Modified phenolic resin for bamboo structure material and preparation method thereof

Abstract

The invention discloses modified phenolic resin for a bamboo structure material, which comprises 35 to 85 percent of phenolic aldehyde stock solution, 0 to 40 percent of aqueous solution of formaldehyde, 7 to 20 percent of alkali aqueous solution and 0.5 to 5 percent of resorcinol. The phenolic aldehyde stock solution is mixed solution prepared from 2 to 85 weight percent of phenol and 15 to 98 weight percent of formaldehyde. A preparation method for the modified phenolic resin comprises the following steps of: adding the phenolic aldehyde stock solution into a reaction kettle, adding the aqueous solution of formaldehyde into the reactor for the first time, adding partial alkali aqueous solution into the reactor, heating the solution to between 30 and 70 DEG C, and reacting the solution for 30 to 90 minutes; adding the aqueous solution of formaldehyde into the reactor for the second time within an additional proportion range, uniformly heating the solution to between 70 and 98 DEG C, and reacting the solution for 20 to 90 minutes with heat preservation; adding the alkali aqueous solution into the reactor within an additional proportion range, and reacting the solution; adding a resorcinol modifying agent into the reactor till the viscosity of the tested glue solution is 15 to 700mPa.s; and cooling the reaction product to below 40 DEG C, and discharging the product. The gluing performance of the resin on the bamboo material is remarkably improved by adding the resorcinol modifying agent to modify the phenolic resin, and the adhesive has low free formaldehyde content and has the characteristics of energy conservation and environmental protection.

Description

technical field [0001] The invention belongs to the technical field of wood-based composite material adhesives, and in particular relates to a modified phenolic resin for bamboo structural materials and a preparation method thereof. Background technique [0002] At present, the structure and processing technology of bamboo-based panels are quite different from those of wood-based panels. The adhesives used in bamboo-based panel factories almost all follow the formula and production process of wood-based panels, and few scholars and manufacturers have conducted in-depth research. In the case of indoor bamboo wood-based panels and low weather resistance requirements, these adhesives can still meet the quality requirements, but the quality of bamboo structural materials has been difficult to guarantee on a long-term scale. The main problems are: low bonding strength, The dipping peeling rate is high, the weather resistance is poor, and the product life cycle is short. The bond...

AI Technical Summary

Problems solved by technology

In the case of bamboo wood-based panels used indoors and low weather resistance requirements, these adhesives can still meet the quality requirements, but the quality of bamboo structural materials has been difficult to guarantee on a long-term scale. The main problems are: low bonding strength, High dipping peeling rate, poor weather resistance, short product life cycle

In the methods of these two patent applications, the liquefaction of bamboo wood powder and bean dregs needs to use concentrated acid as a catalyst, which seriously corrodes the equipment, and the liquefaction in the early stage is catalyzed by acid, and the glue is catalyzed by alkali in the later stage. It will result in an increase in the cost of making glue. In addition, the proportion of resorcinol used in the patent "resorcinol-bamboo wood liquefied product-formaldehyde resin glue production method" is relatively large (10-17%), which will undoubtedly greatly increase The cost of making glue limits the use of this resin