New organic fluidizers for high-end solvent-based coatings and adhesives

Hydrogenated castor oil wax can be dispersed and active in a certain way, making hydrogenated castor oil an organic tactisor or fluidized additive (RA) with excellent performance. These fluidizers provide better anti-sinking, control flow and leveling, and also have better anti-flow hanging properties. Glycerides in castor oil can be replaced by amine-like groups to form alamide wax similar to 12-hydroxybutyric acid. This type of alamide wax is also a very effective fluid control agent, with hydrogenated castor oil to form an effective castor oil wax combination series of products used in coating systems. Castor oil derivative 12-hydroxybutric acid is an effective fluid structure, because it can self-form a spatial network structure, these structures can be throughout the formulation and effectively capture solvents or resins, thus controlling the flow of substances. The formation of the mesh structure is shown in Figure 1.
Figure 1-
12-hydroxybutyric acid acetate acrylic wax powder scanning electroscope (A) and castor oil derivative 12-hydroxybutyric acid additives fully activated after the formation of the rheumogenic active network structure of the scanning electron mirror (B)
micro-powdered castor oil wax needs to be solvent wetting,
dissociation
and high shear dispersion process at a specific temperature to make it effective. The activity of castor oil wax fluidizers requires a specific temperature and is also affected by the polarity of the coating system. Therefore, the selection of suitable castor oil wax flow aid needs to consider solvent types, process temperature control and production equipment and many other factors. The optimal combination of these influence parameters can make the dispersion of the collome more efficient and more conducive to the formation of the fluid active network structure. The correct use of modified castor oil fluidization aids, can make the coating has excellent tentacle performance (shearing thinning), anti-flow hanging performance and pigment suspension.
However, coatings containing castor oil waxes may have problems during the production process due to excessive process temperatures, as castor oil waxes dissolve completely at high temperatures and then form semi-crystalline particles that are then produced when the system cools down, which we call "crystalline". Similar crystal conditions can occur when the solvent/temperature combination is too strong. The crystalline phenomenon, which usually occurs immediately, is easy to detect. However, the more complex crystalline condition occurs before the fluidizer is fully re-active, at which point not all powder waxes are completely transformed into the desired fluidized active pattern, and there are still uninsolt powder waxes in the system, which are often not easily noticed. After a period of storage, these unwaished waxes form particles under the influence of solvent, storage temperature and time, resulting in fine resurrevery and loss of paint film. The new acrylamide-based castor oil derivatives mentioned in this paper have basically overcome the problem of such crystalline pre-emination and can be operated and used under the conditions of existing production equipment.
production processes, such as feed and active temperature, mixing time, shear rate and cooling process, have a greater impact on the thickening and anti-flow properties of coatings and adhesives containing castor oil fluidizers. In addition, the raw materials used in the formulation can have a positive or negative effect on their thickening and fluidization properties. For example, some fillers can improve the rheumor performance of the system, wherein contrast, certain additives such as desmoticizers, dispersants, moisturizers, and epoxy amine curing agents can sometimes reduce the performance of rheumors. Therefore, these ingredients need to be carefully screened and optimized during formulation design.
table 1, 90% solid
two-part epoxy industrial coating A part base paint formula A partproduct supplierseach part weightBPA epoxy resinMiller Stephenson (EEW-187.5 g/mol) 23.52Epoxy active thinnerkadele (alkyl phenol shrinks glycelycerides; EEW-490 g/mol) 0.65epoxy active thinnersair products (new glycol glycesteride ether; EEW-137.5 g/mol) 1.97
flow aid (RA)Multiple suppliers 0.90solventssuppliers 9.68 Titanium dioxide Como 6.77 talcum powder fillers Imerys 8.39 sodium potassium aluminum silicate Salt mineral fillers Unimin 6.77 anticorrosive pigments ket (zinc-containing fillers) 1.67 calcium silicate fillers NYCO (epoxy surface defunation fillers) 7.62
。 BaSO4 Filler Cimbar 14.39 Defouling Agent Haims Special Chemistry (non-silicon fat family) 0.31 Color paste Haims Special Chemistry (pigment black dispersion) 0.31 B parts (mixed)
amine curing agent cadele (natural long chain replacement phenolic amine; AHEW s 132 g/mol) 11.49 amine curing agent BASF (C18 unsaturated fatty acid amino resin; AHEW s 95 g/mol) 5.743
test
in order to quantify these effects, we designed the following formula simulation experiments. Group A base paint is 90% solid containing two-part epoxy industrial coatings, the formula is seen in Table 1. In fact, in some applications, the solids of formulations have been increased to 95% or even 100%. The B-component curing agent component is a mixture of phenolic and amine-basedamides. The solvents used in the formulation are different in order to test their effect on the performance of the system fluidizer. In order to facilitate the comparison of differences, the amount added of fluidizers is fixed, both of which are 1% of the total solid content of the formula, so the results of anti-flow performance may be less common in some commercial applications. Prepare the coating according to the conventional process, add the resin, solvent and rheumate additives to the mixing tank in turn, pre-disperse at 15-20m/s line speed for a certain period of time, then add fillers and moisturizer dispersants, and continue to disperse at the specified temperature at 15-25 m/s line speed until the fineness is achieved.
There are many ways to evaluate the performance of the fluidizer, such as Thelenta anti-sag anti-flow test, Channel sag, Boeing slump, extrusion rate (elastic sealant), increased viscosity viscosity, and viscosity recovery performance and fluid shear recovery test after the shear force is removed, depending on the type of coating or adhesive and the end application. The evaluation method used in this paper is TheLeneta anti-flow test (ASTM D4400). Initial performance (initial) is tested 24 hours after coating preparation, as well as accelerated aging after 7 days of hot storage in an oven at 120 degrees F (approximately 50 degrees C).
2, using the formulation of two coatings with different fluidizers, respectively, using the
spraying and scraping construction methods obtained by the anti-flow hanging performance test results.
Leneta anti-flow hanging performance (mils),
spray construction, scraping construction
Leneta anti-flow hanging performance testing
is the use of a toothed scraper, the paint at a low shear speed of uniform scraping on the substrate. For speed and convenience, laboratory tests use scratching rather than spraying. Of course, on-site coating construction is generally sprayed on the bridge frame or the inner wall of the tank and other vertical facade structure. Spraying construction because of the shear force is large, the recovery of the paint fluid structure has a greater impact, so some people may ask, the results of the laboratory will be different from the actual coating results? Figure 2 is the formulation of two coatings using different fluidizers, which are the result of the anti-flow hanging performance obtained by the construction methods of spraying and scraping respectively. According to the test results, it can be seen that the anti-flow hanging test results obtained by using two different construction methods are relatively close and the trend is basically the same. This gives us a lot of confidence, the laboratory measured anti-flow hanging results are basically similar to the actual construction effect of the paint site.
3: Effects of different solvents and feed temperatures on the anti-hanging properties of epoxy coatings after initial and accelerated aging.
the initial anti-flow performance, accelerate the aging anti-flow performance.
, xylene, ketone MAK, 100% solid
coating formulations, most of the use of different solvents composed of a mixture of solvents. However, different types of solvents also have a greater impact on the anti-flow hanging properties of the fluidizer. There are even some fluidizers that do not work in certain solvents. Figure 3 shows the effect of solvent and feed temperature on the performance of the fluidizer. The test system is 95% solid containing epoxy coating, the selection is commonly used in the market fluidizer, the addition amount is 1% of the total solid content of the formula. The effects of different solvents on the fluid properties of the system were tested at temperatures of 120 degrees F (approximately 50 degrees C) and 150 degrees F (approximately 62.5 degrees C). In addition, we also deducted the solvents in the formulation, made into 100% solid epoxy coating, also did the same test. This 100% solid test result is also applicable to the adhesive system.
Based on the results of Figure 3, we see that the fluidizer has strong anti-flow-hanging properties in the butanol-containing system at two different feed temperatures, and the performance is still stable after accelerated testing in thermal storage tests. However, when ketones (e.g. MAK) or xylene are used as solvents, their anti-flow properties are significantly reduced compared to butanol solvent systems. It can be seen that solvents and temperature have a great impact on the flow-resistant hanging and stability of the fluidizer. In addition, under these two temperature conditions, the solvent-free 100% solid coating, its anti-flow hanging performance has also been reduced, of course, the results are limited to this special fluidizer, coating process and formulation. An ideal fluidizer should be extremely versatile and suitable for different coating formulations, operating processes and temperature conditions.
Leneta anti-flow hanging (mils),
initial anti-flow hanging performance,
accelerated aging anti-flow hanging performance
(A) stirring cooling after feeding,
(B) at higher operating temperature directly under the packaging,
(C) not stirring, direct cooling After the lower packaging
coating thinning / painting phase is usually regarded as the final process of paint manufacturing, for the painting phase, there are generally the following cases, (A) stirring after cooling the lower material; The effect of these lower packaging methods on coating performance is shown in Figure 4. The test results show that mode B and C have strong anti-flow hanging performance, while mode A "stirring and cooling after the material", the anti-flow hanging performance after the curing of the paint film is relatively poor, but in other tests found that the use of mode A under the packaging, the paint storage after the possibility of re-coarse problem is very small. Therefore, when we discuss how to maximize the performance of coatings containing fluidizers by optimizing the coating production process, the coating's thinning/painting phase is also a particularly important consideration. For example, when using pure castor oil wax fluidization aids, it is recommended to use the method (A) to avoid serious false thickening, because if false thickening occurs, even if the later operation, viscosity can no longer be returned to the initial state.
In order to adapt to the current market for the application of alamide-based modified castor oil wax fluidizer, the existing coating production process and operating conditions, such as temperature, shear rate, time, etc., usually need to make certain adjustments. However, an ideal fluidizer should be able to meet existing coating production processes and reduce production operating costs by reducing operating time and energy consumption (i.e. without the need for additional heating equipment).
National generation of fluidizing aids
away from the technology of castor oil wax, new organic gel factors have been freely combined into or flaky, or collosome, or fibrous material structures, these structures have better solvent geling capacity. At the same time, the spatial structure of these unique organic gel factors allows individual molecules to gather non-directionally and produce supermolector beams. This beam structure can further interact, wind and form a staggered network structure. Based on these related molecular techniques, a new generation of organic fluidizers has been designed to meet the performance requirements mentioned above.
table 2, a formula for high-solid PU-containing polyurethane coatings
a new generation of fluidizers. 。 Part A Product Supplier Weight of each part Acrylic polyols in butyl acetate BASF (acrylic polyols, 80% solid in butyl acetate Wt. . . 400 g/mol;O