摘要:
The invention relates to a process for the preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers having (AB) repeat units, via reaction by methods known per se of polyetherdiols with a stoichiometric excess of α,ω-dihydropolydimethylsiloxanes, in the presence of one or more compounds of elements of main group 13 and/or of transition group 3 as catalyst, which comprises, after completed reaction of the alcohol component, continuing the reaction until no remaining ≡Si(H) groups are detectable by a gas-volumetric method, and also to the compounds thus prepared, and to their use as surfactant additives for the production of polyurethane ether foams.
摘要:
The invention relates to a process for the preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers having (AB) repeat units, via reaction of one or more polyetherdiols with a stoichiometric excess of α,ω-dihydropolydimethylsiloxanes and at least one tertiary amine as catalyst, which comprises, after completed reaction of the alcohol component, continuing the reaction in the presence of small amounts of water until no remaining ≡Si(H) groups are detectable by a gas-volumetric method.
摘要:
The invention relates to a process for the transition metal-catalyzed addition of SiH-containing poly-siloxanes onto olefinic compounds, wherein the catalyst used is a combination of at least two compounds of platinum metals, and also to a corresponding catalyst system.
摘要:
The invention provides linear polydimethylsiloxane-polyoxyalkylene block copolymers containing Si—C groups and carboxylic ester groups and having repeating (A1BA2B) units where A1 and A2 are two different polydimethylsiloxane units of the general formula (I) with a number of Si atoms N=(n+2) of 15≦N≦30 and NA1≠NA2 and B is a unit of the formula (II) —CH2—CH2—(CH2)a—CO[O—CH2—CH(R)]c—O-[D-O]e—[—CH2—CH(R)—O]d—OC—(CH2)b—CH2—CH2— (II) where R independently at each occurrence is H, —CH3 or —C2H5, a and b independently of one another are 0 to 20, c and d independently of one another are values≧1, e is 0 or 1 and D is a hydrocarbon radical having 2 to 10 C atoms, the overall molar weight of the unit of the formula II being from 600 to 10 000 g/mol, with the proviso that the average mixed molar weight of the polydimethylsiloxane units (A1+A2) is from >1665 to 0% to ≦50% by weight, based on the overall weight of [O—CH2—CH(R)] in B, a process for preparing them and their use.
摘要:
A continuous process for preparing organomodified polysiloxanes by the transition metal-catalyzed addition of polysiloxanes containing SiH groups onto substances containing C—C multiple bonds, in particular a process for the continuous hydrosilylation of substances containing C—C multiple bonds, which comprises introducing the reactants, in the presence or absence of a homogeneous or heterogeneous catalyst, into a loop-like, heatable and coolable reaction circuit which has a static mixing element and/or a dynamic mixing element to mix starting materials and product formed, leaving the reaction mixture in the reaction circuit until a predetermined degree of conversion has been reached and subsequently transferring the reaction mixture still containing starting materials to a tube reactor to complete the reaction and taking it off via a receiver. In addition, a suitable industrial apparatus for carrying out the process of the invention is described.
摘要:
The invention provides linear polydimethylsiloxane-polyoxyalkylene block copolymers containing Si—C groups and carboxylic ester groups and having repeating (A1BA2B) units where A1 and A2 are two different polydimethylsiloxane units of the general formula (I) with a number of Si atoms N=(n+2) of 15≦N≦30 and NA1≠NA2 and B is a unit of the formula (II) —CH2—CH2—(CH2)a—CO[O—CH2—CH(R)]c—O-[D-O]e—[—CH2—CH(R)—O]d—OC—(CH2)b—CH2—CH2— (II) where R independently at each occurrence is H, —CH3 or —C2H5, a and b independently of one another are 0 to 20, c and d independently of one another are values ≧1, e is 0 or 1 and D is a hydrocarbon radical having 2 to 10 C atoms, the overall molar weight of the unit of the formula II being from 600 to 10000 g/mol, with the proviso that the average mixed molar weight of the polydimethylsiloxane units (A1+A2) is from >1665 to 0% to ≦50% by weight, based on the overall weight of [O—CH2—CH(R)] in B, a process for preparing them and their use.
摘要:
The invention relates to a process for the preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers having (AB) repeat units, via reaction of one or more polyetherdiols with a stoichiometric excess of α,ω-dihydropoly-dimethylsiloxanes and at least one tertiary amine as catalyst, which comprises, after completed reaction of the alcohol component, continuing the reaction in the presence of small amounts of water until no remaining ≡Si(H) groups are detectable by a gas-volumetric method.
摘要:
The invention relates to a process for the preparation of equilibration products of organosiloxanes by rearrangement of the siloxane bond to a cation exchange resin, the organopolysiloxanes thus obtainable and the use thereof.
摘要:
The invention relates to a method for the preparation of toluene solutions of aluminum hydride, which is free of ethers and halides, characterized in that the complex, bound magnesium halide portion is precipitated and removed from halogen magnesium aluminum hydridohalides, which optionally are present in tetrahydrofuran (THF) solutions, of the general formula (Mg.sub.2 X.sub.3 (THF).sub.y).sup.+ (AlH.sub.3 X).sup.- wherein X is chlorine, bromine or iodine Y is a number from 0 to 6, by the consecutive addition of hexane and toluene with successive removal by distillation of hexane and optionally of THF at boiling temperatures up to 90.degree. C. Solutions of aluminum hydride in toluene are obtained, which can be used directly for reductions or yield solid aluminum hydride after removal of the solvent.
摘要翻译:本发明涉及一种制备氢化铝的甲苯溶液的方法,该方法不含醚和卤化物,其特征在于复合结合的卤化镁部分被沉淀并从卤代卤化镁铝卤化物中除去 (THF)溶液,其中X是氯,溴或碘,通式(Mg 2 X 3(THF)y)+(AlH 3 X))是0至6的数,通过连续加入己烷和甲苯,连续除去 在高达90℃的沸点温度下蒸馏己烷和任选的THF。获得氢化铝在甲苯中的溶液,其可以直接用于在除去溶剂之后还原或产生固体氢化铝。
摘要:
The invention relates to a process for producing metal foams of controlled structure and to the metal bodies in foam form obtained in this way, wherein metals from group IB to VIIIB of the periodic system of the elements are added before and/or during the formation of the foam.