WO2008047091A2

WO2008047091A2 - Polymeric materials

Info

Publication number: WO2008047091A2
Application number: PCT/GB2007/003921
Authority: WO
Inventors: Ingeborg Andrea Schreiber; Jürgen Reinert; Horst Herbert Sandner
Original assignee: Victrex Manufacturing Limited; Wacker Chemie Ag
Priority date: 2006-10-17
Filing date: 2007-10-15
Publication date: 2008-04-24
Also published as: WO2008047091A3; EP2081747A2; GB0620557D0; JP2010506765A

Abstract

A method of making a moulded product which includes a polyaryletherketone and a silicone elastomer intimately in contact with the polyaryletherketone comprises moulding the polyaryletherketone and contacting the moulded material with the silicone whilst the polyaryletherketone is at a temperature of greater than 100°C and/or whilst the polyaryletherketone is at a sufficiently high temperature that it retains sufficient latent heat to cure the second material. Curing of the second material may take place without any additional heat being supplied to the mould or materials therein.

Description

Polymeric Materials

This invention relates to polymeric materials and particularly, although not exclusively, relates to moulded polymeric materials. Preferred embodiments relate to moulded materials comprising a thermoplastic material and a softer, rubbery material.

It is known to injection mould a thermoplastic material such as PBT or nylon, followed by co-moulding or over- moulding with a liquid silicone rubber (LSR) . Such materials are used for items such as baby bottles, components/seals for medical devices in healthcare, in seals/connectors for automotive applications and insulated/cable accessories in electrical/electronic applications.

Known processes for over-moulding may involve moulding a rigid component from a thermoplastic in a conventional manner. Then the rigid component may be stored until convenient to over-mould it. In over-moulding, the rigid component is placed in a second mould as an insert and silicone rubber may be moulded onto it.

It is an object of preferred embodiments of the present invention, to simplify the apparatus and/or procedures for producing components which comprise a thermoplastic material and another material which may be softer, such as an LSR.

The present invention is based on the discovery that thermoplastic polymers may be moulded and then subsequently contacted with another polymeric material in a co-moulding or over-moulding process, such that the latent heat in the thermoplastic material is sufficient to

^' cure the other polymeric material and, consequently, this may avoid the provision of additional heaters for curing the other polymeric material and reduce processing times.

According to the first aspect of the invention, there is provided a method of making a moulded product which includes a first polymeric material and a second polymeric material intimately in contact with the first material, the process comprising:

a) moulding the first polymeric material; b) contacting the first material with the second polymeric material (or one or more precursors thereof) whilst the first material is at a temperature of greater

^■ than 100⁰C, whereby the temperature of the first material aids curing of the second polymeric material.

The temperature of the first polymeric material may be at least 120⁰C, preferably at least 130⁰C, more preferably at least 140⁰C, especially at least 150⁰C when it is contacted with said second material (or one or more precursors thereof) . In some cases, the temperature may be at least 160⁰C or at least 170⁰C when said first material is contacted with said second material (or one or more precursors thereof) .

According to a second aspect of the invention, there is provided a method of making a moulded product which includes a first polymeric material and a second polymeric material intimately in contact with the first material, the process comprising:

a) moulding the first material; b) contacting the first material with the second material (or one or more precursors thereof) whilst the first material is at a sufficiently high temperature that it retains sufficient latent heat to cure the second material, preferably without increasing the temperature of said second material (or one or more precursors thereof) or application of heat from a heat source other than said first material .

Thus, in accordance with the second aspect, the second material (or one or more precursors thereof) may be contacted with the first material and heat from the first material may cure the second material, without application of heat from an external heat source.

Further details on the first and second aspects are provided below.

Said first polymeric material may be injection moulded. Suitably said first polymeric material is at a temperature in excess of 300°C, preferably in excess of 350⁰C, more preferably in excess of 400°C, prior to contact with a mould.

Prior to contact with said first polymeric material, the surface temperature of a surface of said mould which contacts said first polymeric material may be at a temperature in the range 160°C to 200⁰C, preferably 160°C to 190⁰C. Said first polymeric material is preferably moulded in a first mould. Contact of said first polymeric material with said second polymeric material (or one or more precursors thereof) may take place whilst said first polymeric material is in said first mould. Thus, the method may comprise injecting said second polymeric material (or one or more precursors thereof) into said first mould, suitably so that said second polymeric material (or one or more precursors thereof) contacts said first material in selected positions so that said second polymeric material may define a moulded component which is intimately contacted with said first polymeric material.

Contact of said second polymeric material (or one or more precursors thereof) with said first polymeric material may take place substantially immediately after moulding, of said first polymeric material. For example, the time elapsing between the completion of injection of said first polymeric material into the first mould and contact of said first polymeric material with second polymeric material (or one or more precursors thereof) may be less than 30 minutes, suitably less than 15 minutes, preferably less than 5 minutes, more preferably less than 3 minutes, especially less than 1 minute. Contact of said first and second polymeric materials (or one or more precursors thereof) as aforesaid is preferably effected whilst the moulded component defined by said first polymeric material is at a sufficiently high temperature that it retains sufficient latent heat which can be transferred to said second polymeric material (or one or more precursors thereof) to effect curing, suitably without any heating of the first mould. Initial contact of the first and second materials (or one or more precursors thereof) as aforesaid may take place when the moulded component defined by said first polymeric material is at a temperature of at least 100⁰C, suitably at least 110⁰C, preferably at least 120°C, more preferably at least 140⁰C, especially at least 160⁰C. Preferably, initial contact of the first and second materials (or one or more precursors thereof) takes place when the first material is at a temperature at which the second material cures or is in excess thereof.

In some (preferred) embodiments, the second polymeric material may be formed by reaction of a first precursor and a second precursor. In this case, said first and second precursors, which may be intimately mixed, may be contacted with said first polymeric material, for example in said first mould. In this case, after moulding of said first material, said first and second precursors may be introduced into the first mould and contacted with the first polymeric material. The first and second precursors may be caused to cure to define said second polymeric material, suitably by the latent heat contained in said first polymeric material.

In an alternative, less preferred embodiment, said first polymeric material may be moulded in a first mould. Contact of said first polymeric material with said second polymeric material (or one or more precursors thereof) may take place in a second mould. In this case, moulded first polymeric material may be transferred from said first mould to a second mould prior to contact with said second polymeric material (or one or more precursors thereof) . Any such transfer is suitably effected so that when the moulded first polymeric material is in said second mould and is contacted with said second polymeric material (or one or more precursors thereof) it contains sufficient latent heat and/or is at a sufficient temperature as described herein to effect curing of said second polymeric material (or one or more precursors thereof) .

In the methods, said first polymeric material is preferably over-moulded with said second polymeric material.

After the second polymeric material (or one or more precursors thereof) has/have been intimately contacted with said first polymeric material, the combination may. be allowed to cool, suitably passively, to ambient temperature. Thereafter, the combination of first and second polymeric materials may be removed from the mould.

Advantageously, it has been found that by contacting said first polymeric material whilst it is still relatively hot as described with said second polymeric material (or one or more precursors thereof) , the second polymeric material adheres surprisingly well to the first polymeric material.

Said second polymeric material is preferably an elastomer.

Said second polymeric material is preferably softer than said first polymeric material. Said second polymeric material may have a hardness, measured on the Shore A scale, of less than 120, suitably less than 110, preferably less than 90, more preferably less than 80, especially 70 or less. The hardness on said Shore A scale may be greater than 5, preferably 10 or greater.

Said first polymeric material may have a hardness on the Rockwell R Scale of greater than 70, suitably greater than 90, preferably greater than 100, more preferably greater than 110, especially greater than 120. Preferably said first polymeric material has a hardness on the Rockwell R scale in the range 120 to 130.

Said second polymeric material (or one or more precursors thereof) is/are suitably curable at a temperature in the range 100 to 250°C, preferably 150 to 250⁰C, more preferably 160 to 220⁰C, especially 170 to 210⁰C. Preferably, said second polymeric materials (or one or more precursors thereof) is/are subjected to a temperature in said ranges in the methods .

Immediately prior to introduction into a mould to contact said first polymeric material, said second polymeric material (or one or more precursors thereof) may be at a temperature of less than 100⁰C, preferably less than 75°C, more preferably less than 50⁰C, especially less than 35°C.

Said second polymeric material (or one or more precursors thereof) may be at ambient temperature prior to said introduction .

Said second polymeric material preferably comprises a silicone rubber. Such a silicone rubber may have methyl and/or vinyl substitutions on the polymer chain. Said second polymeric material (or one or more precursors thereof) is/are preferably flowable at a temperature of less than 50⁰C, more preferably less than 30⁰C. Suitably, said second polymeric material (or one or more precursors thereof) is/are arranged to cure in less than 1 minute, preferably in less than 50 seconds, more preferably in less than 40 seconds, especially in less than 30 seconds, after contact with said first polymeric material. Preferably, said second polymeric material need not be subjected to post-curing.

Said second polymeric material (or one or more precursors thereof) preferably comprise (s) a liquid silicone rubber. Such a rubber may be formed from first and second components which may be introduced into a mould (suitably at a weight ratio of first to second components in the range 0.3 to 3, preferably 0.75 to 1.3) in which said first polymeric material is arranged. The components may then cure as they are heated to the curing temperature by transfer of latent heat from said first polymeric material. The curing process may involve a hydrosilylation reaction.

Said first polymeric material may comprise a first polymer.

Said first polymer may have a Tg of less than 260⁰C, for example less than 220⁰C or less than 200⁰C. In some cases, the Tg may be less than 190⁰C, 180⁰C or 170⁰C.

Said first polymer suitably has a melt viscosity (MV) of at least 0.06 kNsm^"2, preferably has a MV of at least 0.08 kNsπf², more preferably at least 0.09 kNsirf². MV is suitably measured using capillary rheometry operating at 400^cC at a shear rate of 1000s^"1 using a tungsten carbide die, 0.5x3.175mm.

Said first polymer may have a MV of less than 1.00 kNsirf², preferably less than 0.5 kNsirf², more preferably less than 0.38 kNsπf², especially less than 0.25 kNsirf².

Said first polymer may have a tensile strength, measured in accordance with ASTM D790 of at least 40 MPa, preferably at least 60 MPa, more preferably at least 80 MPa. The tensile strength is preferably in the range 80- 110 MPa, more preferably in the range 80-100 MPa.

Said first polymer may have a flexural strength, measured in accordance with ASTM D790 of at least 145 MPa. The flexural strength is preferably in the range 145-180 MPa, more preferably in the range 145-165 MPa.

Said first polymer may have a flexural modulus, measured in accordance with ASTM D790, of at _.least 2 GPa, preferably at least 3GPa, more preferably at least 3.5 GPa. The flexural modulus is preferably in the range 3.5- 4.5 GPa, more preferably in the range 3.5-4.1 GPa.

Said first polymer may have a tensile strength, measured in accordance with ASTM D790 of at least 20 MPa, preferably at least 60 MPa, more preferably at least 80 MPa. The tensile strength is preferably in the range 80-110 MPa, more preferably in the range 80-100 MPa.

Said first polymer may have a flexural strength, measured in accordance with ASTM D790 of at least 50 MPa, preferably at least 100 MPa, more preferably at least 145 MPa. The flexural strength is preferably in the range 145-180MPa, more preferably in the range 145-164 MPa.

Said first polymer may have a flexural modulus, measured in accordance with ASTM D790, of at least 1 GPa, suitably at least 2 GPa, preferably at least 3 GPa, more preferably at least 3.5 GPa. The flexural modulus is preferably in the range 3.5-4.5 GPa, more preferably in the range 3.5- 4.1 GPa.

Preferably, said first polymer has a moiety of formula

and/or a moiety of formula

and/or a moiety of formula

wherein the phenyl moieties in units I, II, and III are independently optionally substituted and optionally cross- linked; and wherein m,r,s,t,v,w and z independently represent zero or a positive integer, E and E¹ independently represent an oxygen or a sulphur atom or a direct link, G represents an oxygen or sulphur atom, a direct link or a -O-Ph-0- moiety where Ph represents a phenyl group and Ar is selected from one of the following moieties (i)**, (i) to (vi) which is bonded via one or more of its phenyl moieties to adjacent moieties

0^«)

Unless otherwise stated in this specification, a phenyl moiety has 1,4-, linkages to moieties to which it is bonded.

In (i) , the middle phenyl may be 1,4- or 1, 3-substituted. It is preferably 1, 4-substituted.

Said first polymer may include more than one different type of repeat unit of formula I; and more than one different type of repeat unit of formula II; and more than one different type of repeat unit of formula III. Preferably, however, only one type of repeat unit of formula I, II and/or III is provided.

Said moieties I, II and III are suitably repeat units. In the first polymer, units I, II and/or III are suitably bonded to one another - that is, with no other atoms or groups being bonded between units I, II and III.

Phenyl moieties in units I, II and III are preferably not substituted. Said phenyl moieties are preferably not cross-linked.

Where w and/or z is/are greater than zero, the respective phenylene moieties may independently have 1,4- or 1,3- linkages to the other moieties in the repeat units of formulae II and/or III. Preferably, said phenylene moieties have 1,4- linkages.

Preferably, the polymeric chain of the first polymer does not include a -S- moiety. Preferably, G represents a direct link.

Suitably, "a" represents the mole % of units of formula I in said first polymer, suitably wherein each unit I is the same; "b" represents the mole % of units of formula II in said first polymer, suitably wherein each unit II is the same; and "c" represents the mole % of units of formula III in said first polymer, suitably wherein each unit III is the same. Preferably, a is in the range 45-100, more preferably in the range 45-55, especially in the range 48- 52. Preferably, the sum of b and c is in the range 0-55, more preferably in the range 45-55, especially in the range 48-52. Preferably, the ratio of a to the sum of b and c is in the range 0.9 to 1.1 and, more preferably, is about 1. Suitably, the sum of a, b and c is at least 90, preferably at least 95, more preferably at least 99, especially about 100. Preferably, said first polymer consists essentially of moieties I, II and/or III. Said first polymer may be a homopolymer having a repeat unit of general formula

or a homopolymer having a repeat unit of general formula

or a random or block copolymer of at least two different units of IV and/or V

wherein A, B, C and D independently represent 0 or 1 and E,E' ,G,Ar,m,r,s,t,v,w and z are as described in any statement herein.

As an alternative to a first polymer comprising units IV and/or V discussed above, said first polymer may be a homopolymer having a repeat unit of general formula

or a homopolymer having a repeat unit of general formula

or a random or block copolymer of at least two different units of IV* and/or V*, wherein A, B, C, and D independently represent 0 or 1 and E, E', G, Ar, m, r, s, t, v, w and z are as described in any statement herein.

Preferably, m is in the range 0-3, more preferably 0-2, especially 0-1. Preferably, r is in the range 0-3, more preferably 0-2, especially 0-1. Preferably t is in the range 0-3, more preferably 0-2, especially 0-1. Preferably, s is 0 or 1. Preferably v is 0 or 1. Preferably, w is 0 or 1. Preferably z is 0 or 1.

Preferably, said first polymer is a homopolymer having a repeat unit of general formula IV.

Preferably Ar is selected from the following moieties (vii) to (xiii) and (xi) **

In (vii), the middle phenyl may be 1,4- or 1, 3-substituted. It is preferably 1, 4-substituted.

Preferably, (xi) is selected from a 1,2-, 1,3-, or a 1,5- moiety; and (xii) is selected from a 1,6-, 2,3-, 2,6- -or a 2,7- moiety.

Suitable moieties Ar are moieties (i) , (ii) , (iii) and (iv) and, of these, moieties (i) , (ii) and (iv) are preferred. Other preferred moieties Ar are moieties (vii) , (viii) , (ix) and (x) and, of these, moieties (vii) , (viii) and (x) are especially preferred.

An especially preferred class of first polymers are polymers (or copolymers) which consist essentially of phenyl moieties in conjunction with ketone and/or ether moieties. That is, in the preferred class, the first polymer material does not include repeat units which include -S-, -SO₂- or aromatic groups other than phenyl. Preferred first polymers of the type described include:

(a) a polymer consisting essentially of units of formula IV wherein Ar represents moiety (iv) , E and E' represent oxygen atoms, m represents 0, w represents 1, G represents a direct link, s represents 0, and A and B represent 1 (i.e. polyetheretherketone) .

(b) a polymer consisting essentially of units of formula IV wherein E represents an oxygen atom, E' represents a direct link, Ar represents a moiety of structure (i) , m represents 0, A represents 1, B represents 0 (i.e. polyetherketone) ;

(c) a polymer consisting essentially of units of formula IV wherein E represents an oxygen atom, Ar represents moiety (i) , m represents 0, E' represents a direct link, A represents 1, B represents 0, (i.e. polyetherketoneketone) .

(d) a polymer consisting essentially of units of formula IV wherein Ar represents moiety (i) , E and E' represent oxygen atoms, G represents a direct link, m represents 0, w represents 1, r represents 0, s represents 1 and A and B represent 1. (i.e. polyetherketoneetherketoneketone) .

(e) a polymer consisting essentially of units of formula IV, wherein Ar represents moiety (iv) , E and E¹ represents oxygen atoms, G represents a direct link, m represents 0, w represents Q, s, r, A and B represent 1 (i.e. polyetheretherketoneketone) .

(f) a polymer comprising units of formula IV, wherein Ar represents moiety (iv) , E and E' represent oxygen atoms, m represents 1, w represents 1, A represents 1, B represents 1, r and s represent 0 and G represents a direct link (i.e. polyether- diphenyl-ether-phenyl-ketone-phenyl-) .

Said first polymer may be amorphous or semi-crystalline. Amorphous polymers may be used wherein, for example, the component is not subjected to a harsh chemical environment in use.

Said first polymer is preferably semi-crystalline. The level and extent of crystallinity in a polymer is preferably measured by wide angle X-ray diffraction (also referred to as Wide Angle X-ray Scattering or WAXS) , for example as described by Blundell and Osborn (Polymer 24,

953, 1983) . Alternatively, crystallinity may be assessed by Differential Scanning Calerimetry (DSC) .

The level of crystallinity in said first polymer may be at least 1%, suitably at least 3%, preferably at least 5% and more preferably at least 10%. In especially preferred embodiments, the crystallinity may be greater than 30%, more preferably greater than 40%, especially greater than 45%.

The main peak of the melting endotherm (Tm) for said first polymer (if crystalline) may be at least 300⁰C.

Said first polymer may consist essentially of one of units (a) to (f) defined above.

Said first polymer preferably comprises, more preferably consists essentially of, a repeat unit of formula (XX)

where tl, and wl independently represent 0 or 1 and vl represents 0, 1 or 2. Preferred polymeric materials have a said repeat unit wherein tl=l, vl=0 and wl=0; tl=0, vl=0 and wl=0; tl=0, wl=l, vl=2; or tl=0, vl=l and wl=0. More preferred have tl=l, vl=0 and wl=0; or tl=0, vl=0 and wl=0. The most preferred has tl=l, vl=0 and wl=0.

In preferred embodiments, said first polymer is selected from polyetheretherketone, polyetherketone, polyetherketoneetherketoneketone and polyetherketoneketone. In a more preferred embodiment, said polymeric material is selected from polyetherketone and polyetheretherketone. In an especially preferred embodiment, said polymeric material is polyetheretherketone . Said first polymer may make up at least 60wt%, suitably at least 70wt%, preferably at least 80wt%, more preferably at least 90wt%, especially at least 95wt%, of the total amount of thermoplastic polymer (s) in said first polymeric material. Preferably, substantially the only thermoplastic polymer in said first polymeric material is said first polymer.

Said first polymeric material could include a filler means.

Said filler means may include a fibrous filler or a non- fibrous filler. Said filler means may include both a fibrous filler and a non-fibrous filler.

A said fibrous filler may be continuous or discontinuous. In preferred embodiments a said fibrous filler is discontinuous .

A said fibrous filler may be selected from inorganic fibrous materials, non-melting and high-melting organic fibrous materials, such as aramid fibres, and carbon fibre.

A said fibrous filler may be selected from glass fiber, carbon fibre, asbestos fiber, silica fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, fluorocarbon resin fibre and potassium titanate fiber. Preferred fibrous fillers are glass fibre and carbon fibre.

A fibrous filler may comprise nanofibres . A said non-fibrous filler may be selected from mica, silica, talc, alumina, kaolin, calcium sulfate, calcium carbonate, titanium oxide, ferrite, clay, glass powder, zinc oxide, nickel carbonate, iron oxide, quartz powder, magnesium carbonate, fluorocarbon resin, graphite, carbon powder, nanotubes and barium sulfate. The non-fibrous fillers may be introduced in the form of powder or flaky particles.

Preferably, said filler means comprises one or more fillers selected from glass fibre, carbon fibre, carbon black and a fluorocarbon resin. More preferably, said filler means comprises glass fibre or carbon., especially discontinuous, for example chopped, glass fibre or carbon fibre.

Suitably, the total amount of filler means in said polymeric material is less than 40%, preferably less than 30wt%. Preferably, said first polymeric material includes substantially no filler means.

Said first polymeric material may include:

(i) 70-100wt% of thermoplastic polymer (s); and (ii) 0-30wt%, (suitably 0-30wt%, preferably 0-20wt%, more preferably 0-10wt%, especially 0-5wt%) of filler means .

Said first polymeric material may include: '

(i) 70-100wt% of said first polymer, preferably a polymer of formula (XX) referred to above, (ii) 0-30wt% of a second polymer; (iii) 0-20wt% of filler means;

(iv) 0-10wt% of other additives which may be selected, for example, from other polymers, processing aids, colours .

Suitably, said first polymeric material includes at least 80wt%, preferably at least 90wt%, more preferably at least 95wt%, especially at least 99wt% of said first polymer especially a polymer of formula (XX) referred to above.

According to a third aspect of the invention, there is provided a method of making a moulded product which includes a first polymeric material and a second polymeric material, the method comprising:

a) moulding the first polymeric material; b) contacting the first polymeric material with the second polymeric material (or one or more precursors thereof) , wherein said first polymeric material comprises a first polymer as described according to the preceding aspects, for example of formula (XX) and said second polymeric material includes: a material having a hardness which is less than the hardness of said first polymeric material; or said second polymeric material comprises an elastomer; or said second polymeric material comprises a liquid silicone resin.

According to a fourth aspect of the invention, there is provided a moulded product which comprises a first polymeric material and, intimately in contact therewith, a second polymeric material wherein preferably said first polymeric material comprises a first polymer as described according to the preceding aspects, for example of formula (XX) and said second polymeric material includes a material having a hardness which is less than the hardness of said first polymeric material; or said second polymeric material comprises an elastomer; or said second polymeric material comprises and/or is derived from a liquid silicone resin.

The moulded product of the preceding aspect preferably comprises an over-moulding of an elastomer onto a rigid plastics material.

In a preferred embodiment, there is provided a moulded product which includes a first polymeric material which comprises a first polymer of formula XX, referred to herein, wherein said first polymeric material is over- moulded with a second polymeric material, wherein said second polymeric material may be as described in any statement herein but is preferably a silicone elastomer.

The invention extends to a method of making a moulded product which comprises a first polymeric material, over- moulded with a second polymeric material, wherein the moulding of said first and second polymeric materials takes place in the same mould.

A moulded product as described herein may comprise a gasket, seal, cushioning pad or ruggedized electronic or other devices .

Any feature of any aspect of any invention or embodiment described herein may be combined with any feature of any aspect of any other invention or embodiment described herein mutatis mutandis. Specific embodiments of the invention will now be described.

The following materials are referred to hereinafter.

PEEK90GL30 - polyetheretherketone having a melt viscosity (MV) of 0.09 kNsm^"2 filled with 30wt% glass fibre obtained from Victrex PIc;

PEEK150GL30 - as per PEEK90GL30 expect the polyetheretherketone has a melt viscosity (MV) of 0.15 kNsm^"2.

Elastosil LR3070/40 - a liquid silicone rubber (LSR) obtained from Wacker Chemie.

PEEK90GL30 was injected moulded to define a first product which was over-moulded with the LSR.

In a first embodiment, PEEK150GL30 is injection moulded in a first mould. The PEEK is injected at 400°C into the cavity of the injection moulding machine which is at a temperature in the range 160°C to 190°C. Consequently the PEEK contains a substantial about of heat energy. After some cooling of the PEEK, the LSR (Elastosil LR3070/40) may be injection moulded onto the PEEK in predetermined positions, without removal of the PEEK moulding from its mould. Provided the LSR is contacted with the PEEK when the PEEK is still at a high temperature (e.g. 180⁰C) the latent heat in the PEEK is sufficient to rapidly cure the LSR and, accordingly, additional heating of the LSR in the mould is not required. This saves time (e.g. curing time) and expense. In an alternative embodiment, the injection moulded PEEK of the first embodiment may be removed from the mould whilst it is still hot (greater than 200°C) and placed in a second mould. Thereafter, LSR is injected into the second mould to contact the PEEK, which is still at a relatively high temperature (e.g. 180°C) and consequently the latent heat in the PEEK is sufficient to cure the LSR as before.

Furthermore, in the processes described the LSR is found to adhere very strongly to the PEEK.

Claims

1. A method of making a moulded product which includes a first polymeric material and a second polymeric material intimately in contact with the first polymeric material, the process comprising:

a) moulding the first polymeric material; b) contacting the first polymeric material with the second polymeric material (or one or more precursors thereof) whilst the first material is at a temperature of greater than 100°C, whereby the temperature of the first polymeric material aids curing of the second polymeric material .

2. A method according to claim 1, wherein said temperature of the first polymeric material is at least 150°C.

3. A method of making a moulded product which includes a first polymeric material and a second polymeric material intimately in contact with the first polymeric material, the process comprising:

a) moulding the first polymeric material; b) contacting the first polymeric material with the second polymeric material (or one or more precursors thereof) whilst the first polymeric material is at a sufficiently high temperature that it retains sufficient latent heat to cure the second polymeric material.

4. A method according to any preceding claim, wherein first polymeric material is injection moulded and said first polymeric material is at a temperature in excess of 300°C prior to contact with a mould.

5. A method according to claim 4, wherein said first polymeric material is at a temperature in excess of 400°C prior to contact with said mould.

6. A method according to any preceding claim, wherein prior to contact with said first polymeric material, the surface temperature of a surface of said mould which contacts said first polymeric material is at a temperature in the range 160°C to 200 °C.

7. A method according to any preceding claim, wherein said first polymeric material is moulded in a first mould and contact of said first polymeric material with said second polymeric material or one or more precursors thereof takes place whilst said first polymeric material is in said first mould.

8. A method according to claim 7, wherein the time elapsing between the completion of injection of said first polymeric material into the first mould and contact of said first polymeric material with the second polymeric material or one or more precursors thereof is less than 30 minutes .

9. A method according to any preceding claim, wherein initial contact of the first and second materials or one or more precursors thereof takes place when the first material is at a temperature at which the second material cures or is in excess thereof.

10. A method according to any preceding claim, wherein after moulding of said first polymeric material, first and second precursors of said second polymeric material are introduced into the first mould and contacted with the first polymeric material .

11. A method according to any preceding claim, wherein said second polymeric material is an elastomer.

12. A method according to any preceding claim, wherein said second polymeric material has a hardness, measured on the Shore A scale, of less than 120.

13. A method according to any preceding claim, wherein said second polymeric material has a hardness, measured on the Shore A scale, of 10 or greater and 70 or less.

14. A method according to any preceding claim, wherein said first polymeric material has a hardness on the Rockwell R scale of greater than 70.

15. A method according to any preceding claim, wherein said second polymeric material or one or more precursors thereof is/are curable at a temperature in the range 150 to 250⁰C.

16. A method according to any preceding claim, wherein said second polymeric material comprises a silicone rubber .

17. A method according to any preceding claim, wherein said first polymeric material comprises a first polymer which is a homopolymer having a repeat unit of general formula

or a homopolymer having a repeat unit of general formula

or a random or block copolymer of at least two different units of IV and/or V;

or a homopolymer having a repeat- unit of general formula

or a homopolymer having a repeat unit of general formula

or a random or block copolymer of at least two different units of IV* and/or V*, wherein A, B, C and D independently represent 0 or 1, m, r,-s,t,v,w and z independently represent zero or a positive integer, E and E' independently represent an oxygen or a sulphur atom or a direct link, G represents an oxygen or sulphur atom, a direct link or a -O-Ph-0- moiety where Ph represents a phenyl group and Ar is selected from one of the following moieties (i) **, (i) to (vi) which is bonded via one or more of its phenyl moieties to adjacent moieties

18. A method according to any preceding claim, wherein said first polymer comprises a repeat unit of formula (XX)

where tl and wl independently represent 0 or 1 and vl represents 0, 1 or 2.

19. A method according to any preceding claim, wherein said first polymer is polyetheretherketone .

20. A method according to any preceding claim, wherein said first polymeric material includes :

(i) 70-100wt% of thermoplastic polymer(s); and (ii) 0-30wt% of filler means.

21. A method of making a moulded product which includes a first polymeric material and a second polymeric material, the method comprising:

a) moulding the first polymeric material; b) contacting the first polymeric material with the second polymeric material (or one or more precursors thereof) , wherein said first polymeric material comprises a first polymer and said second polymeric material includes: a material having a hardness which is less than the hardness of said first polymeric material; or said second polymeric material comprises an elastomer; or said second polymeric material comprises a liquid silicone resin.

22. A moulded product which comprises a first polymeric material and, intimately in contact therewith, a second polymeric material wherein said first polymeric material comprises a first polymer of formula (XX)

where tl and wl independently represent 0 or 1 and vl represents 0, 1 or 2 and said second polymeric material includes a material having a hardness which is less than the hardness of said first polymeric material; or said second polymeric material comprises an elastomer; or said second polymeric material comprises and/or is derived from a liquid silicone resin.

23. Α moulded product according to claim 22, which comprises an over-moulding of an elastomer onto a rigid plastics material.

24. A moulded product which includes a first polymeric material which comprises a first polymer of formula (XX)

where tl and wl independently represent 0 or 1 and vl represents Q,- 1 or 2, wherein said first polymeric material is over-moulded with a second polymeric material, wherein said second polymeric material is a silicone elastomer.

25. A method of making a moulded product which comprises a first polymeric material, over-moulded with a second polymeric material, wherein the moulding of said first and second polymeric materials takes place in the same mould.