PYRIMIDINE DERIVATIVES AS HARDNESS STABILIZING AGENTS Russian patent published in 2005 - IPC

FIELD: organic chemistry, rubber industry.

SUBSTANCE: invention relates to a vulcanizing composition comprising rubber vulcanized with sulfur, sulfuric vulcanizing agent, accelerating agent taken among a group comprising of non-thiazolsulfenamide accelerating agents and agent providing stabilization of hardness that comprises derivative of pyrimidine of the formula (I):

wherein X represents hydrogen atom (H), radical from R₁ to R₄, NR₃R₄, OR₅, SR₅, SO₂R₆, M, (SO₃)_zM (wherein M represents metal ion); n and z can be similar or different and = 1, 2 or 3 depending on the corresponding valence of X and M = 1, 2 or 3; radicals from R₁ to R₄ are similar or different and taken among the group comprising of H, halogen atom, -OH, -NH₂, alkyl, cycloalkyl, aryl, alkylaryl, alkylaryl, aralkyl and each among substitutes has optionally additional functional groups taken among the group consisting of -NH₂, -OH, substituted amino-group, substituted hydroxyl, halogen atom and carbonyl-containing group; R₃ and R₄ in the same link in common with nitrogen atom (N) can form a heterocyclic group; R₅ can mean any radical from R₁ to R₄ formed by carbon-base heterocyclic group comprising at least one sulfur (S) or nitrogen (N) atom or both S and N; R₆ is taken among any radical from R₁ to R₄, -OH, -OM, -OR₅, -NH₂, NR₃R₄. The corresponding amount of accelerating agent and hardness stabilizing agent is effective in order to not inhibit vulcanization and to stabilize hardness property of indicated rubber after vulcanization. The amount of accelerating agent in indicated composition is above about 0.6 part per 100 parts of rubber when indicated rubber represents butadiene styrene rubber (SBR), and at least 0.5 part per 100 parts of rubber when indicated rubber represents the natural rubber, and the amount of the hardness stabilizing agent is at least about 0.5 part per 100 parts of rubber. Also, invention involves a method for enhancing hardness stabilization of the composition comprising rubber vulcanized with sulfur by addition of above indicated accelerating agents and pyrimidine derivative to the composition.

EFFECT: valuable properties of compounds.

28 cl, 8 tbl, 4 ex