EP 0720143 A1 19960703 - Absorbing material for acoustic waves
Title (en)
Absorbing material for acoustic waves
Title (de)
Absorbierendes Material für Schallwellen
Title (fr)
Matériau absorbant les ondes acoustiques
Publication
Application
Priority
FR 9415646 A 19941226
Abstract (en)
Absorbing compsn. for sound waves comprising: (a) a structural material (I) imparting limited rigidity to the compsn.; and (b) an absorbing material (II) having a lesser rigidity than the compsn. in order to dissipate the sound wave energy; is characterised in that (I) is a thixotropic material constituted by macromolecules (III) carrying electric charges of a same sign and having no mutual covalent bonds, the electric charges being neutralised by small and mobile counter ions. Pref. (I) is a plastic porous material impregnated with the thixotropic material. At least part of the counter ions carry hydroxyl groups allowing hydrogen bonding. (III) is (i) an acid polymer, such as polyacrylic acid, polystyrenesulphonic acid and carboxycellulose, the counter ions being derived from organic bases, such as ammonia, aminoalcohols (mono-, di- or tri-ethanol amine) and quat. ammoniums; or (ii) a basic polymer, such as polyethylene-imine, the counter ions being derived from carboxylic acids, such as citric acid, propionic acid, glycolic acid and sebacic acid, sulphonic acids or phosphonic acids.
Abstract (fr)
Composition absorbante pour ondes sonores, comportant: un matériau de structure conférant une rigidité limitée à ladite composition, et un matériau absorbant présentant par lui-même une rigidité plus faible que ladite composition pour dissiper l'énergie d'ondes sonores se propageant dans cette composition, ladite composition étant caractérisée par le fait que ledit matériau absorbant est un matériau thixotropique constitué de macromolécules porteuses de charges électriques d'un même signe et dépourvues de liaisons covalentes mutuelles, ces charges électriques étant neutralisées par des contre-ions mobiles et de petite taille. De préférence ledit matériau de struture est un matériau poreux déformable imprégné par ledit matériau thixotrique. <IMAGE>
IPC 1-7
IPC 8 full level
G10K 11/16 (2006.01); G10K 11/162 (2006.01)
CPC (source: EP)
G10K 11/162 (2013.01)
Citation (search report)
- [PX] EP 0653464 A2 19950517 - BRIDGESTONE CORP [JP]
- [YA] EP 0360037 A2 19900328 - SIEMENS AG [DE]
- [Y] US 4374172 A 19830215 - SCHWARZ HERWIG J [DE], et al
- [A] US 3843576 A 19741022 - PARKINSON R
- [A] DE 3708961 A1 19881013 - PELZER HELMUT [DE]
- [A] PATENT ABSTRACTS OF JAPAN vol. 018, no. 572 (M - 1696) 2 November 1994 (1994-11-02)
- [A] DATABASE WPI Section Ch Week 8702, Derwent World Patents Index; Class A88, AN 87-010871
Designated contracting state (EPC)
CH DE FR GB IT LI SE
DOCDB simple family (publication)
EP 0720143 A1 19960703; EP 0720143 B1 20000906; DE 69518730 D1 20001012; FR 2728715 A1 19960628; FR 2728715 B1 19970131
DOCDB simple family (application)
EP 95402932 A 19951222; DE 69518730 T 19951222; FR 9415646 A 19941226