DE1520620C - Process for the production of molded articles and coatings from polyimides - Google Patents

Description

Aromatic polyimides are known for their chemical and thermal resistance. Because they neither easily melt or loosen, their deformation is difficult. From the French patent specification 1 256 203 it is known not to deform the polyimides, but rather precursors, namely polyamic acids, those during or after deformation by heat or treatment with compounds such as acetic anhydride and pyridine can be converted into polyimides. The polyamic acids often migrate however, already during storage in polyimides, while in other cases they are very are stable and only rearrange after exposure to temperatures appropriate for organic Materials are extraordinarily high.

The invention relates to a process for the production of moldings and coatings Polyimides made from aromatic diamines of the general formula

H ₂ NR ^ -NH ₂

(I)

20th

in which R ^{1 is} a divalent aromatic radical, each of the amino groups being on a different carbon atom of the radical R ¹ , and from dianhydrides of aromatic tetracarboxylic acids of the general formula

Il / ^c \

(Π)

30th

35

in which R is a tetravalent aromatic radical, each carbonyl group der'Anhydridringe directly to a different carbon atom that is part of an aromatic Ring is, the radical R is bonded and two carbonyl groups in ortho- or in peri-steepness are arranged to each other, built up are, which is characterized in that diester diacyl halides, which are derived from the dianhydrides of the above general formula (II) and which from these dianhydrides by reaction with aliphatic or substituted aliphatic alcohols with 1 to 12 carbon atoms, with phenol or with other aromatic alcohols and then by reaction with a thionyl halide, a phosphorus halide, a benzal halide, an oxalyl halide or a carbonyl halide, with at least one Diamine of the above general formula (I) in an inert organic solvent which at least the diamine dissolves, at temperatures below 175.degree. C. to form polyamic acid esters, the units of the general Structural formula

O
R ² - O - C _n

HN - Q '

' Il O

Il

/ C - O - R ²

Il ο

Have meaning and in which R ^{2 is} an alkyl or a substituted alkyl radical with 1 to 12 carbon atoms or an aryl radical, converts these polyamic acid esters into moldings or applies them to substrates and then by heating them to temperatures of at least 125 ° C or by treatment converted with a monocarboxylic anhydride into polyimide moldings or polyimide coatings.

The polyamic acid esters obtained according to the invention are sufficiently stable to be stored for a long time but on the other hand sufficiently unstable to be relatively easily converted into polyimides, if desired to be converted.

The inherent viscosity of the polyamic acid esters should be at least 0.1, preferably 0.3 to 5.0, at 30 ° C. measured on a 0.5% solution in a suitable solvent (e.g. concentrated Sulfuric acid or N, N-dimethylacetamide).

In the aromatic diamines of the general formula (I) used, R ¹ preferably denotes phenylene, naphthylene, diphenylene, anthrylene

Furylen, Benzfurylen and "ο 3C ator where R ^{3 is} an alkylene chain with 1 to - o - s - - SO; OR ⁴ O
Il I Il - N -
I. I I. I!
- C —N— —C - O - R ⁴ R ⁴
I. R ⁴ R ⁴
j I • I
T> - Si— "- O - Si-
I j -0 - O R ⁵ R ⁵
or
R ⁴

60

■ απ)

have, in which R and R ^{1 have} the abovementioned —O — PO—

Il ο

and R ⁴ and R ^{5 represent} unsubstituted or substituted alkyl or aryl groups.

Diamines that can be used include m - phenylenediamine, ρ - phenylenediamine, 2,2 - bis (4 - aminophenyl) - propane, 4,4 '- diamino - diphenyl - methane, 4,4' - diamino - diphenyl sulfide, 4,4 '- diamino - diphenyl - sulfone, 3,3' - diamino - diphenyl - sulfone, \ 4,4 '- diamino - diphenyl ether, 2,6-diamino-pyridine, bis (4-aminophenyl) diethyl - silane, bis - (4 - amino - phenyl) - diphenyl - silane, Benzidine, 3,3 '- dichlorobenzidine, 3,3' - dimethoxybenzidine, bis (4 - aminophenyl) - ethyl - phosphine oxide, Bis (4 - aminophenyl) - phenyl - phosphine oxide, bis - (4 - aminophenyl) - N - butylamine, bis (4 - aminophenyl) - N - methylamine, 1,5 - diamino - naphthalene, 3,3 '- dimethyl - 4,4' - diaminobiphenyl, N - (3 - amino-

phenyl) - 4 - aminobenzamide, 4 - amino - phenyl - - aminobenzoate and mixtures thereof.

In the aromatic tetracarboxylic acid dianhydrides used of the general formula (II), R is z. B.

wherein R ^{5 is the} same as R ³ or

- C -

Suitable dianhydrides are, for example

Pyromellitic dianhydride,

2,3,6,7-Naphthalene-tetracarboxylic acid dianhydride, S ^ '^^' - Diphenyl-tetracarboxylic acid dianhydride, 1,2,5,6-naphthalene-tetracarboxylic acid diannydride, 2,2 ', 3,3'-diphenyltetracarboxylic acid dianhydride, 2,2-bis- (3,4-dicarboxyphenyl) -propane-diane-

hydride,.

. Bis- (3,4-dicarboxyphenyi) -sulfon-dianhydride, 3,4,9,10-perylene-tetracarboxylic acid-dianhydride, Bis (3,4-dicarboxyphenyl) -ether-dianhydride, naphthalene-1,2,4,5-tetracarboxylic acid-dian-

hydride,
Naphthalene-1,4,5,8-tetracarboxylic acid-dian-

hydride,
2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic acid

dianhydride,
2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic acid

dianhydride,
2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetra-

carboxylic acid dianhydride,
Phenanthrene-1,8,9,10-tetracarboxylic acid dianhydride,

2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 1,1 -BisP ^ -dicarboxyphenylVethane dianhydride, l, l-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, Bis (3,4-dicarboxyphenyl) -metnan-dianhydride, bis (3,4-dicarboxyphenyl) -sulphone-dianhydride, Benzene-l ^^ - tetracarboxylic acid dianhydride, SAS '^' - Benzophenone-tetrecarboxylic acid-dian-

hydride,; .

^, S ^^ '- Benzophenone-tetracarboxylic acid-dian- *

hydride and ■

2,3,3 ', 4'-Benzophenone tetracarboxylic acid dianhydride.

The diester diacyl halides, which are derived from the dianhydrides of the above general formula (II) and for the preparation of which no protection is claimed here, are prepared in the following manner: The aromatic dianhydride, usually as a solid, is reacted with an alcohol to form the diester diacid . The alcohols that can be used include methanol, ethanol, n-propanol, iso'-propanol, the butanols, the pentanols, the hexanols, 2-ethylhexanol, isooctyl alcohol, lauryl alcohol, cyanoethanol and other aliphatic or substituted aliphatic alcohols containing 1 to 12 carbon atoms, phenol and other aromatic alcohols. The lower aliphatic alcohols are preferred. This reaction is carried out at room temperature. Excess alcohol is usually removed by distillation or extraction. The diester diacid obtained is then converted into the corresponding diester diacyl halide in a solvent at room temperature by means of a thionyl halide, a phosphorus halide, a benzal halide, an oxalyl halide or carbonyl halide.
The organic solvents which can be used as solvents are those whose functional groups do not react to any appreciable extent either with the diester diacid, the diester diacyl halide or the later added diamine. In addition to the inactivity towards the system and the preferred effect as a solvent for the polyamic acid ester, the organic solvent should represent a solvent for the diamines and preferably for all reaction components. In other words, the organic solvent is an organic liquid that is neither a reaction component nor a homologue of one of the reactants, is a solvent for the diamines and contains functional groups that are not primary and secondary amino groups and not dicarboxyl anhydro groups. The normally liquid organic solvents of the class of Ν, Ν-dialkylcarbon-. Acid amides can be used as solvents. The preferred solvents are the low molecular weight members of this class, in particular N, N-dimethylformamide and Ν, Ν-dimethylacetamide. They can easily be removed from the polyamic acid esters and / or the molded articles produced from the polyamic acid esters by evaporation, displacement or diffusion. Other typical compounds of this useful class of solvents are N, N - diethylformamide, N, N - diethylacetamide, Ν, Ν-dimethylmethoxy-acetamide and N-methylcaprolactam. Other solvents that can be used are dimethyl sulfoxide, N - methyl - 2 - pyrrolidone, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl phosphoramide, tetramethylene sulfone, formamide, N-methyl formamide and butyrolactone. These solvents can be used either alone, as a combination or in combination with poorer solvents such as benzene, benzonitrile, dioxane, xylene, toluene, acetone and cyclohexane. The solvents used in the preparation of the diester diacyl halides and later in their reaction with the diamines are preferably the same.
The reaction of the diester diacyl halides with at least one of the aforementioned diamines can be carried out in such a way that the diamine is added to a solution of the diester diacyl halide or

returns. The diamine is usually added in a solvent, generally the same solvent used for the diester diacyl halide. You can also add the diester diacyl halide alone to a solution of the diamine. The conversion is increased by slightly heating the reaction components, usually not above 100 ^° C., and by agitation. A starting temperature of 20 to 25 ° C is preferred. The maximum allowable temperature depends on the diamine used, the diester diacyl halide used, the solvent, the percentage of polyamic acid ester desired in the final mixture and the minimum time desired.

The polyamic acid ester composition can be stored for later use or it can be used immediately be deformed.

After deformation, e.g. B. to a thread, tube, rod, powder or a film, or after application to a substrate, the polyamic acid ester is converted into the polyimide. This is done by heating, so there is preferably used a temperature of at least 150 ° C. At 300 ⁰ C, the conversion takes place in about 10 minutes. The polyimide has the following structural formula

-N

R NR ¹ -

dipping, brushing, spraying) can be applied to substrates. Such documents are e.g. B. Copper, brass, aluminum, steel and other metals in the form of plates, fibers, or wires Seven, mineral structures such as asbestos, glass in the form of plates, fibers, foams or fabrics, polymeric materials such as cellulose products, wood, paper, polyolefins, polyesters, polyamides, polyimides, Perfluorocarbon polymers or polyurethanes in the form of "sheets, fibers, foams, woven and non-woven fabrics or screens, or sheets of leather. The polymeric substrates can be in front of metallized or coated with a conventional adhesive or other means be provided to improve the absorption capacity of the surface. Films made from the polyimide can with any of the above documents, often with the help of a commercially available adhesive, be laminated.

The polyamic acid esters are colorless or light yellow colored solid substances. They have strong ultra-red bands at 3.0 to 3.07 microns (N-H), at 5.8 microns (C = O bonds of the ester) and at 6.05 microns (C = O bonds of the amide):

The inherent viscosity was determined according to L. H. C r a g g, "Journal of Colloid Science", Vol. 1 (May 1946), Pp. 261 to 269, as

- inherent viscosity =

In relative viscosity

35

wherein R and R ^{1 have} the above meanings and η is an integer large enough to have an inherent viscosity of at least 0.1, preferably from 0.3 to 5.0, measured as a 0.5% solution in a suitable solvent.

The finished molded body can consist of polyimide alone or of a mixture with other polymers and / or modified with inert materials. Inert materials can be used before or after Shaping can be added. So z. B. fillers such as pigments, electrically conductive carbon black and electrically conductive metal particles, abrasives, dielectrics and lubricating polymers in more useful Way to the polymeric intermediate as such or a solution of the polymeric intermediate be added before shaping. Certain abrasives and electrically conductive Materials become more functional than surface layers upset. A cell structure or a foam of the polyimide can be formed by adding a conventional one Blowing agent to the polymeric intermediate and then heating to form the blowing agent to decompose and form the polyimide. As an alternative, cellular Products by dispersing bubbles (from air, carbon dioxide or nitrogen) in a melt or Solution of the polymeric intermediate can be produced before the deformation.

The liquid composition containing the polyamic acid ester can also be used either alone or after modification with fillers and / or blowing agents. according to customary techniques (doctor blade application; rolling on, defined, in which the relative viscosity is the ratio of the viscosity of the solution to the viscosity of the solvent and C is the concentration of the dissolved substance in the solution, measured in grams of the polymer per 100 ml of solution.

example 1

2.5 - Dicarbethoxy - tephthalic acid - chloride (0.03 mol) is mixed with an equimolar amount of y, y-bis- (4-aminophenyl) -propane in 30 ml Ν, Ν-dimethylacetamide reacted, the solution to was frozen to a pulp. Stirring is continued for 30 minutes. The hydrochloride of the solvent is neutralized. The solution is then cast into a film of the polyamic acid ester. the inherent viscosity of this polyamic acid ester, measured as a 0.5% solution in N, N-dimethylacetamide, 0.60. A 16-hour exposure to a steam bath changes this very little. Heating at 300 ° C for 10 minutes completely converts the polyamic acid ester into the corresponding one Polyimide around.

The polyamic acid esters are therefore much more stable to hydrolysis under neutral conditions than the corresponding polyamic acids.

Example 2

A solution of 3.24 g (0.03 mol) of m-phenylenediamine in 60 ml of freshly distilled N, N-dimethylacetamide is frozen in a dry ice bath. For this 10.41 g (0.03 mol) of 2,5-dicarbethoxy-tephthalic acid chloride are added. The reaction mixture forms a solid slurry. The one from .this Slurry isolated polyamic acid ester has an inherent viscosity of 0.24 in concentrated sulfuric acid.

If this reaction is repeated with the diamine solution at room temperature, the reaction mixture becomes very hot and cloudy. After about 5 minutes the mixture solidifies into a solid paste. The polyamic acid ester isolated therefrom has an inherent one Viscosity of 0.28 in concentrated sulfuric acid and can be obtained after diluting the paste with Ν, Ν-dimethylacetamide cast into a film or extruded into a thread.

The polyamic acid ester does not have a polymer melting temperature, but changes beforehand when heated to about 200 ° C into the corresponding polyimide.

B ei s ρ i e 1 3

To 3.39 g of 2,2 - bis (4 - aminophenyl) - propane in 20 ml of Ν, Ν-dimethylacetamide in an ice bath 5.20 g of 2,5-dicarbethoxytherephthalic acid chloride were added in one shot. The reaction mixture quickly turns into a yellow viscous solution, from which the polyamic acid ester is isolated in 3 ways will. Precipitation with water gives a polyamic acid ester with an inherent viscosity of 0.60 (in N, N-dimethylformamide). A sample precipitated and washed in methanol has an inherent one Viscosity of 0.66 in concentrated sulfuric acid and of 0.70 in Ν, Ν-dimethylformamide (after one hour Heating to 100 ° C and cooling). A third part of the original solution is about Heated on a steam bath for 45 minutes. The inherent viscosity of the precipitated polyamic acid ester is 0.64 in concentrated sulfuric acid. The precipitated polyamic acid ester can be in powder form are present. The powder can be pressed into a plate.

The polyamic acid ester does not have a polymer melting temperature, but changes at the Heat to about 200 ° C into the corresponding polyimide.

• Example 4

Example 5

The corresponding polyamic acid methyl ester, which has an inherent viscosity of 0.66, is in in the same way using 2,5-dicarbmethoxy-tephthalic acid chloride manufactured. Both esters can be stored in solution and later be shaped into useful objects.

The polymeric product has no polymer melt temperature, but transforms on heating to about 200 ° C in the corresponding polyimide in order.

Example 6

To a solution of 0.020 g mol of diethyl pyromellitic acid dichloride (the same product as in Examples 1, 2, 3 and 5) in 75 ml of Ν, Ν-dimethylacetamide an equimolar amount of 4,4'-diamino-diphenyl-ether, dissolved in 75 ml Ν, Ν-dimethylacetamide, added. After 20 minutes it becomes inherent Viscosity of the polyamic acid ester determined, which is 0.61. The polyamic acid ester is through Adding a small amount of triethylamine to the solution and heating for 35 minutes converted into the corresponding polyimide under reflux at the boiling point (165 to 170 ° C).

Claims (1)

Claim: 30th 35 4 ° Process for the production of moldings and coatings from polyimides, those from aromatic diamines of the general formula H ₂ NR ¹ -NH ₂ in which R ^{1 is} a divalent aromatic radical, each of the amino groups being on a different carbon atom of the radical R ¹ , and from dianhydrides of aromatic tetracarboxylic acids of the general formula To a solution, cooled in an ice water bath, of 1.08 g of m-phenylenediamine in 13 ml of Ν, Ν-dimethylacetamide 3.97 g of 2,5-dicarb - (/? - cyanethoxy) -therephthalic acid chloride admitted in one shot. The reaction mixture becomes very quickly, extremely hot. After cooling it separates the polyamic acid ester peeled off to some extent, but went off when heated or after Adding solvent back into solution. The inherent viscosity of this polymeric product is in concentrated sulfuric acid 0.19. The solution can be stored and then in conventional Way to be cast into a foil or shaped into a thread. · The polymeric product does not have a polymer melting temperature, but changes when heated to about 200 ° C into the corresponding polyimide. A, OR _{n 6o} A solution of 8.68 g (0.035 mol) of 4,4'-diaminodiphenyl sulfone in 60 ml of Ν, Ν-dimethylacetamide is frozen in a dry ice bath. Then 12.145 g of 2,5-Dicarbäthoxy-terephthalic acid chloride in admitted to a shot. After the reaction has occurred, the product is isolated. It has a inherent viscosity of 0.62 in Ν, Ν-dimethylformamide. in which R is a tetravalent aromatic radical, each carbonyl group of the anhydride rings directly to another carbon atom that is part of an aromatic ring, the radical R is bonded and each two carbonyl groups arranged in ortho- or in peri-position to one another are built up, characterized in that diester diacyl halides, which are derived from the dianhydrides of the above general formula (II) and which from these dianhydrides by reaction with aliphatic or substituted aliphatic Alcohols with 1 to 12 carbon atoms, with phenol or with other aromatic alcohols and then by reaction with a thionyl halide, a phosphorus halide, a Benzal halide, an oxalyl halide or a carbonyl halide have been produced, 209 622/71 with at least one diamine of the above general formula (I) in an inert organic Solvent that dissolves at least the diamine, R ² —O - ίο at temperatures below 175 ° C to polyamide acid esters, the units of the general structural formula ο. ο have, in which R and R ^{1 have} the meaning given above and in which R ^{2 is} an alkyl or a substituted alkyl radical having 1 to 12 carbon atoms or an aryl radical, converts these polyamic acid esters into molded articles —O —R ² ^ C - NH - R ¹ Hi-...: (III) forms or applies to substrates and then by heating to temperatures of at least 125 ° C or by treatment with a monocarboxylic anhydride in polyimide molding or Transferred polyimide coatings.