In this patent document the term"polymer"refers to a thermoplastic polymer, unless mentioned expressly otherwise.

Combinations of polymers are of great commercial interest because of the potential to combine the valuable attributes of a number of polymers into one composition.

Multi-layer structures of two or more polymers are widely used in e. g. barrier packaging and pipe applications where the barrier properties of one material are combined with the low cost and mechanical properties of another.

Also the blending of polymers can result in desirable combinations of, for example, barrier/cost, chemical resistance/dimensional stability, toughness/strength.

It is well known that most polymer combinations are mutually not miscible, which means that upon blending they do not form a blend which consists of a single phase. The non-miscible polymers frequently do not have enough interaction to generate strong interfacial bonding. Weak interfacial bonding results in de- lamination and loss of properties. The compatibilization of the polymer/polymer interface, i. e. the achievement of a lower interfacial tension or an improved physical or chemical interaction, is of critical importance as this leads to the strong interfacial bonds necessary to achieve and maintain the desired properties of the

polymer combination. The desired properties are better maintained in the case of strong interfacial bonds because the strong interfacial bonds prevent the ingress in the interface of water or other liquids such as hydrocarbons, i. e. so-called wetting, which would otherwise result in a weakening of the interfacial bonds.

Polymers of carbon monoxide and olefinically unsaturated compounds, which are commonly called polyketones or polyketone polymers, have been known and are available for some time. Of particular interest are the alternating polyketone polymers, disclosed in numerous patent documents, for example in US-A-4880865 and US-A-4818811. Polyketone polymers have excellent mechanical and chemical resistance and barrier properties which make them particularly attractive for use in combination with other polymers.

WO-95/16744 discloses a polymer composition which is a combination of (a) a first polymer which is a polyketone polymer, (b) a second polymer which is not miscible with the polyketone polymer, and (c) a compatibilizing polymer which is obtainable by reacting a diamine with a polymer comprising carboxyl groups.

The compatibilizing polymer of WO-95/16744 is in particular a maleic anhydride grafted polymer, thus carrying groups of a 5-membered cyclic anhydride (i. e. a succinic anhydride group or-formally-a 2,4-dioxo-3- oxacyclopentyl group), which is reacted with a diamine having two primary amino groups.

The polymer compositions of WO-95/16744 can be in the form of a polymer blend which can be obtained by a melt blending process, wherein the compatibilizing polymer is thought to be present as a layer between the polyketone polymer and the second polymer. The polymer compositions

can also'be in the form of a multi-layer structure which can be obtained by (co-) extruding the compatibilizing polymer as an adhesive layer between a layer of the polyketone polymer and a layer of the second polymer.

Examples of such structures are multi-layer pipes and multi-layer sheets and films. The compatibilizing polymer can also be used as a coating layer for a polyketone polymer object, in which case no second polymer will be present.

In the polymer compositions of WO-95/16744 the interfacial bonding with the polyketone polymer is thought to result from a grafting reaction of the polyketone polymer with the amine, in which reaction pyrrole structures may be formed from 1,4-diketone moieties occurring in the polyketone polymer backbone and/or imine (Schiff's base) structures may be formed from single ketone groups.

However, problems may be met with the polymer compositions of WO-95/16744 when they are used for producing objects of larger dimensions. Producing such larger objects frequently requires a longer residence time of the polymers at a high temperature. During the processing at the high temperature which is normally employed there is an increase of the melt viscosity as time progresses and there is a tendency to form gels.

These lead to a poor stability of the processing operation, to the formation of bubbles or lumps and-when multi-layer structures are produced-to an uneven distribution of the layers, for example forming a so- called waves pattern. The gels may deteriorate the performance properties of the polymer compositions. For example, they may act as stress concentrators, thereby decreasing the impact resistance.

Without wishing to be bound by any theory, it is thought that these phenomena are caused by cross-linking

occurring during the processing at high temperature, in particular at longer residence times. Namely, it is known that the compatibilizing polymers of WO-95/16744, as well as the polyketone polymers, show a tendency to cross-link at temperatures which are typical for the melt processing. Further, it is well conceivable that the basic and nucleophilic amino groups of the compatibilizing polymer have a further worsening effect on the polyketone polymer in its tendency to cross-link.

Various measures are known in the art for combating cross-linking of the compatibilizing polymer, cf. e. g.

US-A-5373065, WO-96/27622. For example, it has been proposed to use the diamine in the form of a neutralised salt. Another approach involves end-capping of the amino group of the diamine which remains after its reaction with the polymer comprising carboxyl groups. To this end, amidation/imidation reactions with acetic anhydride or n-octenylsuccinic anhydride and formamide forming reactions with formyl compounds have been proposed. Yet another proposal is applying the diamine in an excess with respect to the carboxyl groups. However, none of these approaches are considered practicable as they require additional steps in the preparation or work-up of the compatibilizing polymer.

Summary of the invention It has now unexpectedly been found that a substantial improvement in the situation of WO-95/16744 can be achieved by applying a compatibilizing polymer which is a reaction product of an amine and a polymer which carries groups of a carboxylic acid (i. e. formally hydroxycarbonyl groups), as opposed to groups of the succinic anhydride. The amine in question comprises at least a primary amino group which is attached to an aliphatic carbon atom which carries at most one hydrogen atom. This particular combination of reactants leads to

a much reduced tendency of the polymer composition to increase in viscosity during its melt processing and to form gels whilst, on the other hand, the compatibilizing polymer exerts strong interfacial bonds with the polyketone polymer. To the skilled person this is all a surprising result because he would expect that any change in the nature of the amino groups resulting in less reactivity in cross-linking reactions should go hand-in- hand with a reduced interaction of the amine with the polyketone polymer interface, which interaction is thought to be necessary for obtaining good interfacial bonding.

Another special and unexpected feature is that the molar quantity of the amine relative to the carboxylic acid groups may be kept low, for example below 0.1 mole/mole. Not only that this leads to less cross- linking, this is also advantageous because less of the amine can be used which is significant from the point of view of economy and also environment, health and safety.

Further, at a low quantity of the amine used, carboxylic acid groups remain unconverted in the compatibilizing polymer, which makes the polymer also suitable for use as the compatibilizing polymer in combination with other polar polymers as the second polymer, such as polyamides and poly (vinyl alcohol) s.

Accordingly, the present invention relates to a polymer composition comprising a combination of (a) a first polymer which is a polyketone polymer, (b) optionally a second polymer which is not miscible with the polyketone polymer, and (c) an amine modified polymer which is obtainable by reacting an amine with a third polymer, which amine comprises two primary amino groups at least one of which is attached to an aliphatic carbon atom which carries at

most one hydrogen atom, and which third polymer is a polymer comprising carboxylic acid groups.

The invention also relates to a process for preparing the polymer compositions according to this invention which comprises at least a step of contacting the polyketone polymer and optionally the second polymer with the amine modified polymer.

The invention also relates to the amine modified polymer of this invention, as far as it is obtainable by applying in the reaction of the amine with the third polymer a molar ratio of the amine to the carboxylic acid groups of less than 0.1, in particular less than 0.05.

In addition the invention relates to a kit of parts suitable for producing a composition according to this invention, of which kit of parts (a) a first part comprises a first polymer which is a polyketone polymer, (b) an optional, second part comprises a second polymer which is not miscible with the polyketone polymer, and (c) a third part comprises an amine modified polymer which is obtainable by reacting an amine with a third polymer, which amine comprises two primary amino groups at least one of which is attached to an aliphatic carbon atom which carries at most one hydrogen atom, and which third polymer is a polymer comprising carboxylic acid groups.

Detailed description of the invention The polyketone polymers for use in this invention are polymers of carbon monoxide and at least one olefinically unsaturated compound. In particular, they are linear alternating copolymers of carbon monoxide and the olefinically unsaturated compound (s). In the linear alternating polymers the monomer units of carbon monoxide alternate with the monomer units of the olefinically unsaturated compound (s), which implies that the polymers

contain one monomer unit of carbon monoxide for each monomer unit of the olefinically unsaturated compound (s).

Suitable olefinically unsaturated compounds comprise up to 20 carbon atoms and include compounds which comprise exclusively carbon and hydrogen and compounds which in addition comprise hetero atoms, such as unsaturated esters, ethers and amides. Unsaturated hydrocarbons are preferred. Examples of suitable olefinically unsaturated compounds are aliphatic a-olefins, such as ethene, propene and butene-1, cyclic olefins such as cyclopentene, aromatic compounds, such as styrene and a- methylstyrene and vinyl esters, such as vinyl acetate and vinyl propionate. The preferred polyketone polymers are linear alternating polymers of carbon monoxide and ethene or linear alternating polymers of carbon monoxide, ethene and another olefinically unsaturated compound of at least 3 carbon atoms, particularly an a-olefin such as propene or butene-1.

When the preferred polyketone polymers of carbon monoxide, ethene and another olefinically unsaturated compound are employed, there will be within the polymer typically at least 2 units incorporating a moiety of ethene for each unit incorporating a moiety of the other olefinically unsaturated compound (s). Preferably, there will be from 10 units to 100 units incorporating a moiety of ethene for each unit incorporating a moiety of the other olefinically unsaturated compound (s). The preferred polyketone polymers are therefore represented by the repeating formula [CO (CH2-CH2)] X+CO (G) +y where G is the moiety of the olefinically unsaturated compound of at least 3 carbon atoms polymerized through the olefinic unsaturation and the ratio of y: x is typically no more than 0.5, more typically no more than 0.25, preferably no more than 0.1. The ratio of y: x is

typically at least 0.01. When linear alternating polymers of carbon monoxide and ethene only are employed in the compositions of the invention, there will be no second olefinically unsaturated compound present and the polymers are represented by the above formula wherein y is zero. When y is other than zero the-CO+CH2-CH2+ units and the-CO-+G+-units are found randomly throughout the polymer chain. The precise nature of the end groups does not appear to influence the properties of the polymer to any considerable extent so that the polymers are fairly represented by the formula for the polymer chains as depicted above.

The polyketone polymers of weight average molecular weight from 2000 to 1,000,000, particularly those of weight average molecular weight from 10,000 to 500,000 as determined by gel permeation chromatography are of particular interest. The physical properties of the polymer will depend in part upon the molecular weight, whether the polymer is based on a single or on a plurality of olefinically unsaturated compounds and on the nature and the proportion of the olefinically unsaturated compounds. Typical melting points for the polyketone polymers are above 175 °C, more typically from 190 °C to 300 °C, especially from 210 °C to 270 °C, as determined by differential scanning calorimetry (DSC).

The polyketone polymers have typically a limiting viscosity number (LVN), measured in m-cresol at 60 °C in a standard capillary viscosity measuring device, from 0.5 dl/g to 10 dl/g, more typically from 0.8 dl/g to 4 dl/g.

Preferred methods for the production of the polyketone polymers are known from US-A-4808699 and US-A-4868282. US-A-4808699 teaches the production of polyketone polymers by contacting ethene and carbon monoxide in the presence of a catalyst comprising a

Group VIII metal compound, an anion of a non- hydrohalogenic acid with a pKa less than 6 and a bidentate phosphorus, arsenic or antimony ligand.

US-A-4868282 teaches the production of polyketone polymers by contacting carbon monoxide and ethene in the presence of one or more hydrocarbons having an olefinically unsaturated group with a similar catalyst.

The optional, second polymer is not miscible with the polyketone polymer. The skilled person will understand that the non-miscibility relates in particular to the blend morphology at ambient temperature, i. e. 20 °C.

Namely, some combinations of polymers may form a single phase upon blending at a high temperature whilst they show phase separation upon cooling.

The second polymer may be an addition polymer or a condensation polymer. The addition polymer is suitably a polymer of one or more olefinically unsaturated compounds polymerized through their olefinic unsaturation, for example ethene, propene, butene-1, styrene, methyl (meth) acrylate, vinyl acetate or combinations thereof.

The addition polymer is preferably a polymer of one or more olefinically unsaturated hydrocarbons, in particular hydrocarbons having up to 10 carbon atoms. The well- known polyolefins are preferred, such as polyethene, polypropene, poly (butene-1) and polystyrene. A suitable polyethene is high-density polyethene, i. e. having a density above 930 kg/m3 and mostly below 970 kg/m3, but low-density polyethene and linear low-density polyethene, i. e. having a density below 930 kg/m3, preferably above 880 kg/m3, are suitable as well. A preferred polypropene is isotactic polypropene. Suitable condensation polymers are, for example, polyamides such as polyamide-6, polyamide-6,6, polyamide-11 and polyamide-12, and poly (phenylene oxide).

The weight average molecular weight of the second polymer is suitably in the range of 2000-1,000,000, in particular 10,000-500,000, as determined by gel permeation chromatography. The crystalline melting point of the second polymer is suitably in the range of 80-300 °C, as measured by DSC, or, if the second polymer does not possess a crystalline melting point, its glass transition temperature is in the range of-80 to 200 °C, as measured by DSC.

With respect to the amine modified polymer of this invention, the skilled person will appreciate that-if a second polymer is present-the nature of the third polymer is preferably such that there is a good compatibility, e. g. good adhesion, between the second polymer and the amine modified polymer. For example, if the second polymer is a polyolefin, the third polymer is suitably a similar polyolefin which contains carboxylic acid groups, or if the second polymer is a poly- (phenylene-oxide), the third polymer is suitably a polystyrene which contains carboxylic acid groups. More of such combinations will be apparent to the skilled person, cf."Encyclopedia of Polymer Science and Technology", Volume 7,1987, pp. 119,120. If no second polymer is present, the skilled person will be able to select a suitable third polymer in accordance with the specific requirements connected with the application envisaged. For example, there may be specific requirements related to the use of the amine modified polymer as a coating for the polyketone polymer.

The carboxylic acid groups attached to the third polymer may be groups of an olefinically unsaturated carboxylic acid which is incorporated in the third polymer during its preparation, viz. by polymerizing the olefinically unsaturated carboxylic acid as the sole type of monomer, or by copolymerizing the olefinically

unsaturated carboxylic acid with the other monomer (s) on which the third polymer is based. The copolymerization is preferred and it is in particular a random copolymerization. Alternatively, the carboxylic acid groups may be groups which are attached after the polymerization by a grafting reaction, e. g. by radical grafting of an olefinically unsaturated carboxylic acid or an azidosulphonylbenzoic acid. Preferably the route of the random copolymerization is applied in the preparation of the third polymer.

The olefinically unsaturated carboxylic acid may be a monocarboxylic acid or a polycarboxylic acid, for example a dicarboxylic acid or a tricarboxylic acid. The skilled person will be aware that when the carboxylic acid groups originate from an olefinically unsaturated polycarboxylic acid, the carboxylic acids groups may mutually be positioned such that they easily form cyclic anhydride groups. This is especially the case when the carboxylic acid groups are separated by two atoms, in which case they may form succinic anhydride groups. This is no preferred situation because, as indicated hereinbefore, the existence of succinic anhydride groups in the third polymer may lead to an increased tendency of the amine modified polymer to form gels at high temperature and for the melt to increase in viscosity. Therefore, if the olefinically unsaturated carboxylic acid is an olefinically unsaturated polycarboxylic acid, the carboxylic acid groups are preferably separated from each other by a single atom or by at least 3 atoms, in particular at least 4 atoms. However, it is preferred that the olefinically unsaturated carboxylic acid is an olefinically unsaturated monocarboxylic acid.

The olefinically unsaturated carboxylic acids have at least 3 carbon atoms and they suitably have up to 15 carbon atoms, in particular up to 10 carbon atoms.

They may or may not have further heteroatoms, besides those of the carboxylic acid group, for example one or more halogen, oxygen or silicon atoms. Examples of suitable olefinically unsaturated carboxylic acids are o-undecenoic acid and 4-vinylbenzoic acid. Preferred olefinically unsaturated carboxylic acids are <BR> <BR> <BR> a- unsaturated alkenoic acids. Examples of suitable<BR> <BR> <BR> <BR> a-P unsaturated alkenoic acids are atropic acid, crotonic acid, and in particular acrylic acid, methacrylic acid and ethacrylic acid.

The quantity of the carboxylic acid groups present in the third polymer is not material to the invention.

Suitably the third polymer is based on between 0.05 and 50 % w of the olefinically unsaturated carboxylic acid relative to the weight of the third polymer, in particular between 0.1 and 30 % w, more in particular between 0.5 and 20 % w, on the same basis.

Preferred third polymers are random copolymers of, on the one hand, one or more olefinically unsaturated non- acidic compounds polymerized through their olefinic unsaturation, for example ethene, propene, butene-1, styrene, methyl (meth) acrylate, vinyl acetate or combinations thereof, with, on the other hand, the olefinically unsaturated carboxylic acid. The olefinically unsaturated non-acidic compounds are preferably olefinically unsaturated hydrocarbons, in particular hydrocarbons having up to 10 carbon atoms.

The weight average molecular weight of the third polymer is suitably in the range of 2000-1,000,000, in particular 10,000-500,000, as determined by gel permeation chromatography. The crystalline melting point of the third polymer is suitably in the range of 80- 300 °C, as measured by DSC, or, if the third polymer does not possess a crystalline melting point, its glass

transition temperature is in the range of-80 to 200 °C, as measured by DSC.

Examples of preferred third polymers are random poly (ethene-acrylic acid) and random poly (ethene- methacrylic acid). These are particularly suitable for use in connection with high density polyethene or low density polyethene as the second polymer. If the quantity of the amine relative to the carboxylic acid groups is sufficiently low the random poly (ethene-acrylic acid) and the random poly (ethene-methacrylic acid) are also suitable for use in connection with polyamides as the second polymer. Particularly preferred are poly (ethene-acrylic acid) which contains 9 % w acrylic acid, available from Dow Chemical under the trademark PRIMACOR 1430, poly (ethene-methacrylic acid) which contains 4 % w methacrylic acid, and in particular poly (ethene-methacrylic acid) which contains 9 % w methacrylic acid, which are available from Dupont under the trademarks NUCREL 407 and NUCREL 903, respectively.

Examples of other third polymers are random poly (propene- acrylic acid) and polypropene grafted with acrylic acid; these are useful for use in accordance with this invention in combination with e. g. polypropene or poly (butene-1) as the second polymer.

The skilled person will understand that the third polymer will in general be free or substantially free of groups of a cyclic carboxylic anhydride, in particular groups of a succinic anhydride. In the present context this means that the quantity of the cyclic carboxylic anhydrides groups, if they are present, is typically less than 20 mole-%, more typically less than 10 mole-%, in particular less than 5 mole-%, more in particular less than 1 mole-% of the quantity of carboxylic acid groups.

If appropriate, the amine modified polymer may be used as a blend with another polymer, as to adjust the

properties of the amine modified polymer to the requirements of the specific use of the polymer composition. For example, it may be made more flexible, softer or more impact resistant by blending with a very low density polyethene, i. e. a polyethene having a density of less than 930 kg/m3.

The amine for use in this invention has typically at least 4 carbon atoms, more typically at least 5 carbon atoms and preferably at least 6 carbon atoms. The amine has typically up to 30 carbon atoms and preferably up to 20 carbon atoms. The hydrocarbyl moiety which connects the two primary amino groups may be wholly or partly aliphatic, wholly or partly cycloaliphatic or partly aromatic in nature. This hydrocarbyl moiety may contain heteroatoms, such as oxygen, nitrogen or halogen.

The amine for use in this invention comprises at least two primary amino groups at least one of which is attached to an aliphatic carbon atom which carries at most one hydrogen atom. In particular two primary amino groups are attached to an aliphatic carbon atom which carries at most one hydrogen atom. The aliphatic carbon atom to which a primary amino group is attached carries preferably a single hydrogen atom. If one of the said primary amino groups is not attached to an aliphatic carbon atom which carries at most one hydrogen atom, it may be attached to an aromatic carbon atom, but preferably it is attached to an aliphatic carbon atom which carries two hydrogen atoms. One or, in particular, two said primary amino groups may be attached to an aliphatic carbon atom which is a part of an aliphatic carbon chain. In another embodiment, one or, in particular, two said primary amino groups may be attached to an aliphatic carbon atom which is a part of a cycloaliphatic structure, in particular a monocyclic cycloaliphatic structure, preferably a cyclohexane ring.

In this context the term"monocyclic"means that there are no two or more cyclic structures which have one or more atoms in common, which would be the case in spiro ring structures and in fused ring structures.

More than two amino groups may be present in the amine of this invention, which additional amino groups may be primary amino groups attached to, e. g., a carbon atom which carries a single hydrogen atom or which does not carry a hydrogen atom or which may form a part of an aromatic structure, or the additional amino groups are secondary amino or tertiary amino groups.

Examples of suitable amines are 1,3-diaminopentane, 1,5-diaminohexane, bis (3-aminopentyl) ether, bis (4-di- aminohexyl) amine, tris (3-aminopentyl) amine and isophoronediamine. Very suitable amines are, for example, 1,4-diaminocyclohexane, 1,4-diaminocyclooctane, 2,2-bis (4-aminocyclohexyl) propane and 2,2-bis (4-amino-3- methylcyclohexyl) propane. Preferred amines are bis (4- aminocyclohexyl) methane and bis (4-amino-3-methylcyclo- hexyl) methane. Other preferred amines are amines of the general formula wherein n is an integer in the range of 1 to 9, inclusive, preferably 1 to 6, inclusive. Such amines are present in diaminopolypropylene glycols sold under the trademark JEFFAMINE.

It is noted that, if desirable, it is possible to use the amine in a wholly or partly neutralized from, i. e. as a salt of an acid. Preferably such salts are employed of which the acid is relatively volatile, so that it is easily removed during the reaction of the amine with the third polymer.

The molar quantity in which the amine may be used, relative to the carboxylic acid groups present in the third polymer, may vary within a broad range. Typically

this quantity is at least 0.0001 mole/mole, preferably at least 0.001 mole/mole, more preferably at least 0.005 mole/mole. Typically this quantity is at most 1 mole/mole, more typically at most 0.5 mole/mole, preferably at most 0.1 mole/mole, more preferably at most 0.05 mole/mole. It was found that cross-linking reactions may be better suppressed with less amine present relative to the quantity of carboxylic acid groups present in the third polymer.

The amine modified polymer of this invention may be made by melt blending the third polymer with the amine by any suitable means, for example by using an extruder or a Brabender mixer. A suitable temperature for melt blending may be, for example, above 100 °C, typically above 120 °C, but it is generally below 300 °C. A preferred temperature range is 150-250 °C. If desirable, the preparation of the amine modified polymer may be effected simultaneously with a melt processing step which is carried out when preparing the composition of this invention, as set out below. It is also possible to perform the reaction between the amine and the third polymer by heating the reactants dissolved in a suitable solvent, for example at 100-200 °C. Suitable solvents are, for example, p-xylene, diethyleneglycol dimethylether and triethyleneglycol dimethylether.

The polymer compositions of this invention are suitably obtainable by contacting the polyketone polymer and optionally the second polymer with the amine modified polymer. The contacting is typically carried out such that the polyketone polymer can react with the amine modified polymer. This frequently involves the application of an elevated temperature, say above 100 °C, but generally below 300 °C.

In one embodiment the polymer composition of this invention may be in the form of a blend, in which the

amine modified polymer has the function of a compatibilizer. Such blends can be made by any melt blending process which effects an intimate blending of the components of the composition. Such processes are well known to the skilled person. They may be carried out, for example, in an extruder or in a Brabender mixer.

The weight ratio in which the polyketone polymer is blended with the second polymer is not material to this invention. This weight ratio may vary within a broad range, for example between 5/95 and 95/5, typically between 10/90 and 90/10, more typically between 20/80 and 80/20. The quantity of the amine modified polymer will generally relate to the quantity of the polyketone polymer or of the second polymer which is used as the minor component. For example it may suitably be used in a quantity which amounts to 1-40 % w and typically 2-20 % w, relative to the weight of the minor component.

In a preferred embodiment of this invention the polymer composition is in the form of a multi-layer structure, in which the polyketone polymer forms a first layer, the second polymer forms a second layer, both layers being bonded together by an intermediate layer of the amine modified polymer, which has the function of an adhesive layer. It will be clear that the multi-layer structures are not limited to structures consisting of these two layers and the intermediate layer; more layers may be possible, if necessary with additional intermediate layers as adhesive.

Such multi-layer structures can be made, for example, by extruding a melt of the amine modified polymer in between the pre-formed first and second layers, which may be heated, e. g. at a temperature above 100 °C, generally below 270 °C, simultaneously or in a later stage, thus effecting interfacial bonding. Variants of this technique are compression moulding and co-injection

moulding. It is however preferred to employ a co- extrusion process in which a melt of the amine modified polymer is extruded in between a melt of the polyketone polymer and a melt of the second polymer. The three melts will be brought together in a suitable multi-layer manifold prior to exiting the die. The manifold will be kept suitably at temperature of at least 150 °C, more suitably at least 180 °C, in general below 300 °C, preferably in the range of 200-280 °C. In the manifold the temperature is generally the highest of the extrusion temperatures. The total residence time in the manifold can vary from less than one minute, for example 10 seconds, to more than 10 minutes, for example up to 20 minutes. The skilled person will realise that for making good multi-layer structures it is preferred to employ polymers with similar melt viscosity at the prevailing conditions. For making the more extensive multi-layer structures more streams of polymer melts will be guided into the multi-layer manifold, as appropriate.

The multi-layer structures may be processed further, for example, by bending (e. g. tubes, pipes), by stretching (e. g. of sheet to form film) or by thermoforming or blow moulding (e. g. to form a container).

In the multi-layer structures of this invention, the thickness of the first and the second layer will depend on the specific requirements related to the application of the multi-layer structure. For example the thickness may range from 5-5000 (xm, e. g. in a film or sheet application, to 0.1-100 mm in other applications, such as in tubing or in pipe applications. The thickness of the intermediate layer will frequently range from 5-1000 pm.

In a third and in a fourth embodiment of this invention no second polymer is present. In the third embodiment the amine modified polymer is used as a

coating to a polyketone polymer object or, vice versa, the polyketone polymer is used as a coating to an object made of the amine modified polymer. The coated object may be in any form, for example, in the form of a tube, a pipe, a sheet or a film. The fourth embodiment relates to a multi-layer structure in which the amine modified polymer is used as an adhesive between a layer of the polyketone polymer and a layer of another material which is not a thermoplastic polymer, for example glass, metal, such as aluminium or copper, or a thermosetting resin, such as a phenol-formaldehyde resin. The considerations as set out in the previous paragraphs in connection with the multi-layer structures also apply to the third and fourth embodiment of this invention, evidently only in so far as these considerations relate to the first polymer and the amine modified polymer.

The skilled person will become aware of more embodiments in which the invention can usefully be applied.

The polyketone polymer, the second polymer and the amine modified polymer may contain additives such as reinforcing fillers, non-reinforcing fillers, extenders, lubricants, pigments, plasticizers, and other polymeric materials to improve or otherwise alter its properties.

The compositions in accordance with this invention are outstanding in quality, in particular as regards the homogeneity in respect of gels, bubbles or lumps and as regards their performance properties, such as the impact resistance, chemical resistance and the barrier properties; the multi-layer structures have a very good thickness distribution of the various layers. The compositions of this invention, in particular in the form of multi-layer structures, do not show de-lamination and they maintain these performance properties when they are

applied'in the presence of water or other liquids such as hydrocarbons.

The parts of the kit of parts suitable for producing the polymer compositions according to this invention may comprise any of the polymers in any suitable physical form, for example in the form of a liquid, a powder, nibs or crumbs.

The invention will now be illustrated by means of the following examples.

Example 1 An amine modified polymer was prepared as follows.

A random copolymer of ethene and methacrylic acid (NUCREL 903 HC, available from Dupont) was fed through a feed hopper to a 25-mm twin-screw extruder. The random copolymer contained 9 % w methacrylic acid calculated on polymer. The feed rate of the random copolymer was 15 kg/h. Through the same feed hopper bis (4-amino- cyclohexyl) methane (AMICURE PACM (AMICURE PACM is a trademark), available from Air Products) was simultaneously fed at a rate of 75 g/h. The bis (4-amino- cyclohexyl) methane was used in a quantity of 0.023 mole/mole methacrylic acid present in the copolymer of ethene and methacrylic acid. The screw speed was 250 rpm. The barrel and the die were heated such that the melt temperature was 180 °C. The melt was obtained in the form of a strand, it was cooled in a water bath and granulated.

Example 2 A polyketone which is a linear alternating copolymer of carbon monoxide, ethene and propene was prepared by copolymerizing the monomers in the presence of a catalyst composition based on palladium acetate, 1,3-bis [bis (2- methoxyphenyl) phosphino] propane and trifluoroacetic acid.

The copolymer had an LVN of 1.7 dl/g, measured in

m-cresol at 60 °C, and a melting point of 220 °C, measured by DSC.

Example 3 A multi-layer sheet of polyketone/amino modified polymer/low density polyethene was produced in a co- extrusion line as follows.

The co-extrusion line comprised a 25-mm single screw main extruder equipped with a multi-layer manifold with a die of the so-called coat-hanger type, two 20-mm single screw side extruders and a suitable haul-off/cooling unit. The polyketone as obtained in Example 2 was fed to the main extruder, which was operated with a screw speed of 24 rpm. The amine modified polymer as obtained in Example 1 was fed to the first side extruder, which was operated with a screw speed of 20 rpm. A low density polyethene (Grade 25-020FA, available from Montell) was fed to the second side extruder, which was operated with a screw speed of 98 rpm. The extruder barrels and further equipment in contact with the polymer melts were heated such that the polymer melts adopted a temperature of 240 °C in the multi-layer manifold and the die. The line speed was 0.7 m/min. A sheet was produced having a polyketone outer layer of 0.3 mm thickness, an outer layer of low density polyethene of 0.9 mm thickness and an intermediate layer of amine modified polymer of 0.15 mm thickness.

There was a good adhesion between the layers of the sheet and the layers did not show irregularities in their thickness.

Examples 1 and 3 were repeated using bis (4-amino-3- methylcyclohexyl) methane (EPICURE 113 is a trademark) and an amine of the general formula H2N-CH (CH3)-CH2---F-0-CH (CH3)-CH2--]--n-NH2 which has a molecular weight of about 230 (JEFFAMINE D230), instead of bis (4-aminocyclohexyl)-

methacrylic acid. Virtually the same results were obtained as with bis (4-aminocyclohexyl) methane.

Example 4 Multi-layer pipes of polyketone/amine modified polymer/high density polyethene were produced in a co- extrusion line as follows.

A commercial size co-extrusion line was configured similarly as indicated in Example 3, except that it comprised a multi-layer manifold with die and a haul- off/cooling unit suitable for producing pipe, instead of sheet. The polyketone polymer as obtained in Example 2 was used. The amine modified polymer obtained in Example 1 was used. The high density polyethene used was of a commercially available grade. Multi-layer pipes were produced having diameters in the range of from 63 mm to 110 mm and having a structural outer layer of high density polyethene of about 5 mm thickness, an polyketone inner layer of about 1 mm thickness and an intermediate layer of amine modified polymer of about 0.2 mm thickness.

There was a good adhesion between the layers and the layers did not show irregularities in their thickness.

The co-extrusion process could be continued for hours without deterioration of the quality of the pipes in the aspects of adhesion and layer thickness; the inner surface of the pipes continued to be smooth and glossy and no gels were observed.

Example 5 (for comparison) An amine modified polymer was prepared as described in Example 1, except that 4,9-dioxa-1,12-diaminododecane (available from BASF) was used at a feed rate of 38 g/h, instead of bis (4-aminocyclohexyl) methane.

Example 6 (for comparison) Multi-layer pipes of polyketone/amine modified polymer/high density polyethene were produced as

described in Example 4, except that the amine modified polymer as obtained in Example 5 was used, instead of the polymer as obtained in Example 1.

There was a good adhesion between the layers of the pipes. However, already after 15 minutes of the co- extrusion run inspection of the inner surface of the pipes revealed the appearance of gels and that the pipes had serious irregularities in the thickness of the layers.