1. Nkọwa na ọrụ nke thickener
A na-akpọ ihe mgbakwunye ndị nwere ike ịbawanye viscosity nke agba ndị na-eme mmiri n'ụzọ dị ukwuu.
Thickers na-ekere òkè dị mkpa na mmepụta, nchekwa na iwu nke mkpuchi.
Isi ọrụ nke thickener bụ ịbawanye viscosity nke mkpuchi iji mezuo ihe achọrọ nke usoro dị iche iche nke ojiji. Otú ọ dị, viscosity chọrọ site na mkpuchi na ọkwa dị iche iche dị iche iche. Dịka:
N'oge usoro nchekwa, ọ na-achọsi ike inwe nnukwu viscosity iji gbochie pigmenti edozi;
N'oge usoro ihe owuwu, ọ na-achọsi ike inwe viscosity na-agafeghị oke iji hụ na agba nwere ezigbo brushability na-enweghị oke agba agba;
Mgbe emechara, a na-atụ anya na viscosity nwere ike ịlaghachi ngwa ngwa na nnukwu viscosity mgbe obere oge gachara (usoro nhazi ọkwa) iji gbochie sagging.
Mmiri mmiri nke mkpuchi mmiri na-abụghị nke Newtonian.
Mgbe viscosity nke agba na-ebelata na mmụba nke ike ịkwa akwa, a na-akpọ ya mmiri mmiri pseudoplastic, ọtụtụ n'ime agba bụ mmiri mmiri pseudoplastic.
Mgbe omume ịgba ọsọ nke mmiri mmiri pseudoplastic metụtara akụkọ ihe mere eme ya, ya bụ, ọ dabere na oge, a na-akpọ ya mmiri mmiri thixotropic.
Mgbe ị na-emepụta ihe mkpuchi, anyị na-ejikarị nlezianya na-agbalị ime ka mkpuchi thixotropic, dị ka ịgbakwunye ihe mgbakwunye.
Mgbe thixotropy nke mkpuchi ahụ kwesịrị ekwesị, ọ nwere ike dozie esemokwu nke usoro dị iche iche nke mkpuchi ahụ, ma gboo mkpa teknụzụ nke viscosity dị iche iche nke mkpuchi na nchekwa, nhazi ọkwa, na ihicha ọkwa.
Ụfọdụ thickeners nwere ike inye agba na thixotropy dị elu, nke mere na ọ nwere viscosity dị elu na ezumike ma ọ bụ na ọnụ ala dị ala (dị ka nchekwa ma ọ bụ njem njem), iji gbochie pigmenti dị na agba ka ọ edozi. Na n'okpuru ọnụ ọgụgụ dị elu (dị ka usoro mkpuchi), ọ nwere obere viscosity, nke mere na mkpuchi ahụ nwere oke mmiri na nhazi.
A na-anọchi anya Thixotropy site na thixotropic index TI wee tụọ ya site na Brookfield viscometer.
TI = viscosity (a tụrụ na 6r / min) / viscosity (tụtara na 60r / min)
2. Ụdị thickeners na mmetụta ha na mkpuchi mkpuchi
(1) Ụdị N'ihe gbasara chemical mejupụtara, thickeners na-ekewa abụọ edemede: organic na inorganic.
Ụdị inorganic gụnyere bentonite, attapulgite, aluminum magnesium silicate, lithium magnesium silicate, wdg, ụdị organic dị ka methyl cellulose, hydroxyethyl cellulose, polyacrylate, polymethacrylate, acrylic acid ma ọ bụ methyl acrylic homopolymer ma ọ bụ copolymer na polyurethane wdg.
Site n'echiche nke mmetụta na rheological Njirimara nke coatings, thickeners na-ekewa n'ime thixotropic thickeners na associative thickeners. N'ihe banyere arụmọrụ chọrọ, ọnụ ọgụgụ nke thickener kwesịrị ịdị ntakịrị na mmetụta dị nro dị mma; ọ dịghị mfe ịbụ ndị enzymes mebiri emebi; mgbe okpomọkụ ma ọ bụ pH uru nke usoro ahụ gbanwere, viscosity nke mkpuchi agaghị ebelata nke ukwuu, a gaghịkwa emegharị pigmenti na ihe mkpuchi. ; Nkwụsi ike nchekwa dị mma; ezigbo njide mmiri, ọ dịghị ihe doro anya na-agbapụta ụfụfụ na enweghị mmetụta ọjọọ na arụmọrụ nke ihe nkiri mkpuchi.
① Cellulose thickener
Ihe mkpuchi cellulose a na-eji na mkpuchi bụ tumadi methylcellulose, hydroxyethylcellulose na hydroxypropylmethylcellulose, na nke abụọ a na-ejikarị eme ihe.
Hydroxyethyl cellulose bụ ngwaahịa enwetara site na dochie otu hydroxyl na nkeji glucose nke cellulose eke na otu hydroxyethyl. Nkọwapụta na ụdị nke ngwaahịa ndị a na-ahụkarị dị ka ogo nnọchi na viscosity si dị.
A na-ekewakwa ụdị hydroxyethyl cellulose dị iche iche n'ụdị mgbasa ozi nkịtị, ụdị mgbasa ngwa ngwa na ụdị nkwụsi ike nke ndu. N'ihe gbasara usoro eji eme ihe, hydroxyethyl cellulose nwere ike ịgbakwunye na ọkwa dị iche iche na usoro mmepụta mkpuchi. Enwere ike ịgbakwunye ụdị ngwa ngwa na-agbasa ngwa ngwa n'ụdị ntụ ntụ. Otú ọ dị, uru pH nke usoro ahụ tupu ịgbakwụnye kwesịrị ịbụ ihe na-erughị 7, tumadi n'ihi na hydroxyethyl cellulose na-agbaze nwayọọ nwayọọ na ọnụ ala pH dị ala, na e nwere oge zuru ezu maka mmiri ịbanye n'ime akụkụ ahụ, mgbe ahụ, uru pH na-abawanye ka ọ na-agbaze ngwa ngwa. A pụkwara iji usoro ndị kwekọrọ na-edozi ụfọdụ ntinye nke ngwọta gluu ma tinye ya na usoro mkpuchi.
Hydroxypropyl methylcellulosebụ ngwaahịa enwetara site na iji otu methoxy dochie otu hydroxyl na glucose unit nke cellulose eke, ebe nke ọzọ na-eji otu hydroxypropyl dochie akụkụ nke ọzọ. Mmetụta ya na-agba agba bụ isi na nke hydroxyethyl cellulose. Ọ na-eguzogidekwa mmebi nke enzymatic, ma mmiri ya adịghị mma dị ka nke hydroxyethyl cellulose, ọ na-enwekwa ọghọm nke gelling mgbe ọ na-ekpo ọkụ. Maka hydroxypropyl methylcellulose a na-agwọ elu, enwere ike itinye ya ozugbo na mmiri mgbe ejiri ya. Mgbe ịmechara ma gbasaa, gbakwunye ihe ndị dị na alkaline dị ka mmiri amonia iji dozie uru pH na 8-9, ma kpalie ruo mgbe agbazere kpamkpam. Maka hydroxypropyl methylcellulose na-enweghị ọgwụgwọ elu, enwere ike ịtinye ya ma zaa ya na mmiri ọkụ dị elu karịa 85 ° C tupu ejiri ya, wee mee ka ọ dị jụụ n'ime ụlọ, wee kpoo ya na mmiri oyi ma ọ bụ mmiri ice iji gbazee ya kpamkpam.
② Inorganic thickener
Ụdị thickener bụ tumadi ụfọdụ ndị na-arụ ọrụ ụrọ ngwaahịa, dị ka bentonite, magnesium aluminum silicate ụrọ, wdg Ọ na-ji na na mgbakwunye na nke ndim mmetụta, ọ na-enwe ezi nkwusioru mmetụta, nwere ike igbochi imi, na agaghị emetụta mmiri na-eguzogide nke mkpuchi. Mgbe mkpuchi ahụ akpọnwụwo ma mee ka ọ bụrụ ihe nkiri, ọ na-eme ihe dị ka onye na-eme ihe na fim mkpuchi, wdg. Ihe na-adịghị mma bụ na ọ ga-emetụta nke ọma n'ókè nke mkpuchi ahụ.
③ Synthetic polymer thickener
Synthetic polymer thickeners na-akasị eji na acrylic na polyurethane (associative thickeners). Acrylic thickeners bụ ọtụtụ acrylic polymers nwere otu carboxyl. Na mmiri nwere pH uru nke 8-10, otu carboxyl na-ekewa ma na-aza aza; mgbe pH uru dị ukwuu karịa 10, ọ na-agbaze na mmiri ma na-efunahụ mmetụta na-ekpo ọkụ, ya mere mmetụta na-egbuke egbuke na-enwe mmetụta nke ukwuu na uru pH.
The ndim usoro nke acrylate thickener bụ na ya ahụ nwere ike adsorbed n'elu nke latex ahụ na agba, na-etolite a mkpuchi oyi akwa mgbe alkali ọzịza, nke na-abawanye olu nke latex ahụ, na-egbochi Brownian ngagharị nke ahụ, na-abawanye viscosity nke agba usoro. ; Nke abụọ, ọzịza nke thickener na-abawanye viscosity nke oge mmiri.
(2) Mmetụta nke thickener na mkpuchi ihe
Mmetụta nke ụdị thickener na rheological Njirimara nke mkpuchi bụ dị ka ndị a:
Mgbe ọnụọgụ nke thickener na-abawanye, viscosity static nke agba na-abawanye nke ukwuu, na mgbanwe mgbanwe viscosity na-agbanwe agbanwe mgbe etinyere ya na ike mpụta mpụta.
Site na mmetụta nke thickener, viscosity nke agba na-ada ngwa ngwa mgbe a na-agbanye ya ike, na-egosi pseudoplasticity.
Iji cellulose thickener hydrophobically gbanwetụrụ (dị ka EBS451FQ), na oke shiee ọnụego, viscosity ka dị elu mgbe ego buru ibu.
Iji polyurethane thickeners associative (dị ka WT105A), na nnukwu shiee ọnụego, viscosity ka dị elu mgbe ego buru ibu.
Iji acrylic thickeners (dị ka ASE60), ọ bụ ezie na static viscosity na-ebili ngwa ngwa mgbe ego buru ibu, viscosity na-ebelata ngwa ngwa na ọnụ ọgụgụ dị elu.
3. Associative thickener
(1) usoro ndina
Cellulose ether na alkali-swellable acrylic thickeners nwere ike naanị thicken mmiri na-adọ, ma ọ dịghị ndim mmetụta na ndị ọzọ mmiri na agba, ma ọ bụ na ha nwere ike ime ka ịrịba mmekọrịta n'etiti pigments na agba na ahụ nke emulsion, otú The rheology nke agba enweghị ike gbanwee.
Associative thickeners e ji na na mgbakwunye na ndim site hydration, ha na-ndina site mkpakọrịta n'etiti onwe ha, na-achụsasị irighiri, na ndị ọzọ mmiri na usoro. Njikọ a na-ekewapụ na ọnụ ọgụgụ dị elu ma na-ejikọta ya na ọnụ ọgụgụ dị ala, na-ekwe ka rheology nke mkpuchi gbanwee.
Usoro nke na-eme ka ihe na-emekọ ihe na-emekọ ihe bụ na molekul ya bụ eriri hydrophilic linear, polymer compound na lipophilic dị iche iche na nsọtụ abụọ ahụ, ya bụ, o nwere hydrophilic na hydrophobic dị iche iche na nhazi ahụ, ya mere o nwere njirimara nke ụmụ irighiri ihe. okike. Ndị dị otú ahụ thickener ụmụ irighiri nwere ike ọ bụghị naanị hydrate na zaa ka thicke na mmiri na-adọ, ma na-etolite micelles mgbe ịta nke mmiri mmiri ngwọta karịrị a ụfọdụ uru. The micelles nwere ike na-akpakọrịta na polymer irighiri nke emulsion na pigmenti ahụ nke adsorbed dispersant na-etolite a atọ akụkụ netwọk Ọdịdị, na-njikọ na-ejikọta ọnụ na enangled na-amụba viscosity nke usoro.
Ihe dị mkpa karịa bụ na mkpakọrịta ndị a nọ n'ọnọdụ nguzozi siri ike, na micelles ndị ahụ metụtara nwere ike ịhazigharị ọnọdụ ha mgbe a na-etinye ya n'okpuru ike mpụga, nke mere na mkpuchi ahụ nwere nhazi ọkwa. Na mgbakwunye, ebe ọ bụ na molekul ahụ nwere ọtụtụ micelles, ihe owuwu a na-ebelata ọchịchọ nke mkpụrụ ndụ mmiri ịkwaga ma si otú a na-abawanye viscosity nke mmiri mmiri.
(2) Ọrụ na mkpuchi
Ọtụtụ n'ime ihe ndị na-emekọ ihe ọnụ bụ polyurethane, na ịdị arọ ha dị n'etiti 103-104 iwu nke ịdị ukwuu, iwu abụọ dị ala karịa polyacrylic acid nkịtị na cellulose thickeners na ihe dị arọ molecular dị n'etiti 105-106. N'ihi ịdị arọ molekụla dị ala, mmụba dị irè mgbe hydration dị obere, ya mere viscosity curve ya dị larịị karịa nke ndị na-abụghị ndị na-akpakọrịta.
N'ihi ịdị arọ molekụla dị ala nke associative thickener, njikọ intermolecular ya na oge mmiri dị oke, yabụ mmetụta ọ na-abawanye na mmiri mmiri adịghị mkpa. Na ala shiee ọnụego nso, mkpakọrịta ntughari n'etiti ụmụ irighiri ihe karịrị mkpakọrịta mbibi n'etiti ụmụ irighiri ihe, dum usoro na-ekwusi ihe pụta ụwa nkwusioru na dispersion steeti, na viscosity dị nso na viscosity nke dispersion media (mmiri). Ya mere, ihe ndị na-emekọ ihe ọnụ na-eme ka usoro agba nke mmiri na-eme ka mmiri na-egosiputa viscosity dị ala mgbe ọ nọ na mpaghara ọnụ ala dị ala.
Associative thickeners dịkwuo ike ike n'etiti ụmụ irighiri n'ihi na mkpakọrịta n'etiti ahụ na achụsasịwo agba. N'ụzọ dị otú a, a na-achọkwu ume iji mebie njikọ dị n'etiti ụmụ irighiri ihe na ọnụ ọgụgụ dị elu, na ike nke na-eme ka ọ dị mkpa iji nweta otu ihe ahụ na-eme ka ọ dịkwuo ukwuu, nke mere na usoro ahụ na-egosipụta ọnụ ọgụgụ dị elu dị elu na ọnụ ọgụgụ dị elu. Viscosity pụtara ìhè. The elu elu-shiee viscosity na ala ala shiee viscosity nwere ike ime ka elu maka enweghị nkịtị thickeners na rheological Njirimara nke agba, ya bụ, abụọ thickeners nwere ike ji mee ihe na Nchikota ka mezie fluidity nke latex agba. Ịrụ ọrụ dị iche iche, iji mezuo ihe ndị a chọrọ nke mkpuchi n'ime ihe nkiri siri ike na mkpuchi ihe nkiri.
Oge nzipu: Eprel-28-2024