Patents

PATENT NUMBER 4,166,644
Pressure-sensitive record material containing urea-formaldehyde resin pigment

Abstract

Improved print speed and image intensity are obtained in a pressure-sensitive record sheet material by incorporating a cross-linked urea-formaldehyde agglomerated resin pigment in the coated surface of the acid-reacting sheet. A typical formulation of the coating comprises kaolin clay, a zinc-modified phenol-formaldehyde resin, said urea-formaldehyde resin pigment and a suitable binder. When contacted under pressure with a surface containing microscopic rupturable capsules of a colorless chromogeneous material, a colored mark is formed by transfer of the colorless chromogeneous material to the acidic pigment coating.

 

Current U.S. Class:	503/212; 428/325; 428/326; 428/327; 428/531; 428/535; 428/914; 503/214; 503/217; 503/225
Intern'l Class:	B41L 001/36
Field of Search:	282/27.5 428/323,325,452,531,914,307,326,327,535

Chemicals Referenced

"A pressure-sensitive record sheet material comprising a first substrate having a coating of pressure rupturable capsules containing an oily solution of a colorless chromogenic dye precursor and in contiguous relationship therewith a second substrate having a coating comprising kaolin clay, an oil-soluble zinc-modified phenol-formaldehyde resin, about 1 to 25% by weight of a substantially water-insoluble, cross-linked urea-formaldehyde agglomerated resin pigment having a mean agglomerate size of from about 2 to about 10 microns and a latex or starch binder therefor." Chemicals: "binder is a styrene-butadiene latex; Crystal Violet Lactone (CVL) or Benzoyl Leuco Methylene Blue;Halogen-substituted aromatic hydrocarbons, alkylated aromatic hydrocarbons and dialkylphthalates; white urea-formaldehyde resin pigments (Cab-O-Lite 100);phenol-formaldehyde resin (Durez Resin 28875); A pressure-sensitive record sheet material which comprises a substrate coated with a formulation comprising kaolin clay, an oil-soluble metal salt of a phenol-formaldehyde resin, about 1 to 25% by weight of a substantially wateer-insoluble, cross-linked urea-formaldehyde agglomerated resin pigment having a mean agglomerate size of from about 2 to about 10 microns, and a latex or starch binder; phenol-formaldehyde resin salt is a zinc-modified phenol-formaldehyde resin; urea-formaldehyde resin pigment has a mean agglomerate size of from about 7 to about 9 microns; wherein the BET specific surface area of said urea-formaldehyde resin pigment is about 40 to about 75 square meters per gram; molar ratio of urea to formaldehyde in said urea-formaldehyde resin pigment is from about 1:1.3 to about 1:1.8; These urea-formaldehyde pigments are prepared by reacting formaldehyde with urea in a molar proportion of urea to formaldehyde ranging from about 1:1.3 to about 1:1.8 in an aqueous solution." "oil-soluble metal salt of a phenol-formaldehyde novolak resin, for example, as described in U.S. Pat. No. 3,732,120 of Brockett et al and U.S. Pat. No. 3,737,410 of Mueller." "Such novolak resins have been used in the art in making acid-reactant record material sheets capable of developing color in oil solutions of base-reacting colorless, chromogenic dye-precursor materials.""metal resinate salts can be prepared by the reaction of an oil-soluble phenol-aldehyde resin, preferably a para-substituted-phenol-formaldehyde novolak resin, with the desired metal hydroxide or oxide."