反应详情

温度

65 °C

A phenol/formaldehyde resole resin is prepared in the following manner: a charge of 188 grams (2 mols) of phenol, 243 grams of aqueous 37 weight percent (3 mols) of formaldehyde solution and 1.88 grams of flake sodium hydroxide as catalyst, is placed in a glass reaction vessel equipped with a reflux condenser and stirrer. The mixture is stirred and heated at 65° C for 6 hours, then neutralized to a pH of about 7.0 with oxalic acid. The neutralized mixture is stirred and heated under reduced pressure; i.e., subatmospheric pressure, while removing volatile ingredients including water to leave a residue or product consisting of about 80 percent by weight resole resin and about 20 percent water. The product has a viscosity of 6000 centipoise at 25° C. A catalyst mixture is prepared by employing equal parts of ethylene glycol and concentrated hydrochloric acid. The catalyst used is 5.4 cubic centimeters per 90 grams of the resole resin, plus 1.08 grams of an alkylsilane/alkylene oxide block copolymer commercially available under the trade designation "DC 193" manufactured by the Dow Corning Corporation, and about 6 cubic centimeters of 1,1,1,-trichloro-2,2,2-trifluoroethane. Various foams are prepared employing the foregoing basic recipe. The components are added to the resin and mixed in the following order - DC 193, blowing agent catalyst and acid acceptor, where used. The mixture is then cast into a mold measuring 4 × 5 × 2 inches at a temperature of about 80° C. The results are set forth in Table I which follows.

1. customis placed in a glass reaction vessel
2. customequipped with a reflux condenser and stirrer
3. stirringThe neutralized mixture is stirred
4. temperatureheated under reduced pressure
5. customi.e., subatmospheric pressure, while removing volatile ingredients
6. customto leave a residue or product
7. customat 25° C
8. customA catalyst mixture is prepared
9. customVarious foams are prepared
10. additionThe components are added to the resin
11. additionmixed in the following order - DC 193
12. customat a temperature of about 80° C