Degradable foam materials
AssigneeE. I. Du Pont de Nemours and Company
InventorsHoward S. Hammel, Robert O. York
Life of this patent
Estimating the term…
Abstract
Closed cell rigid polyhydroxy acid resin compositions foamed with environmentally benign, which compositions are degradable and cause minimal environmental impact when discarded.
Claims14
A rigid resin foam composition degradable by hydrolysis of less than 20 pounds per cubic foot density, having a significant percentage of closed cells which contain inert environmentally benign blowing agent, which composition is moldable into useful shapes and comprises degradable polyhydroxy acid resin containing at least 50% by moles resin, the amounts of which are selected from the group consisting of lactic acid and glycolic acid units, the remainder comprising comonomer units selected from the group consisting of;
- (1) (OCR.sup.1 R.sup.2).sub.n (CO).sub.p
- (2) (OCR.sup.1 R.sup.2 COOCR.sup.1 R.sup.2 CO).sub.q
- (3) (OCR.sup.1 R.sup.2 CR.sup.1 R.sup.2 OCR.sup.1 R.sup.2 CO).sub.r
- (4) (OCR.sup.1 R.sup.2 CR.sup.1 R.sup.2 OCR.sup.1 R.sup.2 CR.sup.1 R.sup.2 CO).sub.s
- wherein n is a whole number 2, 4 & 5;
- the total of p, q, r and s being 50 to about 5,000;
- and R.sup.1 and R.sup.2, which can be the same or different, are selected from the group consisting of hydrogen, hydrocarbyl containing 1 to 12 carbon atoms, and substituted hydrocarbyl containing 1 to 12 carbon atoms.
Dependencies are inferred from the claim text.