Explanationofterms
1.Theuniquefragranceinthepineforest.
TangXuhun'spoem"SuKaiyuanTempleTower":"Thebamboocoloriscoldandclear,andtherosindyesthegreenscorpion."TangLuoye"SpringPassestheShouanMountainPavilion"poem:"ThecurtainopensthemountainandthecolorleavesthepavilionIntheafternoon,stepintothespringofRosinIsland."
2.Thealiasofrosin.
MingLiShizhen"CompendiumofMateriaMedica·Muyi·Song":"Rosin,alsoknownaspinecream,pinefat,pinegum,androsin."
3.Referstothesubstanceafterrosindistillation.Solid,transparent,insolubleinwater,hardandbrittle,lightyelloworbrown.Itisanindustrialrawmaterialforthemanufactureofpaint,soap,paper,matches,etc.
Basicmeaning
1.Theuniquefragranceinthepineforest.
2.Alsoknownaspinecream,pinefat,andpineglue.
3.Referstothesubstanceafterthedistillationofrosin.Solid,transparent,insolubleinwater,solubleinalcohol,hardandbrittle,lightyelloworbrown.Itisanindustrialrawmaterialformakingpaint,soap,paper,matches,etc.
4.Rosinistheoilfromthepinetreetrunkthatismeltedintowaterathightemperature,andbecomesamassivesolid(withoutafixedmeltingpoint)afterdrying.Itscolorisbrownanddeepred.Itisanimportantchemicalrawmaterial.Indailylife,itismainlyusedasafluxwhensolderingcircuitboards.Formusicalinstruments,rosinisappliedtothebowhairsoferhu,violin,matouqinandotherstringinstrumentstoincreasethefrictionbetweenthebowhairandthestrings.Forlearningballet,rosinplaysanon-slipeffect.
Physicalandchemicalproperties
Accordingtoitssource,rosincanbedividedintothreetypes:gumrosin,woodrosin,andtalloilrosin.Gumrosinisalsocalledrelaxingfragrance,withlightcolor,highacidvalueandhighsofteningpoint;woodrosinisalsocalledextractrosin,itsqualityisnotasgoodasgumrosin,itscolorisdark,itsacidvalueissmall,anditiseasytocrystallizefromsomesolvents;talloilrosinAlsoknownastalloilrosin.Rosinisatransparent,brittlesolidnaturalresin,whichisarelativelycomplexmixture,composedofresinacids(abieticacid,pimaricacid),asmallamountoffattyacids,rosinacidanhydrideandneutrals.Themaincomponentofrosinisresinacid,whichaccountsforabout90%.ItsmolecularformulaisC19H29COOH,anditsmolecularweightis302.46.Resinacidisthemostrepresentativerosinacid.Itisanunsaturatedacidandcontainsconjugateddoublebonds.Itstronglyabsorbsultravioletlightandcanbeoxidizedautomaticallyorafterinductionintheair.Theappearanceofrosinislightyellowtolightbrown,withglassyluster,withthesmellofturpentine,andthedensityis1.060~1.085g/cm3.Itisamorphous,hasnomeltingpoint,softeningpoint(ringandballmethod)72～76℃,boilingpointabout300℃(0.67kPa).TheglasstransitiontemperatureTgis30～38℃.Therefractiveindexis1.5453.Flashpoint(opencup)216℃.Theignitionpointisabout480~500℃.Itiseasytooxidizeintheair,andthecolorbecomesdarker.
Itissolubleinethanol,ether,acetone,toluene,carbondisulfide,dichloroethane,turpentine,petroleumether,gasoline,oilandalkalisolutions.Reducedsolubilityingasoline.Insolubleincoldwater,slightlysolubleinhotwater.Rosinhasexcellentpropertiessuchasviscosityincreasing,emulsification,softening,moisture-proof,anti-corrosion,andinsulation.Thedisadvantageisthatithasalargetendencytocrystallizeinsolvents.Thecrystallinityofrosinisduetothedifferentsolubilityofisomersinrosininsomesolventsandthedifferenceinwatercontentinrosin.Thecontentofrosinperfume<0.15%doesnotcrystallize>0.15%easilycrystallizes>0.16%crystallizesbadly.Rosincrystallizationisoneoftheimportantproblemsthataffectthequalityofrosin.Itwillcauseflocculentorprecipitatesmallparticlesintheadhesive,andalsomaketheglueliquidopaque.Thecrystallinityofrosincanbetestedbythefollowingmethod:take10gofrosinfragmentsand10mLofacetoneintoatesttube,plugtightly,dissolve,andletstand.Ifitcrystallizeswithin15minutes,therosiniseasytocrystallize;ifitdoesnotseparateoutafter2h,Itshowsthattherosinisnoteasytocrystallizeandcanbeusedwithconfidence.
Thequalityofrosindependsonitscolor,acidvalue,softeningpoint,transparency,etc.Generally,thelighterthecolor,thebetterthequality;themorerosinacidcontent,thegreatertheacidvalueandthehigherthesofteningpoint.
Rosinhasverygoodviscosity,especiallypressuresensitivity,fastviscosity,andlowtemperatureviscosity,butithaspoorcohesion.Becauserosincontainsdoublebondsandcarboxylgroups,ithasstrongreactivity,soitislessstabletolight,heatandoxygen,exhibitspooragingresistance,poorweatherresistance,andispronetochalkinganddiscoloration.TherosinisextremelyfineThemixtureofdustandairhasanexplosionhazard.Rosinisdividedinto6grades:special,one,two,three,four,andfive.
Sourceprocessing
Gumrosin
Therosinobtainedbycollectingrosinintheformofharvestingandreprocessingiscalledgumrosin.Itscharacteristicisthatthepinetreescanbeharvestedcontinuously,whichisconducivetothefulluseofresources.Chinaisrichinrosinresourcesandisthecountrywiththelargestoutputofgumrosin.Theoutputofgumrosinwillremainabove350,000tonsforalongtime.Therefore,itisestimatedthatinthenext20-30years,theannualoutputofgumrosinintheworldcanstillbemaintainedat650,000-700,000tons.
Woodrosin
Itistherosinthatisrefinedbycuttingpinerootsortreetrunks,leachingouttheresinwithasolvent,andprocessing.MainlyproducedintheUnitedStates,therawmaterialsaredependentontheprimitivepineforestsinthesoutheastofthecountry.Duetothereductionofforestresources,therawmaterialofwoodrosinisinshortsupply.Theoutputdroppedfrom316,000tonsin1950to20,000tons.WoodrosinwasalsoproducedintheformerSovietUnion,andtheoutputalsodroppedsharplyduetoreducedresources.Itisestimatedthattheworld'scurrentwoodrosinproductiononlyaccountsforlessthan5%ofthetotalrosin.
Highoilrosin
Itcomesfromthewoodpulpingandpapermakingindustry.Itisobtainedfromtheblackliquorrecoveredfromthekraftpulpingprocess.Itwasoriginallynotasgoodasgumrosininperformance.Later,duetoitsqualityWithcontinuousimprovement,theperformanceisnowsimilartothatofgumrosin.Duetothereductionintheproportionofpineusedinpapermaking,therosinyieldfromslickoilfractionationwasreduced(from27%to21%).Therefore,althoughthefractionationcapacityofcrudeoilhasincreasedinrecentyears,theoutputofhighoilrosinhasremainedrelativelystable,accountingforabout30%-35%ofthetotalrosin.
Qualityindex
Metricname | SpecialClass | FirstClass | Level2 | Level3 | Level4 | Level5 |
Appearance | Transparenthardandbrittlesolid | |||||
Color | Slightyellow | Lightyellow | Yellow | Darkyellow | Yellowbrown | Yellowred |
Softeningpoint(ballandballmethod)/℃≥ | 76 | 76 | 75 | 75 | 74 | 74 |
acidvalue/(mgKOH/g)≥ | 166 | 166 | 165 | 165 | 164 | 164 |
Unsaponifiablemattercontent/%≤ | 5 | 5 | 5 | 6 | 7 | 7 |
Ethanolinsolublematter/%≤ | 0.03 | 0.03 | 0.03 | 0.03 | 0.04 | 0.04 |
Ash/%≤ | 0.02 | 0.02 | 0.03 | 0.03 | 0.04 | 0.04 |
Industrialapplication
Rosinisoftenusedasatackifierinhotmelt,pressuresensitiveandsolvent-basedadhesivesResin,increaseinitialviscosityandimprovebondingstrength.Rosincanalsoimprovethedrynessandpeelingstrengthofthewater-basedacryliccompoundfilmadhesive,andthebestdosageis6%ofthetotalmonomer.Rosinisaweaklyacidicsubstance.IftheamountofSBStypeuniversalglueorsprayglueistoolarge,itwillcausetheironpackagingtobecorroded,causingthegluetoquicklyturnbrownandblack.Althoughitdoesnotaffectthebondingperformance,theappearanceisItissuspicious.
Rosinisverysensitivetotheeffectsoflight,heat,andoxygen,especiallyinpowderform,whichisveryeasytooxidize,soitshouldbestoredasawholetopreventoxidationfromdarkeningitscolorandchangingitsproperties.Whenthesurfaceofthebulkrosinisoxidized,anoxidefilmisformed,whichcanpreventfurtheroxidationoftheinternalrosin.Moisturecanacceleratetheoxidationprocessofrosinandreleaseaceticacidduringdeepoxidation.Rosinisaveryimportantchemicalrawmaterialandiswidelyusedinvariousindustrialsectors.Itsmainusesareasfollows:
Soapindustry
Rosiniscookedtogetherwithsodaashorcausticsodatoformrosinsoap.Rosinsoaphasgreatdetergency,iseasilysolubleinwater,candissolvegrease,andiseasytofoam.Rosinisstickyandcanmakesoaplesslikelytocrackandrancid.
Papermakingindustry
Rosinisusedasapapermakingcompoundinthepapermakingindustry.Rosinandcausticsodamakerosinsodiumsoap,namelysizingmaterial.Thesizingmaterialismixedwithpulpandaddedwithalumtomaketherosinbecomewater-insolublefreeresinacidparticlesattachedtothesmallfibers.Whenthepulpisrolledonthedryingcylinder,itisheatedWhentherosinsoftensandfillsbetweenthefibers,thiseffectiscalled"sizing"or"sizing".Afterthepaperis"glued",itcanenhancewaterresistance,preventinkpenetration,improvestrengthandsmoothness,andreducestretch.
Paintandcoatingindustry
Rosiniseasytodissolveinvariousorganicsolvents,anditiseasytoformafilmandhasluster.Itisoneofthebasicrawmaterialsforpaintandcoating.Theroleofrosininthepaintistomakethepaintbrighter,dryquickly,andthepaintfilmissmoothandnoteasytofalloff.
InkIndustry
Rosinismainlyusedasavehicleinprintinginksandenhancestheadhesionofinktopaper.Ifrosinisnotusedintheink,theprintedinkwillhaveadullandblurredtone.
Adhesiveindustry
Adhesivesbasedonrosinestersandhydrogenatedrosinestersareoftenusedashot-meltadhesives,pressure-sensitiveadhesivesandrubberadditives.Adhesive.
Rubberindustry
Rosinisusedasasoftenerintherubberindustrytoincreaseitselasticity.Potassiumdisproportionatedrosinsoapcanbeusedassyntheticrubber.
Foodindustry
Heatandmelthydrogenatedrosinglyceridewithnaturalcarbohydrategum,wax,vinylacetate,etc.,andthenaddspices,sugarandcoloringstomixthoroughlytomakechewinggum.Whenslaughteringpigs,cattleandsheepintheslaughterhouse,afterusingdehairingmachinery,thehairleftontheanimal'sbodyandheadcanbeusedasadepilatorycomposedof88-94%moltenrosinand6-12%cottonseedoilToremove.
Electricalindustry
Use35%rosinand65%brightoiltomakeinsulatingoil,whichisusedasaprotectivefilmonthecabletoprovideinsulationandheatresistance.Rosinismixedwithbakeliteandotherartificialresinstobeusedasinsulatingvarnish.
Buildingmaterialsindustry
Rosinismainlyusedasconcretefoamingagentandfloortilebinderinbuildingmaterialsindustry.Rosinisalsousedasabinderforvinylchlorideasbestostiles.Rosinandlinseedoil,calciumcarbonate,charcoal,pigments,etc.canbemixedtogethertomakecarpettiles.
MakingFixingLiquid
Becauseofthesolubility,volatility,andtheprinciplethatrosincanquicklycondenseintoalayerof"sturdyandtransparentfilm"aftervolatilization,theartistprotectsthepictureandprevents""Sketchdrawing"isrubbedoff,andusuallymakea"fixeddrawing"liquidbyyourself,thatis:onepartofrosinpowder,ninepartsofalcohol,orxylenesolventratio,firstputtherosininawell-sealedglassware,andthenputthealcohol,Orxylene,pouritin,closethelid,anddissolveitbyitselftwodayslater.Whenitisused,shakeitandpouritintothewateringcan,20cmawayfromthescreen,andsprayevenlyonthescreen,sprayatanytime,volatilizeatanytime,itwilldryoutafterafewminutes,andyouwillnotbeafraidofbeingrubbedoffinthefuture.Note:Thereshouldnotbetoomuchrosin,itwillturnyellowanddarkifitistoomuch.
Flux
Sincethemetalsurfaceisincontactwithair,anoxidefilmwillbeformed.Thehigherthetemperature,thethickertheoxidelayer.Thisoxidefilmpreventsliquidsolderfrominfiltratingthemetal,justasoilonglasspreventswaterfrominfiltratingtheglass.Fluxisaspecialmaterialtoremoveoxidefilm,alsoknownasflux.Fluxhasthreefunctions:
1.Removalofoxidefilm:Theessenceisthatthesubstanceinthefluxundergoesareductionreactiontoremovetheoxidefilm,andthereactionproductbecomesasuspendedslag,Floatingonthesoldersurface.
2.Preventoxidation:Afteritmelts,itfloatsonthesurfaceofthesoldertoformanisolationlayer,thuspreventingtheoxidationofthesolderingsurface.
3.Reducesurfacetension:Increasesolderfluidityandhelpsoldertowettheweldment.
Instrumentattached
Rosinisappliedtothebowhairoferhu,violinandotherinstrumentstoincreasethefrictionofthebowhaironthestrings.Therefinedtransparentlumpyrosinisthebest,andthenaturalcrystallinerosinsecretedandsolidifiedfromtheChinesepinecanalsobesubstituted.
Thepopularfolkmethodofrosinistosplitabamboopieceintoacrackinadvance,andthensandwichtherosininit.Thenignitethebamboosliceswithfire,maketherosinhotanddripitonthepianotube.Thismethodiscalled"hotincense".Althoughburningincenseismoreconvenientandtrouble-freeforplaying,ithinderstheperformanceofcertainbowingtechniques.Atthesametime,thepianotubeandtheskinarenotcleanenough.
Themorepopularoneis"scenting",whichmeansusingrosintowipethebowhairsbackandforthrepeatedly.Afterrubbingtherosininthisway,itcanpullatleastanhour.Practicehasprovedthatthesoundofthepianojustafter"smearingthefragrance"isnotverysatisfactory.Ittakestwoorthreeminutestoplaythepianobeforeitgraduallybecomesnormal.Whenrubbingthefragrance,donotusetoomuchforcetoavoidbreakingthebowhair.
Theoldrosinwillbeeffectiveonlyafewhoursafterusingthenewrosin.
Withoutrosin,thebowwillbeslipperywhenpulledonthestringsandwillnotmakeasound.Withalittlerosin,thebowhairwillhavesomestickiness,andwhenitisplayed,itwill"grab"thestringandmakeitvibratetomakeasound.Whenrosinisbought,itiswrappedinclothorasmallbox.Itisnotonlystickybutalsoveryhard.Generally,itcanbeusedforalongtime.Thehardertherosin,theeasieritistobreak.
Manybrandsofrosincomeintwocolors,butthepriceisthesame,thelighterislikehoney,andthedarkerislikelicorice.Whenplaying,therosinwillturnintopowder,anditscolorwillbethesamewhiteatthistime.
Thehardnessofrosinisveryhigh.Therosinofonebrandmaybeharderthantherosinofanotherbrand.Whentherosinispressedhardwiththebow,thehardnesscanbeidentified.Thesoftrosinwillmakethestringsvibratebetter,butbecauseitistoosticky,itiseasytoproducenoise,especiallyonthegutstrings.
Color
Therosincolorisatransparentandbrightcolorthattheancientsusedgarciniaororpimenttomixwithwaterinastrictratio(about5:2).Itismostlyusedtodyewindowscreensandbelongstohigh-gradedyes.CaoXueqinmentionedin"ADreamofRedMansions"and"WaiyizhaiManuscript"thatoneoftheancient"softsmoke"windowscreenswasrosincolored.
Toxicityhazard
Industrialrosinismainlyusedinpaint,papermaking,rubbermanufacturing,etc.Itisnotverytoxictothehumanbody,butbecauseitoftencontainsheavymetalssuchasleadandtoxiccompounds,andtheperoxideproducedafteroxidationwillseriouslyaffecthumanhealth.
InApril2012,CCTVreportedthatattheYangjiashanPoultryWholesaleMarketinChangshaCity,HunanProvince,vendorsusedindustrialrosintofurnishducksinoneminute.Asaresult,themarketwasinvestigatedanddealtwithbythelocalfoodsafetyandindustryandcommercedepartmentsandclosedforrectification.Lawenforcementofficialssaidthatrosinduckcontainsheavymetalsandothertoxiccompounds,whichcancausecancer.