JPS605063A - Ceramic composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates to moldable ceramic compositions, particularly compositions in which the ceramic component is a dielectric material.

BACKGROUND OF THE INVENTION Multilayer capacitors are most widely used in ceramic capacitors in thin film hybrid microelectric systems due to their high volumetric efficiency and resulting small dimensions. These carriers are manufactured by stacking ceramic substrate thin plates with appropriate electrode patterns printed on their surfaces and firing them. Each electrode/gut layer is formed so as to be exposed alternately at each edge of the assembly. The exposed ends of the electrodes/turns are coated with a conductive material to connect all the layers, thus forming a group of parallel connected capacitors in the stack. This type of capacitor is often referred to as a monolithic capacitor.

The thin sheets of ceramic substrate used in the manufacture of multilayer capacitors are commonly referred to as "green tape" and include thin layers of fine dielectric particles interconnected by organic polymeric substances. Green tape is a slurry of dielectric particles dispersed in a solution of polymer, plasticizer, and solvent.
- slipcasting onto a carrier such as polypropylene, Mylar® polyester film or stainless steel;
L, which is then manufactured by adjusting the thickness of the molded film by passing the molding slurry under a doctor bread.

T102-Glass, (Baffr)TiO3, (Ba,
Pb) Ties - Glass, PbZr0. TiO,-B
aTiO3-pb monosilicate glass, BaTiO3
B1703+ ZnO, BaTiO3-Cd yW C
'Silicate glass, BaT105- BaAt2-5
iOB+BaT10. -Pb2Bi4Ti50. A wide variety of capacitor materials can be made by the above method, including B and many others.

Traditionally, various polymeric materials have been used as binders in green tape; for example, poly(vinyl butyral), poly(vinyl acetate), poly(vinyl alcohol);
Cellulosic polymers such as methylcellulose, ethylcellulose, hydroxyethylcellulose, methylhydroxyethylcellulose; atactic polypropylene, polyethylene; silicone polymers such as poly(methylsiloxane), poly(methylphenylsiloxane); polystyrene, butadiene/polystyrene copolymers, poly( polyamides, high molecular weight polyethers, copolymers of ethylene oxide and propylene oxide; polyacrylamides; and various acrylic polymers such as sodium polyacrylates, poly(lower alkyl acrylates), poly(lower alkyl methacrylates) , and copolymers and multipolymers of lower alkyl acrylate and methacrylate. Copolymers of ethyl methacrylate and methyl acrylate and terpolymers of ethyl acrylate, methyl methacrylate and methacrylic acid have previously been used as binders for slip molding materials.

Mainly due to technical reasons for slip molding equipment, the ceramic dispersion system (slip) for molding dielectric films is
00-4000 cp, preferably 500-3000
cp (Brookfield LVT Viscometer A2 spindle, 6 rpm * 25°C). Within these viscosity limits, it is preferred to use a molding slip containing the highest content of ceramic material and the lowest content of polymeric binder and solvent. This method allows the amount of material that must be removed by pyrolysis to be kept to a minimum and also reduces problems with delamination of the layers. To date, a persistent problem has been that the viscosity of polymers that have a high enough molecular weight to provide suitably durable tapes and require the use of relatively small amounts of binder has been too high. High viscosity polymers are critical in limiting the amount of dielectric solid that can be used. Still, the ratio of organic material to dielectric solid will have to be increased and more organic material will have to be pyrolyzed.

On the other hand, low molecular weight polymers which have a suitably low viscosity and therefore may contain higher amounts of dielectric solids provide only very brittle layers.

The above-mentioned drawbacks of the rheological properties of conventional ceramic suspensions used as constituent molding slips of the invention are substantially overcome by the present invention. The present invention comprises: (a) finely divided particles of ceramic solid; (b) 0 to 100 by weight - carbon atoms 1 to 8;
of an alkyl methacrylate, a multipolymer of 100 to 0% by weight of a C1 to 8 alkyl acrylate and 0 to 5% by weight of an ethylenically unsaturated carganic acid or amine, and (c) a non-aqueous organic solvent: A moldable ceramic composition comprising a dispersion of: The above multipolymer has a number average molecular weight (Mn) of 50.000 to 100,
000, weight average molecular weight (Mw) is 150,000 to 3
50.000 and the ratio of Mw to Mn is not greater than 5.5, the total amount of unsaturated carboxylic acid or amine in the multipolymer mixture is from 0.2 to 2.0 wt. If present, the plasticizer has a glass transition temperature of -30°C to +45°C.

Furthermore, the present invention provides a method of casting a thin layer of the above composition on a flexible substrate such as a steel belt or a polymeric film;
The present invention relates to a method of manufacturing green tape comprising heating the thin layer to remove volatile solvents therefrom.

Furthermore, the present invention provides a capacitor manufactured by laminating and firing the green tapes described above, each of which has a suitable electrode pattern formed on its surface by an offset method or the like. The ends of the electrodes are formed so as to be exposed alternately from opposite edges of the laminated structure, and the exposed ends are electrically connected by a conductive coating.

Detailed Description of Construction A. Ceramic Solid The present invention can be applied to virtually any high melting point inorganic solid ukiyte. However, it is particularly suitable for the production of moldable dispersions of dielectric solids such as tita≠r11 zirconates and stannates. It is also applicable to precursors of such materials, ie solid materials that are converted to dielectric solids and any mixtures thereof upon calcination.

When the composition of the invention is used for slip molding, it is preferred that the particle size does not exceed 15 μm, preferably not more than 5 μm. On the other hand, it is preferred that the particles are no smaller than 0.1 μm. In order to obtain more powerful characteristics, the surface area of the particles is at least 1 m2/II, preferably 4 m2
/g. It has been found that particles with a surface area of 3-6 m /1/ are quite satisfactory for most applications. Particles with even larger areas, for example 10 m 2 /11 or more, can also be used, but must be weighed against the fact that larger surface areas require more organic medium to obtain a given dispersion viscosity. . For this reason, the average surface area of the particles is preferably 3 to 8 m/9.

Among the many dielectric solids that can be used in the present invention are, for example, BaSnO3+ CaTiO3,5rTi05. P
bTiO3+CaZrO3,, BaZrO2, MnO,
Fe20y, , alumina, silica and various glass frits, CaSnO3, BaSnO3゜Bi OB1T
103. These include BaSnO3, kyanite, mullite, polsteite, and zircon. The present invention is also very useful as a binder for low-fire dielectric materials such as those disclosed in Bouchard U.S. Pat. Nos. 4,048,546 and 4,228,482. It is desirable that the ceramic solid have no swelling properties in the organic dispersion.

This is because swelling substantially changes the rheological properties of the dispersion.

B0 Polymer Binder As mentioned above, the binder component of the dispersion system of the present invention is 0
~100% by weight of C1-8 alkyl methacrylate, 100-0% by weight of C1-8 alkyl acrylate, and 0~5% by weight of ethylenically unsaturated carboxylic acid. a mixture of multipolymers of acids or amines, the multipolymers having a number average molecular weight (Mn) of 50,00
0 to 100,000, weight average molecular weight (Mw) is 15
0.000 to 350,000, the ratio of Mw to Mn is 5.5 or less, and the total amount of unsaturated carboxylic acid or amine in the multipolymer mixture is 0.2 to 2.0.
% by weight, and the glass transition temperature of said polymer and of said plasticizer, if present, is between -30<0>C and +45<0>C.

The above polymer is a random copolymer, and the above 3
It includes both terpolymers and higher multipolymers as long as the basic comonomers of the species are used in proportions within the above ranges.

The relative amounts of the carboxylic acid or amine distributed along the polymer chain are critical. In particular, in order to obtain a suitable dispersion of the ceramic solid, at least 0.2% by weight of the monomer containing the functional moiety in the polymer mixture is required, preferably at least 0.5% by weight. I understand. On the other hand, to prevent agglomeration of the dispersed ceramic solids, it is necessary that the comonomers containing functional moieties do not exceed 5.0% by weight of any polymer or 2.0% by weight in the polymer mixture. . Polymer mixtures containing in some cases 18% acid-containing monomers with regard to dispersion properties? -Is it Daline?
Several cases were observed where the performance was poor or even insufficient. In many instances of this type, the use of more polar solvents still allows such polymers to be used in the present invention. Accordingly, polymer mixtures containing up to 2.0% of functional group-containing monomers can be used, although polymer mixtures containing as much as 1.5% of functional monomers are preferred. More preferably, such functional monomer does not exceed 1.0% by weight.

For similar reasons, it is preferred that none of the polymers contained in the polymer mixture contain more than 5.0% by weight of functional monomer. Furthermore, in order to obtain adequate dispersibility, it is preferred that none of the polymers contain less than 0.2% by weight of functional monomer. Therefore,
The polymeric binder is a mixture of polymers, some of which do not contain any functional moieties, as long as the content of functional comonomer in the total mixture is within the range of 0.2 to 2.0% by weight. , and may contain 5.0% by weight of functional comonomer. However, it is preferred that the polymeric binder consist entirely of acrylic polymers as described above containing 0.2-2.0% by weight of functional comonomer.

In any case, all polymers constituting the polymer binder must be compatible. This means that when the solvent is removed from a solution of the polymer in a co-solvent, a clear transparent film is formed. That is, the polymer mixture is single-phase.

Preferred copolymerizable carnic acids have zero ethylenically unsaturated
3-6 monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; and C4~. Dicardic acid, such as fumaric acid, itaconic acid, 7) laconic acid, vinylcono-acid, etc.
phosphoric acid and maleic acid: and their /%-esters, and where appropriate, their anhydrides and mixtures thereof, such monomers comprising at least 0% of the polymer.
．． 2% by weight and preferably at least 0.5% by weight.

Of course, the amine component is not directly incorporated into the chain by copolymerization of the amine-containing monomer, but indirectly by the post-polymerization reaction of the side chain reactive portions of the polymer chain. This is evidenced by the primary amine added by reaction of the glycidel compound with the side chain carboxylic acid group in the presence of ammonia. Thus, as used herein, the term "ethylenically unsaturated amine" is meant to include polymers derived from amine-containing comonomers as well as other comonomers that form amine groups in postpolymerization reactions. Primary, secondary and tertiary amines are each similarly effective. Comonomers suitable for adding side chain amine groups directly into the binder polymer chain include diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, and t-butylaminoethyl methacrylate. Suitable monomers that provide side chain functionality suitable for post-polymerization reactions that provide amine functionality include the ethylenically unsaturated epoxides mentioned above, such as glycidel acrylate or glycidel methacrylate.

It is possible for the polymer binder of the invention to contain up to 100% by weight of acrylic or methacrylic monomers. Nevertheless, within the above ranges of these monomer stocks, it is preferred that the alkyl methacrylate constitutes 40 to 80% by weight of the copolymer and the alkyl methacrylate constitutes 60 to 20% by weight of the copolymer. The weight ratio of alkyl methacrylate to alkyl acrylate is preferably 1.5 to 2.5:1;
Particularly preferred is 5 to 2.0:1.

The polymeric binder may contain comonomers other than the acrylic and acidic comonomers listed above, such as styrene, acrylonitrile, vinyl acetate, acrylamide, etc., in an amount of about 10
It can be contained up to % by weight. However, it is preferred to use less than about 5% by weight of such mono→-. It is currently unknown whether the use of such other comonomers adds anything to the efficacy of the copolymers used in this invention.

However, such comonomers in the limited amounts described above do not reduce the effectiveness of the cypolymer as long as it meets all compositional and physical criteria.

In addition to the compositional factors mentioned above, it has been observed that the physical factors of the polymeric binder have a completely unexpected importance in the compositions of the present invention.

In particular, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer and the ratio of these two properties must be limited within narrow limits to obtain the advantages of the present invention. In order to obtain sufficient strength, the polymer binder must have a number average molecular weight within the above range.
In order to obtain a sufficiently low viscosity, the weight average molecular weight of the polymer binder must be within the above range.

Furthermore, surprisingly, the ratio of these two properties (Mw
/Mn) is 5.5 or less and 6. D, preferably 4.0 or less. A polymer with a MyO to Mn ratio as small as possible, that is, a ratio Mw/Mn of 11 is 1.
．． 5. Ideally, it is preferable to use a polymer close to 1.0. However, such polymers are not available with current commercial scale polymerization techniques.

A suitable Mn value for the polymeric binder is 50.000
It has been found that the Mn value is in a relatively narrow range of ˜100,000, and a preferable Mn value is in the range of 60.000 to so,ooo.

Similarly, suitable MY values for polymeric binders are
The range is o, ooo to 'aso, oooo.

Preferably, the Mw value is 200.000 to 300.000
is within the range of

In addition to the above physical properties, it is practical that the binder polymer, including any plasticizers, has a lath transition temperature (Tg) of at least -30°C and not exceeding +45°C. Necessary for application reasons. The Tg of the binder including the plasticizer is preferably -20°C to +20°C. If the Tg exceeds 45° C., the solvent-free dispersion has very low adhesion to other layers and is extremely brittle.

Although polymers meeting all of these specific criteria are not known, they can nevertheless be produced by those skilled in the art of acrylate polymerization by conventional solution polymerization techniques. Typically, acidic acrylate polymers are prepared by combining an α-β-ethylenically unsaturated acid with one or more copolymerizable vinyl monomers in a relatively low boiling point (75-150°C) organic solvent. 20-6
It is produced by making a 0% monomer mixture solution, then adding a polymerization catalyst to cause polymerization, and heating the mixture to the reflux temperature of the solution at atmospheric pressure. After the polymerization reaction is completed, the resulting acid polymer solution is cooled to room temperature, and a sample is taken to measure the viscosity, molecular weight, acid equivalent, etc. of the polymer.

In order to obtain a better binding effect, it is preferred to use at least 2% by weight of polymer binder to 98% by weight of ceramic solids. More preferred is at least 5% by weight of polymeric binder. The amount of binder depends in part on the surface area of the ceramic solid particles. Generally, large surface area ceramic solids require larger amounts of binder.

C1 Organic Medium The organic medium in which the ceramic solid is dispersed is a polymeric binder dissolved in a volatile organic solvent and, optionally, plasticizers, mold release agents, etc.).

Consists of other dissolved substances such as bee agents, stripping agents, antifouling agents and wetting agents.

By adjusting the rheological properties of the dispersion system of the present invention, υ
and by varying the solvent content of the organic medium, the compositions of the present invention can be applied to substrates by methods other than molding, such as screen printing. When the composition is used for screen printing, the conventional organic media materials used for thick film materials can be used as long as the acrylic polymer is completely dissolved therein at the temperature of use.

For molding solutions, the solvent component of the organic medium is sufficient to obtain a complete solution of the polymer and to allow the solvent to be evaporated from the dispersion by application of relatively low levels of heat at atmospheric pressure. selected to provide high volatility. In addition,
The solvent must readily boil at a temperature below the boiling point and decomposition temperature of any other additives contained in the organic medium. Therefore, solvents with a boiling point of 150° C. or less at atmospheric pressure are often used. Such solvents include benzene, acetone, xylene, methanol, ethanol, methyl ethyl ketone, 1,1.1-chloroethane, tetrachloroethylene, amyl acetite, 2,2.4-) ethylpentanediol-1,3-monoisobutyrate. , toluene, methylene chloride, 2-propanol and Freon(TM) TF ()lichlorotrifluoroethane)
including.

However, it is often desirable to apply the compositions of the invention as a film paste by techniques such as screen printing. In this case, the composition needs to have a suitable viscosity so that it can easily pass through the screen. In addition, in order to set up quickly after screen printing, they must be thixotropic, which gives good resolution. Rheological properties are of paramount importance, but organic media are preferred to provide adequate wetting of solids and substrates, good drying rates, dry film strength to resist rough handling, and good sinterability. is preferably formed. Good appearance of the fired composition is also important.

On the other hand, if the dispersion is applied as a thick film paste, the usual thick film organic media can be used, subject to appropriate rheological adjustment and the use of less volatile solvents. The organic medium for most chic film compositions is typically a solution of a resin in a solvent, often containing both a resin and a thixotropic agent. This solvent usually boils in the range of 130-350°C.

Particularly preferred resins for this purpose are polymethyl acrylates of lower alcohols and moptyl ethers of ethylene glycol monoacetites.

The most widely used solvent for thick films is α-
or terpenes such as β-tylpinol, or mixtures thereof with other solvents such as kerosene, dibutyl phthalate, butyl carpitol, butyl carpitol acetite, hexylene glycol, and high boiling alcohols and alcohol esters. . Various combinations of these and other solvents are prepared to obtain the desired viscosity and required volatility.

Commonly used thixotropic agents are hydrogenated castor oil and its derivatives.

Of course, shear thinning (5hear
It is not always necessary to incorporate thixotropic agents, as the solvent/resin properties together with thinning can meet this requirement by themselves.

The ratio of organic medium to inorganic solids in the dispersion can vary considerably and depends on the manner in which the dispersion is applied and the type of organic medium used. Usually, to obtain good coverage,
The dispersion contains 60-90% by weight solids and 40-10% by weight organic medium. Such dispersions are usually in a semi-liquid state and are commonly referred to as "pastes".

This paste is conveniently manufactured in a three roll mill. The viscosity of the paste, when measured at room temperature using a Brookfield viscometer at low, medium and high shear speeds, is typically within the following ranges: (Pa, ts) Viscosity (Pa, ts)
) 0.2 100-5000 - aOO-2000 Good 600-1500 Best 4 40-400 - 100-250 Good 140-200 Best 384 7-40 - 10-25 Good 12- Tech 8 Best organic medium used (vehicle ) is determined by the final desired viscosity and print thickness.

As mentioned above, the organic medium controls the Tg of the binder polymer.
Plasticizers which serve to reduce t- may be included in small amounts compared to the binder polymer. However, the use of such materials should be kept to a minimum in order to reduce the amount of organic material that must be removed when firing the cast film. The choice of plasticizer is, of course, primarily dependent on the polymer to be modified. Plasticizers that have been used in various binder systems include diethyl phthalate, dibutyl phthalate, dioxyphthalate, butylbenzyl phthalate, alkyl phthalates, polyalkylene glycols, glycerol, poly(ethylene oxide), hydroxyethyl These include alkylphenols, dialkyldithiophosphonates, and poly(imbutylene). Of course, butylbenzyl phthalate is most often used in acrylic polymer systems because it is effective at relatively low concentrations. The amount of plasticizer used in the compositions of the invention depends on how effective a particular plasticizer is in reducing the Tg of the polymer in which it is used and relative to the Tg change required for that polymer. determined by the percentage of Thus, the amount of plasticizer can vary from 0 to 75% by weight of the base polymer.

Test Methods In the following examples, the test methods described below were used to determine the properties of the polymeric binder of the compositions of the present invention and the properties of the green tape made from the compositions.

A1 Molecular Weight Weight average and number average molecular weights for a solution of the test polymer dissolved in tetrahydrofuran, Model 60
Measurements were made using a water chromatography system equipped with a 00A pump, a Model 401 R1 detector and a set of 4 μm Styrogel columns (10°10', 5 x 102 and 102).

The measurement standard polymer was poly(methyl methacrylate), L
It was uctte 40. (Lucite is 1. du Pont d, E., Wilmint, Prayer.

Nemours and Company+ Inc.
is a trademark related to acrylic resin. B. Viscosity All slip viscosities were measured using a Brookfield LVT viscometer, A2 spindle, at 6 RPM and a temperature of 25°C.

C, glass transition temperature The glass transition temperature of the binder polymer, whether plasticized or not, is determined by Du, Pont Mode 1990
Thermal Analyzer and Du PontModel
Measurements were made using a combination of 951 Thermogravimetric Analyzer modules.

Preparation of Molded Slips In the following examples, the organic medium used to prepare the molded slips had the following composition: Table 1 Slip Composition Ingredients A B -■■■■■■■■Hibiki■ −−inside−field■−１−■■■■■
■■１－－－１－－１－－■－KEN■■■－－■■
――――――■1 Melting N--Polymer 12.15 12
．． 71 Methyl ethyl ketone 2835 29.67 Santi
cizer 160(1) 2.94 3.08i, t,
i-Trichloroethane 52.12 54.54 (10
CH wt,) 100fl 100D (1) Mon5ant of St. Louis, Missouri.

Chemical co, trademark for butylbenzyl phthalate.

(2) Hercu, Wilmington, Prayer
les, Inc. trademark for partially polymerized resins.

The following ceramic dielectric materials were used in the examples: (1) Ct, 750 is an NPO-type dielectric material (Ashi, BaTiOs and NbTiOs).
5 and also includes bismas.

(2) BL162 is a bismuth-containing dielectric material of Bx,'x7R-type, based on BaTiO3. :(3) H602 is a Z5U-type bismuth-free dielectric material based on BaTiO3.

do. j The three types of dielectric materials mentioned above are Prayer State.

E of Wilmington, 1. du Pont de Ne
mours and Company Inc., Division 5solid 5tateDielectrics
In the production of 0-molded slips, the product of which the organic medium, ceramic powder and mixed flint are placed in a ceramic jar and ground for 14 hours. The milled dispersion is transferred from the mill jar to a lath jar, which is placed in a constant temperature bath or oven for a sufficient time to bring the temperature of the slip to 25°C. Slip viscosity is measured at 25°C.

In the examples below, all compositional proportions are in weight percent (1 wt) unless otherwise specified.

Examples Examples 1-3 Three molding slips were made from acidic acrylic terpolymers with varying amounts of acidic comonomer from 0.4 to 1.8 inches. Molding slips were made for each terpolymer using the methods and proportions described above, and the viscosity of the slips was measured.

Table 2 Effect of polymer acidic component on slip viscosity Examples 1 2 3 Polymer composition Ethyl methacrylate 62.3 61.9 61.6
Methyl acrylate 37.1 36.9 36.6 Methacrylic acid 0.6 1.2 1.8 Polymer properties Tg ('C) 35 32 38 Mn 80,000 73.000 75,800Mw
266.000 272,000250,000My
/Mn:3. :3 :3. s:3. :3 Slip viscosity (Pa-s) 0.42 0.80 4-19 From the above data, slips made from highly acidic polymers are unstable and have very high viscosity, and this property is due to the agglomeration of dielectric materials. It can be seen that there is a tendency to On the contrary, the two low acid polymers exhibited low viscosities that were quite stable. Preferably, the polymeric binder component of the present invention contains no more than 1.5% by weight of side chain functional group-containing comonomer.

Examples 3-6 Three polymers having the same composition as Claim 1 were each cast as a 30 weight solution in methyl ethyl ketone on a glass plate to form a 6 mil wet thickness film. The dried film was then dried at room temperature for 48-72 hours with a thickness of 1-1.5 mils. Tensile υ samples measuring 2 in. x 2 in. (1.27 x 6.35 crn) were cut and tested through an In5tron testing machine at a tensile speed of 2 in/sec (5.1 cm/sec). These data are shown in Table 3: Table 3 Polymer composition Ethyl methacrylate 62.3 61.9 62.6
Methyl acrylate 37.1 36.9 36.8 Methacrylic acid 0.6 1.2 0.6 Polymer 9 Properties Tg (C) 35 32 38 Mn 80,000 73,000 73,000M9
F 266.000272.000450000My/
Mn 3.3 3.8 6.2 Solution viscosity (Pa, s) 0.46 0.40 1.8 Film properties Modulus (tbs-/1n,”), 52,000 4
8.000 34,000 Elongation at break (%) 178
128 19 Breaking stress (tbs,/in,”) 2J
OO1,4003,400 breaking energy (ft, tb
, ) 0.32 0.27 0.04 From the above data,
Despite the fact that the polymers of the invention (Examples 4 and 5) have significantly lower weight average molecular weights than the polymer of Example 6, they have significantly higher flexibility, elongation at break and toughness (fracture energy). It can be seen that it has The solution viscosity of the polymers used in this invention is also fairly low.

Examples 7-8 Polymers similar to Examples 4 and 6 were used to make two molding slips as described above. The composition of both slips was the same with respect to the amount of solids, plasticizer and solvent. Green tape was later produced from both slips. Example 4~
Tensile samples having the same dimensions as those of Example 6 were prepared, and these were made into a 15-layer laminate without electrodes, and the tensile properties were tested in the same manner as in Examples 4 to 6. The data are shown in Table 4 below: Table 4 Polymer composition Ethyl methacrylate 62.3 62.6 Methyl acrylate 37.1 36.8 Methacrylic acid 0.6
0.6 Polymer properties Tg (C) 35 38 Mn 80,000 73,000 Mw 266,000450,000 Mw/Mn 3.3 6.2 Solution viscosity (Pa -s) 0.46 1.8 Slip composition L-16271,465,2 Polymer 3.5 4.2 Methyl ethyl ketone 8.0 9.7 Santicizer 160 0.8 1.01.1
．． 1-Trichloroethane 14.9 17.9Poly
Pale resin 0.1 0.2100.0 100.0 Modulus (tbs, /in, 2) 2.5 3.6 Elongation at break (chi) 36 28 Breaking stress (tbs, /in, 2) 224 235 Energy kdt'-(ft, tb,) 0.12 0.09
The above data show that green tapes made from the molding slips of the present invention have high flexibility as measured by elongation at break and high toughness as measured by energy to break.

Examples 9-11 Three types of moldable ceramic slips were also produced, each having a viscosity of 600-650 cpa. This molding slip was made from three different acrylic polymers using the same dielectric solid. Green tapes were cast from each of the three slips and dried at room temperature for 36-48 hours. The data in Table 5 below is based on the composition of the invention (Example 9).
) using a conventional polymeric binder (Example 1)
0.11), indicating that it contained a significantly higher amount of dielectric material with a comparable viscosity. In addition, Example 11 shows that the higher Tg requires more plasticizer to obtain a good lamination bond. It will be seen from Example 11 that a suitably dispersible molding slip can also be obtained from an acrylic polymer without acid groups.

However, to have such dispersibility they must have very high molecular weight and are therefore not preferred for use in the compositions of the invention.

Table 5 Effect of molecular weight and molecular weight distribution on slip solids Polymer composition Ethyl methacrylate 62.3 62.6 -Methyl acrylate 37.1 36.8 Ethyl acrylate 29.0 Methyl methacrylate 71.0 1oo, o ioo, o ioo,.

Polymer properties Tg (℃) 35 38 54 Mn 80,000 73,000300.000M
w 266. OO0450,000744,000My
/Mn 3.3 6.2 2.5 Slip composition L162 62.0 55.6 44.9 Polymer
4.8 5.1 5.0 Plasticizer 1.2 1.4 4.0 ioo, o ioo, o ioo,.

Drying tape composition Dielectric solid 91.2 89.5 83.2 Organic matter 8
．． 8 10.5 16.8 Examples 12-20 Nine molding slip compositions were prepared and compared to compositions containing commercially available polymers whose molecular weights were not compatible with the relationships of the invention. Explain how many ceramic solids can be mixed into a product.

Table 6 Molecular weight and weight relative to solid content Example 1
2 13 14 15 16 Volima monocomponent ethyl methacrylate 62.3 62,3 62,3
62,6 62.6 Methyl acrylate 37.1
37.1 37:1 36.8 36.8 Methacrylic acid 0.6 0.6 0.6 0.6 0.6 Polymer properties Tg ('C) 35 35 35 38 38Mn
80,000 80,000 80,000 73,0
00 73,000My 266.000266β00
266.000 450,000 450.000Mw
/Mn 3.3 3.3 3.3 6.2 6.2 Slip composition (parts by weight) Ceramic solid 200 220 2!40 160
167 Binder Polymer 9.9 9.9 9.9
9.9 9.9 Solvent (2) 77.0 77.0 ? 7
,0 77.0 77.0 Plasticizer (3) 2.7 2.
7 2.7 2.7 2.7 Viscosity reducing agent (4) 0.
4 0.4 0.4 0.4 0.4 Ceramic mass concentration (ch) 69.0 71.0 72.7 64.0
65.0 Ceramic mass 93.9 94.4 94.
9 92.6 92.8 Organic matter 6.1 5.6 5.
1 7.4 7.2(3) 8anticizer 1
60 (4) Effect of Polypale resin molecular weight distribution 17 18 19 20 62.6 62,6 62,6 62.636.8 3
6,8 36.8 36.80.6 0.6 0.6
0.6 38 38.38 38 73.000 73,000 73,000 73,0
00450, f) 00 '450,000 450,0
00 450.0006.2 6.2 6.2 6.2 180 200 220 240 9.9ゝ 9.9 9.9 9.9 77.0 77.0 77.0 77.02.7 2.
7 2.7 2.7 0.4 0.4 0.4 0.4 66.7 69.0 710 72.71280 17
50 2400 480093.3 93.8 94.
4 94.96.7 6.1 5°65.1 -Trichloroethane From the above data, a molding slip using a polymer outside the scope of the invention at a ceramic level of 200 parts by weight is 17
It is interesting to note that it has a viscosity of 50 cpg, whereas the composition of the present invention has a viscosity of only 590 cps. Similarly, at an amount of 240 parts by weight, the viscosity of slips with conventional polymers is 4800 cps, compared to 1000 cps with the composition of the invention. Based on the same viscosity (1000 cps), there are approximately 44 more solids that can be incorporated into molding slips with binder polymers within the scope of the present invention. Additionally, the amount of organic material removed by pyrolysis is reduced by 29%.

Examples 21-26 Several additional molding slips were made to study the effect of viscosity reducing agent concentration on slip viscosity. In addition, the effect of a viscosity reducing agent at a constant concentration on slip viscosity was observed for two further compositions, only one of which was based on a binder polymer within the scope of the present invention.

Table 7 Slip viscosity versus dispersant concentration Polymer composition Ethyl methacrylate 62.3 62.3 62.3
Methyl acrylate 37.1゛37.1 37.1 Methacrylic acid 0.6 0.6 0.6 Polymer properties Tg (℃) 35 35 35 M n 80,000 80,000 8α000Mw
266.000 266.000 266.000Mw
/Mn 3.3 3.3 3.3 Slip composition (parts by weight) Dielectric solid (1) 600 600 600 Binder polymer 47 38 37 Viscosity reducer (2) 0
．． 7 1.5 Solvent (a) 3i0 252 252 Plasticizer (4) 11. 9 9 Slip viscosity (Pa, s) 0.6 RPM O,90,60,3 12, ORPM 1.0 0.8 0.5(1)H60
2 (2) Polypale resin (3) Mixture of MEK, TgC and Ingropanol (4) 5 anticizar 160 performance 62.3 62.3 100.0 37.1 37.1 0.6 0.6 - 35 35 66 8α0008α000 93,000 266.000 266.000 341,0003.
3 3.3 3.7 600 720 600 35 30 37 3.0 1.5 1.5 252 252 252 9 9 9 8.3 1.0 55.0 1.7 0.9 10.0 From this data, Viscosity reducers are effective in reducing slip viscosity at low concentrations, but at the 3.0g level (0.5% by weight of dielectric solids) they can destabilize the dispersion, resulting in high viscosity, unstable It can be seen that this leads to viscosity and solid agglomeration. However, it is very interesting to note that the use of viscosity reducing agents was even less effective in the molding slip (Example 26) which utilized a binder polymer without acid functionality.

Examples 27-31 The importance of molecular weight and the ratio of weight-average molecular weight to number-average molecular weight is demonstrated by the following experiments in which transparent films were made using the methods described in Examples 3-6 using five different polymers. Illustrated by example. The polymeric film of Example 27, which is within the scope of the present invention, did not break even after being folded 1800 times five times and was completely rigid. Example 28, which is outside the scope of the invention, showed good fastness but had excessive solution viscosity. On the other hand, Examples 29-31, which are outside the scope of the present invention, were very brittle. That is, when folded, they broke. This brittleness of the cast film affects the ease of cutting of multilayer capacitors made from the corresponding slip.

Examples 32-35 Four types of molding slips were prepared in the same manner as above. One had a polypale resin viscosity reducer added, the other two had a small amount of glacial acetic acid, and the remaining one had a standard composition with no additives. After testing the viscosities of four types of slips, it was found that glacial acetic acid was also effective in reducing slip viscosity.

Table 9 Acid system force on slip viscosity 1 Ethyl methacrylate 62.3 Methyl acrylate 37.1 Methacrylic acid 0.6 Polymer properties Tg (°C) 35 M n 80,000 Mw 266.000 My/Mn 3.3 Slip Composition Dielectric Solid (1) 200 Binder Polymer 12.4 Solvent 82.2 Plasticizer 3.0 Polypale Resin Glacial Acetic Acid (1) Effect of H602 1 62.3 62.3 62.3 37-1 37.1 37. 1 0.6 0.6 0.6 35 35 35 80.000 80,000 80.000266.0
00 266.000 266.0003.33.33
．． 3 200 200 200 12.4 12.4 12.4 82.2 82.2 82.2 3.0 3.0 3.0 0.2- 0.2 0.1 1.78 1.66 1.95 Examples 36 to 46 Furthermore, several compositions with different polymer compositions were prepared,
Dispersion tests were conducted to determine the compatibility of each polymer with molding slips. In this variance test, 4.5
JJ ceramic powder (BL 162), 45.0
, P of xylene or 1.1.1-trichloroethane and 50I! A polymer solution (3096 polymer in MgK) was placed in a Naohiko-sized bottle, shaken for 30 minutes on a mechanical paint shaker, and then allowed to stand for 8 hours. After 8 hours, turbidity or clarity was observed. A cloudy sample indicated that it was well dispersed, whereas a clear sample indicated that it was unstable and therefore lacked the desired dispersion properties.

Table 10: Methyl acrylate on polymer assembly for slip stability - -82,040,035,0 Ethyl methacrylate 62.3 62.3 - Butyl methacrylate 9.0 Methyl acrylate 37.1 36.8 - ~ Ethyl acrylate butyl acrylate - -18,060,846,0
2-Ethylhexyl acrylate - methacrylic acid
0.6 0.6 - - 10.0 Methacrylic acid, iminated diethylamine ethyl methacrylate - Glycidyl methacrylate, anti-oxidation - Good xx -x Transparent XX Father's effect 35.0 32.5 81.0 70. 0-615
9.0 64.0 - :jo, 0 - -- 13.
0 38.0 46.0 - 18.0 - - - 87.0 - - 0.5' 10.0 - - - - 1,〇- 3,5----- xxx-x -XX- Example 38 , 39, 44 and 45 show that good dispersion cannot be obtained without side chain functionality. Examples 41-43 show that in addition to acid groups, amine groups can be used to obtain good dispersion.

Examples 47-54 Several slip compositions with similar polymer compositions were prepared. Each slurry was subjected to the turbidity tests of Examples 36 to 46, as well as Haake Rotovisc.

The viscosity was measured before and after storage for 2 weeks at fi40°C using a W3 viscometer, and its changes were investigated.

Example 52 shows that excessive side chain functionality is detrimental to dispersion stability as shown by the Haaka viscosity stability test. Example 54 shows that the lack of side chain functionality is detrimental to dispersion stability, even though the viscosity of the slip remains stable upon heat aging. Molding slips made from polymers meeting the compositional requirements of the present invention (Examples 47-51) exhibited good dispersibility and good viscosity stability.

Example 56 Another slip composition was prepared using a solvent containing a sufficient amount of trichlorotrifluoroethane to obtain a slip composition with a closed cup flash point (ASTM Test Method D56) of 200° C. or greater. A 4 mil thick tape was cast from this slip using the method described above. The resulting tape was strong and free of pinholes. In addition, the tape had a uniform thickness and was easy to stack when used to make multilayer capacitors. This slip had the composition shown below.

Nonflammable slip composition Glass powder 32.2 cm wt.

At20316.5 Sin24.0 Polymer (1) 3.5 Dioctyl phthalate 1.3 1.1.1-)lichloroethane 33.2 Methylene chloride 2.0 2-propatol 1.7 Trichlorotrifluoroethane 3.0 Methyl ethyl ketone 2.3 (1) 62.3/37.110.6 methyl methacrylate/methyl acrylate/methacrylic acid Examples 56-60 To observe the effect of plasticizers on the glass transition temperature (Tg) of polymers Four solutions of plasticizer and polymer were prepared, and the amount of plasticizer was varied up to 100% by weight of that of the polymer. The solution was made by adding a plasticizer to a solution of the polymer and then removing the solvent. The data shown in Table 12 below shows that using equal amounts of plasticizer and polymer makes quite a substantial difference.

56 100 33 57 100 24 -6 58 100 50 -23 59 100 25 -44 60 100 100 -47 Applicant's agent Patent attorney Suzue Takehiko Commissioner of the Japan Patent Office Manabu Shiga 1, Case indication patent application 1982- No. 115632 No. 2, Title of the invention Ceramic composition 3 Relationship to the Nagisa case making the amendment Name of patent applicant EI du Pont Doc Φ Nemours & Company 4, Agent 7 Contents of the amendment Claims fljJ 'l 'All lt6. Correct the trace.

2. Claim 1: 0 to 100% by weight dissolved in a non-aqueous organic solvent
Alkyl methacrylate having 1 to 8 carbon atoms, 100 to 0
Weight% of alkyl thicrylates having 1 to 8 carbon atoms and 0 to 8 carbon atoms
A ceramic composition comprising a dispersion of fine particles of a ceramic solid dispersed in a solution of a mixture of multipolymers of ethylenically unsaturated carboxylic acids or amines of 5% by weight; the number average molecular weight (Mn) of the multipolymers; is 50,0
00 to 100,000, a weight average molecular weight (MW) of 150,000 to 350,000, a ratio of MW to Mn of 5.5 or less; The ceramic composition, characterized in that the total amount is 0.2 to 20% by weight, and the glass transition temperature of the multipolymer and the plasticizer that may be present therein is between -30°C and +45°C. .

2. The composition according to claim 1, wherein the alkyl methacrylate is ethyl methacrylate, and the alkyl acrylate is methyl acrylate.

3. The composition of claim 1, wherein the ethylenically unsaturated carboxylic acid is monoacrylic acid selected from acrylic acid, methacrylic acid, and mixtures thereof.

4. The composition according to claim 1, wherein the carboxylic acid is methacrylic acid.

5. The composition according to claim 1, wherein the ethylenically unsaturated carboxylic acid is a dicarboxylic acid selected from itaconic acid, fumaric acid, maleic acid, maleic anhydride, halfesters thereof, and mixtures thereof. .

6. The composition of claim 1, wherein said multipolymer comprises 40-80% by weight of alkyl methacrylate and 60-20% by weight of alkyl acrylate.

7. Alkyl acrylate of alkyl methacrylate)
! 2. The composition of claim 1, wherein the weight ratio of 2 to 2 is from 1.5 to 25:1.

8. Mn is 60,000 to 80,000.

The composition of claim 1, having a MW of 200,000 to 300,000.

9. The composition of claim 1, wherein the ceramic solid is a dielectric solid or a precursor thereof.

J, 0. 10. The composition of claim 9, wherein said dielectric solid is selected from tetanates, zirconates, stannates, precursors thereof and mixtures thereof.

11. The dielectric solid is BaTi0. , CaTiO
s.

Sr'f'i0. , pb'rto8. Nb'r+
10. The composition of claim 9, wherein the composition is a tetanate selected from O3, noble metal titanates, precursors thereof and mixtures thereof.

12. The dielectric solid is selected from Ba or Ca stannates, precursors thereof and mixtures thereof.
The composition of claim 50.

13. The composition of claim 1O, wherein the dielectric solid is selected from 13a or Ca zirconates, precursors thereof and mixtures thereof.

Claims (1)

[Scope of Claims] 1. 0 to 100% by weight of a C1 to C8 furkyl methacrylate, 100 to 0% by weight of a C1 to C8 alkyl acrylate, and 0-5
A ceramic composition comprising a dispersion of fine particles of a ceramic solid dispersed in a solution of a mixture of multipolymers of ethylenically unsaturated carboxylic acids or amines of 50.
000 to 100,0.00, weight average molecular weight (M
w) is 150,000 to 350,000, M of Mw
5.5 or less, the total amount of unsaturated carboxylic acid or amine in the multipolymer mixture is from 0.2 to 2.0% by weight, and the multipolymer and the amine present therein The above-mentioned ceramic composition, characterized in that the glass transition temperature of the plasticizer is between 130°C and +45°C. 2. The composition according to claim 1, wherein the alkyl methacrylate is ethyl methacrylate, and the alkyl acrylate is methyl acrylate. 3. The composition of claim 2, wherein the ethylenically unsaturated carboxylic acid is monoacrylic acid selected from acrylic acid, methacrylic acid, and mixtures thereof. 4. The composition according to claim 1, wherein the carboxylic acid is methacrylic acid. 5. The ethylenically unsaturated carboxylic acid is itaconic acid,
The composition of claim 1, wherein the dicarboxylic acid is selected from fumaric acid, maleic acid, maleic anhydride, halfesters thereof, and mixtures thereof. 6. The composition of claim 1, wherein the multipolymer comprises 40-80% by weight alkyl methacrylate and 60-20% by weight alkyl acrylate. 7. The composition of claim 1, wherein the weight ratio of alkyl methacrylate to alkyl acrylate is from 1.5 to 2.5:1. 8. The composition according to claim 1, wherein Mn is 60,000 to 80,000 and sb and Mw are 200,000 to 300,000. 9. The composition of claim 1, wherein the ceramic solid is a dielectric solid or a precursor thereof. 10. The composition of claim 9, wherein said dielectric solid is selected from titanates, zorconates, stannates, precursors thereof and mixtures thereof. 11. The dielectric solid is BaTiO3, CaT105+
5rTi03. pbT'to,, Nb'rio, ,
10. The composition of claim 9, which is a titanate selected from noble metal titanates, their precursors and mixtures thereof. 12. Stannate in which the dielectric solid is H& or Ca;
11. A composition according to claim 10 selected from these precursors and mixtures thereof. 13. The composition of claim 10, wherein said dielectric solid is selected from Ba or Ca zorconates, precursors thereof and mixtures thereof.