Ikhemistri ye-UV eqhutywa ngamanzi (WB) ibonise ukukhula okukhulu kwiimarike zeenkuni zangaphakathi kuba ubuchwepheshe bubonelela ngokusebenza okugqwesileyo, ukukhutshwa kwe-solvent ephantsi kunye nokusebenza kakuhle kwemveliso okwandisiweyo. Iinkqubo zokugquma i-UV zibonelela umsebenzisi wokugqibela ngeenzuzo zokuxhathisa iikhemikhali kunye nokukrwela okugqwesileyo, ukumelana okuhle kweebhloko, ii-VOC eziphantsi kakhulu kunye nomgangatho wezixhobo ezincinci kunye nendawo encinci yokugcina efunekayo. Ezi nkqubo zineempawu ezithelekiswa kakuhle neenkqubo ze-urethane ezinamacandelo amabini ngaphandle kweengxaki ze-crosslinkers ezinobungozi kunye neengxaki zobomi beembiza. Inkqubo iyonke ixabisa kakhulu ngenxa yesantya sokuvelisa esonyukayo kunye neendleko zamandla eziphantsi. Ezi zibonelelo zifanayo zinokuba luncedo kwizicelo zangaphandle ezisetyenziswa ngumzi-mveliso kubandakanya iifreyimu zeefestile kunye neengcango, i-siding kunye neminye imisebenzi yokugaya. Ezi candelo zemarike zisebenzisa i-acrylic emulsions kunye ne-polyurethane dispersions kuba zinokukhanya okuhle kunye nokugcinwa kombala, kwaye zibonisa ukuqina okuphezulu. Kolu phononongo, ii-resin ze-polyurethane-acrylic ezine-UV zivavanyiwe ngokweenkcazo zoshishino kwizicelo zeenkuni zangaphakathi nezangaphandle zemizi-mveliso.
Iintlobo ezintathu zeengubo ezisekelwe kwi-solvent zisetyenziswa kakhulu kwizicelo zeenkuni zoshishino. I-Nitrocellulose lacquer idla ngokuba ngumxube we-nitrocellulose kunye neeoyile okanye ii-alkyd ezisekelwe kwioyile. Ezi ngubo zoma ngokukhawuleza kwaye zinamandla okukhazimla aphezulu. Zihlala zisetyenziswa kwizicelo zefenitshala yokuhlala. Zinengxaki yokuba tyheli ngokuhamba kwexesha kwaye zinokuba buthathaka. Zikwanakho nokumelana kakuhle neekhemikhali. Ii-lacquer ze-Nitrocellulose zine-VOCs eziphezulu kakhulu, zihlala kwi-500 g/L okanye ngaphezulu. Ii-lacquer ezilungiselelwe kwangaphambili ziindibaniselwano ze-nitrocellulose, iioyile okanye ii-alkyd ezisekelwe kwioyile, iiplastiki kunye ne-urea-formaldehyde. Zisebenzisa i-catalyst ye-asidi ebuthathaka efana ne-butyl acid phosphate. Ezi ngubo zinobomi beshelufu obumalunga neenyanga ezine. Zisetyenziswa kwifenitshala yeofisi, yesikhungo neyendawo yokuhlala. Ii-lacquer ezilungiselelwe kwangaphambili zinokumelana ngcono neekhemikhali kunee-lacquer ze-nitrocellulose. Zikwanakho nee-VOCs eziphezulu kakhulu. Ii-varnishes zokuguqulwa ziindibaniselwano zee-alkyd ezisekelwe kwioyile, i-urea formaldehyde kunye ne-melamine. Zisebenzisa i-asidi enamandla e-catalyst efana ne-p-toluene sulfonic acid. Zinobomi bembiza obuziiyure ezingama-24 ukuya kuma-48. Zisetyenziswa kwiikhabhathi zasekhitshini, kwifenitshala yeofisi nakwiindawo zokuhlala. Ii-varnish zokuguqula zineempawu ezilungileyo kwiintlobo ezintathu zeengubo ezisekelwe kwi-solvent ezisetyenziswa kakhulu kwiinkuni zemizi-mveliso. Zinee-VOC eziphezulu kakhulu kunye nokukhutshwa kwe-formaldehyde.
Ii-emulsion ze-acrylic ezizidibanisa ngokwazo emanzini kunye ne-polyurethane dispersions zinokuba zezinye iindlela ezilungileyo endaweni yeemveliso ezisekelwe kwi-solvent kwizicelo zeenkuni zemizi-mveliso. Ii-emulsion ze-acrylic zibonelela ngokumelana okuhle kakhulu kweekhemikhali kunye neebhloko, amaxabiso aphezulu obulukhuni, ukuqina okugqwesileyo kunye nokumelana nemozulu, kunye nokunamathela okuphuculweyo kwiindawo ezingenazimbobo. Zinexesha elikhawulezayo lokoma, okuvumela ikhabhinethi, ifenitshala okanye umenzi wemveliso yokwakha ukuba aphathe iindawo ngokukhawuleza emva kokusetyenziswa. Ii-PUD zibonelela ngokumelana okuhle kokukrweleka, ukuguquguquka, kunye nokumelana nokukrweleka kunye nokonakala. Zingamaqabane amahle okuxuba kunye nee-emulsion ze-acrylic ukuphucula iimpawu zoomatshini. Zombini ii-emulsion ze-acrylic kunye nee-PUD zinokusabela kwiikhemikhali ezidibanisayo ezifana nee-polyisocyanates, i-polyaziridine okanye ii-carbodiimides ukwenza iingubo ze-2K ezineempawu eziphuculweyo.
Iingubo ezinyangwa ngamanzi ze-UV ziye zaba lukhetho oludumileyo kwiimveliso zeenkuni zemizi-mveliso. Abavelisi beekhabhathi zasekhitshini kunye nefenitshala bakhetha ezi ngubo kuba zinokumelana okuhle kunye neempawu zoomatshini, iimpawu ezintle zokusetyenziswa kunye nokukhutshwa kwe-solvent ephantsi kakhulu. Iingubo ze-WB UV zinokumelana okuhle kakhulu kweebhloko emva kokulungiswa, okuvumela ukuba iindawo ezigqunyiweyo zibekwe, zipakishwe kwaye zithunyelwe ngqo kumgca wemveliso ngaphandle kwexesha lokuhlala lokuphuhliswa kokuqina. Uphuhliso lokuqina kwingubo ye-WB UV luyamangalisa kwaye lwenzeka ngemizuzwana. Ukumelana kweekhemikhali kunye namabala kweengubo ze-WB UV kungaphezulu kunoko kwee-varnish eziguqulweyo ezisekelwe kwi-solvent.
Iingubo ze-WB UV zinezibonelelo ezininzi. Ngelixa ii-oligomers ze-UV eziqinileyo eziyi-100% zihlala ziphezulu kwi-viscosity kwaye kufuneka zixutywe nee-reactive diluents, ii-WB UV PUDs ziphantsi kwi-viscosity, kwaye i-viscosity ingalungiswa ngee-modifiers ze-WB rheology zendabuko. Ii-WB UV PUDs ekuqaleni zinobunzima obuphezulu be-molecular kwaye azakhi ubunzima be-molecular njengoko ziphilisa kakhulu njenge-100% ye-UV eqinileyo. Ngenxa yokuba zincinci okanye azinciphisi kangako njengoko ziphilisa, ii-WB UV PUDs zinamathela kakuhle kwiindawo ezininzi. Ukukhazimla kwezi ngubo kulawulwa lula ngee-agents zendabuko zokuthambisa. Ezi polymers zinokuba nzima kakhulu kodwa ziguquguquke kakhulu, nto leyo ezenza zibe ngabaviwa abafanelekileyo kwiingubo zangaphandle zomthi.
Ixesha leposi: Matshi-07-2024
