DE1720752C3 - Process for improving the stability of cis-M-polylsoprene vulcanizates - Google Patents

Description

Mixed catalyst-containing solutions of polyisoprenes in organic solvents are in particular the solutions mentioned at the beginning, as described directly in

incurred during the polymerization. According to the invention

25 stop means used preferably consists of lower aliphatic alcohols, e.g. B. methanol or ethanol, a common stabilizer and a small one Amount of an aliphatic or cycloaliphatic amine, which together in an organic 30 solvents, preferably the polyisoprene solvent As is known, it can be dissolved with an organometallic isoprene solution.

Mixed catalysts of the Ziegler type under cis-l ^ Ver. As amines are particularly those aliphatic

linking of the monomer units to a table in the build-up or; cycloal.phatic wet nurse suitable who polymer, a product similar to natural rubber - a longer-chain and a shorter alkyl or sate. The vulcanizates of these polyisoprenes contain 35 cycloalkyl radicals. Are particularly suitable but in critical areas of application of the intrinsic derivatives of methylamine, in which cm hydrogen »Structure of the corresponding natural rubber volcanic atom through a straight-chain or branched one sate off. The natural rubber surpasses the handeis- alkyl radical with 9 to 24 carbon atoms .st. Common cis-1,4-polyisoprene in the crosslinking process. Examples of suitable nurses are Ui-2-athyIhexylbeute and network structure, as can be seen on the pulpy amine, dicyclohexylammine and N-mearylmethylamine. teren and higher plateau for the tensile and structural The amine is preferably used in amounts of strength with simultaneously higher stress values 0.2 to 0.7 percent by weight, based on solid cauders Can recognize vulcanizates. This is especially true of chuk.

for unfilled and weakly filled vulcanizates, which The lower aliphatic alcohols to be used

weakly reinforcing carbon blacks, e.g. B. medium-fine thermal hole, z. B. methanol or ethanol, are contained in all odor, less pronounced, but are used in amounts of 0.2 to 5 percent by weight, also known for mixtures of tread qualities on solid rubber,
tat, the highly abrasion-resistant and very highly abrasion-resistant As examples of common stabilizers used in

Oven soot included. Amounts of 0.1 to 2 percent by weight are used

The polymerization of isoprene with organometallic catalysts are called 2,6-di-tert-butyI-4-methylphenic mixed catalysts [e.g. B. Al (iC ₄ H ₉ ) ₃ / TiCi ₄ ] nol, 2,2-dihydroxy-3,3'-di-tert-butyl-5,5'-dimethyl-di is known. It is usually in solution by phenylmethane, phenyl-0-naphthylamine.
guided. One can work as follows, for example: The three connections are generally in

The catalyst is an 8 to 30% isoprene concentration as high as possible (z. B. 2 to 25%), in solution in an aliphatic or aromatic 55 inert solvent, the polyisoprene hydrocarbon with the exclusion of oxygen and a solution that still contains an active catalyst, Added moisture. Used as a solvent added. The stabilizer can also be used separately one z. B. pentane, hexane, cyclohexane, benzene or the other compounds subsequently incorporated-toluene. The catalysts can, for example, be mixed.

Mixtures of aluminum trialkyls, optionally 60 The solution thus obtained is worked up together with their etherates and titanium tetrachloride in the usual way z. B. used by steam will. Suitable polymerization distillation.

temperatures are about -20 to + 8O ⁰ C. After the overall result of this type of inactivation of the catalyst

desired sales, e.g. B. from 90% and more of a polyisoprene is obtained, the vulcanizates of which are monomers, the catalyst can be modified by adding significantly improved vulcanizate properties and a suitable substance, e.g. B. of alcohols such as methanol have a reduced tendency to reverse.
or ethanol, can be inactivated. After addition, the improvement of the vulcanizate stability, ie the

suitable stabilizers, e.g. B. l, 6-di-tert-butyl-4-me- reduction in reversion occurs mainly in the

3 4

critical, ie unfilled or inactively filled, on the achievable crosslinking yield and the mixtures, somewhat less pronounced but also uniformity of the network structure, in very highly abrasion-resistant or highly abrasion-resistant
Vulcanizates containing furnace black. Furthermore, the scorch behavior and before 5 recipe are improved:

especially the optimal values for tensile and structural strength rubber 100.0 parts

speed with increased voltage values, as well as their _{7 o} -> 5 -p _e j | _e

Reversion resistance in all aging processes ⁿ 7 '_ ..

of Vukanisaten, e.g. starting with high stearic acid 1.0 1 rush

temperature vulcanization of heavily dimensioned articles io sulfur 2.0 parts

up to dynamic continuous stress, e.g. B. Dibenzthiazyl disulfide 0.7 parts

in heavy duty tires. Diphenylguanidine 0.3 parts

The obtained by the method described
cis-1,4-polyisoprene rubbers achieve the property level of good processing to a much greater extent:

Natural rubber grades (RSS N. 1) ali the handeis roller 400 X 200

usual cis-M-polyisoprenes. Temperature 40 ⁰ C

The polyisoprenes produced according to the invention rotate at 24 rpm

can be used anywhere else natural egg - 1.1?

good quality rubber is used, ie 20 Friction ί ■ Ui-

especially for dynamic, highly stressed rubber mixing time ^ minutes

parts, e.g. B. Truck tires.

ο. ... mixture with thermal soot (medium fine)

B e 1 s ρ 1 e 1 I

Polymerization This mixture with inactive carbon black filling (weak

acidic) and weakly basic acceleration system

Isoprene was obtained in a 10% solution in n-Hcxane with a relatively strong differentiating value - the use of an organometallic mis-catalyst level. The inactive filler does not lead to a sators based on TiCl ₁ and Al (C ₂ Hj) ₃ poly- 30 leveling of the properties, as is the case with active merized. Fillers, e.g. B. highly abrasion-resistant or very high

abrasion-resistant furnace soot is often the case. This test work-up mixture speaks on the basis of the balanced neutral Adjustment of soot and accelerator

The polymerization batch (conversion 93% = 93 ° "35 which is critical to the quality of the polymers: solids content) was divided and once marked with a plateau and reversion of the tensile mixture of 10% hexane, 2.5% ethanol and 1% and structural strength the quality of the vulcanized material 2,6-di-tert-butyl-4-methylphenol (based on poly- particularly clear, isoprene) stopped and stabilized: polymer A;
the second part of the batch was ZEP with a mixture of 40 R _e! ur from 10% hexane, 2.5% ethanol, 0.5% N-methyl '_"innnT ..

stearylamine and 1%, 2,6-di-tert-bulyl-4-methylphenol rubber 100.0 parts

(based on polyisoprene) stopped and stabilized: ZnO 5.0 leile

Polymer B. Stearic acid 2.0 parts

For testing and evaluating the vulcanization 45 thermal carbon black 30.0 parts

Behavior and the vulcanizates, the poly-sulfur were 2.5 parts

isoprene solutions after stopping and stabilizing. '"Yy." i _fi , n's TViI *

size by steam distillation of the solution Dibenzth.azyld.sulfid 0.5 part

by means of worked up. The resulting rubber diphenylguanidine 0.2 parts

crumbs were dried at 30 ° C in a vacuum. 50

The polymers A and B were in the Vulkani- processing: sat test with a commercially available, with a 400 X 200 m / m

Titanium catalyst produced cis- ^1,4 -polyisoprene (bewaize '

marked as a commercial product) in a filler-free temperature 4UC

Mixture (gum stick), a thermal carbon black mixture 55 friction 1: 1.2

and in a mixture r.lit highly abrasion-resistant furnace soot RPM 24

additionally compared with natural rubber. Mixing time 22 minutes

Details of the test _6o tread quality

1. Gum stick with highly abrasion-resistant furnace soot

The investigation of the vulcanizates of the complete property profile of an all-purpose compound is critical

Gum stick. Unadulterated by fillers and other rubbers, testing with active carbon blacks belongs 1

The vulcanization compound is a mixed component here

keep the pure polymers recorded, as only those for truck tires. Here, peak values for train and

the crosslinking absolutely necessary chemicals structural strength can be achieved at the same time high

are good against. The test result gives z. B. Determination of stress values and hardnesses.

5
Recipe:

Rubber 100.0 parts

ZnO 5.0 parts

Stearic acid 2.0 parts Highly abrasion-resistant furnace soot ... 50.0 parts

Highly aromatic mineral oil .. 10.0 parts N-phenyl-N'-isopropyl-

p-phenylenediamine 1.0 part

Phenyl-a-naphthylamine 1.0 part Sulfur 2.5 parts N-cyclohexyl-2-benzthiazyl-

sulfenamide 0.5 parts

Test formulation: thermal carbon black

20 752

Processing: Temperature ⁴ O ⁰ C Rotation 40 rpm Mixing order:

Rubber 0 minutes

Everything except S. and accelerator 1 minute

Sweep the manhole 3 minutes

Empty 5 minutes

N-CyclohexyW-benzthiazyl sulfenamide and

Sulfur is mixed in on the batch-off roller.

product ML 4 '/ 100 ^° C Defo Mooney VuIk. F. D. module 500% ) 56 hardness Elast. Continue Raw mixed. ^(81/0 C)
Raw Bulging
Kan isation 3atü 300% 101 23/75 23/75 tear-resistant
ability *) chew
chuk rubber 5ME 99 120 ⁰ C Min. (kp / cm ² (%) (kp / cm ² 93 CC) ( ¹ C) (kp'4 mm) ice-1,4-Po- 86 20 1375/30 2 B' 10 175 755 21 85 41/43 64/71 15th lyisoprene 20th 1S5 650 37 37 49/50 70/76 13th 30th 160 615 35 90 49/50 70/78 11th 45 163 635 35 87 48/49 69/76 10 60 155 640 32 83 47/48 67/74 7th Polymeri 85 20 ms / 26 45 ' 10 100 780 12th 78 32/30 60/60 6th sat A 20th 180 660 30th 77 47/48 71/71 16 30th 160 625 28 115 47/47 70/71 11th 45 150 650 25th 112 45/45 69/71 6th 60 145 655 23 107 45/46 68/70 4th Polymeri 82 19 1325/33 31 ' 10 205 750 27 96 44/45 69/73 22nd sat B 20th 195 * 650 39 48/50 72/77 20th 30th 192 650 37 48/49 72/77 15th 45 180 640 36 46/48 71/76 12th 60 170 650 32 45/47 68/74 10

·) Structure or tear strength according to P ο h 1 e.

F = tensile strength.

D = max. Elongation.

ME = Mooney units according to DIN 53523.

Test recipe: gum stick

product ML4 '/ 100 ° C Defo Mooney VuIk. F. D. module 500% *) 21 hardness Blast. Hamlet- Raw mixed. (8O ⁰ C)
Raw Anvulcanic
nization 3 atü 300% 29 23/75 23/75 tearproof
speed chew
chuk rubber 5 ME 28 120 ⁰ C Min. (kp / cm ^! (%) (kp / cm 28 ( ⁰ C) CC) (kp / 4 mm) cis-l, 4-po- 86 36 1375/30 19 ' 10 163 830 12th 24 37/37 80/75 20th lyisoprene 20th 180 775 13th 16 38/40 75/80 21 30th 155 750 13th 27 38/40 74/77 20th 45 140 655 13th 27 38/39 74/77 19th 60 140 860 12th 24 38/38 71/77 18th Polymeri 85 35 1275/26 33 ' 10 110 855 10 24 32/34 70/77 18th sat A 20th 170 775 12th 23 37/39 75/80 21 : io 195 800 14th 33 37/39 74/78 20th 45 155 785 13th 34 37/38 75/77 21 60 150 795 11th 30th 36/38 73/75 18th Polymeri 81 35 1325/33 23 ' 10 155 815 12th 28 37/37 76/77 22nd sate 20th 208 775 17th 40/40 76/77 24 30th 180 760 17th 40/40 77/77 23 45 175 775 15th 39/39 75/76 20th 60 175 790 13th 39/38 72/76 19th

Test recipe: Mixture with highly abrasion-resistant furnace soot

'roduct

ML 47 100 ° C Defo 80 ⁰ C
Raw mixed. Raw mixed.

rubber

rubber

Moo-VuIk. FD
ney-an 3 atü
vulcanization
5 ME

(kp /
120 ⁰ C min. Cm ² ) (%)

Module hardness Elast. Continue-

300% 500% 23 ° C 75 ° C 23 ° C 75 ⁰ C {* ^ "

wedge

(kp / 4 mm)

Nature- 89
rubber

cis -l ^ -Po- 86
lyisoprene

Poly- 85

mer A

300/41 825/11 37 '

1375/30 825/11 41 '

1275/26 725/11 45 '

Poly- 82
mer B

1325/33 750/12 36 '

10 20 30 45 60 90

10 20 30 45 60 90

10 20 30 45 60 90

10 20 30 45 60 90

100 192 197 187 179 181

47 186 195 181 166 166

10 170 195 185 170 160

29 210 210 200 180 175

485 45

535 83

525 89

520 88

515 78

500 83

530 21

570 76

560 83

545 78

535 70

545 70

720 5

660 58

585 81

550 75

535 60

330 60

505 10

575 81

550 91

540 86

535 78

540 70

110 46

174 54

182 56

184 56

172 55

176 54

44 35

156 54

169 56

159 56

151 55

148 52

25 '-

140 51

165 55

145 54

140 54

135 53

23 32

172 54

187 56

177 56

167 55

168 55

38
52
54
53
52
51

32
53
55
54
53
53

50
54
52
52
51

38
53
54
54
52
50

39
42
42
41
41
40

34
41
41
41
40
39

42
43
42
41
41

32 44 44 44 43 42

38 49 49 49 47 46

33 48 50 48 47 47

48 49 50 48 47

28 52 54 53 49 47

12 36 38 34 32 32

36 34 27 24 25

32 35 30 24 100

6 38 38 35 30 26

Checking the optimal heating levels

Comparison of natural rubber, commercial product, polymer A and polymer B

Test recipe: Mixture with highly abrasion-resistant furnace soot

Raw mixture Natural rubber cis-1,4-poly isoprene Polymer A Polymer B ML 4 '(100 ° C) 54 57 55 52 Defo (80 ° C) 825/11 825/11 1075/14 800/12 Mooney vulcanization (12O ⁰ C) 5 ME 37 41 45 36 Relaxation (%) 38.8 24.0 24.0 28.0 Tackmeter (stickiness) 846 912 600 880 Optimal heating: 30 '/ 3, O atü DIN abrasion, 40 grade emery 176 162 172 167 60s emery 102 93 124 113 Slip resistance, wet 53 52 52.3 52.5 De Mattia (bends = χ 10 ^a ) Cracking 50% breakage 95 45 70 83 100% breakage 144 71 85 132 Crack growth 2 to 4 m / m 61 37 40 44 4 to 8 m / m 118 68 67 84 8 to 12 m / m 161 88 85 107 Compression set. Meth. B. ASTM 70h / RT 9.1 5.5 4.7 4.9 22h / 70 ° C 31.3 25.1 29.4 23.5 70h / 100 ° C 65.5 62.2 60.1 59.4

(Continuation of the table above)

Raw mixture Δ T over 100 ⁰ C after 10 ' Natural rubber cis-1,4-polyisoprene Polymer A Polymer B Ball attrition 25 ' Service life (revolution) 60 ' 19 370 14 580 13 535 17 480 Temperature (° C at rev.) Flow at 100 ⁰ C (%) after 10 ' 178/7830 183/6680 185/6680 181/7560 Goodrich Flexometer (0.0875 inch) 25 ' T over RT after 10 min. 60 ' 27.5 ^° C 30.0 ° C 29.0 ⁰ C 26.0 ⁰ C 25 min. 33.5 ⁰ C 36.0 ° C 34.5 ° C 31, O ⁰ C 60 min. 36, O ⁰ C 38, O ⁰ C 36, O ⁰ C 32, O ⁰ C Flow at RT in (%) after 10 ' - 2.4 + 1.0 + 1.2 + 1.4 25 ' - 3.5 + 0.5 + 0.2 + 0.6 60 ' - 5.7 - 1.2 - 1.5 - 0.8 15.0 ⁰ C 14, O ⁰ C 15.0 ° C 12.5 ^° C 20.0 ⁰ C 18.0 'C 19, O ⁰ C 15.0 ^a C 33.0 ° C 32.0 ° C 39.0 ° C 19, O ⁰ C - 4.1 - 3.0 - 3.8 - 2.0 - 7.6 - 7.8 - 9.1 - 6.7 -25.0 -19.0 -20.3 -12.0

Examples 2 to 8

In the following Examples 2 to 8, the inventive effect of secondary amines using the example of N-methyl-stearylamine with a number of primary and tert. Amines compared. The polyisoprene solutions were prepared as in Example 1 and using the following amines according to Example ^; el 1 deals with :

example Amine % *) 2 NH ₃ 0.035 3 C ₃ H ₇ NH ₂ 0.12 4th C ₁₈ H ₃₇ NH ₂ 0.49 5 (C ₂ H ₅ ) ₂ NH 0.15 6th (C ₂ H ₅ ) ₃ N 0.20 7th C ₁₂ H ₂₅ N (CH ₃ ), 0.43 8th C ₁₈ H ₃₅ NHCH ₃ 0.50

♦) All amines are used in equivalent amounts.

The polymers from Examples 2 to 8 were used in the test formulation with thermal carbon black checked (see following table).

A comparison of the vulcanizate data of Examples 2 to 8 shows that N-methylstearylamine (Example 8) reached the most favorable values for the network yield and network structure, indicated by the high and broad plateau of strength with simultaneously high values for modulus and hardness. ammonia (Example 2) and the tert. Amines (Examples 6 and 71 do not give satisfactory vulcanizate values. The crosslinking yield is not sufficient. The primary Amines (Examples 3 and 4) and diethylamine are somewhat more favorable in terms of the crosslinking yield but by no means reach the level of Example 8 Above all, the tendency to reverse (decrease in Strength, tension and hardness values) too large. Dif

Reversion is due to N-methylstearylamine (Example 8; greatly reduced.

Test formulation: thermal carbon black
Vulcanization values

Example amine No.

VuIk. 3atü

Min.

(kp / crn *) (%)

module 300% 500%

(kp / cm ² ) Hardness 23/75 ( ⁰ Q

Elast. 23/75
CC)

structure

(kp / 4mm

NH ₃ 10 90 795 11th 29 20th 157 660 27 77 30th 150 650 27 77 45 144 665 24 71 60 135 650 24 69 HC ₃ H ₇ NH ₂ 10 175 715 21 67 20th 154 625 30th 88 30th 157 645 27 83 60 155 660 25th 79 90 158 665 21 69

33/34 61/60 5 45/46 67/71 14th 46/46 68/71 8th 44/45 68/71 5 43/42 68/70 5 46/46 70/71 16 48/49 73/71 11th 47/47 72/71 8th 47/47 68/69 5 44/45 68/69 5

11th

(Continuation of the table above)

12th

example Amine VuIk. F. D. module 500% hardness Elast. Structure box No. 3atü 300% 23/75 23/75 Min. (kp / cm ») (%) (kp / cm ') CC) CC) (kp / 4 m

C ₁₈ H ₃₇ NH, 10

20 30 60 90

10 20 30 60 90

10 20 30 60 90

C ₁₂ H ₂₅ N (CH ₃ ), 10 20 30 60 90

(C ₂ H ₅ ) ₂ NH

(C ₂ H ₅ J ₃ N

C ₁₈ H ₃₇ NHCH ₃

10 20 30 45 60 90

165 140 147 146 135

170 170 160 155 148

160 26 20 30

153 162 145 120 137

186 175 175 160 163 160

660 585 600 610 610

675 620 660 615 620

725 275 280 340 405

755 655 625 615 650

685 605 590 600 585 600

29 32 32 32 27

24 35 35 29 27

19th

25 25 24

16 27 27 24 21

27 40 41 37 37 32

88 96 93 91 83

80

101

103

93

88

59

45 75 77 72 67

83 121 120 111 111 101

48/49 49/50 48/49 48/48 46/47

46/45 49/49 48/48 48/48 45/47

43/40 48/48 46/47 45/46 43/45

44/40 48/48 47/48 47/47 44/45

43/46 49/51 49/50 48/49 48/49 47/48

71/70 74/73 70/69 68/69 66/68

71/71 73/73 71/72 71/71 70/69

66/67 71/71 70/70 66/68 65/67

66/67 70/69 67/68 65/68 65/55

69/72 72/73 71/73 70/72 70/72 69/71

Claims (2)

ethylphenol, 2,2'-dihydroxy-3,3'-di-tert-butyI-5,5'-dimethyl-diphenylmethane or PhenyI - /? - naphthylamine, Claims: ^ _311n J ₀₃₃ the polymer by adding a precipitant, such as ethanol or acetone, from the ιοί. Isolate method to improve stability of 5 solution. Technically, the polyisoprene is used to obtain cis-l ^ polyisoprene vulcanizates, characterized generally from the hydrocarbon solution by the fact that steam is removed (stripping) after production. The rubber obtained in the process of polyisoprene, the catalyst-containing solution, is dried in the vasung in an organic solvent with a vacuum cabinet, on an apron conveyor or with the help of a mixture of a lower aliphatic alio from a screw. alcohol, a conventional stabilizer and a chemical. It has now been found that Vulkarjsate des wrestle amount of an aliphatic or cycloaliphatic cis-1,4-polyisoprene with improved properties tables secondary amine whose alkyl or is obtained if after the preparation of the Poly.so-Cydoalkylreste altogether at least 10 carbon prens the mixed catalyst-containing solution in one containing atoms of matter, treated. * 5 organic solvents with a mixture of 2. The method according to claim 1, wherein a lower aliphatic alcohol, a conventional däres amine derivatives of methylamine stabilizer and a small amount of an aliphatic or cycloaliphatic secondary amine _{are used as a second.} whose alkyl or cycloalkyl radicals together contain at least 10 carbon atoms.