Composite absorbent particles

Abstract

Composite particles and methods for making the same. An absorbent material is formed into a particle. An optional performance-enhancing active is coupled to the absorbent material before, during, or after the particle-forming process, homogeneously and/or in layers. Additionally, the composite absorbent particle may include a core material. Preferred methods for creating the absorbent particles include a pan agglomeration process, a high shear agglomeration process, a low shear agglomeration process, a high pressure agglomeration process, a low pressure agglomeration process, a rotary drum agglomeration process, a mix muller process, a roll press compaction process, a pin mixer process, a batch tumble blending mixer process, an extrusion process, and a fluid bed process.

1 . A composite particle, comprising: 
 an absorbent core;    an absorbent material surrounding the core and forming a particle; and    at least one performance-enhancing active added to the absorbent material.    
   
   
       2 . A composite particle as recited in  claim 1 , wherein the absorbent material is a liquid-absorbing material and is selected from a group consisting of: a mineral, fly ash, absorbing pelletized material, perlite, silica, organic materials, and mixtures thereof.  
   
   
       3 . A composite particle as recited in  claim 2 , wherein the absorbent material is a mineral selected from a group consisting of: bentonite, zeolite, montmorillonite, diatomaceous earth, opaline silica, crystalline silica, silica gel, Georgia White clay, sepiolite, calcite, dolomite, slate, pumice, tobermite, marls, attapulgite, kaolinite, halloysite, smectite, vermiculite, hectorite, Fuller's earth, fossilized plant materials, expanded perlite, gypsum, and mixtures thereof.  
   
   
       4 . A composite particle as recited in  claim 1 , wherein the absorbent material comprises sodium bentonite granules having a mean particle diameter of about 5000 microns or less.  
   
   
       5 . A composite particle as recited in  claim 1 , wherein the core includes a liquid-absorbing material and is selected from a group consisting of: a mineral, fly ash, absorbing pelletized material, perlite, silica, organic materials, and mixtures thereof.  
   
   
       6 . A composite particle as recited in  claim 1 , wherein the added performance-enhancing active includes at least one of an antimicrobial, an odor reducing material, a binder, a fragrance, a health indicating material, a color altering agent, a dust reducing agent, a nonstick release agent, a superabsorbent material, cyclodextrin, zeolite, activated carbon, a pH altering agent, a salt forming material, a ricinoleate, silica gel, crystalline silica, activated alumina, a clump enhancing agent, and mixtures thereof.  
   
   
       7 . A composite particle as recited in  claim 1 , wherein a performance-enhancing additive is sprayed onto the particles.  
   
   
       8 . A composite particle as recited in  claim 1 , wherein granules of a performance-enhancing additive are dry-blended with the particles.  
   
   
       9 . A composite particle as recited in  claim 1 , wherein the performance-enhancing active comprises a boron-containing compound.  
   
   
       10 . A composite particle as recited in  claim 9 , wherein the boron containing compound is present in an antimicrobially effective amount, wherein the boron containing compound is selected from a group consisting of borax pentahydrate, borax decahydrate, boric acid, polyborate, tetraboric acid, sodium metaborate, anhydrous, boron components of polymers, and mixtures thereof.  
   
   
       11 . A composite particle as recited in  claim 1 , wherein the performance-enhancing active inhibits the formation of odor, the active comprising a water soluble metal salt selected from a group consisting of: silver, copper, zinc, iron, and aluminum salts and mixtures thereof.  
   
   
       12 . A composite particle as recited in  claim 1 , wherein the core includes silica gel, the absorbent material includes bentonite, and the active includes activated carbon.  
   
   
       13 . A composite particle as recited in  claim 1 , wherein the core includes crystalline silica, the absorbent material includes bentonite, and the active includes activated carbon.  
   
   
       14 . A composite particle as recited in  claim 1 , wherein the core includes zeolite, the absorbent material includes bentonite, and the active includes activated carbon.  
   
   
       15 . A composite particle as recited in  claim 1 , wherein the core includes both zeolite and a silica material, the absorbent material includes bentonite, and the active includes activated carbon.  
   
   
       16 . A composite particle as recited in  claim 1 , wherein the core includes a superabsorbent polymer, the absorbent material includes bentonite, and the active includes activated carbon.  
   
   
       17 . A composite particle as recited in  claim 1 , wherein the performance-enhancing active is activated carbon, wherein the activated carbon is present in about 5 weight percent or less based on a weight of the composite particle.  
   
   
       18 . A composite particle as recited in  claim 1 , wherein the performance-enhancing active is a binder selected from a group consisting of: water, lignin sulfonate, polymeric binders, fibrillated polytetrafluoroethylene, carboxymethylcellulose and its derivatives and its metal salts, guar gum cellulose, xanthan gum, starch, lignin, polyvinyl alcohol, polyacrylic acid, styrene butadiene resins, polystyrene acrylic acid resins, crosslinked polyester network, and combinations thereof.  
   
   
       19 . A composite particle as recited in  claim 1 , wherein the performance-enhancing active is a superabsorbent polymer capable of absorbing at least 5 times its weight of water.  
   
   
       20 . A composite particle as recited in  claim 1 , wherein the performance-enhancing active is a superabsorbent polymer capable of absorbing at least 10 times its weight of water.  
   
   
       21 . A composite particle as recited in  claim 1 , wherein the performance-enhancing active is bound to an outer surface of the composite particle.  
   
   
       22 . A composite particle as recited in  claim 1 , wherein the core is formed of agglomerated particles of an absorbent material.  
   
   
       23 . A composite particle as recited in  claim 1  wherein the performance-enhancing active is powdered activated carbon present in an amount effective to reduce sticking of clumps of composite particles to a surface.  
   
   
       24 . A composite particle, comprising: 
 an absorbent material formed into a particle; and    at least one performance-enhancing active added to the absorbent material, the performance-enhancing active being selected from a group consisting of; zeolite, crystalline silica, silica gel, activated carbon, and a super absorbent polymer.    
   
   
       25 . A composite particle as recited in  claim 24 , wherein the performance-enhancing active is bound to an outer surface of the composite particle.  
   
   
       26 . A composite particle as recited in  claim 24 , wherein the at least one performance-enhancing active is substantially homogeneously dispersed throughout at least a portion of the absorbent material.  
   
   
       27 . A composite particle as recited in  claim 24 , wherein the at least one performance-enhancing active is physically dispersed in at least one layer.  
   
   
       28 . A composite particle as recited in  claim 24 , wherein the performance-enhancing active is physically dispersed in pockets in the particle.  
   
   
       29 . A composite particle as recited in  claim 24 , wherein the performance-enhancing active is powdered activated carbon present in an amount effective to reduce sticking of clumps of composite particles to a surface.  
   
   
       30 . An animal litter, comprising: 
 multiple composite particles, each composite particle comprising: 
 an absorbent core including a material selected from a group consisting of zeolite, crystalline silica, silica gel, activated alumina, activated carbon, and a superabsorbent polymer;  
 an absorbent material surrounding the core, the absorbent material including bentonite clay;  
 activated carbon added to the absorbent material; and  
 optionally at least one other performance-enhancing active added to the absorbent material.  
   
   
   
       31 . The animal litter as recited in  claim 30 , wherein the activated carbon is present in about 1 weight percent or less based on a weight of the animal litter.  
   
   
       32 . An animal litter, comprising: 
 multiple composite particles, each composite particle comprising: 
 an absorbent material; and  
 at least one performance-enhancing active added to the absorbent material  
   wherein at least a portion of the composite particles are colored.    
   
   
       33 . An animal litter as recited in  claim 32 , further comprising bentonite particles admixed with the composite particles.  
   
   
       34 . An animal litter as recited in  claim 32 , wherein at least some of the composite particles further include a performance-enhancing active.  
   
   
       35 . An animal litter as recited in  claim 34 , wherein the performance-enhancing active includes at least one of an antimicrobial, an odor reducing material, a binder, a fragrance, a health indicating material, a color altering agent, a dust reducing agent, a nonstick release agent, a superabsorbent material, cyclodextrin, zeolite, activated alumina, activated carbon, a pH altering agent, a salt forming material, a ricinoleate, silica gel, crystalline silica, a clump enhancing agent, and mixtures thereof.  
   
   
       36 . A method for preparing a litter box for use by animals, comprising: 
 selecting a receptacle with a closed bottom, a plurality of interconnected generally upright side walls forming an open top and defining an inside surface; and    adding a litter material of absorbent composite particle form to the box.    
   
   
       37 . A method as recited in  claim 36 , wherein the litter material further includes a performance-enhancing active mixed with the particles.  
   
   
       38 . An animal litter, comprising: 
 multiple composite particles, each composite particle comprising: 
 an absorbent material; and  
 at least one performance-enhancing active added to the absorbent material;  
   wherein the litter has a malodor rating below about 15 as measured by a Malodor Sensory Method.    
   
   
       39 . An animal litter, comprising: 
 multiple composite particles, each composite particle comprising: 
 an absorbent material; and  
 at least one performance-enhancing active added to the absorbent material;  
   wherein the litter has a malodor rating below about 15 as measured by a Malodor Sensory Method.    
   
   
       40 . An animal litter, comprising: 
 multiple composite particles, each composite particle comprising: 
 an absorbent material; and  
 at least one performance-enhancing active added to the absorbent material;  
   wherein the litter has a feline inducement to use index of at least about 9 as measured by a Feline Inducement to Use Index Test.    
   
   
       41 . An animal litter, comprising: 
 multiple composite particles, each composite particle comprising: 
 an absorbent material; and  
 at least one performance-enhancing active added to the absorbent material;  
   wherein the litter has a multiple cat usage index of at least about 8 as measured by a Multiple Cat Usage Index Test.