Pressure-sensitive recording sheet with microcapsules having polyurea walls

Claim 2

A PRESSURE-SENSITIVE RECORDING SHEET WHICH COMPRISES A BASE MATERIAL AND (1) A LAYER OF A COLORLESS OR SUBSTANTIALLY COLORLESS COLOR-FORMING SUBSTANCE RENDERED COLORED UPON REACTION WITH A DEVELOPER, ENCAPSULATED IN WALLS OF A POLYUREA OBTAINED BY THE REACTION OF A POLYISOCYANATE OR ISOCYANATECONTAINING POLYISOCYANATE ADDUCT WITH A POLYAMINE OR POLYAMINE ADUCT, AND (2) A LAYER OF DEVELOPER CAPABLE OF GIVING A COLORED SUBSTANCE BY REACTION WITH SAID COLOR-FORMING SUBSTANCE, LAYERS (1) AND (2) BEING ON THE SAME SURFACE OF SAID BASE MATERIAL.

Claim 3

The pressure-sensitive recording sheet of claim 1, wherein said isocyanate-containing polyisocyanate adduct is an adduct formed between a polyisocyanate and a compound containing a hydrophilic group.

Claim 4

The pressure-sensitive recording sheet of claim 2, wherein said compound containing a hydrophilic group is selected from the group consisting of polyamines, polycarboxylic acids, polyols, polythiols, polyhydroxy compounds and epoxy compounds.

Claim 5

The pressure-sensitive recording sheet of claim 1, wherein said polyamine adduct is an adduct formed between a polyamine and an epoxy compound.

Claim 6

The pressure-sensitive recording sheet of claim 1, wherein the polyurea is obtained from an isocyanate containing polyisocyanate adduct which has at least two uncombined isocyanate groups.

Claim 7

The pressure-sensitive recording sheet of claim 1, wherein the polyurea is obtained from a polyamine adduct which has at least two uncombined amine groups.

Claim 8

The pressure-sensitive recording sheet of claim 1, wherein the polyisocyanate is selected from the group consisting of dithioisocyanates, diisocyanates and triisocyanates.

Claim 9

The pressure-sensitive recording sheet of claim 1, wherein the polyisocyanate is a polyisocyanate monomer.

Claim 10

The pressure-sensitive recording sheet of claim 1, wherein the polyisocyanate per se or polyisocyanate used to form the adduct is selected from the group consisting of m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4''-diisocyanate, 3,3''-dimethoxy-4,4''-biphenyl-diisocyanate, 3,3''-dimethyl diphenylmethane-4,4''-diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, 4,4''-diphenylpropane diisocyanate, trimethylene diisocyanata, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, ethylidine diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, xylylene-1,4-diisothiocyanate, ethylidinne diisothiocyanate, hexamethylene dithioisocyanate, 4,4'',4''''-triphenylmethane triisocyanate, toluene-2,4,6-triisocyanate, polymethylene polyphenyl isocyanate, and 4,4''-dimethyldiphenyl methane-2,2'',5, 5''-tetraisocyanate.

Claim 11

The pressure-sensitive recording sheet of claim 1, wherein the polyamine per se or polyamine used to form the adduct is an aromatic amine having at least two free amino groups in the molecule.

Claim 12

The pressure-sensitive recording sheet of claim 1, wherein the polyamine per se or polyamine used to form the adduct is an aliphatic amine having at least two free amino groups in the molecule.

Claim 13

The pressure-sensitive recording sheet of claim 1, wherein the polyurea is obtained from a polyamine per se or the polyamine used to form the adduct is selected from the group consisting of o-phenylene diamine, p-phenylene diamine, diamino naphthalene, 1, 1,3-propylene napthalene or hexymethylene diamine.

Claim 14

The pressure-sensitive recording sheet of claim 1, wherein a polyisocyanate is reacted with the polyamine or the polyamine adduct.

Claim 15

The pressure-sensitive recording sheet of claim 1, wherein a isocyanate-containing polyisocyanate adduct is reacted with the polyamine or polyamine adduct.

Claim 16

The pressure-sensitive recording sheet of claim 1, wherein a polyamine is reacted with the polyisocyanate or the isocyanate-containing polyisocyanate adduct.

Claim 17

The pressure-sensitive recording sheet of claim 1, wherein a polyamine adduct is reacted with the polyisocyanate or isocyanate-containing polyisocyanate adduct.

Claim 18

The pressure-sensitive recording sheet of claim 3, wherein the compound is a polyamine.

Claim 19

The pressure-sensitive recording sheet of claim 3, wherein the compound is a polycarboxylic acid.

Claim 20

The pressure-sensitive recording sheet of claim 3, wherein the compound is a polythiol.

Claim 21

The pressure-sensitive recording sheet of claim 3, wherein the compound is a polyhydroxy compound.

Claim 22

The pressure-sensitive recording sheet of claim 3, wherein the compound is an epoxy compound.

Claim 23

The pressure-sensitive recording sheet of claim 3, wherein the compound is a polyol.

Claim 24

Pressure sensitive microcapsules containing a colorless color forming substance in an oily liquid encapsulated in walls of a polyurea produced by the reaction of a polyisocyanate or isocyanate-containing polyisocyanate adduct with a polyamine or polyamine adduct comprising: a. dissolving the polyisocyanate or isocyanate-containing polyisocyanate adduct in the oily liquid having dissolved therein the color forming substance; b. emulsifying the product of step (a) in a polar liquid; c. adding to the product of step (b) the polyamine or polyamine adduct; and d. subjecting the system of step (c) to polymerization conditions, whereby the oily liquid having dissolved therein the color forming substance is encapsulated in the polyurea product formed.

Claim 25

Pressure sensitive microcapsules containing a colorless color forming substance in an oily liquid encapsulated in walls of a polyurea produced by the reaction of a polyisocyanate or isocyanate-containing polyisocyanate adduct with a polyamine or polyamine adduct comprising: a. dissolving the polyisocyanate or isocyanate-containing polyisocyanate adduct in the oily liquid having dissolved therein the color forming substance; b. emulsifying the product of step (a) in a polar liquid; c. adding to the product of step (b) the polyamine or polyamine adduct; and d. subjecting the system of step (c) to polymerization conditions, whereby the oily liquid having dissolved therein the color forming substance is encapsulated in the polyurea product formed.