PTC composition, method of making the same, and thermistor body obtained therefrom
AssigneeTDK Corporation
InventorsHisanao Tosaka, Yasuhide Yamashita, Tokuhiko Handa, Katsumi Kobayashi
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Abstract
In a first aspect of the present invention, a PTC composition contains (a) a crosslinked polymer matrix having a gel fraction of at least 10%, and (b) an electrically conductive substance. An article shaped therefrom yields an electric resistance of at least 50 mΩ at 25° C. after being placed in an environment repeating 200 times of a temperature change between −40° C. and +85° C., and exhibits no thermal deformation when placed on a hot plate at 200° C. for 5 minutes.
Claims10
A method of making a PTC composition, said method comprising:
- a first step of preparing a mixture by mixing, at least, a polymer matrix and an electrically conductive substance;
- a second step of yielding an article by shaping said mixture;
- and
- a third step of irradiating said article by a dose of 40 to 300 kGy with an electron beam having an acceleration voltage of at least 250 kV.
A method of making a PTC composition, said method comprising:
- a first step of preparing a mixture by mixing, at least, a polymer matrix and an electrically conductive substance;
- a second step of yielding an article by shaping said mixture;
- and
- a third step of setting a dose of an electron beam dose within the range of 40 to 300 kGy, setting an acceleration voltage of said electron beam such that said dose and said acceleration voltage yield a product of 80,000 to 600,000 kGy kV, and irradiating said article with said electron beam.
Dependencies are inferred from the claim text.