US Patent 7716872 Removable protective coating

A greenhouse comprising: a substantially transparent surface; a protective coating comprising a pigment and a binder. The binder comprises a vinyl polymer based on one or more of the monomers selected from the group consisting of methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, styrene, methacrylic acid and acrylic acid, having a weight-average molecular weight of 10,000-100,000 and an acid value of 40-250. The binder has a polydispersity of 2-6 and a glass transition temperature of 10 to 60° C. The protective coating is on said substantially transparent surface and the protective coating is removable with a removing agent comprising a base and a complex former.