Benzyl Phthalates are the preferred plasticizer for urethane, polysulfide and acrylic (see caulks) sealants. Their high compatibility (polarity) makes them excellent plasticizers for these high-performance polymers. Due to their low reactivity (i.e. low hydroxyl number), Benzyl Phthalates can be used as viscosity modifiers and resin extenders with very little impact on the end product.
Specifically, Santicizer® 261 finds several applications in the insulated glass sealant (IGS) market because of its low volatility and outstanding compatibility with both urethanes and polysulfides. In fact, compared to other plasticizers, Santicizer® 261 has a very low argon transmission coefficient, which allows longer life cycles and lower energy costs in windows produced with a sealant made with Santicizer®.