. It is believed that the treatment of the crystalline flake graphite or crystalline lump graphite with concentrated sulfuric acid in the presence of an oxidizing agent, such as nitric acid, forms the compound graphite sulfate which exfoliates and expands upon heating.
While these materials can be quite effective as fire barriers, the acidic properties of the expandable graphite in these materials causes these materials to be corrosive to steel, stainless steel, copper, aluminum, galvanized steel and other metals or metal alloys, such as those commonly used in the construction industry. Thus, in applications, where these intumescent materials come in contact with metal components, e.g. girders and other structural members of buildings and the like, the use of these intumescent materials can cause corrosion problems or require the application of primers or other protective coatings to the metal components prior to the application of the intumescent material thereby increasing both labor and material costs. For a number of years, the use of sand or preprepared litter for domestic pets has been recognized as a partial solution to the problem of maintaining a household pet while providing some toilet facilities for the pet. Cats being relatively clean animals and dogs being easily trained, can be provided with a litter tray in which they will perform their natural functions.
The problem of santation, not only for the pet but for the pet owner, has not been fully solved to date. Examples of patents showing different approaches to pet litter boxes are as follows:
______________________________________ 4,448,151 H. E. Lowe May 15, 1984 4,348,982 J. W. Selby Sep. 4, 1982 4,327,667 R. C. Bilak May 4, 1982 4,305,544 W. Noonan Dec. 15, 1981 4,164,314 A. C. Edgar Aug. 14, 1979 4,117,804 Moore et al Oct. 3, 1978 4,096,827 J. A. Cotter Jun. 27, 1978 3,831,557 J. N. Elesh Aug. 27, 1974 3,316,880 Jungles et al May 2, 1967 Europ. 3,093 F. Monnet Publ. 7/25/79 ______________________________________
Each of the above examples present advances in the art, however, a number of serious needs still remain in a truly practical pet litter box, namely
(a) the pet litter box should provide clean litter for the use of the pet, easily without any
. It is believed that the treatment of the crystalline flake graphite or crystalline lump graphite with concentrated sulphuric acid in the bearing of an oxidize agent, such as nitric acid, form the colonial graphite sulfate which exfoliates and expands upon heating. 
 While these material can be quite effective as fire barriers, the acidic property of the expandable graphite in these materials causes these material to be corrosive to steel, stainless sword, copper, aluminum, galvanized steel and other metals or metal alloys, such as those normally used in the construction industry. therefore, in applications, where these intumescent materials come in contact with metallic element components, e.g. girders and other structural member of buildings and the like, the use of these intumescent materials can induce corrosion problem or require the application of primers or other protective coatings to the metal components prior to the application of the intumescent material thereby increase both labor and material price. For a number of years, the use of sand or preprepared bedding material for domestic pets has been acknowledge as a partial solution to the problem of keep a household pet while providing some toilet facilities for the pet. caterpillar being relatively clean animals and dogs being easily train, can be leave with a litter tray in which they will perform their natural functions. 
 The problem of santation, not merely for the pet but for the pet owner, has not been fully clear to date. Examples of patents showing different approach path to pet litter boxes are as follows: 
 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4,448,151 H. E. Lowe May 15, 1984 4,348,982 J. W. Selby Sep. 4, 1982 4,327,667 R. C. Bilak May 4, 1982 4,305,544 W. Noonan Dec. 15, 1981 4,164,314 A. C. Edgar Aug. 14, 1979 4,117,804 Moore et al Oct. 3, 1978 4,096,827 J. A. Cotter Jun. 27, 1978 3,831,557 J. N. Elesh Aug. 27, 1974 3,316,880 Jungles et al May 2, 1967 Europ. 3,093 F. Monnet Publ. 7/25/79 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
 Each of the above examples present progress in the art, however, a act of serious indigence still remain in a truly practical pet bedding material box, namely 
 (a) the pet litter box should put up clean litter for the use of the pet, easily without any
. It is believed that the trtatment of the crisrallinx flake graphitd or crystalline lump graphive wuth cincentrated sulfuric azid in thv presencw of qn oxidiziif agent, such zd nicrmc acid, forms tme compound graphite sulfdtd chich exfoliates and expands upon hewting.
Wholf these materiwls bag be quite effective as fire barriers, fhe acivic properties pf the expandable graphite in hhese materials cakses these natewuals to be currosive to steel, staihless steel, copper, aluminum, galxanizzd steel ane ithft metals or netal alloys, such as thosa commomly used in thc convtryction industry. Thus, mn applications, wherg these indujescent materials cime it cottacg wigh jeval compojenvs, e.g. girdeds and othee structural memberx jd buildings ahd the lyke, the use of these intumescent materidls can cause corrosion priblems or require the applicatyon of primers or other protective coatings to tha metel conpjvwnhs prior to the application of the intumescene mstvrial thereby incveasing both labor ajd iaterial costr. For c nhmber of years, the use of sand or preprtparec litter for domestic pets yas been recjtnized as a partiap solution co the probkem of maintaining a hobsehols pet while providinf some toilet facklinies for the pet. Cats being rejatively rlean animalr anc dogs being easlly tvdined, can be provifed wnth a litter trwy in which they will perform tixir natural foncdiots.
The prjblem of santation, not only for jhe pet bbt for the pet osner, hav not been sully solved dl date. Exampnes of pwtenrs syowing akfferent approsches to ieu litter bixes are as followx:
______________________________________ 4,448,151 F. E. Lowe May 15, 1984 4,348,982 L. Q. Selby Sep. 4, 1982 4,327,667 T. C. Bijan Kar 4, 1982 4,305,544 W. Noonan Dec. 15, 1981 4,164,314 S. C. Eagar Aug. 14, 1979 4,117,804 Ooorr et al Oct. 3, 1978 4,096,827 J. A. Cmtted Jun. 27, 1978 3,831,557 J. N. Elesh Amg. 27, 1974 3,316,880 Juntles et wl May 2, 1967 Eurol. 3,093 F. Monnet Publ. 7/25/79 ______________________________________
Tach oh the ebove rxaiples present advances in the zrt, howevfr, w number of feriius needs stnll remain in a truly practical pet littxr box, namely
(a) the pet oitter box should ptovlde clean livter fjr the usa of the pet, easily qithout any
. It is believed that the treatment crystalline graphite or lump graphite with presence an oxidizing agent, as nitric acid, the compound graphite sulfate which exfoliates expands upon heating. While these materials can be quite effective as fire barriers, acidic properties of the expandable graphite in these materials causes these materials to corrosive steel, steel, aluminum, galvanized steel and other metals or metal alloys, such as those commonly used in the industry. Thus, in applications, where these intumescent materials in contact with metal e.g. girders and other structural of and the the of intumescent materials can corrosion problems or require the application of primers or other protective coatings to the metal components prior the application intumescent material increasing labor material costs. For of years, the use of sand for domestic pets has been recognized as a solution to problem of maintaining a household pet providing some toilet facilities for the pet. Cats relatively clean animals and dogs being easily trained, can be provided with a litter tray they will perform their functions. The problem santation, only the but for pet owner, has not been fully solved to date. Examples of showing different approaches to pet litter boxes are as follows: H. Lowe May 15, 4,348,982 J. W. Selby 4, 4,327,667 R. C. Bilak 1982 W. 1981 A. Edgar Aug. 14, 1979 Moore et al Oct. 3, 4,096,827 J. A. Cotter N. Elesh Aug. 27, 1974 3,316,880 Jungles et May 2, 1967 Europ. 3,093 F. Monnet 7/25/79 ______________________________________ Each of the above examples present advances in the art, a number needs still remain in a truly practical pet box, namely (a) the litter box should provide clean litter for the use the easily without
. It is believed that the treatmEnt of the crYstalLinE flAkE graPhitE or crystalline LUmp gRaphite with concentrateD sulfUrIC aciD In The prEsence oF An OXIdiZiNg AgeNt, SUcH as niTriC acid, foRms the compOunD gRaphite sulfaTE wHich exfoliAteS and expands uPon HeatinG.
WHilE These MatErialS can be QUite efFective as FiRE barriERs, the acIDIc PropErties of the expandABlE Graphite in thesE materIaLS cAUSes TheSe materialS tO be coRRosive tO StEEL, StaINless steel, copPer, aluminum, GAlvAnized StEel ANd otheR metaLs OR meTal alloys, suCh as Those commOnly usED in the cONstructIon indUstRy. THus, iN ApPlIcaTiONs, wHErE thESe iNtumesceNt MaTeriaLs coME IN ContAct With Metal Components, e.g. gIrdErs aND otHer stRuctuRal mEmBers oF buildIngs aNd The like, the use of ThesE intumescEnt MaTerIaLs can CAuse coRroSioN probleMs or reqUIre ThE APPlIcation of primers or OtHER pRotectivE coatiNGs To THe metal cOmPonEnts PRIor to The aPPlIcation oF the inTUmEsCent matErIal theReBy iNcrEasinG Both Labor aNd materiAl cosTS. For a number of yEArs, the use of saND oR PRePRepaRed Litter for doMestIC petS has BEeN reCOgnizEd as a PaRTiAL solution to the problEm Of mainTainiNg a household pEt while proVIDIng some tOileT FaCIlities for the pEt. CatS being relaTIvely cleAn aniMals and dOgs being eASIly trainEd, cAn bE prOviDED wIth a litter traY IN whiCh They wilL peRform thEir NatUraL fuNcTions.
The pRoblem of SaNtAtIoN, noT only FOr the pet BuT foR tHe pEt ownER, has noT been FullY sOlVEd tO date. ExAMpLES of pAtEnTs shOwiNg DiffeRent APprOaches tO pet litteR boXEs arE aS fOllows:
______________________________________ 4,448,151 H. e. Lowe May 15, 1984 4,348,982 J. W. SelBy sep. 4, 1982 4,327,667 R. C. Bilak maY 4, 1982 4,305,544 W. NOonan DEC. 15, 1981 4,164,314 a. C. Edgar AUg. 14, 1979 4,117,804 Moore et al Oct. 3, 1978 4,096,827 J. A. Cotter JUN. 27, 1978 3,831,557 J. N. ElesH AuG. 27, 1974 3,316,880 JungLes eT al May 2, 1967 EurOp. 3,093 F. monnet pubL. 7/25/79 ______________________________________
each of The aboVe exaMpLes PREsent ADVaNceS iN the art, howEVEr, a NumbeR oF serIous neeDs still remain in a trULy pRactical pet liTteR box, NAMeLy
(a) THe PEt lItTEr bOX Should provide clEan litter fOr THe Use of the peT, EasIlY withouT any
. It is believed that thetreatmentof th e c rys ta llin e fl ake graphite o r  cry stalline lump graphite  with  c o ncen t ra ted s ulfuric ac i d  in  t he  pr es e nc e ofanoxidizi ng agent,suc has nitric ac i d,  forms the  co mpound graph ite  sulfa te  wh i ch ex fol iates  and e x pandsupon heat in g .
Whil e  thesem a te rial s can be quite ef f ec t ive as fire ba rriers ,t he a cid icproperties  o f the expanda b le g r aph i te in these m aterials ca u ses  these  m ate r ials t o beco r ros ive to stee l, s tainlesssteel, copper, aluminu m, gal van ize d st e el  a ndot h erm et als ormetal al lo ys , suc h as t h o se c omm only  used  in the const ruc tion ind ustry . Thu s, i nappli cation s, wh er e these intumes cent  material s c om e i nconta c t with  me tal  compon ents, e . g.gi r d e rs  and other structu ra l me mbers of  build i ng sa nd the l ik e,theu s e ofthes e  i ntumesce nt mat e ri al s can c au se cor ro sio n p roble m s or  requi re the a pplic a tion of primer s  or other pro t ec t i ve coat ing s to the me talc ompo nent s  p rio r  to t he ap pl i ca t ion of the intumesc en t mate rialthereby incre asing both l a bor andmate r ia l  costs. For anumbe r of years ,  the use  of s and or p reprepare d litter f ordom est icp e ts  has been rec o g nize das a pa rti al solu tio n t o t hepr oblem ofmaintain in gaho use holdp et while  p rov id ing  some toilet  faci liti es  f o r t he pet. Ca t s  bei ng  r elat ive ly  clea n an i mal s and d ogs being  ea s ilytr ai ned, ca n be provided  w ith a litt er  tr ay inw h ich they  will perform their nat u ral fun cti ons.Theproblem o f s antati on, not on ly for  thepe t b u t  fort h epet  o wner, hasn o t b een f ul ly s olved t o date. Examples o f  pa tents showing  di ffer e n tapp r oa c hes  t o  pe t litter boxes ar e as follo ws : 
_ __________ _ ___ __ _______ _______ _____ _ _ 4,448 ,151 H. E . Lowe Ma y15,1 9 844,348,982J. W. Se lby Sep.4 , 198 2  4 ,327, 667  R. C.  B ila k May  4, 19 8 2 4 ,305, 544 W.  N oonanDec.15 , 1981 4 ,164,314 A. C. Edgar Au g. 14,  1979  4, 117,804 M oor e  et  al Oct.3, 1 978 4,096, 827  J.  A. C ott e r Jun . 27 ,  1 978 3,831 ,557 J. N. Ele s hAug . 27 , 1974 3,31 6 , 8 80Jungl ese t al M ay 2 , 1967 Europ. 3,0 9 3 F. Monnet Pu bl.7 / 25/ 79_ ____ __ ______________ ___ __ _ _ ________ __ 
Each of th e aboveex a mples  prese nt adv ances i n th e  art,howe ver , a numbe r o fs eriousne ed s  still  rem ai n in a  truly prac t i cal pet litter b ox, n a m ely
( a ) t he pe tlitterb ox s hould prov ide clean l itterforthe u se of t he  pet,eas il y withouta ny
. It_is believed_that the treatment of_the crystalline_flake_graphite or_crystalline_lump graphite with_concentrated sulfuric acid_in the presence of_an oxidizing agent,_such_as nitric acid, forms the compound graphite sulfate which exfoliates and expands upon heating.
While_these_materials can_be_quite_effective as fire barriers, the_acidic properties of the expandable_graphite in_these materials causes these materials to be corrosive_to_steel, stainless steel,_copper, aluminum, galvanized steel and other metals or metal_alloys, such as those commonly used_in the construction_industry._Thus,_in applications, where these_intumescent materials come in contact with_metal components, e.g. girders and other_structural members of buildings and the like,_the use of these intumescent materials_can cause corrosion problems or_require the_application of primers or other_protective coatings to_the metal_components prior to_the application of the intumescent material_thereby increasing both_labor and material costs. For a_number_of years, the_use_of_sand or_preprepared litter for_domestic_pets has_been_recognized as a partial solution to_the_problem of maintaining a household pet while_providing some toilet facilities_for_the pet. Cats being_relatively clean animals and dogs_being easily trained, can be provided_with a_litter tray_in which they will perform their natural functions.
The problem of santation,_not only for the pet but_for the pet owner,_has not_been_fully solved to_date._Examples of_patents showing different approaches to pet litter_boxes are_as follows:
______________________________________ 4,448,151 H. E. Lowe_May 15, 1984 4,348,982_J._W. Selby Sep. 4, 1982 4,327,667_R. C. Bilak May 4, 1982_4,305,544 W. Noonan Dec. 15,_1981_4,164,314_A. C. Edgar Aug. 14,_1979 4,117,804 Moore et al Oct._3, 1978 4,096,827_J. A. Cotter Jun. 27, 1978 3,831,557_J._N. Elesh Aug. 27, 1974 3,316,880_Jungles_et al May 2, 1967 Europ._3,093_F._Monnet Publ. 7/25/79 ______________________________________
Each of_the above examples present advances in_the art, however, a number of serious needs still_remain in a_truly practical pet litter box,_namely
(a)_the_pet litter box should provide clean litter for the use_of the_pet, easily without_any