Overview of Pigment Additives and Performance Introduction (4)

15. Loss of light and light

There are many factors related to the brightness of the paint, such as the color of the final processing, the angle of observation, the angle of reflection, the form of the surface, and the smoothness of the paint. In general, light brightness is a property of surface light reflection and is generally the same as the light emission properties, the degree of clarity of the reflected image, and the like. If the PVC of the same pigment is the same, the use of a well-wet paint base will produce a brighter coating compared to a less wetted base. Additives that improve brightness also tend to improve the wetting properties of the coating base. Such additives include zinc naphthenates, various amines, lichenin, and fatty acids.

Loss of light may have the following reasons:

(1) Fine wrinkles are slowly developed. This phenomenon can be improved by adjusting the content and type of metal in desiccants and desiccants;

(2) Exposure to ultraviolet light causes the surface of the coating film to degrade, and its degree of degradation can be minimized by the use of anti-pulverized titanium dioxide;

(3) The composition of the base material is not proper, lack of light durability, can add certain components, such as fatty acid, in the base material;

(4) In certain paints and enamels, the phenomenon of loss of light will occur, which can be remedied by changing the composition of the base material;

(5) Reducing the brightness of the reactants, such as soaps;

(6) Polymerization proceeds in the dry coating film, resulting in loss of light. An improved method is to select an appropriate base material, processing method, or pigment.

16. Pingguang

Sometimes it is necessary to obtain a dim coating effect. If pigments are used, PVC can be added to achieve a clear flat effect. The simplest method is to use diatomaceous earth or amorphous silica.

17. Brushing

Poor brushability refers to the continuous drag phenomenon when brushing paint. There are many reasons for this phenomenon, such as improper coating formulation and poor compatibility of the binder components, resulting in thickening or gel formation. Adding a coupling solvent or a high-solvent solvent and a heating coating can all be corrected; on the contrary, brushing on a cold surface often causes drag. A good brushing performance requires that the brushed surface and the brushed surface are joined at intervals. At certain intervals, the adjacent paint needs to have enough fluidity so that it can touch the previous brushing surface. Adding more binders, using less volatile solvents, or adding additives can improve the brushing properties of the coating.

18. Color durability

The white, light-colored or transparent color film will be more or less yellow or brown due to sunlight, artificial light or heat, and the baking process will produce the same result. This change is partly due to accelerated oxidation, and partly due to decomposition, which usually produces acidic products. The reason for the yellowing may be the base material, the pigment or other ingredients, especially the desiccant, or the reason for the combination. In general, the base material has the greatest influence on the color of the film. The length of time for drying, the temperature level, and the surrounding weather conditions will affect the color of the base material.

Adjusting the relevant factors can improve the durability of the color, such as adding additives. The most effective outdoor application is ultraviolet light absorbers, which can reduce the effect of ultraviolet light. Suitable indoor applications are some excellent wetting agents.

19. Infiltration

The so-called infiltration refers to the property of the coating penetrating or penetrating into the surface at the application surface. Good infiltration is often associated with a good wetting base, but a good wetting base is not necessarily an infiltration base. The degree of infiltration is neither good nor bad. It is entirely dependent on the circumstances. Certain additives can improve the infiltration.

20. Wrinkles

Wrinkles are the phenomenon in which the coating forms a fold on the surface when dried, depending on the application or formulation, or both. Excessive thick coating, or sometimes excessive use of desiccant, often produces wrinkles; when the skin surface of the coating is formed, drying under the surface can cause the surface to expand, resulting in wrinkles; sometimes humidity changes during drying can also be excessive. Cause wrinkles.

In unfavorable circumstances, if the coating film is thin and uniform, wrinkles can be avoided. Adding too much linseed oil to the paint will promote wrinkles or even surface unevenness. Wrinkles may also form if the coating is concentrated too much in one place. In general, the final processing with baking is better than wrinkling in the air. There are several ways to reduce wrinkles:

(1) Reduce the amount of desiccant;

(2) Use less cobalt desiccant, increase the amount of lead desiccant, or use zinc naphthenate;

(3) When there is lead, calcium naphthenate can be used.

There is a type of coating that requires wrinkles, the so-called "wrinkle" processing. For this case, the base material is very important, and an appropriate desiccant such as a cobalt-manganese desiccant should be selected.

21. Gum liquid guarantee agent and base agent

The colloidal liquid assuring agent and the base material include many substances. The linear type includes methyl cellulose, acrylate, starch, carbonyl cellulose, hydroxyethyl cellulose, and the like. The three-dimensional type includes casein and soy protein. And so on, the proper amount of use can increase the viscosity so as to stabilize the colloidal liquid while preventing their particles from coming close to each other and being linked together. These substances can also often improve the coating application properties without affecting the properties of the coating.