| 摘要 |
It has now been found that when there is a partial or complete replacement of the sodium hydroxide, that is used to make a sodium phenolate resole resin, by a molar equivalent of potassium hydroxide, a far faster curing resin is obtained. Such potassium-modified phenolic resins exhibit significant improvement in cure speed without loss of flowability. To the contrary, these resins act as though they were lower molecular weight condensation products. Reduced application rates are possible. The combination of faster cure and lower application rates has allowed such resins to be used as effective adhesives for plywood, for example, with veneer and interior plies having a higher moisture content than was previously possible. Generally, resins according to the invention may contain from about 1% to about 15%, and preferably from about 1% to about 7% by weight, of potassium hydroxide, or more. |
