The present invention provides a resist base material containing a compound having a specific structure and/or a resin derived from the compound as a monomer.

A rubber composition comprises at least one phenol/aldehyde resin based on at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functions in the meta position relative to one another, the two positions ortho to at least one of the hydroxyl functions being unsubstituted, and at least one aldehyde of formula (A): ##STR00001##
in which X comprises N, S or O, and R represents H or CHO.

A rubber composition comprises at least one phenol/aldehyde resin based on at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functions in the meta position relative to one another, the two positions ortho to at least one of the hydroxyl functions being unsubstituted, and at least one aldehyde of formula (A): ##STR00001##
in which X comprises N, S or O, and R represents H or CHO.

An aromatic polyphenol derivative comprising at least one aromatic ring bearing at least two OZ groups in the meta position relative to one another, the two positions ortho to at least one of the OZ groups being unsubstituted, is used for the manufacture of a phenol-aldehyde resin for reinforcing a rubber composition. Each OZ group represents an OSi(R.sub.1R.sub.2R.sub.3) group with R.sub.1, R.sub.2, R.sub.3 representing, independently of one another, a hydrocarbon-based radical or a substituted hydrocarbon-based radical.

An aromatic polyphenol derivative comprising at least one aromatic ring bearing at least two OZ groups in the meta position relative to one another, the two positions ortho to at least one of the OZ groups being unsubstituted, is used for the manufacture of a phenol-aldehyde resin for reinforcing a rubber composition. Each OZ group represents an OSi(R.sub.1R.sub.2R.sub.3) group with R.sub.1, R.sub.2, R.sub.3 representing, independently of one another, a hydrocarbon-based radical or a substituted hydrocarbon-based radical.

There is provided a novel resist underlayer film forming composition comprising a polymer having a repeating structural unit of formula (1a) and/or (1b): ##STR00001##
[wherein two R.sup.1s are each independently a C.sub.1-10 alkyl group, a C.sub.2-6 alkenyl group, an aromatic hydrocarbon group, a halogen atom, a nitro group, or an amino group, two R.sup.2s are each independently a hydrogen atom, a C.sub.1-10 alkyl group, a C.sub.2-6 alkenyl group, an acetal group, an acyl group, or a glycidyl group, R.sup.3 is an aromatic hydrocarbon group optionally having a substituent or a heterocyclic group, R.sup.4 is a hydrogen atom, a phenyl group, or a naphthyl group, two ks are each independently 0 or 1, m is an integer of 3 to 500, p is an integer of 3 to 500, X is a benzene ring, and two C(CH.sub.3).sub.2 groups bonded to the benzene ring are in a meta position or a para position], and a solvent.

There is provided a novel resist underlayer film forming composition comprising a polymer having a repeating structural unit of formula (1a) and/or (1b): ##STR00001##
[wherein two R.sup.1s are each independently a C.sub.1-10 alkyl group, a C.sub.2-6 alkenyl group, an aromatic hydrocarbon group, a halogen atom, a nitro group, or an amino group, two R.sup.2s are each independently a hydrogen atom, a C.sub.1-10 alkyl group, a C.sub.2-6 alkenyl group, an acetal group, an acyl group, or a glycidyl group, R.sup.3 is an aromatic hydrocarbon group optionally having a substituent or a heterocyclic group, R.sup.4 is a hydrogen atom, a phenyl group, or a naphthyl group, two ks are each independently 0 or 1, m is an integer of 3 to 500, p is an integer of 3 to 500, X is a benzene ring, and two C(CH.sub.3).sub.2 groups bonded to the benzene ring are in a meta position or a para position], and a solvent.

A rubber composition comprises at least one phenol/aldehyde resin based on at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functions in the meta position relative to one another, the two positions ortho to at least one of the hydroxyl functions being unsubstituted, and at least one aromatic polyaldehyde selected from 1,3-benzenedicarboxaldehyde, 1,4-benzenedicarboxaldehyde and mixtures of these compounds, the rubber composition having a nominal secant modulus at 10% elongation, measured according to standard ASTM D 412, 1998, of greater than or equal to 25 MPa.

A rubber composition comprises at least one phenol/aldehyde resin based on at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functions in the meta position relative to one another, the two positions ortho to at least one of the hydroxyl functions being unsubstituted, and at least one aromatic polyaldehyde selected from 1,3-benzenedicarboxaldehyde, 1,4-benzenedicarboxaldehyde and mixtures of these compounds, the rubber composition having a nominal secant modulus at 10% elongation, measured according to standard ASTM D 412, 1998, of greater than or equal to 25 MPa.

A rubber composition comprises at least one phenol/aldehyde resin based on at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functions in the meta position relative to one another, the two positions ortho to at least one of the hydroxyl functions being unsubstituted, and at least one aromatic polyaldehyde selected from 1,3-benzenedicarboxaldehyde, 1,4-benzenedicarboxaldehyde and mixtures of these compounds.