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:
Dec. 07, 1976
Filed:
Sep. 15, 1975
Charles T O'Neill, Petersburg, MI (US);
Edward L Steiger, Toledo, OH (US);
Allied Chemical Corporation, Morris Township, NJ (US);
Abstract
In the production of urea/formaldehyde molding resins, wherein urea and formaldehyde are reacted under alkaline conditions to form a liquid resinous composition, the composition is blended with a filler and the filled composition is dried, there is provided an improvement comprising reducing the level of formaldehyde fumes discharged to the atmosphere during drying by a process which comprises the steps of: A. charging urea and formaldehyde to a reaction vessel in amounts to provide an initial mol ratio of formaldehyde to urea of about 1.0 to about 2.0 mols formaldehyde per mol of urea; B. reacting the urea and formaldehyde in water at a temperature in the range of about 50.degree. to 65.degree. C. and at a pH of about 7.0 to about 9.0; C. continuing the reaction until the mol ratio of formaldehyde to urea in the resin is at least about 75 percent of the initial mol ratio; and D. adding additional urea in an amount of about 0.5 to 10 percent by weight based upon the amount of urea initially charged; whereby the amount of formaldehyde discharged to the atmosphere is reduced.