| http://www.w3.org/ns/prov#value | - The hydrophilic optical brighteners useful in the present invention are those having the structural formula: ##STR15## wherein R1 is selected from anilino, N-2 -bis-hydroxyethyl and NH-2-hydroxyethyl; R2 is selected from N-2-bis-hydroxyethyl, N-2-hydroxyethyl-N-methylamino, morphilino, chloro and amino; and M is a salt-forming cation such as sodium or potassium.
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