Acetal group-containing alkoxy-styrene polymers, method of preparing the same and chemical amplified photoresist composition mainly comprising the same

A method for preparing alkoxy-styrene polymers represented by the following formula I ##STR15## wherein R.sub.1 and R.sub.3 may the same or different, and represent a hydrogen atom or a methyl group;

• R.sub.2 represents ##STR16## wherein R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 may be the same or different, and independently represent a hydrogen atom, an alkyl group or an aryl group;
• m+n=1;
• k is an integer of 1-5;
• and l is an integer 0-5,
• comprising the polymerization of acetal group-containing alkoxy-styrene represented by the following formula II:
• ##STR17## wherein R.sub.1, R.sub.2, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are as defined above, in the presence of a polymerization initiator.

A method for preparing alkoxy-styrene polymers represented by the following formula I ##STR18## wherein R.sub.1 and R.sub.3 may the same or different, and represent a hydrogen atom or a methylene group;

• R.sub.2 represents ##STR19## wherein R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 may be the same or different, and independently represent a hydrogen atom, an alkyl group or an aryl group;
• m+n=1;
• k is an integer of 1-5;
• and l is an integer of 0-5,
• comprising substituting an active hydrogen of the hydroxy group in the polyvinyl phenol represented by the following general formula III:
• ##STR20## wherein R is a hydrogen atom or a methylene group, with acetal group-containing halide represented by the following general formula IV, V or VI:
• ##STR21## wherein X is C.sub.1 or Br;
• and R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, k and l are as hereinbefore defined.