Title of Invention

MOLDING COMPOSITION BASED ON POLYETHERAMIDES

Abstract

A molding composition which comprises the following components: I. from 97 to 80 parts by weight of a polyetheramide based on a linear aliphatic diamine having from 6 to 14 carbon atoms, on a linear aliphatic or aromatic dicarboxylic acid having from 6 to 14 carbon atoms, and on a polyetherdiamine which has at least 3 carbon atoms per ether oxygen and has primary amino groups at the chain ends, II. from 3 to 20 parts by weight of a rubber containing functional groups, where the total of the parts by weight of I. and II. is 100, is suitable for the extrusion of flexible pipes, and also for the production of flexible blow moldings.

Full Text

Molding composition based on polyetheramides The invention relates to polyetheramide molding compositions with excellent heat resistance and hydrolysis resistance, and with suitability for the extrusion of flexible pipes, and for the production of flexible blow moldings. Plasticized semicrystalline polyamide molding compositions, in particular based on PAll or PA 12, have long been extruded to give pipes for use in automotive construction, since they have excellent mechanical strength and chemicals resistance. However, these moldings stiffen after a short period of use at the high usage temperatures increasingly demanded in recent times under the engine hood, this being due to the volatility of the external plasticizers used. In addition, when exposed to pressure they have a tendency toward irreversible deformation at the increased usage temperatures now demanded, from 110 to 150°C. Although these disadvantages can be avoided by using molding compositions based on higher-melting polyetheresteramides, for example as described in EP-A-0 095 893, this class of polyamide elastomer is unsuitable for producing pipes usable for the abovementioned applications, since in relation to the hydrolysis resistance also demanded for this application these molding compositions fall far short of the resistance of traditional polyamide molding compositions, and fail after just a few weeks. The object is therefore to produce hydrolysis-resistant molding compositions with high heat resistance and with high melt viscosity, these therefore being readily capable of extrusion or blow molding. The resultant moldings should, without any need for use of external plasticizers, have adequate long-lasting flexibility and also very good low-temperature impact strength. This object is achieved by way of a molding composition which comprises the following components: I. from 97 to 80 parts by weight, preferably from 95 to 85 parts by weight, of a polyetheramide based on a linear aliphatic diamine having from 6 to 14 carbon atoms, on a linear aliphatic or aromatic dicarboxylic acid having from 6 to 14 carbon atoms, and on a polyetherdiamine which has at least 3 carbon atoms per ether oxygen and has primary amino groups at the chain ends, II. from 3 to 20 parts by weight, preferably from 5 to 15 parts by weight, and particularly preferably from more than 5 to 15 parts by weight, of a rubber containing functional groups, where the total of the parts by weight of I and II. is 100, III. from 0 to 50% by weight, preferably from 0.1 to 30% by weight, particularly preferably from 1 to 20% by weight, based on the molding composition, of other polymers, and IV. from 0 to 10% by weight, based on the molding composition, of conventional additives. Polyetheramides are known in principle, e.g. from DE-A 30 06 961. However, the polyetheramides based on caprolactam or laurolactam and described in more detail in that reference cannot be used, since firstly their melting points are too low and secondly their melt viscosities are too low. The polyetheramides to be used according to the invention as component I have a melting point Tm to ISO 11357 which is preferably at least 160°C and particularly preferably at least 175°C, a relative solution viscosity Tirei which is preferably at least 1.80 and particularly preferably at least 1.85, measured in a 0.5% strength by weight solution in m-cresol at 23°C to ISO 307, and a zero-shear viscosity at 220°C which is preferably at least 500 Pas, particularly preferably 800 Pas, measured in a mechanical spectrometer (cone/plate) to ASTM D 4440. The resultant molding composition of the invention is ideally intended to have a zero-shear viscosity above 2 000 Pas and in particular above 5 000 Pas at 220°C, measured in the same way to ASTM D 4440, since otherwise stable extrusion with retention of dimensions to give the desired pipes or other moldings is impossible, or possible only within a temperature range which is too narrow for cost-effective manufacture. If the abovementioned melt viscosities or solution viscosities of the polyetheramides are achieved or exceeded, the incorporation of the rubber of component II then leads without difficulty to the desired additional increase in melt viscosity. Examples of a diamine used in preparing the polyetheramide are 1,6-hexamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, and 1,12-dodecamethylenediamine. Examples of the dicarboxylic acid used are adipic acid, suberic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, terephthalic acid and 2,6-naphthalenedicarboxylic acid. Suitable polyetherdiamines are obtainable via conversion of the corresponding polyetherdiols through reductive amination, or coupling to acrylonitrile with subsequent hydrogenation (e.g. EP-A-0 434 244; EP-A-0 296 852). They generally have a number-average molecular weight of from 230 to 4 000, their proportion in the polyetheramide preferably being from 5 to 50% by weight. Commercially available polyetherdiamines derived from propylene glycol are available from Huntsman as JEFFAMIN® D grades. In principle, polyetherdiamines derived from 1,4-butanediol or 1,3-butanediol also have good suitability, as have polyetherdiamines of mixed structure, e.g. with random or block distribution of the units derived from diols. A desirable degree of difunctionality in the polyetherdiamines intended for use, expressed in terms of the molar proportion of acetylatable amino and hydroxy end groups, is generally at least 95%, and preferably at least 98%, and the desired diamine content here is at least 90%, preferably at least 95%, for example as determined acidimetrically. In view of the high molar masses which have to be achieved, it is hardly necessary to mention the further requirement for approximate equivalence between the dicarboxylic acid used and the entirety of diamine and polyetherdiamine. Practical amino : carboxy molar ratios used are from 0.98 : 1 to 1.02:1. With a view to the desired build-up of molecular weight, side reactions which adversely affect the end groups or cleave the chains have to be very substantially suppressed. The practical temperature range for the melt polycondensation is therefore restricted to from 220 to about 245 °C, the low limit resulting from the melting points of the underlying poly amides and the upper limit from the start of thermal decomposition of the polyetherdiamines. Suprisingly drastic conditions have to be selected for any solid-phase post-condensation which may have to be carried out: whereas experience has shown that temperatures of from 155 to 165°C are sufficient for aliphatic polyamides, such as PA612, PAIOIO, PA1012, or PA1212, post-condensation temperatures of from 165 to 185°C are required for the polyetheramides derived from these and used according to the invention. In order to avoid caking, the solid-phase post-condensation temperature should not be higher than 10 K below the crystallite melting point Tm. It will be obvious to the person skilled in the art that post-condensation is carried out either under high vacuum or in a stream of inert gas. A possible reason for the relatively low post-condensation activity of the polyetheramides may be that the reactivity of their amino end groups, which are to some extent sterically hindered, is lower than that of conventional amino end groups deriving from aliphatic diamines. It is preferably that at least 30% of the end groups in the resulting polyetheramide are amino end groups, and it is particularly preferable that at least 50% of the end groups, in particular at least 60% of the end groups, are amino end groups. By way of example, the rubber used according to the invention is a copolymer selected from the group - ethylene-a-olefin copolymers containing anhydride groups, - styrene-ethylene/butylene block copolymers containing anhydride groups, - ethylene-glycidyl (meth)acrylate copolymers, - ethylene-(meth)acrylate-glycidyl (meth)acrylate terpolymers, and/or - ethylene-(meth)acrylate-a,p-unsaturated carboxylic anhydride terpolymers. The ethylene-a-olefin copolymer containing anhydride groups is prepared in a known manner by free-radical reaction of an ethylene-a-olefin copolymer with an a,P-imsaturated dicarboxylic anhydride or with a precursor thereof, e.g. maleic anhydride, monobutyl maleate, maleic acid, fumaric acid, aconitic acid, itaconic acid, or itaconic anhydride. The ethylene-a-olefin copolymer may, by way of example, be an ethylene-C3-C12-a-olefin copolymer having from 20 to 96% by weight, preferably from 25 to 85% by weight, of ethylene, or an ethylene-C3-C12-a-olefin-unconjugated diene terpolymer having from 20 to 96% by weight, preferably from 25 to 85% by weight, of ethylene, and having up to at most about 10% by weight of an unconjugated diene, such as bicyclo[2.2.1 ]heptadiene, 1,4-hexadiene. dicyclopentadiene, or 5-ethylidenenorborene. By way of example, propene, 1-butene, l-pentene, 1-hexene, 1-octene, 1-decene, or 1-dodecene is suitable as C3-Ci2-a-olefin. Typical examples are ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), ethylene-butylene rubber, LLDPE (linear low-density polyethylene), and VLDPE (very-low-density polyethylene). The copolymer generally contains from 0.5 to 6% by weight, preferably from 1 to 5% by weight, and particularly preferably from 2 to 4% by weight, of units which derive from the a,p-unsaturated dicarboxylic anhydride. The styrene-ethylene/butylene block copolymers used preferably comprise styrene-ethylene/butylene-styrene block copolymers (SEBS), these being obtainable via hydrogenation of styrene-butadiene-styrene block copolymers. However, it is also possible to use diblock systems (SEB) or multiblock systems. Block copolymers of this type are prior art. The styrene-ethylene/butylene block copolymer containing anhydride groups is prepared in a known manner via free-radical reaction of a styrene-ethylene/butylene block copolymer with an a,p-unsaturated dicarboxylic anhydride or with a precursor thereof, e.g. maleic anhydride, monobutyl maleate, maleic acid, fumaric acid, aconitic acid, itaconic acid, or itaconic anhydride. The block copolymer generally contains from 0.5 to 6% by weight, preferably from 1 to 5% by weight, and particularly preferably from 2 to 4% by weight, of units which derive from the a,p-unsaturated dicarboxylic anhydride. The units substantively present in the ethylene-glycidyl (meth)acrylate copolymers are usually those of the following monomers: - from 20 to 98% by weight, preferably from 30 to 97% by weight, and particularly preferably from 40 to 96% by weight, of ethylene, and - from 2 to 80% by weight, preferably from 3 to 70% by weight, and particularly preferably from 4 to 60% by weight, of glycidyl acrylate and/or glycidyl methacrylate. The units substantively present in the ethylene-(meth)acrylate-glycidyl (meth)acrylate terpolymer are usually those of the following monomers: - from 20 to 97.9% by weight, preferably from 30 to 69.9% by weight, and particularly preferably from 40 to 95.9% by weight, of ethylene, - from 0.1 to 78% by weight, preferably from 1 to 67% by weight, and particularly preferably from 2 to 56% by weight, of an acrylate and/or methacrylate with a C1-C12 alcohol, and - from 2 to 80% by weight, preferably from 3 to 70% by weight, and particularly preferably from 4 to 60% by weight, of glycidyl acrylate and/or glycidyl methacrylate, where, by way of example, the acrylates or methacrylates used comprise the following compounds: methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, dodecyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and/or 2-ethylhexyl methacrylate. The units substantively present in the ethylene-(meth)acrylate-a,P-unsaturated carboxylic anhydride terpolymer are usually those of the following monomers: - from 20 to 97.5% by weight, preferably from 30 to 95% by weight, and particularly preferably from 40 to 92% by weight, of ethylene, - from 2 to 79.5% by weight, preferably from 4 to 69% by weight, and particularly preferably from 6 to 58% by weight, of an acrylate or methacrylate, and - from 0.5 to 6% by weight, preferably from 1 to 5% by weight, and particularly preferably from 2 to 4% by weight, of an a, P-unsaturated carboxylic anhydride, where, by way of example, the compounds mentioned by way of example at an earlier stage may be used as acrylate or methacrylate, or as a,p-unsaturated carboxylic anhydride or its precursor. Suitable polymers of component III are predominantly those which are compatible with the polyetheramide, an example being a polyamide. It is preferable to use a polyamide whose type is the same as that of the hard sequences of the polyetheramide. The polyamide advantageously has a relative solution viscosity n rel of at least 1.9. Suitable additives which may be mentioned for component IV are predominantly stabilizers, conductivity black, flame retardants, e.g. melamine cyanurate, pigments, and processing aids. Polymers included in the definition of component III are excluded here. The incorporation of the copolymer of component II, and, where appropriate, of the additives of components III and IV, takes place in the melt, with shear, for example in a twin-screw extruder or co-kneader. By way of example, the inventive molding composition may be processed via extrusion, conventional blow molding or 3D blow molding, e.g. parison extrusion into an open half of a mold, 3D parison manipulation, or 3D suction blow molding, or sequential blow molding to produce hard/soft composites, or via any other blow molding procedure. Other methods of processing the molding composition are coextrusion, coextrusion blow molding, coextrusion 3D blow molding, coextrusion suction blow molding, etc. to give a multilayer composite. The molding composition may also be processed by injection molding, and this includes versions of the process such as GIT (internal gas pressure technique) or WIT (water injection technique). Examples of products which may be produced by the processes mentioned are single-layer pipes and multilayer pipes. These pipes may be smooth or have corrugation in some regions or throughout. The molding composition is also used for the production of profiles of any type, such as sealing profiles, or hollow articles, e.g. containers. Examples of uses of the moldings produced according to the invention are in motor vehicle construction, in mechanical engineering and chemical engineering, and in medical technology, in particular as a subatmospheric-pressure line, e.g. for brake servos, an air line, a pressure hose, such as a compressed air line, a control line, a coolant line, a fuel line, a ventilation line, a windshield-wash system line, a line for hydraulic coupling systems, a servo control line, a line for air-conditioning systems of motor vehicles, a cable sheath or wire sheath, a line for the mechanical or chemical engineering sector, or m medical technology, or an injection-molded part of an oil filter or of a fuel filter. These moldings are likewise provided by the invention. The invention is illustrated by way of example below. Preparation of the polvetheramide: A 200 1 stirred autoclave was charged with the following starting materials: 26.11 kg of hexamethylenediamine in the form of a 75% strength aqueous solution, 52.94 kg of 1,12-dodecanedioic acid, 25.55 kg of JEFFAMIN®D400, 100 g of a 50% strength aqueous solution of hypophosphorous acid. The starting materials were melted under nitrogen and heated, with stirring, to about 220°C in the sealed autoclave, the resultant internal pressure being about 20 bar. This internal pressure was retained for 2 hours, and then the melt was heated further to 230°C, with continuous depressurization to atmospheric pressure, and then held for 1.5 hours at this temperature in a stream of nitrogen. The vessel was then evacuated to 28 mbar within a period of 3 hours, and held for a further 3 hours at this pressure, until the indicated torque showed no further rise in melt viscosity. The melt was then discharged by gear pump and strand-pelletized. The pellets were dried for 24 hours under nitrogen at 80°C. The properties of the product were as follows: Crystallite melting point Tm: 193°C Relative solution viscosity n rel: 1.91 COOH end groups: 21 mmol/kg Amino end groups: 26 mmol/kg On the basis of the ratio of the monomers used, this polyetheramide formally has a PA612 block with an average molecular weight of 1 083. 50 kg of these pellets were post-condensed for 24 hours at 175°C jacket temperature under nitrogen (250 1/h) in a tumbling dryer of capacity 2501. After this time, the properties of the product were as follows: Crystallite melting point Tm: 193°C Relative solution viscosity n rel: 2.06 COOH end groups: 14 mmol/kg Amino end groups: 20 mmol/kg Preparation of the molding compositions: The mixing specification for the molding compositions is given in parts by weight. The individual constituents of the mixing specification were incorporated in a twin-screw extruder from Werner & Pfleiderer, the barrel temperature being 250°C. It is apparent that a marked improvement in notched impact strength both at room temperature and at -40°C is obtained when the fall-off in modulus of elasticity resulting from the rubber addition is compensated by simultaneous addition of polyamide. The modulus of elasticity can be adjusted as desired via the mixing ratio of the components. The melt viscosity of the molding compositions obtained in examples 1 to 6 was higher than that of the reference molding composition, and at the same time they had higher pseudoplasticity (gradient of curve of melt viscosity plotted against shear), this making them particularly suitable for extrusion applications or blow molding applications. What is claimed is: 1. A molding composition which comprises the following components: I. from 97 to 80 parts by weight of a polyetheramide based on a liner aliphatic diamine having from 6 to 14 carbon atoms, on a linear aliphatic or aromatic dicarboxylic acid having from 6 to 14 carbon atoms, and on a polyetherdiamine which has at least 3 carbon atoms per ether oxygen and has primary amino groups at the chain ends, II. from 3 to 20 parts by weight of a rubber containing functional groups, where the total of the parts by weight of I. and II. is 100. 2. The molding composition as claimed in claim 1, wherein the amount present of component I. is from 95 to 85 parts by weight, and the amount present of component 11. is from 5 to 15 parts by weight. 3. The molding composition as claimed in any of the preceding claims, wherein the amount present of component II. is more than 5% by weight. 4. The molding composition as claimed in any of the preceding claims, wherein the polyetheramide of component I has a crystallite melting point Tm of at least 160°C. 5. The molding composition as claimed in claim 4, wherein the crystallite melting point Tm is at least 175°C. 6. The molding composition as claimed in any of the preceding claims, wherein the relative solution viscosity T rel of the polyetheramide is at least 1.80. 7. The molding composition as claimed in claim 6, wherein the relative solution viscnsity n rel of the polyetheramide is at least 1.85. 8. The molding composition as claimed in any of the preceding claims, wherein the zero-shear viscosity of the polyetheramide at 220°C is at least 500 Pas. 9. The molding composition as claimed in claim 8, wherein the zero-shear viscosity of the polyetheramide at 220°C is at least 800 Pas 10. The molding composition as claimed in any of the preceding claims, wherein the polyetherdiamine used to prepare the polyetheramide has a number-average molecular weight of from 230 to 4 000. 11. The molding composition as claimed in any of the preceding claims, wherein that fraction of the polyetheramide which derives from the polyetherdiamine is from 5 to 50% by weight. 12. The molding composition as claimed in any of the preceding claims, whose zero-shear viscosity at 220°C is at least 2 000 Pas. 13. The molding composition as claimed in claim 12, whose zero-shear viscosity at 220°C is at least 5 000 Pas. 14. The molding composition as claimed in any of the preceding claims, which comprises, based on the molding composition, at most 50% by weight of other polymers. 15. The molding composition as claimed in any of the preceding claims, which comprises, based on the molding composition, at most 10% by weight of conventional additives. 16. The molding composition as claimed in any of the preceding claims, wherein component 11. has been selected from the group - ethylene-a-olefin copolymers containing anhydride groups, - styrene-ethylene/butylene block copolymers containing anhydride groups, - ethylene-glycidyl (meth)acrylate copolymers, - ethylene-(meth)acrylate-glycidyl (meth)acrylate terpolymers, and/or - ethylene-(meth)acrylate-a,P-unsaturated carboxylic anhydride terpolymers. 17. A molding produced from the molding composition as claimed in any of the preceding claims. 18. The molding as claimed in claim 17, produced by extrusion, coextrusion, blow molding, 3D blow molding, coextrusion blow molding, coextrusion 3D blow molding, coextrusion suction blow molding, or injection molding. 19. The molding as claimed in claim 17 or 18, which is a single-layer pipe, a multilayer pipe, a profile, or a hollow article. 20. The molding as claimed in any of claims 17 to 19, which is a subatmospheric-pressure line, e.g. for brake servos, an air line, a compressed air line, a control line, a coolant line, a fuel line, a ventilation line, a windshield-wash-system line, a line for hydraulic coupling systems, a servo control line, a line for air-conditioning systems of motor vehicles, a cable sheath or wire sheath, a line for the mechanical or chemical engineering sector, or in medical technology, or an injection-molded part of an oil filter or of a fuel filter. 21. The use of the molding composition as claimed in any of claims 1 to 16 for producing moldings by means of extrusion or blow molding. 22. A molding composition, substantially as herein described and exemplified.

Documents:

641-CHE-2004 AMENDED PAGES OF SPECIFICATION 03-08-2011.pdf

641-CHE-2004 AMENDED CLAIMS 03-08-2011.pdf

641-che-2004 form-1 03-08-2011.pdf

641-che-2004 form-3 03-08-2011.pdf

641-CHE-2004 OTHER PATENT DOCUMENT 03-08-2011.pdf

641-CHE-2004 EXAMINATION REPORT REPLY RECEIVED 03-08-2011.pdf

641-CHE-2004 CORRESPONDENCE OTHERS 22-12-2010.pdf

641-CHE-2004 CORRESPONDENCE OTHERS.pdf

641-CHE-2004 CORRESPONDENCE PO.pdf

641-CHE-2004 FORM-18.pdf

641-CHE-2004 FORM-3.pdf

641-CHE-2004 FORM-13 5-01-2010.pdf

641-che-2004-abstract.pdf

641-che-2004-claims.pdf

641-che-2004-correspondnece-others.pdf

641-che-2004-description(complete).pdf

641-che-2004-form 1.pdf

641-che-2004-form 26.pdf

641-che-2004-form 3.pdf

641-che-2004-form 5.pdf

641-che-2004-other documents.pdf