DE1645434A1 - Process for the production of high-temperature-resistant, flexible polycondensates - Google Patents

Description

Process for the production of high-temperature-resistant, flexible

Polycondensates

It is known to produce high-temperature-resistant, very tough polypyromeliithimides from pyromellitic dianhydride and diamines. In addition to their high thermal resistance, these products are also characterized by their ability to shield high-energy rays. They also have very good electrical properties, so that they can be used as an insulating material even at high temperatures. The mechanical and electrical properties of this class of materials are kept practically constant over a wide temperature range. The polyimides are generally produced. by reaction of the dianhydride (I) itself, the tetracarboxylic acid formed from the dianhydride by reaction with water (III ¹ R = H) or with the diester dicarboxylic acid formed by reaction with alcohols (ilj R = alkyl) with a primary diamine (H ₂ NR ^f -NH ₂ ), heating the reaction product to relatively low temperatures * whereby mainly linear, alkali-soluble polyamide-carboxylic acids (III) are formed and finally by heating this substance to temperatures around 3> oo °, whereby the formation of the five-membered imide rings ( VJ) is carried out.

-R ¹ / -N

IV

It has been found that the precondensation stage (TTl) i. a. still some solubility in solvents and a melting point below the decomposition point of the substance. The finished product, on the other hand, is I. a. remeltable and in Organic solvents, apart from phenols in some types, are no longer soluble, so that the last stage of condensation must represent the final shape of the finished workpiece. Since water escapes in the last stage of this polycondensation, it is difficult to produce a bubble-free end product.

If an amino group of the diamine is replaced by another suitable one Grouping, such as B. phenolic or alcoholic hydroxyl, carboxyl or ester groups «, the specific deterioration valuable properties of the polyimides produced therefrom, such as. B. the temperature resistance "However, these substance classes have the advantage of being in organic solvents, such as B. pyridine, dioxane or dimethylformamide to solve and to melt at higher temperatures without decomposition. This property means that the end product is processed possible in the melt flow or from solution.

So one has z. B. from pyromellitic dianhydride or trimellitic anhydride using p-aminophenol, ethanolamine, p-aminobenzoic acid or p-aminobenzoic acid ester condensable Starting substances produced and polycondensed or polyadded with suitable partners.

Pyromellitic dianhydride and ethanolamine, for example, ^{produce Ν, Ν 1-} bis (2-hydroxyethyl) -pyromellithimide, which reacts with adipic acid, phosgene or hexamethylene diisocyanate to form polyesterimides or polyurethaneimides, some of which are soluble and meltable. However, these substances only have a thermal stability of up to 26o ° e.

"--3 009840/1783

Duroh reaction from cö, ο? -Bis- (tf -aminopropyl) -polysiloxanes and pyromellitic dianhydride have also succeeded in producing soluble and meltable polyimide derivatives. They are stable up to Job ⁰ C, but have the disadvantage that the technical production of these diamines is expensive and complicated. This makes the production of such a plastic uneconomical. (Literature: Abstract by Greber and Peuse, Makromolekulares Kolloquium, Freiburg, March 1966).

It has now v surprisingly found '/ ground that by condensation * of pyromellitic with trimethyl hexamethylene diamine! Or a mixture of isomers of this substance a fusible and to 5 ¹ Io ⁰ C resistant, flexible, tranparentes polyimide having the above excellent properties of these Fabric group can be produced. By partially replacing the trimethylhexamethylenediamine with 3-aminomethyl ~ 3,5> 5-trimethylcyclohexylamine up to 95 mol $ in the polyimide, the plastic becomes harder with increasing contents of the isoyclic diamine. At the same time, flexibility decreases. That way you got it (

len to be able to.

(in the hand, to adapt to specific needs of the practice-

The invention therefore relates to a polymide condensate Pyromellitic acid or its anhydride and trimethyl! Hexamethylenediamine and a method for producing the high temperature resistant Condensate from carboxylic acids and diamines, which thereby is characterized in that one is used as the starting material for the condensation Pyromellitic acid or pyrotnellitic anhydride and trimethylhexamethylenediamine begins.

The precondensation stage can be carried out directly by reacting pyromellitic dianhydride and trimethyl! hexamethylenediamine or below Addition of ^ -aminomethyl- ^ jSi ^ -trimethylcyclohexylamine at about 70 to 27o ° C can be reached. But it is also possible that To react pyromellitic dianhydride beforehand with water or alcohol for the purpose of the ring openings, with the trimethylhexamethylene diamine or J-aminomethyl-J, 5,5-trimethylcyclohexylamine thereof

009849/176 3

produce a salt and this salt or salt mixture at about loo preferably up to 300 ⁰ C _{1 is} about 150 to 270 ⁰ C, vorzukondensieron with elimination of water. For the purpose of a more complete reaction, a vacuum (e.g. 150 "- 0.1 min Hg) can be applied. The polyimide can be formed in suitable kneading machines or in presses at temperatures not higher than 100 G and one pressure of preferably loo - 300 are attr performed this gives slightly discolored transparent molded article In the aforementioned temperatures, the resulting product can be deformed repeatedly in organic solvents, this is ¹ new plastic insoluble...!.

The diamine used for reacting with pyromellitic dianhydride, e.g. B. an isomer mixture of et v / a 60 % 2,4,4- and 40 % 2,2,4-trimthylhexamethylenediamine, according to the DBP 1 14j 5q3> DBP 1 2o5 517, DBP 1 242 21o, DBP 1 249 85o , the patent applications P 15 18'345.6 and P 12 06 882.5 can easily be obtained from acetone via the isophorone and trimethyladipic acid.

The one used as an additive to methylene! Hexamethylenediamine J-aminomethyl- ^ jSiS-trimeth-ylcyclohexylamine is a cis-trans isomer mixture, which can be achieved by catalytic pressure hydrogenation in In the presence of ammonia from J-cyano-Ji 5> 5-trimethylcyclohexanone gev / inside can. The ^ -Cyano- ^ jS ^ -t ^ ime ^ is hylcyclohexanone. in good yields accessible by the addition of hydrocyanic acid to isophorone. (See DBP 1 24o 854).

Of course, it is possible to use the product "fillers, such as z. B. aluminum oxide, titanium dioxide, etc. or glass barrels.

By addition of dicarboxylic acids and amines Dl η respectively, of their salts., Suitably up 5o wt.% Based on the starting materials, can naturally produce mixed condensates and thereby vary the properties of polyimides more.

0098 "4 ^ / 1763

That's how it is ζ. B. succeeded by adding z. B. ko% of a salt of adipic acid and trimethy! Hexamethylenediamine and / or adipic acid and ^ -aminomethyl-3., SiS-fcrimethylcyelohexylamine and / or by adipic acid-hexamethylenediamine and / or adipic acid-dodecamethylenediamine condensates, although the heat resistance is lower were, but partly above Io fo addition in organic solvents, such as. B. phenol, cresol, etc. are soluble. The same applies to ζ. B. of additions of the salts of other dicarboxylic acids than adipic acid, such as. B. azelaic acid, sebacic acid, decanedicarboxylic acid, undecanedicarboxylic acid, mono-, di- and trimethyladipic acid ect.

As the amount of the imide content increases, the properties tend these copolymers in the direction of the polyimide according to this patent application.

It is also possible to use amino acids, such as. B. £ -aminocaproic acid and / or öderca -amino-lauric acid or its lactams to be added.

009849/1763

Examples

The specified ball indentation hardness is determined according to DIN 57 J5o2 (ball pressure gauge 5 mm, test load 5o kg). The first value to be set (Ο ¹¹ ) is given as the ball indentation hardness.

As a measure of the molecular weight, the reduced specific viscosity (% red), which is measured as a solution in formic acid at 2o ° G, is given, provided the substances become looser.

The melting range is determined in a melting point tube " that into a copper block near the melting point at a rate of 2 ° / min. is heated.

1.) Production of a polyimide from pyromellitic acid and the Mixture of isomers of 2,4,4- and 2,2,4-trimethylhexanemethylenediamine.

Salt production

21.6 g of pyromellitic acid dianhydride were in 5o enr hot Dissolved water and with a cold solution of 15.8 g Trimethylhexamethylenediamine crosslinked in 100 cm of n-propanol.

The salt crystallized out in the cold and was after Filtering off a mixture of 100 ml of n-propanol and Io ml of water recrystallized. The yield was 9o 0. - \

w Polycondensation

30 g of the salt obtained were heated with 30 g of water in an autoclave at 120 ° C. in an oil bath for 2 hours. Then distilled off the water, raising the temperature to 28o - 300 ⁰ C and put a vacuum of 1 mm Hg for 8 hours. The resulting precondensate was then in a platen press (Platteί 1 mm layer thickness) in jk> min. At 3oo ⁰ C and a pressure of 250 atm condensed to an end. The resulting polyimide had great surface hardness and great elasticity.

- 7 -009849 / 1T63 bath

It was insoluble in all solvents and could be in the Plate press deformed several times under the same conditions will.. .

2.) Production of a miseh condensate from pyromellitic acid and Trimethylhexaniethylenediansine with various dicarboxylic acids and diets.

In the same way as described under 1.) Mixtures of pyromellitic acid and trinethylhexamethylenediarnine reacted with various dicarboxylic acids and diamines.

The results and compilations are based on the following List.

Pyr ornellitic acid -

Trimethylhexamethylene diamine
(Wt, %)

Adipic acid- i (-red

Trimethylhexa-

methylenediamine

(Wt, %)

S chmelaberei ch ball pressure ( ⁰ C), (kg / cm ² )

67
9ο

25 2ο Io

230-560

12οο 1326 1447

The mixed condensates were visibly discolored and flexible.

- 8th-

009849/176

BATH ORIGINAL

B wt. %

Weight

D. E. ■ Io Weight % Weight Io 15th

G pressed at judgement Weight % 22o ° C / 2oo atm flexible - 22o ° C / 2oo atm flexible 15: l9o ° C / 2oo atm more brittle than 1) and 2) - 21o ° C / 2oo atm brittle - 25o ° C / 2oo atm flexible - 23o ⁰ C / 2oo- atü flexible

6o 7o 6o 6o 6o 8o

25 2o

K ₀

2ο

2o 2o

A -

=

η _

D =

Fyromellitic acid, trimethylhexamethylenediamine

Adipic acid hexamethylenediamine

Adipic acid 5-aminomethyl ~ 3,5,5-trimethylcyclohexylamine

Decanedicarboxylic acid dodecamethylenediamine Terephthalic acid hexamethylenediamine caprolactam laurolactam

CD

CD

1.) Manufacture of polyimides from
hexamethylenediamine and
trimethylcyelohexylamine _; ^v

Salt production from pyroroellitic acid and 3-aminqmethyl-3 »5j5 -, trimethylcyelohexylamine V. *

21.8 g of pyromellitic dianhydride were dissolved in 5o Wl of hot water geXöst. While stirring, a cold mixture of 17.0 gI ' Aminomethyl- ^ jSiS-trimethylcyelohexylamine in Xoö ml of n-propanol slowly admitted. The salt crystallized out in the cold and was made twice more from 2oo ml of n-propanol and lo # Recrystallized water The yield was $ 85

Polycondensation .;

Various salt mixtures of Pyromellithsaure-Ilrimethyl- hexamethylene diamine and pyromellitic - ^ - ^ aminomethyl iSjS · "fcrirteöiylcyGlohexylamin were precondensed with $ 30> water in a small reactor at 25o C ^0% Ölbadtemperafcur hours," during which a pressure of 10-15 atmospheres ceased. After the reaction time had elapsed, the water was distilled off. Oils obtained in this way precondensates represent weakly discolored pesticides * which are insoluble in formic acid, cresol and dimethyryl amide. By heating diesel * substances to 300-3ÖO ⁰ C at a pressure of 2öq-3öö atti on a plate press (1 mm layer thickness) for 10 minutes, high-temperature-resistant mixed polyimides were obtained, which can be recompressed under the above conditions.

Pyromellitic acid Pyromellitic acid Sehmel factory. Ball thrust 3-aminomethyl- trimethylhexa- (C) (kg / om) J5 / 5 * 5-trimethyl- «methylenediamine
eyclohexylamiß

(Mol- ^ 5

5o 5o 290-360 I4lo - ■■ »■ 7o 300-360 ■■ '"■ - ■:. I5ao ' '■■ 9o Io 300-370 152o

Claims (1)

1. Process for the production of hair temperature resistant Condensates from carboxylic acids and biamines, characterized in that that you can use as feedstocks for the condensation Pyromelitic acid or pyromellitic anhydride and trimethylhexamethylene diamine begins. Method according to spoke 1, characterized in that the diamine used is an isomeric device consisting of about 60% 2,4,4- and about% 0 % 2,2,4 * · triniethylhexamethylene diamine · "" - '; -, % Process according to claim 1 and Z, characterized * that the Triraethylhexaraethyienaiamln \>% ε to 95 mol $ by the ^ -aminoinethyl- ^ jS ^ S-triniethylcycloiiexylamln he * - substitutes, 4 «Method according to claim 1 to 3 * characterized in that Γ dai3 fillers are added * 5. The method according to claim 1 to 4, characterized in that that up to 30 wt with the equimolar amounts of diamines or their salts and / or amino acids or #. their lactams added will" . 6 »Polyimide made by the condensation of pyromellitic acid or "their dianhydride with trimethylhexainethylene diamine" 00984S /