Plastic composite moulded bodies obtainable by welding in an electromagnetic alternating field

Translation of description of equivalent WO 2007042368 A2

p0001By welding in an alternating electromagnetic field available plastic composite molding

p0002The invention relates, by welding in an alternating electromagnetic field available plastic composite moldings in which the weld is achieved with the aid of a plastic material containing nanoscale, magnetic oxidic particles.

p0003Plastic moldings can be connected to a wide variety of plastic welding process. Current methods are hot plate welding, heating spiral welding, ultrasonic welding, vibration welding, laser welding, spin welding and high frequency welding.

p0004Joining processes by alternating electromagnetic field or microwave are used less frequently and are still considered special procedures.

p0005When laser beam welding at least that the radiation source facing molding for the laser beam must be transparent so that the selection of eligible plastic materials with respect to limited pigmentation and color scheme.

p0006When welding in an alternating electromagnetic field, however, the limitations on the colorants do not occur.

p0007For welding with electromagnetic radiation (induction welding) is typically a welding tool is required that is magnetically activated as such or because of corresponding ingredients. By hysteresis and / or eddy current losses in an alternating electromagnetic field, the welding tool is heated, wherein the energy input in the inductive heating is about 1500-fold higher than the heat conduction. The induction welding passes through the phases of melting, melt fusion and consolidation, the welding process can be carried out continuously or intermittently.

p0008The welding tool can be placed in the form of semi-finished or sheets between the joining surfaces of the to be joined moldings. The magnetic activation capacity is often caused by metallic deposits, but what complicates the production process to be joined Kunstoffformteile and the secondary product are possibly undesirable. Welding aids with particulate ferromagnetic fillers are relatively expensive and have poor efficiency, so that the proceedings against the established joining methods hitherto could not prevail.

p0009The invention was therefore based on the object to develop plastic materials by suitable additives magnetically activated to providing weldability in an alternating electromagnetic field. These materials should be usable either as an integral part of to be joined Kunstoffformteile or as an additional welding tool.

p0010In DE-AI 9924138 an adhesive composition is claimed, which contains, inter alia, nanoscale particles with superparamagnetic properties.

p0011In DE-A-10163399 a nanoparticulate preparation is described, the dispersed a coherent phase and at least one fact particulate phase of superparamagnetic, nanoscale particles having. Here preparations are preferably in the form of an adhesive composition.

p0012The compositions of DE-A-19924138 and DE-A-10163399 can be heated in an alternating electromagnetic field. applies to both DE-A-19924138 as well as DE-A-10163399 that the particles used are preferably surface-modified or surface-coated to prevent agglomeration or coalescence of the nanoscale particles and / or to have a good dispersibility of the particulate phase in the coherent phase to ensure. The disadvantage here is that the substances used for surface coating or surface modification, insbesonderen at high temperatures and / or mechanical influences, can solve. This has the consequence that the nanoscale particles agglomerate or may coalesce, causing their superparamagnetic properties are lost. The rheological properties of the nanoparticulate preparation according to DE-A-10163399 or the adhesive wave of ha composition according to DE-A-19924138 can be adjusted by the type and amount of dispersing agent in a wide range. However, it is not or only partially possible to adjust adjust the rheology of the preparation by the nanoscale, superparamagnetic particles themselves, since the superparamagnetic properties are bound to certain particle sizes. The particles are present in the preparation before virtually as primary particles, thereby adjusting the rheology, such as a thickener, only by simultaneous variation of the content of superparamagnetic particles is possible.

p0013In the past, German patent application DE 102004057830 from 01.12.2004, reference is made to the entire contents, an adhesive composition is described comprising a polymerizable monomer and / or a polymer and, dispersed therein superparamagnetic oxide particles are composed of aggregated primary particles, the primary particles of magnetic metal oxide domains with a diameter of 2 to 100 nm in a nonmagnetic metal oxide or metalloid oxide matrix is ​​constructed.

p0014Surprisingly, it has now been found that nanoscale, magnetic oxidic Partikelals additives are suitable for plastic materials, to providing weldability in an alternating electromagnetic field.

p0015The invention provides the use of nanoscale, magnetic oxide Partikelnals additives in plastic materials to providing weldability in an alternating electromagnetic field.

p0016The invention further provides a process for producing Kunststoffverbundformkorper by welding in an alternating electromagnetic field in which the weld is achieved with the aid of a plastic material containing nanoscale, magnetic oxidic particles.

p0017The invention in particular by welding in an alternating electromagnetic field erhaltliche Kunststoffverbundformkorper in which the weld is achieved with the aid of a plastic material, the nano-scale, magnetic oxidic particles.

p0018In the inventive plastic materials the nanoscale, magnetic oxide particles distributed largely homogeneously and in particular in non-agglomerated form are. In particular these particles are thermally stable in the plastic materials and show no agglomeration even at high temperatures. Furthermore, it is possible to control the rheology of the compositions largely independent of the content of such particles. By aggregated for the purposes of the present invention three-dimensional structures of intergrown primary particles are understood. Multiple units can be combined to form agglomerates. These agglomerates can be about by mechanical action, for example, extrusion processes, easily be separated again. In contrast, the decomposition of the aggregates is not possible in the primary particles in the rule. The aggregate diameter of the nano-scale, magnetic oxidic particles may be preferably greater than 100 nm and less than 1 micron.

p0019Preferably, the aggregates of the nano-scale, magnetic oxidic particles may comprise at least in one spatial direction, a diameter of not more than 250 nm. This situation is illustrated in Figure 1, in which two side arms have an aggregate diameter of 80 nm and 135 nm.

p0020Subdomains are spatially separate regions in a matrix to understand. The domains of the nanoscale, magnetic particles have a diameter between 2 and 100 nm.

p0021Nanoscale, magnetic oxidic particles in particular superparamagnetic particles are to be understood.

p0022The domains may also contain non-magnetic regions, but then not contribute to the magnetic properties of the particles.

p0023In addition, magnetic domains which, showing no superparamagnetic because of their size and induce remanence. This leads to the increase in the volume-specific saturation magnetization. According to the present invention is that the superparamagnetic particles containing such number of superparamagnetic domains in order to heat up the plastic materials of the invention by an electrical, magnetic or electromagnetic field to the melting temperature can.

p0024The domains of the superparamagnetic particles can completely or partially from the surrounding matrix be enclosed. Partly enclosed means that individual domains protrude from the surface of an aggregate.

p0025In any case, the superparamagnetic domains of the Pertikel are non-agglomerated.

p0026The domains may have one or more metal oxides.

p0027The magnetic domains may preferably comprise the oxides of iron, cobalt, nickel, chromium, europium, yttrium, samarium or gadolinium. In these domains, the metal oxides may be present in a uniform modification or in various modifications.

p0028A particularly preferred magnetic domain is iron oxide in the form of gamma-Fe2θ3 (γ-Fe2θ3), Fe 3 O₄, Mixtures of gamma-Fe2θ3 (γ-Fe2θ3) and / or Fe 3 O₄, The magnetic domains may furthermore be present as a mixed oxide of at least two metals with the metal components iron, cobalt, nickel, tin, zinc, cadmium, magnesium, manganese, copper, barium, magnesium, lithium or yttrium.

p0029The magnetic domains can still substances having the general formula M¹¹Fe₂O₄ be, where M¹¹ is a metal component comprising at least two different, divalent metals. Preferably may be one of the divalent metals manganese, zinc, magnesium, cobalt, copper, cadmium or nickel. Furthermore, the magnetic domains may be made of ternary systems of the general formula (M^ai__x__y M^b_xFe_y) ¹¹Fe₂¹¹¹O₄ be constructed, where M^a, Or M^b be the metals manganese, cobalt, nickel, zinc, copper, magnesium, barium, yttrium, tin, lithium, cadmium, magnesium, calcium, strontium, titanium, chromium, vanadium, niobium, molybdenum, with x = 0.05 to 0, 95, y is from 0 to 0.95 and x + y <1st

p0030Particular preference may ZnFe₂O₄, MnFe₂O₄, Mn₀, 6Feo,₄Fe₂0₄, Mn₀, 5Zn₀, 5Fe₂O₄, Zn₀, IFei, gO₄, Zn₀.₂Fei, sO₄, Zn₀, 3Fe₃., 7O₄, Zn₀.₄Fei, 6θ₄ or Mn₀, 39Zn₀.₂7Fe₂.₃₄O₄, MgFe₂O₃, Mgi,₂Mn₀.₂Fei,₆O₄, Mgi,₄Mn₀.₄Fei,₂O₄, Mg ^₆Mn₀, 5Fe₀^ O₄, Mgi,_8thMnO,_8thFe₀.₄0₄ be. The choice of the metal oxide of the nonmagnetic matrix is ​​not limited. This may be oxides of titanium, zirconium, zinc, aluminum, silicon, cerium or tin preferred. In the context of the invention also includes metalloid oxides, such as silica, to the metal oxides.

p0031Furthermore, the matrix and / or the domains may be present in amorphous and / or crystalline.

p0032The proportion of the magnetic domains in the particles is not limited as long as the spatial separation of matrix and domains is given. Preferably, the proportion of the magnetic domains in the superparamagnetic particles may be from 10 to 90 wt .-%.

p0033The plastic materials of the invention may preferably contain a proportion of superparamagnetic particles in a range of 0.1 to 40 wt .-%.

p0034Suitable superparamagnetic particles are described for example in EP-A-1284485 and in DE 10317067, to which reference is made in full. The superparamagnetic oxide particles can thus be obtained by a process comprising the steps of:

p0035Together or separately, the evaporation of a compound containing the metal or metalloid component of the nonmagnetic matrix, and a compound containing the metal component of the superparamagnetic domains, wherein at least comprises a compound of chlorine, and wherein the vapor composition to the subsequently desired ratio of the superparamagnetic domains and nonmagnetic matrix corresponds,

p0036Feeding this mixture in a mixing zone, in which it is mixed with air and / or oxygen and a fuel gas and supplying the mixture into a burner known design and combustion of this mixture in a flame within a combustion,

p0037Cooling the hot gases and the solid product, the gases from the solid product and optionally purifying the solid product separated by a heat treatment by means of steam gases moistened.

p0038The particles can also be obtained by a process comprising the steps of:

p0039Producing an aerosol by nebulization of a precursor containing the metal component of the superparamagnetic domains and which is present in the form of a solution or a dispersion of a salt,

p0040Mixing said aerosol with the gas mixture of a flame hydrolysis or flame oxidation containing the precursor of the non-magnetic matrix, in a mixing zone, the vapor corresponds to the ratio subsequently desired of superparamagnetic domains and the non-magnetic matrix,

p0041- Introduction of the aerosol-gas mixture into a burner of known design and combustion of this mixture in a flame within a combustion

p0042Cooling the hot gases and the solid product, the gases from the solid product and optionally purifying the solid product separated by a heat treatment by means of steam gases moistened,

p0043wherein the precursor of the superparamagnetic domains and / or the precursor of the nonmagnetic matrix is ​​a chlorine-containing compound.

p0044The particles can also be obtained by a process comprising the steps of: Separately or together, producing an aerosol by atomization of a precursor of the superparamagnetic domains and of a precursor of the non-magnetic matrix, where these precursors are in the form of a solution or dispersion of salts, wherein the aerosol composition corresponds to the ratio subsequently desired of superparamagnetic domains and the non-magnetic matrix,

p0045Together or separately, supplying the aerosols of the precursors into a mixing zone where they are mixed with air and / or oxygen and a fuel gas, and

p0046Introduction of the aerosol-gas mixture into a burner of known design and combustion of this mixture in a flame within a combustion

p0047Cooling the hot gases and the solid product, the gases from the solid product and optionally purifying the solid product separated by a heat treatment by means of steam gases moistened,

p0048wherein the precursor of the superparamagnetic domains and / or the precursor of the nonmagnetic matrix is ​​a chlorine-containing compound.

p0049As fuel gases hydrogen or methane can be used preferably.

p0050With regard to the weldability which the plastic material according to the invention underlying polymeric materials are selected so that the plastic material is thermoplastic softened. This generates the weld plastics material may preferably on or two-component polyurethane, one- or two-component polyepoxide, single- or two-component silicone polymer, silane-modified polymer, polyamide (meth) acrylatfunktionellem polymer, polyester, Polycarbonate, cycloolefin copolymer, polysiloxane, poly (ether) sulphone, polyether ketone, polystyrene, polyoxymethylene, polyamideimide, polytetrafluoroethylene, polyvinylidene fluoride, fluorinated ethylene propylene copolymer, perfluoroalkoxy copolymer, methacrylate / butadiene / styrene copolymer and / or liquid crystalline copolyester based.

p0051The containing nanoscale, magnetic oxidic particles plastic material is preferably prepared in such a way that mixing the underlying polymeric materials in powder or granular form with the nanoscale, magnetic oxidic particles in the form of a powder, extruded, extrusion pressing and then granulated. This form can be particularly advantageous for polyamide polymers.

p0052The plastic material is then in the form of granules, which can in turn be processed by extrusion to give moldings, semifinished products, sheets and so on. In addition to polymers, the plastic material may optionally polymerizable monomers, water or organic dispersing agents. Suitable organic dispersion media can be, for example, chosen from oils, fats, waxes, esters of C6-C30-monocarboxylic acids with mono-, di- thereof or trihydric alcohols, saturated acyclic and cyclic hydrocarbons, fatty acids, low molecular weight alcohols, fatty alcohols, and mixtures. They may include, for example, paraffin and paraffin oils, mineral oils, linear saturated hydrocarbons generally having more than 8 carbon atoms, such as tetradecane, hexadecane, octadecane, etc., cyclic hydrocarbons such as cyclohexane and decahydronaphthalene, waxes, esters of fatty acids, silicone oils, etc. Preference for . for example, linear and cyclic hydrocarbons and alcohols. The plastic material containing the nano-scale, magnetic oxidic particles is used according to the invention as the weld is providing agent in the manufacture of plastics composite molding via welding in an alternating electromagnetic field.

p0053The to be joined plastic moldings can be made of plastic material completely or partly containing from the nanoscale, magnetic oxidic particles.

p0054It consists of at least one of to be joined moldings at least in the area of ​​the joint surface of this plastic material.

p0055The production of plastic moldings can be produced in a conventional manner and in any form design.

p0056Partially, as provided only in the region of the joining surfaces with the nanoscale, magnetic oxidic particles Foermkörper can be obtained for example by coextrusion or sequential coextrusion, multilayer extrusion, multicomponent injection Giesen or by coating.

p0057The preforms to be joined can represent, for example, components of hollow bodies. These can then be processed into composite hollow bodies such as containers, pipes or cables, which are welded directly or via connecting elements such as sleeves, fittings or flanges.

p0058This generates the weld plastic material can also be present separately in the form of sheets or films, which are placed between two-dimensional plastic parts and connecting as a welding agent.

p0059The plastic composite molding thus obtained are then present in the form of multilayer composites of elements welded as plates and / or sheets. In the corresponding method, to be joined plastic moldings are at least in the area of ​​the joint surface exposing an electrical, magnetic or electromagnetic field, said generates the weld plastic material is heated to melting temperature.

p0060Preferably, an alternating electromagnetic field is applied at a frequency ranging from 30 Hz to 100 MHz for heating. Suitably, the frequencies of common inducers, for example center frequencies, in a range of 100 Hz to 100 kHz or high frequencies in a range of 10 kHz to 60 MHz, particularly 50 kHz to 3 MHz.

p0061The magnetic and in particular the nanoparticulate domains of the superparamagnetic particles permit utilization of the energy input of available electromagnetic radiation in a particularly effective manner.

p0062The same applies to heating by electromagnetic alternating fields of microwave radiation. Preferably microwave radiation is used with a frequency in the range of 0.3 to 300 GHz. For adjusting the resonance frequency, a DC magnetic field having a field strength in the range of approximately 0.001 is preferably used in addition to 10 Tesla for the microwave radiation. Preferably, the field strength is in a range from 0.015 to 0.045 Tesla and in particular from 0.02 to 0 06 Tesla. example 1

p0063Preparation of superparamagnetic particles

p0064Particles PI:

p00650.57 kg / h SiCl₄ are vaporized at about 200 ° C and with 4.1 Nm³/ H of hydrogen and 11 Nm³/ H air is fed into a mixing zone. In addition, an aerosol, obtained from a 25 percent by weight aqueous iron (III) chloride solution (1.27 kg / h) is obtained by means of a carrier gas (3 Nm³/ H of nitrogen) is introduced into the mixing zone within the burner. The homogeneously mixed gas-aerosol mixture burns there at an adiabatic combustion temperature of about 1200⁰C and a residence time of about 50 msec. After the reaction, the reaction gases and the resultant powder particles are cooled and separated by a filter from the exhaust gas stream in a known manner. In a further step to be removed from the powder by treatment with nitrogen containing still adhering hydrochloric acid residues.

p0066Particles P-2:

p00670.17 kg / h SiCl₄ are vaporized at about 200 ° C and with 4.8 Nm³/ H of hydrogen and 12.5 Nm³/ H air is fed into a mixing zone. In addition, an aerosol, obtained from a 25 percent by weight aqueous iron (III) chloride solution (2.16 kg / h) is obtained by means of a carrier gas (3 Nm³/ H of nitrogen) is introduced into the mixing zone within the burner. The homogeneously mixed gas-aerosol mixture burns there at an adiabatic combustion temperature of about 1200⁰C and a residence time of about 50 msec. After the reaction, the reaction gases and the resultant powder particles are cooled and separated by a filter from the exhaust gas stream in a known manner. In a further step to be removed from the powder by treatment with nitrogen containing still adhering hydrochloric acid residues. Parti cle P- 3:

p00680.57 kg / h of the matrix precursor SiCl₄ are vaporized at about 200 ° C and with 4 Nm³/ H of hydrogen and 11 Nm³/ H of air and 1 Nm³ / H nitrogen are fed into the reactor.

p0069An aerosol comprising the Domänenprecursoren, the chloride from an aqueous iron (II), magnesium (II) -, manganese chloride solution is obtained by means of a binary nozzle by means of a carrier gas (3 Nm³/ H of nitrogen) was introduced into the reactor. The aqueous solution containing 1.8 wt .-% MnCl2, 8.2 wt .-% MgCl₂ and 14.6 wt .-% FeCl₂ ,

p0070The homogeneously mixed gas-aerosol mixture flows in the reactor, and burns there at an adiabatic combustion temperature of about 1350⁰C and a residence time of about 70 msec.

p0071The residence time is calculated from the ratio of the flow-through volume of investment and the operating volume flow of the process gases at the adiabatic combustion temperature.

p0072After the flame hydrolysis, the reaction gases and the resulting doped zinc magnesium ferrite silica powder are cooled in a known manner and the solid is separated from the exhaust gas stream by means of a filter.

p0073In a further step to be removed from the powder by treatment with nitrogen containing still adhering hydrochloric acid residues. example 2

p0074Producing superparamagnetic particles containing plastic materials

p0075example 2.1

p00762 kg of particles P from Example 1 with 8 kg of polyamide pellets (Vestamid® L1901; designation according to ISO 1874-1: PAL2, XN, 18-010; Degussa AG) in a twin-screw extruder ZE25-33D Berstorff at 250 ° C and a melt blended rate of 10 kg / h, extruded and granulated.

p0077example 2.2

p00782 kg of particles P from Example 1 with 8 kg of polybutylene terephthalate GranulatVestodur® X9407; Degussa AG in a twin-screw extruder from Berstorff at 250 ZE25-33D⁰melt mixed C and a throughput of 10 kg / h, extruded and granulated.

p0079example 2.3

p00802 kg of particles P from Example 1 with 8 kg of polypropylene copolymer pellets (Admer® QF551A; Mitsui Germany GmbH) in a twin-screw extruder from Berstorff at 200 ZE25-33D⁰melt mixed C and a throughput of 10 kg / h, extruded and granulated.

p0081example 2.4

p00822 kg of particles P from Example 1 with 8 kg of polyamide 6 pellets (Ultramid® B4; BASF AG) are melt blended in a twin screw extruder ZE25-33D Berstorff at 250 ° C and a throughput of 10 kg / h, extruded and granulated ,

p0083example 2.5 2 kg of particles P from Example 1 with 8 kg of polyvinylidene fluoride (DYFLOR® X7394; Degussa AG) are melt blended, extruded and granulated in a twin-screw extruder ZE25-33D Berstorff at 250 ° C and a throughput of 10 kg / h.

p0084example 2.6

p00852 kg of particles P from Example 1 with 8 kg of polyamide pellets (Vestamid® D18; Degussa AG) are melt blended, extruded and granulated in a twin-screw extruder ZE25-33D Berstorff at 200 ° C and a throughput of 10 kg / h.

p0086example 2.7

p00872 particles P-2 from Example 1 with 8 kg of polyamide pellets (Vestamid® D18; Degussa AG) are melt blended, extruded and granulated in a twin-screw extruder ZE25-33D Berstorff at 200 ° C and a throughput of 10 kg / h.

p0088Example 3 welding in an alternating electromagnetic field Kunsstoffformkörpern

p0089General Procedure:

p0090The superparamagnetic particles containing plastic materials according to examples 2.1 to 2.7 were extruded into sheets of thickness 1 mm.

p0091But any such plate was placed between each one plate of the same or different plastic base material (without superparamagnetic particles) and the multilayer structure wrapped securely with tape. The multilayer structure was placed in an alternating electromagnetic field for predetermined times at 100% power.

p0092The inductor had it the following data: Dimensions: 200 x 45 x 40 mm³ (L x W x H) Material: copper pipe square 10 x 6 x 1 mm cable cross-sectional area: 28 mm² Coil feed length: 120 mm coil windings: 3 coil winding length (eff.): 35 mm

p0093Coil diameter (internal): 20 mm to 40 mm coils inside surface: 720 mm² Inductance (at 100 kHz): ca. 270 nH Arbeitsfreqenz: 323 kHz The high-frequency semiconductor generator used has the following following data:

p0094Manufacturer: STS - Systemtechnik GmbH Skorna Type: STS type M260S clamping power: 6 kW Inductance range: 250-1200 nH

p0095Operating frequency: 150 - 400 kHz (323 kHz with the inductor coil used) I i

p0096After removing the sample from the alternating field, the adhesive strength according to the following scores were evaluated:

p00970 no adhesion.

p00981 slight adhesion.

p00992 some adhesion; to separate with little effort.

p01003 Good adhesion; to separate only with great difficulty and possibly with the aid of tools

p01014 inseparable adhesion; Separation only through cohesion fracture

p0102Examples:

p0103Multilayer structure welding duration Liability note with:

p0104Vestamid® L1901 30 seconds 4 Example 2.1 Vestamid® L1901

p0105Vestamid® L1901 45 seconds 4 Example 2.1 Trogamid® X7323

p0106Vestamid® L1901 30 seconds 4 Example 2.1 Vestamid® D18

p0107Vestamid® L1901 45 seconds 4 Example 2.2 VESTODUR® 2000

p0108DYFLOR® X7394 45 seconds 4 Example 2.2 VESTODUR® 2000

p0109Vestamid® X7297 45 seconds Example 2.3 polypropylene 4

p0110VestamidR® Xl291 45 seconds 4 example 2.3

p0111Ultramid® B4

p0112Vestamid® D18 30 seconds 4

p0113example 2.4

p0114Ultramid® B4

p0115Vestamid® X7297 45 seconds 4

p0116example 2.5

p0117Ultramid® B4

p0118Vestamid® X7297 45 seconds 4

p0119example 2.5

p0120Plexiglas® 8N

p0121Vestamid® X7297 45 seconds 4

p0122example 2.5

p0123DYFLOR® LE

p0124Vestamid® L1901 30 seconds 4

p0125example 2.6

p0126Vestamid® D18

p0127Vestamid® L1901 30 seconds 4

p0128example 2.7

p0129Vestamid® D18

p0130Vestamid® X7297 45 seconds 4

p0131example 2.5

p0132PLEXIMID® 8815