Types, characteristics and applications of main rheological AIDS Variety Feature Application Methyl Cellulose The water system is thickened and has high efficiency, but the water resistance is not good, it is easy to be degraded by microorganisms, moldy and smelly, and the thixotropy after thickening with the system is strong, and the leveling property is not good. Generally not used in waterborne wood coating systems Acrylic alkali swelling type Sensitive to pH,the compactness of the film is relatively better,and can provide medium and low shear viscosity, can prevent the film from sag, effectively prevent sedimentation, slightly affect the gloss, but improper use and system flocculation, resulting Particles require high in-tank viscosity or where strong thixotropic sag is required. Generally used in waterborne wood primers and anti-adhesive finishes Polyurethane associative thickener The pseudo-plastic water resistance is good, the compactness of the coating film is good, the gloss is hardly affected, the low shear viscosity is provided, the sag is prevented from being used synergistically, and the balance of high, medium and low shear viscosity can be provided, the leveling is good, and the amount is small. Acrylic alkali solubilized thickener with better effect Widely used in waterborne wood finishes The amount of the rheological additive is usually from 0.1% to 1.0% of the total amount of the paint. Several leveling agents can be used in conjunction with the application of widened shear stress. Sinograce Chemical produces water based additives, such as thickener, crosslinking agent, wetting agent.

Rheological AIDS provide a leveling effect under high shear conditions, allowing the painted fluid to level out as quickly as possible, reducing brush marks and avoiding spatter. However, as the drying time goes by, this leveling effect weakens and the film is fixed, which can prevent the fluid from sagging on the vertical surface. Rheological additives can be divided into high, medium and low shear viscosity types: low shear viscosity rheological additives can provide viscosity inside the tank, prevent pigment settling, and effectively control the paint liquid in the standing Snails generated during surface operations; rheological additives that provide medium to high shear viscosity can improve the fullness and leveling of waterborne wood coatings, while rheological additives that increase high shear viscosity help leveling, Prevent splashing and improve roller and brush application performance.Therefore, the type and amount of rheological additives must be selected according to the requirements and system of the construction. Generally, the type of rheological additive is selected according to the different construction methods, and is often matched by three rheological additives of shear viscosity. In order to achieve the required construction results. Polyurethane associative thickeners are currently the most widely used in waterborne wood coatings, but the choice of such thickeners in aqueous wood coating systems is closely related to the other ingredients in the formulation.For example, the thickening effect has a great relationship with the polymer particle size and hydrophobicity and the cosolvent in the waterborne wood coating. If the polymer particles in the waterborne wood coating are smaller, the more hydrophobic, and the distribution of the cosolvent in the polymer. The higher the coefficient, the higher the thickening efficiency, otherwise a large amount of such thickeners do not reach the desired viscosity.At the same time, it is recommended to dilute with water and add it under reasonable shearing force. Otherwise, it may also flocculate with the system to produce particles. Sinograce Chemical produces water based additives, such as thickener, crosslinking agent, wetting agent.

Variety Feature Application Traditional surfactants (mainly anionic or nonionic) Poor water resistance Easy to foam and stabilize foam cheap price Putty and low-grade system · Fluorocarbon polymer Efficient Reduce static surface tension Good effect on contaminated substrates Easy to cause surface problems Not easy to control High price Very difficult to attach substrates And contaminated substrates PSAMS Wetting effect、Good resistance to foaming, shrinkage and water resistance Wide adaptability Common application Non-silicon non-fluorine Minimize possible defects Minimize possible defects Low water sensitivity Low foaming Good dynamic effect expensive All kinds of coating The ideal wetting agent should contain the following aspects: 1. Effectively reduce the surface tension of the system and improve its wettability and permeability to the substrate. 2. Foaming and foam stabilization as low as possible. 3. As low a water sensitivity as possible. 4. Does not affect interlayer adhesion 5. A good balance of surface tension can improve the wetting of the substrate without affecting the leveling or defects due to excessive reduction of surface tension. Generally, the dosage of levelling agent is 0.1%~1.0%, and it is better to control it at 0.3%. When the defoaming agent exceeds the quantity, in order to overcome shrinkage cavity, the dosage of levelling agent can even exceed 1% in the putty formula without levelling agent . Sinograce Chemical produces water based additives, such as thickener, crosslinking agent, wetting agent.

Formulation design system for water based coatings - wetting leveling agent The wetting leveling agent can effectively reduce the surface tension of the system and significantly improve the construction effect of the waterborne wood lacquer.After the addition of the wetting leveling agent, the wetting property and permeability of the paint increase, the leveling property of the paint liquid is improved, and sometimes the shrinkage (frame effect) problem can be overcome.More importantly, the leveling agent can solve the common shrinkage cavity problem, especially the shrinkage cavity caused by excessive use of the defoaming agent.Excessive leveling agent will offset the defoaming effect of the defoaming agent, so that the paint liquid will generate bubbles during construction, and some will have obvious foam stabilization effect. Therefore, it should be used with good leveling property, low foaming property and stable foaming. Small wet wetting leveling agent.The combination of leveling agent and defoamer, including the selection of varieties and the control of dosage, is the focus of research on waterborne wood lacquer formulations.