I. Definition et munus De Thickener
Additives quod potest significantly auget viscositas aqua-fundatur depingit dicuntur.
Thquillantes ludere an maximus munus in productio, repono et constructione coatings.
Pelagus munus in Thickener est ad augendam viscositas de coating in occursum de requisitis diversis gradibus usum. Tamen, in viscositas requiritur a coating ad diversas gradus differt. EG:
Per repono processus, est optandum habere excelsum viscositas ne pigmento a sedes;
Per constructione processus, est appetibile habere modicum viscositas ut pingere habet bonum Brushability sine nimia pingere maculat;
Post constructione speratur quod visecositas potest cito redire ad altum viscositas post brevi TEMPUS Lag (adtritio processus) ne sagging.
Et fluiditatem waterborne coatings non-Newtonian.
Cum ad viscositas pingunt decrescit cum incremento de tondendis vi, dicitur a pseudoplastic fluidi, et maxime de pingunt est pseudoplastic fluidi.
Cum autem fluunt mores a Pseudoplastic fluidi est ad suam historiam, id est, tempus, dependens, dicitur a Thixotropic fluidum.
Cum vestibulum coatings, saepe scienter conantur facere coatings Thixotropic, ut addit additives.
Cum Thixotropy de coating oportet, quod potest solvere contradictionibus variis gradibus de coating, et occursum technica necessitatibus diversis viscositas coating in repono, constructione adveniens et siccatio.
Quidam thestotropy potest dotare pingunt cum princeps Thixotropy, ut non habet altiorem viscositas ad quiescere vel ad low tondendas rate (ut repono vel in pingunt a stibio. Et sub magno tondendas rate (ut coating processus), quod est humilis viscositas, ut coating sufficiens fluxus et adtritio.
Thixotropy est per Thixotropic Index TI et metiri per Brookfeld VECEMETER.
TI = Viscosity (metiri ad 6r / min) / Viscosity (metiri ad 60R / min)
II. Genera thestiónibus et eorum effectus in coating proprietatibus
(I) types in terms of chemical compositionem, sponsionibus sunt in duo genera: organicum et inorganicis.
Inorganicis genera includit Bentonite, Attapulgite, Aluminium Magnesium Silate, Lithium Magnesium silicate, etc., organicum types ut methyl cellulosa, hydroxyethl cellulosa et polyacture, polyaclice homopolymer et acidum et Polyacturon etc.
Ex perspective de influentia in proprietatibus coatings, sponsionibus dividitur in Thixotropic thestotopen et consuetudines. In terms of perficientur requisita, moles thickener sit minus et crasso effectus est bonum; Non facile eroded enzymes; Cum temperatus et PH valorem systematis mutat, et viscositas de coating non sit significantly reducitur et pigmento et filler et non flocculatentur. ANTOLIUM; Bonum repono stabilitatem; Bonus aqua retention, non obvious spumans phaenomenon et non adversa effectus in perficientur de coating film.
①Celluloss Thickener
In Cellulose thessionum in coatings sunt maxime methylcellosus, hydroxyethylcellulose et hydroxypropylmethylcellulose et hi duo sunt communiter.
Hydroxyethyl Cellulose est productum adeptus per repositoque ad hydroxyl coetus in GLYCOSA unitates naturalis Cellulose cum hydroxyethyl coetus. Specifications et exempla ex products sunt maxime distinguantur secundum gradum substitutionis et viscosity.
In varietates hydroxyethyl Cellulose sunt etiam divisa in normalis dissolution type, celeri dispersio genus et biologicum stabilitatem genus. Quatenus modum usus est de, hydroxyethyl cellulosa potest addidit ad diversas gradus in coating productio processus. Et ieiunium-dispersio genus potest addidit directe in forma siccis pulveris. However, the pH value of the system before adding should be less than 7, mainly because hydroxyethyl cellulose dissolves slowly at low pH value, and there is sufficient time for water to infiltrate into the inside of the particles, and then the pH value is increased to make it Dissolves quickly. Correspondentes gradus potest etiam esse ad praeparet quaedam concentratio de gluten solutio et addere eam ad coating ratio.
Hydroxypropyl methylcellosus est productum adeptus per repositoque in hydroxyl coetus in GLYCOSA unitas naturalis Cellulose cum a Mthoxy coetus, cum alia pars est per hydroxypropyl coetus. Et crasso effectus est basically idem quod de hydroxyethyl cellulosose. Et repugnant ad enzmaticum degradation, sed aquam solubility non est bonum quod de hydroxyethyl Cellulose et non habet incommodum gelling cum succensa est. Nam superficies-tractata hydroxypropyl methylcellosus, potest esse directe addit aqua cum solebat. Post turbantes et disperso, addere alkaline substantias ut ammonia aquae ad adjust Phale ad 8-9, et movent donec plene dissolvi. Nam hydroxypropyl methylcellosa sine superficie curatio, potest madefactus et intumescebat calida aqua super LXXXV ° C ante usum, et refrigeratum ad locus temperatus, tunc suscitavit cum frigore aqua glacies aqua plene dissolvere.
②inorganic Thickener
This kind of thickener is mainly some activated clay products, such as bentonite, magnesium aluminum silicate clay, etc. It is characterized in that in addition to the thickening effect, it also has a good suspension effect, can prevent sinking, and will not affect the water resistance of the coating. Post coating aruit et formatae in film, actus est ut a filler in coating film, etc in iniquo factor est quod significantly afficiunt ad adtritio de coating.
③ Saccharum Polymer Thickener
Saccharum Polymer Thessyernis sunt plerumque in acrylic et polyurethane (adiecto thessionum). Acrylic TRIBUTIONE sunt plerumque acrylic polymeners quibus carboxyl coetus. In aquis cum PH valorem de 8-10, in carboxyl coetus dissociates et fit tumidus; Cum PH valorem est major quam X, dissolvit in aqua et perdidit in ira effectum, ita crasso effectum est valde sensitivo ad PH valorem.
Incrassatus mechanism de acrylate Thickener est particulas potest adsorbed super superficiem LATEX particulas in pingere, et formare coating accumsan post alkali tumor, quod crescit in volumine LATEX particulas, quod crescit in particularum LATEX particulas, quod auget in motu et crescit viscositas pingere ratio. ANTOLIUM; Secundo tumor Torcerni auget viscositas aquarum.
(II) auctoritas de Thickener in coating proprietatibus
Et effectus est genus Thickener in Rheology proprietatibus de coating est ut sequitur:
Cum moles Thickener augetur, stabilis viscositas pingunt auget significantly et viscosity mutatio trend est basically consistit subiecta externi tondendas.
Cum autem effectus a Thickener, et viscositas pingunt guttae cursim cum subiecta est vi, showing pseudoplasticity.
Using a hydrophobically modified celluloso Thickener (ut EBS451FQ), ad excelsum tondendas rates, in Viscositas adhuc altum cum quantum est magna.
Using consuetudine polyurethane thestióners (ut wt105a), ad altum tondendas rates, in viscositas est adhuc princeps cum quantum est magna.
Usura acrylic sporteners (ut ASE60), quamvis stabilis viscositas resurget cursim cum moles magna, in viscositas decrescit cursim ad altiorem tondendas rate.
III. Associative Thickener
(I) crasso mechanism
Cellulose ether and alkali-swellable acrylic thickeners can only thicken the water phase, but have no thickening effect on other components in the water-based paint, nor can they cause significant interaction between the pigments in the paint and the particles of the emulsion, so The rheology of the paint cannot be adjusted.
Sociative thessionen sunt characterised in ut praeter crassis per hydratationis, etiam in associationibus inter se, cum dispersis particulas et aliis components in ratio. Hoc consociatio disassociates ad altum tondendas rates et rursus societates ad humilis tondendas rates, permittens in Rheology de coating ad esse adaequatum.
The thickening mechanism of the associative thickener is that its molecule is a linear hydrophilic chain, a polymer compound with lipophilic groups at both ends, that is, it has hydrophilic and hydrophobic groups in the structure, so it has the characteristics of surfactant molecules. Natura. Tales Thickener moleculis non solum hydrate et tumescere ad spissior aqua phase sed etiam formare micelles cum concentration ejus aqueo solutio excedit certum valorem. Et micelles potest socia cum Polymer particulas ex EMULSIO et pigmento particulas qui habent adsorbed dispersant ad formare tres dimensional network structuram et internonected et implicit ad augendam viscosity systematis.
Quid magis est quod haec consociationes in statu dynamic statera et consociata micelles potest adjust eorum positions cum subiecta externa viribus, ut coating adtritio proprietatibus. Praeterea, cum moleculo pluribus micelles, hoc structuram reducit tendentia aqua moleculis migrare et sic augetur viscositas Aqueum Phase.
(II) in partes in coatings
Plerique consuetudine, et Polyurethanes, et relativum Molecular pondera sunt inter 103-104 ordines magnitudinis, duo ordines magnitudinis inferior quam Ordinarius Polyacrypal acidum et Cellulose thestiónibus cum relativis Molecular et cellulosa in relativa, inter Molecular et cellulosis thest ... Ob humilis MOLECULA pondus, ad effective volumine crescat post hydratationis minus, ita et ejus viscositas curva sit blandiri, quam non-consortio.
Ob humilis molecular pondus consuetudinis, eius intermolecular in aqua tempus limited, ita et crasso effectum in aqua tempus non significant. In low tondendas rate range, in consociatione conversionem inter moleculis plus consociatione interitus inter moleculis, totum ratio maintains inhaerens suspensio et dispersionem statum, et viscositas proxima ad viscositatem medium (aquam). Ideo in consuetudine Thickener facit aqua-fundatur pingere system exhibere inferioribus apparent Viscosity cum est in humili tondendas rate regione.
Associative thessionum auget in potential industria inter moleculis debitum ad consociationem inter particulas in dispersionem tempus. Et hoc modo, magis industria est opus ad conteram consociationem inter moleculis ad altum tondendas rates et tondendas vi requiritur ad consequi idem tondendas eleemosynam est etiam maius, ut ratio exhibet in altiorem tondendas rate ad altum tondendas rates. Apparent viscositas. In altiorem summus tondendas viscositas et inferior humilis-tondere viscositas potest iustus faciunt pro indigentiam commune thestiónen in rhematicis proprietatibus pingere, quod est, duo thestex determinatus in tandem ad adjust ad adjust ad adjust in liceex esse in tandem ad adjust ad adjust ad adjust in LATEX Poining. Variabilis perficientur, in occursum ad comprehensive requisita de coating in densissima film et coating film influunt.
Post tempus: Nov, 24-2022