Water - based coating formulation design system - matting agent Matting agents are additives used to control the gloss of waterborne wood coatings to meet the broad needs of mainstream matt paints in today's market.The extinction mechanism of the matting agent can be arranged in an orderly manner on the surface of the coating film, so that the surface of the coating film is uneven, causing the light on the surface of the coating film to diffusely reflect, thereby achieving the purpose of extinction. The solid content of the resin used in the waterborne wood coating is relatively low, and the effective component of the waterborne wood coating is not high. In addition, it is a dispersion system, so the matting of the waterborne wood coating is relatively easy, but the matting of different waterborne resin systems is difficult. Generally, the acrylic emulsion is relatively well-extruded than the aqueous polyurethane dispersion, but is better than the aqueous polyurethane dispersion in terms of anti-settling properties.Therefore, the selection of matting powder must be considered in different systems and uses.The matting agent can select the refractive index similar to the refractive index of the water-based resin to reduce the transparency of the coating film, and also consider its matting effect, dispersibility, anti-sinking property and hand feeling in the system. Sinograce Chemical produces water based additives, such as thickener, crosslinking agent, wetting agent.

The types and functions of surface control agents include: 1.Improve flow and leveling 2.Reduce friction coefficient and increase slip 3.Enhanced scratch resistance 4.Anti-blocking 5.Enhance the arrangement of matte powder, etc. 6.Special feel, such as softness, etc. 7.Others such as improving the water resistance and stain resistance of the coating film On the one hand, they balance the surface tension of the drying process to achieve uniform drying and flow, and reduce surface roughness; on the other hand, they concentrate on the surface during the drying process to form a smooth coating film, which increases the slip and other special properties. There are two main types of such additives: 1.Organosilicon: This kind of surface control additive can effectively improve the scratch resistance and abrasion resistance of the coating film when it is added in a small amount. Generally, it has poor compatibility with the system. If it is not properly selected, it will affect the coating film. Gloss and adhesion between coating layers. 2.Wax emulsions, such as palm wax and polyethylene wax: affect the gloss of the coating to a certain extent, which is related to its particle size and distribution. The wax emulsion should be added to 2% to 8% of the total amount of the formulation to have obvious effect. Excessive wax emulsion affects the strength of the film and reduces the adhesion between the layers. The recommended optimum dosage is 3% to 5%. Putty does not use wax emulsion unless there is a special surface effect. In general, there is no need to add wax emulsion in the solid color paint. Sometimes wax emulsions can be replaced with wax powder. The combination of two types of surface control agents is more effective, but the following aspects should be paid attention to: 1.Whether it seriously affects the gloss of the coating 2. Effect on adhesion between layers 3.Evaluation of foam stability 4.Storage stability of the system Sinograce Chemical produces water based additives, such as thickener, crosslinking agent, wetting agent.

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.