Adhesive

Abstract

The invention discloses an adhesive. The adhesive is characterized in that the adhesive is prepared from raw materials including 12,666 to 12,726kg of aqueous formaldehyde solution, 9,972 to 10,237.2kg of urea, 55 to 65kg of polyvinyl alcohol, 1,176 to 1,224kg of melamine and 11 to 13kg of aqueous sodium hydroxide solution. In the aqueous formaldehyde solution, the mass percent of formaldehyde is36.5 to 37.5; in the urea, the mass percent of nitrogen is 46.0 to 46.4; and in the aqueous sodium hydroxide solution, the mass percent of sodium hydroxide is 25 to 35. The adhesive has the advantages that the productive technology is simple, the solid content is high, the free formaldehyde content is low, formaldehyde catcher or modifying agent is not required to be added during adhesive mixing process when the adhesive is used for manufacturing particle boards, the curing time of the mixed adhesive is short, and the formaldehyde emission of the particle boards manufactured through the adhesive is stable, and can meet the standard of E0F4 level of Japan and the standard on formaldehyde emission in the second stage according to Composite Wood Products Airborne Toxic Control Measure (ATCM)of California, USA.

Description

technical field [0001] The invention relates to an adhesive, which is suitable for the manufacture of composite wood products such as particle boards. Background technique [0002] In recent years, the awareness of environmental protection in various countries in the world has been increasing, and the standards for the formaldehyde emission of urea-formaldehyde resin products have been set higher and higher. According to the "Toxic Air Pollutant Control Measures for Reducing Formaldehyde Emissions from Composite Wood Products" issued by California, USA, the formaldehyde emission of particleboard produced before January 1, 2009 must be below 0.18ppm; the formaldehyde emission of particleboard produced before January 1, 2011 The amount must be below 0.09ppm. Japan's JISA5908-2003 standard stipulates that the formaldehyde emission of F4 star particleboard must be below 0.3mg / L. [0003] But at this stage, due to the convenient use of urea-formaldehyde resin adhesives and high...

AI Technical Summary

Problems solved by technology

In the production method of E0 grade particleboard, if modified dehydration urea-formaldehyde resin adhesive is used, the wastewater released in the production process needs to be treated before discharge, which increases production costs; while using non-dehydrated modified urea-formaldehyde resin adhesive, in It is necessary to add formaldehyde scavenger or modifier or compound additives when mixing glue to make the environmental protection level of the produced particleboard reach E0 level, but adding formaldehyde scavenger or modifier when mixing glue will cause short stirring time and easy Cause the capture agent or modifier and the adhesive to be stirred unevenly, so that the formaldehyde emission of the produced particleboard board is unstable, which can reach the E0F4 level in Japan, and the "Toxic Air Pollutant Control Measures for Reducing Formaldehyde Emissions from Composite Wood Products" in California, USA. The standard for formaldehyde emission in the second stage is even less

Images