沉淀白炭黑新工艺Word文件下载.docx

沉淀白炭黑新工艺Word文件下载.docx

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Assignee:

RhodiaChimie（Courbevoie,FR）

Appl.No.:

09/248,921

Filed:

February11,1999

RelatedU.S.PatentDocuments

ApplicationNumberFilingDatePatentNumberIssueDate

737976

ForeignApplicationPriorityData

Mar29,1995[FR]9503676

CurrentU.S.Class:

106/492;

106/482;

423/335;

423/339

CurrentInternationalClass:

C01B33/193（20060101）;

C08K3/00（20060101）;

C08K3/36（20060101）;

C01B33/00（20060101）;

C09C1/28（20060101）;

C09C1/30（20060101）;

C01B033/12（）

FieldofSearch:

106/492,482423/335,338,339

ReferencesCited[ReferencedBy]

U.S.PatentDocuments

4040858August1977Wason

4161455July1979Wason

5403570April1995Chevallieretal.

5587416December1996Chevallieretal.

PrimaryExaminer:

Marcheschi;

Michael

Attorney,AgentorFirm:

Seugnet;

Jean-Louis

ParentCaseText

ThisapplicationisadivisionofU.S.applicationSer.No.08/737,976,filedonMar.03,1997,U.S.Pat.No.5,958,127,whichisanapplicationunder35U.S.C.Section371ofInternationalApplicationNo.PCT/FR96/00462,filedMar.28,1996.

Claims

Whatisclaimedis:

1.Aprecipitatedsilicahaving:

aCTABspecificsurfaceofbetween90and250m.sup.2/g,

aBETspecificsurfaceofbetween90and250m.sup.2/g,

aDOPoiluptakelowerthan300ml/100g,

azinccontentofbetween1and5%byweight,

saidsilicabeingintheformofsphericalbeadswithameansizeofatleast80.mu.m,apowderwithameansizeofatleast15.mu.m,orgranuleshavingalengthofatleast1mmalongtheaxisoftheirlargerdimension,and

whereinthenumberNofstearicacidmoleculesconsumedpernm.sup.2ofsilicasurface,whenstearicacidisreactedwiththesaidsilicainxylenefor2hoursat120.degree.C.,isatleast1.

2.Asilicaaccordingtoclaim1,whereinthezincisnotinacrystallineform.

3.Asilicaaccordingtoclaim1,whereinthezinccontentisatleast1.5.

4.Asilicaaccordingtoclaim1,having:

aCTABspecificsurfaceofbetween90and185m.sup.2/g,

amediandiameter（.Oslashed..sub.50）,afterdisintegrationwithultrasound,smallerthan4.mu.m,and

anultrasonicdisintegrationfactor（F.sub.D）higherthan6ml.

5.Asilicaaccordingtoclaim1,having:

aCTABspecificsurfacehigherthan185m.sup.2/gandlowerthan220m.sup.2/g,and

amediandiameter（.Oslashed..sub.50）,afterdisintegrationwithultrasound,smallerthan7.mu.m.

6.Asilicaaccordingtoclaim5,havingaDOPoiluptakeofbetween200and295ml/100g.

7.Asilicaaccordingtoclaim1,havingaporedistributionandaporevolumesuchthattheporevolumeconsistingoftheporeswhosediameterisbetween175and275.ANG.representsatleast50%oftheporevolumeconsistingoftheporesofdiameterssmallerthanorequalto400.ANG..

8.Asilicaaccordingtoclaim1,beingintheformofsphericalbeadswithameansizeofatleast80.mu.m.

9.Asilicaaccordingtoclaim8,whereinsaidmeansizeisofatleast150.mu.m.

10.Asilicaaccordingtoclaim1,beingintheformofpowderwithameansizeofatleast15.mu.m.

Description

Thepresentinventionrelatestoanewprocessforthepreparationofprecipitatedsilica,toprecipitatedsilicaswhichareinparticularintheformofpowder,ofsubstantiallysphericalbeadsorofgranules,andtotheirapplicationasareinforcingfillerforelastomers.

Itisknownthatprecipitatedsilicahasbeenemployedforalongtimeasawhitereinforcingfillerinelastomers.

However,likeanyreinforcingfiller,itisappropriatethatitshouldbecapableof,ontheonehand,beinghandledandaboveall,ontheotherhand,ofbeingeasilyincorporatedintothemixtures.

Itisknowningeneralthat,toobtaintheoptimumreinforcingpropertiesconferredbyafiller,itisappropriatethatthelattershouldbepresentintheelastomermatrixinafinalformwhichisbothasfinelydividedaspossibleanddistributedashomogeneouslyaspossible.However,suchconditionscanbeachievedonlyinsofaras,ontheonehand,thefillerhasaverygoodabilitytobeincorporatedintothematrixduringmixingwiththeelastomer（incorporabilityofthefiller）andtodisintegrateortodeagglomerateintotheformofaveryfinepowder（disintegrationofthefiller）andas,ontheotherhand,thepowderresultingfromtheabovementioneddisintegrationprocesscanitself,initsturn,beperfectlyandhomogeneouslydispersedintheelastomer（dispersionofthepowder）.

Moreover,forreasonsofmutualaffinities,silicaparticleshaveanunfortunatetendency,intheelastomermatrix,toagglomeratewitheachother.Thesesilica/silicainteractionshaveadetrimentalconsequenceoflimitingthereinforcingpropertiestoalevelthatissubstantiallylowerthanthatwhichitwouldbetheoreticallypossibletoexpectifallthesilica/elastomerinteractionscapableofbeingcreatedduringthemixingoperationwereactuallyobtained（thistheoreticalnumberofsilica/elastomerinteractionsbeing,asiswellknown,directlyproportionaltotheexternalsurfaceofthesilicaemployed）.

Furthermore,intherawstate,suchsilica/silicainteractionstendtoincreasethestiffnessandtheconsistencyofthemixtures,thusmakingthemmoredifficulttoprocess.

Theproblemarisesofhavingavailablefillerswhich,whilebeingcapableofbeingrelativelylargeinsize,improvetheTheologicalpropertiesofelastomersandadvantageouslyhaveagooddispersibilityinelastomers.

Theaimofthepresentinventionistoovercometheabovementioneddisadvantagesandtosolvetheabovementionedproblem.

Moreprecisely,itsaimisespeciallytoproposeanewprocessforthepreparationofprecipitatedsilicawhich,advantageously,hasagooddispersibility（anddisintegratability）andverysatisfactoryreinforcingproperties,inparticularwhich,whenemployedasareinforcingfillerforelastomers,impartsexcellentrheologicalpropertiestothelatterwhileprovidingthemwithgoodmechanicalproperties.

Theinventionalsorelatestoprecipitatedsilicaswhich,preferably,areintheformofpowder,ofsubstantiallysphericalbeadsor,optionally,ofgranules,andwhich,whilebeingofrelativelylargesize,haveverysatisfactoryreinforcingpropertiesand,inapreferredmanner,averygooddispersibility（anddisintegratability）.

Itrelates,finally,totheuseofthesaidprecipitatedsilicasasreinforcingfillersforelastomers.

Inthedescriptionwhichfollows,theBETspecificsurfaceisdeterminedaccordingtotheBrunauer-Emmett-TellermethoddescribedintheJournaloftheAmericanChemicalSociety,Vol.60,page309,February1938andcorrespondingtoNFTstandard45007（November1987）.

TheCTABspecificsurfaceistheoutersurfacedeterminedaccordingtoNFTstandard45007（November1987）（5.12）.

TheDOPoiluptakeisdeterminedaccordingtoNFTstandard30-022（March1953）byusingdioctylphthalate.

Thepackingdensity（PD）ismeasuredaccordingtoNFTstandard030100.

ThepHismeasuredaccordingtoISOstandard787/9（pHofasuspensionataconcentrationof5%inwater）.

Finally,itisspecifiedthatthegivenporevolumesaremeasuredbymercuryporosimetry,theporediametersbeingcalculatedfromtheWashburnrelationshipwithanangleofcontactthetaequalto130.degree.andasurfacetensiongammaequalto484dynes/cm（MICROMERITICS9300POROSIMETER.RTM.）.

Thedispersibilityandthedisintegratabilityofthesilicaaccordingtotheinventioncanbequantifiedbymeansofaspecificdisintegrationtest.

Thedisintegrationtestiscarriedoutaccordingtothefollowingprocedure:

thecohesionoftheagglomeratesisassessedbyaparticlesizemeasurement（usinglaserscattering）,performedonasilicasuspensionpreviouslydisintegratedbyultrasonictreatment;

thedisintegratabilityofthesilicaisthusmeasured（ruptureofobjectsfrom0.1toafewtensofmicrons）.ThedisintegrationunderultrasoundisperformedwiththeaidofaVIBRACELLBIOBLOCK（600W.RTM.）sonictransducerequippedwithaprobe19mmindiameter.TheparticlesizemeasurementisperformedbylaserscatteringonaSympatecparticlesizeanalyser.

2gramsofsilicaaremeasuredoutintoaspecimentube（height:

6cmanddiameter4cm）andaremadeupto50gramsbyaddingdemineralizedwater;

anaqueoussuspensioncontaining4%ofsilicaisthusproduced,whichishomogenizedfor2minutesbymagneticstirring.Thedisintegrationunderultrasoundisnextperformedasfollows:

withtheprobeimmersedtoadepthofcm,thepowerisadjustedsoastoobtainaneedledeflectiononthepowerdialindicating20%（whichcorrespondstoanenergyof120watts/cm.sup.2