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UF resin used crosslinking agent
2017-7-29 11:37:52
UF resin used crosslinking agent
The UF resin was first synthesized by b.t. ollens in 1844 and was developed in 1929 as a adhesive for adhesive wood. Man-made board and wooden products with glue is about 90% of UF resin, and the application of UF resin and production is closely related to the crosslinking agent, the crosslinking process of UF resin not only affect the quality of the processing of man-made board and wooden products, but also directly affect the production efficiency of man-made board and wooden products.
Generally, the pH value of the finished UF resin is between 7.5 and 8.0. In such an alkaline condition, the resin light depends on the acidity of the wood itself, which is difficult to complete crosslinking.
In order to shorten the time of crosslinking, improve the production efficiency, and make the resin reach a certain level of bonding strength, a certain amount of crosslinking agent must be added in the use of UF resin to promote resin-condensation and crosslinking. Crosslinking agent is a substance that converts monomers or oligomers into polymers or mesh crosslinking polymers.
Crosslinking is the continuation of condensation polymerization, which is the key process for resins to obtain the bonding strength. Therefore, the selection of crosslinking agent, the study of cross-linking theory and the properties of UF resin are particularly important.
UF resin is also called the urea formaldehyde resin, urea formaldehyde resin, hereinafter referred to as UF, the structural formula is: the UF resin is a kind of amino resin, urea and formaldehyde by polycondensation, belongs to the medium water resistance adhesive. From the appearance, UF resin can be divided into liquid resin (syrupy or emulsion) and powdery resin.
Chinese name: Diethyl toluene diamine(DETDA)
The UF resin was first synthesized by b.t. ollens in 1844 and was developed in 1929 as a adhesive for adhesive wood. Man-made board and wooden products with glue is about 90% of UF resin, and the application of UF resin and production is closely related to the crosslinking agent, the crosslinking process of UF resin not only affect the quality of the processing of man-made board and wooden products, but also directly affect the production efficiency of man-made board and wooden products.
Generally, the pH value of the finished UF resin is between 7.5 and 8.0. In such an alkaline condition, the resin light depends on the acidity of the wood itself, which is difficult to complete crosslinking.
In order to shorten the time of crosslinking, improve the production efficiency, and make the resin reach a certain level of bonding strength, a certain amount of crosslinking agent must be added in the use of UF resin to promote resin-condensation and crosslinking. Crosslinking agent is a substance that converts monomers or oligomers into polymers or mesh crosslinking polymers.
Crosslinking is the continuation of condensation polymerization, which is the key process for resins to obtain the bonding strength. Therefore, the selection of crosslinking agent, the study of cross-linking theory and the properties of UF resin are particularly important.
UF resin is also called the urea formaldehyde resin, urea formaldehyde resin, hereinafter referred to as UF, the structural formula is: the UF resin is a kind of amino resin, urea and formaldehyde by polycondensation, belongs to the medium water resistance adhesive. From the appearance, UF resin can be divided into liquid resin (syrupy or emulsion) and powdery resin.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine packingļ¼ net weight 200KG/ galvanized iron drum (a small cabinet pallet loaded 16 tons), 1000KG/IB barrels (a small cabinet loaded 18 tons or 23 tons of ISOTANK).
Liquid resin is milky white or light brown sticky liquid, solid content varies with manufacturing conditions. This kind of resin has a large instability qualitatively. If the production process is not strictly controlled, the storage period of the resin will be greatly shortened. Liquid resin is divided into two categories, concentrated and not concentrated, due to the current production of UF resin used formaldehyde content is about 37% more, contains a lot of water, to produce high solid content of resin, will the water removal.
The concentrated liquid resin is the resin which is obtained by vacuum dehydration, which can shorten the time of pressing the adhesive products and improve the product quality. Compared with non-condensing type, its production process is complex, the period is long and consumes more energy, thus the cost is higher. Meanwhile, the waste water discharged during the vacuum dehydration stage contains formaldehyde and methanol, resulting in environmental pollution. Therefore, deciding which resin to choose mainly depends on the adhesive products and the adhesive process requirements.
Liquid UF resin can be stored for 2 ~ 6 months. The storage period is too long, the resin thickens gradually, and even the gel loses its effect.
Need to the spray drying powder resin was prepared, its low molecular condensation polymer is soluble in water, does not need special solvents, and can shorten the crosslinking time, no matter under the condition of normal temperature or heat can quickly crosslinking, easy to use. The storage period of powdery UF resin can be as long as 1 ~ 2 years.
But the powder resin is made of liquid resin by spray drying, which consumes a lot of energy and makes the resin cost increase. The production of powdery UF resin in our country is small, which is because most of the factories producing UF resin are used for self-use or for local use, without the need to make powdery resins.
Secondly, according to the condition of resin crosslinking, UF resin can be divided into thermosetting and cold solid. The thermosetting UF resin adhesive is suitable for continuous production of adhesive products. After crosslinking, the adhesive strength is high, but the equipment is more complex, consuming more energy and high investment expense.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Liquid resin is milky white or light brown sticky liquid, solid content varies with manufacturing conditions. This kind of resin has a large instability qualitatively. If the production process is not strictly controlled, the storage period of the resin will be greatly shortened. Liquid resin is divided into two categories, concentrated and not concentrated, due to the current production of UF resin used formaldehyde content is about 37% more, contains a lot of water, to produce high solid content of resin, will the water removal.
The concentrated liquid resin is the resin which is obtained by vacuum dehydration, which can shorten the time of pressing the adhesive products and improve the product quality. Compared with non-condensing type, its production process is complex, the period is long and consumes more energy, thus the cost is higher. Meanwhile, the waste water discharged during the vacuum dehydration stage contains formaldehyde and methanol, resulting in environmental pollution. Therefore, deciding which resin to choose mainly depends on the adhesive products and the adhesive process requirements.
Liquid UF resin can be stored for 2 ~ 6 months. The storage period is too long, the resin thickens gradually, and even the gel loses its effect.
Need to the spray drying powder resin was prepared, its low molecular condensation polymer is soluble in water, does not need special solvents, and can shorten the crosslinking time, no matter under the condition of normal temperature or heat can quickly crosslinking, easy to use. The storage period of powdery UF resin can be as long as 1 ~ 2 years.
But the powder resin is made of liquid resin by spray drying, which consumes a lot of energy and makes the resin cost increase. The production of powdery UF resin in our country is small, which is because most of the factories producing UF resin are used for self-use or for local use, without the need to make powdery resins.
Secondly, according to the condition of resin crosslinking, UF resin can be divided into thermosetting and cold solid. The thermosetting UF resin adhesive is suitable for continuous production of adhesive products. After crosslinking, the adhesive strength is high, but the equipment is more complex, consuming more energy and high investment expense.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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