High-molecular-weight soluble novolak resin and process for preparation thereof

Claim 2

An organic solvent-soluble, high-molecular-weight novolak resin having an inherent viscosity of at least 0.1, which is obtained by reacting a polyfunctional phenol with an aldehyde, said polyfunctional phenol being at least one member selected from the group consisting of phenol and compounds represented by the formulae: ##STR4## in which R 1 and R 2 independently represent an alkyl group having 1 to 10 carbon atoms, a phenyl group, a halogen atom or a hydroxyl group, and X represents --CH 2 --, --C(CH 3 ) 2 -- or --O--, and at least 30% by mole of the polyfunctional phenol having a functionality of at least 3; and said novolak resin having a solubility in acetone of at least 95% at 25° C.

Claim 3

A radiation-sensitive resist which comprises as the resin component an organic solvent-soluble, high-molecular-weight novolak resin having an inherent viscosity of at least 0.1, wherein said novolak resin is obtained by reacting a polyfunctional phenol with an aldehyde, said polyfunctional phenol being at least one member selected from the group consisting of phenol and compounds represented by the formulae: ##STR5## in which R 1 and R 2 independently represent an alkyl group having 1 to 10 carbon atoms, a phenyl group, a halogen atom or a hydroxyl group, and X represents --CH 2 --, --C(CH 3 ) 2 -- or --O--, and at least 30% by mole of the polyfunctional phenol having a functionality of at least 3; and said novolak resin having a solubility in acetone of at least 95% at 25° C.

Claim 4

A radiation-sensitive resist which comprises as the resin component an organic solvent-soluble, high-molecular-weight novolak resin having an inherent viscosity of at least 0.1, wherein said novolak resin is obtained by reacting a polyfunctional phenol with an aldehyde, said polyfunctional phenol being at least one member selected from the group consisting of phenol and compounds represented by the formulae: ##STR5## in which R 1 and R 2 independently represent an alkyl group having 1 to 10 carbon atoms, a phenyl group, a halogen atom or a hydroxyl group, and X represents --CH 2 --, --C(CH 3 ) 2 -- or --O--, and at least 30% by mole of the polyfunctional phenol having a functionality of at least 3; and said novolak resin having a solubility in acetone of at least 95% at 25° C.

Claim 5

A high-molecular-weight novolak resin according to claim 1, wherein the inherent viscosity is at least 0.15.

Claim 6

A high-molecular-weight novolak resin according to claim 1, wherein the molar ratio of the aldehyde to the polyfunctional phenol is within the range of from 0.85 to 1.20

Claim 7

A high-molecular-weight novolak resin according to claim 1, wherein the polyfunctional phenol comprises at least 50 mole % of a phenol having a functionality of at least 3.

Claim 8

A high-molecular-weight novolak resin according to claim 1, wherein the polyfunctional phenol is at least one member selected from the group consisting of phenol, compounds represented by the formulae ##STR6## in which R 3 and R 4 independently represent an alkyl group having 1 to 3 carbon atoms, and resorcinol.

Claim 9

A high-molecular-weight novolak resin according to claim 6, wherein the polyfunctional phenol is at least one member selected from the group consisting of phenol, o-cresol, m-cresol, p-cresol and 3,5-xylenol.

Claim 10

A high-molecular-weight novolak resin according to claim 1, wherein the aldehyde is at least one member selected from the group consisting of formaldehyde, trioxane, tetraoxane and paraformaldehyde.

Claim 11

A process for the preparation of an organic solvent-soluble, high-molecular-weight novolak resin having an inherent viscosity of at least 0.1, which comprises reacting a polyfunctional phenol with an aldehyde at an aldehyde/polyfunctional phenol molar ratio of from 0.85 to 1.20 in the presence of an acidic catalyst in a solution state, wherein the polyfunctional phenol comprises at least 3 mole % of a phenol having a functional of at least 3.

Claim 12

A process for the preparation of an organic solvent-soluble, high-molecular-weight novolak resin having an inherent viscosity of at least 0.1, which comprises reacting a polyfunctional phenol with an aldehyde at an aldehyde/polyfunctional phenol molar ratio of from 0.85 to 1.20 in the presence of an acidic catalyst in a solution state, wherein the polyfunctional phenol comprises at least 3 mole % of a phenol having a functional of at least 3.

Claim 13

A process for the preparation of a high-molecular-weight novolak resin according to claim 9, wherein the molar ratio of the aldehyde to the polyfunctional phenol is in the range of from 0.90 to 1.15.

Claim 14

A process for the preparation of a high-molecular-weight novolak resin according to claim 9, wherein the polyfunctional phenol is at least one member selected from the group consisting of phenol and compounds represented by the formulae ##STR7## in which R 1 and R 2 independently represent an alkyl group having 1 to 10 carbon atoms, a phenyl group, a halogen atom or a hydroxyl group, and X represents --CH 2 --, --C(CH 3 ) 2 -- or --O--.

Claim 15

A process for the preparation of a high-molecular-weight novolak resin according to claim 9, wherein the polyfunctional phenol comprises at least 50 mole % of a phenol having a functionality of at least 3.

Claim 16

A process for the preparation of a high-molecular-weight novolak resin according to claim 11, wherein the polyfunctional phenol is at least one member selected from the group consisting of phenol, compound represented by the formulae ##STR8## in which R 3 and R 4 independently represent an alkyl group having 1 to 3 carbon atoms, and resorcinol.

Claim 17

A process for the preparation of a high-molecular-weight novolak resin according to claim 12, wherein the polyfunctional phenol is at least one member selected from the group consisting of phenol, o-cresol, m-cresol, p-cresol and 3,5-xylenol.

Claim 18

A process for the preparation of a high-molecular-weight novolak resin according to claim 13 wherein the aldehyde is at least one member selected from the group consisting of formaldehyde, trioxane, tetraoxane and paraformaldehyde.

Claim 19

A process for the preparation of a high-molecular-weight novolak resin according to claim 9, wherein the acidic catalyst is a protonic acid.

Claim 20

A process for the preparation of a high-molecular-weight novolak resin according to claim 1, wherein the reaction is proceeded in the presence of an alcohol or thioalcohol having 2 to 20 carbon atoms in an amount of at least 0.3 mole per mole of the aldehyde.

Claim 21

A process for the preparation of a high-molecular-weight novolak resin according to claim 17, wherein the alcohol is at least one member selected from the group consisting of aliphatic monohydric alcohols, alkyl and aryl ethers of polyhydric alcohols and hydroxycarboxylic acids.

Claim 22

A high-molecular-weight novolak resin according to claim 1, wherein the molar ratio of the aldehyde to the polyfunctional phenol is within the range of from 0.90 to 1.15.

Claim 23

A high-molecular-weight novolak resin according to claim 3, wherein the molar ratio of the aldehyde to the polyfunctional phenol is within the range of from 0.85 to 1.20.

Claim 24

A high-molecular-weight novolak resin according to claim 9, wherein the aldehyde is at least one member selected from the group consisting of formaldehyde, trioxane, tetraoxane and paraformaldehyde.

Claim 25

A high-molecular-weight novolak resin according to claim 3, wherein the molar ratio of the aldehyde to the polyfunctional phenol is within the range of from 0.90 to 1.15.