WO1995001399A2

WO1995001399A2 - Polymer blends for heat resistant inks

Info

Publication number: WO1995001399A2
Application number: PCT/US1994/006553
Authority: WO
Inventors: Peter W. Raynolds
Original assignee: Eastman Chemical Company
Priority date: 1993-06-29
Filing date: 1994-06-13
Publication date: 1995-01-12
Also published as: WO1995001399A3

Abstract

Disclosed are polymer blends of polyesters or polyesteramides and a styrene polymer. The blends are preferably prepared by polymerizing a styrene monomer in the presence of the polyester or polyesteramide. The blends impart superior gloss and block resistance.

Description

POLYMER BLENDS FOR HEAT RESISTANT INKS

Field of the Invention

The present invention concerns polymer blends of a polyester or polyesteramide and a styrene polymer as well as a process for preparation thereof. These polymer blends impart improved heat resistance to aqueous inks.

Description of the Related Art

There continues to be much interest in water— dispersible polymers for inks because of the problems associated with solvent emissions from solvent—based inks. Certain polyesters are water—dispersible as a result of sulfonate groups on the polyester backbone. These polyesters have been described in, for example, U. S. Patents 3,734,874; 3,546,008 and 3,779,993.

Water—dispersible polyesters have been used in textile sizes and have been used to develop aqueous inks. Inks containing a water—dissipatable polyester are well known in the art as disclosed in U. S. Patents 4,704,309 and 4,738,785. Water-dispersible polyester- polystyrene blends useful as coatings and adhesives have been generally disclosed in U. S. Patents 4,939,233 and 4,946,932. These inks have many desirable features, including excellent gloss and color development, good rewet characteristics, and low odor. However, because of the wide range of printing conditions and substrates used in the printing industry, a given ink formulation can have ideal properties for some applications and poor properties for other applications. Heat resistance is a property that is highly desirable for many ink applications. It would be highly desirable to have a material that imparts good heat resistance to films prepared from aqueous polyester dispersions while *-. maintaining the other advantages associated with the use of the water-dispersible polyester.

A water-dispersible polyester-polystyrene blend having an additional small amount of "hydrophilic vinyl polymer" is disclosed in Japanese Kokai Patent Application No. Hei 3[1991]-146549. The use of a non¬ ionic unsaturated polyester as a surfactant in the polymerization of styrene to obtain a coarse dispersion is disclosed in European Patent Application EP 400,410. A phthalic anhydride-5—sodiosulfoisophthalic acid- tetraethyleneglycol condensation polymer was used as a surfactant and dispersing polymer for dyes (K. M. Chen and H. J. Liu, J. Appl. Poly. Sci., 1987, No. 34, pp. 1879—1888) , and this surfactant was used in an emulsion polymerization with styrene (T. L. McCartney and I. Piirma, Polymer Bull., April 1990, No. 23, pp. 367-371) The need for low—odor, zero-VOC emulsion polymers has been described in a review article of new developments in water—borne acrylics for the printing ink industry (H. J. Hartschuh, American Ink Maker, January 1991, pp. 34 ff.). This invention addresses all of these needs, and achieves the desired result with the use of a water-dispersible polyester as both a polymeric surfactant and coalescing aide.

Summary of the Invention

One object of the present invention is to provide water-dispersible polyester-styrene blends, useful as coatings and inks that exhibit high gloss and excellent heat blocking characteristics.

Another object of the present invention is to provide water-dispersible polyester-styrene blends having low odor levels, and substantially no volatile organic solvents. Yet another object of the present invention is to , provide a method of producing the useful polyester- styrene blends of the present invention.

Accordingly, one form of the present invention relates to a polymer blend comprising:

(A) about 2 weight percent to about 50 weight percent of a water-dispersible sulfonate group- containing polyester or polyester amide comprising;

(a) aromatic and aliphatic and alicyclic and ionic dicarboxylic acids such that

(i) the mole percent of ionic diacid is about 5 mole percent to about 25 mole percent, and

(ii) the mole percent of aromatic diacids is less than 50 %, (b) diols comprising no more than about 50 mole percent, preferably 0 mole percent, of the total diols being selected from the group consisting of 1,4—cyclohexanedimethanol, 1,3—cyclohexanedimethanol, and 1,2—cyclohexanedimethanol; (B) about 50 weight percent to about 98 weight percent of a styrene polymer comprising:

(a) about 30 to 100 weight percent of repeating units from a styrene compound.

Another form of the present invention relates to a polymer blend comprising:

(A) about 5 weight percent to about 35 weight percent of a water-dispersible sulfonate group- containing polyester or polyester amide comprising;

(a) aromatic and aliphatic and alicyclic and ionic dicarboxylic acids such that

(ii) the mole percent of aromatic diacids is less than 50%, (b) diols comprising no more than about 50 < mole percent, preferably 25 mole percent, more preferably 0 mole percent, of the total diols being selected from the group consisting of 1,4—cyclohexanedimethanol, 1,3—cyclohexanedimethanol, and 1,2—cyclohexanedimethanol;

(B) about 65 to about 95 weight percent of a styrene polymer comprising:

(a) about 30 to 100 weight percent of repeating units from a styrene compound.

Yet another form of the present invention relates to a polymer blend comprising:

(a) aromatic and aliphatic and alicyclic and ionic dicarboxylic acids such that;

(i) the mole percent of ionic diacid is about 5 mole percent to about 25 mole percent, and (ii) the mole percent of aromatic diacids is less than 50%,

(b) diols comprising no more than about 50 mole percent, preferably 0 mole percent, of the total diols being selected from the group consisting of 1,4-cyclohexanedimethanol, 1,3—cyclohexanedimethanol, and 1,2—eyelohexanedimethano1;

(B) about 50 weight percent to about 98 weight percent of a styrene polymer comprising:

(a) greater than about 50 weight percent of a styrene monomer, and

(b) the balance consisting of repeating units from at least one other ethylenically unsaturated monomer. A further form of the invention relates to a method of preparing a water—dispersed polymer blend comprising the steps of:

(A) preparing an aqueous polymerization mixture by contacting

(1) a water-dispersible sulfonate group- containing polyester or polyesteramide,

(2) one or more monomers, wherein said monomers comprise about 50 weight percent to about 100 weight percent of a styrene monomer,

(3) a polymerization initiator, and

(4) water,

(B) polymerizing said monomers to provide said water-dispersible polymer blend. Preferred forms of the invention, as well as other embodiments, objects, features and advantages of this invention, will be apparent from the following detailed description of the present invention.

Description of the Invention

Polystyrene is inexpensive. It produces coatings and inks with many desirable characteristics. The residual monomer does not have an obnoxious odor (in contrast to many acrylates) , and glossy films are produced when the latex is applied to a surface. One serious deficiency of pure polystyrene latexes is that they do not form films which are physically robust and resistant to rubbing and abrasion. This deficiency occurs because, during drying, the individual particles of polystyrene in the latex do not fuse together to form a strong, continuous film in the absence of special additives called coalescing aides.

Many coalescing aides are slow—evaporating oxygenated organic compounds that act by softening the polymeric particles and allowing them to fuse together into a continuous film. The coalescing aide then evaporates over a period of days or weeks, leaving a hard, abrasion resistant film. While commonly used to achieve strong films, these coalescing aides suffer from certain shortcomings. They contribute to the volatile organic content (VOC) of the coating; they occasionally have a noticeable odor; and they soften the ink or coating film until they evaporate over a period of days or week. Water—dispersed polyesters may be used as coalescing aides. They are similar to the just- mentioned coalescing aides in that they are thought to facilitate fusing together of individual polystyrene particles. Polyesters differ from the coalescing aides just mentioned in that they are permanently incorporated into the polymer film. This can lead to other undesirable characteristics, one of which is decreased blocking temperature. At the "blocking temperature", two coated surfaces will stick together (an undesirable characteristic) under given conditions of temperature, time and humidity. It would be advantageous to design a water dispersible polyester that act as a coalescing aide but which would exhibit a high blocking temperature. The water-dispersible polyesters mentioned herein show further utility in emulsion polymerization by their action as colloidal stabilizers. These charged polyesters allow for the partial or complete elimination of added surfactants during the emulsion polymerization. Normally, the tendency to block is related to the glass transition temperature (Tg) of the polymer: a polymer with a low Tg normally gives a coating or ink with a low blocking temperature. In the case at hand, the tendency of polyester-polystyrene blends to block would normally be attributed to the Tg of the polyester (29°C — 55°C) , which is low relative to the Tg of the . polystyrene (105°C) . It would be predicted that improved blocking resistance would be obtained with a polyester having a higher Tg. It has now been surprisingly found that, in the systems described herein, the Tg of the polyester used as a component in a polyester—polystyrene blend is irrelevant to the blocking resistance of coatings and films. In fact, improved heat—sealer blocking results are obtained by changing the polyester from one having a Tg in the range 29°C — 55°C to polyesters made with aliphatic and alicyclic diacids with Tg in the range —30°C — + 63°C. It has further been surprisingly found that greatly improved heat—sealer blocking results may be obtained even using a composition based on a sticky, liquid adipic acid — based polyester without a distinct Tg, but which produces a heat—sealer blocking temperature of about 200°F. The tendency to block thus appears to depend on the composition of the polyester and not on the Tg of the polyester.

The polyesters used in this invention are water- dispersible as a result of sulfonate groups on the polyester backbone. Suitable compositions are those described in U. S. Patents 3,734,874; 3,546,008; 4,335,220 and 3,779,993, incorporated herein by reference. Basically, these polyesters and polyester¬ amides are described as having carbonyloxy interconnecting groups in the linear molecular structure wherein up to 80 percent thereof may be carbonylamido linking groups, the polymer having an inherent viscosity of at least about 0.1, and the polymer consisting essentially of the following components or ester forming or ester—amide forming derivatives thereof; (a) at least one difunctional dicarboxylic acid; (b) from about 2 to about 25 mole percent, based on a total of all acid, hydroxyl and amino equivalents being equal to 200 mole percent, of at least one difunctional sulfomonomer containing at least one metal sulfonate group attached to an aromatic nucleus wherein the functional groups are hydroxy, carboxyl or amino; and

(c) at least one glycol or a mixture of a glycol and a diamine having two —NRH groups, the glycol containing two —OH groups. Dispersibility is related to mole percent of sulfomonomer.

The polymer may contain at least one difunctional reactant selected from a hydroxycarboxylic acid having one —CH—OH, and aminocarboxylic acid having one —NRH group, an amino alcohol having one —CR₂—OH group and one —NRH or mixtures thereof, wherein each R is an H atom or an alkyl group of 1 to 4 carbon atoms.

The dicarboxylic acid component of the polyester or polyesteramide comprises aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, or mixtures of two or more of these acids. Examples of such dicarboxylic acids include succinic; glutaric; adipic; azelaic; sebacic; itaconic; 1,4— cyclohexanedicarboxylic; phthalic; terephthalic and isophthalic. If terephthalic acid is used as the carboxylic acid component of the polyester, superior results are achieved when at least 5 mole percent of one of the other acids is also used. The mole percent of aromatic diacids should be less than 50% to achieve resistance to heat blocking.

It should be understood that use of the corresponding acid anhydrides, esters, and acid chlorides of these acids is included in the them "dicarboxylic acid". Other suitable acids are disclosed in U. S. Patent 3,779,993. The difunctional sulfo—monomer component of the polyester or polyesteramide may advantageously be a dicarboxylic acid or an ester thereof containing a metal sulfonate group or a glycol containing a metal sulfonate group or a hydroxy acid containing a metal sulfonate group. The metal ion of the sulfonate salt may be Na⁺, Li⁺, K+, NH₄+, and the like. When a monovalent alkali metal ion is used, the resulting polyesters or polyesteramides are less readily dissipated by cold water and more readily dissipated by hot water. Amines (NH₄Θ, θR-_L R₂ R₃ R₄) where R=H, alkyl, benzyl, aromatic. When a divalent or a trivalent metal ion is used, the resulting polyesters or polyesteramides are not ordinarily easily dissipated by cold water but are more readily dissipated in hot water. It is possible to prepare the polyester or polyesteramide using, for example, as sodium sulfonate salt and later by ion- exchange replace this ion with a different ion, and thus alter the characteristics of the polymer. The difunctional monomer component may also be referred to as a difunctional sulfomonomer and is further described hereinbelow.

Advantageous difunctional sulfo—monomer components are those wherein the sulfonate salt group is attached to an aromatic acid nucleus such as benzene, naphthalene, diphenyl, oxydiphenyl, sulfonyldiphenyl or methylenediphenyl nucleus. Preferred results are obtained through the use of sulfophthalic acid, sulfoterephthalic acid, sulfoisophthalic acid, 4—sulfo— naphthalene-2,7-dicarboxylic acid, and their esters; metallosulfoaryl sulfonate as described in U. S. Patent 3,779,993.

Particularly superior results are achieved when the difuctional sulfo-monomer component is 5-sodiosulfo- isophthalic acid or its esters and the glycol is a mixture of ethylene glycol or 1,4-cyclohexanedimethanol with diethylene glycol.

When the sulfonate—containing difunctional monomer is an acid or its ester, the polyester or polyesteramide should contain at least 5 mole percent of said monomer based on total acid content, with more than 10 mole percent giving particularly advantageous results. Total acid content is calculated as the sum of (1) moles of component (a) namely dicarboxylic acids, (2) one-half of the moles of carboxyl—containing compounds of component (d) , (3) moles of component (c) which are dicarboxylic acids, and (4) one—half of the moles of component (c) which are monocarboxy—containing compounds.

Useful glycols for preparing copolyesters may consist of aliphatic, alicyclic, and aralkyl glycols. Examples of these glycols include ethylene glycol; propylene glycol; 1,3—propanediol; 2,4-dimethyl—2— ethylhexane—1,3-diol; 2,2—dimethyl—1,3—propanediol; 2— ethyl-2-butyl-l,3-propanediol; 2-ethyl—2-isobutyl-l,3- propanediol; 1,3—butanediol, 1,4—butanediol; 1,5— pentanediol; 1,6-hexanediol; 2,2,4-trimethyl-l,6- hexanediol; thiodiethanol; 1,2—cyclohexanedimethanol; 1,3—cyclohexanedimethanol; 1,4—cyclohexanedimethanol; 2,2,4,4-tetramethyl—1,3-cyclobutanediol; p-xylylenediol; 2,2-dimethy1-3-hydroxypropy1-2,2-dimethy1—3- hydroxypropionate and 2—methyl—1,3—propanediol. If ethylene glycol is one component of the glycol mixture, superior results are achieved if at least 30% of one other glycol is used. It is preferred that at least about 50 mole percent, more preferably 100 mole percent, of the diols be selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,5—pentanediol, 1,4— butanediol, 1,3—propanediol, 1,3—cylcobutanediol, 2- methyl-l,3-propanediol, butylethylpropanediol, 2,2- dimethyl—3—hydroxypropyl—2,2-dimethy1—3—hydroxy— propionate, and mixtures thereof. Useful polyesters include those wherein the sulfomonomer is a dicarboxylic acid and constitutes about 5 to about 25 mole percent, based on the sum of (1) the moles of the total dicarboxylic acid content of components (a) and (b) , and (2) one—half of the moles of any hydroxycarboxylic acid.

Other useful polyesters include those wherein the sulfomonomer is a glycol and constitutes about 5 mole percent to about 25 mole percent based on the sum of the total glycol content measured in moles of (b) and (c) , and one—half of the moles of any hydroxycarboxylic acid. Thus, a preferred polyester or polyesteramide useful herein comprises a polymer blend wherein said water- dispersible polyester or polyesteramide comprises a polymer having carbonyloxy linking groups in the linear molecular structure wherein up to 80 percent of the linking groups are carbonylamido linking groups, the polymer having an inherent viscosity of from about 0.1 to about 1.0 measured in a 60/40 parts by weight solution of phenol/tetrachloroethane at 25°C and at a concentration of 0.5 gram of polymer in 100 ml of the solvent, the polymer containing substantially equi olar proportions of acid equivalents (100 mole percent) to hydroxy and amino equivalents (100 mole percent) , the polymer comprising the reaction products of reactants selected from (a) , (b) , (c) , and (d) , or the ester forming or esteramide forming derivatives thereof, as follows, wherein all stated mole percentages are based on the total of all acid, hydroxyl, and amino equivalents being equal to 200 mole percent: (a) at least one difunctional dicarboxylic acid; (b) from about 4 to about 25 mole percent of at least one difunctional sulfomonomer containing at least one metallic sulfonate group or nitrogen-containing nonmetallic sulfonate group attached to an aromatic or cycloaliphatic nucleus wherein the functional groups are hydroxy, carboxyl, or amino;

(c) at least one difunctional reactant selected from a glycol or a mixture of a glycol and diamine having two RH groups, the glycol containing two —OH groups; (d) from none to about 40 mole percent of difunctional reactant selected from hydroxycarboxylic acids having one —C(R) —OH group, aminocarboxylic acids having one — NRH group, amino—alcohols having one —C(R)₂—OR group and one —NRH group, or mixtures of said difunctional reactants; wherein each R in the (c) and (d) reactants is a hydrogen atom or an alkyl group of 1 to 4 carbons.

It is preferred for the blends of the invention that the aromatic dicarboxylic acids are selected from the group consisting of terephthalic acid, isophthalic acid, phthalic acid and mixtures thereof.

It is preferred that the aliphatic dicarboxylic acids useful in the blends of the invention are selected from the group consisting of 1,4—cyclohexanedicarboxylic acid, 1,3—cyclohexanedicarboxylic acid, 1,2— cyclohexanedicarboxylic acid, and mixtures thereof.

It is also preferred that the ionic dicarboxylic acids useful in the blends of the invention are selected from the group consisting of 5-sulfoisophthalic acid, 4- sulfophthalic acid and mixtures thereof.

More preferably the polyester has an inherent viscosity of from about 0.1 to 0.4, 9-18 mole percent of sodium 5—sulfoisophthalic acid as the ionic monomer, less than 30 mole percent of an aromatic diacid such as isophthalic acid. Most preferably, the polyester has an IV of 0.2 — <. 0.4, contains 11% sodium 5—sulfoisophthalate, 89% dimethyl cyclohexanedicarboxylate, and the glycol is 100% 2,2—dimethyl—1,3—propanediol.

The styrene monomer useful herein is preferably of the structure

wherein R¹ is H or methyl, R² is a lower alkyl group of 1 to 6 carbon atoms, and m is an integer of 0 to 2. Preferably m is 0 or 1, and R² is methyl.

Preferable styrene monomers are styrene, α—methyl styrene, 4—methyl styrene, 3—methyl styrene, t—butyl styrene, and mixtures thereof. The more preferable styrene monomer is styrene.

The meth(aerylate) monomer useful herein preferably is of the structure

cooi

CH, wherein R³ is H or an alkyl group of 1 to 10 carbon atoms, optionally substituted with one or two substituents selected from the group consisting of C-_|—C₆ alkoxy, hydroxy, epoxy, acetoacetoxy and halogen, and R¹ has the same meaning as previously defined.

It is also preferred that the (meth)acrylate monomer of component (B) of this invention comprise up to 70 percent by weight repeating units selected from the group consisting of acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-methylolacrylonitrile, N- methylolacrylamide, N—methylacrylamide, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n—propyl acrylate, n—propyl methacrylate, isopropyl acrylate, ispropyl methacrylate, n—butyl acrylate, n— butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, stearyl acrylate, stearyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, 2— ethoxyethyl acrylate, 2-ethoxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acetoacetoxyethyl acrylate, acetoacetoxyethyl methacrylate, a diol acrylate, a diol methacrylate, and mixtures thereof. Even more preferably, the (meth)acrylate monomer is selected from the group consisting of butyl acrylate, ethyl acrylate, propyl acrylate, 2—ethylhexyl acrylate, methyl methacrylate, hydroxyethyl methacrylate, glycidyl (meth)acrylate, acetoacetoxyethyl methacrylate, hydroxyethyl acrylate, and mixtures thereof.

It is also preferred that component (B) of the invention, the styrene polymer, comprise up to about 70 wt. percent of repeating units from a compound selected from the group consisting of (meth)acrylate compounds, sodium 2-acrylamide—2-methyl—1—propanesulfonate, ammonium 2—acrylamido—2—methyl—1—propanesulfonate, potassium 2—acrylamido—2—methyl—1—propanesulfonate, potassium 2—acrylamido—2—methyl—1—propanesulfonate, lithium 2—aerylamido—2—methyl—1—propanesulfonate, sodium, 2—acrylamido—2—methyl—1—propanesulfonate, and mixtures thereof.

In the process of the present invention, the monomers are polymerized in the presence of the sulfonate-group containing polymer (i.e., the polyester or polyesteramide) .

In the method of the present invention, the polymer blends of the present invention are prepared in aqueous dispersions. The monomers are generally added to an aqueous dispersion of the water-dispersible polyester and polymerized by free radical initiation in conventional emulsion or suspension polymerization processes. The preferred ratio of polyester to monomer will vary widely and depends on the intended application for the blend. The polymer blends may comprise additives other than coalescing aids, as previously mentioned. These additives may be surfactants, chain transfer agents, alcohols, antifoams, and combinations thereof.

The surfactants useful in the invention include anionic and nonionic surfactants. Preferred nonionic surfactants include nonylphenol ethoxylate, nonylphenoxypoly(ethyleneoxy)ethanol, and one or more block copolymers of propylene oxide and ethylene oxide. The polymerization can be initiated by a water- soluble free radical initiator known in the art such as sodium or potassium persulfate or by an oil—soluble initiator such as AIBN or benzoyl peroxide. Other useful initiators include redox initiators such as sodium persulfate/sodium etabisulfite and sodium formaldehyde sulfoxylate/Fe/hydrogen peroxide. A typical temperature range for the polymerization_, reaction is about 20°C to about 90°C with about 60°C to about 90°c being preferred.

The sulfonate—group containing polymers which are used in the present invention typically become very viscous at concentrations above about 34 percent total solids. Thus, the reaction typically is begun with a polyester or polyesteramide dispersion that is about 30 percent total solids or less. However, the dispersions are prepared at final total solids levels up to from about 20 percent to about 60 percent. A total solids content of about 35 percent to about 50 percent is preferred. The increase in solids level is achieved during polymerization by controlling the amount of water, if any, which is added along with the monomer.

Thus, the method of the present invention for preparing water dispersed polymer blends can be described as comprising the steps of: (A) preparing an aqueous polymerization. ixture by contacting

(2) one or more monomers, wherein said monomers comprise: (a) about 50 to about 100 mole percent of a styrene monomer,

(3) a polymerization initiator, and

(4) water,

(B) polymerizing said monomers to provide said water-dispersible polymer blend.

In the polymerization method, it is preferred that component (A) is present in an amount of about 0.7 - 25 weight percent, and component (B) monomer is present in an amount of about 17.5 — 49 weight percent. The polymerization mixture may also contain up to . 20 weight percent of a C₁ to C₄ alcohol, especially propanol. Lesser amounts of the alcohol (e.g., up to 5 or 10 weight percent) or 15 weight percent can be employed. It has been found that use of the alcohol results in unexpected advantages in the polymerization reaction, especially achieving smaller particle size. It is anticipated that smaller particle size leads to improved dispersion stability and possible improved film—forming properties. In the polymerization method of the invention, more preferred is wherein component (A) is present in an amount of about 0.7 — 25 weight percent, component (B) is present in an amount of about 17.5 — 49 weight percent, and the alcohol is present in an amount of up to 10 weight percent. Even more preferred is wherein component (A) is present in an amount of about 2.0 — 15.8 weight percent, component (B) is present in an amount of about 26 — 42.8 weight percent, and the alcohol is present in an amount of up to 5 weight percent.

The method of the present invention produces polymer blends which are significantly different than mere physical mixing of two performed polymers. For example, the blends produced by the invention method have monodisperse or monomodal particle size distributions. The particle size distribution of the blends produced by the method of the invention preferably has an average particle size diameter of about 40 to about 300 nanometers (nm) . In a preferred embodiment, the sulfonate group- containing polymer is prepared, generally by melt polymerization, and an aqueous dispersion containing from about 20 percent to about 36 percent total solids is prepared from the polyester or polyesteramide directly. A mixture of one or more monomers and the polymerization initiators may then be added to the ^ aqueous dispersion of the polyester or polyesteramide and polymerization initiated to produce an aqueous dispersion. The aqueous dispersion so produced can be prepared with total solids contents from about 20 percent to about 60 percent, preferably 35-50. Prefer¬ ably, the pH is, or is adjusted to be, within the range of about 4—8 in order to minimize hydrolysis of the polyester. The polymer blends of the invention can be useful in ink compositions.

The invention can be further illustrated by the following examples of preferred embodiments thereof, although it will be understood that these examples are included merely for the purposes of illustration and are not intended to limit the scope of the invention unless otherwise specifically indicated. All percentages are by weight, unless otherwise specified.

As used herein, the term "I.V." is inherent viscosity measured in a 60/40 parts by weight solution of phenol/tetrachloroethane at 25°C and at a concentration of 0.5 gram of polymer in 100 mL of the solvent. Also, as used herein, the term "NVM" means non—volatile matter, determined by evaporating the dispersion at 120°F for 16 hours.

EXAMPLES EXAMPLE 1 Preparation of the polyester: A 5 liter round bottom 3-neck flask equipped with a mechanical stirrer, thermometer, distillation head and heating mantle controlled by a thermocouple was charged with 1905 g of adipic acid, 1842 g of a 47% solution of the bis(diethyleneglycolJester of 5—sodiosulfo— isophthalic acid in diethylene glycol, 424 g of diethylene glycol, 0.5 g of sodium acetate and 5 g of a, solution of titanium isopropoxide catalyst in n— propanol, containing 1.58% titanium by weight. The system was flushed with nitrogen and heated. Water began to distill at 170"C, and after the rate of distillation slowed, the temperature was raised to 250°C over 2 hours. A vacuum of 10 torr was then applied and excess diethylene glycol was distilled. The product, a very viscous material, had an acid number of 3.6, a weight average molecular weight of 9052 by gel permea¬ tion chromatography, an IV of 0.271, a ratio of ethylene glycol to diethylene glycol of 9:91 (triethylene glycol, if present, was obscured by the adipic acid); sulfur content = 1.52%, Tg = 19^βC. The product dispersed readily in water containing 0.05% sodium carbonate to give a crystal clear solution, which was adjusted to a pH of 6.54 with 5% sodium carbonate, 40.35% NVM .

Preparation of the polyester—polystyrene blend bv emulsion polymerization:

The reactor was a fully jacketed, 2 liter round bottom 3—neck flask with Morton indentations. The flask was equipped with a mechanical stirrer (100—400 rpm) , thermometer, nitrogen inlet and condenser. Reactions were run under a blanket of nitrogen, but neither the contents of the reactor nor the material to be added to the reactor were sparged with nitrogen. Temperature was maintained with circulating hot water. Reactants were pumped into the reactor through polytetrafluoroethylene tubing with a positive displacement metering pump. A catalyst solution was made from 1.0 g of ammonium persulfate and 50 g of water. An emulsion was formed by hand shaking a mixture of 127 g of deionized water, 0.4 g of sodium carbonate, 36 g of the catalyst solution, 223 g of the polyester dispersion mentioned above, and _t 280 g of styrene. The reactor was charged with the remainder of the catalyst solution, 244 g of water and 74 g of the polyester dispersion. The reactor was heated to 75°C and the emulsion was pumped into the reactor over 2.5 hours. The mixture was heated 2 additional hours at 80°C, cooled and filtered through a 110 micron polyethylene mesh.

The weight ratio of polyester to polystyrene was 30:70 by formulation. No added surfactant was used. The latex had 37.91% NVM, pH = 5.55, viscosity = 21 cps, hydrodyna ic particle diameter = 52 n in 0.01 M NaCl by photon correlation spectroscopy. The dried polymer residue had an IV of 0.733, Tg = 108°C. Blocking Temperature Testing:

This material was drawn down as a thin film over 55 pound clay coated paper printed with a solid red ink, the gloss, without additives, was 42% at a 60° angle and the film was clear and free from haze or opalescence. Blocking was tested with a Packaging Industries, Inc., "Sentinel Heat Sealer". The heated jaws were pressurized with 40 psi air pressure for 5 seconds. The blocking temperature that is reported is the temperature at which the two overprinted surfaces adhered to one another. The blocking temperature of this latex was

200°F (93°C) . The blocking temperature of the red ink surface before overprinting was 100°F (38^βC).

This experiment clearly shows the improvement in heat resistance of the present invention compared to ink printed clay coated paper without an overcoat.

EXAMPLE 2

The polyester and experimental method used in Example 1 were used to generate latexes with various ratios of polyester to polystyrene. The results are shown in Table 1 below. The heat seal blocking was performed using the apparatus and procedures used in Example 1.

Ratio X X pH Vise IV Part. X Heatseal

Polyester to DOSS NVM (cps) Size Gloss Block

Polystyrene nm °F

50/50 0 34.71 5.43 11 0.514 50 54 100

40/60 0 36.53 5.76 11 0.738 49 57 200

30/70 2 41.66 5.79 15 0.908 75 44 220

30/70 0 37.91 5.55 21 0.784 52 39 230

20/80 0 39.28 5.48 45 0.641 55 19 190

*D0SS - sodiun dioctylsulfosuccinate

This example shows good heat resistance characteristics of latexes made following the present invention with a loss in good blocking characteristics at about 50% by weight of this particular polyester.

EXAMPLE 3

Preparation of the polyester:

A 1 liter round bottom 3-neck flask equipped with a mechanical stirrer, thermometer, distillation head and heating mantle controlled by a thermocouple controller was charged with 219 g of adipic acid, 83 g of isophthalic acid, 283 g of a 47% solution of the bis(diethyleneglycol) ester of 5—sodiosulfoisophthalic acid in diethylene glycol, 200 g of diethylene glycol, 0.1 g of sodium acetate and 1 g of a solution of titanium isopropoxide catalyst in n—propanol, containing 1.58% titanium by weight. The polyester was formed by the general procedure described in Example 1. The product, a slightly flexible solid, had an acid number of 0.9, a weight average molecular weight of 8900 by gel permeation chromatography, an IV of 0.233, a ratio of ethylene glycol to diethylene glycol of 25:75 (triethylene glycol, if present, was obscured by the adipic acid); sulfur content = 1.51%. The differential scanning calorimetry analysis showed no distinct and reproducible transitions. The water-dispersible polyester had a molar composition, by formulation, of 65% adipic acid, 22% isophthalic acid and 13% 5— sodiosulfoisophthalic acid. The glycol was diethylene glycol, which, under the reaction conditions, was con¬ verted to a mixture of ethylene glycol, di— and triethylene glycol by an acid catalyzed side reaction. The product dispersed readily in water containing 0.05% sodium carbonate to give a crystal clear solution, which was adjusted to a pH of 5.94, 34.63% NVM.

Preparation of the polvester-polvstyrene blend by emulsion polymerization:

The general procedure described in Example 1 was used. A catalyst solution was made from 1.0 g of ammonium persulfate and 50 g of water. An emulsion was formed by hand shaking a mixture of 258 g of deionized water, 0.4 g of sodium carbonate, 36 g of the catalyst solution, 312 g of the 34.63% NVM polyester dispersion mentioned above, and 280 g of styrene. The reactor was charged with the remainder of the catalyst solution, 60 g of water and 35 g of the polyester dispersion. The reactor was heated to 75^CC and the emulsion was pumped into the reactor over 2.5 hours. The mixture was heated 2 additional hours at 80^βC, cooled and filtered through a 110 micron polyethylene mesh. The weight ratio of polyester to polystyrene was 30:70 by formulation. No added surfactant or solvent was used. The latex had 40.08% NVM, pH = 5.41, viscosity = 27 cps, particle diameter = 57 nm. The dried polymer residue had an IV of 0.969, Tg = 107°C. When drawn down as a thin film over 55 pound clay coated paper printed with a solid red ink, the gloss, without _< additives, was 30% and the blocking temperature was 200°F (93°C).

This example clearly shows that the high temperature block properties are retained when part of the diacid is an aromatic diacid.

EXAMPLE 4 (Comparative Example)

This example demonstrates that a latex made with all aromatic diacid gives poor temperature block resistance compared to latexes_βof the present invention.

A polyester was prepared with a composition, by formulation, of 87% isophthalic acid and 13% 5— sodiosulfoisophthalic acid, with the glycol being diethylene glycol, using the general procedure described above. It was reacted with styrene to give a latex with a composition, by formulation, of 30% polyester and 70% polystyrene. The latex, unformulated, had a gloss of 60% and a heat sealer block of 140°F (60^βC) .

EXAMPLE 5

Preparation of the polyester:

A 5 liter round bottom 3—neck flask equipped with a mechanical stirrer, thermometer, distillation head, vigreux column and heating mantle controlled by a thermocouple was charged with 370 g of dimethyl 5— sodiosulfoisophthalate, 1500 g of neopentyl glycol, 1.0 g of sodium acetate and 10 g of a solution of titanium isopropoxide catalyst in n—propanol, containing 1.58% titanium by weight. The system was flushed with nitrogen and heated. Methanol began to distill at a reactor temperature of 200—210^βC. After most of the ionic monomer had dissolved, 1950 g of dimethyl cyclohexanedicarboxylate (80% cis isomer, 20 % trans isomer) was added. Heating to 260°C with distillation \ of methanol continued for 3 hours. The vigreux column was then removed and distillation was continued under a vacuum of 2 torr with a 260°C reactor temperature for an additional 75 minutes. The product was a clear solid, with an acid number of 0.6, a weight average molecular weight of 7100 by gel permeation chromatography, an IV of 0.183 and a second cycle Tg = 21°C. The product dispersed slowly in water containing 20% n—propanol to give a pale white dispersion, n—Propanol was then distilled through a 30 cm vigreux column; distillation was stopped at a head temperature of 92°C. The cooled dispersion had 21.18% NVM, pH = 5.41 and a viscosity = 19 cps.

Emulsion polymerization:

Following the general procedure of Example 1, a catalyst solution was made from 0.3 g of ammonium persulfate and 15 g of water. An emulsion was made by hand—shaking 24 g of water, 0.1 g of sodium carbonate, 153 g of the polyester dispersion described above, and 84 g of styrene. The reactor was charged with 6 g of water, 8 g of the catalyst solution, and 17 g of the polyester dispersion. The styrene emulsion was pumped into the reactor over 2.5 hours. The remainder of the catalyst solution was added 1 hour after the pumping of the emulsion began. The mixture was heated for an additional 2 hours, cooled and filtered. The product, 38.02% NVM, contained 30% polyester and 70% polystyrene by formulation. The pH was 5.31, the viscosity was 48 cps and the particle size was 93 nm. When coated on paper printed with a red ink, the latex, without further formulation, gave a clear film with a gloss of 40% and a heat—sealer blocking temperature of 170^βF (77°C). This is an example of a presently preferred polyester formulation of the present invention showing both good gloss and good blocking temperature re¬ sistance. The invention has been described in detail with particular reference to the preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. Moreover, all patents, patent applications (published or unpublished, foreign or domestic) , literature references or other publications noted above are incorporated herein by reference for any disclosure pertinent to the practice of this invention.

Claims

CLAIMS We claim:

1. A polymer blend comprising:

(A) about 2 weight percent to about 50 weight percent of a water-dispersible sulfonate group—containing polyester or polyester amide comprising;

(a) aromatic and aliphatic and alicyclic and ionic dicarboxylic acids such that (i) the mole percent of ionic diacid is about 5 mole percent to about 25 mole percent, and (ii) the mole percent of aromatic diacids is less than 50%, (b) diols comprising no more than about 50 mole percent, of the total diols being selected from the group consisting of 1,4—cyclohexanedimethanol, 1,3—cyclo¬ hexanedimethanol, and 1,2—cyclohexane- dimethanol;

(B) about 50 weight percent to about 98 weight percent of a styrene polymer comprising: (a) about 30 to 100 weight percent of repeating units from a styrene compound.

2. The polymer blend as claimed in Claim 1 wherein the styrene compound in component (B) is selected from the group consisting of styrene, α—methyl styrene, 3—methyl styrene, 4—methyl styrene, t—butyl styrene, and mixtures thereof.

3. The polymer blend as claimed in Claim 1 wherein component (B) comprises:

(a) about 30 to 100 weight percent of repeating units from a styrene compound, and (b) up to about 70 weight percent of repeating units from a compound selected from the group consisting of (meth)acrylate compounds, sodium 2—aerylamido—2—methyl—1—propanesulfonate, ammonium 2—acrylamido—2—methyl—1— propanesulfonate, potassium 2—acrylamido—2- methyl—1—propanesulfonate, lithium 2-acrylamido—2—methyl—1—propanesulfonate, sodium 2—acrylamido—2—methyl—1—propane sulfonate, and mixtures thereof.

4. The polymer blend as claimed in Claim 3 wherein component (B) (a) is selected from the group consisting of styrene, a-methyl styrene, 3—methyl styrene, 4— ethyl styrene, t—butyl styrene, and mixtures thereof, and component (B) (b) is selected from the group consisting of acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N—methylolacrylo— nitrile, N— ethylolacrylamide, N—methylacrylamide, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n— propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n—butyl acrylate, n—butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, 2—ethylhexyl acrylate, 2—ethylhexyl methacrylate, stearyl acrylate, stearyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, 2—ethoxyethyl acrylate, 2—ethoxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acetoacetoxyethyl acrylate, acetoacetoxyethyl methacrylate, a diol acrylate, a diol methacrylate, and mixtures thereof. 5. The polymer blend as claimed in Claim 1 wherein said polymer blend also contains additives.

6. The polymer blend as claimed in Claim 5 wherein said additives are selected from the group consisting of surfactants, chain transfer agents, alcohols, anti—foams, coalescing aides, and combinations thereof.

7. The polymer blend of Claim 1 wherein said (A) water-dispersible polyester or polyesteramide comprises a polymer having carbonyloxy linking groups in the linear molecular structure wherein up to 80 percent of the linking groups are carbonylamido linking groups, the polymer having an inherent viscosity of from about 0.1 to about 1.0 measured in a 60/40 parts by weight solution of phenol/tetrachloroethane at 25°C and at a concentration of 0.5 gram of polymer in 100 ml of the solvent, the polymer containing substantially equimolar proportions of acid equivalents (100 mole %) to hydroxy and amino equivalents (100 mole %) , the polymer comprising the reaction products of reactants selected from (a) , (b) , (c) , and (d) , or the ester forming or esteramide forming derivatives thereof, as follows, wherein all stated mole percentages are based on the total of all acid, hydroxyl, and amino equivalents being equal to 200 mole percent: (a) at least one difuctional dicarboxylic acid; (b) from about 7 to about 25 mole percent of at least one difunctional sulfomonomer containing at least one metallic sulfonate group or nitrogen-containing nonmetallic sulfonate group attached to , an aromatic or cycloaliphatic nucleus wherein the functional groups are hydroxy, carboxyl, or amino;

(c) at least one difunctional reactant selected from a glycol or a mixture of a glycol and diamine having two —NRH groups, the glycol containing two —OH groups; and

(d) from 0 to about 40 mole percent of difuctional reactant selected from hydroxycarboxylic acids having one

—C(R)₂—OH group, aminocarboxylic acids having one —NRH group, amino—alcohols having one —C(R)₂—OH group and one —NRH group, or mixtures of said difunctional reactants; wherein each R in the (c) and (d) reactants is a hydrogen atom or an alkyl group of 1 to 4 carbons; (B) said styrene compound is of the structure

wherein R¹ is H or methyl, R² is a lower alkyl group of 1 to 6 carbon atoms, and m is an integer of 0 to 2. The polymer blend as claimed in Claim 1 wherein

(a) the aromatic dicarboxylic acids are selected from the group consisting of terephthalic acid, isophthalic acid, phthalic acid and mixtures thereof;

(b) the aliphatic dicarboxylic acids are selected from the group consisting of acids having the formula

HO0C (CH₂)_n COOH

wherein n is a number of from about 2 to about 12, 1,4—cyclohexanedicarboxylic acid, 1,3—cyclo¬ hexanedicarboxylic acid, 1,2—cyclohexanedicar— boxylic acid, and mixtures thereof,

(c) the ionic dicarboxylic acids are selected from the group consisting of 5—sulfoisophthalic acid, 4—sulfophthalic acid and mixtures thereof, and (d) at least about 50 mole percent of the diols being selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol,

1,5—pentanediol, 1,4—butanediol, 1,3—propanediol, 1,3—cyclobutanediol, butylethylpropanediol, 2,2-dimethy1-3— hydroxypropyl—2,2—dimethyl—3— hydroxypropionate, and mixtures thereof.

9. A polymer blend comprising:

(A) about 5 weight percent to about 35 weight percent of a water-dispersible sulfonate group—containing polyester or polyester amide comprising;

(a) aromatic and aliphatic and alicyclic and ionic dicarboxylic acids such that (i) the mole percent of ionic diacid is about 5 mole percent to about 25 mole percent, and (ii) the mole percent of aromatic diacids is less than 50%, (b) diols comprising no more than about 50 mole percent, of the total diols being selected from the group consisting of 1,4—cyclohexane—dimethanol, 1,3—cyclohexanedimethanol, and 1,2—cyclohexanedimethanol;

(B) about 65 to about 95 weight percent of a styrene polymer comprising: (a) about 30 to 100 weight percent of repeating units from a styrene compound.

10. The polymer blend as claimed in Claim 9 wherein the styrene compound in component (B) is selected from the group consisting of styrene, α—methyl styrene, 3—methyl styrene, 4—methyl styrene, t—butyl styrene, and mixtures thereof.

11. The polymer blend as claimed in Claim 9 wherein component (B) comprises:

(a) about 30 to 100 weight percent of repeating units from a styrene compound, and

(b) up to about 70 weight percent of repeating units from a compound selected from the group consisting of (meth)acrylate compounds, sodium 2—acrylamido—2—methyl—1—propanesulfonate, ammonium 2—acrylamido—2—methyl—1—propane— sulfonate, potassium 2-acrylamidc—2-methyl-l-_l propanesulfonate, lithium 2— crylamido—2- methyl—1—propanesulfonate, sodium 2—acrylamido—2—methyl—1—propane sulfonate, and mixtures thereof.

12. The polymer blend of Claim 11 wherein said (A) water-dispersible polyester or polyesteramide comprises a polymer having carbonyloxy linking groups in the linear molecular structure wherein up to 80 percent of the linking groups are carbonylamido linking groups, the polymer having an inherent viscosity of from about 0.1 to about 1.0 measured in a 60/40 parts by weight solution of phenol/tetrachloroethane at 25°C and at a concentration of 0.5 gram of polymer in 100 ml of the solvent, the polymer containing substantially equimolar proportions of acid equivalents (100 mole %) to hydroxy and amino equivalents (100 mole %) , the polymer comprising the reaction products of reactants selected from (a) , (b) , (c) , and (d) , or the ester forming or esteramide forming derivatives thereof, as follows, wherein all stated mole percentages are based on the total of all acid, hydroxyl, and amino equivalents being equal to 200 mole percent:

(a) at least one difunctional dicarboxylic acid;

(b) from about 4 to about 25 mole percent of at least one difunctional sulfomonomer containing at least one metallic sulfonate group or nitrogen—containing nonmetallic sulfonate group attached to an aromatic or cycloaliphatic nucleus wherein the functional groups are hydroxy, carboxyl, or amino;

—C(R)₂—OH group, aminocarboxylic acids having one —NRH group, amino-alcohols having one —C(R)₂-OH group and one -NRH group, or mixtures of said difunctional reactants; wherein each R in the (c) and (d) reactants is a hydrogen atom or an alkyl group of 1 to 4 carbons; (B) said styrene compound is of the structure

wherein R¹ is H or methyl, R² is a lower alkyl group of 1 to 6 carbon atoms, and is an integer of 0 to 2; and (C) said (meth)acrylic compound is of the structure COOR³

CH,

wherein R³ is H or an alkyl group of 1 to 10 carbon atoms, optionally substituted with one or two substituents selected from the group consisting of hydroxy, acetoacetoxy, C₂—C₆ alkoxy, epoxy and halogen, and R¹ is H or methyl.

13. The polymer blend as claimed in Claim 1 wherein component (B) comprises:

(a) about 30 to 100 weight percent of repeating units from a styrene compound selected from the group consisting of styrene, a—methyl styrene, 3—methyl styrene, 4—methyl styrene, t—butyl styrene, and mixtures thereof, and

(b) up to about 70 weight percent of repeating units from a compound selected from the group consisting of (meth)acrylate compounds, acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, aerylamide, methacrylamide, N—methylolacrylonitrile, N-methylolacrylamide, N— ethylacrylamide, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n—propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n—butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, 2—ethylhexyl acrylate, 2— ethylhexyl methacrylate, stearyl acrylate, stearyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, 2—ethoxyethyl acrylate, 2—ethoxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acetoacetoxyethyl acrylate, acetoacetoxyethyl methacrylate, a diol acrylate, a diol methacrylate sodium 2—acrylamido—2—methyl—1— propanesulfonate, ammonium 2—acrylamido—2— methyl—1—propanesulfonate, potassium 2—acrylamido—2—methyl—1—propanesulfonate, lithium 2—acrylamido—2—methyl—1— propanesulfonate, sodium 2—acrylamido—2— methyl—1—propane sulfonate, and mixtures thereof.

14. The polymer blend as claimed in Claim 9 wherein said polymer blend also contains additives.

15. The polymer blend as claimed in Claim 14 wherein said additives are selected from the group consisting of surfactants, chain transfer agents, alcohols, anti—foams, coalescing aids, and combinations thereof.

16. The polymer blend as claimed in Claim 9 wherein

(b) the aliphatic dicarboxylic acids are selected from the group consisting of acids having the formula HOOC (^CH2)_n ^C00H

wherein n is a number of from about 2 to about 12,1,4—cyclohexanedicarboxylic acid, 1,3—cyclo¬ hexanedicarboxylic acid, 1,2—cyclohexanedicar¬ boxylic acid, and mixtures thereof,

(c) the ionic dicarboxylic acids are selected from the group consisting of 5—sulfoisophthalic acid, 4—sulfophthalic acid and mixtures thereof, and

(d) at least about 50 mole percent, of the diols being selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,5—pentanediol, 1,4—butanediol, 1,3-propanediol, 1,3—cyclobutanediol, 2- methy1—1,3—propanediol, butylethylpropanediol and mixtures thereof.

17. A polymer blend comprising:

(a) aromatic and aliphatic and alicyclic and ionic dicarboxylic acids such that; (i) the mole percent of ionic diacid is about 5 mole percent to about 25 mole percent, and (ii) the mole percent is less than 50%, (b) diols comprising no more than about 50 mole percent, of the total diols being selected from the group consisting of 1,4—cyclohexane—dimethanol, 1,3—cyclohexanedimethanol, and

1,2—cyclohexanedimethanol; (B) about 50 weight percent to about 98 weight percent of a styrene polymer comprising:

(a) greater than about 50 weight percent of a styrene monomer, and

(b) the balance consisting of repeating units from at least one other ethylenically unsaturated monomer.

18. The polymer blend as claimed in Claim 17 wherein component (B) (a) is selected from the group consisting of styrene, α—methyl styrene, 3— ethyl styrene, 4—methyl styrene, t—butyl styrene, and mixtures thereof, and component (B) (b) is selected from the group consisting of acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N- methylolacrylonitrile, N-methylolacrylamide, N- methylacrylamide, methyl acrylate methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n—butyl acrylate, n—butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, 2—ethylhexyl acrylate, 2—ethylhexyl methacrylate, stearyl acrylate, stearyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, 2—ethoxyethyl acrylate, 2—ethoxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acetoacetoxyethyl acrylate, acetoacetoxyethyl methacrylate, a diol acrylate, a diol methacrylate, vinyl acetate, vinylidene chloride, butadiene, 1-methylbutadiene, 2- methylbutadiene, 2—chloro-butadiene, diisobutylene, cyclopentadiene, divinylbenzene, diallyl-phthalate, and mixtures thereof.

19. The polymer blend of Claim 17 wherein said (A) water-dispersible polyester or polyesteramide comprises a polymer having carbonyloxy linking groups in the linear molecular structure wherein up to 80 percent of the linking groups are carbonylamido linking groups, the polymer having an inherent viscosity of from about 0.1 to about l.o measured in a 60/40 parts by weight solution of phenol/tetrachloroethane at 25°C and at a concentration of 0.5 gram of polymer in 100 ml of the solvent, the polymer containing substantially equimolar proportions of acid equivalents (100 mole %) to hydroxy and amino equivalents (100 mole %) , the polymer comprising the reaction products of reactants selected from (a), (b), (c), and (d) , or the ester forming or esteramide forming derivatives thereof, as follows, wherein all stated mole percentages are based on the total of all acid, hydroxyl, and amino equivalents being equal to 200 mole percent:

(a) at least one difuctional dicarboxylic acid;

—C(R)₂-OH group, aminocarboxylic acids having one —NRH group, amino—alcohols having one —C(R)₂—OH group and one —NRH group, or mixtures of said difunctional reactants; wherein each R in the (c) and (d) reactants is a hydrogen atom or an alkyl group of 1 to 4 carbons; (B) said styrene compound is of the structure

wherein R¹ is H or methyl, R² is a lower alkyl group of 1 to 6 carbon atoms, and m is an integer of 0 to 2; and (C) said (meth)acrylic compound is of the structure C00FT-

CH,

wherein R³ is H or an alkyl group of 1 to 10 carbon atoms, optionally substituted with one or two substituents selected from the group consisting of hydroxy, acetoacetoxy, C^C₆ alkoxy, epoxy and halogen, and R¹ is H or methyl.

20. The polymer blend as claimed in Claim 1 wherein (a) the aromatic dicarboxylic acids are selected from the group consisting of terephthalic acid, isophthalic acid, phthalic acid and mixtures thereof; (b) the aliphatic dicarboxylic acids are selected from the group consisting of acids having the formula

wherein n is a number of from about 2 to about 12, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2— cyclohexanedicarboxylic acid, and mixtures thereof, (c) the ionic dicarboxylic acids are selected fro the group consisting of 5—sulfoisophthalic acid, 4—sulfophthalic acid and mixtures thereof, and (d) at least about 50 mole percent, of the diols being selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,5—pentanediol,

1,4—butanediol, 1,3—propanediol, 1,3—cyclobutanediol, 2—methy1—1,3—propanediol, butylethylpropanediol, 2,2-dimethy1—3— hydroxypropyl—2,2—dimethyl—3— hydroxypropionate, and mixtures thereof.

21. The polymer blend as claimed in Claim 17 wherein said polymer blend also contains additives.

22. The polymer blend as claimed in Claim 21 wherein said additives are selected from the group consisting of surfactants, chain transfer agents, alcohols, anti—foams, coalescing aides, and combinations thereof.

23. The polymer blend of Claim 1 prepared by polymerizing monomers to form compound (B) in the presence of said polyester or polyesteramide.

24. An aqueous dispersion comprising water and the polymer blend of Claim 1.

25. The aqueous dispersion of Claim 24 wherein the polymer blend is the polymer blend of Claim 9. 26. The aqueous dispersion of Claim 4 comprising about, 20 to about 60 weight percent solids.

27. The aqueous dispersion of Claim 4 comprising about 35 to about 50 weight percent solids.

28. The aqueous dispersion of Claim 5 comprising about 20 to about 60 weight percent solids.

29. The aqueous dispersion go Claim 5 comprising about 35 to about 50 weight percent solids.

30. The aqueous dispersion of Claim 4 containing up to 15 weight percent of a Cl to C4 alcohol.

31. The aqueous dispersion of Claim 4 containing up to 10 weight percent of a Cl to C4 alcohol.

32. The aqueous dispersion of Claim 31 containing up to 15 weight percent of a Cl to C4 alcohol.

33. A method of preparing a water-dispersed polymer blend comprising the steps of:

(A) preparing an aqueous polymerization mixture by contacting

(2) one or more monomers, wherein said monomers comprise: (a) about 50 weight percent to about 100 weight percent of a styrene monomer,

(3) a polymerization initiator, and

(4) water,

(B) polymerizing said monomers to provide said water-dispersible polymer blend. 34. The method of Claim 33 wherein component (2) comprises

(A) about 30 to 100 weight percent of repeating units from a styrene compound, and (B) up to 70 weight percent of repeating units from a (meth)acrylate compound.

35. An ink composition prepared with the polymer blend of Claim 1.

36. An ink composition comprising the polymer blend of Claim 9.

37. An ink composition comprising the polymer blend of Claim 17.