DE1197615B - Process for making shaped structures from crystallizing thermoplastic polyamides or polyurethanes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

C08g

German KL: 39 b -22/04

Number: File number: Filing date: Display date:

1197 F24233IVc / 39b October 22, 1957 July 29, 1965

In the older patent application F 21283 X / 39 a (cf. German Auslegeschrift 1061063) is a method for the production of shaped structures from crystallizing thermoplastics, such as polyamides, which consists in melting such plastics containing to cool finely and evenly distributed, nucleating solids in a manner known per se. This measure causes such plastics with largely uniform fine-grained solidify morphological structure, whereby castings can be obtained that are practically free from internal tensions. In addition, the plastics solidify due to the additives mentioned faster on cooling, so that the output of castings per unit of time and per mold increases can be. At solids that have this effect, z. B. named: graphite, molybdenum disulfide, Cobalt sulfide, iron (II) sulfide, tungsten (IV) sulfide, scheelite, alkali halides such as lithium fluoride, or finely divided silica. Even the addition of extremely small amounts of such finely divided Solids, for example amounts from 0.001 to about 0.1%, especially up to 0.01%, bring about the effects mentioned emerged.

It has now been found that one can just as quickly solidify, practically stress-free castings with uniform fine-grain structure made of crystallizing thermoplastic polyamides or polyurethane

Process for making shaped articles made of crystallizing thermoplastic polyamides or polyurethanes

Applicant: Farbenfabriken Bayer Aktiengesellschaft, Leverkusen

Named as inventor: Dipl.-Chem. Dr. Wilhelm Hechelhammer, Krefeld-Bockum; Dipl.-Chem. Dr. Ernst Reichold, Krefeld

to add fatty acid salts, whereby the fatty acid salts are used as lubricants for this art

ization is completely different from that of thermoplastic polyamides or urethanes, which crystallize in the actual sense. It was therefore surprising that the addition of such salts of higher fatty acids in the amounts mentioned to the melts of these plastics not only act as a lubricant, but also maintain the course of solidification on cooling and the morphological structure of the castings in a technically advantageous manner can that you influence melting 30.
These substances with a content of 0.1 to 1%, in particular, it is also known to make synthetic resin molding compounds, such as

especially up to about 0.5%, of fine and evenly distributed solid salts of higher saturated or unsaturated fatty acids of magnesium, of calcium, for example
or the zinc cools in a manner known per se. 35 resin molding compounds are to be used. In addition, these additives not only bring the mentioned additives to improve the sprayability of

thermoplastic plastics in the flame spraying process the plastic powders are metal salts of saturated and / or to add unsaturated fatty acids. This addition is intended on the one hand to reduce cause the electrostatic charging of the powder particles and on the other hand the surface tension of the molten plastic droplets, so that they can easily be molded onto the surface Add lubricant. For this, see the 45 contiguous film converge. Farther general waxes and esters of higher fatty acids is the addition of small amounts of heavy metal use. Salts of such acids also like salts, such as those of copper or manganese Polymers have already been used. salt, known to polyamides, to the polyamides There occurs, however, by the addition of such lubricants to stabilize against the effects of light and heat, Medium an improvement in the properties of the cast iron. In addition to copper stearate, this includes manganese stearate and pieces in the above-mentioned sense are not included, since the metal salts of aromatic hydroxycarboxylic acids be behavior those plastics became known in relation to the crystal. Comparative tests show that both

509 628/407

Effects when the melts cool down, but also facilitate in many cases at the same time the detachment of the solidified castings from the molds.

Although it is known to use certain plastics, such as polystyrene or polyvinyl chloride, to achieve one good flowability and to facilitate the detachment of castings made therefrom from the

For example, the addition of manganese stearate to a polyamide does not improve the premature and extremely easy demoulding and a uniform, fine-grained crystalline structure which brings polyamide injection molded parts. This also applies if the salt of an aromatic hydroxycarboxylic acid, such as aluminum salicylate to which polyamide is added.

example

100 parts by weight of a polyamide granulate are mixed well with 0.5 parts by weight of calcium stearate. The mixture is melted and condensed in a manner known per se. When solidifying you not only get molded parts with a completely homogeneous, fine-grained structure, but you can also easily and quickly remove the mold at a high mold temperature without the body sticking to the mold walls.

Claims (1)

Claim: Process for the production of shaped structures from crystallizing thermoplastic polyamides or polyurethanes, characterized in that these are melted Substances containing from about 0.1 to about 1% of finely and evenly distributed solid salts saturated or unsaturated higher fatty acids of magnesium, calcium or des Zinc cools in a known manner. Considered publications:
German Patent Nos. 883 500, 899 861;
French Patent Nos. 955 259, 965 244; Swiss Patent No. 269 518;
British Patent No. 689,629;
Hopf-Müller-Wenger, Berlin, Göttingen, Heidelberg, "The Polyamides", p. 367. 509 628/407 7.65 © Bundesdruckerei Berlin