DE1116399B - Process for the production of foamable polyamides - Google Patents

Description

GERMAN

PATENT OFFICE

B53943IVd / 39c

REGISTRATION DATE: JULY 10, 1959

NOTIFICATION OF THE REGISTRATION AND ISSUE OF THE
EDITORIAL: NOVEMBER 2, 1961

The patent application B 46040 IVb / 39c relates to a process for the production of foamable polyamides by polycondensation of polyamide formers in the presence of a blowing agent mixture of carboxylic acid esters and N-oxyalkylalkylenediamines at temperatures in which condensation occurs, but not yet significant foaming, until the resulting Condensates are at least partially soluble in concentrated sulfuric acid.

It has now been found that foamable polyamides, the foam-shaped ones, can be obtained in this process Providing bodies with particularly good impact strength is obtained when the carboxylic acid ester is the ester of Carboxylic acids with 1 to 3 carbon atoms are used with polyhydric alcohols.

Suitable carboxylic acid esters of polyhydric alcohols are, for example: ethylene glycol diformiate, ethylene glycol diacetate, Ethylene glycol oxalate, propylene glycol diformate, glycerine diformate, glycerine triformate, Trimethylol propane diformate, trimethylol propane triformate, pentaerythritol formate, tetramethylol cyclohexanol formate, Diethanolamino diformiate.

Suitable N-oxyalkylalkylenediamines are, for. B. the Reaction products of alkylene oxides or aldehydes with aliphatic, cycloaliphatic or aromatic ones Diamines, which may also contain heteroatoms. Appropriately if the N-oxyalkylalkylenediamines are used in the form of their dicarboxylic acid salts.

Polyamide formers are compounds or mixtures that form linear polyamides, such as dicarboxylic acid salts of diamines, e.g. B. adipic acid hexamethylenediamine, sebacic acid hexamethylenediamine or carbonic acid octamethylenediamine, «« -aminocarboxylic acids, ζ. Β. «-Aminocaproic acid. Also suitable are polyamide-forming derivatives of these compounds such as lactams, e.g. B. Caprolactam jonanthlactam or capryllactam, or mixtures of different polyamide hams.

In general, the polyamide formers are added with 1 to 15% of their weight of a blowing agent mixture from N-oxyalkylalkylenediamine and Polycondensed esters of polyhydric alcohols. The volume weight and the mechanical properties the foam bodies that can be produced from the foamable masses depend heavily on the quantity and the ratio of additives. To achieve certain properties, it may be useful to to add other substances such as the carboxylic acid esters mentioned in patent application B 46040 IVb / 39c.

The reaction temperature is generally process for preparation
of foamable polyamides

Addition to patent application B 46040 IVb / 39 c
(Interpretation document 1105 166)

Applicant:

Aniline & Soda Factory in Baden

Corporation,

Ludwigshafen / Rhine

Dr. Friedrich Becke, Heidelberg,

and Dr. Kurt Wick, Ludwigshafen / Rhine,

have been named as inventors

150 to 24O ⁰ C, preferably 180 to 240 ⁰ C. In order to remove the water of reaction formed during the condensation viscous mass to be mixed at least temporarily. The polycondensation is therefore carried out with particular advantage in heated kneaders. The tough plastic mass initially formed can be converted into fine, expandable powder by further kneading at the reaction temperature. However, the reaction products can also be ground to powder after cooling. The foamable compositions produced by the process of this invention can be foamed to form porous bodies by heating in an oxygen-free atmosphere to temperatures which are higher than their formation temperatures. Before foaming, the expandable masses are expediently converted into powder form. In this way, plates, rods, solid and hollow bodies can be produced in a wide variety of shapes.

The parts mentioned in the examples are parts by weight.

example 1

100 parts adipinsaures hexamethylene diamine, 3.1 parts of N-Oxyäthylhexamethylendiamin and 1.5 parts of ethylene glycol diformate are heated in an oxygen-free atmosphere with occasional mixing for 2 hours at 200 ⁰ C. The result is a tough, white mass that is hard and brittle after cooling. It is ground to powder and this is heated ^{to 275 ° C. in a mold under nitrogen.} Man

109 737/434

receives a foam body with a density of 0.2 g / cm ³ .

Example 2

100 parts adipinsaures hexamethylene diamine, 4 parts of N-adipinsaures Oxyäthylhexamethylendiamin (or 3.1 parts of the free amine) and 3 parts Äthylenglykoldiformiat are heated in a heatable kneader under nitrogen purge from -200 ⁰ C. After the water released by the polycondensation has been removed, the viscoplastic mass disintegrates with further kneading at 200 ^° C. to a white powder. This powder is kneaded for a further 2 hours at the same temperature. It has a k value of 30 (measured in sulfuric acid).

By heating at 28O ⁰ C under nitrogen in a rectangular shape is formed from the powder has an elastic foam plate with density 0.14 g / cm ^3.

Example 3

100 parts of adipic hexamethylenediamine, 3 parts of N-oxyethylhexamethylenediamine and 3 parts of glycerol formate (half consisting of di- and triformate) are polycondensed as in Example 2. The foamable powder has a k value of 30.

By heating to 275 ° C under nitrogen, a foam body with a density of Oj ^ g / cm ^{3 is obtained} .

Example 4

96 parts of adipic hexamethylenediamine, 3.84 parts of adipic N-oxyethylhexamethylenediamine and 1.44 parts of ethylene glycol oxalate are mixed well and, as indicated in Example 2, polycondensed. After the water produced during the polycondensation has escaped, the viscous mass disintegrates into a white powder on further kneading at 200 ° C. This powder is _{kneaded for about 2} to 2 hours at the same temperature. The k value of the product obtained in this manner is 40. By heating the powder in an appropriate mold under a nitrogen purge at 270 to 28O ⁰ C one obtains a foam board having a density of 0.15 g / cm ^3.

Example 5

100 parts adipinsaures hexamethylene diamine, 4 parts of N-adipinsaures Oxyäthylhexamethylendiamin and 3 parts Pentaerythritformiat are heated in a heatable kneader at 200 ⁰ C under a nitrogen purge, has escaped to the resulting water by polycondensation. In this way, a white powder with a k value of 35 is obtained within about 4 hours. Is obtained by heating at 28O ⁰ C in an appropriate mold an elastic foam plate having a density of 0.32 g / cm ³ from the powder.

Claims (2)

PATENT CLAIMS: 1. A process for the production of foamable polyamides by polycondensation of polyamide formers in the presence of a blowing agent mixture of carboxylic acid esters and oxyalkylalkylene diamines according to patent application B 46040 IVb / 39c, characterized in that the esters of carboxylic acids having 1 to 3 carbon atoms and polyhydric alcohols are used as the carboxylic acid ester . 2. The method according to claim 1, characterized in that the polycondensation in heated Performs kneading. © 109 737/434 10.61