Modified phenol formaldehyde resin and preparation method thereof

Abstract

The invention discloses a modified phenol formaldehyde resin which is synthesized from the following raw materials: 4-25% of phenol, 30-60% of formaldehyde water solution, 2-15% of urea, 2-15% of melamine, 3-8% of alkaline water solution and 10-30% of water. The preparation method comprises the following steps: after adding the formaldehyde water solution, adding the urea, phenol and melamine by stages in an alkaline environment, and controlling the viscosity or water solubility of the intermediate product and the final product in the preparation process, thereby obtaining the modified phenol formaldehyde resin. The raw materials of the modified phenol formaldehyde resin are added by stages to perform sufficient reaction, thereby improving the comprehensive properties of the phenol formaldehyde resin, including lower contents of free aldehyde and free phenol, lighter resin color, higher water boiling property and better wettability. The invention is more suitable for manufacturing of recombined bamboo, and is also applicable to the fields of dipping treatment of paper wood, bamboo, wood and fabric bases as well as manufacturing of grinding tools.

Description

technical field [0001] The invention relates to a modified phenolic resin and a preparation method thereof. Background technique [0002] Phenolic resin (PF for short) is widely used in the manufacture of adhesives and various composite materials due to its good chemical corrosion resistance, mechanical properties, and heat resistance. At present, most of the processing and manufacturing of recombined bamboo materials use phenolic resin adhesives, but almost all of them follow the formula and production process of wood-based panels, which makes it difficult to guarantee the quality of bamboo materials in a long-term scale. The main problems are: low bonding strength, impregnation Poor penetration, short product life cycle, unstable color, high cost, high water expansion rate, etc. [0003] In order to solve the above problems, many scholars continue to explore new methods for modifying phenolic resins. For example, Chinese patent CN201010200167.4 discloses a modified phenol...

AI Technical Summary

Problems solved by technology

At present, most of the processing and manufacturing of recombined bamboo materials use phenolic resin adhesives, but almost all of them follow the formula and production process of wood-based panels, which makes it difficult to guarantee the quality of bamboo materials in a long-term scale. The main problems are: low bonding strength, impregnation Poor penetration, short product life cycle, unstable color, high cost, high water expansion rate, etc.

This method uses urea-formaldehyde resin as the main body, which is only suitable for wood products such as plywood and blockboard, and is not suitable for impregnation of materials.