A polymer material having a carbon-carbon double bond in the molecule thereof such as EPDM, NR and NBR is susceptible to degradation by sunlight (particularly ultraviolet rays) or ozone, so that a problem of weatherability may occur depending on the application. In addition, such a polymer material may be dissolved in a specific organic solvent or the like, and cannot be applied also to a site that may be contacted with such an organic solvent or the like. Therefore, as one countermeasure for extending the application of such a polymer material, there is considered a modification (chemical modification) by a nitrile oxide.
On the other hand, it has been known from long ago that a nitrile oxide which is one of representative 1,3-dipoles, is reacted with a monomer of alkene or alkyne, a monomer of nitrile compounds and the like under a moderate condition. However, a nitrile oxide is, because of its high reactivity, gradually dimerized in a non-polar solvent to be converted to furoxane, so that the isolation and the preservation of a nitrile oxide is difficult. Therefore, in order to perform a modification by a nitrile oxide, a method of generating a nitrile oxide in the reaction system by reacting a base such as triethylamine with halogenated aldoxime that is a precursor of a nitrile oxide becomes general.
However, by this method, when it was attempted to react a polymer material such as NBR and PAN with a nitrile oxide, the reaction hardly progressed, so that a modified polymer material modified by a nitrile oxide cannot be obtained.
Here, Japanese Patent Application Publication JP-A-11-180943 discloses a synthetic method of benzonitrile oxide derivatives such as mesitylenedinitrile oxide and mesitylenemononitrile oxide, but discloses no polymer material modified by a benzonitrile oxide derivative.
In addition, Japanese Patent Application Publication JP-A-2008-163232 discloses that by using a compound having a heterocycle such as 4-(2-oxazolyl)-phenyl-N-phenylnitrone and 4-(2-oxazolyl)-phenyl-N-methylnitrone, a diene-based copolymer rubber is kneaded and reacted in cyclohexane, but discloses no polymer material modified by an aromatic nitrile oxide having a substituent at an ortho-position.