Cellulose sulfate esters

A water-soluble colloidal sulfate ester of cellulose having a degree of substitution of about 0.3 to about 1.0;

• said sulfate ester having a substantially uniform distribution of sulfate ester groups among the polymer units of the cellulose, and
• said sulfate ester being compatible and non-gelable in an aqueous medium in the presence of NH.sub.4.sup.+, Na.sup.+, K.sup.+, Mg.sup.++, Ca.sup.++, Al.sup.+++, Zn.sup.++, Ni.sup.++, Co.sup.++, Cu.sup.++, Cd.sup.++, Fe.sup.++, Cr.sup.+++, Pb.sup.++, Hg.sup.++, Ag.sup.+, Sn.sup.++, Ba.sup.++, Fe.sup.+++ and Ce.sup.+++ ions when a volume of a one percent by weight aqueous solution of said ester is admixed with an equal volume of a solution of a salt containing one of said ions with said salt having a concentration in the salt solution of either 20 percent by weight or the salt saturation concentration when the saturation concentration is less than 20 percent by weight.

A water soluble colloidal cellulose sulfate ester having a degree of substitution of about 1.0 to about 1.3;

• said sulfate ester having a substantially uniform distribution of sulfate ester groups among the polymer units of the cellulose, and
• said sulfate ester being compatible and non-gelable in an aqueous medium in the presence of NH.sub.4.sup.+, Na.sup.+, K.sup.+, Mg.sup.++, Ca.sup.++, Al.sup.+++, Zn.sup.++, Ni.sup.++, Co.sup.++, Cu.sup.++, Cd.sup.++, Fe.sup.++, Cr.sup.+++, Pb.sup.++, Hg.sup.++, Ag.sup.+, Sn.sup.++, Ba.sup.++, Fe.sup.+++, and Ce.sup.+++ ions when a volume of a one percent by weight aqueous solution of said ester is admixed with an equal volume of a solution of a salt containing one of said ions with said salt having a concentration in the salt solution of either 20 percent by weight or the salt saturation concentration when the saturation concentration is less than 20 percent by weight.

A water-soluble colloidal cellulose sulfate ester having a degree of substitution of about 1.3 to about 2;

• said sulfate ester groups being substantially uniformly distributed among the polymer units of the cellulose, and
• said sulfate ester being compatible and non-gelable in an aqueous medium in the presence of NH.sub.4.sup.+, Na.sup.+, K.sup.+, Mg.sup.++, Ca.sup.++, Al.sup.+++, Zn.sup.++, Ni.sup.++, Co.sup.++, Cu.sup.++, Cd.sup.++, Fe.sup.++, Cr.sup.+++, Pb.sup.++, Ag.sup.+ and Sn.sup.++ ions when a volume of a one percent mixture by weight aqueous solution of said ester is admixed with an equal volume of a solution of a salt containing one of said ions with said salt having a concentration in the salt solution of either 20 percent by weight or the salt saturation concentration when the saturation concentration is less than 20 percent by weight.

A thickened aqueous medium containing water and a water-soluble cellulose sulfate ester;

• said sulfate ester having a degree of substitution of about 1.3 to about 2.0;
• said sulfate having a substantially uniform distribution of sulfate ester groups among the polymer units of the cellulose;
• said sulfate ester being compatible and non-gelable in an aqueous medium in the presence of NH.sub.4.sup.+, Na.sup.+, K.sup.+, Mg.sup.++, Ca.sup.++, Al.sup.+++, Zn.sup.++, Ni.sup.++, Co.sup.++, Cu.sup.++, Cd.sup.++, Fe.sup.++, Cr.sup.+++, Pb.sup.++, Hg.sup.++, Ag.sup.+ and Sn.sup.++ ions when a volume of a one percent by weight aqueous solution of said ester is admixed with an equal volume of a solution of a salt containing one of said ions with said salt having a concentraton in the salt solution of either 20 percent by weight or the salt saturation concentration when the saturation concentraton is less than 20 percent by weight.