Allied Chemical Corporation

Charles T O'Neill

Harold W Tuller

Edward L Steiger

Omer E Curtis, Jr

Ralph W Nussbaum

Polyanhydrides are produced by a novel bulk polymerization procedure from maleic monomers and alkyl styrenes. The polyanhydrides, of low molecular weight and containing maleic monomer to alkyl styrene in a ratio greater than 1 to 1, are particularly useful as hardeners for epoxy resin-containing compositions and give rise to epoxy compositions which result in cured products exhibiting high heat distortion temperatures and excellent electrical and shelf life properties.

Production of polyanhydride epoxide prepolymer compositions

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.

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Petersburg, MI, United States of America

Charles T O'Neill