Abstract: Phosphonite and phosphonate compounds ##STR1## wherein X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are each independently a group of the formula ##STR2## wherein R is a hydrogen atom or a methyl group, p is 0 or 1, q is independently 0 or 1 with regard to each repeat unit, and m is an integer of 2 to 10, a stabilizer for organic materials comprising said compound and a stabilized organic material comprising said compound. The compound of the present invention is less volatile at high temperatures. The use of the compound of the present invention as a stabilizer for organic materials affords an extremely useful organic material which is superior in heat stability and free of degradation caused by oxidation. The compound of the present invention has excellent compatibility with the above-mentioned organic materials and hardly migrate from the organic materials.

Abstract: Tetrakis(2,4-di-tert-butyl-5-methylphenyl)-4,4'-biphenylenediphosphonite, stabilizers for organic materials, which contain said compound, and stabilized organic materials containing said compound as a stabilizer. The tetrakis(2,4-di-tert-butyl-5-methylphenyl)-4,4'-biphenylenediphosphonite has particularly superior hydrolysis resistance, and is characterized in that it has superior storage stability due to its scarce hygroscopicity. It can be purified and handled easily since it is in a powder form, and it shows less volatility at high temperatures. By using the compound of the present invention as a stabilizer for organic materials, extremely useful organic materials imparted with superior processing stability, heat resistance and resistance to oxidative degradation can be provided.

Abstract: A selective process for preparing a 2,4- or 3,6-di-substituted phenol compound which comprises reacting an olefin compound of the formula: ##STR1## wherein R.sup.1 is hydrogen, halogen, alkyl, halogen substituted alkyl, aryl, halogen substituted-aryl or alkyl substituted-aryl; and R.sup.2, R.sup.3 and R.sup.4 are the same or different and each is hydrogen, halogen, alkyl, halogen substituted-alkyl or aralkyl; with a phenol compound of the formula: ##STR2## wherein R.sup.5 is hydrogen, hydroxy, halogen, alkyl, halogen substituted-alkyl, alkoxy or --C(R.sup.6)(R.sup.7)CH(R.sup.8)(R.sup.9) (wherein R.sup.6 is hydrogen, halogen, alkyl, halogen substituted-alkyl, aryl, halogen substituted-aryl or alkyl substituted-aryl; and R.sup.7, R.sup.8 and R.sup.9 are the same or different and each is hydrogen, halogen, alkyl, halogen substituted-alkyl or aralkyl), in the presence of a phosphorus compound and a carboxylic acid compound as catalysts.

Abstract: There is provided an antifouling paint composition stabilized against viscosity increase and gelation during storage, which comprises a triorganotin-containing polymer and cuprous oxide as combined active ingredients, a stabilizing amount of a hindered phenol, and a solvent therefor.