Stock material or miscellaneous articles – Structurally defined web or sheet – Physical dimension specified
Reexamination Certificate
1998-08-21
2002-12-17
Le, H. Thi (Department: 1773)
Stock material or miscellaneous articles
Structurally defined web or sheet
Physical dimension specified
C427S352000, C427S388200, C427S409000, C427S457000, C428S338000, C428S339000, C428S457000, C428S458000
Reexamination Certificate
active
06495247
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a functional member having a molecular layer on its surface and, more particularly, to a functional member having a molecular layer formed to coordinate on its surface, and a method of producing the same.
2. Description of the Related Art
Currently, as methods for formation of a molecular layer, there are known a so-called LB method and a chemical adsorption method (K. Ogawa et al., Langnuir, 6,851 (1990)).
The LB method is a method such that amphiphatic molecules developed on a water surface are collected together, with pressure being applied to the molecules in a direction parallel to the water surface, the molecules being then scooped onto a substrate while the pressure is kept constant, whereby a monomolecular layer is formed.
In the chemical adsorption method, a silane-based surface active agent is mainly used in such a way that the surface active agent is caused to go into condensation reaction with functional groups having active hydrogen, such as hydroxyl group and carboxyl group, which are present on the substrate, whereby a monomolecular layer of the silane-based surface active agent is formed on the substrate.
However, the above mentioned forming methods each have problems yet to be solved.
The LB method requires the provision of a developing bath first of all. The developing bath must be protected against vibration so that any slight vibration in the surroundings will not be transferred to the bath to cause the liquid surface to become wavy.
Another problem with the LB method is that since a molecular layer prepared by the LB method is fixed to the substrate by ionic bonding, the layer will be easily peeled off not only by a mechanical scratch, but also by being merely brought into contact with a liquid.
Whilst, the chemical adsorption method involves a problem that hydrogen chloride is produced because the silane-based surface active agent is brought into condensation reaction with a functional group having an active hydrogen atom as already mentioned. Therefore, the chemical adsorption method may be unsuitable for use with a substrate having low acid resistance.
Another problem with this method is that the silane-based surface active agent will not go into condensation reaction with a substrate having no active hydrogen atom; therefore, it is impossible to carry out layer-forming by using such a method.
The present invention has been developed in view of above mentioned state of the art and, therefore, it is an object of the invention to provide a method of forming on the surface of a substrate a molecular layer which involves no such problems mentioned above as have been encountered in the prior art.
It is another object of the invention to provide a novel functional material having a molecular layer firmly bonded to the surface of a component member.
SUMMARY OF THE INVENTION
Therefore, the present invention relates to a functional member having a molecular layer on its surface, wherein the molecular layer is a layer formed on the surface of the member through a coordinate bond, the coordinate bond being a multidentate bond such that at least one molecule is in bond with one metallic atom of the member, and such that two or more ligand atoms of the molecule are coordinated so that the metallic atom is placed between the ligand atoms. The invention also relates to a method of producing the functional member.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A multidentate bond wherein multidentate ligand molecules are in bond with atoms of a substrate metal is known as a chelate bond. A chelate bond is different from a covalent bond in the way in which the bond is formed, but the formed bond per se is same as the covalent bond. In a coordinate bond, both electrons that form the bond come from one of the atoms. Although the bond is covalent in character, a coordinate bond differs from a covalent bond in the origin of the electrons that form the bond. In a covalent bond, one electron originates on each of the two atoms being bonded. Therefore, the multidentate bond provides much higher layer/substrate metal bond strength than a monodentate bond, and accordingly the molecular layer formed can exhibit good performance characteristics, such as high heat resistance. Further, characteristic features of such multidentate ligand molecules can be advantageously utilized in providing the member with various properties, such as insulating property, electrical conductivity, permeability, bonding property, absorption characteristic, and protective property.
Multidentate ligand molecules usable for forming a molecular layer in the present invention include, for example, acetylacetone, acetoethyl acetate, benzoyl acetone, ethylenediamine, diethylenetriamine, triethylenetetramine, diethylamine, thiourea, diethanolamine, triethanolamine, iminodiacetic acid, nitrilotriacetic acid, ethylenediamine tetraacetic acid, quinoline-8-carboxylic acid, quinaldinic acid, o-aminobenzoic acid, oxalic acid, malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid, anthranilic acid, 2-aminoperimidine, galloyl-gallic acid, potassium xanthate, oxine, cupferron, 4-chloro-3-methyl-5-nitrobenzene sulfonate, salicylaldehyde oxime, diantipyrylmethane, diethyl dithiocarbamic acid, p-dimethylamino benzylidene rhodamine, dimethylglyoxime, cinchonine, N-cinnamoyl-N-phenylhydroxylamine, thioacetoamide, thionalide, tetraphenyl borate, trimethylphenyl ammonium, 1-nitroso-2-naphthol, nitrone, neocupferron, bismuthyol II, p-hydroxyphenyl arsonic acid, 8-hydroxy-7-iodo-5-quinoline sulfonic acid, pyrogallol, 1-pyrrolidine carbodithioic acid, phenylarsonic acid,(phenylthio) dantinic acid, phenylfluoron, &agr;-furyldioxime, brucine, benzidine, N-benzoyl-N-phenylhydroxylamine, &agr;-benzoin oxime, benzo[f] quinoline, 2-mercaptobenzothiazole, rhodamine B, 4-tetradecyl-N-methyl salicylaldehyde oxime, 3-tetradecyl pyridine, itaconic acid, and pyromellitic acid.
For use as a component member on which a molecular layer is to be formed in accordance with the present invention, materials having a metallic portion or metallic oxide portion exposed on the surface are most suitable. The member may be in the form of a metallic plate or a material such that a metallic component is dispersed in resin and is contained as a part of the surface component. There is no particular limitation with respect to the configuration and size of the substrate.
In order to form a multidentate bond with a multidentatable molecule, it is necessary that the coordination number of atoms of the component metal should be two or more. Where the coordination number of such atoms is four or more, multidentate molecules which are in bond with one metallic atom may be two or more in number. For example, when the component metal is copper, the coordination number is 2 or 4; when the metal is nickel, the coordination number is 4 or 6; when cobalt, the coordination number is 4 or 6; when silver, the number is 2 or 4; if gold, the number is 4; when platinum, the number is 4 or 6; when aluminum, the number is 6; and in the case of tungsten, the number is 6 or 8.
To form a molecular layer on the surface of the component member, multidentate molecules may be brought into contact with the member. For causing such a molecule to contact the member, a suitable method is to bring the substrate into contact with one of a liquid molecule, a liquid solution having molecules dissolved in a solvent, and a gaseous molecule.
In particular, when a liquid solution is used, it is necessary to suitably select a solvent which will not affect the substrate on which a layer is to be formed. For example, water, alcohols, and ketones are most suitable for this purpose.
The variation of characteristics of a molecular layer and/or the control of molecular layer thickness may be adjusted depending on the kind of multidentate molecules and conditions used for causing the substrate into contact with the multidentate molecule.
In order to enable the formation of a strong chelate bond of the
Mino Norihisa
Onishi Hiroshi
Otake Tadashi
Shiino Toru
Takebe Yasuo
Le H. Thi
Matsushita Electric - Industrial Co., Ltd.
Wenderoth , Lind & Ponack, L.L.P.
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