Shape-memory polybutylene terephthalate film, production process and use thereof, and process for production of polybutylene terephthalate film
OwnerSeiji Kagawainventor
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Abstract
A polybutylene terephthalate laminate film having excellent shape memory and high-temperature dimensional stability obtained by (1) subjecting a laminate film comprising a polybutylene terephthalate film and another film or film laminate to a shaping treatment at a temperature T1 equal to or lower than the glass transition temperature of said polybutylene terephthalate while maintaining a first shape; (2) deforming the shaped laminate film to a second shape at a temperature T2 higher than said glass transition temperature; and (3) cooling said laminate film to a temperature T3 equal to or lower than said glass transition temperature.
Claims64
A shape-memory polybutylene terephthalate laminate film comprising (a) a polybutylene terephthalate film, and (b) at least one selected from the group consisting of a paper sheet, another resin film and a metal foil or a laminate comprising it, which is subjected to a shaping treatment to the first shape at a temperature T1 equal to or lower than the glass transition temperature of said polybutylene terephthalate, deformed to a second shape at a temperature T2 higher than said glass transition temperature, and then cooled to a temperature T3 equal to or lower than said glass transition temperature so that said laminate film is fixed to said second shape, said polybutylene terephthalate laminate film substantially recovering said first shape from said second shape when exposed to said temperature T1 or higher.
A shape-memory polybutylene terephthalate laminate film comprising (a) a polybutylene terephthalate film, and (b) at least one selected from the group consisting of a paper sheet, another resin film and a metal foil or a laminate comprising it, which is subjected to a shaping treatment to the first shape at a temperature T4 higher than the glass transition temperature and lower than the melting point of said polybutylene terephthalate, cooled to a temperature T5 equal to or lower than said glass transition temperature so that said laminate film is fixed to said first shape, deformed to a second shape at a temperature T6 higher than said glass transition temperature and lower than said T4, and then cooled to a temperature T7 equal to or lower than said glass transition temperature so that said laminate film is fixed to said second shape, said polybutylene terephthalate laminate film substantially recovering said first shape from said second shape when exposed to said temperature T4 or higher.
A method for producing a shape-memory polybutylene terephthalate laminate film comprising (a) a polybutylene terephthalate film, and (b) at least one selected from the group consisting of a paper sheet, another resin film and a metal foil, or a laminate comprising it, said method comprising the steps of (1) subjecting a laminate film comprising said polybutylene terephthalate film and another film or film laminate to a shaping treatment at a temperature T1 equal to or lower than the glass transition temperature of said polybutylene terephthalate while maintaining a first shape;
- (2) deforming the shaped laminate film to a second shape at a temperature T2 higher than said glass transition temperature;
- and (3) cooling said laminate film to a temperature T3 equal to or lower than said glass transition temperature so that said laminate film is fixed to said second shape.
A method for producing a shape-memory polybutylene terephthalate laminate film comprising (a) polybutylene terephthalate film, and (b) at least one selected from the group consisting of a paper sheet, another resin film and a metal foil, or a laminate comprising it, said method comprising the steps of (1) (i) laminating said polybutylene terephthalate film with another film or film laminate, after a shaping treatment at a temperature T4 higher than the glass transition temperature and lower than the melting point of said polybutylene terephthalate while maintaining said polybutylene terephthalate film in a first shape, or (ii) producing a laminate film of said polybutylene terephthalate film and another film or film laminate in advance, and subjecting it to a shaping treatment at said temperature T4 while maintaining it in the first shape to produce the shaped laminate film having said first shape;
- (2) cooling the shaped laminate film to a temperature T5 equal to or lower than said glass transition temperature to fix it to said first shape;
- (3) deforming said shaped laminate film to a second shape at a temperature T6 higher than said glass transition temperature and lower than said temperature T4;
- and then (4) cooling the deformed laminate film to a temperature T7 equal to or lower than said glass transition temperature to fix it to said second shape.
A method for producing a polybutylene terephthalate film from a polybutylene terephthalate resin by an air-cooled inflation method, comprising the steps of:
- ejecting a humid air through a first cooling ring disposed near an annular die to cool a neck portion of a bubble to 130° C. or lower;
- ejecting a humid air through a second cooling ring disposed above the annular die by the distance 5 to 10 times the opening diameter of the annular die to cool said bubble to 80° C. or lower;
- and keeping the temperature around a cylindrical net disposed between said first cooling ring and said second cooling ring constant to stabilizing the temperature of said bubble cooled by said first cooling ring and said second cooling ring;
- at a blow-up ratio of 1.5 to 2.8, a resin extrusion temperature of 210 to 250° C., and a resin-extruding pressure of 9.8 to 13.7 MPa.
An easy-to-straight-tear polybutylene terephthalate film comprising a polybutylene terephthalate film having a lot of substantially parallel linear scratches at least one entire surface formed by pressing said polybutylene terephthalate film to a roll or plate while said polybutylene terephthalate film is in sliding contact with said roll or plate having a lot of fine particles with large hardness, whereby it can be torn substantially straight along said linear scratches from any point.
Dependencies are inferred from the claim text.