1. Tlhaloso le mosebetsi oa thickener
Li-additives tse ka eketsang haholo viscosity ea lipente tse thehiloeng metsing li bitsoa thickeners.
Li-thickeners li phetha karolo ea bohlokoa ho hlahiseng, ho boloka le ho haha liaparo.
Mosebetsi o ka sehloohong oa thickener ke ho eketsa viscosity ea ho roala ho finyella litlhoko tsa mekhahlelo e fapaneng ea tšebeliso. Leha ho le joalo, viscosity e hlokoang ke ho roala ka mekhahlelo e fapaneng e fapane. Mohlala:
Nakong ea ts'ebetso ea polokelo, ke ntho e lakatsehang ho ba le viscosity e phahameng ho thibela pigment ho rarolla;
Nakong ea ts'ebetso ea kaho, ke ntho e lakatsehang ho ba le viscosity e itekanetseng ho netefatsa hore pente e na le brushability e ntle ntle le litšila tse feteletseng tsa pente;
Ka mor'a ho hahoa, ho na le tšepo ea hore viscosity e ka khutlela ka potlako ho viscosity e phahameng ka mor'a nako e khutšoanyane ea nako (mokhoa oa ho leka-lekanya) ho thibela ho fokotseha.
Mokelikeli oa liphahlo tse kenngoeng ke metsi ha se oa Newtonian.
Ha viscosity ea pente e fokotseha ka ho eketseha ha matla a ho kuta, e bitsoa pseudoplastic fluid, 'me boholo ba pente ke pseudoplastic fluid.
Ha boitšoaro ba ho phalla ha pseudoplastic fluid bo amana le histori ea eona, ke hore, e itšetlehile ka nako, e bitsoa thixotropic fluid.
Ha re etsa liaparo, hangata re leka ka hloko ho etsa liaparo tsa thixotropic, tse kang ho eketsa li-additives.
Ha thixotropy ea ho roala e loketse, e ka rarolla liphapang tsa mekhahlelo e sa tšoaneng ea ho roala, 'me ea finyella litlhoko tsa tekheniki tsa viscosity e fapaneng ea ho roala sebakeng sa polokelo, boemo ba kaho, le mekhahlelo ea ho omisa.
Li-thickeners tse ling li ka fa pente ka thixotropy e phahameng, e le hore e be le viscosity e phahameng ha e phomola kapa ka tekanyo e tlaase ea ho kuta (e kang ho boloka kapa ho tsamaisa), e le ho thibela pigment ka pente hore e se ke ea lula. 'Me tlas'a tekanyo e phahameng ea ho kuta (e kang mokhoa oa ho roala), e na le viscosity e tlaase, e le hore seaparo se be le phallo e lekaneng le ho lekana.
Thixotropy e emeloa ke thixotropic index TI mme e lekantsoe ke Brookfield viscometer.
TI = viscosity (e lekantsoeng ho 6r / min) / viscosity (e lekantsoe ho 60r / min)
2. Mefuta ea li-thickeners le liphello tsa tsona ho thepa ea ho roala
(1) Mefuta Ho latela sebopeho sa lik'hemik'hale, li-thickeners li arotsoe ka mekhahlelo e 'meli: organic le inorganic.
Mefuta e sa tloaelehang e kenyelletsa bentonite, attapulgite, aluminium magnesium silicate, lithium magnesium silicate, joalo-joalo, mefuta ea lintho tse phelang tse kang methyl cellulose, hydroxyethyl cellulose, polyacrylate, polymethacrylate, acrylic acid kapa methyl Acrylic homopolymer kapa copolymer le polyurethane joalo-joalo.
Ho ea ka pono ea tšusumetso ho thepa ea rheological ea ho roala, li-thickeners li arotsoe ka li-thixotropic thickeners le li-associative thickeners. Mabapi le litlhoko tsa ts'ebetso, palo ea thickener e lokela ho ba tlase 'me phello e teteaneng e ntle; ha ho bonolo ho senyeha ke li-enzyme; ha mocheso kapa pH boleng ba sistimi bo fetoha, viscosity ea ho roala e ke ke ea fokotseha haholo, 'me pigment le filler li ke ke tsa phaphamala. ; Botsitso bo botle ba polokelo; ho boloka metsi hantle, ha ho na ts'ebetso e hlakileng ea foaming mme ha ho na liphello tse mpe mosebetsing oa filimi ea ho roala.
① Setenya sa cellulose
Li-cellulose thickeners tse sebelisoang ho koahela haholo ke methylcellulose, hydroxyethylcellulose le hydroxypropylmethylcellulose, 'me tse peli tsa morao li sebelisoa hangata.
Hydroxyethyl cellulose ke sehlahisoa se fumanoang ka ho nkela lihlopha tsa hydroxyl sebakeng sa tsoekere ea cellulose ea tlhaho ka lihlopha tsa hydroxyethyl. Litlhaloso le mehlala ea lihlahisoa li khetholloa haholo ho ea ka tekanyo ea ho fetola le viscosity.
Mefuta e fapaneng ea hydroxyethyl cellulose e boetse e arotsoe ka mofuta o tloaelehileng oa ho qhibiliha, mofuta oa ho hasana ka potlako le mofuta oa botsitso ba baeloji. Mabapi le mokhoa oa ts'ebeliso, hydroxyethyl cellulose e ka eketsoa ka mekhahlelo e fapaneng ts'ebetsong ea tlhahiso ea ho roala. Mofuta oa ho jala ka potlako o ka eketsoa ka ho toba ka mokhoa oa phofo e omileng. Leha ho le joalo, boleng ba pH ba tsamaiso pele bo eketsa bo lokela ho ba ka tlase ho 7, haholo-holo hobane hydroxyethyl cellulose e qhibiliha butle-butle ka boleng bo tlaase ba pH, 'me ho na le nako e lekaneng ea hore metsi a kenelle ka hare ho likaroloana, ebe joale pH ea boleng e eketseha ho etsa hore e qhibilihe ka potlako. Mehato e lumellanang e ka boela ea sebelisoa ho lokisa motsoako o itseng oa tharollo ea sekhomaretsi le ho e eketsa tsamaisong ea ho roala.
Hydroxypropyl methylcelluloseke sehlahisoa se fumanoang ka ho nkela sehlopha sa hydroxyl sebakeng sa yuniti ea tsoekere ea cellulose ea tlhaho ka sehlopha sa methoxy, ha karolo e 'ngoe e nkeloa sebaka ke sehlopha sa hydroxypropyl. Phello ea eona e teteaneng ha e le hantle e tšoana le ea hydroxyethyl cellulose. 'Me e hanyetsana le ho senyeha ha li-enzymatic, empa ho qhibiliha ha eona ha metsi ha ho molemo joaloka hydroxyethyl cellulose,' me e na le bothata ba gelling ha e futhumala. Bakeng sa hydroxypropyl methylcellulose e phekotsoeng holimo, e ka eketsoa ka kotloloho metsing ha e sebelisoa. Kamora ho sisinya le ho qhalakanya, eketsa dintho tsa alkaline tse kang metsi a ammonia ho lokisa boleng ba pH ho 8-9, mme o hlohlelletse ho fihlela o qhibidiha ka botlalo. Bakeng sa hydroxypropyl methylcellulose ntle le phekolo ea holim'a metsi, e ka kolobisoa le ho ruruha ka metsi a chesang ka holimo ho 85 ° C pele e sebelisoa, ebe e pholile mocheso oa kamore, ebe e tsosoa ka metsi a batang kapa metsi a leqhoa ho e qhaqha ka ho feletseng.
②Setsi sa inorganic
Mofuta ona oa thickener ke haholo-holo lihlahisoa tse ling tsa letsopa tse kentsoeng, tse kang bentonite, magnesium aluminium silicate letsopa, joalo-joalo E khetholloa ka hore ho phaella ho phello e teteaneng, e boetse e na le phello e ntle ea ho emisa, e ka thibelang ho teba, 'me e ke ke ea ama ho hanyetsa metsi a ho roala. Ka mor'a hore seaparo se omisitsoe 'me se thehoe filimi, e sebetsa e le ho tlatsa filimi ea ho roala, joalo-joalo Ntho e sa thabiseng ke hore e tla ama haholo boemo ba ho roala.
③ Synthetic polymer thickener
Li-synthetic polymer thickeners li sebelisoa haholo ka acrylic le polyurethane (associative thickeners). Li-acrylic thickeners hangata ke li-polymer tsa acrylic tse nang le lihlopha tsa carboxyl. Ka metsing a nang le pH ea 8-10, sehlopha sa carboxyl se ikarola ebe se ruruha; ha pH ea boleng e le kholo ho feta 10, e qhibiliha ka metsing 'me e lahleheloa ke phello e teteaneng, kahoo phello e teteaneng e na le maikutlo a mangata haholo ho boleng ba pH.
The thickening mochine oa acrylate thickener ke hore likaroloana tsa eona li ka adsorbed holim'a likaroloana tsa latex ka pente, 'me li theha lera la ho roala ka mor'a ho ruruha ha alkali, e leng ho eketsang molumo oa likaroloana tsa latex, ho sitisa ho tsamaea ha Brownian ea likaroloana,' me ho eketsa viscosity ea tsamaiso ea pente. ; Ea bobeli, ho ruruha ha thickener ho eketsa viscosity ea karolo ea metsi.
(2) Tšusumetso ea thickener ho thepa ea ho roala
Phello ea mofuta oa thickener ho thepa ea rheological ea ho roala ke e latelang:
Ha palo ea botenya e eketseha, viscosity e tsitsitseng ea pente e eketseha haholo, 'me mokhoa oa ho fetola viscosity ha e le hantle o lumellana ha o tlas'a matla a ho kuta a kantle.
Ka phello ea thickener, viscosity ea pente e theoha ka potlako ha e etsoa tlas'a matla a ho kuta, e bontšang pseudoplasticity.
Ho sebelisa hydrophobically modified cellulose thickener (e kang EBS451FQ), ka litekanyetso tse phahameng tsa ho kuta, viscosity e ntse e phahame ha chelete e le khōlō.
Ho sebelisa associative polyurethane thickeners (joaloka WT105A), ka litekanyetso tse phahameng tsa ho kuta, viscosity e ntse e le holimo ha palo e le khōlō.
Ho sebelisa li-acrylic thickeners (tse kang ASE60), le hoja viscosity e tsitsitseng e phahama ka potlako ha palo e le khōlō, viscosity e fokotseha ka potlako ka tekanyo e phahameng ea ho kuta.
3. Associative thickener
(1) mochine o teteaneng
Cellulose ether le alkali-swellable thickeners acrylic thickeners feela e teteaneng karolo ea metsi, empa ha e na phello e teteaneng likarolong tse ling tsa pente e thehiloeng metsing, leha e le hore e ke ke ea baka tšebelisano e kholo pakeng tsa li-pigments ka pente le likaroloana tsa emulsion, kahoo The rheology ea pente e ke ke ea fetoloa.
Li-thickeners tsa associative li khetholloa ka hore ntle le ho teteka ka hydration, li boetse li teteaneng ka ho kopana pakeng tsa bona, ka likaroloana tse qhalakaneng, le likarolo tse ling tsa tsamaiso. Mokhatlo ona o ikarola ka litekanyetso tse phahameng tsa ho kuta 'me o ikopanya hape ka litekanyetso tse tlaase tsa ho kuta, ho lumella rheology ea ho roala hore e lokisoe.
Mokhoa o ntseng o eketseha oa "associative thickener" ke hore molek'hule ea eona ke ketane ea hydrophilic e lekanang, motsoako oa polymer o nang le lihlopha tsa lipophilic lipheletsong tse peli, ke hore, o na le lihlopha tsa hydrophilic le hydrophobic mohahong, kahoo o na le litšobotsi tsa limolek'hule tsa surfactant. tlhaho. Limolek'hule tse joalo tsa thickener ha li khone feela ho hydrate le ho ruruha ho tiisa karolo ea metsi, empa hape li etsa li-micelles ha motsoako oa tharollo ea metsi a eona a feta boleng bo itseng. Li-micelles li ka amahanngoa le likaroloana tsa polymer tsa emulsion le likaroloana tsa pigment tse adsorbed dispersant ho etsa sebopeho sa marang-rang a mararo, 'me li kopantsoe le ho ts'oaroa ho eketsa viscosity ea tsamaiso.
Ntho ea bohlokoa le ho feta ke hore mekhatlo ena e boemong ba ho leka-lekana ho matla, 'me li-micelles tse amanang le tsona li ka fetola maemo a tsona ha li le tlas'a matla a ka ntle, e le hore ho roala ho na le thepa ea ho leka-lekanya. Ho phaella moo, kaha molek'hule e na le li-micelles tse 'maloa, mohaho ona o fokotsa tšekamelo ea limolek'hule tsa metsi ho falla' me kahoo e eketsa viscosity ea karolo ea metsi.
(2) Karolo ea ho roala
Bongata ba li-asociative thickeners ke polyurethanes, 'me boima ba tsona ba limolek'hule bo pakeng tsa 103-104 litaelo tsa boholo, li-oda tse peli tsa boholo bo tlase ho feta tse tloaelehileng tsa polyacrylic acid le cellulose thickeners tse nang le boima ba limolek'hule tse pakeng tsa 105-106. Ka lebaka la boima bo tlaase ba limolek'hule, ho eketseha ha molumo o sebetsang ka mor'a hore hydration e fokotsehe, kahoo sekhahla sa eona sa viscosity se bataletse ho feta sa li-non-associative thickeners.
Ka lebaka la boima bo tlaase ba molek'hule ea associative thickener, ho kenngoa ha eona ka har'a metsi ka har'a metsi ho fokotsehile, kahoo phello ea eona e teteaneng karolong ea metsi ha e bohlokoa. Sebakeng se tlaase sa sekhahla sa sekhahla, phetoho ea mokhatlo pakeng tsa limolek'hule e feta ho timetsoa ha mokhatlo pakeng tsa limolek'hule, tsamaiso eohle e boloka boemo ba tlhaho ba ho emisoa le ho hasana, 'me viscosity e haufi le viscosity ea sebaka sa ho qhalakanngoa (metsi). Ka hona, associative thickener e etsa hore tsamaiso ea pente e thehiloeng metsing e bontše viscosity e tlaase e bonahalang ha e le sebakeng se tlaase sa ho kuta.
Li-thickeners tsa associative li eketsa matla a ka bang teng pakeng tsa limolek'hule ka lebaka la ho kopana pakeng tsa likaroloana karolong e qhalakaneng. Ka tsela ena, ho hlokahala matla a mangata ho senya kamano pakeng tsa limolek'hule ka litekanyetso tse phahameng tsa ho kuta, 'me matla a ho kuta a hlokahalang ho finyella mofuta o tšoanang oa ho kuta le oona o moholo, e le hore tsamaiso e bontše sekhahla se phahameng sa ho kuta ka litekanyetso tse phahameng tsa ho kuta. Viscosity e bonahalang. Li-viscosity tse phahameng ka ho fetisisa le li-viscosity tse tlaase tse tlaase li ka etsa feela ho haella ha li-thickeners tse tloaelehileng ka har'a thepa ea rheological ea pente, ke hore, li-thickeners tse peli li ka sebelisoa hammoho ho lokisa mokelikeli oa pente ea latex. Ts'ebetso e feto-fetohang, ho fihlela litlhoko tse felletseng tsa ho roala filimi e teteaneng le ho phalla ha filimi.
Nako ea poso: Apr-28-2024