Improvements in or relating to siloxanes

摘要

An intermediate organosilicon polymer consisting essentially of (1) at least 2 units of the formula: and (2) units of the formula RdSiO , in which each R and each R1 is a monovalent hydrocarbon (saturated or unsaturated) or halo-hydrocarbon radical, a is 2 or 3, b is 0 or 1, the sum a + b in any unit (1) is not greater than 3, c is 1, 2 or 3, d is 0, 1 or 2 and Z is a divalent hydrocarbon radical of 2 to 18 C atoms and free from aliphatic unsaturation, there being in each molecule an average of 1.3 to 2.0 R radicals per Si atom and at least 7 units of (2), may be made by reacting siloxanes containing SiH groups with silanes of the formula: in which R11 is a monovalent hydrocarbon radical containing -c=cgroup, in the presence of a Pt catalyst at 30 DEG to 150 DEG C.; alternatively the siloxanes may contain SiR11 groups and the silanes the SiH groups. The products can be used a one-component room temperature-curing resins and rubbers, by mixing them with a condensation catalyst and exposing them to moisture. Numerous examples of curing catalysts are given typical classes of which are:-certain organic amines, phosphoric and carboxylic acid salts of basic amin compounds, carboxylic acid salts of quarternary ammonium hydroxide and certain metal carboxylates. Pigments, heat stabilizers, fillers perfurmes and plasticizers may also be added. In a typical example (1), a mixture of a xylene solution of and a solution of chloroplatinic acid in dimethyl phthalate, was refluxed for 24 hours to yield, after removal of solvent, a liquid polymer of the formula: in which Me = methyl. This liquid was catalysed with di-n-hexylamine and cured on exposure to air to a rubbery gel. Specification 684,296 and U.S.A. Specification 2,662,909 are referred to.