The main factors and solutions for paint floating flowering.

Floating color and hair flowers brought about by the trouble:
paint floating color
in the process of paint production and construction often encounter floating color hair flower problem, paint floating hair flower, color and standard plate produce color difference, color adjustment becomes very difficult, both waste pigment and color is not allowed, while the paint canning effect is very poor, and paint dry after the construction coating film color deviation and difficult to apply uniform.
is one of the dynamic separation phenomena of pigments: pigments in the horizontal side of the separation obstacles to the film color is not equal and the appearance of hair flowers. Floating color is the color in the vertical direction of change, paint in storage, film and drying process of one or more pigments separation, one pigment floating to the surface, another pigment in sitant or sink to the bottom, resulting in uneven color phenomenon .
Flowing color and flowering observation
static floating color in the tank: color paint dispersed evenly after a period of time in the tank, one or more pigments in the tank separated surface phenomenon, such as storage for a period of time, after opening the tank to see the surface of the tank appear black, indistinct or white phenomenon.
film dynamic floating color: the phenomenon of pigment particles in the process of coating drying is called dynamic floating color.
of a dynamic floating pigment is divided into two situations: one is the coating film hair flower surface color is not equal, with the naked eye can be directly observed.
refers to the
the other is the coating surface color is the same, but the surface and the underlying color is different. Use finger kneading to identify floating color (also known as finger research), first of all, the paint dumped or coated on the glass plate or black and white paper jam, after a moment of flattening, the finger kneading until the coating film began to become viscous, pigment particles no longer migrate separation, if the paint has floating color, the surface without kneading and kneading surface on the color difference. The main reason is that the pigment is easy to separate during kneading and the appearance of silky streaks, coating film dry surface will appear angular vortex pattern, resulting in color changes.
causes floating color and flowering factors:
paint floating flower factors are many, pigment particle size difference is too large, the surface pressure difference of the various substances in the system, as well as the hydromassive oil-friendly oil balance value (HLB), emulsion and color paste compatibility of each substance, etc. on the floating hair flower caused a greater impact.
1 The particle size of pigment particles on the paint floating flower effect
paint in the drying process, with the volatile part of the paint, these volatiles will also be clamped with a part of the paint, fillers to bring them to the coating film, and these pigment, filler particles are transported to the surface, there is a higher surface area of smaller particles easy to transport, and relatively low surface area of coarse particles are hindered by movement. When the latex paint film is dry, the more hydro-hydrophoto-like substance tends to evaporate quickly, for example, if the white powder is more hydro-hydrogenic than the organic paste, the white slurry is more likely to be brought to the surface by the volatile material of the strong polarity. Coupled with the pigment particle particle size difference is too large, so that the pigment, filler between the mixing capacity becomes very poor, due to the above reasons, with this pigment made of color paint is not good construction, the construction process of the paint floating white phenomenon is serious, the coating film is floating color. Floating white is difficult to adjust dark paint and can cause waste of pigments.
solution is to carefully select the pigment, filler, so that the particle size of the selected pigment to match;
2 The effect of poor surface pressure on paint floating hair flower
In the ordinary color palette, it is often found that some color paste in the white base paint is difficult to disperse evenly, scattered good color paint after a period of rest, soon there is a color or floating phenomenon occurred, or paint canning effect is not good.
In the process of painting, the production of white pulp and the process formula of the color slurry is different, the production of white pulp often uses anion-type dispersants, and the color paste is mostly non-ion dispersants, so the white pigment and color pigment particles adsorbed a different layer of wetting dispersant, resulting in different surface properties, hydromassive oil value is not the same, its surface pressure is not the same. The surface strength of the general ionized surfactant is greater than that of the non-ionized surfactant. Even if they are non-ion surfactants, their surface stress is different because of the different molecular structure of the hydrophobic end.
from the thermodynamic aspects, the surface of low-pressure substances easy adsorption to the interface, and make the system stable. Therefore, if the surface tone between the white slurry or color paste and the system surface tone difference is large, the coating with this slurry configuration is more prone to floating color.
3 system between the phase solubility
emulsion and color paste compatibility is good, paint and coating film floating hair flower situation will be much better, emulsion on the color paste wet good then color paint color display is also very good.
In water coatings often use anionic and non-ionic surfactants as wetting dispersants, most inorderable pigments can act with the added ionized surfactant polar base or ions, shape, pigment particle surface adsorption of surfactants, forming a protective layer. When there is a protective layer of color paste mixed with various types of emulsion or latex paint, pigment particle surface surfactant and emulsion particle surface adsorption of surfactants, namely emulsion or water affinity between large, pigment particles adsorbed surfactant is stripped, so that the pigment particle surface protection layer thinning, resulting in pigment flocculation, resulting in paint coating film floating flowering. Of course, when the emulsifier outside the emulsion particles and color slurry in the pigment, filler particles outside the surfactant compatibility is good, then the emulsion for these colors, filling particles wetting is good, the whole color paint color display is good, colorful, and not floating color.
4 Effect of hydro-hydro-oil balance value on floating-color hair flowers
The concept of hydro-hydro-oil equilibrium value is mainly used in surfactant applications. The combined affinity of hydrophilic and hydrophilic groups to oil or water in surfactant molecules is called hydrophilic-lipophilic balance, HLB value). The hydromassiveness or oil-affinity of the substance can be seen from its hydro-hydro-oil equilibrium value, HLB below 9 is relatively pro-oil, higher than 9 relative hydro-hydro.
Hydro-hydro-oil balance value
in the production of coatings often use a variety of materials: emulsions, pigments, fillers, solvents, solvents, etc. have their own hydro-hydro-oil balance value (HLB value), each material hydro-hydro-oil balance value matching the paint system floating color, flowering, water and other phenomena will be overcome.
Of course, we use emulsions, pigments selected, hydromassive oil balance value is not changed, but you can choose additives, that is, wet dispersants, thickeners, etc. to adjust the HLB value of the entire system, so that the whole system HBL value balance.
oil-friendly substances have a small surface pressure on their pro-oil ends, coatings stored in container storage tanks, these oil-friendly substances are easy to float to the surface, from a thermodynamic point of view, the whole system energy reduction, system stability. When the production of latex paint in static that is floating in the container, not only open the can effect is not good, construction. The solution to the floating color phenomenon of paint under static conditions is to select the appropriate dispersant to match the HLB of different pigments. If the paint floats white, the white pigment is more oil-friendly, so it is necessary to improve the hydromassivity of the white slurry. If the paint floats is the color of the color of the slurry, indicating that the white slurry is more hydro-friendly, the white slurry needs to be made of oil-biased, to prevent the paint floating phenomenon. Improving the viscosity of the coating can only slow down the dynamic process of floating color phenomenon, making the system relatively stable. (It can be understood simply that the more hydro-hydro, the higher the HBL value)
. The ammonium salt dispersant with hydrophobic base group in anion dispersant is more oil-owning than the sodium pyrate dispersant, the HBL value is small, and the ammonium salt dispersant with hydrophobic base group has greatly improved the floating color of latex paint coating. Because when the pigment particles are wrapped in this type of dispersant, the pigment particles are not only surrounded by static resistance, there is also spatial resistance, and the coating film in the drying process, With the evaporation of water, ammonia in ammonium salt is also volatile, making this dispersant more hydrophobic, thus wrapping the pigment particles of such dispersants and film-forming material compatibility is better, coupled with spatial resistance makes the structure very puffy so that the coating film in the drying process film floating color, that is, the floating color in the process of motion is also suppressed.
Some of the false plastic thickeners and HLB value of the larger surfactant has a great affinity, so that it is disinsisted on the pigment surface, resulting in pigment accumulation and flocculation, and then make the system coloring force down and produce floating hair flowers. In organic and inorganic pigment mixing systems, especially when titanium white is shared with turquoise, turquoise and carbon-black slurry, a latex paint with a weak plasticity can be obtained with a more satisfied color. Strong hydrophobic thickeners, such as hydrophobic group adsorption of color slurry particles, cause poor bridge flocculation coloration.
of these reasons, the following methods can be solved
(1) by selecting the compatible or matching between polymers and pigments can solve floating flowers. However, the formulation design is limited, and not fundamentally solve the floating color. The best way to control floating color is to choose suitable wetting dispersant, adjust the surface properties of particles and adjust their motion balance.
wetting dispersant adsorbed on the surface of pigment particles can improve the surface properties of pigment particles, improve color display, improve or control floating color phenomenon. Often used wetting dispersants have ion types: anions, cations, non-ion types, multi-official group types. Wetting the dispersant adsorption on the pigment particle surface adsorption, changing the polarity of the pigment surface, breaking down and changing the structure of the pigment surface, regulating the main film material: the affinity between the polymer and pigment particles.
(2) No matter what causes colored pigment flocculation, floating white, pigment flocculation floating color, can use wetting dispersant to solve flocculation, improve particle surface properties to prevent or control floating color, in the process of controlling floating color several floating color phenomena can change each other. Such as water-based coating system coating film appears color slurry flocculation floating white, the base paint preparation added to the oil-based low-polar additive modified titanium white particles, or the wetting dispersant added to the color slurry, modified slurry pigment particles, anti-floating color additives can resist the coating film floating white.
(3) In some systems, anion-type wetting dispersants are added to the finished paint, adsorbed to the surface of carbon black or organic purple pigment particles, improving the surface properties of pigment particles and enhancing polarity, these non-polar weak polar particles have the same degree of adsorption flocculation as white particles, and polymers have the same degree of adsorption flocculation, and thus in the coating film drying ability of motion equivalent, control floating color. Choose a surfactant that strongly reduces surface pressure, commonly used silicone surfactant, so that it migrates to the surface during film drying process to form a single molecular film, balance the surface pressure and control flowering;
(4) to solve the flocculation flower or floating color can also add some additives that can be made into a tactil structure, so that in the paint film to form a network structure, to prevent pigment separation and flow, control pigment flocculation, subside and Benaud rotary nest flow, reduce the floating flower phenomenon, but the use of silk increase agent may affect the system and construction viscosity, the system pH also needs to be controlled.
specific actions are
. 1. Whether the pigment slurry flocculation, with scraper fineness meter check, less than 20um.
2. If flocculation/fingering color deepens, the coating is added to the non-ionic moisturizer, or anion-type humidifier, at this time before or after the addition is often effective.
. If there is a floating white, consider adding non-ionic moisturizers to the white paint, at this time to add before the production of the paint, after the addition is often ineffective.
4. If floating color / affect the effect of opening the can, consider adding anion-type moisturizer to the coating, at this time is also to be added before.
. If foam floating color is found, it may be taken with defrosting agent (mineral oil), at this time the appropriate choice of silicone;
6. Thickener variety and quantity matching, the combination thickener makes the system form a network, not easy to produce floating color in the tank, especially in the case of large amount of dark outer wall paint emulsion, but when using carbon-black slurry, the use of the combined thickening dose will affect the color-expanding force of carbon black.
7. When producing white paint, titanium white and fillers are generally dispersed with anion dispersant, but as a toning paint, especially when the darker color, the appropriate amount of non-ion or increase the color-expanding force of the anion moisturizer, which can improve the color display of white paint.
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