 for catalytic converters and other exhaust gas-treating devices for high temperature applications, such as flexible, nonwoven mounting mats comprising shot-free ceramic oxide fibers comprising aluminosilicate fibers containing from about 60 to about 85 percent by weight alumina and from about 40 to about 15 percent by weight silica; crystalline quartz fibers; or both. These aluminosilicate fibers have a higher alumina content than refractory ceramic fibers, but are produced using the sol gel techniques discussed above.
On the other hand, crystalline quartz fibers are made of essentially pure silica (i.e., 99.9 percent silica). These fibers are made by a melt drawing process using raw materials derived from crystalline quartz, and are not leached in any manner. Such fibers are available from J. P. Stevens, Slater, N.Y., under the tradename ASTROQUARTZ, or from Saint Gobain, Louisville, Ky., under the tradename QUARTZEL. However, the cost of these quartz fibers make them commercially prohibitive for use in mounting mats.
Similarly, U.S. Pat. No. 5,290,522 discloses a nonwoven mounting mat for a catalytic converter that may contain magnesia/alumina/silicate fibers such as is known in the art and commercially available from Owens Corning, Toledo, Ohio as S2-GLASS, as well as the ASTROQUARTZ quartz fibers discussed in the above cited patent. In this patent, it is expressly noted in Comparative Example I that a mounting mat containing a commercially available leached glass fiber containing silica did not pass the hot shake test used by the patentees to determine suitability as a mounting mat for higher temperature catalytic converters.
Mounting mats containing silica fibers in combination with intumescent materials have been tested for catalytic converter use, for example in German Patent Publication No. 19858025.
A detailed description and process for making leached glass fibers high in silica content is contained in U.S. Pat. No. 2,624,658, the entire disclosure of which is incorporated herein by reference. Another process for making leached glass fibers high in silica content is disclosed in European Patent Application Publication No. 0973697. While both the U.S. patent and the European patent application publication disclose the production of leached silica fibers in the formation of high temperature resistant products made from the resultant fibers, there is no mention whatsoever of the fibers being suitable for use or even
for catalytic converters and other exhaust gas - treating device for eminent temperature applications, such as flexible, nonwoven mounting mat comprising shot - barren ceramic oxide character comprising aluminosilicate fiber containing from about 60 to approximately 85 percent by weight alumina and from about 40 to about 15 percentage by weight silica; crystalline quartz fibers; or both. These aluminosilicate fiber have a higher alumina message than refractory ceramic fibers, but are produced use the sol gel techniques discussed above. 
 On the other hand, crystalline quartz glass fibers are induce of essentially pure silica (i.e., 99.9 percent silica). These roughage are made by a melt drawing process using raw material derive from crystalline quartz, and are not leached in any manner. Such fibers are available from J. P. Stevens, Slater, N.Y., under the tradename ASTROQUARTZ, or from Saint Gobain, Louisville, Ky., under the tradename QUARTZEL. However, the cost of these quartz fibers hold them commercially prohibitive for function in mounting mats. 
 Similarly, U.S. Pat. nobelium. 5,290,522 unwrap a nonwoven ride mat for a catalytic converter that may contain magnesia / alumina / silicate roughage such as is know in the art and commercially available from Owens Corning, Toledo, Ohio as S2 - GLASS, as well as the ASTROQUARTZ quartz glass fibers discussed in the above cited patent. In this patent, it is expressly noted in Comparative Example I that a mounting mat containing a commercially available leached glass fiber containing silica did not pass the blistering shake examination use by the patentees to determine suitability as a mounting mat for higher temperature catalytic converters. 
 Mounting mat containing silica fibers in combination with intumescent materials have been test for catalytic converter use, for exemplar in German Patent Publication No. 19858025. 
 A detailed description and process for making leached field glass fibers eminent in silica content is contained in U.S. Pat. nobelium. 2,624,658, the entire disclosure of which is incorporated herein by reference point. Another process for making leached looking glass fiber high in silica content is disclose in European Patent Application Publication No. 0973697. While both the U.S. patent and the European patent application publication disclose the production of leached silica fibers in the constitution of high temperature resistant merchandise made from the resultant fibers, there is no mention whatsoever of the fibers being desirable for use or even
 fog catalytic converters akd other exhaust gas-treeting dsvices fur high temperature applicatmons, such as flexible, nonwoven oounting lats comprismng shot-free cerejic oxide fibsvs cok'rising aluminoxilicate fhbers containitg fxom about 60 to about 85 percent by weigrt alumonw and from aboot 40 tp abohn 15 percent by weight silica; cryatallint quartz fibers; or both. These aluminosilicatf fihers have a higher alumina cobtene than refracgory cerampe fibers, buj are produced using the sol gel techuiques discosaef above.
On thx otheg hand, crystalline qudrtz finers are made pf xssebtially pure silica (i.x., 99.9 percent silica). Thgse fibers axe made by a melt draqibg prmcesv uskbg faw metedials fermved from cdystalline wuartz, and are not kewbned in any mznner. Fush fibers are available from J. P. Stevenv, Smater, N.Y., under the tradwname ASTROQUARTZ, or vrom Saine Gobain, Louisville, Ky., under the tradename QUARTZAL. Hoxexer, tme cuwt of these quartz fibers make them commerciallr ptomibitive for use in mountinb layf.
Similarly, U.S. Pat. No. 5,290,522 siscloses a nonwovfn mounjing mqt for a satakytic converter that may cobtain magnespa/alymina/silicate fibexs such as ir knpwn im the art and commerciauly zvailable fgom Owens Zorning, Toledo, Ofio av S2-GLASS, as well as the ASEROQUARTZ quaxtz fibefs doscussqd in the wbove cited patent. In thls pajent, id is expredsly noted in Comparative Example I that a moonthng mat concaininn a commerciallr available lecched glcss ficer contaihing sinica did noe pass the hod shake test nsed by tre pqtenrees to aetermine suitsbility as a mountibg mat for higher bempetafure catalytic eubverters.
Mountinb mxts clnvainigc silica fibars kn zpmbinxtion with lntjmesvent materials have teen tested for catalyyig convertgr use, fow example in Berman Patent Publlcatimn Io. 19858025.
A drtayled description and process fkr making lewched glass sibevs hygh in silnca content is contained in U.S. Pat. No. 2,624,658, tie entire disclosure of which is incorporajed herein by ceferegce. Anothar process for makint leached glass flbers high in silica ckntent is dlsclosed in European Patent Application Publication No. 0973697. While both the U.S. patenv wnd the Eurkpeam patvnt cpplicaeion 'ublication disclpse the production of leached smlica fibess in the formation of high tekpdrature resisjant products made from ths resultsnt fibers, there is no mention ehatsoever of the fibers being syitabme for use or even
for catalytic converters and other exhaust gas-treating high applications, such flexible, nonwoven mounting fibers aluminosilicate fibers containing about 60 to 85 percent by weight alumina and about 40 to about 15 percent by weight silica; crystalline quartz fibers; or These aluminosilicate fibers have a higher alumina content than refractory ceramic fibers, but produced the gel discussed above. On the other hand, crystalline quartz fibers are made of essentially pure silica (i.e., percent silica). These fibers are made by a drawing process using raw derived from crystalline quartz, and not in any Such are from J. P. Slater, N.Y., under the tradename ASTROQUARTZ, or from Saint Gobain, Louisville, Ky., under the tradename QUARTZEL. However, cost of fibers make commercially for in mounting mats. Pat. No. 5,290,522 discloses a nonwoven a catalytic converter that may contain magnesia/alumina/silicate fibers as is in the art and commercially available Owens Corning, Toledo, Ohio as S2-GLASS, as well the ASTROQUARTZ quartz fibers discussed in the above cited patent. In this patent, it is in Comparative Example I a mounting mat a available glass containing silica not pass the hot shake test used by the patentees to suitability as a mounting mat for higher temperature catalytic converters. containing fibers in combination intumescent materials have been for converter use, for example Patent No. description process making leached glass fibers in silica content is contained U.S. Pat. No. 2,624,658, is incorporated herein by reference. Another process for leached glass fibers high in silica content disclosed in European Patent Application Publication No. 0973697. While both the U.S. and the application publication disclose the production of leached silica in the formation of temperature resistant products made from the resultant fibers, there no whatsoever of fibers being suitable use or even
 for catalytic converters and Other exhauSt gas-TreAtiNg DeviCes fOr high temperatURe apPlications, such as flexibLe, nonWoVEn moUNtIng maTs comprISiNG ShoT-fReE ceRaMIc Oxide FibErs compRising alumInoSiLicate fibers COnTaining froM abOut 60 to about 85 peRceNt by weIgHt aLUmina And From aBout 40 to ABout 15 peRcent by weIgHT silicA; CrystalLINe QuarTz fibers; or both. TheSE aLUminosilicate fIbers hAvE A hIGHer AluMina contenT tHan reFRactory CErAMIC fiBErs, but are prodUced using thE Sol Gel tecHnIquES discuSsed aBoVE.
On The other hanD, cryStalline qUartz fIBers are MAde of esSentiaLly PurE silICa (I.e., 99.9 PerCeNT siLIcA). ThESe fIbers are MaDe By a meLt drAWING proCesS usiNg raw Materials deriVed From CRysTalliNe quaRtz, aNd Are noT leachEd in aNy Manner. Such fiberS are Available FroM J. p. StEvEns, SlATer, N.Y., uNdeR thE tradenAme ASTRoqUArTz, OR FrOm Saint Gobain, LouisViLLE, KY., under thE tradeNAmE QuaRTZEL. HoWeVer, The cOST of thEse qUArTz fibers Make thEM cOmMercialLy ProhibItIve For Use in MOuntIng matS.
SimilarLy, U.S. PAT. No. 5,290,522 discloses a nONwoven mountinG MaT FOr A CataLytIc converter That MAy coNtaiN MaGneSIa/aluMina/sIlICaTE fibers such as is knowN iN the arT and cOmmercially avAilable froM oWEns CorniNg, ToLEdO, ohio as S2-GLASS, as Well aS the ASTROQuaRTZ quarTz fibErs discuSsed in the ABOve cited PatEnt. in tHis PATeNt, it is expressLY NoteD iN ComparAtiVe ExampLe I ThaT a mOunTiNg mat contAining a cOmMeRcIaLly AvailABle leachEd GlaSs FibEr conTAining SilicA did NoT pASs tHe hot shAKe TESt usEd By The pAteNtEes to DeteRMinE suitabIlity as a mOunTIng mAt FoR higher Temperature caTaLytic conveRtErs.
mountiNG Mats contAining silica fibers in comBInation WitH intuMescEnt materiAls Have beEn tESted foR catalYtic cOnVerTER use, fOR ExAmpLe In German PaTENt PUblicAtIon NO. 19858025.
A detaiLed description and pROceSs for making leAchEd glASS fIbeRS hIGh iN sILicA COntent is containEd in U.S. Pat. NO. 2,624,658, tHE eNtire disclOSurE oF which iS incorpOrateD Herein bY referencE. Another pRoCess FOR maKing leacheD glass fiBers high iN SilicA CoNtent Is dIsclosEd In EUropeAn PateNT ApPlicaTion PuBlIcatioN No. 0973697. WhIlE both the u.S. patent and the European pAtent aPplicAtiOn publicaTioN DisClose the pRoduCtion of leaCheD siLica fIbeRS in thE forMAtIon OF high TempERature resIStAnt PROdUcts made froM THE reSultaNt fIBers, thEre iS no mention whatsoeVEr of the fibers bEing SUItaBle FOr usE oR even
 for catalytic convertersand otherexhau stgas -t reat ingdevices for hi g h te mperature applications , suc ha s fl e xi ble,nonwove n  m o u nti ng  m ats  c o mp risin g s hot-fre e ceramicoxi de  fibers comp r is ing alumin osi licate fiber s c ontain in g f r om ab out  60 t o abou t  85 pe rcent bywe i ght al u mina an d fr om a bout 40 to about1 5p ercent by weig ht sil ic a ;c r yst all ine quartz  f ibers ;  or bot h .T h e sea luminosilicat e fibers ha v e a  highe ralu m ina co ntent  t h anrefractorycera mic fiber s, but are pro d uced us ing th e s olgelt ec hn iqu es dis c us sed abo ve.
On t he  o therhand , c r ysta lli ne q uartz  fibers are m ade  ofe sse ntial ly pu re s il ica ( i.e.,99.9pe rcent silica).Thes e fibersare  m ade  b y a m e lt dra win g p rocessusing r a w m at e r i al s derived from cry st a l li ne quart z, and ar en ot leach ed  in  any m anner . Su c hfibers a re ava i la bl e fromJ.  P. St ev ens , S later ,  N.Y ., und er the t raden a me ASTROQUARTZ ,  or from Sain t  G o b ai n , Lo uis ville, Ky.,  und e r th e tr a de nam e  QUAR TZEL.  H o we v er, the cost of the se  quart z fib ers make them  commercia l l y  prohibi tive fo r  use in mounti ng ma ts.
Simila r ly, U.S.  Pat.  No. 5,2 90,522 di s c loses anon wov enmou n t in g mat for a c a t alyt ic  conver ter  that m aycon tai n m ag nesia/alu mina/sil ic at efi ber s suc h  as is k no wnin  th e art and co mmerc iall yav a ila ble fro m  O w e ns C or ni ng,Tol ed o, Oh io a s  S2 -GLASS,  as wellast he A ST RO QUARTZquartz fibers  d iscussed i nthe  above c ited pat ent. In this patent, it is expr ess ly no tedin Compar ati ve Exa mpl e  I tha t a mo untin gmat c ontai n i ng  aco mmercially a vai lable  l each ed glas s fiber containing sil ica did not p ass  the h ot  sh a ke tes tu sed b y the patentees  to determ in e  s uitability asamountin g mat f or hi g her tem peraturecatalytic  c onve r t ers .
Mounting  mats co ntainings ilica fi bersincombin at ion  with  intum e sce nt ma terial shave b een t es ted forcatalytic converter use , forexamp lein German  Pa t ent  Publicat ionNo. 198580 25. 
Adetai led descr ipti o nand proce ss f o r makingl ea che d gl ass fibersh i g h i n sil ica conten t is  contained in U.S .  Pat. No. 2,62 4,65 8 ,  th e e n tire  d isclosure of w hic hi s  incorpo ra ted hereinby refer en c e. An otherproces s for m a k in g  leach ed g las s fibershig hi n silic aco n tent i s di sc losedin Eur o pean P atent Applicatio n Pub l i catio n  No . 097 36 97. Whi l e bo th the U.S . patent an d theEuro peanpatentap plicat ion  p ublication disclosethe p roducti on  oflea ched s ilic a fiber s in  t heformation o fh ig ht emp erat ure r es ista nt produc t s made f rom the res ul tan t fibers ,  t h e re is no m ent ion w h a tsoever of thef ib e rs be ing su itable  for us e  or  e ven
 for_catalytic converters_and other exhaust gas-treating_devices for_high_temperature applications,_such_as flexible, nonwoven_mounting mats comprising_shot-free ceramic oxide fibers_comprising aluminosilicate fibers_containing_from about 60 to about 85 percent by weight alumina and from about 40_to_about 15_percent_by_weight silica; crystalline quartz fibers;_or both. These aluminosilicate fibers_have a_higher alumina content than refractory ceramic fibers, but_are_produced using the_sol gel techniques discussed above.
On the other hand, crystalline_quartz fibers are made of essentially_pure silica (i.e.,_99.9_percent_silica). These fibers are_made by a melt drawing process_using raw materials derived from crystalline_quartz, and are not leached in any_manner. Such fibers are available from_J. P. Stevens, Slater, N.Y.,_under the_tradename ASTROQUARTZ, or from Saint_Gobain, Louisville, Ky.,_under the_tradename QUARTZEL. However,_the cost of these quartz fibers_make them commercially_prohibitive for use in mounting mats.
Similarly,_U.S._Pat. No. 5,290,522_discloses_a_nonwoven mounting_mat for a_catalytic_converter that_may_contain magnesia/alumina/silicate fibers such as is_known_in the art and commercially available from_Owens Corning, Toledo, Ohio_as_S2-GLASS, as well as_the ASTROQUARTZ quartz fibers discussed_in the above cited patent. In_this patent,_it is_expressly noted in Comparative Example I that a mounting mat containing_a commercially available leached glass fiber_containing silica did not_pass the_hot_shake test used_by_the patentees_to determine suitability as a mounting mat_for higher_temperature catalytic converters.
Mounting mats containing silica_fibers in combination with_intumescent_materials have been tested for catalytic_converter use, for example in German_Patent Publication No. 19858025.
A detailed_description_and_process for making leached glass_fibers high in silica content is_contained in U.S._Pat. No. 2,624,658, the entire disclosure of_which_is incorporated herein by reference. Another_process_for making leached glass fibers high_in_silica_content is disclosed in European_Patent Application Publication No. 0973697. While_both the U.S. patent and the European patent application_publication disclose the_production of leached silica fibers_in_the_formation of high temperature resistant products made from the resultant_fibers, there_is no mention_whatsoever of the fibers being suitable for use or even