 Method of and device for clamping a workpiece |
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| Expansion sleeve for applying precise circumferential stress |
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| Method of and apparatus for producing embossing tools |
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| Plasma etching using a bilayer mask |
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| Method of cleaning a plurality of semiconductor devices |
| OF THE PREFERRED EMBODIMENT Referring now to FIG. 2, there is shown a perforation etch formed ... |
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| Method of forming electrode pattern of semiconductor device |
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| Rapid solidification processing of oxide superconductors |
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| Formation of superconducting articles by electrodeposition |
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| Method for manufacturing oxide superconducting films by laser evaporation |
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| Methods of forming a patterned metal film on a support |
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Amphiphilic polyimide precursor containing c12-c30 hydrophobic groups and langmuir-blodgett films therefrom
| Details |
Inventors: Uekita, Masakazu; Awaji, Hiroshi;
Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha (Osaka, JP)
Primary Examiner: Kight; John
Assistant Examiner: Krass; Frederick
Attorney, Agent or Firm: Armstrong, Nikaido, Marmelstein & Kubovcik
An amphiphilic polyimide precursor having at least 70% by mole of the recurring unit of the formula (1): ##STR1## wherein R.sup.1 is a tetravalent group having at least 2 carbon atoms, R.sup.2 is a bivalent group having at least 2 carbon atoms, and R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are hydrogen atom or a monovalent group having 1 to 30 carbon atoms selected from an aliphatic group, an alicyclic group, an aromatic group, a group in which an aliphatic group is combined with an alicyclic group or an aromatic group, and their groups substituted by a halogen atom, nitro group, amino group, cyano group, methoxy group or acetoxyl group, provided that at least one, preferably at least two, of R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are hydrophobic monomolecular groups having 12 to 30 carbon atoms, the polyamide precursor being able to form a built-up film on substrates according to the Langmuir-Blodgett technique and being able to be converted into polyimide by heat treatment to provide an ultrathin film of of polyimide having a thickness of not more than 10,000 .ANG. and excellent heat resistance, chemical resistance, mechanical property and electric characteristics. |
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DETAILED DESCRIPTION It has now been found that substituent groups for imparting a hydrophobic property to a polyamide acid can be introduced into the polyamide acid, and the monomolecular layer of the so modified polyamide acid having hydrophobic substituent groups is stable on water and can be transferred onto various substrates by the LB technique.
It has also been found that ultrathin polyimide films can be produced from the multilayer films of the so modified polyamide acid.
In accordance with the present invention, there is provided an amphiphilic polyimide precursor having the recurring unit of the formula (1): ##STR2## wherein R.
sup.
1 is a tetravalent group having at least 2 carbon atoms, R.
sup.
2 is a bivalent group having at least 2 carbon atoms, and R.
sup.
3, R.
sup.
4, R.
sup.
5 and R.
sup.
6 are hydrogen atom or a monovalent group having 1 to 30 carbon atoms selected from the group consisting of an aliphatic group, an alicyclic group, an aromatic group, a group in which an aliphatic group is combined with an aromatic group or an aliphatic group, and these groups substituted by a halogen atom, nitro group, amino group, cyano group, methoxy group or acetoxyl group, provided that at least one of R.
sup.
3, R.
sup.
4, R.
sup.
5 and R.
sup.
6 is not hydrogen atom and is not the above-mentioned group which has 1 to 11 carbon atoms.
The amphiphilic precursors of polyimides of the present invention are prepared, for instance, by a process in which a tetracarboxylic acid dianhydride of the formula (4): ##STR3## wherein R.
sup.
1 is as defined above, is reacted with R.
sup.
3 OH and R.
sup.
4 OH wherein R.
sup.
3 and R.
sup.
4 are as defined above, the resulting compound of the formula (5): ##STR4## is converted into an acid halide in a substantially anhydrous polar organic solvent at a temperature of not lower than -10.
degree.
C.
, and the acid halide is reacted with a compound of the formula (6): R.
sup.
5 --NH--R.
sup.
2 --NH--R.
sup.
6 ( 6) wherein R.
sup.
2, R.
sup.
5 and R.
sup.
6 are as defined above, at a temperature of not lower than -10
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Nonmetallic Processes 
