Abstract: A recording material for use in a pressure sensitive copying system has an undercoating layer which is formed on a surface of a base sheet and on which a color former coating layer including microcapsules each encapsulating an oil droplet containing a color former material dissolved or dispersed therein. The undercoating layer comprises finely divided inorganic pigment particles and a binder and is substantially unreactive with the color former material included in the color former layer.

Abstract: The method of making oil-containing microcapsules comprises the steps of (1) preparing an aqueous system comprising an aqueous solution of at least two kinds of hydrophilic colloid materials with opposite electric charges and oil droplets dispersed in said solution (2) causing coacervation in said aqueous system at a temperature above the gelation points of said hydrophilic colloid materials to form a coacervate suspension in which each of said oil droplets is surrounded by a coacervate and (3) cooling said coacervate suspension to a temperature below the gelation points of said hydrophilic colloid materials to form multi-nucleus capsules. During the step of cooling the coacervate suspension, aggregation of particles of oil droplets each having a coacervate therearound is controlled by an agitation flow so as to allow formation of multi-nucleus microcapsules having an average diameter within the range of 3 to 20 microns.

Abstract: The recording material comprises a base sheet and a color former coating layer formed on a surface of the base sheet and the color former coating layer is formed by coating a surface of the base sheet with a coating composition comprising an aqueous dispersion of microcapsules each encapsulating a hydrophobic color former material therein and having a capsule wall of a gelated hydrophilic colloid material. The dispersion further includes(a) a hardener for the hydrophilic colloid material and(b) a water soluble alkali salt of a copolymer of at least one olefinic monocarboxylic acid with at least one monomer copolymerizable with the olefinic monocarboxylic acid.

Abstract: The electrostatic recording material comprises an electroconductive transparent base sheet having a dielectric layer thereon. The base sheet is obtained by moistening a paper prepared from relatively lightly beaten pulp and then subjecting the moistened paper to a calendering treatment with the use of a heated embossing metal roll having a finely engraved surface with sharp reliefs.

Abstract: A process for preparing an acceptor coated sheet used in a pressure sensitive copying system is disclosed. The pressure sensitive copying system utilizes a color forming reaction on a base sheet between the color former in the form of the oily core material encapsulated in microcapsules and the organic acceptor included in an acceptor coating layer formed on said base sheet. The acceptor coating layer includes as a binder a carboxylic latex having an oil swellability smaller than 65% in terms of the swelling with the oily core material. An ester of an organic acid is further included within the microcapsules and/or in the acceptor coating layer.

Abstract: In a heat-sensitive record material comprising a base sheet and a color developing layer formed thereon, a pigment having an oil absorption within the range of 80 to 800 ml/100 g is additionally included in the color developing layer.

Abstract: A matted transparent paper is obtained by moistening a paper prepared from relatively lightly beaten natural pulp and then subjecting the moistened paper to a calendering treatment with the use of a heated embossing metal roll having a finely engraved surface with sharp reliefs.

Abstract: A color developer is obtained by the process which comprises heating a mixture of at least one aromatic carboxylic acid, at least one water-insoluble organic polymer and at least one oxide or carbonate of polyvalent metal to melt at least one of aromatic carboxylic acid and said polymer to form a homogeneous mass. The color developer may be pulverized to form finely divided particles.

Abstract: The surface of a paper material is treated with an aqueous composition comprising a water soluble polymer and a polymer emulsion, said paper material being formed of a fibrous material, at least a part of which is composed of hydrophilic polyolefin fibers. The obtained product has a strong pick resistance and an improved ink receptivity adapted for offset printing.

Abstract: A process for producing an electrostatic recording material which comprises kneading a hydrophobic pigment having a critical surface tension of 50 dynes/cm or less with an aqueous dispersion of a copolymer consisting of (I) 10 to 50% by weight of methacrylic acid, (II) 5 to 50% by weight of a alkenyl aromatic compound and (III) 30 to 85 % by weight of at least one member selected from the group consisting of conjugated diolefins, alkyl acrylates and alkyl methacrylates; having a glass transition temperature (Tg) of 40.degree. C or less; and having an intrinsic viscosity [.eta.] of 0.1 to 1.0 dl/g as measured in tetrahydrofuran at 25.degree.

Abstract: The continuously fed paper sheet is subjected to the successive steps of coating an acceptor composition at its one side, drying, calendering with a calender comprising a metal roll and an elastic roll having a Shore hardness within the range of 65 to 90, further coating a color former composition on the other side and further drying. The continuously fed paper sheet may be subjected to a cylinder ironing treatment between the first drying step and the calendering step.

Abstract: An electrostatic recording material having a good workability and a very good recording characteristic is prepared by coating such a base sheet as paper, plastic film, metal plate, etc.

Abstract: An electrostatic recording material having a good workability and a very good recording characteristic is prepared by coating such a base sheet as paper, plastic film, metal plate, etc. with an aqueous dispersion comprising (A) 100 parts by weight of at least one water-insoluble polymer comprising at least one monomer selected from ethylenic monomers and conjugated diolefinic monomers, and (B) 1-200 parts by weight of at least one water-soluble salt of polymer containing carboxyl groups by means of an air knife coater, roll coater, etc. It is possible to use not more than 6 parts by weight of the heretofore well-known nonionic emulsifier and/or the well-known anionic emulsifier together with said component.

Abstract: A process is described for preparing triarylmethane derivatives of a high purity in an extremely high yield from 3-phenylphthalide derivatives and aniline derivatives or indole derivatives with Friedel-Crafts type catalyst or Friedel-Crafts type catalyst and an oxidizing agent.

Abstract: In a copy sheet for use in a pressure sensitive manifold sheet comprising support having coated thereon a layer of electron accepting reactant material, an improvement which is characterized in that said electron accepting reactant material is a calcined activated clay which is pulverized in water to particle size reduced by at least 10% based on the mean particle size thereof before the pulverization and has a mean particle size of 1 to 10 .mu..

Abstract: The electrostatic recording material comprises an electroconductive transparentized base sheet having a dielectric layer thereon. The transparentized base sheet is obtained by subjecting to a transparentizing treatment with moisture, heat and pressure a fibrous matrix sheet of a mixture of natural pulp with synthetic pulp formed of a blended polymer system consisting essentially of polyvinyl alcohol-acrylonitrile copolymer and acrylonitrile-styrene copolymer.

Abstract: In a process for producing microcapsules of complex hydrophilic colloid material enclosing fine particles of a hydrophobic substance, the improvement characterized in that:An acid-treated gelatin and at least one of carboxy-modified cellulose derivatives are used as the hydrophilic colloid materials, the amount of the cellulose derivative being 1/7 to 1/40 the amount of the gelatin by weight, the cellulose derivative having an average polymerization degree of 50 to 1,000 and a carboxyl substitution degree of 0.4 to 1.5, andThe coacervation of the colloid material solution is effected at a pH of 4.8 to 6.0.

Abstract: Chromogenic compounds for use in pressure sensitive recording sheets represented by the formula: ##SPC1##Are disclosed, wherein R.sub.1 and R.sub.2 are independently, hydrogen substituted or unsubstituted lower alkyl, aliphatic acyl, phenyl substituted aliphatic acyl, benzoyl, aralky, phenyl (the benzene nuclei of those substituents may be further substituted by chlorine, bromine, lower alkyl, lower alkoxy or nitro), allyl, allyl substituted by lower alkyl or phenyl, propargyl, or propargyl substituted by lower alkyl or a phenyl; R.sub.3 and R.sub.4 are independently lower alkyl, benzyl and phenyl (the benzene nuclei or those substiutents may be further substituted by chlorine, bromine, lower alkyl or lower alkoxy), either R.sub.1 or R.sub.2 being other than hydrogen when R.sub.3 and R.sub.4 are both ethyl groups.

Abstract: An electrostatic recording material having excellent recording characteristics is obtained by coating an electrically conductive substrate with a coating composition comprising an insulating polymer and pigment particles on which is adsorbed a fatty acid having at least five carbon atoms, ester or salt thereof, or resin acid or salt thereof.

Abstract: An electrostatic recording sheet is produced by coating the opposite surfaces of a paper sheet with an electroconductive coating composition including a cationic polymer electroconductive agent and a cationic sizing agent to form electroconductive layers and further coating one of said electroconductive layers with a dielectric coating composition in the form of an aqueous polymer dispersion to form a recording layer via a penetration resist layer. The penetration resist layer is formed of a gelated material produced by an ionic reaction on contact of said aqueous polymer dispersion with said electroconductive layer.