| 摘要 |
<p>A granular or powdery resin which is a condensation product of a phenol and an aldehyde and optionally a nitrogen-containing compound having at least two active hydrogens, said granular or powdery resin being characterized by
<UnorderedLists id="ula01" listStyle="none"><ListItem>(A) containing spherical primary particles and secondary particles resulting from the agglomeration of the primary particles, each of said particles having a particle diameter of 0.1 to 150 microns,</ListItem><ListItem>(B) having such a size that at least 50% by weight thereof can pass through a 100 Tyler mesh sieve,</ListItem><ListItem>(C) having a free phenol content, determined by liquid chromatography, of not more than 500 ppm, and</ListItem><ListItem>(D) having a methanol solubility (S) of more than 20% by weight when about 10g of the resin is heated under reflux in 500 ml of substantially anhydrous methanol.</ListItem></UnorderedLists></p><p>The granular or powdery phenol-formaldehyde resin may be produced by a process which comprise contacting a phenol, or both a phenol and a nitrogen-containing compound having at least two active hydrogens with a hydrochloric acid-formaldehyde bath containing (a) hydrochloric acid in a concentration of 3 to 28% by weight and (b) formaldehyde in a concentration of 3 to 25% by weight and aldehydes other than formaldehyde in a concentration of 0 to 10% by weight with (c) the total concentration of hydrochloric acid and formaldehyde being 10 to 40% by weight, while maintaining a bath ratio, defined by the quotient of the weight of the hydrochloric acid-formaldehyde bath divided by the total weight of the phenol and the nitrogen-containing compound, of at least 8, said contacting being effected such that after contacting of the phenol with the bath, white suspended particles are formed and thereafter developed into a granular or powdery solid, and during the contacting, the temperature of the reaction system is maintained not more than 45°C.</p> |
