60/122,597, filed March 3,1999, the disclosure of which is incorporated herein in its entirety by this reference.

Field of the Invention The present invention relates to latex polymer compositions that comprise caprolactam. The present invention further relates nylon 6 polymer compositions that are modified with a polymer colloid system comprising a first polymer. The polymer colloid system is added during the polymerization of caprolactam in conjunction with a nylon 6 ring opening reaction, wherein the first polymer of the polymer colloid system is incorporated into the nylon 6 polymer blend to provide novel polymer blends.

Background of the Invention Latex polymers are utilized in a variety of products due to the unique features of their delivery system. Latex polymers, by nature, have lower viscosities than their solution counterparts. This lower viscosity allows for higher polymer concentrations to be delivered in an application without encountering the numerous problems associated with high viscosity fluids. This unique viscosity behavior of latex polymers results from the heterogeneity of the system. The fact that the latex polymers are dispersed, rather than dissolved, in a continuous low viscosity media reduces the influence of the latex polymer on the viscosity of the media. Therefore, the continuous phase or solvent of the latex is the dominant component affecting the viscosity of the system.

Typically, the continuous phase of most commercial latexes is water. This is beneficial in that water has low toxicity and is not flammable. Water is a good choice when the continuous phase is to be used as a delivery system for the polymer. In some

circumstances, however, water may be detrimental to the substrate, or may not possess acceptable drying characteristics.

Water would generally be considered to be non-reactive. It has been found desirable to prepare latexes with a continuous phase comprising materials other than water when the latex is to be added to a reactive environment. Under such circumstances, the continuous phase may participate in the reaction. When such reactive materials are to be included, it has been found that it is particularly preferable to include diols in the continuous phase of a latex composition. The diol of this process can then be utilized as a reactant in a number of nylon 6-type polymerizations.

A further example of a latex participating in a reaction relates to the invention described herein. In a major aspect of this invention, a polymer colloid system is prepared that comprises a continuous phase, wherein the continuous phase comprises water, caprolactam or a mixture thereof, optionally, comprising a co-solvent. The polymer colloid system may then be utilized in a ring opening nylon 6 polymerization reaction resulting in the first polymer being incorporated in a nylon 6 blend to form a nylon 6/first polymer blend. Latex compositions comprising caprolactam and the methods of preparing the nylon 6 blend compositions of the present invention are novel over the prior art.

Summary of the Invention In one aspect, the invention provides a caprolactam containing latex composition comprising: a. latex polymer particles comprising a residue of an ethylenically unsaturated monomer; b. a surfactant; and c. a continuous liquid phase comprising a caprolactam component, wherein the latex polymer particles are dispersed in the continuous phase.

In a further aspect, the invention provides a method of making a nylon 6/first polymer blend comprising the steps of : a. preparing a polymer colloid system comprising a first polymer dispersed in a liquid continuous phase; b. introducing the polymer colloid system into a nylon 6 ring opening reaction either prior to or during the nylon 6 ring opening reaction medium, wherein the reaction medium comprises caprolactam; and c. opening the ring and reacting the caprolactam, thereby providing a nylon 6/first polymer blend.

In still a further aspect, the invention provides a nylon 6/first polymer blend comprising nylon 6 and a first polymer, wherein the first polymer of the nylon 6/first polymer blend is derived from a polymer colloid system.

Still further, the invention provides a method of making a nylon 6/first polymer blend comprising the steps of : a. preparing a polymer colloid system comprising a first polymer, wherein the first polymer comprises a latex polymer; b. introducing the polymer colloid system into a nylon 6 polymer; and c. extruding the polymer colloid system and the nylon 6 polymer, thereby providing a nylon 6/first polymer blend.

Detailed Description of the Invention The present invention may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the Examples included therein.

Before the present compositions of matter and methods are disclosed and described, it is to be understood that this invention is not limited to specific synthetic methods or to particular formulations, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings: The singular forms"a,""an"and"the"include plural referents unless the context clearly dictates otherwise.

"Optional"or"optionally"means that the subsequently described event or circumstances may or may not occur, and that the description included instances where said event or circumstance occurs and instances where it does not.

"Latex"is herein defined as a dispersion of polymeric particles in a continuous phase, the polymeric particles preferably having a size range of from 10 to 1000 nm.

The polymeric particles are produced through emulsion polymerization.

As used herein, nylon 6 is a polymer of caprolactam.

Throughout this application, where publications are referenced, the disclosures of these publications in their entireties are hereby incorporated by reference into this application to more fully describe the state of the art to which this invention pertains.

Ranges are often expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent"about,"it will be understood that the particular value is another embodiment.

In one aspect, the invention provides a caprolactam containing latex composition comprising: a. latex polymer particles comprising a residue of an ethylenically unsaturated monomer;

b. a surfactant; and c. a continuous liquid phase comprising a caprolactam component, wherein the latex polymer particles are dispersed in the continuous phase.

In a further aspect, the invention provides a method of making a nylon 6/first polymer blend comprising the steps of : a. preparing a polymer colloid system comprising a first polymer dispersed in a liquid continuous phase; b. introducing the polymer colloid system into a nylon 6 ring opening reaction either prior to or during the nylon 6 ring opening reaction medium, wherein the reaction medium comprises caprolactam; and c. opening the ring and reacting the caprolactam, thereby providing a nylon 6/first polymer blend.

In still a further aspect, the invention provides a nylon 6/first polymer blend comprising nylon 6 and a first polymer, wherein the first polymer of the nylon 6/first polymer blend is derived from a polymer colloid system.

Still further, the invention provides a method of making a nylon 6/first polymer blend comprising the steps of : a. preparing a polymer colloid system, comprising a first polymer, wherein the first polymer comprises a latex polymer; b. introducing the polymer colloid system into a nylon 6 polymer, and c. extruding the polymer colloid system and the nylon 6 polymer, thereby providing a nylon 6/first polymer blend.

I. The Caprolactam Containing Compositions As mentioned, in a first major aspect, this invention concerns the preparation of a latex polymer composition comprising from about 1 to about 95% caprolactam in a continuous phase.

As used throughout, the total weight of the continuous phase includes the weight of the caprolactam, water and any co-solvent. The weight of any surfactant is not included in the total weight of the continuous phase.

In embodiments of the invention herein, the caprolactam component is present in the latex polymer composition in an amount of from about 1 to about 95% by weight, further preferably, about 10 to about 95% by weight of the continuous phase, still preferably, about 20 to about 95% by weight of the continuous phase, and, further preferably about 30 to about 95% by weight, based on the total weight of the continuous phase. In a further preferred embodiment, the caprolactam component comprises from about 40 to about 95% by weight of the continuous phase. Still preferably, the caprolactam comprises from about 50 to about 95% by weight, based on the total weight of the continuous phase, and, further preferably, from about 60 to about 95% by weight, based on the total weight of the continuous phase, and, still preferably, from about 70 to about 95% by weight, based on the total weight of the continuous phase. In a further preferred embodiment, the caprolactam component comprises from about 80 to about 95% by weight of the continuous phase. In a further embodiment, the continuous phase consists essentially of caprolactam.

The caprolactam containing latex compositions of the present invention are preferably prepared by emulsion polymerization. The solids content of the reaction is preferably from about 5 to about 60% by weight but more preferably from about 20 to about 50% by weight. The particle size of the latex polymer particles of the latex polymer composition is preferably equal to or below about 1000 nm, and, more preferably from about 20 to about 700 nm, and, even more preferably from about 60 to

about 250 nm. The temperature of the reaction is preferably from about 0 to about 190 °C, more preferably from about 60 to about 90 °C.

The continuous phase of the latex compositions may also preferably comprise a cosolvent. These cosolvents include, but are not limited to, methanol, ethanol, propanol, n-butanol, or a mixture thereof. The cosolvent may be present in the amount of equal to or less than about 90% by weight, and, more preferably, less than about 40% by weight, based on the total weight of the continuous phase. When a cosolvent is present in the caprolactam containing latex compositions, the compositions may comprise caprolactam or a mixture of caprolactam and water.

A surfactant is preferably used to prepare the caprolactam containing latex polymer compositions. The type and amount of surfactant used in the emulsion polymerization reaction depends on the particular monomer combinations and the polymerization conditions. Typical surfactants used in the emulsion polymerization are anionic, cationic, or nonionic surfactants. Anionic surfactants that may be used in the invention include surfactants such as alkali metal or ammonium salts of alkyl, aryl or alkylaryl sulfonates, sulfates, phosphates, or a mixture thereof. Suitable nonionic surfactants include, but are not limited to, alkyl and alkylaryl polydiol ethers, such as ethoxylation products of lauryl, oleyl and stearyl alcohols; alkyl phenol glycol ethers, including but not limited to, ethoxylation products of octyl or nonylphenol. Suitable surfactants may be found in McCutcheon's Volume I : Emulsifiers and Detergents 1996 North American Edition, MC Publishing Co., Glen Rock, NJ, 1996.

The surfactant may or may not be reactive in the polymerization. In one embodiment, useful surfactants are the sulfate/sulfonate salts of nonyl phenol and alkyl alcohol ethoxylates. Preferred surfactants include, but are not limited to, polymerizable or nonpolymerizable alkyl ethoxylate sulfates, alkyl phenol ethoxylate sulfates, alkyl ethoxylates, alkyl phenol ethoxylates, or a mixture thereof.

The caprolactam containing latex compositions may be prepared by any conventional means known in the art for preparing latex polymers. The monomers that

are used to form the caprolactam containing latex polymers may be broadly characterized as ethylenically unsaturated monomers. These include, but are not limited to, non-acid vinyl monomers, acid vinyl monomers, or a mixture thereof. The latex polymers of the invention may be copolymers of non-acid vinyl monomers and acid monomers, mixtures thereof and their derivatives. The latex polymers of the invention may also be homopolymers of ethylenically unsaturated monomers.

Suitable non-acid vinyl monomers that may be used to prepare the latex polymers include, but are not limited to, acetoacetoxy ethyl methacrylate, acetoacetoxy ethyl acrylate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-ethyl hexyl acrylate, isoprene, octyl acrylate, octyl methacrylate, iso-octyl acrylate, iso-octyl methacrylate, trimethyolpropyl triacrylate, styrene, a-methyl styrene, glycidyl methacrylate, carbodiimide methacrylate, Ci-Cig alkyi crotonates, di-n-butyl maleate, a- (3-vinyl naphthalene, di- octylmaleate, allyl methacrylate, di-allyl maleate, di-allylmalonate, methyoxybutenyl methacrylate, isobornyl methacrylate, hydroxybutenyl methacrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl ethylene carbonate, epoxy butene, 3,4- dihydroxybutene, hydroxyethyl (meth) acrylate, methacrylamide, acrylamide, butyl acrylamide, ethyl acrylamide, butadiene, vinyl ester monomers, vinyl (meth) acrylates, isopropenyl (meth) acrylate, cycloaliphaticepoxy (meth) acrylates, ethylformamide, 4- vinyl-1,3-dioxolan-2-one, 2,2-dimethyl-4 vinyl-1,3-dioxolane, and 3,4-di-acetoxy-l- butene, or a mixture thereof. Suitable monomers are described in The Brandon Associates, 2nd edition, 1992 Merrimack, New Hampshire, and in Polymers and Monomers, the 1966-1997 Catalog from Polyscience, Inc., Warrington, Pennsylvania, U. S. A.

Acid vinyl monomers that may be used to prepare the latex polymer include, but are not limited to, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, and monovinyl adipate.

Preferred monomers useful for making the latex polymer/ (co) polymer are ethylenically unsaturated monomers including, but not limited to, acrylates, methacrylates, vinylesters, styrene, styrene derivatives such as 4-sodiosulfostyrene, vinyl chloride, vinylidene chloride, acrylonitrile, isoprene and butadiene. In a more preferred embodiment, the latex polymer comprises (co) polymers of 2-ethyl-hexyl acrylate, styrene, butylacrylate, butylmethacrylate, ethylacrylate, methylmethacrylate, butadiene, isoprene, or a mixture thereof.

In a preferred embodiment, the molecular weight of the latex polymer utilized in the caprolactam containing latex polymer compositions, as well as the latex compositions described below in Section II, is a weight average molecular weight (Mw) of from about 1,000 to about 1,000,000 as determined by gel permeation chromatography (GPC), more preferably a weight average molecular weight of from about 5000 to about 250,000. In one embodiment, the glass transition temperature (Tg) of the latex polymer is greater than or equal to about 170 °C.

The caprolactam containing latex compositions of this invention may be characterized as stabilized latexes in a continuous phase comprising a caprolactam component. A stable latex is defined for the purposes of this invention as one in which the particles are colloidally stable, i. e., the latex particles remain dispersed in the continuous phase for long periods of time, such as 24 hours, preferably 48 hours, even more preferably, one week.

The latex polymer particles generally have a spherical shape. The latex polymer may be a core-shell polymer or a non-core-shell polymer. It is possible to prepare the polymers in a core-shell fashion by staging the monomer addition. For example, the composition of the monomer feed of the polymerization reaction may be changed over the course of the reaction in an abrupt fashion, resulting in a distinct core and shell portion of the polymer. The core-shell polymer particles may also be prepared in a multilobe form, a peanut shell form, an acorn form, or a raspberry form. In such particles, the core portion can comprise from about 20 to about 80 % of the total weight

of said particle and the shell portion can comprise from about 80 to about 20 % of the total weight volume of the particle.

In one embodiment, chain transfer agents are used in the emulsion polymerization reaction. Typical chain transfer agents are those known in the art.

Chain transfer agents that may be used in the emulsion polymerization reaction to form the caprolactam containing latex compositions include, but are not limited to, butyl mercaptan, dodecyl mercaptan, mercaptopropionic acid, 2-ethylhexyl-3- mercaptopropionate, n-butyl-3-mercaptopropionate, octyl mercaptan, isodecyl mercaptan, octadecyl mercaptan, mercaptoacetate, allyl mercaptopropionate, allyl mercaptoacetate, crotyl mercaptoproprionate, crotyl mercaptoacetate, and the reactive chain transfer agents disclosed or described in U. S. Patent No. 5,247,040, which is incorporated herein by this reference. Preferably, the chain transfer agent is selected from the mercaptans and various alkyl halides, including, but not limited to, carbon tetrachloride; more preferably, the chain transfer agent is 2-ethylhexyl-3- mercaptopropionate. Chain transfer agents can be added in amounts from about 0 to about 2 parts per hundred monomer (phm), more preferably about 0 to about 0.5 phm.

The latex polymers of the caprolactam containing latex compositions of the invention can be uncrosslinked or crosslinked.

In a preferred embodiment, the latexes are crosslinked utilizing suitable crosslinking agents which include multifunctional unsaturated compounds including, but not limited to, divinyl benzene, allyl methacrylate, allyl acrylate, multifunctional acrylates, or a mixture thereof. Suitable multifunctional acrylates include, but are not limited to, ethylene diol dimethacrylate, ethylene diol diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritoltetraacrylate, or a mixture thereof. The amount of the crosslinking monomer in the emulsion polymerization can be controlled to vary the gel fraction of the latex at from about 20 to about 100 percent. The gel fraction is the amount that will not dissolve in a good solvent.

In a further preferred embodiment, the polymer colloid system is comprised of a first polymer which is uncrosslinked. It is particularly preferred that the first polymer is an uncrosslinked latex. One of ordinary skill in the art will recognize that uncrosslinked polymers, such as latexes, may be prepared from the same monomers and continuous phases as are utilized to prepare the crosslinked polymer colloid systems, with the exception that a crosslinking agent is not utilized.

The latex particles may be functionalized by including monomers with pendent functional groups. Functional groups that may be incorporated in the latex particle include, but are not limited to, epoxy groups, acetoacetoxy, carbonate groups, hydroxyl groups amine groups, isocyanate groups, amide groups, or a mixture thereof. The functional groups may be derived from a variety of monomers, including, but not limited to, glycidyl methacrylate, acetoacetoxy ethyl methacrylate, vinyl ethylene carbonate, hydroxyl ethyl methacrylate, t-butylaminoethyl methacrylate, dimethylamino methacrylate, m-isopropenyl-alpha, alpha-dimethylbenzyl isocyanate, acrylamide and n-methylolacrylamide. The addition of functional groups allows for further reaction of the polymer after latex synthesis. The functionality may be useful to impart latent crosslinking or it may be used in conjunction with a nylon 6 ring opening reaction as discussed in Section II, below.

Initiators can be used in the emulsion polymerization to form the caprolactam containing latex compositions, which include, but are not limited to salts of persulfates, water or caprolactam soluble organic peroxides and azo type initiators. Preferred initiators include, but are not limited to, hydrogen peroxide, potassium or ammonium peroxydisulfate, dibenzoyl peroxide, lauryl peroxide, ditertiary butyl peroxide, 2,2'- azobisisobutyronitrile, t-butyl hydroperoxide, benzoyl peroxide, or a mixture thereof.

Redox initiation systems (Reduction Oxidation Initiation) such as iron catalyzed reaction of t-butyl hydroperoxide with isoascorbic acid are also useful. It is preferable not to use initiators capable of generating a strong acid as a by-product. This avoids possible side reactions of the caprolactam component of the continuous phase with the acid. Initiators can be added in amounts from about 0.1 to about 2 phm, more preferably in amounts of from about 0.3 to about 0.8 phm.

Reducing agents may also be used in the emulsion polymerization reaction.

Suitable reducing agents are those that increase the rate of polymerization and include, for example, sodium bisulfite, sodium hydrosulfite, sodium formaldehyde sulfoxylate, ascorbic acid, isoascorbic acid, or a mixture thereof. If a reducing agent is introduced into the emulsion polymerization, it is preferably added in an amount of about 0.1 to about 2 phm, more preferably about 0.3 to about 0.8 phm. It is preferable to feed the reducing agent into the reactor over time.

Polymerization catalysts may also be used in the emulsion polymerization.

Polymerization catalysts are those compounds that increase the rate of polymerization and which, in combination with the above described reducing agents, may promote decomposition of the polymerization initiator under the reaction conditions. Suitable catalysts include, but are not limited to, transition metal compounds such as, for example, ferrous sulfate heptahydrate, ferrous chloride, cupric sulfate, cupric chloride, cobalt acetate, cobaltous sulfate, or a mixture thereof.

Buffering agents may also be used in the diol-containing emulsion polymerization to control the pH of the reaction. Suitable buffering agents include, but are not limited to, ammonium and sodium salts of carbonates and bicarbonates. It is preferred that the buffering agents be included when using acid generating initiators, including, but not limited to, the salts of persulfates.

The caprolactam containing latex composition is preferably prepared by first forming an emulsion or solution comprising monomers, an initiator, a surfactant and a continuous phase. In one preferred embodiment, the continuous phase comprises up to about 95% by weight of the caprolactam component. The mixture is then heated which causes the monomer to polymerize and form the latex polymers. Typically, the monomer is fed into the reactor over a period of time and a separate initiator feed is also fed into the reactor over time.

In an alternate embodiment, the caprolactam containing latex compositions are prepared by direct emulsification. In this embodiment, a latex polymer composition is added to the continuous phase, along with a surfactant. Mechanical means, such as a MicroFluidizer, are applied to result in an emulsion.

The caprolactam containing latex composition may contain a stabilizer or a stabilizer does not have to be present. Stabilizers suitable for use in the caprolactam containing latex composition include, but are not limited to, an anionic stabilizer, a nonionic suspension stabilizer, an amphoteric suspension stabilizer or a mixture thereof. The suspension stabilizer must be soluble in the continuous phase, but substantially insoluble with the monomers. If present, the concentration of the suspension stabilizer is from about 3 to about 15 % by weight of the monomers; preferably from about 7 to about 8 % by weight of the monomers.

The caprolactam containing latex compositions of the present invention may further contain water, the (co) solvent (s), a pigment (organic or inorganic) and/or other additives or fillers known in the art. Such additives or fillers, include, but are not limited to, leveling, rheology, and flow control agents such as silicones, fluorocarbons, urethanes, or cellulosics, extenders, reactive coalescing aids such as those described in U. S. Patent No. 5,349,026, flatting agents, pigment wetting and dispersing agents and surfactants, ultraviolet absorbers, ultraviolet light stabilizers, tinting pigments, extenders, defoaming and antifoaming agents, anti-settling, anti-sag and bodying agents, anti-skinning agents, anti-flooding and anti-floating agents, fungicides and mildewcides, corrosion inhibitors, thickening agents, plasticizers, reactive plasticizers, curing agents or coalescing agents. Specific examples of such additives can be found in Raw Materials Index, published by the National Paint & Coatings Association, 1500 Rhode Island Avenue, NW, Washington, DC 20005, U. S. A.

II. Incorporation of a Polymer Colloid System into a Nylon 6 Polymer Blend In a second major embodiment, the invention concerns the introduction of a polymer colloid system comprising a first polymer, wherein the continuous phase either does or does not comprise a caprolactam component, into a reaction that forms a nylon 6 polymer, resulting in a polymer blend having the first polymer incorporated within a nylon 6 polymer blend. When the polymer colloid system comprises a latex polymer composition, the latex polymer will be incorporated into the nylon 6 polymer blend.

The latex polymer that is introduced into the polymerization reaction in one embodiment of the invention herein is defined as crosslinked or uncrosslinked polymer particles dispersed in a continuous phase, the polymer particles preferably having a particle size in the range of from about 0.020 microns to about 1000 microns. The continuous phase may contain small amounts of unreacted monomer, surfactant, etc.

The polymer particles suitable for use in the latex polymer composition comprise those same polymers made from the same ethylenically unsaturated monomers as those described in connection with the caprolactam containing latex composition described in Section I, above, and may be functionalized, crosslinked or uncrosslinked in the same manner as that disclosed for the latex polymers of Section I above. The latex polymer compositions may be prepared from core shell or non-core shell polymers.

One of ordinary skill in the art will recognize that the resulting blends will have particular characteristics that are, in part, related to whether the first polymer of the polymer of the polymer colloid system is crosslinked or uncrosslinked.

In a preferred embodiment, the latex polymer composition of one embodiment herein comprises from about 50 to about 100%, preferably about 70 to about 100%, even more preferably from about 80 to about 100% of the residues of one of the following monomers: 2-ethyl hexyl acrylate, butyl acrylate, isoprene, styrene or styrene derivative, butadiene, acrylonitrile, or a mixture thereof.

In a preferred embodiment, the latex polymer composition to be added to the nylon 6 reaction medium comprises caprolactam, water, mixtures thereof and, optionally, co-solvents.

In the polymer colloid system having a continuous phase comprising caprolactam, the caprolactam in the continuous phase preferably co-reacts with caprolactam in the nylon 6 polymerization reaction. In one embodiment, the caprolactam component preferably comprises about 1 to about 100% by weight of the continuous phase, more preferably about 10 to about 100% by weight of the continuous phase, preferably about 20 to about 100% by weight of the continuous phase, and still more preferably about 30 to about 100% by weight of the continuous phase. In further embodiments, the continuous phase preferably comprises from about 40 to about 100% by weight of the continuous phase, preferably about 50 to about 100% by weight of the continuous phase, more preferably from about 60 to about 100% by weight of the continuous phase, more preferably about 70 to about 100% by weight of the continuous phase, more preferably, about 80 to about 100% by weight of the continuous phase, and even more preferably, from about 90 to about 100% by weight of the continuous phase.

In a preferred embodiment, the continuous phase consists essentially of the caprolactam component. Suitable caprolactam components for the caprolactam based continuous phase of the polymer colloid system include, but are not limited to, the caprolactam components described in Section I.

In the polymer colloid system having a continuous phase comprising caprolactam, the caprolactam in the continuous phase preferably co-reacts with caprolactam in the nylon 6 polymerization reaction. In one embodiment, the caprolactam component preferably comprises about 1 to about 95% by weight of the continuous phase, more preferably about 10 to about 95% by weight of the continuous phase, preferably about 20 to about 95% by weight of the continuous phase, still more preferably about 30 to about 95% by weight of the continuous phase. In further embodiments, the continuous phase preferably comprises from about 40 to about 95% by weight of the continuous phase, preferably about 50 to about 95% by weight of the continuous phase, more preferably from about 60 to about 95% by weight of the

continuous phase, more preferably about 70 to about 95% by weight of the continuous phase, more preferably, about 80 to about 95% by weight of the continuous phase, and, even more preferably, from about 90 to about 95% by weight of the continuous phase.

In a preferred embodiment, the continuous phase consists essentially of the caprolactam component. Suitable caprolactam components for the caprolactam based continuous phase of the polymer colloid system include, but are not limited to, the caprolactam components described in Section I.

The polymerization of caprolactam, for example, in conjunction with a nylon 6 ring opening reaction, can be accomplished by methods known in the art. For example, U. S. Pat. No. 4,204,049 discloses methods for polymerizing caprolactam in the presence of water. Typically, e-caprolactam is placed in a pressurized vessel, such as an autoclave, along with water and, optionally, a catalyst. The mixture is heated to about 200 to about 280 °C for a period of time to produce a mixture of aminocaproic acid polymer, aminocaproic acid, unreacted lactam and water. The pressure is then released, the water allowed to escape, and the second stage of the reaction carried out by heating at about 220 to about 300 °C under atmospheric or subatmospheric pressure.

Catalysts can be added to the polymerization to facilitate the reaction. Some examples of suitable catalysts are high boiling amines as disclosed in U. S. Pat. No. 4,366,306, or acidic species, such as acetic acid.

The caprolactam component may be present in either the continuous phase of the polymer colloid system, the nylon 6 reaction medium, or both. The polymer colloid system may be introduced into the nylon 6 polymerization reaction at various stages.

For example, in a nylon 6 polymerization, the polymer colloid system can be added 1) "up-front"with the caprolactam starting materials; 2) after initiation of the polymerization; 3) during the ring opening polymerization; or 4) near the completion of the polymerization. The final blend can be affected by the time at which the polymer colloid system is added. While not wishing to be bound by any mechanism, when the polymer colloid system comprises an emulsion polymer, such as a latex composition, it is believed that the size and shape of the emulsion polymer in the nylon 6 polymer blend can be affected by the time of the addition. Also, particular chemical interaction

between emulsion polymers and nylon 6 polymers are affected by time of addition, and they, in consequence, affect final blend properties.

The amount of latex polymer in the nylon 6/first polymer blend may comprise a wide range of values. However, it is particularly preferred that the amount of latex polymer in the blend is greater than about 5 % by weight of the blend. Still further, it is preferred that the amount of latex polymer in the nylon 6/first polymer blend be from greater than about 5 to about 50 % by weight of the blend, and, still further preferably, from greater than about 5 to about 25 % by weight of the blend.

In a preferred embodiment, the latex polymer compositions added to the nylon 6 reaction medium comprise from about 10% to about 100% by weight water based upon the total weight of the continuous phase, more preferably, 20 to about 100% by weight water, based upon the total weight of the continuous phase, further preferably, 30 to 100% of the continuous phase, further preferably, 40 to 100% of the continuous phase, further preferably, 50 to 100% of the continuous phase, further preferably, 60 to 100% of the continuous phase, further preferably, 70 to 100% of the continuous phase, further preferably, 80 to 100% of the continuous phase, and further preferably, 90 to 100% of the continuous phase. In a further embodiment, the continuous phase consists essentially of water.

The first polymer of the polymer colloid system may be preferably comprised of functional groups. In a preferred embodiment, the functional groups comprise the following groups: esters, acids, alcohols, isocyanates, epoxy or anhydrides.

The processes of the invention do not require the isolation of the first polymer in the polymer colloid system from the continuous phase, for example, by spray drying.

Thus, the present invention overcomes the necessity of preparing a core-shell polymer or the necessity of harvesting the polymer from the emulsion. Further, since blending takes place during the preparation of the nylon 6 polymer in the polymerization reactor, there is no need for a polymer/polymer post blending step that is energy intensive, expensive and often leads to the reduction of the molecular weight of the nylon 6 polymer.

In a further embodiment, the invention provides introducing a polymer colloid system into a nylon 6 polymer and extruding the nylon 6 and polymer colloid system, thereby providing a nylon 6/first polymer blend. In a particularly preferred embodiment, the first polymer comprises a latex polymer.

Other ingredients may optionally be added to the compositions of the present invention to enhance the performance properties of the nylon 6 polymer/first polymer blend. For example, reinforcing agents, surface lubricants, denesting agents, stabilizers, antioxidants, ultraviolet light absorbing agents, mold release agents, metal deactivators, colorants such as black iron oxide and carbon black, nucleating agents, phosphate stabilizers, zeolites, fillers, mixtures thereof, and the like, can be included herein. All of these additives and the use thereof are well known in the art. Any of these compounds can be used so long as they do not hinder the present invention from accomplishing its objects.

In a particularly preferred embodiment relating to the addition of reinforcing agents to the compositions of the present invention, glass fibers may be added to the nylon 6 compositions to provide particular advantages to the resulting compositions.

Glass fibers that are preferred in the present invention conventionally have an average standard diameter of greater than about 5 microns, with a range of from about 1 to about 20 microns. The length of the glass filaments whether or not they are bundled into fibers, and whether the fibers are further bundled into yarns, ropes or rovings, and the like, are not critical to this invention. However, for the purpose of preparing the present compositions, it is preferable to use filamentous glass in the form of chopped strands of from about 1.5 mm to about 10 mm long, and preferably less than about 6 mm long. In the pellets and molded articles of the compositions, even shorter lengths will be encountered, because during compounding, considerable fragmentation occurs.

This is, however, desirable because the best properties are exhibited for injection molded articles where the filament lengths are between about 0.03 mm and about 1 mm. Especially preferred are glass fibers having an average standard diameter in the range of greater than about 5 microns, preferably about 5 microns to about 14 microns,

and the average filament length dispersed in the molded articles being between about 0.15 and about 0.4 mm. Consequently, glass filaments are dispersed uniformly and the molded articles exhibit uniform and balanced mechanical properties, especially surface smoothness.

The amount of the glass fibers can vary broadly from about 10 to about 50 % by weight, and, most preferably, from about 10 to about 40 % by weight, based on the total polymer composition. These glass fibers are typically conventionally sized with coupling agents, such as aminosilanes and epoxysilanes and titanates, and adhesion promoters such as epoxies, urethanes, cellulosics, starch, cyanurates, and the like.

In one embodiment, when the glass fiber is present in the polymer molding composition, the polymer is preferably from about 70 to about 85 % by weight of the total composition based on the total weight percentages of the nylon 6 and first polymer in the compositions of the present invention, wherein the percentage equals 100 %.

Examples of other reinforcing agents that are useful in addition to glass fibers, include, but are not limited to, carbon fibers, mica, clay, talc, wollastonite, calcium carbonate or a combination thereof. The polymer compositions of the invention may be reinforced with a mixture of glass and other reinforcing agents as described above, such as mica or talc, and/or with other additives.

In accordance with the invention herein, the glass fibers, as well as other reinforcing agents, may be introduced into the nylon 6 ring opening reaction at various stages of the process. In a particularly preferred embodiment of the invention herein, the glass fibers are added directly to the nylon 6 ring opening reaction. Since the glass fibers can be sufficiently blended during this stage, there is no need for a post-blending step, such as extrusion, to incorporate the glass fibers into the compositions. This is particularly advantageous to the present invention because a post-blending step is energy intensive, expensive and may often cause a reduction in the molecular weight of the nylon 6/first polymer blend.

In another embodiment of the invention, a modified nylon 6 polymer, including, but not limited to, an impact modified plastic, is produced from a polymer colloid system comprising first polymers which are core shell or non core shell polymers, and a nylon 6 polymer. The first polymer of the polymer colloid systems in this embodiment has a Tg less than 40 °C, while the nylon 6 polymer has a Tg greater than 40 °C. In a further embodiment, the first polymer has a Tg of greater than 40 °C and the nylon 6 polymer has a Tg of less than 40 °C. In a further embodiment, both the nylon 6 polymer and the first polymer have Tg's of less than about 40 °C. The impact modified plastic is preferably prepared from a polymer colloid system comprising a first polymer which comprises residues of 2-ethyl hexyl acrylate, butyl acrylate, isoprene, butadiene, lauryl acrylate, acrylonitrile, vinylidene chloride, or a mixture thereof.

In a further preferred embodiment, nylon 6/first polymer blends are provided.

In a further still preferred embodiment, nylon 6/first polymer blends are provided wherein the first polymer is a latex polymer. The ranges and other parameters are disclosed above are applicable to the nylon 6/first polymer blend.

In a preferred embodiment, an impact modified nylon 6 is prepared comprising a polymer colloid system to provide a nylon 6/first polymer blend. In one particularly preferred embodiment of the invention, a modified nylon 6 polymer, including, but not limited to, an impact modified plastic, is produced from latex polymer compositions which are core shell polymers and a nylon 6 polymer.

End-use applications for the compositions of the nylon 6/first polymer blends produced according to the instant invention include impact-modified polymers, elastomers, high barrier films and coatings, improved barrier polymers, and polymers having improved mechanical properties, such as improved tensile strength, improved elongation at break, better weathering properties, and improved flexural strength.

Other end-use applications include engineering resins, coatings, containers for barrier applications and molding plastics. In addition, powder coatings may be produced form the modified nylon 6 polymers produced according to the invention. The polymer

blends produced by this invention are useful for thermoplastic engineering resins, elastomers, films, sheets and container plastics.

Examples The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compositions of matter and methods claimed herein are made and evaluated, and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to insure accuracy with respect to numbers (e. g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, parts are by weight, temperature is in °C or is at room temperature and pressure is at or near atmospheric.

Example 1: Preparation of Water Latex To a 2L jacketed reaction kettle equipped with a condenser, nitrogen purge, and stirrer; 845.96 g of water, 10.58 g of ammonium carbonate and 11.44 g of a 18 wt. % Hitenol HS-20 were added. The contents of the reactor were heated to 85 °C. In a separate 1 L flask, a monomer mix of 274.53 g butylacrylate, 247.08 g of 2- ethylhexylacrylate, 137.27 g of methylmethacrylate, 27.45 g of methacrylic acid, and 2.75 g of 2-ethylhexyl-3-mercaptopropionate was prepared. To the heated reactor, 27.56 g of the monomer mix was added. After allowing the contents of the reactor to re-equilibrate, 1.37 g of ammonium persulfate dissolved in 21.6 g of water was added to the reactor. After a few minutes, the reactor appearance changed from clear to white with a bluish white tint indicating the formation of small particles. The remaining monomer mix was feed into the reactor over a period of 250 minutes. During the same time period, 2.06 g of ammonium persulfate dissolved in 108 g of distilled water was feed into the reactor. After all the monomer was added the reaction was cooled to 65 °C and 2.75 g of a 1% ammonium iron sulfate solution and 1.37 g of a 1% EDTA solution was added to the reactor. Next, 2.94 g of 70 wt. % t-butylhydroperoxide solution dissolved in 21.6 g of water and 2.06 g of sodium formaldehyde sulfoxylate

dissolved in 21.6 g of water was feed into the reactor over a 15 minute period while the reactor cooled.

The resulting emulsion was filtered through a 100 mesh screen. This emulsion contained 49 % solids and the particle size was 151 nm as measured by dynamic light scattering.

Example 2: Preparation of Nvlon 6 Nylon 6/Water Latex Blend To a 1 L glass lined autoclave 187g of e-caprolactam is added and melted at 80 °C. Then, over a period of 5 minutes, 200 g of the latex described in Example 1 and 0.4 g of glacial acetic acid is added to the autoclave with continuous stirring. While stirring, the mixture is pressurized to 250 psig and heated to 250 °C for 30 minutes.

The pressure is then reduced to atmospheric over thirty minutes and the reaction is allowed to continue at atmospheric pressure while stirring for 1 hour. The polymer was very flexible and ductile. When molded to and amorphous state, this impact modified nylon 6 was transparent. A Philips CM12 TEM (transmission electron microscope) operated at 80 kV revealed a very fine morphology. Sections were taken of the nylon 6 on a Cryo-ultra microtome operated at-105°C.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected without departing from the scope and spirit of the invention.