HPMC inovandudza sei kunamatira kwepende yelatex?

Hydroxypropyl Methylcellulose (HPMC, Hydroxypropyl Methylcellulose) ndeye semi-synthetic, inert, isiri-chepfu cellulose derivative iyo inoshandiswa zvakanyanya mukugadzira machira, kunyanya latex pendi. Kuwedzerwa kweHPMC hakungogadziri kugadzikana, rheology uye brushability yepende ye latex, asiwo inovandudza zvakanyanya kunamatira kwayo.

Basic maitiro eHPMC

HPMC isiri-ionic cellulose ether ine yakanaka solubility yemvura, firimu-kuumba uye inonamira zvivakwa. Chimiro chayo chemorekuru chine mapoka anoshanda senge hydroxyl, methoxy uye hydroxypropyl, iyo inopa HPMC yakasarudzika yemuviri nemakemikari zvimiro, senge:

Kunyungudika kwemvura kwakanaka: HPMC inokurumidza kunyungudika mumvura inotonhora kuti igadzire mhinduro yakajeka, iri nyore kuparadzira pendi yelatex zvakaenzana.
Yakanakisa thickening zvivakwa: Inogona kunyatso kuwedzera viscosity yependi yelatex uye kugadzirisa kunamatira kwayo panzvimbo dzakamira.
Mafirimu-ekugadzira zvinhu: HPMC inogona kuumba yunifomu firimu panguva yekuomeswa kwepende firimu, ichiwedzera simba remagetsi repende firimu.
Kugadzikana: HPMC mhinduro ine kugadzikana kwakanaka uye haisi nyore kukanganiswa nekushisa uye pH kukosha, iyo inobatsira kuvandudza kugadzikana kwekuchengetedza kwepende ye latex.

Kuumbwa kwepende ye latex uye zvinhu zvinokanganisa kunamatira

Pendi yeLatex inonyanya kuumbwa nezvinhu zvinogadzira firimu (zvakadai semulsion polymers), pigment, fillers, additives (sezvinoita makobvu, disperants, defoaming agents) nemvura. Kunamatira kwayo kunokanganiswa nezvinhu zvakawanda:

Substrate zvivakwa: Hushasha, kuumbwa kwemakemikari uye pamusoro pesimba reiyo substrate pendi zvese zvinokanganisa kunamatira kwependi yelatex.
Coating components: Kusarudzwa kwefirimu-kuumba zvinhu, chiyero chekuwedzera, evaporation rate yezvinonyungudutsa, nezvimwewo zvinokanganisa zvakananga kukwanisa kwekunamatira kwefirimu yepende.
Tekinoroji yekuvaka: Tembiricha yekuvaka, humidity, nzira yekupfekedza, nezvimwe zvinhu zvakakosha zvinokanganisa kunamatira.

HPMC inonyanya kuvandudza kunamatira mu latex pendi kuburikidza neanotevera maficha:

1. Kuvandudza kupfeka firimu chimiro
HPMC inowedzera viscosity yependi yelatex, ichiibvumira kuti igadzire firimu rakafanana, rakatsetseka panguva yekushandisa. Iyi yunifomu yekuputira firimu chimiro inoderedza kuumbwa kwemabhuru uye inoderedza matambudziko ekunamatira anokonzerwa nekuputira firimu kukanganisa.

2. Ipa kuwedzera kunamatira
Iyo hydroxyl uye ether zvisungo muHPMC inogona kushambadzira kana kemikari kusungirirwa neiyo substrate pamusoro, ichipa imwe adhesion. Semuyenzaniso, kupindirana kwehydrogen-bonding pakati peHPMC nehydroxyl kana mamwe mapoka epolar pane substrate anobatsira kusimudzira kunamatira kwefirimu.

3. Wedzera kupararira kwemavara uye mafirita
HPMC inogona kunyatsoparadzira pigments uye mafirita mu latex pendi uye kudzivirira kubva mukusangana, kuitira kuti pigment uye mafirita zvigovane zvakaenzana mufirimu repende. Iyi yunifomu kugovera haisi kungovandudza kutsetseka kwefirimu yepende, asiwo inovandudza simba remagetsi refirimu yepende, kuwedzera kuwedzera kunamatira.

4. Gadzirisa kukurumidza kuoma kwefirimu yepende
HPMC ine inogadzirisa mhedzisiro pakuoma kwekumhanya kwefirimu repende. A mwero kuomesa kumhanya kunobatsira kudzivirira kuderera kwekunamatira kunokonzerwa nekunyanyisa shrinkage kushushikana mufirimu yekuputira. HPMC inoita kuti firimu rependi riome zvakaenzana nekudzikamisa chiyero chekubuda kwemvura, nekudaro ichidzikisa kushushikana mukati mefirimu repende uye kuwedzera kunamatira.

5. Ipa unyoro kuramba uye kutsemuka kuramba
Iyo inoenderera firimu yakaumbwa neHPMC mufirimu repende ine humwe hunyoro-uchapupu mhedzisiro uye inoderedza kukukurwa kweiyo substrate nehunyoro. Pamusoro pezvo, kuoma uye kusimba kwefirimu reHPMC kunobatsira kutora shrinkage kushushikana kwefirimu repende panguva yekuomesa uye kuderedza kuputika kwefirimu repende, nekudaro kuchengetedza kunamatira kwakanaka.

Yekuedza data uye mienzaniso yekushandisa
Kuti uone mashandiro eHPMC pane latex pendi adhesion, data rekuyedza rinogona kuongororwa. Izvi zvinotevera dhizaini yekuyedza uye mhedzisiro kuratidza:

experimental design
Kugadzirira Sample: Gadzirira latex pendi samples ine dzakasiyana siyana dzeHPMC.
Sarudzo ye Substrate: Sarudza simbi yakatsetseka ndiro uye yakakasharara simende bhodhi seye test substrate.
Adhesion bvunzo: Shandisa iyo yekudhonza-apart nzira kana iyo muchinjiko-hatch nzira yekuyedza yekunamatira.

Experimental results
Mhedzisiro dzekuyedza dzinoratidza kuti sezvo iyo HPMC yakawedzera, kunamatira kwependi yelatex pane akasiyana substrates kunowedzera. Kuvandudzwa kwekunamatira ne 20-30% pamapuranga esimbi akatsetseka uye 15-25% pamapaneru esimende.

Iyi data inoratidza kuti kuwedzerwa kwehuwandu hwakakodzera hweHPMC kunogona kuvandudza zvakanyanya kunamatira kwependi yelatex, kunyanya pazvinyoro zvishoma.

Mazano ekushandisa
Kuti ushandise zvizere zvakanakira HPMC mukuvandudza latex pendi adhesion mumashandisirwo anoshanda, zvinotevera pfungwa dzinoda kucherechedzwa:

Gadzirisa huwandu hweHPMC yakawedzerwa: Huwandu hweHPMC hwakawedzerwa hunoda kugadziridzwa zvinoenderana neiyo chaiyo formula yependi yelatex uye maitiro eiyo substrate. Kunyanya kukwirisa kunogona kuita kuti kupfekedzwa kuve kwakanyanyisa, zvichikanganisa mhedzisiro yekupedzisira.
Kudyidzana nezvimwe zvekuwedzera: HPMC inofanirwa kurongeka zvine mutsindo nemakobvu, zvinoparadzira uye zvimwe zvekuwedzera kuti uwane yakanakisa coating kuita.
Kudzora kwemamiriro ekuvaka: Panguva yekupfekedza, tembiricha yakakodzera uye hunyoro hunofanirwa kudzorwa kuti ive nechokwadi chemhedzisiro yeHPMC.

Seyakakosha latex pendi yekuwedzera, HPMC inonatsiridza zvakanyanya kunamatira kwependi yelatex nekuvandudza iyo yekuputira firimu chimiro, ichipa yakawedzera adhesion, inosimudzira pigment dispersion, kugadzirisa kuoma kwekumhanya, uye kupa hunyoro kuramba uye kutsemuka kuramba. Mumashandisirwo chaiwo, huwandu hwekushandisa hweHPMC hunofanirwa kugadziridzwa zvine mutsindo zvinoenderana nezvinodiwa chaizvo uye kushandiswa pamwe chete nezvimwe zvekuwedzera kuti uwane yakanakisa coating kuita uye kunamatira. Iko kushandiswa kweHPMC hakungonatsiridza chete chimiro chemuviri uye chemakemikari zvimiro zvependi yelatex, asi zvakare inowedzera huwandu hwayo hwemashandisirwo pane akasiyana substrates, ichipa mikana yakawanda yeindasitiri yekugadzira yekushongedza.