Abstract: A method of making a polyurea—polyurethane composite structure that is substantially free from emission of volatile organic compounds is disclosed. The composite structure produced according to the method of the subject invention has a flexural modulus of at least 200,000 lb/in2. The composite structure includes first and second layers. A mold substrate is provided and a first-layer polyisocyanate component and a first-layer resin component are reacted and sprayed onto the mold substrate to form the first-layer. The first-layer polyisocyanate component includes an aliphatic polyisocyanate, and the first-layer resin component includes a polyamine thereby forming a polyurea show surface having a Shore D hardness of at least 65. After application of the first-layer, a second-layer polyisocyanate component and a second-layer resin component are reacted and sprayed behind the first-layer to form the second-layer of the composite structure.

Abstract: A composite structure including a polyurea show surface, or top layer, and a polyurethane backing layer is disclosed. Preferably, the show surface of the composite structure is substantially free of volatile organic compounds and is aliphatic such that it is ultraviolet light stable. Specifically, the show surface is the reaction product of an aliphatic polyisocyanate or aliphatic polyisocyanate blend, and of a resin component which is a polyamine. The resin component reacts with the aliphatic polyisocyanate to form a polyurea. The show surface has a Shore D hardness of 70. Like the show surface, the polyurethane backing layer of the composite structure is substantially free of volatile organic compounds. This backing layer is the reaction product of a second polyisocyanate component, such as polymeric diphenylmethane diisocyanate, and of a second-layer resin component, which comprises a polyol having a functionality of at least three.

Abstract: A method of making a polyurea-polyurethane composite structure that is substantially free from emission of volatile organic compounds is disclosed. The composite structure produced according to the method of the subject invention has a flexural modulus of at least 200,000 lb/in2. The composite structure includes first and second layers. A mold substrate is provided and a first-layer polyisocyanate component and a first-layer resin component are reacted and sprayed onto the mold substrate to form the first-layer. The first-layer polyisocyanate component includes an aliphatic polyisocyanate, and the first-layer resin component includes a polyamine thereby forming a polyurea show surface having a Shore D hardness of at least 65. After application of the first-layer, a second-layer polyisocyanate component and a second-layer resin component are reacted and sprayed behind the first-layer to form the second-layer of the composite structure.

Abstract: A composite structure including a polyurea show surface, or top layer, and a polyurethane backing layer is disclosed. Preferably, the show surface of the composite structure is substantially free of volatile organic compounds and is aliphatic such that it is ultraviolet light stable. Specifically, the show surface is the reaction product of an aliphatic polyisocyanate or aliphatic polyisocyanate blend, and of a resin component which is a polyamine. The resin component reacts with the aliphatic polyisocyanate to form a polyurea. The show surface has a Shore D hardness of 70. Like the show surface, the polyurethane backing layer of the composite structure is substantially free of volatile organic compounds. This backing layer is the reaction product of a second polyisocyanate component, such as polymeric diphenylmethane diisocyanate, and of a second-layer resin component, which comprises a polyol having a functionality of at least three.