Cross-linked organosilicon polysulfides

Compounds of the formula

• R4R5R6Si—X3—(—Sy—Y—)m—Sy—X4—SiR7R8R9 (I)
• in which
• X3 and X4 independently of one another are alkylene,
• Y is a divalent, optionally substituted, optionally heteroatom-containing aliphatic, cycloaliphatic or aromatic group,
• y is an integer from 1 to 6,
• m is an integer from 0 to 20 and
• R4, R5, R6, R7, R8 and R9 independently of one another are —OH, —Ometal, alkyl, alkoxy, phenyl or phenoxy and
• at least one of the substituents R4, R5, R6, R7, R8 and R9 is a radical of the formula
• —O—R5R6Si—X3′—(—Sy—Y—)m—Sy—X4—SiR7R8R9 (Ia)
• where the substituents and indices in the formula (Ia) have the definition stated above for formula (I),
• metal is a metal ion from the series of the alkali metals and alkaline earth metals,
• and optionally the radicals of the formula (Ia) are joined via one or more —Si—O—Si— units to further radicals of the formula (Ia).