The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 17, 1998
Filed:
May. 07, 1996
Kevin Rodney Lassila, Kutztown, PA (US);
Jeremiah Patrick Casey, Emmaus, PA (US);
Air Products and Chemicals, Inc., Allentown, PA (US);
Abstract
Polyurethane-urea elastomers are made using as a chain extender 2-methyl-1,3-propanediol-bis-p-aminobenzoate which is the reduction product from hydrogenating 2-methyl-1,3-propanediol-bis-p-nitrobenzoate. The latter composition is preferably made by esterifying p-nitrobenzoic acid and 2-methyl-1,3-propanediol using a stoichiometric excess of the diol initially, adequate to render the reaction mixture processible, and after converting to a nonvolatile form sufficient diol to form diester with substantially all of the acid, removing free diol by distillation while continuing the esterification of unreacted acid and transesterification of monoester formed to diester. This process, which can be applied broadly to esterification of other nitroaromatic acids with other aliphatic diols, produces high yields of diester without needing extraneous solvent for processibility and with only water as a by-product. The 2-methyl-1,3-propanediol-bis-p-aminobenzoate exhibits reactivity and processing characteristics which make it a suitable drop-in replacement for MoCA in polyurethane-urea elastomer manufacture.