A joint thickener that increases viscosity stability when the latex paint is colored.

0 Introduction
is an important subject for water-based coatings. Water-based coatings can use more types of thickeners than solvent-based coatings, such as cellulose ethers, acrylic cool, bentonized soil, or joint thickeners. In high-performance water-based coatings, ligation thickeners are more important than other types of thickeners because of their unique properties, which result in better leveling, brush coating, and reduced splashing during construction. They also give dry films better water resistance. These properties are derived from their unique chemical structure.
is a water-soluble polymer that can be acrylic polymers, cellulose ethers, or high-performance non-ionic products (e.g. polyethyl glycol). These polymers are sealed with non-water-soluble hydrophobic groups such ∃ fatty alcohols. In aqueous solutions or emulsions, these polymers can form a network structure that increases openness. The water-soluble main chain polymer dissolves in water. The water repugnant end is attached to water-repugnant emulsion polymer particles, or together with the water-reporbent part of other polymers forms a glue beam structure (see Figure 1)
. Since each binding thickener polymer contains at least two water-repugnant end-base, a three-dimensional network is formed in the latex, which increases viscosity. This mainly affects high and medium shear opening, so it has better splash resistance and brush coating resistance during construction than other thickeners.1 Amino resin-type connecting thickener
is an excellent connective thickener based on polyglycol, and in most cases the water repugnant end base is connected to polyglycol by forming a polyurethane reaction with isocyanate cool esters. The resulting product is a polyurethane thickener, often referred to as HEUR monk water modified ethyl oxygen-based polyurethane thickener (or PU thickener for short). In this paper, the use of amino resins instead of isocyanate coolly connected to the main chain, thus forming a new improved connective thickener with better performance, we call HEAT water-repugnant modified acetyloxymelic resin thickener (see Figure 2).amino resin bonds are more hydrolytic and water-soluble in most cases than arginine bonds, which is obvious. Because all amino resin polymers can form a transparent aqueous solution relative to the turbid PU thickener aqueous solution. The reaction to the formation of the polymer is the heat absorption balance reaction and the shrink reaction, which is conducive to better control of the reaction, so that the polymer reaction is carried out quickly. The reaction of isocyanate vinegar is a one-way heating addition reaction, which is difficult to control. Changes in polymer composition are more difficult to control, so pu thickener chemical adjustment is poor.the use of special amino resins provides an easy way to change the amount of water-repugnent end base. There are four active function groups in amino resins, which can be used for molecular connections, and not all four function groups react immediately, but two of them react quite quickly, mainly with polyethyl glycol reactions to form linear polymers. Under stronger reaction conditions, it is possible to force a third group of officials to react, and even a fourth group of officials to react. First of all, mainly in the polymer reaction on both ends of the two water-repugnant end-base formation of linear polymer, this, and their own PU thickener is not significantly different. However, when using amino resins, by adding more water-repugnent alcohols and adjusting reaction conditions, the polymer can produce more water-repulsive parts at the end of the chain and even in the middle of the polymer main chain. Thus, without changing the composition of the polymer main chain, a considerable amount of water repugnants can be added to the polymer main chain. The ability to add very high amounts of water repugnants is a chemical characteristic of amino resins. The addition of binary alcohols or surfactants to coatings using this compounding thickener does not cause a decrease in openings, as is the result of the addition of concentrated slurry to the coating.2 coloring stability
the main disadvantage of the joint thickener is that its thickening ability is greatly affected by other components and coating additives. It has been found that when a compounding thickener is used, the thickening effect is significantly reduced when solvents (such as binary alcohols) or surfactants are added to the coating. This situation greatly limits its application. Solvents or surfactants contain water repugnant parts that interfere with the action of the water repugnant end-base of the compounding thickener and prevent it from forming a complete three-dimensional network structure. Due to the weakening of more water repugnant components in the joint thickener molecule or the glue beam structure, the water repugnant part is dispensed from the surface of the latex particle. In most cases, the paint formulation designer is not aware of the chemical composition of all additives, so there are often a variety of potential problems when adding or changing additives. Pigment shading by adding concentrated slurry in color paint is often a
problems (see Figure 3). Concentrated color paste is a pigment concentrate that contains a large amount of wetting dispersants and binary alcohols to maintain the stability of pigments in the system and maintain a low viscosity. Binary alcohols are used to improve the wetting of these concentrated slurry so that they are well compatible with a variety of different systems (and even solvent-based systems).
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