Heat resistant, low dielectric polymers, and films, substrates, electronic parts and heat resistant resin molded parts using the same

A heat-resistant, low-dielectric polymeric resin composition, comprising:

• at least one resin having a weight-average absolute molecular weight of at least 1,000 and comprising a copolymer in which a non-polar α-olefin base polymer segment and/or a non-polar conjugated diene base polymer segment are chemically combined with a vinyl aromatic polymer segment, said copolymer having a multi-phase structure wherein a dispersion phase formed by one segment of said copolymer is finely dispersed in a continuous phase formed by another segment of said copolymer;
• wherein the dispersion phase is in the form of particles ranging from 0.01 to 10 μm in size;
• wherein the sum of the total number of carbon atoms and hydrogen atoms in said composition is at least 99% based on the total number of atoms in said composition;
• wherein said composition has an effective amount of chemical bonds between resin molecules to render the composition insoluble or swellable in xylene;
• and
• wherein said chemical bonds are bonds obtained by crosslinking alone, or are a combination of bonds obtained by crosslinking and at least one bond obtained by block polymerization or graft polymerization.