Process for producing high molecular weight thermoplastic resin composition and its use

A process for producing a high molecular weight thermoplastic resin composition, which comprises the step of mixing a thermoplastic resin with pyromellitic dianhydride to carry out a reaction therebetween to convert the thermoplastic resin into a high molecular weight one, wherein the thermoplastic resin has a functional group reactable with pyromellitic dianhydride;

• with the process being characterized in that the pyromellitic dianhydride has intrinsically linear or needle-like particle forms, wherein the pyromellitic dianhydride exhibits a half band width (half value) of a diffraction peak, corresponding to a (1, 1, 2) plane, in the range of 0.1˜0.17 when analyzed by powder X-ray diffraction spectroscopy (XRD).

A process for producing a high molecular weight thermoplastic resin composition, which comprises the step of mixing a thermoplastic resin with pyromellitic dianhydride to carry out a reaction therebetween to convert the thermoplastic resin into a high molecular weight one, wherein the thermoplastic resin has a functional group reactable with pyromellitic dianhydride;

• with the process being characterized in that the pyromellitic dianhydride has intrinsically linear or needle-like particle forms, wherein the pyromellitic dianhydride exhibits a beginning temperature of not higher than 275° C. of an endothermic peak as assigned to its crystal melting when heat scanned at a rate of 50° C./minute under nitrogen atmosphere with a differential scanning calorimeter.

A process for producing a high molecular weight thermoplastic resin composition, which comprises the step of mixing a thermoplastic resin with pyromellitic dianhydride to carry out a reaction therebetween to convert the thermoplastic resin into a high molecular weight one, wherein the thermoplastic resin has a functional group reactable with pyromellitic dianhydride;

• with the process being characterized in that the pyromellitic dianhydride has intrinsically linear or needle-like particle forms which are characterized by exhibiting a bulk density of 0.4˜0.9 g/ml and exhibits a beginning temperature of not higher then 275° C. of an endothermic peak as assigned to its crystal melting when heat-scanned at a rate of 50° C./minute under nitrogen atmosphere with a differential scanning calorimeter.

A process for producing a high molecular weight thermoplastic resin composition, which comprises the step of mixing a thermoplastic resin with pyromellitic dianhydride to carry out a reaction therebetween to convert the thermoplastic resin into a high molecular weight one, wherein the thermoplastic resin has a functional group reactable with pyromellitic dianhydride;

• with the process being characterized in that the pyromellitic dianhydride has particle forms which are characterized by exhibiting a rest angle of 50˜70 degrees.