Method of producing maleic anhydride modified polyisoprene rubber

Claim 1

A METHOD OF PRODUCING MODIFIED POLYISOPRENE RUBBER, COMPRISING REACTING MALEIC ANHYDRIDE WITH A HIGH CIS-1,4POLYISOPRENE RUBBER HAVING A CIS-1,4 CONTENT OF AT LEAST 95% BY MEANS OF A RADICAL-YIELDING CATALYST, AT A TEMPERATURE OF FROM ABOUT 0* TO 150*C., IN AN INERT SOLVENT FOR SAID RUBBER AS A REACTION MEDIUM AND UNDER AN ATMOSPHERE OF AN INERT GAS, CHARACTERIZED IN THAT THE MALEIC ANHYDRIDE AND THE CATALYST ARE RESPECTIVELY EMPLOYED IN AMOUNTS SATISFYING THE CONDITIONS: A. THE AMOUNT OF MALEIC ANHYDRIDE IS IN THE RANGE OF ABOUT 0.04 TO 3 PARTS BY WEIGHT PER 100 PARTS BY WEIGHT OF THE SAID RUBBER; B. THE VALUE (AMOUNT OF RADICAL-YIELDING CATALYST EXPRESSED IN MILLION PER 100 G. OF SAID RUBBER) X (INITIATOR EFFICIENCY) IS IN THE RANGE OF ABOUT 0.016 TO 1.03; AND C. THE VALUE (A)/(B) IS IN THE RANGE OF ABOUT 0.24 TO 24.2 AND CONDUCTING THE REACTION UNTIL A PRODUCT HAVING A BOUND MALEIC ANHYDRIDE CONTENT OF FROM ABOUT 0.03 TO 0.9 MOL PER 100 RECURRING UNITS OF ISOPRENE MONOMER IN THE POLYISOPRENE POLYMER IS OBTAINED.

Claim 2

A METHOD OF PRODUCING MODIFIED POLYISOPRENE RUBBER, COMPRISING REACTING MALEIC ANHYDRIDE WITH A HIGH CIS-1,4POLYISOPRENE RUBBER HAVING A CIS-1,4 CONTENT OF AT LEAST 95% BY MEANS OF A RADICAL-YIELDING CATALYST, AT A TEMPERATURE OF FROM ABOUT 0* TO 150*C., IN AN INERT SOLVENT FOR SAID RUBBER AS A REACTION MEDIUM AND UNDER AN ATMOSPHERE OF AN INERT GAS, CHARACTERIZED IN THAT THE MALEIC ANHYDRIDE AND THE CATALYST ARE RESPECTIVELY EMPLOYED IN AMOUNTS SATISFYING THE CONDITIONS: A. THE AMOUNT OF MALEIC ANHYDRIDE IS IN THE RANGE OF ABOUT 0.04 TO 3 PARTS BY WEIGHT PER 100 PARTS BY WEIGHT OF THE SAID RUBBER; B. THE VALUE (AMOUNT OF RADICAL-YIELDING CATALYST EXPRESSED IN MILLION PER 100 G. OF SAID RUBBER) X (INITIATOR EFFICIENCY) IS IN THE RANGE OF ABOUT 0.016 TO 1.03; AND C. THE VALUE (A)/(B) IS IN THE RANGE OF ABOUT 0.24 TO 24.2 AND CONDUCTING THE REACTION UNTIL A PRODUCT HAVING A BOUND MALEIC ANHYDRIDE CONTENT OF FROM ABOUT 0.03 TO 0.9 MOL PER 100 RECURRING UNITS OF ISOPRENE MONOMER IN THE POLYISOPRENE POLYMER IS OBTAINED.

Claim 3

A method of producing modified polyisoprene rubber, comprising reacting maleic anhydride with a high cis-1,4-polyisoprene rubber having a cis-1,4 content of at leasat 95% by means of a radical-yielding catalyst, at a temperature of from about 0* to 150*C., in an inert solvent for said rubber as a reaction medium and under an atmosphere of an inert gas, characterized in that the maleic anhydride and the catalyst are respectively employed in amounts satisfying the conditions: A. the amount of maleic anhydride is in the range of about 0.04 to 3 parts by weight per 100 parts by weight of the said rubber; B. the value (amount of radical-yielding catalyst expressed in millimol per 100 g. of said rubber) X (initiator efficiency) is in the range of about 0.016 to 1.03; and C. the value (A)/(B) is in the range of about 0.24 to 24.2 and conducting the reaction until a product having a bound maleic anhydride content of from about 0.03 to 0.9 mol per 100 recurring units of isoprene monomer in the polyisoprene polymer is obtained.

Claim 4

A method of producing modified polyisoprene rubber, comprising reacting maleic anhydride with a high cis-1,4-polyisoprene rubber having a cis-1,4 content of at leasat 95% by means of a radical-yielding catalyst, at a temperature of from about 0* to 150*C., in an inert solvent for said rubber as a reaction medium and under an atmosphere of an inert gas, characterized in that the maleic anhydride and the catalyst are respectively employed in amounts satisfying the conditions: A. the amount of maleic anhydride is in the range of about 0.04 to 3 parts by weight per 100 parts by weight of the said rubber; B. the value (amount of radical-yielding catalyst expressed in millimol per 100 g. of said rubber) X (initiator efficiency) is in the range of about 0.016 to 1.03; and C. the value (A)/(B) is in the range of about 0.24 to 24.2 and conducting the reaction until a product having a bound maleic anhydride content of from about 0.03 to 0.9 mol per 100 recurring units of isoprene monomer in the polyisoprene polymer is obtained.