Abstract: A polybutadiene composition comprising a polybutadiene type polymer and a compound represented by the following formula (I): 1

Abstract: There is provided a co-condensation product obtainable by subjecting a p-alkylphenol to reaction with formaldehyde in the presence of an alkali catalyst to prepare a resol type condensate, and subjecting the resulting resol type condensate to reaction with a m-substituted phenol such as resorcin in the presence of an acid catalyst, wherein the content of the m-substituted phenol is not higher than 4% by weight, and the content of a component having a molecular weight not higher than 1,000 excluding both the p-alkylphenol and the m-substituted phenolis at least 25% by weight based on the total weight of the co-condensation product. This co-condensation product is low in fuming and in hygroscopic properties, exhibits excellent adhesiveness in vulcanizing adhesion between rubber and a reinforcing material, and further provides a vulcanized rubber article of high hardness.

Abstract: Described herein is a process for preparing a hydroxyflavan compound which comprises reacting a polyhydric phenol compound represented by formula(2): ##STR1## wherein at least one of W, X, Y and Z is hydroxy; with a ketone in the presence of (i)an acid catalyst and (ii)water and/or a seed crystal, using an organic solvent which is insoluble in water, procuces the hydroxyflavan compounds in high yield and with high selectivity while maintaining high conversion of the polyhydric phenol.

Abstract: The present invention relates to a method for producing a vulcanized rubber by compounding in a kneading step at a relatively high temperature, a rubber and a flavan compound of the formula (I) ##STR1## wherein R.sup.1, R.sup.2, R.sup.4 and R.sup.5 independently of one another represent a hydrogen or an aliphatic group having 1-6 6 carbon atoms, or R.sup.1 and R.sup.2 together with the carbon atoms to which they are attached and/or R.sup.4 and R.sup.5 together with the carbon atom to which they are attached form an alicyclic ring having 4-10 carbon atoms, R.sup.

Abstract: A rubber composition (1) which comprises:a rubber (A) such as natural rubber, isoprene rubber and the like;a hydroxy flavan compound (B1) represented by the formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are hydrogen or an aliphatic group and X and Y are hydrogen hydroxy or an aliphatic group, such as 2,4,4-trimethyl-2',4',7-trihydroxyflavan (B2); and2,2,4-trimethyl-1,2-dihydroquinoline polymer (C1) containing 1% or less by weight of a primary amine, 3% or less by weight of the monomer and 30% or more by weight of the dimer based on the total weight of the polymer, or a cromane compound (C2) which may be a novel cromane compound.