| 摘要 |
1,145,159. Polymerizable compositions hardenable in air. SCM CORP. 16 May, 1966 [14 May, 1965], No. 21735/66. Headings C3C and C3P. A composition which can be polymerized in air comprises one or more liquid vinyl or vinylidene monomers containing at least one hetero atom and/or an aromatic ring and 0-40% by weight of a vinyl or vinylidene polymer, which may or may not correspond with the monomer(s), together with a peroxide-free redox catalyst system whose oxidizing component is a lipo. philic organic vanadium compound, in which the vanadium has an oxidation state greater than II, and whose reducing component is a mercaptan. Suitable monomers include acrylic, methacrylic and vinyl esters, and styrene and its derivatives such as α-methyl-styrene and pvinyltoluene; these may be used, if desired, in admixture with 1-10% by weight of a crosslinking monomer such as ethylene glycol dimethacrylate, diallyl phthalate or diethylene glycol bis-allyl carbonate. When the monomer is used together with preformed polymer, the combination may be obtained (as illustrated in the examples) by prepolymerizing the monomer. The vanadium compound may be a complex of tri- or tetra-valent vanadium with a tautomeric compound such as acetyl acetone, benzoyl acetone, an acetoacetic ester or a benzoyl acetic ester; also suitable are vanadium derivatives of 5-chloro-8-hydroxyquinoline, 5,7-dibromo-8-hydroxyquinoline, di- (2- ethylhexyl ) - phosphate and p-toluenesulphonic acid. Suitable mercaptan reducing components are aliphatic straight-chain primary mercaptans having 4-16 carbon atoms. The catalyst components may be added simultaneously to the monomer or, alternatively, the oxidizing component may be added after the reducing component; the mercaptans serve to stabilize the monomer for storage purposes. The composition may include an additional stabilizer such as 2-mercaptobenzthiazole or 2-mercaptothiazoline. The composition may be polymerized at a relatively low temperature, e.g. room temperature or 30‹ C. Suitable applications of the compositions include glass fibre laminating, adhesives for acrylic glasses, foams, casting of acrylic resins, and encapsulation of electronic components. The composition can be foamed by including a foaming agent, e.g. azobisisobutyronitrile, therein and heating at elevated temperature after completion of polymerization. This is illustrated in Example 1. |
