MONTREAL - The Protech-Oxyplast Group of Montreal, Canada, has reached an agreement to purchase the thermoplastic powder and liquid coatings businesses of the Thermoclad Co., Erie, PA. Thermoclad produces PVC powder coatings for fabricated metals such as fencing and dishwasher racks. The company also develops environmentally safe paints as well as other thermoplastics such as nylon and co-polyesters.