HONEYCOMB-TYPE POLYESTER-BASED FILTER

PROBLEM TO BE SOLVED: To prepare a heat-shrinkable film for a honeycomb material, which is heat-resistant and excellent in shape stability, exhibits shrinkage results with very little unevenness and excellent unidirectional shrinking properties, can be processed with a solvent, and can be used for making an accurate honeycomb material with high efficiency; and to show an example of application of the heat-shrinkable film in the field of filters. SOLUTION: The filter of this invention is composed of a heat-shrinkable film the maximum heat shrinkage factor of which is 5% or higher, preferably 30% or higher. The film is made of a raw material polyester containing neopentyl glycol and/or cyclohexanedimethanol as a glycol component. Preferably, the filter is composed of a heat-shrinkable polyester film which is used for a honeycomb material and has the following characteristics: the minimum value of the shrinkage factor in the direction transverse to the main shrinkage direction is in the temperature range of 55°C-105°C; the intersection shrinkage factor is 2% or higher; and the solvent adhesion of adjacent films to each other is possible. COPYRIGHT: (C)2005,JPO&NCIPI