WO1998033750A2

WO1998033750A2 - Preparation and utility of water-soluble polymers having pendant derivatized amide, ester or ether functionalities as ceramics dispersants and binders

Info

Publication number: WO1998033750A2
Application number: PCT/US1998/001073
Authority: WO
Inventors: Christopher P. Howland; Kevin J. Moeggenborg; John D. Morris; Peter E. Reed; Jiansheng Tang; Jin-Shan Wang
Original assignee: Nalco Chemical Company
Priority date: 1997-01-31
Filing date: 1998-01-28
Publication date: 1998-08-06
Also published as: EP0956275B1; ATE236106T1; CA2279321A1; AU6033198A; EP1207143A2; DE69812892D1; PL335063A1; EP1207143A3; SK96399A3; EP0956275A2; US5726267A; BR9806806A; WO1998033750A3; JP2001509770A

Abstract

Methods for dispersing and binding ceramic materials in aqueous media are disclosed. The methods utilize water-soluble polymers having pendant derivatized amide, ester or ether functionalites for dispersing and binding various classes of ceramic materials.

Description

PREPARATION AND UTILITY OF WATER-SOLUBLE POLYMERS HAVING

PENDANT DERIVATIZED AMIDE, ESTER OR ETHER FUNCTIONALITIES AS

CERAMICS DISPERSANTS AND BINDERS

Field of the Invention

Methods for dispersing and binding ceramic materials in aqueous media are

disclosed. The methods utilize water-soluble polymers having pendant derivatized

amide, ester or ether functionalities for dispersing and binding various classes of ceramic

materials.

Background of the Invention

Ceramic materials are commonly prepared by mixing powdered ceramic oxides

such as magnesia, alumina, titania and zirconia. in a slurry along with additives, such as

dispersants and binders. The slurry may be spray dried to produce ceramic particles. The

particles are pressed into an aggregate structure, called a "green ceramic." having a

desired shape and subsequently subjected to a severe heat treatment known as sintering.

The sintering process converts the green ceramic into a cohesive "fired ceramic", having a

nearly monolithic polycrystalline ceramic phase. •

The binder serves to hold the ceramic particles of the green ceramic in the desired

shape after pressing. The binder can also provide lubrication while the particles are

pressed. Preferably, the binder combusts or vaporizes completely during the sintering

process leaving no trace of the binder in the fired ceramic. In performing these functions,

binders significantly affect the properties of the fired ceramics which are ultimately

produced. In commercial practice. poly(vinyl alcohols) are widely used as ceramic binders.

Additionally, poly(ethylene oxide) and ethylene-vinyl acetate copolymers reportedly have

been used as binders for particulate material, such as granular silica gel.

For example, polymeric binders containing substantially hydrolyzed copolymers

made from monomers having ester or amide functional groups, poly(vinylformamide) or

a copolymer of vinyl alcohol and vinyl amine are disclosed in U.S. Patent Nos.

5.358.91 1 ; 5.487.855 and 5.525.665.

Furthermore, polymeric treatments have been disclosed in U. S. Patent Nos.

4.680.339; 4.731.419: 4.885.345 and 5.084.520. Utility for the treatments has been

disclosed to be as dispersants in water treatment, scale inhibitors in industrial and natural

waters, flocculants. coagulants and thickeners: but ceramics applications of binding and

dispersancy have not been disclosed

Although commercially available binders are satisfactory for many applications, a

need exists for improved binders which provide still greater strength and/or increased

density in green ceramic materials. Greater green strength reduces breakage during

handling of the green ceramics and. generally, is associated with higher quality fired

ceramics. Preferably, the improved binders would be cheaper and more versatile than

previously known binders.

Spray drying is an evaporative process in which liquid is removed from a slum'

containing a liquid and a substantially non-volatile solid. The liquid is vaporized by direct contact with a drying medium, usually air. in an extremelv short retention time, on •

the order of about 3 to about 30 seconds. The primary controlling factors in a spray

drying process are particle size, particle size distribution, particle shape, slurry density,

slurry viscosity, temperature, residence time, and product moisture.

The viscosity of the slurry must be suitable for handling and spray-drying.

Although spray-drying equipment conditions may be adjusted to handle a variety of

viscosities, larger particles will usually result from higher viscosity slurries.

Those of ordinary skill in the art are familiar with the spray-drying process used in

the production of ceramic materials, and will be able to optimize the control factors of

spray-drying to best advantage. Alternatively, the spray drying process may be replaced

by other well known drying methods, such as granulation, tape casting and slip casting.

Spray drying of the slurry produces substantially dry, free-flowing powder

particles which contain the ceramic, the binder and the optional materials described

above. The dry particles are granules which are generally spheroidal in shape and have

an effective diameter of about 50 to about 300 micrometers. Typically, about 0.5 percent

to about 8 percent of the binder, based on the dry weight of the ceramic powder, is

present in the dry particles.

In granulation, a mixture of dry powder or powders is mixed or rolled, commonly

in a barrel shaped apparatus. Water and/or a binder solution is sprayed into the mixing

powder causing aggregation of the small particles into larger granules. The size of the granules is controlled by the amount of material sprayed into the powders and the speed

with which it is sprayed. Granulated powders may be screened to a desired size and

pressed to shape in a pressing operation prior to sintering. Alternatively, the granules

themselves may be the desired product and may be sintered directly.

Tape casting is commonly used to produce thin substrates for the computer

industry. In the process, a thick ceramic slurry containing ceramic powder, dispersant

and binders is prepared. This slurry is cast onto a smooth surface such as a Mylar or

plastic sheet and the thickness is controlled by passing the sheet under a blade which

smoothes the slurry surface and scrapes off excess material. The slurry tape is dried to a

plastic state and cut and shaped to specification. The amount of binders present in tape

casting is very high, typically on the order of 15 to 20 wt. % of the ceramic powder mass.

In fluidized bed spray drying, small "seed" particles are placed in a column and

hot air is blown into the seed powder from below suspending the particles in the column.

A ceramic slurry is sprayed onto the seed particles from above, causing them to grow.

When the particles reach a large enough size, they are siphoned out of the dryer while

more seed particles are introduced. This process can produce powder for further forming

processes, or the powder itself may represent the desired product, in which case it would

be sintered to produce the final ceramic.

The dry particles are compacted to produce an aggregate, green ceramic structure.

Preferably, the particles are compacted by pressing in dies having an internal volume which approximates the shape desired for the final fired ceramic product. Alternatively,

the particles are compacted by roll compacting or other well-known compacting methods.

The spray dried blend of powder, binder, and optional surfactants and lubricants is

relatively free flowing so that it can enter and closely conform to the shape of the

pressing dies.

Inside the dies, the dry particles are subjected to a pressure which is typically in

the range of about 5000 to about 50.000 psi. Pressing the particles produces an aggregate

structure, called a green ceramic, which retains its shape after removal from the die.

One forming technique used for spray dried or granulated material is roll

compaction, also referred to as roll pressing. This technique takes a dry powder and

crushes it between two rollers in a continuous process. This process produces sheets of

ceramic of various widths and thicknesses. These sheets can be cut to shape and sintered

to produce the final ceramic body. The process is commonly used to produce ceramic

substrates for the electronics industry.

Dry pressing involves filling a shaped die with spray dried or granulated powder

and pressing it at high pressures. The pressing occurs through movable pistons at the top

and/or bottom of the die cavity. The process can be used to produce fairly complex

geometries in a single forming step. The ceramic body that results is ejected from the die

and sintered to produce a final ceramic product. Isostatic pressing is similar to dry pressing in that a ceramic powder is pressed in

a die cavity. In isostatic pressing, however, all or part of the die wall consists of a

flexible material. After filling the die cavity with powder, the die is submerged in a

liquid pressure chamber and pressure is applied to squeeze the die and compact the

powder. Unlike dry pressing, no movable parts are involved. Isostatic pressing is

commonly used on large or very long parts to minimize cracking or lamination of the

final ceramic green body.

Extrusion involves the pushing of a concentrated, plastic, slurry through an

orifice. The orifice is of the size and shape of the desired ceramic body. This process is

commonly used to produce ceramic tubes or similarly shaped pieces. The slurry used is

prepared from dry powders which are mixed with water, organic binders and lubricants,

and a coagulant. This slurry is usually predried in a filter press or similar apparatus to

remove excess water and thicken the slurry to a plastic material. The material is then

extruded through a press which is either piston or screw driven. The extruded material is

cut to length, dried, and sintered.

Jiggering is commonly used in the whiteware industry to shape an extruded or

filter pressed ceramic slurry. Typically, a portion of the plastic slurry is placed on a

rotating wheel and shaped by rollers and/or knife blades to a desired geometry. This

bodv is then dried and sintered. .Another ceramic forming method, that is used for parts of complex shape, is slip

casting. In slip casting, a concentrated ceramic slurry (slip) is poured into a mold with an

internal shape of the desired ceramic body. The slurry used must be highly concentrated

to prevent settling of particles and/or excessive shrinkage during drying. At the same

time, the slip must be fluid enough to completely fill the mold and allow escape of air

bubbles. The presence of a polymeric binder adds strength to the cast body preventing

breakage during mold removal and handling of the body prior to sintering.

Heating the aggregate structure drives off volatile materials such as water, and

burns off organic materials, such as binders or surfactants. When a sufficiently high

temperature is reached, the particles of the aggregate structure begin to fuse, but do not

fuse completely, and become fastened to one another to reproduce a relatively strong

fired ceramic material having essentially the desired shape.

The slurry is. for example, spray dried to produce substantially dry particles. The

particles are preferably pressed to produce an aggregate, green ceramic structure and

heated to produce a fired ceramic material. Alternatively, the particles can be formed into

an aggregate, green ceramic structure by roll compaction or other well-known methods.

need exists for improved binders which provide still greater strength and/or high density

in green ceramic materials. Greater green strength reduces breakage during handling of

the green ceramics and. generally, is associated with higher quality fired ceramics. Preferably, the improved binders would be cheaper and more versatile than previously

known binders.

The present invention also relates to a method for dispersing ceramic materials.

In particular, the present invention relates to a method for dispersing one or more ceramic

materials in an aqueous medium by using a polymeric dispersant formed from acid-

containing monomers and hydroxy functional monomers.

Ceramic materials are often used to prepare lightweight, strong, thermally and

chemically resistant products. Because of difficulties associated with the handling of

solid ceramic materials, it is desirable for the ceramic materials to be in the form of an

aqueous dispersion. Aqueous dispersions of ceramic materials are. however, often

unstable, exhibiting sediment formation upon standing. Upon standing, the dispersion

agglomerates and becomes non-homogeneous, and creates difficulty in handling. These

agglomerates may also damage pipes, pumps, and other dispersion handling mechanical

equipment. The use of dispersants overcomes these difficulties, and also improves

strength and density of formed ceramic parts, particularly those made by dry press, slip

casting, and tape casting processes.

Polymers are known for use as dispersants for ceramic materials. Typical

polymeric dispersants for ceramic materials include polymers formed from acid-

containing monomers such as. for example. poly(acrylic acid) and poly(methacrylic acid).

For example, anionic polymers produced by hydrolyzing a terpolymer of maleic anhydride, N-vinylpyrrolidinone and a vinyl compound selected from the group

consisting of acrylic acid, acrylamide. methyl methacrylate and butyl vinyl ether is

disclosed in U.S. Patent No. 5.266.243. Additionally, polymeric dispersants consisting

of from 5 to 95 percent by weight of one or more hydroxy functional monomers and from

95% to 5% by weight of one or more acid-containing monomers are disclosed in U.S.

Patent Nos. 5,567.353 and 5.532.307. The hydroxy functional monomer is selected from

the group consisting of hydroxypropyl acrylate. hydroxypropyl methacrylate.

hydroxyethyl acrylate. hydroxyethyl methacrylate. allyl alcohol, allyloxyethanol. allyl

propoxylate. vinyl acetate. l-butene-3.4-diol and 3-allyloxy-1.2-propane diol.

Furthermore, imidized aery lie polymers have been disclosed for the increase of

flowability in cement compositions in U.S. Patent No. 5,393.343.

While such polymers perform adequately in dispersing some ceramic materials,

certain ceramic materials are more difficult to disperse, and conventional polymeric

dispersants are not adequate. Ceramic materials which present particular difficulty in

forming dispersions include nitrides such as. for example, boron nitride. U. S. Pat. No.

5.209.885 describes dispersing silicon nitride for extrusion by the use of a graft

copolymer comprising a polyoxyalkylene backbone with polyacrylate side chains.

The present invention seeks to provide a method for dispersing ceramic material,

including several ceramic materials known to be difficult to disperse. Summary of the Invention

Methods for dispersing and binding ceramic materials in aqueous media are

materials.

Description of the Invention

Each of the five classes of polymers described herein may also have utility for

mining applications such as dust control and red mud flocculation: for cooling water

treatment such as scale and corrosion inhibition, such as for calcium carbonate and

calcium phosphonate scale inhibition: for ceramics applications such as green machining

and core forming process of gypsum wall board: for the preparation of gypsum slurries,

for reverse osmosis system treatment such as desalination scale inhibition, for oilfield

applications such as reverse emulsion breakers and barium sulfate and calcium carbonate

scale inhibition; for treatment of pulp and paper systems such as scale control, sizing

agents, dry strength additives and release agents and as a treatment for solids/liquids

separation. Such structures can be used in many applications such as dispersants in water

treatment, scale inhibitors in natural and industrial waters, flocculants, coagulants, and

thickeners among others.

The present invention relates to polymeric binders for preparing ceramic

materials. The method can be used to produce fired ceramic materials from ceramic powders. Suitable powders include but are not limited to: aluminum oxide, silicon

nitride, aluminum nitride, silicon carbide, silicon oxide, magnesium oxide, lead oxide,

zirconium oxide, titanium oxide and neodymium oxide. Aluminum oxide is presently

preferred. The powder can have a weight-averaged median particle size in the range of a

few nanometers to about 1/2 millimeter. Powders having a median size in the range of

about 0.5 to about 10 micrometers are preferred.

In one aspect, the ceramic powder is mixed with an aqueous solution containing a

polymer to produce a slurry. Preferably, the solution is prepared using deionized water.

The slurry may also contain lubricants, plasticizers and surfactants, such as dispersants

and anti-foaming agents.

It is also recognized that the properties of a ceramic such as. but not limited to.

green density, surface quality or milling characteristics, may be varied as desired by

adjusting the ratio of the different monomers in a copolymer. the degree of hydrolysis of

a copolymer and the molecular weight of the polymer used in the binder composition.

Several factors may affect the preferred quantity of the polymeric dispersant to be

used in forming a dispersion of a ceramic material. Because of the range of ceramic

materials that might be used for particular applications, and because different applications

may require different solids levels, the amount of dispersant may range from 0.01 percent

to 3 percent by weight based on powder mass. For example, the morphology of the

ceramic material may affect the optimum level of dispersant. Generally, the more spherical the particles, the less dispersant is required. The surface area of the ceramic

material may also affect the optimum quantity of dispersant. The higher the surface area

of a ceramic material, generally the more dispersant is required.

The ionic strength (or water hardness) of the dispersion may also affect the

optimum level of dispersant. Dispersions having higher ionic strength generally require

more dispersant. The ionic strength of the dispersion can be controlled, for example, by

using distilled, deionized. partially distilled or partially deionized water, by controlling

the level of contaminants introduced into the dispersion by the various components of the

dispersion or by adding one or more conventional chelating agents to the dispersion.

Preferably, the water hardness of the dispersion which is attributable to multivalent

cations is below about 600 parts per million ("ppm") expressed as Ca^"+. most preferably

below about 500 ppm. Generally, the higher the pH of the dispersion, the lower the

quantity of dispersant required. For purposes of the present invention, it is preferred that

the pH not be below 6. The polymeric dispersant of the present invention works

particularly well at a pH of about 8 to 1 1.

Ceramic materials useful in forming a dispersion according to the method of the

present invention include oxide, nitride, and carbide ceramics; in particular: alumina,

aluminum nitride, aluminum titanate, lead titanate, boron nitride, silicon, silicon carbide,

sialon. zirconium nitride, zirconium carbide, zirconium boride. boron carbide, tungsten carbide. tungsten boride, tin oxide, ruthenium oxide, yttrium oxide, magnesium oxide,

calcium oxide, chromic oxide, ferrites. and mixtures thereof among others.

As used herein, "ceramic materials" include ferrites. The ferrites are

ferrimagnetic oxides. The classes of ferrites include spinel ferrites. which are oxides

having the general formula MO.Fe₂O . where "M" represents a divalent metal ion or a

mixture of ions. Particular examples of spinel ferrites are Fe₃O₄ and NiFe₂0 . Another

class of ferrites is the orthoferrites. with the general formulas MFeO₃. MCoO,. or

MMnO₃. where M represents La. Ca. Sr. Ba Y. or a rare earth ion. Another class of

ferrites is the hexagonal ferrites. with the general formula AB₁₂O|₉, where A is a divalent

metal and B is a trivalent metal. Examples of hexagonal ferrites include PbFe,_:O|₉

The term clays as used herein denotes materials utilized in whiteware

manufacture. Examples are kaolin and ball clay among others.

The polymers described herein for the practice of this invention may range in

molecular weight from about 1.000 to about 1.000.000. Preferably, the molecular weight

will be from about 5.000 to about 100.000. For the polymers defined herein, the mer

units defined by formulas I-IV will range from 5 to 75% of the total number of mer units

in the polymer. Preferably, the mer units defined as formulas I-IV will be at least 30% of

the total number of mer units in the polymer.

The polymer classes described herein contain amide, ester and ether mer units

which are functionalized with pendant groups. These pendant groups confer favorable properties to the polymer for use as a binder for ceramic materials. The polymers may be

produced by polymerization using specific monomers, such as might be produced by the

copolymerization of acrylic acid with a poly(ethylene glycol) methacrylate comonomer.

The polymer so produced would contain a hydrophilic backbone with pendant groups

comprised of poly(ethylene glycol). Alternatively, pendant groups could be introduced

into the polymer after polymerization. For example, polyacrylic acid could be amidated

with an ethoxylateαVpropoxylated amine. such as those available from Texaco under the

trade name Jeffamine series, to produce a polymer with a hydrophilic backbone and

ethyleneoxy/propyleneoxy pendant groups. During the amidation process, cyclic imide

structures might form between two adjacent carboxylate or carboxamide units on the

polymer backbone. These imide structures are not expected to have an adverse effect on

the performance of the polymers as a ceramic processing aid.

The invention is a binder for ceramic materials that comprises a water soluble

polymer having:

A) a mer unit of the formula

R³ R°

C CH-

1 • wherein R is selected from the group consisting of hydrogen, and C_{ - C, alkyl: p and q

are integers from 1 - 10: R^" and R^'' are selected from the group consisting of hydrogen

and C, - C₃ alkyl: Het and Het^" selected from the group consisting of oxygen and

nitrogen: R is selected from the group consisting of hydrogen, phosphate, sulfate and ^

- C₂o alkyl R^" and R^h are selected from the group consisting of hydrogen, carboxylate.

C _| - C₃ alkyl. and a cycloalkyl group of 1 to 6 carbon atoms formed by the linkage of R^"""

and R as a ring; and

B) a mer unit selected from the group consisting of acrylic acid, methacrylic

acid, acrylamide. maleic anhydride, itaconic acid, vinyl sulfonic acid, styrene sulfonate.

N-tertbutylacrylamide. butoxymeth\ lacrylamide, N.N-dimethylacrylamide. sodium

acrylamidomethyl propane sulfonic acid, vinyl alcohol, vinyl acetate, N-vinyl

pyrrolidone. maleic acid, and combinations thereof.

As used herein, the monomers described above may be in either their salt or acid

forms. Preferably the binder has the formula wherein p=l : q=l ; R\ R R⁴. R\ and R⁶

are hydrogen; and Het and Het^" are oxygen in formula I of step A: and the mer units of

step B are acrylic acid and acrylamide.

The invention is also an unfired. ceramic precursor material comprising a mixture

of:

A. a ceramic powder selected from the group consisting of aluminum oxide,

silicon nitride, aluminum nitride, silicon carbide, silicon oxide, magnesium oxide, lead

oxide, zirconium oxide, titanium oxide, steatite, barium titanate. lead zirconate titanate.

clays, ferrite. yttrium oxide, zinc oxide, tungsten carbide, sialon. neodvmium oxide and

combinations thereof and

B. a water soluble polymer having:

i) a mer unit of the formula

R⁵ R°

C CH

wherein R¹ is selected from the group consisting of hydrogen, and C, - C₃ alkyl; p and q

are integers from 1 - 10: R^: and R are selected from the group consisting of hydrogen and C| - C₃ alkyl; Het and Het^" selected from the group consisting of oxygen and

nitrogen; R is selected from the group consisting of hydrogen, phosphate, sulfate and C,

- C₂₀ alkyl; R^D and R are selected from the group consisting of hydrogen, carboxylate.

C, - C₃ alkyl. and a cycloalkyl group of 1 to 6 carbon atoms formed by the linkage of R^{"^}

and R as a ring; and

ii) a mer unit selected from the group consisting of acrylic acid,

methacrylic acid, acrylamide. maleic anhydride, itaconic acid, vinyl sulfonic acid,

styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl alcohol,

vinyl acetate. N-vinyl pyrrolidone. maleic acid, and combinations thereof.

The water-soluble polymer preferably has a structure wherein p=l : q=l : R^". R^" .

R⁴. R^'\ and R⁶ are hydrogen: Het¹ and Het^" are oxygen in formula I of step A; and the

mer units of step ii are acrylic acid and acrylamide.

The invention is also a method for preparing a ceramic material, which comprises

the steps of:

A) mixing a ceramic powder with an aqueous solution containing a water-soluble

polymer to produce a slurry, said water-soluble polymer having:

i) a mer unit of the formula R⁵ R°

^■ C CH-

(CHR^:CHR³ Het'-τ -tCHR²CHR³Het R

wherein R , ι i •s selected from the group consisting of hydrogen, and C , - C₃ alkyl: p

and q are integers from 1 - 10; R^" and R are selected from the group consisting of

hydrogen and C, - C₃ alkyl: Het and Het^" selected from the group consisting of oxygen

and nitrogen: R is selected from the group consisting of hydrogen, phosphate, sulfate and

- C₂o alkyl; R^ and R are selected from the group consisting of hydrogen,

carboxy late. C, - C₃ alkyl. and a cycloalkyl group of 1 to 6 carbon atoms formed by the

linkage of R' and R as a ring: and

ii) a mer unit selected from the group consisting of acrylic acid,

methacrylic acid, acrylamide. maleic anhydride, itaconic acid, vinyl sulfonic acid, styrene

sulfonate, N-tertbutylacrylamide. butoxymethylacrylamide. N.N-dimethylacrylamide.

sodium acry amidomethyl propane sulfonic acid, vinyl alcohol, vinyl acetate, N-vinyl

pyrrolidone. maleic acid, and combinations thereof;

B) drying the slurry by a process selected from the group consisting of fluidized

bed spray drying, and spray drying to produce particles which include said copolymer; C) compacting the particles by a process selected from the group consisting of dry-

pressing, roll compaction and isostatic pressing to produce an aggregate structure: and

D) heating the aggregate structure to produce a fired ceramic material.

The water-soluble polymer preferably has a structure wherein p=l : q=l : R^". R .

R . R^"\ and R are hydrogen: Het and Het^" are oxygen in formula I of step i: and the

mer units of step ii are acrylic acid and acrylamide.

Moreover, for the practice of this invention, the particles may be produced by

granulation and the step of compacting the particles to produce an aggregate structure

may be selected from the group consisting of dry pressing and isostatic pressing.

Alternatively, other methods of making ceramics which are suitable for the

purposes of this invention include extrusion, jiggering. tape casting and slip casting.

The invention is a binder for ceramic materials that comprises a water soluble

polymer having:

A) a mer unit of the formula

R⁵ R⁶

C CH

C = O

O

II

wherein p is an integer from 1 - 10: R^" and R^" are selected from the group consisting of

hydrogen and C, - C₃ ajkyl: R is selected from the group consisting of hydrogen,

phosphate, sulfate and C, - C₂₀ alkyl: R^""1 and R are selected from the group consisting of

hydrogen, carboxylate. Ci - C alkyl. and a cycloalkyl group of 1 to 6 carbon atoms

formed by the linkage of R^'' and R*¹ as a ring, with the proviso that when p = 1. R^". R . R .

R and R are not all hydrogens, and with the proviso that when p = 1. R^? is not methyl;

and

B) a water-soluble mer unit selected from the group consisting of acrylic acid,

styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N,N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl alcohol. N-

vinyl pyrrolidone. maleic acid, and combinations thereof. As used herein, the monomers described above may be in either their salt or acid

forms.

of:

A. a ceramic powder selected from the group consisting of aluminum oxide,

oxide, zirconium oxide, titanium oxide, steatite, barium titanate, lead zirconate titanate.

clays, ferrite, yttrium oxide, zinc oxide, tungsten carbide, sialon, neodvmium oxide and

combinations thereof and

B. a water soluble polymer having:

i) a mer unit of the formula

R- R°

^■ C CH

C = O

C)

II wherein p is an integer from 1 - 10: R^" and R^J are selected from the group consisting of

hydrogen and C_\ - C₃ alkyl; R is selected from the group consisting of hydrogen,

phosphate, sulfate and C, - C_:0 alkyl: R^"" and R are selected from the group consisting of

hydrogen, carboxylate. C] - C₃ alkyl. and a cycloalkyl group of 1 to 6 carbon atoms

formed by the linkage of R^{"^} and R as a ring, with the proviso that when p = 1. R^". R^J. R .

R^? and R are not all hydrogens, and with the proviso that when p = 1. R^_ is not methyl:

and

ii) a water-soluble mer unit selected from the group consisting of

acrylic acid, methacrylic acid, acrylamide. maleic anhydride, itaconic acid, vinyl sulfonic

acid, styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

vinyl pyrrolidone. maleic acid, and combinations thereof.

the steps of:

A) mixing a ceramic powder with an aqueous solution containing a water-

soluble polymer to produce a slurry, said water-soluble polymer having:

i) a mer unit of the formula R^> R°

C CH '

C = O

O

II

wherein p is an integer from 1 - 10; R^" and R^J are selected from the group consisting of

hydrogen and C) - C₃ alkyl; R , 4 i •s selected from the group consisting of hydrogen,

phosphate, sulfate and C| - C₂₀ alkyl: R^' and R are selected from the group consisting of

hydrogen, carboxylate. Cj - C alkyl. and a cycloalkyl group of 1 to 6 carbon atoms

formed by the linkage of R^~ and R as a ring, with the proviso that when p = 1 , R\ R^J. R .

R^ and R are not all hydrogens, and with the proviso that when p = 1. R^{"^} is not methyl:

and

ii) a water-soluble mer unit selected from the group consisting of

acrylic acid, methacrylic acid, acrylamide, maleic anhydride, itaconic acid, vinyl sulfonic

acid, styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide, sodium acry amidomethyl propane sulfonic acid, vinyl alcohol. N-

vinyl pyrrolidone, maleic acid, and combinations thereof; B) drying the slurry by a process selected from the group consisting of

fluidized bed spray drying, and spray drying to produce particles which include said

copolymer;

C) compacting the particles by a process selected from the group consisting

of dry pressing, roll compaction and isostatic pressing to produce an aggregate structure:

and

D) heating the aggregate structure to produce a fired ceramic material.

Moreover, for the practice of this method, the particles may be produced by

Alternatively, other methods of making ceramics which are suitable for the

The invention is also a method for dispersing one or more ceramic materials in an

aqueous medium, comprising utilizing an effective dispersing amount of a polymeric

dispersant comprising a water soluble polymer having:

A) a mer unit of the formula R⁵ R⁶

- CH

C = O

O

II

hydrogen and Cj - C₃ alkyl: R is selected from the group consisting of hydrogen,

phosphate, sulfate and C, - C₂₀ alkyl; R^J and R are selected from the group consisting of

hydrogen, carboxylate. C, - C₃ alkyl. and a cycloalkyl group of 1 to 6 carbon atoms

formed by the linkage of R^? and R^b as a ring, with the proviso that when p = 1. R^". R^J. R .

R^ and R are not all hydrogens, and with the proviso that when p = 1 , R^? is not methyl;

and

B) a water-soluble mer unit selected from the group consisting of acrylic acid,

sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-dimethylacrylamide,

sodium acrylamidomethyl propane sulfonic acid, vinyl alcohol, N-vinyl pyrrolidone,

maleic acid, and combinations thereof. Moreover the one or more ceramic materials may be selected from the group

consisting of alumina, aluminum nitride, aluminum titanate. lead titanate.

boron nitride, silicon, silicon carbide, sialon. zirconium nitride, zirconium carbide,

zirconium boride, boron carbide, tungsten carbide, tungsten boride. tin oxide, ruthenium

oxide, yttrium oxide, magnesium oxide, calcium oxide, and ferrites.

Furthermore, the invention is also an aqueous dispersion of ceramic material

prepared according to the method above.

The invention is also a binder for ceramic materials that comprises a water soluble

polymer having:

A) a mer unit of the formula

R⁵ R⁶

C CH

wherein p is an integer from 1 - 10; R^: and R^J are selected from the group consisting of

hydrogen and C, - C₃ alkyl: R⁴ is selected from the group consisting of hydrogen,

phosphate, sulfate and C, - C_2ϋ alkyl; R^? and R⁶ are selected from the group consisting of

hydrogen, carboxylate. C , - C₃ alkyl. and a cycloalkyl group of 1 to 6 carbon atoms formed by the linkage of R^ and R as a ring, with the proviso that when p = 1. R". R

R . R^ and R are not all hydrogens and with the proviso that when p = 1. R^" is not

methyl and with the proviso that when p = 1. R^J is not methyl; and

B) a water-soluble mer unit selected from the group consisting of acrylic acid,

sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-dimethylacrylamide.

sodium acrylamidomethyl propane sulfonic acid, vinyl alcohol. N-vinyl pyrrolidone.

maleic acid, and combinations thereof.

forms.

of:

A. a ceramic powder selected from the group consisting of aluminum oxide,

oxide, zirconium oxide, titanium oxide, steatite, barium titanate, lead zirconate titanate,

clays, ferrite. yttrium oxide, zinc oxide, tungsten carbide, sialon, neodvmium oxide and

combinations thereof and

B. a water soluble polymer having:

i) a mer unit of the formula R³ R^c

^■ C CH

wherein p is an integer from 1 - 10: R^" and R^J are selected from the group consisting of

hydrogen and C, - C₃ alkyl: R is selected from the group consisting of hydrogen,

phosphate, sulfate and C, - C₂₀ alkyl: R^ and R are selected from the group consisting of

formed by the linkage of R^ and R as a ring, with the proviso that when p = 1. R^". R\

R . R^{'^} and R are not all hydrogens and with the proviso that when p = 1. R^" is not

methyl and with the proviso that when p = 1. R^J is not methyl; and

ii) a water-soluble mer unit selected from the group consisting of

acid, styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide, sodium acrylamidomethyl propane sulfonic acid, vinyl alcohol. N-

vinyl pyrrolidone. maleic acid, and combinations thereof.

the steps of: A) mixing a ceramic powder with an aqueous solution containing a water-soluble

polymer to produce a slurry, said water-soluble polymer having:

i) a mer unit of the formula

R⁵ R⁶

C CH

wherein p is an integer from 1 - 10: R^" and R^' are selected from the group consisting of

hydrogen and C_j - C₃ alkyl; R is selected from the group consisting of hydrogen,

phosphate, sulfate and Ci - C₂₀ alkyl: R^" and R are selected from the group consisting of

hydrogen, carboxylate. C, - C alkyl. and a cycloalkyl group of 1 to 6 carbon atoms

formed by the linkage of R and R as a ring, with the proviso that when p = 1. R\ R^J.

R⁴. R^{'^} and R⁶ are not all hydrogens and with the proviso that when p = 1. R^" is not

methyl and with the proviso that when p = 1. R^" is not methyl: and

ii) a water-soluble mer unit selected from the group consisting of

acid, styrene sulfonate. N-tertbutylacrylamide, butoxymethylacrylamide, N.N- dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl alcohol. N-

vinyl pyrrolidone. maleic acid, and combinations thereof;

B) drying the slurry by a process selected from the group consisting of

copolymer;

C) compacting the panicles by a process selected from the group consisting

and

D) heating the aggregate structure to produce a fired ceramic material.

Moreover, for the practice of this invention, the panicles may be produced by

Alternatively, other methods of making ceramics which are suitable for the

dispersant comprising a water soluble polymer having:

A) a mer unit of the formula R³ R°

C CH

CH,

O

hydrogen and ^ - C₃ alkyl; R is selected from the group consisting of hydrogen,

phosphate, sulfate and C| - C₂o alkyl: R^{'^} and R⁶ are selected from the group consisting of

formed by the linkage of R^" and R as a ring, with the proviso that when p = 1. R^". R^J.

R . R^' and R are not all hydrogens and with the proviso that when p = 1. R^" is not

methyl and with the proviso that when p = 1. R³ is not methyl; and

B) a water-soluble mer unit selected from the group consisting of acrylic acid,

styrene sulfonate. N-tertbutylacrylamide. buioxymethylacrylamide. N,N-

vinyl pyrrolidone. maleic acid, and combinations thereof.

Furthermore, the one or more ceramic materials may be selected from the group

consisting of alumina, aluminum nitride, aluminum titanate, lead titanate. boron nitride, silicon, silicon carbide, sialon. zirconium nitride, zirconium carbide,

oxide, yttrium oxide, magnesium oxide, calcium oxide, and ferrites.

The invention is also an aqueous dispersion of ceramic material prepared

according to the method described above.

The invention is also a binder for ceramic materials that comprises a water-soluble

polymer having:

A) a mer unit of the formula

R⁵ R⁶

- CH '

IV

wherein R , ι i •s selected from the group consisting of hydrogen, and C, - C₃ alkyl; p is an

integer from 1 - 10; R , 4 • is selected from the group consisting of hydrogen, phosphate. sulfate and C, - C₂₀ alkyl; R^? and R° are selected from the group consisting of hydrogen,

carboxylate, C, - C₃ alkyl. and a cycloalkyl group of 1 to 6 carbon atoms formed by the

linkage of R^ and R as a ring: and

B) a mer unit selected from the group consisting of acrylic acid, methacrylic

N-tertbutylacrylamide. butoxymethylacrylamide. N.N-dimefhylacrylamide. sodium acrylamidomefhyl propane sulfonic acid, vinyl alcohol, vinyl acetate. N-vinyl

pyrrolidone. maleic acid, and combinations thereof.

forms.

Preferably, the binder is of a structure wherein p=2; R , R , R\ and R^h are

hydrogen in formula IV of step A: and the mer units of step B are acrylic acid and

acrylamide.

Additionally, the binder may be of a structure wherein p=3; R^{"^} . R . and R are

hydrogen: R is methyl in formula IV of step A: and the mer units of step B are acrylic

acid and acrylamide.

Moreover, for the practice of this invention, mer units of general structure IV

with polyoxy N-pendant groups

also be effective, as well as the alkyloxy groups

described above. For example multihydroxy N-pendant groups such as those alkyl derivatives having dihydroxy and trihydroxy. as well as alkyl derivatives containing

diether and triether moieties may also be effective.

of:

A) a ceramic powder selected from the group consisting of aluminum oxide,

combinations thereof and

B) a water-soluble polymer having:

i) a mer unit of the formula

R R°

C CH

IV

wherein R is selected from the group consisting of hydrogen, and C - C₃ alkyl; p is an

integer from 1 - 10; R is selected from the group consisting of hydrogen, phosphate,

sulfate and C, - C₂₀ alkyl: R^{"^} and R° are selected from the group consisting of hydrogen,

carboxylate. C_{ - C alkyl. and a cycloalkyl group of 1 to 6 carbon atoms formed by the

linkage of R^ and R as a ring: and

ii) a mer unit selected from the group consisting of acrylic acid,

styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

vinyl acetate. N-vinyl pyrrolidone. maleic acid, and combinations thereof.

Preferably, the water-soluble polymer of the method described above has a

structure wherein p=2; R . R . R\ and R are hydrogen for formula IV of step i; and the

mer units of step ii are acrylic acid and acrylamide.

Alternatively, the water-soluble polymer of the method described above has a

structure wherein p=3: R^' R¹ . and R are hydrogen; R is methyl for formula IV of step

i and the mer units of step ii are acrylic acid and acrylamide.

the steps of: A) mixing a ceramic powder with an aqueous solution containing a water-

soluble polymer to produce a slurry, said water-soluble polymer having:

i) a mer unit of the formula

R⁵ R⁶

C CH

wherein R is selected from the group consisting of hydrogen, and C - C₃ alkyl: p is an

integer from 1 - 10: R is selected from the group consisting of hydrogen, phosphate,

sulfate and C, - C ₀ alkyl: R^"' and R⁶ are selected from the group consisting of hydrogen,

carboxylate. C, - C₃ alkyl. and a cycloalkyl group of 1 to 6 carbon atoms formed by the

linkage of R^{'^} and R as a ring: and

ii) a mer unit selected from the group consisting of acrylic acid,

methacrylic acid, acrylamide, maleic anhydride, itaconic acid, vinyl sulfonic acid, styrene

sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide, N,N-dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl alcohol, vinyl acetate. N-vinyl

pyrrolidone. maleic acid, and combinations thereof;

B) drying the slurry by a process selected from the group consisting of

copolymer;

C) compacting the particles by a process selected from the group consisting

and

D) heating the aggregate structure to produce a fired ceramic material.

Preferably, the water-soluble polymer of the method described above has a

structure wherein p=2; R . R . R\ and R⁶ are hydrogen for formula IV of step I and the

mer units of step ii are acrylic acid and acrylamide.

Alternatively, the water-soluble polymer of the method described above has a

structure wherein p=3: R^'' . R⁶ . and R¹ are hydrogen: R is methyl for formula IV of step

i and the mer units of step ii are acrylic acid and acrylamide.

Furthermore, in the method described above, the particles may be produced by

Alternatively, other methods of making ceramics which are suitable for the

purposes of this invention include extrusion, jiggering, tape casting and slip casting. The invention is also a method for dispersing one or more ceramic materials in an

dispersant comprising a water-soluble polymer having:

A) a mer unit of the formula

R- R^c

C CH

IV

wherein R is selected from the group consisting of hydrogen, and C] - C₃ alkyl; p is an

sulfate and C, - C₂₀ alkyl: R' and R^h are selected from the group consisting of hydrogen,

carboxylate. C , - C₃ alkyl. and a cycloalkyl group of 1 to 6 carbon atoms formed by the

linkage of R^? and R as a ring; and B) a mer unit selected from the group consisting of acrylic acid, methacrylic •

N-tertbutylacrylamide. butoxymethylacrylamide, N.N-dimethylacrylamide. sodium

acrylamidomethyl propane sulfonic acid, vinyl alcohol, vinyl acetate. N-vinyl

pyrrolidone, maleic acid, and combinations thereof.

Preferably, the water-soluble polymer of the method described above has a

structure wherein p=2: R . R . R\ and R^b are hydrogen for formula IV of step A: and the

mer units of step B are acrylic acid and acrylamide.

Alternatively, the water-soluble polymer of the method described above has a

structure wherein p=3: R^ . R . and R are hydrogen: R is methyl for formula IV of step

A: and the mer units of step B are acrylic acid and acrylamide.

For the practice of this invention, the one or more ceramic materials may be

selected from the group consisting of alumina, aluminum nitride, aluminum titanate. lead

titanate. boron nitride, silicon, silicon carbide, sialon, zirconium nitride, zirconium

carbide, zirconium boride. boron carbide, tungsten carbide, tungsten boride, tin oxide,

ruthenium oxide, yttrium oxide, magnesium oxide, calcium oxide, and ferrites.

Moreover, the method may include an aqueous dispersion of ceramic material.

The following examples are presented to describe preferred embodiments and

utilities of the invention and are not meant to limit the invention unless otherwise stated

in the claims appended hereto. Example 1

The synthesis of an ammonium acrylate/ N-(hydroxyethoxy)ethyl acrylamide

copolymer was effected with the following reactants in the following amounts:

Reactant Amount (g)

Poly(AA). 25.6 weight % in water 100.00 Aminoethoxyethanol 1 1.92

Ammonium Hydroxide. 29 weight % 2.51

To prepare the polymer. poly(AA) (25.6 weight percent poly(acrylic acid)

solution. pH = 3.8. 16.000 MW) was placed in a beaker, which was cooled using an ice

bath. Aminoethoxyethanol (available from Huntsman Petrochemical Co.. in Houston.

Texas) was added dropwise into the poly(acrylic acid)/water solution with vigorous

stirring. Afterwards, the solution was stirred for another 15 minutes. The pH of the

reaction mixture was measured using water-wet pH strips. Aqueous caustic was added to

adjust the pH to about 5. Next, the reaction mixture was transferred into a 300 mL Pan-

reactor with a pressure rating of at least 800 psi. The reactor then was assembled and

purged with nitrogen for 60 minutes. The Pan reactor was then slowly heated to 160°C

(or less, as the case may be) and held at that temperature for 8 hours (or more, as the case

may be). Afterwards, the reactor was cooled to room temperature and the pressure

released. The product was then transferred to storage.

^JC NMR confirmed product formation. The content of N-(hydroxyethoxy)ethyl

acrylamide was 21 mole %. based on the total moles of mer units on the polymer, which represents both secondary amide and imide mer units. The polymer^'s molecular weight

was 24.000.

Example 2

The synthesis of an ammonium acr late/acrylamide/N-(hydroxyethoxy)ethyl

acrylamide terpolymer was effected in the following manner with the reactants in the

amounts listed below:

Reactant Amount (g)

Poly(NH₄AA/AcAm). 50/50 mol % solution polymer. 38.2 weight % 300.00 Aminoethoxyethanol 1 14.00

To prepare the polymer. Poly(NH₄AA/AcAm) (50/50 mol % ammonium

acrylate/acrylamide copolymer. 38.2 weight percent. pH = 5.5, 33.000 MW) was placed

in a beaker, which was cooled using an ice bath. Aminoethoxyethanol (available from

Huntsman Petrochemical Co.. in Houston. Texas) was added dropwise into the above

water solution with vigorous stirring (pH = 10.1 ). Afterwards, the solution was stined for

another 15 minutes. The pH of the reaction mixture was measured using water-wet pH

strips. Next, the reaction mixture was transfened into a 600 mL Pan reactor with a

pressure rating of at least 800 psi. The reactor then was assembled and purged with

nitrogen for 60 minutes. The Pan reactor was then slowly heated to 138°C and held at that temperature for 14 hours. Afterwards, the reactor was cooled to room temperature

and the pressure released. The product was then transfened to storage.

C NMR confirmed product formation. The content of N-(hydroxyethoxy)ethyl

acrylamide was 33.3 mole %. based on the total moles of mer units on the polymer. The

polymer had a molecular weight of 35.000. and a mole ratio of N-(hydroxyethoxy)ethyl

acrylamide/acrylic acid/acrylamide of 33/41/26.

Example 3

The synthesis of a sodium acrylate/acrylamide/N-(hydroxyethoxy)ethyl

amounts listed below:

Reactant Amount (g

Poly(NaAA/AcAm). 50/50 mol % solution polymer. 32.0 weight % 100.00 Aminoethoxyethanol 32.00

Sulfuric Acid (95%) 1 1.5

To prepare the polymer. Poly(NaAA/AcAm) (50/50 mol % sodium

acrylate/acrylamide copolymer. 32.0 weight %. pH = 5.2. 1 1 ,000 MW) was placed in a

beaker, which was cooled using an ice bath. Aminoethoxyethanol (available from

water solution with vigorous stining. Afterwards, the solution was stined for another 15

minutes. The pH of the reaction mixture was measured using water-wet pH strips. Sulfuric acid was added to adjust the pH to about 5.6. Next, the reaction mixture was

transfened into a 300 mL Parr reactor with a pressure rating of at least 800 psi. The

reactor then was assembled and purged with nitrogen for 60 minutes. The Pan reactor

was then slowly heated to 138°C and held at that temperature for 12 hours. Afterwards.

the reactor was cooled to room temperature and the pressure released. The product was

then transfened to storage.

^JC NMR confirmed product formation. The content of N-(hydroxyethoxy)ethyl

acrylamide was 33 mole %. based on the total moles of mer units on the polymer. The

mole ratio was 42/22/33 of acrylic acid/acrylamide(including 3% imide mer units )/N-

(hydroxyethoxy)ethyl acrylamide (including imide mer units). The product polymer had

a molecular weight of 12.000.

Example 4

The synthesis of a sodium acrylate/acrylamide/N -Methoxypropyl acrylamide

terpolymer was effected in the following manner with the reactants in the amounts listed

below:

Reactant Amount(g)

Poly(NaAA/AcAm). 50/50 mol % solution polymer. 32.0 weight % 100.00 Methoxypropylamine 23.32

Sulfuric Acid (95%) 1 1.23 To prepare the polymer, Poly(NaAA/AcAm) (50/50 mol%, 32.0 weight %. pH =

5.2, 1 1.000 MW) was placed in a beaker, which was cooled using an ice bath.

Methoxypropylamine (available from Aldrich Chem. Co.. in Milwaukee. WI) was added

dropwise into the above water solution with vigorous stirring. Afterwards, the solution

was stined for another 15 minutes. The pH of the reaction mixture was measured using

water- et pH strips. Sulfuric acid was added to adjust the pH to about 5.6. Next, the

reaction mixture was transfened into a 300 mL Parr reactor with a pressure rating of at

least 800 psi. The reactor then was assembled and purged with nitrogen for 60 minutes.

The Pan reactor was then slowly heated to 138°C and held at that temperature for 12

hours. Afterwards, the reactor was cooled to room temperature and the pressure released.

The product was then transfened to storage.

^{, J}C NMR confirmed product formation. The content of methoxypropyl

acrylamide was 34.2 mole %. based on the total moles of mer units on the polymer. The

mole ratio of the product was 41/17/34 which represents acrylic acid/acrylamide

(including 6% imide mer units)/methoxypropyl acrylamide (including imide mer units).

The product^'s molecular weight was 1 1.000.

Example 5

The synthesis of a sodium acrylate/acrylamide N-hydroxy(ethylamino)ethyl

amounts listed below: Reactant Amount(g)

PolyfNaAA/AcAm). 50 '50 mol % solution poKmer. 24 0 weight % 80 00

(Amιnoefh\ lamιne)ethanol 19 02

Sulfuπc Acid (95%) 12.23

To prepare the pohmer.

3 5. 15.000 MW) was placed in a beaker, which was cooled using an ice bath

lamιno)ethanol

trom Λldπch Chem Co . in Milwaukee. W'l) was

added dropwise into the above water solution with \ igorous stirnng Afterwards, the

solution was stined for another 15 minutes The pH of the reaction mixture was

measured using water-wet pH strips Sulfuπc acid was added to adjust the pH to about

5 6 Next, the reaction mixture was transfened into a 300 mL Parr reactor w ith a pressure

rating of at least 800 psi The reactor then was assembled and purged with nitrogen for

60 minutes The Pan reactor was then slow h heated to 138°C and held at that

temperature for 14 hours Afterwards, the reactor was cooled to room temperature and

the pressure released The product was then transfened to storage

^{1 J}C NMR confirmed product tormaiion The content of hydroxy(ethylamιno)

eth\ l acr lamide was 46 mole %. based on the total moles of mer units on the polymer,

representing both secondary amide and imide mer units The polymer also contained

51% of acrylic acid units The product poh mer's molecular weight was 15.000 Example 6

The synthesis of an acrylic acid/acrylamide/ N-(hydroxyethoxy)ethyl acrylamide

teφolymer was effected in the following manner with the reactants in the amounts listed

below:

Reactant AmounUg

Poly(AcAm). 50 weight % 50.00

Aminoethoxyethanol 12.9

Deionized water 50.0

Sulfuric Acid (95%) 6.1

To prepare the polymer. Poly(AcAm) (50wt%. available from Aldrich Chemical

Co.. 10.000 MW) was placed in a beaker, which was cooled using an ice bath.

Aminoethoxyethanol (available from Huntsman Petrochemical Co.. in Houston. Texas)

was added dropwise into the above water solution with vigorous stirring. Afterwards, the

solution was stined for another 15 minutes. The pH of the reaction mixture was

measured using water-wet pH strips. Sulfuric acid was added to adjust the pH to about

5.6. Next, the reaction mixture was transfened into a 300 mL Parr reactor with a pressure

rating of at least 800 psi. The reactor then was assembled and purged with nitrogen for

60 minutes. The Pan reactor was then slowly heated to 138°C and held at that

temperature for 14 hr. Afterwards, the reactor was cooled to room temperature and the

pressure released. The product was then transfened to storage.

¹ C NMR confirmed product formation. The content of N-(hydroxy ethoxy) ethyl acrylamide was 19.6 mole %. based on the total moles of mer units on the polymer. The

product^'s mole ratio was 32/44/20 which represents acrylic acid/acrylamide N-

(hydroxyethoxy) ethyl acrylamide.

Example 7

The synthesis of a 33/50/17 mole percent acrylic acid/acrylamide/N-

(hydroxyethyl) acrylamide terpolymer was effected in the following manner. To 100 g of

a 52/48 mole ratio AA/AcAm copolymer (42.7% polymer actives, weight average

molecular weight = 34.100) in a Parr reactor was added 17.4 g of ethanolamine. The pH

was adjusted with 8.32 g of 36% hydrochloric acid to between 5.0 to 5.5. The solution

was purged with nitrogen for 1.0 hour and heated at 138-142

°C for about 8 hours. NMR analysis results indicated the terpolymer composition was

38/52/10 N-(hydroxyethyl) acrylamide/ AA/AcAm. The weight average molecular

weight of the product was 128.000. indicating the polymer was lightly crosslinked. To

the stined half amount of the product was added dropwise 50% NaOH solution ( 19.24g)

at pH<l 1.39. The solution was further stined for 3.5 hours at room temperature. The pH

was adjusted to about 7 with 36% hydrochloric acid. The weight average molecular

• weight was 42,600. NMR analysis results showed this product was a terpolymer of

33/50/17 N-(hydroxyethyl)acrylamide/AA/Am. Example 8

The synthesis of a 35/51/14 mole percent N-(hydroxyethyl) acrylamide/acrylic

acid/acrylamide terpolymer was effected in the following manner. To 100 g of a 52/48

AA Am copolymer (42.7% polymer actives, weight average molecular weight 34.100) in

a Pan reactor was added 25.3 g. of ethanolamine. The pH was adjusted with 18.8 g of

36% hydrochloric acid to about 5.3. The solution was purged with nitrogen for 1.0 hour

and heated at 136 - 138°C for about 7 hours. 37.0 g of 50% NaOH was added dropwise

to the stined solution at pH<12 and at room temperature. After the solution was stined

for further 5 hours, the pH was adjusted with 36% hydrochloric acid to 8.5. NMR

analysis results indicated the terpolymer composition was 35/51/14 N-(hydroxyethyl)

acrylamide/ AA/Am. The weight average molecular weight of the terpolymer was 31.000.

Example 9

To determine the dispersancy of the polymers, the following experimental

procedure was followed. 1500g slips were prepared to 80 weight percent alumina powder

(99.5% calcinated alpha alumina oxide available from Alcan, C90 LSB Alumina) in

water using 0.25 weight percent (polymer/powder) of the polymer to be tested.

Each slip was milled 3 hours in a 1 -liter jar mill using 1500g milling media.

Then, resulting slips were filtered through a 60 mesh screen, and Brookfield viscosity

was measured using an LVT type viscometer using a #2 spindle. For comparison

purposes, a commercially available, common alumina additive polymer was utilized. Polymer B is an ammonium poly(methacry ate) available from R.T. Vanderbilt Co..

Norwalk, CT. Polymer A is a polymer synthesized according to the procedure of

Example 2.

The viscosity of a slurry must be suitable for necessary handling and spray drying.

Although spray dry equipment and running conditions may be adjusted to handle a

variety of viscosities, larger particles will result from higher viscosity slunies. The

resultant large particles may lead to larger interstices between particles and hence a lower

strength. The binder may contribute to viscosity of the continuous phase of the slurry by

virtue of its molecular weight, solubility, conformation in solution, and possible

incompatibility with the combination of powder and dispersant. Since a lower viscosity

is more desirable for ceramic applications, the results of Table I show that a polymer of

this invention, prepared in accordance with the procedure of Example 2. works better than

the common treatment.

TABLE I

Dispersancy in Alumina

Example 10

The polymers were also tested in order to determine the effects of slip viscosity as

a function of binder type, according to the following procedure. Deflocculated slips were

prepared as in the procedure of Example 9. To each slip so prepared, the polymeric

treatment to be tested was added, to be a total of 4.0 weight percent (polymer/powder)

level. Next, each binder-containing slip was propeller mixed at 800 rpm for one hour.

For any necessary dilution, deionized water was added to attain the tabulated powder

solids level. Finally, the slip viscosity was measured using the method described in

Example 9.

The results of Table II illustrate that even though the binder composition was

varied, the polymers of this invention caused lower viscosity of the slip than the cunent

commercially available polymer treatment. In Table II. Polymer C is a poly(vinyl

alcohol) which has a molecular weight of 30.000 to 50.000 and is 88% hydrolyzed. It is

available from Air Products of Allentown, Pa. Polymer A is a polymer synthesized

according to the procedure in Example 2. For each polymer tested, 4 weight percent was

utilized, and the viscositv was measured at 3.14 sec^' . TABLE II

Slip Viscosity as a Function of Binder Type

1 = Brookfield viscosity

Example 11

A copolymer synthesized by the procedure described in Example 2 above, was

tested as a binder for alumina particles of the type that are commonly used for producing

ceramic materials.

The slip preparation described in Example 10 was utilized in this Example to

further examine the characteristics of the binders.

The milled slurry was spray dried in a Yamato DL-41 laboratory spray dryer.

Dryer operating conditions were: 250°C. air inlet temperature, atomizing air setting of

1.2. slurry feed pump setting of 5. and drying air feed rate of 0.7 cubic meters per minute.

A dry powder was produced which was recovered, screened and stored overnight in a 20

percent relative humidity chamber.

The screened powder was pressed into nine pellets in a Carver laboratory press,

three at 5,000 pounds per square inch pressing force, three at 15,000 pounds per square

inch pressing force, and three at 25.000 pounds per square inch pressing force. The pellets were approximately 28.7 millimeters in diameter and 5 to 6 millimeters in height.

The dimensions and weights of the pellets were measured and the pellets were crushed to

determine the force required to break them. Diametral compression strength (DCS) for

each of the pellets was determined from the breaking force and the pellet dimensions.

The average diametral compression strength in megapascals for each set of three pellets is

presented below in Table III.

Green body diametral compressional strength is important in ceramics

applications for the following reasons. The principal function of the binder is to hold the

compacted form together after pressing. The method utilized for determination of

suitable "green strength^" is the diametral compression strength or DCS of a cylindrical

section across its diameter. DCS is actually a measure of tensile strength. The unit of

measurement of pressure tolerance is the megapascal (Mpa). Typical values for DCS of

""green^" parts are in the range of 0.3 - 3.0 Mpa. Polymer A is a polymer prepared

according to the procedure in Example 2. Polymer C is the conventional additive

described in Example 10. Therefore, since a higher DCS value indicates a more efficient

binder. Table III shows that the polymers of the instant invention are more efficient than a

conventional treatment. D is another additive that is often used in conjunction with these

polymeric treatments for ceramic applications. Since a greater density is more desirable, the results of Table III illustrate that the

polymers of the instant invention are more advantageous in this respect also, as indicated

by the higher numbers obtained than in the case of the conventional treatment.

The springback characteristic is another important measure of the efficiency of a

polymer for ceramics applications for the following reasons. Upon filling a die. the

resulting compacted part must be smoothly ejected, be as dense as possible, and not suffer

significant dimensional change from that of the die. Chemical additives have a major

effect on the desired lubricity. The compressed powder will undergo stress relaxation in

the form of expansion on release from the die. This phenomenon is refened to as

"springback" and is undesirable from the standpoint of dimensional accuracy as well as

density and strength. For this example, D was used as a plasticizer. Maintenance of net

shape is important, as the occunence of a larger amount of springback can cause

lamination defects, or undesirable density gradients. Therefore, the lower values for

springback obtained for the polymers of this invention in Table III demonstrate that such

polymers are more efficient than the conventional treatment.

The pressure required for die ejection was also measured. The same test

equipment was utilized as described above, except that after the pellet is pressed, a

plunger on the bottom of the apparatus is utilized to apply force to the die. A lower

pressure is more desirable, and was obtained by the use of polymers of the instant

invention over polymers conventionally utilized for ceramic purposes. TABLE III

Comparison of Green Body Properties

D = poly(ethylene oxide/propylene oxide) ether linked to ( 1.2-ethandiyldintriio) tetrakis

[propanol], 0.8 weight percent D^" = as D above, 3.0 weight percent

Example 12

The procedures utilized in Example 1 1 were utilized to obtain the results of Table

IV. Rather than utilize a range of pressures as in the previous example, the

characteristics were evaluated at a single density. The pressure which was required to

produce that density was recorded in the table. The polymers A. C and D are as defined

in Example 1 1 above. Even when measured at pellets pressed to a constant density, the

polymers of the instant invention provide superior performance over the conventional

polymeric treatment.

TABLE IV

Comparative Green Body Properties at Green Density 2.4 g/mL

D = poly(ethylene oxide/propylene oxide) ether linked to ( 1 ,2-ethandiyldintrilo) tetrakis

[propanol], 0.8 weight percent D^" = as D above. 3.0 weight percent

Changes can be made in the composition, operation and arrangement of the

method of the present invention described herein without departing from the concept and

scope of the invention as defined in the following claims:

Claims

A binder for ceramic materials that comprises a water soluble polymer having:

A) a mer unit of the formula

R⁵ R⁶

C CH-

wherein R is selected from the group consisting of hydrogen, and C] - C₃ alkyl: p

and q are integers from 1 - 10: R^" and R are selected from the group consisting of

hydrogen and C, - C₃ alkyl; Het and Het^" selected from the group consisting of

oxygen and nitrogen; R is selected from the group consisting of hydrogen,

phosphate, sulfate and C₍ - C_2ϋ alkyl; R^Λ and R are selected from the group

consisting of hydrogen, carboxylate. C, - C₃ alkyl. and a cycloalkyl group of 1 to

6 carbon atoms formed by the linkage of R^ and R as a ring; and

B) a mer unit selected from the group consisting of acrylic acid, methacrylic

acid, acrylamide. maleic anhydride, itaconic acid, vinyl sulfonic acid, styrene

sulfonate. N-tertbutyl acrylamide. butoxymethylacrylamide, N,N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol, vinyl acetate. N-vinyl pyrrolidone. maleic acid, and combinations thereof.

2. The binder of Claim 1. wherein p=l : q=l : R^". R\ R⁴. R\ and R⁶ are hydrogen;

and Het and Het are oxygen in formula I of step A: and the mer units of step B are

acrylic acid and acrylamide.

3. An unfired. ceramic precursor material comprising a mixture of:

A. a ceramic powder selected from the group consisting of aluminum oxide,

silicon nitride, aluminum nitride, silicon carbide, silicon oxide, magnesium oxide,

lead oxide, zirconium oxide, titanium oxide, steatite, barium titanate. lead

zirconate titanate. clays, fenite. yttrium oxide, zinc oxide, tungsten carbide,

sialon. neodvmium oxide and combinations thereof and

B. a water soluble polymer having:

i) a mer unit of the formula

R⁵ R⁶

C CH-

I

(CHR^:CHR Het'- rfCl IR²CHR HetV^"R⁴

wherein R , ι is selected from the group consisting of hydrogen, and C) - C₃ alkyl: p

and q are integers from 1 - 1 : R" and R³ are- selected from the group consisting of

hydrogen and C, - C₃ alkyl: Het¹ and Het^" selected from the group consisting of

oxygen and nitrogen: R is selected from the group consisting of hydrogen. phosphate. sulfate and C, - C₂₀ alkyl; R" and R° are selected from the group

6 carbon atoms formed by the linkage of R^" and R⁶ as a ring; and

ii) a mer unit selected from the group consisting of acrylic acid,

styrene sulfonate, N-tertbutylacrylarnide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol, vinyl acetate, N-vinyl pynolidone. maleic acid, and combinations

thereof.

4. The water-soluble polymer of Claim 3. wherein p=l ; q=l : R^", R . R . R\ and R

1 "* are hydrogen; Het and Het^" are oxygen in formula I of step A: and the mer units of step

ii are acrvlic acid and acrvlamide.

5. A method for preparing a ceramic material, which comprises the steps of:

A) mixing a ceramic powder with an aqueous solution containing a water-

soluble polymer to produce a slurry, said water-soluble polymer having:

i) a mer unit of the formula R^J R°

- C CH-

wherein R , ι i ^■s selected from the group consisting of hydrogen, and C, - C₃ alkyl: p

and q are integers from 1 - 10; R^" and R^' are selected from the group consisting of

hydrogen and C, - C alkyl: Het and Het^" selected from the group consisting of

oxygen and nitrogen: R is selected from the group consisting of hydrogen,

phosphate, sulfate and C, - C₂₀ alkyl; R^ and R are selected from the group

consisting of hydrogen, carboxylate, C, - C₃ alkyl. and a cycloalkyl group of 1 to

6 carbon atoms formed by the linkage of R^{"^} and R as a ring: and

ii) a mer unit selected from the group consisting of acrylic acid,

styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol, vinyl acetate. N-vinyl pynolidone. maleic acid, and combinations

thereof;

B) drying the slurry by a process selected from the group consisting of

fluidized bed spray drying, and spray drying to produce particles which include

said copolymer; C) compacting the particles by a process selected from the group consisting

of dry pressing, roll compaction and isostatic pressing to produce an aggregate

structure; and

D) heating the aggregate structure to produce a fired ceramic material.

6. The water-soluble polymer of Claim 5. wherein p=h q=l ; R~, R^J. R . R\ and R

are hydrogen; Het and Het^" are oxygen in formula I of step i; and the mer units of step

ii are acrylic acid and acrylamide.

7. The method of Claim 5 wherein the particles are produced by granulation and the

step of compacting the particles to produce an aggregate structure is selected from the

group consisting of dry pressing and isostatic pressing.

8. A binder for ceramic materials that comprises a water soluble polymer having:

A) a mer unit of the formula

R⁵ R⁶

C CH

C = O

O

II wherein p is an integer from 1 - 10; R^" and R^J are selected from the group

consisting of hydrogen and C, - C alkyl; R is selected from the group consisting

of hydrogen, phosphate, sulfate and C, - C₂₀ alkyl; R^? and R are selected from

the group consisting of hydrogen, carboxylate. C, - C₃ alkyl, and a cycloalkyl

group of 1 to 6 carbon atoms formed by the linkage of R^ and R as a ring, with

the proviso that when p = 1. R^". R^"5. R . R^{'^} and R*¹ are not all hydrogens, and with

the proviso that when p = 1. R^{^} is not methyl; and

B) a water-soluble mer unit selected from the group consisting of acrylic acid,

methacrylic acid, acrylamide. maleic anhydride, itaconic acid, vinyl sulfonic

acid, styrene sulfonate, N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol. N-vinyl pynolidone. maleic acid, and combinations thereof.

9. An unfired, ceramic precursor material comprising a mixture of:

A. a ceramic powder selected from the group consisting of aluminum oxide,

lead oxide, zirconium oxide, titanium oxide, steatite, barium titanate, lead

zirconate titanate. clays, fenite. yttrium oxide, zinc oxide, tungsten carbide,

sialon. neodvmium oxide and combinations thereof and

B. a water soluble polymer having:

i) a mer unit of the formula R³ R"

C CH

C = O

O

II

wherein p is an integer from 1 - 10: R^" and R^J are selected from the group

consisting of hydrogen and C , - C₅ alkyl: R is selected from the group consisting

of hydrogen, phosphate, sulfate and C, - C₂₀ alkyl: R^""1 and R are selected from

the group consisting of hydrogen, carboxylate. C, - C₃ alkyl. and a cycloalkyl

group of 1 to 6 carbon atoms formed by the linkage of R^? and R as a ring, with

the proviso that when p = 1. R^". R^J. R . R^ and R are not all hydrogens, and with

the proviso that when p = 1. R^'"1 is not methyl: and

ii) a water-soluble mer unit selected from the group consisting of

acrylic acid, methacrylic acid, acrylamide, maleic anhydride, itaconic acid, vinyl

sulfonic acid, styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide.

N.N-dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol. N-vinyl pynolidone. maleic acid, and combinations thereof.

10. A method for preparing a ceramic material, which comprises the steps of:

A) mixing a ceramic powder with an aqueous solution containing a water-

soluble polymer to produce a slurry, said water-soluble polymer having: i) a mer unit of the formula

R⁵ R"

C CH

C = O

O

II

wherein p is an integer from 1 - 10: R^" and R^"' are selected from the group

consisting of hydrogen and C, - C₃ alkyl; R is selected from the group consisting

of hydrogen, phosphate, sulfate and C, - C₂₀ alkyl: R^ and R are selected from

the group consisting of hydrogen, carboxylate. Ci - C alkyl. and a cycloalkyl

group of 1 to 6 carbon atoms formed by the linkage of R^""1 and R as a ring, with

the proviso that when p = 1. R\ R\ R . R^' and R are not all hydrogens, and with

the proviso that when p = 1. R^? is not methyl: and

ii) a water-soluble mer unit selected from the group consisting of

acrylic acid, methacrylic acid, acrylamide. maleic anhydride, itaconic acid, vinyl

sulfonic acid, styrene sulfonate. N^'-tertbutylacrylamide. butoxymethylacrylamide.

N.N-dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol. N-vinyl pyrrolidone. maleic acid, and combinations thereof;

B) drying the sluny by a process selected from the group consisting of

fluidized bed spray drying, and spray drying to produce particles which include

of dry pressing, roll compaction and isostatic pressing to produce an aggregate

structure; and

D) heating the aggregate structure to produce a fired ceramic material.

1 1. The method of Claim 10 wherein the particles are produced by granulation and

the step of compacting the particles to produce an aggregate structure is selected from the

group consisting of dry pressing and isostatic pressing.

12. A method for dispersing one or more ceramic materials in an aqueous medium,

comprising utilizing an effective dispersing amount of a polymeric dispersant comprising

a water soluble polymer having:

A) a mer unit of the formula

R R°

C CH

C = O

O

II

wherein p is an integer from 1 - 10: R² and R are selected from the group

consisting of hydrogen and C, - C₃ alkyl: R 4 i •s selected from the group consisting of hydrogen, phosphate, sulfate and C, - C₂₀ alkyl: R^? and R⁶ are selected from the

group consisting of hydrogen, carboxylate. C_[ - C₃ alkyl. and a cycloalkyl group

of 1 to 6 carbon atoms formed by the linkage of R^ and R⁶ as a ring, with the

proviso that when p = 1 , R^". R R , R^ and R° are not all hydrogens, and with the

proviso that when p = 1. R^ is not methyl; and

B) a water-soluble mer unit selected from the group consisting of acrylic acid,

styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol. N-vinyl pynolidone. maleic acid, and combinations thereof.

13. The method of Claim 12 wherein the one or more ceramic materials is selected

from the group consisting of alumina, aluminum nitride, aluminum titanate. lead titanate.

zirconium boride. boron carbide, tungsten carbide, tungsten boride. tin oxide, ruthenium

oxide, yttrium oxide, magnesium oxide, calcium oxide, and fenites.

14. An aqueous dispersion of ceramic material prepared according to the method of

Claim 12.

15. A binder for ceramic materials that comprises a water soluble polymer having:

A) a mer unit of the formula R⁵ R°

^■ C CH

wherein p is an integer from 1 - 10: R^" and R^J are selected from the group

consisting of hydrogen and C, - C₃ alkyl: R is selected from the group consisting

of hydrogen, phosphate, sulfate and C, - C₂₀ alkyl: R^? and R are selected from

the group consisting of hydrogen, carboxylate. C_j - C₃ alkyl. and a cycloalkyl

group of 1 to 6 carbon atoms formed by the linkage of R^ and R as a ring with the

proviso that when p = 1. R^". R^"\ R . R^ and R⁶ are not all hydrogens and with the

proviso that when p = 1. R^" is not methyl and with the proviso that when p = 1 , R^J

is not methyl: and

B) a water-soluble mer unit selected from the group consisting of acrylic acid,

styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol. N-vinyl pynolidone. maleic acid, and combinations thereof.

16. An unfired. ceramic precursor material comprising a mixture of: A. a ceramic powder selected from the group consisting of aluminum oxide,

lead oxide, zirconium oxide, titanium oxide, steatite, barium titanate. lead

zirconate titanate. clays, fenite. yttrium oxide, zinc oxide, tungsten carbide,

sialon. neodvmium oxide and combinations thereof and

B. a water soluble polymer having:

i) a mer unit of the formula

R⁵ R°

- C CH

wherein p is an integer from 1 - 10: R^" and R are selected from the group

the group consisting of hydrogen, carboxylate. C , - C₃ alkyl. and a cycloalkyl

group of 1 to 6 carbon atoms formed by the linkage of R^J and R as a ring with the

proviso that when p = 1. R^". R \ R . R^'"" and R are not all hydrogens and with the

proviso that when p = 1. R^" is not methyl and with the proviso that when p = 1 , R

is not methyl; and ii) a water-soluble mer unit selected from the group consisting of

N.N-dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol. N-vinyl pynolidone. maleic acid, and combinations thereof.

17. A method for preparing a ceramic material, which comprises the steps of:

A) mixing a ceramic powder with an aqueous solution containing a water-

soluble polymer to produce a slurry, said water-soluble polymer having:

i) a mer unit of the formula

R⁵ R⁶

^• C CH

wherein p is an integer from 1 - 10: R^" and R are selected from the group

consisting of hydrogen and C, - C_? alkyl; R is selected from the group consisting

of hydrogen, phosphate, sulfate and C, - C₂₀ alkyl; R^ and R⁶ are selected from

the group consisting of hydrogen, carboxylate. C_| - C₃ alkyl. and a cycloalkyl

group of 1 to 6 carbon atoms formed by the linkage of R and R as a ring with the

proviso that when p = 1. R². R^"\ R⁴. R^? and R° are not all hydrogens and with the proviso that when p = 1. R^" is not methyl and with the proviso that when p = 1. R^"'

is not methyl; and

ii) a water-soluble mer unit selected from the group consisting of

N.N-dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol. N-vinyl pynolidone. maleic acid, and combinations thereof;

B) drying the slurry by a process selected from the group consisting of

fluidized bed spray drying, and spray drying to produce particles which include

said copolymer:

C) compacting the particles by a process selected from the group consisting

of dry pressing, roll compaction and isostatic pressing to produce an aggregate

structure; and

D) heating the aggregate structure to produce a fired ceramic material.

18. The method of Claim 17 wherein the particles are produced by granulation and

group consisting of dry pressing and isostatic pressing.

19. A method for dispersing one or more ceramic materials in an aqueous medium,

a water soluble polymer having: A) a mer unit of the formula

R⁵ R°

C CH

CH,

O

wherein p is an integer from 1 - 10; R^" and R^J are selected from the group

consisting of hydrogen and C, - C, alkyl; R is selected from the group consisting

of hydrogen, phosphate, sulfate and C_! - C₂₀ alkyl; R^ and R are selected from

the group consisting of hydrogen, carboxylate. C_] - C₃ alkyl. and a cycloalkyl

group of 1 to 6 carbon atoms formed by the linkage of R^? and R as a ring, with

the proviso that when p = 1. R^". R^"\ R⁴. R^? and R⁶ are not all hydrogens and with

the proviso that when p = 1. R^" is not methyl and with the proviso that when p =

1. R^J is not methyl: and

B) a water-soluble mer unit selected from the group consisting of acrylic acid,

styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol. N-vinyl pyrrolidone. maleic acid, and combinations thereof.

20. The method of Claim 19 wherein the one or more ceramic materials is selected

oxide, vttrium oxide, magnesium oxide, calcium oxide, and ferrites.

21. An aqueous dispersion of ceramic material prepared according to the method of

Claim 19.

22. A binder for ceramic materials that comprises a water-soluble polymer having:

A) a mer unit of the formula

R⁵ R⁶

_CH .

IV

wherein R¹ is selected from the group consisting of hydrogen, and C, - C₃ alkyl; p

is an integer from 1 - 10: R⁴ is selected from the group consisting of hydrogen, phosphate, sulfate and C, - C₂₀ alkyl; R^? and R⁶ are selected from the group

6 carbon atoms formed by the linkage of R^ and R as a ring; and

B) a mer unit selected from the group consisting of acrylic acid, methacrylic

acid, acrylamide. maleic anhydride, itaconic acid, vinyl sulfonic acid, styrene

sulfonate, N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol, vinyl acetate. N-vinyl pynolidone. maleic acid, and combinations

thereof.

23. The binder of Claim 22 wherein p=2: R . R⁴. R\ and R⁶ are hydrogen in formula

IV of step A: and the mer units of step B are acrylic acid and acrylamide.

24. The binder of Claim 22 wherein p=3: R^? . R . and R are hydrogen: R is methyl

in formula IV of step A: and the mer units of step B are acrylic acid and acrylamide.

An unfired. ceramic precursor material comprising a mixture of:

A) a ceramic powder selected from the group consisting of aluminum oxide,

lead oxide, zirconium oxide, titanium oxide, steatite, barium titanate, lead

zirconate titanate. clays, fenite. yttrium oxide, zinc oxide, tungsten carbide,

sialon. neodymium oxide and combinations thereof and B) a water-soluble polymer having:

i) a mer unit of the formula

R^> R

C CH

IV

wherein R , ι i ■s selected from the group consisting of hydrogen, and C) - C₃ alkyl; p

is an integer from 1 - 10: R is selected from the group consisting of hydrogen,

phosphate, sulfate and C, - C₂₀ alkyl; R^'" and R⁶ are selected from the group

6 carbon atoms formed by the linkage of R¹ and R as a ring; and

ii) a mer unit selected from the group consisting of acrylic acid,

styrene sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide, N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol, vinyl acetate. N-vinyl pynolidone. maleic acid, and combinations

thereof.

26. The water-soluble polymer of Claim 25 wherein p=2: R . R , R\ and R are

hydrogen for formula IV of step i; and the mers unit of step ii are acrylic acid and

acrvlamide.

27. The water-soluble polymer of Claim 25 wherein p=3: R^ . R . and R are

hydrogen; R is methyl for formula IV of step i and the mer units of step ii are acrylic

acid and acrvlamide.

'.8. A method for preparing a ceramic material, which comprises the steps of:

A) mixing a ceramic powder with an aqueous solution containing a water-

soluble polymer to produce a slurry, said water-soluble polymer having:

i) a mer unit of the formula

R⁵ R⁶

C CH

wherein R is selected from the group consisting of hydrogen, and C, - C₃ alkyl; p

is an integer from 1 - 10: R⁴ is selected from the group consisting of hydrogen. phosphate. sulfate and C, - C₂₀ alkyl: R^" and R^h are selected from the group

consisting of hydrogen, carboxylate. C, - C-, alkyl. and a cycloalkyl group of 1 to

6 carbon atoms formed by the linkage of R^ and R^h as a ring; and

ii) a mer unit selected from the group consisting of acrylic acid,

styrene sulfonate. N-tertbutyiacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol, vinyl acetate. N-vinyl pynolidone. maleic acid, and combinations

thereof;

B) drying the sluny by a process selected from the group consisting of

fluidized bed spray drying and spray drying to produce particles which include said

copolymer:

C) compacting the particles by a process selected from the group consisting

of dry pressing, roll compaction, isostatic pressing to produce an aggregate

structure: and

D) heating the aggregate structure to produce a fired ceramic material.

29. The water-soluble polymer of Claim 28 wherein p=2; R . R , R^" . and R are

hydrogen for formula IV of step I and the mer units of step ii are acrylic acid and

acrvlamide.

30. The water-soluble polymer of Claim 28 wherein p=3; R^J , R , and R are

acid and acrylamide.

31. The method of Claim 28 wherein the particles are produced by granulation and

group consisting of dry pressing and isostatic pressing.

32. A method for dispersing one or more ceramic materials in an aqueous medium,

a water-soluble polymer having:

A) a mer unit of the formula

R^? R°

C CH

IV wherein R is selected from the group consisting of hydrogen, and C, - C₃ alkyl; p

is an integer from 1 - 10; R is selected from the group consisting of hydrogen,

phosphate, sulfate and C, - C₂₀ alkyl: R^{"^} and R° are selected from the group

6 carbon atoms formed by the linkage of R^ and R as a ring; and

B) a mer unit selected from the group consisting of acrylic acid, methacrylic

acid, acrylamide. maleic anhydride, itaconic acid, vinyl sulfonic acid, styrene

sulfonate. N-tertbutylacrylamide. butoxymethylacrylamide. N.N-

dimethylacrylamide. sodium acrylamidomethyl propane sulfonic acid, vinyl

alcohol, vinyl acetate. N-vinyl pynolidone. maleic acid, and combinations

thereof.

33. The water-soluble polymer of Claim 32 wherein p=2: R , R , R^" . and R are

hydrogen for formula IV of step A; and the mer units of step B are acrylic acid and

acrvlamide.

34. The water-soluble polymer of Claim 32 wherein p=3; R^{'^} , R , and R are

hydrogen; R⁴ is methyl for formula IV of step A; and the mer units of step B are acrylic

acid and acrylamide.

35. The method of Claim 32 wherein the one or more ceramic materials is selected

from the group consisting of alumina, aluminum nitride, aluminum titanate, lead titanate. boron nitride, silicon, silicon carbide, sialon, zirconium nitride, zirconium carbide,

oxide, yttrium oxide, magnesium oxide, calcium oxide, and ferrites.

36. An aqueous dispersion of ceramic material prepared according to the method of

Claim 32.