content_image/914015.jpg content_image/914016.jpg content_image/914018.jpg content_image/914017.jpg
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Examples of the monomer Mb2 are given below, but not limited thereto. Herein RA and RB are as defined above. 

<img src='content_image/914016.jpg'>

-continued 

<img src='content_image/914018.jpg'>

The acid labile groups represented by R 3 and R 4 may be selected from a variety of such groups. The acid labile groups may be the same or different and preferably include groups of the following formulae (A-1) to (A-3). 

<img src='content_image/914017.jpg'>

-continued 

