DE1570369A1 - Process for the production of polyamides modified with finely divided fillers in powder form - Google Patents

Description

Process for the production of fine modified polvamids in powder form

Usually, polyamides are obtained by melt condensation. The final state of condensation is a viscous melt that cannot be mixed quickly because it does so Heat accumulations occur which would thermally break down the polycondensate. The solidified melt then becomes mechanical crushed, usually into granules or into a powder.

If you want such polyamides inorganic fillers in finely divided Mix in the form, so you can do this in a thin liquid state before the actual condensation, if the density of the filler is similar to that of the polyamide, i.e. around 1. In addition, the filler must not be exposed to water up to temperatures of approx. 260 C react.

Inorganic fillers rarely meet these two conditions. Therefore you have to post the shredded polyamide Mix the condensation with the filler in special machines. Here too, if there is a large difference in density, between Polyamide and filler easily segregate again.

By adding fillers to polyamides, a wide variety of achieve technical advantages. The only examples are »electrical conductivity, magnetizability, improved sliding properties, self-luminous molded parts or coatings, etc.

In the Argentine patent I42 945 from February 11, 1965 (German Application C 31 683 IV d / 39 c) is a process for the production of polyamides from iso- and / or terephthalic acid and aliphatic Diamines in fine-grained form described, the diphenyl esters of these acids with the diamines in an inert Solvent precondensed at temperatures of 20 - 150 ° C and then at higher temperatures, which come close to the melting range of the polyamide shown, can be post-condensed.

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In the German patent application G 33 i? <2 IV i / 39 c, a Equivalent process for the production of aliphatic polyamides Dicarboxylic acid. described.

In both cases, foiyarsiie are found in a single-core fora.

It has now been found that finely divided fillers can be divided into uniform distribution containing polyamide powder by translation the diaryl ester of iso- and / or terephthalic acid ", and / or the aliphatic dicarboxylic acids ixt primary aliphatic and / or cycicaliphatic and / or araliphatic Diamines are obtained in inert solvents when you use the product before the polycondensation in the inert solvent by vigorous stirring evenly distributed and then the cast in his presence.

This gives puiverfcrmige Semische in which the filler is umschxosoen of the polyamide and is therefore not as stirring or views more by simple mechaniscne operations ■ * ■ shaking - vcn leaves the polyamide separate.

Such mixtures can be processed on plastic processing machines or work well as a pre-sintering puiver. As fillers those are possible which are against aromatics, phenols, diamines and diphenyl esters under the condensation conditions behave indifferently. It can be for example:

Metal powder (iron, copper, aluminum, tin, zinc, etc.), metal oxides or metal sulfides (TiO-JFe ₀ O ^ jFe ₁ O-JZnS ₁ ItOS ₀ JCdS),

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Metal salts,

Luminous pigments,

Graphite,

Plastic powder, such as Tetrafiucräthylen and similar,

The method described is particularly suitable for converting inorganic Incorporate fillers with a high specific weight, or fillers that look with water at higher temperatures or the like.

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set, such as metal sulfides,

The upper limit of the amount of filler that can be eiratrine is thereby given that the volume of condensed polyamide is sufficient the Püllstoiiteiichen zn enclose. So you can, for example without difficulty! thes sewing parts iron powder with one Cover part by weight of polyamide. A whitish light gray powder is obtained; in contrast, shows a corresponding mechanical PuivermisGtang- the dark iron color.

When looking at such mixtures under the microscope,.-An in many cases that enveloping the opaque filler particle light-colored polyamidescfc not recognize. With other fillers one sees, on the other hand, that there are many tiny polyamide spheres have arranged tightly around the filler particle.

The particle size of the respective polyamide can be influenced by the choice of solvent for the precondensation. With benzene you get the finest powders, with dialkylbenzenes you can highly congomerated particles; through appropriate mixtures the solvent is obtained in intermediate sizes.

When determining the specific viscosity numbers were in each case the filler-reducing amounts with a phenolic -Tetrachloroethane mixture: {6O / 4O) - in a ratio of 1 g of polyamide to 100 ml of solvent - extracted and the measurement carried out with the filtrate.

example 1

Polyhexamethylene isophtίlalalaid / -terephthalamid (70/30) with Wt .-? T copper powder

In one with stirrer, thermometer, dropping funnel and attached 1 liter round bottom flask equipped with a fractionating column 61.5 g copper powder in 500 ml benzene by stirring vigorously. Evenly distributed «Then 29 g of hexamethylenediamine are added. (0.25 mol and heated the mixture to 60 ° C. Under

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79 % of a mixture of? O ^c / o isophthalic acid diphenyj.e: 3rd r.nd jO ^r / ö terephthalic acid diphenyiester (0.25 mol) are added well stirring. Pre-condensation takes place at 80 ° C. for two hours. Thereafter distilling the benzene over a small column, and outputs in the same Ma3e Diathylbenzol to _r until the internal temperature on V (U C is increased. At this temperature, three hours post-condensed, during which slow the liberated phenol as an azeotrope with a portion of the After cooling, it is sharply suctioned off, washed with methanol and then dried in vacuo.

An easily gigantic powder is obtained, which is deposited on it an injection molding machine can be processed into format parts. Under the microscope, at 80 times magnification in transmitted light, one can see that there is a uniform pattern around every copper particle condensed through the soft skin of polyamide.

The specific viscosity number of the polyamide is 2.10.

Example 2

Polyhexamethylene isophthalamide Z-terephtualaaid (70/30) with 50 percent by weight iron powder

The reaction erioigt, as described in Example 1, only 61.5 g of fine iron powder are stirred in instead of the copper powder.

A white-gray powder is obtained.

The viscosity number of the polyamide is 2.24.

On a Koibenspri + zgussmaschine could without any difficulties Standard small rods are injected. The molded parts are attracted by »magnets»

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Example 3

Polyhexametnyienatipamid with 83 Jew. »- ¹ Jb iron powder

615 β fine iron powder are suspended by vigorous stirring in 1000 ml of dodecylbenzoi, which contains 50 g of hexamethylenediamine (C, :; ■ mol). at ^; ^ 0 C, 149 g of adipic acid diphenyiester (0.5 mol), dissolved in 200 ml of dodeoyibenzene, are added dropwise. After one hour the temperature is increased to 190 ° C. and condensation is continued for another three hours, where the released phenol is slowly distilled off.

Renait a neil gray powder, which, as in Example 1 described, is isolated, whereDei is washed with benzene.

The specific viscosity number of the extracted polyamide was determined with 1.7 *

Example 4

Polyhexamethyleni30phthalamid / -terephthalaInid (70/30) with 50 δβΐτ. ~ ^Σ 'ο aluminum

The reaction takes place as described in Example 1. Instead of the copper powder, 61.5 g of aluminum powder are stirred in.

A white-gray powder is obtained.

The viscosity number of the polyamide is 1.4-1

Example 5. '

Polyhexamethylene isophthalamide / = terephthalamide (70/30) with 5 Sew .- ^ Graphite -.

The reaction takes place as described in Example 1. 6.5 g graphite

are suspended in 50U ml of di-. *. hylbenzcl. At 80 C 159 g of a Diphenylestergemischea 70 ^c 'o isophthalic acid, and 30 ⁰ B terephthalic acid (0, ~ mol) dissolved in diethylbenzene and then with good stirring, a solution of 58 g of hexamethylene diamine (υ, 5 moles) in 500 al benzene run calmly. At ⁹⁰ C a Stunie is precondensed and then distilled off as much benzene, is increased until the temperature in the reaction mixture at 16O C. At this temperature, condensation takes place for three hours. The phenol is then distilled off as an azeotrope, ia vacuum, so that the temperature does not rise above 160 ° C.

The polyamide powder is isolated as described in Example 1. The specific viscosity number is 1.55

Test sheets are made with the powder according to the fluidized bed sintering process coated. A completely smooth, lackai ^ ti ^ - - glossy deep black coating. In contrast to this, with a polyamide powder, the 50 weight ~ $ graphite by ^ Uf * rub were mixed in, a dark grque, with numerous » Coating formed in depressions.

Example 6

Polyhexamethylene isophthalamide Z-terephthalaaid (7 & / 3Ο) with 5 weight percent molybdenum disulfide

The implementation takes place as described in example - _y . The 6.5 g MoS ^ used in place of the graphite and the condensation carried out in pure xylene. The lfachkondensationsteeperatur 140 ⁰ C.

The specific viscosity number is 0.86.

In the case of vortex sintering tests, observations very similar to those described in test 5 were made.

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Example 7

Polyhβxaraethyieriisophthalamid / -terephthalamiά (7O / 3O) with 75% by weight of special carbonyl iron oxide (Fe-O,)

The reaction takes place as described in Example 1. There are 369 g Fe ₉ O ₅ . suspended in 1200 ml of benzene and condensed 0.5 mol of polyamide in this suspension. The isolation of the dark brown-red powder is the same as that described in Example 1.

The viscosity number of the polyamide is 2.0.

Example 8

(7O / 3O) with 30 wt. ~ * Fo luminous pigment

There are suspended 26.4 E a luminescent pigment based on zinc sulfide in a mixture of 350 ml benzene and diethylbenzene 5OO ml. 79.5 g of diphenyl ester mixture ^{(0.5 mol) are dissolved in this mixture at 80 °} C. and 29 g of hexamethylenediamine (0.5 mol), dissolved in 50 ml of benzene, are added dropwise.

After a condensation time of two hours at 80 ° C., it becomes soriel Benzene was distilled off until the internal temperature rose to 15Ο C. is. After three hours at 150 ° C., the condensation occurs canceled and, as described in Example 1, the polyamide powder suspended "

The specific viscosity number of the polyamide is 0.87.

With the powder mixture, iron sheets can be produced using the fluidized bed sintering process coat.

A viscosity number of 1.54 was measured on a peeled coating. . .

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The eschi'ihtunfer glow in the dark.

Example 9

Polyhexar-otnyleMsophtiiaiamidZ-terephthalamid (70/30) with 2.5 wt .- 'ti titanium; oxide and 2.5 wt .- ^ o ultramarine

As described in Example 6, the molybdenum disulfide 3 »25 g of tdfendioxid and '.» ^ 5 g of ultramarine powder. The condensation is carried out in xylene.

The specific viscosity number is L, 8 ^.

With the lulled polyamide powder, iron sheets were made according to the ■ Vortex sintering process coated. You get a blue one Coating with high surface gloss.

A viscosity number of 1.46 measured.

Example 10

Polyhexaaethylene isophthalamide Z-terephthalamide (70/30) with 10 wt. Τδ polytetrafluoroethylene

5088 g of a biphenyl ester mixture (? 0/30) of isophthalic acid and terephthalic acid are placed in a mixture of 12.8 liters of diethylbenzene and 11.2 liters of benzene in a 50 liter stirred tank equipped according to the flask described in Example 1 solved. Then 440 g of polytetrafluoroethylene powder are stirred. At 80 C a solution mf§56 j $ hexamethylenediamine in eight liters Bensol is allowed to run in with good stirring at 80 * C for two hours and then the pre-condensed benzene ^ slowly distilled off and replaced simultaneously against, Biäthylbenzol. Then the phenol is used as an azeotrope. Diethylbenzene distilled off at 173 ° C. . . ,,., .--,

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The zuruckbieibenae Suspensicn is thrown off after it has cooled down and the filter cake is washed with methanol and then dried in vacuo.

The specific viscosity number of the polyamide is 1.8.

Example 11

Mixing polyamide of hexamethylenediamine + ■ 4 "4 'diamino-biscyclohexylmetnan and Isophthaisaure / terephthalic acid (4O / 6O) with 75 wt. -Fp copper powder

As described in Example 1, 176 g of Cu powder in 400 ml Benzene suspended. Then 63 »b g of diphenyl iso / terephthalate (4O / 6O) - 0.2 mol with a mixture of 11.6 g of hexamethylenediamine and 21.0 g of 4 »4'-diamino-biscyclohexylmethane reacted.

The insulation of the copper-polyamide-powder mixture is that same as described in Example 1.

The viscosity number of the polyamide is 1.86.

Example 12

Polyamide from p-xyiylenediamine and azelaic acid with 15 wt .- ^ graphite

A monochlorinated trimethylbenzene isomer mixture is used as the condensation medium with an initial boiling point of 190 C.

5 »1 g of graphite are obtained in 300 μl of chlorinated triethylbenzene suspended. Thereafter, 34 »1 β in the suspension at 80 C Azeiainsäurediphenylester (0.1 Hol) dissolved and then reacted with 13 »6 g of p-xylylenediamine. After 2 hours the temperature will slowly increased to 19ΟC. At this temperature is post-condensed for a further 6 hours. This distills released phenol slowly. .

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After cooling down, the polyamide is isolated as usual. The specific viscosity of the polyamide is 1.58.

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Claims (2)

Claims 1.) Terians for the production of finely divided fillers in plyaric powders containing pieicnmäiisreT distribution by reaction of the aryl esters of iso- and / or terepenthalic acid, and / or the aliphatic dicarboxylic acids with primary aliphatic isones and / or c.-cloaii phatic and / or araliphatic diamines in inert solutions. characterized in that before the polycondensation, the Fuxistoif is equally distributed in the inert solvent by rapid stirring and the reaction is then carried out in its presence. 2.) Process according to claim 1, characterized in that one preferably neutral reacting inorganic powdery Uses high-density fillers. Pat.-Dept. Dr-ITe / Ha July 20, 1965 009310 / 16-00 BAD .ORIGINAL, λ ..