Silicone resins are high-molecular, three-dimensionally crosslinked compounds that are based – like quartz – on a silicon/oxygen skeleton. Unlike quartz, however, every fourth oxygen atom of a silicone resin is replaced by an organic group R. It can therefore be described as an organically modified quartz structure. All silicone resins consist of 30 to 80 trifunctional silicon-T units with molecular weights of 2,000 to 5,000 – which is very low compared to organic resins. They also contain 2 to 4 wt. percent of residual alcohol. Chemically speaking, silicone resins form an intermediate class between purely inorganic and purely organic substances.

Silicone resins are formed by polycondensation of silanes. During this reaction, viscous and solid polymeric siloxanes (referred to as liquid and solid resins) are formed, which are soluble in organic solvents. These silicone resins – almost exclusively methyl silicone resins – are used as binders in silicone resin paints and silicone resin plasters.

Methyl silicone resins dry from organic solution or emulsion to form a non-tacky film, which is already fully water-repellent. In a process referred to as chemisorption, the remaining alcohol groups undergo a condensation reaction with available substrate groups (usually OH−), forming silanol; the alcohol groups also react with one another, thus further crosslinking the silicone resin into a silicone resin network .