Abstract In microcapsules of the type used for pressure-sensitive, carbonless copy papers, having walls formed from aliphatic diisocyanate and diamine and containing a solvent mixture with a dye precursor dissolved therein, the solvent mixture containing a component which easily dissolves the dye precursor and the capsule wall material and a component which only poorly dissolves the dye precursor and the capsule wall, the improvement comprising the poorly disolving solvent component is an alkylbenzene having from 8 up to 14 C-atoms in the alkyl moiety; and the easily dissolving solvent component is selected from the group consisting of diisopropyl naphthaline, a hydrogenated terphenyl, an alkylated diphenyl, a diphenyl alkane, a chloroparaffin and a mixture thereof, the ratio of easily to poorly dissolving components ranging from 15:85 to 75:25 vol %, and being adjusted within this range so that a solution of the wall-forming aliphatic diisocyanate is just at the turbidity point in the mixture of easily dissolving and poorly dissolving components.
In microcapsules of the type used for pressure-sensitive, carbonless copy papers, having walls formed from aliphatic diisocyanate and diamine and containing a solvent mixture with a die precursor dissolved therein, the solvent mixture containing a component which easily dissolves the dye precursor and the capsule wall material and a component which only poorly dissolves the dye precursor and the capsule wall, the improvement comprising the poorly dissolving solvent component is an alkylbenzene having from 8 to 14 C-atoms in the alkyl moiety; and the easily dissolving solvent component is a chloroparaffin, the ratio of easily to poorly dissolving components ranging from 15:85 to 75:25 vol %, and being adjusted within this range so that a solution of the wall-forming aliphatic diisocyanate is just at the turbidity point in the mixture of easily dissolving and poorly dissolving components.
Claim 2
Dependent Claim
137 words
In microcapsules of the type used for pressure-sensitive, carbonless copy papers, having walls formed from aliphatic diisocyanate and diamine and containing a solvent mixture with a die precursor dissolved therein, the solvent mixture containing a component which easily dissolves the dye precursor and the capsule wall material and a component which only poorly dissolves the dye precursor and the capsule wall, the improvement comprising the poorly dissolving solvent component is an alkylbenzene having from 8 to 14 C-atoms in the alkyl moiety; and the easily dissolving solvent component is a chloroparaffin, the ratio of easily to poorly dissolving components ranging from 15:85 to 75:25 vol %, and being adjusted within this range so that a solution of the wall-forming aliphatic diisocyanate is just at the turbidity point in the mixture of easily dissolving and poorly dissolving components.
Claim 3
Dependent Claim
25 words
The microcapsules of claim 1 wherein the easily dissolving solvent component is n-C 14 to n-C 17 chloroparaffins with a chlorine content of about 45%.
Claim 4
Dependent Claim
13 words
The microcapsules of claim 2 wherein the poorly dissolving solvent component is dodecylbenzene.
Claim 5
Dependent Claim
14 words
The microcapsules of claim 1 wherein the easily dissolving solvent component is stabilized chloroparaffin.