US4525573A
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US
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Thermoset polymers and prepolymers obtained by polycondensation of alkyl pyridine with hydroxyl aromatic monoaldehydes
Assignee: Office National d'Études et de Recherches Aérospatiales
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Filing: 1984-08-24
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Granted: 1985-06-25
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Expires: 2004-08-24
Abstract
Abstract The object of the invention are new thermoset polymers and prepolymers, a process for their preparation, and their uses. The new thermoset prepolymers consist, at least in part, of the polycondensation products of one or more pyridine derivatives containing at least two activated methyl groups with one or more aromatic monoaldehydes containing at least one hydroxyl group. These prepolymers are used to prepare composite materials, in particular laminates, that can be used at high temperatures.
Inventors
- 👤 Marcel Ropars
- 👤 Bertrand Bloch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:25
CPC Classifications
C; C08; C08G; C08G16/00; C08G16/02; C08G16/025; C08G16/0268; C08J; C08J5/00; C08J5/24; C08J5/241; C08J5/243; C08J5/244; C08J5/249
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
44 words
Thermoset prepolymers wherein they consist, at least in part, of the polycondensation reaction products of one or more pyridine derivatives containing at least two activated methyl groups in the 2, 4, 6-positions with one or more aromatic monoaldehydes containing at least one hydroxyl group.
Claim 2
Dependent Claim
44 words
Thermoset prepolymers wherein they consist, at least in part, of the polycondensation reaction products of one or more pyridine derivatives containing at least two activated methyl groups in the 2, 4, 6-positions with one or more aromatic monoaldehydes containing at least one hydroxyl group.
Claim 3
Dependent Claim
14 words
Prepolymers according to claim 1, wherein an aromatic dialdehyde takes part in the polycondensation.
Claim 4
Dependent Claim
16 words
Prepolymers according to claim 1, wherein the pyridine derivative is selected from 2,4,6-trimethylpyridine, 2,4-dimethylpyridine or 2,6-dimethylpyridine.
Claim 5
Dependent Claim
15 words
Prepolymers according to claim 1 wherein the aromatic monoaldehyde contains one or two hydroxyl groups.
Claim 6
Dependent Claim
16 words
Prepolymers according to claim 4 wherein the aromatic monoaldehyde is selected from o-hydroxybenzaldehyde, m-hydroxybenzaldehyde or p-hydroxybenzaldehyde.
Claim 7
Dependent Claim
19 words
Prepolymers according to claim 2 wherein the aromatic dialdehyde is selected from phthalic aldehyde, isophthalic aldehyde or terephthalic aldehyde.
Claim 8
Dependent Claim
61 words
Prepolymers according to claim 1 wherein they are in the form of viscous liquids soluble in solvents such as alcohol or ketone type solvents, in particular ethanol, propanol, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, alone or as a mixture; solvents of the dipolar aprotic type, in particular dimethylformamide, dimethylacetamide, N-methyl-pyrrolidone, and chlorinated solvents, in particular chloroform, 1,2-dichloroethane, and 1,1,2,2-tetrachloroethane.
Claim 9
Dependent Claim
64 words
Prepolymers according to claim 1 wherein they are in the form of fusible vitreous solids and are soluble in solvents such as solvents of the alcohol or ketone type, in particular ethanol, propanol, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, alone or mixed; solvents of the dipolar aprotic type, in particular dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and chlorinated solvents, in particular chloroform, 1,2-dichloroethane, and 1,1,2,2-tetrachloroethane.
Claim 10
Dependent Claim
42 words
Process for preparing polymers according to claim 1, wherein a pyridine derivative containing at least two activated methyl groups in the 2, 4, 6-positions, in particular 2,4,6-trimethylpyridine, is reacted with an aromatic monoaldehyde containing at least one hydroxyl group, in particular salicylaldehyde.
Claim 11
Dependent Claim
72 words
Process for preparing prepolymers according to claim 9, wherein it consists of reacting respective amounts of pyridine derivative containing at least two activated methyl groups and aromatic monoaldehyde corresponding to the presence of about one aldehyde group per one activated methyl group, at a temperature between about 175° C. and about 215° C., preferably at the reflux temperature of the reaction mixture, until a viscous liquid or a vitreous solid is obtained.
Claim 12
Dependent Claim
32 words
Process according to claim 9, wherein about 1 to about 2 moles of aromatic monoaldehyde and about 0 to 0.5 mole of aromatic dialdehyde are reacted per 1 mole of pyridine derivative.
Claim 13
Dependent Claim
64 words
Process according to claim 9 wherein it comprises, in addition, the addition of a catalyst for the polycondensation reaction of an aromatic monoaldehyde with a pyridine derivative containing activated methyl groups, such as sulphuric acid, p-toluenesulphonic acid, aluminium chloride, zinc chloride, tin fluoride, methyl iodide or benzyl chloride, used in an amount of about 0.5 to about 10 mole % with respect to pyridine.
Claim 14
Dependent Claim
23 words
Process according to claim 9, wherein the polycondensation reaction is carried out in the presence of a dehydrating agent such as acetic anhydride.
Claim 15
Dependent Claim
45 words
Process according to claim 9, wherein the polycondensation reaction is carried out in an inert solvent whose boiling point is preferably greater than 150° C., such as a dipolar aprotic solvent, a chlorinated solvent, or a ketone having a boiling point greater than 150° C.
Claim 16
Dependent Claim
67 words
Process for preparing new polymers, wherein prepolymers according to claim 1 are shaped and formed by any known process, in particular by moulding the prepolymers in the liquid state, if necessary dissolved in a solvent, or by pressure moulding of prepolymers in powder form, and in that the resultant products are cured by a heat treatment at a temperature of the order of 200° to 300° C.
Claim 17
Dependent Claim
33 words
Process according to claim 15, wherein the curing heat treatment comprises maintaining a shaped or formed prepolymer at a temperature of the order of 200° C., before subsequent heating at above 220° C.
Claim 18
Dependent Claim
32 words
Use of the prepolymers according to claim 1 for producing composite materials, in particular laminates, by impregnating fibrous materials with the said prepolymers and curing the thus impregnated fibre materials under pressure.
Claim 19
Dependent Claim
22 words
Composite materials, in particular in the form of laminates, consisting of fibres such as carbon fibres and prepolymers according to claim 1.
References Cited (Backward Citations)
US3994862A
Cited
US4362860A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-24 | 1988-12-24 | 1989-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-24 | 1992-12-24 | 1993-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-24 | 1996-12-24 | 1997-06-25 | $7700.00 | Window Closed / Lapsed |