Hydroxyethyl Cellulose (HEC) yog ib qho uas tsis yog-ionic dej-soluble polymer compound nrog cov thickening zoo heev, dej tuav, thiab cov khoom ua yeeb yaj kiab. Yog li ntawd, nws yog dav siv nyob rau hauv coatings, latex xim, thiab kua nplaum. Adhesives thiab lwm yam kev lag luam. Cov xim latex yog ib qho tseem ceeb ntawm cov khoom siv kho kom zoo nkauj niaj hnub, thiab qhov sib ntxiv ntawm HEC tuaj yeem tsis tsuas yog txhim kho kev ruaj ntseg ntawm cov xim latex, tab sis kuj txhim kho nws cov kev tsim kho.
1. Cov yam ntxwv tseem ceeb ntawm hydroxyethyl cellulose
Hydroxyethyl cellulose yog dej-soluble polymer tau los ntawm kev hloov kho tshuaj siv cov cellulose ntuj ua raw khoom. Nws cov yam ntxwv tseem ceeb muaj xws li:
Thickening: HEC muaj cov nyhuv thickening zoo, uas tuaj yeem ua kom cov viscosity ntawm cov xim latex thiab muab cov xim latex zoo heev thixotropy thiab rheology, yog li tsim cov txheej txheem thiab ntom ntom thaum siv.
Kev tuav dej: HEC tuaj yeem tiv thaiv dej los ntawm evaporating sai heev nyob rau hauv cov xim, yog li ncua lub sij hawm qhib ntawm cov xim latex thiab txhim kho cov ziab thiab cov yeeb yaj kiab tsim cov khoom ntawm cov xim pleev xim.
Kev ruaj ntseg: HEC muaj cov tshuaj lom neeg ruaj khov zoo hauv cov xim pleev xim, tuaj yeem tiv taus cov kev hloov pauv ntawm pH, thiab tsis muaj kev cuam tshuam rau lwm cov khoom xyaw hauv cov xim (xws li pigments thiab fillers).
Leveling: Los ntawm kev kho tus nqi ntawm HEC, qhov fluidity thiab leveling ntawm latex xim tuaj yeem txhim kho, thiab cov teeb meem xws li sagging thiab txhuam cov cim hauv cov xim xim tuaj yeem zam tau.
Salt kam rau ua: HEC muaj qee qhov kam rau electrolytes, yog li nws tseem tuaj yeem tswj tau qhov kev ua tau zoo hauv cov qauv uas muaj ntsev lossis lwm yam electrolytes.
2. Cov txheej txheem ua haujlwm ntawm hydroxyethyl cellulose hauv cov xim latex
Raws li cov thickener thiab stabilizer, lub ntsiab mechanism ntawm kev txiav txim ntawm hydroxyethyl cellulose nyob rau hauv cov xim latex tuaj yeem txheeb xyuas los ntawm cov hauv qab no:
(1) Thickening nyhuv
HEC dissolves sai sai hauv dej thiab tsim cov kua dej ntshiab. Los ntawm kev tsim hydrogen bonds nrog dej molecules, HEC molecules nthuav dav thiab ua kom cov viscosity ntawm cov tshuaj. Los ntawm kev kho tus nqi ntawm HEC, viscosity ntawm cov xim latex tuaj yeem raug tswj kom ua tiav kev tsim kho zoo. Cov nyhuv thickening ntawm HEC kuj muaj feem xyuam rau nws qhov hnyav molecular. Feem ntau, qhov siab dua qhov hnyav molecular, qhov tseem ceeb ntawm cov nyhuv thickening.
(2) Stabilizing nyhuv
Muaj ntau cov emulsions, pigments thiab fillers nyob rau hauv cov xim latex, thiab kev sib cuam tshuam ntawm cov khoom no yuav tshwm sim, uas ua rau delamination los yog nag lossis daus ntawm latex xim. Raws li kev tiv thaiv colloid, HEC tuaj yeem tsim cov txheej txheem ruaj khov nyob rau hauv cov dej theem kom tiv thaiv cov xim thiab cov fillers los ntawm kev daws teeb meem. Tsis tas li ntawd, HEC muaj kev tiv thaiv zoo rau kev hloov pauv ntawm qhov kub thiab txias, yog li nws tuaj yeem ua kom muaj kev ruaj ntseg ntawm cov xim latex thaum khaws cia thiab kev tsim kho.
(3) Txhim kho constructability
Daim ntawv thov kev ua tau zoo ntawm cov xim latex nyob ntawm nws cov khoom rheological. Los ntawm thickening thiab txhim kho rheology, HEC tuaj yeem txhim kho qhov kev ua haujlwm ntawm cov xim latex, uas tso cai rau nws sib npaug ntawm qhov chaw ntsug thiab ua rau nws tsis tshua muaj dej ntws. Nyob rau tib lub sijhawm, HEC tseem tuaj yeem txuas ntxiv lub sijhawm qhib cov xim latex, muab sijhawm rau cov neeg ua haujlwm tsim kho kom hloov kho thiab txo cov txhuam hniav thiab cov cim ntws.
3. Yuav ua li cas ntxiv hydroxyethyl cellulose rau latex xim
Txhawm rau kom ua tiav cov txiaj ntsig ntawm hydroxyethyl cellulose, txoj kev sib ntxiv yog qhov tseem ceeb. Feem ntau hais lus, kev siv HEC hauv cov xim latex suav nrog cov kauj ruam hauv qab no:
(1) Pre-dissolution
Txij li thaum HEC dissolves maj mam hauv dej thiab nws yooj yim rau clumping, nws yog feem ntau pom zoo kom pre-dissolve HEC nyob rau hauv dej los tsim ib tug uniform colloidal tov ua ntej siv. Thaum dissolving, HEC yuav tsum tau ntxiv maj mam thiab stirred tsis tu ncua kom tiv thaiv agglomeration. Kev tswj qhov kub thiab txias dej thaum lub sij hawm dissolution txheej txheem kuj tseem ceeb heev. Nws yog feem ntau pom zoo kom ua tiav ntawm qhov kub ntawm 20-30 ° C kom tsis txhob muaj dej kub dhau los cuam tshuam rau cov qauv molecular ntawm HEC.
(2) Ntxiv kev txiav txim
Hauv cov txheej txheem tsim cov xim latex, HEC feem ntau yog ntxiv thaum lub sij hawm pulping. Thaum npaj cov xim latex, cov xim thiab cov khoom ntim tau muab tso ua ntej hauv cov dej theem los tsim cov slurry, thiab tom qab ntawd cov tshuaj HEC colloidal ntxiv rau lub sijhawm dispersion los xyuas kom meej tias nws tuaj yeem sib npaug sib npaug thoob plaws hauv lub cev. Lub sij hawm ntawm kev ntxiv HEC thiab kev siv ntawm stirring yuav cuam tshuam rau nws cov nyhuv thickening, yog li nws yuav tsum tau hloov kho raws li cov txheej txheem tshwj xeeb hauv kev tsim khoom tiag tiag.
(3) Kev tswj kev noj tshuaj
Tus nqi ntawm HEC muaj qhov cuam tshuam ncaj qha rau kev ua haujlwm ntawm cov xim latex. Feem ntau, qhov sib ntxiv ntawm HEC yog 0.1% -0.5% ntawm tag nrho cov xim latex. HEC tsawg dhau yuav ua rau cov nyhuv thickening tsis tseem ceeb thiab cov xim latex ua kua dej ntau dhau, thaum HEC ntau dhau yuav ua rau cov viscosity siab dhau, cuam tshuam rau kev ua haujlwm. Yog li ntawd, hauv kev siv tswv yim, ntau npaum li cas ntawm HEC yuav tsum tau kho kom haum raws li cov qauv tshwj xeeb thiab kev tsim kho ntawm cov xim latex.
4. Daim ntawv thov piv txwv ntawm hydroxyethyl cellulose hauv cov xim latex
Hauv kev tsim khoom tiag tiag, HEC tau siv dav hauv ntau hom latex xim, xws li:
Sab hauv phab ntsa latex xim: Lub thickening thiab dej-retaining zog ntawm HEC pab kom nws ho txhim kho lub leveling thiab anti-sag zog ntawm cov xim zaj duab xis nyob rau hauv sab hauv phab ntsa latex xim, tshwj xeeb tshaj yog nyob rau hauv high-temperature ib puag ncig uas nws tseem muaj peev xwm tuav tau zoo heev workability.
Sab nrauv phab ntsa latex xim: Kev ruaj ntseg thiab ntsev tsis kam ntawm HEC pab kom nws txhim kho huab cua thiab kev laus tiv thaiv nyob rau sab nrauv phab ntsa latex xim thiab txuas ntxiv lub neej kev pab cuam ntawm cov xim zaj duab xis.
Anti-mildew latex xim: HEC tuaj yeem cuam tshuam cov tshuaj tiv thaiv kab mob mildew hauv cov xim los tiv thaiv mildew latex thiab txhim kho nws qhov sib xws hauv cov xim zaj duab xis, yog li txhim kho cov nyhuv anti-mildew.
Raws li ib qho zoo heev latex xim additive, hydroxyethyl cellulose tuaj yeem txhim kho kev ua haujlwm ntawm cov xim latex los ntawm nws cov thickening, dej tuav, thiab stabilizing teebmeem. Hauv kev siv tswv yim, kev nkag siab tsim nyog ntawm kev ntxiv thiab ntau npaum li cas ntawm HEC tuaj yeem txhim kho kev tsim kho thiab siv cov nyhuv ntawm cov xim latex.
Post lub sij hawm: Oct-22-2024