Poly (phthalates glycol) esters are carbon-black ultra-dispersants in solventized chains (3)

in carbon-black paint, there are higher requirements for gloss, when gloss is 70 for highlights, 30 to 70 for bright, 30 for light. The test results for coating the film gloss are shown in Figure 4.As can be seen from Figure 4, compared to the blank sample, four kinds of PAEG ultra-dispersant samples were added, their 20-degree gloss is greater than 70, to meet the high-gloss coating standards, of which THEG-3 gloss and BYK163 gloss is almost consistent.
color and gloss studies show that when the relative molecular mass of 2,000 PAEG as a solvent chain, the preparation of polyester resin system ultra-dispersant, PAEG-3 compared to other ultra-dispersant chromats closest to BYK163 chromats, and its gloss is basically the same as BYK163, therefore, polyethylene amine is its preferred anchor group.
2. 3 Ultra-dispersant storage performance test in coatings
The storage performance of ultra-dispersants in coatings refers to the grinding color paint stored at a certain temperature for a certain period of time, to detect changes in coating fineness and coating viscosity, as well as the paint solidified into a film after the color phase and gloss changes. In this paper, according to the needs of the practical application of enterprises, the storage temperature is set at 50 degrees C, 70 degrees C, 90 degrees C, storage time is 12 d, PAEG-2, PAEG-3 and BYK163 for comparative evaluation, the results are shown in Figure 5 to 7, Table 2.. As can be found from Figure 5, after storing 12 d at 50 degrees C, the fineness of the coating is 15 m, still maintaining the ideal fineness value before storage, when the temperature rises to 70 degrees C, the fineness of the coating increases to 16. The fineness of the coating has increased to 20 m at 90 degrees C, with a clear tendency to "re-coarse" compared to pre-storage. This may be due to higher temperatures, a surge in inter-molecular motor capacity, and greater desolysing capacity between carbon black and ultra-dispersants, while higher temperatures do not help the anchoring effect of ultra-dispersants. BYK163 and PAEG-3 have the same trend of change, and the temperature has the same effect on both, both greater than PAEG-2.
figure 6 shows that the viscosity of the coating increases to varying degrees compared to before storage, and increases with the temperature. At the same time, it can be seen that in the range of 50 to 90 degrees C, the effect of PAEG-3 is always slightly better than PAEG-2, and close to BYK163.
From Table 2, it can be seen that with the increase of temperature, the hue has a certain degree of change, in which the color fastness is slightly reduced, the yellow-green tendency is greater, but the overall change is not large, and THE-3 and BYK163 values are basically the same.figure 7 shows that although PAEG-3 has decreased slightly over time at 90 degrees C, it is generally not much different from BYK163.
, after different temperature 12 d storage, although in some indicators decreased, but overall PAEG-3 basically reached the stability requirements of BYK163.3 Conclusion
In view of the dispersion of carbon black pigments in polyester resin system, this paper designs and develops a class of ultra-dispersants with poly (phthalates glycol) as solvent chain, and obtains the following conclusions
after systematic evaluation: <3> <5> (1) poly (phthalates glycol) ester solvent chain of the best relative molecular mass of 2,000, at this time the resulting paint fineness of the best 15 m, paint deciscovery effect also reached the optimal state.
(2) This experiment preferably polyethylene subamine as the anchoring group of the ultra-dispersant, at this time, the color fastness of carbon black in the paint film (L-value), the paint film phase (a, b-value), contrast color difference (E) and similar products abroad BYK163 is very close.
(3) will be preferred after the ultra-dispersant PAEG-3 and BYK163 parallel storage experiments, the results show that the storage temperature is different, there are some differences in dispersion performance, but overall PAEG-3 can basically reach the level of BYK163. It should be noted that in terms of storage stability, PAEG ultra-dispersants still have room for improvement, it is recommended to select anchoring groups with stronger adsorption properties to improve the adsorption properties of dispersants to carbon black particles, to prevent their analysis at high temperature storage.
(4) This study is only applicable to polyester resin-based coating systems, if needed for other resin systems, need to be evaluated in advance..