抄録
In order to improve the water-resistance of the layer produced by silane coupling agents such as 3-methacryloxypropyltrimethoxysilane (3-MPS), the effect of addition of various hydrophobic silanes to 3-MPS was studied. The hydrophobic silanes were trifluoropropyltrimethoxysilane (LP1-T), nonafluorohexyltrimethoxysilane (LP4-T), heptadecafluorodacanyltrimethoxysilane (LP8-T), heptadecafluorodacanylmethyldimethoxysilane (LP8-D), phenyltriethoxysilane (PS) and octyltrimethoxysilane (Oct). The tensile bond strengths of acrylic resin to the glass plate treated with the mixed silane increased with increasing content of the hydrophobic silane in the mixed silane and reached to a maximum when the content was 40-50% by weight, and decreased at the content above 50%. The tendency of the strength was almost the same among those silanes. For example, in the case of a mixture of LPl-T and 3-MPS, the strength of the resin was 29 MPa when the content of LP1-T in the mixed silane was 40% and was higher than that of 20 MPa of 3-MPS alone, and the strength at the content of 80% of LP1-T was 21 MPa. There was a difference in the strength of those specimens after 2000 thermal cycles. In the above thermal cycles, the specimens were alternately immersed for 1 minute in water baths having temperatures of 4°C and 60°C. The addition of LP1-T and LP4-T to 3-MPS was excellent in durability against water, that of PS and Oct was slightly effective, and LP8-T and LP8-D was poor. A higher bonding strength and better water-resistance produced by using a mixture of 3-MPS and a hydrophobic silane may be due to the increase of diffusion of the matrix resin into the hydrophobic siloxane layer, and the formation of an interpenetrating polymer network between the resin and the layer.
