DE1720191C3 - Pneumatic tire with an elastomeric cover strip for the sidewalls - Google Patents

Description

P j g 2 is a cross section of a pneumatic tire with a white side wall and a cover strip according to the

The embodiment of FIG Invention shows a tire made from a fabric-reinforced carcass 10 made from conventional carcass material with overlying tread 21 and a blacken Side wall 12 consists of a conventional composition on one side. On the other ropes

there is a layer of a white wall material 13, about 62% ethylene, 33% propylene and 5% dicyclopentadiene for the most part from a material according to the invention (iodine number 10); its Mooney viscosity is 53 maize cover strip 14 is covered, with a behavior (ML.-4/100 ° C). The batch 1-C contains a terpolymer-like narrow zone 15, in which merisate with about 46% ethylene, 47% propylene and the cover strip material has been ground away, 7% 1,4-hexadiene (iodine number 12); his Mooney Viscoma to make a band of the white material visible. _{l5 sjtät amounts to g2} (ML-4/100 "C). The approach 1-D da-The tread, the carcass and the black against contains a terpolymer with approximately 55%

rubber, polychloroprene and a terpolymer with dicyclopentadiene as the third monomer represents the composition used according to the invention. Approaches 1-C and 1-D based on natural rubber, Polychloroprene and terpolymers with 1,4-hexadiene or methylene-norbornene as the third monomer are outside the scope of the invention and are for comparison purposes. The one used in this example Approach 1-B contains a terpolymer with Ä l

The La

Sidewall material can in itself usually up -emischt _se j _{n un} d consists of highly unsaturated, conjugated diene elastomers, primarily butadiene-Styröl Mischpolyrnerisaten (natural or synthetic), polyisoprene or product obtained by solution or emulsion polymerization of polybutadiene.

The following examples are all given Parts mean parts by weight illustrate the invention.

B e i s ρ i e 1 1

According to Table 1, four different cover strip approaches were produced, namely from a mixture on the one hand natural rubber and polychloroprene (batch 1-A) for comparison and on the other hand from Approaches made from natural rubber, polychloroprene and three different ethylene-propylene-diene terpolymers, as given in Table 1 below. Approach 1-B based on natural

Table 1 - ethylene, 42.5% propylene and 2.5% methylene norbornene (iodine number 6); its Mooney viscosity is 90 (ML-4/100 ^° C.). The formulations and the test results obtained from the samples vulcanized at 160 ° C. for 30 minutes are shown in Table 1. The dynamic flexural strength was measured in the outside atmosphere at Naugatuck, Connecticut (a total of 3,500,000 bends), the ozone resistance in the ozone chamber test (50 parts ozone per 10 ^B parts air; 12.5% elongation; total exposure time 816 hours) and the static aging the outside atmosphere at Naugatuck, Connecticut (26 days in total). In Table 1:

VVS very, very little cracking; VS very little cracking; S little cracking;

C rili formation;

OK no cracks.

Cover strips

1-A 1-B

1-C

1-D

Natural rubber

Ethylene propylene dicyclopentadiene terpoly

merisat

Ethylene-propylene-1. ^ hexadiene terpolymensate

Ethylene propylene methylene norbornene

Terpolymer

Polychloroprene

Oven soot that can be sprayed quickly

Zinc oxide

Stearic acid

Light emollient oil

Dibenzothiazyl disulfide

Diphenylguanidine

sulfur

Dynamic flexural strength test in the external atmosphere (10 ³ bends)

50.00

50.00
25.00
3.50
2.00
3.00
0.50
0.35
1.30

50.10

20.00

30.00
25.00
3.50
2.00
3.00
0.50
0.35
1.30

50.00

20.00

30.00 25.00 3.50 2.00 3.00 0.50 0.35 1.30

ys · ·

S'T .. C.

Condition after 3,500,000 bends

379 1705

3S54 C without errors

WS

VS

S.

Condition after 816 hours

Ozone Chamber Test (hours) 32
48
96
144

without mistakes

492 1705

3327 C

144 384 684

50.00

20.00

30.00

25.00

3.50

2.00

3.00

0.50

0.35

1.30

492 1705

3559 C

384 C

Table 1 (continued)

l-Λ

l-H

1-C

Static aging bar in the outside atmosphere (days)

Condition after 26 days

7 14

VS without errors

OK

OK

When reviewing Table 1 in conjunction with Fig. 1, which is after a photograph of patterns was drawn after it was subjected to a dynamic flexural strength test of 3500 kilocycles it turns out that approach 1-B, which has the Terpolymcrisul made with dicyclopentadiene contains, is free of cracks, during the control salting l-Λ and the approach; 1-C and 1-D severe cracking (in fact, test samples 1-C and 1-D are inferior to control 1-A). The test in the ozone chamber shows that the approach containing the terpolymer produced with dicyclopentadiene cnl-IvAIt, is completely protected, while the other Tcrpolymcrisule failed in the cover strip.

It is particularly noteworthy that this is extremely strong improved resistance to cracking is achieved while at the same time providing a satisfactory one Adhesion between the lugs and between the surfaces, such as the carcass and the sidewalls, is retained.

Example 2

This example explains the practical testing of the invention with ethylene / propylene / dicyclopediae polymer polymers, which have different viscosities, lodine numbers and ethylene: propylene ratios.

Three Dackstrcifcnansiüze were prepared according to the formulation 1-B of Example 1, on the basis of 50 parts of natural rubber and 20 parts of terpolymer. the Mooney viscosities, iodine numbers, and ethylene: propylene ratios had as shown in Table 2. The physical properties of the batches after vulcanization for various periods of time at a temperature of 177 ° C. are given. The results of the analysis on samples which had been vulcanized for 30 minutes at 177 ° C are also entered, namely the dynamic flexural strength in the outside atmosphere, the static old pressure in the outside atmosphere at Naugatuck, Connecticut, and the ozone chamber test (50 parts ozone per 10 ^s parts of air: 12.57, elongation).

In the tests to determine the dynamic flexural strength, the duration was up to the kintrilt of the break far beyond the I 913 000 bends that for silicone wall salts based on natural rubber were found. All approaches of the Table 2 are free of cracks due to the effects of ozone even after an exposure period of tOOn hours.

Table 2
Effect of viscosilate-iodine value-ethylene: propylene ratio

liuonsehaften ties
Ethyl-l'ropylcn-Uicyclopcntmlien-rci'polymeriMiis

Mooncy viscosity (ML-4 at 100 "C)

.lod number

Ethylene; Propylene ratio

300'Vo module (kg / cm ^a )

Tensile strength (kg / cm ^a )

Strain (%)

Vulcanized at 177 C

15 '30' 45 '15' 30 '45' 15 '30' 45 '2-Λ

Cover strips
2-U

2-C

88 12.5 52: 48 63.3 67.5 66.8

165

161

149

550

500

500

55 90 10 10 65; 35 65: 35 65.4 68.2 63.3 65.4 62.6 64.7 166 166 165 151 153 139 550 510 530 500 500 480

The dynamic collision of the outer surface with the kilo-cycle blooms to break, “without error, with 13,664,000 bends; Static alteration of the Aulloiliitnuiäphllrc, nllo without l'chlcr me 57 virtues;
Ozonkummor-TcM, ulic ohno error me 1000 hours,

siitc described in Example 1 was used.

U e I a ρ I e I 3 The AnsiiU 3-B, which is a Tcrpolymcrisiit with dicyclo-

pcntadlen cnthlUt corresponds to the invention. The An ·

This example crlttulcrt the properties of 63 set 3 · is a comparison test without terpolymer, cover strips for tires according to the invention with The Ansiluc 3-C and 3-D are outside the rest polyisoprene in the coverings, like in mcns of the invention . The technical superiority de; Table 3 ungcgobon Ist, Fs were three terpolymers batch 3-B can be seen from Table 3.

7 8

Table 3
Comparison of mixtures containing polyisoprene

Vulcanized at 160 "C

Black cover strip 3-B I 3-C

Synthetic polyisoprene rubber.
Ethylene propylene dicyclopentadiene

Terpolymer

Ethylene-propylene-l ^ -hexadiene-terpoly-

mcrisat

Ethylene propylene methylene norbornene

Tripolymer

Polychloroprene

Titanium dioxide

Zinc oxide

Oven soot that can be sprayed quickly

Stearic acid

Light emollient oil

wax

Dibenzothiazyl disulfide

Telramethylthiuram disulfide

sulfur

300% module (kg / cm ² )

Tear strength (kg / cm ² )

Strain ("/") .

15 '30' 60 '15' 30 '60' 15 '30' 60 '

Mooncy viscosity (ML-4 at 100 ⁰ C)

1.2 0.3 1.3 41.5 57.0 63.3 193 221 236 710 660 630 42 50
20th

30th

3.5
25th
2
3

1.2
0.3
1.3
44.3
55.5
63.3
162
168
156
640
600
540
48

Test result after 30 minutes of vulcanization

Dynamic flexural strength test in the outside atmosphere at Naugatuck 10 ³ bends ...

VVS VS S C

Static aging test in the outside atmosphere - days VVS

VS

Ozone Chamber Tcst - Curved Loop - 50 parts of ozone per 10 »parts of air - total ·

cxposure time 1000 hours VVS

VS

Ozone Chamber Test - 12.7% elongation - 50 parts ozone per 10 'parts air - total " exposure duration 1000 hours VVS

S C

788

804

568

080

50

20th

30th

3.5 25 2 3

1.2 0.3 1.3 45.7 69.6 66.8 154 157 162 620 550 520 49

504

3276

without errors after 27 days

anyway mistake

anyway mistake

104 307 379 499

without mistakes

50

20 30

3.5 25 2 3

1.2 0.3 1.3 44.3 58.4 69.6 155 168 148 610 570 490 42

252 1761

3276

167 734

without mistakes

Example

Example 3 was reworked, with a different type of technically available polyisoprene, wherein the approaches given in Table 4 are used. The superiority of approach 4-B to that of the invention corresponds to, results from the numerical values in Table 4.

709830/429

VBV

Table 4

Comparison of mixtures containing polyisoprene

Synthetic polyisoprene

Ethylene-propylene-dicyclopentadiene-polymer

Ethylene-propylene-M-hexadiene terpolymer

Ethylene-propylene-methylene-norbornene terpolymer

Polychloroprene

Titanium dioxide

Zinc oxide

Oven soot that can be sprayed quickly

Stearic acid

Light process oil

Wax (with improved sun light resistance wedge) Dibenzthiazyl disulfide

Diphenylguanidine

Tetramethylthiuram monosulfide

sulfur

N-Cyclohexyl-2-benzothiazylsulphamide

Dynamic flexural strength test in the outside atmosphere at Naugatuck 10 ³ bends VVS

VS S C

Dynamic flexibility in the external atmosphere in Los Angeles 10 ³ bends

VVvS VS S C

Static aging test on the outside

sphürc - days VVS

VS

Ozone Sorrow Test - Curved Loop - 50 parts of ozone per 10 "parts of air - Total exposure time 1000 hours

Ozonkummcr-Tcst - 12Va ⁰ Z ₀ elongation - 50 parts of ozone per IO ⁸ parts of air - total exposure within 1000 hours

VVS VS S C

VVS VS S C

4-Λ

50

50

3.5 25 2

0.35

2 0.6

1512 4788 8316 8519

18th

16 159 323 375

20 ul 159 371

Black cover stripe
Ί-UI 4-C

50
20th

30th

3.5
25th
2

0.35

2
0.6

without mistakes

375

50 20

30th

3.5 25 2 3

0.35

2 0.6

268

989

12194

without error without error

without mistakes

48

74

159

32 111 159 203

4-D

50

20 30

3.5 25 2 3

0.35

2 0.6

756 1764

4788

without fail

48 54 70

without a foal

Example 5

Example 4 was followed, using the formulations containing In TnMi * < "« .... u ».,« Ι ,,, ι «« «around«, and otherwise the results cited are obtained

Table 5

12th

Comparison of mixtures containing polyisoprene

Polyisoprene

Ethylene-Propylcn-Dicyclopcntadicn-Tcrpolymerisal

Ethylene-Propylene-M-Hexadicn-Tcrpolymcrisat

Ethylene-propylene-methyl-norbornene polymer

Polychloroprene

Titanium dioxide

Zinc oxide

Oven soot that can be sprayed quickly

Stearic acid

Light process oil

Wax (with improved sunlight resistance) N-Cyclohexyl-2-benzthiazylsulfenamide Dibenzthiazole disulfide

Diphenylguanidine

sulfur

Dynamic flexural strength test in the outside atmosphere at Naugatuck - 10 ³ bends

VVS VS S C

Static aging of the outside atmosphere - days VVS

VS S C

Ozone Chamber Tcst - Curved Loop - 50 parts ozone per 10 "parts air Total exposure time 816 hours VVS

VS S C

O / .onkammer-Tcst - 12Vb ° / o elongation -

50 parts of ozone per 10 parts of air VAV

5-Λ

0.5 0.35 1.3

Black cover strip 5-U I 5-C

50 50 50 20th - 20th - 20th 30th 30th 30th 25th 25th 25th 2 2 2 3 3 3 0.5 0.5 0.5 5 0.35 0.35 0.35 1.3 1.3 1.3 3327 492
1705
3327
3559 492
739
3327
3559 without mistakes 4th
48
72
96 4th
8th
24
32 - 144 144 without mistakes 384 384

For this 2 MuH drawings

Claims (1)

ϊ 2 two different "monoolefins and one service Claim: connection is established and common are referred to as "EPDM" compounds, but only Pneumatic tires with an elastomeric cover strip with those containing dicyclopentadiene. Terpoly for the side walls, thereby characterizing 5, for example, 1,4-hexadiene or methylene, that the cover strip made of a zu- norbornen contain no mixtures that There is a total settlement which resists to 100 parts by weight against cracking under the action of ozone elastomeric material are capable of 15 to 35 parts by weight, as in the examples below Ethylene-propylene-dicyclopentadiene terpolymer is monstered. merisates with 45 to 70% bound ethylene, io The masses for the cover strips can be the usual Contains 30 to 55% bound propylene and 2 to 12.5% mixture components, especially volcanic bound material Dicyclopentadiene. 15 to 35 weighting agents, such as sulfur or sulphurizing distributors Polychloroprene and 40 to 60 parts by weight of bonds, accelerators, plasticizers and a synthetic polyisoprene or a natural processing aid. Although the cover strips or butadiene-styrene rubber as well as 15 batches of the organic 20 up to 30 parts by weight of carbon black per 100 parts by weight see ozone protection agents are free (with self-elastomers contains. constantly small residual amounts of during the Poiy- Merisat production-mixed stabilizers present can be), they are remarkably 20 resistant to cracking caused by the action of ozone and against other forms of aging. In the manufacture of pneumatic tires for vehicles, the terpolymers used in accordance with the invention are cover strips for the side walls, which are exposed to the 45 to 70% bonded ethylene, 30 to 55% of the particularly ozone-containing 25 bonded propylene and 2 to 12.5% bonded di- The outside atmosphere does not crack and the dynamic cyclopentadiene have an iodine number of 4 to 25 and see bending stress that the side walls are exposed to during a Mooney viscosity between 25 and 120 (ML-4 / end of use, 100 ⁰ C) on. ability, of particular importance. A good The terpolymer used can be oil-extended Resistance to cracking and at the same time 30, for example with 15 to 100 or more parts to achieve good abrasion resistance and a non-discoloring oil, based on 100 parts at the same time good adhesive strength to the terpolymer below. The pneumatic tires according to the invention can also be found to be a problem which is particularly difficult to solve. be prepared in the usual way, namely under Although Belgian patent 660 420 35 uses the customary rubber mixes made of natural rubber, butadiene-styrene chewing and molding equipment. The mixed-up and purposeful or mixtures thereof with 5 to 50 parts of a moderately extruded or calendered terpolymer of ethylene, propylene and a cover strip of suitable size and 0.5 to 5 parts of polytrimethyl dihydro- sets are applied to the raw tire carcass applied, quinoline known, the z. 3. For the production of 40 useful when the carcass is used on the usual shoe uppers. The mandatory pre-tire manufacturing drum rests, after which the written antioxidant results, however, in the tire molded and in a form under the usual quantities used brown discoloration, which the conditions is vulcanized. Excludes at the type of driving use in light colored tires. Tire tires, which have a relatively narrow band of ozone resistance and tear resistance to 45 white sidewall, the cover strip covers what is desired, so that such masses for tire manufacture usually the entire sidewall, and after the formation are out of the question. Vulcanizing the tire is a tape of the top-It has been found that an elastomeric top-strip sanded away in the desired width, strip superior for the sidewalls of pneumatic tires so as to make a band of the white material visible to ozone resistance, adhesive strength and flexural strength . If one wishes to produce a tire which has a composition which has a wide white sidewall, it is customary to have 15 to a relatively narrow cover strip for only 100 parts by weight of elastomeric material - 35 parts by weight of an ethylene propylene dicyclopene bring only a part of the edge of the white material tadiene terpolymer with 45 to 70% bonded at the junction between the white mate ethylene, 30 to 50% bonded propylene and 2 to 55 rial overlaps and the black tread. After the 12.5% bound dicyclopentadiene, 15 to 35 Ge vulcanization of the tire, part of the whiteness by weight polychloroprene and 40 to 60 weight overlapping cover strip is sanded off, so that part of a synthetic polyisoprene or a natural one is a clean, even connection between white borrowed or butadiene-styrene rubber as well as 20 bis and black colored material.
30 parts by weight of carbon black per 100 parts by weight of elastomer contains an example of a mer according to the invention. Drawings depicting pneumatic tires means The masses according to the invention result in deck Fig. 1 is a sketch based on a photograph of strips for tire sidewalls that test samples of vehicle tires with inventive due to the effect of ozone, the appropriate sidewall cover strips have been drawn continuously, and in addition, in particular with regard to the tensile strength 65 after this pattern has been subjected to a dynamic bending ability under dynamic loads subjected to favorable intrinsic strength tests in the outside atmosphere have shafts. The better results will have been; EPDM means an ethylene not achieved with all terpolymers made from propylene-diene terpolymer.