DENTIFRICE WITH ANIONIC POLYELECTROLYTE POLYMER WITH A POLYVALENT METAL CATION

摘要

ABSTRACTA dentifrice toothpaste or gel having a viscosity of about50,000 to 420,000 cps (measured at 10 rpm with #7 spindle on BrookfieldViscometer Model RBF at 22°C), said viscosity being sufficiently high sothat said dentifrice is not liquid and runny and not so high that it isdifficult to extrude from a dentifrice containing a normally water-insolubledentally acceptable polishing agent, up to about 89.5% by weight of waterand requiring added humectant and gelling agents, said dentifrice containingas its essential humectant and gelling agent, a water-absorbent anionicpolyelectrolyte polymer which provides and imparts both gelling and humectantcharacteristics to said dentifrice, said anionic polyelectrolyte polymerconsisting essentially of a polyacrylic acid ionically complexed with0.01 - 5.0 milli-equivalents of cation per gram of polyelectrolyte of apolyvalent metal cation selected from the group consisting of aluminum,zirconium, iron and zinc at a pH between 2.0 and 8.5 which pH is below thepH of reversibility of the ionic complex of said polyvalent cation and saidwater absorbent anionic polyelectrolyte, said ionically complexed poly-electrolyte polymer having a particle size such that at least about 90% ofthe particles are larger than 2 microns, each of said particles having alinkage density at the particle surface greater than the linkage density inthe particle interior, the linkages at the particle surface comprising atleast in part ionic complexing of said anionic polyelectrolyte polymer bysaid polyvalent metal cations, said anionic polyelectrolyte polymer beingprovided in said dentifrice in an amount of about 0.5 to 20% by weight,said dentifrice containing a humectant and gelling agent selected from thegroup consisting of: (a) said anionic polyelectrolyte polymer as the solehumectant and gelling agent; (b) said anionic polyelectrolyte polymer as thesole gelling agent and up to about 20% by weight of an additional humectant;(c) said anionic polyelectrolyte polymer as the sole humectant and up toabout half the amount of said anionic polyelectrolyte polymer of an additionalgelling agent; and (d) said anionic polyelectrolyte polymer with up toabout 20% by weight of an additional humectant and up to about half theamount of said anionic polyelectrolyte polymer of an additional gellingagent; wherein said additional humectant and said additional gelling agentprovide rheological modifications in the character of said dentifrice.