The present invention provides a method for manufacturing a highly pure
2,6-dimethylnaphthalene having a purity of 99% or more even when a mixture
of dimethylnaphthalene isomers containing 5 wt % or more of
2,7-dimethylnaphthalate is used as a feedstock. The method for
manufacturing 2,6-dimethylnaphthalene comprises a step of performing
crystallization and solid-liquid separation of a liquid primarily
containing dimethylnaphthalene isomers so that the liquid is separated
into a cake containing the dimethylnaphthalene isomers and a mother
liquor, and a step of performing separation/purification of the cake. In
the method described above, the crystallization and the solid-liquid
separation are performed under the condition in which the ratio of the
content of 2,6-dimethylnaphthalene in the mother liquor to that of
2,7-dimethylnaphthalene therein is not less than 1 so that the content of
2,6-dimethylnaphthalene in the cake is 60% or more and that the content of
2,7-dimethylnaphthalene therein is 6.5% or less. As a result, a highly
pure 2,6-dimethylnaphthalene is obtained by performing the
separation/purification of the cake.
A invenção atual fornece um método manufaturando um 2,6-dimethylnaphthalene altamente puro que tem um purity de 99% ou mais uniformes quando uma mistura dos isomers do dimethylnaphthalene que contêm 5 pesos % ou mais de 2,7-dimethylnaphthalate é usada como um feedstock. O método para manufaturar 2,6-dimethylnaphthalene compreende uma etapa de executar a cristalização e a separação do solid-liquid de um líquido que contem primeiramente isomers do dimethylnaphthalene de modo que o líquido seja separado em um bolo que contem os isomers do dimethylnaphthalene e um licor de mãe, e uma etapa de separation/purification executando do bolo. No método descrito acima, a cristalização e a separação do solid-liquid é executada sob a circunstância em que a relação do índice de 2,6-dimethylnaphthalene no licor de mãe àquela de 2,7-dimethylnaphthalene não é nisso menos de 1 de modo que o índice de 2,6-dimethylnaphthalene no bolo seja 60% ou mais e aquele o índice de 2,7-dimethylnaphthalene seja nisso 6.5% ou menos. Em conseqüência, um 2,6-dimethylnaphthalene altamente puro é obtido executando o separation/purification do bolo.
