Quaternary resin adhesive for manufacturing plywood board for bottom board of container

Abstract

The invention discloses a quaternary resin adhesive for manufacturing a plywood board for a bottom board of a container. The quaternary resin adhesive comprises formaldehyde, urea, melamine and polyvinyl alcohol in a molar ratio of 1:0.4-0.53:0.15-0.17:0.02-0.03. A preparation method comprises the following steps of: adding the formaldehyde and the polyvinyl alcohol into a reaction kettle, heating, regulating pH to 8.5 to 9.0 and adding 48 to 52 percent of urea; when the temperature of reaction liquid is raised to be between 79 and 81 DEG C, adding 43 to 47 percent of urea; when the liquid temperature is raised to be between 89 and 91 DEG C, closing a steam valve and keeping the temperature of between 90 and 93 DEG C for 55 to 65 minutes; regulating the liquid temperature to 88 to 89 DEG C and the pH to 5.9 to 6.2 and reacting for 13 to 17 minutes; regulating the pH to 5.3 to 5.7 and reacting for 13 to 17 minutes; regulating the pH value to 4.0 to 4.4 until the reaction liquid is cloud-like when dropping into 25 DEG C water; regulating the pH value to 8.3 to 8.7 and the liquid temperature to 88 to 91 DEG C; adding the melamine, regulating the pH to 7.3 to 7.7 and the liquid temperature to 80 and 82 DEG C and reacting for 18 to 22 minutes; adding 3 to 7 percent of urea, regulating the pH to 7.2 to 7.5 and the liquid temperature to 78 to 80 DEG C and reacting for 10 to 15 minutes; cooling and regulating the pH to 7.0 to 8.5; and reducing the liquid temperature to 38 to 40 DEG C.

Description

technical field [0001] The invention relates to a quaternary resin adhesive used for manufacturing plywood for the bottom plate of a container. Background technique [0002] In today's rapidly developing container transportation industry in the world, my country has become a major container manufacturing and exporting country. In 2007, my country exported 3.13 million containers, requiring more than 1.65 million cubic meters of plywood for container floors. In the next few years, The production quantity of containers still needs to be greatly increased. [0003] To manufacture a container, it is necessary to use plywood for the bottom plate of the container. The plywood for the bottom plate belongs to the structural load-bearing material and is one of the important components of the container. Therefore, the plywood used for the bottom plate of the container needs to have special properties such as good load-bearing, shock resistance, impact resistance, and weather resistanc...

AI Technical Summary

Problems solved by technology

[0005] First: The main chemical raw materials for the manufacture of phenolic resin adhesives are phenol, formaldehyde, and sodium hydroxide. Among them, phenol is a highly toxic substance. A certain amount of phenol will be released during the process of dissolving phenol, manufacturing phenolic resin adhesives, and producing plywood. Free phenol pollutes the environment. Workers engaged in related production suffer from allergies to varying degrees. Some workers are transferred because they are not suitable for related work.

[0006] Second: The phenolic resin adhesive has very strict requirements on the moisture content of the veneer. The moisture content of the veneer is required to be dried below 6-8%, which makes it difficult to dry the veneer, with a large dry shrinkage rate, serious warping and deformation, and difficult to dry. Storage, difficult processing, high energy consumption, otherwise, the slabs are prone to bubbling and delamination during hot-press gluing, resulting in serious waste

[0007] Third: Phenol is expensive, so the cost of manufacturing phenolic resin adhesives is also very high, making it unbearable for manufacturers

[0008] To sum up, in order to ensure the physical and mental health of employees, create a good natural environment, reduce energy consumption as much as possible, and reduce product production costs on the premise of ensuring product quality, in order to overcome the fact that ordinary melamine-urea-formaldehyde resin modified adhesives cannot meet the needs of containers Due to the shortcomings of the physical and mechanical properties of the plywood for the bottom plate, such as elastic modulus, static bending strength, and wet bonding strength, a new type of resin adhesive that can completely replace the traditional phenolic resin adhesive in the production of plywood for the container bottom plate is developed. The unshirkable sacred duty of those skilled in the art

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