HEC (hydroxyethyl cellulose) yog nonionic cellulose ether dav siv hauv kev lag luam coatings. Nws cov haujlwm muaj xws li thickening, dispersing, suspending thiab stabilizing, uas tuaj yeem txhim kho kev tsim kho thiab kev ua yeeb yaj kiab ntawm cov txheej txheem. HEC tshwj xeeb yog siv dav hauv cov txheej txheem dej vim nws muaj dej solubility zoo thiab tshuaj lom neeg ruaj khov.
1. Mechanism ntawm kev ua ntawm HEC
Thickening nyhuv
Ib qho ntawm cov haujlwm tseem ceeb ntawm HEC hauv cov txheej txheej yog thickening. Los ntawm kev nce qib ntawm txheej viscosity ntawm txheej txheej, txheej txheej txheej thiab leveling cov khoom tuaj yeem raug txo kom zoo, thiab txheej sagging tuaj yeem ua ib qho kev sib tw npog ntawm phab ntsa lossis lwm qhov chaw. Tsis tas li ntawd, HEC muaj lub peev xwm thickening muaj zog, yog li nws tuaj yeem ua tiav qhov zoo tagnrho thickening nyhuv txawm tias me me ntxiv, thiab muaj kev lag luam zoo.
Kev ncua thiab stabilization
Hauv cov txheej txheem txheej txheej, cov khoom siv xws li cov xim pigments thiab cov fillers yuav tsum tau sib npaug ntawm cov khoom siv hauv paus, txwv tsis pub nws yuav cuam tshuam rau cov tsos thiab kev ua haujlwm ntawm txheej. HEC tuaj yeem tswj tau qhov sib txawv ntawm cov khoom sib txawv, tiv thaiv los nag, thiab ua kom cov txheej ruaj khov thaum khaws cia. Qhov kev ncua sij hawm no tso cai rau cov txheej txheem rov qab mus rau lub xeev zoo li qub tom qab khaws cia ntev, txo stratification thiab nag lossis daus.
Kev tuav dej
HEC tuaj yeem pab cov dej hauv cov xim tso tawm maj mam thaum lub sijhawm pleev xim, yog li txuas ntxiv lub sijhawm ziab ntawm cov xim thiab ua kom nws ua tiav qib siab thiab zaj duab xis-tsim rau ntawm phab ntsa. Qhov kev tuav dej no yog qhov tseem ceeb tshwj xeeb rau kev tsim kho, tshwj xeeb tshaj yog nyob rau hauv qhov kub thiab txias kev tsim kho ib puag ncig, HEC tuaj yeem txo qhov teeb meem ntawm cov yeeb yaj kiab tsis zoo uas tshwm sim los ntawm cov dej nrawm dhau.
Rheological kev cai
Cov khoom rheological ntawm cov xim ncaj qha cuam tshuam rau kev xav thiab zaj duab xis zoo ntawm kev tsim kho. Cov tshuaj uas tsim los ntawm HEC tom qab dissolving hauv dej muaj pseudoplasticity, uas yog, viscosity txo nyob rau hauv siab shear quab yuam (xws li txhuam thiab dov), uas yog ib qho yooj yim rau txhuam; tab sis lub viscosity rov qab nyob rau hauv qis shear quab yuam, uas yuav txo tau sagging. Qhov no tsis tsuas yog yooj yim rau kev tsim kho, tab sis kuj ua kom cov uniformity thiab thickness ntawm txheej.
2. Qhov zoo ntawm HEC
Zoo solubility dej
HEC yog dej-soluble polymer khoom. Cov kev daws teeb meem tsim tom qab kev sib cais yog qhov tseeb thiab pob tshab, thiab tsis muaj kev cuam tshuam rau cov xim xim dej. Nws cov solubility kuj txiav txim siab nws yooj yim ntawm kev siv hauv cov xim, thiab nws tuaj yeem yaj sai sai yam tsis muaj cov khoom siv los yog agglomerate.
Tshuaj stability
Raws li tsis yog-ionic cellulose ether, HEC muaj tshuaj lom neeg ruaj khov thiab tsis yooj yim cuam tshuam los ntawm cov khoom xws li pH, kub, thiab hlau ions. Nws tuaj yeem nyob ruaj khov hauv qhov chaw muaj zog acid thiab alkaline, yog li nws tuaj yeem hloov mus rau ntau hom txheej txheej txheej.
Kev tiv thaiv ib puag ncig
Nrog rau kev txhim kho ntawm ib puag ncig kev paub, VOC qis (volatile organic compound) coatings tau dhau los ua neeg nyiam. HEC tsis muaj tshuaj lom, tsis muaj mob, tsis muaj cov kuab tshuaj organic, thiab ua tau raws li kev tiv thaiv ib puag ncig, yog li nws muaj ntau yam kev thov kev cia siab nyob rau hauv cov dej-raws li environmentally friendly coatings.
3. Cov txiaj ntsig ntawm HEC hauv kev siv tswv yim
Sab hauv phab ntsa coatings
Hauv cov txheej txheem phab ntsa sab hauv, HEC ua cov thickener thiab rheology hloov kho tuaj yeem txhim kho kev tsim kho ntawm cov txheej txheem, muab nws zoo leveling thiab adhesion. Tsis tas li ntawd, vim nws cov dej tuav tau zoo heev, HEC tuaj yeem tiv thaiv cov kab nrib pleb lossis hmoov txheej txheej sab hauv phab ntsa thaum lub sijhawm ziab.
Sab nrauv phab ntsa coatings
Sab nrauv phab ntsa txheej yuav tsum muaj huab cua zoo heev thiab dej tsis kam. HEC tuaj yeem tsis tsuas yog txhim kho cov dej tuav thiab rheology ntawm txheej, tab sis kuj txhim kho cov khoom tiv thaiv sagging ntawm txheej, kom cov txheej tuaj yeem tiv taus cua thiab nag tom qab kev tsim kho thiab txuas ntxiv nws lub neej kev pab cuam.
Latex xim
Nyob rau hauv cov xim latex, HEC tuaj yeem tsis tsuas yog ua cov thickener, tab sis kuj txhim kho cov xim zoo nkauj thiab ua rau cov yeeb yaj kiab txheej smoother. Nyob rau tib lub sijhawm, HEC tuaj yeem tiv thaiv cov nag lossis daus ntawm cov xim, txhim kho qhov ruaj khov ntawm cov xim, thiab ua kom cov xim latex ruaj khov tom qab khaws cia ntev.
IV. Kev ceev faj rau kev ntxiv thiab siv HEC
Txoj kev tawg
HEC feem ntau yog ntxiv rau cov xim hauv cov hmoov hmoov. Thaum siv, nws yuav tsum tau maj mam ntxiv rau hauv dej thiab tag nrho stirred kom yaj nws tusyees. Yog tias qhov kev sib cais tsis txaus, cov tshuaj granular yuav tshwm sim, cuam tshuam rau qhov zoo ntawm cov xim.
Kev tswj noj tshuaj
Tus nqi ntawm HEC yuav tsum tau hloov kho raws li cov qauv ntawm cov xim thiab cov nyhuv thickening yuav tsum tau. Tus nqi ntxiv yog 0.3% -1.0% ntawm tag nrho cov nyiaj. Kev sib ntxiv ntau dhau yuav ua rau cov viscosity ntawm cov xim ntau dhau, cuam tshuam rau kev tsim kho; tsis txaus ntxiv yuav ua rau muaj teeb meem xws li sagging thiab tsis txaus lub zog zais.
Compatibility nrog lwm cov khoom xyaw
Thaum siv HEC, xyuam xim rau kev sib raug zoo nrog lwm cov khoom xyaw xim, tshwj xeeb tshaj yog cov pigments, fillers, thiab lwm yam. Nyob rau hauv cov xim sib txawv, hom lossis ntau npaum li cas ntawm HEC yuav tsum tau kho kom tsis txhob muaj kev phiv tshuaj.
HEC ua lub luag haujlwm tseem ceeb hauv kev lag luam txheej txheej, tshwj xeeb tshaj yog nyob rau hauv cov txheej txheem dej. Nws tuaj yeem txhim kho kev ua haujlwm, cov khoom ua yeeb yaj kiab thiab kev ruaj ntseg ntawm cov txheej txheem, thiab muaj cov tshuaj lom neeg ruaj khov thiab kev tiv thaiv ib puag ncig. Raws li tus nqi-zoo thickener thiab rheology modifier, HEC yog dav siv nyob rau hauv sab hauv phab ntsa coatings, sab nrauv phab ntsa coatings thiab latex xim. Hauv kev siv cov tswv yim, los ntawm kev tswj hwm kev noj tshuaj kom tsim nyog thiab cov txheej txheem sib cais kom raug, HEC tuaj yeem muab qhov zoo tshaj plaws thickening thiab stabilization cuam tshuam rau coatings thiab txhim kho tag nrho cov kev ua tau zoo ntawm cov txheej.
Post lub sij hawm: Nov-01-2024