Modified urea-formaldehyde resin for producing ecological floors and preparation method for modified urea-formaldehyde resin

Abstract

The invention discloses modified urea-formaldehyde resin for producing ecological floors and a preparation method for the modified urea-formaldehyde resin. The method comprises the following steps: adding formaldehyde to a reaction kettle; adjusting a liquid pH value in the reaction kettle to 7.5-8.5; adding a first part of urea to the reaction kettle, and raising temperature of the reaction kettle; adding a formic acid solution, and adjusting the pH value to 4.3-5.0; adjusting the pH value to 5.8-6.8, adding a second part of urea, a first part of a reinforcing agent and a first part of a molecular weight modifier, and performing a reaction for 15-45 minutes; adjusting the pH value to 7.0-8.5, adding a second part of a molecular weight modifier, then adding a second part of a reinforcing agent, and performing a reaction until resin is water-clear at the temperature of 13-20 DEG C; adjusting the pH value to 8.5-9.5, starting water cooling, and adding a third part of urea; and continuously performing cooling until the temperature is 40-50 DEG C, and releasing glue to obtain the modified urea-formaldehyde resin. The modified urea-formaldehyde resin provided in the invention has the characteristics of a long storage period, an ultra-low formaldehyde release amount, high bonding strength, boiling water resistance, low costs and the like.

Description

technical field [0001] The invention relates to a modified urea-formaldehyde resin, in particular to a modified urea-formaldehyde resin used for manufacturing ecological floors with ultra-low formaldehyde emission, high boiling resistance and low cost, and a preparation method thereof. Background technique [0002] Ecological flooring is mainly used for indoor floor decoration, and should have good water resistance, and the lower the formaldehyde emission, the better. Therefore, it is required that the urea-formaldehyde resin used in the manufacture of ecological flooring has higher boiling water resistance, lower free formaldehyde and the characteristics that it is not easy to degrade after curing. In order to reduce the amount of formaldehyde released, the existing urea-formaldehyde resin manufacturing technology generally reduces the molar ratio of formaldehyde to urea, but with the reduction of the molar ratio, the storage period of the resin becomes shorter and the bond...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a low-cost modified urea-formaldehyde resin for the production of ecological flooring with ultra-low formaldehyde release, high boiling resistance and low cost, aiming at the shortcomings of existing floor modified urea-formaldehyde resins, such as excessive formaldehyde content, poor water resistance, poor storage stability, and high cost. Resin and its preparation method, the modified urea-formaldehyde resin of the present invention has the advantages of formaldehyde emission less than 0.3mg / L, bonding strength greater than 0.8MPa, resistance to boiling water for 4 hours, storage period greater than 30 days and low cost, etc.