SI20526A - Barium titanate dispersions - Google Patents

Abstract

The invention provides slurries, dispersions, or slips of barium titanate-based particles in a non-aqueous medium and methods of their production. The particles have a coating comprising a metal oxide, metal hydrous oxide, metal hydroxide or organic acid salt of a metal other than barium or titanium. At least 90 percent of the particles have a particle size less than 0.9 micrometer when the coated particles are dispersed by high shear mixing.

Description

CABOT CorporationCABOT Corporation

Disperzije barijevega titanataDispersions of barium titanate

Predloženi izum se nanaša na disperzije barijevega titanata, bolj podrobno pa se nanaša na disperzije barijevega titanata v nevodnih medijih.The present invention relates to dispersions of barium titanate, and more specifically relates to dispersions of barium titanate in non-aqueous media.

Zaradi visokih dielektričnih konstant materialov na osnovi barijevega titanata so le-ti prikladni za večplastne keramične kondenzatorje, navadno imenovane MLC. MLC obsegajo izmenične plasti dielektričnih in električnih prevodnih materialov. Primeri za MLC so opisani v US-patentnih št. 3,612,963 in 4,435,738. Paladij, srebro, paladijsrebme zlitine, baker in nikelj so navadni električni prevodni materiali, uporabljeni v MLC. Dielektrične plasti MLC navadno pripravijo iz disperzije z visoko vsebnostjo trdnih snovi, znane v tehniki kot slip (pastozna oblika disperzije). Taki slipi značilno obsegajo praškasti material na osnovi barijevega titanata in polimerno vezivo v vodnem ali nevodnem topilu. Filme iz praška, stabiliziranega z vezivom, narejene z ulivanjem ali prevlečenjem s slipom, posušijo, da zagotovijo zeleno (nesintrano) plast keramičnega dielektrika. Zelene plasti prevlečejo s prevodnimi materiali v vzorcu in nato zložijo v skladanice, da zagotovijo laminat izmeničnih plasti zelenega keramičnega dielektrika in prevodnika. Skladanice nato razrežejo v kocke, velikosti MLC, ki jih nato segrevajo, da zgorijo organski materiali, kot npr. vezivo in dispergant, in jih nato žgejo, da se sintrajo delci iz materiala na osnovi barijevega titanata, da se tvori kondenzatorska struktura z laminiranimi gostimi keramičnimi dielektričnimi in prevodnimi plastmi. Temperature sintranja so značilno v območju od pribl. 1000 °C do 1500 °C. Med sintranjem se doseže povečanje keramične dielektrične gostote kot rezultat spajanja in združevanja delcev, da tvorijo zrna. Celo pri uporabi inhibitorjev za rast zrnje velikost keramičnih zrn v dielektrični plasti MLC značilno večja, npr. za faktor 3 do 5, kot je velikost originalnih primarnih delcev. Poleg tega pa se med postopkom sintranja ne odstrani vsa poroznost. Značilno ostane med pribl. 2 % in 10 % poroznosti v dielektričnih plasteh MLC. Te pore ali luknjasti defekti v dielektrični plasti imajo tendenco, da so večji v keramikah z večjo velikostjo zrn. Na določene kritične lastnosti kondenzatorja, kot sta npr. prebojna napetost in enosmerni tok puščanja, vpliva dielektrična gostota, velikost zrn in defekti por. Tako je npr. ugotovljeno, da je za učinkovite dielektrične plasti treba, da imajo debelino nekaj zrn, npr. vsaj debelino 3 do 5 zrn. Ker je defekt v katerikoli plasti MLC lahko poguben za njegovo delovanje, so MLC izdelani z zadostno debelino dielektrične plasti, da se učinkovito zmanjša vpliv keramičnih defektov, ki so lahko povzročeni z naključno velikimi zrni ali porami, ki škodljivo vplivajo na lastnosti MLC.Due to the high dielectric constants of barium titanate based materials, they are suitable for multilayer ceramic capacitors, commonly referred to as MLCs. MLCs comprise alternating layers of dielectric and electrical conductive materials. Examples of MLC are described in U.S. Pat. No. 3,612,963 and 4,435,738. Palladium, silver, palladium silver alloys, copper and nickel are common electrical conductive materials used in MLC. MLC dielectric layers are typically prepared from a high solids dispersion known in the art as a slip (paste form of dispersion). Such slips typically comprise barium titanate-based powder material and a polymeric binder in an aqueous or non-aqueous solvent. Binder-stabilized powder films made by slip casting or slip coating are dried to provide a green (unsintered) layer of ceramic dielectric. The green layers are coated with conductive materials in the sample and then stacked to provide alternating layers of green ceramic dielectric and conductor. The piles are then cut into MLC-sized cubes, which are then heated to burn organic materials such as e.g. binder and dispersant, and then fired to sinter barium titanate-based material particles to form a capacitor structure with laminated dense ceramic dielectric and conductive layers. The sintering temperatures are typically in the range of approx. 1000 ° C to 1500 ° C. During sintering, an increase in ceramic dielectric density is achieved as a result of coupling and pooling of the particles to form grains. Even when grain growth inhibitors are used, the size of ceramic grains in the MLC dielectric layer is significantly larger, e.g. by a factor of 3 to 5 such as the size of the original primary particles. In addition, not all porosity is removed during the sintering process. It typically stays between approx. 2% and 10% porosity in dielectric MLC layers. These pores or hole defects in the dielectric layer tend to be larger in ceramics with larger grain sizes. To certain critical properties of the capacitor, such as. breakthrough voltage and direct current leakage, influenced by dielectric density, grain size and pore defects. Thus, e.g. found that for effective dielectric layers to have a thickness of some grains, e.g. at least a thickness of 3 to 5 grains. Because a defect in any MLC layer can be detrimental to its operation, MLCs are fabricated with sufficient dielectric layer thickness to effectively reduce the impact of ceramic defects that can be caused by randomly sized grains or pores that adversely affect the properties of the MLC.

Zaradi zahtev tržišča za miniaturizacijo oblik elektronskih naprav obstaja potreba v industriji MLC po keramičnih materialih, ki bi dopuščali tanjše dielektrične plasti, ne da bi povzročali katastrofalne učinke zaradi velikih dimenzij zrn in por glede na dielektrično gostoto.Due to the market requirements for miniaturization of electronic devices, there is a need in the MLC industry for ceramic materials that would allow thinner dielectric layers without causing catastrophic effects due to the large grain size and pore size of the dielectric density.

Praški barijevega titanata, proizvedeni po znanih postopkih, npr. s kalcinacijo ali hidrotermalnimi postopki, imajo velike delce in/ali močno aglomerirane fine delce velikosti, ki je v bistvu večja od 1 pm. Taki delci in aglomerati niso enostavni za proizvodnjo MLC s finozmatimi ultratankimi dielektričnimi plastmi, npr. manj od 4-5 pm. Zato bi bilo za tehniko prednostno, da bi zagotovili material na osnovi barijevega titanata in disperzijo, ki bi bila prikladna za izdelavo MLC s tanjšimi dielektričnimi keramičnimi plastmi, npr. manj od 4 pm, s sprejemljivimi ali izjemnimi električnimi lastnostmi, ki vključujejo enosmerni tok puščanja in prebojno napetost, ne da bi bilo potrebno obsežno krogelno mletje.Barium titanate powders produced by known methods, e.g. by calcination or hydrothermal processes, having large particles and / or heavily agglomerated fine particles of a size substantially greater than 1 pm. Such particles and agglomerates are not easy to produce MLCs with fine-ultra-thin dielectric layers, e.g. less than 4-5 pm. Therefore, it would be advantageous for the technique to provide barium titanate-based material and dispersion that is suitable for producing MLCs with thinner dielectric ceramic layers, e.g. less than 4 pm, with acceptable or exceptional electrical properties including DC leakage and breakthrough voltage without the need for extensive ball milling.

Z enega vidika predloženi izum zagotavlja brozgo, disperzijo ali slip, ki vključuje delce na osnovi barijevega titanata, dispergirane v nevodnem mediju. Delci vključujejo prevleko, ki obsega kovinski oksid, kovinski vodni oksid, kovinski hidroksid ali organsko kislinsko sol kovine, drugačne od barija ali titana, pri čemer ima vsaj 90 % delcev velikost manjšo od 0,9 pm, kadar jih dispergiramo z visoko učinkovitim mešanjem.In one aspect, the present invention provides a slurry, dispersion or slip comprising barium titanate-based particles dispersed in a non-aqueous medium. The particles include a coating comprising a metal oxide, a metal aqueous oxide, a metal hydroxide or an organic acid salt of a metal other than barium or titanium, with at least 90% of the particles having a size less than 0.9 pm when dispersed by highly efficient mixing.

Kot uporabljamo tukaj, se izraz na osnovi barijevega titanata nanaša na barijev titanat, barij ev titanat, ki ima prevleko iz drugega kovinskega oksida, in na druge okside na osnovi barija in titanata, ki imajo splošno strukturo ABO3, kjer A pomeni eno ali več divalentnih kovin, kot npr. barij, kalcij, svinec, stroncij, magnezij in cink, ter B pomeni eno ali več tetravalentnih kovin, kot npr. titan, kositer, cirkonij in hafnij.As used herein, the term barium titanate-based refers to barium titanate, barium titanate having a coating of another metal oxide, and to other barium and titanate-based oxides having the general structure ABO3, where A is one or more divalent metals, such as barium, calcium, lead, strontium, magnesium and zinc, and B represents one or more tetravalent metals, such as e.g. titanium, tin, zirconium and hafnium.

Z drugega vidika predloženi izum zagotavlja postopek za tvorbo brozge, disperzije ali slipa. Postopek vključuje stopnjo dispergiranja delcev na osnovi barij evega titanata v nevodnem mediju z visoko učinkovitim mešanjem, dokler 90 % delcev nima velikosti, manjše od 0,9 pm. Delci imajo prevleko, ki obsega kovinski oksid, kovinski vodni oksid, kovinski hidroksid ali organsko kislinsko sol kovine, kije drugačna od barija ali titana.In another aspect, the present invention provides a process for forming a slurry, dispersion or slip. The process involves the dispersion of barium-based titanate particles in a non-aqueous medium with high-efficiency mixing until 90% of the particles have a size smaller than 0.9 pm. The particles have a coating comprising a metal oxide, a metal aqueous oxide, a metal hydroxide or an organic acid salt of a metal other than barium or titanium.

Z drugega vidika predloženi izum zagotavlja drug postopek za tvorbo brozge, disperzije ali slipa. Ta postopek vključuje tvorbo brozge iz delcev na osnovi barijevega titanata v vodnem mediju s hidrotermalnim postopkom. Postopek nadalje vključuje tvorbo prevleke na delcih, ki vključuje kovinski oksid, kovinski vodni oksid, kovinski hidroksid ali organsko kislinsko sol kovine, ki je drugačna od barija ali titana. Postopek nadalje vključuje nadomeščanje vodnega medija z nevodnim in disergiranje delcev na osnovi barijevega titanata v nevodnem mediju z visoko učinkovitim mešanjem.In another aspect, the present invention provides another process for forming a slurry, dispersion or slip. This process involves the formation of a barium titanate-based particle broth in an aqueous medium by a hydrothermal process. The process further includes forming a particle coating which includes a metal oxide, a metal aqueous oxide, a metal hydroxide or an organic acid salt of a metal other than barium or titanium. The process further includes replacing the aqueous medium with non-aqueous and dispersing barium titanate-based particles in non-aqueous medium with high-efficiency mixing.

Kratek opis slikShort description of the pictures

Fig. ΙΑ, IB in 1C so diagrami porazdelitve velikosti delcev za eno izvedbo delcev barijevega titanata v smislu predloženega izuma po visoko učinkovitem mešanju 45 minut, po dodatnem mešanju v horizontalnem medijskem mlinu 30 minut in po dodatnem mešanju v horizontalnem medijskem mlinu 45 minut, inFIG. ΙΑ, IB, and 1C are particle size distribution diagrams for one embodiment of barium titanate particles of the present invention after highly efficient stirring for 45 minutes, after further mixing in a horizontal media mill for 30 minutes, and after further mixing in a horizontal media mill for 45 minutes, and

Fig. 2A in 2B sta diagrama porazdelitve velikosti delcev za drugo izvedbo delcev barijevega titanata v smislu predloženega izuma po visoko učinkovitem mešanju 10 minut in po visoko učinkovitem mešanju 30 minut.FIG. 2A and 2B are particle size distribution diagrams for another embodiment of barium titanate particles of the present invention after highly efficient stirring for 10 minutes and after highly efficient stirring for 30 minutes.

Druge nove značilnosti in vidiki izuma bodo postali jasni iz nadaljnjega podrobnega opisa izuma ob upoštevanju priloženih slik in iz patentnih zahtevkov.Other novel features and aspects of the invention will become apparent from the following detailed description of the invention in the light of the accompanying drawings and claims.

Predloženi izum se nanaša na brozge, disperzije ali slipe delcev na osnovi barijevega titanata, dispergirane v nevodnem mediju. Delci vključujejo prevleko vsaj na delu njihove površine. Prevleka obsega kovinski oksid, kovinski vodni oksid, kovinski hidroksid ali organsko kislinsko sol kovine, ki je drugačna od barija ali titana, ali njihove zmesi. Prevlečeni delci imajo velikost manjšo od 0,9 pm, kadar jih dispergiramo z visoko učinkovitim mešanjem. Delci na osnovi barij evega titanata so disperzibilni, ne da bi bilo potrebno krogelno mletje, v podmikrometrske disperzije v nevodnih medijih, kar je prednostno pri izdelavi MLC s tankimi dielektričnimi plastmi, ki imajo podmikrometrsko velikost zrn in visoko prebojno napetost. Visoko učinkovito mešanje je učinkovito pri zmanjševanju velikosti aglomeratov delcev na osnovi barijevega titanata in vključuje deaglomeracijo ali ločevanje aglomeratov v manjše prevlečene delce brez krogelnega mletja, ki vključuje udarjanje delcev s trdimi mediji za krogelno mletje, kot so npr. palice, krogle ali delci cirkonijevega oksida ipd. Ker krogelno mletje lahko razcepi delce na velikost, kije manjša od primarnih delcev, kar ima za posledico neenakoosne delce z eksponirano, neprevlečeno površino (površinami), v prednostni izvedbi delcev v smislu izuma ne izpostavimo krogelnemu mletju in imajo delci glavni del površine prekrit s prevleko. Z drugega vidika izuma so nemleti delci enakoosni ali sferični.The present invention relates to barium titanate-based slurries, dispersions or slips of particles dispersed in a non-aqueous medium. Particles include a coating at least on part of their surface. The coating comprises a metal oxide, a metal aqueous oxide, a metal hydroxide or an organic acid salt of a metal other than barium or titanium, or mixtures thereof. The coated particles have a size less than 0.9 pm when dispersed by highly efficient mixing. Particles based on barium titanate are dispersible, without the need for ball milling, to sub-micrometer dispersions in non-aqueous media, which is advantageous in the manufacture of MLCs with thin dielectric layers having a sub-micrometer grain size and high breakthrough voltage. High-efficiency mixing is effective in reducing the size of barium titanate-based particle agglomerates and involves deagglomeration or separation of agglomerates into smaller coated particles without ball milling, which involves hitting particles with solid ball milling media, such as e.g. zirconium oxide rods, spheres or particles, and the like. Because ball milling can split particles to a size smaller than primary particles, resulting in unequal particles with exposed, uncoated surface (s), in the preferred embodiment of the particles according to the invention, the ball milling is not exposed and the particles have a main surface coated with the coating . In another aspect of the invention, the non-ground particles are equiaxed or spherical.

Delci na osnovi barijevega titanata so uporabni pri zagotavljanju monolitnih kondenzatorjev, ki obsegajo keramično telo, ki ima velikost zrn manjšo od 0,3 pm. Prednostni MLC imajo X7R ali Y5V temeperatumi koeficient kapacitance in dielektrično debelino manjšo od 5 pm, dielektrično jakost pa vsaj 50 V/pm.Barium titanate-based particles are useful in providing monolithic capacitors comprising a ceramic body having a grain size of less than 0.3 pm. Preferred MLCs have an X7R or Y5V temperature coefficient of capacitance and a dielectric thickness of less than 5 pm and a dielectric strength of at least 50 V / pm.

Primarno velikost delcev na osnovi barijevega titanata lahko določimo s postopki, znanimi strokovnjakom. Primeri za take postopke so vrstična elektronska mikroskopija (SEM) ali presevna elektronska mikroskopija (TEM). Čeprav je razumljivo, da delci na osnovi barijevega titanata lahko obsegajo primarne delce različnih velikosti, pa imajo prevlečeni delci na osnovi barij evega titanata povprečno primarno velikost delcev manjšo od 0,6 pm. Prednostno imajo delci primarno velikost manjšo od 0,5 pm, bolj prednostno, manjšo od 0,4 pm, še bolj prednostno imajo delci primarno velikost manjšo od 0,3 pm, najbolj prednostno pa imajo delci primarno velikost manjšo od 0,2 pm.The primary particle size based on barium titanate can be determined by methods known to those skilled in the art. Examples of such procedures are scanning electron microscopy (SEM) or screening electron microscopy (TEM). Although it is understood that barium titanate based particles may comprise primary particles of different sizes, coated barium titanate particles have an average primary particle size of less than 0.6 pm. Preferably, the particles have a primary size of less than 0.5 pm, more preferably less than 0.4 pm, more preferably the particles have a primary size of less than 0.3 pm, and most preferably, the particles have a primary size of less than 0.2 pm.

Delci na osnovi barijevega titanata so lahko v oblikah, ki so drugačne od primarnih delcev, npr. kot agregati primarnih delcev in/ali aglomerati agregatov primarnih delcev. SEM in TEM nista učinkovita postopka pri razlikovanju porazdelitve velikosti med primarnimi delci, agregati primarnih delcev in aglomerati agregatov primarnih delcev. Analiza porazdelitve velikosti delcev, kot so npr. tehnike sipanja svetlobe, je prednostni postopek za označevanje velikosti delcev na osnovi barijevega titanata, pod pogojem, da priprava za analizo ne vključuje obdelovanje, ki bi spremenilo porazdelitev agregiranih ali aglomeriranih delcev, kot je npr. deaglomeracija, zaradi ultrazvočne obdelave, visoko učinkovitega mešanja ali mletja. Taka avtomatizirana tehnika sipanja svetlobe uporablja analizator velikosti delcev s sipanjem svetlobe HORIBA LA-910™ laser ali podobno napravo. Taka analiza značilno predstavlja volumsko frakcijo, normalizirano za frekvenco diskretnih velikosti delcev, ki vključujejo primarne delce, agregate in aglomerate v desetiških grupacijah ali decilih. Kot uporabljamo tukaj, se izraz velikost delcev nanaša na individualne delce v prašku in lahko vključuje primarne delce, agregate primarnih delcev, aglomerate agregatov in njihove zmesi. Z enega vidika predloženega izuma ima vsaj 90 % delcev na osnovi barijevega titanata, prevlečenih s kovinskim oksidom v disperziji delcev na osnovi barijevega titanata, velikost manjšo od 0,8 pm; prednostno, manjšo od 0,7 pm; bolj prednostno, manjšo od 0,6 pm. V bolj prednostnih izvedbah predloženega izuma ima vsaj 90 % delcev v disperziji barijevega titanata velikost manjšo od 0,5 pm; prednostno, manjšo od 0,4 pm; in bolj prednostno, manjšo od 0,3 pm.Barium titanate based particles may be in forms other than the primary particles, e.g. as primary particle aggregates and / or primary particle aggregates. SEM and TEM are not effective procedures in distinguishing the size distribution between primary particles, primary particle aggregates and agglomerates of primary particle aggregates. Analysis of particle size distribution, such as light scattering techniques is a preferred process for indicating barium titanate-based particle size, provided that the preparation for analysis does not include machining that would alter the distribution of aggregated or agglomerated particles, such as e.g. deagglomeration due to ultrasonic treatment, highly efficient mixing or grinding. This automated light scattering technique uses a particle size analyzer with a HORIBA LA-910 ™ laser or similar device. Such analysis typically represents the volume fraction normalized to the frequency of discrete particle sizes that include primary particles, aggregates, and agglomerates in decimal groups or deciles. As used herein, the term particle size refers to individual particles in a powder and may include primary particles, primary particle aggregates, aggregates of aggregates and mixtures thereof. In one aspect of the present invention, at least 90% of barium titanate-based particles coated with metal oxide in barium titanate-based particle dispersion have a size of less than 0.8 pm; preferably less than 0.7 pm; more preferably, less than 0.6 pm. In more preferred embodiments of the present invention, at least 90% of the particles in the barium titanate dispersion have a size of less than 0.5 pm; preferably less than 0.4 pm; and more preferably less than 0.3 pm.

Značilnosti porazdelitve velikosti delcev vključujejo D₉₀, ki je najmanjša velikost delcev v decilu največjih delcev; D₅o, ki pomeni srednji premer, in D₁₀, ki je največja velikost delcev v decilu najmanjših delcev. Razmerje D_9o/Dio je prikladna značilnost za identificiranje širine krivulje porazdelitve velikosti delcev. Pri raznih vidikih predloženega izuma je porazdelitev velikosti delcev ozka, prednostno z razmerjem D₉₀/D₁₍) manjšim od 4; bolj prednostno je razmerje D₉₀/Di₀ manjše od 3; in bolj prednostno je razmerje D₉₀/Di₀ manjše od 2,5.Particle size distribution features include D ₉₀ , which is the smallest particle size in the decile of the largest particles; D ₅ o, which is the mean diameter, and D ₁₀ , which is the largest particle size in the decile of the smallest particles. The D _9o / Dio ratio is a convenient feature to identify the width of the particle size distribution curve. In various aspects of the present invention, the particle size distribution is narrow, preferably with a D ₉₀ / D _{1 (} ) ratio of less than 4; more preferably, the D ₉₀ / Di ₀ ratio is less than 3; and more preferably, the D ₉₀ / Di ₀ ratio is less than 2.5.

Kot uporabljamo tukaj, se izraz disperzija nanaša na dvofazne sisteme trdnih delcev, suspendiranih v nevodnem mediju. V prednostni izvedbi lahko stabilnost disperzije ali odpornost suspendiranih trdnih delcev pred usedanjem povečamo z uporabo dispergirnega sredstva.As used herein, the term dispersion refers to two-phase systems of solids suspended in a non-aqueous medium. In a preferred embodiment, the stability of the dispersion or the resistance of the suspended solids before settling can be increased by using a dispersing agent.

Razen tam, kjer je iz konteksta jasno, da je mišljen le kovinski oksid, uporabljamo tukaj izraz kovinski oksid za to, da opišemo prevleke iz kovinskih oksidov, kovinskih hidroksidov, vodnih kovinskih oksidov in organskih kislinskih soli kovine. Tako organsko kislinsko sol lahko pretvorimo v oksid ali hidroksid, npr. s termalno razgradnjo, do katere pride med segrevanjem za zgorevanje keramičnega veziva in/ali med keramičnim sintranjem.Except where it is clear from the context that only metal oxide is intended, the term metal oxide is used herein to describe coatings of metal oxides, metal hydroxides, aqueous metal oxides and organic acid salts of metal. Such an organic acid salt can be converted to an oxide or hydroxide, e.g. by thermal decomposition occurring during heating for combustion of the ceramic binder and / or during ceramic sintering.

Kot uporabljamo tukaj, pomeni izraz visoko učinkovito mešanje, mešanje v tekočem mediju, ki daje dovolj energije, da se ločijo aglomerati prevlečenih delcev v manjše delce brez udarcev s trdnimi sredstvi, kot so palice, valji ali trdi sferični mediji, kot so npr. kroglice cirkonijevega oksida. Trdi mediji se uporabljajo v določenih napravah za visoko učinkovito mešanje, kjer so uporabljeni mediji majhnih velikosti, da se ustvari učinkovitost brez udarcev. Čeprav visoko učinkovito mešanje lahko povzročimo z različnimi napravami, kot so opisane spodaj, je težko natančno definirati silo, aplicirano za ločitev aglomeratov pri visoko učinkovitem mešanju.As used herein, the term "high-efficiency mixing" means mixing in a liquid medium that provides sufficient energy to separate agglomerates of coated particles into smaller particles without impact by solid means such as rods, cylinders or solid spherical media such as e.g. zirconium oxide beads. Hard media is used in certain high-efficiency mixing devices where small-size media is used to create impact without impact. Although highly efficient mixing can be caused by a variety of devices as described below, it is difficult to precisely define the force applied to separate agglomerates in highly efficient mixing.

Kot je definirano zgoraj, se izraz na osnovi barijevega titanata nanaša na barijev titanat, barijev titanat, ki ima prevleko iz drugega kovinskega oksida, in na druge okside na osnovi barija in titanata, ki imajo splošno strukturo ABO3, kjer A pomeni eno ali več divalentnih kovin, kot npr. barij, kalcij, svinec, stroncij, magnezij in cink, ter B pomeni eno ali več tetravalentnih kovin, kot npr. titan, kositer, cirkonij in hafnij. Prednostni materiali na osnovi barijevega titanata, ki ga lahko značilno uporabimo pri Y5V aplikacijah, ima strukturo Ba(i._xjA_xO.Ti(i._y)ByO₂, kjer sta x in y lahko v območju od 0 do 1, A pomeni eno ali več divalentnih kovin, ki so drugačne od barija, kot npr., svinec, kalcij ali stroncij, in B pomeni eno ali več tetravalentnih kovin, ki so drugačne od titana, kot npr. kositer, cirkonij in hafnij. Kjer so prisotne druge kovine kot nečistoče, bo vrednost za x in y majhna, npr. manjša od 0,1. V drugih primerih, lahko uvedemo drugo kovino ali kovine, da zagotovimo spojino, ki jo je možno identificirati, kot npr. barij-kalcijev titanat, barij-stroncij ev titanat, barij ev titanatcirkonat ipd. Se v nadaljnjih primerih, kjer je x ali y 1, lahko barij ali titan nadomestimo z drugo kovino z ustrezno valenco, da zagotovimo spojino, kot npr. svinčev titanat ali barijev cirkonat. Še v nadaljnjih primerih ima lahko spojina več delnih substitucij barija ali titana. Primer za tak večkrat delno substituiran sestavek je prikazan s strukturno formulo:As defined above, the term barium titanate-based refers to barium titanate, barium titanate coated with another metal oxide, and other barium and titanate oxides having the general structure ABO3, where A is one or more divalent metals, such as barium, calcium, lead, strontium, magnesium and zinc, and B represents one or more tetravalent metals, such as e.g. titanium, tin, zirconium and hafnium. Preferred materials based on barium titanate, which typically can be used in applications Y5V, having a structure of Ba (i. _X jA _x O.Ti (i. _Y) BYO _2, where x and y can be in the range of 0 to 1, A means one or more divalent metals other than barium, such as lead, calcium or strontium, and B means one or more tetravalent metals other than titanium, such as tin, zirconium and hafnium. other metals than impurities, the value for x and y will be small, e.g., less than 0.1. In other cases, another metal or metals may be introduced to provide an identifiable compound, such as barium calcium titanate, barium strontium titanate, barium titanate zirconate, etc. In further cases where x or y is 1, barium or titanium may be replaced by another metal of appropriate valence to provide a compound such as lead titanate or barium zirconate. in further cases, the compound may have several partial substitutions for barium or titanium the partially substituted composition is represented by the structural formula:

Ba(i._x._X'._X)Pb_xCa_X'Sr_XO»Ti(i._y.y'.y)Sn_yZry'Hf_yO2 kjer je vsak x, x', x, y, y' in y > 0, in je (x+x'+x )< 1, mje(y+y'+y) < 1. V mnogo primerih bo material na osnovi barijevega titanata izkazoval perovskitno kristalno strukturo in zato je prednostno, da ima material barijev titanat perovskitno strukturo.Ba (i. _{X. X. X)} Pb _x Ca _X Sr _X O "Ti (i. _Y .y'.y) Sn _y Zry'Hf _y O2 where each of x, x ', x, y, y 'and y> 0, and is (x + x' + x) <1, m (y + y '+ y) <1. In many cases, barium titanate-based material will exhibit a perovskite crystal structure and is therefore preferred. that the barium titanate material has a perovskite structure.

Medtem ko se hidrotermalno proizvedeni delci barijevega titanata konvencionalno sušijo do praška, se delci oblikujejo v relativno močno aglomerirane delce, ki jih ni mogoče učinkovito deaglomerirati z enostavnim visoko učinkovitim mešanjem. Disperzije, izdelane iz takih suhih aglomeriranih delcev na osnovi barijevega titanata, ki imajo podmikrometrsko primarno velikost delcev, zahtevajo v bistvu dolgotrajno udarno mletje, da zagotovimo delce v območju 1 mikrometra, in daljše, bolj intenzivno mletje za podmikrometrske delce. V nasprotju s tem lahko aglomerirane delce na osnovi barijevega titanata, prevlečene s kovinskim oksidom, ki imajo podmikrometrsko primarno velikost delcev, deaglomeriramo do območja podmikrometrske velikosti prevlečenih delcev z zmernim delovanjem visoko učinkovitega mešanja brozg, disperzij ali slipov, ki obsegajo take delce v nevodnih medijih.While hydrothermally produced barium titanate particles are conventionally dried to powder, the particles are formed into relatively strongly agglomerated particles that cannot be effectively deagglomerated by simple, highly efficient mixing. Dispersions made from such dry agglomerated barium titanate based particles having a submicrometer primary particle size require substantially long impact grinding to provide particles in the range of 1 micrometer, and longer, more intense grinding for the submicrometer particles. In contrast, agglomerated metal oxide-coated barium titanate particles having a submicrometer primary particle size can be deagglomerated to a submicrometer particle size range of coated particles with moderate action of highly efficient mixing of slurries, dispersions or slips that do not include such particles in the interparticles .

Nevodne brozge, disperzije ali slipe delcev na osnovi barijevega titanata v smislu izuma lahko pripravimo iz delcev na osnovi barijevega titanata, proizvedenih hidrotermalno, in jih vzdržujemo v vodnem okolju, kot npr. vodni brozgi, vsaj dokler delcev ne oskrbimo s prevleko, nato pa vodno fazo nadomestimo z nevodno, kot je opisano spodaj.Non-aqueous splashes, dispersions or slips of barium titanate-based particles of the invention can be prepared from barium titanate-based particles produced hydrothermally and maintained in an aqueous environment such as e.g. water slurry, at least until the particles are coated, and then the aqueous phase is replaced by a non-aqueous one as described below.

Brozgo podmikrometrskih delcev na osnovi barijevega titanata lahko pripravimo s hidrotermalnim postopkom, kot je npr. opisano v US-patentih št. 4,832,939, 4,829,033 in 4,863,833. Pri takih hidrotermalnih postopkih dodamo prebitno količino, prebitek do pribl. 20 mol.%, raztopine barijevega hidroksida v vodno brozgo titanovega oksida in značilno segrevamo do temperature v območju od pribl. 100 °C do 200 °C, da oblikujemo podmikrometrske delce s perovskitno kristalno strukturo. Velikost delcev in porazdelitev velikosti delcev lahko vzdržujemo z nadzorovanjem različnih spremenljivk pri postopku, kot je npr. temperatura brozge in raztopin, hitrost dodajanja, hitrost segrevanja do temperature tvorbe perovskita ter hitrost ohlajanja od le-te. Izbiro procesnih spremenljivk za želeni produkt iz delcev lahko strokovnjaki enostavno določijo po splošnih principih za kristalizacijo. Večje delce lahko npr. pripravimo z relativno počasnim dodajanjem barijevega hidroksida v brozgo, vzdrževano pri relativno nizki temperaturi, npr. pribl. 35 °C, manjše delce pa lahko pripravimo z relativno hitrim dodajanjem barijevega hidroksida v brozgo, vzdrževano pri relativno visoki temperaturi, npr. pribl. 95 °C. Dobro mešanje je pomembno za pripravo enakomernih delcev.Barium titanate-based submicrometer particle casting can be prepared by a hydrothermal process, such as e.g. described in U.S. Pat. No. 4,832,939, 4,829,033 and 4,863,833. In such hydrothermal processes an excess amount is added, with an excess of up to approx. 20 mol% barium hydroxide solution in a water titanium oxide broth and typically heated to a temperature in the range of approx. 100 ° C to 200 ° C to form submicrometer particles with a perovskite crystal structure. Particle size and particle size distribution can be maintained by controlling various variables in the process, such as e.g. the temperature of the slurry and the solutions, the rate of addition, the rate of heating to the formation temperature of the perovskite and the cooling rate therefrom. The choice of process variables for the desired particle product can be readily determined by one skilled in the art according to general principles for crystallization. Larger particles can e.g. is prepared by the relatively slow addition of barium hydroxide to the broth maintained at a relatively low temperature, e.g. approx. 35 ° C and smaller particles can be prepared by the relatively rapid addition of barium hydroxide to the slurry maintained at relatively high temperature, e.g. approx. 95 ° C. Good mixing is important for preparing even particles.

Potem ko delci barijevega titanata dobijo perovskitno strukturo s toplotno obdelavo brozge, delce prednostno speremo, da odstranimo nezreagirane kovinske speciese, kot npr. barijeve ione. Izpiranje lahko izvedemo z deionizirano vodo z amoniakom pri pH 10, da preprečimo raztapljanje barija iz delcev. Izpiralno vodo lahko odstranimo od usedlih delcev s filtracijo ali dekantiranjem. Število izpiralnih ciklov je določeno z želeno čistočo v vodni fazi, tako da npr. zagotovimo brozgo z nizko ionsko jakostjo, ki ima prevodnost manjšo od 5 mS, prednostno manjšo od 1 mS. Ugotovili smo, da od 4 do 5 izpiralnih ciklov ustreza za to, da zmanjšamo ionsko vsebnost vodne faze na nizek nivo, označen s prevodnostjo, ki ni večja od pribl. 100 pS.After the barium titanate particles have obtained a perovskite structure by thermal treatment of the slurry, the particles are preferably washed to remove unreacted metal species, such as e.g. barium ions. The rinsing can be carried out with deionized water with ammonia at pH 10 to prevent the barium from dissolving from the particles. The wash water can be removed from the sediment by filtration or decantation. The number of rinsing cycles is determined by the desired purity in the aqueous phase such that e.g. a low ionic strength broth having a conductivity of less than 5 mS, preferably less than 1 mS, is provided. It has been found that 4 to 5 wash cycles are suitable for reducing the ionic content of the aqueous phase to a low level, characterized by a conductivity of not more than approx. 100 pS.

Delce barijevega titanata lahko vzdržujemo v vodnem stanju do postopka prevlečenja. Kot je navedeno zgoraj, lahko delci na osnovi barijevega titanata vključujejo prevleko, ki obsega oksid, vodni oksid, hidroksid ali organsko kislinsko sol vsaj ene kovine, ki je drugačna od barija in titana. Prevleke lahko zagotovimo tako, da v mešano brozgo delcev na osnovi barijevega titanata dodajamo vodno raztopino (raztopin) soli, kot so npr. nitrati, borati, oksalati ipd. kovin, ki ustrezajo želeni prevleki. Obarjanje za prevleko pospešimo z ustreznim pH. Solne raztopine lahko dodamo bodisi kot eno zmes soli, da tvorimo homogeno prevleko z eno plastjo, ali ločeno in zaporedno, da tvorimo individualne plasti iz oksida, vodnega oksida, hidroksida ali organske kislinske soli. V primeru kovin z relativno višjimi topnostmi, kot so npr. kobalt in nikelj, imajo oksidne prevleke tendenco, da se teže aplicirajo in vzdržujejo brez resolubilizacije. Zato je pogosto prednostno, da apliciramo oksidne prevleke takih, bolj topnih kovin kot zgornjo prevleko čez plasti kovinskih oksidov, ki se laže deponirajo. Alkalno okolje prav tako zmanjša solubilizacijo barija in enostavno zagotavlja delce s prevlekami brez barija in titana. Prevleke delcev, namenjenih za aplikacije pri keramičnih kondenzatorjih, imajo značilno debelino manjšo od 10 % premera delca, pogosto manjšo od 20 nm in prednostno ne večjo od 5 nm do 10 nm.The barium titanate particles can be maintained in an aqueous state until the coating process. As noted above, barium titanate-based particles may include a coating comprising an oxide, an aqueous oxide, a hydroxide or an organic acid salt of at least one metal other than barium and titanium. Coating can be ensured by adding an aqueous solution (s) of salts such as e.g. nitrates, borates, oxalates and the like. metals corresponding to the desired coating. The precipitation for the coating is accelerated to an appropriate pH. Salt solutions can be added either as one mixture of salts to form a homogeneous coating with one layer or separately and sequentially to form individual layers of oxide, aqueous oxide, hydroxide or organic acid salt. In the case of metals with relatively higher solubilities such as e.g. cobalt and nickel, the oxide coatings tend to be applied and maintained without resolution. It is therefore often advantageous to apply oxide coatings of such, more soluble metals than the top coat over easily deposited metal oxide layers. The alkaline environment also reduces barium solubilization and easily provides barium and titanium-free coated particles. Particle coatings intended for applications to ceramic capacitors have a typical thickness of less than 10% of the particle diameter, often less than 20 nm and preferably not greater than 5 nm to 10 nm.

Uporabne prevleke iz organskih kislinskih soli vključujejo tiste, ki so organske soli kovin, ki imajo nizko topnost. Primeri takih prevlek iz organskih kislinskih soli so kovinske soli oksalne kisline (npr. niobijev oksalat), citronske kisline, vinske kisline in palmitinske kisline. Verjamemo, da se organska kislinska sol pretvori v kovinski oksid med zgorevanjem veziva. Izbiro kovine naredimo na osnovi prispevanih izboljšanj za procesiranje ali lastnosti MLC. Kovina v prevlekah je značilno izbrana izmed bizmuta, litija, magnezija, kalcija, stroncija, skandija, cirkonija, hafnija, vanadija, niobija, tantala, volframa, mangana, kobalta, niklja, cinka, bora, silicija, antimona, kositra, itrija, lantana, svinca in lantanidnih elementov. Prednostno imajo delci barijevega titanata prevleko kovinskega oksida brez barija in titana. Če želimo keramične kondenzatorje z dielektričnimi lastnostmi X7R je koristno, da zagotovimo delce barij evega titanata z dopanti, kot so npr. niobijev oksid, tantalov oksid ali neodijev oksid, v kombinaciji z nikljevim oksidom ali kobaltovim oksidom. Če želimo, da zagotovimo keramične kondenzatorje, ki so sintrani pri relativno nizkih temperaturah, npr. v območju od pribl. 1000 °C do 1200 °C, v primerjavi s pribl. 1300 °C in 1600 °C, je koristno, da zagotovimo delce barijevega titanata z dopantom, ki izboljša nizkotemperatumo sintranje. Take pomožne snovi za nizkotemperatumo sintranje vključujejo bizmutov oksid, cinkov oksid, cinkov borat, cinkov vanadat, litijev borat in njihove kombinacije. Kovinske okside za modificiranje dielektričnosti in zniževanje temperature sintranja lahko učinkovito dodamo delcem na osnovi barijevega titanata potem ko le-te izperemo, in pred tvorbo disperzibilnega mokrega kolača.Useful coatings of organic acid salts include those which are organic salts of metals that have low solubility. Examples of such organic acid salt coatings are metal salts of oxalic acid (eg niobium oxalate), citric acid, tartaric acid and palmitic acid. It is believed that the organic acid salt is converted to metal oxide during the combustion of the binder. Metal selection is made based on the improvements made to the processing or the properties of the MLC. Coating metal is typically selected from bismuth, lithium, magnesium, calcium, strontium, scandium, zirconium, hafnium, vanadium, niobium, tantalum, tungsten, manganese, cobalt, nickel, zinc, boron, silicon, antimony, tin, yttrium, lanthanum , lead and lanthanide elements. Preferably, the barium titanate particles have a metal oxide coating free of barium and titanium. If ceramic capacitors with X7R dielectric properties are desired, it is advantageous to provide barium particles of one titanium with dopants, such as e.g. niobium oxide, tantalum oxide or neodymium oxide, in combination with nickel oxide or cobalt oxide. If we want to provide ceramic capacitors that are sintered at relatively low temperatures, e.g. in the range of approx. 1000 ° C to 1200 ° C, compared to approx. 1300 ° C and 1600 ° C, it is advantageous to provide barium titanate particles with a dopant that improves low-temperature sintering. Such auxiliaries for low-temperature sintering include bismuth oxide, zinc oxide, zinc borate, zinc vanadate, lithium borate and combinations thereof. Metal oxides for modifying the dielectricity and lowering the sintering temperature can be effectively added to the barium titanate-based particles after they have been washed and before the dispersion of the wet cake is formed.

Potem ko apliciramo prevleko na hidrotermalno proizvedene delce na osnovi barijevega titanata, lahko brozgo speremo in vodno vsebnost brozge zmanjšamo, da zagotovimo koncentrirano brozgo, mokri kolač ali prašek. Poleg tega lahko brozgo, mokri kolač ali prašek obdelamo z dispergimim sredstvom, da zagotovimo disperzijo, in nadalje obdelamo z vezivom ali drugimi aditivi, da zagotovimo slip. Vodo prednostno odstranimo s sredstvom, s katerim se izognemo ali minimiziramo tvorbo močno aglomeriranih delcev, kot npr. pri kalcinaciji. Prevleke iz določenih kovinskih oksidov imajo lahko za to, ker niso kalcinirane ali sušene, tendenco, da ostanejo v obliki hidratiranega kovinskega oksida, kije lahko topen, če ga ne vzdržujemo pri pH, ki je blizu tistega za minimalno topnost tega kovinskega oksida. Nikljev oksid ali kobaltovi oksidi imajo npr. tendenco, da so nekoliko topni, če jih ne vzdržujemo pri pH blizu 10. Tako za vzdrževanje pravilno prevlečenega delca vzdržujemo pH vodne komponente prednostno v območju od 9 do 11. Brozge delcev na osnovi barijevega titanata, prevlečenih s kovinskim oksidom, prikladno proizvedemo pri relativno nizkem nivoju trdnih snovi, npr. manjšem od 30 mas.% delcev na osnovi barijevega titanata. Višji nivoji trdnih snovi so značilno prednostni za proizvodnjo MLC. Tako je v primeru, ko je treba uporabiti brozgo v smislu izuma direktno pri izdelavi MLC, koristno, da koncentriramo brozgo npr. z odstranjevanjem vode, kot npr. s filtracijo, vsaj do 40 mas.% trdnih snovi, prednostno vsaj do 50 mas.% trdnih snovi, bolj prednostno vsaj do 55 mas.% trdnih snovi in celo bolj prednostno do območja vsaj pribl. 60 ali 75 mas.% trdnih snovi. Dispergimo sredstvo in vezivo lahko dodamo v koncentrirano brozgo, da zagotovimo slip ali stabilno disperzijo delcev na osnovi barij evega titanata.After applying the coating to hydrothermally produced barium titanate-based particles, the slurry can be washed and the water content of the slurry reduced to provide a concentrated slurry, wet cake or powder. In addition, the slurry, wet cake or powder may be treated with a dispersing agent to provide dispersion and further treated with a binder or other additives to provide a slip. Preferably, water is removed by a means to avoid or minimize the formation of highly agglomerated particles, such as e.g. in calcination. Certain metal oxide coatings may have a tendency to remain in the form of a hydrated metal oxide, which cannot be calcined or dried, which can be soluble if not maintained at a pH close to that for the minimum solubility of this metal oxide. Nickel oxide or cobalt oxides have e.g. the tendency to be slightly soluble when not maintained at a pH close to 10. Thus, to maintain a properly coated particle, the pH of the aqueous components is preferably in the range of 9 to 11. Barium titanate-coated particles of oxide coated metal are conveniently produced at relatively low levels of solids, e.g. less than 30% by weight of barium titanate based particles. Higher solids levels are typically preferred for MLC production. Thus, when it is necessary to use the slurry of the invention directly in the manufacture of MLCs, it is useful to concentrate the slurry e.g. by removing water, such as by filtration, at least up to 40% by weight of solids, preferably at least up to 50% by weight of solids, more preferably at least up to 55% by weight of solids, and even more preferably up to an area of at least approx. 60 or 75% by weight of solids. The dispersant agent and binder can be added to the concentrated slurry to provide slip or stable dispersion of the particles based on the barium titanium.

Kot je navedeno zgoraj, lahko potem, ko delce na osnovi barij evega titanata prevlečemo, vodno fazo nadomestimo z nevodno. Vodno fazo lahko nadomestimo z organsko tekočo fazo s solventno izmenjavo ali destilacijo. Pri postopku solventne izmenjave lahko uporabimo filtracijsko napravo. V prednostni izvedbi je filtracijska naprava filter Funda™, ki vključuje ravne pladnje, obložene z ultrafiltracijsko membrano, nameščene na centralnem rezervoarju. Tekočina teče skozi filter Funda™ in jo odstranimo skozi ta centralni rezervoar. Po končani operaciji filtriranja filtrimi kolač z vrtenjem ločimo od pladnjev s centrifugalno silo. Trdne snovi nato spustimo skozi ventil v naslednjo procesimo stopnjo. Ultrafiltracijski membranski material uporabimo zaradi podmikrometrske velikosti delcev hidrotermalnega barij evega titanata.As stated above, after the particles have been coated on the basis of the barium titanium, the aqueous phase can be replaced by a non-aqueous one. The aqueous phase can be replaced by an organic liquid phase by solvent exchange or distillation. A filtration device can be used in the solvent exchange process. In a preferred embodiment, the filtration device is a Funda ™ filter, which includes flat trays lined with an ultrafiltration membrane mounted on a central reservoir. The fluid flows through the Funda ™ filter and is removed through this central reservoir. After the filtration operation is completed, the cake filters are rotated to be separated from the trays by centrifugal force. The solids are then passed through the valve to the next process step. The ultrafiltration membrane material is used because of the submicrometer size of the hydrothermal barium particles of eve titanate.

Solventni izmenjalni postopek pri operaciji najprej vključuje črpanje vodne brozge delcev barij evega titanta v napravo za filtriranje. Vodo odstranimo skozi ultrafiltracijsko membrano. Potem ko odstranimo večino vode, uvedemo brezvodno organsko topilo, ki se meša z vodo, kot npr. metiletilketon (MEK) ali toluen (opisano spodaj), v napravo za filtriranje. To topilo, ki se meša z vodo, dodajamo in odstranjujemo iz naprave za filtriranje skozi ultrafiltracijski membranski material, dokler vsebnost vode v filtrimem kolaču barij evega titanata ne pade na želeno vrednost. Potem ko odstranimo vodo iz filtrimega kolača z uporabo topila, topnega v vodi, dodamo topilo, netopno v vodi. Dodamo dovolj topila, netopnega v vodi, in ga odstranimo skozi ultrafiltracijski material, da razredčimo koncentracijo topila, topnega v vodi na želeno vrednost. Barijev titanat nato z vrtenjem ločimo od ultrafiltracijskega materiala in ga spustimo v mešalni tank, nameščen pod napravo za filtriranje.The solvation exchange procedure during surgery first involves the pumping of an aqueous titre of barium particles of one titant into a filter device. The water is removed through an ultrafiltration membrane. After removing most of the water, an anhydrous, water miscible organic solvent is introduced, such as e.g. Methyl ethyl ketone (MEK) or toluene (described below) into a filter device. This water miscible solvent is added and removed from the filtration device through the ultrafiltration membrane material until the water content of the titanium barium filtrate cake drops to the desired value. After removing the water from the filter cake using a water-soluble solvent, a water-insoluble solvent is added. Sufficient water-insoluble solvent is added and removed through the ultrafiltration material to dilute the concentration of the water-soluble solvent to the desired value. The barium titanate is then rotated to be separated from the ultrafiltration material and dropped into a mixing tank located below the filtration device.

Potem ko pride barijev titanat v mešalni tank, nameščen pod napravo za filtriranje, dodamo dispergant in vsebino v posodi mešamo, dokler ne dobimo homogene brozge. Če je želena nizka vsebnost vode, lahko dodamo sušila, kot npr. aktivirano glinico. Dispergirano brozgo nato črpamo v mletje in pakiranje.After the barium titanate enters the mixing tank placed under the filter device, the dispersant is added and the contents of the vessel are stirred until a homogeneous slurry is obtained. If a low water content is desired, dryers such as e.g. activated alumina. The dispersed slurry is then pumped into grinding and packaging.

Drug postopek za izvedbo solventne izmenjave je destilacijski postopek. Le-ta vključuje destilacijsko posodo z mešano šaržo, kondenzacijski toplotni izmenjalnik in tank za ločevanje faz. Pri tej operaciji vodno brozgo barijevega titanata črpamo v destilacijski tank in dodamo želeno organsko topilo. Če se želeno organsko topilo ne meša z vodo, lahko dodamo majhno količino topila, ki se meša z vodo, kot npr. alkohol z visoko molekulsko maso. Komponente nato zmešamo, da dobimo emulzijo, in segrejemo. Destilacijski postopek prednostno uporabimo pri topilih z visoko molekulsko maso, ki imajo višje vrelišče kot voda. Segrevanje zmesi selektivno izžene vodo, pri čemer ostane barij ev titanat dispergiran v organskih medijih. Tank za ločevanje faz, ki je nameščen navzdol od kondenzacijske enote, loči vodo od kakršnegakoli topila, ki bi bilo prav tako odstranjeno med destilacijo. Topilo nato črpamo nazaj v destilacijsko posodo, vodo pa izčrpamo do ostanka. Pri tem tanku za ločevanje faz bi prav tako lahko uporabili vakuum, da bi pospešili destilacijo, da bi potekala pri nižji temperaturi. Med destilacijskim postopkom lahko dodamo dispergant, da preprečimo solidifikacijo brozge v destilacijski posodi. Ko dosežemo želeno vsebnost vode, topila ne recikliramo več, zmes pa nato koncentriramo z destilacijo, da dosežemo želen odstotek trdnih snovi.Another process for performing solvent exchange is the distillation process. This includes a mixed batch distillation vessel, a condensing heat exchanger and a phase separation tank. In this operation, a barium titanate water broth is pumped into the distillation tank and the desired organic solvent is added. If the desired organic solvent is not miscible with water, a small amount of miscible water miscible, such as e.g. high molecular weight alcohol. The components are then mixed to form an emulsion and heated. The distillation process is preferably used for high molecular weight solvents having a higher boiling point than water. Heating the mixture selectively expels water, leaving the barium titanate dispersed in organic media. The phase separation tank, located downstream of the condensing unit, separates the water from any solvent that would also be removed during distillation. The solvent is then pumped back into the distillation vessel and the water is exhausted to the residue. With this phase separation tank, vacuum could also be used to accelerate the distillation to take place at a lower temperature. A dispersant may be added during the distillation process to prevent solidification of the slurry in the distillation vessel. Once the desired water content is reached, the solvent is no longer recycled and the mixture is then concentrated by distillation to obtain the desired percentage of solids.

Podobno ultrafiltracijskemu postopku, opisanemu zgoraj, lahko v primeru, da je želena nizka vsebnost vode, zmes v destilacijskem tanku polnimo skozi blazino, ki vsebuje sušilo, kot npr. aktivirano kremenico ali aktivirano glinico. Termodinamično učinkovitost destilacijskega postopka lahko izboljšamo tudi z dodajanjem ultrafiltracijskih modulov, višje od uvajanja vodne brozge barijevega titanata v destilacijsko posodo. Ti ultrafiltracijski moduli bi odstranili večino vode iz vodne brozge barijevega titanata preden le-to uvedemo v destilacijski postopek.Similar to the ultrafiltration process described above, in the case where a low water content is desired, the mixture in the distillation tank can be filled through a cushion containing a dryer, e.g. activated quartz or activated alumina. The thermodynamic efficiency of the distillation process can also be improved by adding ultrafiltration modules higher than the introduction of barium titanate water in the distillation tank. These ultrafiltration modules would remove most of the water from the barium titanate water broth before introducing it into the distillation process.

Nevodno brozgo lahko tudi koncentriramo, npr. s filtracijo, da zagotovimo trden mokri kolač, ki je netekoča trdna snov, ki obsega delce na osnovi barijevega titanata, prevlečene s kovinskim oksidom, in tekočino. Nevodni mokri kolač je lahko v trdnem stanju s pribl. 60 mas.% trdnih snovi, zmešanih z nevodno raztopino. Bolj prednostno mokri kolač obsega vsaj 65 mas.% trdnih snovi in bolj prednostno vsaj 70 mas.% trdnih snovi. Mokri kolač lahko obsega do pribl. 85 mas.% trdnih snovi. V nevodnem mokrem kolaču naj bi imela nevodna raztopina pH večji od 8, da se prepreči raztapljanje kovine. Prednostno območje pH je med pribl. 8 in 12, bolj prednostno je med pribl. 9 in 11. Mokri kolač delcev na osnovi barijevega titanata je prekurzor koloidne disperzije. To pomeni, da lahko mokri kolač dispergiramo npr. s pomešanjem z dispergimim sredstvom. Zelo malo, če sploh kaj, dodatnega tekočega medija je treba za pretvorbo mokrega kolača iz trdnega stanja v tekočo disperzijo.Non-aqueous slurry can also be concentrated, e.g. by filtration to provide a solid wet cake, which is a non-liquid solid comprising barium titanate based metal oxide coated particles and a liquid. The non-aqueous wet cake may be in solid state with approx. 60% by weight of solids mixed with a non-aqueous solution. More preferably, the wet cake comprises at least 65% by weight of solids and more preferably at least 70% by weight of solids. A wet cake can range up to approx. 85% by weight of solids. A non-aqueous wet cake should have a non-aqueous solution having a pH greater than 8 to prevent the metal from dissolving. The preferred pH range is between approx. 8 and 12, more preferably between approx. 9 and 11. A barium titanate-based wet cake is a precursor of colloidal dispersion. This means that the wet cake can be dispersed e.g. by mixing with a dispersing agent. Very little, if any, additional liquid medium is required to convert a wet cake from a solid state to a liquid dispersion.

Vsaj v primeru nevodnega mokrega kolača ostanejo delci v kolaču šibko aglomerirani relativno dolgo časa, dokler kolač vzdržujemo z vsebnostjo tekočine vsaj 15 mas.%, bolj prednostno, dokler kolač vzdržujemo z vsebnostjo tekočine vsaj 20 mas.%, in bolj prednostno, dokler kolač vzdržujemo z vsebnostjo tekočine vsaj 25 mas.%.At least in the case of a non-aqueous wet cake, the particles in the cake remain weakly agglomerated for a relatively long time until the cake is maintained with a liquid content of at least 15% by weight, more preferably until the cake is maintained with a liquid content of at least 20% by weight, and more preferably until the cake is maintained with a liquid content of at least 25% by weight.

Prednostno mokri kolač inkapsuliramo v zaporo za vlago, da preprečimo zgubo vsebnosti vode, ki bi lahko pospešila tvorbo močno aglomeriranih delcev, ki se ne deaglomerirajo enostavno. Take zapore za vlago, kot so npr. polietilenske vrečke ali vlakneni valji, prevlečeni s polietilenom, lahko zagotovijo podaljšano dobo shranjevanja vsaj en dan ali več, prednostno podaljšano dobo shranjevanja vsaj 3 dni, bolj prednostno podaljšano dobo shranjevanja vsaj 30 dni in najbolj prednostno podaljšano dobo shranjevanja vsaj 90 dni. Take značilnosti olajšajo shranjevanje in transport mokrega kolača v smislu predloženega izuma.Preferably, the wet cake is encapsulated in a moisture barrier to prevent loss of water content that could accelerate the formation of highly agglomerated particles that do not easily deagglomerate. Such moisture barriers as e.g. polyethylene bags or fiber cylinders coated with polyethylene may provide an extended shelf life of at least one day or more, preferably an extended shelf life of at least 3 days, more preferably an extended shelf life of at least 30 days, and most preferably an extended shelf life of at least 90 days. Such features facilitate the storage and transportation of the wet cake according to the present invention.

Mokri kolač enostavno pretvorimo v tekočo disperzijo z vgrajevanjem dispergimega sredstva v kolač brez znatnega dodatka tekočine. Čeprav kolaču lahko dodamo tekočino, pa je potrebna količina dispergimega sredstva, da pretvori trdni kolač v tekočo disperzijo, precej majhna, npr. značilno manjša od 2 mas.% glede na maso materiala na osnovi barijevega titanata. V nekaterih primerih ni potrebna druga dodatna tekočina, razen tekočinskega volumna dispergimega sredstva za pretvorbo mokrega kolača v tekočo disperzijo. Preizkušena dispergima sredstva so polielektroliti, ki vključujejo organske polimere z anionskimi ali kationskimi funkcionalnimi skupinami. Anionsko fimkcionalizirani polimeri vključujejo polimere karboksilne kisline, kot npr. polistirensulfonsko kislino in poliakrilno kislino; kationsko funkcionalizirani polimeri vključujejo poliimide, kot npr. polieterimid in polietilenimin. Poliakrilne kisline so prednostne za mnoge aplikacije. Medtem ko se polimerne kislinske skupine lahko protonirajo, je prednostno, da imajo take kislinske skupine nasprotni kation, da se izognemo zmanjšanju pH disperzije na nivo, ki bi pospešil raztapljanje barija ali drugih kovinskih speciesov, ki so lahko prisotni v prevlekah dopantov. Za kondenzatorske aplikacije je prednostni kation amonijev ion. V nekaterih primerih je lahko mogoče, da uporabimo dopantne kovine kot nasprotni kation za polimerne kislinske dispergante. Ne glede na izbrano dispergimo sredstvo lahko strokovnjaki enostavno določijo ustrezno količino dispergimega sredstva s postopkom titracije. Kadar je količina izbranega dispergimega sredstva tista, ki zagotavlja najnižjo viskoznost za disperzijo, lahko koncentracijo dispergimega sredstva zmanjšamo pri uporabi disperzije, kot npr. z razredčenjem ali interakcijo z aditivi, in povzročimo, da viskoznost naraste na nezaželeno visok nivo. Tako je za mnoge aplikacije želeno, da se uporabi dispergimo sredstvo v količini za minimiziranje viskoznosti.The wet cake can be easily converted into liquid dispersion by incorporating the dispersing agent into the cake without significant addition of liquid. Although liquid may be added to the cake, the amount of dispersant required to convert the solid cake into liquid dispersion is quite small, e.g. typically less than 2% by weight based on the weight of barium titanate based material. In some cases, no additional fluid is required other than the liquid volume of the dispersing agent to convert the wet cake into liquid dispersion. The dispersant agents tested are polyelectrolytes that include organic polymers with anionic or cationic functional groups. Anionically functionalized polymers include carboxylic acid polymers, such as e.g. polystyrenesulfonic acid and polyacrylic acid; cationically functionalized polymers include polyimides such as e.g. polyetherimide and polyethyleneimine. Polyacrylic acids are preferred for many applications. While the polymeric acid groups may be protonated, it is preferable that such acid groups have the opposite cation to avoid reducing the pH of the dispersion to a level that would accelerate the dissolution of barium or other metal species that may be present in the dopant coatings. For capacitor applications, ammonium ion cation is preferred. In some cases, it may be possible to use dopant metals as the opposite cation for polymeric acid dispersants. Whatever the dispersing agent is selected, experts can easily determine the appropriate amount of the dispersing agent by the titration process. When the amount of selected dispersant is that which provides the lowest viscosity for dispersion, the concentration of dispersant may be reduced by the use of dispersion, such as e.g. by diluting or interacting with the additives, causing the viscosity to rise to an undesirable high level. Thus, for many applications, it is desirable to use a dispersing agent in an amount to minimize viscosity.

Ugotivili smo, da je prednostno dispergimo sredstvo za uporabo v koloidnih disperzijah, namenjenih za kondezatorske aplikacije in za tako preizkušanje, poliakrilna kislina z amoniakom, ki ima številčno povprečje molekulske mase pribl. 8000. Ugotovili smo, daje za pretvorbo mokrega kolača v tekočo disperzijo uporabno npr. 0,75 mas.% take poliakrilne kisline z amoniakom (kot 40 mas.% vodna raztopina). Vgradnjo dispergimega sredstva lahko izvedemo na prikladen način, kot npr. z mehanskim pomešanjem disperganta v mokri kolač. Kadar uporabimo visoko učinkovito mešanje se porabi prebitek dispergimega sredstva zaradi nove specifične površine delcev, eksponirane z deaglomeracijo. Tako je lahko prikladno, da dodamo dispergimo sredstvo s prirastkom med visoko učinkovitim mešanjem.It has been found that the preferred dispersing agent for use in colloidal dispersions intended for condenser applications and for such testing is polyacrylic acid with ammonia having a number average molecular weight of approx. 8000. It has been found that for the conversion of wet cake into liquid dispersion, e.g. 0.75% by weight of such polyacrylic acid with ammonia (as 40% aqueous solution). The incorporation of the dispersing agent can be conveniently carried out, such as e.g. by mechanically mixing the dispersant into a wet muffin. When highly efficient mixing is used, the excess dispersant is consumed due to the new specific surface of the particles exhibited by deagglomeration. Thus, it may be convenient to add a dispersant with an increment during high-efficiency mixing.

Mokri kolač se razlikuje od brozg, disperzij, slipov in suhih praškov po tem, daje le-ta netekoča trdna snov, medtem ko so brozge, disperzije in slipi tekoče tekočine, suhi praški pa so tekoče trdne snovi. Mokri praški lahko tečejo ali pa tudi ne, odvisno od količine vsebovane tekočine. Več tekočine ko odstranimo, tem bolj postaja mokri prašek suh. Razumljivo je seveda, da suhi prašek ni nujno popolnoma dehidratiran. Pršilno sušenje, liofilizacija in nizko temperaturno sušenje v vakuumu so prednostni postopki za zagotavljanje suhih praškov iz prevlečenih delcev na osnovi barijevega titanata, ki ostanejo disperzibilni le z vmešanjem v raztopino, vsebujočo dispergimo sredstvo, npr. z visoko učinkovitim mešanjem. Tako so suhi praški prevlečenih delcev na osnovi barijevega titanata presenetljivo disperzibilni v disperzije podmikrometrskih delcev, ne da bi potrebovali dolgotrajno udarno mletje. Drugače kot pri znanih materialih visokoenergijsko mletje več ur ni potrebno, da znižamo velikost delcev do točke, kjer lahko disperzije ali slipe iz prevlečenih delcev na osnovi barijevega titanata uporabimo za izdelavo kondenzatorjev s fmozmatimi tankimi dielektričnimi plastmi in visoko prebojno napetostjo.Wet cake is different from splashes, dispersions, slips and dry powders in that it is a non-liquid solids, whereas splashes, dispersions and slips are liquid liquids and dry powders are liquid solids. Wet powders may or may not flow, depending on the amount of liquid contained. The more liquid that is removed, the wetter the dry powder becomes. It is understandable, of course, that dry powder is not necessarily completely dehydrated. Spray drying, lyophilization and low temperature vacuum drying are preferred methods for providing dry powders of barium titanate-based coated particles that remain dispersible only when mixed with a solution containing a dispersing agent, e.g. with highly efficient mixing. Thus, the dry powders of barium titanate-based coated particles are surprisingly dispersible into sub-micrometer particle dispersions without the need for long-term impact milling. Unlike conventional materials, high-energy milling does not require several hours to reduce the particle size to the point where dispersions or slips of coated barium titanate particles can be used to produce capacitors with thin, thin dielectric layers and high breakthrough voltages.

Drugi vidik predloženega izuma zagotavlja postopke za izdelavo disperzije podmikrometrskih prevlečenih delcev na osnovi barijevega titanata v raztopini z deaglomeriranjem disperzije velikih (večjih od 1 pm) šibko aglomeriranih delcev na osnovi barijevega titanata, prevlečenih s kovinskim oksidom, dokler niso v bistvu vsi delci manjši od 1 pm. Pri prednostnem postopku v smislu izuma deaglomeriramo disperzije z visoko vsebnostjo trdnih snovi, ki obsegajo med pribl. 30 mas.% in 75 mas.% delcev, z visoko učinkovitim mešanjem z dispergimim sredstvom. Optimalni čas za visoko učinkovito mešanje z lahkoto določimo z rutinskim eksperimentiranjem. Visoko učinkovito mešanje lahko povzročimo v centrifugalnem črpalnem deaglomeracijskem mlinu, komercialno dosegljivem npr. pri Silverson Machine Inc. (East Longmeadow, MA). Druge naprave, uporabne za zagotavljanje deaglomeriranih disperzij, vključujejo tiste, znane kot: supermlini, koloidni mlini in kavitacijski mlini.Another aspect of the present invention provides processes for producing dispersion of submicrometer coated barium titanate based particles in solution by deagglomerating the dispersion of large (greater than 1 pm) weakly agglomerated barium titanate based particles coated with metal oxide until substantially all particles are smaller than 1 pm. In the preferred method of the invention, the high-solids dispersions comprising between approx. 30% and 75% by weight of the particles, with high efficiency mixing with the dispersing agent. The optimal time for highly efficient mixing is easily determined by routine experimentation. Highly efficient mixing can be caused in a centrifugal pump deagglomeration mill commercially available e.g. at Silverson Machine Inc. (East Longmeadow, MA). Other devices useful for providing deagglomerated dispersions include those known as: supermills, colloid mills and cavitation mills.

Supermilini imajo komoro za mletje, napolnjeno z mediji, z vrtečimi se diski z visoko hitrostjo na centralni osi in so komercialno dosegljivi npr. pri Premier Mili (Reading, PA). Koloidni mlini imajo odprtino za mletje med razširjenimi površinami rotorja z visoko hitrostjo in fiksiranim statorjem in so prav tako komercialno dosegljivi npr. pri Premier Mili. V kavitacijskih mlinih, ki so komercialno dosegljivi npr. pri Arde Barinco Inc. (Norwood, NJ), se črpa tekočina skozi vrsto hitro odpirajočih in zapirajočih se komor, ki hitro komprimirajo in dekomprimirajo tekočino, ki da visokofrekvenčni učinkovitostni učinek, ki lahko deaglomerira delce. Pričakujemo, da se bodo koncentrirana brozga, disperzija, mokri kolač, mokri prašek ali suhi prašek vedli enako dobro pri zagotavljanju slipov za izdelavo visoko zmogljivostnih kondenzatorjev, odvisno od izdelovalnih pripomočkov ali postopkov za posebne kondenzatorje.The supermillins have a media-filled grinding chamber with high speed rotary discs in the central axis and are commercially available e.g. at Premier Mile (Reading, PA). Colloidal mills have a grinding opening between the extended surfaces of the high-speed rotor and the fixed stator and are also commercially available e.g. at Premier Mili. In cavitation mills that are commercially available e.g. at Arde Barinco Inc. (Norwood, NJ), fluid is pumped through a series of rapidly opening and closing chambers that rapidly compress and decompress fluid to give a high-frequency performance effect that can deagglomerate particles. Concentrated slurry, dispersion, wet cake, wet powder or dry powder are expected to behave equally well in providing slips for the production of high performance capacitors, depending on the manufacturing aids or procedures for special capacitors.

Preizkus za določevanje učinkovite količine dispergirnega sredstva za šibko aglomerirane prevlečene delce na osnovi barijevega titanata obsega uporabo visoko učinkovitega mešalnika, kot je npr. visoko učinkoviti laboratorijski mešalnik Silverson model L4R, opremljen z visoko učinkovitim zaslonom s kvadratno odprtino, da visoko učinkovito zmeša 500 g vzorca disperzije, ki obsega 70 mas.% prevlečenih delcev v alkalni nevodni raztopini v temperaturnem območju med 25 °C in 30 °C, pH, pri katerem se prevleka ne raztopi, in pri čemer vsebuje učinkovito količino dispergirnega sredstva, in sicer učinkoviti čas za deaglomeriranje prevlečenih delcev. Učinkovita količina dispergima sredstva je zadostna za vzdrževanje ločenih aglomeratov in agregatov pri manjših velikostih delcev brez reaglomeriranja. Učinkovita količina dispergirnega sredstva se spreminja odvisno od faktorjev, kot so npr. velikost delcev, narava prevleke in jakost dispergirnega sredstva. Učinkovito količino dispergirnega sredstva in učinkoviti čas lahko strokovnjaki enostavno določijo z nekoliko rutinskih eksperimentov z opazovanjem učinkov spremenljivk, kot so koncentracija dispergirnega sredstva in čas za visoko učinkovito mešanje, na zmanjševanje magnitude porazdelitve velikosti delcev. Učinkovita količina teh spremenljivk bo dopustila analizo velikosti delcev, ki kaže resnični učinek visoko učinkovitega mešanja na deaglomeracijo. Pri mnogih primerih smo ugotovili, da je učinkovita količina dispergirnega sredstva poliakrilne kisline z amoniakom (številčno povprečje molekulske mase pribl. 8000) pribl. 1 mas.% dispergirnega sredstva na celotno maso delcev in dispergirnega sredstva, in je učinkoviti čas za visoko učinkovito mešanje pribl. 1 minuta.The test for determining the effective amount of dispersant for weakly agglomerated barium titanate-based coated particles involves the use of a highly efficient mixer, such as e.g. a high-efficiency Silverson L4R laboratory mixer equipped with a high-efficiency square-mesh screen to mix effectively 500 g of a dispersion sample comprising 70% by weight of coated particles in an alkaline non-aqueous solution in the temperature range between 25 ° C and 30 ° C, pH at which the coating does not dissolve and containing an effective amount of dispersant, an effective time to deagglomerate the coated particles. An effective amount of dispersant of the agent is sufficient to maintain separate agglomerates and aggregates at smaller particle sizes without re-agglomeration. The effective amount of the dispersing agent varies depending on factors such as e.g. particle size, nature of coating and strength of dispersant. The effective amount of dispersant and the effective time can be easily determined by one of ordinary skill in the art by observing the effects of variables such as the concentration of the dispersing agent and the time for highly efficient mixing on reducing the magnitude of the particle size distribution. An effective amount of these variables will allow particle size analysis to show the true effect of highly efficient mixing on deagglomeration. In many cases, the effective amount of ammonia polyacrylic acid dispersing agent (molecular weight average approx. 8000) has been found to be approx. 1% by weight of the dispersant to the total weight of the particles and dispersant, and the effective time for highly efficient mixing is approx. 1 minute.

Prevlečeni delci na osnovi barijevega titanata, pripravljeni s hidrotermalnimi postopki, so po videzu v bistvu sferični in enakoosni. Taki delci ostanejo v bistvu sferični celo po zmanjševanju velikosti z visoko učinkovitim mešanjem. Priložnostno so lahko v bistvu sferični delci dvojni. Pojav dvojnih delcev je zaželeno redek. Uporaba sferičnih delcev, v primerjavi z nesferičnimi zmletimi praški, zagotavlja praške, označene z izjemno visoko specifično površino, ki imajo BET-specifično površino vsaj pribl. 4 m /g, prednostno imajo sferični delci BET-specifično površino vsaj pribl. 8 m /g, bolj nCoated barium titanate based particles prepared by hydrothermal processes are substantially spherical and equiaxial in appearance. Such particles remain essentially spherical even after resizing with highly efficient mixing. Occasionally, the spherical particles may be essentially double. The occurrence of double particles is preferably rare. The use of spherical particles, compared to non-spherical ground powders, provides powders characterized by an extremely high specific surface area having a BET-specific surface area of at least approx. 4 m / g, preferably spherical particles have a BET-specific surface area of at least approx. 8 m / g, more n

prednostno imajo sferični delci BET-specifično površino vsaj pribl. 12 m /g.preferably, spherical particles have a BET-specific surface area of at least approx. 12 m / g.

Podmikrometrski prevlečeni delci barijevega titanata so suspenzibilni z velikim številom veziv, dispergantov in sredstev za sproščanje z uporabo nevodnih topil, da zagotovimo keramične ulivne slipe.Submicrometer coated barium titanate particles are suspensable with a large number of binders, dispersants and release agents using non-aqueous solvents to provide ceramic castings.

Delce na osnovi barijevega titanata dispergiramo v organskem topilu, ki vsebuje raztopljeno polimerno vezivo in po izbiri druge raztopljene materiale, kot npr. plastifikatorje, maziva, dispergima sredstva, ločevalna sredstva, sredstva za preprečevanje gnitja in omakala. Uporabna organska topila imajo nizko vrelišče in vključujejo: benzen, metil etil keton, aceton, ksilen, metanol, etanol, propanol, 1,1,1trikloroetan, tetrakloroetilen, amil acetat, 2,2,4-trietil pentandiol-l,3-monoizobutirat, toluen, metilen klorid, terpentin, etil alkohol, bromoklorometan, butanol, diaceton, metil izobutil keton, cikloheksanon, metil alkohol, n-propil alkohol, izopropil alkohol, n-butil alkohol, n-oktil alkohol, benzil alkohol, glicerol, etilen glikol, benzaldehid, propionsko kislino, n-oktanojsko kislino, etilacetat, butilbutirat, n-heksan ipd., vključno njihove zmesi in zmesi z vodo, kot npr. zmesi metanola in vode. Tudi različne azeotropske organske topilne zmesi imajo nizka vrelišča in jih lahko uporabimo kot nosilni vehikel. Topilne zmesi lahko vključujejo npr.: 72 % trikloroetilena /28 % etil alkohola, 66 % metil etil ketona/34 % etil alkohola, 70 % metil etil ketona/30 % etil alkohola, 59 % metil etil ketona/41 % etil alkohola, 50 % metil etil ketona/50 % etil alkohola, 80 % toluena/20 % etanola, 80 % toluena/20 % etil alkohola, 70 % toluena/30 % etil alkohola, 60 % toluena/40 % etil alkohola, 70 % izopropil alkohola/30 % metil etil ketona, 40 % metil etil ketona/60 % etil alkohola in njihove zmesi.The barium titanate-based particles are dispersed in an organic solvent containing a dissolved polymer binder and optionally other dissolved materials such as e.g. plasticizers, lubricants, dispersing agents, separators, rotting agents and wetting agents. Useful organic solvents have a low boiling point and include: benzene, methyl ethyl ketone, acetone, xylene, methanol, ethanol, propanol, 1,1,1 trichloroethane, tetrachloroethylene, amyl acetate, 2,2,4-triethyl pentanediol-1,3-monoisobutyrate , toluene, methylene chloride, turpentine, ethyl alcohol, bromochloromethane, butanol, diacetone, methyl isobutyl ketone, cyclohexanone, methyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, n-octyl alcohol, benzyl alcohol, glycerol, ethylene glycol, benzaldehyde, propionic acid, n-octanoic acid, ethyl acetate, butyl butyrate, n-hexane and the like, including mixtures thereof and mixtures with water, such as e.g. mixtures of methanol and water. Also, various azeotropic organic solvent mixtures have low boiling points and can be used as a carrier solvent. Solvent mixtures may include, for example: 72% trichloroethylene / 28% ethyl alcohol, 66% methyl ethyl ketone / 34% ethyl alcohol, 70% methyl ethyl ketone / 30% ethyl alcohol, 59% methyl ethyl ketone / 41% ethyl alcohol, 50 % methyl ethyl ketone / 50% ethyl alcohol, 80% toluene / 20% ethanol, 80% toluene / 20% ethyl alcohol, 70% toluene / 30% ethyl alcohol, 60% toluene / 40% ethyl alcohol, 70% isopropyl alcohol / 30% methyl ethyl ketone, 40% methyl ethyl ketone / 60% ethyl alcohol and mixtures thereof.

Disperganti (deflokulanti/omakala), uporabni v nevodnih disperzijah podmikrometrskih delcev barijevega titanata, prevlečenih s kovinskim oksidom, vključujejo poleg tistih, navedenih zgoraj, npr. tudi: fosfatni ester, glikol trioleat, etoksilat, 2-amino-2-metil-l-propanol, hidroksietilimidazolin talovega olja, oleinski hidroksietilimidazolin, maščobne kisline, kot npr. glicerol trioleat, lanolinske maščobne kisline, poli(vinil butiral), natrijev bis(tridecil)sulfosukcinat, diizobutil natrijev sulfosukcinat, natrijev dioktil sulfosukcinat, etoksiliran alkilgvanidin amin, natrijev diheksilsulfosukcinat, natrijev diizobutilsulfosukcinat, benzensulfonsko kislino, sulfonate, topne v olju, alkil eter polietilen glikola), adukte oleinske kisline in etilenoksida, sorbitan trioleat, adukte amida sterične kisline in etilen oksida, alkilaril polieterske alkohole, etil eter polietilen glikola), etil fenil glikol, polioksietilen acetat, polioksi etilen ester ipd. Prednostna dispergima sredstva za suspenzije v organskih topilih in za slipe vključujejo menhadenovo (ribje) olje, koruzno olje, polietilenimin in poliakrilno kislino z amoniakom.Dispersants (deflocculants / wetting agents) useful in non-aqueous dispersions of submicrometer barium titanium particles coated with metal oxide include, in addition to those mentioned above, e.g. also: phosphate ester, glycol trioleate, ethoxylate, 2-amino-2-methyl-1-propanol, hydroxyethylimidazoline of tall oil, oleic hydroxyethylimidazoline, fatty acids such as e.g. glycine trioleate, lanolin fatty acids, poly (vinyl butyral), sodium bis (tridecyl) sulfosuccinate, diisobutyl sodium dioctyl sulfosuccinate, ethoxylated alkylguanidine amine, sodium dihexyl sulfosulfonate glycol), oleic acid and ethylene oxide adducts, sorbitan trioleate, steric acid and ethylene oxide adducts, alkylaryl polyether alcohols, ethyl ether polyethylene glycol), ethyl phenyl glycol, polyoxyethylene acetate, polyoxy ethylene ester and polyoxy ethylene ester, Preferred dispersing agents for suspensions in organic solvents and slides include menhaden (fish) oil, corn oil, polyethyleneimine and polyacrylic acid with ammonia.

Med polimernimi vezivnimi materiali, uporabnimi v nevodnih slipih, so npr.: poli(vinil butiral), poli(vinil acetat), poli(vinil alkohol), celulozni polimeri, kot npr. metil celuloza, etil celuloza, hidroksietil celuloza, metilhidroksietil celuloza, celulozni acetat butirat, nitroceluloza, polipropilen polietilen, silicijevi polimeri, kot npr. poli(metil siloksan) in poli(metilfenil siloksan), polistiren, butadien/stirenski sopolimer, poli(vinil pirolidon), poliamidi, polietri, poli(etilen oksid-propilen oksid), poliakrilamidi, in akrilni polimeri, kot npr. natrijev poliakrilat, poli(metil akrilat), poli(metil metakrilat), poliakrilatni estri in sopolimeri, kot npr. sopolimeri etil metakrilata in metil akrilata, poli(vinil alkohol), poli(vinil klorid), vinil klorid acetat, poli(tetrafluoroetilen), poli(a-metilstiren), ipd. Polimerna veziva so značilno uporabna v območju med pribl. 5 in 20 mas.%. Prednosten komercialno dosegljiv polimer je ACRYLOID™ B-7 akrilatni polimer (Rohm & Haas Co., Philadelphia, PA).Among the polymeric binders useful in non-aqueous slips are, for example: poly (vinyl butyral), poly (vinyl acetate), poly (vinyl alcohol), cellulose polymers, such as e.g. methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, methylhydroxyethyl cellulose, cellulose acetate butyrate, nitrocellulose, polypropylene polyethylene, silicon polymers such as e.g. poly (methyl siloxane) and poly (methylphenyl siloxane), polystyrene, butadiene / styrene copolymer, poly (vinyl pyrrolidone), polyamides, polyethers, poly (ethylene oxide-propylene oxide), polyacrylamides, and acrylic polymers such as e.g. sodium polyacrylate, poly (methyl acrylate), poly (methyl methacrylate), polyacrylate esters and copolymers such as e.g. copolymers of ethyl methacrylate and methyl acrylate, poly (vinyl alcohol), poly (vinyl chloride), vinyl chloride acetate, poly (tetrafluoroethylene), poly (α-methylstyrene), and the like. Polymer binders are typically useful in the range between approx. 5 and 20 wt.%. A preferred commercially available polymer is the ACRYLOID ™ B-7 acrylate polymer (Rohm & Haas Co., Philadelphia, PA).

Pogosto organski medij vsebuje tudi majhno količino plastifikatorja za znižanje temperature steklastega prehoda (Tg) vezivnega polimera. Izbira plastifikatorja je primarno določena s polimerom, ki mora biti modificiran, in lahko vključuje ftalatne estre (in mešane ftalatne estre), kot npr. dimetil ftalat, dietil ftalat, dibutil ftalat, dioktil ftalat, butil benzil ftalat, alkil fosfate, poli(alkilen glikol), polietilen glikol, glicerol, polietilen okside), hidroksietiliran alkil fenol, dialkil ditiofosfonat, poli(izobutilen), butil stearat, metil abietat, trikrezil fosfat, dipropilglikol dibenzoat ipd.Often, the organic medium also contains a small amount of plasticizer to reduce the glass transition temperature (Tg) of the binder polymer. The choice of plasticizer is primarily determined by the polymer to be modified and may include phthalate esters (and mixed phthalate esters), such as e.g. dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, butyl benzyl phthalate, alkyl phosphates, poly (alkylene glycol), polyethylene glycol, glycerol, polyethylene oxides), hydroxyethylated alkyl phenol, dialkyl dithiophosphate, methyl isobutyl) abietate, tricresyl phosphate, dipropylglycol dibenzoate and the like.

V eni izvedbi slip na osnovi organskega topila v smislu izuma na 100 masnih delov delcev na osnovi barijevega titanata obsega:In one embodiment, the organic solvent-based slip of the invention per 100 parts by weight of barium titanate-based particles comprises:

od 25 do 40 delov organskega topila od 2 do 5 delov dispergirnega sredstva od 5 do 20 delov polimernega veziva in od 0 do 15 delov plastifikatorja.from 25 to 40 parts of an organic solvent from 2 to 5 parts of a dispersing agent from 5 to 20 parts of a polymeric binder and from 0 to 15 parts of a plasticizer.

Disperzijo delcev na osnovi barijevega titanata v različnih nevodnih topilih lahko izboljšamo z aplikacijo različnih prevlek, kot npr. pripojitvenih sredstev, na površino delcev. Široko področje dosegljivih silanskih pripojitvenih sredstev zlasti zagotavlja način za oblikovanje površine delcev za izbrani nosilni vehikel. Prevleka hidrotermalno izvedenih delcev na osnovi barijevega titanata s silanskim pripojitvenim sredstvom ne bi bila uporabna samo za posušene praške, ampak tudi za delce, ki ostanejo v raztopini. Čeprav lahko silanska pripojitvena sredstva apliciramo na površino praškov, ki so bili sušeni ali niso bili, pa naj bi prednostno pripojitveno sredstvo aplicirali po sušenju delcev, da olajšamo njihovo dispergiranje v nosilnem vehiklu. Poleg tega zagotavlja sušenje praškov enostaven mehanizem, da določimo, ali smo dosegli popolno prevleko, s preizkušanjem dispergiranja obdelanega praška v vodi. Neprevlečeni ali delno prevlečeni praški se delno ali popolnoma dispergirajo v vodi, medtem ko popolnoma prevlečeni delci splavajo na površino vode celo pri mešanju.The dispersion of barium titanate-based particles in various non-aqueous solvents can be improved by applying different coatings, such as e.g. of coupling agents, to the particle surface. The wide range of attainable silane coupling agents in particular provides a way of forming a particle surface for the carrier selected. Coating of hydrothermally derived barium titanate based particles with a silane coupling agent would not only be useful for dried powders but also for particles remaining in solution. Although silane coupling agents can be applied to the surface of powders that have been dried or not, the preferred coupling agent should preferably be applied after drying the particles to facilitate their dispersion in the carrier solvent. In addition, powder drying provides an easy mechanism to determine whether a complete coating has been achieved by testing the dispersion of the treated powder in water. Uncoated or partially coated powders are partially or completely dispersed in water, while fully coated particles float to the water surface even when mixed.

Delce lahko prevlečemo v enem nosilnem vehiklu in nato prenesemo v drugi nosilni vehikel s postopkom izmenjave topila (kot je opisano zgoraj) ali z destilacijskim postopkom. Čeprav lahko silanska pripojitvena sredstva apliciramo na površino praškov pred izmenjavo topila ali po njej, pa je prednostno, da apliciramo prevleko po postopku izmenjave topila. Silanska pripojitvena sredstva lahko vežemo na površino delcev, da olajšamo disperzijo v želenem nosilnem vehiklu in pripomoremo k pasivaciji površine delca.The particles can be coated in one carrier solvent and then transferred to another carrier solvent by the solvent exchange process (as described above) or by distillation. Although silane coupling agents can be applied to the surface of the powders before or after the solvent exchange, it is preferable to apply the coating after the solvent exchange process. Silane coupling agents can be bonded to the particle surface to facilitate dispersion in the desired carrier solvent and to assist in the passivation of the particle surface.

Splošna formula organosilana R„SiX(4._n) kaže dva razreda funkcionalnosti. Skupina X je vključena v reakcijo z anorganskim substratom. Vez med X in atomom silicija v pripojitvenih sredstvih je nadomeščena z vezjo med anorganskim substratom in atomom silicija. X je hidrolizibilna skupina, značilno alkoksi, aciloksi, amino ali klor. Najbolj običajni alkoksi skupini sta metoksi in etoksi, ki dajeta metanol in etanol kot stranska produkta med reakcijami pripajanja. Ker klorosilani proizvedejo vodikov klorid kot stranski produkt med reakcijami pripajanja, se le-ti na splošno manj uporabljajo kot alkoksisilani. R je nehidrolizabilni organski radikal, ki ima funkcionalnost, ki omogoča, da se pripojitveno sredstvo veže z organskimi smolami in polimeri. Večino široko uporabljenih organosilanov ima en organski substituent. V večini primerov silan izpostavimo hidrolizi pred površinsko obdelavo. Po hidrolizi se tvori reaktivna silanolna skupina, ki se lahko kondenzira z drugimi silanolnimi skupinami, npr. tistimi na površini kremenovih polnil, da se tvorijo siloksanske vezi. Stabilni kondenzacijski produkti se tvorijo tudi z drugimi oksidi, kot npr. aluminijevimi, cirkonijevimi, kositrovimi, titanovimi in nikljevimi. Manj stabilne vezi se tvorijo z oksidi bora, železa in ogljika. Oksidi in karbonati alkalijskih kovin ne tvorijo stabilnih vezi z Si-O-.The general formula of organosilane R 'SiX (4. _n ) shows two classes of functionality. Group X is involved in the reaction with the inorganic substrate. The bond between X and the silicon atom in the coupling agents is replaced by the bond between the inorganic substrate and the silicon atom. X is a hydrolysable group, typically alkoxy, acyloxy, amino or chlorine. The most common alkoxy groups are methoxy and ethoxy, which give methanol and ethanol as by-products during coupling reactions. Because chlorosilanes produce hydrogen chloride as a by-product during coupling reactions, they are generally less used than alkoxysilanes. R is a non-hydrolysable organic radical that has a functionality that allows the coupling agent to bind to organic resins and polymers. Most widely used organosilanes have one organic substituent. In most cases, silane is exposed to hydrolysis prior to surface treatment. After hydrolysis, a reactive silanol group is formed which can condense with other silanol groups, e.g. those on the surface of the quartz fillers to form siloxane bonds. Stable condensation products are also formed with other oxides, such as e.g. aluminum, zirconium, tin, titanium and nickel. Less stable bonds are formed by oxides of boron, iron, and carbon. Alkali metal oxides and carbonates do not form stable bonds with Si-O-.

Voda za hidrolizo je lahko iz različnih virov. Lahko jo dodamo, lahko je navzoča na površini substrata, ali lahko pride iz atmosfere. Reakcija teh Silanov vključuje štiri stopnje, prikazane spodaj, s trimetoksi hidrolizibilno skupino X.Hydrolysis water can be from a variety of sources. It can be added, it can be present on the substrate surface, or it can come from the atmosphere. The reaction of these Silanes involves the four steps shown below with the trimethoxy hydrolysable group X.

1. Na začetku pride do hidrolize treh k temu nagnjenih skupin X, vezanih na silicij.1. Initially, the hydrolysis of three silicon-bound X-linked groups occurs.

RSi(OMe)₃ + 3H₂O -> RSi(OH)₃ + 3MeOHRSi (OMe) ₃ + 3H ₂ O -> RSi (OH) ₃ + 3MeOH

2. Nato poteče kondenzacija do oligomerov:2. Condensation to oligomers then expires:

R R R 'I i IR R R 'I and I

3RSi(OH)j - HO- Si-O-Si-O-Si-OH + 2HjO3RSi (OH) j - HO- Si-O-Si-O-Si-OH + 2HjO

OH OH OHOH OH OH

3. Oligomeri se nato vežejo z vodikovimi vezmi z OH skupinami substrata:3. The oligomers then bind with hydrogen bonds to the OH groups of the substrate:

R R R I I IR R R I I I

3RSKOK)j -» HOSto-Si-OStott I · I . I nit on OH3RSKOK) j - »HOSto-Si-OStott I · I. And neither he OH

*.*.

• OH OH OH ‘ .1.,1 .1...,,1 .• OH OH OH '.1., 1 .1 ... ,, 1.

substratsubstrate

4. Končno se med sušenjem ali utrjevanjem tvori kovalentna vez s substratom z istočasno izgubo vode.4. Finally, during drying or curing, a covalent bond with the substrate is formed with simultaneous loss of water.

HO-Si—0—Si—O-Si-OK R λ A HHO-Si-0-Si-O-Si-OK R λ A H

H K H . K K K 0H K H. K K K 0

v.V v —i—u—i— —a.v.V v —i — u — i— —a.

substratsubstrate

R •1. O—Si·R • 1. O — Si ·

O—SiO — Si

OH +2HiQ ·OH + 2HiQ ·

O-HO-H

Na vmesni ploskvi je navadno le ena vez od vsakega silicija organosilana s substratno površino. Obe drugi silanolni skupini sta navzoči bodisi vezani na druge silicijeve atome pripojitvenega sredstva ali sta v prosti obliki.In the intermediate plane, there is usually only one bond from each silicon organosilane with a substrate surface. The two other silanol groups are present either bound to the other silicon atoms of the coupling agent or in free form.

S slipi na osnovi organskega topila lahko tvorimo zelene trakove na površinah nosilca s postopki, znanimi strokovnjakom. Npr.: J.C. Williams, str. 173-197, Ceramic Fabrication Processes, vol. 9 Treatise on Materials Science and Technology, Academic Press (1976) in US patenta št. 3,717,487 in 4,640,905, vse je vključeno tukaj z referenco.Organic solvent based slips can form green strips on the surfaces of the carrier using methods known to those skilled in the art. Eg: J.C. Williams, p. 173-197, Ceramic Fabrication Processes, vol. 9 Treatise on Materials Science and Technology, Academic Press (1976) and US Pat. No. 3,717,487 and 4,640,905, all incorporated herein by reference.

Obstajajo tudi številne tehnike za pretvorbo slipov v tanke filme, zelene plasti in žgane keramike. Verjamemo, da bodo disperzije v smislu predloženega izuma uporabne z manjšimi modifikacijami, kot so npr. izbira prednostnega suspenzijskega medija in veziva, razredČevanje do želene viskoznosti tekočine itd., pri različnih keramičnih postopkih za izdelavo dielektričnih plasti za MLC. Slipe lahko oblikujemo v filme s pršenjem, nanašanjem plasti na gibljivo ploskev iz kaskad ali matrice (kot je zdravniška lopatica) in z drugimi postopki, uporabljenimi v industriji MLC. Ko odstranimo iz filma dovolj nevodne tekočine, zagotovimo kohezivni trdni zeleni film, ki ga lahko prevlečemo v registriranem vzorcu po eni ali obeh straneh s prevodniškim materialom ali prekurzorjem le-tega, kot je npr. črnilo, ki vsebuje fine delce paladija, srebra, niklja ali zlitin paladija in srebra. Taka prevodna črnila lahko vsebujejo fine delce kovine in keramike. Ploskve zelenega filma značilno zložimo, npr. do 250 plasti ali več, in razrežemo na kocke velikosti MLC, ki jih žgemo, da zgori polimerno vezivo in dispergant, ter sintramo, da tvorimo gosto večplastno kondenzatorsko strukturo s fmozmato strukturo dielektričnih plasti. Prevodna kovina, aplicirana na koncih, lahko poveže izmenične prevodne vmesne plasti, ki tvorijo MLC.There are also numerous techniques for converting slips into thin films, green layers, and burning ceramics. It is believed that the dispersions of the present invention will be useful with minor modifications such as e.g. selection of the preferred suspension medium and binder, dilution to the desired viscosity of the liquid, etc., in various ceramic processes for making dielectric layers for MLC. Slips can be molded into films by spraying, depositing layers on a moving cascade or die surface (such as a medical spatula), and other processes used in the MLC industry. When sufficient non-aqueous liquid is removed from the film, a cohesive solid green film is provided which can be coated in a registered pattern on one or both sides with conductive material or a precursor thereof, such as e.g. ink containing fine particles of palladium, silver, nickel or alloys of palladium and silver. Such conductive inks may contain fine particles of metal and ceramics. Green film surfaces are typically folded, e.g. up to 250 layers or more, and cut into MLC sized cubes that are burned to burn the polymer binder and dispersant, and sintered to form a dense multilayer capacitor structure with a phosmous dielectric layer structure. The conductive metal applied at the ends can connect the alternating conductive intermediate layers that form the MLC.

Za lastnost enotne velikosti delcev pri delcih na osnovi barijevega titanata v smislu izuma pričakujemo, da omogoča proizvodnjo novih MLC z ultratankimi plastmi dielektrične keramike, ki ima podmikrometrska zrna. Taki dielektrični materiali naj bi olajšali precejšen porast volumetrične kapacitance. Poleg tega pričakujemo, da bodo imeli MLC nepričakovano visoko prebojno napetost. Odsotnost velikih delcev, npr. večjih od 1 pm, naj bi dopustila komercialno proizvodnjo z visokimi dobitki, npr. večjimi od 98 %, za MLC, ki obsegajo mnogo, npr. več od 40, dielektričnih plasti. Za delce v smislu izuma pričakujemo, da naj bi se prednostno uporabili za proizvodnjo MLC z dielektrično keramično plastjo, ki ima maksimalno velikost zrn 0,9 pm ali manjšo, bolj prednostno maksimalno velikost zrn manjšo od 0,8 pm, najbolj prednostno velikost zrn 0,7 pm ali manjšo.The property of uniform particle size for barium titanate-based particles of the invention is expected to allow the production of new MLCs with ultra-thin dielectric ceramic layers having sub micrometer grains. Such dielectric materials should facilitate a significant increase in volumetric capacitance. In addition, MLCs are expected to have unexpectedly high breakthrough voltages. Absence of large particles, e.g. greater than 1 pm, it is expected to allow high-profit commercial production, e.g. greater than 98% for MLCs comprising many, e.g. more than 40 dielectric layers. The particles of the invention are expected to be preferably used for the production of MLCs with a dielectric ceramic layer having a maximum grain size of 0.9 pm or less, more preferably a maximum grain size of less than 0.8 pm, most preferably a grain size of 0 , 7 pm or less.

Drugi vidiki v smislu izuma zagotavljajo X7R ali Y5V kondenzatorje, ki obsegajo več kot 20 dielektričnih plasti materiala na osnovi barijevega titanata, sintranega v keramični strukturi, pri čemer imajo plasti debelino manjšo od 5 pm, npr. v območju od 2 do 4 pm. Visoko število dielektričnih plasti, npr. 250 ali 500, je lahko prednostno, odvisno od modela MLC. Tanke dielektrične plasti dopuščajo, da MLC s povečanim številom dielektričnih plasti, ki jih je treba uporabiti v MLC s standardno velikostjo ali MLC s fiksiranim številom plasti, prilagodimo za paket z manjšo velikostjo. Rezultat je, da lahko kapacitanco MLC paketa standardne velikosti enostavno povečamo za faktor 5 do 10 ali več.Other aspects of the invention provide X7R or Y5V capacitors comprising more than 20 dielectric layers of barium titanate based material sintered in a ceramic structure, the layers having a thickness of less than 5 pm, e.g. in the range of 2 to 4 p.m. High number of dielectric layers, e.g. 250 or 500 may be preferred depending on the MLC model. Thin dielectric layers allow the MLC with increased number of dielectric layers to be used in standard size MLCs or fixed number MLCs to be adjusted for a smaller size package. The result is that the standard size MLC capacitance of a standard size package can easily be increased by a factor of 5 to 10 or more.

Za zagotavljanje monolitičnih X7R MLC delce, uporabljene za izdelavo dielektrika, prednostno prevlečemo z oksidi niobija, kobalta, niklja in mangana. Za nizko žgalno sposobnost, npr. sintranje pod 1200 °C, lahko prednostna prevleka kovinskega oksida vsebuje tudi bizmutov oksid. Da dosežemo ultratanke dielektrične plasti z debelino manjšo od 4 pm imajo delci prednostno primarno velikost manjšo od 0,3 pm, najbolj prednostno v območju od 0,1 do 0,2 pm. Enakomerna finozmata velikost, npr. manjša od 0,3 pm, zagotavlja v ultratankih dielektričnih plasteh odlično dielektrično jakost s prebitkom 100 V/pm in nizek faktor sipanja. Te lastnosti zagotavljajo povečano gotovost za visoko kapacitanco visokonapetostnih keramičnih kondezatorjev. Sposobnost, da zagotovimo tanke dielektrične plasti, je dopustila proizvodnjo kondenzatorjev, ki imajo 5 do 10-kratno kapacitanco velikosti standardnih primerov. Taki MLC prednostno obsegajo monolitično keramično telo, npr. barij ev titanat, dopiran s kovinskim oksidom, dve skupini prepletenih elektrod, izgorenih v navedenem telesu in ki se raztezajo glede na nasprotna konca telesa ter dve prevodni terminaciji, ki sta v stiku z navedenima skupinama glede na navedena nasprotna konca. MLC z lastnostmi X7R imajo temperaturni koeficient kapacitance v temperaturnem območju od -55 °C do 125 °C, ki ne variira več kot ±15 % od kapacitance pri 25 °C. V prednostnem vidiku predloženega izuma ima keramika v X7R MLC velikost zrn manjšo od 0,3 pm in obsega od 93 do 98 mas.% keramike na osnovi barijevega titanata in od 2 do 7 mas.% drugih kovinskih oksidov.To provide the monolithic X7R MLC, the particles used to make the dielectric are preferably coated with oxides of niobium, cobalt, nickel and manganese. For low burning ability, e.g. sintering below 1200 ° C, the preferred metal oxide coating may also contain bismuth oxide. In order to achieve ultra-thin dielectric layers with a thickness of less than 4 pm, the particles preferably have a primary size of less than 0.3 pm, most preferably in the range of 0.1 to 0.2 pm. Even fine size, e.g. less than 0.3 pm, provides ultra-thin dielectric layers with excellent dielectric strength with an excess of 100 V / pm and low scattering factor. These features provide increased certainty for the high capacitance of high voltage ceramic capacitors. The ability to provide thin dielectric layers allowed the production of capacitors having a capacity of 5 to 10 times the size of standard cases. Such MLCs preferably comprise a monolithic ceramic body, e.g. barium titanate doped with metal oxide, two groups of intertwined electrodes burned in said body and extending towards opposite ends of the body, and two conductive terminations in contact with said groups with respect to said opposite ends. MLCs with X7R properties have a temperature coefficient of capacitance in the temperature range of -55 ° C to 125 ° C, which does not vary more than ± 15% of the capacitance at 25 ° C. In a preferred aspect of the present invention, the ceramics in the X7R MLC have a grain size of less than 0.3 µm and range from 93 to 98% by weight of barium titanate-based ceramics and from 2 to 7% by weight of other metal oxides.

Spodnji Primeri niso namenjeni za omejitev obsega predloženega izuma.The examples below are not intended to limit the scope of the present invention.

PRIMER 1EXAMPLE 1

Za določitev učinkovitosti dispergiranja delcev na osnovi barijevega titanata v nevodnem topilu dispergiramo hidrotermalno izvedene nizko žgalne delce X7R po sušenju v raztopini iz 80 toluena/20 etanola s fosfat estrskim dispergantom.To determine the dispersion efficiency of barium titanate-based particles in a non-aqueous solvent, hydrothermally derived low-burning X7R particles are dispersed after drying in a solution of 80 toluene / 20 ethanol with a phosphate ester dispersant.

X7R formuliran hidrotermalno izveden mokri kolač barijevega titanata, ki vsebuje 72 mas.% trdnih snovi in 28 mas.% vode, posušimo pri 200 °C v vrteči se sušilni enoti pod vakuumom.The X7R formulated hydrothermally derived wet barium titanate cake containing 72% by weight of solids and 28% by weight of water is dried at 200 ° C in a rotary drying unit under vacuum.

Nato zmešamo 9000 g posušenih X7R formuliranih hidrotermalno izvedenih delcev barijevega titanata s 3041,8 g topilne zmesi iz 80 toluena/20 etanola, da tvorimo brozgo. Brozgo nato mešamo z visoko učinkovitim mešalnikom DISPERSATOR™ (Premier Mili) 45 minut, medtem ko dodajamo 363,2 g fosfat estrskega disperganta RHODAFAC RS-410™ (Rhone-Poulenc). Nato izmerimo porazdelitev velikosti delcev dobljene brozge (vzorec 1), rezultati pa so navedeni spodaj in ponazorjeni na Fig. 1A.Then, 9000 g of dried X7R formulated hydrothermally derived barium titanate particles are mixed with 3041.8 g of a 80 toluene / 20 ethanol solvent mixture to form a slurry. The slurry was then mixed with a highly efficient DISPERSATOR ™ (Premier Mili) mixer for 45 minutes while 363.2 g of the RHODAFAC RS-410 ™ ester dispersant phosphate (Rhone-Poulenc) was added. The particle size distribution of the resulting broth is then measured (sample 1), and the results are given below and illustrated in Figs. 1A.

Brozgo nato mešamo v horizontalnem medijskem mlinu PREMIER™ 30 minut (Premier Mili). Nato izmerimo porazdelitev velikosti delcev dobljene brozge (vzorec 2), rezultati so navedeni spodaj in ponazorjeni na Fig. IB.The slurry was then stirred in a PREMIER ™ horizontal media mill for 30 minutes (Premier Mili). The particle size distribution of the resulting broth is then measured (sample 2), the results are given below and illustrated in Figs. IB.

Brozgo nato mešamo v horizontalnem medijskem mlinu PREMIER™ dodatnih 15 minut (skupaj 45 minut). Nato izmerimo porazdelitev velikosti delcev dobljene brozge (vzorec 3), rezultati so navedeni spodaj in ponazorjeni na Fig. 1C. Za vsebnost končnih trdnih snovi ugotovimo, da je 78 mas.%.The slurry was then stirred in a PREMIER ™ horizontal media mill for an additional 15 minutes (45 minutes total). The particle size distribution of the resulting broth is then measured (sample 3), the results are given below and illustrated in Figs. 1C. The final solids content is found to be 78% by weight.

VZOREC SAMPLE Dio Part D50 D50 D90 D90 D90/D10 D90 / D10 1. 45 min. visoko učinkoviti mešalnik 1. 45 min. highly efficient mixer 10,6 10.6 65,3 65,3 225,6 225,6 21,3 21.3 2. 30 min. horizontalni medijski mlin 2. 30 min. horizontal media mill 0,136 0,136 th most common 0,205 0.205 0,347 0.347 2,6 2.6 3. 45 min. horizontalni medijski mlin 3. 45 min. horizontal media mill 0,133 0,133 0,192 0,192 0,356 0.356 2,7 2.7

Zgornji eksperimentalni rezultati ponazarjajo, da lahko posušeni hidrotermalno izvedeni X7R-prašek dispergiramo v topilni zmesi iz 80 toluena/20 etanola z uporabo fosfat estrskega disperganta. To kaže, da lahko proizvedemo brozgo z delci, ki imajo razmerje (D₉₀/D₁₀) manjše od 3, iz hidrotermalno izvedenega X7R-praška v nevodnem topilu z izbiro ustreznega disperganta. Verjamemo, da se lahko uporabijo tudi alternativna topila (kot npr. tista, prikazana zgoraj) z ustreznim dispergantom, da nastanejo brozge z delci, ki imajo razmerje (D_9o/Dio) manjše od 3.The above experimental results illustrate that the dried hydrothermally derived X7R powder can be dispersed in a solvent mixture of 80 toluene / 20 ethanol using a phosphate ester dispersant. This indicates that a particle broth having a ratio (D ₉₀ / D ₁₀ ) of less than 3 can be produced from a hydrothermally derived X7R powder in a non-aqueous solvent by selecting the appropriate dispersant. It is believed that alternative solvents (such as those shown above) with a suitable dispersant may also be used to form particle broths having a ratio (D _9o / Dio) of less than 3.

Čeprav je iz rezultatov razvidno, da lahko X7R-formuliran hidrotermalno izveden mokri kolač barijevega titanata posušimo in redispergiramo v nevodnem topilu, da tvorimo brozgo z delci, ki imajo razmerje (D_9O/Dio) manjše od 3, pa se posušeni delci oblikujejo v relativno močno aglomerirane delce, ki se ne deaglomerirajo učinkovito z visoko učinkovitim mešanjem. Disperzije, narejene iz takih, suhih, aglomeriranih delcev na osnovi barijevega titanata, ki imajo podmikrometrsko primarno velikost delcev, potrebujejo v bistvu dolgotrajno medijsko mletje, da zagotovimo delce v podmikrometrskem območju. Verjamemo tudi, da segrevanje, uporabljeno za sušenje mokrega kolača, posebno če ga izvedemo pri visoki temperaturi in/ali v zelo dolgi časovni periodi, lahko potencialno vpliva na prevleko na delcih na osnovi barijevega titanata. Taki potencialni negativni učinki vključujejo npr. vezanje vodne oksidne prevlečne plasti med delci, kar bi lahko postalo težavno za ločevanje brez lupljenja ali drobljenja prevlečne plasti iz nekaterih delcev na osnovi barijevega titanata.Although the results show that the X7R-formulated hydrothermally derived wet barium titanate cake can be dried and redispersed in a non-aqueous solvent to form a broth with particles having a ratio (D _9O / Dio) of less than 3, however, the dried particles are formed into a relatively heavily agglomerated particles that do not deagglomerate effectively with highly efficient mixing. Dispersions made from such dry, agglomerated barium titanate-based particles having a submicrometer primary particle size need substantially long-lasting media milling to provide particles in the submicrometer range. It is also believed that heating used for drying a wet cake, especially if carried out at high temperature and / or for a very long period, can potentially affect the coating on barium titanate based particles. Such potential negative effects include e.g. bonding the aqueous oxide coating layer between the particles, which may become difficult to separate without peeling or crushing the coating layer from some barium titanate based particles.

PRIMER 2EXAMPLE 2

Za določitev učinkovitosti dispergiranja delcev na osnovi barijevega titanata v nevodnem topilu izpostavimo hidrotermalno izvedene nizko žgalne X7R-delce postopku izmenjave topila, nato pa disperziji s fosfat estrskim dispergantom. Hidrotermalno izvedeni nizko žgalni X7R-delci so na začetku v vodi. Vodo nadomestimo s topilno zmesjo iz 80 toluena/20 etanola.To determine the dispersion efficiency of barium titanate-based particles in a non-aqueous solvent, hydrothermally low-firing X7R particles are exposed to the solvent exchange process, followed by phosphate ester dispersion. Hydrothermal low-firing X7R particles are initially in water. Water is replaced by a solvent mixture of 80 toluene / 20 ethanol.

Iz 1 kg X7R-formuliranega hidrotermalno izvedenega mokrega kolača barijevega titanata, ki vsebuje 72 mas.% trdnih snovi in 28 mas.% vode, naredimo brozgo z 1 kg etanola. Brozgo damo nato v Buchnerjev lij, ki vsebuje ultrafiltracijsko membrano, ki jo uporabimo kot filtrimi medij. Etanol, filtriran skozi tvorjeni mokri kolač, in razpoke, ki se tvorijo, mehansko eliminiramo. Ko je prva filtracija skoraj končana, prelijemo preko 1 kg etanola in ga filtriramo skozi mokri kolač. To stopnjo ponovimo, potem ko je druga filtracija skoraj končana.From 1 kg of X7R-formulated hydrothermally derived wet barium titanate cake containing 72% by weight of solids and 28% by weight of water, make a slurry with 1 kg of ethanol. The slurry was then placed in a Buchner funnel containing an ultrafiltration membrane, which was used as a filter medium. The ethanol filtered through the wet cake formed and the cracks that formed are mechanically eliminated. When the first filtration is almost complete, pour over 1 kg of ethanol and filter it through a wet cake. We repeat this step after the second filtration is almost complete.

Po končani filtraciji etanola dodamo 1 kg toluena in ga filtriramo skozi mokri kolač. Mokri kolač nato pustimo, da se posuši do vsebnosti trdnih snovi 75 mas.%.After the ethanol filtration is complete, 1 kg of toluene is added and filtered through a wet cake. The wet cake is then allowed to dry to a solids content of 75% by weight.

Dobljeni mokri kolač (859,3 g) nato zmešamo z visoko učinkovitim mešalnikom DISPERSATOR™ (Premier Mili) in 26,81 g fosfat estrskega disperganta RHODAFAC RS-410™ (Rhone-Poulenc). Visoko učinkoviti mešalnik pustimo, da meša mokri kolač 10 minut (vzorec 4) in 30 minut (vzorec 5). Nato izmerimo porazdelitev velikosti delcev; rezultati so navedeni spodaj in ponazorjeni na Fig. 2A in Fig. 2B.The resulting wet cake (859.3 g) was then mixed with a highly efficient DISPERSATOR ™ mixer (Premier Mili) and 26.81 g RHODAFAC RS-410 ™ ester dispersant phosphate (Rhone-Poulenc). Allow the high-performance mixer to stir the wet cake for 10 minutes (sample 4) and 30 minutes (sample 5). We then measure the particle size distribution; the results are given below and illustrated in FIG. 2A and FIG. 2B.

VZOREC SAMPLE D10 D10 D50 D50 D90 D90 D90/D10 D90 / D10 4. 10 min. visoko učinkoviti mešalnik 4. 10 min. highly efficient mixer 0,381 0,381 0,869 0.869 1,908 1,908 th most common 5,0 5.0 5. 30 min. visoko učinkoviti mešalnik 5. 30 min. highly efficient mixer 0,351 0.351 0,764 0.764 1,805 1,805 th most common 5,1 5.1

Zgornji eksperimentalni rezultati ponazarjajo, da lahko izmenjavo topila uporabimo, da nadomestimo vodna topila z nevodnimi, če je želeno, nato pa dodamo ustrezni dispergant, da dosežemo sprejemljivo razmerje (D90/D10). S postopkom izmenjave topila zagotovimo disperzije, ki imajo mnogo ožje porazdelitve velikosti delcev, le z visoko učinkovitim mešanjem (brez horizontalnega medijskega mlina) v krajšem času, kot pa je to pri disperzijah, ki jih dobimo iz posušenih praškov (kot je prikazano v Primeru 1, vzorec 1). Verjamemo, da lahko razmerje (D_9O/Dio), manjše od 3, iz hidrotermalno izvedenega X7R-praška v nevodnem topilu (iz postopka izmenjave topila) dosežemo z izbiro ustreznega disperganta z manj nadaljnjega procesiranja v horizontalnem medijskem mlinu (odvisno od drugih faktorjev, kot je npr. velikost šarže). Verjamemo tudi, da lahko uporabimo alternativna topila (npr. tista, prikazana zgoraj) z ustreznim dispergantom, da tvorimo brozge z delci, ki imajo sprejemljiva razmerja (D90/D10).The above experimental results illustrate that solvent exchange can be used to replace aqueous solvents with non-aqueous ones, if desired, and then the appropriate dispersant is added to achieve an acceptable ratio (D90 / D10). With the solvent exchange process, dispersions having a much narrower particle size distribution are only ensured by highly efficient mixing (without horizontal media mill) in a shorter time than is the case with the dispersions obtained from dried powders (as shown in Example 1 , sample 1). We believe that a ratio (D _9O / Dio) of less than 3 from a hydrothermally derived X7R powder in a non-aqueous solvent (from the solvent exchange process) can be achieved by selecting the appropriate dispersant with less further processing in a horizontal media mill (depending on other factors, such as batch size). It is also believed that alternative solvents (e.g. those shown above) with a suitable dispersant can be used to form particle broths having acceptable ratios (D90 / D10).

Poleg zgoraj navedenega se s postopkom izmenjave topila izognemo potencialnim negativnim učinkom na prevlečno plast na delcih na osnovi barijevega titanata pri sušenju mokrega kolača, posebno pri visoki temperaturi in/ali v dolgi časovni periodi.In addition to the above, the solvent exchange process avoids the potential negative effects on the barium titanium based particulate coating of drying the wet cake, especially at high temperature and / or over a long period of time.

PRIMER 3EXAMPLE 3

Za določitev učinkovitosti uporabe silanskih pripojitvenih sredstev, da izboljšajo disperzijo delcev na osnovi barijevega titanata v nevodnem topilu, prevlečemo hidrotermalno izvedeni X7R-prašek z uporabo metiltrimetoksisilana kot pripojitvenega sredstva.To determine the efficiency of using silane coupling agents to improve the dispersion of barium titanate-based particles in a non-aqueous solvent, hydrothermally derived X7R powder is coated using methyltrimethoxysilane as the coupling agent.

Metiltrimetoksisilan zagotavlja hidrofobno prevleko in ga apliciramo na površino X7R formuliranih hidrotermalno izvedenih delcev BaTiO₃ takole:Methyltrimethoxysilane provides a hydrophobic coating and is applied to the surface of X7R formulated hydrothermally derived BaTiO ₃ particles as follows:

1. 95 ml etanola zmešamo s 5 ml deionizirane vode. pH raztopine naravnamo na 4 z 0,1 m HNO3. Metiltrimetoksisilan (5 g) dodamo v nakisano etanolno/vodno raztopino in mešamo 5 minut, da dopustimo hidrolizo treh k temu nagnjenih metoksi skupin.1. Mix 95 ml of ethanol with 5 ml of deionized water. The pH of the solution was adjusted to 4 with 0.1 m HNO3. Methyltrimethoxysilane (5 g) was added to the acidified ethanol / aqueous solution and stirred for 5 minutes to allow hydrolysis of the three methoxy prone groups.

2. X7R-formulirani mokri kolač BaTiO₃ (70 mas.% trdnih snovi) razredčimo z 250 ml etanola in emulgiramo pri 7000 vrt./min 1 minuto.2. Dilute the X7R-formulated BaTiO ₃ wet cake (70% by weight of solids) with 250 ml of ethanol and emulsify at 7000 rpm for 1 minute.

3. Etanolno/vodno raztopino, ki vsebuje hidrolizirano silansko pripojitveno sredstvo, dodamo v brozgo, ki vsebuje X7R-formulirane hidrotermalne delce in emulgiramo 30 sekund pri 7000 vrt./min.3. An ethanol / aqueous solution containing the hydrolyzed silane coupling agent is added to the broth containing X7R-formulated hydrothermal particles and emulsified for 30 seconds at 7000 rpm.

4. Dobljeno brozgo pustimo, da se suši na zraku 24 ur, da odstranimo prebitek nosilca. Dobljeni material damo v vakuumsko sušilno peč pri 80 °C za 12 ur, da popolnoma posušimo prašek.4. Allow the resulting slurry to air-dry for 24 hours to remove excess carrier. The resulting material was placed in a vacuum oven at 80 ° C for 12 hours to completely dry the powder.

Razredčitev X7R-formuliranega mokrega kolača z etanolom ima za posledico zelo viskozno suspenzijo po emulgiranju. Dobljeni posušeni prašek preizkusimo z uporabo preizkusa za potopitev/splavanje v vodi, da določimo, ali je hidrofobna prevleka ustrezno vezana na površini praška. Prašek previdno zmeljemo v terilnici s pestilom in nato razpršimo po vodi v čaši. Na začetku delci splavajo na površino vode, po mešanju pa se nekateri delci potopijo v raztopino. Kadar X7R-formulirani mokri kolač na začetku razredčimo z etanolom, dosežemo le delno prevleko površine. Ta delna prevleka je verjetno rezultat visoke viskoznosti, ki nastane, kadar X7R-mokri kolač na začetku razredčimo z etanolom. Visoka viskoznost ima za posledico prevleko aglomeratov s tendenco za porušitev, kadar jih mešamo pri preizkusu za potopitev/splavanj e.Dilution of the X7R-formulated wet cake with ethanol results in a very viscous suspension after emulsification. The dried powder obtained is tested using a dipping / rafting test in water to determine whether the hydrophobic coating is properly bonded to the powder surface. Carefully grind the powder in a mortar with the pestle and then spread it over the water in a beaker. Initially, the particles float to the surface of the water, and after mixing, some particles are immersed in the solution. When the X7R-formulated wet cake is initially diluted with ethanol, only a partial coating of the surface is achieved. This partial coating is probably the result of the high viscosity that occurs when the X7R wet cake is initially diluted with ethanol. High viscosity results in the coating of agglomerates with a tendency to burst when mixed in the immersion / rafting test e.

PRIMER 4EXAMPLE 4

Za določitev učinkovitosti uporabe silanskih pripojitvenih sredstev, da izboljšajo disperzijo delcev na osnovi barijevega titanata v nevodnem topilu, prevlečemo hidrotermalno izveden X7R-prašek z metiltrimetoksisilanom kot pripojitvenim sredstvom.To determine the efficacy of using silane coupling agents to improve the dispersion of barium titanate-based particles in a non-aqueous solvent, hydrothermal X7R-powder is coated with methyltrimethoxysilane as the coupling agent.

Metiltrimetoksisilan zagotavlja hidrofobno prevleko in ga apliciramo na površino X7R- formuliranih hidrotermalno izvedenih delcev BaTiO₃ takole:Methyltrimethoxysilane provides a hydrophobic coating and is applied to the surface of X7R-formulated hydrothermally derived BaTiO ₃ particles as follows:

1. 95 ml metanola zmešamo s 5 ml deionizirane vode. pH raztopine naravnamo na z 0,1 m HNO₃. Metiltrimetoksisilan (5 g) damo v nakisano metanolno/vodno raztopino in mešamo 5 minut, da dopustimo hidrolizo treh k temu nagnjenih metoksi skupin.1. Mix 95 ml of methanol with 5 ml of deionized water. Adjust the pH of the solution to 0.1 m HNO ₃ . Methyltrimethoxysilane (5 g) was added to the acidified methanol / aqueous solution and stirred for 5 minutes to allow hydrolysis of the three methoxy prone groups.

2. X7R-formuliran BaTiO₃ mokri kolač (70 mas.% trdnih snovi) razredčimo z 250 ml metanola in emulgiramo pri 7000 vrt./min 1 minuto.2. Dilute the X7R-formulated BaTiO ₃ wet cake (70% by weight of solids) with 250 ml of methanol and emulsify at 7000 rpm for 1 minute.

3. Metanolno/vodno raztopino, ki vsebuje hidrolizirano silansko pripojitveno sredstvo, damo v brozgo, ki vsebuje X7R-formulirane hidrotermalne delce in emulgiramo 30 sekund pri 7000 vrt./min.3. The methanol / aqueous solution containing the hydrolyzed silane coupling agent is placed in a broth containing X7R-formulated hydrothermal particles and emulsified for 30 seconds at 7000 rpm.

4. Dobljeno brozgo pustimo, da se suši na zraku 24 ur, da odstranimo prebitek nosilca. Dobljeni material damo nato v vakuumsko sušilno peč pri 80 °C za 12 ur, da popolnoma posušimo prašek.4. Allow the resulting slurry to air-dry for 24 hours to remove excess carrier. The resulting material was then placed in a vacuum oven at 80 ° C for 12 hours to completely dry the powder.

Dobljeni posušeni prašek preizkusimo z uporabo preizkusa za potopitev/splavanje v vodi, da določimo, ali je hidrofobna prevleka zadosti vezana na površini praška. Prašek rahlo zmeljemo v terilnici s pestilom in nato razpršimo po površini vode v čaši. Delci splavajo na površino vode in ostanejo na površini celo med mešanjem. Kadar X7R- formulirani mokri kolač na začetku razredčimo z metanolom dosežemo popolno prevleko površine. Razredčitev X7R-formuliranega mokrega kolača z metanolom ima za posledico dobro dispergirano brozgo z nizko viskoznostjo. To omogoča popolno prevleko delcev, kadar dodamo hidrolizirano raztopino silanskega pripojitvenega sredstva.The dried powder obtained is tested using a dipping / rafting test in water to determine whether the hydrophobic coating is sufficiently bonded to the surface of the powder. Grind the powder gently in a mortar with pestle and then spread it over the surface of the water in a beaker. The particles float to the surface of the water and remain on the surface even during mixing. When the X7R-formulated wet cake is initially diluted with methanol, a complete surface coating is achieved. Dilution of the X7R-formulated wet cake with methanol results in a well-dispersed low-viscosity broth. This allows the particles to be completely coated when a hydrolysed solution of the silane coupling agent is added.

Strokovnjaki bodo zlahka upoštevali, da so vsi tukaj navedeni parametri mišljeni le kot zgledi in da so dejanski parametri odvisni od specifične aplikacije, za katere se postopki in naprave v smislu izuma uporabijo. Zato je treba razumeti, da so predhodne izvedbe predstavljene le s Primeri in da je možno na osnovi priloženih zahtevkov in njihovih ekvivalentov izum izvesti tudi drugače, kot je specifično opisan.It will be readily appreciated by those skilled in the art that all of the parameters herein are intended to be exemplary only and that the actual parameters depend on the specific application for which the processes and devices of the invention are used. Therefore, it should be understood that the foregoing embodiments are presented by way of Examples only and that the invention may be carried out in a manner other than as specifically described, based on the appended claims and their equivalents.

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LJUBLJANA, ČOPOVA 14LJUBLJANA, ČOPOVA 14

Claims (38)

PATENTNI ZAHTEVKIPATENT APPLICATIONS 1. Brozga, disperzija ali slip, ki obsega delce na osnovi barijevega titanata, dispergirane v nevodnem mediju, pri čemer imajo delci prevleko, ki obsega kovinski oksid, kovinski vodni oksid, kovinski hidroksid ali organsko kislinsko sol kovine, drugačne od barija ali titana, pri čemer ima vsaj 90 % delcev velikost manjšo od 0,9 μπι, kadar jih dispergiramo z visoko učinkovitim mešanjem.A slurry, dispersion or slip comprising barium titanate-based particles dispersed in a non-aqueous medium, the particles having a coating comprising a metal oxide, a metal oxide, a metal hydroxide or an organic acid salt of a metal other than barium or titanium, with at least 90% of the particles having a size smaller than 0.9 μπι when dispersed by highly efficient mixing. 2. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da imajo delci decilno razmerje porazdelitve velikosti delcev D_9O/Dio manjše od 4.Spray, dispersion or slip according to claim 1, characterized in that the particles have a decay particle size distribution ratio D _9O / Dio of less than 4. 3. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da imajo delci decilno razmerje porazdelitve velikosti delcev D90/D10 manjše od 3.A slurry, dispersion or slip according to claim 1, characterized in that the particles have a particle size distribution ratio D90 / D10 of less than 3. 4. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da imajo delci decilno razmerje porazdelitve velikosti delcev D₉₀/Di₀ manjše od 2,5.4. Splash, dispersion or slip according to claim 1, characterized in that the particles have a particle size distribution ratio D ₉₀ / Di _{0 of} less than 2.5. 5. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da ima vsaj 90 % delcev velikost manjšo od 0,8 pm, kadar so delci dispergirani z visoko učinkovitim mešanjem.A slurry, dispersion or slip according to claim 1, characterized in that at least 90% of the particles have a size smaller than 0.8 pm when the particles are dispersed by highly efficient mixing. 6. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da ima vsaj 90 % delcev velikost manjšo od 0,7 pm, kadar so delci dispergirani z visoko učinkovitim mešanjem.6. A slurry, dispersion or slip according to claim 1, characterized in that at least 90% of the particles have a size smaller than 0.7 pm when the particles are dispersed by highly efficient mixing. 7. Brozga, disperzija ali slip, po zahtevku 1, označen s tem, da ima vsaj 90 % delcev velikost manjšo od 0,6 pm, kadar so delci dispergirani z visoko učinkovitim mešanjem.7. A slurry, dispersion or slip according to claim 1, characterized in that at least 90% of the particles have a size smaller than 0.6 pm when the particles are dispersed by highly efficient mixing. 8. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da ima vsaj 90 % delcev velikost manjšo od 0,5 pm, kadar so delci dispergirani z visoko učinkovitim mešanjem.8. A slurry, dispersion or slip according to claim 1, characterized in that at least 90% of the particles have a size smaller than 0.5 pm when the particles are dispersed by highly efficient mixing. 9. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da ima vsaj 90 % delcev velikost manjšo od 0,4 pm, kadar so delci dispergirani z visoko učinkovitim mešanjem.9. A slurry, dispersion or slip according to claim 1, characterized in that at least 90% of the particles have a size smaller than 0.4 pm when the particles are dispersed by highly efficient mixing. 10. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da ima vsaj 90 % delcev velikost manjšo od 0,3 pm, kadar so delci dispergirani z visoko učinkovitim mešanjem.10. A slurry, dispersion or slip according to claim 1, characterized in that at least 90% of the particles have a size smaller than 0.3 pm when the particles are dispersed by highly efficient mixing. 11. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da obsega vsaj 50 mas.% delcev.11. A slurry, dispersion or slip according to claim 1, characterized in that it comprises at least 50% by weight of particles. 12. Brozga, dipserzija ali slip po zahtevku 1, označen s tem, da obsega vsaj 60 mas.% delcev.12. A slurry, dispersion or slip according to claim 1, characterized in that it comprises at least 60% by weight of particles. 13. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da obsega vsaj 75 mas.% delcev.A slurry, dispersion or slip according to claim 1, characterized in that it comprises at least 75% by weight of particles. 14. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da nadalje obsega dispergant.14. A slurry, dispersion or slip according to claim 1, further comprising a dispersant. 15. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da delci vključujejo prevleko pripojitvenega sredstva na površini delcev.15. A slurry, dispersion or slip according to claim 1, characterized in that the particles include a coating of the coupling agent on the surface of the particles. 16. Brozga, disperzija ali slip po zahtevku 15, označen s tem, da pripojitveno sredstvo obsega organosilan.16. Splash, dispersion or slip according to claim 15, characterized in that the coupling agent comprises organosilane. 17. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da nadalje obsega med 3 in 20 mas.% vezivnega sestavka, ki obsega raztopljen ali suspendiran polimer, ki tvori film.17. A slurry, dispersion or slip according to claim 1, further comprising between 3 and 20% by weight of a binder composition comprising a dissolved or suspended film forming polymer. 18. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da so v bistvu vsi delci enakoosni ali sferični.18. A slurry, dispersion or slip according to claim 1, characterized in that substantially all particles are equiaxed or spherical. 19. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da so delci proizvedeni hidrotermalno.A slurry, dispersion or slip according to claim 1, characterized in that the particles are hydrothermally produced. 20. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da prevleka prekriva glavni del površine delcev.20. A slurry, dispersion or slip according to claim 1, characterized in that the coating covers the main part of the particle surface. 21. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da prevleka obsega vsaj eno kovino, izbrano iz skupine, ki jo sestavljajo: bizmut, litij, magnezij, kalcij, stroncij, skandij, cirkonij, hafnij, vanadij, niobij, tantal, volfram, mangan, kobalt, nikelj, cink, bor, silicij, antimon, kositer, itrij, lantan, svinec ali lantanidni element.21. A slurry, dispersion or slip according to claim 1, characterized in that the coating comprises at least one metal selected from the group consisting of: bismuth, lithium, magnesium, calcium, strontium, scandium, zirconium, hafnium, vanadium, niobium, tantalum, tungsten, manganese, cobalt, nickel, zinc, boron, silicon, antimony, tin, yttrium, lanthanum, lead or lanthanide element. 22. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da nevodni medij obsega organsko topilo.A slurry, dispersion or slip according to claim 1, characterized in that the non-aqueous medium comprises an organic solvent. 23. Brozga, disperzija ali slip po zahtevku 22, označen s tem, da nevodni medij obsega zmes organskega topila in vode.A slurry, dispersion or slip according to claim 22, characterized in that the non-aqueous medium comprises a mixture of an organic solvent and water. 24. Brozga, disperzija ali slip po zahtevku 22, označen s tem, da organsko topilo izberemo iz skupine, ki jo sestavljajo: benzen, metil etil keton, aceton, ksilen, metanol, etanol, propanol, 1,1,1-trikloroetan, tetrakloroetilen, amil acetat, 2,2,4-trietil pentandiol-l,3-monoizobutirat, toluen, metilen klorid, terpentin, etil alkohol, bromoklorometan, butanol, diaceton, metil izobutil keton, cikloheksanon, metil alkohol, n-propil alkohol, izopropil alkohol, n-butil alkohol, n-oktil alkohol, benzil alkohol, glicerol, etilen glikol, benzaldehid, propionska kislina, n-oktanojska kislina, etilacetat, butilbutirat, n-heksan in njihove zmesi.24. Splash, dispersion or slip according to claim 22, characterized in that the organic solvent is selected from the group consisting of: benzene, methyl ethyl ketone, acetone, xylene, methanol, ethanol, propanol, 1,1,1-trichloroethane, tetrachloroethylene, amyl acetate, 2,2,4-triethyl pentanediol-1,3-monoisobutyrate, toluene, methylene chloride, turpentine, ethyl alcohol, bromochloromethane, butanol, diacetone, methyl isobutyl ketone, cyclohexanone, methyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, n-octyl alcohol, benzyl alcohol, glycerol, ethylene glycol, benzaldehyde, propionic acid, n-octanoic acid, ethyl acetate, butylbutyrate, n-hexane and mixtures thereof. 25. Brozga, disperzija ali slip po zahtevku 24, označen s tem, da je organsko topilo etanol.25. A slurry, dispersion or slip according to claim 24, characterized in that the organic solvent is ethanol. 26. Brozga, disperzija ali slip po zahtevku 1, označen s tem, da nevodni medij obsega zmes iz več kot enega organskega topila.26. Splash, dispersion or slip according to claim 1, characterized in that the non-aqueous medium comprises a mixture of more than one organic solvent. 27. Brozga, disperzija ali slip po zahtevku 26, označen s tem, da je zmes izbrana iz skupine, ki jo sestavljajo: 72 % trikloretilena/28 % etil alkohola, 66 % metil etil ketona/34 % etil alkohola, 70 % metil etil ketona/30 % etil alkohola, 59 % metil etil ketona/41 % etil alkohola, 50 % metil etil ketona/50 % etil alkohola, 80 % toluena/20 % etanola, 80 % toluena/20 % etil alkohola, 70 % toluena/30 % etil alkohola, 60 % toluena/40 % etil alkohola, 70 % izopropil alkohola/30 % metil etil ketona, 40 % metil etil ketona/60 % etil alkohola in njihove zmesi.27. Splash, dispersion or slip according to claim 26, characterized in that the mixture is selected from the group consisting of: 72% trichlorethylene / 28% ethyl alcohol, 66% methyl ethyl ketone / 34% ethyl alcohol, 70% methyl ethyl ketone / 30% ethyl alcohol, 59% methyl ethyl ketone / 41% ethyl alcohol, 50% methyl ethyl ketone / 50% ethyl alcohol, 80% toluene / 20% ethanol, 80% toluene / 20% ethyl alcohol, 70% toluene / 30% ethyl alcohol, 60% toluene / 40% ethyl alcohol, 70% isopropyl alcohol / 30% methyl ethyl ketone, 40% methyl ethyl ketone / 60% ethyl alcohol and mixtures thereof. 28. Brozga, disperzija ali slip po zahtevku 27, označen s tem, daje nevodni medij 80 % toluena/20 % etanola.28. The slurry, dispersion or slip according to claim 27, wherein the non-aqueous medium is 80% toluene / 20% ethanol. 29. Postopek za tvorbo brozge, disperzije ali slipa, označen s tem, da obsega:29. A method for forming a slurry, dispersion or slurry, characterized in that it comprises: tvorbo brozge delcev na osnovi barijevega titanata v vodnem mediju s hidrotermalnim postopkom tvorbo prevleke na delcih, ki obsega kovinski oksid, kovinski vodni oksid, kovinski hidroksid ali organsko kislinsko sol kovine, drugačne od barija ali titana nadomeščanje vodnega medija z nevodnim in dispergiranje delcev v nevodnem mediju z visoko učinkovitim mešanjem.formation of barium titanate-based particle slurry in an aqueous medium by hydrothermal process forming a particle coating comprising a metal oxide, a metal oxide, a metal hydroxide or an organic acid salt of a metal other than barium or titanium substitution of an aqueous medium with non-aqueous and dispersing particles in a non-aqueous medium with highly efficient mixing. 30. Postopek po zahtevku 29, označen s tem, da delce dispergiramo v nevodnem mediju z visoko učinkovitim mešanjem, dokler 90 % delcev nima velikosti manjše od 0,9 pm.30. A method according to claim 29, characterized in that the particles are dispersed in a non-aqueous medium with high-efficiency mixing until 90% of the particles have a size smaller than 0.9 pm. 31. Postopek po zahtevku 29, označen s tem, da nadomestitev vodnega medija z nevodnim obsega postopek izmenjave topila.31. The method of claim 29, wherein the replacement of the aqueous medium with a non-aqueous one comprises a solvent exchange process. 32. Postopek po zahtevku 31, označen s tem, da postopek izmenjave topila obsega:32. The method of claim 31, wherein the solvent exchange process comprises: filtriranje brozge delcev na osnovi barijevega titanata v vodnem mediju in uvajanje filtriranih delcev v nevodni medij.filtering the barium titanate-based particle slurry in aqueous medium and introducing the filtered particles into the non-aqueous medium. 33. Postopek po zahtevku 29, označen s tem, da nadomestitev vodnega medija z nevodnim obsega postopek za destilacijo.33. The process of claim 29, wherein the replacement of the aqueous medium with a non-aqueous one comprises a process for distillation. 34. Postopek po zahtevku 33, označen s tem, da postopek za destilacijo obsega:34. The process of claim 33, wherein the distillation process comprises: dodajanje nevodnega medija v brozgo delcev na osnovi barijevega titanata v vodnem mediju in uparevanje vodnega medija.adding non-aqueous medium to a barium titanate-based particle broth in aqueous medium and evaporating the aqueous medium. 35. Postopek po zahtevku 29, označen s tem, da nadalje obsega nanašanje pripojitvenega sredstva na površino delcev po nadomestitvi vodnega medija z nevodnim.The method of claim 29, further comprising applying the coupling agent to the particle surface after replacing the aqueous medium with a non-aqueous one. 36. Postopek po zahtevku 29, označen s tem, da nadalje obsega apliciranje pripojitvenega sredstva na površino delcev po tvorbi prevleke na delcih in pred nadomestitvijo vodnega medija z nevodnim.The method of claim 29, further comprising applying the coupling agent to the particle surface after forming the particle coating and before replacing the aqueous medium with a non-aqueous one. 37. Postopek po zahtevku 35 ali 36, označen s tem, da pripojitveno sredstvo obsega organosilan.A method according to claim 35 or 36, characterized in that the coupling agent comprises organosilane. 38. Postopek za tvorbo brozge, disperzije ali slipa, označen s tem, da obsega: dispergiranje delcev na osnovi barijevega titanata v nevodnem mediju z visoko učinkovitim mešanjem, dokler 90 % delcev nima velikosti manjše od 0,9 pm, pri čemer imajo delci prevleko, ki obsega kovinski oksid, kovinski vodni oksid, kovinski hidroksid ali organsko kislinsko sol kovine, drugačne od barija ali titana.38. A process for forming a slurry, dispersion or slurry, characterized in that it comprises: dispersing barium titanate-based particles in a non-aqueous medium with high-efficiency mixing until 90% of the particles have a size of less than 0.9 pm, the particles having a coating , comprising a metal oxide, a metal aqueous oxide, a metal hydroxide or an organic acid salt of a metal other than barium or titanium.