CH626108A5 - Polyamide composition - Google Patents

Description

The invention relates to a polyamide composition, the following apparatus, preferably injection molding machines and extrusion

contains the following components in a mixture with each other: 55, at deformation temperatures of 23 0 to 280 ° C,

1) aliphatic polyamide, preferably 240 to 270 ° C. The moldings

2) copolymer that are 60 to 99 wt .-% polymeric are generally flexible and very impact resistant.

Alkadiene with 4 to 6 carbon atoms and the rest

40 to 1% by weight consists of polymerized acrylonitrile, examples of the total weight of components 1) and 2) 40 to 99.9% 60. A twin-screw extruder was used for component 1) for the compounding. ZSK 53 from Werner & Pfleiderer with a screw length

This mass and the moldings produced therefrom have used approx. 25 D.

For example, the PA-6 and PA-6,6 used had a relative

characteristics, but also at T below 0 ° C. solution viscosity of 3.02 or 2.97, measured on a solution

This improvement with the aid of the nitrile rubbers was not 65 of 1 g of polyamide in 99 g of m-cresol at 25 ° C. As a nitrile chew

expect, since at Kirk-Othmer, Encyclopedia of Chemical Techchuk mostly commercial copolymers from Bu-

nology, 2nd edition, vol. 17, p. 602, the low flexibility of tadien and acrylonitrile (Perbunane ® from Bayer AG)

Nitrile rubbers are highlighted at low temperatures. were used deformed. Only to examine the

3rd

626 108

The copolymers were produced especially for the experiments described here (experiments h + i in Table 1), in the limits of the quantitative ratios of butadiene and acrylonitrile.

The melt temperatures during the compounding were in the range of in the case of the PA-6 alloys

250-260 ° C, for PA-6.6 alloys in the range of 270-280 ° C.

The individual tests and the properties of the products obtained are summarized in the following tables.

Table 1

Experiments with polyamide-6, values measured at 20 ° C

Examples

% By weight

Copolymer

Notched impact strength

Flexural strength

Acrylonitrile

Acrylonitrile / butadiene

KJ / m2 DIN 53 453

MPA DIN 53 452

in the copoly in the mixture

meren

a.

28

10th

9.5

80.1

b.

28

25th

13.6

59.6

c.

18th

35

25.3

44.7

d.

28

35

22

46.2

e.

28

45

31.7

37.2

f.

28

35

20th

43.9

f.

33

35

16.8

45.4

H.

3rd

35

23.4

45.8

i.

50

35

11.8

55.8

Table 2

Tests with polyamide-6.6, values measured at 20 ° C

a.

18th

35

24.6

47.3

b.

28

10th

8.7

83.5

c.

28

35

22.8

48.7

Table 3

Notched impact strengths in KJ / m2 of alloys made of PA-6 and acrylonitrile / butadiene copolymers with 28% by weight acrylonitrile at low temperatures

Tempe

10% by weight

25% by weight

45% by weight

12% by weight

maturity

Copolyme

Copolymer

Copolymer

N-methylbene

risat in the

benzenesulfonamide

mixture

20 ° C

9.5

13.6

31.7

13

0 ° C

6.4

10th

13

3rd

-20 ° C

5.1

6.2

7.7

3rd

- 40 ° C

3rd

4.4

4.4

2.7

C.

Claims (4)

626108 2 PATENT CLAIMS - The polyamides modified with nitrile rubbers 1. Polyamide composition which generally contains the following components in a mixture which are good viscoplastic properties at - 20 ° C: shade. The notched impact strength only drops at - 40 ° C 1) aliphatic polyamide, compositions or moldings according to the invention usually on 2) Copolymer which contains 60 to 99% by weight of polymeric values which, when using the previously customary soft plastic alkadiene with 4 to 6 carbon atoms and to the rest of them can already be reached at 0 ° C. 40 to 1% by weight consists of polymerized acrylonitrile. The usual disadvantages of low molecular weight soft 40 of the total weight of components 1) and 2) can be used when using the nitrile up to 99.9% are attributable to component 1). rubbers can be avoided. For example, they are not 2. polyamide composition according to claim 1, characterized gekennzeich- i0 volatile, they do not sweat and are neither by What-net that 50 to 97% on component 1) and 50 to 3% on water, or other common solvents from the polyamides component 2) is not required. detached. 3. Polyamide composition according to claim 1, characterized in that the nitrile rubbers can be used in much larger amounts that the copolymer can be polymerized from 70 to 92% by weight than the low molecular weight plasticizers and therefore from alkadiene and from 30 to 8% by weight. % polymerized acrylic is pre-nitrile depending on the ratio of the components. Set the given flexibility and toughness precisely. 4. Use of polyamide compositions according to claim 1. The nitrile rubbers can also be used together with the bis-for the production of impact-resistant molded articles. her usual plasticizers are used. The nitrile rubbers used are preferably copoly- 20 mers from butadiene and / or isoprene and / or pentadiene-1,3 and acrylonitrile. As a plasticizer for aliphatic polyamides, the nitrile rubbers can be used in liquid form, as solid Usually on a technical scale, mainly low-molecular rubber, in the form of curvature or in powder form. aromatic sulfonamides, mostly N-alkyl-benzenesulfonamides. The molecular weight is used in the range, for example. These are generally very effective, have 25 out of 2,000-500,000, preferably in the range of 2,000- but some serious disadvantages: 250,000. Preferably the nitrile rubbers are in liquid Because of their high vapor pressure used in processing or powder form. Temperatures of the polyamides (250-320 ° C) evaporate the sul- As aliphatic polyamides are preferably polyamphonamide plasticizers partially during their incorporation into de-6, -6.6, -6, -10, -11, -12, their mixtures, from the polyami-polyamide. This leads to considerable losses and loads 30 on the block polymers and copolymers produced from the outside world. Furthermore, the sulfonamide plasticizers tend to use components of the polyamides mentioned, to exude and are dissolved out by water from the form, fillers, auxiliary and reinforcing materials as well as color pigments. A particular disadvantage of sulfonamides, together with the rubbers, can soften the polyamides is their failure at low temperatures. Worked under or added later. The additives at half 0 ° C no longer work. 35 can also be used in one or more starting materials. Other low molecular weight plasticizers, e.g. components. The additives include For example, in the Plastics Handbook, Volume VI, Polyamides, Carl Hanser Verses: Talc, silica, asbestos, glass fibers and -ku-lag, Munich, 1966, page 242 f., the same are liable, Ca Stearate, Zn stearate, ZnS, TiOs, CdS. Disadvantages such as the sulfonamide plasticizers: The incorporation of the nitrile rubbers into the polyamides evaporate in part during processing and are generally ineffective at low temperatures in the usual screw press temperatures. sen. There are usually both single-shaft and two-shaft In the DRP 744 119 the use of rubber (powermachines is suitable. The blends can also be made on lybutadiene, polyisoprene) for the modification of polyamide rolling mills or internal mixers as described. - When trying to incorporate polybutadiene into rubber processing. In this case, aliphatic polyamides in extruders with residence times of 10-45 should normally be observed to exclude air. After 60 s there was a complete incompatibility of the compo. According to a preferred mixing method, especially around the nenten. In doing so, brittle, strongly shedding product mixing processes were shortened, the mixtures can be obtained in unity. Effect of shear fields with shear gradients of> 150 sec.-1 Surprisingly, it has now been found that copoly- are produced in the usual screw extruders, preferably in double merisates from alkadienes and acrylonitrile with aliphatic powell extruders. The mixtures are generally well tolerated and are not vulcanized at home when incorporated. into polyamide in conventional extruders to produce products from the blends of aliphatic polyamides and Ni gender flexibility and impact resistance. tril rubbers can moldings on the usual molding