Poly α-amino acid and ferroelectric memory element using same

摘要

Ferroelectric memory elements which contain a poly α-amino acid which is a copolymer containing a glutamic acid-γ-ester unit represented by the formula (I), defined herein, and a glutamic acid-γ-ester unit represented by the formula (II), defined herein, in a molar ratio of units of formula (I) to units of formula (II) of 10/90-90/10 are useful as recording elements such as RFID and the like.

主权项

1. A ferroelectric memory element, comprising a ferroelectric layer, wherein said ferroelectric layer comprises a poly α-amino acid which is a copolymer comprising:
(i) a glutamic acid-γ-ester unit represented by formula (I): wherein R1 is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, or a benzyl group optionally substituted by a halogen atom, an alkoxy group or a nitro group; and either (iia) a glutamic acid-γ-ester unit represented by formula (II): wherein R2 is an unsubstituted alkyl group having 3 to 16 carbon atoms, or an alkyl group having 1 to 6 carbon wherein a part or all of the hydrogen atoms are substituted by a halogen atom, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, a phenyl group in which a part or all of the hydrogen atoms are optionally substituted by a halogen atom or an alkoxy group, a phenyl alkoxy group in which a part or all of the hydrogen atoms are optionally substituted by a halogen atom or an alkoxy group, or a phenylalkyl carbamate group in which a part or all of the hydrogen atoms are optionally substituted by a halogen atom or an alkoxy group, provided that R2 is not the same as R1; or (iib) an alanine, phenylalanine or N-substituted lysine unit represented by formula (III): wherein R3 is a methyl group, a benzyl group or a —(CH2)4—NHX group (wherein X is a benzyloxycarbonyl group optionally substituted by a halogen atom or an alkoxy group, an alkylcarbonyl group optionally substituted by a halogen atom, an allyloxycarbonyl group, a fluorenylalkoxycarbonyl group, a benzenesulfonyl group optionally substituted by an alkyl group or a nitro group, or an alkyloxycarbonyl group), wherein the molar ratio of units of formula (I) to units of formula (II) or units of formula (III), (I)/(II) or (I)/(III), is 10/90 to 90/10.