Upende weLatex uyingxube yezingulube, i-filler dispersions kanye ne-polymer dispersions, futhi izithasiselo kufanele zisetshenziswe ukulungisa i-viscosity yayo ukuze ibe nezakhiwo ze-rheological ezidingekayo esigabeni ngasinye sokukhiqiza, ukugcinwa nokwakhiwa.Izithasiselo ezinjalo ngokuvamile zibizwa ngokuthi ama-thickeners, ezingakhuphula i-viscosity yezingubo futhi zithuthukise izakhiwo ze-rheological ze-coatings, ngakho-ke zibizwa nangokuthi i-rheological thickeners.
Okulandelayo kwethula kuphela izici eziyinhloko zama-cellulose thickeners asetshenziswa kakhulu kanye nokusetshenziswa kwawo kumapende e-latex.
Izinto ze-Cellulose ezingase zifakwe embotsheni zihlanganisa i-methyl cellulose, i-hydroxyethyl cellulose, ne-hydroxypropyl methyl cellulose.Isici esikhulu kunazo zonke se-cellulose thickener ukuthi umphumela wokuqina uyamangalisa, futhi unganikeza upende umphumela othile wokugcina amanzi, ongabambezela isikhathi sokumisa upende ngezinga elithile, futhi wenze upende ube ne-thixotropy ethile, ukuvimbela upende ukuthi wome.Imvula kanye ne-stratification ngesikhathi sokugcina, nokho, ama-thieners anjalo anesimo esibi sokungalinganisi kahle upende, ikakhulukazi uma usebenzisa amamaki e-viscosity ephezulu.
I-Cellulose iyisakhi esinomsoco wezinambuzane ezincane, ngakho-ke izinyathelo zokulwa nomkhuhlane kufanele ziqiniswe lapho uyisebenzisa.Ama-cellullosic thickeners angakwazi ukujiya isigaba samanzi kuphela, kodwa angabi nomthelela wokuqina kwezinye izingxenye kupende osuselwe emanzini, futhi angeke abangele ukuxhumana okubalulekile phakathi kwe-pigment kanye nezinhlayiya ze-emulsion kupende, ngakho azikwazi ukulungisa i-rheology yopende. , Ngokuvamile, ingakhuphula kuphela i-viscosity ye-coating ngamanani aphansi naphakathi okugunda (okuvame ukubizwa ngokuthi yi-KU viscosity).
1. I-Hydroxyethyl cellulose
Ukucaciswa namamodeli wemikhiqizo ye-hydroxyethyl cellulose ahlukaniswa ngokuyinhloko ngokwezinga lokushintshwa kanye ne-viscosity.Ngaphezu komehluko ku-viscosity, izinhlobonhlobo ze-hydroxyethyl cellulose zingahlukaniswa zibe uhlobo olujwayelekile lokuncibilika, uhlobo lokuhlakazeka okusheshayo kanye nohlobo lokuzinza kwebhayoloji ngokuguqulwa kwenqubo yokukhiqiza.Ngokuphathelene nendlela yokusetshenziswa, i-hydroxyethyl cellulose ingangezwa ngezigaba ezihlukene enqubweni yokukhiqiza yokumboza.Uhlobo oluhlakazeka ngokushesha lungangezwa ngokuqondile ngesimo sempushana eyomile, kodwa inani le-pH yesistimu ngaphambi kokuyengeza kufanele libe ngaphansi kuka-7, ikakhulukazi ngoba i-hydroxyethyl cellulose incibilika kancane ngenani eliphansi le-pH, futhi kunesikhathi esanele amanzi ukuze angene ngaphakathi kwezinhlayiyana, bese enyusa inani le-pH ukuze ayenze incibilike ngokushesha.Izinyathelo ezihambisanayo zingasetshenziswa futhi ukulungisa ukugxila okuthile kweglue bese uyengeza ohlelweni lwepende.
2. I-Hydroxypropyl Methyl Cellulose
Umphumela wokujiya we-hydroxypropyl methylcellulose ngokuyisisekelo uyafana nalowo we-hydroxyethylcellulose, okungukuthi, ukukhulisa i-viscosity ye-coating ngamanani aphansi naphakathi okugunda.IHydroxypropyl methylcellulose imelana nokuwohloka kwe-enzymatic, kodwa ukuncibilika kwayo emanzini akufani naleyo ye-hydroxyethyl cellulose, futhi inobubi bokwenza i-gelling uma ishisisiwe.Ukuze uthole i-hydroxypropyl methylcellulose ephethwe phezulu, ingafakwa ngokuqondile emanzini lapho isetshenziswa, ngemva kokunyakaziswa nokuhlakazwa, engeza izinto ezine-alkaline ezifana namanzi e-ammonia, lungisa inani le-pH libe ngu-8-9, futhi ugqugquzele kuze kube yilapho selincibilike ngokuphelele.Nge-hydroxypropyl methylcellulose ngaphandle kokwelashwa okungaphezulu, ingacwiliswa futhi ivuvukele ngamanzi ashisayo angaphezu kuka-85 ° C ngaphambi kokusetshenziswa, bese ipholiswa ekamelweni lokushisa, bese ixutshwa ngamanzi abandayo noma amanzi e-ice ukuze incibilike ngokugcwele.
3. I-methyl cellulose
I-Methylcellulose inezici ezifanayo ne-hydroxypropylmethylcellulose, kodwa azinzile ku-viscosity kanye nezinga lokushisa.
I-Hydroxyethyl cellulose iyi-thickener esetshenziswa kakhulu kupende we-latex, futhi isetshenziswa kumapende we-latex webanga eliphakeme, eliphakathi neliphansi kanye nopende abawugqinsi be-latex.Isetshenziswa kakhulu ekuqinisweni kopende ojwayelekile we-latex, i-gray calcium powder latex kapende, njll. Owesibili i-hydroxypropyl methylcellulose, ebuye isetshenziswe ngenani elithile ngenxa yokukhuthazwa kwabakhiqizi.I-Methyl cellulose ayisetshenziswa neze kumapende e-latex, kodwa isetshenziswa kakhulu ku-powdery yangaphakathi nangaphandle kwe-wall putty ngenxa yokuhlakazeka kwayo ngokushesha kanye nokugcinwa kahle kwamanzi.I-high-viscosity methyl cellulose inganikeza i-putty nge-thixotropy evelele nokugcinwa kwamanzi, iyenze ibe nezindawo ezinhle zokukhuhla.
Isikhathi sokuthumela: Jan-03-2023