Abstract: Windows for vehicles particularly windscreens comprise sheets of glass adhesively bonded together by means of a hot melt adhesive which is an ethylene copolymer containing from 7 to 18% by weight of methacrylic acid and sufficient methyl methacrylate such that together the methyl methacrylate and methacrylic acid constitute from 20 to 35% by weight of the copolymer and the copolymer has a melt flow index of at least 0.1 and not more than 2. Also disclosed are ethylene copolymers as defined above.

Abstract: a process is provided in which a solid compound of a transition metal of Groups IVA to VIA is ground with at least one polymeric material containing sulphone groups and containing at least two repeat units of the formula:--Ar--SO.sub.2 --in which Ar is a bivalent aromatic radical and may vary from unit to unit in the polymer chain. The Ar radical preferably contains two aromatic rings linked together, as in: ##STR1## where X is an O or S atom, a direct link or the residue obtained by removing H from each --OH group present in an aromatic diol. If Ar varies the material is a copolymer. The polymeric material can be a polyethersulphone.The transition metal can be zirconium, vanadium or titanium. Preferably the transition metal compound is a halide such as titanium trichloride.