Ricoh Company, Ltd.

Hiroshi Yaguchi

Satoru Miyamoto

Hisashi Sakai

Nobutaka Kinoshita

Masami Tomita

Yasuo Asahina

Tomomi Suzuki

Hideo Aihara

Takanori Motosugi

Keiichi Maruta

Takashi Ueda

Kenji Uematu

Yasuaki Iwamoto

Hiroyuki Fushimi

Hiroshi Sakamoto

Kanjiro Kawasaki

Kanijiro Kawasaki

A color toner comprises a binder resin, a coloring agent, a release agent and a charge controlling agent, wherein the release agent dispersed in the binder resin has an average particle diameter of from about 0.1 to about 2 &mgr;m and wherein a fixed color toner image, which is developed and fixed using the toner, has a Haze factor less than about 20% when the image has an image density of 1.5. The color toner produces images having good image qualities such as good color reproducibility.

Color toner and manufacturing method thereof and image forming method using the color toner

A color toner comprises a binder resin, a coloring agent, a release agent and a charge controlling agent, wherein the release agent dispersed in the binder resin has an average particle diameter of from about 0.1 to about 2 .mu.m and wherein a fixed color toner image, which is developed and fixed using the toner, has a Haze factor less than about 20% when the image has an image density of 1.5. The color toner produces images having good image qualities such as good color reproducibility.

Color toner and manufacturing method thereof and image forming method

An apparatus for pulverizing solid particles including an impact-type pulverizing device, a mechanical-type pulverizing device and a piping system connected to the pulverizing devices such that the solid particles may be selectively pulverized in the impact-type pulverizing device and in the mechanical-type pulverizing device successively in this or reverse order.

Pulverizing apparatus

A yellow toner for full-color electrophotography is made of yellow toner particles, each toner particle containing a binder resin and C.I. Pigment Yellow 62 and/or C.I. Pigment Yellow 168 as a yellow coloring agent. The above-mentioned yellow toner is used in combination with a carrier to prepare a two-component yellow developer.

Yellow toner for color electrophotography

A color toner includes a binder resin composition comprising a binder resin A with a softening point in the range of 85.degree. to 110.degree. C., and a binder resin B with a softening point in the range of 115.degree. to 135.degree. C., with the binder resin A and the binder resin B being compatible with each other; a coloring agent; and a wax with a melting point in the range of 65.degree. to 90.degree. C., which is not compatible with the binder resin composition and dispersed in the binder resin composition.

Color toner comprising two binder resins of differing softening point

A thermosensitive recording material comprising a support, an intermediate layer including a foamed portion with minute voids on the support, and a thermosensitive coloring layer formed on the intermediate layer is disclosed, which is particularly improved in such a manner that the voidage of the upper portion of the intermediate layer close to the thermosensitive coloring layer is smaller than the voidage of the lower portion of the intermediate layer close to the support, or the voidage of the intermediate layer is increased from the upper portion thereof towards the lower portion thereof.

Thermosensitive recording material

A thermosensitive recording material which comprises a support, an intermediate layer including a foamed portion with minute voids, having a smoothness of 2,000 seconds or more in terms of Bekk's smoothness, and a thermosensitive coloring layer, successively formed on the support, and which layers show the compression strain of 20% or more when a pressure of 0.55 kg/cm.sup.2 is applied in accordance with the Japanese Industrial Standards (JIS) P-8118. This thermosensitive recording material shows the compression strain of 5% or more as a whole when a pressure of 0.55 kg/cm.sup.2 is applied in accordance with the JIS P-8118.

A thermosensitive recording material is disclosed, which comprises (a) a support material; (b) a first thermosensitive coloring layer which comprises a first colorless or light-colored leuco dye having formula (I), ##STR1## and a first color developer having formula (II) capable of inducing color formation in said first leuco dye upon application of heat thereto; ##STR2## (c) a second thermosensitive coloring layer which comprises at least a second leuco dye having formula (III), ##STR3## the first and second thermosensitive coloring layers being formed on the support.

A thermosensitive recording material is disclosed, which comprises a support, an intermediate layer comprising an expanded plastic filler, formed on the support, and a thermosensitive coloring layer formed on the intermediate layer, in which an electroconductive agent is contained in an effective amount in at least one of the intermediate layer or the thermosensitive coloring layer.

A thermosensitive recording material comprising a support material and a thermosensitive coloring layer formed on said support material, said thermosensitive coloring layer comprising a colorless or light-colored leuco dye and a color developer capable of inducing color formation in said leuco dye upon application of heat thereto, the improvement wherein said leuco dye is a compound having general formula (I), ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each represent hydrogen or an alkyl group having a substituent, R.sup.5 and R.sup.6 each represent hydrogen or a phenyl group which may have a substituent, and R.sup.7 represents an alkyl group which may have a substituent or a phenyl group which may have a substituent, and said color developer is a compound having general formula (II), ##STR2## wherein X.sup.1, X.sup.2, X.sup.3 and X.sup.4 each represent hydrogen or an alkyl group having 1 to 4 carbon atoms.

A thermosensitive recording material is disclosed which comprises (a) a support material, (b) a plurality of undercoat layers successively overlaid on the support material, and (c) a thermosensitive recording layer formed on the undercoat layers.

Growing community of inventors

Numazu, Japan

Hiroshi Yaguchi