CH665648A5 - THERMOPLASTICALLY PROCESSABLE MASSES MADE OF POLYAMIDE, THERMOPLASTIC POLYURETHANE AND ACTIVATED POLYOLEFIN. - Google Patents

Description

DESCRIPTION

Polyamides are ideal for thermoplastic processing. Today there are many areas of application for polyamides, most of which are rather rigid, dimensionally stable construction parts. A disadvantage of most aliphatic polyamides is their dimensional change and their decrease in stiffness during use due to moisture absorption. Their resistance to abrasion is relatively good, but often does not meet practical requirements. Flexible polyamides have recently become known. The flexibility is achieved by adding monomeric plasticizer, but also by building segmented polymer structures, whereby elastomer blocks are inserted between normal polyamide blocks. i5 These generally consist of polytetramethylene oxide with a molecular weight of 600-3000.

In the case of the polyamides containing monomeric plasticizers, these can be removed on contact with water or organic liquids. Segmented polyamides 20 are complex to manufacture; but they are very easy to process. They have disadvantages with regard to abrasion behavior, elastic resilience and generally with regard to stability to hydrolysis.

Thermoplastic polyurethanes cover a wide range of properties. Their hardness can cover a wide range from approx. 80 Shore A to approx. 75 Shore D. Their abrasion resistance and elastic resilience, especially after tempering, are excellent. Their low temperature flexibility and toughness can be influenced to a limited extent by choosing the type and proportion of the elastomer segment. There are 3 main components of soft segments:

1. Tetramethylene oxide polyether

2. Poly-a-caprolactone

35 3. Adipic acid polyester with ethylene glycol or mixed ethylene glycol / butanediol possibly hexanediol as a diol component

The hard segments are mostly based on aromatic diisocyanates, especially the diphenylmethane diisocyanate 40 types (MDI) or the isophorone diisocyanate (IPDI) or the toluene diisocyanate (TDI), which are often reacted with butanediol. The main disadvantage of thermoplastic polyurethanes is their difficult processability in injection molding, but especially in extrusion. 45 The class of polyamides is e.g. described in the plastics handbook, volume VI (1966), the class of polyurethanes in the plastics handbook, volume 7 (1983), both published by Carl Hanser Verlag, Munich.

There has been no lack of attempts to combine the properties and the good processability of polyamides with the properties of the thermoplastic polyurethanes.

In Org. Coat. Plastic. Chem., 40 (1979) are described on pages 664-668 blends from TPUR with a variety of thermoplastics. Extensive incompatibility was found with pure polyamide 6 and partial compatibility with polyamide 12.

The thermoplastic PA-TPUR blends described in the patent literature are therefore distinguished by the fact that a special copolyamide of low softening temperature and generally containing dimerized tall oil fatty acid with 36 carbon atoms is used. These are e.g.

Euro application 109 342, US Pat. No. 4,384,083, DE-OS 2,431,984, such products being mostly suitable as hot melt adhesives.

65 Often, due to insufficient tolerance, the TPUR content is also severely restricted, e.g. in U.S. Patent 4,369,285 and USSR Patent 352,915. In Fr. Note 2,207,955, Yes. Note 7 278 673 and Yes. Note 7 434 947 is the addition of

3rd

665 648

monomeric plasticizer described, which in addition to reducing the rigidity of the end product improves plasticity, miscibility and compatibility.

By choosing soft, low-melting copolyamides, however, the rigidity, strength and heat resistance are reduced. The possibility of adding only a little TPUR limits the possibility of specifically setting property combinations. Monomeric plasticizer can exude during processing or use, which leads to undesirable side effects.

We are looking for blends made of polyamide with thermoplastic polyurethane with the broadest possible range of miscibility between the polyamide and polyurethane, which are easy to process and enable new combinations of properties.

It has now been shown that a thermoplastically processable composition according to claim 1 has good thermoplastic processability and leads to products with new combinations of properties. With a ratio of a: b of 0.2-5, the masses are particularly easy to process if at least 10% by weight of component c) is present.

All linear, thermoplastically processable polyamides which have a softening range below approx. 235 ° C. are suitable as polyamides. Linear, aliphatic polyamides such as polyamide 6, polyamide 6.9, polyamide 6.10, polyamide 6.12, polyamide 11 and polyamide 12 are particularly suitable.

The polyamide compositions can also be copolyamides composed mainly of aliphatic monomers or alloys composed of 2 polyamides. If polyamide 66 is also used, a melting point depression can occur in the case of real alloys, so that the softening temperature drops to 235 ° C and below or, if the polyamide 66 does not form the main component, it can be used as a disperse phase, e.g. in the matrix of the other polyamide (e.g. polyamide 6), so that the mass can still be processed at 235 ° C and below. The same applies to mixtures of others, e.g. also amorphous, polyamides.

All types that are suitable for processing with polyamides in terms of their thermal stability are suitable as thermoplastic polyurethanes. Masses that can be processed particularly well are obtained when using so-called polyether polyurethanes. But the polyurethanes with polycaprolactone as the soft segment also result in products that are easy to process. It is particularly interesting, however, that the types of adipate which are sensitive to hydrolysis and difficult to process by mixing in accordance with the present process also result in easily processable compositions with new combinations of properties.

The so-called activated copolyolefins are copolymers of ethylene with at least one α-olefin with 3 and more carbon atoms, the copolymer being grafted with an organic carboxylic acid or a derivative of a carboxylic acid which has 1 or more -COOH groups or their derivatives. The grafting must be carried out in such a way that about 0.05-2% by weight of acid or its derivative is grafted on. Maleic anhydride or fumaric acid are most commonly used for grafting. Copolymers of ethylene with propylene, butene, hexene and octene are used as copolyolefins. Copolyolefins with a predominant proportion of ethylene are common, but it can also happen that the copolyolefin part, e.g. Propene and octene predominate. In addition to α-olefin, the copolyolefins can additionally contain an amount of a non-conjugated diene, such as 1,4-hexadiene or diethylidene norbornene, which is suitable for subsequent grafting.

The technique of grafting these copolyolefins is state of the art and has been widely described. So treat e.g. DE-OS 2 722 720 and Japan Kokai 7 801 291 the grafting using organic peroxide and US Pat. No. 4,026,967 and Euro Note 0 109 342 the peroxide-free grafting, which rather requires higher temperatures, and copolyolefins, which also use a diolefin with non-conjugated double bonds.

The activated copolyolefins can therefore vary in their properties in a wide range, for example by their crystalline content 1-35% and their so-called MFI (melt flow index according to ASTM D 1238) can be 0.1-50 g / 10 minutes.

Of course, the thermoplastically processable compositions according to the invention can be further modified in accordance with the prior art by adding additives such as fillers, e.g. Glass and / or mineral, plasticizers, small amounts of other thermoplastics, processing aids such as internal and external lubricants, mold release agents, stabilizers (heat, light, oxidation), carbon black, dyes, pigments, anti-flame agents etc. as well as combinations of these additives as required .

The invention will now be explained in more detail by means of examples.

Examples 1 to 9

The comparison tests are marked with an asterisk (*) in Table 1 and the proportions of the individual components are parts by weight.

The materials used are characterized in more detail in the Appendix to Table 1.

For the purpose of carrying out the experiment, granules of polyamide, TPUR and, in the case of the experiments, activated polyolefin, which had been dried to water values below 0.05% (weight), were mixed, and the additives were then added in premixed form and mixed further until the additives in a thin layer were uniform spread on the granules. Now this mixture was fed to the feed hopper of a twin-shaft kneader type ZSK-30 from Werner and Pfleiderer, Stuttgart, and at a screw speed of 150 rpm, the temperatures of the 6 heating zones in the range of 180-230 ° C were adjusted so that under Using a 4 mm nozzle resulted in a strand that was as homogeneous as possible and easily granulated. The throughput was approx. 8 kg / hour. A typical setting profile of the 6 heating zones is e.g. 180/190/220/230/220 each ° C. The extrusion strand was passed through a water bath, granulated and the granules dried to a water content below 0.05% (weight).

The temperatures of the melt measured at the nozzle are entered in Table 1.

An assessment of the melt strand after the nozzle gave an interesting first result:

In all cases, the addition of the activated polyolefin resulted in a homogeneous strand of a smooth surface, while in the absence of the blend component according to the invention, this was humped and rough, and often came out pulsating.

The addition of an activated polyolefin to a pellet mixture of polyamide and TPUR therefore results in a significantly more favorable behavior already during the production of the polymer alloy.

The test specimens (small DIN bars, DIN 53 453, tension rod, DIN 53 455/3) were each produced on an injection molding machine from Netstal, CH-Niederurnen, type Neomat N 110/565, which contains an effective melting extruder .

The melting parameters such as the temperature profile of the melting screw, speed, etc. were each made the best possible

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

665 648

4th

As the comments on injection molding processing in Table 1 show, problems arose in all cases of the comparative tests. In contrast, the formulations according to the invention could be processed into homogeneous test specimens with a beautiful, smooth surface. Only in the case of the blends with TPUR contents over 50% did the demolding time have to be extended somewhat.

In addition to the better processability, the blends according to the invention also have a significantly higher toughness according to DIN 53 453. In Table 1 above, means: test specimen

IliÉijfMlflìi

The flow behavior according to DIN 53 455 also shows a favorable picture. While e.g. If polyurethane-rich polyamide 12 blends cannot be produced and processed 5 without the addition of an activated polyolefin (comparative experiment 7), the force-elongation diagram of the corresponding blends according to the invention shows a high breaking strength and elongation at break without a pour point being visible.

If no values for flow resistance and flow elongation are entered in Table 1, the force-strain diagram does not show any defined flow point.

Table 1

Trial No. 123456789

* Comparison test * * * *

Composition:

- PA 12, type 1

80

70

80

70

20th

25th

25th

- PA 12, type 2

80

70

-TPUR, type 1

20th

20th

20th

20th

-TPUR, type 2

20th

20th

80

65

55

- Activated polyolefin

10th

10th

10th

10th

20th

- Additions

1

1

1

1

1

1

1

1

1

Extrusion:

- temperature of the melt (° C)

216

223

231

222

216

225

-

191

184

Processing:

- Problems that arise (see attachment)

1)

1)

1), 3)

5)

4)

4)

Mechanical specifications:

- Notched impact strength, DIN 53 453

23 ° C (kJ / m2)

11

if

27th

if

16

if

-

if

if

- 20 ° C (kJ / m2)

5

8th

7

8th

5

9

-

if

if

- 40 ° C (kJ / m2)

5

5

5

5

5

6

-

if

if

Tensile test, Din 53 455/3, at 23 ° C:

- flow resistance (N / mm2)

34.8

27.7

-

-

23.4

-

-

- breaking strength (N / mm2)

27.2

38.8

27.0

30th

25.0

17.8

16.3

- yield elongation (%)

7.7

15.8

-

-

18.5

-

-

- elongation at break (%)

34.7

198.2

3.2

66.5

31.5

250

225

Bending modulus of elasticity, DIN 53 452:

23 ° C (N / mm2)

1215

791

1045

823

1302

677

-

78.1

67.4

0 ° C (N / mm2)

1630

980

-20 ° C (N / mm2)

1887

1122

-40 ° C (N / mm2)

2104

1192

1550

1182

Limit bending stress, DIN 53 452:

23 0 C (N / mm2)

57.4

39.8

47

39.4

58

32.6

-

5.1

4.5

0 ° C (N / mm2)

86

55

-20 ° C (N / mm2)

104

65

-40 ° C (N / mm2)

121

71

94

70

Appendix to Table 1

It means:

- PA 12, type 1: medium viscosity injection molding type, chain length control in such a way that the following end groups (each expressed as equivalent / kg polymer) result: -COOH = 49, -NH2 = 27

- PA 12, type 2: medium-viscosity injection molding type, chain length control so that the following end groups result: -COOH = 20, -NH2 = 57

- TPUR, type 1: Pellethane 2102-80A, polyester type

- TPUR, type 2: Pellethane 2103-80AE, polyether type from Upjohn Europa SA, CH-St. Gallen

- Additives: Mixture of processing aids and stabilizers, which consists of (% by weight): 20% Tinuvin P, 20% Irganox 1076.20% Irganox 1098 (stabilizers from Ciba-Geigy AG, CH-Basel), 20% Lubricant PAT-712/11 from Wurtz GmbH, D-Bingen-Sponsheim, as well as 10% zinc stearate and magnesium stearate from O. Bärlocher, D-8000 Munich 50

- Activated polyolefin: APO, AP 712 T from Mitsubishi Chemical Industries, Tokyo

- In the case of injection molding processing, the comments mean: 1) non-homogeneous blend, skin detachments, 2) tensile

55 be DIN 53 455/3 not producible, 3) decomposition of the melt when spraying; Test specimens have a blistered surface. Tension rod (DIN 53 455/3) cannot be produced, 4) test specimen with a beautiful, smooth surface, easy sticking in the mold, 5) Even the production of the blends in a double-shaft 60 kneader was impossible due to signs of decomposition and incompatibility.

Examples 10 to 14 and Comparative Examples 15 to 19

After it was shown in Examples 1-9 that the producibility, processability and various mechanical properties are improved by adding an activated polyolefin, in the examples which now follow only blends containing activated polyolefin are used

5

665 648

described and compared in their behavior with the pure polyamide and polyurethane types.

The blends were produced and processed in accordance with the conditions listed above, although a single-screw extruder with an effective mixing part was used for the blend production. The exact processing parameters for the respective formulation were optimized as best as possible.

The comparative materials in accordance with experiment 15-19 were subjected to the usual conditions for these thermoplastics

Composition (% by weight) polyamide 12, Grilamid L 20 G polyamide elastomer, Grilamid ELY-60

Polyamide 6, Grilon A-28 TPUR:

Adipate type, Pellethane 2355-90A lactone type, Elastollan E 590 FNAT

Polyether type, Elastollan E 190 FNAT

Activated polyolefin, APO AP 712 T

Mechanical properties test: standard: unit:

ASTMD breaking strength 638 elongation at break 638 shore hardness A 2240 modulus of elasticity 790 rebound resilience

Density 792

Notched impact strength, with oB = without break

Appendix to Table 2

The raw materials used are commercial products from the following companies:

- The polyamide types used by Ems-Chemie AG, CH-7013 Domat / Ems

- Pellethane 2355-90A from Upjohn, USA-La Porte

- Elastollan E 590 FNAT and E 190 FNAT from Elasto-gran-Chemie GmbH, D-Lemförde

- APO, AP 712 T from Mitsubishi Chemical, Tokyo processed.

The polyamide 12 injection molding material used for most experiments, Grilamid L 20 G from Ems-Chemie AG, CH-7013 Domat / Ems, already contains processing aids and stabilizers, so that no additives other than the base polymers were used for the blend formulations .

The composition of the blends and the mechanical values measured on them are shown in Table 2.

In order to make the new property combinations of the blends according to the invention more visible, a number of comparative special tests were carried out. The results of these tests are summarized in Table 3. Instead of numerical values, the general behavior is shown with symbols with the aim of such a good overview.

The symbols with a decreasing scale of values are: + 00-, i.e. with + = very favorable behavior and - = comparatively bad behavior.

Table 2

Examples 10

11

12

13

14

Comparative Examples 15 16

17th

18th

19th

20th

20th

35

60

100

35

100

20th

15

70

30th

100

70

35

100

30th

100

10th

10th

15

15

10th

200

410

270

280

350

610

350

440

450

450

450

585

390

570

450

310

300

550

500

550

92

87

96

92

90

-

-

92

90

90

1000

1000

2800

3200

3500

11000

2750

-

-

-

57

58

60

44

50

75

60

45

50

45

1.10

1.11

1.01

1.02

1.03

1.01

1.01

1.20

1.18

1.22

if

if

if

if

if

8th

8th

if

if

if

kg / cm2

%

kg / cm2

%

g / cm3 kgcm / cm2

665 648

6

Table 3

Test No. Experiment Examples Comparative Examples

10 11 12 13 14 15 16 17 18 19

1 Flexibility at low temperatures +

2 Resistance to fatigue in the + fatigue test

3 Adhesive strength of bonds with a + polyurethane adhesive system

4 Kink resistance +

5 Gluing in the mold during demolding + (injection molding processing)

6 Resistance to hydrolysis +

Tests No. 1-6 in Table 3 are briefly explained below:

- No. 1: The moduli of elasticity according to the invention are contained in Tables 1 and 2. For a favorable flexibility behavior at low temperatures it is required that the value of the modulus of elasticity at -40 ° C deviates as little as possible from the value at 23 ° C. This is achieved much better in the blends according to the invention than in the case of the pure polyamide-TPUR blends.

- No. 2: Test specimens according to Table 2 were provided with a notch of 2 mm depth and subjected to a continuous bending test of 105 cycles:

Formulations according to the invention and comparative examples 16 and 19 = no change ascertainable,

Comparative Example 18 and polyamide 6 injection molding material = break after 800 cycles,

• Comparative example 17 resp. 18 = break after 17,000 resp. 20,000 cycles.

- No. 3: To test the adhesive strength with polyurethane glue, a peel strength test was carried out.

For this purpose, strip-shaped test specimens according to Table 2 were glued with synthetic leather using a polyurethane adhesive. Bostic 4120 H and isocyanate hardener, mixed in a ratio of 100: 5, were used as the adhesive. The test speed was 200 mm / min.

The sample was torn at:

• Examples 10 and 11 as well as the pure polyurethanes in the leather or in the test specimen, but not on the adhesive seam

• Example 12, 13, 14 70% in leather or test specimen and only 30% by peeling off the adhesive seam, the peel strength being 13 kg / 25 mm

• In comparative example 15, corresponding to polyamide 12, the peel strength was only 5 kg / 25 mm (the same applies to polyamide 6); in comparative example 16 it was 12 kg /

25 mm.

This result shows that when the blends according to the invention are used as the material for shoe soles, it is no longer necessary to sew them to the shoe upper, since gluing with the adhesive described produces sufficient strength. In contrast, shoe soles made of pure nylon have to be sewn to the shoe upper.

+

+

+

+

-

O

-

+

+

+

+

+

-

+

o o

+

+

o o

o e

+

+

+

+

o o

O

__

+

+

+

+

+

+

+

+

+

©

e

©

+

+

+

+

+

+

_

O

- No. 4: To test the kink resistance, pipes with an outer diameter of 18 mm and an inner diameter of 17 mm were manufactured and subjected to a permanent kink test.

20 fen-

• In example 10 and 11, no kink was observed even after many cycles

• In Examples 12, 13 and 14, the first crease marks only appeared after 50 cycles

25 • In comparative examples 15 and 16, there were clear kinks immediately after the start of the test

• From the comparative examples 17, 18 and 19, that is to say the pure polyurethanes, no pipes of the named

30 th dimension can be produced. From tests on flat bars, however, it is known that polyurethanes have good kink resistance.

- No. 5: tendency to stick in the tool

When manufacturing the test specimens according to the table

35 2 as well as in the manufacture of pipes showed that test specimens or pipes without the tendency to stick in the mold (tool) can only be produced with the blends according to the invention and the pure polyamides. It was also e.g. not possible at all, based on the pure TPUR types

40 (corresponding to comparative experiments 17-19) to produce thin-walled tubes for the kink test.

- No. 6: Resistance to hydrolysis

To check these, pipes with dimensions of 6 mm outer and 4 mm inner diameter were manufactured

45 and subjected to a burst pressure test of 15 kg / cm2, which all passed. Now they were filled with water, sealed and kept in a warming cabinet at about 60 ° C for 20 days. They were then exposed to an internal pressure of 15 kg / cm2 at room temperature.

50 • The tubes remained undamaged in accordance with Examples 10-14 and in Comparative Examples 15 and 16 (pure nylon tubes)

■ The TPUR pipes according to Comparative Example 17-19 all broke.

55 This shows that formulations according to the invention have a significantly improved resistance to hydrolysis.

Claims (13)

665 648 1. Thermoplastic processable composition containing: a) 5-90% by weight of at least one thermoplastic polyamide, b) 5-90% by weight of a thermoplastic polyurethane (= TPUR), c) 5-50% by weight of a thermoplastic, activated polyolefin. 2,3: 5,6-dibenzooctadiene (2,5) dicarboxylic acid (7,8) anhydride or mixtures of such products is or are. 2. Thermoplastic processable mass according to claim 1, characterized in that for a weight ratio of a: b of 0.2-5 at least 10 wt .-% of component c) must be present. 2nd PATENT CLAIMS 3. Thermoplastic processable mass according to claim 1, characterized in that the polyamide can be a homopolyamide, a copolyamide, a segmented polyamide (= elastomeric polyamide) or a mixture or an alloy of different polyamides and the polyamide has a softening point of less than 235 ° C owns. 4. Thermoplastic processable mass according to claim 3, characterized in that polyamide 12 or polyamide 11 is included as the polyamide. 5. Thermoplastic processable mass according to claim 3, characterized in that polyamide 6 is included. 6. Thermoplastic processable composition according to claim 3, characterized in that an aliphatic condensation polyamide made of diaminohexane and a dicarboxylic acid containing at least 9 carbon atoms is included. 7. Thermoplastic processable composition according to claim 3, characterized in that a polyamide elastomer or a polyamide blend containing a polyamide elastomer is included. 8. Thermoplastic processable mass according to claim 1, characterized in that a thermoplastic polyurethane of the polyester type is included. 9. Thermoplastic processable mass according to claim 1, characterized in that a thermoplastic polyurethane of the polyether type is included. 10. Thermoplastic processable composition according to claim 1, characterized in that the activated polyolefin according to c) is an olefin copolymer which contains 0.1-2% by weight, based on the amount of polyolefin, of at least one unsaturated carboxylic acid or a derivative thereof Carboxylic acid is grafted. 11. Thermoplastic processable composition according to claim 10, characterized in that the acid or the acid derivative is a dicarboxylic acid and derivatives such as fumaric acid, maleic anhydride and bicyclo [2,2,2] - 12. Thermoplastic processable mass according to claim 11, characterized in that the activated copolyolefin has a glass transition temperature of less than - 20 ° C, a degree of crystallization of 1-35% and a melt index of 0.2-50 g / 10 minutes at 190 ° C and has 21.19 N load. 13. Thermoplastic processable mass according to claim 1, characterized in that the activated polyolefin consists of a mixture of grafted copolyolefin according to patent claims 10-12 and non-grafted copolyolefin and wherein the proportion of the grafted copolyolefin is at least 30 wt .-% based on the amount activated Polyolefin.