| 摘要 |
PURPOSE: To obtain a new modified epoxy resin having a specific structure, capable of providing a coating film excellent in adhesiveness, resistance to scratch, water and chemicals and flexibility on a metallic substrate and capable of preventing crack development at the flexed parts of a coated plate during its processing. CONSTITUTION: This modified epoxy resin containing >=50wt.% of polyalkylene oxide units 2-70 in average degree of polymerization (mav ) and having a number- average molecular weight (Mn ) of 2000-5500 is expressed by formula I [R<1> and R<2> are each H, methyl, etc.; E is of formula II, formula III (R<3> and R<4> are each CH2 CH<2> OH, or one party is CH2 CH2 OH, the other a 1-4C alkyl, benzyl, etc.), etc.; (h), (m) and (n) are each an integer of >=1]. It is recommended that this resin be obtained by reaction of a bisphenol-type epoxy resin with a bisphenol compound such as bisphenol A, anα,ω-diamine of formula IV and a sec-alkanolamine such as diethanolamine. It is preferable that this resin have an epoxy content of 0-30×10<-5> (eq/g) and a primary alcoholic OH content of 30×10<-5> to 150×10<-5> (eq/g).
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