DE1520052C - Process for the production of polyamides - Google Patents

Description

1 2

It is already known to use polymerized fatty acids to react further with other resins

usually also called dimeric fatty acids, with their firmness no longer suitable at all

polyvalent organic amines, optionally.

with the addition of shorter-chain dicarboxylic acids, such as The present invention aims at the production of adipic acid, sebacic acid and terephthalic acid, to condense into 5 new polyamides, which are more heat- and oxidation-resistant, polyamides. Depending on the type and clear, low-viscosity and therefore easily mixed with other components, the proportions of the starting products will be. This object is achieved here with liquid to high-melting polyamides by the method according to the invention,
low to medium molecular weight obtained The invention relates to a process for the preparation (cf. US Pat. These polyamides found numerous rival organic amines with polybasic reversal possibilities. So the so-called araliphatic carboxylic acids or their esters with reactive types, the more or less considerable monohydric alcohols containing 1 to 4 carbon atoms in free amino or carboxyl groups, optionally with the addition of adipin, including other thermo-15 acids , Sebacic acid, isophthalic acid, terephthalic acid converted into plastic reactive resins, e.g. B. with or from polymeric fatty acids, which are characterized by epoxy resins and phenolic resins, with hardening being characterized in that such polybasic infusible, extremely resistant araliphatic carboxylic acids or their esters are formed, as detailed in DE, which is produced by cationic copolymerization of Floyd, Polyamide Resins, New York / London, 20 1 mol of unsaturated fatty acids with conjugated 1958 is described. Double bond or their esters with monovalent,

The alcohols, polyamides containing 1 to 4 carbon atoms obtained from the polymeric fatty acids have valuable properties or their mixtures with saturated or isolated also serious disadvantages, primarily unsaturated fatty acids or their fatty acid esters, primarily due to the constitution and composition of the 25 with 0.1 to 5 moles of styrene or its homologues in polymeric fatty acids. The commercial accelerating and radical copolymerization used for the presence of the cationic copolymerization in the polyamide production contain dimeric fatty acids, due to their production-inhibiting substances with a gradual increase in the way, namely not only dibasic carbon temperature to 50 to 150 ⁰ C and then further acids , but also considerable proportions, 30 heating up to 18O ⁰ C until the end of the coin, usually 20 to 25%, tribasic and higher polymerization have been produced,
functional carboxylic acids. Although it is technically more possible to use the invention to separate the dimeric acids from this mixture in basic araliphatic carboxylic acids, for their relatively pure form, but no protection is claimed here, this requires considerable effort; the lack of usability, preferably with a ratio of 0.5 to 2 moles, of the styrene or its homologues per 1 mole of the conjuene-higher polycarboxylic acids is also disadvantageous. fatty acid produced.

On the other hand, the presence of the latter in styrene and its homologues, such as -methylstyrene Polymeric fatty and vinyl toluene used to produce polyamides can also be mixed with one-of-a-kind acids the risk of premature crosslinking reactions, 40 other are used. As unsaturated fatty acids hence gelations, in themselves, which are both the production with conjugated double bonds, both the polyamides and their usability are considerably naturally occurring, as well as from isolated-light weight. This is mainly known as artificially produced conjuene fat in general for saturated fatty acids is, in a poor heat stability of the acids, z. B. eleostearic acid, licanic acid, isomeriauf Noticeable polyamides produced on this basis, 45 ized linolenic acid and isomerized polyene fatty acids which is suitable with special application techniques and the marine animal oils. Substances that are cationic the crosslinking-suppressing additives of some- accelerate copolymerization are those that can be met, but not fully emitting protons, e.g. B. sulfuric acid, hydrochloric acid, with constantly fix. Other acids of their use dealt with bleaching earths, sulfonic acids, and catalytic converters Aggravating disadvantages are the 50 ion exchangers in their acid form and Friedel proportions high viscosity and oxidation Crafts catalysts such as aluminum chloride and susceptibility of polyamides based on polymeric tin tetrachloride. Among the substances that are radical ierte fatty acids, which inhibit each other particularly with the solid copolymerization, belong among other things Types noticeable by skin formation of the melts hydroquinone and butylpyrocatechol. The cationic power. 55 Copolymerization of conjugated unsaturated fatty

Furthermore, from the USA patent specification 2,573,433 acids or their esters with monovalent, 1 to 4 carbon

already known, by reacting unsaturated alcohols containing lenstoffatome can also be used in

Fatty acids or halogenated unsaturated fatty acids - presence of inert solvents such as toluene,

acids or their derivatives, e.g. B. Esters, done with aroma, after which these and other low molecular weight

table compounds that have two or more rings on- 60 components, such as unreacted saturated and

have, in the presence of Friedel-Crafts-Kataly- isolated-unsaturated fatty acids or their esters, not

Sators polybasic, araliphatic carboxylic acids converted styrene or its homologues, or styrene

produce and these with organic diamines to containing monocarboxylic acids or their esters by

Condense polyamides. A substantial post-distillation can be separated. During the

Part of these products consists in the fact that the copolymerization already increases the viscosity of the reaction

obtained polybasic araliphatic carbon mixture continuously until they are at the end of the copoly-

acids are highly viscous and strongly colored, during merization a maximum, constant value

their condensation products with the diamines is enough.

3 4

The polybasic densation to be used according to the invention can also be carried out under reduced pressure

araliphatic carboxylic acids can also be seen in the presence of inert solvents, such as aromatic

low molecular weight dibasic carboxylic acids, such as hydrocarbons and aliphatic alcohols, through-

Adipic acid, sebacic acid, isophthalic acid and tere- are performed.

Phthalic acid, as well as polymeric fatty acids, add 5 The risk of crosslinking and thus gelation

are set. of the condensation build-up as it occurs during use

For the production of polyamides according to the invention consists of polymeric fatty acids, is in accordance with the invention Method suitable polyvalent polybasic aralinic aralinic ones to be used organically Amines are primary and secondary amines with phatic carboxylic acids or their esters within at least two amino groups, such as ethylenediamine, io the specified temperature ranges not to be-diethylenetriamine, Fear triethylenetetramine, tetraethylene. Neither a rapid increase in temperature pentamine, hexamethylene diamine and phenylene diamine. heating for several hours Mixtures of these amines are also suitable. the upper temperatures mentioned change the

The type and proportions of the condensation approaches to the polycondensation in a disadvantageous manner or

The reaction components that arrive at the system will make them unusable. This is one of the essential

taking into account their acidity and basicity, the invention conferred advantages.

expressed by their acid number or saponification. The polyamides produced according to the invention are

number and by their amine number, depending on the desired - depending on the type and proportions of the

th polyamide type set. Equivalent amounts of the ingredients liquid to balsamic or soft or

polybasic araliphatic carboxylic acids or ao hard to glass-hard and have an almost water-white to

their esters and diamines lead to resins, the yellow-brown color. Their molecular weight is about

melt between 60 and 120 ⁰ C and only in 700 to 5000. They are more or less in polar

very small amounts of free carboxyl or amino solvents such as halogenated hydrocarbons and

groups included. Between 120 and 200 ⁰ C-melting, aliphatic alcohols, or aromatic Kohzende resins can be obtained when a 25 bons, such as toluene and xylene, completely

Part of the polybasic araliphatic carboxylic acids soluble. They dissolve particularly well in mixtures

by d ¹ e mentioned low molecular weight dicarbons the aromatic hydrocarbons mentioned and

acids ^e rsetzt. Are either the polyhydric aliphatic alcohols, such as isopropanol and Bu-

organic amine or the polybasic acid in tanol.

Excess is used, resulting reactive poly ₃₀ during the polyamides from polymeric fatty acids amides having free amino or carboxyl groups, which are only limited compatibility with other materials, erAnteil indicated by the amine value and acid value, the compatibility of the enforced according to the invention. When using esters of the araliphatically produced polyamides unexpectedly on a polybasic carboxylic acids, a large number of other groups of substances are demented. You are beisprechend obtained only with excess polyvalent ₃₅ game example with epoxy resins, phenolic resins and amine reactive polyamides. In the case of ordinary aminoplasts, natural rubber, various synthetic-temperature elastomers or elastomers lent in the range of 25 to 75 ° C, polyvinyl chloride, polyvinyl-melting polyamides can be made from polybasic chloride, polyethylene, polypropylene, polystyrene, coaeraliphatic carboxylic acids or their esters with resin resins, thermoplastic polyurethanes, many monovalent, 1 to 4 carbon atoms containing ₄₀ polyesters such as alkyd resins and waxes miscible alcohols and such polyhydric aliphatic and mineral oil products, such as SCvExtrakten, amines are produced whose primary amino certain types of bitumen, further groups with coal tar are connected by at least 3 atoms . and asphaltene partially compatible.
These atoms can be carbon or other atoms because of their polar structure they show a. Suitable polyvalent aliphatic amines of these ₄₅ unusual adhesiveness. So they stick type are, for example, diethylenetriamine, triethylenes extremely firmly on metal, wood, glass and the tetramine, tetraethylenepentamine, hexamethylenediamine. a wide variety of plastics. Their ungewöhn-Je Liehe according to the proportions of the reaction and resistance not to be expected heat and Oxydationskomponenten and function of the training means in addition to their extraordinary guide the condensation can here either ₅₀ resistance to the influence of acids, all or only the primary or only some of the alkalis and numerous solvents - the above primary amino groups are converted. The above are naturally excluded - one of the last two cases mentioned thus also gives rise to a further essential advantage of the polyamides which are reactive according to the invention here. manufactured polyamides, since the named properties

The manufacture of the polyamides according to the invention their application properties The method according to the invention takes place under the known methods and thus their handling is crucially customary Conditions of polyamide formation. The tempers.

temperature control and the duration of the condensation The properties described open up a considerable amount of components depending on the type and proportion of the polyamides produced in accordance with the invention, as well as the required area of application in each case. You can use products for yourself alone. The main reaction is usually used or mixed with other substances by heating to 120 to 180 ⁰ C for several hours, for example for the production of paint, and finally the condensation under materials, printing inks, foils, cast or pressed temperature increase up to about 200 Molded parts, sealing and potting compounds and adhesives are complete up to 230 ° C. It is always important to ensure that the 65 substances. Their reactive types set themselves together with the amount of water or alcohol split off from the reactive resins in the cold or hot conditions and that no polyvalent amines are lost when they are removed to form spatially crosslinked, infusible masses. The consumer.

In US Pat. No. 2,952,648, the copolymerization of styrene or its homologues, ζ. Β. α-methylstyrene and vinyltoluene, with dehydrated Castorol fatty acids (= ricine fatty acid) with heating, preferably in the presence of free radicals forming polymerization catalysts, such as organic peroxides, and of polymerization inhibitors, such as lauryl mercaptan, to polybasic araliphatic carboxylic acids and their condensation with polyvalent organic amines such as ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine and phenylenediamine, have already been described. However, both differ polybasic araliphatic ones prepared by the process of U.S. Patent 2,952,648 Carboxylic acids and the polyamides produced from them are substantially different from those according to the invention polybasic araliphatic carboxylic acids used and those prepared from them according to the invention Polyamides.

These differences are due to the fact that after the method of the USA 2 952 648 the copolymerization of styrene or its homologues with the conjugated-unsaturated fatty acid initiated by radicals and leads to a non-uniform mixture. According to the invention too polybasic araliphatic carboxylic acids used are, however, by cationic copolymerization of styrene or its homologues with conjugated unsaturated fatty acids or their esters manufactured. Due to the different, more selective reaction mechanism of the cationic copolymerization more uniform products are created, i. H. polybasic araliphatic carboxylic acids, mainly Are dicarboxylic acids. In the case of cationic copolymerization, the substituting Addition and graft polymerization, which leads to polystyrene branches on a fatty acid molecule, are avoided.

Because of these differences in the structure of the polybasic araliphatic carboxylic acids used the polyamides produced according to the invention differ from those from the USA patent 2,952,648 known polyamides clearly in their properties, as also from the following Comparative experiments is evident. Unexpectedly, the invention using the The same polyvalent organic amine produced a completely clear polyamides with the same amine number Appearance and viscosity significantly lower than that made in U.S. Patent 2,952,648 Polyamides that are cloudy in appearance.

Comparative experiments

Table 1

Acid number

Saponification number

Peroxide number

Conjugated linoleic acid

(UV measurement)

Isolated linoleic acid
(UV measurement according to
analytical isomerization)

Isomerized

Safflower fatty acid

methyl ester

6.2
196.3
0

65.4 °

Ricinic fatty acid

197.0
0.5
65.9%

17.7%

Try AIa

Cationic copolymerization of the isomerized
Safflower fatty acid methyl ester with styrene

1500 g of isomerized safflower fatty acid methyl ester and 350 g of styrene (stabilized) were initially mixed with 2 g Butyl catechol and then mixed with 25 g of acid activated fuller's earth. The mix was heated to 120 ° C. with stirring for 3 hours and the temperature increased to 180 ° C. in a further hour. Under reduced pressure (up to 100 torr), only a very slight distillation was carried out at this temperature Amount (about 1 g) of volatile substances. The product was put into ground joint flasks for further conversions and examinations kept.

Try AIb

Radical copolymerization of the isomerized
Safflower fatty acid methyl ester with styrene

1500 g of isomerized safflower fatty acid methyl ester, 350 g of styrene and 1.5 ml of lauryl mercaptan were warmed gently until the mixture was uniform. Then 1.5 ml of di-tertiary butyl peroxide were added, and the mixture was refluxed for 4 hours. Then another 1.5 ml of di-tert-butyl peroxide were added added, and the mixture was heated to boiling again for 15 hours. In the end 0.75 ml of di-tert-butyl peroxide were again added, whereupon the mixture was again 8 hours was heated to reflux. Then at 180 ° C under reduced pressure (up to 100 Torr) the volatile components distilled off in an amount of 15 g.

The product obtained and the distillate were in ground-glass bottles for further reactions and investigations kept.

In the test series AI, a conjuene fatty acid methyl ester, namely the isomerized one which is commercially available under the name "Isomerginate SF" Safiorfettsäuremethylester, and in the further test series A II dehydrated castor oil fatty acid (= Ricinic fatty acid), which, in addition to conjugated unsaturated fatty acids, also contains a considerable proportion of isolated unsaturated Contains fatty acids, with styrene cationic (= a), radical (= b) and thermal (= c) copolymerized under otherwise identical working conditions. Table 1 contains the properties of the used fatty acids or their methyl esters.

Try AIc

Thermal copolymerization of the isomerized
Safflower fatty acid methyl ester with styrene

1500 g of isomerized safflower fatty acid methyl ester, 350 g of styrene (stabilized) and 2 g of butylpyrocatechol were refluxed for 27 hours. Then under reduced pressure (up to 100 Torr) at 180 ° C 21g of volatile components distilled off. The product obtained and the distillate were placed in ground joint flasks for further reactions and examinations kept.

^; · '. "■■ ■■'" ■ 'TryÄIIb · "■

Radical copolymerization of ricineal fatty acid with styrene

1500 g of ricineal fatty acid, 275 g of styrene and 0.8 ml of lauryl mercaptan were gently heated until the mixture was uniform. 1.5 ml of di-tert-butyl peroxide were then added; the mixture was 5 hours heated to boiling under reflux. A further 1.5 ml of di-tert-butyl peroxide were then added, and the mixture was heated to boiling for a further 2 hours. At appropriate intervals Two times 1.5 ml of di-tert-butyl peroxide were added and the refluxing was ceased continued for a long time until a total boiling time of 40 hours was reached. A total of 6 ml of di-tert-butyl peroxide was thus obtained used. Thereupon under reduced pressure (up to about 100 torr) the highly volatile Shares distilled off in an amount of 17 g. The product obtained and the distillate were in ground joint bottles retained for further conversions and investigations.

Trial A lic

Thermal copolymerization of ricineal fatty acid with styrene

1500 g of ricineal fatty acid, 275 g of styrene (stabilized) and 2 g of butylpyrocatechol were refluxed for 40 hours. Then 16 g of volatile constituents were distilled off ^{at 180 °} C. under reduced pressure (up to 100 torr). The product obtained and the distillate were kept in ground-glass bottles for further reactions and investigations.

Those obtained under AIa, AIb, AIc, AIIb and all Copolymers were examined for the following key figures and properties:

a) Viscosity tjei 20 and 50 ⁰ C in centipoise (cP),

b) ° / o unsaponifiables (ether method),

c) iodine number after purchase ma η η,

d) acid number,

e) saponification number.

* In Table 2 below are the obtained Results compiled:

Table 2

5
attempt viscosity
in cP at 50 ° C % Unver
soapable JZ SZ VZ 2O ⁰ C 60 AIa 110 65 0.9 97.6 7.5 151.6 AIb 100 68 4.5 89.6 6.1 158.3 ¹⁰ AIc 120 186 4.3 93.6 6.9 158.4 AIIb 570 192 3.8 117.6 159.5 174 All 720 4.2 116.6 154 164.2

Further, the separation of the monomeric fatty acids or their Methylester was carried out by vacuum distillation: vacuum 0.1 Torr, temperature at the bottom to 250 ° C, g on the top of the column to 210 ⁰ C, the batch quantity depending 600th

The yields obtained are listed in Table 3 below.

Table 3

Copolymer
after attempt

AIa

AIb

AIc

AIIb

A lic

distillate 25.0 Back in g 61.7 in g 150.0 64.6 450.0 370.0 58.3 230.0 387.5 56.7 212.5 350.0 250.0 340.0 260.0

75.0 38.3 35.4 41.7. 43.3

The distillates and residues obtained in this way were examined further; the results are in the following Tables 4a and 4b summarized:

Table 4a
Investigation of the distillates

Copolymer
after attempt Acid number Saponification
number Conjunctive
fatty acid
in ° / o AIa
AIb
AIc
AIIb
All 5.7
6.5
7.6
199.0
195.0 172.0
191.0
188.0
199.0
196.3 0
51.7
56.6
57.2
59.6

Table 4b Investigation of the residues

Copolymer
after attempt viscosity
in cP
at 50 ⁰ C Acid number Saponification
number Iodine number »/" Styrene
leftovers equivalent to
Weight Middle
Molecular
Weight
after rest AIa .......
AIb
AIc
AlIb
All ...... 128
7 400
15 650
20 400
36,000 11.6
4.8
5.0
108.0
101.0 144.8
107.0
102.0
138.5
126.0 97.1
37.4
35.2
57.5
53.9 26.5
42.8
46.4
27.1
33.5 387.4
524.3
550.0
405.1
445.3 780
2200
1510

These differences in properties clearly show that the cationic copolymerization of the Styrene (A Ia) with conjugated-unsaturated fatty acids or their esters to form other, polybasic products araliphatic carboxylic acids, performs as the radical or thermal copolymerization of the Styrene with conjugated-unsaturated or isolated-unsaturated fatty acids or their esters (AIb, AIc, AIIb and all).

The different nature of these copolymers is also reflected in the properties of the Polyamides made from them by condensation with

polyvalent organic amines have been produced. For comparison purposes, diethylenetriamine was condensed with the products obtained according to A Ia, AIb and AIc (test series BI) and with the products obtained according to AIIb and A lic (test series B II). : - \ .. ^:

Test series B I

1500 g of each; Copolymers (Ala, Aib, AIc) and 500 Diäthyjentriämin (98.5 ° / _o pure) were heated for 1 hour at about 13O ⁰ C with stirring and Rüek'fluß. Then IConics further heating was distilled off, the methanol released, the main amount passed within about I ¹ I ₂ hours. After gradually increasing the temperature to 250 ° C. within 2 hours, the remaining amount of methanol was obtained.

After the end of the condensation, the mixture was cooled under a gentle stream of nitrogen and that on Polyamide cooled to around 80 ° C on ground-glass bottles drained and retained for further investigation.

Test series B II

1500 g of the respective copolymers (AIIb and all) were mixed with 435 g Diäthyientriämin (98.5 ° / ₀ solution) and 0.5 g of silicone oil as antifoam under stirring and passing, a weak stream of nitrogen IVa hours a water-cooled reflux condenser, heated to boiling, then the water-cooled reflux condenser was replaced by a corresponding descending condenser and the water released was distilled off with further heating of the reaction mixture.

As soon as the amount of water to be expected had passed over, one was removed from the reaction mixture The acid number is determined from the sample taken. It was found in all cases that. it on in the above way of working had dropped below 5.

The resulting polyamide was cooled under a gentle stream of nitrogen to about 8O ⁰ C ,, then to cut bottles drained and saved for further studies.

The polyamides obtained in the test series B I and BII were tested for the following properties and Key figures examined:

Appearance, especially transparency;

Color (G a r d η e r);

Viscosity at 25 ⁰ C (Viskowaage);

Acid number; 5 <>

Amine number.

The results are summarized in the following table 5:

Table 5

60

Poly
amide
after color
(Gard
ner) acid
number Amine
number viscosity
in cP at
25 ° C Look BTa ...
BIb ...
BIC ...
BIIb ..
BiIc .. 8th
10
10
10
12th 2.1
1.7
3.1
2.7
2.5 270
290
287
272
266 3100
11400
9 600
8,000
9 500 clear
I cloudy,
Γ semi-solid

65

While all the free-radical or thermally produced copolymers with diethyientriamine resulted in cloudy and highly viscous or semi-solid polyamides, the cationically produced copolymer to be used according to the invention was converted into a ^; Obtained 'clear *'"bare polyamide with a low viscosity. The above opaque polyamides also gave opaque curing products with epoxy resins. A particularly, clear difference was shown in the resistance to these opaque and non-cloudy curing products

Xylene ,,, ■ .- '.: ... _Ί Υ- ■ . ■ '.. ''>■' - '. ■. . · '· The invention .If in the following examples further explained. ■; _v:

'' a) Manufacture of the starting product

Isomerized soybean oil fatty acid methyl ester containing 56% conjugated-unsaturated fatty acid methyl ester, was with styrene in a ratio of 1.12 moles of styrene per mole of conjugated-unsaturated fatty acid methyl ester cationically copolymerized. After removal of the volatile components at 0.6 torr to 260 ° C. by distillation the result was a product consisting essentially of an araliphatic dicarboxylic acid methyl ester of pale yellow color, the amount of which a yield of 65% of the starting materials used corresponded. Its saponification number was 148.2, corresponding to an equivalent weight of 378.,

example 1

38 kg of the product obtained according to a) and 3 kg of ethylenediamine (about 98%) (equivalent ratio about 1: 1) were under; Stirring and nitrogen ^{heated to 120 0} C and kept under reflux at this temperature for 1 hour. During the subsequent distillation of the liberated methanol, the temperature of the reaction mixture was gradually increased to 200 to 220 ° C over the course of 4 hours and held at this level for a further 1 hour. It fell overall. 3.2 kg of distillate, which consisted of 3.1 kg of methanol and about 100 g of ethylenediamine, which corresponded to the theoretical / expected amount. After cooling to about 13O ⁰ C under nitrogen, the contents of the reaction container in a flat metal shell, which was provided with a coating of polyfluoroethylene was emptied and allowed to cool now complete. The polyamide was light yellow in color, crystal clear and had an amine number <5. It melted at 90 to 92 ° C and had the viscosity 843 cps at 150 ⁰ C, as measured in a rotational viscometer.

To test the heat and oxidation stability, samples of about 100 g each were used, which were heated in Petri dishes to 160 or 220 ° C for a longer period with the access of air. The samples kept at 160 ° C. had changed neither visibly nor noticeably in their viscosity after 20 hours. The samples held at 220 ° C were significantly discolored after 3 hours and left to individual 3V2 hours brownish flakes, while the viscosity in 4 hours from 843 to 2176 cP, measured at 150 ⁰ C increase.

In contrast, a polyamide, the dimeric from commercially available fatty acids and ethylenediamine was used in an equivalent ratio of 1: 1 was prepared, after tündigem V ^ Store at 200 ⁰ C in air skinning and was gelled after IV2 hours.

Araliphatic dicarboxylic acid methyl esters or dicarboxylic acids, which are produced by cationic copolymerization of wood oil fatty acid methyl ester or of dehydrated

Sated castor oil fatty acid with mixtures of styrene and α-methylstyrene (90 parts of styrene to 10 parts of oc-methylstyrene) produced upon condensation with ethylenediamine as above is described, polyamides with practically the same properties.

Example2

_M 38 kg of the product obtained according to a) and 6 kg of ethylene diamine (about 98 ° / ₀ ig) (equivalent ratio of about 1: 2) were condensed under the conditions of Example 1. Fig. This resulted in a total of 3.3 kg of distillate, which consisted of 3.1 kg of methanol and 200 g of ethylenediamine. The polyamide obtained was a material that was soft at ordinary temperature and had an amine number of 121; its viscosity was about 6OcP at 150 ⁰ C, measured with a rotational viscometer.

A held at 16O ⁰ C with access of air sample was not changed appreciably after 16 hours. Only the viscosity had risen to 190 cP (measured at 150 ^° C.). After 7stündigem heating at 220 ⁰ C under otherwise identical conditions only a brown coloration of the sample was observed, while the viscosity was also only 19OcP (measured at 150 ⁰ C) increased. There were no further changes, such as skin formation or the separation of parts that had become infusible.

In contrast, was a polyamide which had been prepared from commercially available dimeric fatty acids with an otherwise identical composition completely gelled at 220 ⁰ C after 7stündigem heating. This polyamide originally had a viscosity of 1170 cP, which after 2 hours of heating at 220 ° C. had already risen to 2475 cP (measured at 150 ° C.).

At s ρ i el 3

75 kg of the product obtained according to a) and ethylenediamine (7.6 kg about 98 ° / _o tg) were stirred at 16O ⁰ C first condensed under the conditions of Example 1. Fig. After the addition of 5 kg of sebacic acid, the condensation at 200 to 220 ° C. was completed within 2 hours. This resulted in a total of 9 liters of a distillate consisting of water and methanol. The polyamide obtained was clear and as hard as glass at ordinary temperature. Its amine number was below 3 and its acid number about 10; the melting point was 150 to 155 ^° C.

By increasing the proportions of ethylenediamine and sebacic acid in the equivalent ratio of up to 9.1 and 10.1 kg, respectively, under otherwise identical conditions, polyamides were obtained which had an upper melting point of about 200 ^° C. A sample of the melt at 150 to 155 ° C polyamide pointed lstündigem heating at 220 ⁰ C in air, a slight skin formation and gelled after a further 3 hours. Polyamides of the same type made from commercially available dimeric fatty acids separated out immediately after melting that they had become infusible.
The stability properties of these polyamides produced according to Example 3 are even more clearly expressed when they are mixed with the polyamide described in Example 2. For example, a mixture of 50 parts showed a polyamide prepared according to Example 3 with the melting point 155 ° C and 50 parts of a polyamide, for example 2 except in accordance with 24 hours, heating in air at 160 and 220 ⁰ C, no change of a light brown coloration. From commercial dimeric fatty acids analog polyamide mixtures produced on the other hand in air at 160 ⁰ C were already at heating for 8 hours a skin had completely gelled after 8 hours of heating at 220 ° C.

B e i s ρ i e 1 4

Of the product obtained in a) and 26.6 kg of diethylene triamine (93 kg about 95 ° / _o solution) (molar ratio about 1: 2) were condensed under the conditions described in Example 1 conditions. A total of 10 l of methanol and 50 g of diethylenetriamine were obtained as distillate. The reaction product was liquid at room temperature and had a balsamic consistency. Its amine value was 283, its viscosity 5300 cP (measured at 5O ⁰ C).

Claims (1)

Claim: Process for the preparation of polyamides by condensation of polybasic organic amines with polybasic araliphatic carboxylic acids or their esters with monohydric alcohols containing 1 to 4 carbon atoms, optionally with the addition of adipic acid, sebacic acid, isophthalic acid, terephthalic acid or polymeric fatty acids, characterized in that such polybasic araliphatic carboxylic acids or their esters are used, which by cationic copolymerization of 1 mole of unsaturated fatty acids with conjugated double bond or their esters with monohydric alcohols containing 1 to 4 carbon atoms or their mixtures with saturated or isolated-unsaturated fatty acids or their fatty acid esters with 0.1 to 5 mol styrene or its homologues in the presence of substances which accelerate the canonical copolymerization and which inhibit free radical copolymerization, with the temperature gradually increasing to 50 to 150 ^° C. and then further Heating have been produced up to 18O ⁰ C until completion of the copolymerization.