Classified by the reaction process catalyzed, e.g. catalysts used for hydrogenation are called hydrogenation catalysts.
For styrene-acrylic emulsions, the amount of benzyl alcohol is lower than Texan ol. It may be because of the similar principle of compatibility, benzyl alcohol can soften the styrene-acrylic emulsion particles to the greatest extent, so that the minimum film-forming temperature of the emulsion can be reduced with a smaller amount. Reduce to 0°C. In addition, benzyl alcohol is more toxic and has poor compatibility with other types of emulsions. Ethylene glycol butyl ether is soluble in water and has a high volatilization rate. Therefore, a large amount is used and the film-forming effect is poor. Propylene glycol phenyl ether test results are still good.
It is the case that Texan ol, dipropylene glycol ether and diethylene glycol diethyl ether reduce the MFT of silicone styrene-acrylic emulsion.
For silicone-styrene-acrylic emulsions, diethylene glycol diethyl aldehyde is the most effective in reducing MFT.
Compatibility of film forming aids and emulsion
The compatibility of film-forming aids and emulsions is one of the issues that must be considered in the formulation. Tables 18-16 are the test results of the compatibility of various film-forming aids wax dispersion index in some emulsions.
Texan ol has good compatibility with different types of emulsions and is easy to add. Propylene glycol phenyl ether and pure acrylic emulsion will cause flocculation. Benzyl alcohol is only compatible with styrene-acrylic emulsion, while ethylene glycol butyl ether is only compatible with Changxing 6512 styrene-acrylic emulsion.
Side effects of film forming aids
M. Schwartz et al. 1191 believe that film-forming additives can reduce MFT and improve scrubbing resistance, but also affect the development of film hardness and the surface viscosity of the entire service life, that is, affect the stain resistance of the film.
Usually, with the addition of film-forming aids, the stability of emulsions and latex paints will be reduced. This has been clearly seen in the introduction of the compatibility of film-forming aids and emulsions. , And some even cause emulsion breaking and film forming aids are volatile organic compounds (VOC), which is not good for the environment,
The film-forming auxiliary has an influence on the thickening effect of the associative thickener, which makes the adjustment of the thickening system more complicated.
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