Focus on Cellulose ethers

"Ama-ejenti" amahlanu wezingubo ezisekelwe emanzini!

isifinyezo

1. I-ejenti yokumanzisa nokuhlakaza

2. I-Defoamer

3. Ukuqina

4. Izithasiselo ezakha ifilimu

5. Ezinye izithasiselo

I-ejenti yokumanzisa nokuhlakaza

Izembatho ezisekelwe emanzini zisebenzisa amanzi njenge-solvent noma i-dispersion medium, futhi amanzi ane-dielectric engaguquki, ngakho-ke izimbobo ezisekelwe emanzini ziqiniswa ngokuyinhloko ukuxoshwa kwe-electrostatic lapho ungqimba oluphindwe kabili lukagesi ludlulana.

Ngaphezu kwalokho, ohlelweni lokumboza olusekelwe emanzini, kuvame ukuba nama-polymers nama-non-ionic surfactants, akhangiswa ebusweni bokugcwalisa i-pigment, okwenza isithiyo se-steric futhi azinzise ukuhlakazeka. Ngakho-ke, amapende asekelwe emanzini kanye nama-emulsions afinyelela imiphumela ezinzile ngokusebenzisa isenzo esihlangene sokuxoshwa kwe-electrostatic kanye nokuvimbela i-steric. Ububi bayo ukungezwani kahle kwe-electrolyte, ikakhulukazi kuma-electrolyte anenani eliphezulu.

1.1 I-ejenti yokumanzisa

Ama-ejenti okumanzisa okufakwa emanzini ahlukaniswe abe i-anionic ne-nonionic.

Inhlanganisela ye-ejenti yokumanzisa kanye ne-ejenti ehlakazayo ingafinyelela imiphumela emihle. Inani le-ejenti yokumanzisa ngokuvamile limbalwa ngenkulungwane. Umphumela walo omubi ukhihliza amagwebu futhi unciphisa ukumelana namanzi kwefilimu yokumboza.

Enye yezindlela zokuthuthukiswa kwama-ejenti wokumanzisa ukufaka kancane kancane esikhundleni se-polyoxyethylene alkyl (benzene) phenol ether (APEO noma i-APE) ama-ejenti wokumanzisa, ngoba kuholela ekunciphiseni kwamahomoni wesilisa kumagundane futhi kuphazamise i-endocrine. I-Polyoxyethylene alkyl (benzene) phenol ethers isetshenziswa kakhulu njengama-emulsifiers ngesikhathi se-emulsion polymerization.

Ama-Twin surfactants nawo ayintuthuko entsha. Kungama-amphiphilic molecule amabili axhunywe i-spacer. Isici esiphawuleka kakhulu sama-surfactants angama-twin cell ukuthi i-critical micelle concentration (CMC) ingaphezu kwe-oda le-magnitude ephansi kunaleyo yama-surfactants abo "eseli elilodwa", okulandelwa ukusebenza kahle okuphezulu. Njenge-TEGO Twin 4000, iyi-twin cell siloxane surfactant, futhi inegwebu elingazinzile kanye nezakhiwo eziqeda amagwebu.

1.2 Umsakazi

Izisabalalisi zopende we-latex zihlukaniswe izigaba ezine: ama-phosphate dispersants, ama-polyacid homopolymer dispersants, ama-polyacid copolymer dispersants namanye ama-disperants.

Ama-phosphate dispersants asetshenziswa kakhulu yi-polyphosphates, njenge-sodium hexametaphosphate, i-sodium polyphosphate (i-Calgon N, umkhiqizo we-BK Giulini Chemical Company eJalimane), i-potassium tripolyphosphate (KTPP) kanye ne-tetrapotassium pyrophosphate (TKPP).

Indlela yesenzo sayo ukuzinzisa ukuhoxiswa kwe-electrostatic ngokusebenzisa i-hydrogen bonding kanye ne-chemical adsorption. Inzuzo yayo ukuthi umthamo uphansi, cishe u-0.1%, futhi unomphumela omuhle wokuhlakazeka kuma-pigments we-inorganic kanye nezigcwalisi. Kodwa futhi kukhona ukushiyeka: eyodwa, kanye nokukhushulwa kwenani le-pH kanye nezinga lokushisa, i-polyphosphate i-hydrolyzed kalula, ibangela ukuqina kokugcina isikhathi eside kubi; Ukuncibilika okungaphelele phakathi kuzothinta ukucwebezela kopende ocwebezelayo we-latex.

I-1 phosphate dispersant

Izisabalalisi ze-Phosphate ester zizinzisa ukuhlakazeka kwe-pigment, okuhlanganisa nama-pigments asebenzayo njenge-zinc oxide. Ekwakhekeni kopende ocwebezelayo, kuthuthukisa ukucwebezela nokuhlanzeka. Ngokungafani nezinye izithasiselo zokumanzisa nezihlakazayo, ukungezwa kwama-phosphate ester dispersants akuthinti i-KU ne-ICI viscosity ye-coating.

I-polyacid homopolymer dispersant, njenge-Tamol 1254 ne-Tamol 850, i-Tamol 850 iyi-homopolymer ye-methacrylic acid.

I-polyacid copolymer dispersant, njenge-Orotan 731A, okuyi-copolymer ye-diisobutylene ne-maleic acid. Izici zalezi zinhlobo ezimbili zama-dispersants ukuthi zikhiqiza i-adsorption eqinile noma i-anchoring ebusweni be-pigment kanye nezigcwalisi, zinamaketanga ama-molecular amade ukuze zenze isithiyo se-steric, futhi zibe nokuncibilika kwamanzi ekugcineni kweketango, kanti ezinye zengezwa ukuxoshwa kwe-electrostatic ukuze thola imiphumela ezinzile. Ukwenza i-dispersibility ibe nokuhlakazeka okuhle, isisindo samangqamuzana kufanele silawulwe ngokuqinile. Uma isisindo samangqamuzana sincane kakhulu, kuyoba nesithiyo esinganele se-steric; uma isisindo samangqamuzana sikhulu kakhulu, i-flocculation izokwenzeka. Kuma-polyacrylate dispersants, umphumela omuhle kakhulu wokuhlakazeka ungafinyelelwa uma izinga le-polymerization liyi-12-18.

Ezinye izinhlobo zokusabalalisa, njenge-AMP-95, zinegama lekhemikhali elithi 2-amino-2-methyl-1-propanol. Iqembu le-amino likhangisiwe phezu kwezinhlayiya ze-inorganic, futhi iqembu le-hydroxyl lidlulela emanzini, elidlala indima yokusimamisa ngokusebenzisa isithiyo esibulalayo. Ngenxa yobukhulu bayo obuncane, isithiyo se-steric sinqunyelwe. I-AMP-95 ngokuyinhloko isilawuli se-pH.

Eminyakeni yamuva nje, ucwaningo lwama-dispersants luye lwanqoba inkinga ye-flocculation ebangelwa isisindo esiphezulu samangqamuzana, futhi ukuthuthukiswa kwesisindo samangqamuzana aphezulu kungenye yezitayela. Isibonelo, i-high molecular weight dispersant EFKA-4580 ekhiqizwa yi-emulsion polymerization ithuthukiswe ngokukhethekile ukumbozwa kwezimboni ezisekelwe emanzini, ezifanele ukuhlakazeka kwe-pigment ye-organic kanye ne-inorganic, futhi inokumelana okuhle kwamanzi.

Amaqembu e-amino anobudlelwane obuhle bemibala eminingi ngokusebenzisa i-acid-base noma i-hydrogen bonding. I-block copolymer dispersant ene-aminoacrylic acid njengoba iqembu lokunamathisela linakiwe.

2 Isabalalisa nge-dimethylaminoethyl methacrylate njengeqembu le-anchoring

Isengezo se-Tego Dispers 655 esimanzisa nesihlakazayo sisetshenziswa opende bezimoto abaphuma emanzini hhayi nje ukukhomba umbala kodwa futhi ukuvimbela impushana ye-aluminium ukuthi ingasabeli emanzini.

Ngenxa yokukhathazeka kwemvelo, ama-ejenti abolayo okumanzisa kanye nezihlakazayo athuthukisiwe, njenge-EnviroGem AE uchungechunge lwama-twin cell wetting and dispersing agents, okungama-ejenti okumanzisa anegwebu eliphansi kanye neziwahlakazayo.

I-Defoamer

Kunezinhlobo eziningi zama-defoam kapende asekelwe emanzini endabuko, ngokuvamile ahlukaniswa ngezigaba ezintathu: ama-mineral oil defoamers, ama-polysiloxane defoamers namanye ama-defoam.

Ama-mineral oil defoamers avame ukusetshenziswa, ikakhulukazi kumapende we-latex ayisicaba kanye ne-semi-gloss latex.

Ama-polysiloxane defoamers anengcindezi ephansi ebusweni, amandla aqinile okukhipha amagwebu kanye ne-antifoaming, futhi ayithinti isicwebezelisi, kodwa uma esetshenziswa ngendlela engafanele, azodala amaphutha njengokushwabana kwefilimu enamathelayo kanye nokungakwazi ukuphinda kuhlanganiswe kahle.

Ama-defoams wendabuko asekelwe emanzini asekelwe emanzini awahambisani nesigaba samanzi ukuze afeze injongo yokukhipha amagwebu, ngakho-ke kulula ukukhiqiza ukukhubazeka okungaphezulu kwefilimu yokugqoka.

Eminyakeni yamuva nje, kuye kwasungulwa ama-defoam asezingeni lamangqamuzana.

Le ejenti ye-antifoaming iyi-polymer eyakhiwe ngokuxhunyelelwa ngokuqondile izinto ezisebenzayo ze-antifoaming entweni ethwalayo. Iketango lamangqamuzana e-polymer lineqembu elimanzisa i-hydroxyl, into esebenzayo ekhipha ugwebu isakazwa ku-molecule, into esebenzayo akulula ukuyihlanganisa, futhi ukuhambisana nesistimu yokumboza kuhle. Ama-defoamers anjalo e-molecular-level ahlanganisa amafutha amaminerali - uchungechunge lwe-FoamStar A10, uchungechunge oluqukethe i-silicon - i-FoamStar A30 uchungechunge, kanye ne-non-silicon, ama-polymers angewona amafutha - uchungechunge lwe-FoamStar MF.

Le defoamer yesikali se-molecular isebenzisa i-polymer yenkanyezi egxunyekwe kakhulu njengesisetshenziswa esisebenza ngaphandle esingahambelani futhi sizuze imiphumela emihle ekusetshenzisweni kokumboza emanzini. I-Air Products i-defoamer yezinga le-molecular ebikwe ngu-Stout et al. iyi-ejenti yokulawula igwebu esekelwe ku-acetylene glycol kanye ne-defoamer enezinto zombili zokumanzisa, njenge-Surfynol MD 20 ne-Surfinol DF 37.

Ngaphezu kwalokho, ukuze kuhlangatshezwane nezidingo zokukhiqiza i-zero-VOC coatings, kukhona nama-defoams angenayo i-VOC, njenge-Agitan 315, i-Agitan E 255, njll.

ukuqina

Kunezinhlobo eziningi zokujiya, okwamanje ezisetshenziswa kakhulu i-cellulose ether kanye nokuphuma kwayo, ama-alkali-swellable thickeners (HASE) nama-polyurethane thickeners (HEUR).

3.1. I-cellulose ether kanye nokuphuma kwayo

I-Hydroxyethyl cellulose (HEC)yaqala ukukhiqizwa ngokwezimboni yiNkampani ye-Union Carbide ngo-1932, futhi inomlando weminyaka engaphezu kwengama-70.

Njengamanje, ukuqina kwe-cellulose ether nokuphuma kwayo ikakhulukazi kufaka i-hydroxyethyl cellulose (HEC), i-methyl hydroxyethyl cellulose (MHEC), i-ethyl hydroxyethyl cellulose (EHEC), i-methyl hydroxypropyl Base cellulose (MHPC), i-methyl cellulose (MC) kanye ne-xanthan gum. njll., lawa ama-thickeners angewona ama-ionic, futhi angezama-thickeners wesigaba samanzi angahlobene. Phakathi kwazo, i-HEC isetshenziswa kakhulu kupende we-latex.

3.2 I-alkali-swellable thickener

I-alkali-swellable thickeners ihlukaniswe izigaba ezimbili: i-non-associative alkali-swellable thickeners (ASE) kanye ne-associative alkali-swellable thickeners (HASE), okuyi-anionic thickeners. I-ASE engahlotshaniswa nayo i-emulsion yokuvuvukala ye-polyacrylate alkali.

3.3. I-polyurethane thickener kanye ne-hydrophobically modified non-polyurethane thickener

I-Polyurethane thickener, ebizwa ngokuthi i-HEUR, iyi-hydrophobic group-modified ethoxylated polyurethane water-soluble polymer, okungeye-non-ionic associative thickener.

I-HEUR yakhiwe izingxenye ezintathu: iqembu le-hydrophobic, i-hydrophilic chain neqembu le-polyurethane.

Iqembu le-hydrophobic lidlala indima yokuhlangana futhi liyisici esinqumayo sokujiya, ngokuvamile i-oleyl, i-octadecyl, i-dodecylphenyl, i-nonylphenol, njll.

Kodwa-ke, izinga lokushintshwa kwamaqembu e-hydrophobic kuzo zombili iziphetho zamanye ama-HEUR atholakalayo kwezohwebo lingaphansi kuka-0.9, futhi elingcono kakhulu lingu-1.7 kuphela. Izimo zokusabela kufanele zilawulwe ngokuqinile ukuze kutholwe i-polyurethane thickener enokusabalalisa kwesisindo samangqamuzana amancane nokusebenza okuzinzile. Ama-HEUR amaningi ahlanganiswa nge-stepwise polymerization, ngakho-ke ama-HEUR atholakala ngokuthengisa ngokuvamile ayingxube yezisindo zamangqamuzana abanzi.

Ngaphezu komugqa wokujiya we-asociative polyurethane ochazwe ngenhla, kukhona nokujiya okufana nekama associative polyurethane. Okubizwa ngokuthi i-comb association polyurethane thickener kusho ukuthi kuneqembu elilengayo le-hydrophobic phakathi kwe-molecule ngayinye yokuqina. Ama-thickeners afana ne-SCT-200 ne-SCT-275 njll.

Uma wengeza inani elivamile lamaqembu e-hydrophobic, kunamaqembu amabili kuphela e-hydrophobic end-capped, ngakho-ke i-amino thickener ehlanganisiwe ye-hydrophobically ayihlukile kakhulu ku-HEUR, njenge-Optiflo H 500, bheka Umfanekiso 3.

Uma amaqembu e-hydrophobic engeziwe engeziwe, afika ku-8%, izimo zokusabela zingashintshwa ukuze kukhiqizwe ama-amino thickeners namaqembu amaningi avinjiwe we-hydrophobic. Yiqiniso, lokhu kubuye kube ukuqina kwekama.

Le hydrophobic modified amino thickener ingavimbela i-viscosity kapende ukuthi ingawi ngenxa yokwengezwa kwenani elikhulu lama-surfactants kanye nezincibilikisi ze-glycol lapho ukufanisa umbala kwengezwa. Isizathu siwukuthi amaqembu aqinile e-hydrophobic angavimbela ukuchithwa, futhi amaqembu amaningi e-hydrophobic anobudlelwane obuqinile.


Isikhathi sokuthumela: Dec-26-2022
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