Abstract: A process for preparing microcapsules for pressure sensitive manifold paper characterized by emulsifying in a hydrophilic liquid a hydrophobic liquid containing an aromatic isocyanate represented by the formula ##STR1## wherein n is an integer of 1 to 10, an aliphatic isocyanate and an electron donating organic chromogenic material, and forming a polymer at the interface to cover hydrophobic liquid droplets with the polymer.

Abstract: This invention concerns with an improved microcapsule dispersion prepared by adding the following components to a known microcapsule dispersion containing PVA; a pulp having a specific weighted average fiber length, another type of pulp, carboxymethyl cellulose and/or a specified periodic acid type compound, and is characterized by overcoming the drawbacks of known microcapsule dispersions attended by use of PVA.

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 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: 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: 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: 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..