DE4328270A1 - Polyimide and polyamic acid compsns. modified with polyarylene ether - used in prodn. of flexible laminate with metal foil esp. for printed circuit with good solvent resistance and low thermal expansion coefft. - Google Patents

Abstract

The claim cover : compsns. (I) contain 75-99 wt.% homo- or copolyimide (II) and 1-25 wt.% polyarylene ether (III), comprising 1-100 mole.% units of the formula -(-Ar1-O-Ar2-O-)- (IIIA) and 99-0 mole.% units of the formula -(-Ar3-O-Ar2-O-)- (IIIB); and (b) compsns. (IV) contg. 75-99 wt.% polyamic acid (V) and 1-25 wt.% (III). (II) comprises 75-100 mole.% units of formula (IIA) and 0-25 mole.% units of formula (IIB); and (V) comprises 75-100 mole.% units of formula (VA) and 0-25 mile.% units of formula (VB). In the formulae, R is 1-6C alkyl, 1-6C alkoxy, 6-14C aryl or halogen; n is 0-4; R1 is e.g. 2-12C alkylene, -Phe-, -PHe-CH2-, -CH2-Phe-CH2-, -Naph-, -Phe-X-Phe- etc.; X is e.g. a direct bond, -CH2- -CHMe-, -S-, -O-, -SO2-, -CO-, -NHCO- etc.; R2 is e.g. phen-1,2,4,5-tetrayl, naphth-1,4,5,8-tetrayl, diphenyl-2,2',3,3'-tetrayl, =Phe'-X-Phe'=, =Phe'-X-Phe=X-Phe'= etc.; Ar1 is e.g. -Phe-, -PHe-Phe-, phenyl-substd.-Phe-, -Naph-, -Phe-Z-Phe-, -Phe-Z-Phe-Z-Phe- etc. ; Z is e.g. -CH2-, -CMe2-, -C(Me)(Ph)-, -C(CF3)2-, -S-, -O-, -SO-, -SO2- etc.; Q is a direct bond, -CH2-, -O- or -CO-; Ar2 is -Phe"-Y-(Phe-Y-)a-Phe"-, -Phe"-Y-(Phe-)b-Y--Phe"-, cyanophenylene, pyridindiyl or pyridazindiyl; Y is -SO-, -SO2- or -CO-; a is 0 or 1; b is 2 or 3; Ar3 = as Ar1 or p-quinon-2,5-diyl. -Phe- is phenylene; -Naph- = naphthylene; -Cyc- is cyclohexylene; -Cyc'- is 1,4-cyclohexylene; =Phe'- and -Phe= are phen=1,3,4-tetrayl; -Phe"- is p-phenylene; in R1-2 and Ar1-3, the aromatic and cycloaliphatic rings may have 1-6C alkyl, 1-6C alkoxy or halo substit(s). Prodn. of flexible laminates is also claimed. USE/ADVANTAGE - (I) are used in laminates of metal foil(s), pref. Cu foil, and directly applied film(s) of (I); and (IV) in the prodn. of flexible laminates with metal foils (claimed). The laminates are useful for making electrical circuits, esp. printed circuits. (I) can be used as matrix resins, lacquers, adhesives and coatings for making various industrial prods., e.g. fibre-reinforced composites, films, sheets or compression mouldings. Addn. of (II) makes (I) highly flexible, without impairing the high solvent resistance and low coefft. of thermal expansion of (II).

Description

The present invention relates to polyimide / polyarylene ether compositions, Polyamic acid / polyarylene ether compositions, laminates based thereon Compositions and a process for their preparation.

Polyimides are found due to their very good mechanical, thermal and electrical Properties versatile applications in the electrical and electronics industry. When Coating materials for metal foils for the production of flexible laminates are the usual polyimides, however, are not very suitable since they are typical of polymers have coefficients of thermal expansion which are generally considerably higher lie than that of metals. Different coefficients of thermal expansion between base material and metal can lead to undesirable laminate properties, such as Rolls or warps.

U.S. Patent 4,690,999 discloses specific aromatic based polyimides Diamines, which have low coefficients of thermal expansion and are used for Suitable for the production of laminates. However, the flexibility of laminates is based these polyimides are insufficient for certain applications.

By adding thermoplastic polymers, such as. B. polyether sulfones, the Increase flexibility. For example, in JP-A 63/304057 and JP-A 63/304056 describes blends of specific polyetherimides and polysulfones, the u. a. for the production of molded plastic parts in the electrical and automotive industries can be used. However, these compositions have that for polymers typical high thermal expansion coefficients as well as an insufficient Resistance to solvents.

It has now been found that laminates with high flexibility are obtained when as Coating material is a polyimide with low thermal expansion Coefficient used with a defined amount of a specific Polyarylene ether is modified. Surprisingly, the addition of the  thermoplastic polyarylene ether no adverse change in thermal Expansion and solvent resistance.

The present invention relates to compositions comprising

• (a) 75-99% by weight, based on the total composition, of a homo- or copolyimide containing 75-100 mol% of recurring structural elements of the formula (I) and 0-25 mol% of recurring elements different from the formula (I) Structural elements of the formula (II) wherein in the formula (I) R is C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, C ₆ -C ₁₄ aryl or halogen and n is an integer between 0 and 4, in which in the formula (II) R _{1 is} a straight-chain or branched C ₂ -C ₁₂ alkylene radical or a radical of the formulas (IIIa) - (IIIl) wherein the bridge members X independently of one another for a direct bond, -CH ₂ -, -CH (CH ₃ ) -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -S-, -O-, -SO ₂ -, -CO- or -NHCO-,
  R _{2 represents} a radical of the formulas (IVa) - (IVk) in which X has the meaning given above and in which the aromatic or cycloaliphatic rings in the formulas (IIIa) - (IIIl) and (IVa) - (IVk) are unsubstituted or by one or more C ₁ -C ₆ -alkyl groups, C ₁ -C ₆ alkoxy groups or halogen atoms are substituted, and
• (b) 1-25 wt .-%, based on the total composition of a polyarylene ether containing 1-100 mol% recurring structural elements of the formula (Va) Ar₁-O-Ar₂-O (Va) and 99-0 mol% recurring Structural elements of the formula (Vb) Ar₁-O-Ar₂-O (Vb) wherein Ar _{1 is} a radical of the formulas (VIa) - (VIi) wherein Z-CH ₂ -, -C (CH ₃ ) ₂ -, -C (CH ₃ ) (C ₆ H ₅ ) -, -C (CF ₃ ) ₂ -, -S-, -O-, -SO- , -SO ₂ -, or -CO- means Q is a direct bond, -CH ₂ -, -O- or -CO-,
  Ar _{2 represents} a radical of the formulas (VIIa) - (VIIe) where Y is -SO-, -SO ₂ - or -CO-, a is the number 0 or 1 and b is the number 2 or 3,
  Ar _{3 has} one of the meanings given for Ar ₁ or for a radical of the formula and in which the aromatic or cycloaliphatic rings in the formulas (VIa) - (VIi) and (VIIa) - (VIIe) are unsubstituted or substituted by one or more C ₁ -C ₆ -alkyl groups, C ₁ -C ₆ -alkoxy groups or halogen atoms are.

Are the aromatic or cycloaliphatic rings in the formulas (IIIa) - (IIIl), (IVa) - (IVk), (VIa) - (VIi) or (VIIa) - (VIIe) by C ₁ -C ₆ alkyl groups or C When C ₁ -C ₆ alkoxy groups are substituted or R in the formula (I) is C ₁ -C ₆ alkyl or C ₁ -C ₆ alkoxy, these are branched or, in particular, straight-chain radicals.

Examples of alkyl groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl and n-hexyl.

Examples of alkoxy groups are methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy and n-hexoxy.

Are the aromatic or cycloaliphatic rings in the formulas (IIIa) - (IIIl), (IVa) - (IVk), (VIa) - (VIi) or (VIIa) - (VIIe) are substituted by halogen atoms or R in the formula (I) for halogen, it is fluorine, iodine or in particular Chlorine or bromine.

R as C ₆ -C ₁₄ aryl can be, for example, phenyl, biphenyl, naphthyl or anthryl.

The aromatic or cycloaliphatic rings in the formulas (IIIa) - (IIIl), (IVa) - (IVk), (VIa) - (VIi) or (VIIa) - (VIIe) are preferably unsubstituted.

In formula (I), n is preferably zero.

Polyimides are preferably used as component (a), in which R ₁ in the formula (II) for

and R _{2 is} a radical of the formulas (IVa), (IVb), in which X is -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -O-, -SO ₂ - or -CO- , or (IVk) means.

Particularly preferred as component (a) are polyimides, in which R ₁ in the formula (II) is

and R _{2 is} a radical of the formulas

represents.

Component (b) is preferably a polyarylene ether containing recurring structural elements of the formula (Va), in which Ar _{1 is}

and Ar _{2 represents} a remainder of the formulas

represents.

Particularly preferred as component (b) are polyarylene ethers containing recurring structural elements of the formula (Va), in which Ar _{1 is}

means.

Also preferred as component (b) are polyarylene ethers containing recurring structural elements of the formula (Vb), in which Ar _{3 is}

stands.

The compositions according to the invention preferably contain 85-98% by weight,  in particular 88-96% by weight of component (a) and 2-15% by weight, in particular 4-12% by weight of component (b).

Component (a) of the compositions according to the invention preferably contains 90-100 mol%, in particular 95-100 mol%, of structural elements of the formula (I) and 0-10 mol%, in particular 0-5 mol%, structural elements of the formula (II).

Polyimides containing recurring structural elements of the formula (I) are known from US Pat. No. 4,690,999 and can be prepared by known methods, for example by polycondensation of 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride and p-phenylenediamine or by one or more C ₁ -C ₆ alkyl groups, C ₁ -C ₆ alkoxy groups or halogen atoms substituted p-phenylenediamine and subsequent cyclization of the polyamic acid thus obtained to the corresponding polyimide at elevated temperature or with the addition of cyclizing agents, such as. B. a mixture of acetic anhydride and triethylamine.

The copolyimides containing structural elements of the formula (I) and up to 25 mol% Structural elements of formula (II) can be synthesized in an analogous manner to Example by reaction of a mixture of 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride and one or more tetracarboxylic acid dianhydrides of the formula (X)

wherein R _{2 has} the same meaning as in formula (II), with a mixture of unsubstituted or substituted by one or more C ₁ -C ₆ alkyl groups, C ₁ -C ₆ alkoxy groups or halogen atoms, p-phenylenediamine and a diamine of the formula (XI)

H ₂ NR ₁ -NH ₂ (XI)

wherein R _{1 has} the same meaning as in formula (II) and subsequent cyclization of the polyamic acid thus obtained.

Further possible display methods for polyimides containing structural elements of the Formula (I) or copolyimides containing structural elements of the formulas (I) and (II) are for example the reaction of tetracarboxylic acid derivatives, e.g. B. the tetracarboxylic acid diester or the tetracarboxylic diester dichloride, with diamines or the reaction of Diisocyanates with tetracarboxylic anhydrides.

Examples of suitable tetracarboxylic dianhydrides of the formula (X) are: Pyromellitic dianhydride, benzophenone-3,3 ′, 4,4′-tetracarboxylic dianhydride, 2,2 ′, 5,5,6,6′-hexafluorobenzophenone-3,3 ′, 4,4′-tetracarboxylic acid dianhydr-id, 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride, diphenylmethane 3,3 ′, 4,4′-tetracarboxylic acid dianhydride, diphenyl ether-3,3 ′, 4,4′-tetracarboxylic acid dianhydride, 2,2 ′, 5,5′6,6′-hexafluorodiphenyl ether-3,3 ′, 4,4′tetracarboxylic acid dianhydride, Diphenylsulfone-3,3 ′, 4,4′tetracarboxylic acid dianhydride, bicyclo [2.2.2] octene-7-tetracarbon acid-2,3,5,6-dianhydride, cyclopentane-2,3,4,5-tetracarboxylic acid dianhydride or 5- (2,4-Dioxotetrahydrofurfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride (Epiclon®B 4400 from Dainippon Ink).

Suitable diamines of the formula (XI) are, for example, the unsubstituted or substituted with one or more C ₁ -C ₆ alkyl groups, C ₁ -C ₆ alkoxy groups or halogen atoms, o-, m- and p-phenylenediamine, m-xylylenediamine, 4, 4'-diamino diphenylmethane, 3-ethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diamino diphenylmethane 4,4'-diaminodiphenyl-2,2-propane, 4,4'-diamino - 2.2 ', 3.3', 5.5 ', 6,6'-octafluorodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylthioether, 4,4'-diaminodiphenyl sulfone , 3,3'-diaminodiphenyl sulfone, 3,3 ', - or 4,4'-diaminobenzophenone, 1.8 or 1.5 diamine naphthalene, bis (4-aminocyclohexyl) methane and bis (3-aminocyclohexyl) - methane.

The polyarylene ethers (component (b) of the compositions according to the invention) containing structural elements of the formula (Va) and (Vb) are also known and Part commercially available.

They can be made by known methods, for example by how e.g. B. described in EP-A 388 358, a dihalo compound of formula (XII)

Hal-Ar ₂ -Hal (XII)

wherein Hal is halogen, in particular fluorine or chlorine and Ar _{2 has} the same meaning as in the formulas (Va) and (Vb), with a dihydroxy compound of the formula (XIIIa)

HO-Ar ₁ -OH (XIIIa)

wherein Ar _{1 has} the same meaning as in formula (Va), or with a mixture of a compound of formula (XIIIa) and a dihydroxy compound of formula (XIIIb) contained therein up to 99 mol%,

HO-Ar ₃ -OH (XIIIb)

wherein Ar _{3 has} the same meaning as in formula (Vb), polycondensed in a conventional manner in the presence of alkaline catalysts in a polar aprotic solvent.

Suitable dihalogen compounds of the formula (XII) are, for example, 4,4'-difluoro benzophenone, 2,6-difluorobenzonitrile, 4,4′-dichlorobenzophenone, 1,3-bis (4-fluorobenzoyl) benzene and preferably 4,4'-difluorodiphenyl sulfone and 4,4'-dichlorodiphenyl sulfone.

The dihydroxy compounds of the formulas (XIIIa) and (XIIIb) are also known and some are commercially available. Examples include hydroquinone, bisphenol-A, Bisphenol-F, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxybenzophenone, phenylhydroquinone, 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 9,9-bis (4-hydroxyphenyl) fluorene, 2,2'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 2,5-dihydroxybenzoquinone and preferably 4,4'-dihydroxydiphenyl sulfone.

Examples of commercially available polyarylene ethers of the formula (Va) are Victrex® (ICI), Ultrason® (BASF), Radel® (Amoco) and Udel® (Amoco).

The compositions according to the invention can be used, for example, as matrix resins, Paints, adhesives and coating compositions for the manufacture of industrial products of all kinds, such as fiber-reinforced composites, laminates, bonds, Coatings, films, foils or compacts can be used.  

Before processing the powder, film, suspension or dispersion Mixtures can be conventional additives, such as fillers, pigments, Stabilizers or reinforcing agents, such as carbon, boron, metal or glass fibers, be added. A leveling agent is preferably added (e.g. BYK® S 706).

As suitable substrates that are suitable for coating with the invention Suitable compositions are mentioned: metals or alloys, such as copper, Brass, aluminum or steel, glass fiber materials, and polymers, such as. B. polyester or polyamides.

The coatings with the polyimide / polyarylene ether according to the invention Compositions are characterized by good adhesion, preferably to metals, and by a low coefficient of thermal expansion. The Compositions according to the invention are therefore preferably for the production of suitable for flexible laminates.

Laminates containing at least one therefore form a further subject of the invention Metal foil and at least one layer of a directly applied thereon polyimide / polyarylene ether composition according to the invention.

A copper foil is preferably used as the metal foil in the laminates according to the invention used.

Preferred use of such laminates, which are very flexible and free of warping and can be folded several times without breaking, i.e. a high, so-called "Flex-life" takes place in the electronics industry for the manufacture of circuits, especially printed circuits.

The metal foils coated in this way can be used directly for the production of printed circuits can be used by using the on the metal side with a Photoresist-coated film exposed through a photomask and the exposed metal film developed in a known manner. Flexible, printed circuits are obtained.

The compositions according to the invention from the polyimide (a) and the Polyarylene ethers (b) are usually due to the high proportion of polyimide  only slightly soluble in common organic solvents. With certain Applications, e.g. B. in the production of laminates, is a high level of homogeneity Mixtures advantageous, which are best when processing from a solution to achieve.

In a preferred embodiment of the invention, the Polyarylene ether (b) and instead of the polyimides (a) their (soluble) precursors, namely the corresponding polyamic acids (c), dissolved in an organic solvent and on applied the metal foil. In a subsequent drying process at higher Temperatures, for example above 40 ° C. and preferably above 100 ° C., and optionally with IR radiation, the solvent is removed and the Polyamic acid cyclized with elimination of water to the corresponding polyimide.

A further subject of the invention thus form compositions

• (c) 75-99% by weight, based on the total composition, of a polyamic acid containing 75-100 mol% of recurring structural elements of the formula (VIII) and 0-25 mol% of recurring structural elements of the formula different from the formula (VIII) (IX) wherein R, n, R ₁ and R _{2 have} the same meaning as in the formulas (I) and (II) and
• (d) 1-25% by weight, based on the total composition, of those defined above Component (b).

Suitable organic solvents for the inventive Polyamic acid / polyarylene ether compositions are, for example, N, N-dimethyl acetamide, N, N-diethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N-methyl-ε-caprolactam, N, N, N ′, N ′, - tetramethyl urea, Sulfolane, dimethyl sulfoxide and γ-butyrolactone.

Mixtures of such solvents and mixtures of these are preferred Solvents with other inert organic solvents, such as Toluene, xylene, cyclohexane, pentane, hexane, petroleum ether, methylene chloride, Tetrahydrofuran, cyclohexanone or dioxane can be used.

The coating of the metal foils with the inventive Polyamic acid / polyarylene ether compositions can be used either by hand or with Coating machines are made. When it comes to coating, it is only important that a tack-free coating is obtained so that this laminate if desired can be rolled up.

After application of the polyamic acid / polyarylene ether The metal foils coated in this way become compositions at temperatures above 40 ° C, preferably above 100 ° C, especially above 200 ° C, and optionally dried under IR radiation. The solvent evaporates, and the Polyamic acid is cyclized to the corresponding polyimide.

Another object of the invention is a method for producing flexible Laminates, characterized in that a metal foil with a solution from a polyamic acid / polyarylene ether composition according to the invention in one organic solvent is coated and then the coated film Temperatures above 40 ° C, preferably above 100 ° C, especially above 200 ° C as long as it is dried until the solvent is completely removed.

The laminates obtained in this way are characterized by high solvents resistance, high flexibility and low thermal expansion coefficients.  

Examples I. Synthesis of polyamic acids 1.1. Polyamic acid 1

In a double-jacket reaction vessel with an internal thermometer and stirrer Inert gas 176.53 g (0.6000 mol) 3.3 ', 4,4'-biphenyltetracarboxylic acid dianhydride and 850 g Weighed in N-methylpyrrolidone (NMP). The reaction vessel is evacuated three times and gassed with nitrogen. After cooling to -7 ° C, the suspension is within 45 min 64.92 g (0.6000 mol) of p-phenylenediamine were added in portions under nitrogen. To Adding 150 g of NMP, the reaction mixture is warmed to room temperature and left overnight. The solution is then stirred at 34 ° C. for 8 h. The so obtained solution with an inherent viscosity (0.5 wt .-% solid in NMP at 25 ° C) of 1.30 dl / g is used in the following application examples.

I.2. Polyamic acid 2

Analogous to the preparation of polyamic acid 1 described above is a polyamic acid from 0.6058 mol 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride, 0.5995 mol p-phenylenediamine and 0.0126 mol m-anisidine with an inherent viscosity of 1.37 dl / g.

II. Polyarylene ethers used

In the following application examples, the following, e.g. T. commercial available polyarylene ether used:

• A) Victrex® 5003 P (ICI) containing recurring units of the structure
• B) Ultrason® E 2010 (BASF) containing repeating units of the structure
• C) Udel® P 1800 (Amoco) containing recurring units of the structure
• D) Polyether sulfone of the following structure

The above-mentioned copolymer D) is prepared analogously to the general process described in EP-A 388 358 by condensation of 0.1807 mol of 4,4'-dihydroxydiphenyl sulfone, 0.0203 mol of 2,5-dihydroxybenzoquinone and 0.2001 mol of 4, 4'-dichlorodiphenylsulfone using xylene as an entrainer (reaction conditions: 1 h / 224 ° C, 1 h / 254 ° C, 4 h / 281 ° C).
Reduced viscosity (1 g polymer dissolved in 100 ml NMP at 25 ° C): 0.17 dl / g
Glass transition temperature: 187 ° C

III. Preparation of the polyamic acid-polyarylene ether mixture and properties of the Laminates

To the polyamic acid solution prepared according to Example I. a solution is one of the Polyarylene ether A-D in NMP (20 wt .-%) added, so that those listed in Table 1 Weight ratios of polyamic acid / polyarylene ether result. Both Compositions of Examples 1-7 and Comparative Examples 12 and 13 contain the Solution additionally a leveling agent (BYK 5706) in a concentration of 0.5% by weight (based on total solids).  

To produce a flexible laminate, this mixture is made using a lacquer dumbbell applied to a copper foil (layer thickness: 200 µm in Examples 1-7 and 12-13, 60 µm in Examples 8-11). The coated copper foil is then in the Circulating air drying cabinet dried, the polyamic acid / polyarylene ether mixture is cyclized to the corresponding polyimide / polyarylene ether mixture.

In Examples 1-7 and 12-13, the coated film is used during drying additionally irradiated with IR light (IR lamp: Heraeus model MMs 1200).

A measure of the flexibility of the laminate is the so-called "Flex-Life", i. H. the number of Folds until the laminate breaks, using the Universal Model 2 FDF Flex Ductility Tester with tensile weight 224 g and 2 mm mandrel is determined.

The solvent resistance of the laminate is based on the weight change one or two hours immersion in NMP measured.

The property values of the laminates of Examples 1-11 according to the invention and of Comparative examples 12 and 13 are given in Table 1.

The laminates according to the invention have a very good flat lay and surfaces texture and a compared to a pure polyimide laminate (Comparative Example 12) significantly higher flexibility without the solvents stability is significantly affected. In contrast, with a pure Polyethersulfone copper laminate the polymer coating during an hour Immersion in NMP completely dissolved (Comparative Example 13).  

Table 1

Flex-life and solvent stability

IV. Determination of the linear coefficient of thermal expansion

As in Example III. a copper foil with a Polyamic acid / polyarylene ether mixture of the composition given in Table 2 coated and in a circulating air dryer for 1 h at 220 ° C and then 1 h at 299 ° C dried, the polyamic acid being cyclized to the corresponding polyimide.  

The copper layer is then etched off. After washing and drying the linear thermal expansion coefficient α of the resulting film measured (Mettler TMA). In the range between 50 ° C and 280 ° C, the results given in Table 2 result Averages.

Table 2

Linear coefficient of thermal expansion

Claims (15)

1. Containing compositions

• (a) 75-99% by weight, based on the total composition, of a homo- or copolyimide containing 75-100 mol% of recurring structural elements of the formula (I) and 0-25 mol% of recurring elements different from the formula (I) Structural elements of the formula (II) wherein in the formula (I) R is C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, C ₆ -C ₁₄ aryl or halogen and n is an integer between 0 and 4, in which in the formula (II) R _{1 is} a straight-chain or branched C ₂ -C ₁₂ alkylene radical or a radical of the formulas (IIIa) - (IIIl) wherein the bridge members X independently of one another for a direct bond, -CH ₂ -, -CH (CH ₃ ) -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -S-, -O-, -SO ₂ -, -CO- or -NHCO-,
  R _{2 represents} a radical of the formulas (IVa) - (IVk) in which X has the meaning given above and in which the aromatic or cycloaliphatic rings in the formulas (IIIa) - (IIIl) and (IVa) - (IVk) are unsubstituted or by one or more C ₁ -C ₆ -alkyl groups, C ₁ -C ₆ alkoxy groups or halogen atoms are substituted, and
• (b) 1-25 wt .-%, based on the total composition, of a polyarylene ether containing 1-100 mol% recurring structural elements of the formula (Va) Ar₁-O-Ar₂-O (Va) and 99-0 mol% recurring Structural elements of the formula (Vb) Ar₃-O-Ar₂-O (Vb) wherein Ar _{1 is} a radical of the formulas (VIa) - (VIi) wherein Z is -CH ₂ -, -C (CH ₃ ) ₂ -, -C (CH ₃ ) (C ₆ H ₅ ) -, -C (CF ₃ ) ₂ -, -S-, -O-, -SO- , -SO ₂ -, or -CO- means Q is a direct bond, -CH₂-, -O- or -CO-,
  Ar _{2 represents} a radical of the formulas (VIIa) - (VIIe) where Y is -SO-, -SO ₂ - or -CO-, a is the number 0 or 1 and b is the number 2 or 3,
  Ar _{3 has} one of the meanings given for Ar ₁ or one of the radicals of the formula and in which the aromatic or cycloaliphatic rings in the formulas (VIa) - (VIi) and (VIIa) - (VIIe) are unsubstituted or by one or more C ₁ -C ₆ -alkyl groups, C ₁ -C ₆ -alkoxy groups or halogen atoms are substituted.

2. Compositions according to claim 1, comprising as component (a) a polyimide, wherein in formula (I) the number 0. 3. Compositions according to claim 1, containing as component (a) a polyimide, wherein R ₁ in formula (II) for and R _{2 is} a radical of the formulas (IVa), (IVb),
where X is -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -O-, -SO ₂ - or -CO-, or (IVk). 4. Compositions according to claim 1, containing as component (a) a polyimide, wherein R ₁ in the formula (II) for and R _{2 is} a radical of the formulas represents. 5. Compositions according to claim 1, containing as component (b) a polyarylene ether containing recurring structural elements of the formula (Va), wherein Ar ₁ for and Ar _{2 represents} a remainder of the formulas represents. 6. Compositions according to claim 1, containing as component (b) a polyarylene ether containing recurring structural elements of the formula (Va), wherein Ar ₁ for stands and- means. 7. Compositions according to claim 1, comprising as component (b) a polyarylene ether containing recurring structural elements of the formula (Vb),
wherein Ar ₃ for stands. 8. Compositions according to claim 1, containing 85-98% by weight of component (a) and 2-15% by weight of component (b). 9. Compositions according to claim 1, containing 88-96 wt .-% of component (a) and 4-12% by weight of component (b). 10. Compositions according to claim 1, containing as component (a) a polyimide containing 90-100 mol% of structural elements of the formula (I) and 0-10 mol% Structural elements of formula (II). 11. Compositions according to claim 1, containing as component (a) a polyimide containing 95-100 mol% of structural elements of the formula (I) and 0-5 mol% Structural elements of formula (II). 12. Laminates containing at least one metal foil and at least one directly thereon applied plastic layer of a composition according to claim 1. 13. Laminates according to claim 12, wherein the metal foil is a copper foil.   14. Containing compositions

• (c) 75-99% by weight, based on the total composition, of a polyamic acid containing 75-100 mol% of recurring structural elements of the formula (VIII) and 0-25 mol% of recurring structural elements of the formula different from the formula (VIII) (IX) wherein R, n, R ₁ and R _{2 have} the same meaning as in claim 1 and
• (d) 1-25% by weight, based on the total composition, of component (b) defined in claim 1.

15. A process for the production of flexible laminates, characterized in that a metal foil with a solution of a polyamic acid / polyarylene ether The composition of claim 14 coated in an organic solvent is and the coated film then at temperatures above 40 ° C as long is dried until the solvent is completely removed.