content_image/886637.jpg content_image/886638.jpg
n represents an integer of 1 to 5. n is preferably an integer of2 to 4. 

Specific examples of the repeating unit containing a fluo› rine atom or a silicon atom are illustrated below. In specific examples, X, represents a hydrogen atom, -CH$_{3}$ , -F or -CF$_{3}$ , andX$_{2 }$ represents -F or----CF$_{3}$ . 

<img src='content_image/886637.jpg'>

<img src='content_image/886638.jpg'>

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