Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2001-09-12
2003-07-01
Hampton-Hightower, P. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S125000, C528S126000, C528S128000, C528S171000, C528S172000, C528S173000, C528S174000, C528S176000, C528S179000, C528S183000, C528S184000, C528S220000, C528S229000, C528S310000, C528S312000, C528S332000, C528S335000, C528S336000, C528S350000, C528S351000, C528S189000, C528S353000, C528S331000, C528S322000
Reexamination Certificate
active
06586555
ABSTRACT:
TECHNICAL FIELD
This invention relates to processes of preparing condensed polymers that are polyamides, polyimides, or polyamidimides and more specifically, it relates to processes of preparing condensed polymers that are polyamides, polyimides, or polyamidimides by reacting mixtures of polyamines and polycarboxylic acids or the like in solvents by using arylboric acids as polycondensation catalysts; processes of preparing condensed polymers that are polyamides, polyimides, or polyamidimides by reacting mixtures of polyamines and polycarboxylic acids or the like by using pentamethylbenzene as a solvent in the presence of polycondensation catalysts; and processes of preparing condensed polymers that are polyamides, polyimides, or polyamidimides by reacting mixtures of polyamines and polycarboxylic acids or the like by using m-terphenyl as a solvent in the presence of polycondensation catalysts.
BACKGROUND OF THE INVENTION
Polyamides, with amide bonds in their principal chain, are used as fiber materials in great quantity due to their excellent frictional resistance, elasticity, chemical resistance, and dyeability. Further, they are used not only for parts of various machines and electronics, but also for films due to their excellent mechanical, abrasion-resistant, thermo-tolerant and oilproof properties, and their low coefficient of friction. Polyimides, with imide bonds in their principal chain, are one of most heat-resistant plastics, and are used for those parts of products on which high reliability is required such as airplanes, transportation, machines, and electric or electronic machines. Polyamideimides, with amide and imide bonds in their chain, are used for various molded materials.and insulating varnish because these are excellent in workabilities and abrasion resistance. The following several processes have been proposed to prepare these polyamides, polyimides, and polyamideimides.
In Japanese Laid-Open Patent Publication No. 49-106597, there is disclosed a process of preparing a macromolecular aromatic polyamide by thermal polycondensation of an aromatic diamine and an aromatic dicarboxylic acid diester, or an aromatic aminocarboxylic ester without solvent by using at least one compound of silicon, germanium, tin or lead as a polycondensation catalyst.
In Japanese Laid-Open Patent Publication No. 59-8728, there is disclosed a process of preparing an aromatic polyamide by thermal polycondensation of an aromatic aminocarboxylic acid and/or a mixture of aromatic dicarboxylic acid and an aromatic diamine in a polar solvent in the presence of a dehydration catalyst at a temperature of about 160° C. or over.
In Japanese Laid-Open Patent Publication No. 61-14219, there is disclosed a stable process of preparing a polyamide and/or a polyamide acid which can be easily polycondensed, by using a sulfolane containing substantially no sulfolene and/or isopropylsulfolanylether as a solvent in the process of preparing a polyamide and/or polyamide acid by reacting one or more polyvalent carboxylic acids and one or more diisocyanates in the presence of one or more catalysts selected from alkali metal hydroxides, alkali metal carbonates, and alkali metal hydrogencarbonates.
In Japanese Laid-Open Patent Publication No. 8-333450, there is disclosed a process for preparing a polyimide which is stable in dimension with little residual solvent, by thermally and chemically imidising a polyimide precursor which is produced by reacting in a mixed solvent of two or more solvents selected from water soluble ether compounds, water soluble alcohol compounds, water soluble amid compounds, water soluble ketona compounds, and water, a specific aromatic diamine compound and a tetracarboxylic acid dianhydride.
In Japanese Laid-Open Patent Publication No. 8-302015, there is disclosed a polymide with a specific molecular weight and a specific structural unit, which dissolves in organic solvents having a wide range of boiling points with high solvency, is excellent in molding workabilities, and has excellent thermal resistance in spite of its softening temperature, and is useful for varnish, modling products and the like.
In Japanese Laid-Open Patent Publication No. 8-239470, there is disclosed a process of preparing a water- and oil-repellent and heat-stable polyimide resin with low surface free energy and high glass transmission temperature by reacting a specific aromatic diamine and a specific aromatic tetracarboxylic acid dianhydride.
In Japanese Laid-Open Patent Publication No. 57-133126, there is disclosed a process for preparing a polyamideimide by polycondensing a tribasic acid anhydride and a diisocyanate compound in the presence of a tertiary amine catalyst in a sulfolane solvent.
In Japanese Laid-Open Patent Publication No. 62-297329, there is disclosed a process of preparing an aromatic polyamideimide by thermal polycondensation of an aromatic tricarboxylic acid and/or aromatic tricarboxylic acid anhydride and an aromatic diamine in the presence of a dehydration catalyst and a solvent, wherein a compound selected from the group consisting of nitrobenzene, o-nitrotoluene, and benzonitrile is used as the solvent.
The present inventors, on the other hand, reported that arylboric acids with electron-withdrawing groups such as 3,4,5-trifluorophenylboric acid and 3,5-bis(trifluoromethyl)phenylboric acid can be catalysts in amide condensation of carboxylic acids and amines. (J. Org. Chem. 61, 4196-4197, 1996)
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide processes of preparing polyamides, polyimides, and polyamineimides, which are easy to purify after the reaction, and especially aromatic polyamides (aramids), aromatic polyimides, and aromatic polyamideimides, which are said to be difficult to synthesize by direct polycondensation reactions from polyvalent carboxylic acids and polyvalent amines with high yield and without side reactions such as a change in color to black.
As mentioned above, the present inventors have already reported that arylboric acids can be a catalyst in the amide condensation of carboxylic acids and amines. In the case of polycondensation reactions where arylboric acids are used as a catalyst to prepare polyamides, it is important to select an appropriate solvent in polycondensation reaction system because the polymerization will not proceed unless trimers and dimers produced by the polycondensation are dissolved in the solvent. The inventors found a process of preparing polyamides, especially aromatic polyamides (aramids), which are said to be difficult to synthesize by direct polycondensation reactions, with high yield by direct thermal polycondensation reactions by employing combinations of the arylboric acids and appropriate solvents, and completed the present invention. The inventors also found that there are no side reactions accompanying a change of color to black when the direct polycondensation reactions of aromatic polyamides are performed at 200° C. or over using pentamethylbenzene or m-terphenyl as solvents, and completed the present invention.
BEST MODES FOR CARRYING OUT THE INVENTION
Polyamides, polyimides, and polyamideimides are examples of the condensed polymers in the processes of preparing condensed polymers where polycarboxylic acids and polyamines, polycarboxylic acids, polyamines and aminocarboxylic acids, or aminocarboxylic acids are reacted in solvents in the presence of arylboric acids as polycondensation catalysts of the present invention, or where polycarboxylic acids and polyamines, polycarboxylic acids, polyamines and amiocarboxylic acids, or aminocarboxylic acids are reacted in the presence of polycondensation catalysts in pentamethylbenzene or m-terphenyl as solvents of the present invention. Examples diamines, semiaromatic polyamides-produced from aromatic dicarboxylic acids and aliphatic diamines, or aliphatic dicarboxylic acids and aromatic diamines.
The polycarboxylic acids used in the present invention can be any of those having two or more carboxyl groups within a molecule. Dicarboxylic acids includes fumar
Ishihara Kazuaki
Yamamoto Hisashi
Hampton-Hightower P.
Hobbs Ann S.
Japan Science and Technology Corporation
Kinberg Robert
Venable
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