The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 16, 1988
Filed:
May. 22, 1986
Masao Ishii, Kashima, JP;
Takayuki Okamura, Okayama, JP;
Keishiro Igi, Kurashiki, JP;
Osamu Kusudo, Kurashiki, JP;
Yoshito Hamamoto, Kurashiki, JP;
Kuraray Co., Ltd., Kurashiki, JP;
Abstract
A copolyester film is disclosed which comprises a copolyester in which the dicarboxylic acid component comprises 100 to 85 mole percent of terephthalic acid and the diol component comprises 65 to 97 mole percent of 1,4-butanediol and 3 to 35 mole percent of a polyethylene glycol with a molecular weight of 106 to 550. The copolyester has a reduced viscosity in the range of 0.8 to 1.4 dl/g as measured at a concentration of 0.5 g/dl in a 1:1 (by weight) solvent mixture of phenol and tetrachloroethane at 30.degree. C. The copolyester has a main endothermic peak with a peak maximum temperature of 160.degree. C. to 200.degree. C. and at least one subsidiary endothermic peak with a peak maximum temperature of 30.degree. C. to 80.degree. C. in differential scanning calorimetry with the ratio (R) of the area occupying not less than 40.degree. C. in the subsidiary endothermic peak, the main endothermic peak area being within the range of 3 percent to 20 percent. A hot melt adhesive comprising the copolyester film and a method for producing the copolyester film are also disclosed. The hot melt adhesive has a high initial modulus of elasticity at high temperature (30.degree.-50.degree. C.) and features improved processability or workability while retaining the required properties of a hot melt adhesive.