METHOD OF MANUFACTURING MICROPOROUS FILM HAVING ZONE OF DEFORMATION

• Main Authors: BURNS, JOHN, GLASGOW, JR, MACHIDA, KENICHIRO, YAMASHITA, FUMITAKE, KISHIDA, KAZUSHIGE
• Format: Patent
• Language: English; French
• Published: 16.03.2000
• Edition: 7
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; BANDAGES, DRESSINGS OR ABSORBENT PADS; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF,TUBULAR STRUCTURES OF THE BODY, E.G. STENTS; FILTERS IMPLANTABLE INTO BLOOD VESSELS; FIRST-AID KITS; FOMENTATION; HUMAN NECESSITIES; HYGIENE; MEDICAL OR VETERINARY SCIENCE; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; PERFORMING OPERATIONS; PROSTHESES; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; TREATMENT OR PROTECTION OF EYES OR EARS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

A method of manufacturing a microporous film having breathability and a zone of deformation is disclosed. The method comprises the steps of: (1) stretching a mixture of a thermoplastic resin and inorganic fillers at least in one direction to obtain the microporous film with an average material strain at break of not greater than about 650 % and a water vapor transmission rate of at least about 250 g/m /24hr, (2) heating at least a portion of the microporous film to at least about 40 DEG C, and (3) deforming the heated portion of the microporous film at an average applied strain of between about 170 % and about 260 %. A film produced by the method, and an absorbent article having such a film are also disclosed. L'invention concerne un procédé de fabrication d'un film microporeux respirant qui possède une zone de déformation. Le procédé consiste en ce qui suit: (1) étirer un mélange d'une résine thermoplastique et de charges inorganiques dans au moins une direction pour obtenir le film microporeux possédant une contrainte matérielle moyenne à la rupture inférieure ou égale à environ 650 % et un débit de transmission de la vapeur d'eau égal ou supérieur à environ 250 g/m /24h; (2) chauffer au moins une partie du film microporeux à une température égale ou supérieure à environ 40 DEG C et; (3) déformer la partie chauffée du film microporeux avec une contrainte moyenne appliquée comprise entre environ 170 % et environ 260 %. L'invention concerne aussi un film produit par ce procédé et un article absorbant muni de ce film.