Novolac resins and use in rubber compositions
AssigneeSumitomo Chemical Company, Limited
InventorsTamon Itahashi, David P. McNaughton, Koichiro Tajima, Michael C. Walkup
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Abstract
A resorcinolic novolac resin composition comprising the reaction product of (i) an aldehyde or ketone, and (ii) aralkyl-substituted resorcinol and resorcinol, where the moles of the aralkyl-substituted resorcinol to the total moles of the resorcinol and aralkyl-substituted resorcinol is 0.01:1 to 0.4:1.
Claims15
A pastille or prill comprising a resorcinolic novolac resin composition including:
- (i) a resin including units defined by the formula (I)
- where R1 is a hydrogen atom or an aralkyl group, at least one of R2 and R3 is an alkylene bridge, and the other of R2 and R3 is an alkylene bridge or a hydrogen atom;
- and
- (ii) unreacted resorcinolic compounds defined by the formula (II)
- where R1 is a hydrogen atom or an aralkyl group, and where 1 mole % to 10 mole % of the total resorcinolic aromatic rings in formula (I) and formula (II) have been aralkylated, and wherein the composition has an aldehyde to resorcinol molar ratio of from about 0.50:1 to about 0.62:1, and
- wherein the pastille or prill only exhibits up to 0.56 weight % fines when tested for brittleness as measured with a Tyler Ro-Tap Model B sieve shaker.
A method for forming a pastille or prill comprising an aralkyl-substituted resorcinolic novolac resin, the method comprising:
- reacting (i) an aldehyde or ketone with (ii) an aralkyl-substituted resorcinol and resorcinol, in the presence of a catalyst of toluene sulfonic acid, where the moles of the aralkyl-substituted resorcinol to the total moles of the resorcinol and aralkyl-substituted resorcinol is 0.01:1 to 0.1:1, to provide a solid resorcinolic novolac resin;
- and
- forming the solid resorcinolic novolac resin into the form of a pastille or prill, and wherein the pastille or prill only exhibits up to 0.56 weight % fines when tested for brittleness as measured with a Tyler Ro-Tap Model B sieve shaker.
An improved rubber composition comprising (1) per 100 parts diene rubber component selected from natural rubber, synthetic rubber or combinations thereof, and (2) 0.1 to 10 parts aralkyl-substituted resorcinolic novolac resin having from 1 mole % to about 10 mole % of the resorcinol aralkylated with one or more compounds selected from the group consisting of styrene, alpha-methyl styrene, beta-methyl styrene and p-methyl styrene, wherein the resin is disposed in the natural rubber in the form of pastilles or prills, and wherein the pastilles or prills only exhibit up to 0.56 weight % fines when tested for brittleness as measured with a Tyler Ro-Tap Model B sieve shaker.
Dependencies are inferred from the claim text.