1. Incazelo kanye nomsebenzi wesithambisi
Izithasiselo ezingakhulisa kakhulu ubulukhuni bamapende asekelwe emanzini zibizwa ngokuthi ama-thickeners.
Izithisi zidlala indima ebalulekile ekukhiqizweni, ekugcinweni nasekukhiqizweni kwezimbozo.
Umsebenzi oyinhloko wesithambisi ukwandisa ukuthamba kwesembozo ukuze kuhlangatshezwane nezidingo zezigaba ezahlukene zokusetshenziswa. Kodwa-ke, ukuthamba okudingekayo kwesembozo ezigabeni ezahlukene kuhlukile. Isib:
Ngesikhathi senqubo yokugcina, kuyinto efiselekayo ukuba ne-viscosity ephezulu ukuvimbela i-pigment ukuthi ingahlali;
Ngesikhathi senqubo yokwakha, kuyafiseleka ukuthi kube nokuthamba okulinganiselwe ukuqinisekisa ukuthi upende uyakwazi ukuxubha kahle ngaphandle kokudaya upende ngokweqile;
Ngemva kokwakhiwa, kunethemba lokuthi i-viscosity ingabuyela ngokushesha ku-viscosity ephezulu ngemva kokulibala isikhathi esifushane (inqubo yokulinganisa) ukuze kuvinjelwe ukugoba.
Ukugeleza kwezembozo ezitholakala emanzini akulona i-Newtonian.
Uma i-viscosity yopende incipha ngokwanda kwamandla okusika, ibizwa ngokuthi i-pseudoplastic fluid, futhi iningi lopende liyi-pseudoplastic fluid.
Uma ukuziphatha kokugeleza koketshezi oluyi-pseudoplastic kuhlobene nomlando walo, okungukuthi, kuncike esikhathini, kubizwa ngokuthi uketshezi lwe-thixotropic.
Lapho sikhiqiza izembozo, sivame ukuzama ngamabomu ukwenza izembozo ze-thixotropic, njengokufaka izithasiselo.
Uma i-thixotropy yengubo ifaneleka, ingaxazulula ukungqubuzana kwezigaba ezahlukene zengubo, futhi ihlangabezane nezidingo zobuchwepheshe zobukhulu obuhlukene bengubo ezigabeni zokugcina, zokulinganisa ukwakhiwa, nezokomisa.
Ezinye izinto zokujiya zinganika upende i-thixotropy ephezulu, ukuze ube ne-viscosity ephezulu lapho uphumule noma ngesilinganiso esiphansi sokucheba (njengokugcina noma ukuthuthwa), ukuze kuvinjelwe umbala opende ukuthi ungahlali. Futhi ngaphansi kwesilinganiso esiphezulu sokucheba (njengenqubo yokumboza), uba ne-viscosity ephansi, ukuze i-viscosity ibe nokugeleza okwanele kanye nokuhleleka.
I-Thixotropy imelelwa yi-thixotropic index TI futhi ilinganiswa yi-Brookfield viscometer.
I-TI=ukuthamba (kukalwa ku-6r/min)/ukuthamba (kukalwa ku-60r/min)
2. Izinhlobo zezithisi kanye nemiphumela yazo ezimpahleni zokumboza
(1) Izinhlobo Ngokuphathelene nokwakheka kwamakhemikhali, izinto zokujiya zihlukaniswe ngezigaba ezimbili: eziphilayo kanye nezinto ezingaphili.
Izinhlobo ezingaphili zifaka phakathi i-bentonite, i-attapulgite, i-aluminium magnesium silicate, i-lithium magnesium silicate, njll., izinhlobo eziphilayo ezifana ne-methyl cellulose, i-hydroxyethyl cellulose, i-polyacrylate, i-polymethacrylate, i-acrylic acid noma i-methyl i-Acrylic homopolymer noma i-copolymer kanye ne-polyurethane njll.
Ngokombono wethonya ezimpahleni ze-rheological zezingubo zokumboza, izithambisi zihlukaniswe zibe izithambisi ze-thixotropic kanye nezithambisi ezihambisanayo. Ngokuphathelene nezidingo zokusebenza, inani lesithambisi kufanele libe lincane futhi umphumela wokujiya muhle; akulula ukuguguleka ngama-enzyme; lapho izinga lokushisa noma inani le-pH lesistimu lishintsha, i-viscosity yesithambisi ngeke yehliswe kakhulu, futhi i-pigment kanye ne-filler ngeke kufakwe i-flocculated. ; Ukuqina okuhle kokugcina; ukugcinwa kwamanzi okuhle, akukho senzakalo esicacile sokugqwala futhi akukho miphumela emibi ekusebenzeni kwefilimu yokumboza.
①Isithambisi se-cellulose
Izithako zokuqinisa i-cellulose ezisetshenziswa ekumbozweni ikakhulukazi i-methylcellulose, i-hydroxyethylcellulose kanye ne-hydroxypropylmethylcellulose, kanti ezimbili zokugcina zivame ukusetshenziswa.
I-Hydroxyethyl cellulose iwumkhiqizo otholakala ngokufaka amaqembu e-hydroxyethyl esikhundleni samayunithi e-glucose e-cellulose yemvelo ngamaqembu e-hydroxyethyl. Imininingwane namamodeli emikhiqizo ahlukaniswa kakhulu ngokwezinga lokushintshana kanye ne-viscosity.
Izinhlobo ze-hydroxyethyl cellulose nazo zihlukaniswe ngohlobo olujwayelekile lokuncibilika, uhlobo lokusabalala okusheshayo kanye nohlobo lokuzinza kwezinto eziphilayo. Ngokuphathelene nendlela yokusebenzisa, i-hydroxyethyl cellulose ingangezwa ngezigaba ezahlukene enkambisweni yokukhiqizwa kokumboza. Uhlobo lokuhlakazeka okusheshayo lungangezwa ngqo ngesimo sempuphu eyomile. Kodwa-ke, inani le-pH lesistimu ngaphambi kokungeza kufanele libe ngaphansi kuka-7, ikakhulukazi ngoba i-hydroxyethyl cellulose incibilika kancane ngenani eliphansi le-pH, futhi kunesikhathi esanele sokuba amanzi angene ngaphakathi kwezinhlayiya, bese inani le-pH liyakhushulwa ukuze lincibilike ngokushesha. Izinyathelo ezihambisanayo zingasetshenziswa futhi ukulungiselela ukuhlushwa okuthile kwesisombululo seglue bese usifaka ohlelweni lokumboza.
I-Hydroxypropyl methylcelluloseiwumkhiqizo otholakala ngokufaka iqembu le-hydroxyl esikhundleni se-glucose unit ye-cellulose yemvelo ngeqembu le-methoxy, kuyilapho enye ingxenye ithathelwa indawo yiqembu le-hydroxypropyl. Umphumela wayo wokujiya ufana kakhulu nowe-hydroxyethyl cellulose. Futhi imelana nokuwohloka kwe-enzyme, kodwa ukuncibilika kwayo emanzini akukuhle njengokwe-hydroxyethyl cellulose, futhi inezinkinga zokugaya uma ishiswa. Kwi-hydroxypropyl methylcellulose ephathwe phezulu, ingafakwa ngqo emanzini uma isetshenziswa. Ngemva kokuyixuba nokuyihlakaza, engeza izinto ze-alkaline ezifana namanzi e-ammonia ukuze ulungise inani le-pH libe ngu-8-9, bese uyixuba kuze kube yilapho incibilika ngokuphelele. Kwi-hydroxypropyl methylcellulose ngaphandle kokwelashwa kwendawo, ingacwiliswa futhi ivuvuke ngamanzi ashisayo angaphezu kuka-85°C ngaphambi kokusetshenziswa, bese ipholiswa ekushiseni kwegumbi, bese ixutshwa ngamanzi abandayo noma amanzi eqhwa ukuze iyixube ngokuphelele.
②Isithambisi esingakhiqizi izinto eziphilayo
Lolu hlobo lwesithako esikhulu ikakhulukazi imikhiqizo yobumba esebenzayo, njenge-bentonite, ubumba lwe-magnesium aluminium silicate, njll. Lubonakala ngokuthi ngaphezu komphumela wokujiya, luphinde lube nomphumela omuhle wokumisa, lungavimbela ukucwila, futhi ngeke luthinte ukumelana kwamanzi kwesithako. Ngemva kokuba isithako somile futhi senziwe ifilimu, sisebenza njengesigcwalisi efilimini yesithako, njll. Isici esingathandeki ukuthi sizothinta kakhulu ukuhleleka kwesithako.
③ Isithambisi se-polymer esenziwe ngokwenziwa
Izithako zokwenziwa ze-polymer zisetshenziswa kakhulu kuma-acrylic kanye ne-polyurethane (izithako zokuhlanganisa). Izithako zokwenziwa ze-acrylic ikakhulukazi ama-polymer e-acrylic aqukethe amaqembu e-carboxyl. Emanzini anenani le-pH elingu-8-10, iqembu le-carboxyl liyahlukana futhi livuvuke; lapho inani le-pH lingaphezu kuka-10, liyancibilika emanzini bese lilahlekelwa umphumela wokujiya, ngakho-ke umphumela wokujiya uzwela kakhulu enanini le-pH.
Indlela yokujiya kwe-acrylate thickener ukuthi izinhlayiya zayo zingamuncwa ebusweni bezinhlayiya ze-latex kupende, futhi zakhe ungqimba lokumboza ngemva kokuvuvukala kwe-alkali, okwandisa ivolumu yezinhlayiya ze-latex, kuvimbele ukunyakaza kwe-Brownian kwezinhlayiya, futhi kwandise i-viscosity yesistimu yopende. ; Okwesibili, ukuvuvukala kwe-thickener kwandisa i-viscosity yesigaba samanzi.
(2) Ithonya lesithambisi ezimpahleni zokumboza
Umphumela wohlobo lwe-thickener ezimpahleni ze-rheological zengubo yile ndlela elandelayo:
Uma inani le-thickener landa, i-viscosity engaguquki yopende iyanda kakhulu, futhi umkhuba wokushintsha kwe-viscosity uyafana kakhulu uma ubhekene namandla angaphandle okucheba.
Ngomphumela we-thickener, i-viscosity yopende yehla ngokushesha uma icindezelwa amandla, okubonisa ukuthi ayi-pseudoplastic.
Ukusebenzisa i-hydrophobically modified cellulose thickener (njenge-EBS451FQ), ngamanani aphezulu okusika, i-viscosity isesephezulu uma inani likhulu.
Ukusebenzisa ama-associative polyurethane thickeners (njenge-WT105A), ngamanani aphezulu okusika, i-viscosity isesephezulu uma inani likhulu.
Ukusebenzisa izithina ze-acrylic (njenge-ASE60), yize i-viscosity engaguquki ikhuphuka ngokushesha lapho inani likhulu, i-viscosity iyancipha ngokushesha ngesivinini esiphezulu sokusika.
3. Isithambisi esihlangene
(1) indlela yokujiya
I-cellulose ether kanye ne-alkali-vulsive acrylic thickeners zingenza ukuqina kwesigaba samanzi kube kukhulu kuphela, kodwa azinawo umthelela wokuqina kwezinye izingxenye kupende olusekelwe emanzini, futhi azikwazi ukubangela ukusebenzisana okuphawulekayo phakathi kwama-pigment kupende kanye nezinhlayiya ze-emulsion, ngakho-ke i-rheology yopende ayikwazi ukulungiswa.
Ama-thickener ahlangene abonakala ngokuthi ngaphezu kokujiya ngenxa yokumanzisa amanzi, ajiya nangokuhlangana phakathi kwawo, nezinhlayiya ezihlakazekile, kanye nezinye izingxenye ohlelweni. Lokhu kuhlangana kuyahlukana ngesivinini esiphezulu sokucheba futhi kuphinde kuhlobane ngesivinini esiphansi sokucheba, okuvumela ukuthi i-rheology yengubo ilungiswe.
Indlela yokujiya kwe-associative thickener ukuthi i-molecule yayo iyi-linear hydrophilic chain, i-polymer compound enamaqembu e-lipophilic kuzo zombili izinhlangothi, okungukuthi, ineqembu le-hydrophilic kanye ne-hydrophobic esakhiweni, ngakho-ke inezici zama-molecule e-surfactant. Ama-molecule anjalo e-thickener awakwazi nje kuphela ukumanzisa nokuvuvukala ukuze ajiye isigaba samanzi, kodwa futhi akhe ama-micelles lapho ukuhlushwa kwesisombululo sawo samanzi kudlula inani elithile. Ama-micelles angahlotshaniswa nezinhlayiya ze-polymer ze-emulsion kanye nezinhlayiya ze-pigment eziye zathinta i-dispersant ukuze zakhe isakhiwo senethiwekhi esinezinhlangothi ezintathu, futhi zixhumene futhi ziboshwe ukuze kwandiswe i-viscosity yesistimu.
Okubaluleke kakhulu ukuthi lezi zinhlangano zisesimweni sokulinganisela okuguquguqukayo, futhi lawo ma-micelles ahlobene angalungisa izikhundla zawo lapho ebhekene namandla angaphandle, ukuze uqweqwe lube nezakhiwo zokulinganisa. Ngaphezu kwalokho, njengoba i-molecule inama-micelles amaningana, lesi sakhiwo sinciphisa ukuthambekela kwama-molecule amanzi ekufudukeni futhi ngaleyo ndlela sandise i-viscosity yesigaba samanzi.
(2) Indima ekumbozweni
Iningi lama-thickeners associative angama-polyurethane, futhi isisindo sawo sama-molecule siphakathi kwama-oda angu-103-104 ubukhulu, ama-oda amabili ngobukhulu aphansi kune-polyacrylic acid evamile kanye nama-thickeners e-cellulose anesisindo sama-molecule esiphakathi kuka-105-106. Ngenxa yesisindo sama-molecule esiphansi, ukwanda kwevolumu okuphumelelayo ngemva kokufaka amanzi kuncane, ngakho-ke i-viscosity curve yayo ithambile kuneye-thickeners engeyona i-associate.
Ngenxa yesisindo esiphansi sama-molecule se-associative thickener, ukuvaleka kwayo phakathi kwama-molecule esigabeni samanzi kunqunyelwe, ngakho-ke umphumela wayo wokujiya esigabeni samanzi awubalulekile. Ebangeni eliphansi le-shear rate, ukuguqulwa kobudlelwano phakathi kwama-molecule kungaphezu kokubhujiswa kobudlelwano phakathi kwama-molecule, lonke uhlelo lugcina isimo sokumiswa kanye nokuhlakazeka, futhi i-viscosity iseduze ne-viscosity ye-dispersion medium (amanzi). Ngakho-ke, i-associative thickener yenza uhlelo lopende olusekelwe emanzini lubonise i-viscosity ephansi ebonakalayo uma lusesifundeni se-shear rate ephansi.
Ama-thickeners ahlangene andisa amandla angaba khona phakathi kwama-molecule ngenxa yokuhlangana phakathi kwezinhlayiya esigabeni esihlakazekile. Ngale ndlela, kudingeka amandla engeziwe ukuze kuphulwe ukuhlangana phakathi kwama-molecule ngesivinini esiphezulu sokusika, futhi amandla okusika adingekayo ukuze kufezwe uhlobo olufanayo lokusika nawo makhulu, ukuze uhlelo lubonise izinga eliphezulu lokusika ngesivinini esiphezulu sokusika. I-viscosity ebonakalayo. I-viscosity ephezulu yokusika ephezulu kanye ne-viscosity ephansi yokusika ephansi kungenza kube lula ukuntuleka kwama-thickeners avamile ezimpahleni ze-rheological zopende, okungukuthi, ama-thickeners amabili angasetshenziswa ngokuhlanganiswa ukulungisa ukugeleza kopende we-latex. Ukusebenza okuguquguqukayo, ukuhlangabezana nezidingo eziphelele zokumboza zibe ifilimu ejiyile kanye nokugeleza kwefilimu yokumboza.
Isikhathi sokuthunyelwe: Ephreli-28-2024