GB2550830A

GB2550830A - Welding of polymeric materials

Info

Publication number: GB2550830A
Application number: GB1510125.6A
Authority: GB
Inventors: Tanaka Masakazu; Padey Didier
Original assignee: Victrex Manufacturing Ltd
Current assignee: Victrex Manufacturing Ltd
Priority date: 2015-06-10
Filing date: 2015-06-10
Publication date: 2017-12-06
Also published as: GB201510125D0

Abstract

A method of joining a first component to a second component, wherein the first component comprises a surface (a) and one or more polymeric material selected from: a polymeric material (A) having a repeat unit of formula (I) -O-Ph-O-Ph-CO-Ph and a repeat unit of formula (II) -O-Ph-Ph-O-Ph-CO-Ph wherein Ph represents a phenylene moiety; and/or ii) a polymeric material (B) having a repeat unit of formula (III) -X-Ph-(X-Ph-),X-Ph-CO-Ph- and a repeat unit of formula (IV) -X-Y-W-Ph-Z- wherein Ph represents a phenylene moiety; each X independently represents an oxygen or sulphur atom; n represents an integer of 1 or 2; Y is selected from a phenylene moiety, a —Ph-Ph moiety and a naphthalenyl moiety; W is a carbonyl group, an oxygen or sulphur atom, Z is selected from -X-Ph-S02-Ph , -X-Ph-S02-Y-S02-Ph-, and -CO-Ph-; wherein the second component comprises a surface (b); and wherein the method comprises: welding the surface (a) and the surface (b) together to produce a welded article.

Description

Welding Of Polymeric Materials

This invention relates to the welding of polymeric materials, specifically the welding of copolymers containing either i) poly-(ether-phenyl-ether-phenyl-carbonyl-phenyl)- (i.e. polyetheretherketone, PEEK) and poly-(ether-phenyl-phenyl-ether-phenyl-carbonyl-phenyl)-(i.e. polyetherdiphenyletherketone, PEDEK), ii) poly-(ether-phenyl- ether-phenyl-ether-phenyl-carbonyl-phenyl)- (i.e. polyetheretheretherketone, PEEEK) and PEDEK or iii) PEEEK and poly-(ether-phenyl- ether-phenyl-ether-phenyl-sulphonyl-phenyl)- (i.e. polyetheretherethersulphone, PEEES).

There is a wide range of thermoplastic polymeric materials available for use in industry, either alone or as part of composite materials. Polyetheretherketone (PEEK) is a high performance, semi-crystalline thermoplastic with excellent mechanical and chemical resistance properties. PEEK is the material of choice for many commercial applications due to its high level of crystallinity and hence outstanding chemical resistance. Whilst PEEK has a suitable glass transition temperature (Tg) of 143°C, its melting temperature (Tm) of 343°C is much higher than is desirable for processing. Thus for some applications it is beneficial to use materials such as PEEK-PEDEK-copolymers, PEEEK-PEDEK-copolymers and/or PEEEK-PEEES-copolymers which possess relatively low Tm values but exhibit Tg values that are comparable to PEEK. These copolymers have improved fracture toughness while still maintaining a high level of crystallinity.

The above copolymers may be used in applications in which it is necessary to attach a component of the copolymer to another component. For example, mechanical fastenings in the form of rivets, bolts and snap fittings have been proposed. However, their use may not be suitable in many cases such as on blind holes. It would therefore be desirable to formulate new methods for attaching a first component comprising one or more of the above copolymers to a second component to form a high strength joint.

According to a first aspect of the present invention there is provided a method of joining a first component to a second component, wherein the first component comprises a surface (a) and one or more polymeric material selected from: i) a polymeric material (A) having a repeat unit of formula

I and a repeat unit of formula

II wherein Ph represents a phenylene moiety; and/or ii) a polymeric material (B) having a repeat unit of formula

III and a repeat unit of formula

IV wherein Ph represents a phenylene moiety; each X independently represents an oxygen or sulphur atom; n represents an integer of 1 or 2; Y is selected from a phenylene moiety, a -Ph-Ph moiety and a naphthalenyl moiety; W is a carbonyl group, an oxygen or sulphur atom, Z is selected from

wherein the second component comprises a surface (b); and wherein the method comprises: welding the surface (a) and the surface (b) together to produce a welded article.

The inventors of this invention have devised a method of joining components that surprisingly secures the components together with a high strength physio-chemical interaction (as opposed to solely a mechanical interaction), wherein at least the first component has excellent chemical resistance and long term mechanical properties.

In the following discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of other components. The term “consisting essentially of” or “consists essentially of” means including the components specified but excluding other components except for materials present as impurities, unavoidable materials present as a result of processes used to provide the components, and components added for a purpose other than achieving the technical effect of the invention. Typically, when referring to compositions, a composition consisting essentially of a set of components will comprise less than 5% by weight, typically less than 3% by weight, more typically less than 1% by weight of non-specified components.

The term “consisting of” or “consists of” means including the components specified but excluding other components.

Whenever appropriate, depending upon the context, the use of the term “comprises” or “comprising” may also be taken to include the meaning “consists essentially of” or “consisting essentially of”, and also may also be taken to include the meaning “consists of” or “consisting of”.

References herein such as “in the range x to y” are meant to include the interpretation “from x to y” and so include the values x and y.

The welding may be performed by an external heat source, e.g. hot plate welding, hot bar/impulse welding, hot gas welding and/or extrusion welding; mechanical movement, e.g. linear vibration welding, spin welding and/or ultrasonic welding; and/or electromagnetism, e.g. resistive welding, induction welding, high frequency welding, infrared welding and/or laser welding. Preferably the welding is performed by ultrasonic welding and/or laser welding. Most preferably the welding is performed by ultrasonic welding.

The ultrasonic welding may comprise holding surface (a) of the first component and surface (b) of the second component together under pressure and subjecting said first and second components to ultrasonic vibrations. The ultrasonic welding may be suitably carried out using a sonotrode under manual or computer control. The sonotrode preferably has a terminal welding surface which is circular or substantially equilaterally polygonal in shape. The terminal welding surface may be planar or curved and may be flat (i.e. smooth) or roughened. The sonotrode may preferably comprise a terminal welding surface having a maximum width of 100mm or less, more preferably of 20mm or less, even more preferably of 6mm or less. The maximum width is measured through the centroid of the terminal welding surface.

The sonotrode may contact the first component or the second component. The sonotrode introduces ultrasonic vibration into the component that it contacts, so that either surface (a) or surface (b) is moved with high frequency over surface (b) or surface (a) respectively and heat is generated in a welding region at said surfaces creating an ultrasonic welding joint. Preferably the ultrasonic welding is carried out at an amplitude of from 0.001 mm to 1 mm, more preferably from 0.01mm to 0.5mm, even more preferably from 0.02mm to 0.1mm, most preferably from 0.03mm to 0.06mm. Preferably the ultrasonic welding is carried out at an applied pressure of from 0.1 MPa to 100MPa, more preferably from 1MPa to 30MPa, even more preferably from 4MPa to 20MPa. Preferably the ultrasonic welding is carried out for a weld time of from 0.1s to 10min, more preferably from 0.5s to 1 min, even more preferably from 1s to 20s, most preferably from 1,5s to 10s. Preferably the ultrasonic welding is carried out at a frequency of from 5kHz to 300kHz, more preferably from 15kHz to 200kHz, even more preferably from 20kHz to 100kHz.

Preferably surface (a) and/or surface (b) has a longest dimension of at most 50cm, more preferably at most 25cm, even more preferably at most 10cm, most preferably at most 5cm. Preferably surface (a) or surface (b) comprises a projection. Said projection may taper to an apex. Such a projection is useful for ultrasonically welding a projection joint by affording a small, uniform initial contact area that acts as an energy director. The purpose of the energy director is to focus the ultrasonic energy at the apex, resulting in a rapid build-up of heat. This causes the projection to melt and flow across a joint interface, forming a weld. The projection may preferably have a longest dimension measured at a right angle from said surface (a) or surface (b) from which it projects of from 0.01mm to 5cm, more preferably from 0.05mm to 1cm, even more preferably from 0.1mm to 5mm, most preferably from 0.2mm to 1mm. Preferably said projection has a generally triangular cross section. As an alternative to a projection joint, the welding may form a shear joint via the shearing of a component inside another component, providing self-location.

The laser welding may involve melting at least a portion of either or both of surfaces (a) and (b) and subsequently holding said surfaces together under pressure. Alternatively, the laser welding may involve transmission laser welding, wherein surfaces (a) and (b) are held together and a laser beam passes through surface (a) and/or surface (b), wherein the laser beam is at least partly absorbed by at least one of surface (a) and/or surface (b). Preferably the laser is an IR laser.

Preferably surface (a) and/or surface (b) comprises one or more of a polymeric material and/or a metal. More preferably surface (a) and/or surface (b) comprises one or more polymeric material comprising a repeat unit of formula (V):

wherein t1 and w1 independently represent 0 or 1 and v1 represents 0, 1 or 2.

Most preferably surface (a) and/or surface (b) comprises one or more of polymeric material (A) and/or (B). Preferably surface (a) and/or surface (b) comprises one or more of a polymeric material and/or a metal to a depth of at least 0.1 pm, more preferably at least 1pm, even more preferably at least 10pm, most preferably at least 100pm.

The following features are applicable to polymeric material (A):

Preferably the repeat units I and II are in the relative molar proportions l:ll of from 65:35 to 95:5, e.g. 75:25.

Preferably, in polymeric material (A), the following relationship applies: logio (X%) > 1.50 - 0.26 MV; wherein X% refers to the % crystallinity measured as described in Example 31 of WO2014207458A1 incorporated herein, and MV refers to the melt viscosity measured using capillary rheometry operating at 340°C at a shear rate of 1000s"1 using a circular cross-section tungsten carbide die, 0.5mm (capillary diameter) x 3.175mm (capillary length). The MV measurement is taken 5 minutes after the polymer has fully melted, which is taken to be 5 minutes after the polymer is loaded into the barrel of the rheometer.

The phenylene moieties (Ph) in each repeat unit may independently have 1,4- para linkages to atoms to which they are bonded or 1,3- meta linkages. Where a phenylene moiety includes 1,3- linkages, the moiety will be in the amorphous phase of the polymer. Crystalline phases will include phenylene moieties with 1,4- linkages. In many applications it is preferred for the polymeric material to be highly crystalline and, accordingly, the polymeric material preferably includes high levels of phenylene moieties with 1,4- linkages.

In a preferred embodiment, at least 95%, preferably at least 99%, of the number of phenylene moieties (Ph) in the repeat unit of formula I have 1,4-linkages to moieties to which they are bonded. It is especially preferred that each phenylene moiety in the repeat unit of formula I has 1,4- linkages to moieties to which it is bonded.

In a preferred embodiment, at least 95%, preferably at least 99%, of the number of phenylene moieties (Ph) in the repeat unit of formula II have 1,4-linkages to moieties to which they are bonded. It is especially preferred that each phenylene moiety in the repeat unit of formula II has 1,4- linkages to moieties to which it is bonded.

Preferably, the phenylene moieties in repeat unit of formula I are unsubstituted. Preferably, the phenylene moieties in repeat unit of formula II are unsubstituted.

Said repeat unit of formula I suitably has the structure

Said repeat unit of formula II suitably has the structure

Preferred polymeric materials (A) in accordance with the invention have a crystallinity which is greater than expected from the prior art. Preferably, log10 (X%) > 1.50 - 0.23 MV. More preferably logio (X%) > 1.50 - 0.28 MV + 0.06 MV2.

Said polymeric material (A) may include at least 68 mol%, preferably at least 71 mol% of repeat units of formula I. Particular advantageous polymeric materials (A) may include at least 72mol%, or, especially, at least 74 mol% of repeat units of formula I. Said polymeric material (A) may include less than 90 mole%, suitably 82mol% or less of repeat units of formula I. Said polymeric material (A) may include 68 to 82 mol%, preferably 70 to 80 mol%, more preferably 72 to 77 mol% of units of formula I.

Said polymeric material (A) may include at least 10mol%, preferably at least 18 mol%, of repeat units of formula II. Said polymeric material (A) may include less than 32 mol%, preferably less than 29 mol% of repeat units of formula II. Particularly advantageous polymeric materials (A) may include 28 mol% or less; or 26 mol% or less of repeat units of formula II. Said polymeric material (A) may include 18 to 32mol%, preferably 20 to 30mol%, more preferably 23 to 28mol% of units of formula II.

The sum of the mol% of units of formula I and II in said polymeric material (A) is suitably at least 95mol%, is preferably at least 98mol%, is more preferably at least 99mol% and, especially, is about 100mol%.

The ratio defined as the mol% of units of formula I divided by the mol% of units of formula II may be in the range 1.8 to 5.6, is suitably in the range 2.3 to 4 and is preferably in the range 2.6 to 3.3.

The Tm of said polymeric material (A) (suitably measured as described herein) may be less than 330°C, is suitably less than 320Ό, is preferably less than 310°C. In some embodiments, the Tm may be less than 306°C. The Tm may be greater than 280^, or greater than 290°C, 295°C or 300°C. The Tm is preferably in the range 300°C to 310°C.

The Tg of said polymeric material (A) (suitably measured as described herein) may be greater than 130°C, preferably greater than 135°C, more preferably 140°C or greater. The Tg may be less than 175°C, less than 165°C, less than 160°C or less than 155°C. The Tg is preferably in the range 145Ό to 155°C.

The difference (Tm-Tg) between the Tm and Tg may be at least 130°C, preferably at least 140°C, more preferably at least 150°C. The difference may be less than 170¾ or less than 165°C. In a preferred embodiment, the difference is in the range 145-165°C.

In a preferred embodiment, said polymeric material (A) has a Tg in the range 145°C-155°C, a Tm in the range 300°C to 310°C and the difference between the Tm and Tg is in the range 145°C to 165°C.

Said polymeric material (A) may have a crystallinity of at least 25%, measured as described in Example 31 of WO2014207458A1 incorporated herein.

Said polymeric material (A) suitably has a melt viscosity (MV) of at least 0.10 kNsm'2, preferably has a MV of at least 0.15 kNsm"2, more preferably at least 0.20 kNsm"2, especially at least 0.25 kNsm'2. MV is suitably measured using capillary rheometry operating at 340¾ at a shear rate of 1000s'1 using a tungsten carbide die, 0.5mm x 3.175mm. Said polymeric material (A) may have a MV of less than 1.8 kNsm"2, suitably less than 1.2 kNsm'2.

Said polymeric material (A) may have a tensile strength, measured in accordance with IS0527 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 polymeric material (A) may have a flexural strength, measured in accordance with IS0178 of at least 130 MPa. The flexural strength is preferably in the range 135-180 MPa, more preferably in the range 140-150 MPa.

Said polymeric material (A) may have a flexural modulus, measured in accordance with IS0178 of at least 2 GPa, preferably at least 3GPa. The flexural modulus is preferably in the range 3.0-4.5 GPa, more preferably in the range 3.0-4.0 GPa.

Said polymeric material (A) may be in the form of pellets or granules, wherein the pellets or granules include at least 95wt%, preferably at least 99wt%, especially about 100wt% of said polymeric material (A). Pellets or granules may have a maximum dimension of less than 10mm, preferably less than 7.5mm, more preferably less than 5.0mm.

The following features are applicable to polymeric material (B):

The phenylene moieties in each repeat unit may independently have 1,4- linkages to atoms to which they are bonded or 1,3- linkages. Where a phenylene moiety includes 1,3- linkages, the moiety will be in amorphous phases of the polymer. Crystalline phases will include phenylene moieties with 1,4- linkages. In many situations it is preferred for the polymeric material to be crystalline and, accordingly, said polymeric material preferably includes phenylene moieties with 1,4- linkages.

In a preferred embodiment, each Ph moiety in the repeat unit of formula III has 1,4- linkages to moieties to which it is bonded.

In a preferred embodiment, each Ph moiety in the repeat unit of formula IV has 1,4- linkages to moieties to which it is bonded.

In repeat unit III, each X preferably represents an oxygen atom.

Preferably, n represents 1.

In repeat unit III, preferably each phenylene moiety has 1,4- linkages to atoms to which it is bonded.

In repeat unit IV, each X preferably represents an oxygen atom.

Preferably, Y is selected from a phenylene moiety and a -Ph-Ph- moiety, wherein each Ph moiety in said -Ph-Ph- includes 1,4- linkages. More preferably, Y is a -Ph-Ph- moiety wherein each phenylene moiety has 1,4- linkages.

Preferably, W represents an oxygen atom.

Preferably, Z is -CO-Ph-, suitably wherein Ph has 1,4- linkages.

In a preferred embodiment, said repeat unit of formula III has the structure:

and said repeat unit of formula IV has the structure:

The Tm of said polymeric material (B) may be less than 298°C, alternatively less than 296^0, is suitably less than 293^, is preferably less than 290°C. In some embodiments, the Tm may be less than 287°C or less than 285°C. The Tm may be greater than 270¾. or greater than 275°C, 280°C or 285°C. The Tm is preferably in the range 280°C to 295°C.

The Tg of said polymeric material (B) may be greater than 120°C, preferably greater than 130°C, more preferably 133¾ or greater. The Tg may be less than 175°C, less than 150°C, less than 140°C or less than 130°C. The Tg is preferably in the range 130°C to 140°C.

The difference (Tm-Tg) between the Tm and Tg may be at least 130¾. preferably at least 140°C, more preferably at least 150°C. The difference may be less than 170¾ or less than 161 °C. In a preferred embodiment, the difference is in the range 150-160°C.

In a preferred embodiment, said polymeric material (B) has a Tg in the range 130°C-140°C, a Tm in the range 285°C to 292°C and the difference between the Tm and Tg is in the range 150°C to 161 °C.

Said polymeric material (B) may have a crystallinity, measured as described in Example 31 of WO2014207458A1 incorporated herein, of at least 10%, preferably at least 20%, more preferably at least 25%. The crystallinity may be less than 50% or less than 40%.

Said polymeric material (B) suitably has a melt viscosity (MV) of at least 0.06 kNsm'2, preferably has a MV of at least 0.08 kNsm"2, more preferably at least 0.085 kNsm"2, especially at least 0.09 kNsm'2. MV is suitably measured using capillary rheometry operating at 400¾ at a shear rate of 1000s"1 using a tungsten carbide die, 0.5x3.175mm. Said polymeric material (B) may have a MV of less than 1.00 kNsm'2, suitably less than 0.5 kNsm'2.

Said polymeric material may (B) 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 polymeric material (B) 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 polymeric material (B) 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 polymeric material (B) may include at least 50mol%, preferably at least 60mol%, more preferably at least 65mol%, especially at least 70mol% of repeat units of formula III. Particular advantageous polymeric materials (B) may include at least 72mol%, or, especially, at least 74mol% of repeat units of formula III. Said polymeric material (B) may include less than 85 mole%, suitably 80mol% or less of repeat units of formula III. Said polymeric material (B) may include 68 to 82 mole%, preferably 70 to 80mol%, more preferably 72 to 77mol% of units of formula III.

Said polymeric material (B) may include at least 15mol%, preferably at least 20mol%, of repeat units of formula IV. Said polymeric material (B) may include less than 50mol%, preferably less than 40mol%, more preferably less than 35mol%, especially less than 30mol% of repeat units of formula IV. Particularly advantageous polymeric materials (B) may include 28mol% or less; or 26mol% or less. Said polymeric material (B) may include 18 to 32mol%, preferably 20 to 30mol%, more preferably 23 to 28mol% of units of formula IV.

The sum of the mole% of units of formula III and IV in said polymeric material is suitably at least 95mol%, is preferably at least 98mol%, is more preferably at least 99mol% and, especially, is about 100mol%.

The ratio defined as the mole% of units of formula III divided by the mole% of units of formula IV may be in the range 1.8 to 5.6, is suitably in the range 2.3 to 4 and is preferably in the range 2.6 to 3.3.

The following features are generally applicable to the present invention:

Said polymeric material may form part of a composition which may comprise said polymeric material and 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. 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 fibre, carbon fibre, asbestos fibre, silica fibre, alumina fibre, zirconia fibre, boron nitride fibre, silicon nitride fibre, boron fibre, fluorocarbon resin fibre and potassium titanate fibre. 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.

Said composition may define a composite material which could be prepared as described in Impregnation Techniques for Thermoplastic Matrix Composites. A Miller and A G Gibson, Polymer & Polymer Composites 4(7), 459 - 481 (1996), EP102158 and EP102159, the contents of which are incorporated herein by reference. Preferably, in the method, said polymeric material and said filler means are mixed at an elevated temperature, suitably at a temperature at or above the melting temperature of said polymeric material. Thus, suitably, said polymeric material and filler means are mixed whilst the polymeric material is molten. Said elevated temperature is suitably below the decomposition temperature of the polymeric material. Said elevated temperature is preferably at or above the main peak of the melting endotherm (Tm) for said polymeric material. Said elevated temperature is preferably at least 300fiC. Advantageously, the molten polymeric material can readily wet the filler and/or penetrate consolidated fillers, such as fibrous mats or woven fabrics, so the composite material prepared comprises the polymeric material and filler means which is substantially uniformly dispersed throughout the polymeric material.

The composite material may be prepared in a substantially continuous process. In this case polymeric material and filler means may be constantly fed to a location wherein they are mixed and heated. An example of such a continuous process is extrusion. Another example (which may be particularly relevant wherein the filler means comprises a fibrous filler) involves causing a continuous filamentous mass to move through a melt or aqueous dispersion comprising said polymeric material. The continuous filamentous mass may comprise a continuous length of fibrous filler or, more preferably, a plurality of continuous filaments which have been consolidated at least to some extent. The continuous fibrous mass may comprise a tow, roving, braid, woven fabric or unwoven fabric. The filaments which make up the fibrous mass may be arranged substantially uniformly or randomly within the mass. A composite material could be prepared as described in PCT/GB2003/001872, US6372294 or EP1215022.

Alternatively, the composite material may be prepared in a discontinuous process. In this case, a predetermined amount of said polymeric material and a predetermined amount of said filler means may be selected and contacted and a composite material prepared by causing the polymeric material to melt and causing the polymeric material and filler means to mix to form a substantially uniform composite material.

The composite material may be formed into a particulate form for example into pellets or granules. Pellets or granules may have a maximum dimension of less than 10mm, preferably less than 7.5mm, more preferably less than 5.0mm.

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 fibre.

The composition, may consist or consist essentially of the polymeric material, or may include, for instance from 60 to 100%, say from 75 to 100% of the polymeric material, with from 0 to 40%, say from 0 to 25% of other materials. A composition or composite material as described may include 20 to 99.9wt% (e.g. 20 to 70wt%) of said polymeric material and 0.1 to 80wt% (e.g. 30 to 80wt%) of filler means. Preferred embodiments include greater than 40wt% of filler means.

The second component may comprise one or more metal, polymeric material, ceramic, concrete, glass, and/or wood. The metal may comprise any suitable metal such as one or more of aluminium, titanium, iron, chromium, nickel, copper, zinc, palladium, silver and/or gold. The metal may comprise an alloy such as steel.

The second component may comprise a polymeric material, preferably a thermoplastic polymeric material. The second component may be formed of a composition that comprises a polymeric material. Preferably the second component is formed of a composition comprising a polymeric material (C), wherein the polymeric material comprises a repeat unit of formula (V):

wherein t1 and w1 independently represent 0 or 1 and v1 represents 0,1 or 2.

The polymeric material (C) preferably consists essentially of a repeat unit of formula V. Preferred polymeric materials (C) comprise (or consist essentially of) a repeat unit wherein tl =1, v1 =0 and w1 =0; t1 =0, v1 =0 and w1 =0; t1 =0, w1 =1, v1 =2; or t1 =0, v1 =1 and w1 =0. More preferred polymeric materials (C) comprise (or consist essentially of) a repeat unit wherein t1=1, v1=0 and w1=0; or t1 =0, v1=0 and w1=0. The most preferred polymeric material (C) comprises (or consists essentially of) a repeat unit wherein t1=1, v1=0 and w1=0: in other words a homopolymeric polyetheretherketone.

In preferred embodiments, the polymeric material (C) is selected from polyetheretherketone, polyetherketone, polyetherketoneetherketoneketone and polyetherketoneketone. In a more preferred embodiment, the polymeric material (C) is selected from polyetherketone and polyetheretherketone. In another preferred embodiment, the polymeric material (C) is polyetheretherketone such as a homopolymer polyetheretherketone.

The polymeric material (C) may have a Notched Izod Impact Strength (specimen 80mm x 10mm x 4mm with a cut 0.25mm notch (Type A), tested at 23fiC, in accordance with ISO180) of at least 4KJm"2, preferably at least 5KJm'2, more preferably at least 6KJm"2. The Notched Izod Impact Strength may be less than 10KJm"2, suitably less than 8KJm"2. The Notched Izod Impact Strength may be at least 3KJm"2, suitably at least 4KJm'2, preferably at least 5KJm"2. The impact strength may be less than 50 KJm"2, suitably less than 30KJm"2.

The polymeric material (C) suitably has a melt viscosity (MV) of at least 0.06 kNsm"2, preferably has a MV of at least 0.09 kNsm"2, more preferably at least 0.12 kNsm'2, or at least 0.15 kNsm"2. Advantageously, the MV may be at least 0.35 kNsm'2 and/or at least 0.40 kNsm" 2l An MV of 0.45 kNsm"2 has been found to be particularly advantageous in the manufacture of strong joints.

The polymeric material (C) may have a MV of less than 1.00 kNsm'2, preferably less than 0.5 kNsm"2.

The polymeric material (C) may have a MV in the range 0.09 to 0.5 kNsm'2, preferably in the range 0.14 to 0.5 kNsm"2, more preferably in the range 0.4 to 0.5 kNsm'2.

The polymeric material (C) may have a tensile strength, measured in accordance with IS0527 (specimen type 1 b) tested at 23°C at a rate of 50mm/minute 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.

The polymeric material (C) may have a flexural strength, measured in accordance with IS0178 (80mm x 10mm x 4mm specimen, tested in three-point-bend at 23°C at a rate of 2mm/minute) 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.

The polymeric material (C) may have a flexural modulus, measured in accordance with IS0178 (80mm x 10mm x 4mm specimen, tested in three-point-bend at 23°C at a rate of 2mm/minute) 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.

The polymeric material (C) may be amorphous or semi-crystalline. It is preferably crystallisable. It is preferably semi-crystalline. The level of crystallinity of the polymeric material (C) may be at least 1%, suitably at least 3%, preferably at least 5% and more preferably at least 10%. In or preferred embodiments, the crystallinity may be greater than 25%. It may be less than 50% or less than 40%.

The main peak of the melting endotherm (Tm) of the polymeric material (C) (if crystalline) may be at least 300^.

For the polymeric material (C), it is preferred that t1 =1, v1 =0 and w1 =0.

The polymeric material of the first component may be the same polymeric material as the polymeric material of the second component, or, alternatively, the polymeric material of the first component may be a different polymeric material to the polymeric material of the second component. In some embodiments the second component may comprise one or more of polymeric material (A) and/or (B).

In the context of the present invention, the Glass Transition Temperature (Tg), the Cold Crystallisation Temperature (Tn), the Melting Temperature (Tm) and Heat of Fusions of Nucleation (ΔΗη) and Melting (ΔΗιτι) are determined using the following DSC method: A dried sample of a polymer is compression moulded into an amorphous film, by heating 7g of polymer in a mould at 400°C under a pressure of 50bar for 2 minutes, then quenching in cold water producing a film of dimensions 120 x120mm, with a thickness in the region of 0.20mm. A 8mg plus or minus 3mg sample of each film is scanned by DSC as follows:

Step 1 Perform and record a preliminary thermal cycle by heating the sample from 30°C to 400°C at 20°C /min.

Step 2 Hold for 5 minutes.

Step 3 Cool at 20°C/min to 30°C and hold for 5mins.

Step 4 Re-heat from 30°C to 400°C at 20°C/min, recording the Tg, Tn, Tm, ΔΗη and AHm.

From the DSC trace resulting from the scan in step 4, the onset of the Tg is obtained as the intersection of the lines drawn along the pre-transition baseline and a line drawn along the greatest slope obtained during the transition. The Tn is the temperature at which the main peak of the cold crystallisation exotherm reaches a maximum. The Tm is the temperature at which the main peak of the melting endotherm reaches a maximum.

The Heats of Fusion for Nucleation (ΔΗη) and Melting (ΔΗιτι) are obtained by connecting the two points at which the cold crystallisation and melting endotherm(s) deviate from the relatively straight baseline. The integrated areas under the endotherms as a function of time yield the enthalpy (mJ) of the particular transition, the mass normalised Heats of Fusion are calculated by dividing the enthalpy by the mass of the specimen (J/g).

According to a second aspect of the present invention there is provided a welded article produced in accordance with the method of the first aspect.

According to a third aspect of the present invention there is provided a welded article comprising a first component welded to a second component, wherein the first component comprises a surface (a) and one or more polymeric material selected from: i) a polymeric material (A) having a repeat unit of formula

I and a repeat unit of formula

III and a repeat unit of formula

wherein the second component comprises a surface (b); and wherein surface (a) and surface (b) are welded together.

Preferably surface (a) and surface (b) have been welded together by ultrasonic welding and/or laser welding.

According to a fourth aspect of the present invention there is provided the use of welding to join a first component to a second component, wherein the first component comprises a surface (a) and one or more polymeric material selected from: i) a polymeric material (A) having a repeat unit of formula

I and a repeat unit of formula

III and a repeat unit of formula

Preferably the welding comprises ultrasonic welding and/or laser welding.

According to a fifth aspect of the present invention there is provided the use of the welded article produced in accordance with the first aspect, or the welded article in accordance with the second or third aspects, in automotive, medical, electronic, oil and/or gas applications.

It will be appreciated that optional features applicable to one aspect of the invention can be used in any combination, and in any number. Moreover, they can also be used with any of the other aspects of the invention in any combination and in any number. This includes, but is not limited to, the dependent claims from any claim being used as dependent claims for any other claim in the claims of this application.

The reader’s attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A method of joining a first component to a second component, wherein the first component comprises a surface (a) and one or more polymeric material selected from: i) a polymeric material (A) having a repeat unit of formula

I and a repeat unit of formula

III and a repeat unit of formula

2. The method according to claim 1, wherein the welding is performed by ultrasonic welding and/or laser welding.

3. The method according to any preceding claim, wherein surface (a) and/or surface (b) comprises one or more of a polymeric material and/or a metal.

4. The method according to any preceding claim, wherein surface (a) and/or surface (b) comprises one or more polymeric material comprising a repeat unit of formula (V):

wherein t1 and w1 independently represent 0 or 1 and v1 represents 0, 1 or 2.

5. The method according to any preceding claim, wherein surface (a) and/or surface (b) comprises one or more of polymeric material (A) and/or (B).

6. The method according to any preceding claim, wherein the repeat units I and II are in the relative molar proportions l:ll of from 65:35 to 95:5, e.g. 75:25.

7. The method according to any preceding claim, wherein at least 95%, preferably at least 99%, of the number of phenylene moieties (Ph) in the repeat unit of formula I have 1,4-linkages to moieties to which they are bonded, and/or wherein at least 95%, preferably at least 99%, of the number of phenylene moieties (Ph) in the repeat unit of formula II have 1,4-linkages to moieties to which they are bonded.

8. The method according to any preceding claim, wherein said repeat unit of formula I has the structure

and/or wherein said repeat unit of formula II has the structure

9. The method according to any preceding claim, wherein polymeric material (A) has a crystallinity of log10 (X%) > 1.50 - 0.26 MV wherein X% refers to the % crystallinity.

10. The method according to any preceding claim, wherein polymeric material (A) includes 68 to 82mol% of units of formula I.

11. The method according to any preceding claim, wherein polymeric material (A) includes 18 to 32mol% of units of formula II.

12. The method according to any preceding claim, wherein the Tm of polymeric material (A) is in the range 300¾ to 310°C.

13. The method according to any preceding claim, wherein the polymeric material (A) has a Tg in the range 145Ό-155°0, a Tm in the range 300°C to 31 CPC and the difference between the Tm and Tg is in the range 145¾ to 165°C.

14. The method according to any preceding claim, wherein each Ph moiety in the repeat unit of formula III has 1,4- linkages to moieties to which it is bonded and/or wherein each Ph moiety in the repeat unit of formula IV has 1,4- linkages to moieties to which it is bonded.

15. The method according to any preceding claim, wherein in repeat unit III, each X represents an oxygen atom, and/or wherein in repeat unit IV, each X represents an oxygen atom.

16. The method according to any preceding claim, wherein said repeat unit of formula III has the structure:

and said repeat unit of formula IV has the structure:

17. The method according to any preceding claim, wherein the Tm of said polymeric material (B) is less than 298°C, preferably less than 296°C; and/or the Tg of said polymeric material (B) is greater than 120°C, preferably greater than 130°C; and/or the difference (Tm-Tg) between the Tm and Tg is at least 130°C, preferably at least 140¾.

18. The method according to any preceding claim, wherein said polymeric material (B) includes at least 60mol% of repeat units of formula III and less than 40mol% of repeat units of formula IV.

19. The method according to any preceding claim, wherein the second component comprises one or more metal, polymeric material, ceramic, concrete, glass, and/or wood.

20. The method according to claim 19, wherein the metal comprises one or more of aluminium, titanium, iron, chromium, nickel, copper, zinc, palladium, silver and/or gold.

21. The method according to any preceding claim, wherein the second component is formed of a composition comprising a polymeric material (C), wherein the polymeric material comprises a repeat unit of formula (V):

wherein t1 and w1 independently represent 0 or 1 and v1 represents 0, 1 or 2.

22. The method according to claim 21, wherein the polymeric material (C) is selected from polyetheretherketone, polyetherketone, polyetherketoneetherketoneketone and polyetherketoneketone.

23. The method according to any preceding claim, wherein the one or more polymeric material of the first component is different to the one or more polymeric material of the second component.

24. The method according to any preceding claim, wherein said polymeric material (A), (B) and/or (C) forms part of a composition which comprises said polymeric material and a filler means, wherein preferably said filler means comprises one or more fillers selected from glass fibre, carbon fibre, carbon black and a fluorocarbon resin.

25. A welded article produced in accordance with the method of any of claims 1 -24.

26. A welded article comprising a first component welded to a second component, wherein the first component comprises a surface (a) and one or more polymeric material selected from: i) a polymeric material (A) having a repeat unit of formula

I and a repeat unit of formula

III and a repeat unit of formula

27. The welded article according to claim 26, wherein surface (a) and surface (b) have been welded together by ultrasonic welding and/or laser welding.

28. The use of welding to join a first component to a second component, wherein the first component comprises a surface (a) and one or more polymeric material selected from: i) a polymeric material (A) having a repeat unit of formula

I and a repeat unit of formula

III and a repeat unit of formula

IV wherein Ph represents a phenylene moiety; each X independently represents an oxygen or sulphur atom; n represents an integer of 1 or 2; Y is selected from a phenylene moiety, a -Ph-Ph moiety and a naphthalenyl moiety; W is a carbonyl group, an oxygen or sulphur atom, Z is selected from -X-Ph-S02-Ph--X-Ph-S02-Y-S02-Ph- and -CO-Ph-; wherein the second component comprises a surface (b); and wherein surface (a) and surface (b) are welded together.

29. The use according to claim 28, wherein the welding comprises ultrasonic welding and/or laser welding.

30. The use of the welded article produced in accordance with any of claims 1-24, or the welded article in accordance with any of claims 25-27, in automotive, medical, electronic, oil and/or gas applications.