Highly reactive aromatic hydrocarbon-formaldehyde resin and process for preparing the same
US4689392A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1986 |
| Grant date | Aug 25, 1987 |
| Priority date | — |
| Expiry date | Mar 26, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G10/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A highly reactive aromatic hydrocarbon-formaldehyde resin having a diarlymethane content of not more than 5% by weight, essentially containing reactive groups of any one of CH.sub.2 OH, CH.sub.2 OCH.sub.3 and CH.sub.2 OCH.sub.2 OCH.sub.3 at both molecular terminals and having a xylenol value of at least 15 mol/kg as an index of reactivity with a compound having active hydrogen atoms is prepared by reacting an aromatic hydrocarbon such as xylene, mesitylene or naphthalene with formaldehyde at a molar ratio of the formaldehyde to the aromatic hydrocarbon of 2.0 to 5.0, a sulfuric acid concentration of 15 to 35% by weight in an aqueous layer and a reaction temperature of 80.degree. to 110.degree. C. while controlling a formaldehyde conversion within a range of 50 to 70% by mole over the range 4 to 8 hours. By reaction of the aromatic hydrocarbon-formaldehyde resin with the compound having reactive hydrogen atoms such as phenols and carboxylic acids, a modified aromatic hydrocarbon resin capable of giving a cured resin having a high mechanical strength and a high heat resistance can be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.