A method of producing a polyoxyethylene derivative (1):

##STR00001##

where L1 is a divalent linker, X is a functional group capable of reacting with a physiologically active substance, a is 1 or 2, and n is from 11 to 3,650. The method includes Step (A): protecting 4 or 6 hydroxyl groups in a polyhydric alcohol having 5 or 7 hydroxyl groups by cyclic benzylidene acetalization to obtain a compound having a hydroxyl group at a 1-position and a protective group of a cyclic benzylidene acetal structure; Step (B): polymerizing from 11 to 3,650 moles of ethylene oxide to the compound obtained in the step (A) to obtain a polyoxyethylene derivative; Step (C): converting the hydroxyl group at a terminal of the polyoxyethylene derivative to a functional group capable of reacting with a physiologically active substance; and Step (D): deprotecting the protective group of the polyoxyethylene derivative.

A fluorine-containing ether compound represented by the following formula (1) is provided.

R.sup.2CH.sub.2R.sup.1CH.sub.2OCH.sub.2CH(OH)(CH.sub.2).sub.nCH(OH)CH.sub.2OCH.sub.2R.sup.1CH.sub.2R.sup.2(1)

(in the formula (1), n is an integer of 2 to 6, R.sup.1 is a perfluoropolyether chain, R.sup.2 is OCH.sub.2CH(OH)CH.sub.2O(CH.sub.2).sub.mOH (m in the formula is an integer of 2 to 4)).

The present invention provides a fluorine-containing ether compound represented by the following formula:
R.sup.1R.sup.2CH.sub.2R.sup.3CH.sub.2R.sup.4R.sup.5
(in the formula, R.sup.3 represents a perfluoropolyether chain; R.sup.1 and R.sup.5 each independently represent any of an alkyl group which may have a substituent, an organic group having a double bond or a triple bond, and a hydrogen atom; R.sup.2CH.sub.2R.sup.3 is represented by -[A]-[B]OCH.sub.2R.sup.3; R.sup.3CH.sub.2R.sup.4 is represented by R.sup.3CH.sub.2O[C]-[D]-; [A] is represented by Formula (4), [B] is represented by Formula (5), [C] is represented by Formula (6), and [D] is represented by Formula (7)): ##STR00001##

A branched hetero polyethylene glycol according to the present invention is represented by the formula [1]: ##STR00001##
wherein X and Y represent each an atomic group containing at least a functional group which reacts with a functional group present in a bio-functional molecule to form a covalent bond and the functional group contained in the atomic group X and the functional group contained in the atomic group Y are different from each other; s is an integer of 2 to 8, which represents the number of polyethylene glycol chains; n is the number of average added moles for the polyethylene glycol chain and 20n2000; and E is a branching linker moiety having s-valent bonding valency for the polyethylene glycol chains and having monovalent bonding valency for the functional group Y.

An object to provide a lubricant that makes it possible, in a magnetic disk device in which energy assisted recording technology such as HAMR is employed, to prevent or reduce oxidative decomposition in an oxygen-containing atmosphere and maintain high heat resistance in the oxygen-containing atmosphere is attained by a fluoropolyether compound containing at least one ether bond in a molecule, wherein at least one hydrogen atom bonded to a carbon atom bonded to an oxygen atom of the ether bond in the molecule is substituted with fluorine.

To provide a fluorinated compound capable of obtaining a cured product which is excellent in heat resistance and mold release and has a high Abbe number; a curable composition containing such a compound; and a cured product which is excellent in heat resistance and mold release and has a high Abbe number. The fluorinated compound is represented by the following formula (A):
[ZOCH.sub.2CF.sub.2CF.sub.2CF.sub.2OCFHCF.sub.2X].sub.nQ(A)
where n is an integer of at least 1, Q is a n-valent organic group, X is O, NH or S, and Z is a group having at least one polymerizable functional group.

The present invention relates to (per)fluoropolyether (PFPE) amino derivatives, a method for their manufacturing and their uses.

An ionic lubricant includes a single lubricant compound having a perfluoropolyether main chain, wherein each end of the perfluoropolyether main chain is terminated by an end group, and at least one of the end groups includes an ionic bond and at least one functional group. The ionic perfluoropolyether lubricant has unique characteristics that allows its ultra-thin and uniform distribution over a protective overcoat layer of a magnetic recording medium, while at the same time providing its molecules with strong adhesion power to the protective overcoat layer of the magnetic recording medium compared to existing lubricants, so as to provide shorter magnetic spacing between the magnetic recording medium and the magnetic head, and enable longer operation hours for the magnetic recording medium.

The present disclosure relates to a novel material and composition to perform purification and concentration of biological sample or nucleic acid in single step. The present disclosure also relates to a method to use of the same in two phase system to purify and concentrate the target biological materials and/or nucleic acids with an improved detection accuracy for diagnostics performance.

The invention provides semi-solid systems for delivering biologically active materials that include a polymer comprising 1) one or more polycaprolactone (PCL) units and 2) at least one or more polyethylene glycol (PEG) units; wherein at least one of said polycaprolactone units is conjugated to a PEG forming an acetal group.