product name |
Urea formaldehyde resin adhesive modifier, new environment-friendly resin adhesive powder, urea formaldehyde resin adhesive powder, taste removing and viscosity increasing agent |
Region oriented |
|
Manufacturer (place of origin) |
Jining, Shandong |
Specifications |
powdery |
Content ≥ (%) |
ninety-nine point nine nine |
Implement quality standards |
national standard |
Supply mode |
goods in stock |
CAS |
9011-05-6 |
Brand |
Lv Wei |
density |
2g/m3 |
Urea formaldehyde resin adhesive modifier, new environment-friendly resin powder, urea formaldehyde resin powder
Modification
Due to the shortcomings of urea formaldehyde resin, such as poor initial viscosity, large shrinkage, high brittleness, water resistance, easy aging, formaldehyde release and curing formaldehyde release, which pollute the environment and damage health, the urea formaldehyde resin was modified, improved and expanded in application. The modification methods are listed as follows:
1. Increase initial viscosity
To improve the initial viscosity of urea formaldehyde resin, modifiers such as polyvinyl alcohol, polyethylene glycol and hydroxymethyl cellulose can be added, but these substances are expensive, so starch can be selected, especially when starch is added at the beginning of the synthesis of urea formaldehyde resin, with better effect. In the process of synthesis, starch may be hydrolyzed to produce various dextrins. Due to the high molecular weight of starch and the high viscosity after dissolution, a small amount of starch can be added to produce urea formaldehyde resin with high viscosity. At the same time, hydroxyl and hydroxymethyl groups on the starch molecular chain, as well as aldehyde groups generated by hydrolysis, may participate in the synthesis of urea formaldehyde resin, which not only improves the initial viscosity, but also improves the adhesive strength and storage stability.
2. Reduce shrinkage
Urea formaldehyde resin has large curing shrinkage, which is easy to crack, and the adhesive layer produces internal stress, which reduces the viscosity and strength. In order to reduce the shrinkage of urea formaldehyde resin during curing, some fillers, such as flour, starch, blood powder, a-cellulose powder, wood powder, soybean powder, etc., are usually added to the resin glue solution.
3. Reducing brittleness
In order to reduce brittleness and improve toughness, polyvinyl alcohol, polyvinyl formal solution, polyvinyl acetate emulsion, VAE solution, etc. can be added, and the initial viscosity and aging resistance can also be improved.
4. Improved water resistance
Adding a small amount of defoamer, phenol, resorcinol, alkyl amine, sugar aldehyde, etc. in the synthesis of urea formaldehyde resin can effectively improve the water resistance of urea formaldehyde resin. Adding aluminum sulfate, aluminum phosphate, etc. as crosslinking agent can also significantly improve the water resistance. Adding wood flour, flour, soybean flour, ferric oxide, expansive soil and other fillers in mixing can also improve the water resistance.
The urea formaldehyde resin was modified by phenol, and the benzene ring structure was introduced into the resin, which sealed the water absorbing group of the resin, so that the water resistance and aging resistance of the resin were significantly improved. The water resistance can also be improved by adding resorcinol or defoamer to the curing agent components, and by blending acrylate copolymer emulsion with urea formaldehyde resin.
5. Improve bonding strength
Multi composite additives such as polyvinyl alcohol and phenol can improve brittleness, water resistance and adhesive strength. Then the composite process of neutral weak acid weak base was adopted, and the reaction was carried out at medium temperature. The shear strength of the urea formaldehyde resin was more than 10 times that of the original urea formaldehyde adhesive, and the water resistance and boiling resistance were greatly improved.
According to different application requirements, the performance of urea formaldehyde resin can be significantly improved by adding modifiers.
It supplies new environment-friendly resin glue powder nationwide, without formaldehyde or urea, mixed with water to form glue, reaching E0E1 environmental protection standard. There are also urea formaldehyde resin powder, urea formaldehyde resin modifier, formaldehyde elimination viscosity enhancer, deodorant adhesive, etc.
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