SILRES® BS 7070
SILRES® BS 7070 is a methacrylate-containing formulation of a functional Silicone resin. It is used as a binder in the production of highly UV-stable engineered stone (also known as artificial, composite, or quartz stone).
特性
Engineered stones based on SILRES® BS 7070 as binder exhibit excellent UV-stability without yellowing and are, thus, suitable for the use in outdoor applications.
Typical applications for such stones are outdoor kitchen countertops, flooring, facade cladding as well as outdoor furniture.
Moreover, engineered stones based on SILRES® BS 7070 can also be used in very bright indoor areas exposed to sunlight, for example as a windowsill.
数据表
SILRES® BS 7070 is used as a binder for engineered stone, typically based on quartz or replacements like e.g. glass or feldspar. The binder is cured in a radical reaction which is initiated by using a peroxidic radical initiator. The amount of binder depends on the formulation and is typically in a range of 7-13 % by weight.
The functional Silicone resin is admixed with a radical initiator and, if desired, a metal-based accelerator, before adding it to the solid mixture. It is recommended to use about 1 % of radical initiator based on the weight of the binder. All standard radical initiators can be used. Best results can be obtained when using TBPIN (tert-butylperoxy-3,5,5-trimethylhexanoate) as initiator. The use of an additional silane-based adhesion promotor is not required.
Typically, no major adjustment of process parameters compared to the standard process using unsaturated polyester resins (UPR) is necessary. Best results can be obtained when the compacted mixture is cured at temperatures roughly 20 °C higher than for mixtures based on UPR.
To ensure ideal UV-stability, it is recommended to use inorganic pigments only. Consequently, engineered stone based on SILRES® BS 7070 exhibits excellent UV-stability and is, thus, suitable for the installation in outdoor areas. Upon exposure to UV-light, no yellowing occurs. Colored engineered stone can, however, show a slight lightening upon extended UV-light exposure. Typically, ΔE-values of < 1 after 2,000 hours of QUV-B-testing are obtained for white and bright as well as for colored slabs.
Upon request, WACKER offers additives to extend the pot life of mixtures of binder and solids.
WACKER additives can also be used to pretreat quartz granules: These increase the interaction of the binder with the solids, especially with the pigments, thus increasing UV-stability and further reducing the possibility of potential whitening.
储存
The 'Best use before end' date of each batch is shown on the product label. Storage beyond the date specified on the label does not necessarily mean that the product is no longer usable. In this case, however, the properties required for the intended use must be checked for quality assurance reasons.
It is recommended to store the product in a cool and dark place. Upon extended periods of storage or with increased storage temperatures, the viscosity of the product can slightly increase.