content_image/885446.jpg content_image/885444.jpg content_image/885445.jpg content_image/885434.jpg content_image/885433.jpg content_image/885432.jpg content_image/885431.jpg content_image/885430.jpg content_image/885429.jpg
(pl) to (pV). Structures resulting from replacement of a hydrogen atom of a carboxylic acid group or sulfonic acid group with any of the structures of the general formulae (pl) to (p V) are preferred. 

As preferred repeating units having any of the alkali- soluble groups protected by the structures of the general formulae (pl) to (p V), there can be mentioned those of general formula (pA) below. 

<img src='content_image/885446.jpg'>

A represents any one or a combination of two or more groups selected from the group consisting of a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amido group, a sulfonamido group, a urethane group and a urea group. A single bond is preferred. 

Ppl represents any of the groups of the above general formulae (pl) to (p V). 

The repeating units of the general formula (pA) are most preferably those derived from a 2-alkyl-2-adamantyl(meth) acrylate and a dialkyl(l-adamantyl)methyl(meth)acrylate. 

Specific examples of the repeating units of the general formula (pA) will be shown below. 

<img src='content_image/885444.jpg'>

<img src='content_image/885445.jpg'>

<img src='content_image/885434.jpg'>

<img src='content_image/885433.jpg'>

<img src='content_image/885432.jpg'>

<img src='content_image/885431.jpg'>

<img src='content_image/885430.jpg'>

<img src='content_image/885429.jpg'>

