Vim tias cov txheej txheem tsim khoom ntawm urea formaldehyde resin, txoj kev loj hlob ntawm melamine kev lag luam tau ntsib cov txheej txheem ceev heev.Cov ntaub ntawv tshawb fawb thawj zaug qhia txog kev sib txuas ntawm melamine resin nyob rau hauv 1933. America Cyanamide Company pib tsim thiab muag melamine hmoov laminates thiab coatings thiab lwm yam nyob rau hauv 1939. Nyob rau hauv lub 1950s thiab 1960s, Nyiv paub tag nrho cov industrialization ntawmmelamine molding compound.Nyob rau xyoo 1960, Tuam Tshoj pib ua kom paub cov tshuab melamine ntau lawm.Tom qab ntau xyoo ntawm txoj kev loj hlob, lub peev xwm ntawm cov khoom melamine yog tam sim no siab tshaj plaws nyob rau hauv lub ntiaj teb no, accounting rau ntau tshaj 80 9/6 ntawm lub ntiaj teb no ua lag luam feem.
Yuav kom paub ntau ntxiv txog melamine hmoov, cia peb saib cov txheej txheem tsim cov melamine hmoov ua ntej.
Lub ntsiab raw khoom ntawm melamine khoom yog melamine molding compound, tseem hu ua melamine formaldehyde resin hmoov los yog melamine hmoov.Lub ntsiab raw khoom ntawm melamine hmoov yog melamine resin nrog siab reactivity thiab crosslinkability.melamine resin yog high-dandelion polymer synthesized los ntawm tshuaj lom neeg cov tshuaj tiv thaiv ntawm melamine thiab aqueous formaldehyde tov nyob rau hauv nruj tej yam kev mob.Cov tshuaj tiv thaiv feem ntau yog ua nyob rau hauv lub reactor nruab nrog ib tug stirring, cua sov thiab condensing chav tsev, feem ntau nyob rau hauv ob kauj ruam.
1. Thawj kauj ruam yog cov tshuaj tiv thaiv ntxiv.Ua ntej, ntxiv 37% aqueous formaldehyde tov rau cov tshuaj tiv thaiv hlab ntsha thiab kho cov pH mus rau 7-9 kom tau txais ib qho nruab nrab lossis tsis muaj zog alkaline nruab nrab.Tom qab ntawd ntxiv qhov tsim nyog ntawm melamine los ua kom lub moore formaldehyde thiab melamine nyob nruab nrab ntawm 2 thiab 3. Qhov kub ntawm lub reactor raug kho kom nws maj mam rhuab mus rau 60-85 ° C. Lub sijhawm no, formaldehyde thiab melamine raug thaiv los ntawm cov tshuaj tiv thaiv methylolation. , thiab ib qho linear melamine oligomer uas muaj 1 txog 6 pawg methylol tau tsim.Cov tshuaj tiv thaiv saum toj no yog cov tshuaj tiv thaiv exothermic inexistible.Qhov siab dua qhov kev faib ua feem ntawm formaldehyde, qhov yooj yim dua nws yog tsim polymethylol melamine.
2. Cov kauj ruam thib ob yog cov tshuaj tiv thaiv condensation.Nyob rau hauv qhov kub thiab txias, lub siab reactive methylol melamine yog ntxiv etherified los yog polycondensed los ua ib tug crosslinked linear resin compound uas muaj ib tug methylene daim ntawv cog lus los yog ib tug dimethylene ether daim ntawv cog lus.los ntawm intramolecular los yog molecular txhais tau tias nyob rau hauv ib qho acidic nruab nrab ib puag ncig.Thaum cov pab pawg methylol me me, feem ntau ntawm methylene daim ntawv cog lus yog qhov tseem ceeb;Nyob rau hauv ib tug sorghum-raws li resin, ib tug dimethylene ether daim ntawv cog lus yog feem ntau tsim, thiab ib tug methylene daim ntawv cog lus yog tsim.Qhov ntau dua qhov condensation ntawm cov tshuaj tiv thaiv polycondensation, qhov qis dua cov dej solubility ntawm melamine formaldehyde resin tov thiab cov viscosity ntau dua.
Hauv cov txheej txheem tshuaj tiv thaiv saum toj no, qhov hnyav molecular ntawm cov khoom kawg yog txiav txim siab los ntawm cov tshuaj tiv thaiv tshwj xeeb, thiab cov dej solubility ntawm cov khoom kuj tseem hloov pauv.Cov ntaub ntawv khoom yog dav muaj los ntawm cov kev daws teeb meem rau cov tsis zoo soluble thiab insoluble thiab infusible solids.Cov tshuaj resin muaj kev ruaj ntseg tsis zoo thiab tsis haum rau kev khaws cia.Nyob rau hauv qhov tseeb ntau lawm, nws yog feem ntau siv raws li ib tug substrate thiab kuj inorganic cov ntaub ntawv xws li d-cellulose, ntoo pulp, silica, colorants ntxiv.Nws yog tsim los rau hauv cov hmoov nplej uas yog hu ua melamine hmoov los ntawm cov tshuaj tsuag ziab pob zeb.
Huafu Chemicals yog xws li lub Hoobkas tsimmelamine resin hmoov.Yog tias koj txaus siab, thov hu rau pebEmail : melamine@hfm-melamine.com
Post lub sij hawm: Sep-20-2019