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7585984 |
Perdeuterated polyimides, their process of preparation and their use as materials which are transparent within the region from 2500 to 3500 cm-1
The present invention relates to a deuterated polyimide, the backbone of which comprises an alternation between:
at least one repeat unit corresponding to the following formula (I):
...
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7446214 |
Method for purifying oxybisphthalic anhydrides
A method for purifying dianhydrides is provided. In one aspect, purified oxybisphthalic anhydrides, intermediates useful in the preparation of polyetherimides are provided. In one embodiment, a...
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7268237 |
Direct dianhydride synthesis
This invention is related to a method for making diether dianhydrides by the reaction of halophthalic anhydride and a metal salt of an aromatic dihydroxy compound in the presence of a solvent and a...
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7217827 |
Halogen-containing aromatic compound
The present invention relates to halogen-containing aromatic compounds and methods thereof. The present invention relates a halogen-containing aromatic acid dianhydride, halogen-containing aromatic...
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6881815 |
Method for the preparation poly(etherimide)s
A method for the synthesis of poly(etherimide)s comprises the reaction of 4-halotetrahydrophthalic anhydride with an activating primary amine to yield an activated 4-halotetrahydrophthalimide....
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6727370 |
Method for preparing oxydiphthalic anhydrides using bicarbonate as catalyst
Oxydiphthalic anhydrides such as 4-oxydiphthalic anhydride are prepared by the reaction of a halophthalic anhydride with an alkali metal carbonate such as potassium carbonate in the presence of a...
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6710187 |
Process to isolate dianhydrides
A process to isolate dianhydride from an exchange reaction comprises extracting a bisimide/anhydride exchange reaction aqueous phase with an organic solution comprising an exchange catalyst at a...
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6706897 |
Method for preparing oxydiphthalic anhydrides using guanidinium salt as catalyst
Oxydiphthalic anhydrides such as 4-oxydiphthalic anhydride are prepared by the reaction of a halophthalic anhydride with an alkali metal carbonate such as potassium carbonate. The reaction proceeds...
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6600053 |
Method of preparing photosensitive resin composition
A 6,6′-dialkyl-3,3′,4,4′-biphenyltetracarboxylic dianhydride is prepared by brominating a 4-alkylphthalic anhydride at its 5-position, and coupling the bromination product in the presence of...
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6590108 |
Methods for the preparation of dianhydrides
A method for the synthesis of a dianhydride comprises transimidation of bis (imide) (IV) in the presence of a substituted phthalic anhydride or 4-substituted tetrahydrophthalic anhydride to...
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6204394 |
Method for preparing oxy-diphthalic anhydrides
Disclosed is a method for preparing oxy-diphthalic anhydrides, which comprises reacting a halo-phthalic anhydride represented by the formula (1): ##STR1## where Hal represents F, Cl, Br or I, with...
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6060575 |
1,4-bis(3,4-dicarboxyphenoxy)-2-tert-butylbenzene dianhydride and method of using the same
The present invention provides a series of easily processable poly(ether-imide)s that are organic-soluble and can afford colorless films, their organic solutions and their manufacturing process....
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6031061 |
Bis (triaklyltrimellitic anhydride) derivative and polyesterimide for optical communications formed therefrom
A bis(trisubstitutedtrimellitic anhydride) derivative and a polyesterimide for optical communications, the polyesterimide being formed therefrom. The polyesterimide has a high refractive index, so...
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6028203 |
Phase transfer catalyzed method for prepared oxybisphthalic compounds
Oxybisphthalic compounds such as 4,4'-oxybis(N-methylphthalimide) and 4,4'-oxybis(phthalic anhydride) are prepared from the corresponding nitro- or halo-substituted phthalic compounds by reaction...
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5750731 |
Perfluorinated aromatic compounds
A perfluorinated aromatic compound represented by general formula (7): ##STR1## wherein R 3 is a tetravalent perfluorinated aromatic group represented by formula (8): ##STR2## wherein (R 4 )s are...
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5675020 |
Ortho-bis(etherdianhydrides)
Disclosed herein are novel poly(imide-ethers) containing ortho substitution in the main chain of the polymer. These polymers are made from novel aromatic bis-carboxylic anhydrides which contain two...
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5412009 |
Flame retardant compounds comprising fully brominated dianhydrides
The invention provides a compound of general formula I ##STR1## in which X represents a direct bond or a ##STR2## group.
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5342968 |
Process for producing sulfonylbis (phthalic anhydride)
A process for making relatively high purity eulfonylbis(phthalic anhydride) is provided. 3,3',4,4'-tetramethyl diphenyl sulfone is catalytically oxidized in a solvent under liquid phase elevated...
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5336788 |
Method of making oxydiphthalic anhydride
Disclosed is a method of making oxydiphthalic anhydride from oxydiphthalic acid. The oxydiphthalic acid is mixed with an organic liquid that codistills with water and the resulting slurry is heated...
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5336787 |
Process of making selected poly(dianhydrides) compounds
A process of making poly(dianhydride) compounds having formulae (I) and (II): ##STR1## where m is 0 to 50. ##STR2## wherein n is 0 to 20 and X is bond junction, oxygen atom, sulfur atom, SO 2 ,...
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5274126 |
Partially fluorinated tetracarboxylic acid and the dianhydride thereof, a process for their preparation and their use
A compound of the formula ##STR1## and the dianhydride thereof are prepared by air oxidation in the presence of a catalyst mixture composed of at least 2 heavy metal salts and also bromine in an...
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5258530 |
Process for producing biphenyltetracarboxylic dianhydride
A process for producing a biphenyltetracarboxylic dianhydride which comprises the step of: heating phthalic anhydride at a temperature of from 135° to 300° C. in the presence of a palladium...
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5235070 |
Suppression of dust from solid aromatic anhydrides
A method for reducing the formation of dust produced by solid aromatic anhydrides, and aromatic anhydride compositions that have a reduced tendency to emit aromatic anhydride dust, are disclosed....
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5206335 |
Selected poly(dianhydrides)
Poly(dianhydride) compounds having formulae (I) and (II): ##STR1## where m is 0 to 50. ##STR2## wherein n is 0 to 20 and X is bond junction, oxygen atom, sulfur atom, SO 2 , C(CF 3 ), CO, C(CH 3 )...
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5198555 |
Dianhydrides from catalyzed reaction of monoanhydide monoacid halides with polyalkylated mononuclear aromatics
The invention relates to the preparation of novel dianhydrides of the formula: ##STR1## wherein R is a polyalkylated mononuclear aromatic radical, preferably a phenylene radical. The mononuclear...
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5194633 |
Preparation of 1,1,1,3,3,3-hexafluoro-2,2-Di(3,4-dicarboxyphenyl)propane anhydride
A process for preparing 1,1,1,3,3,3-hexafluoro-2,2-di(3,4-dicarboxyphenyl) propane anhydride is disclosed. 1,1,1,3,3,3-hexafluoro-2,2-di(3,4 -dimethylphenyl) propane is oxidized under liquid phase...
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5187285 |
Producing bis(alicyclic) thioethers
3,3'-Thiobis(2,5-dihydrothiophene-1,1-dioxides) on heating with a reactive Diels-Alder dienophile undergo a reaction producing thioethers having two six-membered alicyclic rings in the molecule,...
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5185454 |
Process for the preparation of symmetrical diarylacetylenes
Symmetrical diaryl-acetylenes can be prepared by reacting an aryl halide with acetylene in the presence of a palladium catalyst and a base. If the acetylene is introduced into the liquid reaction...
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5183838 |
Acid anhydride complex and process for producing same, and composition containing same
An acid dianhydride complex which is characterized in anti-hydrolysis, good stability, and high solubility in an organic solvent, is prepared by a reaction of a basic organic compound having a...
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5153335 |
Process for the preparation of oxydiphthalic anhydride and acyloxyphthalic anhydrides
A method for the preparation of acyloxyphthalic anhydride or oxydiphthalic anhydride which comprises the reaction of a halophthalic anhydride with an alkali metal salt and at least a catalytically...
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5145971 |
Process for the preparation of oxydiphthalic acid and purified oxydiphthalic anhydride from crude oxydiphthalic anhydride
A process for the preparation of purified oxydiphthalic acid from impure oxydiphthalic anhydride, by treating with a mixture of water and propionic acid or butyric acid to produce oxydiphthalic...
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5126462 |
Sulfur-containing aromatic tetracarboxylic acids and derivatives thereof
Aromatic tetracarboxylic acids or derivatives thereof of the general formula I ##STR1## in which R denotes a divalent radical of the formula II ##STR2## Ar denotes tri- or tetravalent aromatic...
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5122617 |
Tetracarboxylic acid dianhydrides
Tetracarboxylic acid anhydrides represented by the following formulae [IA] and [IB] are provided: ##STR1## where n is an integer of 1 to 3. The tetracarboxylic acid anhydrides give polyimides...
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5117002 |
Preparation of diphenyl ether
A process for the production of diaryl ethers which comprises heating, to a temperature of 80° C. to 220° C., a compound of the formula ##STR1## wherein X and Y are selected from the group...
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5101006 |
Polyimides and copolyimides based on halo-oxydiphthalic anhydrides
Novel halogenated polyimides and co-polyimides comprise recurring imide structural units of the formula ##STR1## where X is F, Cl, Br or I; Y is H, F, Cl, Br or I; and R is a divalent organic radical.
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5098991 |
Process of preparing polyamide-imide and polyimide polymers from acid anhydrides and dianhydrides of disubstituted maleic anhydrides
A process is disclosed for preparation of anhydrides containing additional carboxylic acid moieties and dianhydrides of disubstituted maleic anhydride compounds wherein the acid anhydrides and...
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5095144 |
Process for dimerizing aromatic halogen compound
A process for dimerizing an aromatic halogen compound is disclosed, which comprises the step of: subjecting an aromatic halogen compound having at least one halogen atom bonded to an aromatic...
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5077415 |
Disubstituted aromatic dianhydrides
Aromatic dianhydrides being substituted in the positions ortho to the bridging moiety, said substituent groups including halogen, alkyl, hydroxy, nitro, cyano, ester, alkoxy, perfluoroalkyl,...
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5047560 |
Process for producing highly pure 3,3',4,4'-biphenyltetracarboxylic acid or dianhydride thereof
Highly pure 3,3',4,4'-biphenyltetracarboxylic acid (BPTA) and dianhydride thereof (BPDA) are produced by heating crude BPTA to give BPDA, treating the BPDA with hot water to give highly pure BPTA,...
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5021168 |
Process for the preparation and recovery of oxydiphthalic anhydrides
Oxydiphthalic anhydrides of the formula ##STR1## are prepared by reacting a halophthalic anhydride with potassium carbonate in: (1) a solvent-free reaction medium wherein the molar ratio of...
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5003086 |
Process of preparing dioxydiphthalic anhydride
Dioxydiphthalic anhydride is prepared by the reaction of dihalophthalic anhydride with an alkali metal compound, such as potassium carbonate. The compound is particularly useful as a monomer in the...
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5003031 |
Polyimides and co-polyimides based on dioxydiphthalic anhydride
Novel polyimides and co-polyimides are prepared by the condensation polymerization of an aryl diamine with dioxydiphthalic anhydride or a mixture thereof with oxydiphthalic anhydride. The...
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4987238 |
Process for the preparation of high-purity 5,5'-[2,2,2-trifluoro-1-(trifluoromethyl)-ethylidene]bis-1,3-isobenzofur andione
A process for the preparation of high-purity perfluorinated compounds, specifically of an aromatic tetracarboxylic acid and its anhydride,...
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4973707 |
Acetylene bis-phthalic compounds and polyimides made therefrom
Polyimides made by reacting 1,2-acetylene-4,4'-di(phthalic anhydride) with an aromatic diamine are useful in high temperature applications that require solvent resistance. Applications include...
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4958001 |
Dicyclohexyl-3,4,3',4'-tetracarboxylic acid or dianhydride thereof and polyamide-acid and polyimide obtained therefrom
A polyimide obtained from a polyamide-acid or polyamide-acid ester prepared by reacting dicyclohexyl-3,4,3', 4'-tetracarboxylic acid or dinanhydride with a diamine is excellent in transparency,...
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4958002 |
High purity crystals of biphenyltetracarboxylic dianhydride and process for their preparation
High purity crystals of a biphenyltetracarboxylic dianhydride produced by dehydration of a biphenyltetracarboxylic acid, which contain almost no biphenyltricarboxylic acid or its anhydride, or a...
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4952708 |
Method for preparing biaryl compounds
An improved method for making biaryl compounds is disclosed, in which an aromatic acid halide having at least one strong electron-withdrawing group attached to or within the aromatic ring is...
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4948904 |
Process for the preparation of oxydiphthalic anhydrides
Oxydiphthalic anhydride is prepared by reacting an hydroxyphthalic anhydride with a bromophthalic or fluorophthalic anhydride and potassium fluoride in the presence of a solvent and a copper catalyst.
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4946985 |
Catalyzed process for the preparation of oxydiphthalic anhydrides
Oxydiphthalic anhydrides are prepared by reacting a halophthalic anhydride with water and an alkali metal compound such as KF, CsF, or K 2 CO 3 in the presence of a copper catalyst.
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4943642 |
Halo-oxydiphthalic anhydrides
Novel halo-oxydiphthalic anhydrides are of the formula ##STR1## where X is F, Cl, Br, or I; X' is H, F, Cl, Br, or I.
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