Ngenxa yenkqubo yokuvelisa i-urea formaldehyde resin, uphuhliso loshishino lwemelamine lufumene inkqubo ekhawulezayo.Uxwebhu lophando lwachaza okokuqala nge-synthesis ye-melamine resin ngo-1933. Inkampani yaseMelika iCyanamide yaqala ukuvelisa kunye nokuthengisa i-melamine powder laminates kunye ne-coatings njl ngo-1939. Kwiminyaka ye-1950 kunye ne-1960s, iJapan yaqaphela ushishino olupheleleyo lwei-melamine yokubumba ikhompawundi.Ngeminyaka yee-1960, iChina yaqala ukwazisa ubuchwepheshe bokuvelisa i-melamine.Emva kwamashumi eminyaka yophuhliso, umthamo wemveliso yeemveliso ze-melamine ngoku uphezulu kwihlabathi, ubala ngaphezu kwe-80 9/6 yesabelo semarike yehlabathi.
Ukuze ukwazi ngakumbi malunga ne-melamine powder, makhe sijonge inkqubo yokuvelisa i-melamine powder kuqala.
Eyona nto iphambili yemveliso ye-melamine yi-melamine yokubumba ikhompawundi, ekwabizwa ngokuba yi-melamine formaldehyde resin powder okanye i-melamine powder.Eyona nto ingundoqo ye-melamine powder yi-melamine resin ene-reactivity ephezulu kunye nokuxhamla.I-melamine resin yi-polymer ephezulu ye-dandelion eyenziwe yi-chemical reaction ye-melamine kunye nesisombululo se-formaldehyde esimanzi phantsi kweemeko ezingqongqo.Ukusabela ngokuqhelekileyo kuqhutyelwa kwi-reactor exhotyiswe ngeyunithi yokuvuselela, ukufudumeza kunye nokujiya, ngokubanzi kwiinqanaba ezimbini.
1. Inyathelo lokuqala yimpendulo yokongeza.Okokuqala, yongeza i-37% yesisombululo se-aqueous formaldehyde kwisitya sokusabela kwaye ulungelelanise i-pH kwi-7-9 ukufumana i-alkaline engathathi hlangothi okanye engenamandla.Emva koko yongeza umlinganiselo ofanelekileyo we-melamine ukwenza i-moore formaldehyde kunye ne-melamine phakathi kwe-2 kunye ne-3. Ubushushu be-reactor buhlengahlengiswe ukuze bufudumale ngokukhawuleza ukuya kwi-60-85 ° C. Ngeli xesha, i-formaldehyde kunye ne-melamine zavalwa yi-methylolation reaction. , kunye ne-linear melamine oligomer equkethe i-1 ukuya kwi-6 amaqela e-methylol yenziwe.Le mpendulo ingentla yi-exothermic reaction engabonakaliyo.Ukuphakama komlinganiselo we-formaldehyde, kulula ukwenza i-polymethylol melamine.
2. Inyathelo lesibini kukusabela kwe-condensation.Ngaphantsi kweemeko eziphezulu zokushisa, i-methylol melamine esebenzayo kakhulu iphinda i-etherified okanye i-polycondensed ukuvelisa i-crosslinked linear resin compound equkethe ibhondi ye-methylene okanye i-dimethylene ether bond.ngeendlela ze-intramolecular okanye zemolekyuli kwindawo eneasidi ephakathi.Xa inani leqela le-methylol lincinci, ibhondi ye-methylene idla ngokulawula;kwi-resin esekelwe kwi-sorghum, ibhondi ye-dimethylene ether yenziwa ngokubanzi, kwaye ibhondi ye-methylene yenziwe.Iqondo elikhulu lokujiya kwe-polycondensation reaction, iyancipha ukunyibilika kwamanzi kwisisombululo se-melamine formaldehyde resin kunye ne-viscosity enkulu.
Kule nkqubo yokusabela ingentla, ubunzima bemolekyuli yemveliso yokugqibela bumiselwa yimeko ethile yokusabela, kwaye ukunyibilika kwamanzi kwemveliso nako kutshintshiwe kakhulu.Iifom zemveliso zifumaneka ngokubanzi ukusuka kwizisombululo ze-resin ukuya kwizinto ezinganyibiliki kakuhle nezinganyibilikiyo nezingaxutywanga.Isisombululo se-resin sinozinzo olubi kwaye aluhambisani nokugcinwa.Kwimveliso yokwenyani, ihlala isetyenziswa njenge-substrate kunye nezinto ezingaphiliyo ezifana ne-d-cellulose, i-pulp yomthi, i-silica, ii-colorants zongezwa.Yenziwe ibe ngumgubo oqinileyo obizwa ngokuba ngumgubo we-melamine ngesitshizi sokumisa ibhola.
I-Huafu Chemicals yimveliso enjalo yokuvelisamelamine resin powder.Ukuba unomdla, nceda uqhagamshelane nathiEmail : melamine@hfm-melamine.com
Ixesha lokuposa: Sep-20-2019