Cov xim latex yog ib qho sib xyaw ntawm cov xim, muab tub lim dispersions thiab polymer dispersions, thiab cov khoom siv ntxiv yuav tsum tau siv los kho nws cov viscosity kom nws muaj cov khoom rheological xav tau rau txhua theem ntawm kev tsim khoom, khaws cia thiab kev tsim kho. Xws li additives feem ntau hu ua thickeners, uas tuaj yeem ua rau kom cov viscosity ntawm cov txheej txheej thiab txhim kho cov khoom rheological ntawm txheej txheej, yog li lawv tseem hu ua rheological thickeners.
Cov hauv qab no tsuas yog qhia txog cov yam ntxwv tseem ceeb ntawm feem ntau siv cellulose thickeners thiab lawv daim ntawv thov hauv cov xim latex.
Cellulosic cov ntaub ntawv uas tuaj yeem siv rau txheej txheej muaj xws li methyl cellulose, hydroxyethyl cellulose, thiab hydroxypropyl methyl cellulose. Qhov loj tshaj plaws ntawm cellulose thickener yog tias cov nyhuv thickening yog qhov zoo tshaj plaws, thiab nws tuaj yeem muab cov xim rau cov dej tuav, uas tuaj yeem ncua sij hawm ziab ntawm cov xim rau qee yam, thiab tseem ua rau cov xim muaj qee yam thixotropy, tiv thaiv cov xim kom qhuav. Los nag thiab stratification thaum khaws cia, txawm li cas los xij, cov thickeners no kuj muaj qhov tsis zoo ntawm cov xim tsis zoo, tshwj xeeb tshaj yog thaum siv cov qib siab viscosity.
Cellulose yog cov khoom noj khoom haus rau cov kab mob, yog li kev ntsuas tiv thaiv kab mob yuav tsum tau ntxiv dag zog thaum siv nws. Cellulosic thickeners tsuas tuaj yeem ua rau cov dej tuab, tab sis tsis muaj cov nyhuv thickening ntawm lwm cov khoom hauv cov xim dej, thiab lawv tsis tuaj yeem ua rau muaj kev cuam tshuam loj ntawm cov xim thiab cov khoom emulsion hauv cov xim, yog li lawv tsis tuaj yeem kho cov rheology ntawm cov xim. , Feem ntau, nws tsuas tuaj yeem ua kom cov viscosity ntawm cov txheej txheem qis thiab nruab nrab shear tus nqi (feem ntau hu ua KU viscosity).
1. Hydroxyethyl cellulose
Cov kev qhia tshwj xeeb thiab cov qauv ntawm cov khoom siv hydroxyethyl cellulose feem ntau txawv raws li qib kev hloov pauv thiab viscosity. Ntxiv nrog rau qhov sib txawv ntawm viscosity, ntau yam ntawm hydroxyethyl cellulose tuaj yeem muab faib ua hom solubility ib txwm, hom dispersion sai thiab hom kev ruaj ntseg lom los ntawm kev hloov kho hauv cov txheej txheem ntau lawm. Raws li txoj kev siv kev txhawj xeeb, hydroxyethyl cellulose tuaj yeem ntxiv rau ntau theem hauv txheej txheej txheej txheej. Cov khoom nrawm nrawm tuaj yeem ntxiv ncaj qha rau hauv daim ntawv ntawm cov hmoov qhuav, tab sis tus nqi pH ntawm lub cev ua ntej ntxiv nws yuav tsum tsawg dua 7, feem ntau vim tias hydroxyethyl cellulose dissolves maj mam ntawm tus nqi pH tsawg, thiab muaj sijhawm txaus rau dej kom nkag mus rau sab hauv ntawm cov khoom, thiab tom qab ntawd nce pH tus nqi kom nws yaj sai. Cov kauj ruam sib thooj kuj tuaj yeem siv los npaj qee qhov concentration ntawm cov kua nplaum thiab ntxiv rau hauv cov xim pleev xim.
2. Hydroxypropyl Methyl Cellulose
Cov nyhuv thickening ntawm hydroxypropyl methylcellulose yog qhov pib zoo ib yam li hydroxyethylcellulose, uas yog, ua kom cov viscosity ntawm cov txheej txheem qis thiab nruab nrab shear. Hydroxypropyl methylcellulose yog resistant rau enzymatic degradation, tab sis nws cov dej solubility tsis zoo li ntawm hydroxyethyl cellulose, thiab nws muaj qhov tsis zoo ntawm gelling thaum rhuab. Rau saum npoo-kho hydroxypropyl methylcellulose, nws tuaj yeem ncaj qha ntxiv rau dej thaum siv, tom qab nplawm thiab dispersing, ntxiv alkaline tshuaj xws li ammonia dej, kho tus nqi pH rau 8-9, thiab do kom txog thaum tag nrho yaj. Rau hydroxypropyl methylcellulose yam tsis muaj kev kho saum npoo, nws tuaj yeem tsau thiab o nrog dej kub siab tshaj 85 ° C ua ntej siv, thiab tom qab ntawd txias rau chav sov, ces nplawm nrog dej txias lossis dej khov kom yaj tag nrho.
3. Methyl cellulose
Methylcellulose muaj cov khoom zoo sib xws rau hydroxypropylmethylcellulose, tab sis tsis ruaj khov hauv viscosity nrog kub.
Hydroxyethyl cellulose yog cov khoom siv dav siv ntau tshaj plaws hauv cov xim latex, thiab nws yog siv rau hauv cov xim siab, nruab nrab thiab qib qis thiab cov xim tuab tuab. Dav siv nyob rau hauv lub thickening ntawm zoo tib yam latex xim, grey calcium hmoov latex xim, thiab lwm yam. Qhov thib ob yog hydroxypropyl methylcellulose, uas yog tseem siv nyob rau hauv ib tug tej yam nyiaj txiag vim hais tias ntawm kev nce qib ntawm manufacturers. Methyl cellulose tsis yog siv nyob rau hauv cov xim latex, tab sis nws yog dav siv nyob rau hauv powdery sab hauv thiab sab nrauv phab ntsa putty vim nws instant dissolution thiab zoo tuav dej. High-viscosity methyl cellulose tuaj yeem ua rau cov putty nrog thixotropy zoo thiab tuav dej, ua rau nws muaj cov khoom zoo.
Post lub sij hawm: Jan-03-2023