(I) (II) A primer comprises a carrier and compound (I) or (II), wherein R1 to R11 are independently selected from H, OH,
halogen, CH3, linear or branched C2-C6
alkyl, linear or branched C2-C6 alkoxy, linear or branched C2-C6 alkenyl, C2-C6 alkynyl, C3-C9 cycloalkyl, C4-C9 cycloalkenyl, C4-C9 cycloalkynyl, C3-C9
aryl, C3-C9 heteroaryl, C3-C9 heteroalicyclyl, C6-C12 aralkyl, C6- C12 heteroaralkyl, C6-C12 (heteroalicyclyl)
alkyl, hydroxy, protected hydroxyl, C2-C6 alkoxy, C4-C6 aryloxy, C2-C6 acyl, ester, mercapto, alkylthio, arylthio, cyano,
halogen, carbonyl, thiocarbonyl, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, S-sulphonamido, N-sulphonamido, C-carboxy, protected C-carboxy, O-carboxy, isocyanato, thiocyanato, isothiocyanato, nitro, silyl, sulphenyl, sulphinyl, sulphonyl, haloalkyl, haloalkoxy, trihalomethanesulphonyl, trihalomethanesulphonamido, and amino. Preferably, the compound is 4-
hydroxybenzoic acid, orcinol, trihydroxybenzene, 3-
hydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4,5-trihydroxybenzoic acid, 4-hydroxy-2-methylbenzoic acid, or 4-fluoro-2-methylbenzoic acid. The compound may be present in an amount of 0.1-10 wt.%. Typically, the carrier is
isopropyl alcohol. A method of bonding substrates using the primer and an
adhesive is disclosed.