NOVELTY - A back-surface protection sheet consists of a weather-resistant resin layer (1), an aluminum foil (2), a plastic film (3), and an easy-bonding layer (4). The resin layer is formed using a composition containing an acrylic type copolymer, a polyisocyanate compound, and pigment. The copolymer is a copolymer of acryl type monomer (1-50 wt.%) having glycidyl group or oxetanyl group, acryl type monomer having a functional group reactive with an isocyanate group, and another acryl type monomer. The copolymer has a glass transition temperature of 0-60 degrees C.    USE - Back-surface protection sheet is used for solar cells used in solar cell modules (claimed).    ADVANTAGE - The back-surface protection sheet has excellent economical efficiency, abrasion resistance, weather resistance, heat-and-moisture resistance, and water-vapor barrier property.    DETAILED DESCRIPTION - A back-surface protection sheet consists of a weather-resistant resin layer, an aluminum foil, a plastic film, and an easy-bonding layer laminated sequentially. The resin layer is formed using a composition containing an acrylic type copolymer, a polyisocyanate compound, and pigment. The copolymer is a copolymer of acryl type monomer (1-50 wt.%) having glycidyl group or oxetanyl group, acryl type monomer having a functional group reactive with an isocyanate group, and another acryl type monomer. The copolymer has a glass transition temperature of 0-60 degrees C, a weight average molecular weight of 30000-150000, a hydroxyl value of 2-100 mg potassium hydroxide/g, and an aromatic ring content of 50 wt.% or less. The number of isocyanate groups in the polyisocyanate group is 0.1-5 with respect to 1 hydroxyl group of copolymer. An INDEPENDENT CLAIM is included for solar-cell module.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the back-surface protection sheet.    Weather-resistant resin layer (1)    Aluminum foil (2)    Plastic film (3)    Easy-bonding layer (4)    Adhesive bond layer (5)