Title of Invention

PLASTICS COMPOSITE MOULDINGS OBTAINABLE VIA WELDING IN AN ALTERNATING ELECTROMAGNETIC FIELD

Abstract

Plastics composite mouldings obtainable via welding in an alternating electroxnagnetic field The invention relates to plastics composite mouldings obtainable via welding in an alternating electromagnetic field, in which the weld is obtain ed with the aid of a plastics material which comprises nano-scale, frenetic oxidic particles, which are composed of aggregated primary particles, and where the primary particles are compos ed of magnetic metal oxide dorrains whos e diamet er is from 2 to 100 nm in a non¬magnetic metal oxide matrix or non-magnetic metalloid oxide matrix.

Full Text

Plastics composite mouldings obtainable via welding in an alt ernating electromagn etic fi eld The invention relates to plastics corrposite mouldings obtainable via welding in an alternating elect romagn etic f i eld, wher e the weld is achieved with the aid of a plastics material which corrprises nano-scale, magnetic oxidic particles. Plastics mouldings can be bonded by a very wide variety of plastics welding processes. Familiar processes are heat ed-t ool welding, heat ed-coil welding, ultrasound welding, vibration welding, las er trans mission welding, spin welding and high-f r equenc y welding. Processes of jointing by means of an alternating el ect romagn etic f i eld or by means of microwaves ar e 1 ess of t en us ed and are still considered to be specia1ized processes. In the case of laser transmission welding, at least the moulding facing towards the radiation sourc e has to be transparent to the las er beam, thus restricting the pigmentation and c olouring of the plastics materials that can be used. In contrast, the r estrictions in r elation to colorants do not arise in the case of welding in an aut omating el ect romagn etic f i eld. Welding with elect romagnetic radiation (induction welding) usually requires a welding aid which is magnetically activatable per se or by virtue of appropriate ingredients. The welding aid becomes heated via hysteresis losses and/or eddy-current losses, and energy input here during inductive heating is about 1500 times higher than when conducted heat is used. The phas es of induction welding include melting, melt fusion and consolidation, and the welding process can ■« be carried out continuously or batchwise. The welding aid can, for example, be placed in the form of sheets or foils between the joint areas of the mouldings to be joined. Magnetic activatabilit y is often generated via metallic inclusions, but this complicat es the production process of the plastics parts to be joined and these inclusions are sometimes undesirable in the downstream product. Welding aids with particulate f erroiragnetic fillers are relatively expensive and exhibit poor ef f ectiveness factors, and this has hitherto prevented the process from becoming one of the well-established jointing processes. It was ther ef or e an obj ect of the invention to develop plastics mat erials which are magnetically activatable via appropriat e additives, thus providing weldabilit y of the same in an alternating electromagnetic field. Thes e mat erials should be capable of use either in the f or m of int egral c onstituents of the plastics mouldings to be joined or in the form of additional welding aids, DE-A-19 92 4138 claims an adhesive composition which corrpris es int er alia nano-scale particles with super-pararragnetic properti es. DE-A-1016 3399 describes a nanoparticulat e pr eparation which has a coherent phase and at least one particulate phas e coirpos ed of superparamagnetic nano-scale particles dispersed therein. Preference is given here to preparations in the form of an adhesive conposition. The conpositions of DE-A-19924138 and DE-A-10163399 can be heat ed in an alt ernating electromagnetic f i eld. The particles used not only in DE-A-19924138 but also in DE-A-10 16 339 9 have pr ef erably been surf ac e-modif led or surface-coated, in order to inhibit agglomeration or accretion of the nano-scale particles and/or in order r to provide good dispersibilit y of the particulate phase in the coherent phase. A disadvantage here is that the substanc es us ed f or surf ac e coating or f or surf ac e modification can be released in particular on exposure to high t enperatures and/or to high levels of mechanical action. A consequence is that the nano-scale particles can agglomerat e or accr et e, thus losing their s up er par a magn et ic pr op ert i es. The rheological properties of the nan oparticulat e preparation according to DE-A-1016 3399 or of the adhesive corrposition according to DE-A-1992 4138 can be adjusted widely via the nature and amount of the dispersion medium However, it is impossible, or possible only to a li mit ed ext ent, to adjust the rheology of the pr eparation via the nano-scale, super-pararragnetic particles thems elves, sine e the super¬paramagnetic properties are associat ed withc ertain particle sizes. The particles almost entirely take the f or m of pri mar y particles in the preparation, and therefore the only possible method for adjusting rheology, f or example thickening, at the same ti me involves variation in the content of superparamagn etic particl es. The previous patent application DE 10 20 0 40 57 8 30 of 01. 12. 2004, which was unpublished at the earliest pri or it y dat e of the pr es ent invention, and the entire c ont ent of which is inc orporat ed her ein by way of reference, describes an adhesive corrposition corrprising a polymerizable monomer and/or a polymer and superparamagnetic oxidic particles dispersed therein which are composed of aggregat ed primary particles , where the prirrery particles are corrposed of rregnetic metal oxide domains whose diameter is from 2 to 100 nm in a non-magn etic metal oxide matrix or non-magn etic metalloid oxide matrix. Surprisingly, it has now been found that nano-scale, magnetic oxidic particles are suitable additives for plastics materials, for providing weldability of the same in an alternating electromagnetic field. Accordingly, the invention provides the use of nano-scale, magnetic oxidic particles as additives in plastics materials, for providing weldability of the same in an alternating electromagnetic field. The invention also provides a process for the production of a plastics corrposite moulding via welding in an alt ernating electromagn etic f i eld, in which the weld is achieved with the aid of a plastics rraterial which c orrpris es nano-scale, magn etic oxidic particles. The invention in particular provides plastics composite weldings obtainable via welding in an alt ernating electromagn etic field, wher e the weld is achieved with the aid of a plastics material which corrprises nano-scale, magnetic oxidic particles. The HBgnetic oxidic particles are very substantially in homogeneous dispersion within the inventive plastics riBterials and in particular are in non-agglomerat ed form Within the plastics Jiaterials, these particles are in particular stable to temperature variation and exhibit no agglomeration even at high t errperatur es. It is moreover possible to control the rheology of the compositions very substantially independently of the content of these particles. For the purposes of the present invention, the term aggr egat ed indie at es three-dimensional structures of accr et ed pri mary particles. Bonding between a pluralit y of aggregates can give agglomerates. These agglomerates can readily be separat ed again via mechanical action, e. g. during extrusion proc edur es. In contrast to this, it is generally not possible to break d own the aggregates to give the primary particles. The diameter of the aggregates of the nano-scale, magnetic oxidic particles can preferably be greater than 100 nm and smaller than 1 µm. It is preferable that the diameter of the aggregates of the nano-scale, magnetic oxidic particles, at least in one spatial direction, is not more than 250 nm. Figure 1 illustrat es this situation, in which the diamet er of two branches of an aggr egat e is 80 n m and 135 n m The term domains indieat es regions spatially separat e from one another in a matrix. The diameter of the domains of the nano-scale, iragnetic particles is from 2 to 100 nm The t er m nano-scal e, magn etic oxidic particles in particular indie at es superparamagnetic particles. The domains can also have non-magn etic regions, but these then make no contribution to the rregnetic proper¬ties of the particles. There may also be magnetic dorrains present which, by virtue of their size, do not exhibit any superpara-magnetism, and induce remanence. This leads to an increase in volume-specific saturation magn etization. According to the pr es ent invention, the number of superparamagnetic domains pr es ent in the superpara-rregnetic particles is such that the inventive plastics materials can be heated to melting point by means of an alt ernating electrical, magnetic or electromagnetic field. The surrounding matrix can entirely or only partially surround the domains of the superparamagnetic particles. The t er m partially surround indieates that individual doirains can protrude from the surf ac e of an aggr egat e. The superparamagnetic domains of the particles are always non -agglomerat ed. The domains can comprise one or more metal oxides. The magnetic domains can preferably conprise the oxides of iron, c obalt, nickel, chromium, europium, yttrium, samarium or gadolinium The form in which the metal oxides are pr es ent in thes e domains can be a single form or various forrre. One particularly pr ef err ed magnetic dorrain is iron oxide in the form of gamrrB-Fe203 (Y-Fe203) , Fe304, or a mi xtur e corrpos ed of gamira-F 6203 ( y-F e203) and/or Fe304. The inventive plastics rrat erials can pr ef erably have a proportion of superparanagn etic particles in the range from 0. 1 to 40% by weight.- Suitable superparanagn etic particles are described by way of exanple in EP-A-128 4485, and also in DE 10317067, the entire content of which is inc orporat ed herein by way of reference. Accordingly, the superparamagnetic particles can be obtained via a proc ess encorrpassing the f oil owing St eps: - vaporization, together or s eparately, of a compound which conpris es the metal c orrponent or metalloid component of the non-rmgnetic matrix and of a compound which coirprises the metal component of the superparamagnetic domains, where at least one compound contains chlorine and where the constitution of the vapour corresponds to the ratio subsequently desired of superparamagnetic domains and of non-magnetic matrix, - introduction of this mixture into a mixing zone, in which it is mixed with air and/or oxygen and with a combustion gas, and introduction of the mixture into a burner of known design, and cem¬bustion of this mixtur e in a flame within a c ombustion chamber, - cooling of the hot gases and of the solid product, removal of the gases from the solid product and, if appropriate, purification of the solid product via heat -treat ment by means of gas es moistened with water vapour. The particles can moreover be obtained via a process enc orrpassing the following steps: - pr oduct i on- of an a er os ol vi a at omization of a pr ecursor which conpris es the metal conponent of the superparamagnetic domains and which takes the form of a solution or dispersion of a salt, - mixing of this aerosol with the gas mixture from a flame hydrolysis process or from a flame oxidation process, where the mixture comprises the precursor of the non-magnetic • matrix, in a mixing zone, where the constitution of the vapour corresponds to the ratio subs equehtly desired of superpara magnetic domains and of non-magnetic matrix, - introduction of the aerosol-gas mixture into a burn er of kn own d es i gn and combus t i on of this mixture in a flame within a combustion chamber, - cooling of the hot gases and of the solid product, removal of the gas es from the solid product and, if appropriate, purification of the solid product via heat -treat ment by means of gas es moist en ed with water vapour, where the precursor of the superparamagnetic domains and/or the pr ecursor of the non-magnetic matrix is a chlorine-containing compound. The particles can moreover be obtained via a process encompassing the following steps: - production, s eparately or together, of an aerosol via atomization of a pr ecursor of the superpara-iragnetic doirains and of a precursor of the non-magnetic rratrix, where thes e precursors take the form of a solution or dispersion of salts, and where the constitution of the aerosol corresponds to the ratio subs equently desired of superpara-magn etic domains and of non-magn etic matrix, - introduction, separately or together, of the aerosols of the precursors into a mixing zone, in which they are mixed with air and/or oxygen and with a combustion gas, and - introduction of the aerosol-gas mixture into a burn er of kn own d es i gn and c o mbustion of this mixture in a flame within a combustion chamber, - cooling of the hot gases and of the solid product, removal of the gas es from the solid product and, if appropriate, purification of the solid product via heat -tr eat ment by means of gas es moist en ed with water vapour, where the precursor of the superparamagnetic domains and/or the precursor of the non-magnetic matrix is a chlorine-containing compound. Combustion gases which can be used with preferenc e ar e h ydr og en or met han e. With respect to weldability, the selection of the polymer mat erials underlying the inventive plastics material is such, that the plastics material is thermoplastically softenable. The plastics mat erial generating the weld can preferably be bas ed on single- or two-corrponent polyur ethan e, single- or two-conponent polyepoxide, single- or two-conponent si lie one polymer, silan e-modif i ed polymer , polyamide, ( meth) acrylat e- functiona1 polymer , polyester, polycarbonat e, cyclo- olefin copolymer, polysiloxane, poly( ether) sulphone, polyether ketone, polystyrene, polyoxymethyl en e, polyamideimide, polytetraf luoroethylene, polyvinylidene fluoride, perf luoro ethylene-propylene copolymer, perf luoroalkoxy copolymer, methacr ylat e/butadiene/ styrene copolymer and/or liquid-crystalline copolyester. The production method for the plastics mat erial corrprising nano-scale, magnetic oxidic particles pref erably mixes, extrudes, and then pelletizes the underlying polymer materials in the form of powder or of pellets with the nano-scale, magnetic oxidic particles in the form of a powder. This form can be particularly advantageous for polyamide polymers. The plastics mat erial then takes the f or m of pellets, which can in turn be proc ess ed via extrusion to give mouldings , s emlf inished products , sheets , foils and the lik e. The plastics material can, if appropriate, corrprise not only polymers but also polymerizable monomers, wat er or organic dispersion media. Suitable, organic dispersion media can by way of example be selected from oils, f ats, waxes, est ers of C6 -C30 monocarboxylic acids with mono-, di - or trihydric ale ohols, saturat ed ac yclie and cyclie hydrocarbons , f atty acids , low-molecular-weight aleohols , f atty aleohols and mi xtur es of thes e. Among these are by way of example paraffins and paraffin oils, mineral oils, linear saturat ed hydrocarbons gen er ally having more than 8 carbon atoms , e. g. tetra-d ecan e, hexadecane, octadecan e, etc. , c yclic hydro¬carbons , e. g. c yclohexan e and d ecahydronaphthalene, waxes, est ers of f att y acids, silicon e oils, etc, Pr ef erred exarrples are lin ear and c yclic hydrocarbons and ale ohols. The plastics mat erial which corrpris es the nano-scale, magnetic oxidic particles is used according to the invention as means that generat es the weld during the production of a plastics corrposit e moulding via welding-in an alt ernating electronagn etic f i eld. The plastics mouldings to be joined can be compos ed entirely or to some extent of the plastics material comprising nano-scale, magnetic oxidic particles. At least one of the mouldings to be joined her e is conposed, at least in the region' of the joint area, of this plastics mat erial. The plastics mouldings can be produc ed in a rrenn er known per se and with any desired shape. Mbuldings provided partially with the nano-seale, magnetic oxidic particles, f or example only in the region of the joint areas, can be obtained by way of exanple via coextrusion or sequential coextrusion, multilayer extrusion, multicomponent in j action moulding, or coating. Th,e preliminary products to be joined can by way of exarrple be components of hollow bodies. These can then be proc ess ed to give ass embled hollow bodies, such as c ont ain ers, pipes or lin es, which have been w eld ed dir ect ly or by way of conn ecting elements, such as sleeves, fittings or f langes. The plastics material that generates the weld can also be pr es ent s eparately, for exarrple in the f or m of sheets or foils which are plac ed between sheet -like plastics parts and which bond thes e, as a means of welding. The resultant plastics composite mouldings then take the f or m of multilayer conposit es compos ed of elements welded in the mann er of a sheet, examples being sheets and/or foils. In the corresponding process, the plastics mouldings to be joined are exposed at least in the region of the joint area to an alt ernating electrical, magnetic or electromagnetic field, where the plastics material that generates the weld is heated to melting point. For the heating process, it is preferable to use an alt ernating electromagnetic field whos e f r equenc y is in the range from 30 Hz to 100 MHz. The frequencies of familiar inductors are suitable, exarrples being medium frequencies in the range from 100 Hz to 100 kHz or high f r equencies in the range from 10 kHz to 60 IVHz, in particular from 50 kHz to 3 NHz. The rragn etic dorrains and in particular the nano-part iculat e dorrains of the superparamagnetic particl es permit particularly effective utilization of the energy input of available electromagnetic radiation. This also applies by analogy to heating via alternating el ectroimgnetic f i elds of microwave radiation. It is pr ef erable here to use microwave radiation whos e frequency is in the range from 0, 3 to 300 GHz. In addition to the microwave radiation, it is preferable to mak e us e of a DC magnetic f i eld whos e f i eld str ength is in the range from about 0.001 to 10 tesla, for resonant frequenc y s etting. The field strength is preferably in the range from 0.015 to 0.045 tesla and in particular from 0.02 to 0.06 tesla. Exanple 1 Production of superparanagnetic partial es Particles P-1: 0.57 kg/h of SiCl4 are vaporized at 200° C and fed into a mi xing zone with 4.1 Nm3/h of hydrogen, and also 11 Nm3/h of air. An aerosol which is obtained from a 25 per c ent by weight aqueous iron( III) chloride solution (1.27 kg/h) is also introduced by means of a carrier gas (3 Nm/h of nitrogen) into the mixing zone, within the burner, wher e the homogeneously mixed gas -aerosol mixtur e is subj ect ed to combustion at an adiabatic combustion terrperature of about 1200° C and with a residenc e ti me of about 50 msec. After the reaction, a kn own met hod is used to cool the r eac t i on gases and the resultant particle powder, and this is isolated by means of a filter from the exhaust gas strearn In a further step, reimining adherent hydrochloric acid residues are removed from the powder via treat ment with nitrogen coirprising wat er vapour. Particl es P-2: 0.17 kg/h of SiCl4 are vaporiz ed at 200° C and f ed into a mixing zone with 4. 8 Nm^/h of hydrogen, and also 12. 5 Nm3/h of air. An aerosol which is obtained from a 25 per c ent by weight aqueous iron (III) chloride solution (2.16 kg/h) is also introduced by means of a carrier gas (3 Nm3/h of nitrogen) into the mixing zone, within the burner, wher e the homogen eously mixed gas -aerosol mixture is subj ect ed to combustion at an adiabatic combustion temperature of about 1200° C and with a r esidenc e ti me of about 50 ms ec. Mt er the reaction, a known method is used to cool the reaction gases and the resultant particle powder, and this is isolat ed by means of a filter from the exhaust gas stream In a further st ep, remaining adherent hydrochloric acid residues ar e removed from the powder via treatment with nitrogen comprising water vapour. Particles P-3: 0.57 kg/h of the matrix precursor SiCl4 are vaporized at about 200° C and f ed with 4 Nm3/h of hydrogen, and also 11 Nm /h of air and 1 Nm /h of nitrogen, into the r eactor. An aerosol composed of the domain precursors and obtained by means of a twin-fluid nozzle from an aqueous solution in which iron( II) chloride, rragn esium(II) chloride and manganes e c hi or id e are pr es ent is also introduc ed into the reactor by means of a carri er gas (3 Nm /h of nitrogen) . The aqueous solution coirprises 1. 8% by weight of M1CI2/ 8. 2% by weight of iy^Cl2 and 14.6% by weight of FeCl2- The homogeneously mixed gas -aerosol mixtur e f lows int o the reactor, where it is subjected to combustion at an adiabatic c ombustion temperatur e of about 1350' C and with a residence time of about 70 msec. Residenc e time is calculated from the quoti ent of the plant volume through which the substanc es flow and the operating volume flow rate of the process gases at an adiabatic combustion temperatur e. -Affer the flame hydrolysis process, the reaction gases and the resultant zinc -magnesium-ferrit e-doped silie on dioxide powder are cooled, and the solid is isolated by means of a filter from the exhaust gas stream. In a further step, remaining adherent hydrochloric acid residues are removed from the powder via treatment with nitrogen comprising wat er vapour. Example 2 Production of plastics xcaterials conprising superparaniagnebic particles Example 2. 1 2 kg of particles P-1 from Exanple1 are mixed in the melt, extruded and pelletiz ed with 8 kg of polyamide pellets ( Vestamid® L1901; terminology to ISO 1874-1: PA12, XN, 18-010; Degussa AG) in a ZE25-33D twin-screw extrud er from Berst orf f, at 250° C with throughput of 10 kg/h. Exarrpl e 2, 2 2 kg of particles P-1 from Example 1 are mixed in the melt; extrud ed and pell etiz ed with 8 kg of Vest odur® X9 40 7 polybut ylene t er ephthalat e pellets from Degussa AG in a ZE25-33D twin-screw extruder from Berstorff, at 250° C with throughput of 10 kg/h. Example 2. 3 2 kg of particles P-1 from Exarrple 1 are mixed in the melt, extruded and pelletiz ed with 8 kg of polypropylene copolymer pellets ( Mmer® QF551A from Mitsui Deutschland GmbH) in a ZE25-33D twin-screw extruder from Berstorff, at 200° C with throughput of 10 kg/h. Exarrpl e 2. 4 2 kg of particles P-1 from Example 1 are mixed in the melt, extruded and pelletized with 8 kg of nylon-6 pellets (Ultramld® B4 from BASF AG) in a ZE25-33D twin-screw extruder from Berst orf f , at 250°C with throughput of 10 kg/h. Exarrple 2. 5 2 kg of particles P-1 from Example 1 are mixed in the melt, extruded and pelletiz ed with 8 kg of polyvinylidene fluoride ( DYFLOR® X7394 from Degussa AG) in a ZE25-33D twin-so r ew extruder from Berst orf f, at 250° C with throughput of 10 kg/h. Exarrple 2. 6 2 kg of particles P-1 from Example 1 are mixed in the melt, extruded and pelletiz ed with 8 kg of polyamide pellets ( Vestamid® D18 from Degussa AG) in a ZE25-33D twin-screw extruder from Berstorff, at 200°C with throughput of 10 kg/h. Exarrple 2. 7 2 kg of particles P-2 from Example 1 are mixed in the melt, extruded and pelletized with 8 kg of polyamide pellets (Vestamid® D18 from Degussa AG) in a ZE25-33D twin-screw extruder from Berstorff, at 200°C with throughput of 10 kg/h. Exanple 3 Welding of plastics mouldings in an alternating electronagnetic field Gen eral method: The plastics materials according to Examples 2.1 to 2.1, comprising superpararragnetic particles, were extruded to give sheets of thickness 1 mm Each of thes e sheets was alt ernat ed with a sheet of the same or dif f er ent underlying plastics mat erial ( without superparamagnetic particles) , and this multilayer structure was secured by the winding of adhesive tape. The multilayer structure was then placed f or prescribed times in an alt ernat ing electromagn eticfield at 100 % power. The data for the inductor coil here was as follows: Measurements: 200 x 45 x 40 mm^ (L x W x H) lyfet erial: tetragonal copper tube 10 x 6 x 1 mm Effective cross-s ectional area: 28 mm2 Coil f eed length: 120 mm Number of turns on c oi 1: 3 Coil winding length ( ef f. ) : 35 mm Coil diamet er ( int ernal): from 20 mm to 40 mm Int ernal ar ea of coil: 7 20 mm2 Inductance (at 100 kHz): about 270 nH Operating frequency: 323 kHz The data for the high frequency semiconduct or generator used were as follows: Producer: STS - Syst emt echnik Skorna GmbH Model: STS type M260S Terminal power: 6 kW Inductance range: from 250 - 1200 nH Operating frequency: from 150 to 400 kHz ( 323 kHz with the inductor coil used) The following grades wer e us ed to ass ess adhesion after the removal of the specimen from the alternating field: 0 No adhesion. 1 Very little adhesion. 2 Some adhesion; easy to separate. 3 Good adhesion; cannot be s eparat ed without great effort and sometimes use of tools. 4 Ins eparable bonding; irrpossible to s eparat e without cohesive fracture. Claims: 1. A plastics composit e moulding obtainable via welding in an alternating electromagnetic field, charact rized in that the weld is obtain ed with the aid of a plastics material which comprises nano-scale, magnetic oxidic particles. 2. A plastics corrposite moulding according to claim 1, characterized in that the weld is obtained with the aid of a plastics meterial which comprises nano-scale, rragnetic oxidic particles which are composed of aggregated primary particles, where the primar y particles are compos ed of magnetic metal oxide domains whose diameter is from 2 to 100 nm in a non-magnetic metal oxide matrix or non-magnetic metalloid oxide matrix. 3. A plastics composite moulding according to claim 1 or 2, characterized in that the plastics material that generates the weld corrprises nano-scale, rragnetic oxidic particles. 4. A plastics composite moulding according to claims, characterized in that the plastics material that generates the weld comprises nano-scale, magnetic oxidic particles which are compos ed of aggr egated primar y particles , where the aggregat e size of the nagnetic oxidic particles is greater than 100 n m and s mailer than 1µm 5. A plastics corrposite moulding according to an y of claims 1 to 4, charact eriz ed in that the magn etic domains of the magnetic oxidic particles comprise iron oxide. 6. A plastics corrposite moulding according to any of claims 1 to 5, charact erized in that the nano-scale, magnetic oxidic particles have non-agglomerat ed superparanagn etic domains, 7. A plastics composite moulding according to an y of claims 1 to 6 , charact eriz ed in that the magnetic dorreins of the superparamagnetic oxidic particles comprise f errites. 8. A plastics corrposite moulding according to any of claims 1 to 7, characterized in that the rragnetic domains of the superparamagn eticoxidic particles are composed of ternary systems of the general formula ( lyfi-x-yNPxF ey) IIFe2III04 where lyP or lyf -mangan es e, c obalt, nick el, zinc , c opper, magn esium, barium, yttrium, tin, lithium, cadmium, magnesium, calcium, strontium, titanium, chromium, vanadium, niobium or molybdenum and x = from 0.05 to 0. 95, y - from 0 to 0. 95 and x + y 9. A plastics composite moulding according to claims1 to 8, charact erized in that the proportion of the rragnetic doirains in the nano-scale, magnetic oxidic particles is from 10 to 90% by weight. 10. A plastics corrposite moulding according to any of claims1 to 9, charact erized in that the proportion of the nano-scale, magnetic oxidic particles in the plastics mat erial that generat es the weld is from 0. 1 to 40% by weight. 11. A plastics composite moulding according to any of claims 1 to 10, charact erized in that the plastics rrat erial that generat es the weld is thermoplastically softenable. 12. A plastics corrposite moulding according to claim 11, characterized in that the plastics material that generates the weld is based on single- or two-corrponent polyurethane, single- or two-corrpon ent poly epoxide, single- or two-corrpon ent si lie on e polymer, silan e-modif i ed polymer, polyamide, ( meth) acrylat e-function a1 polymer, polyest er, polycarbonate, cyclool ef in copolymer, polysiloxan e, poly( ether) sulphon e, polyether ketone, polyst yr ene, polyoxymethylen e, polyamidei mide, polyt etraf luoroethyl en e, poly-vinylidene f luorid e, polyf luoroethyl en e-propylen e copolymer, perf luor oalkoxy copolymer, methacrylat e/butadi en e/st yrene copolymer and/or liquid-crystallin e copolyester. 13. A plastics corrposit e moulding according to any of claims 1 to 12 in the form of ass embled hollow bodies, such as contain ers, tubes or lin es, which have been welded directly or by way of connecting elements, such as sleeves, fittings or flanges. 14. A plastics corrposite moulding according to any of claimsl to 13 in the form of a multilayer composite conposed of elements welded in the manner of sheets, exarrples being sheets and/or foils. 15. A process for the production of a plastics composite moulding via welding in an alt ernating electr oiragnetic field, charact erized in that the weld is achi eved with the aid of a plastics mat erial which corrpris es nano-soale, rragnetic oxidic particl es which are compos ed of aggr egat ed primary particles, where the primrary particles are corrposed of rragn etic metal oxide domains whos e diamet er is from 2 to 100 nm in a non -magn etic metal oxide matrix or non -rragnetic metalloid oxid e matrix . 16. 'A proc ess according to claiml5, characteriz ed in that at least one of the mouldings to be joined is composed at least in the region of the joint area of a plastics material which conprisas nano-scale, magnetic oxidic particles which are corrposed of aggr egat ed pri mar y particles , where the pri rrar y particles are corrposed of magnetic metal oxide dormins whose diameter is from 2 to 100 nm in a non-magnetic metal oxide matrix or non-rragnetic met all old oxid e mat r i x. 17. A process according to claim 15 or 16, characterized in that the plastics mouldings to be j oin ed ar e expos ed at least in the region of the joint area to an alternating electrical, rragnetic or electromagnetic f i eld, where the plastics material that generates the weld is heated to melting point. 18. The use of nano-scale, magnetic oxidic particles as additives in plastics rrat erials, where thes e particles are compos ed of aggr egat ed pri rrar y particles, and where the pri rrar y particl es are corrpos ed of magnetic metal oxide dorrains whos e diameter is from 2 to 100 nm in a non-rragnetic metal oxide rratrix or non -magnetic metalloid oxide rratrix, in order t o provide weldabilit y of the same in an alt ernating electromagnetic f i eld.

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1822-CHENP-2008 AMENDED PAGES OF SPECIFICATION 17-01-2013.pdf

1822-CHENP-2008 AMENDED CLAIMS 17-01-2013.pdf

1822-CHENP-2008 CORRESPONDENCE OTHERS 28-05-2012.pdf

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1822-CHENP-2008 EXAMINATION REPORT REPLY RECEIVED 17-01-2013.pdf

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