Westvaco Corporation

Sten I Falkehag

Peter Dilling

David V Braddon

Humbert T Dellicolli

Carl W Bailey, Iii

Disclosed herein are cross-linked lignin gels which have been found useful as pesticide carriers in controlled release pesticide systems. The carrier is a highly reswellable cross-linked lignin gel prepared by reacting alkali lignin with from 1 mole to 10 moles of cross-linking agent, such as formaldehyde, per 1,000 grams of lignin. An aqueous solution of lignin and the cross-linking agent is reacted at elevated temperatures until cross-linking occurs to the point where a discernible increase in viscosity takes place and the gel is formed. The gels are allowed to dehydrate, and the pesticide in an amount from 0.1:1.0 to 2:1 (pesticide to carrier) is included by reswelling the dehydrated gel in an aqueous solution of the pesticide.

Cross-linked lignin gels

Stabilizing compositions comprising at least one triaryl phosphite, trialkyl phosphite or mixtures thereof and at least one modified lignin, the weight ratio of the phosphite to modified lignin is from 97/3 to 10/90. The modified lignins are produced by heat treating lignins in the presence of a nucleophile, such that a portion of the original guaiacyl structures are converted to catechols via a demethylation reaction. Elastomers may be protected against atmospheric degradation by the addition thereto of 0.01 to 5.0 parts by weight, preferably 0.25 to 2.0 parts, per 100 parts of elastomer of the stabilizing composition.

Stabilizer composition of phosphite and lignin

The surfactants of this invention are phenolic-formaldehyde resins that have been sulfomethylated with from 1-13 moles of sulfomethylation per 1000 grams of the starting resin and further modified by reaction with up to 20 moles, preferably 0.25 to 10 moles, per 1000 grams of starting resin of a blocking agent of the type X(CHR).sub.m (CH.sub.2).sub.n Y, wherein X is a halogen, an activated double bond, epoxy ring or halohydrin, Y is a property group such as sulfonate, phosphonate, carboxylate or hydroxyl, R is another property group such as hydrogen, hydroxyl, mercaptan or amine, and n and m are integers from 0 to 5, with n or m being at least 1, to at least partially block the phenolic hydroxyl group of the resin. The phenolic-formaldehyde resin may also be cross-linked to tailor its molecular weight and then treated with urea or ammonia, if desired.

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Mount Pleasant, SC, United States of America

Sten I Falkehag