Abstract:
PROBLEM TO BE SOLVED: To provide a method for continuously manufacturing a polycarbonate-polyorganosiloxane copolymer with a carbon tetrachloride concentration of below 4 ppm.mass.SOLUTION: This continuous manufacturing method comprises: a step A of continuously or intermittently removing, from a reactor, a polymerization reaction liquid obtained by polymerizing a carbonate precursor and a polyorganosiloxane in the presence of an aqueous alkaline compound solution and a water-insoluble organic solvent; a step B of separating the polymerization reaction liquid into an aqueous phase and a water-insoluble organic solvent phase; a step C of washing and then separating the water-insoluble organic solvent phase into an aqueous phase and a water-insoluble organic solvent phase; a step D of condensing the water-insoluble organic solvent phase; and a step E of partially or entirely recovering and then distilling and purifying the water-insoluble organic solvent; the water-insoluble organic solvent of the step E is recycled as the water-insoluble organic solvent of the step A or as the aqueous phase extracting solvent of the step B or as both, and the distilling purification at the step E is executed while the copolymer concentration within the bottom liquid of the distillation column is being controlled at 6 mass% or below.
Abstract:
A process for removing an impurity from a siloxane comprising i) flowing a first liquid through a fiber bundle comprising a plurality of fibers extending lengthwise in a conduit, wherein the bundle has an upstream end and a downstream end, and the first liquid flows in a direction from the upstream end of the bundle to the downstream end; and ii) while continuing (i), flowing a second liquid comprising a siloxane and an impurity through the fiber bundle in a direction from the upstream end of the bundle to the downstream end of the bundle to effect transfer of at least a portion of the impurity from the second liquid to the first liquid, wherein the first liquid and the second liquid are substantially immiscible.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing a low-odor glycerol derivative-modified silicone, a large amount of which can be inexpensively simply and at one time treated for low odor, and which exhibits little odor and is suppressed in scenting during formulation and over time; and to provide an external preparation, a cosmetic and a raw material thereof containing the low-odor glycerol derivative-modified silicone produced by the method.SOLUTION: There are provided: a method for producing a low-odor glycerol derivative-modified silicone or a composition containing the same, the method including a step of treating a glycerol derivative-modified silicone or a composition containing the glycerol derivative-modified silicone with at least one acidic inorganic salt which is solid at 25°C and water-soluble and has a pH at 25°C of ≤4 when 50 g of the salt is dissolved in 1 L of ion-exchange water; and an external preparation, a cosmetic and a raw material thereof containing the low-odor glycerol derivative-modified silicone produced by the method.