Play Composition Including Crosslinkable Binder

Abstract

The present invention is directed toward water based play compositions including a crosslinkable network polymer and a crosslinking system effective to crosslink the polymer. The crosslinking system is a water-soluble salt complex including a primary crosslinking agent, a secondary crosslinking agent, and a tertiary crosslinking agent. The crosslinking system contains a diminished amount of boron compounds while remaining effective in crosslinking network polymers including polyvinyl alcohol (to form moldable dough compositions) and guar gum (to form hydrogels).

1 . A flowable play gel composition comprising:
 water;   a binder; and   a crosslinking system to crosslink the binder, the crosslinking system comprising:
 a primary crosslinking agent comprising a first alkali metal salt, and 
 a secondary crosslinking agent comprising a second alkali metal salt, wherein the crosslinking density generated in the binder by the secondary crosslinking agent is less than the crosslinking density generated in the binder by the primary crosslinking agent, and 
 a tertiary crosslinking agent that is present in an amount of about 0.50% or less by weight of the gel composition; 
   wherein the crosslinking system and the binder cooperate to form a hydrogel including a polymer network expanded throughout its volume by the water.   
     
     
         2 . The flowable play gel composition of  claim 1 , wherein the binder is guar gum. 
     
     
         3 . The flowable play gel of  claim 2 , wherein the tertiary crosslinking agent comprises a borate salt. 
     
     
         4 . The flowable play gel of  claim 3 , wherein the tertiary crosslinking agent is present in an amount of about 0.10% or less by weight of the gel composition. 
     
     
         5 . The flowable play gel of  claim 2 , wherein:
 the primary crosslinking agent is a phosphoric acid salt;   the secondary crosslinking agent is a carbonic acid salt; and   the tertiary crosslinking agent is a boric acid salt.   
     
     
         6 . The flowable play gel composition of  claim 5 , wherein:
 the primary crosslinking agent is disodium hydrogen phosphate;   the secondary crosslinking agent is sodium carbonate; and   the tertiary crosslinking agent is sodium tetraborate.   
     
     
         7 . The flowable play gel composition of  claim 2 , wherein:
 the water is present in a range of about 75% to about 95% by weight of the gel composition;   the guar gum binder is present in a range of about 0.50% to about 3% by weight of the gel composition; and   the crosslinking system is present in a range of about 0.10% to about 2.5 wt % by weight of the gel composition.   
     
     
         8 . The flowable play gel composition of  claim 7 , wherein:
 the primary crosslinking agent is present within the gel composition in an amount of about 0.10 wt % to about 1.5 wt %;   the secondary crosslinking agent is present within the composition in an amount of from about 0.01 wt % to about 0.50 wt %; and   the tertiary crosslinking agent is present within the composition in an amount of from about 0.005 wt% to about 0.50 wt %.   
     
     
         9 . The flowable composition of  claim 2 , wherein:
 the guar gum is carboxylmethyl hydroxypropyl guar;   the cross-linking system comprises:
 disodium hydrogen phosphate, 
 sodium carbonate, and 
 sodium tetraborate; and 
   the water is present within the composition in an amount of from about 75 wt % to about 95 wt %, the guar gum is present within the composition in an amount of from about 0.50 wt % to about 3 wt %, and crosslinking system is present within the composition in an amount of from about 0.1 wt % to about 2.5 wt %.   
     
     
         10 . The flowable play gel composition of  claim 1 , wherein the crosslinking system is present within in a range of from about 0.10% to about 2.5% by weight of the gel composition. 
     
     
         11 . A moldable dough composition comprising:
 water;   a binder; and   a crosslinking system to crosslink the binder, the crosslinking system comprising:
 a primary crosslinking agent comprising a first alkali metal salt, wherein the primary crosslinking agent generates a first crosslink density in the binder, and 
 a secondary crosslinking agent comprising a second alkali metal salt, wherein the secondary crosslinking agent generates a second crosslink density in the binder, and 
 a tertiary crosslinking agent that is present within the composition in an amount of 0.50 wt % or less, 
   wherein the first crosslink density generated by the first crosslinking agent is greater than the second crosslink density generated by the secondary crosslinking agent.   
     
     
         12 . The moldable dough composition of  claim 10 , wherein:
 the binder comprises polyvinyl alcohol; and   the dough composition further comprises a diol compound.   
     
     
         13 . The moldable dough composition of  claim 12 , wherein:
 the water is present in an amount of about 25% to about 75% by weight of the dough composition;   the polyvinyl alcohol is present in an amount of about 4% to about 15% by weight of the dough composition; and   the diol compound is present in an amount of about 2% to about 10% by weight of the dough composition.   
     
     
         14 . The moldable dough composition of  claim 12  further comprising a thickener present in an amount of about 0.30% to about 1.5% by weight of the dough composition. 
     
     
         15 . The moldable dough composition of  claim 11 , wherein:
 the primary crosslinking agent is potassium bicarbonate;   the secondary crosslinking agent is sodium carbonate; and   the tertiary crosslinking agent is sodium tetraborate.   
     
     
         16 . The moldable dough composition of  claim 15 , wherein the crosslinking system is present in an amount of about 0.45% to about 4.0% by weight of the dough composition. 
     
     
         17 . The moldable dough composition of  claim 11 , wherein:
 the primary crosslinking agent is present within the composition in an amount of from about 0.5 wt% to about 3 wt %;   the secondary crosslinking agent is present within the composition in an amount of from about 0.10 wt % to about 0.80 wt %; and   the tertiary crosslinking agent is present within the composition in an amount of from about 0.005 wt% to about 0.50 wt %.   
     
     
         18 . A crosslinking system to crosslink a polymeric binder within a play composition, the crosslinking system comprising:
 a primary crosslinking agent selected from the group consisting of an alkali metal bicarbonate and a salt of a phosphoric acid, wherein the primary crosslinking agent generates a first crosslink density in the binder;   a secondary crosslinking agent comprising an alkali metal carbonate, wherein the secondary crosslinking agent generates a second crosslink density in the binder, and   a tertiary crosslinking agent that generates a third crosslink density in the binder,   wherein the crosslinking system crosslinks the polymeric binder forming the play composition, and wherein the first crosslink density is greater than both the second crosslink density and the third crosslink density.   
     
     
         19 . The crosslinking system of  claim 18 , wherein:
 the primary crosslinking agent is effective to crosslink the binder in a pH range of 8.5-10; and   the secondary crosslinking agent is effective to crosslink the binder in a pH range of 5.1 to 8.4.   
     
     
         20 . The crosslinking system of  claim 18 , wherein:
 the primary crosslinking agent is selected from the group consisting of sodium phosphate dibasic and potassium bicarbonate;   the secondary crosslinking agent is sodium carbonate; and   the tertiary crosslinking agent is sodium tetraborate.