Primer composition and curtain wall unit

Abstract

Provided are a primer composition that can adhere well to a variety of adherends and ensures a long workable time together with excellent durability, and a curtain wall unit. A primer composition comprising: (A) 100 parts by mass of an organosiloxane polymer having a three-dimensional network structure comprising RSiOunits (R independently represents a C1-6 substituted or unsubstituted monovalent hydrocarbon group) and SiOunits, the molar ratio of RSiOunits to SiOunits being 0.6-1.2; (B) 300-1,000 parts by mass of a mixture of organo-oxy-group-containing titanium compounds containing 75 mol % or more of an organo-oxy-group-containing titanium compound represented by formula (1)Ti(OR)(RCHCOCHCOOCHR)  (1)(Rmay be the same or different and are substituted or unsubstituted monovalent hydrocarbon groups, Rmay be the same or different and are hydrogen atoms and/or substituted or unsubstituted monovalent hydrocarbon groups); and (C) 1,000-8,000 parts by mass of a solvent.