Silicon-containing soluble polyimide precursor, its cured material, and method for preparing them

Claim 1

A silicon-containing soluble polyimide precursor which comprises a component represented by the following formula I and which has a logarithmic viscosity number of 0.05 to 5 dl/g when measured at a concentration of 0.5 g/dl at 30±0.01° C. in a solvent: [R.sup.4.sub.3-k SiR.sup.3 --L--(R.sup.2 --L).sub.n --R.sup.3 --SiR.sup.4.sub.3-m O.sub.(k+m)/2 ]p[SiO.sub.2 ]q (I) wherein L is a structural unit of any of the following formula (II), (III) and (IV); R 2 is an aliphatic group having 2 to 12 carbon atoms, an alicyclic group having 4 to 30 carbon atoms, an aromatic aliphatic group having 6 to 30 carbon atoms, a carbon cyclic aromatic group having 6 to 30 carbon atoms including a group represented by the formula ##STR19## wherein r is 0 or 1, A polysiloxane group represented by the following formula (V) or a group represented by the following formula (V'); R 3 is ##STR20## wherein s is an integer of 1 to 4; and R 4 is independently an alkyl group having 1 to 6 carbon atoms, a phenyl group or an alkyl-substituted phenyl group having 7 to 12 carbon atoms; k is an integer of 0≦k≦3; m is 0≦m≦3, k+m≦1; n is an integer of at least 1; and each of p and q is a positive integer; ##STR21## wherein R 1 is a tetravalent carbon cyclic aromatic group, and two carbonyl groups constituting one imide in the formulae (II) and (III) are mutually attached to ortho positions, and one carboamide group and one carboxyl group in the formulae (III) and (IV) are mutually attached to ortho-positions: ##STR22## wherein R 5 is independently ##STR23## wherein s is an integer of 1 to 4, and R 6 is independently an alkyl group having 1 to 6 carbon atoms, a phenyl group or an alkyl-substituted phenyl group having 7 to 12 carbon atoms, l is a value of 1≦l≦100; ##STR24## R 7 is an aliphatic group having 8 or less carbon atoms, an aromatic aliphatic group or hydrogen; said logarithmic viscosity number being ηinh which can be represented by the following formula: .sub.ηinh =ln(η/η.sub.o)/C wherein η is the viscosity measured at 3±0.01° C. at a concentration of 0.5 g/dl in a solvent by the use of a Ubbelode's viscometer, η is the viscosity of the solvent at the same temperature by the use of the same viscometer, and C is a concentration of 0.5 g/dl.

Claim 11

A method for preparing a silicon-containing soluble polyimide precursor which comprises a component represented by the following general formula (I) and which has a logarithmic viscosity number of 0.05 to 5 dl/g, said method comprising the steps of first mutually mixing the following five compounds, (a) a mole of an acid anhydride represented by the following general formula (VI) or its diester, (b) b mole of a compound represented by the general formula (VII), (c) c mole of compounds having the general formula (VIII) and (VIII'), and (d) d mole of a compound having the general formula (IX) in ratios in the range of the following formulae (X) and (XI) in the presence of 70% by weight or more of a solvent; carrying out reaction at a temperature of 0° to 200° C. for 0.2 to 20 hours; or alternatively mixing the former four compounds having the general formula (VI) to (VIII') in any order; carrying out further reaction at a temperature of 20° to 200° C. for a period of 0.2 to 10 hours; then adding the fifth compound (e) having the general formula (IX) thereto; and carrying out reaction at 50° to 200° C. for 0.2 to 30 hours: ##STR34## wherein L is a structural unit of any of the following formula (II), (III) and (IV); R 2 is an aliphatic group having 2 to 12 carbon atoms, an alicyclic group having 4 to 30 carbon atoms, an aromatic aliphatic group having 6 to 30 carbon atoms, a carbon cyclic aromatic group having 6 to 30 carbon atoms including a group represented by the formula ##STR35## wherein r is 0 to 1, a polysiloxane group represented by the following formula (V) or a group represented by the following formula ##STR36## wherein s is an integer of 1 to 4; and R 4 is independently an alkyl group having 1 to 6 carbon atoms, a phenyl group or an alkyl-substituted phenyl group having 7 to 12 carbon atoms; k is an integer of 0≦k≦3, m is 0≦m≦3, k+m≧1, n is an integer of 1 or more, and each of p and q is a positive integer; ##STR37## wherein R 1 is a tetravalent carbon cyclic aromatic group, and two carbonyl groups constituting one imide in the formulae (II) and (III) are mutually attached to ortho positions, and one carboamide group and one carboxyl group in the formulae (III) and (IV) are mutually attached to ortho positions; ##STR38## wherein R 5 is independently ##STR39## wherein s is an integer of 1 to 4, and R 6 is independently an alkyl group having 1 to 6 carbon atoms, a phenyl group or an alkyl-substituted phenyl group having 7 to 12 carbon atoms, l is a value of 1≦l≦100; ##STR40## wherein R 7 is an aliphatic group having 8 or less carbon atoms, an aromatic aliphatic group or hydrogen; X 1 and X 2 are independently an alkoxy group, an acetoxy group, a halogen or a hydroxyl group; said logarithmic viscosity number being ηinh which can be represented by the following formula: η.sub.inh =ln(η/η.sub.o)/C wherein η is a viscosity measured at 30°±0.01° C. at a concentration of 0.5 g/dl in a solvent by the use of a Ubbelohde's viscometer, η o is a viscosity of the solvent at the same temperature by the use of the same viscometer, and C is a concentration of 0.5 g/dl.

Claim 12

A method for preparing a silicon-containing soluble polyimide precursor which comprises a component represented by the following general formula (I) and which has a logarithmic viscosity number of 0.05 to 5 dl/g, said method comprising the steps of first mutually mixing the following five compounds, (a) a mole of an acid anhydride represented by the following general formula (VI) or its diester, (b) b mole of a compound represented by the general formula (VII), (c) c mole of compounds having the general formula (VIII) and (VIII'), and (d) d mole of a compound having the general formula (IX) in ratios in the range of the following formulae (X) and (XI) in the presence of 70% by weight or more of a solvent; carrying out reaction at a temperature of 0° to 200° C. for 0.2 to 20 hours; or alternatively mixing the former four compounds having the general formula (VI) to (VIII') in any order; carrying out further reaction at a temperature of 20° to 200° C. for a period of 0.2 to 10 hours; then adding the fifth compound (e) having the general formula (IX) thereto; and carrying out reaction at 50° to 200° C. for 0.2 to 30 hours: ##STR34## wherein L is a structural unit of any of the following formula (II), (III) and (IV); R 2 is an aliphatic group having 2 to 12 carbon atoms, an alicyclic group having 4 to 30 carbon atoms, an aromatic aliphatic group having 6 to 30 carbon atoms, a carbon cyclic aromatic group having 6 to 30 carbon atoms including a group represented by the formula ##STR35## wherein r is 0 to 1, a polysiloxane group represented by the following formula (V) or a group represented by the following formula ##STR36## wherein s is an integer of 1 to 4; and R 4 is independently an alkyl group having 1 to 6 carbon atoms, a phenyl group or an alkyl-substituted phenyl group having 7 to 12 carbon atoms; k is an integer of 0≦k≦3, m is 0≦m≦3, k+m≧1, n is an integer of 1 or more, and each of p and q is a positive integer; ##STR37## wherein R 1 is a tetravalent carbon cyclic aromatic group, and two carbonyl groups constituting one imide in the formulae (II) and (III) are mutually attached to ortho positions, and one carboamide group and one carboxyl group in the formulae (III) and (IV) are mutually attached to ortho positions; ##STR38## wherein R 5 is independently ##STR39## wherein s is an integer of 1 to 4, and R 6 is independently an alkyl group having 1 to 6 carbon atoms, a phenyl group or an alkyl-substituted phenyl group having 7 to 12 carbon atoms, l is a value of 1≦l≦100; ##STR40## wherein R 7 is an aliphatic group having 8 or less carbon atoms, an aromatic aliphatic group or hydrogen; X 1 and X 2 are independently an alkoxy group, an acetoxy group, a halogen or a hydroxyl group; said logarithmic viscosity number being ηinh which can be represented by the following formula: η.sub.inh =ln(η/η.sub.o)/C wherein η is a viscosity measured at 30°±0.01° C. at a concentration of 0.5 g/dl in a solvent by the use of a Ubbelohde's viscometer, η o is a viscosity of the solvent at the same temperature by the use of the same viscometer, and C is a concentration of 0.5 g/dl.