MXPA00011151A - Process to prepare a polymer nanocomposite composition - Google Patents

Abstract

In situ polymerization of polyamide monomers and silicate materials followed by solid state polymerization produces polyamide nanomix materials with suitable physical properties, the nanomix materials produced include homopolymers and copolymers, the properties of the nanomix materials can be varied by the selection of monomers, silicate type and polymerization conditions

Description

METHODS FOR THE PREPARATION OF NANOMIXATE POLYAMIDE COMPOSITIONS BY IN SITU POLYMERIZATIONS AND OF SOLID STATE FIELD OF THE INVENTION This invention relates to a process for preparing nanomixed material comprising a polymeric matrix having a silicate dispersed therein. More particularly, this invention relates to a process for preparing a nanomixed material comprising forming a fluid mixture from a polyamide and a silicate material, dissociating the silicate, and subjecting the dissociated fluid mixture to a polymerization step in the state solid to produce nanomix material CROSS REFERENCE WITH RELATED REQUESTS The present application is related to the provisional application E.U.A. Serial No. 60 / 074,639 filed on February 13, 1998, and the PCT application Serial No. PCT / US99 / 03097 filed on February 12, 1999.

BACKGROUND OF THE INVENTION The international application WO 93/04118 describes a • process for preparing a polymeric nanomixto material having 5 platelet-like particles dispersed therein. The process involves processing the polymer, in the molten state, with an interleaved and expandable stratified material compatible with the polymer and subjecting it to a sufficient cutting effort to undo the layers. The stratified material is made compatible with one or more "effective compatibilization / expansion agents" that have • a silane functional group or an onium cation functional group. The international application WO 93/04117 describes a process for preparing a polymeric nanomixte material having platelet-like particles dispersed therein, in which the polymer and the intercalated and expandable laminate material compatible with polymer are 15 process in the molten state. The stratified material is compatibilized with one or more "effective expansion / compatibilization agents" that are selected • of primary ammonium, secondary ammonium and quaternary phosphonium ions. The selected expansion / compatibilization agents "... make their surfaces more organophilic than those compatible through 20 tertiary and quaternary ammonium ion complexes ... ", facilitate the exfoliation, which results in less shear stress in the mixing and less decomposition of the polymer, and thermally stabilizes the mixed material more than the other cations (such as cations) of quaternary ammonium) of the expansion / compatibilization agents International patent application WO 94/22430 describes a • nanomixta composition having a polymer matrix constituted by at least one gamma-phase polyamide, and dispersed in the polyamide is a matrix of a particulate material at nanometric scale. The addition of the particulate material to nylon 6 results in an improvement of the flexural modulus and the flexural strength (from 7 to 35%), when compared to unfilled nylon 6. The addition of the particulate material to nylon 6.6 gives as • 10 result in a very low improvement (1 to 3%) of flexural modulus and flexural strength when compared to unfilled 6,6 nylon. The international patent application WO 93/10098 describes a polymeric mixed material made by melt processing of a polymer with interleaved and expandable laminated material 15 compatible with polymer comprising layers having reactive organosilane species covalently bound to their surfaces. International patent application WO 95/14733 describes a method for producing a polymeric mixed material that does not exhibit melting or glass transition by melt processing of a polymer 20 with a crystalline silicate containing stratified galley. Examples include intercalated sodium silicate and a crystalline polyethylene oxide, montmorillonite intercalated with a quaternary ammonium and polystyrene, and montmorillonite intercalated with a quaternary ammonium and nylon 6.

International patent application WO 98/29499 describes nanomixet polyester compositions containing clay particles. The clay particles are preferably synthetically or chemically modified. 5 The patent E.U.A. No. 4,889,885 (issued December 26, 1989) describes a mixed material of a non-polyamide resin and a dispersed layered silicate. The silicate is treated with an onium salt exchanger and added to a monomer or oligomer. The patent E.U.A. No. 5,514,734 (issued May 7, • 10 1996) describes mixed polymeric materials containing fibrillated or stratified particles obtained with organosilanes, organotitanates, or organozirconates. Mixed materials are characterized by their thickness, diameter and distances between layers. The international patent application WO 93/11190 describes a polymeric mixed material containing an exfoliated material derivatized with a reactive organosilane. The polymers are added before mixing in a • extruder The international patent application WO 94/11430 discloses gamma crystalline phase polyamides containing dispersed layered inorganic materials. EPO application 0 358 415 A1 describes a polyamide-type resin containing a dispersed layered silicate which has been treated with an organic cation of a lactam as an expanding agent.

The Japanese patent Kokai no. SHO 62

[1987] -252426 describes the polymerization of a nylon 6 monomer in the presence of a silicate. The cooling rate of the polymer is controlled to achieve particular crystalline structures in the resulting mixed material. None of the above references, alone or in combination, describe the present invention, as claimed.

BRIEF DESCRIPTION OF THE INVENTION This invention relates to a process for preparing a polymeric nanomixta composition suitable for automotive, electronic, film and fiber applications, in which a combination of tensile strength, tension modulus and flexural modulus is required. Additionally, the claimed polymeric nanomixta composition has desirable surface appearance, stiffness, ductility and dimensional stability. The composition is well processed and tolerates a wide range of molding conditions. The present invention relates to a process for preparing the above polymeric nanomixta composition comprising forming a fluid mixture of a polyamide and a silicate and dissociating material (as this term is described in greater detail below) by at least about 50% but not all the silicate, and subjecting the polyamide in the dissociated fluid mixture to a solid state polymerization step. Optionally, the silicate is a silicate material treated with at least one of ammonium of the formula: wherein R t, R 2, R 3 and R are independently selected from a group consisting of a saturated or unsaturated C 1 to C 22 hydrocarbon, substituted hydrocarbon and branched hydrocarbon, or in which Ri and R form an N ether , N-cyclic. Examples include saturated or unsaturated alkyls • 10 saturated, including alkylen; substituted alkyls such as hydroxyalkyls, alkoxyalkyls, alkoxys, aminoalkyls, acid alkyls, halogenated alkyls, sulphonated alkyls, nitrated alkyls and the like; branched alkyls, aryls and substituted aryls, such as alkylaryl, alkyloxyaryl, alkylhydroxyaryl, alkylalkoxyaryl and the like. Optionally, 15 one of Ri, R2, R3 and R4 is hydrogen. The milligrams of treatment per 100 grams of silicate (MER) of the treated silicate, described in greater detail • subsequently, they are preferably from about 10 milliequivalents / 100 g below the cation exchange capacity of the untreated silicate to about 30 milliequivalents / 100 g per 20 above the cationic exchange capacity of the silicate wit treatment. One additional embodiment of the invention relates to nanomixed compositions comprising a polyamide and a silicate. The polyamide can have a concentration of amine groups of at least 10 mol% greater than the concentration of the carboxylic acid end groups. Preferably the polyamide has a weight average molecular weight in the range of about 30,000 D to about • 40,000 D. Alternatively, the polyamide can have a weight average molecular weight of at least 40,000 D. An additional embodiment is directed to a nanomix composition comprising a polyamide and a silicate, in which the silicate is treated with an ammonium ion of the formula: + NRaRbRcRd; wherein Ra, Rb, and Rc are hydrogen (H) and Rd includes a carboxylic acid moiety. The mixed polymeric matrix material of the present invention demonstrates, when tested, an improvement in the modulus of tension and in the flexural modulus, without a substantial reduction in tensile strength or stiffness when compared to those of the polymer. without the silicate. 15 BRIEF DESCRIPTION OF THE FIGURES • The following figures are part of the present specification and are included to additionally demonstrate some aspects of the present invention. The invention will be better understood by referring to 20 one or more of these drawings in combination with the detailed description of the specific embodiments presented in the present invention. Figure 1 shows the effects of molecular weight with 7 w / 0 2M2HT-montmorillonite.

Figure 2 shows the effect of molecular weight on the rigidity of the nanomixto material with 7 w / 0 2M2HT-montmorillonite. Figure 3 is a plot of tension against tensile strength, without SSP. 5 Figure 4 is a graph of tension versus tensile strength, with SSP. Figure 5 is a graph of intrinsic viscosity versus polymerization time in the solid state. Figure 6 is a plot of intrinsic viscosity against the • 10 times at 220 ° C. Figure 7 is a graph of UTS vs. Ash% vs. SSP. Figure 8 is a graph of eu vs. Ash% vs. SSP. Figure 9 is a graph of Izod slotted vs. P.M. vs. SSP. Figure 10 is a graph of Izod not slotted vs. amine / acid 15 vs. SSP. Figure 11 is a graph of E vs. SSP vs. % ash • Figure 12 is a comparison of the voltage modulus of the polymerized mixed material in situ with the tension module of the mixed material in the molten state. DETAILED DESCRIPTION OF THE INVENTION The polyamides of the present invention are synthetic linear polycarbonamides characterized by the presence of recurring carbonamide groups as an integral part of the polymer chain, which are separated from each other by at least two carbon atoms. Polyamides of this type include polymers, generally known in the art as nylons, which can be obtained from diamines and dibasic acids having the recurring unit represented by the general formula: -NHCOR5COHNR6-in which R5 is an alkylene group of at least 2 carbon atoms, preferably from about 2 to about 11 or an arylene having at least about 6 carbon atoms, preferably from about 6 to about 17 carbon atoms; and R6 is selected from R5 and aryl groups. Also included are copolyamides, terpolyamides and the like obtained by known methods, for example, by condensation of hexamethylenediamine and a mixture of dibasic acids consisting of terephthalic acid and adipic acid. The polyamides of the above description are well known in the art and include, for example, poly (hexamethylene adipamine) (nylon 6,6), poly (hexamethylene sebacamide) (nylon 6,10), poly (hexamethylene phosphthalamide), poly ( hexamethyleneterephthalamide), poly (heptamethylene pimelamide) (nylon 7.7), poly (octamethylensuberamide) (nylon 8.8), poly (nonametjlenazelamide) (nylon 9.9), poly (decamethyllenasebacamide), (nylon 10.9), pol (Decamethylene sebacamide) (nylon 10.10), poly [bis (4-aminocyclohexyl) methan-1,10-decanecarboxamide)], poly (m-xyleneadipamide), poly (p-xylene sebacamide), poly (2,2, 2-5 trimethylhexamethyleneterephthalamide), poly (piperazinsebacamide), poly (p-phenyleneterephthalamide), poly (metaphenyleneisophthalamide), and copolymers and terpolymers of the above polymers. Additional polyamides include nylon 4, 6, nylon 6.9, nylon 6.10, nylon 6.12, nylon 11, nylon 12, amorphous nylons, aromatic nylons and their copolymers. • Other useful polyamides are those formed by polymerization of amino acids and derivatives thereof, such as for example lactams. As examples of these useful polyamides are poly (caprolactam) (nylon 6), poly (4-aminobutyric acid) (nylon 4), poly (7-aminoheptanoic acid) (nylon 7), poly (8-aminooctanoic acid) (nylon 8). ), poll (acid) 15 9-aminononanoic) (nylon 9), poly (10-aminodecanoic acid) (nylon 10), poii (11-aminoundecanoic acid) (nylon 11), poly (12-aminododecanoic acid) • (nylon 12) and similar. The preferred polyamide is Vydyne® nylon, which is poly (hexamethylene adipamide) (nylon 6,6), which gives a mixed material with the The desired combination of tensile strength, tensile modulus and flexural modulus for the applications contemplated in the present invention (Vydyne® is a registered trademark of Solutia Inc.).

The preferred molecular weight of the polyamide is in the range of about 30,000 to about 80,000 D (average weight) with a more preferred molecular weight in the range of about 30,000 to about 40,000 D. The most preferred molecular weight of the polyamide is at least approximately 40,000 D (average weight). Increasing the weight average molecular weight of the polyamide from about 35,000 to about 55,000 D results in an unexpected increase in stiffness, as indicated by the Izod slotted impact test. While a ß 10 increase in weight average molecular weight from about 35,000 to about 55,000 D in the pure polyamide results in a small increase in stiffness, the same increase in molecular weight in the nanomix material results in approximately twice as much of increase in rigidity. Therefore, the increase in stiffness is improved 15 in the nanomixto material when compared with that of the pure polyamide. In a preferred embodiment, the polyamide has a ratio of • final amine group / final acid group greater than one (1). More preferred, the concentration of amine end groups is at least 10 mole% higher than the concentration of the carboxylic acid end groups. In a Even more preferred embodiment, the polyamide has a concentration of amine end groups of at least 20 mole% higher than the concentration of the carboxylic acid end groups, and in a more preferred embodiment, the polyamide has a concentration of amine end groups of at least 30 mole% higher than the concentration of the carboxylic acid end groups. In another embodiment, the concentration of the amine end groups is essentially equal to the concentration of the final acid groups • carboxylic. Among the preferred embodiments are nylon 6, nylon 6,6, mixtures thereof and copolymers thereof. The range of nylon 6 / nylon 6,6 ratios in the mixtures is from about 1/100 to 100/1. Preferably, the range is from about 1/10 to 10/1. The range of ratios of nylon 6 / nylon 6,6 in the copolymers 10 is from about 1/100 to 100/1. Preferably, the range is from about 1/10 to 10/1. Optionally, the non-comix composition comprises at least one additional polymer. Examples of suitable polymers include polyethylene oxide, polycarbonate, polyethylene, polypropylene, poly (styrene-acrylonitrile), poly (acrylonitrile-butadiene-styrene), poly (ethylene terephthalate), poly (butylene terephthalate), poly (terephthalate), trimethylene), poly (naphthalate • ethylene), poly (ethylene terephthalate-cyclohexanedimethalate), polysulfones, poly (phenylene oxide) or poly (phenylene ether), poly (hydroxybenzoic acid-co-ethylene terephthalate), poly (hydroxybenzoic acid) -co-acid 20 hydroxynaphthenic), poly (esteramide), poly (etherimide), poly (phenylene sulfide), poly (phenylene terephthalamide). The mixture may include various optional components which are additives commonly used with polymers. Such optional components include surfactants, nucleating agents, coupling agents, fillers, impact modifiers, chain extenders, plasticizers, compatibilizers, colorants, lubricants for mold release, antistatic agents, pigments, flame retardants and the like. Suitable examples of filler materials include carbon fiber, glass fiber, kaolin clay, wollastonite, mica and talc. Suitable examples of compatibilizers include acid-modified hydrocarbon polymers, such as maleic anhydride-grafted propylethylene, maleic anhydride-grafted polypropylene, ethylene-butylene-styrene block copolymer grafted with maleic anhydride. Suitable examples of lubricants for mold release include alkylamine, stearamide, and dialuminium or tri-aluminum stearate. Suitable examples of impact modifiers include ethylene-propylene rubber, ethylene-propylenediene rubber, methacrylate-butadiene-styrene (with shell-core morphology), poly (butylacrylate) with or without carboxyl modification, poly (ethylene acrylate), poly (ethylene methacrylate), poly (ethylene acrylic acid), poly (ethylene acrylate) ionomers, poly (ethylenemethacrylate-acrylic acid) terpolymer, poly (styrene-butadiene) block copolymers, poly (styrene-butadiene) block terpolymers -styrene), block terpolymers of poly (styrene-ethylene / butylene-styrene) and block terpolymers of poly (styrene-ethylene / butylene-styrene carboxylate).

Suitable coupling agents include coupling agents of the silane, titanate and zirconate type. Silane-type coupling agents are well known in the art and are useful in the present #invention. Examples of suitable coupling agents include 5 octadecyltrimethoxysilane, N-trimethoxysilylpropyl-N (beta-aminoethyl) amine, gamma-aminopropyltriethoxysilane trimetoxisililundecilamina, gamma- aminopropyltrimethoxysilane, gamma-aminopropilfenildimetoxisilano, glicidoxipropiltripropoxisilano gamma-, 3,3-epoxycyclohexylethyltrimethoxysilane, propionamidotrietoxisilano gamma-, trimethoxysilyl-2-chloromethylphenylethane, 10-trimethoxysilylethylphenylsulfonyl azide, N-trimethoxysilylpropyl-N, N, N -trimethylammonium chloride, N- (trimethoxysilylpropyl) -N-methyl-N, N-diallylammonium chloride, trimethoxysilylpropylcinnamate, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane chloride, and Similar. The preferred silane is gamma-aminopropyltriethoxysilane. The silane-type coupling agent is added in Optionally the polymeric mixed material in the range of from about 0.5 to about 5% by weight of silicate • stratified. The preferred concentration range of the silane coupling agent is from about 1 to about 3% by weight of the layered silicate in the mixed material. In one embodiment, the nanomix composition also comprises a composition in which a final group of the polyamide is bonded to a surface of the silicate treated by a silane-type coupling agent.

The silicate materials of the present invention are selected from the group consisting of stratified silicates and fibrous chain silicates, and include phyllosilicates. Examples of stringy, fibrous silicates include chain type minerals, for example sepiolite and attapulgite, with sepiolite being preferred. Such silicates are described, for example, in Japanese Patent Application Kokoku 6-84435 published October 26, 1994. Examples of layered silicates include stratified smectite clay minerals such as montmorillonite, nontronite, beidelite, volkonskoite, Laponite® synthetic hectorite. , natural hectorite, saponite, sauconite, magadiite, and kenyaite; vermiculite; and similar. Other useful materials include stratified lita minerals such as ledikite and mixtures of litas with one or more of the clay minerals named above. The preferred stratified silicates are the smectite clay minerals such as montmorillonite, nontronite, beidelite, volkonskoite, Laponita® synthetic hectorite, natural hectorite, saponite, sauconite, magadite, and kenyaite. Layered silicate materials suitable for use in the present invention are well known in the art, and are sometimes referred to as "expandable sheet material". A further description of the claimed layered silicates and of the platelets formed when processed in the molten state with the polyamide is found in International Patent Application WO 93/04117, which is incorporated herein by reference. Layered silicate materials typically have ordered planar layers in a coherent coplanar structure in which the bond within the layers is stronger than the bond between the layers such that the materials exhibit increased interlayer spacing when processed. The layered silicate materials can be treated as described in more detail below with the ammonium ion of the present invention to improve interlayer expansion and / or useful separation for the performance of the treated silicate of the present invention. As used in the present invention, the "interlayer space" refers to the • 10 distance between the faces of the layers as they are assembled in the treated material before any delamination (or delamination) process takes place. Preferred clay materials generally include interlayer or interchangeable cations such as Li +, Na +, Ca2 +, K +, Mg2 + and the like. In this state, these materials have separation between layers 15 usually equal to or less than about 4 A and only delaminate to a lesser degree in polymeric melt materials • hosts without taking into account the mixing. In the claimed modalities, the cationic treatment is a kind of ammonium that can be interchanged with the cations between layers such as Li +, Na +, Ca2 +, K +, Mg2 + and the like 20 in order to improve the delamination of the layered silicate. The treated silicate of the present invention is a silicate material as described above, which is treated with at least one ammonium ion of the formula + NR? R2R3R4 wherein: Ri, R2, 3 and R4 are independently selected from a group consisting of saturated or unsaturated C1 to C22 hydrocarbons, substituted hydrocarbon and branched hydrocarbon, or in which Ri and R2 form an ether N, N-cyclic. Examples include saturated or unsaturated alkyls, including alkylene; substituted alkyls such as hydroxyalkyls, alkoxyalkyls, alkoxyls, aminoalkyls, acid alkyls, halogenated alkyls, • 10 sulphonated alkyls, nitrated alkyls and the like; branched alkyl; substituted aryls and aryls, such as alkylaryls, alkoxyaryls, alkylhydroxyaryls, alkylalkoxyaryls, and the like. Optionally, one of R-i, R2, R3 and R4 is hydrogen. The present invention contemplates a mixture of two or more ammonium ions. In one embodiment of the present invention, R1 is selected from the group consisting of hydrogenated tallow, unsaturated tallow or a hydrocarbon having at least 6 carbon atoms, and R2, R3 and R4 independently have from one to eighteen carbon atoms. Sebum is predominantly composed of octadecyl chains with amounts 20 small ones of inferior homologs, with an average of 1 to 2 degrees of unsaturation. The approximate composition is 70% C-iß, 25% C16, 4% Cu and 1% C12. In another preferred embodiment of the present invention, R-) and R 2 are independently selected from the group consisting of hydrogenated tallow, unsaturated tallow or a hydrocarbon having at least 6 carbon atoms and R 3 and R 4 have independently from one to twelve carbon atoms. Examples of suitable R1, R2, R3 and R4 groups are alkyl 5 such as methyl, ethyl, octyl, nonyl, tert-butyl, ethylhexyl, neopentyl, isopropyl, sec-butyl, dodecyl and the like; alkenyl such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 1-heptenyl, 1-octenyl and the like; cycloalkyl such as cyclohexyl, cyclopentyl, cyclooctyl, cycloheptyl and the like, alkoxy such as ethoxy; hydroxyalkyl; alkoxyalkyl such as methoxymethyl, • 10-ethoxymethyl, butoxymethyl, propoxyethyl, pentoxybutyl and the like; aryloxyalkyl and aryloxyaryl such as phenoxyphenyl, phenoxymethyl, phenoxyidecyl, phenoxyoctyl and the like; arylalkyl such as benzyl, phenylethyl, 8-phenyloctyl, 10-phenyldecyl and the like, alkylaryl such as 3-decylphenyl, 4-octylphenyl, nonylphenyl and the like. The appropriate ammonium ions used in the treatment of 15 silicate materials include oniums such as dimethyldi (hydrogenated tallow) ammonium, dimethylbenzyl tallow hydrogenated ammonium, dimethyl (ethylhexyl) hydrogenated tallow ammonium, hydrogenated trimethylseboammonium, methylbenzyldi (hydrogenated tallow) ammonium, N, N-2-cyclobutoxidi (tallow hydrogenated) ammonium, hydrogenated trimethylammonium, methyldihydroxyethylseboammonium, 20 octadecylmethyldihydroxyethylammonium, hydrogenated tallow ammonium dimethyl (ethylhexyl) and mixtures thereof. Particularly preferred ammoniums include quaternary ammoniums, for example, dimethyldi (hydrogenated tallow ammonium), hydrogenated dimethylbenzyl tallow ammonium, methyldihydroxyethylseboammonium, octadecylmethyldihydroxyethyl ammonium, hydrogenated tallow ammonium dimethyl (ethylhexyl) and mixtures thereof. Treatment with the ion or ammonium ions, also called "cationic treatments", includes the introduction of the ions into the silicate material by ion exchange. In the modality in which the silicate material is a layered silicate, cationic treatments may be introduced into the spaces between each layer, near each layer or in a larger fraction of the layers of the stratified material such as the resultant platelet layers comprising less than about 20 particles in thickness. The platelet layers are preferably less than about 8 particles thick, more preferred less than about 5 particles thick, and more preferred still, about 1 or about 2 particles thick. The treated silicate has a MER of about 10 milliequivalents / 100 g below the cation exchange capacity of the untreated silicate to about 30 milliequivalent / 100 g above the cation exchange capacity of the untreated silicate. The MER are the milliequivalents of treatment per 100 g of silicate. Each untreated silicate has a cation exchange capacity, which is the milliequivalents of cations available for exchange per 100 g of silicate. For example, the cation exchange capacity of the layered silicate montmorillonite can be about 95, and the sepiolite exchange capacity is in the range of about 10 to about 20. When the MER of the treated silicate is substantially greater than the capacity of cation exchange, there is an excess of cationic treatment that may be available to react with the polyamide. This excess can cause the degradation of the properties of the polyamide. The higher the MER, the lower the silicate concentration in the treated silicate. Therefore, a first sample of nanomixed material may have a higher concentration of treated silicate but a lower concentration of silicate, than a second sample of nanomixed material, because the first sample has a higher MER than that of the second. sample. If the MER value of the treated silicate is substantially less than its exchange capacity, for example about 85 MER for the preferred montmorillonite, there is a very low amount of the cationic treatment to have a beneficial effect. If the MER is greater than about 125, the excess ammonium can be detrimental to the properties of the nylon. Preferably, when the untreated montmorillonite has an exchange capacity of about 95, the treated layered silicate has a cation exchange capacity of about 85 to about 125. The amount of silicate included in the composition is in the range of about 0.1 to about about 12% by weight of the mixed material. The concentration is adjusted to provide a polymer matrix of mixed material that demonstrates, when tested, an increase in the modulus of tension and in the flexural modulus, without a substantial reduction in tensile strength. Preferably, the increase in the tension modulus and in the flexural modulus is at least about 10%. More preferred, the increase in the tension modulus and in the flexural modulus is at least about 20%. A very low amount of silicate can not provide the desired increase in the modulus of tension and in the flexural modulus. A high amount of silicate provides a mixed polyamide material with reduced tensile strength. In addition, it may be desirable to have the crystalline regions of the polyamide in the nanomixta composition less than about 1.0 μm. The particle size of the silicate is such that optimal contact between the polymer and the silicate is facilitated. The range of particle size can vary from about 10 microns to about 100 microns. Preferably, the particle size is in the range of about 20 to about 80 microns. More preferably, the particle size is below about 30 microns, such as those passing through 450 mesh sieves, result in polymer nanomix material having improved performance properties. Optionally, the silicate can be treated with one or more ammonium ions of the formula 'NRaRbRcRd wherein at least one of Ra, Rb and Rc is hydrogen (H) and R is selected • from a group consisting of saturated or unsaturated C-t to C22 hydrocarbons, substituted hydrocarbon and branched hydrocarbon. Examples include saturated or unsaturated alkyls, including alkylene; substituted alkyl such as hydroxyalkyls, alkoxyalkyls, alkoxys, aminoalkyls, acid alkyls, halogenated alkyls, sulphonated alkyls, nitrated alkyls and the like; branched alkyl; aryls and substituted aryls, such as alkylaryl, 10 alkoxyaryl, alkylhydroxyaryl, alkylalkoxyaryl and the like. Because the definition of the Rd group for the ammonium ion above is generally the same as the definition for the group R_? in the ammonium ion, the examples given above for the group R4 are also examples of the group Rd. In a separate embodiment Ra, Rb and Rc are hydrogen (H), and the Group Rd contains a portion of carboxylic acid in such a way that the ammonium ion • NRaR RcRd is an amino acid, for example 12-aminoluric acid-ammonium. In this embodiment, it is particularly preferred that the ratio of final amine groups / acid end groups of the polyamide be greater than one (1). Optionally, the above ammonium ions can be mixed with at least one quaternary ammonium ion, said mixture being used to treat the silicate. The quaternary ammonium ion preferably has a hydrocarbon chain. The hydrocarbon chain can be saturated or unsaturated. The hydrocarbon chain can be obtained from a • natural source such as tallow, or from a synthetic source such as a chain of C- | 2, C14, Cie or C-iß synthesized or purified. A preferred mixture includes at least one dimethyldi (hydrogenated tallow) ammonium, dimethyldihydroxyethyl tallow ammonium, hydrogenated dimethylbenzyl alcohol ammonium and / or hydrogenated dimethyl (ethylhexyl) tallow ammonium, either alone or in a combination with 12-aminoluric acid-ammonium. • Optionally, the silicate can be further treated with cationic azine dyes such as nigrosines or anthracycines. Such cationic dyes will impart color firmness and uniformity in addition to increasing the interlacing of the polymer molecules. It is also desired to have a mixed polymeric material that provides 15 both the desired strength and flexibility and still remain light weight. This is achieved by minimizing the silicate concentration in the material • nanomix. The preferred nanomix material contains a silicate concentration from about 0.1 to 12.0% by weight of the mixed material. The preferred nanomix material contains a silicate concentration from 20 about 0.5 to about 6.0% by weight of the mixed material. In a first embodiment of the present invention, the nanomix composition is prepared using a three-step process.

One step includes forming a fluid mixture of the polyamide as a polymeric melt material and the silicate material. The second step includes dissociating at least 50% but not all silicate material. The term "dissociate", as used in the present invention, means delaminate or separate the silicate material to submicron scale structures comprising single units or multiple small units. For the embodiment in which a stained silicate is used, this dissociation step includes delamination of the silicate material into submicron scale platelets comprising individual layers or multiple small layers. For the • In a manner in which fibrous, chain type silicates are used, this dissociation step includes separating the silicate material into submicron scale fibrous structures comprising single units or small multiple units. As referred to in the training step of the The mixture, a fluid mixture is a mixture that can disperse the dissociated silicate material to a submicron scale. A polymeric molten material • it is a polymer or mixture of polymers that can be processed in the molten state which have been heated to a high enough temperature to produce a low enough viscosity for mixing to occur 20 at submicron scale. The processing temperature must be at least as high as the melting point of the polyamide used and be below the degradation temperature of the polyamide and the organic treatment of the silicate. The actual temperature of the extruder may be below the melting point of the polyamide used, because heat is generated by the flow. The process temperature is high enough that the polymer will remain in the polymer melt during the course • of the procedure. In the case of a crystalline polyamide, that temperature is above the melting temperature of the polymer. For example, a typical nylon 6 having a melting point of about 225 ° C can be melted in an extruder at any temperature equal to or greater than about 225 ° C, such as for example between about 225 ° C and about 260 ° C. . A nylon is normally used for nylon 6.6 • 10 preferably from about 260 ° C to about 320 ° C. Conventional methods can be used to form the fluid mixture. For example, the fluid mixture can be prepared by using conventional polymer and additive mixing means, in the Wherein the polymer is heated to a temperature sufficient to form a polymeric melt material and combined with the desired amount of the material • silicate in granulated or powdered form in a suitable mixer, such as for example an extruder, a Banbury® type mixer, a Brabender® type mixer, Farrel continuous mixers, and the like. In one embodiment, the fluid mixture can be formed by mixing the polyamide with a preformed silicate-containing concentrate material. The concentrate includes the silicate and a polymer vehicle. The concentration of the silicate material in the concentrate, and the amount of concentrate is selected to provide the desired silicate concentration for the desired nanomoxide composition. Examples of polymers suitable for the vehicle polymer include polyamide, ethylene-propylene rubber, ethylene-propylenediene rubber, ethylene-ethyl acrylate, ethylene-ethyl methacrylate or ethylene-methacrylate. Examples include the lotek® ionomer and the Escor® acid terpolymer, both available from Exxon. Suitable polyamide type polymers for the carrier polymer include nylons such as nylon 6, nylon 6,6, nylon 4,6, nylon 6,9, nylon 6,10, nylon 6,12, nylon 11, nylon 12, nylons amorphous, aromatic nylons and their copolymers. The polymer of the vehicle can be the same or different from the polyamide of the fluid mixture. For example, both polymers can be a polyamide, particularly nylon 6,6, but can have the same molecular weight or have different molecular weight. The preferred weight average molecular weight of the carrier polymer of the concentrate is in the range of about 5,000 D to about 60,000 D. The most preferred range of the weight average molecular weight for the vehicle polymer is in the range of about 10,000 to about 40,000 D. In this embodiment, the dissociation step of the present process, as described below, can be presented at least in part by the formation of the concentrate in such a way that the dissociation step can precede the step of forming the mixture. fluid It is therefore understood that the procedural steps (eg, training and dissociation) can be presented sequentially without taking into account the order, simultaneously or in a combination thereof. In the second step, the fluid mixture is mixed sufficiently to form the structure of dispersed dissociated silicate nanomoxide material in the polymer melt, and • after this it cools down. The silicate can be dissociated by subjecting it to a shear stress having an effective shear stress. As used in the present invention, an effective shear stress is a shear stress that is effective to assist the dissociation of the silicate and provide a composition comprising a polyamide matrix having the silicate substantially homogeneously dispersed in the same without having to 10 substantially break individual units (e.g. platelets or fibrous chains). Any method used to apply shear stress to a fluid mixture or any polymeric melt material can be used. The shear force action can be provided by 15 any suitable method, such as by mechanical means, by thermal shock, by pressure alteration, or by ultrasound. From • Preferably, the fluid polymer blend is subjected to shear stress by mechanical methods in which the portions of the molten material are flowed past other portions of the mixture by the use of 20 mechanical means such as agitators, mixers of the Banbury® type, mixers of the Brabender® type, continuous mixers of the Farrel type and extruders. Most preferably the mixture is subjected to multiple cutting efforts. In addition to the increased cutting effort provided by the multiple cutting efforts, increased residence time is also provided, which results in improved performance properties. Another procedure uses thermal shock in which the shear cut is achieved by alternatively raising or lowering the temperature of the mixture causing the thermal expansions and resulting in the internal stresses that cause the shear stress. Even in other procedures, shear stress is achieved by sudden pressure changes in pressure alteration methods; by ultrasonic techniques in which cavitation or resonant vibrations cause portions of the mixture to vibrate or be excited to different phases and thus be subjected to shear stress. These methods of shear stressing of fluid polymer blends and polymer melts are representative only of useful methods, and any method known in the art for shear stressing of fluid polymer blends and polymer melts can be used. The shear stress can be achieved by introducing the polymeric tablets at one end of the extruder (single screw or twin screw) and receiving the polymer subjected to shear stress at the other end of the extruder. A preferred twin screw extruder is a co-rotating type of complete intermixing, such as the ZSK series manufactured by Werner and Pfleiderer Company. The silicate can be supplied in the twin screw extruder in the feed throat or in the downstream vent. The preferred method is to supply the silicate in the downstream vent, which produces a mixed polymer with improved performance properties. Another preferred continuous mixer is the Farrel continuous mixer (FCM). For mixed materials using Vydyne® nylon, the preferred temperature of the molten material is in the range of about 275 to 315 ° C, with the most preferred range being about 275 ° C to 295 ° C. The polymer melt material containing nanometric dispersed dissociated silicate material can also be formed by reactive extrusion in which the silicate material is initially dispersed as it is added on a nanoscale to a solid liquid monomer and this monomer is subsequently polymerized in a extruder or similar. Alternatively, the polymer can be granulated and mixed dry with the treated silicate material, and thereafter, the composition can be heated in a mixer until the polymer melts to form the fluid mixture. The third step of the process is a solid state polymerization step, in which the mixed tablets are maintained for several hours at an elevated temperature at least about 20 ° C below the melting or softening point of the polymer. For example, for nylon 6 and nylon 6,6 the solid state polymerization conditions are to heat the solid polymer in the range of about 200 ° C to about 240 ° C for a period of about 2 to about 5 hours. It is desirable to remove the water produced during the polymerization, for example by a flow of • dry nitrogen. Said additional process step results in an increase in molecular weight and an improvement in stiffness, ductility and tensile strength of the nanomixed material. The polymerization step in the solid state can also be carried out with a catalyst that increases the molecular weight of the polyamide, for example a phosphorus-containing catalyst such as monosodium phosphate. • 10 Such phosphorus-containing catalysts are described in the patent E.U.A. No. 4,966,949. For mixed materials that include a catalyst, milder treatment conditions are needed to effect the desired polymerization. For example, the treatment temperature may be below the temperature used in the polymerization in the state Solid in the absence of the catalyst and using the same polyamide, ie more than 20 ° C below the melting or softening point of the polyamide.

• The treatment time can be decreased to the range of approximately 0.5 hours to approximately 5 hours. An optional processing step is a treatment step 20 with heat, in which the composition is heated to improve the interlacing of the nylon molecules in the silicate structure. Said heat treatment step is performed by heating the composition at a temperature in the range of about 200 ° C to about 240 ° C for a period of about 2 hours to about 5 hours. The heat treatment step can be optionally incorporated in the dissociation step by increasing the residence time of the mixture in the mixer or extruder, whereby it is heat treated under melt conditions. The process for forming the nanomix material preferably is carried out in the absence of air, such as for example in the presence of an inert gas, such as argon, neon or nitrogen. The process can be carried out in batches or discontinuously, such as, for example, by carrying out the . 10 procedure in a sealed container. Alternatively, the process can be carried out in a continuous mode in a single processing zone such as, for example, by using an extruder, from which air for the most part is excluded, or in a plurality of such reaction zones in series or in parallel. In another embodiment of the present invention, the process for preparing a composition of polymeric nanomixte material comprises forming a first fluid mixture of a polyamide, at least one monomer and a silicate material; dissociate at least 50% but not all silicate material; polymerize the monomer; and subject the polyamide in the mixture to 20 polymerization in solid state. It should be understood that the polymerization of the monomer step can occur simultaneously or sequentially with one or more other steps in the method of this embodiment. Preferably, at least one monomer of this embodiment includes monomers such as e-caprolactam, lauryl lactam and their corresponding lactones. Even in another embodiment of the present invention, the • process for preparing a composition of polymeric nanomix 5 material comprises forming a fluid mixture of a polyamide and a treated silicate material; dissociate at least about 50%, but not all treated silicate material; adding an additional amount of said polyamide, preferably during said dissociation step; and subjecting the polyamide in the mixture to solid state polymerization. • Each of the above embodiments of the process for preparing the composition of polymeric nanomixte material can be followed by additional steps or treatments, or the additional melt polymerization of the composition increasing the residence time in the mixer with the removal of the product. of water condensation. The increased residence time can also improve the intercalation of the polyamide in the silicate, as discussed above.

W The composition of the present invention can be made in, but not limited to, the shape of a fiber, film or molded article. Solid state polymerization increases rigidity, 20 resistance and ductility of the polymer produced, while generally maintaining the processing capacity and the modulus. Solid-state polymerization could improve properties such as relaxation stretch, stress-to-crack elongation, flex modulus, elastic modulus and both Izod slotted and non-slotted impact resistors. Additional catalysts may be added, but they are not required. Clay treatments with an acid functional group are # particularly docile to SSP (for example SCPX 1016 and SCPX 1255). These 5 could be used to build polymer-clay bonds by adding the nylon molecules to the adsorbed acidic portions. The stoichiometric balance of amine and acid groups can impact the properties of the resulting polymer. A higher ratio of amine / acid in nylon is desirable, especially in the case of silicates treated with amino acid. The use of Solid state polymerization to terminate the nanomix material could allow initiation with a lower RV nylon that could increase interleaving, leading to a greater exfoliation of the clay layers. The inherent brittleness of the nanomixed materials mixed in the FCM can be overcome with an SSP finish to make the FCM a 15 viable alternative of low cost processing. The following examples are included to demonstrate the preferred embodiments of the invention. Those skilled in the art should appreciate that the techniques described in the examples that follow represent techniques discovered by the inventors which work well in practice. 20 of the invention, and therefore must be considered so that they constitute preferred modes for their practice. However, those skilled in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments described and still obtain an equal or similar result without departing from the scope and scope of the invention. .

• EXAMPLES Materials The following types of nylon 6,6 polymers have been used in the nanomix materials described in the present invention. 10 Nylon matrix resins fifteen The montmorillonite clay used has an exchange capacity of approximately 95 milliequivalents per 100 g of silicate. 20 EXAMPLE 1 Conventional mixing without SSP It has been found that a high molecular weight in the nylon matrix of the nanomixed materials is even more beneficial for the ductility and rigidity of the nanomix materials than for the nylon polymer in pure form. Smectite silicates reduce the molecular weight of nylon during the mixing operation, especially in the first step, resulting in a loss of ductility and stiffness. For example, a • 10 drop in molecular weight of nylon d from 36,500 to 31,500 D in a single step of 7% montmorillonite treated with dimethyl di (hydrogenated tallow) ammonium (2M2HT-montmorillonite) using a 40 mm twin screw extruder ZSK manufactured by Krup Werner & Pfleiderer Company. A second step reduced the molecular weight also to only 21, OOD. He The second step under dry conditions could instead improve the mechanical performance due to both the molecular weight increase as well as the • an exfoliation and increased dispersion of the nano-platelets. Solid state polymerization (SSP) can be implemented in mixed nanomix materials under conditions 20 similar ones used for the pure polymer as a more efficient method to increase the molecular weight. Improvements in tensile strength and elongation are obtained, as well as Izod impact resistance, both grooved and non-grooved. Sometimes there are slight losses in the modulus, perhaps due to the breaking of the thin delaminated platelets during the flow of the higher viscosity nylon matrix.

Effects of molecular weight The effects of the molecular weight of nylon 6,6 or its viscosity in relative equivalent solution (RV) on the mechanical properties are shown in figures 1 and 2 for nanomix materials prepared by conventional mixing in a twin screw extruder without Later SSP. The RV of nylon is that of the raw material supplied to the extruder. P1 and P2 in Figure 2 refer to the first and second steps through the mixer. A higher ratio of amino / carboxyl end group in nylon is preferred for nanomixed materials, including those that are subsequently subjected to SSP. The inherent Lewis acidity of the clay surface in combination with any introduced acidity from the clay treatment, either in the form of an amino acid cation or the polyacrylate peptizer used in some grades of clay, could alter the balance of the group nylon end, resulting in a certain degree of depolymerization. For example, an acidity of 40 μequiv / g (4.0 mequv / 100 g of clay) -COOH was measured for both montmorilonite-Na-coated with acrylate and 2M2HT-montmorillonite. The degrees exchanged with amino acids could have higher acid levels in accordance with the degree of substitution, as measured by the ratio of exchanges of milequivalents (MER) of milliequivalents of cation per 100 g of silicate. Therefore, nylons a, and c are preferred over nylon b. The highest final amine group concentration of nylon d could be especially important in the case of silicates treated with amino acid cations, which can react with the nylon amine end groups. These treated silicates show a stronger response to the effects of SSP, resulting in greater increases in the above properties than in nanomixed materials containing pristine silicates or those treated with non-reactive portions. Changes in molecular weight to nylon with high amine content due to mixing with 4% of montmorillonite exchanged with 12-aminolauric acid (ALA-montmorillonite) and subsequently polymerized in solid state have been analyzed by GPC.

The symbols used in this table have the following meanings: Mw: weight average molecular weight Mn: number average molecular weight IV: intrinsic viscosity measured in formic acid EXAMPLE 2 Solid State Polymerization (SSP) In the previous table it is observed that the extrusion process does not change the molecular weight or its distribution in the nylon in a significant way. Although there is a greater increase in the molecular weight of the nanomoxide material during SSP, it is reduced from that of the pure resin (which gels) by the presence of the acidic portions in the clay. In addition, there is evidence that the nylon matrix binds to the clay even during the mixing operation. During solid state polymerization, nylon does not branch or additionally bind with the organosilicate to form very high molecular weight species that become insoluble. Solid state polymerization was practiced by heating the plastic tablets at 200-240 ° C (typically 220 ° C) with a dry nitrogen sweep to remove the condensation water for a period of 2-4 hours (typically 4 hours). It was not necessary to add additional catalyst in addition to the existing one from the initial molten polymerization, although monosodium or sodium phosphate could be added at 100-500 ppm. In one case, adding 1, 000 ppm of monosodium phosphate resulted in a mixed molecular weight increase from 27,400 to 30,600 D (SSP was not performed). Typically, the dryer for SSP is set at 243 ° C oil temperature and the nanomixto nylon material is heated for 4 5 hours at 220 ° C (230 ° C shell temperature) after a heating period of about 2 hours. hours. The resulting time-temperature profiles are shown below for the solid state polymerization runs of the representative nanomix material. 6.6% by weight of 2 2HT-montmorilopta in polymerized nylon in solid state • 10 for 5 hours fifteen • 3.7% by weight of 2M2HT-montmorillonite in nylon polymerized in solid state for four hours. twenty • 3. 7% by weight of 2M2HT-montmorillonite in nylon polymerized in 10 solid state for five hours. fifteen * 4. 0% by weight of ALA-montmorillonite in nylon polymerized in solid state for three hours. twenty • 12. 2% by weight of montmorillonite treated with cation of seboammonium dimethylbenzyl hydrogenated (2MBHT-montmorillonite) in nylon c, polymerized in solid state for 4 hours. • 10 fifteen • 8.4% by weight of 2MBHT-montmorillonite in nylon c polymerized in solid state for 2 hours. twenty 6. 2% by weight of 2M2HT-montmoriionite of nylon b polymerized in solid state for three hours; 650 ppm of monosodium phosphate monobasic as a catalyst. • • 10 EXAMPLE 3 Introduction of ductility An example of the introduction of ductility through SSP is shown by the stress-strain curves (Figures 3 and 4) for 4.0% on p / o of ALA-montmorillonite in nylon a.

EXAMPLE 4 Molecular Weight Increase 20 The molecular weight increase of the nylon matrix is indicated by the intrinsic viscosity measurements shown in the following table.

Intrinsic viscosity versus SSP time • 5 The intrinsic viscosity increases linearly with time in the SSP dryer, as shown for example by the following data and the graph (Figure 5). • 10 fifteen twenty The rate of increase is faster for the acid-terminated ammonium cations at long residence times in a nylon matrix of high amine content, as shown by the data from • ALA-montmorillonite in the following graph (figure 6).

EXAMPLE 5 Invention molding of nanomixed materials polymerized in solid state • 10 Solid state polymerized nanomixes based on nylons c and d, are molded more easily with temperature set points higher than at lower temperatures. Between these two nylons, nanomixtos materials based on nylon d are molded more easily than those based on nylon c, perhaps because the nylon matrix c reaches a 15 viscosity level greater than nylon d. Lower packing and retention pressures may also be used. However, in both cases, packing pressures and retention pressures are preferred higher than those conventionally used for injection molding nylon 6.6 to pack better 20 the mold.

Molding comparisons Said higher packing and retention pressures also tend to tend to increase the tension modulus and the tensile strength. Without SSP, lower molding temperatures are preferred for greater • ductility in the molded parts due to less thermal degradation of the polymer. However, the higher ductility with SSP is achieved rather through a higher molecular weight, thus allowing the use of higher temperatures that are known to benefit the rigidity of the molded nanomixto material. In this way, an additional degree of processing freedom is introduced through the SSP procedure, through the 10 which injection molding parameters can be adjusted to optimize the property spectrum and molding process in general.

EXAMPLE 6 Mechanical Properties for Concentrating the Way Using Nylon Matrix of High Amine Content • The use of a high amine content terminal nylon vehicle in a concentrate was evaluated to improve the properties induced by solid state polymerization of the final nanomixta composition. A high amine content nylon concentrate comprising 17% ALA-montmorillonite in nylon d was then applied in three different resins having a molecular weight scale and concentration of amine / acid end groups, with and without polymerization in Subsequent solid state before molding. A rather intense worm design was used in the 40 mm ZSK twinworm extruder with a feed speed of 43.5 kg / hr and a worm speed of 250 rpm. The temperatures in the barrel area were adjusted to 270 ° C. For solid state polymerization, the polymerization dryer was adjusted to an oil temperature of 243 ° C from start to finish, giving a residence time of up to 4 hours at a resin temperature of 220 ° C and a coating temperature of 230 ° C. The mechanical properties and descriptions of the sample are given in the following table. 10 fifteen • Stress measured at 5% strain. 20 The above table shows the beneficial effect of solid state polymerization on improving the ultimate mechanical properties of elongation and tensile strength, as well as the impact resistance with and without Izod notch. Its strong effect on nanocomposite materials comprising ALA-montmorillonite compensates for any weight degradation molecule of nylon that could have occurred during mixing. The effects of the parameters can be analyzed more quantitatively by using the CAD / Chem program of the neutral network (AlWare, Cleveland, OH). In this procedure, nylons are described by their nominal weight-average molecular weight and the nominal ratio of amine / acid end groups. The mineral content of the nanomix material is retained as a correlation variable representing the minor differences between the samples. On this basis, the following linear correlation coefficients are obtained. SSP refers to the polymerization time in solid state, in hours.

These results show that the solid state polymerization generally increases the tensile properties together with both types of Izod impact resistance, while having a negligible overall effect on the flexural properties. A higher initial molecular weight in the nylon (before mixing) could also be a bit beneficial for impact strength with izod notch, but does not positively affect the properties. It is observed that a higher ratio of amine / acid end groups is generally advantageous for ductility (elongation) and toughness (impact strength without Izod notch), since it helps maintain the molecular weight of the nylon by counteracting the additional acidity introduced by the treatment with clay. • 10 However, strong interactions between the parameters not evident in the previous table occur and can be observed in the following response surfaces. With a solid state polymerization time of four hours, it is predicted that a nanomixto material comprising 4.9% by weight of ALA-montmorillonite (3.9% mineral ash) in 15 a 40,000 molecular weight nylon having balanced end groups, has the following properties: tensile strength of 984.2 kg / cm2, • Young's modulus of 43023.6 kg / cm2, final elongation of 21.6%, modulus of flexion of 39227.4 kg / cm2, bending stress of 1313.2 kg / cm2 at 5% deformation (under deformation at break), Izod's notch 0.049 20 kg-m / cm, without Izod notch of 2.38 kg-m / cm and 241.3 μ / 2.54 cm of shrinkage. Figure 7 shows the increase in tensile strength with SSP time when nanoclay is present, but not in pure nylon.

However, the ductility and tenacity of nanomixed materials are significantly increased by polymerization in the solid state, to a lesser degree by the higher initial molecular weight and amine / acid ratio of the nylon (Figures 8, 9 and 10). The concentration of ALA-montmorillonite in the last two figures is 4.9%. The stiffness (modulus of tension) is slightly increased by the polymerization in the solid state, perhaps through the formation of networks between the nylon of high molecular prisoner and the clay by reactive resistance of the polymer molecules of nylon to the ammonium ions adsorbed • 10 on the surface of the clay (figure 11).

EXAMPLE 7 Data tabulation 15 A comprehensive list of composition data, time of SSP and mechanical properties, is given in the following table for all the • Preparations of nanomixed materials of ALA-montmorillonite, 2M2HT-montmorillonite, 2MBHT-montmorilonite and sepiolite that imply polymerization in solid state. • o n o n Hear • • I heard? It is observed that the organoarcilla of amino acids provides the most favorable mixing of properties of the material nanomixto after SSP. Nevertheless, can cause more embrittlement than other types of clay if SSP is not practiced. It is thought that acid functionalization competes for the amine end groups in the nylon chains, thereby disturbing the terminal group balance and degrading the molecular weight of the nylon during mixing. Higher initial molecular weight or ratio of amine / acid end groups in the selected nylon would help counteract this effect, but SSP would preferably be carried out after mixing to restore or even increase the molecular weight of the nylon. It is observed that the primitive sepiolite is less destructive to the ductility and tenacity than is the montmorilonite. Nanomixto material mixed with a single pass through Farrell's continuous mixer, which tends to impart a high modulus but embrittlement in nanomix materials, could be polymerized in solid state to restore ductility and toughness along with a possible increase in strength to the tension. Mixing FCM with SSP would represent a low-cost process for a tenacious, yet firm, nanocompound nanomix material.

On-site polymerization of nylon nanomix materials Description of the process: In situ polymerization represents a great promise to improve the dispersion of the clay and increase the strength of the interface 5 of silicate-nylon over that obtained by melt mixing. Efficient reinforcement has been found comprising more than 20% increase in modulus for a nanomixed material containing only 0.1% by weight of nanosilicate. Silane can be added to the reactor feed to improve the interfacial bond in the final nanomixate material. • Compositions of polyamide nanomixate material can be formed by a process comprising forming an aqueous mixture of a treated silicate material and a polylamide monomer, treating the mixture to polymerize the polyamide monomer, and dissociating at least about 50% of the silicate material to form a 15 polyamide nanomixta composition. In a specific modality, silicates can be incorporated • stratified (montmorillonite, saponite, hectorite, laponite) and chain (sepiolite) in nylon 6,6 and nylon 6,6 / 6 copolymers, exfoliating and dispersing the clay in hexamethylene nylon 6,6 saline solution 20 adipamide (AMF) before polymerization. 6.6 / 6 nylon copolymers including a caprolactam epsilon component can be produced in the monomer feed. The procedure has been demonstrated in autoclaves at laboratory and pilot scale (113 kg).

In an alternative embodiment directed towards the preparation of copolymers, the silicates may be predispersed in the caprolactam component before their addition to the saline solution. Alternatively, it • can obtain concentrates in nylon 6 or in their precursor caprolactam solution 5, preferably with the addition of a peptide, for later addition to the nylon 6,6 polymerization mixture. Low molecular weight liquid polyamides can be used as carriers for the nanoclay. Concentrates from the exfoliated nanoclay in these vehicles by high shear homogenization can be added • 10 then in the nylon 6,6 polymerization cycle after the aqueous ionic environment is removed. The following parameters can affect the performance of the procedure: a. dDispersion of the clay in water, or the use of clay never wet-dried, before its introduction into the polymerization mixture; b. Application of high shear stress, ultrasonic energy or venturi cavitation flow, to increase the exfoliation of the clay layers before polymerization; 20 c. Salt concentration; d. pH; and. Ratio of diamine / acid in the saline solution of HMA; F. Ion exchange of cations on the surface of the clay to alter its hydrophobic character and reactivity or physical interaction with the nylon polymer matrix; • g. Concentration of clay; 5 h. Silicate type; i. Molecular weight of nylon at the point where the clay is added to the polymerization; and j. Polymer / nylon copolymer composition. It may be preferable to perform the procedure with a "spike" • 10 diamine ", that is, a higher molar concentration of hexamethylene diamine (HMD) that of adipic acid in the mixture to counteract any acidity due to the clay or its treatment, as well as to compensate for the loss of HMD by vaporization during the polymerization cycles. The higher viscosity resulting from the polymerized molten material indicates a 15 largest increase in molecular weight in the polymer matrix.

• Silicate materials Certain types of minerals are preferable for use in the in situ polymerization process, including synthetic Laponite, 20 commercially available from SCP under the trade name of Laponite®, hectorite, sepiolite, saponite and montmorillonite, at various points in the reaction cycle. It has been found that it is preferable to first achieve a good dispersion of the exfoliated silicate layers in water before coming into contact with the saline solution. In this regard, it may be useful to start with an aqueous dispersion or aqueous suspension never dried instead of dry silicate. Alternatively, the dry silicate can be hydrated before its • participation in the polymerization process. The silicate can be dispersed through high shear homogenization or ultrasonically generated cavitation, or by throttling the aqueous suspension through a venturi tube or other methods known in the art. The silicate material can be modified organically to produce a stronger interface with the nylon matrix phase of the material • 10 final nanomix. Said organoclays are more hydrophobic than the primitive minerals, and thus may not form stable colloidal dispersions in water or in nylon 6.6 saline solution. However, as in the melt mixing process of the above patent application, the polymer can intersperse the layered clay structure later in the cycle of Polymerization after the aqueous phase has been removed mainly by evaporation. In fact, its lower molecular weight must actually increase the intercalation rate, leading to a more complete state of layer exfoliation and greater reinforcement of the final mixed material by the reing smaller particle thicknesses 20 obtained by direct melt mixing with a prepolymerized nylon resin.

Nonionic Conditions In a mode designed to completely avoid an ionic environment, the silicate material can then be added in the polymerization cycle after the salt has been converted to oligomers or low molecular weight polymers. An alternative procedure to avoid ionic effects is to start the process with molten anhydrous salt instead of the saline solution.

Peptidizers • 10 To avoid gelling, it may be preferable to limit the concentration to 2% or possibly up to 4% of the other minerals. Concentrations greater than up to about 2 times these limits may be feasible when a peptide is also in the mixture. These contain phosphate ions which can delay the accumulation of 15 structures in aqueous suspensions. Phosphates also function as pH regulators to control pH, which may also be desirable • to achieve a high degree of clay dispersion.

EXAMPLES 20 Four types of clay received from Southern Clay Products, Inc., Gonzales, TX-Mineral Colloids BP and MO together with Claytone AF and APA types, were dispersed in water, a 70% solution of caprolactam in water and a 50% aqueous solution of hexamethylene adipamide (HMA) at 1% using a Dispermat mixer running at 50 cycles per second for 60 seconds. Of these four clays, only the dispersion of BP in water was stable. High shear mixing is preferred. An Omni mixer is an example of a commercially available machine capable of achieving high shear mixing. It was found that the treatment of the clay with aminolauric acid provides improved stability to the colloidal suspension of clay in saline. In addition, a macroscopically uniform product of • 10% aminolauric acid treated with montmorillonite, was polymerized in nylon 6.6 in a laboratory autoclave. However, transmission electron microscopy (TEM) and wide-angle X-ray scattering (WAXS) revealed that the silicate of this mixed material is not fully exfoliated. The mechanical properties of specimens molded by 15 injection were not improved by the presence of clay. Foaming was experienced during the polymerization • in situ in a laboratory autoclave with tallow-based organoclay (for example, seboammonium dimethyl dihydrogenase (2M2HT), while untreated (primitive) sodium and calcium montmorillonites did not exfoliate, 20 according to visible masses by optical microscopy. It was found that the treatment of tertiary ammonium silicate more than its quaternary counterparts, reduces foam formation.

A nylon 6 / 6.6 97.5 / 2.5 copolymer was polymerized in the presence of 4% by weight of organomontmorilonite of 12-aminolauric acid. The product showed considerably improved toughness and ductility over the nanomixt material of nylon 6,6 homopolymer. Optical microscopy 5 indicated the absence of size clay residues in microns, suggesting a higher degree of clay lamination than for the first homopolymer. This was confirmed by transmission electron microscopy (TEM). The properties of this molded sample by injection were high, showing an increase of 25% in the tensile modulus and 50% increase in the • 10 resistance to loosening, with only about 1% silicate on a volume basis- a high reinforcing efficiency. It was observed that the alkoxy-modified organoclays comprising the more polar ammonium ions synthesized from alkoxy-functional Jeffamines, produce more stable colloidal suspensions in 15 solutions of HMA / caprolactam. Polymerization in situ was successfully carried out with an ethoxy modified montmorillonite.

• Initially, the temperature was kept low (<260 ° C) to provide protection against degradation of the clay coating. Sized polymerizations were carried out for smaller test tubes with Stirring in a Parr reactor on a scale in sequencing of ethylene oxide / propylene oxide on the ammonium cation of the treated montmorillonite. The WAXS measurements showed the same degree of polymer intercalation in the silicate structure as in the samples obtained with stirring in a laboratory autoclave. The coating compositions allowed the nylon 6,6 content to rise up to 12% without clogging the silicate intercalation. A quaternary polypropylene oxide produced a particularly stable colloidal suspension in a 50/50 mixture of nylon 6,6 saline solution and caprolactam solution which did not separate the phases for several days at room temperature. "In contrast, it was found that suspensions of primitive sodium montmorillonite are not stable at room temperature through a range of compositions of HMA / caprolactam mixtures, • 10 although in situ polymerization of straight nylon 6 nanomixto material from caprolactam solution comprising Gelwhite and primitive calcium montmorillonite supplied by Southern Clay Products, Inc., gave a uniform flow concentrate that was then placed in nylon 6. , 6 to form a mixed nanomixto material. 15 Nanocomix materials Gelwhite L concentration of 5, 10 and 15% in nylon 6 prepared in a laboratory autoclave, were • deposited in nylon 6,6, adding them to the saline solution of hexamethylene adipamide before the polymerization of nylon 6,6. Although the resulting mixed fibers were bright and uniform, indicating the absence of 20 clay masses, no improvements in physical properties were observed.

Silicate hydration It was discovered that when montmorillonite is completely pre-hydrated, either as a suspension never dried or by first completely suspending dry clay in water, it forms a more stable colloidal suspension in hexamethylene adipamide saline solution. The following types were found to produce stable colloidal suspensions at 3% in water after high shear mixing with an Omni homogenizer: Gelwhite H and Gelshite L (sodium montmorillonite exchanged for sodium), mineral colloid BP (primitive sodium montmorillonite) , montmorillonite treated with polypropylene oxide, and a montmorillonite treated with polyethylene oxide / propylene oxide copolymer terminated with hydroxy. 72 hours after the addition of the saline solution to the aqueous suspensions at a level corresponding to 4% clay in the final nanomixate material, the following types remained in suspension: Gelwhite H and L, mineral colloid BP and some of the polyether organoclays. The other suspensions were stable for at least 1 hour. It was also found that clays that did not hydrate in water did not come into suspension when nylon saline was added. The suspensions of the following clays obtained by the prior art were then polymerized without mixing in test tubes using a Parr reactor: Gelwhite H and L, mineral colide BP and some of the polyether organoclays. However, the separation d of the silicate layer measured by WAXS in the resulting nanomixed material was still low (13.9 - 14.3 A), indicating little intercalation of polymer in at least a portion of the clay. However, the separation is greater than that found in sodium montmorillonite-colloid mineral BP received. The addition of carboxymethylcellulose (CMC) was investigated to retain the clay surfaces until a low molecular weight polymer formed.

Examples of nylon 6 By using a batch polymerization cycle of nylon 6,6 modified from two hours, nylon 6 nanomixed materials were prepared in situ from an aqueous solution of caprolactam containing a range of primitive nanoclays, including calcium montmorillonite, sodium montmorillonite, laponite RD, synthetic hectorite and attapulguite. The laponite seemed to disperse more rapidly, showing no peaks in the WAXS spectrum of the resulting nanomix material. The relative viscosity (RV) of the resulting nanomix material was equal to the pure control, and its translucency indicated good clay dispersion. An increase of 4-9 ° C in the recrystallization temperature against the control indicates that the nanoparticles are altering the crystal structure of the nylon matrix in the form of nucleating agents.

• It is thus observed that the presence of silicate does not appear to affect the polymerization of nylon. The stress data in film samples of • 10 nylon 6 nanomixto material prepared by hot pressing in autoclaved extruded material between flat plates, show a general increase in stiffness with increasing concentration of Gelwhite H - primitive calcium montmorillonite, while resistance to tension and elongation , they are a bit reduced. It was found that the module 15 mixed materials obtained from mineral colloid BP - primitive sodium montmorillonite, is significantly higher (40%) than any of the other clays tested. twenty The previous experiment was repeated at 1% and 2.5% ore with the addition of Laponite B ore as an additional cycle. The addition of tetrasodium pyrophosphate peptide (TSPP) to the Gelwhite H sample during homogenization facilitated the formation of a dispersion. The resulting fiber was dull compared to the other candidates. All materials nanomixed at 1% showed a 10% increase in recrystallization temperature. Layered silicate intercalation experiments with molten low molecular weight nylon were carried out in primitive calcium montmorillonite. The fiber of nylon 6 nanomixto material spun from the polymerization autoclave and comprising 2.5% Laponite RD silicate, showed a measure of electrical conductivity under high voltage test. At concentrations of 5% and 10%, the viscosity of the molten material was so high that the molten material of the nanomixed material could not be discharged from the autoclave. Additional mechanical results were obtained in nylon 6 fiber: Gelwhite L and Laponite RD are preferred over mineral colloid BP, Gelwhite H, Laponite B and attapulguite to improve the module without loss of tenacity and elongation. The spun and stretched threads were bright and free of fiber buttons.

• All types of clay showed nucleation activity. The above experiments were repeated in part at clay levels of 0.5% • 10 and 1.0%, the clays being predispersed in a solution of caprolactam to 70% The fourth cycle of the nylon 6.6 standard polymerization cycle was extended from 30 to 60 minutes. fifteen • twenty These nanoclays produced an improved module at 0.5% and 1.0% levels, along with a certain increase in toughness at 0.5%. It was also observed that they are efficient nucleating agents for nylon 6. However, they also produced higher gel levels, showing CLAR fluorescence numbers of around 100 ppm versus 0-1 ppm for nylon control.

Examples of nylon 6,6 Nylon 6,6 nanocomposites can be polymerized by standard industrial processes as described in "Nylon Plastics Handbook "(Melvin I. Kohan, Hanser Publishers, Munich, 1995, pp. 17-23). Gelwhite L can be made in a concentrate of up to 20% nylon 6,6 by in situ polymerization (with Tamol 850, a sodium polymethacrylate from Rohm and Haas Company, to aid clay dispersion). These concentrates were extruded at the end of the third cycle of the standard polymerization process and cooled with water.

The nanocomposites were pulverized and added again to a nylon 6,6 polymerization, either in the saline solution at the beginning of the process or after the batch reached a temperature of 220 ° C. The last mentioned technique generated gels, and none provided any improvement in the mechanical properties of the spun fiber.

A suspension that never dries of a calcium montnorilonite with ion exchange where all Ca2 + ions have. changed by Na +, and containing polyacrylate as a peptizer was also polymerized into fiber • nylon 6,6 in a concentration of 1%, but without improvement in the properties of 5 yarn. The viscosity of the molten material had a high value, but could still be spun. The appearance of the resulting yarn was uniform, but without luster. Ca2 + mineralized materials are attractive for fiber applications due to their white color. However, the aspect ratio of its exfoliated platelets is known to be less than that of sodium montmorillonite. • 10 mineralized. If the dispersion of clay in the saline solution of nylon 6,6 is allowed to age, even for a few hours, it begins to coagulate. Polymerization of a one-day old dispersion resulted in a lower RV of nylon 6.6. 15 Silicate Concentrate Vehicle Solutions An alternative embodiment for the preparation of silicate / polyamide nanocomposites by in situ polymerization is to pre-disperse the clay in a high concentration in a vehicle 20 (such as a "concentrate") to be added to the polymerization vessel. For example, it was found that it is possible to disperse Gelwhite L in concentrations of 10 to 30% in an aqueous solution comprising 25% (based on the weight of the clay component) of a solution of caprolactam of 70% epsilon in water and a Tamol 850 dispersing agent of 1% to 5%. These dispersions remained stable for more than three weeks at room temperature. Without the dispersing agent, the dispersion of Geiwhite L in concentrations of more than 10% becomes gels that can not be discharged. An advantage of the use of this clay concentrate is its possible addition to the reaction mixture later in the polymerization cycle after the aqueous ionic environment has largely dissipated through vaporization, thereby reducing the opportunities for flocculation In this example, the dispersion was injected in an intermittent nylon 6,6 polymerization when the temperature was within a range of 220 ° -235 ° C. The resulting fibers contained buttons that fluoresced under UV light indicating the presence of gel. The fiber properties were consequently not improved over control nylon. In another example of the prior art, Laponite RD could be dispersed in a high concentration of 10% in a 70% solution of caprolactam in water by combining 3% Tamol® 850 with 100% ethylene glycol, both concentrations based on the weight of the clay It was found that tetrasodium pyrophosphate (TSPP) and carboxymethyl cellulose (CMC) are not effective peptizers for stabilizing montmorillonite suspensions after addition to nylon 6,6 saline, in accordance with the WAXS data. The Tamol® dispersing agent was effective in the polymerization of 1.5-2% of colloidal mineral BP nanocomposites in nylon blends comprising 20 to 30% nylon 6 in nylon 6.6 aqueous mixtures of caprolactam and hexamethylene adipamide. However, the viscosity of the 2% nanocomposite was so high that it could not be exempted from the reactor. The • The composition of the copolymer is attractive because the lower salt concentration reduces clay flocculation while the caprolactam component improves the intercalation of the clay structure, leading to more effective exfoliation. It was discovered that potassium tripolyphosphate (KTPP) is an effective peptizer for nanosilicates in nylon 6,6 saline solution.

It is also believed that it suppresses gel formation. The spun and drawn fibers prepared by injecting a Gelwhite suspension stabilized later in the polymerization cycle of nylon 6,6 were bright and gel-free, unlike the buttons and fluorescent gels obtained routinely with the TSPP and Tamol peptizers ® 850. The fiber that 15 contained 0.3% of nanoclay retained its matrix properties. • twenty Note: A suspension of 10% GELWHITE L in a 70% aqueous caprolactam solution was prepared with various amounts of KTPP. However, in 5820350 * and 5820351 *, the GELWHITE solution • L / caprolactam was maintained at 1/1. 5 Fiber comprising 0.6% colloidal mineral BP, KTPP at 1% based on the weight of clay and a small amount of caprolactam also appeared bright only with a lower generation of buttons. Many quaternary ammonium halide salts, such as those used in organomontmorilonites do not have the thermal stability that is • 10 required to withstand polymerization temperatures of nylon 6.6 of 280-300 ° C. A lauryl-dimethyl-3-sulfopropyl betaine (Ralufon DL from Raschip Corp.) with superior temperature stability successfully intercalated primitive Gelwhite L with calcium montmorillonite at a concentration of 1% in a 70% caprolactam solution which, when 15 was subsequently injected into the polymerization cycle of nylon 6.6 produced a nylon fiber 6.6 with a mineral concentration of 0.3% with good luster • and absence of gel, together with acceptable mechanical properties. Nanocompounds at 2% mineral colloidal BP, aminoluric acid and modified montmorillonite with (2-ethylhexyl dimethyl-sebo) 20 hydrogenated) were made by infiltration of molten adipamide hexamethylene salts and low RV (9-10) of nylon 6,6 polymer, to avoid exposure to the ionic environment of the saline solution. The WAXS data shows the posterior focus to improve the intercalation of the polymer when opening the clay structure. The nylon 6,6 nanocomposites comprising 1% of • Nanoclay was prepared from aqueous suspensions that do not dry, with the exception of dry Gel-White H that had to be re-dispersed in water. The previous dispersions are further mixed under high shear with an Omni homogenizer for 10 minutes after the introduction to the saline solution. • 10 fifteen 20 All the previous clays were obtained from SCP. The suspension of calcium montmorillonite had an ion exchange with sodium ions and also contained an acrylic peptizer.

Samples 8515, 8517 and 8520 could not be exempted from the polymerization autoclave due to the high viscosity of molten material, suggesting an important degree of clay exfoliation despite the • presence of a WAXS peak at 14.4Á. The wider the peak indicates that the original sheet stacks in the clay have somehow reduced their thickness. A nylon 6,6 nanocomposite comprising 1% nanoclay from a non-dried suspension of sodium montmorillonite demonstrated a high reinforcing efficiency with a 15% increase in tensile modulus of elasticity. The sample 8522 was molded by injection 10 in tension test bars that showed an increase of 15% in the module from 30580.5 to 35150 kg / cm2, a very high efficiency boost from the small amount of clay present. The presence of clay apparently has no significant effect on the molecular weight of the polymer formed, or its distribution. The The presence of CMC in sample No. 8515 reduces the molecular weight, as expected. • Five replications of modified cord fibers for industrial tires and asphalts with 0.5% and 1.0% Gelwhite L were prepared in a small autoclave from a predispersion of clay to the 20% in a 70% aqueous caprolactam solution containing 1% KTPP and Tamol 850 based on the weight of the clay. The clay suspension was injected in a nylon 6,6 polymerization during the second process cycle at 235 ° C. The modulus increased by 10 to 20% in the spun fibers at both concentration levels, although this utility was retained after extracting only at the asphalt fiber at the lower concentration level. The tenacity and elongation of the spun fibers and • Stretches of both types showed small decreases. It was subsequently shown that it is preferable to omit the Tamol ingredient in this particular formulation. An important level of nano-reinforcement was achieved in injection molded nylon 6,6 nanocomposites made by in situ polymerization in a lot of 113 kg with a very high mineral concentration. • 10 low. An improvement in the module of elasticity to the traction of 6327 kg / cm2 (20%) on nylon net due to the incorporation of only 0.72% of the mineral content in weight of synthetic hectorita of RD laponita represents ten times the maximum benefit that can be anticipated of the classic reinforcement mechanisms. A very small crystallite size, which indicates nucleation, 15 was detected in these nanocomposites by optical microscopy through crossed poiarisers. • It was shown that primitive sepiolite, a silicate similar to a chain, is equally effective as montmorillonite or hectorite for the reinforcement of nylon fiber by in situ polymerization. To a 20 concentration of 0.1% provides a high stretching capacity and improved mechanical properties. In a stretch ratio of 6.5 the following fiber properties were obtained in comparison with a pure nylon control fiber: modulus of 84 vs. 76 g / d, tenacity of 10.2 vs. 9.1 g / d and elongation of 12.3 vs. 10.4% to failure. The nylon RV matrix was equivalent to the pure nylon control. Sepiolite (1%) increased the flexural modulus by 13% in nylon 6,6 polymerized in a laboratory autoclave. However, in the autoclave escalation of 113 kg, the sepiolite compounds did not show as much improvement over the nanocomposite as in the smaller scale experiments. Injection molds containing 0.09% by weight of primitive sepiolite showed less reinforcement than with the corresponding laponite materials. The tensile strength still • 10 increased significantly from 780.33 to 843.6 kg / cm2 compared to nylon without reinforcement. The increase in the module was only a modest 6%, although the lengthening even reached a 30% load. As with laponite, the presence of the sepiolite material during the polymerization of nylon had no effect on the nylon polymer, which 15 recorded an RV of 42 and final acid / amine group concentrations of 72 / 52.4. An advantage of sepiolite is that it can effectively disperse • Directly in the HMA saline solution without the need to elaborate a previous dispersion in water. Silane, particularly aminopropyltriethoxysilane, can 20 incorporated into polyamides as nylon 6,6 by the addition to the saline solution together with the nanoclay before polymerization. At low levels (0.12-0.25%), it did not provide a significant benefit in the properties of the resulting nanocomposite fibers that also comprised low levels (0.1%) of nanoclay. However, at higher silane concentrations (up to 0. 5%) and nanoclay (up to 2%) used for injection molding, serves to improve the ductility of the nanocomposite. Apparently the resistance • interfacial usually attributed to the silanes in the melted composite systems can also be effective by in situ polymerization. On the other hand, in the absence of silicate the silane only showed some potential of reinforcement by itself in the stretched fiber. The higher aspect ratio in the reinforcements generally produces higher properties in the extruded fiber of nylon 6,6 nanocomposites polymerized in situ. In this way montmorillonite and hectorite are more effective than laponite B, which at the time is more effective than laponite RD. The crystallinity increased slightly and the recrystallization temperatures increased in general (up to 8 ° C) through the incorporation of the nanoclay during the polymerization. Sepiolite, saponite and, to a lesser degree, hectorite, are the most important nanosilicate nucleators. • effective. Additional examples of spun and drawn fibers of nylon 6,6 nanocomposites polymerized in situ in the pilot plant scale comprise montmorillonite, hectorite and laponite B, both primitive and ion exchange with ammonium cations. The 15% increments in modulus and tenacity were achieved along with a 30% increase in tightening resistance at a low mineral concentration of only 0.1% by weight which would be important for tire cord applications. Higher increases of up to 30% in the module with 10% in tenacity were observed in the scale of marks. Of particular interest, the secant modulus of 2% of the stretched asphalt yarn of the primitive hectorite nanocomposite at 0.1% of 16.6 g / denier was 44% higher than the control yarn with 11.7 g / denier produced in the same test and extruded with the same denier. Elongation to failure was equivalent to control, while tenacity improved slightly. The good performance of this nanocomposite can be attributed to the previous dispersion of the silicate into a minor caprolactam component of the formulation. Dihydroxyethyl-octadecylammonium is the preferred exchange cation in polysilicate minerals for in situ polymerization in nylon 6,6. A nanocomposite polymerized in situ with 0.2 and 0.4% montmorillonite pretreated with this cation demonstrated improved appearance retention in asphalt sidewalk tests. Due to their lower hydrophilic nature, the organoclays are pre-dispersed up to a 5% concentration directly in a nylon saline solution instead of pure water, as preferred for the primitive minerals. A slight inhibition of nylon 6,6 polymerization that can occur at higher silicate concentrations (eg, 2%) can be overcome by increasing the residence time in the reactor in the finishing cycle by about 30%.

The improved module together with a slightly reduced ductility, indicate a better dispersion of nanoparticles resulting from the application of ultrasonic energy to the initial suspension of clay. The ideal concentration of minerals for spinning fibers appears to be less than about 1%, preferably from about 0.1% to about 0.2% by weight. For injection molding applications, high injection molding properties were found for 1.5% silicate content: tensile strength of 91 Mpa, modulus of 3.4 Gpa and final elongation of 47%, while a nylon 6 homopolymer, 6 almost • 10 typical would show 80 Mpa, 3.0 Gpa and 60%, respectively.

Applications of the fibers Applications of the fibers can be used through the benefit of the in situ polymerization process from the objectives 15 minor modulus against plastic molding applications, such as lower levels of clay concentration, where the interactions • Nanoscale play an important role. Higher orientation levels can be generated in fiber spinning and stretching processes than in injection molding. The use of a stretching temperature Furthermore, it improves the performance of the nanomaterial material by controlling the molecular deformation. The characteristics of luster, uniformity (absence of fiber buttons) and opacity are indicators of the size of the residual particles of the clay inclusions in spun and drawn fibers.

Solid state polymerization of polymerized nanomaterials in situ Solid state polymerization was carried out for 1.5 hours at 200 ° C using nylon 6,6, which had been polymerized in situ with four different silicates. Molecular weights were determined before and after polymerization in the solid state. It was found that samples of nanomixed material increase their molecular weight in a similar way to nylon 6,6.

Comparison of in situ polymerization compositions against melt mixing A well-hydrated and never-dried suspension of mineral colloid BP (sodium montmorillonite) was added to a nylon 6-saline solution., 6 to 50%, homogenized and polymerized to produce nanomixed materials of 1.0% and 1.25% by weight of silicate. Nanomix materials were injection molded and tested for tension according to ASTM method D-638. Comparative nanomix materials were mixed in a twinworm extruder from similar montmorillonites that had been pretreated with ammonium compounds to allow their intercalation and exfoliation by a nylon fusion, as • describes in the first patent application of the authors. The two treatments, which produced almost identical results, were seboammonium dihydrogenated cations and hydrogenated dimethyl (ethylhexyl) seboammonium. The voltage modulus data plotted as a function of the mineral content of the nanomixed material, show that the compositions polymerized in situ have a higher yield to the • Same load as the comparative materials obtained by melt mixing (figure). Both are superior to traditional mixed materials filled with kaolin clay that is not exfoliated into nanoparticles. All compositions, methods and apparatus described and claimed herein can be obtained and executed without experimentation 15 unduly in the light of the present description. Although the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those skilled in the art that variations can be made to the compositions, methods and apparatus and in the steps or sequence of steps of the compositions. procedures described in 20 present, without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents that are chemically related can be substituted by the agents described herein, while achieving the same or similar results. All substitutes and similar modifications apparent to those skilled in the art should be within the spirit, scope and concept of the invention.

Claims (24)

NOVELTY OF THE INVENTION CLAIMS •

1. A process for preparing a polyamide nanomix composition, the method comprising: forming an aqueous mixture of a silicate material and a polyamide monomer; treating the mixture to polymerize the polyamide monomer; and subjecting the mixture to solid state polymerization conditions that allow the polymer nanomix composition to be formed.

2. The process according to claim 1, further characterized in that the monomer is hexamethylene adipamide, e-caprolactam, lauryl lactam, e-caprolactone or lauryl lactone.

3. The process according to claim 1, further characterized in that the monomer is hexamethylene adipamide.

4. The process according to claim 1, further characterized in that the monomer is a mixture of hexamethylene adipamide and e-caprolactam.

5. The method according to claim 1, further characterized in that the polyamide is nylon 6, nylon 6,6, nylon 4,6, nylon 6,9, nylon 6,10, nylon 6,12, nylon 11, nylon 12, amorphous nylons, aromatic nylons, or copolymers thereof.

6. - The method according to claim 1, further characterized in that the polyamide is a copolymer of nylon 6 and nylon 6,6.

7. The process according to claim 1, further characterized in that the silicate material is laponite, hectorite, sepiolite, saponite, attapulguite or montmorillonite.

8. The process according to claim 1, further characterized in that the silicate material is added in fully hydrated form, in the form of a suspension never dried, or in the form of an aqueous suspension.

9. The process according to claim 1, further characterized in that the silicate material is an organically treated silicate.

10. The process according to claim 1, further characterized in that the mixture further comprises a dispersing agent.

11. The process according to claim 10, further characterized in that the dispersing agent is sodium polymethacrylate.

12. The process according to claim 1, further characterized in that the mixture further comprises a silane.

13. The process according to claim 12, further characterized in that the silane is aminopropyltriethoxysilane.

14. - The process according to claim 1, further characterized in that the concentration of silicate material in the polyamide nanomixate composition is less than about 2 per cent.

• Weight percent. 15. The process according to claim 1, further characterized in that the concentration of silicate material in the polyamide nanomix composition is less than about 1 weight percent.

16. The method according to claim 1, 10 further characterized in that the concentration of silicate material in the polyamide nanomix composition is between about 0.05 weight percent and about 0.2 weight percent.

17. The process according to claim 1, further characterized in that the solid state polymerization comprises 15 heat the mixture after the polymerization step at a temperature in the range from about 200 ° C to about 240 ° C for a period of about 2 hours to about 5 hours.

18. The process according to claim 1, further characterized in that the polymerization in the solid state comprises: adding a catalyst, and heating the mixture after the polymerization step at a temperature at least 20 ° C lower than the point of melting or softening of the polyamide for a period of from about 0.5 hours to about 5 hours, wherein: the molecular weight of the nanomixta composition formed in the presence of the catalyst is greater than the molecular weight of the nanomixta composition formed in the absence thereof.

19. The method according to claim 1, • further characterized in that it comprises treating the composition 5 nanomixta with heat at a temperature in the range from about 200 ° C to about 240 ° C for a period of about 2 hours to about 5 hours.

20. The process according to claim 1, further characterized in that the mixture has a higher molar concentration • 10 hexamethylene diamide than adipic acid.

21. The process according to claim 1, further characterized in that it comprises dissociating at least about 50% of the silicate material before polymerization in the solid state.

22. The process according to claim 21, further characterized in that the silicate material is dissociated by a mechanical unit, pressure alteration, ultrasound, a stirrer or a high shear homogenizer.

23. The process according to claim 1, further characterized in that the mixture further comprises an oligomer of the polyamide monomer or a low molecular weight polymer of the polyamide monomer before the polymerization step.

24. - A polyamide nanomix composition prepared by the method of claim 1. 25.- A polyamide nanomix composition comprising a polyamide and a silicate material, wherein: the tension module of the composition is greater than the tension module of a composition prepared from the concentration of identical starting materials and starting materials, when prepared by intercalation of molten material; and the molecular weight of the polyamide nanomixate composition is greater than the molecular weight of a composition prepared from the concentration of the identical starting materials and starting materials, when prepared by in situ polymerization without solid state polymerization.