Patents

PATENT NUMBER 4,873,219 
Desensitizable self-contained record material useful for security documents and the like

Abstract

An improved self-contained record material having tamper resistance through an indicator quality is disclosed. The self-contained record material of the invention is suitable for forming a visible mark with a focused means of pressure application such as a stylus, needle, or pen and which mark can then later be in part fixed by unfocussed light. The self-contained record material comprises a substrate on which is coated two sets of microcapsules only one of which is made photosensitive to change in viscosity upon exposure to actinic radiation, and the first of which are conventional microcapsules. The color formers in each of the sets of microcapsules are selected to express a different observed color. Original markings, for example, could be black (combination of the orange and blue color formers). After exposure to actinic radiation desensitizing the blue color former containing capsules, subsequent markings are orange indicating the aspect of the subsequence in time.

Chemicals Referenced

"ethyleneglycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane triacrylate (TMPTA), trimethylol propane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate; 3-oximino-2-butanone methacrylate poly 4'-alkyl acylophenones; benzoin alkyl ethers; alkoxy phenyl ketones; O-acylated oximinoketones; polycyclic quinones; benzophenones, substituted benzophenones, xanthones, thioxanthones; chlorosulfonyl and chloromethyl polynuclear aromatic compounds, chlorosulfonyl; chloromethyl heterocyclic compounds, chlorosulfonyl; chloromethyl benzophenones; fluorenones; haloalkanes; 2,2'-dimethoxy-2-phenylacetophenone; isopropylxanthone; ethyl para-dimethylaminobenzoate; Michler's ketone; benzoin methyl ether; urea-formaldehyde resin and/or melamine formaldehyde resin (U.S. Pat. Nos. 4,001,140; 4,081,376, 4,089,802; 4,100,103; 4,105,823; 4,444,699 or 4,552,811); triarylmethane compounds; bisphenylmethane compounds; xanthene compounds; fluorans; thiazine compounds; spiropyran compounds; phthalide; leucauramine; fluoran; color formers include Crystal Violet Lactone (3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide, U.S. Pat. No. Re. 23,024) )3,3-bis(4-diethylaminophenyl)-6-dimethylaminophthalide,; phenyl-, indol-, pyrrol-, and carbazol-substituted phthalides (for example, in U.S. Patent Nos. 3,491,111; 3,491,112; 3,491,116; 3,509,174); nitro-, amino-, amido-, sulfonamido-, aminobenzylidene-, halo-, anilino-substituted fluorans (for example, in U.S. Pat. Nos. 3,624,107; 3,627,787; 3,641,011; 3,642,828; 3,681,390); spirodipyrans (U.S. Pat. No. 3,971,808); and pyridine and pyrazine compounds (for example, in U.S. Pat. Nos. 3,775,424 and 3,853,869); 3-diethylamino-6-methyl-7-anilino-flouran (U.S. Pat. No, 3,681,390); 2-anilino-3-methyl-6-dibutylamino-fluoran (U.S. Pat. 4,510,513) also known as 3-dibutylamino-6-methyl-7-anilino-fluoran; 3-dibutylamino-7-(2-chloroanilino)fluoran; 3-(N-ethyl-N-tetrahydrofurfurylamino)-6-methyl-7-3,5',6-tris(dimethylamino ) spiro[9H-fluorene-9,1'(3'H)-isobenzofuran]-3'-one; 7-(1-ethyl-2-methylindol-3-yl)-7-(4-diethylamino-2-ethoxyphenyl)-5,7-dihyd rofuro[3,4-b]pyridin-5-one (U.S. Pat. No. 4,246,318); 3-diethylamino-7-(2-chloroanilino)fluoran (U.S. Pat. No. 3,920,510); 3-(N-methylcyclohexylamino)-6-methyl-7-anilinofluoran (U.S. Pat. No. 3,959,571); 7-(1-octyl-2-methylindol-3-yl)-7-(4-diethylamino-2-ethoxyphenyl)-5, 7-dihyd rofuro[3,4-b]pyridin-5-one; 3-diethylamino-7,8-benzofluoran; 3,3-bis(1-ethyl-2-methylindol-3-yl)phthalide; 3-diethylamino-7-dibenzylamino-2,2'-spiro-di- [2H-1-benzoaromatic carbozylic acids; phenolic developers (U.S. Pat. Nos. 3,244,550 and 4,573,063); acidic polymeric material such as phenol-formaldehyde polymers, etc. (U.S. Pat. Nos. 3,455,721 and 3,672,935); and metal-modified phenolic resins (U.S. Pat. Nos. 3,732,120; 3,737,410; 4,165,102; 4,165,103;4,166,64;4,188,456); ethyldiphenylmethane (U.S. Pat. No. 3,996,405); benzyxylenes (U.S. Pat. No. 4,130,299); alkylbiphenyls; propylbiphenyl (U.S. Pat. Nos. 3,627,581 and butylbiphenyl (U.S. Pat No. 4,287,074); dialkylphthalates; dibutyl phthalate dioctylphthalate, dinonyl phthalate and ditridecylphthalate; 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (U.S. Pat. No. 4,027,065); .sup.C 10-.sup.C 14 alkyl benzenes such as dodecyl benzene; alkyl or aralkyl benzoates such as benzyl benzoate; alkylated naphthalenes such as dipropylnaphthalene (U.S. Pat. No. 3,806,463); partially hydrogenated terphenyls; high-boiling straight or branched chain hydrocarbons; Styrenebutadiene, Dow 620 Latex." "Internal Phase (IP) 25.0 g Sure Sol 290, sec-butylbiphenyl solvent; 25.0 g Norpar 13, n-paraffin .sup.C 13 solvent 2.5 g PSD-O (Shin Nisso Kako Co., Ltd.) (orange dye) 3'-chloro-6'-(N-cyclohexylamino flouran) Resin Grind (C) 90.0 g #32420 Resin (Durex), phenolic resin 10.0 g Tamol 731 (Rohm and Haas) (25%), surfactant 150.0 g Water; 3.00 g Tetraethyl CVL, (3,3-bis(4-diethylaminophenyl)-6-dimethylaminophthalide) 0.75 g 2-Chlorothioxanthone, (photoinitiator)." Preparation of Second Set of Microcapsules (E) These are prepared like (A), except the IP consists of: 25.0 g Sure Sol 290; 25.0 g Norpar 13; 2.5 g I6B (Ciba Geigy), red dye, 3,3-bis(1-octyl-1-methyl indol-3yl) phthalide."