MXPA99001830A - High performance ionomer blends - Google Patents

Abstract

Blends of highly-neutralized ionomers of copolymers of ethylene and high weight percentages of&agr;,&bgr;-ethylenically-unsaturated C3-C8 carboxylic acids dispersed in a continuous or co-continuous polyamide phase are provided and a process for making such blends. The blends are particularly useful in applications such as molded parts where toughness, high gloss, abrasion/scratch (mar) resistance, UV resistance, high temperature properties and stiffness are desired.

Description

HIGH PERFORMANCE IONOMER MIXTURES FIELD OF THE INVENTION This invention relates to ionomer / polyamide blends, particularly mixtures of highly neutralized copolymers of ethylene, and high percentages by weight of carboxylic acids of 3 to 8 carbon atoms, ß-ethylenically unsaturated, dispersed in semicrystalline polyamides such as nylon 6. These blends are particularly useful in applications such as molded parts where a combination of stiffness, high luster, abrasion-scratch resistance (resistance) to usual wear, ultraviolet light resistance, high temperature properties and toughness is desired.

BACKGROUND OF THE INVENTION There is a total need for molded parts, particularly in automotive applications such as fenders, bumper extensions, bucket lids and other dashboard components and molded outer parts, for products that have high luster, REF. 29408 good resistance to environmental conditions, high impact strength and high temperature properties (for example, tensile strength and dimensional stability such as creep resistance and plastic deformation resistance). It is also desirable to be able to mold in solid and metallic colors and, optionally, to be able to paint the parts. The "solid" colors present a homogeneous finish, even in close inspection. All the ingredients, which can be of substantial number, are ground and mixed in such a way that, when applied, they seem to have been produced from a single homogeneous ingredient. The solid color does not flash or reflect when illuminated directly by a light source, nor does it seem to change significantly when it is. observe from different angles. The "metallic" colors (including pearls) contain discrete pigments in the form of flakes, which may be in the range of flake-like flakes of aluminum flakes or mica flakes. These leaflets are large enough to be discreetly identifiable within the field of color that is observed. The metallic color has a remarkable "flash" when the surface is directly illuminated by a light source, but appears to change color as the panel is rotated between an angle perpendicular to an oblique angle. This property is called "polychromaticity". This change in heat as the observation angle is rotated is also referred to as "travel" or "flop". BEXLOY® automotive engineering resin, a mixture of ionomer and polyethylene reinforced by glass fiber, marketed by E.l. du Pont de Nemours and Company, has found increasing use in molded parts such as automobile fenders, because it meets most of these needs. Its benefits include good luster (appearance), moderate resistance to usual wear, good processing capacity and high impact resistance, at a relatively low cost. The solid color can be incorporated into the material, but the success and incorporation of metallic colors has been limited. Also, the adhesion of the paint to the BEXLOY® resin is poor and the application of the paint that requires the use of high-temperature paint baking ovens (Original Equipment Manufacturing "OEM" Painting) is not feasible since BEXLOY® W lacks adequate properties at high temperature. For applications such as in automotive dashboards (fenders, for example), a higher wear resistance than that inherent in BEXLOY® W resin is needed. Thus, when BEXLOY® resin is used, a grain is typically applied. light to the surface to improve the wear resistance usual. Any addition of grain, however light and glossy, substantially retards the "Distinction of Image" (DOI), a key index used to evaluate the perceived quality of an exterior finish in the automotive industry. DOI, a measure of the "clarity" or "degree of definition" of a reflection of an object in a colorful finish, compared to the actual object itself, is measured from the angle of reflection of a beam of light coming from a spherical surface. The DOI can be measured using a Hunterlab Lusterometer Model No. D47R-6F Doigon. The test panel is placed on the sensor of the instrument and the sharpness of the reflected image is measured. The details of the DOI test procedure are described in the General Motors TM-204-M test specification.

In the automotive industry, satisfactory finishes on a smooth surface or "Class A" will typically have a finish with a DOI value of at least 60, preferably 80 or greater. A lightweight commercial BEXLOY® W resin instrument panel, used on a Neon car, has a DOI of 0. While still retaining other important performance characteristics, there is a need for high gloss (at least value of 60 when measured at 20 °, and at least 75 when measured at 60 ° C) and higher DOI (at least 60), faster processing, better high temperature properties, and improved strength with such usual wear and tear without the need for light grain. Also, there is a need to be able to incorporate metallic colors and, alternatively, to be able to paint the molded part. Certain mixtures of ionomers with polymers other than polyethylene are known in the art. (polyamides, for example). However, these prior art blends with nylon would not be suitable for solving the problems experienced with BEXLOY® W resin.

U.S. Patent No. 4,335,223 issued to Flood et al., For example, teaches improvement of Izod impact strength to notching of molded shaped objects from 50 to 99% by weight of nylon 6 or nylon 66 mixed with an α-olefin / 3 to 8 carbon atoms, β-ethylenically unsaturated carboxylic acid ("ethylene-acid copolymers") by the addition of 0.05 to 1% by weight of selected metal compounds such as antimony oxide and magnesium oxide. U.S. Patent No. 3,845,163 issued to Murch, for example, teaches the improvement of rigidity in the welding line of polyamide blends with ethylene-acid copolymers by neutralizing at least 10 percent of the acid groups with metal ions such as sodium, calcium and zinc in solid form or aqueous solution. One might expect hydrolysis of the polyamide to result with the use of the aqueous solution. Mixing in molten form in conventional equipment and in solution mixing or dry mixing, followed by extrusion or injection molding, are also shown. No preference is suggested for high intensity mixing. U.S. Patent No. 3,845,163 teaches samples containing at least 50 weight percent (% p) of polyamide (60-85% by weight is claimed, and 80% by weight is exemplified). While a wide range of acid levels and degrees of neutralization are described, the highest acid level used in the reference is 12% by weight, and the highest neutralization is 76%. They have been elaborated, by means of the use of compatibilization agents, mixtures of polyamide and ionomer, where the ionomer is the main component, but the polyamide is the continuous or co-continuous phase. U.S. Patent No. 5,091,478 issued to Saltman, for example, teaches mixtures of 25 to 50% by volume polyamide with ionomer using polymeric graft agents containing certain reactive groups. Preferred grafting agents are copolymers derived from ethylene / n-butyl acrylate / glycidyl methacrylate and ethylene / glycidyl methacrylate.

BRIEF DESCRIPTION OF THE INVENTION The desired improvements have been made by the present invention. The important performance or performance characteristics of BEXLOY® W resin have been retained and higher luster has been achieved, faster processing, better high temperature properties, and improved resistance against usual wear without the need to add light grains. The need for fiberglass reinforcement has been eliminated. The molded parts made using the blends of this invention have high luster showing DOIs at least comparable to the best of the paint finishes on smooth or "Class A" surfaces, particularly DOIs above 80 and as high as 90 to 95. The colors solid and metallic can be incorporated, and the parts can be painted. The high temperature properties are sufficient to allow OEM type painting without the need for work mounts or special hangers to maintain the shape of the part during the baking step. The molded parts with addition of standard UV stabilizers for the ionomer and polyamide show surprising resistance to environmental conditions, particularly stability when exposed to ultraviolet light for extended periods of time. Improved automotive instrument panels, having DOI of at least 80 and above, can be made from the mixture of this invention. This invention relates to the ionomer / polyamide blends (preferably 60 to 40 weight percent (% p) of ionomer / 40 to 60% by weight of polyamide based on the total weight of the ionomer and the polyamide) wherein the Polyamide forms a continuous (or co-continuous) phase. The ionomer, preferably present in a higher percentage by volume than the polyamide, is dispersed in the continuous or co-continuous phase of the polyamide. Preferably, the ionomer forms small particles which are preferably oblong, and curvilinear or ellipsoid in a co-continuous polyamide phase, or are essentially spherical in a continuous polyamide phase. The average diameter of the particles are essentially spherical (diameter in cross section or length of the minor axis of the oblong / ellipsoid particles) is preferably from about 0.1 to about 0.2 micrometers (μm). The ionomers suitable for this invention are formed from copolymers of ethylene and high percentages by weight of carboxylic acids of 3 to 8 carbon atoms, β-ethylenically unsaturated, preferably methacrylic or acrylic acid. The percentage of acid that is considered "high" depends on the acid used. In the case of methacrylic acid, it is preferably from 15 to 25% by weight, based on the total weight of the copolymer. The lowest preference for acrylic acid is 14% by weight, as a result of differences in molecular weight. In the final mixture, the acid portions in the copolymer are highly neutralized (preferably 65 to 100 percent) with metal cations, particularly cations compatible with the polyamide, preferably zinc. The polyamides suitable for this invention are preferably one or more semicrystalline polyamides such as polyepsiloncaprolactam (nylon 6) and polyhexamethylene adipamide (nylon 66). The amorphous polyamides can be replaced by some semicrystalline polyamide. It has been found that ionomer / polyamide blends, where the ionomer is the largest component by volume, but is dispersed in a continuous or co-continuous phase in the polyamide, can be made without the use of compatibilizing agents. In order to make the mixtures of this invention, the ethylene-acid copolymer which is more preferably partially neutralized (preferably at about 35 to about 40 mol%) is mixed in molten form with the polyamide under sufficiently intense mixing conditions while it neutralizes concurrently (or is neutralized further if the ionomer is the initial material) at a high level of neutralization to achieve the desired morphology. This "in situ" neutralization has been found to be effective for obtaining high neutralization, while maintaining the conditions during mixing in molten form, wherein the polyamide although present at a lower percentage by volume than the ionomer, it forms a continuous or co-continuous phase without the need for a compatibilizer, and the ionomer is uniformly dispersed therein at high percentages of ionomer. The combination of the acid level and the high neutralization, together with the intense mixing of the components, provides the desired viscosity ratio of the ionomer to the polyamide and the stabilization of the dispersed phase of the ionomer in the nylon matrix. This is particularly true when a cation such as zinc is used, which is compatible with nylon, to neutralize the ethylene-acid copolymer. As used herein, the term "consisting essentially of" or "consists essentially of" means that the ingredients are essential, however, other ingredients may also be included that do not prevent the advantages of the present invention from being realized.

FIGURES Figures 1 (a) and 1 (b) are photographs with a large amplification (obtained through the Electronic Transmission Microscope) of a plate having essentially spherical ionomer particles dispersed in a continuous polyamide phase. Figure 1 (a) is in the direction parallel to the flow within the mold and Figure 1 (b) is in the perpendicular direction. Figure 2 (a) and 2 (b) are photographs of a large amplification (obtained through the Transmission Electron Microscope) of the plate having oblong and curvilinear ionomer particles dispersed in a co-continuous polyamide phase. Figure 2 (a) is in a direction parallel to the flow towards the mold and Figure 2 (b) is in the perpendicular direction.

DETAILED DESCRIPTION OF THE INVENTION The present invention is a mixture of dispersed ionomer in a continuous polyamide phase (or co-continuous). Preferably, the mixture 60 to 40 (more preferably 50 to 45, also 60 to 55)% by weight of ionomer and 40 to 60 (more preferably 50 to 55, also 40 to 45)% by weight of polyamide (the percentages are based on the ionomer and the 'total polyamide). Preferably, the ionomer is dispersed in a reasonably uniform manner as essentially spherical particles, small for the most part with their average diameter, preferably from 0.1 to about 0.2 μm in a continuous polyamide phase, as can be seen in Figures 1 (a ) and 1 (b). Also, the ionomer is preferably dispersed as oblong-shaped and curvilinear or ellipsoidal particles for the most part with an average cross-sectional diameter (minor axis length) of from about 0.1 to about 0.2 μm in a co-continuous polyamide phase, as can be seen in figures 2 (a) and 2 (b). The average ratio of the length of the major axis to the length of the minor axis may be from about 2 to about 10 or greater. The mixture may also contain components such as ultraviolet light stabilizers, antioxidants and thermal stabilizers, pigments and dyes, fillers, anti-slip agents, plasticizers, nucleating agents, and the like for the polyamide and ionomer. Preferably, these components are present in amounts of about 1 to about 3 (preferably about 1.5 to about 3) parts per hundred parts by weight of the ionomer / polyamide mixture, but may be present at lower or higher levels. The compounds of the present invention and the method for preparing the mixtures are as follows: Ionomer The ionomers of the present invention are derivatives of direct copolymers of ethylene and carboxylic acid of 3 to 8 carbon atoms, β-ethylenically unsaturated ("ethylene-acid copolymers") by neutralization with metal ions. By "direct copolymer", it is understood that the copolymer is made by polymerizing the monomers together at the same time, which is different from a "graft copolymer" where a monomer is coupled or polymerized onto an existing polymer chain. Methods for the preparation of such ionomers are well known and are described in U.S. Patent No. 3,264,272 which is incorporated by reference herein. The preparation of the direct ethylene-acid copolymers on which the ionomers are based is described in US Patent 4,351,931 which is also incorporated by reference herein. Ethylene-acid copolymers with high acid levels are difficult to prepare in continuous polymerizers, due to the phase separation of the monomer-polymer. This difficulty can be avoided, however, by the use of "co-solvent technology" as described in U.S. Patent No. 5,028,674 which is also incorporated by reference herein, through the use of somewhat higher pressures than those a which can be prepared copolymers with lower acid. The ethylene-acid copolymers used to make the ionomeric copolymer of this invention can be E / X / Y copolymers where E is ethylene; X is a smoothing comonomer and Y is the carboxylic acid of 3 to 8 carbon atoms α, β-ethylenically unsaturated, particularly acrylic or methacrylic acid. Preferably, however, the ethylene-acid copolymer is a dipolymer (without softening comonomer). The preferred acid portions are methacrylic acid and acrylic acid. By "softening" it is meant that the polymer is made less crystalline. The suitable "smoothing" comonomers (X) are monomers selected from alkyl acrylate, and alkyl methacrylate, wherein the alkyl groups have from 1 to 12 carbon atoms, which, when present, may be up to 30 (preferably up to 25, more preferably up to 15)% by weight of the ethylene-acid copolymer. The preferred ethylene-acid dipolymers are ethylene / acrylic acid and ethylene / methacrylic acid. Other specific copolymers include ethylene / n-butyl acrylate / acrylic acid, ethylene / n-butyl acrylate / methacrylic acid, ethylene / iso-butyl acrylate / methacrylic acid, ethylene / iso-butyl acrylate / acrylic acid, ethylene / n-butyl methacrylate / methacrylic acid, ethylene / methyl methacrylate / acrylic acid, ethylene / methyl acrylate / acrylic acid, ethylene / methyl acrylate / methacrylic acid, ethylene / methyl methacrylate / methacrylic acid, and ethylene / methacrylate n-butyl / acrylic acid. The ethylene-acid copolymers used to make the ionomeric copolymers of this invention have the acid moiety present in a high amount. The amount that will be considered "high" will depend on which acid portion is used, particularly the molecular weight of the acid portion. In the case of ethylene / methacrylic acid, the preferred acid level is from 15 to 25, (preferably from 18 to 25, more preferably 19 to 22)% by weight of the copolymer. In the case of ethylene / acrylic acid, the preferred acid level is from 14 to 25 (preferably from 16 to 25, more preferably 18 to 22)% by weight of the copolymer. Particularly in view of the descriptions herein, one of skill in the art will be able to determine the "high" acid levels, for other acidic portions that are necessary to obtain the desired luster levels and abrasion resistance. It will be recognized that it is possible to mix more than one copolymer, that the acid level of one or more which are outside the "high" range of the invention, to obtain an average acid level before neutralization is within the high levels of acid, percentage, preferred. Preferably, in the case of mixtures, the weight percent acid in each acid polymer from which the ionomeric components are derived should be close to the preferred range, and more preferably they should be within this range. The acid portion is preferably highly neutralized metal cations, particularly monovalent and / or divalent metal cations. It is preferable to neutralize with metal cations that are compatible with nylon, that is, with cations that also interact with the amide bonds of the polyamide. Preferred metal cations include lithium, magnesium, calcium, and zinc, or a combination of such cations. Zinc is the most preferred. Potassium and sodium are poor choices. The ethylene-acid copolymers neutralized with potassium tend to absorb water adversely affecting the nylon. Sodium ionomers are difficult to stabilize to ultraviolet radiation. Magnesium and calcium are preferably used in combination with zinc. • While the neutralizing agent (eg, zinc oxide, magnesium oxide, and calcium oxide) can be added in solid form, it is preferably added as a concentrate in a copolymer ethylene-acid carrier. This concentrate is made by careful selection of the ethylene-acid copolymer under the mixing conditions to ensure that the neutralizing agent does not significantly neutralize the carrier. This neutralization concentrate can also contain small amounts (up to about 2% by weight) of one or more salts of the metal cations (for example, acetates and stearates). To achieve the desired morphology (dispersed ionomer in the continuous or co-continuous nylon phase), the ionomer is neutralized at a high enough level to achieve a higher viscosity than that of nylon. It is preferred to first mix a partially neutralized, lower viscosity ethylene acid copolymer within the nylon and then further neutralize to raise the viscosity of the ionomer while the melt is mixed under conditions of intense mixing. As will be appreciated by one of skill in the art based on the teachings described herein, the preferred level of neutralization will depend on the ethylene-acid copolymers employed and the properties desired. The neutralization of the mixture should be sufficient to raise the melting index (MI) of the ionomer of the mixture, measured as grams of ionomer that exits through a hole of 2.09 mm (0.0823 inches) in ten minutes (gm / 10 min) to 190 ° C with a weight of 2160 grams of applied force (ASTM D-1238 condition E), at a level such that, if the ionomer alone (not in the mixture with nylon) were neutralized at that level, there would be a very low flow to essentially null (preferably less than about 0.2 grams / 10 minutes). For example, for an ethylene-ethylene acid / 19% by weight methacrylic acid dipolymer, the following MI values result when the dipolymer is neutralized to the indicated degree: In this case the percentage neutralization could be approximately 60% or more, since the grams of ionomer that exit through the orifice are less than 0.2 grams per 10 minutes. One skilled in the art can easily determine the preferred percent neutralization for other ionomers. Preferably, in the final molten mixture with polyamide, the mole percent of the neutralized acid is 65 to 100%, more preferably 75 to 100%, alternatively 75 to 85%. The acid level and the degree of neutralization can be adjusted to achieve the particular properties desired. The luster is improved by raising the average acid level. The high neutralization produces more lustrous, harder products, while the more moderate neutralization produces more rigid products.

Nylon Semi-crystalline polyamides can be used in the present invention. The term "semicrystalline polyamide" is well known to those of skill in the art. Semi-crystalline polyamides suitable for this invention are generally prepared from lactams or amino acids or from the condensation of diamines such as hexamethylenediamine with dibasic acids such as sebacic acid. The copolymers and terpolymers of these polyamides are also included. Preferred semicrystalline polyamides are polyepsiloncaprolactam (nylon-6), polyhexamethylene adipamide (nylon-66), more preferably nylon-6. Other semicrystalline polyamides useful in the present invention include nylon-11, nylon-12, nylon 12,12 and copolymers and terpolymers such as nylon-6/66, nylon-6/610, nylon-6/12, nylon 66/12 , nylon-6/66/610 and nylon-6 / 6T. The amorphous polyamides can be replaced by some semicrystalline polyamide to raise the glass transition temperature (Tg) of the nylon phase. Up to about 10% by weight, preferably up to about 5% by weight, of the polyamide phase can be amorphous polyamides. The term "amorphous polyamide" is well known to those of skill in the art. "Amorphous polyamide" as used herein, refers to those polyamides, which lack crystallinity, as shown by the lack of endothermic crystalline melting peak in a Differential Scanning Calorimeter ("DSC") measurement (ASTM). D-3417) at a heating rate of 10 ° C / minute. Examples of the amorphous polyamides that can be used include hexamethylenediamine isophthalamide, terpolymer of hexamethylenediamine isophthalamide / terephthalamide having iso / terephthalic portion ratios of 100/0 to 60/40, mixtures of 2,2,4- and 2, 4,4-trimethylhexamethylenediamineterephthalamide, copolymers of hexamethylenediamine and 2-methylpentamethylenediamine with iso- or terephthalic acids, or mixtures of these acids. Polyamides based on hexamethylenediamine-iso / terephthalamide containing high levels of terephthalic acid portions may also be useful provided that a second diamine such as 2-methyldiaminopentane is incorporated to produce a processable amorphous polymer. The amorphous polyamides may contain, as comonomers, smaller amounts of lactam-type species such as caprolactam or lauryl-lactam, although the polymers based on these monomers alone are not amorphous, as long as they do not impart crystallinity to the polyamide. In addition, up to about 10% by weight of a liquid or solid plasticizer such as glycerol, sorbitol, mannitol, or aromatic sulfonamide compounds (such as "Santicizer 8" from Monsanto) can be included with the amorphous polyamide. The amorphous polyamide can be a mixture of ethylene vinyl alcohol and amorphous nylon, wherein the polyamide component comprises about 5 to about 95% by weight of the total EVOH composition, plus the polyamide, preferably about 15 to about 70% by weight, and more preferably about 15 to about 30% by weight. The polyamide component must have a viscosity under the conditions of mixing in molten form, which is high enough to provide the mechanical properties, but low enough to create the phase relationship of this invention. The viscosity of the polyamide should be higher than that of the ethylene-acid or ionomer copolymer at low neutralization levels, but should be lower than the ionomer at high levels of neutralization.

Other components The additives normally composed of plastics can be included in the mixture, for example, UV stabilizers, antioxidants and thermal stabilizers, processing aids, pigments and the like. When they are included, these components. they are preferably present in amounts of about 1 to about 3 (preferably about 1.5 to about 3) parts per hundred parts by weight of the ionomer / polyamide mixture, but may be present in lower or higher amounts. Of particular importance, if the part is to be exposed to 'ultraviolet (UV) light is the inclusion of one or more UV stabilizers for the nylon and for the ionomer. Typical UV stabilizers useful include: benzophenones such as hydroxydedeloxybenzophenone, 2,4-dihydroxybenzophenone, hydroxybenzophenones containing sulphonic groups and the like; triazoles such as 2-phenyl-4- (2 ', 2'-dihydroxylbenzoyl) -triazoles; substituted benzothiazoles such as hydroxyphenylthiazoles and the like; triazines such as 3, 5-dialkyl-4-hydroxyphenyl derivatives of triazine, sulfur-containing derivatives of the dialkyl-4-hydroxyphenyltriazines, hydroxyphenyl-1,3,5-triazine and the like; benzoates such as diphenylolpropane dibenzoate, tert-butyl benzoate diphenylolpropane and the like; and others such as phenols containing lower alkylthiomethylene, substituted benzenes such as l, 3-bis- (2'-hydroxybenzoyl) benzene, metal derivatives of 3,5-di-t-butyl-4-hydroxyphenylpropionic acid, oxalic acid asymmetric, diarylamides, alkylhydroxyphenylthioalkanoic acid ester, and hindered amines of bipiperidyl derivatives. Preferred UV stabilizers, all available from Ciba Geigy, are TINUVIN® 234 (2-) 2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol), TINUVIN® 327 ( 2- (3 ', 5' -di-tert-butyl-2 '-hydroxyphenyl) -5-chlorobenzotriazole), TINUVIN® 328 (2- (2'-hydroxy-3', 5'-di-tert-amylphenyl) benzotriazole ), TINUVIN® 329 (2- (2 '-hydroxy-5'-tert-octylphenyl) benzotriazole), TINUVIN® 765 (bis-sebacate) (1, 2, 2, 6, 6-pentamethyl-4-piperidinyl), TINUVIN® 770 (bis ((2,2,6,6-tetramethyl-4-piperidinyl)) dekanedioate, and CHIMASSORBMR 944 (polymer of (N, N'-bis (2, 2, 6,6-tetramethyl-4-piperidinyl) -1,6-hexandiamine with 2,4,6-trichloro-1,3,5-triazine and 2, 4, 4-trimethyl-1,2-pentanamine.) Preferred thermal stabilizers, all available from Ciba Geigy, are IRGANOX®, 259 (hexamethylene bis (3, 5-di-tert-butyl-4-hydroxyhydrocinnamate). ), IRGANOX® 1010 (2, 2-bis [[3- [3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] -l-oxo-propoxy] methyl] -1,3-propandiyl ester of (3 , 5-bis (1, 1-dimethylethyl) -4-hydroxybenzenepropanoic acid), IRGANOX® 1076 (octadecyl 3, 5-di-tert-butyl-4-hydroxyhydroxycinnamate), IRGANOX® 1098 bis (3,5-di-ter- butyl-4-hydroxyhydrocinnamamide) of N, N'-hexamethylene, IRGANOX® 215 (33/67 mixture of IRGANOX® 1010 with tris- (2,4-di-tert-butylphenyl) phosphite), IRGANOX® B225 (mixture 50 / 50 of IRGANOX® 1010 with tris- (2, 4-di-tert-butylphenyl) phosphite), and IRGANOX® B1171 (50/50 mixture of IRGANOX® 1098 with tris (2,4-di-tert-butylphenyl) phosphite) The process auxiliaries Preferred compositions include aluminum distearate and zinc stearate, particularly zinc stearate. The pigments include clear pigments such as inorganic siliceous pigments (silica pigments for example) and conventional pigments used in the coating compositions. Conventional pigments include metal oxides such as titanium dioxide, and iron oxide; metal hydroxides; metal flakes such as aluminum flake; chromates such as lead chromate; sulfides; sulfates; carbonates; carbon black; silica; talcum powder; china clay; blue and green phthalocyanine; organic reds; Organic brown and other organic pigments and dyes. Particularly preferred are pigments that are stable at high temperatures.

The pigments are generally formulated in a grinding base by mixing the pigments with a dispersant resin which may be the same as or compatible with the material into which the pigment is to be incorporated. The pigment dispersions are formed by conventional means such as sand grinding, ball milling, friction grinding or two roller milling. Other additives, while generally not necessary or used, such as glass fiber and mineral fillers, anti-slip agents, plasticizers, nucleating agents, and the like, can also be incorporated.

Preparation method In order to obtain the desired morphology (and resulting properties) in the mixtures in the ionomer / polyamide of the present invention, it is necessary to obtain a mixture of ionomer, particularly ethylene-acid copolymer with high acid content, which is highly neutralized , in a continuous polyamide phase (or co-continuous) even when the volume ionomer is greater than that of the polyamide. The present invention does this without the use of polymeric grafting agents containing certain reactive groups such as ethylene / n-butyl acrylate / glycidyl methacrylate and the ethylene / glycidyl methacrylate employed in the present US Patent No. 5,091,478 to Saltman . The correlation of percent by weight to percent by volume for the range of ethylene / methacrylic acid ionomer and nylon-6 employed in this invention is approximately as indicated in the following table.

At a high degree of neutralization, the viscosity of the ionomer will exceed that of the polyamide at the processing conditions. It has been found, however, that a process in which the ethylene-acid copolymer is first highly neutralized by methods known in the art, and then is blended in molten form under conditions of intense mixing with the nylon, is not preferred. Rather, a one-step process or "on-site neutralization" process is preferred. In this one-step process, ethylene-acid copolymers, preferably those with high acid levels, they are neutralized to their last level while the copolymers are being mixed with the polyamide under conditions of intense mixing. The ethylene-acid copolymer which is not neutralized (or low neutralized), with a high acid content, can be mixed in molten form in the polyamide with all its neutralization, which is carried out during the continuous mixing. The viscosity of the ethylene-acid copolymer in the non-neutralization or low neutralization will be lower than that of the nylon at the processing temperature (approximately 250 ° C to approximately 270 ° C for nylon-6), and nylon could be expected is dispersed in the ethylene-acid copolymer. The desired dispersion of the ionomer in the nylon can be caused by further neutralization while the ethylene-acid copolymers and the polyamides are being mixed under conditions of intense mixing. For example, nylon-6 (ULTRAMID® B3 available from BASF) has the following viscosities under molten-form mixing conditions (cutting speeds other than 240 ° C and 260 ° C). The data in the table is the viscosity of the polymer in pascals-seconds. As can be seen, the viscosity exceeds that of the SURLYN® 9120 ionomer (E / MAA 19% by weight, neutralized to 38% with zinc) available from E.l. du Pont de Nemours and Company in each case, but, after further neutralization up to 67-70%, the ratio changes.

* The viscosity of the highly neutralized ionomer at the cutting speed of 596-sec-1 and at the temperature of 260 ° C is estimated based on other measured data.

The processing can be greatly simplified if the ethylene-acid copolymer is partially neutralized but at a lower level than that desired at the end, before mixing in molten form of the nylon or, preferably, if the ionomers such as the various ionomers SURLYN ®, particularly those with high levels of acid, available from EI du Pont de Nemours and Company, are employed as the initial ionomer which is subsequently neutralized concurrently with or subsequent to mixing with the polyamide, at the desired neutralization percent. The initial ionomers can be made by processes well known in the art (see above). It should be noted that the ethylene-acid copolymers can reach a large range of viscosities through the pseudo-crosslinks obtained by partial neutralization of the carboxylic acids. As the degree of neutralization increases, the viscosity increases, eventually reaching a "no flow" state in a melt index (MI) test. The level of neutralization at which this occurs depends on factors well known to those of experience in the ionomer art (eg, the carboxylic acid type of 3 to 8 carbon atoms a, β-ethylenically unsaturated, the level of acid , and the type of cationic counterion). Typically, for a system with low acid content (approximately 10% by weight), the maximum neutralization is approximately 70%, but for systems with a high acid content, the conditions of "no flow" will occur at the lowest percentage of neutralization. . It is important that, before mixing with the polyamide, the neutralization percent should be sufficiently low so that the ethylene-acid / ionomer copolymer does not reach the "no-flow" state. Preferably, however, the neutralization percent must be sufficiently high so that the viscosity of the ethylene-acid copolymer is closer to that of the nylon at the start of mixing. Preferably, the viscosity should be within about 50 percent of the viscosity of the polyamide at the mixing temperature. By partially neutralizing, preferably, about 35 to about 40 percent of the acid, the viscosity of the ethylene-acid copolymer, the viscosity of the ethylene-acid copolymer is raised closer to that of the nylon at the start of mixing, while not reaching the state of "no flow". To achieve the desired morphology, the ethylene-acid copolymer preferably partially neutralized with a cation that is compatible with nylon, and the polyamide must be mixed in molten form under conditions of intense mixing (high cut) with subsequent neutralization as mixing occurs . The mixing should be at a sufficient intensity, temperature and residence time to obtain the desired morphology. An efficient devolatilization system is necessary to eliminate the water that forms during the neutralization process. The efficiency of devolatilization is more important if a low or no neutralization is started as more water will form. Preferably, there should be some vacuum zone in the molten composition with at least 630 mmHg of vacuum applied to remove moisture.

The various initial ingredients can be combined first with one another in what is commonly referred to as a "salt and pepper" mixture. These can also be combined by simultaneous or separate dosing, or these can be divided and mixed in one or more steps in one or more mixing sections of the mixing equipment, such as extruders, Banbury mixers, Buss kneaders, continuous mixers Ferrell or similar. If more than one feeding area is available, the nylon, the neutralizing agent preferably as a concentrate, and some of the ionomer, can be added to the feed gate in the most rear part with the rest of the ionomer that is added in the last feeding zone. The polymer strands exiting the extruder are preferably turned off in a water bath before being cut into pellets. Alternative methods well recognized by someone of skill in the art to form pellets, including underwater cutting and air quenching, can also be used. The preferred equipment for mixing is equipment such as that employed in the examples, particularly a twin screw extruder optionally equipped with a static mixer such as that sold by Kenics Company, located between the extruder screws and the die. The extruder used in the examples is preferably run at a screw speed of 175 to 250 rpm. The 16 sections of the bushings comprise feeding sections, mixing sections of kneading blocks (reaction), a vacuum extraction section with reverse thread screws, and a die section. Preferably, the mixing and the degree of neutralization must be sufficient to cause the phase inversion (the ionomer in bulk percent dispersed in the continuous or co-continuous nylon phase) in the mixing equipment. It should be recognized, however, that the complete inversion may not occur in the mixing equipment, but may result from further work of mixing in injection molding operations to form plates and the like. The differential scanning calorimeter (DSC) cooling exotherm can be easily and quickly determined and is a useful indicator of the morphology and sufficiency of the mixing conditions for the desired morphology.

The DSC cooling exotherm will differ depending on the nylon used, but can be easily determined by someone skilled in the art. Preferably, the DSC cooling exotherm when nylon 6 is used should be 160 ° C to 180 ° C when the cooling is carried out at a fast speed (for example 30 ° C / min). The presence of this exotherm indicates that the desired phase relationship has been reached. Tensile tests are also useful indicators of product morphology. When the morphology is correct, the ratio of Tension to Break (TB) at room temperature (23 ° C) to TB at elevated temperature (150 ° C) is preferably less than about 12 to 15.

Molded parts The molded parts of the mixture of the present invention, made using standard injection molding techniques, show high luster and improved resistance to the usual wear without the need for the addition of light grains. Without the addition of light grains, these molded parts show DOI's of at least 80 and as high as 90 to 95. Solid and metallic colors can be incorporated and parts can be painted. Since the blends allow processing faster than the resins used in the prior art dashboards, the molded parts can be more easily processed. The high temperature properties of the mixture are sufficient to allow the OEM painting of the molded parts, without the need for special fasteners or hangers to maintain the shape of the part during the baking step. The molded parts of the blends of this invention with the addition of standard UV stabilizers for the ionomer and the polyamide show surprising resistance to environmental conditions, particularly stability when exposed to ultraviolet light for extended periods of time. These molded parts show the lowest color displacement, measured using, for example, the CIÉ 1976 color scale (CIÉ LAB), necessary for the molded parts used in external explanations. These show color shift values of less than about 3 (a level considered suitable for outdoor automotive applications) when exposed to 2500 kilojoules / square meter in an apparatus to produce artificial Xenon arc climate (SAE J1960 ). The improved automotive instrument panels having DOI of at least 80 and superior resistance to the usual wear, can be made from the mixture of this invention.

EXAMPLES Process Except as otherwise indicated, mixing in each of the examples was in a twin screw extruder of 28 mm, with five heating zones, equipped with a Kenics Company static stirrer between the tip of the extruder and a die plate. with simple hole. The extruder in each case was operated at a screw speed of 200 revolutions per minute (rpm) with the vacuum or run gate at approximately 630 mm of mercury vacuum with ingredients fed at a rate of approximately 4.536 kg (10 pounds) per time to the rear feed zone of the extruder. A nitrogen atmosphere was maintained on the feed hopper. The temperature profile through the extruder nozzle was: Throat, approximately 25 ° C; Zone 1, 220 ° C; Areas 2, 3, 4 and 5, 250 ° C; Adapters 1 and 2, 250 ° C; and Die, 265 ° C. The residence time for the samples was approximately 2.5 minutes. The samples were turned off in a water bath (approximately 23 ° C) before cutting them into pellets. Except as otherwise indicated, the samples in each case were injection molded onto a 170 g (6 oz) capacity injection molding machine of a molding machine using a general purpose screw with the barrel temperature set to achieve melting temperatures in the range of 260 ° C. The molding conditions used were of fast initial speed, screw speed 60 rpm, back pressure of 3.51 kg / cm2 (50 pounds per square inch (psig)), injection pressure of 28.12-56.24 kg / m2 (400-800 psig), injection time, 20 seconds (sec. ), retention time, 30 sec., and 3.97 mm (5/32 inch) nozzle. The standard additive / stabilizer packages or packages were used in each case. Preferred packages include stabilizers for nylon and ionomer. The package, for example, may include various components as described above, including, for example, the stabilizers IRGANOX®, TINUVIN®, and CHIMMASORB®. The neutralization agent concentrates used in these examples are mixtures of the main neutralizing agent (for example zinc oxide in the ZnO Concentrate and magnesium hydroxide in the MgO Concentrate) in a copolymer carrier of ethylene / methacrylic acid with low per percent in weight (5 to 10) elaborated under conditions that assure the insignificant neutralization of the carrier. The concentrate may also contain low levels (up to 2% by weight) of metal salts such as acetates and stearates. The "percent" indicated with respect to the concentrate is the percent by weight (based on the total weight of the concentrate) of the main neutralizing agent in the concentrate. That is, the 50% MgO Concentrate used in the examples contains 50% by weight (based on the total weight of the concentrate) of magnesium oxide in an ethylene / 5% by weight copolymer of methacrylic acid. The 30% ZnO Concentrate contains 30% by weight (based on the total weight of the concentrate), zinc oxide in an ethylene / 5% methacrylic acid copolymer, and the 45% ZnO Concentrate contains 45% by weight (based on the total weight of the concentrate) of zinc oxide in an ethylene / 10% by weight methacrylic acid copolymer. Unless indicated otherwise, the nylon 6 used in the examples was the nylon 6 CAPRON® 8202 available from Allied Signal.Tests Tests on the injection molded test specimens (discs or plates, as the case may be) reported in the examples were the Tensile to Breakthrough (ASTM D1708) and Elongation to Breaking (ASTM D1708) at 23 ° C and 150 ° C, and the flexural module (ASTM D790A) at 23 ° C. The morphologies of the specimen were also examined with the Electronic Transmission Microscope (TEM). Very thin sectional samples of the specimens were cut in microtome, at cryogenic temperatures in the machine direction (parallel to the flow) and in the transverse direction (perpendicular to the flow). The samples were stained with phosphotungstic acid which binds to the nylon component and increases the contrast of the transmission image (the ionomer appears brighter and the darker nylon in high amplification photographs). The luster was measured using a Novo Lustrometer at an angle of 60 ° (standard black = 93.64).

Example 1 49. 8% by weight of nylon-6, 48.6% by weight of SURLYN® 9220 (E / 20% by weight of MAA, approximately 34% neutralized with zinc) further neutralized to approximately 75% with zinc and 1.6% by weight of Additive Package and Stabilizer, were fed to the extruder.

Example 2 4% by weight of the 45% zinc oxide concentrate was added to the extruder feed to further neutralize the ionomer (4% by weight of the ionomer was removed to represent the 45% ZnO concentrate, everything else as in Example 1 Example 3 Example 1 was run with the following changes: (a) SURLYN® 9220 was neutralized to approximately 67% with zinc, (b) the screw speed on the extruder was reduced to 150 rpm, and (c), the static mixer Kenics was not used.

Table 1 In Examples 1 and 2, the ionomer is observed as dispersed throughout the continuous nylon phase, mainly as spherical particles in the range of 0.1 to 0.2 μm (see Figure 1). In Example 3, the ionomer appears spherical in the sample cut perpendicular to the flow, but is distorted to a large extent in the cut sample parallel to the flow (see Figure 2). The ionomer and nylon appear to be co-continuous in Example 3.

Example 4 - Comparison to BEXLOY® W The SURLYN® ionomer / nylon mixture in Table II is a mixture of 55% by weight nylon blend, 43.4% by weight E / 19% by weight of MAA neutralized with 68% zinc, and 1.6% by weight of stabilizer package. BEXLOY® W 501 is a commercially available blend of polyolefin and ionomer without glass filler.

Table II Examples 5 - 25 Several series of experiments were run. Due to 'differences in the quality of the mold surface and in the operation of the molding machine, it is safer to compare the values within a series. In each example, a disc or test plate was molded and tested for mechanical and luster properties. The average results of five luster readings are described in Table III. The mechanical properties measured are described in Table VI (no measurements were made in cases where the data are not present).

First Series Example 5 55% by weight of nylon-6; 37% by weight of ionomer (E / 20% MAA initially approximately 40% neutralized with MG + 2) and 1.3% by weight stabilizer package were intensively mixed and further neutralized during mixing (in situ) with 6.7% by weight of 50% MgO Concentrate up to about 90%. The resulting disk had a very low luster value. Melt fracture was clearly evident during extrusion. The properties were poor.

Example 6 In a first step, SURLYN® 9220 was first neutralized with ZnO Concentrate at % up to about 72%. In a second step, 40% by weight of the resulting ionomer; 55% by weight of nylon-6; and 1.3% by weight of the stabilizer package were intensively mixed and neutralized in situ to approximately 100% with 3.7% by weight of 30% ZnO concentrate.

Example 7 40.0% by weight of the ionomer prepared in the first step of Example 6 were intensively mixed; 50% by weight of nylon-6; 5% by weight of SELAR® PA (6 isophthalic / 6 terephthalic) amorphous nylon; 3.7% by weight of the 30% ZnO Concentrate; and 1.3% by weight of stabilizer package.

Example 8 .0% by weight of the ionomer prepared in the first step of Example 6 were intensively mixed; 55% by weight of nylon-6; 5% by weight of SELAR®PA; 3.7% by weight of 30% ZnO concentrate; and 1.3% by weight of stabilizer package.

Example 9 In a single-pass process, 55% by weight of nylon-6 was intensively mixed; 37% by weight of E / 20% MAA neutralized with Mg + 2 up to about 40%; and 1.3% by weight of stabilizer package, and subsequently neutralized during mixing with 6.7% by weight of 30% ZnO concentrate to approximately 100% neutralization.

Example 10 In a one-step process, 37.2% by weight of SURLYN® 9220 was mixed intensively with 54% by weight of nylon-6; and 1.3% by weight stabilizer package, and neutralized in situ to approximately 100% with 7.5% by weight of 30% ZnO concentrate to approximately 95% neutralization.

Second Series Comparative example 11 61.95% by weight of ALATHON® 6580 polyethylene, 1.25% by weight stabilizer package, and 32.4% by weight of SURLYN® 9120 (E / 19% by weight of MAA neutralized by 38% with zinc) were fed to an extruder. they were mixed, neutralized further with 4.4% by weight of 30% ZnO concentrate to 76% neutralization. The high luster did not result even with the high acid ionomer and the high degree of neutralization.

Comparative Example 12 45% by weight of ALATHON® 7030 polyethylene, 51.2% by weight of SURLYN® 9120, and 0.8% by weight of the stabilizer package were fed to the extruder and while mixing, further neutralized with 3.0% by weight of 30% ZnO concentrate. % up to a neutralization of 57%. The high luster did not result even with the ionomer with high acid content and a moderate degree of neutralization.

Example 13 46% by weight of nylon-6, 43.6% by weight of SURLYN® 9120, and 1.8% by weight of the stabilizer package were fed to the extruder, and while mixing they were additionally neutralized with 8.6% by weight of 30% ZnO concentrate. up to about 97% neutralization.

Example 14 43% by weight of nylon-6, 49.05% by weight of SURLYN® 9120, and 1.8% by weight of the stabilizer package were fed to the extruder, and while mixing were additionally neutralized with 8.6% by weight of 30% ZnO concentrate and 0.55% by weight of CaO powder to approximately 100% neutralization.

Example 15 40% by weight of nylon-6, 48.95% by weight of SURLYN® 9120, and 1.8% by weight of stabilizer package, were intensively mixed and extruded and while mixing, further neutralized with 8.7% by weight of ZnO concentrate at 30% and 0.55% by weight of CaO powder up to approximately 100% neutralization.

Example 16 46% by weight of nylon-6, 49.6% of SURLYN® 9520, (E / 10% by weight of MAA neutralized with zinc up to 72% neutralization) and 1.8% by weight of stabilizer package, and while mixing were intensively mixed. further neutralized with 2.6% by weight of 30% ZnO concentrate to approximately 100% neutralization.

Third Series Example 17 45% by weight of nylon-6, 50.7% by weight of SURLYN® 9320, (E / 24% by weight of nBA / about 10% by weight of MAA, 67% neutralized with zinc) and 1.8% by weight were intensively mixed. of stabilizer package, and while mixing were additionally neutralized with 2.5% by weight of 30% ZnO concentrate to approximately 95% neutralization.

Example 18 45% by weight of nylon-6, 25.4% of SURLYN® 9320, plus 25.3% of SURLYN® were intensively mixed. 9520, and 1.8% by weight of stabilizer package, and further neutralized with 2.5% by weight of 30% ZnO concentrate to approximately 95% neutralization.

Example 19 45% by weight of Nylon-6, 25.2% of SURLYN® 9320, plus 25.3% of SURLYN® 9520, and 1.8% by weight of stabilizer package were intensively mixed, and further neutralized with 2.5% by weight of ZnO concentrate at 30% and 0.2% by weight of CaO powder up to approximately 100% neutralization.

Example 20 45% by weight of nylon 6 and 50.7% by weight of SURLYN® 9020 (E / 10% by weight of iBA / 10% by weight of MAA, 73% neutralized) and 1.8% by weight of stabilizer packing were intensively mixed, and then they were subsequently neutralized with 2.5% by weight of 30% ZnO concentrate to approximately 95% neutralization.

Example 21 45% by weight of nylon 6, 25.2% by weight of SURLYN® 9520 and 22.3% by weight of SURLYN® 9120 with high acid content, and 1.8% of stabilizer package and then neutralized further with 5.7% by weight were intensively mixed. of 30% ZnO concentrate to approximately 97% neutralization.

Example 22 45% by weight of nylon 6, 25.2% by weight of SURLYN® 9520 and 22.3% by weight of SURLYN® 9120 and 1.8% of the stabilizer package were intensively mixed and then further neutralized with 5.7% by weight of 30% ZnO concentrate. % up to about 97% neutralization.

Example 23 45% by weight of nylon 6, and 44.2% by weight of SURLYN® 9120, 1.8% of stabilizer package and 0.5% zinc stearate, were mixed intensively, and then further neutralized with 8.5% by weight of 30% ZnO concentrate. % up to about 97% neutralization.

Fourth Series Example 24 44% by weight of nylon 6 ULTRAMID®, 45.7% by weight of SURLYN® 9120, and 1.9% of stabilizer package plus 1.0% by weight of zinc stearate processing aid were mixed intensively, and then neutralized with 7.4% by weight of 30% ZnO concentrate to a neutralization of approximately 88%, and were extruded at vague speeds later in a twin screw extruder with a diameter of 40 mm. The samples were molded into 3.17 mm (1/8 inch) thick discs using the molding conditions described above and the mold temperatures given below. 24A: Extrusion Speed of 56.7 kg per hour (125 pounds per hour). Mold temperature of 60 ° C. 24B: Extrusion Speed of 56.7 kg per hour (125 pounds per hour). Mold temperature of 25 ° C. 24C: Extrusion Speed of 68.0 kg per hour (150 pounds per hour). Mold temperature of 25 ° C.

Example 25 44% by weight of nylon 6 ULTRAMID®, 46.9% by weight of SURLYN® 9120, and 1.9% by weight of stabilizer package plus 1.0% by weight of zinc stearate as a processing aid were mixed intensively, then neutralized with 6.2% by weight of 30% ZnO concentrate to a neutralization of approximately 80%, and extruded at the speeds given below. After drying in the vacuum oven for at least 8 hours at 80 ° C, the samples were molded into 3.17 mm (1/8 inch) thick discs using the molding conditions described above and the molding temperatures given below. . 25A: Extrusion Speed of 56.2 kg per hour (124 pounds per hour). Mold temperature of 60 ° C. 25B: Extrusion Speed of 45.3 kg per hour (100 pounds per hour). Mold temperature of 60 ° C. 25C: Extrusion Speed of 45.3 kg per hour (100 pounds per hour). Mold temperature of 25 ° C.

Table III (Luster Reading) (continued) Table IV (Mechanical Properties) (continued) ** EMAX (Elongation to maximum traction) *** Tests run at 95 ° C It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (27)

1. CLAIMS Having described the invention as above, the content is claimed as contained in the following: 1. A mixture of ionomer / polyamide of one or more polyamides, the polyamides forming a continuous or co-continuous phase, with one or more dispersed ionomers in this, the ionomer (s) are present in the range of 60 to 40 weight percent, and the polyamide (s) are present in the range of 60 to 40 weight percent, based on the total weight of the ionomer and the polyamide, the ionomer (s) are direct copolymer (s) comprising ethylene and 3- to 8-carbon, α-ethylenically unsaturated carboxylic acid, wherein the average acid of the direct copolymers before neutralization is present in a sufficiently high percentage, and wherein sufficient acid in the range of 65 to 100 mole percent of the acid, is neutralized with one or more metal cations to increase the viscosity of the ionomer (s). r above that of the polyamide (s) at the melting temperature.
2. 2. The ionomer / polyamide mixture according to claim 1, characterized in that the carboxylic acid of 3 to 8 carbon atoms, β-ethylenically unsaturated is methacrylic acid constituting 15 percent to 25 percent by weight of the direct copolymer of ethylene and methacrylic acid.
3. 3. The ionomer / polyamide mixture according to claim 1, characterized in that the carboxylic acid of 3 to 8 carbon atoms α, β-ethylenically unsaturated is acrylic acid constituting 14 percent to 25 weight percent of the direct ethylene copolymer and acrylic acid.
4. 4. The ionomer / polyamide mixture according to claim 1, characterized in that one or more of the direct copolymers further comprises a softening monomer selected from alkyl acrylate and alkyl methacrylate.
5. 5. The ionomer / polyamide mixture according to claim 4, characterized in that the direct copolymers are present as a mixture of one or more dipolymers wherein the acid before neutralization in the polymer is present in a high percentage, and one or more E / X / Y copolymers where E is ethylene, X is the softening monomer selected from alkyl acrylate and alkyl methacrylate, and Y is carboxylic acid of 3 to 8 carbon atoms, β-ethylenically unsaturated, the acid level of the mixture before neutralization.
6. 6. The ionomer / polyamide mixture according to claims 1, 2, 3, 4 or 5, characterized in that the metal cation also interacts with the amide bonds of the polyamide.
7. 7. The ionomer / polyamide mixture according to claim 6, characterized in that the cation is zinc.
8. 8. The ionomer / polyamide mixture according to claim 1, characterized in that the ionomer is dispersed as mainly spherical particles having an average diameter of from about 0.1 to about 0.2 μm or as ellipsoid particles having an axis length of less than about 0.1 up to approximately 0.2 μm.
9. 9. The ionomer / polyamide mixture according to claim 1, characterized in that the ellipsoid particles have a ratio of the length of the axis greater than the length of the minor axis, greater than about 10 to 1.
10. 10. The ionomer / polyamide mixture according to claim 1, characterized in that the polyamides comprise semicrystalline polyamides.
11. 11. The ionomer / polyamide mixture according to claim 10, characterized in that the polyamide comprises polyepsiloncaprolactam (nylon 6).
12. 12. The ionomer / polyamide mixture according to claim 10, characterized in that the polyamides comprise a mixture of semicrystalline polyamides and up to about 10% by weight of amorphous polyamide based on the total weight of the polyamide.
13. 13. The ionomer / polyamide mixture according to claim 12, characterized in that the amorphous polyamide is terpolymer of hexamethylenediamine isophthalamide / terephthalamide.
14. 14. The ionomer / polyamide mixture according to claim 1, characterized in that it also comprises one or more UV stabilizers for the ionomer and the polyamide.
15. 15. An article, characterized in that it is molded from the ionomer / polyamide mixture according to claim 1.
16. 16. The article according to claim 15, characterized in that the ionomer / polyamide mixture from which it is molded further comprises one or more UV stabilizers for the ionomer and the polyamide.
17. 17. The article according to claim 16, characterized in that it is in the form of a car dashboard.
18. 18. The article according to claim 17, characterized in that the automobile instrument panel is a shock absorber having a DOI of at least 80.
19. 19. A process for the manufacture of a mixture of about 60 to about 40% by weight of one or more ionomers in a continuous or co-continuous phase of about 40 to about 60% by weight of one or more polyamides, characterized in that the process comprises mixing in molten form, under conditions of intense mixing, of the components consisting essentially of one or more direct copolymers of ethylene / carboxylic acid of 3 to 8 carbon atoms to, β-ethylenically unsaturated, having a high level of acid carboxylic acid of 3 to 8 carbon atoms a, β-ethylenically unsaturated and one or more polyamides, and, while mixing, the acid is neutralized with one or more metal cations, sufficiently to raise the viscosity of the ionomer resulting from neutralizing the copolymer direct to a higher level than that of polyamide at melting temperatures.
20. 20. The process according to claim 19, characterized in that the ionomer is present in a higher percentage by volume than the polyamide.
21. 21. The process according to claim 19, characterized in that the cation also interacts with the amide bonds of the polyamide.
22. 22. The process according to claim 21, characterized in that the cation is zinc.
23. 23. The process according to claim 19, characterized in that one or more direct copolymers are partially neutralized before mixing in molten form, with the polyamide.
24. 24. The process according to claim 23, characterized in that the degree of neutralization before mixing in molten form is from about 35 to about 40 percent.
25. 25. The process according to claim 19, characterized in that the level of acid in the direct copolymer before neutralization is high.
26. 26. The process according to claim 25, characterized in that the acid in the direct copolymer is methacrylic acid present in a range of 15 to 25% by weight of the copolymer, or is acrylic acid present in a range of 14 to 25% by weight of the copolymer.
27. 27. The process according to claim 26, characterized in that the neutralization while mixing is at a percentage neutralization of at least 65%.