Mitsubishi Paper Mills Limited

Mitsui Toatsu Chemicals, Incorporated

501 Mitsubishi Paper Mills, Ltd.

Fumio Okumura

Masahiro Higuchi

Sadao Morishita

Masahiro Miyauchi

Hirokazu Tsukahara

Naomasa Koike

Syun Kamei

Akihiro Yamaguchi

Yoshimitsu Tanabe

Masakatsu Nakatsuka

Atsuo Otsuji

Kiyoharu Hasegawa

Atsuo Goto

Haruhiko Ikeda

Kazuyoshi Kikkawa

Takao Kosaka

Akinori Okada

Akira Kawai

Yuki Kobayashi

Shun Kamei

Kazuhiko Ito

A heat-sensitive recording material comprising a color forming, electron donating compound and a salicylic acid derivative represented by the formula (1): ##STR1## wherein X.sub.1 and X.sub.2 are a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group or a halogen atom, Y.sub.1 and Y.sub.2 are an oxygen atom or a sulfur atom, R.sub.1 is a hydrogen atom, an alkyl group, an aralkyl group or an aryl group , and R.sub.2 is an alkyl group, an alkenyl group, an aralkyl group or an aryl group, and/or a metal salt of the salicylic acid derivative as an electron accepting compound, is disclosed.

Salicylic acid derivatives, the process for preparing the same and the

A heat-sensitive recording material comprising a support and a heat-sensitive recording layer provided on the support, said heat-sensitive recording layer comprising an electron-donating, colorless or pale-colored dye precursor, an electron-accepting developer which reacts with the dye precursor to form images upon heating, a binder, and a specific aromatic compound. The heat-sensitive recording material has an excellent heat responsiveness, and hence recorded images having a sufficient optical density can be printed even with low energy.

Heat-sensitive recording material

A heat-sensitive recording material comprising a dye precursor which is colorless or light-colored in the usual state and a color developing agent capable of reacting with said dye precursor upon heating to develop a color which is a combination of compounds of the following chemical formulas (I) and (II). Said material may comprise further the compounds of the following formula (III): ##STR1##

A heat-sensitive recording material is disclosed. The material comprises a support and a heat-sensitive recording layer, between which is provided an undercoat layer which comprises a first layer comprising urea-formaldehyde resin and a second layer comprising a pigment provided on the first layer. The first layer may additionally contain a pigment.

Disclosed is a colorless dye for use in recording materials comprising a compound represented by the general formula: ##STR1## Said recording materials are of the types which utilize a color developing reaction between an electron-donating colorless dye and an electron-accepting color developer, such as, carbonless pressure-sensitive recording materials, thermosensitive recording materials, etc.

Colorless carbazole dyes for recording materials

A stable emulsion of microcapsules is obtained by polymerizing at least one water-soluble vinyl monomer in an aqueous solution of an oil-soluble vinyl monomer-maleic anhydride-maleic ester multipolymer to prepare a water-soluble resin, dispersing or emulsifying discrete fine particles of a hydrophobic material in an acidic aqueous solution of the water-soluble resin, adding an amino resin precursor separately prepared to the dispersion or emulsion, and heating the mixture.

Process for producing microcapsules

A thermosensitive recording paper consisting of a dye precursor and a color developer capable of coloring said dye precursor on heating, wherein one type of overcoat layer selected from the group consisting of alginates, alumina sol, colloidal silica and a mixture of alumina sol with colloidal silica is provided as the topmost layer thereof to give improved chemical resistance and good printing quality with a reduced deterioration in sensitivity and no residues and sticking.

Chemically resistant thermosensitive recording paper

By using, in production of microcapsules, a partially esterified product of a styrene-maleic anhydride copolymer as an emulsifier, advantages are obtained that coloring of emulsion can be reduced/prevented at the time of emulsification and, when the microcapsules produced are used in a carbonless copying paper, a desensitizer component is not transferred to a lower paper and accordingly color development is not hindered.

Microcapsule and process for their production

A thermosensitive recording material of improved color generation characteristics is obtained by using as the color developer a fused mixture of a conventional color developing bisphenol compound and other phenolic compounds.

Thermosensitive recording material

In the heat-sensitive recording paper produced by coating a support such as paper or the like with a coating solution containing a normally colorless or light-colored dye precursor and a developer capable of making the precursor develop color upon heating, the abrasion of a thermal head can be decreased by adjusting the total amount of sodium and potassium ions in the coating on the heat-sensitive recording paper to 1,051 ppm or less, preferably 500 ppm or less, most preferably 400 ppm or less.

Heat-sensitive recording paper causing reduced thermal head abrasion

A heat-sensitive recording composition with an improved image stability comprises 3-(N-methylcyclohexylamino)-6-methyl-7-anilinofluorane, 4,4'-isopropylidenediphenol capable of color-developing the fluorane through reaction by heating, fatty acid amide as a sensitizer and water-insoluble modified phenol resin having a softening point of 80.degree. to 190.degree. C., where at least 20% by weight of N-monosubstituted fatty acid amide is contained on the basis of total fatty acid amide, and 5 to 50% by weight of the water-insoluble, modified phenol resin is contained on the basis of the 4,4'-isopropylidenediphenol.

Heat-sensitive recording composition with improved image stability

A heat-sensitive recording paper in which a necessary heat-sensitive image-forming layer is provided on a neutral or alkaline paper prepared by practising the sizing process by the use of a combination of anionic sizing agent and cationic fixing agent, a combination of reactive sizing agent and neutral fixing agent or a self-fixable cationic sizing agent is improved in the keeping quality of ground color so that the ground is protected against coloration for a long period of time even at high temperature at high humidity or at high temperature, which enables to use 3-pyrrolidino-6-methyl-7-anilinofluoran or 3-N-methylcyclohexylamino-6-methyl-7-anilinofluoran as a color-forming agent in combination with Bisphenol A as an acidic color-developing agent.

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Kunitachi, Japan

Fumio Okumura