EP0295494A2 - Multilayer film for loudspeaker membranes - Google Patents

Multilayer film for loudspeaker membranes Download PDF

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Publication number
EP0295494A2
EP0295494A2 EP88108730A EP88108730A EP0295494A2 EP 0295494 A2 EP0295494 A2 EP 0295494A2 EP 88108730 A EP88108730 A EP 88108730A EP 88108730 A EP88108730 A EP 88108730A EP 0295494 A2 EP0295494 A2 EP 0295494A2
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EP
European Patent Office
Prior art keywords
loss factor
temperature range
mechanical loss
thick
factor tan
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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EP88108730A
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German (de)
French (fr)
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EP0295494A3 (en
Inventor
Joachim Dipl.-Ing. Wank
Dieter Dr. Freitag
Werner Dipl.-Ing. Waldenrath
Claus Dr. Burkhardt
Hans-Wolfgang Dipl.-Ing. Schmoranzer
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Bayer AG
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Bayer AG
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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/04—Plane diaphragms
    • H04R7/06—Plane diaphragms comprising a plurality of sections or layers
    • H04R7/10—Plane diaphragms comprising a plurality of sections or layers comprising superposed layers in contact
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/12—Non-planar diaphragms or cones
    • H04R7/122—Non-planar diaphragms or cones comprising a plurality of sections or layers
    • H04R7/125—Non-planar diaphragms or cones comprising a plurality of sections or layers comprising a plurality of superposed layers in contact
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2307/00—Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by H04R7/00 or H04R31/003, not provided for in any of its subgroups
    • H04R2307/029—Diaphragms comprising fibres

Definitions

  • Films I suitable according to the invention with an elastic modulus of 1000 to 200000 MPa are those from known thermo plastic plastics such as cellulose esters, aromatic polycarbonates, aromatic polyarylsulfones, polyphenylene sulfide and from known metallic materials with a density ⁇ 5 g / cm3, preferably ⁇ 4 g / cm3 such as titanium, magnesium, aluminum or their alloys.
  • Films I which are particularly suitable according to the invention are films made from thermoplastic aromatic polycarbonates with molecular weights M w (weight average) from 25,000 to 200,000, preferably from 30,000 to 120,000 and in particular from 30,000 to 80,000 ( M w determined from the relative viscosity ⁇ rel in CH2Cl2 at 20 ° C at a concentration of 0.5 g per 100 ml).
  • Further films I made from thermoplastic materials which are suitable according to the invention are those made from known thermoplastic polyarylsulfones, which can be linear (see DE-OS 27 35 144) or branched (see DE-OS 27 35 092 and DE-OS 23 05 413).
  • linear polyarylsulfones are known aromatic polysulfones or polyether sulfones with molecular weights M w (weight average measured by light scattering) between approximately 15,000 and approximately 55,000, preferably between approximately 20,000 and approximately 40,000.
  • M w weight average measured by light scattering
  • Such polyarylsulfones are described, for example, in DE-OS 17 19 244 and US Pat. No. 3,365,517.
  • Suitable branched polyarylsulfones are in particular the branched polyaryl ether sulfones according to DE-OS 23 05 413 and US Pat. No. 3,960,816, their molecular weight M w are between about 15,000 and about 50,000, preferably between about 20,000 and 40,000.
  • Cellulose esters suitable according to the invention can be obtained by conventional processes by esterifying the cellulose with aliphatic monocarboxylic anhydrides, preferably acetic and butyric or acetic and propionic anhydrides. As a rule, these are cellulose esters that still contain OH groups.
  • the partial hydrolysis required for its preparation is generally carried out in the crude solution and controlled by a slight excess of water so that a hydroxyl content corresponding to a hydroxyl number of 4 to 25 is obtained.
  • the oxidative bleaching of the cellulose ester isolated from the solution must be carried out in such a way that no oxidizing agent can be detected in the end product; aftertreatment may have to be carried out with reducing agents.
  • the free hydroxyl groups of the cellulose ester are esterified with a predetermined amount of acetic anhydride in pyridine, the excess acetic anhydride is reacted with water and back-titrated (see. Industrial and Engineering Chemistry, Vol. 14, No. 12, page 935 to 940 (1942)).
  • Particularly suitable cellulose esters are those whose 20% by weight solution in acetone has a viscosity of 0.3 to 0.5 poise.
  • Preferred cellulose esters have In the case of acetobutyrates, an acetic acid content of 17 to 23% by weight and a butyric acid content of 45 to 50% by weight, in the case of acetopropionates a propionic acid content of 61 to 69% by weight and an acetic acid content of 2 to 7% by weight on.
  • the hydroxyl numbers are between 4 and 25.
  • the weight average molecular weights M w are between 10,000 and 1,000,000, preferably between 100,000 and 500,000.
  • Films II suitable according to the invention whose mechanical loss factor tan ⁇ lies between 10 Wu2 and 101, can be produced from polyester, polyether and polyether carbonate urethanes.
  • Suitable polyether urethanes can be prepared according to DE-PS 2 302 564.
  • Suitable polyester urethanes can be obtained according to DE-OS 2 842 806 and suitable polyether carbonate urethanes according to DE-OS 2 248 382.
  • Thermoplastic sealing layers III suitable according to the invention are e.g. those made of nitrocellulose and those made of an aliphatic or aromatic polyurethane layer which is tack-free at room temperature.
  • Particularly preferred are polyether carbonate urethanes with a specific weight of 1.13 to 1.17, preferably 1.15 g / cm3.
  • aqueous dispersions of preferably linear polyester polyurethanes which dry to transparent films and which optionally contain a more highly functional polyisocyanate as crosslinking agent.
  • Suitable polyurethane dispersions are for example those made from linear polyester diols, aromatic or aliphatic diisocyanates and, if appropriate, customary chain extenders which have been prepared using ionic structural components in accordance with the teaching of US Pat. No. 3,479,310 or DE-AS 14 95 847.
  • Aqueous dispersions of carboxylate and sulfonate groups, preferably linear polyester polyurethanes, as can be obtained according to DE-OS 28 04 609, are also very suitable.
  • polyester polyurethanes are preferably reaction products of (i) aromatic diisocyanates such as 2,4- and / or 2,6-diisocyanatotoluene, 4,4-diisocyanatodiphenylmethane, hexamethylene diisocyanate, isophorone diisocyanate, or 1,5-diisocyanatonaphthalene or mixtures thereof with ( ii) polyester diols of the molecular weight range ( M w ) 1000 to 4000, in particular based on adipic acid and suitable glycols such as ethylene glycol, 1,4-dihydroxybutane, 1,6-dihydroxyhexane and their mixtures and optionally (iii) chain extenders, for example the latter glycols, the reactants while maintaining an NCO / OH equivalent ratio of 0.9: 1
  • aromatic diisocyanates such as 2,4- and / or 2,6-diisocyanatotoluene, 4,4-d
  • Suitable solvents for such polyester polyurethanes are, for example Ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone or mixtures consisting of such solvents.
  • the dispersions or solutions are generally used with a solids content of 10 to 40% by weight. It can often be expedient to incorporate minor amounts of a more highly functional polyisocyanate, for example tris (6-isocyanathexyl) biuret, into the solutions mentioned in order to improve the mechanical properties of the polyurethane film ultimately obtained.
  • Thermoplastic sealing layers III which are also suitable according to the invention are those made of nitrocellulose.
  • thermoplastic film I and thermoplastic polyurethane layer II can be produced either by coextrusion of the two materials using a thermally separated 2-channel slot die, or by extrusion coating of polyurethane film II with the melt of thermoplastic I.
  • the melt of the coextrudate or the melt-coated polyurethane film are drawn off over cooling rolls and wound up.
  • a film made from aromatic polycarbonate based on bisphenol A with a M of 30,000 (determined from the relative viscosity ⁇ rel in CH2Cl2 at 20 ° C and a concentration of 0.5 g / 100 ml) with a thickness of 250 ⁇ m is in the extrusion coating process with the melt of a polyether carbonate urethane, the density 1, 15 g / cm3, coated, so that the total thickness of the composite is 300 microns ( ⁇ 15%).
  • a loudspeaker cone is produced from this composite material using the thermoforming process.
  • This speaker cone is further processed in a manner known per se to form a speaker system.
  • the special properties of this system according to the invention are notable for - low natural resonance in the frequency range ⁇ 1000 Hz - high sensitivity up to frequencies> 10 000 Hz.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Laminated Bodies (AREA)
  • Diaphragms For Electromechanical Transducers (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

Multi-layer films of a thickness of 0.05 to 0.7 mm, comprising a 0.02 to 0.6 mm thick thermoplastic film or metallic foil having a modulus of elasticity of 1,000 to 200,000 MPa, a 0.01 to 0.03 mm thick film of thermoplastically processible material having a mechanical loss factor tan delta in the temperature range -40 to +200 DEG C of between 10<-><2> and 10<1> and a 0.05 to 0.1 mm thick thermoplastic sealing layer, the mechanical loss factor tan delta of which in the temperature range -40 to 200 DEG C lies between 10<-><2> and 10<2>, as well as its use for the production of loud speaker membranes or cones.

Description

Gegenstand der Erfindung sind Mehrschichtfolien einer Dicke von 50 bis 700 µm bestehend aus

  • I. einer 0,02 bis 0,6 mm dicken Folie mit einem E-­Modul von 1000 bis 200000 MPa, vorzugsweise 1500 bis 5000 MPa
  • II. einer 0,01 bis 0,3 mm dicken Folie aus thermo­plastisch verarbeitbarem Material deren mechani­scher Verlustfaktor tan δ im Temperaturbereich -40 bis +200°C, insbesondere -40 bis +160°C zwischen 10⁻² und 10¹ liegt und gegebenenfalls
  • III. einer 0,05 bis 0,1 mm dicken thermoplastichen Siegelschicht deren mechanischer Verlustfaktor tan δ im Temperaturbereich -40 bis +200°C zwischen 10⁻² und 10² liegt.
The invention relates to multilayer films with a thickness of 50 to 700 μm consisting of
  • I. a 0.02 to 0.6 mm thick film with a modulus of elasticity of 1000 to 200000 MPa, preferably 1500 to 5000 MPa
  • II. A 0.01 to 0.3 mm thick film made of thermoplastically processable material whose mechanical loss factor tan δ in the temperature range -40 to + 200 ° C, in particular -40 to + 160 ° C between 10⁻² and 10¹ and optionally
  • III. a 0.05 to 0.1 mm thick thermoplastic sealing layer with a mechanical loss factor tan δ in the temperature range -40 to + 200 ° C between 10⁻² and 10².

Erfindungsgemäß geeignete Folien I mit einem E-Modul von 1000 bis 200000 MPa sind solche aus bekannten thermo­ plastischen Kunststoffen wie Celluloseester, aromati­schen Polycarbonaten, aromatischen Polyarylsulfonen, Polyphenylensulfid sowie aus bekannten metallischen Werkstoffen mit einer Dichte ≦5 g/cm³, bevorzugt ≦4 g/cm³ wie Titan, Magnesium, Aluminium oder deren Legierungen.Films I suitable according to the invention with an elastic modulus of 1000 to 200000 MPa are those from known thermo plastic plastics such as cellulose esters, aromatic polycarbonates, aromatic polyarylsulfones, polyphenylene sulfide and from known metallic materials with a density ≦ 5 g / cm³, preferably ≦ 4 g / cm³ such as titanium, magnesium, aluminum or their alloys.

Erfindungsgemäß besonders geeignete Folien I sind solche aus thermoplastischen aromatischen Polycarbonaten mit Molekulargewichten M w (Gewichtsmittel) von 25 000 bis 200 000, vorzugsweise von 30 000 bis 120 000 und insbe­sondere von 30 000 bis 80 000 (M w ermittelt aus der relativen Viskosität ηrel in CH₂Cl₂ bei 20°C bei einer Konzentration von 0,5 g pro 100 ml). Weitere erfindungs­gemäß geeignete Folien I aus thermoplastischen Kunst­stoffen sind solche aus bekannten, thermoplastischen Polyarylsulfonen, welche linear (vgl. DE-OS 27 35 144) oder verzweigt (vgl. DE-OS 27 35 092 und DE-OS 23 05 413) sein können.Films I which are particularly suitable according to the invention are films made from thermoplastic aromatic polycarbonates with molecular weights M w (weight average) from 25,000 to 200,000, preferably from 30,000 to 120,000 and in particular from 30,000 to 80,000 ( M w determined from the relative viscosity η rel in CH₂Cl₂ at 20 ° C at a concentration of 0.5 g per 100 ml). Further films I made from thermoplastic materials which are suitable according to the invention are those made from known thermoplastic polyarylsulfones, which can be linear (see DE-OS 27 35 144) or branched (see DE-OS 27 35 092 and DE-OS 23 05 413).

Besonders geeignete lineare Polyarylsulfone sind bekann­te aromatische Polysulfone oder Polyethersulfone mit Molekulargewichten M w (Gewichtsmittel gemessen durch Lichtstreuung) zwischen etwa 15 000 und etwa 55 000, vorzugsweise zwischen etwa 20 000 und etwa 40 000. Solche Polyarylsulfone sind beispielsweise in DE-OS 17 19 244 und US-PS 33 65 517 beschrieben.Particularly suitable linear polyarylsulfones are known aromatic polysulfones or polyether sulfones with molecular weights M w (weight average measured by light scattering) between approximately 15,000 and approximately 55,000, preferably between approximately 20,000 and approximately 40,000. Such polyarylsulfones are described, for example, in DE-OS 17 19 244 and US Pat. No. 3,365,517.

Geeignete verzweigte Polyarylsulfone sind insbesondere die verzweigten Polyarylethersulfone gemäß DE-OS 23 05 413 und US-PS 39 60 816, deren Molekulargewicht M w zwischen etwa 15 000 und etwa 50 000, vorzugsweise zwischen etwa 20 000 und 40 000 liegen.Suitable branched polyarylsulfones are in particular the branched polyaryl ether sulfones according to DE-OS 23 05 413 and US Pat. No. 3,960,816, their molecular weight M w are between about 15,000 and about 50,000, preferably between about 20,000 and 40,000.

Für nähere Einzelheiten sei auf DE-AS 30 10 143 ver­wiesen.For further details, reference is made to DE-AS 30 10 143.

Erfindungsgemäß geeignete Celluloseester können nach üblichen Verfahren durch Veresterung der Cellulose mit aliphatischen Monocarbonsäureanhydriden, vorzugsweise Essigsäure- und Buttersäure- oder Essigsäure- und Propionsäureanhydrid gewonnen werden. Es handelt sich in der Regel um Celluloseester die noch OH-Gruppen ent­halten. Die zu ihrer Herstellung erforderliche Teil­hydrolyse wird im allgemeinen in der Rohlösung durch­geführt und durch einen geringen Wasserüberschuß so ge­steuert, daß ein Hydroxylgehalt entsprechend einer Hy­droxylzahl von 4 bis 25 erhalten wird. Die oxidative Bleiche des aus der Lösung isolierten Celluloseesters muß so durchgeführt werden, daß im Endprodukt kein Oxidationsmittel mehr nachweisbar ist; gegebenenfalls muß mit Reduktionsmitteln nachbehandelt werden. Zur Bestimmung der Hydroxylzahl oder OH-Zahl werden die freien Hydroxylgruppen des Celluloseesters mit einer vorgegebenen Menge Acetanhydrid in Pyridin verestert, der Überschuß Acetanhydrid mit Wasser umgesetzt und zurücktitriert (vgl. Industrial and Engineering Chemistry, Vol. 14, Nr. 12, Seite 935 bis 940 (1942)).Cellulose esters suitable according to the invention can be obtained by conventional processes by esterifying the cellulose with aliphatic monocarboxylic anhydrides, preferably acetic and butyric or acetic and propionic anhydrides. As a rule, these are cellulose esters that still contain OH groups. The partial hydrolysis required for its preparation is generally carried out in the crude solution and controlled by a slight excess of water so that a hydroxyl content corresponding to a hydroxyl number of 4 to 25 is obtained. The oxidative bleaching of the cellulose ester isolated from the solution must be carried out in such a way that no oxidizing agent can be detected in the end product; aftertreatment may have to be carried out with reducing agents. To determine the hydroxyl number or OH number, the free hydroxyl groups of the cellulose ester are esterified with a predetermined amount of acetic anhydride in pyridine, the excess acetic anhydride is reacted with water and back-titrated (see. Industrial and Engineering Chemistry, Vol. 14, No. 12, page 935 to 940 (1942)).

Besonders geeignete Celluloseester sind solche deren 20 gew.-%ige Lösung in Aceton eine Viskosität von 0,3 bis 0,5 Poise besitzt. Bevorzugte Celluloseester weisen im Falle der Acetobutyrate einen Essigsäuregehalt von 17 bis 23 Gew.-% und einen Buttersäuregehalt von 45 bis 50 Gew.-%, im Falle der Acetopropionate einen Propionsäure­gehalt von 61 bis 69 Gew.-% und einen Essigsäuregehalt von 2 bis 7 Gew.-% auf. Die Hydroxylzahlen sind zwischen 4 und 25. Die Gewichtsmittel der Molekulargewichte M w sind zwischen 10 000 und 1 000 000, vorzugsweise zwi­schen 100 000 und 500 000.Particularly suitable cellulose esters are those whose 20% by weight solution in acetone has a viscosity of 0.3 to 0.5 poise. Preferred cellulose esters have In the case of acetobutyrates, an acetic acid content of 17 to 23% by weight and a butyric acid content of 45 to 50% by weight, in the case of acetopropionates a propionic acid content of 61 to 69% by weight and an acetic acid content of 2 to 7% by weight on. The hydroxyl numbers are between 4 and 25. The weight average molecular weights M w are between 10,000 and 1,000,000, preferably between 100,000 and 500,000.

Erfindungsgemäß geeignete Folien II, deren mechanischer Verlustfaktor tan δ zwischen 10⁻² und 10¹ liegt können aus Polyester-, Polyether- und Polyethercarbonat-Uretha­nen hergestellt werden. Geeignete Polyetherurethane kön­nen hergestellt werden gemäß DE-PS 2 302 564. Geeignete Polyesterurethane können gemäß DE-OS 2 842 806 erhalten werden und geeignete Polyethercarbonaturethane gemäß DE-OS 2 248 382.Films II suitable according to the invention, whose mechanical loss factor tan δ lies between 10 zwischen² and 10¹, can be produced from polyester, polyether and polyether carbonate urethanes. Suitable polyether urethanes can be prepared according to DE-PS 2 302 564. Suitable polyester urethanes can be obtained according to DE-OS 2 842 806 and suitable polyether carbonate urethanes according to DE-OS 2 248 382.

Erfindungsgemäß geeignete thermoplastische Siegel­schichten III sind z.B. solche aus Nitrocellulose und solche aus einer bei Zimmertemperatur klebfreien ali­phatischen oder aromatischen Polyurethanschicht. Beson­ders bevorzugt sind Polyethercarbonat-Urethane mit einem spezifischen Gewicht von 1,13 bis 1,17, bevorzugt 1,15 g/cm³.Thermoplastic sealing layers III suitable according to the invention are e.g. those made of nitrocellulose and those made of an aliphatic or aromatic polyurethane layer which is tack-free at room temperature. Particularly preferred are polyether carbonate urethanes with a specific weight of 1.13 to 1.17, preferably 1.15 g / cm³.

Zur Herstellung der erfindungsgemäß geeigneten Siegel­schichten III können wäßrige, zu transparenten Filmen auftrocknende Dispersionen von vorzugsweise linearen Polyesterpolyurethanen, die gegebenenfalls ein höher­funktionelles Polyisocyanat als Vernetzer enthalten, verwendet werden. Geeignete Polyurethandispersionen sind beispielsweise solche aus linearen Polyesterdiolen, aro­matischen oder aliphatischen Diisocyanaten und gegebe­nenfalls üblichen Kettenverlängerungsmitteln, die unter Mitverwendung von ionischen Aufbaukomponenten entspre­chend der Lehre der US-PS 34 79 310 oder der DE-AS 14 95 847 hergestellt worden sind. Sehr gut geeignet sind auch wäßrige Dispersionen von Carboxylat- und Sulfonatgruppen aufweisenden, vorzugsweise linearen Polyesterpolyurethanen, wie sie gemäß DE-OS 28 04 609 erhalten werden können. Im Falle der Verwendung von organischen Lösungen von vorzugsweise linearen Poly­esterpolyurethanen kommen vorzugsweise Lösungen von nicht-ionischen linearen Polyesterpolyurethanen in geeigneten Lösungsmitteln in Betracht. Bei diesen Polyurethanen handelt es sich vorzugsweise um Umset­zungsprodukte von (i) aromatischen Diisocyanaten wie 2,4- und/oder 2,6-Diisocyanatotoluol, 4,4-Diisocyanato­diphenylmethan, Hexamethylendiisocyanat, Isophorondi­isocyanat, oder 1,5-Diisocyanatonaphthalin oder deren Gemischen mit (ii) Polyesterdiolen des Molekularge­wichtsbereichs (M w) 1000 bis 4000, insbesondere auf Basis von Adipinsäure und geeigneten Glykolen wie Ethylenglykol, 1,4-Dihydroxybutan, 1,6-Dihydroxyhexan und deren Gemischen und gegebenenfalls (iii) Ketten­verlängerungsmitteln, beispielsweise den zuletztge­nannten Glykolen, wobei die Reaktionspartner unter Ein­haltung eines NCO/OH-Äquivalentverhältnisses von 0,9:1 bis 1:1,1, vorzugsweise 0,95:1 bis 1:1 zum Einsatz ge­langen, und wobei pro Mol Polyesterdiol gegebenenfalls 0,1 bis 2 Mol Kettenverlängerer bzw. Kettenverlängerer­gemisch zum Einsatz gelangen. Geeignete Lösungsmittel für derartige Polyesterpolyurethane sind beispielsweise Ethylacetat, Butylacetat, Methylethylketon, Methyliso­butylketon oder aus derartigen Lösungsmitteln bestehende Gemische. Die Dispersionen oder Lösungen werden im all­gemeinen mit einem Feststoffgehalt von 10 bis 40 Gew.-% verwendet. Oft kann es zweckmäßig sein, den genannten Lösungen untergeordnete Mengen eines höherfunktionellen Polyisocyanats, beispielsweise an Tris-(6-isocyanat­hexyl)-biuret einzuverleiben, um die mechanischen Eigen­schaften des letztendlich erhaltenen Polyurethanfilms zu verbessern.For the production of the sealing layers III suitable according to the invention it is possible to use aqueous dispersions of preferably linear polyester polyurethanes which dry to transparent films and which optionally contain a more highly functional polyisocyanate as crosslinking agent. Suitable polyurethane dispersions are for example those made from linear polyester diols, aromatic or aliphatic diisocyanates and, if appropriate, customary chain extenders which have been prepared using ionic structural components in accordance with the teaching of US Pat. No. 3,479,310 or DE-AS 14 95 847. Aqueous dispersions of carboxylate and sulfonate groups, preferably linear polyester polyurethanes, as can be obtained according to DE-OS 28 04 609, are also very suitable. If organic solutions of preferably linear polyester polyurethanes are used, preference is given to solutions of non-ionic linear polyester polyurethanes in suitable solvents. These polyurethanes are preferably reaction products of (i) aromatic diisocyanates such as 2,4- and / or 2,6-diisocyanatotoluene, 4,4-diisocyanatodiphenylmethane, hexamethylene diisocyanate, isophorone diisocyanate, or 1,5-diisocyanatonaphthalene or mixtures thereof with ( ii) polyester diols of the molecular weight range ( M w ) 1000 to 4000, in particular based on adipic acid and suitable glycols such as ethylene glycol, 1,4-dihydroxybutane, 1,6-dihydroxyhexane and their mixtures and optionally (iii) chain extenders, for example the latter glycols, the reactants while maintaining an NCO / OH equivalent ratio of 0.9: 1 to 1: 1.1, preferably 0.95: 1 to 1: 1, and optionally 0.1 to 2 mol of chain extender or chain extender mixture are used per mole of polyester diol . Suitable solvents for such polyester polyurethanes are, for example Ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone or mixtures consisting of such solvents. The dispersions or solutions are generally used with a solids content of 10 to 40% by weight. It can often be expedient to incorporate minor amounts of a more highly functional polyisocyanate, for example tris (6-isocyanathexyl) biuret, into the solutions mentioned in order to improve the mechanical properties of the polyurethane film ultimately obtained.

Erfindungsgemäß ebenfalls geeignete thermoplastische Siegelschichten III sind solche aus Nitrocellulose.Thermoplastic sealing layers III which are also suitable according to the invention are those made of nitrocellulose.

Die Herstellung des Verbundes aus der thermoplastischen Folie I, und der thermoplastischen Polyurethanschicht II kann entweder durch Coextrusion der beiden Materia­lien mittels einer thermisch getrennten 2-Kanalbreit­schlitzdüse erfolgen, oder durch Extrusionsbeschichtung der Polyurethanfolie II mit der Schmelze des thermopla­stischen Kunststoffes I.The composite of thermoplastic film I and thermoplastic polyurethane layer II can be produced either by coextrusion of the two materials using a thermally separated 2-channel slot die, or by extrusion coating of polyurethane film II with the melt of thermoplastic I.

Die Schmelze des Coextrudates bzw. die schmelzbeschich­tete Polyurethanfolie werden über Kühlwalzen abgezogen und aufgewickelt.The melt of the coextrudate or the melt-coated polyurethane film are drawn off over cooling rolls and wound up.

Für das Verbundsystem Metallfolie gemäß I und thermo­plastischer Polyurethanfolie II hat sich die Beschich­tung der Metallfolie I mit der Schmelze des thermopla­stischen Polyurethans als am geeignetsten erwiesen. Bei Verwendung der erfindungsgemäß geeigneten Polyurethane ist eine Vorbehandlung der Metallfolien nicht erforder­lich.For the composite system of metal foil according to I and thermoplastic polyurethane foil II, coating the metal foil I with the melt of the thermoplastic polyurethane has proven to be the most suitable. Pretreatment of the metal foils is not necessary when using the polyurethanes suitable according to the invention.

Beispielexample

Eine Folie aus aromatischem Polycarbonat auf Basis Bis­phenol A mit einem M von 30 000 (ermittelt aus der rela­tiven Viskosität ηrel in CH₂Cl₂ bei 20°C und einer Kon­zentration von 0,5 g/100 ml) mit einer Dicke von 250 µm wird im Extrusionsbeschichtungsverfahren mit der Schmelze eines Polyethercarbonat-Urethans, dessen Dichte 1,15 g/cm³ beträgt, beschichtet, so daß die Gesamtdicke des Verbundes 300 µm (± 15 %) beträgt.A film made from aromatic polycarbonate based on bisphenol A with a M of 30,000 (determined from the relative viscosity η rel in CH₂Cl₂ at 20 ° C and a concentration of 0.5 g / 100 ml) with a thickness of 250 µm is in the extrusion coating process with the melt of a polyether carbonate urethane, the density 1, 15 g / cm³, coated, so that the total thickness of the composite is 300 microns (± 15%).

Aus diesem Verbundwerkstoff wird ein Lautsprecherkonus im Thermoformverfahren hergestellt.A loudspeaker cone is produced from this composite material using the thermoforming process.

Dieser Lautsprecherkonus wird in an sich bekannter Weise zu einem Lautsprechersystem weiterverarbeitet.This speaker cone is further processed in a manner known per se to form a speaker system.

Die besonderen Eigenschaften dieses erfindungsgemäßen Systems zeichnen sich aus durch
- geringe Eigenresonanz im Frequenzbereich <1000 Hz
- hohe Ansprechempfindlichkeit bis zu Frequenzen >10 000 Hz.The special properties of this system according to the invention are notable for
- low natural resonance in the frequency range <1000 Hz
- high sensitivity up to frequencies> 10 000 Hz.

Claims (4)

1. Mehrschichtfolien einer Dicke von 0,05 bis 0,7 mm bestehend aus I. einer 0,02 bis 0,6 mm dicken thermoplastischen Kunststoff- oder metallischen Folie mit einem E-Modul von 1000 bis 200000 MPa II. einer 0,01 bis 0,3 mm dicken Folie aus thermo­plastisch verarbeitbarem Material mit einem mechanischen Verlustfaktor tan δ im Tempera­turbereich -40 bis +200°C, insbesondere -40 bis +160°C, zwischen 10⁻² und 10¹ und gegebe­nenfalls III. einer 0,05 bis 0,1 mm dicken thermoplastichen Siegelschicht deren mechanischer Verlustfaktor tan δ im Temperaturbereich von -40 bis +200°C zwischen 10⁻² und 10² liegt. 1. multilayer films with a thickness of 0.05 to 0.7 mm consisting of I. a 0.02 to 0.6 mm thick thermoplastic or metallic foil with an E-module of 1000 to 200000 MPa II. A 0.01 to 0.3 mm thick film made of thermoplastically processable material with a mechanical loss factor tan δ in the temperature range -40 to + 200 ° C, in particular -40 to + 160 ° C, between 10⁻² and 10¹ and optionally III. a 0.05 to 0.1 mm thick thermoplastic sealing layer with a mechanical loss factor tan δ in the temperature range from -40 to + 200 ° C between 10⁻² and 10². 2. Folie gemäß Anspruch 1, dadurch gekennzeichnet, daß II aus einem Polyethercarbonat-urethan mit einem spezifischen Gewicht von 1,13 bis 1,17 besteht.2. Film according to claim 1, characterized in that II consists of a polyether carbonate urethane with a specific weight of 1.13 to 1.17. 3. Folie gemäß Anspruch 1, dadurch gekennzeichnet, daß die Siegelschicht aus einem aliphatischen Poly­esterurethan besteht.3. Film according to claim 1, characterized in that the sealing layer consists of an aliphatic polyester urethane. 4. Verwendung der Folie gemäß Anspruch 1 zur Herstel­lung von Lautsprechermembranen oder -konen.4. Use of the film according to claim 1 for the manufacture of speaker membranes or cones.
EP88108730A 1987-06-13 1988-06-01 Multilayer film for loudspeaker membranes Withdrawn EP0295494A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3719879 1987-06-13
DE19873719879 DE3719879A1 (en) 1987-06-13 1987-06-13 MULTILAYER FILMS FOR SPEAKER MEMBRANE SYSTEMS

Publications (2)

Publication Number Publication Date
EP0295494A2 true EP0295494A2 (en) 1988-12-21
EP0295494A3 EP0295494A3 (en) 1990-07-18

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP88108730A Withdrawn EP0295494A3 (en) 1987-06-13 1988-06-01 Multilayer film for loudspeaker membranes

Country Status (3)

Country Link
EP (1) EP0295494A3 (en)
JP (1) JPS645300A (en)
DE (1) DE3719879A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0391189A2 (en) * 1989-04-06 1990-10-10 Bayer Ag Multi-ply sheets for crash-pads
EP0475220A2 (en) * 1990-09-12 1992-03-18 Bayer Ag Laminates
CN113411738A (en) * 2020-03-17 2021-09-17 3M创新有限公司 Sound film for micro loudspeaker and preparation method thereof
CN113411737A (en) * 2020-03-17 2021-09-17 3M创新有限公司 Sound film for micro loudspeaker and preparation method thereof
CN114502376A (en) * 2019-09-26 2022-05-13 3M创新有限公司 Multilayer film and method for producing same

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8389672B2 (en) 2006-01-23 2013-03-05 Mitsubishi Plastics, Inc. Diaphragm for electro-accoustic transducer
JP5127198B2 (en) * 2006-01-23 2013-01-23 三菱樹脂株式会社 Speaker diaphragm
JP4990601B2 (en) * 2006-11-20 2012-08-01 三菱樹脂株式会社 Diaphragm for electroacoustic transducer and film for the diaphragm

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1435588A (en) * 1973-05-30 1976-05-12 Mitsui Petrochemical Ind Process
FR2345048A1 (en) * 1976-03-19 1977-10-14 Harwood Hugh ELECTRO-ACOUSTIC TRANSDUCER MEMBRANE
EP0183516A2 (en) * 1984-11-28 1986-06-04 Polyplastics Co. Ltd. Method of manufacturing a laminated film

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1435588A (en) * 1973-05-30 1976-05-12 Mitsui Petrochemical Ind Process
FR2345048A1 (en) * 1976-03-19 1977-10-14 Harwood Hugh ELECTRO-ACOUSTIC TRANSDUCER MEMBRANE
EP0183516A2 (en) * 1984-11-28 1986-06-04 Polyplastics Co. Ltd. Method of manufacturing a laminated film

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0391189A2 (en) * 1989-04-06 1990-10-10 Bayer Ag Multi-ply sheets for crash-pads
US4970108A (en) * 1989-04-06 1990-11-13 Bayer Aktiengesellschaft Multilayer films from the use in crash pads
EP0391189A3 (en) * 1989-04-06 1991-04-03 Bayer Ag Multi-ply sheets for crash-pads
EP0475220A2 (en) * 1990-09-12 1992-03-18 Bayer Ag Laminates
EP0475220A3 (en) * 1990-09-12 1992-05-13 Bayer Ag Laminates
US5219643A (en) * 1990-09-12 1993-06-15 Bayer Aktiengesellschaft Multilayered films
CN114502376A (en) * 2019-09-26 2022-05-13 3M创新有限公司 Multilayer film and method for producing same
CN113411738A (en) * 2020-03-17 2021-09-17 3M创新有限公司 Sound film for micro loudspeaker and preparation method thereof
CN113411737A (en) * 2020-03-17 2021-09-17 3M创新有限公司 Sound film for micro loudspeaker and preparation method thereof
WO2021186277A1 (en) * 2020-03-17 2021-09-23 3M Innovative Properties Company Diaphragm for microspeaker and manufacturing method thereof
CN113411737B (en) * 2020-03-17 2023-03-10 3M创新有限公司 Sound film for micro loudspeaker and preparation method thereof
CN113411738B (en) * 2020-03-17 2023-08-22 3M创新有限公司 Sound membrane for micro-speaker and preparation method thereof

Also Published As

Publication number Publication date
DE3719879A1 (en) 1988-12-29
JPS645300A (en) 1989-01-10
EP0295494A3 (en) 1990-07-18

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