subject: Silicone Resin Exterior Wall Coating Design And Performance Of The Formula - Wall Paint - Paint [print this page] Sun Shunjie, Hong Yongshun, Zhang Lin Sun Shunjie, Hong Yongshun, Zhang Lin
(Shantou Economy SAR Lake Technical Center Co., Ltd. Beijing, Beijing 100076)
Abstract: Silicone Exterior wall paint Formulation of the coating performance factors, such as PVC, fillers, latex and silicone resins and additives, through testing, to determine its resistance to the powder coating resistance, permeability, water absorption, water resistance, alkali resistance and stain resistance and other performance effects.
0 Introduction As an environmentally friendly, convenient construction, decoration materials, in recent years Waterborne Coatings Wall decoration in wider and wider application. However, due to environmental moisture, dust, UV and other factors, as well as most paint brush in concrete, mortar and other basic substrates prone to staining, efflorescence, water is poor, fading and other quality problems, especially in the north area, to prevent cracking the grassroots, many works using flexible coating, but flexible coating permeability is poor, prone to blisters and even lead paint off the case, and thus the development of a water-repellent, breathable silicone coating is of great significance.
1 formulation factors and basic formula
1.1PVC ( Pigment Volume concentration) Coating formulation design, the pigment volume concentration (PVC) is a coating formulation is an important parameter, different PVC of the coating of the scrub, gloss, water-resistance, weather resistance and other properties have a significant impact. In general, PVC CPVC, the emulsion polymer can not paint, and fill the gap completely full of particles, will retain a certain amount of air, film properties have a greater change, increased permeability, and abrasion resistance will be decreased to some extent, weather will greatly decrease.
1.2 emulsion For most types of external wall of the emulsion is Acrylic emulsion And styrene-acrylic emulsion. According to the synthesis of monomers, acrylic emulsion properties very different, but usually acrylic emulsion has better UV resistance, low water absorption, usually for low PVC paint formulations. The styrene-acrylic emulsion adhesive ability of the pigments and fillers perform well, and low water absorption, resistance to saponification good performance. Add the amount of silicone
1.3 For the silicone modified wall Latex paint Most silicone resin emulsion modified by silicone acrylic emulsion, is divided into two types of grafting and the blending, but there the problem of low levels of organic silicon. Germany WACKER Provided a silicone resin, which BS43N emulsion is diluted with water-based silicone emulsion, the active substance content of up to 42%.
1.4 types of pigments and fillers and the addition of
Many types of pigments and fillers, different fillers on the coating of gloss, weather resistance greater impact, in which a white pigment to Titanium dioxide The best performance, exterior wall coating should adopt rutile titanium dioxide, other pigments such as iron oxide series of good performance. Common types of filler have heavy calcium carbonate, wollastonite powder, mica, talc, kaolin, dolomite.
1.5 Additives Silicone coating additives and similar to ordinary wall paint, because silicon-based film-forming thermosetting resin is, so the formula should be reduced by the amount of film-forming additives. Lower the surface tension of silicone, defoamer used when selecting suitable species and processing capacity. Other wetting agent and dispersing agent dosage on the development of colored paint color is critical. Taken together, the basic formulation shown in Table 1.
Table 1 silicone resin based wall paint formulations
Note: The table X, Y, respectively, increases the amount of water and emulsion, can coating formulation of PVC and decentralized water needed to determine the specific dosage.
White paint formulations, using titanium dioxide pigment. Colored coatings, with m (titanium dioxide): m (iron oxide red) = 2:1. Filler with two different powder. Emulsion and water by adjusting the general increase in the amount of PVC coating in different formulations available.
