Brother Kogyo Kabushiki-Kaisha

Jun Ikami

Masateru Kawamura

Tomoaki Hattori

Kumiko Suzuki

Yasuhiro Hattori

Kouji Inaishi

Takanori Uno

Takayuki Higuchi

Emi Shimizu

Yasutomo Imai

An image forming apparatus has a photosensitive member configured to transport a developer containing a compound that causes cis-trans isomerization reaction by light absorption to induce phase transition; a first exposure device configured to emit ultraviolet light having a wavelength of 300 nm-400 nm to a developer image; and a pressing member configured to press a recording sheet holding a developer image exposed by the first exposure device thereon. It is possible to achieve conservation of energy during image formation.

Image forming apparatus

There is provided a toner, including toner mother particles which contain a binder resin, a colorant, and a wax, wherein a difference between a density of the wax in a solid state and a density of the wax in a liquid state is not less than 0.11 g/cm; the density of the wax in the liquid state is not more than 0.835 g/cm; and a heat quantity of the wax per unit mass which is obtained from an endothermic peak area at a low temperature side measured by a differential scanning calorimetry is not less than 190 mJ/mg.

Toner and method for producing the same

There is provided a toner block, which is formed by preparing a toner suspension in which toner particles are dispersed in water so that a water amount is 32.5 to 37% by mass; absorbing water contained in the toner suspension by a water absorptive material which absorbs 0.2 ml of water within 3 minutes to prepare an aggregate of the toner particles containing water of not more than 32.3% by mass; and drying the aggregate, and which has a maximum compressive stress of 80000 to 550000 N/mupon collapse.

Toner block

There is provided a method for producing a toner block. The method includes: preparing a toner suspension in which toner particles are dispersed in water so that the toner suspension is a dilatant fluid; preparing an aggregate of the toner particles in a form of cake by absorbing water contained in the toner suspension by a water absorptive material; and drying the aggregate.

Method for producing toner block

Provided is a method for producing a toner having excellent particle size distribution and storage stability. The method set forth in the present specification is a method for producing a toner by aggregating and fusing base microparticles whose main component is a binder resin including anionic groups, wherein an aggregate is produced by aggregating the base microparticles in a base microparticle suspension, in a presence of a non-ionic surfactant such that a surface tension of an aqueous solution thereof is not lower than 45 mN/m at any concentration at or above a critical micelle concentration, and the toner is produced through fusion of the aggregate. According to this method, drops in a glass transition temperature of the toner can be curbed, and the toner having excellent storage stability and good particle size distribution can be obtained.

Method for producing toner

A developing apparatus is described. The developing apparatus includes a transport member including a plurality of electrodes forming a traveling wave electric field by successively applied voltages and a casing storing a toner transported by the transport member, wherein the activity of the toner based on the following measuring method shown in (1) to (3) is not more than 2.0&#xd7;10mol/g: (1) dipping the toner in an aqueous solution containing an excess equivalent of benzethonium chloride with respect to electrostatically active polar groups present on the surface of the toner to electrostatically react the polar groups and the benzethonium chloride with each other; (2) adding sodium lauryl sulfate dropwise to the aqueous solution to react the same with the residual benzethonium chloride, thereby measuring the quantity of the sodium lauryl sulfate reacting with the residual benzethonium chloride; and (3) calculating the activity on the surface of the toner from the quantity of the reacting sodium lauryl sulfate.

Developing apparatus

Provided is a method for producing a toner including the steps of: preparing a resin liquid by mixing at least a binder resin made of polyester resin and a colorant with an ester organic solvent represented by the following general formula (1); dispersing the resin liquid in an aqueous medium to form an emulsion; and removing the ester organic solvent from the emulsion to produce a toner, in which the ester organic solvent before the preparation of the resin liquid contains water in an amount of not less than 1% by weight and up to the saturation solubility at 25&#xb0; C. to the ester organic solvent: (in which R1 is a hydrogen atom or a methyl group, and R2 is an alkyl group having 1 to 4 carbon atoms).

A method for producing a positively chargeable toner is described. The method for producing a positively chargeable toner may include the steps of: mixing and emulsifying a charge-controlling resin having a positive polar group, an organic solvent and an aqueous medium to form an emulsion, and then removing the organic solvent from the emulsion, to thereby form a suspension of the charge-controlling resin having a positive polar group in the range of 5.0&#xd7;10to 6.0&#xd7;10mol/g; mixing the suspension of the charge-controlling agent with a suspension of toner base particles containing a binder resin and a colorant, to thereby form a mixture; and heating the mixture containing the suspension of the toner base particles and the suspension of the charge-controlling resin, to thereby fix the charge-controlling resin on the surfaces of the toner base particles.

Method for producing positively chargeable toner

In a toner production method, a volatile solvent gas is jetted into a dispersion of aggregated resin particles where at least resin particles dispersed in a continuous phase are aggregated. A form of the aggregated resin particles is controlled by jetting the volatile solvent gas into the dispersion of aggregated resin particles. The volatile solvent is removed from the form-controlled aggregated resin particles.

Toner production method, toner and toner production apparatus

Methods are described for rendering toner particles that are capable of being sufficiently and uniformly charged. The particles may be positively chargeable, non-magnetic, single component toner particles. At least one production method includes emulsifying a charge-controlling agent formed of a synthetic resin in an aqueous medium, the charge-controlling agent having been dissolved in or swollen with an organic solvent; removing the organic solvent; mixing with a suspension of toner base particles containing a binder and a colorant; and heating to fix the charge-controlling agent on the surfaces of the toner base particles. According to at least one method, a positively chargeable non-magnetic single component toner can be produced such that the amount of the charge-controlling agent deposited on the surfaces of the toner base particles falls within a range of 0.2 to 3.0 wt. %, with respect to the total weight of the toner.

Method for producing toner and positively chargeable non-magnetic single component toner

A method for manufacturing toner includes combining a polymer resin and an organic solvent to obtain an oil-based solvent; combining a dispersion stabilizer with water to obtain a water-based solvent; adding an amphiphilic solvent to the water-based solvent; emulsifying the oil-based solvent in the water-based solvent to form emulsion particles; and removing the organic solvent from the emulsion particles.

Manufacturing method for a toner

An electrostatic developing toner which can effectively suppress image fogging*1 by setting a ratio (d/D) of the average particle diameter D of the toner and the average particle diameter d of iron oxide particles contained in the toner as a colorant to within a predetermined range, and by setting the value of a ratio (&#x3c3;r/&#x3c3;s) between the residual magnetization &#x3c3;r and saturation magnetization &#x3c3;s of the iron oxide particles to a predetermined value or less, is provided. The value of the ratio (d/D) of the average particle diameter D of the toner and the average particle diameter d of iron oxide particles contained in the toner as a colorant is set to within the range of 0.01-0.03, and the value of the ratio (&#x3c3;r/&#x3c3;s) between the residual magnetization &#x3c3;r and saturation magnetization &#x3c3;s of the iron oxide particles is set to 0.3 or less.

Electrostatic developing toner

An image-forming apparatus forms an image by applying a control electric field having a polarity corresponding to recording information, to a recording medium having microcapsules including chargeable particles dispersed in a dispersion medium. The image-forming apparatus includes an alternating electric field-applying unit for applying an alternating electric field to the microcapsules. The alternating electric field is applied to the microcapsules of the recording medium before the image formed on the recording medium is rewritten. Accordingly, the chargeable particles are separated from the wall surfaces of the microcapsules and from the other chargeable particles, making it possible for the chargeable particles to perform free electrophoresis. The recording medium is initialized to improve the response performance with respect to the control electric field for forming a new image. The recording density is increased, and the blur is reduced.

Image-forming method and image-forming apparatus on recording medium including microcapsules

The display device, which is devoid of display defects and capable of being drived with low power, comprises a large number of microcapsules 10 in which disperse systems of charged particles 2 in a liquid dispersion medium 4 are encapsulated, and a pair of transparent electrodes 14 faced to each other disposed such that these microcapsules 10 is sandwiched therebetween. The diameters of the charged particles 2 are about 1/1000 to about 1/5 of the particle diameters of the microcapsules 10, and the charged particles 2 are dispersed such that the dispersion degree of the particle diamter distribution, expressed as volume-average particle diameter/number-average particle diameter, ranges from 1 to about 2, where the volume-average particle diameter indicates an average particle diameter derived from a volume-based particle diameter distribution and the number-average particle diameter indicates an average particle diameter derived from a number-based particle diameter distribution.

Display device

An electrostatic latent image developer is produced by adding 1 part by weight or more of an agent improving transfer efficiency, the agent having an average particle size of 0.1 to 3 .mu.m, together with 0.3 to 5 parts by weight of a hydrophobic silica fine powder of a BET specific surface area of 50 to 300 m.sub.2 /g to 100 parts by weight of a toner. The electrostatic latent image developer of the invention improves the transfer efficiency from a photosensitive material onto a recording medium while the flowability of the toner can be retained, whereby any cleaning mechanism in a developer system can be omitted.

Growing community of inventors

Nagoya, Japan

Jun Ikami