The hydrophobically modified ethoxylated aminoplast thickener (HEAT) turns the special amine resin into one that can be connected to four capped hydrophobic groups, but the activity of these four reaction points is not the same. At normal hydrophobic group addition, only two of them are connected to the capping hydrophobic group, so that the synthesized hydrophobic modified aminoplast thickener is not much different from HEUR, such as Optiflo H 500.
If more hydrophobic groups are added, such as up to 8%, and the reaction conditions are adjusted, the amino thickener with more than one capped hydrophobic group can be produced. Of course, this is also a comb thickener. This hydrophobic modified amino thickener can prevent color matching, due to the addition of color paste, bring in a large number of surfactants and diol solvents, and the coating viscosity drop problem. The reason is that the strong hydrophobic group can prevent desorption, as well as multiple hydrophobic group has a strong linkage effect. This kind of thickening agent such as Optiflo TVS.
Organically modified inorganic thickener
For a long time, silicate and modified silicate have played a major role in coating development and performance improvement.
Amorphous silica. It is an intermediate concentrated to unstable orthosilicic acid H, SiO, which passes through orthodisilic acid (calcined silicic acid) H, Siz O, and forms a ring in the form of further concentrated chains. Spherical polysilicic acid (SiO 2) with crystalline and cage-like structure, . These polysilicic acids are randomly connected by their edges into SiO: tetrahedrons. Their irregular structure cannot show clear signals in ptfe wax quality X-ray structural analysis, so they are often described as silicic anhydride. At the same time, irregular X-rays naturally define it precisely as diatomaceous earth. Contrary to these natural definitions, silicic acids such as quartz sand, tridymite, and cristobalite show regularly arranged SiO, tetrahedral structures, which are the so-called basic units. They are water crystals and diffract X-rays. Nowadays, they are amorphous. Silica [771 can be processed by flame hydrolysis and wet precipitation.
Continuous flame processing is performed on silicon tetrachloride, and it is transformed into gaseous state under hydrogen-oxygen flame calcination at about 1000°C: 2H: +O, -SiC l—SiO g+4HCl wet precipitation processing is to process alkaline potassium water glass Acidify at high temperature.
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