzou Teramoto

Kousuke Satou

Eiji Shirai

Takashi Kubo

Koji Shimokusa

Manabu Suzuki

Nobumichi Kamiyoshi

Shinichi Sata

Takashi Mukai

Katsutoshi Aoki

Takehiro Tsutsumi

Koji Kameyama

Takayuki Ikenaga

Hiromi Nambu

Yutaka Murai

Hiroto Soma

Takashi Okuno

Hidehito Ikebata

Yasuhiro Shidahara

Keishi Yokota

Manato Ikeda

Kojiro Kameyama

The present invention provides a water-based ink that is excellent in adhesion to a resin printing medium formed of a resin such as polyethylene terephthalate, polyvinyl chloride, polyethylene, polypropylene, nylon, etc., gloss and anti-blocking properties upon storage of the printing medium after printing. The present invention relates to [1] a water-based ink including a colorant, polyester resin particles and modified polyolefin resin particles, in which the polyester resin particles are constituted of a resin containing an amorphous polyester having a glass transition temperature of not lower than 40&#xb0; C. and not higher than 100&#xb0; C., and a mass ratio of the polyester resin particles to the modified polyolefin resin particles (polyester resin particles/modified polyolefin resin particles) is not less than 10/90 and not more than 90/10, and [2] an ink-jet printing method including the steps of allowing the water-based ink according to the above [1] to adhere onto a resin printing medium by an ink-jet printing method; and then heating the resin printing medium onto which the water-based ink is adhered, to a temperature of not lower than 40&#xb0; C. and not higher than 100&#xb0; C.

Aqueous ink

According to the present invention, there are provided a process for producing a toner for development of electrostatic images which is capable of suppressing desorption and exposure of a releasing agent therein, and excellent in fusing property, suppression of toner cloud and durability; a process for producing a dispersion, and a kit for producing the dispersion. The present invention relates to a process for producing a toner for development of electrostatic images which includes the following steps (1) to (3): step (1) of mixing and emulsifying a releasing agent and a dispersion of resin particles (A) containing a polyester in an amount of not less than 90% by mass on the basis of a resin component in the resin particles (A) to obtain a dispersion of releasing agent particles; step (2) of mixing and aggregating the dispersion of the releasing agent particles obtained in the step (1) and a dispersion of resin particles (B) containing a polyester in an amount of not less than 90% by mass on the basis of a resin component in the resin particles (B) to obtain aggregated particles; and step (3) of coalescing the aggregated particles obtained in the step (2) to obtain coalesced particles, in which an acid component constituting the polyester in the resin particles (A) contains an aliphatic carboxylic acid; the resin particles (A) have a volume median particle size of not less than 0.02 &#x3bc;m and not more than 0.50 &#x3bc;m; and a content of a surfactant in the dispersion of the releasing agent particles is not more than 0.5 part by mass on the basis of 100 parts by mass of the releasing agent; a process for producing the dispersion of the releasing agent particles which includes the above step (1); and a kit for producing the dispersion of the releasing agent particles.

Process for manufacturing toner for developing electrostatic image

The present invention relates to a process for producing a toner for electrophotography which is capable of suppressing liberation of a wax from a resin binder and exposure of the wax to a surface of respective toner particles in the step of obtaining fused particles upon production of the toner, and reducing a content of fine powders in the toner, and which is characterized by an excellent low-temperature fusing property and an excellent anti-high-temperature offset property. The process for producing a toner for electrophotography according to the present invention includes the following steps 1 to 3: Step 1 of mixing and emulsifying a wax, a resin emulsion containing a resin having an acid value of from 10 to 300 mgKOH/g, and an oxazoline group-containing polymer with each other to obtain a water dispersion of releasing agent particles; Step 2 of mixing and aggregating the water dispersion of the releasing agent particles obtained in the step 1 with a water dispersion of resin particles containing a carboxyl group-containing resin binder to obtain aggregated particles; and Step 3 of fusing the aggregated particles obtained in the step 2 to obtain fused particles.

Process for producing electrophotographic toner

The present invention relates to a process for producing a toner for electrophotography which includes the step of fusing aggregated particles containing resin particles (A) and releasing agent particles in an aqueous mixed solution containing the aggregated particles and an anionic surfactant having a polyalkylene glycol moiety with an average molar number of addition of an alkylene oxide having 2 to 3 carbon atoms of from 5 to 100 after and/or while adjusting a pH value of the aqueous mixed solution to 2.0 to 6.0 as measured at 25&#xb0; C., and a toner for electrophotography obtained by the process.

Process for producing toner for electrophotography

The present invention relates to a process for producing a toner for development of electrostatic latent images which includes a step (1) of mixing and aggregating resin particles (A), releasing agent particles and an aggregating agent formed of a divalent to pentavalent amine salt in an aqueous medium to obtain aggregated particles, and a toner for development of electrostatic latent images obtained by the process.

Method for producing electrostatic latent image developing toner

The present invention relates to a process for producing a toner for electrophotography which is excellent in dispersibility of a colorant in the toner and capable of considerably improving an image density, as well as a toner for electrophotography which is produced by the process. There is provided a process for producing a toner for electrophotography which includes the step of mixing a dispersion of colorant-containing polymer particles with a dispersion of resin particles containing substantially no colorant to aggregate the colorant-containing polymer particles and the resin particles, wherein the polymer contains a constitutional unit derived from a salt-forming group-containing monomer (a) and a constitutional unit derived from an aromatic ring-containing monomer (b).

The present invention relates to a process for producing a dispersion of polyester particles which includes the step of emulsifying mixed polyester containing (1) an amorphous polyester containing a constitutional unit derived from a trivalent or higher-valent carboxylic acid in an amount of from 2.0 to 12.0 mol % on the basis of whole constitutional units of the whole amorphous polyester and (2) a crystalline polyester, in an aqueous medium in a single vessel, or the step of mixing the mixed polyester with an organic solvent and then adding the aqueous medium to the resulting mixture to emulsify the mixed polyester in a single vessel. The present invention also relates to a dispersion of polyester particles produced by the above production process, as well as a toner for electrophotography which is produced by subjecting the dispersion of the polyester particles to aggregation and coalescence and is excellent in both of a low-temperature fusing property and an anti-hot offset property, and a process for producing the toner.

Manufacturing method for polyester particle dispersion liquid

The invention provides a process for producing a toner for electrophotography including the following (1) to (4): (1): adding an aggregating agent to a resin particle dispersion (a) so as to attain an aggregating agent concentration Ea (wt %), to thereby produce an aggregated particle dispersion (A); (2): adding a resin microparticle dispersion (b) to the dispersion (A), to thereby produce a dispersion (B) having an aggregating agent concentration Eb (wt %) satisfying 0.60&#x2266;Eb/Ea&#x3c;1; (3): modifying the aggregating agent concentration of the dispersion (B), to thereby produce a dispersion (C) of resin microparticle-deposited aggregated particles, having an aggregating agent concentration Ec (wt %) satisfying 0&#x3c;Ec/Ea&#x2266;0.30; and (4): heating the resin microparticle-deposited aggregated particles in the dispersion (C) at a temperature falling within a range between Tg and Tg+20 (0 C) of the resin microparticles in the resin microparticle dispersion (b), to thereby coalesce the aggregated particles.

Process for producing a toner for electrophotography

A method for producing an electrophotographic toner, including steps of: (1) preparing a thermally treated resin particle dispersion by retaining, for one hour or longer at a temperature satisfying the formula: (melting point of the crystalline polyester (a1)&#x2212;35) (&#xb0; C.)&#x3c;T&#x3c;melting point of the crystalline polyester (a1) (&#xb0; C.), a dispersion of resin particles (A) having a volume median particle size of 0.02-2 &#x3bc;m and containing a resin containing a crystalline polyester (a1) of 1-50 wt % and an amorphous polyester (b1); (2) preparing an aggregated particle dispersion by aggregating thermally treated resin particles contained in the thermally treated resin particle dispersion prepared through step 1; (2a) preparing resin-fine-particle-attached aggregated particles by adding, to the aggregated particle dispersion prepared through step 2, a dispersion of resin fine particles (B) containing an amorphous polyester (b2) of 70 wt % or more; and (3) unifying the resin-fine-particle-attached aggregated particles prepared through step 2a.

Process for production of electrophotographic toner

The present invention relates to a resin emulsion being produced by neutralizing a resin binder containing acid group with a basic compound in an aqueous medium wherein the resin binder containing acid group contains a polyester produced from a raw monomer composition containing a trivalent or higher-valent polyhydric alcohol in an amount of 1 to 15 mol %; a process for producing the resin emulsion; and a toner for electrophotography using the resin emulsion. In the resin emulsion of the present invention, a resin is readily emulsified therein even when using a crosslinked polyester as the resin, and the resin emulsion is substantially free from hydrolysis of the resin and can produce a toner having an excellent heat-resistant storage property.

Resin emulsion

The present invention relates to a toner for electrophotography including a polyester obtained by subjecting a crystalline polyester-containing aqueous dispersion and a non-crystalline polyester-containing aqueous dispersion to aggregation and coalescence, as a resin binder, wherein the crystalline polyester is produced by polycondensing an alcohol component containing 70 mol % or more of an aliphatic diol having 2 to 8 carbon atoms with a carboxylic acid component containing 50 mol % or more of terephthalic acid. The toner is excellent in low-temperature fusing ability and pressure storage stability.

Toners for electrophotography

The present invention relates to a toner for electrophotography which exhibits an excellent heat-resistant storage property and a wide fusing temperature range, and a process for producing the toner for electrophotography. There are provided a process for producing a toner for electrophotography which includes (A) a step of emulsifying a resin binder containing a polyester having a constitutional unit derived from a trivalent or higher-valent carboxylic acid in an aqueous medium; (B) a step of aggregating emulsified particles contained in an emulsion obtained in the step (A); and (C) a step of coalescing aggregated particles obtained in the step (B), said process further including the following steps which are to be conducted after the step (A): (a) a step of adding a compound having at least one functional group selected from the group consisting of an oxazoline group and a glycidyl group; and (b) a step of forming a chemical bond between the compound having the at least one functional group and the resin binder containing the polyester, as well as a toner for electrophotography obtained by the process.

The present invention relates to a resin emulsion which has a good emulsification performance even when produced by using a crosslinked polyester resin as a binder resin, and also is capable of producing a toner having an excellent storage property therefrom; and a process for producing the resin emulsion. The process for producing a resin emulsion according to the present invention, includes the steps of: (a) mixing a resin containing a polyester having at least one constitutional unit selected from the group consisting of a constitutional unit derived from a trivalent or higher-valent alcohol component and a constitutional unit derived from a trivalent or higher-valent carboxylic acid component, an anionic surfactant, a nonionic surfactant and an aqueous medium with each other at a temperature not lower than a softening temperature (Ts) of the resin as measured by a flow tester method, the nonionic surfactant and the aqueous medium being used in amounts of from 0.1 to 1.0 part by weight and from 10 to 50 parts by weight, respectively, on the basis of 100 parts by weight of the resin; and (b) neutralizing a mixture obtained in the step (a) with a basic compound in an aqueous medium at a temperature not higher than a softening point (T) of the resin as measured by a flow tester method.

Method for production of resin emulsion

The present invention relates to a polyester having an excellent hydrolysis resistance even when used in a process for producing a toner for electrophotography which includes a step of forming a raw material into particles in an aqueous medium, and a toner for electrophotography which contains the polyester and is excellent in storage stability and fixing property. There are provided a polyester for a toner for electrophotography which is used in a process for producing a toner including a step of forming a raw material component into particles in an aqueous medium or a solution, and produced by polycondensing an alcohol component with a carboxylic acid component containing at least one compound selected from the group consisting of an alkyl succinic acid and an alkenyl succinic acid, as well as a toner for electrophotography which contains the polyester.

Polyesters for toner for electrophotography

Magnetic toner involves magnetic powderhaving the particle shape of an octahedronthat is a convex polyhedron surrounded by eight triangles as a basis, each of the vertexes and edges of the octahedron being in a curved surface shape, and having a portionthat can be taken as a straight line on the outer periphery of its projected image. Therefore, the magnetic toner is superior in both two contradictory properties, that is the property of making it easy for a charging amount to quickly rise as well as improving the charging amount and the property of making it difficult for charge-up to occur, thereby making it possible to form a good image under a wide environment. In an image forming method, an electrostatic latent image is developed into a toner image by a magnetic one-component jumping developing method using the magnetic toner.

Growing community of inventors

Wakayama, Japan

Hiroshi Mizuhata