Modified cis-1,4-polyisoprene rubber, a process for manufacturing the same, and a composition containing the same
AssigneeKuraray Co., Ltd.
InventorsHideo Takamatsu, Shobu Minatono
Life of this patent
Estimating the term…
Abstract
Modified cis-1,4-polyisoprene rubber obtained by incorporating into cis-1,4-polyisoprene rubber a side chain formed by succinimide residue containing in the N position a hydrocarbon residue having at least one tertiary nitrogen atom. This rubber is excellent in green strength at ordinary room temperature, and flowability at an elevated temperature. Its vulcanizate is comparable to, or better than natural rubber in breaking strength and hardness.
Claims10
A modified cis-1,4-polyisoprene rubber, comprising:
- a solid synthetic cis-1,4-polyisoprene rubber having a side chain functional group of the formula (I) incorporated into said synthetic rubber, said modified rubber containing at least 0.01 mole of said functional group per 100 recurring units of isoprene monomer in said synthetic rubber:
- ##STR10## wherein R.sup.1 represents hydrogen, or a covalent bond with a rubber molecule, R.sup.2 represents a hydrocarbon residue having not more than 20 carbon atoms, optionally containing an oxygen or sulfur atom in its principal chain, and A represents a dihydrocarbylamino residue having not more than 20 carbon atoms, or a heterocyclic residue having not more than 20 carbon atoms and containing at least one tertiary nitrogen atom alone as a hetero nitrogen atom.
A process for manufacturing modified cis-1,4-polyisoprene rubber, which comprises:
- adding a compound selected from the group consisting of maleic anhydride, maleic acid, maleic acid monoesters and maleic acid diesters to solid synthetic cis-1,4-polyisoprene rubber having a molecular weight ranging from 200,000 to 2,000,000 in the quantity of at least 0.01 mole per 100 recurring units of isoprene monomer in said synthetic rubber;
- reacting the resulting product with an amine of formula (II)
- H.sub.2 N--R.sup.2 --A (II)
- wherein R.sup.2 represents a hydrocarbon residue having not more than 20 carbon atoms, optionally containing an oxygen or sulfur atom in its principal chain, and A represents a dihydrocarbylamino residue having not more than 20 carbon atoms, or a heterocyclic residue having not more than 20 carbon atoms and containing at least one tertiary nitrogen atom alone as a hetero nitrogen atom;
- and
- subjecting the reaction product to dehydration or dealcoholization to form an imide ring.
A process for manufacturing a modified cis-1,4-polyisoprene rubber, which comprises:
- reacting a solid synthetic cis-1,4-polyisoprene rubber with at least 0.01 mole of a maleimide derivative of the formula (I) per 100 recurring units of isoprene monomer in said synthetic rubber:
- ##STR11## wherein R.sup.2 represents a hydrocarbon residue having not more than 20 carbon atoms, and optionally containing an oxygen or sulfur atom in its principal chain, and A represents a dihydrocarbylamino residue having not more than 20 carbon atoms, or a heterocyclic residue having not more than 20 carbon atoms and containing at least one tertiary nitrogen atom alone as a hetero nitrogen atom.
A vulcanized rubber composition, comprising:
- as its rubber constituent, modified cis-1,4-polyisoprene rubber comprising solid synthetic cis-1,4-polyisoprene rubber having a side chain functional group of formula (I) incorporated in said synthetic rubber, said modified rubber containing at least 0.01 mole of said functional group per 100 recurring units of isoprene monomer in said synthetic rubber:
- ##STR12## wherein R.sup.1 represents hydrogen, or a covalent bond representing bonding of the functional group to the rubber molecule, R.sup.2 represents a hydrocarbon residue having not more than 20 carbon atoms, optionally containing an oxygen or sulfur atom in its principal chain, and A represents an N,N-dihydrocarbylamino residue having not more than 20 carbon atoms or a heterocyclic residue having not more than 20 carbon atoms, and containing at least one tertiary nitrogen atom alone as a hetero nitrogen atom.
Dependencies are inferred from the claim text.