Pente ea latex ke motsoako oa li-pigments, li-filler dispersions le polymer dispersions, 'me li-additives li tlameha ho sebelisoa ho fetola viscosity ea eona hore e be le thepa ea rheological e hlokahalang bakeng sa mohato o mong le o mong oa tlhahiso, polokelo le kaho. Li-additives tse joalo ka kakaretso li bitsoa li-thickeners, tse ka eketsang viscosity ea liaparo le ho ntlafatsa thepa ea rheological ea liphahlo, kahoo li boetse li bitsoa rheological thickeners.
Se latelang se hlahisa feela litšobotsi tsa mantlha tsa li-cellulose thickeners tse sebelisoang hangata le ts'ebeliso ea tsona lipenteng tsa latex.
Lisebelisoa tsa cellulose tse ka sebelisoang ho koahela li kenyelletsa methyl cellulose, hydroxyethyl cellulose, le hydroxypropyl methyl cellulose. Ntho e kholo ka ho fetisisa ea cellulose thickener ke hore phello e teteaneng e tsoteha, 'me e ka fa pente phello e itseng ea ho boloka metsi, e ka liehisang nako ea ho omisa ea pente ho isa tekanyong e itseng, hape e etsa hore pente e be le thixotropy e itseng, ho thibela pente ho omella. Pula le stratification nakong ea polokelo, leha ho le joalo, li-thickeners tse joalo li boetse li na le bothata ba ho fokotsa pente, haholo-holo ha ho sebelisoa limaraka tse phahameng tsa viscosity.
Cellulose ke ntho ea limatlafatsi bakeng sa likokoana-hloko, kahoo mehato e khahlanong le hlobo e lokela ho matlafatsoa ha e sebelisoa. Li-cellulosic thickeners li ka tiisa karolo ea metsi feela, empa ha li na phello e teteaneng likarolong tse ling tsa pente e thehiloeng metsing, leha e le hore li ka baka tšebelisano e kholo pakeng tsa pigment le likaroloana tsa emulsion ka pente, kahoo li ke ke tsa fetola rheology ea pente. , Ka kakaretso, e ka eketsa viscosity ea ho roala ka litekanyetso tse tlaase le tse mahareng tsa ho kuta (tseo hangata li bitsoang KU viscosity).
1. Hydroxyethyl cellulose
Litlhaloso le mefuta ea lihlahisoa tsa hydroxyethyl cellulose li khetholloa haholo ho latela boemo ba ho fetola le viscosity. Ntle le phapang ea viscosity, mefuta e sa tšoaneng ea selulose ea hydroxyethyl e ka aroloa ka mofuta o tloaelehileng oa ho qhibiliha, mofuta oa ho hasana ka potlako le mofuta oa botsitso ba likokoana-hloko ka ho fetola mokhoa oa tlhahiso. Mabapi le mokhoa oa ts'ebeliso, hydroxyethyl cellulose e ka eketsoa ka mekhahlelo e fapaneng ts'ebetsong ea tlhahiso ea ho roala. Mofuta oa ho qhala ka potlako o ka eketsoa ka kotloloho ka mokhoa oa phofo e omileng, empa boleng ba pH ba sistimi pele o e eketsa e lokela ho ba tlase ho 7, haholo hobane cellulose ea hydroxyethyl e qhibiliha butle ka boleng bo tlase ba pH, 'me ho na le nako e lekaneng ea metsi ho kenella ka hare ho karoloana, ebe o eketsa boleng ba pH ho etsa hore e qhibilihe kapele. Mehato e tsamaellanang e ka boela ea sebelisoa ho lokisa motsoako o itseng oa sekhomaretsi le ho e eketsa tsamaisong ea pente.
2. Hydroxypropyl Methyl Cellulose
Phello e matla ea hydroxypropyl methylcellulose ha e le hantle e tšoana le ea hydroxyethylcellulose, ke hore, ho eketsa viscosity ea ho roala ka litekanyetso tse tlaase le tse mahareng tsa ho kuta. Hydroxypropyl methylcellulose e hanyetsana le ho senyeha ha enzymatic, empa ho qhibiliha ha eona ha metsi ha ho hantle joaloka hydroxyethyl cellulose, 'me e na le bofokoli ba gelling ha e futhumala. Bakeng sa hydroxypropyl methylcellulose e entsoeng ka holim'a metsi, e ka kenyelletsoa ka ho toba metsing ha e sebelisoa, ka mor'a ho hlohlelletsa le ho qhalakanya, eketsa lintho tsa alkaline tse kang metsi a ammonia, fetola boleng ba pH ho 8-9, 'me u hlohlelletse ho fihlela o qhibiliha ka ho feletseng. Bakeng sa hydroxypropyl methylcellulose ntle le phekolo ea holim'a metsi, e ka kolobisoa le ho ruruha ka metsi a chesang ka holimo ho 85 ° C pele e sebelisoa, ebe e pholile mocheso oa kamore, ebe e tsosoa ka metsi a batang kapa metsi a leqhoa ho e qhaqha ka ho feletseng.
3. Methyl cellulose
Methylcellulose e na le thepa e ts'oanang le ea hydroxypropylmethylcellulose, empa ha e tsitsitse ka viscosity le mocheso.
Hydroxyethyl cellulose ke eona e teteaneng e sebelisoang haholo penteng ea latex, 'me e sebelisoa lipenteng tsa latex tse phahameng, tse mahareng le tse tlase le lipente tse teteaneng tsa latex. E sebelisoa haholo ho teteaneng ha pente e tloaelehileng ea latex, pente ea grey calcium powder latex, joalo-joalo ea bobeli ke hydroxypropyl methylcellulose, e sebelisoang hape ka chelete e itseng ka lebaka la ho khothaletsoa ha bahlahisi. Methyl cellulose ha e sebelisoe lipenteng tsa latex, empa e sebelisoa haholo ka har'a powdery ka hare le bokantle ba lebota putty ka lebaka la ho qhibiliha ha eona hang-hang le ho boloka metsi hantle. High-viscosity methyl cellulose e ka fa putty ka thixotropy e ikhethang le ho boloka metsi, e etsa hore e be le thepa e ntle ea ho senya.
Nako ea poso: Jan-03-2023