3 results about "Base free" patented technology

The invention discloses a method for preparing a heavy metal-free pharmaceutical intermediate difluoromethyl ether proline derivative, which belongs to the technical field of organic synthesis and is suitable for industrial large-scale production. Difluorocarbene is produced by using a cheap base free of heavy metals as an additive, and the difluoromethylation of the proline derivative is completed to obtain an important difluoromethyl ether proline derivative pharmaceutical intermediate. Compared with existing synthesis methods, the method has mild reaction conditions, does not require the participation of heavy metals, can produce a large amount of fluorine-free products, uses inexpensive and readily available reagents, and has a high yield.

Provided is a martensite-based free-cutting stainless steel bar that is characterized by: having a chemical composition of C at 0.60% exclusive to 1.00% inclusive, Si at 0.10% to 2.0%, Mn at 0.10% to 3.0%, S at 0.050% or less, P at 0.10% or less, and Cr at 11.0% to 16.0%, the balance being Fe and impurities; and having: an average Cr carbide equivalent spherical diameter of no greater than 1.20 μm, a Cr carbide number density of at least 0.10 particles / μm2, an average Cr nitride equivalent spherical diameter of no greater than 0.80 μm, and a Cr nitride number density of at least 0.05 particles / μm2.

This invention provides a resin composition and its application. The resin composition, by weight, comprises the following components: (A) 1-10 parts of a nitrogen-containing polyether resin containing unsaturated double bonds; (B) 45-75 parts of filler; and (C) 1-10 parts of a compounded free radical initiator. The compounded free radical initiator (C) comprises an organic peroxide free radical initiator and a carbon-based free radical initiator in a mass ratio of (0.2-5):1. By introducing free radical initiators with different half-lives into the resin composition, combined with the nitrogen-containing polyether resin containing unsaturated double bonds and filler, the prepreg prepared from this resin composition exhibits thick copper filler properties, and its cured product has high Tg, low XY-CTE, and good electrical and PS properties. It can be applied in thin HDI, carrier plates, and high-speed applications, showing broad application prospects.