DE1810467A1 - Polyimides and processes for their preparation - Google Patents

Description

Priority: December 27, 1967 - V.St JL

The invention "relates to thermoplastic, fast-curing, stable polyimides of high molecular weight and a process for their preparation which is characterized in that a polyfunctional amine is reacted with a polyanhydride and maleic anhydride to form fully cyclized polyimide prepolymers of relatively low molecular weight High molecular weight thermoplastic, fast curing, "permanent" polyimides of the present invention obtained by heating low molecular weight polyimide prepolymers are characterized by having a specific terminal or endcapping group which is stable at ambient and elevated temperatures , for example 200 to 35O ⁰ Oi tinter formation of polymers with average

009831/1988

can xyerden polymerized chen molecular weights of at least 10,000 _e Polyimide Prapolysiepisste be dm? ch environmental ■ setsimg a polyamino "" For example, an aromatic diamine "with a dianhydride ,, for example, an aromatic dianhydride, and maleic anhydride as Endrsrkapp-angs" · or end group retained * The prepolysate polymerize "when heated to increased © Iemparaturen. d * h "about 200 ⁰ C or above, to dea Endaa weiter'untsr formation of polymers having an average molecular weight of about 10,000 or more.

The polyimide prepolymer is obtained in particular by one at elevated temperatures in the presence of an organic Solvent a diamine, a dianhydride and maleic anhydride are reacted with one another in constant quantities a completely cyclized niedermolalmlaai'ss polyimide prepolymer What is obtained is this polyimide prepolyrisate with relatively low molecular weight through Application of Hitae to polymers with low molecular weight further polymerized, which are characterized by it., that they have improved thermal and mechanical properties, which make them useful for various purposes, especially in the space industry *

In general, the polyimide resins available hitherto are known for their balanced physical and chemical properties and, in particular, for their resistance to elevated temperatures. Because of these advantageous properties, the polyimides sahireiche applications in the field of advanced technology where materials with high strength and high! Temperature resistance are required have "found * Although the polyimides previously available are desirable but _t they have in economic terms the disadvantage ^ that difficulties during the hardening stage in which polymers occur, for example, the polyimides previously heard were obtained by being more constant in the presence of processing

Q0 98 31/1 86 8 sad

How? s * B * of a Konoanhy & rids. _r a Bianhydrid and an E'iteina ° öde.i? "implemented" bio-joint implementation of this Jen provided by chain extension; or polymerization over a period of about 1/2. "to 4 hours a PolyamicL-Sätires if the polysmia ~ acid * image was of the intermediate product, if its immediate no provision was _t gohaltan in solution * lind hermetically sealed "cooled Such was" the special packaging for dis storage, and you; s.nschl5.eßende Yeriirendung a Eosteiiauf '^ ma · ,, de:; i passed consumer e of ds! If the aniide acid is used, then the intermediate product can be hardened for 16 hours or more at elevated temperatures without the development of volatile substances which occur during the reaction and evaporation dos IfSsirngSELitt-els are formed.

In the case of the polymers according to the invention and the process according to the invention and their production, the production of polyamide-acid intermediates and the development of volatile substances are avoided. Ea is to be made possible, for example _v Polymsrisatmatrisen without any ncrldiche 2at- ■ i ^ ickluns of volatiles ,, the herrüin from the evaporation of the solvent and the chemical tfmseteung s?, The ar ~ f indungsgeaäßen polymers are for a Hä3? TungsEiechanis "louse formed _t is unique in that * as the polymerisation of the polyimide prepolymers by the application of Hitse ,. The process consists in that polyamide prepolymers with a relatively low molecular weight with maleic anhydride groups at the terminal positions are produced, which apparently follow a Diels-Alder mechanism the ends polynorisieren formation of polyimides with high Molekui-arge "weight without development of volatile substances,

The thermoplastic polyimides according to the invention child therniaclr. constant and for this reason can be used for many Zx -.'- packs * has been used, for example as a protective cover «· ;, liemin.ni» e,

■ Z ... S- ■ 00 9 831/1868

Eoketips from missiles., Evaporating © heat shield © for satellites and other applications la the Eauiafahrto In addition, the process advantages in the production of the polymers according to the invention allow their © use as a laminate © with a significantly lower pore content than the laminates »di © made from the polyimides previously available be prepared * The resistant Präpolyaerisate -can aiii * fabric or fiber reinforcements, etc. ₀ followed Härtimg "at moderate Drusken ^, for example _14% of 1 kg / cm (200 psi) are brought to on training periods) ,.

Accordingly, one aim of the present invention is to provide high molecular weight polyimides which have a high resistance to thermal and oxidative environmental influences *

Another object of the present invention is to provide a novel process for the preparation of polyimides with high Molelcalargewicht, which are characterized by high stability and improved mechanical properties ,, and which are obtained by pyrolytic polymerization of the prepolymers _t.

Another object of the present invention ordered is to provide resistant polyimide prepolymers with low molecular weight _t by the application of heat without evolution of volatiles zn thermoplastic polymers. be polymerized with high molecular weight ο

Further objects of the present invention are to provide a new process for the preparation of high molecular weight polyimides obtained by polymerization at the ends as a result of dsr Application of heat from prepolymers with relatively; low molecular weight? a process for the pyrolytic polymerization of polyimide «· - Prepolymers with a relatively low molecular weight without development of volatile substances, di® normally formed during the cyclization of the polyamide acids.

'■. \ 00983 1/1868

will;

and polyimide prepolymers with low molecular weight ? which are stable at room temperatures and therefore require no special treatment and can be polymerized to high molecular weight polymers by the application of heat without the development of any substantial amount of volatile substances.

These and other objects of the present invention are apparent from US Pat following and. more detailed description of the invention outο

It has been found _T that obtained by pyrolytic ^ polymerization of Pülyisiiä-prepolymers having an average molecular weight in the range of about 500 and 3 _f 000 thermoplastic polyimides with relatively high molecular weight v / can ground "In particular, it was found that, by application of 'heat d * h "from temperatures in the range from about 200 to 350 ° C." to the imide prepolymers _? which are obtained by the joint reaction of a diamine, for example an aromatic diamine, a dianhydride and maleic anhydride in oetoichiometric amounts under the conditions known to those skilled in the art for the production of polyimides by cyclization, _v polyimides with a relatively high molecular weight can be produced ,

These prepolymers can be used as a chain-extended polyimide be characterized, the an aliphatic and / or an aromatic basic structure (backbone) with reactive, at ambient temperature contains persistent terminal groups. When curing the prepolymer by applying heat, the terminal Groups chemically reactive; this causes the polyamide prepolymer chains chemically condense at the ends to form macromolecules with molecular weights of at least about 10,000. These high molecular ~ weight are obtained from prepolymers by the

009831/1868

the following general formula can be characterized., -

in the H ^ and Rg an aliphatic ^ and / or a Mean group and η has a value from 1 to 8 *

The common implementation or 'the Polymei isat *? / Oh £ jtiim begins with the application of heat simultaneously with the removal of the solvent "On further heating However, polymers are obtained with higher molecular weight ,, the thermal stability at above about 349 ⁰ O ( 660 ⁰ F).

The polyimide according to the invention ~ prepolymers kb'mien by conventional methods by reacting one equivalent of an polyamines _β d "h _e a diamine with one equivalent of a group consisting of a dianhydride and maleic anhydride mixture is prepared" The maleic anhydride present in the anhydride mixture in amounts which sufficient. * to cap the polyimide prepolymer at the ends "The relative amount of maleic anhydride used in the reaction varies depending on the average molecular weight of the prepolymers." ie diamine, are equal to the total equivalents of dianhydride and maleic anhydride.

It is possible according to the invention produce prepolymers "by polyf oint ioneile amines such» B ₀ üiriamine and used tetramines, the diamines are preferred "Examples of the aur Preparation of polyimide prepolymers usable polyfunlctionellen amines are: p» Phenyiendi £ tmin , m-Piienylenediamine, 4,, 4-Diamino-diphenylpropane, ^
Benaidin _f 4> _i 4 ^l -Diamino »diphenylsulfite,

sulfone, 3 ^ 3'-diamino-diphenylsulfone, *, 4 ·· -Diamino-diphenyl-

009831/1868

later 5 1 * 5-diamino-napiithaliii, 3 "3 '-Dimetliojqy-benaidin j 2 _t 4 ~ B: is- (β-amino-tert""''butyl) toluene, bis-Cp-β-amino-tert. -butyl-pheayl) "ether _t Bis- Cp-ß-methyl-δ-amiao-pentyl) 'bensol, bis-p ~ (1 * 1 -» dimethyl-5- ^ ißiiio ~ pentyl) benzene _f 1 ~ isopropyl- 2, 4-metapheaylen "" disrain »m-xylylenediamine, hexamethylenediamine ^ heptamethylenediamine" Octamethylendiamia, Nonaaethylendiaain, Deceaaethylendiamin "diamino-propyl-tetrametliylendiamia _t 3-methyl-höpta ~ methylendiainin, 4 _t 4 ~ Dimetliyliieptamethylöadiaiain, 2" 11-diamino «· dodecane. i- _? .2 bis (3-aiaino-> propoxy) ethane _t 2,2-dimethylpropylenediamine, 3- ^ etho3q5r ~ fee3camethylendiaain _il 3,3'-diiaethylbenaidin _t 2 _s 5i-dimethyl-liexamethylenediamine »2,5-diinethylb. eptamethylenediamine »

^ -Methyl-nonametlaylendisaöin * 2 ^ 17-Diamino-eieosadeeaiii 1,4

J) iaaino-cyo lohexane, 1,10-diaaino-1,10-dimethyl-decane, 1 ,. 12-diamino-octadecane and OJriamine, such as "1,3 2 ^ _i 6-O? Riamino" s-tria2! In _t 1,2 _f 3 "(i} riamiiiopropan, amino" tripheriy! Methane and 4 _t 4- ' _f 4 "-Q? Riamino-triphenylcarbinol"

Examples of polyfunctional anhydrides, de h «, dianhydrides _{f which} can be used to produce the polyamide prepolymers are as follows:

Pyromellitic dianhydride

Benzophenone tetracarboxylic acid dianhydride

2 "3 _i 6" 7 - ^ 'aplithalin-tetracarboxylic acid aianhydride

3 n 3 'j4,4' ~ Diphenyl-tetracarboxylic acid dianhydride. 1 _f 2 _f 5 * e-naphthalene-tetracarboxylic acid dianhydride 2,2 *, 313 ^f -diphenyl-tetracarboxylic acid dianhydride 2 s, 2-bis (3 _i 4-dicarbo3Qn> b-enyl) propane dianhydride 3 * 4, 9 * 1O-perylene-tetracarboxylic acid dianhydride bis (3 _s 4-dicarboxyphenyl) ether dianhydride ithyrlene tetracarboxylic acid dianhydride taphthalene-1,2,4, -tetracarboxylic acid dianhydride ETaphthalene-i _t 4 _t 5t8-cyanaphthalic acid-dianhydride -I _f 4 _t 5 _t 8-tetracarboxylic acid dianlihydride 4- "e-Biiaethyl-i _f 2 ₁ 3 ₁ 5" .6 _t 7 ~ hexahydror! Aphthalene ~ 1.2 ₁ 5.,. 6-fcefcra- "ariVo7" Bäi "r <-" dianhydride

2 ^ .e-Dichlnrafiphthalin-i, 4,5,8-tetracarboxylic acid diaiibydride

009831/1868

- β

2 , 7 ~

2, j J «β f 7 - ^? Et2 ⁱ aclil € iiMiaplfctl £ aliM« »- 1 _?

1 _s 2 _f 3

3 * ^ y

₁ 1-bis (5

3 _t

The following example © sc * il®a ä ± e erlätifceiMi _t olm® sie- ^ eeLoeli <§aa? Atif · sit

In 170 ml BiiietiijifoniaiffiM anS 400 nil üaitaal. w «rdea efer ^ Gewichftsteile ^, ^" ^ - Me ^ ijlöMiaiiiliEtf 32 _ft S SenictMrsiiGile

Göwiciitsteile Maleineäitreaiiliydirid dissolved ^ The loaxiag wux * de for 18 hours tiofeei? RScIrflTiS come, where for 4 time the water is collected; miräe · ¥ ac & le © m <äi © mg des under reflux was © die Eösimg a «f Mraiatapteiaieiiatm? vmä. filtrierfc · A corsetry or an insoluble FrafeMon was ßeaasiHielt and over Machf; at 110% untGi * Vaktitsm dried. Bas filtrate was added slowly, in a 5 1 vehemently poured geruEtrtes water and the Rilbren. murde iifcer night continued »While stirring a second urie € er'aclalag _{i arose;} which was collected by filtration and fiber night hei 110 ⁰ C under Va? "uum dried. The first and the second tumbled precipitate are mixed separately with a body of mild and a fine powder

and the sides Fiederschlag amounted to 28., 4 Gewiöhtteil © or »52 _? 6 weight steep. 1 part by weight of the steep sweitsm fraction and 1 ßewiülitateiX the first fraction were mechanically mixed together and containing the powder in 50 ml Gin ~ beaker gegebs.-3 .-- i Bas Baehörglas was ⁰ C for 30 minutes in an oven at 35O gestallt, and then cooled to room temperature _o The theraogravimetric analysis showed that the Polymarisat Ms 400 ⁰ C was stable under nitrogen = the residue on ignition was black and glossy and had the original shape of the sample with a slight loss of mechanical strength.

Example WitlPfilW 'WwHII MiMMiIIiII W Uli «

A solution was prepared by adding 1000 ml of dimethylformamide and 100 ml of toluene, the 122 _t ? Weight in part "4.4 ^J " oxydianiline were added ^ mixed with one another. The solution was stirred until all of the diaiain had gone into solution and there were 58%. 8 pbw of maleic anhydride ind \ added slowly stirred until solution * To the solution was added about 100.8 parts by weight of 3,3 '4,4 ^t ₁ "Benz.ophenon" fceti ⁱ acaA'fconsäuredianhydrid added and the solution was lai 18 hours} .g boiled under reflux ₄ during which time the Waasep n was collected with the help of a Dean-Stark template. After the refluxing was complete, the solution was cooled to Zisimer temperature and filtered. A precipitate was collected and overnight at 110 ⁰ C dried under vacuum. Paa Piltr & t was slowly stirred in 10 l of vigorously stirred water and stirred overnight. A second precipitate was collected by filtration and dried overnight at 110 ⁰ O dried under vacuum. The first and second precipitates were ground separately with a mortar and pestle to a fine powder. "The yields for the first and second precipitates were 81.5 parts by weight or" 1? 3 "5 parts by weight.

Beis p iel \

Yeah Bimz? Lösung3raittelmischung of 700 ml of dimethylformamide and 700 ml! ÖluQl were about 87, '0 Gewiohtsteile 4 _t 4 ^l ~ 0xydianili.n

009831/1868

Dissolved in this solution were 39% by weight of maleic acid hydride and 65% by weight of 1% by weight of S-NaplitlialiatetsaoarboM-säiu? e ^ diaahgrdri & tragegebes® The solution was refluxed for 18 hours boiled vxs & the water was collected in a Baan-Stark-TTorlage »The solution was on ZiHraertsmperatuj? cooled and filtered "It © was collected in precipitation and laughs" dried at 110 ⁰ G sub Yakut® "The filtrate was slowly poured into wxö 7 X tteftig stirred water. fiüteea the irarde continued overnight" Bin sweiter precipitation

cteok ^ iltratioa gesaamslt "mad about" laughs at 110 ° 0 under getroctaiete Bea? First of all, the sweit © · 'precipitate were mixed separately to a fine powder.

As an alternative or in addition to the above mentioned ¥ erj: alireu, it may be desirable in the production of the polyimide prepolymerization to improve the cyclization of the amide acid to the polyimide by the condensation in counterpart from 5 to 10 % water acetate in glacial acetic acid completed "Sa can, for example, at the end of the period, if a stoichi © metric amount of water is not obtained, which indicates complete cyclization" remove the solvent under vacuum; and the product obtained was about 1/2 to 1 1/2 hours ntliält in-glacial acetic acid) d © r about 8% ÜJatriumacetat © ₄ erliitsrfc * Furthermore, it may be desirable to 0 «5 ΜθΛ, Ο 6öw _o% of a free Hadikal® delivering initiator _φ such as % <> B ₀ Äsobiaisobut ^ ronitril * siiJaugeTboAj to reduce the rate of polymerization in the final hardening stages

Except for the production of laminates plastisch® ,, "and the like are DI® © rfindungsgemäßen polyimides botjonders useful aur production iroa coatings _t since they besitssen in their Präpolymerisatform long © lagerungsbeetändigkeit and readily using known methods in inen © with aineax Pinish varsehenea coating converted will be able to. To the

BADORIQINAt 0.0.98 31 / '1868

creation of solutions and / or suspensions de? Polyimides _t with which a substrate can be coated and which. then to achieve © iiies hard film with good adhesion and flexibility can be cured versehiadene solvents can be used "The solvents used are typical solvents, and for example, organic liquids, such <B _e furfural _f butyrolactone, 1" H © thyl- 2-pyrrolidos * toluene, dimethylformamide * benzene, benzonitrile »dioxane» xylene, butyrenesctone, cyelohexane and mixtures thereof.

Although the present invention has been described in terms of a number of specific examples, it is clear. that other changes and modifications can be made without the scope of the present invention. as shown in particular in the following claims "is _f su

PATCNTAHWXLTC OR.-IHS. H. f INCB =, DIPL-IMG. H. BOK

009831/1868

Claims (1)

• 1 "Scfonsliiiärtendö high-molar thermoplastic polyimides * kulargevdeht * dadia? eh marked "that they from themselves y / iöder * · fetching units of a prepoly beer d @ r general For »· a, in the Κ, ι and H ₅ aromatic and / or aliphatic © Gruppea. mean xiaß. η ^ inea ¥ ert in the range from 1 to 8 possessed » 2 * Process kitp Manufacture of the tendon hardness ^ aer. Thermoplastic polyimides of high molecular weight according to claim 1, characterized in that they are produced by Polyserkcadencatior. by DiGBiitisn ,. Dianhydrides and maleic acid hydrides polymerized in ίΊ; νν & stoichiosistrischsa amounts eräpolyaeriE-at © "by TecLperaturoa above 20O ⁰ O pyrolyfeiscli,. 3o method according to claim 2 * dadiirch identified seiclinet ,, that the Iraid prepolymers have average molecular weights have at least 500 " 4ο method according to claim 2, characterized in _that% di fast curing polyimides durchsoimittliehe more than about 10 000 "foesitsea" 5 «Method according to Ansprueli 2 _f wherein _f gekeiinseichnefc that ALSs diamines, aromatic diamines uad as dianhydrides arosiirliä sohc Bianhydr-ide used DiiEgichnsi; - > ^: \ r & alt-: 6 «Method according to claim 5? thereby ßsk diamine phenylondiaruin and ale biarihydric. F hydride - / err; endöt to be «, _nflO11 / "", Patent attorneys OR.-INO.H. FlNCKD, DIPL-IHG. H. BOHR BAD OFIfQINAt