Polyformals having low methylol end-group content and polyurethanes produced therefrom
Patent 3959227 Issued on May 25, 1976. Estimated Expiration Date: 
May 25, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 25, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3475383 3477994 3557058 3565863 3575930 3756985 InventorsAssigneeApplicationNo. 356553 filed on 05/02/1973US Classes:528/266, With nonaldehyde or nonaldehyde derivative nitrogen-containing compound528/367, FROM REACTANT HAVING A NITROGEN ATOM DIRECTLY BONDED TO THE CARBON ATOM OF A CARBONYL GROUP, I.E., N-C(=O)-528/59, From N=C=X reactant having at least two -C-NH-C(=X)- groups528/61, With organic nitrogen reactant which contains two NH, =NH, or HNH groups528/65, With reactant having two -XH groups528/76With ether or thioether compound containing at least two -C-X-C- groupsExaminersPrimary: Cockeram, H. S.Attorney, Agent or FirmAbstractAn improved polyformal is provided which has the formula:wherein R is the hydrocarbon portion of an ,ω-glycol, containing at least 4 carbon atoms in a single chain or a 4 carbon atom chain interrupted by a heteroatom which is oxygen or sulfur; wherein V is (a) --OCH2 OH or (b) --OCH2 ROH and W is (c) --ROCH2 OH or (d) ROH, R being as defined, wherein the ratio of the total of (b) and (d) to the total of (a) and (c) is not less than 9:1; and x is an integer representing the degree of polymerization of a magnitude sufficient to produce a molecular weight of at least 500. In addition, improved isocyanate terminated prepolymers and polyurethanes are also provided, as well as processes for preparing the improved polyformal. | |
