Global Patent Index - EP 0720143 B1

EP 0720143 B1 2000-09-06 - 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

EP 0720143 B1 (FR)

Application

EP 95402932 A

Priority

FR 9415646 A

Abstract (en)

[origin: EP0720143A1] 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.

IPC 1-7 (main, further and additional classification)

G10K 11/162; C08L 101/00; G10K 11/16

IPC 8 full level (invention and additional information)

G10K 11/16 (2006.01); G10K 11/162 (2006.01)

CPC (invention and additional information)

G10K 11/162 (2013.01)

Designated contracting state (EPC)

CH DE FR GB IT LI SE

EPO simple patent family

EP 0720143 A1 19960703; EP 0720143 B1 20000906; DE 69518730 D1 20001012; FR 2728715 A1 19960628; FR 2728715 B1 19970131

INPADOC legal status


2001-09-28 [REG FR ST] NOTIFICATION OF LAPSE

2000-10-18 [18W] WITHDRAWN

- Date of withdrawal: 20000725

2000-10-12 [REF] CORRESPONDS TO:

- Document: DE 69518730 20001012

2000-10-11 [DB1] DELETION OF B1 DOCUMENT

2000-09-29 [REG CH PK] CORRECTION

- Free text: RECTIFICATIONS

2000-09-15 [REG CH EP] ENTRY IN THE NATIONAL PHASE

2000-09-06 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: B1

- Designated State(s): CH DE FR GB IT LI SE

1999-09-15 [17Q] FIRST EXAMINATION REPORT

- Effective date: 19990802

1999-02-24 [RAP3] CORRECTION OF THE ADDRESS OR NAME OF APPLICANT (A DOCUMENT)

- Owner name: ALCATEL

1997-02-12 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 19961214

1996-07-03 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A1

- Designated State(s): CH DE FR GB IT LI SE