Thermosensitive recording material, and synthesis method of oligomer compositon for the recording material

Abstract

a thermosensitive recording material comprising a thermosensitive layer provided on a substrate, and the thermosensitive layer comprises as main ingredients a leuco dye and a developer to make colored state of said leuco dye when heated, wherein the developer is an oligomer composition obtained from the reaction of a polyvalent isocyanate compound represented by following Formula (I) with an aromatic amine represented by following Formula (II); X(NCO)a   Formula (I) where X represents a try- or more-valent group, a represents an integer numeral of 3 or more, b and c represent respectively integer numerals in the range of 0 to 5 and they satisfy a relation of b+c=1 to 5, Z represents hydrogen atom, alkyl group, allyl group or aryl group, and the aryl group may include condensed ling structure thereof, and d represents an integer numeral in the range of 0 to 4. This developer shows excellent reliabilities of both image and background area, and also shows an excellent color-developing characteristics (color developing sensitivity and image density).

1 - 7 . (canceled).  
     
     
         8 . A synthesis method of an oligomer composition which is obtained from a reaction of a polyvalent isocyanate compound with an aromatic amine, wherein the reaction is conducted in ethyl acetate, and the polyvalent isocyanate compound is one represented by following Formula (I), and the aromatic amine is one represented by above described Formula (II);  
       X(NCO)a   Formula (I)                    
       in which X represents a tri- or more-valent group, a represents an integer numeral of 3 or more, b and c represent respectively integer numerals in the range of 0 to 5 and they satisfy a relation of b+c=1 to 5, Z represents hydrogen atom, alkyl group, allyl group or aryl group, and the aryl group may include condensed ling structure thereof, and d represents an integer numeral in the range of 0 to 4.  
     
     
         9 . The synthesis method of the oligomer composition according to  claim 8 , wherein the X in the Formula (I) is a tri-valent structure represented by above described Formula (III) or Formula (IV).  
     
     
         10 . The synthesis method of the oligomer composition according to  claim 8 , wherein the aromatic amine represented by the Formula (II) is an amino salicylic acid derivative represented by above described Formula (V).