摘要:
Compositions, stable in the absence of oxygen, are formed by mixing the following substantially in the absence of oxygen: (A) 100 parts by weight of at least one mercapto-functional organosiloxane containing at least two mercapto-functional substituents per molecule; (B) a catalytic amount of an iron carbonyl compound catalyst selected from the group consisting of Fe(CO)5, Fe2(CO)9, Fe3(CO)12, dicyclopentadienyldiiron tetracarbonyl, butadieneiron tricarbonyl and cyclohexadieneiron tricarbonyl, preferably from 0.1 to 6 parts by weight of catalyst per 100 parts by weight of part (A); (C) optionally, at least one filler; and (D) 0.1 to 6 parts by weight per 100 parts by weight of redox compound such as copper (II) sulfate or iron (III) oxide. The compositions polymerize or cure to form higher molecular weight products upon exposure to oxygen. The use of a redox compound appears to increase the cross-link density of the cured composition and results in harder resins and more durable elastomers. An important novel feature of the redox compounds is that their use enables one to formulate compositions which cure to low-modulus elastomers possessing excellent unprimed adhesion to many common substrates such as glass, metal and concrete. Such low-modulus elastomeric compositions are very desirable for use as building sealants.
摘要:
Oxygen curable compositions are provided by mixing mercoaptoorganopolysiloxanes with a metal salt of a carboxylic acid wherein the metal is iron, copper, cobalt, manganese, or nickel.
摘要:
Mixing mercaptoorganopolysiloxanes with a selected transition metal compound, an organic peroxide and optionally a filler, provides useful new compositions such as materials curable to elastomers at room temperature.
摘要:
Compositions which are stable in the absence of oxygen are obtained by mixing the following substantially in the absence of oxygen: (A) 100 parts by weight of an ingredient selected from either (1) at least one mercapto-functional copolymer, containing both silicon-free organic segments and organosiloxane segments or (2) a mixture of at least two different types of components selected from the following types (a) at least one copolymer as described in (A) (1) above, (b) at least one silicon-free mercapto-functional organic compound and (c) at least one mercapto-functional organosilane or organosiloxane; (B) 0-200 parts of at least one filler; and (C) a catalytic amount, preferably from 0.1 to 6 parts, of a metal carbonyl catalyst selected from the group consisting of Fe(CO)5, Fe2(CO)9, Fe3(CO)12, dicyclopentadienyldiiron tetracarbonyl, butadieneiron tricarbonyl, cyclohexadieneiron tricarbonyl, Ni(CO)4, dicyclopentadienyldinickel dicarbonyl, Mn2(CO)10, methylcyclopentadienylmanganese tricarbonyl and dicyclopentadienylcobalt dicarbonyl. Such compositions polymerize or cure to form higher molecular weight products upon exposure to oxygen at room temperature. The higher molecular weight products formed are useful as coatings, impregnants for porous materials and elastomeric sealans. Cured products possessing a combination of some of the advantages possessed by organosiloxanes and some of the advantages possessed by organic polymers are easily obtained by exposing these compositions to oxygen.