Abstract: A connector for connecting a hose or a tube according to the present invention is constituted by a nipple (1), into which the hose (100) can be inserted, a cap nut (10), an inner member (2), a cap (5) and a tapered washer (7), wherein projections (5b) are formed on an outer periphery of the cap (5), a groove (5c) is formed between the projections (5b), and a protrusion (2b) that can engage with an inner periphery of the hose (100) is formed on the inner member (2) or a tubular member (21) in a position corresponding to the projections formed on the outer periphery of the cap.

Abstract: A phosphate treatment solution for composite structures which is here disclosed is characterized by containing 0.3-2.0 g/l of zinc ions, 0.3-4.0 g/l of nickel ions, 0.3-2.0 g/l of manganese ions, 3-10 g/l of sodium ions, 0.1-10 g/l of potassium ions, 5.0-25.0 g/l of phosphate ions, 0.1-20 g/l of total fluorine ions, 4.0 g/l or more of nitrate ions and 0.01-1.0 g/l of nitrite ions as main components, the aforesaid treatment solution having a pH of 2.0-3.5.