Surface-treated metal plate for polyolefin resin bonding and composite member using same

A surface-treated metal sheet for polyolefin resin bonding, comprising:

• a metal substrate;
• an adhesive layer laminated on at least one surface of the metal substrate;
• and
• a chemical conversion coating film interposed between the metal substrate and the adhesive layer,
• wherein the chemical conversion coating film is a coating film obtained by applying onto the metal substrate a coating liquid comprising a colloidal silica, a silane coupling agent, and resin;
• wherein the resin of the chemical conversion coating film comprises a first acid-modified polyolefin resin consisting of an acid-modified polypropylene resin,
• wherein a coating amount of the chemical conversion coating film is in a range of from 0.2 to 3 g/m2 in terms of dry mass,
• wherein the adhesive layer comprises a second acid-modified polyolefin resin consisting of an acid-modified polypropylene resin,
• wherein the first acid-modified polyolefin resin in the chemical conversion coating film has an acid value of 5 to 76 mg KOH/g,
• wherein, relative to 100 mass % of total resin in the adhesive layer, a content of the second acid-modified polyolefin resin is 80 mass % or more and 100 mass % or less,
• wherein the second acid-modified polyolefin resin in the adhesive layer has an acid value in a range of from 13 to 49 mg KOH/g, and
• wherein the adhesive layer has a thickness in a range of from 6 to 90 μm.