Dispex G40

Sodium salt of an acrylic copolymer

Ciba Specialty Chemicals

·ÖÉ¢¼Á >> Àà±íÃæ»îÐÔ¼Á >> ¾Û±ûÏ©ËáÄÆ/¾Û±ûÏ©Ëá Dispersing agents >> Surfactants-like >> Sodium polyacrylates / Polyacrylic acids Í¿²ã >> Ë®Éú Coatings >> Waterborne Water *HQHUDO DISPEX G40 and DISPEX GA40 are derivatives of a family of highly effective, low viscosity dispersing agents for water-borne coating systems. The products are especially suited for the dispersion of inorganic pigments. Compared with other dispersing agents DISPEX G40 and DISPEX GA40 allow formulation of high-gloss / low pigment volume concentration coatings in addition to standard matt formulations. DISPEX G40 is solution of a sodium salt of an acrylic copolymer in water. DISPEX GA40 is solution of an ammonium salt of an acrylic copolymer in water. Both belong to a family of products which are based on an acrylic copolymer. The copolymer is manufactured to a relatively narrow molecular weight distribution thus resulting in a consistent product quality with maximum effectiveness. DISPEX G40 and the DISPEX GA40 are ideal dispersing agents for a wide range of water-borne coatings. The special copolymer backbone is designed for complete compatibility with polypropylene and hexylene glycols used in high proportions in water-borne high gloss coatings to promote wet edge time. Use of DISPEX G40 and DISPEX GA40 is especially recommended when high-gloss / low pigment volume concentration coatings are formulated. The neutralising alkali used in conjunction with the acrylic polymer can significantly impact the properties of the final coating. DISPEX GA40 releases ammonia during the drying process and therefore has little impact on water and alkaline resistance of the dry film while the sodium-based DISPEX G40 often contributes slightly negatively to the coating properties. DISPEX G40 is effective over a pH range 5-12 and up to temperatures in excess of 100°C. Use of DISPEX GA40 should be limited to pH 5-10.5 and temperatures lower than 70°C due to potential loss of volatile ammonia. Compared with inorganic dispersing agents, e.g. polyphosphate products, the organic polymer based DISPEX G40 and DISPEX GA40 provide improved storage stability of both, the pigment dispersion and the formulated paint. There is little or no adverse reaction to high temperatures or pH changes as indicated in the graphs below, which are examples showing the accelerated effects in laboratory formulations. With respect to this specific property the behaviour of DISPEX G40 or DISPEX GA40 containing formulations is comparable to formulations containing the dispersing agent DISPEX N40. Incorporation of DISPEX G40 or DISPEX GA40 It is recommended to add the pigment to heavily stirred water containing the dispersing agent as opposed to addition of the dispersing agent to a pigment slurry. In general, the pH of the final preparation should be in the region of 8.5 to obtain optimum dispersing efficiency. The optimum amount of dispersing agent required to form a stable dispersion strongly depends on the pigment¡¯s chemical nature, the particle surface and shape. The polymer base of the latex also plays a very important part in the stability equation. In general, significant overdosing may deteriorate the coatings properties (e.g. water resistance) and also generates an economic disadvantage. Likewise insufficient dispersing agent will lead to instability on storage. In common with other dispersing agents, because of the batch-to-batch variations of the demands of a specific pigment or latex type it is recommended that the formulator uses 1.5 - 2.0 times the determined optimum level of the dispersing agent. Dispersing agents for a wide range of water-borne coatings. The special copolymer backbone is designed for complete compatibility with polypropylene and hexylene glycols used in high proportions in water-borne high gloss coatings to promote wet edge time. Recommended when high-gloss / low pigment volume concentration coatings are formulated. The neutralising alkali used in conjunction with the acrylic polymer can significantly impact the properties of the final coating. Contributes slightly negatively to the coating properties. Effective over a pH range 5-12 and up to temperatures in excess of 100°C. Compared with inorganic dispersing agents, e.g. polyphosphate products, provides improved storage stability of both, the pigment dispersion and the formulated paint. There is little or no adverse reaction to high temperatures or pH changes. Add the pigment to heavily stirred water containing the dispersing agent as opposed to addition of the dispersing agent to a pigment slurry. In general, the pH of the final preparation should be in the region of 8.5 to obtain optimum dispersing efficiency. Recommended usage level: 0.5-2.0% based on total pigment weight.