Method for preparing biodegradable fabric softening compositions

A method for preparing aqueous biodegradable shelf-stable fabric softening compositions comprising the steps of:

• (a) combining a C.sub.1 -C.sub.4 monohydric alcohol with a biodegradable quaternary ammonium softening compound of the formula:
• ##STR19## wherein each R is a C.sub.1 -C.sub.6 alkyl or hydroxyalkyl group, or mixtures thereof;
• each R' is a C.sub.13 -C.sub.19 hydrocarbyl group, or mixtures thereof;
• R" is a C.sub.1 -C.sub.4 hydrocarbyl group;
• and X.sup.- is a softener-compatible anion;
• to form a mixture wherein the amount of the C.sub.1 -C.sub.4 monohydric alcohol comprises from about 5% to about 50% by weight of the biodegradable quaternary ammonium softening compound;
• (b) heating said mixture to a temperature of from about 60.degree. C. to about 90.degree. C. to form a fluidized melt;
• (c) diluting said melt with water, heated to a temperature of from about 50.degree. C. to about 85.degree. C., to a concentration of from about 1% to about 25% by weight of the biodegradable quaternary ammonium softening compound to form a dilute mixture;
• (d) mixing said dilute mixture with a high shear mixer to form a homogeneous mixture with the softener compound having a particle size of from about 0.1 to about 0.5 microns;
• and
• (e) adjusting the pH of said homogenous mixture to from about 2.0 to about 5.0 by adding a sufficient amount of a Bronsted acid to the homogeneous mixture to thereby form said fabric softening compositions wherein said compositions are maintained substantially free of free amines.