Asphalt filled polymer foam
View Patent ↗This invention relates to foam insulating products, particularly extruded polystyrene foam, containing asphalt as an infrared attuation and process additives for improving the insulating properties and for reducing the manufacturing cost of the foam products.
1. A process for making an extruded polymer foam comprising the steps of:
a) heating to a melt mixing temperature, a resin mixture comprising polystyrene, an infrared attenuating agent and asphalt into foamable gel;
b) incorporating one or more blowing agents into the resin mixture under a pressure sufficient to prevent pre-foaming of the gel;
c) cooling the gel to a die melt temperature; and
d) extruding the gel through a die to a region of lower die pressure to form the foam.
2. The process of claim 1 , wherein the asphalt is added in amount of from about 0.1 to about 15% by weight based on the polymer.
3. The process of claim 2 , wherein the asphalt is added in an amount of from about 1 to about 4% by weight based on the polymer.
4. The process of claim 1 , wherein the asphalt has a softening point of from about 105° C. to about 155° C.
5. The process of claim 1 , further including the step of adding one or more additives selected from the group consisting of infrared attenuating agents, plasticizers, flame retardant chemicals, pigments, elastomers, extrusion aids, antioxidants fillers, antistatic agents and UV absorbers.
6. The process of 1 , further comprising the step of adding an infrared attenuating agent selected from the group consisting of silicates, oxides, and group IB, IIB, IIIA, IVA chemical elements.