The rubber composition comprises at least one resin based: (A1) on at least one aromatic compound comprising at least one aromatic ring bearing at least two functional groups, one of these functional groups being a hydroxymethyl functional group and the other being an aldehyde functional group or a hydroxymethyl functional group; and (A2) on at least one phenolic compound chosen from (A21) at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functional groups in the meta position with respect to one another, the two positions ortho to at least one of the hydroxyl functional groups being unsubstituted; and/or (A22) at least one aromatic monophenol comprising at least one six-membered aromatic ring bearing a single hydroxyl functional group, the two positions ortho to the hydroxyl functional group being unsubstituted or at least one position ortho to and the position para to the hydroxyl functional group being unsubstituted; and their mixtures.

The rubber composition comprises at least one resin based: (A1) on at least one aromatic compound comprising at least one aromatic ring bearing at least two functional groups, one of these functional groups being a hydroxymethyl functional group and the other being an aldehyde functional group or a hydroxymethyl functional group; and (A2) on at least one phenolic compound chosen from (A21) at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functional groups in the meta position with respect to one another, the two positions ortho to at least one of the hydroxyl functional groups being unsubstituted; and/or (A22) at least one aromatic monophenol comprising at least one six-membered aromatic ring bearing a single hydroxyl functional group, the two positions ortho to the hydroxyl functional group being unsubstituted or at least one position ortho to and the position para to the hydroxyl functional group being unsubstituted; and their mixtures.

The 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,

R represents —H or —CHO.

The 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,

R represents —H or —CHO.

The 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,

R represents —H or —CHO.

A run flat tire having improved run flat durability is provided. The run flat tire has a side wall part reinforced by a side reinforcing rubber part, and the side reinforcing rubber part is formed by a rubber composition which comprises 100 parts by mass of a diene rubber containing natural rubber and polybutadiene rubber, and from 0.1 to 4.0 parts by mass of a mercaptobenzimidazole compound.

A run flat tire having improved run flat durability is provided. The run flat tire has a side wall part reinforced by a side reinforcing rubber part, and the side reinforcing rubber part is formed by a rubber composition which comprises 100 parts by mass of a diene rubber containing natural rubber and polybutadiene rubber, and from 0.1 to 4.0 parts by mass of a mercaptobenzimidazole compound.

A run flat tire having improved run flat durability is provided. The run flat tire has a side wall part reinforced by a side reinforcing rubber part, and the side reinforcing rubber part is formed by a rubber composition which comprises 100 parts by mass of a diene rubber containing natural rubber and polybutadiene rubber, and from 0.1 to 4.0 parts by mass of a mercaptobenzimidazole compound.

A method of forming a pattern, the method comprising: applying a photoresist underlayer composition over a substrate to provide a photoresist underlayer; forming a photoresist layer over the photoresist underlayer; patterning the photoresist layer; and transferring a pattern from the patterned photoresist layer to the photoresist underlayer. The photoresist underlayer composition includes a polymer that includes a repeating unit represented by Formula 1 as described herein, a compound including a substituent group represented by Formula 2 as described herein, and a solvent.

##STR00001##

A method of forming a pattern, the method comprising: applying a photoresist underlayer composition over a substrate to provide a photoresist underlayer; forming a photoresist layer over the photoresist underlayer; patterning the photoresist layer; and transferring a pattern from the patterned photoresist layer to the photoresist underlayer. The photoresist underlayer composition includes a polymer that includes a repeating unit represented by Formula 1 as described herein, a compound including a substituent group represented by Formula 2 as described herein, and a solvent.

##STR00001##