Patent ID: 7009033

Claim:
A heterofunctional polyethylene glycol or polyethylene oxide, and salts thereof, and wherein the polyethylene glycol or polyethylene oxide is represented by one of the formulas I to IV defined as follows: wherein: m is an integer from 5 to 10,000; n is an integer from 1 to 20; each A is independently an alkyl, a substituted alkyl group or a hydrogen atom, and wherein for formulas (I), (III) and (IV), each R is independently an organic substituent, and optionally comprises at least one heteroatom, and wherein for formula (II), R represents one of the following groups: COOX, wherein X represents a substituted alkyl group when A is independently an alkyl, a substituted alkyl or a hydrogen, or wherein X represents an alkyl group when at least one A is an alkyl or substituted alkyl; COOSi(A) 3 , wherein each A independently represents an alkyl, a substituted alkyl group or a hydrogen atom; BCOONL, wherein B and L independently represent an alkyl, a substituted alkyl group or a hydrogen atom; an alkyl or a substituted alkyl group; COHal, wherein Hal is a halogen atom; CONYZ, wherein each of Y and Z independently represents an alkyl group or a substituted alkyl group or a hydrogen atom; NX″Y″, wherein each of X″ and Y″ independently represents an alkyl, a substituted alkyl group or a hydrogen atom; (CH 2 )pCOOH, wherein p=4–10 (CH 2 ) 2 COOH or COOH when at least one A is an alkyl or substituted alkyl with the proviso that in formula (I), when each A represents a hydrogen atom, n is an integer from 3 to 20.