I-Tetramethoxymethyl glycoluril (TMMGU), i-TGIC yoTshintsho lweKhemistri
I-Tetramethoxymethyl glycoluril (TMMGU),
TGIC Replacement Chemistries
I-Hydroxyl polyester / i-TMMGU inhlanganisela, efana ne-powderlink 1174, ephuhliswe yi-Cytec, inokunika ithuba elihle kakhulu lokutshintsha i-TGIC kwizicelo ezifuna ukwakhiwa kwefilimu encinci. Njengoko le khemistri yonyango iyindlela yokusabela kwi-condensation, ezinye zeengxaki zesicelo ezichazwe kwicandelo le-HAA yonyango nazo zenzeka ngolu nyango. Nangona kunjalo, uphononongo lwakutsha nje kunye nedatha ibonisa ukuba umngxuma wokugquma wasimahla unokufumaneka nge-hydroxyl polyester / TMMGU indibaniselwano naxa ukwakhiwa kwefilimu kudlula i-4 mils.
Olu hlobo lwekhemistri ludinga i-acid catalyst enamandla, njenge-methyltolylsulfonimide (MTSI) okanye i-cyclamic acid (CA). I-Acid catalysts ineentsilelo ezithile: ukugcinwa kwexesha elide kwe-acid-catalyzed electrostatic yengubo inokutshintsha ukusebenza kwakhona kweendlela ezinjalo. Kwaye ezinye iicatalysts zeasidi zinokuchaphazeleka, okanye neutrali-ized, ngee-pigments ezisisiseko okanye izihluzi, ezifana ne-calcium carbonate, ngaphandle kokuba ezi zixhobo zifakwe ngaphambili okanye zigqunywe.
Ukusetyenziswa kwe-acid catalysts kunokubangela iingxaki ze powder formulators ngokwemiqathango yedosi ye-catalyst kunye nokukhethwa kwezizalisi. Iireyini ezifakwe ngaphambili ( ngaphakathi catalyzed ) sele zifumaneka ngokurhweba , zinika enye indlela yokuyilungisa nge , kunye nokuphathwa kwe, catalysts zeasidi. Eyona nto ingathandekiyo enkulu yeresin esele ifakwe ngaphambili kukuba azivumeli ii-formulators ukuba zilungelelanise unyango lweenkqubo ze-TMMGU.
Ii-catalyts ze-asidi ezivaliweyo kunye nezingavaliweyo zisebenza ngohlobo lwe-TMMGU lwekhemistri. Ekubeni iinkqubo ze-TMMGU eziqulethe i-acids evaliweyo kufuneka zivule ukuze zisebenze, zenza ufuzoralIfuna amaqondo obushushu aphezulu okubhaka okanye amaxesha amade okubhaka kuneefomyula ezineeasidi ezingavalwanga. I-acids evaliweyo inozinzo olungcono lokugcinwa kunye nokunyamezela okuphezulu kwee-pigments ezisisiseko kunye nezihluzi kune-acids ezingavaliweyo, nangona kunjalo. Ngaphezu koko, umsebenzi wakutsha nje kunye ne-nonyellowing amine ivalwe i-MTSI ivelise umgubo owakha ukuya kuthi ga kwi-4 ukuya kwi-5 mils (i-100 ukuya kwi-125 microns) ngaphandle kweziphene ezibonakalayo. I-advanteji yeeasidi ezingavalwanga kukuba zibonelela ngamaqondo obushushu onyango ngokwesiqhelo angaphantsi kunalawo e-TGIC okanye iinkqubo ze-IPDI.
I-MTSI ivelisa i-gloss finishes ephezulu ngelixa i-CA ivelisa iimveliso ezinoluhlu lwegloss phakathi kwe-low kunye ne-intermediate ngaphandle kwesidingo se-flatting agents. Iifilimu ezifayo ezifayo zinokufumaneka ngokudibanisa amanani amancinci e-CA kwi-resin esele ifakwe ngaphambili.
Imveliso ye-condensation evela kwi-polyester/TMMGU yokusabela yi-methanol, ephakamisa iinkxalabo zokusingqongileyo, ngakumbi kwi-applications ye-powder coatings. Ukunyanga amanqanaba aguquguqukayo e-methanol alinganiswe malunga ne-1 ukuya kwi-1.5 yepesenti yobunzima obupheleleyo. I-TMMGU ikwakhupha ama-300 ukuya kuma-600 ppm e-formaldehyde (kwizinto eziqinileyo zepeyinti) ngexesha lokunyanga. Oku, nangona kunjalo, malunga namaxesha angama-20 ngaphantsi kwexabiso le-melamine aminoplast yonyango eveliswayo kwi-coating yesiqhelo.
Kwicala elincomekayo, inkqubo ye-TMMGU ibonelela ngeendidi ngeendidi zeemveliso ezinokwenzeka ukusuka ekubhetyebhetye ngokugqithisileyo ukuya koqina kakhulu, ngaphandle kweeyaleko ezingafakwanga. Ukuhamba, ukulinganisa, kunye neempawu zemozulu ziyimfuzarally kuhle kakhulu ukugqwesa .Idatha ye-QUV evela kwi-powders eyenziwe nge-hydroxy polyester / TMMGU /MTSI ecacileyo iinkqubo zibonisa ukuba i-powders enjalo igcina ngaphezu kwe-70 yepesenti yeglosi emva kwe-1000hours yokuvezwa xa iqulunqwe ngaphandle kwe-UV absorbers. Xa yenziwe nge-Absorbeers ye-UV, umgubo ugcina i-85 ukuya kwi-90 yepesenti yeglosi. Oku kuthelekisa ngokuncomekayo ne-TGIC kunye neenkqubo ze-IPDI. EFlorida uvavanyo lwe-exposure, ezinye iinkqubo ze-TMMGU ziye zamelana neenyanga ze-20 zemozulu ngaphandle kokulahlekelwa okubonakalayo kwe-gloss.
I-Tetramethoxymethyl glycoluril (TMMGU)