DE2060920A1 - Rubber articles - Google Patents

Description

Dr, F. Zumstein Sr. - Dr. E. Assmann Dr. R. Koenlgsberger - Dlpl.-Fhys. R. Holzbauer - Dr. F. Zurnsteln jun.

PATENT LAWYERS

TELEPHONE: COLLECTIVE NO. 225341

TELEGRAMS: ZUMPAT

CHECK ACCOUNT: MUNICH 91139

BANK ACCOUNT:
BANK H. HOUSES

S MUNICH 2.

Rc. 4-739 / 4-750

THE DUHLOP COMPANY LIMITED, London S.V.1./England

Chew items

The present invention relates to rubber articles, in particular reinforced rubber objects or articles "

It is known that yarns, foils and cords are certain materials like polyester when heated in rubbery compositions become, decompose and lose strength. The prevention or reduction of decomposition is with regard to the use of such reinforcing materials in ties, straps or belts, vehicle suspension devices, and others reinforced rubber articles of importance.

According to an object of the present invention, a reinforced Rubber article or rubber article a layer of moisture-sensitive reinforcing material, which is supported by a Layer is surrounded by rubber, or is adjacent to such a layer, which has a low moisture absorption capacity owns.

According to another object of the present invention includes a reinforced rubber article or articles one layer of a moisture-sensitive reinforcing material, which is at least is partially surrounded by at least one layer of an elastomeric composition with a relatively high moisture absorption capacity or is adjacent to it and at least one protective chewing

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ORIGINAL BATHROOM

schukschicht, which has a relatively low absorption capacity.

Reinforcing materials that are affected by moisture include synthetic and regenerated materials, such as polyester, e.g., polyethylene terephthalate, rayon and nylon. The reinforcing material can be in the form of sheets, tapes, individual Filaments or multifilaments are present, e.g. in the form of a thread (Cord) or a woven or non-woven fabric.

Rubbers which have a low moisture absorption capacity and are therefore suitable for use as a protective layer are rubbers which normally contain less than 0.7% and preferably less than 0.5% by weight of soaps. In addition, it is preferred that the protective layer be formed from a chewing sheet which has a total protein content of less than 1.5% by weight, and more preferably less than 0.5% by weight. Furthermore, the water-soluble ash content of the rubber is preferably less than 0.4% by weight. The soap and ash content of the rubber can be determined by ASTM D1416-56T.

The rubbers suitable for use as a protective layer can be made by the solution polymerization technique and are coagulated by the addition of an incompatible organic liquid or, for example, by emulsion polymerization processes can be prepared using a resin acid or fatty acid or a mixture of acids as an emulsifier and alum or a mixture of glue and a mineral acid as a coagulant uses v / earth.

Examples of rubbers with low water absorption capacities are polyisoprene, polybutadiene, styrene / butadiene copolymers, butyl rubbers and polyethylene-polypropylene copolymers, produced by the above-mentioned methods. In the case of the two goals according to the invention, others can Types of rubbers used in admixture with a rubber or rubbers that have a low moisture absorption capacity should only have a smaller one

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Make up the proportion of the rubber compound, i.e. not more than 50

The elastomeric composition used in the second embodiment adjacent to or surrounding the reinforcing material may be based on natural rubber or a synthetic one Rubber which has been emulsion polymerized by conventional methods, are present.

In the second embodiment according to the invention, this is Ratio of the total thickness of the elastomeric composition that adjacent to the reinforcing material, to the total thickness of the protective layer, preferably at most 1 to 1 and more preferably high- ^ at least 1 to 2. ■

It is not necessary that the protective layer be the rubber that adjacent to the reinforcing material, completely covered, or that the protective layers are of the same thickness. In the pail of a tire For example, the protective layer can be applied to the tread, the under tread and the sidewall.

The rubbers that are applied to the reinforcing material and the rubber that forms the protective layer can be stabilized with antioxidants and, in order to improve processability, partially crosslinked with divinylbenzene, for example, and can be oil-extended. Λ

In the following examples, Examples Λ and 2 illustrate the advantages of using a rubber having a low moisture absorption capacity, and Examples 3 and 4 illustrate the advantage of using a protective layer in the manufacture of reinforced rubber articles. In the examples, all parts are parts by weight.

Example Λ

Compositions were made according to the following formulation: 100 parts rubber, 6.0 parts aromatic oil, 1.2 parts

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Stearic acid, 4.0 parts of zinc oxide, 45 parts of GPF carbon black, 0.9 parts Using mercaptobenzothiazole and 2.7 parts insoluble sulfur of natural rubber, SBR 1502, Solpren 1204 and Cariflex IR.305 as a rubber-like component of the compounding. Solpren 1204 is a solution polymerized styrene / butadiene rubber, Cariflex IR.305 is a solution polymerized cis-polyisoprene rubber and SBR 1502 is an emulsion polymerized one Styrene / butadiene rubber. Portions of each composition were calendered into sheets 0.4 mm and 4.0 mm thick.

In the case of the natural rubber compositions, portions of the sheet having a thickness of 0.4 mm on both sides became one Layer of terylene threads applied to form inner layers that are directly adjacent to the threads. These inner layers were then covered with parts of the 4.0 mm thick sheet of natural chewing school compounding, so that the same structure appears comprised inner (0.4 mm) and outer (4.0 mm) layers on both sides of the cord or thread layer. The cord-rubber structure thus formed was then vulcanized at 153 ° C. for 30 minutes.

Vulcanized cord chews were made according to the above procedure Schuk structure produced using the compositions based on Solpren 1204, SBR 1502 and Cariflex IR.305 rubbers.

The strength of the threads in the vulcanized structure was determined directly after vulcanization and after aging of the vulcanized structure at 160 ^° C. for 3 and 6 hours. Then the percentage loss of thread strength due to heat aging was calculated. The following results were achieved:

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- 5 - ■ -; · '- ";: =!;, ■; ■■ ■■■ '• V ". ■ ν .- - 2.9 Solpren More natural 7.5 1204 Rubber compounding i Chew SBR 2060920 14.28
(51.4) 14.68
(52.4) 1502 Cariflex Initial shop party
. speed, kg (Ib) IR.505 0.9 Loss of thread strength
(%) after: 9.0 14.70 14.50
(52.5) (52.0) 5.4 5 hours at 160 ^° C 27.8 6 hours at 16 ° C 1.8 9.8

These results show that rubbers with low moisture absorption capacities, i.e. rubbers which have been produced by solution polymerization, result in lower thread or cord strength losses than the corresponding compounding. genes made from natural rubber or emulsion polymers rubbers synthesized by the process were produced »

Example 2

Three rubbery compositions were made according to the following Formulation made: 100 parts rubber, 1.2 parts stearic, acid, 6.0 parts aromatic oil, 4.0 parts zinc oxide, 45.0 parts ßPF carbon black, 0.9 parts of mercaptobenzothiazole and 2.7 parts of sulfur.

In Composition 1, the rubber comprised a blend of 70 parts of natural rubber (cis-polyisoprene) and 50 parts of an emulsion polymerized styrene / butadiene rubber containing 25.5% styrene.

The rubber of Composition 2 consisted of a mixture from 70 parts of a solution polymerized cis-polyisoprene rubber and 50 parts of the styrene / butadiene rubber disclosed in US Pat Composition 1 was used.

In Composition 5, the rubber consisted of a mixture of 70 parts of the cis-polyisoprene rubber used in Composition 2 and 50 parts of Solpren 1204, a solution polymerized Styrene / butadiene rubber.

The compositions were calendered into sheets and coated on both sides of a 2/1000 denier Terylene Type B (polyester) layer

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Filaments applied in a vulcanization mold and the structure was vulcanized by heating to 153 ° C for 30 minutes.

The filaments were removed from the cured structure and its strength (unaged) after the vulcanization, and further, after the structure had been aged in the vulcanization mold for 6 hours at 16O ⁰ C was determined. The following results were achieved:

Composition; 1_ 2 2.

Rubber: 70 natural 70 solution 70 solution

Rubber / 30 IB / 30 Emul- IR / 30 Solution Emulsions SBR sion SBR SBR

Thread strength 15.40 15.45 15.32 unaged, (34.0) (34.1) (33.7) kg (Ib)

Thread strength 11.98 12.50 14.10 kg (Ib) after aging for 6- (26.4) (27.5) (31.0) hours
at 160 ^° C

Loss of thread strength (%) 22.4 19.4 8.0

The above results show the benefit of using rubbers with low moisture absorption capacity in blends to reduce polyester degradation.

Example 3

Compositions were made according to the following formulation: 100 parts of rubber, 6.0 parts of aromatic oil, 1.2 parts of stearic acid, 4.0 parts of zinc oxide, 45 parts of GPF carbon black, 0.9 parts Mercaptobenzothiazole and 2.7 parts insoluble sulfur using natural rubber, SBR 1402 and Solpren 1204 as rubbery portions of the composition. Parts of any composition were calendered into sheets 0.4 mm and 4.0 mm thick. To inner layers directly adjacent to the threads To form, on both sides of the layer of polyester thread were sheets 0.4 mm thick of each composition

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upset. These inner layers were then made with a 4.0 mm thick sheet of a different composition covered.

The yarn / rubber structure thus formed were in during 30 Hinuten vulcanized 155 ⁰ C.

The strength of the threads or the cord in the vulcanized structure was determined directly after vulcanization and after aging of the vulcanized structure for 3 and 6 hours at 160 ° C. The percentage loss of thread strength due to the Heat aging was calculated. The following results were obtained:

composition

outer layer (4.0mm) Natural Solpren SBR Solpren

Rubber 1204 1502 1204

inner layer (4.0 mm) Solpren natural- Solpren SBR

1204 rather rubber 1204 1502 schuk

initial threadfeet 14.50 14.24 15.32 15.05 stiffness kg (Ib) (32.0) (31.3) (33.7) (33.1)

Loss of thread strength
(%) after:

3 hours at 160 ° C 12.5 5.8 8.3 5.7 6 hours at 160 ° C 22.2 12.1 13.6 10.8

The results show that lower thread strength losses are achieved if the composition is applied directly to the layer adjacent to the threads, which is the one to be assumed that it would cause the greatest disintegration of the thread.

Example 4

Vulcanized thread / rubber structures were, as indicated in Example 3, but using only the natural rubber composition and the Solpren 1204 composition as an inner or outer protective layer. In addition, the thicknesses of the inner and protective layers have been changed.

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The strength of the yarns in the cured microstructures were determined directly after vulcanization, and again after aging the vulcanized structure for 6 hours at 160 ⁰ C. The following results were achieved:

Layer thickness (mm) Thickness ratio initial Fa strength

Outside inner ; outer strength (51.9) loss (%) after layer layer kg (Ib) (51.8) 6 hours at 4.0 1 : 10 (51.4) 160 ⁰ C Inside 5.6 1 ι 4.5 (51.4) 2.8 1 > 1.75 (50.6) 0.4 2.0 1 0.83 14.51 (51.4) 10.9 0.8 1.2 1 . 0.38 14.46 10.7 1.6 no 14.28 12.1 2.4 14.28 20.4 5.2 15.87 21.5 4.4 14.28 21.0

Another investigation in which the vulcanized structure is before aging for 6 hours at 160 ° C for 8 hours in boiling water were immersed gave the following results:

Layer thickness (mm) Thickness ratio initial Fa strength ratio

27.9

27.4

36.8.

37.4

35.6

37.0

The above results show that the ratio of the thickness of the inner layer to the outer (protective) layer is at most 1: 1, should preferably be at most 1: 2.

Outside inner outer _ strength (31.6) layer layer kg (Ib) (31.7) Inside 4.0 1 10 (52.1) 5.6 1 . 4.5 (52.4) 0.4 2.8 1 1.75 14.35 (51.2) 0.8 2.0 1 . 0.85 14.42 (51.6) 1.6 1.2 1 . 0.58 14.55 2.4 no 14.68 5.2 14.19 4.4 14.33

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¹ - 9 -

With reference to the preferred embodiments shown in the accompanying drawings, the invention is exemplified below explained in more detail:

Fig. 1 shows a sectional drawing of a transport or conveyor belt,

Fig. 2 shows a sectional drawing of a hose and the Fig. 3 shows a diagrammatic sectional drawing of a pneumatic Tire.

In Fig. 1, a conveyor belt comprises a reinforcing layer Threads 11 on the two layers 12 of an elastomeric composition adjoin. Protective layers 15 are applied adjacent to layers 12.

In Fig. 2, a hose 14 consists of a reinforcing layer 15 surrounded by layers 16 and 17 of an elastomeric composition. Adjacent to the layer 16 is a protective layer 18 attached. -

In Fig. 3, a pneumatic tire 19 is shown, the one reinforcing layer of textile thread 20 comprises. The layer of threads 20 is made up of a layer of an elastomeric composition 21 surrounded, which has a high moisture absorption capacity. Adjacent to the layer 21 is a protective layer 22, formed from a rubber that has a low level of moisture sabsorption capacity.

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Claims (16)

- ίο - Patent claims marriage i1.i Reinforced rubber article characterized by '' trine layer of moisture-sensitive reinforcement material, that by a layer of rubber with a low moisture absorption capacity is surrounded or is adjacent to this layer. 2. Reinforced rubber article according to claim 1, characterized through a layer of moisture-sensitive reinforcement material, which is at least partially surrounded by or is adjacent to at least one layer of an elastomeric composition with a relatively high moisture absorption capacity and at least one protective rubber layer that has a relatively low Has moisture absorption capacity. 3. Reinforced rubber article according to claim 1 or 2, characterized in that the moisture-sensitive reinforcing Material is a polyester. 4 ·. Reinforced rubber article according to claim 1 or 2, characterized in that the moisture sensitive reinforcing material is nylon. 5. Reinforced rubber article according to claim 1 or 2, characterized in that the moisture-sensitive pre-strengthening Material is rayon. 6. Reinforced rubber article according to any one of the preceding claims, characterized in that the reinforcing material is in the form of a film or a tape. 7 Reinforced rubber article according to Claims 1 to 5, characterized in that the reinforcing material is in the form of single filaments or multifilaments. 8. Reinforced rubber article according to any one of the claims 1 to 5, characterized in that the reinforcing material 109830/1 706 bath is in the form of a woven or non-woven fabric. 9 · A reinforced rubber article according to any one of the preceding claims, characterized in that the rubber having a low or relatively low moisture absorption capacity of less than 0.7 weight -% contains soaps.. 10. Reinforced rubber article according to claim 9 »characterized in that the rubber with a low or contains relatively low moisture absorption capacity less than 0.3% by weight of soaps .. 11. Reinforced rubber article according to any one of the preceding Claims, characterized in that the rubber has a low or relatively low moisture absorption capacity has a total ash content of less than 1.5% by weight. 12. A reinforced rubber article of claim 11, characterized in that the rubber having a relatively low moisture absorption capacity in accordance with a total ash content of less than 0.4 percent - has.%. 13 · Reinforced rubber article according to any one of the preceding Claims, characterized in that the rubber has a relatively low moisture absorption capacity is solvent polymerized rubber. Reinforced rubber article according to claim 13, characterized characterized in that the rubber having a low or relatively low moisture absorption capacity is a solvent-polymerized one cis-polyisoprene rubber or a solvent-polymerized one Is styrene / butadiene rubber. 15. Reinforced rubber article according to any one of the claims 2 to 14, characterized in that the total of the elastomeric »composition, adjacent to the reinforcing material, to the total thickness of the protective layer at most 1: 1 109830/1706 amounts to. 16. Reinforced rubber article according to claim 15) thereby characterized in that the total thickness of the elastomeric composition, adjacent to the reinforcing material, is at most 1: 2 to the total thickness of the protective layer. 10983Π / 1706