Abstract: A cross-linked polymer including a structure wherein at least a portion of phenolic hydroxyl groups in the polymer is protected by a group represented by the following formula (1): wherein R1 represents an alkyl group having 1 to 5 carbons and n represents an integer from 1 to 5; and * represents a bond part of the phenolic hydroxyl group to a residue other than a hydrogen atom, and a structure wherein at least a portion of phenolic hydroxyl groups in the polymer is protected by a group represented by the following formula (2): wherein R2 represents a divalent saturated hydrocarbon group having 2 to 17 carbons, containing an aromatic ring; and * represents a bond part of the phenolic hydroxyl group to a residue other than a hydrogen atom, and the polymers are cross-linked to each other.

Abstract: The present invention provides: an acetal compound represented by the following general formula (1): wherein R1 represents an alkyl group having from 1 to 12 carbon atoms, a cycloalkyl group having from 5 to 12 carbon atoms or an acyl group having from 1 to 12 carbon atoms; n represents an integer from 1 to 5; m represents an integer from 2 to 4; and Ar represents a residue obtained by removing a hydrogen atom(s) from the hydroxyl groups of a polyhydric phenol having a valence of m; and a resist composition for forming a thick resist film, including the same.

Abstract: [Problem to be Solved] To Provide a method for producing an acid-decomposable polymer having a reduced metal ion content, which suppresses decomposition and deprotection of the acid-decomposable polymer. [Means to Solve the Problem] The method for producing an acid-decomposable polymer according to the present invention comprises the steps of: preparing a polymer solution comprising an acid-decomposable polymer; washing an acidic cation exchanger with an organic solvent until the water content in the organic solvent discharged from the acidic cation exchanger falls to 400 ppm or less; and passing the polymer solution through the washed acidic cation exchanger to reduce the metal ion content of the polymer.

Abstract: The present invention provides a polymer comprising a structural unit derived from p-hydroxystyrene and a structural unit having a structure in which a carboxylic acid is protected by an acetal group, wherein the structural unit generated by elimination of the acetal group or migration of the acetal group during the production process is extremely small; and a process for producing the same. A solution containing a polymer comprising a structural unit derived from p-acetoxystyrene and a structural unit having a structure in which a carboxylic acid is protected by an acetal group is subjected to deprotection reaction at 50° C. or lower in the presence of a base in which a pKa of a conjugated acid is 12 or more.

Abstract: A cross-linked polymer including a structure wherein at least a portion of phenolic hydroxyl groups in the polymer is protected by a group represented by the following formula (1): wherein R1 represents an alkyl group having 1 to 5 carbons and n represents an integer from 1 to 5; and * represents a bond part of the phenolic hydroxyl group to a residue other than a hydrogen atom, and a structure wherein at least a portion of phenolic hydroxyl groups in the polymer is protected by a group represented by the following formula (2): wherein R2 represents a divalent saturated hydrocarbon group having 2 to 17 carbons, containing an aromatic ring; and * represents a bond part of the phenolic hydroxyl group to a residue other than a hydrogen atom, and the polymers are cross-linked to each other.

Abstract: [Problem to be Solved] To Provide a method for producing an acid-decomposable polymer having a reduced metal ion content, which suppresses decomposition and deprotection of the acid-decomposable polymer. [Means to Solve the Problem] The method for producing an acid-decomposable polymer according to the present invention comprises the steps of: preparing a polymer solution comprising an acid-decomposable polymer; washing an acidic cation exchanger with an organic solvent until the water content in the organic solvent discharged from the acidic cation exchanger falls to 400 ppm or less; and passing the polymer solution through the washed acidic cation exchanger to reduce the metal ion content of the polymer.

Abstract: Provided is a method for producing a polymer for an electronic material having a low content of metal ion impurities and a polymer for an electronic material obtained by such method. The method for producing a polymer for an electronic material according to the present invention comprises a polymerization step of obtaining a polymer by polymerizing a monomer(s) and a purification step of adding a strong acid having 0 or less pKa to the polymer solution and subsequently performing an ion exchange treatment to reduce the concentration of the metal ion impurities.

Abstract: Provided is a method for producing a polymer for an electronic material having a low content of metal ion impurities and a polymer for an electronic material obtained by such method. The method for producing a polymer for an electronic material according to the present invention comprises a polymerization step of obtaining a polymer by polymerizing a monomer(s) and a purification step of adding a strong acid having 0 or less pKa to the polymer solution and subsequently performing an ion exchange treatment to reduce the concentration of the metal ion impurities.

Abstract: A method of producing a homopolymer or random copolymer of hydroxyl group-containing vinyl ether by polymerizing a monomer component comprising at least one hydroxyl group-containing vinyl ether using an oil-soluble radical polymerization initiator in the absence or presence of a solvent.

Abstract: [Object] To provide a method of producing a homopolymer or random copolymer of hydroxyl group-containing vinyl ether simply and conveniently as well as efficiently. [Means for solving problem] A method of producing a homopolymer or random copolymer of hydroxyl group-containing vinyl ether according to the present invention comprises the step of polymerizing a monomer component comprising at least one hydroxyl group-containing vinyl ether using an oil-soluble radical polymerization initiator in the absence or presence of a solvent.