| abstract |
Procedure for obtaining resins based on novolaks, with a planning point of 50 to 130ºC, an OH number of 250-400 and an iodine number of 90-160, characterized in that an alkylphenol-formaldehyde novolac, or a novolac The alkylphene-formaldehyde mixture is reacted under acid-catalyzed conditions with a polynuclear phenol or a mixture of polynuclar phenol and formaldehyde and / or an aliphatic aldehyde or aliphatic aldehyde mixture, increasing the weight ratio between the alkylphenol or the mixture of phenoalkyl and polynuclar phenol or the polynuclear phenol mixture at 2.2: 1 to 1:10. |