DD266578A1 - METHOD FOR PRODUCING GIANT-RELATED RUBBER BOOTS - Google Patents

Abstract

The invention relates to a process for the production of free-flowing rubber shoings which serve for further processing into technical rubber articles. The rubber crumbs are treated with an SiO 2 -containing compound of the composition of 20 to 200 mm, wherein the mass ratio of rubber: SiO 2 compound is 200-10: 1. The SiO 2 -containing compounds contain elemental or oxidic substances. These can be treated with hydrophobic agents.

Description

Field of application of the invention

The invention relates to an ancestor for the production of free-flowing rubber fillers for further processing into technical rubber articles.

Characteristics of the known state of the art

It is known that gumarticol of a wide variety of uses is natural or synthetic rubber blends

- Including ingredient to produce different effects. In this case, the production of the rubber mixture, in particular the homogenization of the ingredients, is technically complicated and often has to be carried out in several stages, so that continuous processes are problematic, i. b. by the block form of rubber bales. Various procedures have been proposed for the preparation of suitable free flowing rubbers.

Thus, according to the teaching of DE-OS 2214121 free-flowing Kautschukkrümol when hydrophilic substances as release agents, for. B.

Oxalkylato dor alkylamino be eingosotzt.

It is also known oine precipitation of the rubber with silicic acids of certain specific properties according to the teachings of DE-OS 1148067, 1 204404.1 204405.1 215918 and 1 297058.

Flocculations of aluminum and iron hydroxides have also been proposed as rubber crumb release agents.

Finally, according to the teaching dor DD-PS 222 608 rieselfähigo rubbers are formed by the duss rubber after the Trockenstufo or granulation are superficially treated with rubber dust.

Weitore effective release agents are carbon black and zinc oxide. All proposed methods have several disadvantages. Soot as a release agent Is inappropriate because of the pollution rorf Dosiur- and conveyors. Silicas must be prepared to achieve a specific habit of complicated processes, and high levels of addition are required. Metal oxides (Zin!>, Aluminum) are expensive and can also be fed to higher finishes.

Object of the invention

The object of the invention is to improve the processability of rubber crumbs, including the creation of favorable mixing conditions.

Explanation of the essence of the invention ι

Dei invention is the object of developing an ancestor for Erzeuyury riosolfähigon rubbers by superficial treatment with such low-cost materials that can be used as a filler in the vulcanization.

The object is achieved erfindungsgomäß characterized in that rubber crumbs with SiOj-naltigen compounds which may contain C, Al, Ti, Fe, Mo, V and / or other inorganic substances in elemental and / or oxidic form, the grain size (20-200μηι) treated, wherein oo mass ratio of rubber / SiOrVorbindung of (200-10: 1) is maintained. SiO ₂ -containing compounds and mixtures are slags (silicate slags, Phophhorschlackon, titanium slags), contact materials (Vanadinkontaktmasse), ashes (graphite ash, Kraftwerksasche) and dusts (Korobonstäube) understood. For the preparation of the storage and free-flowing rubber are the rubber (regardless of its origin) siliceous powders of various origins, which additionally with hydrophobic substances such. As oils, fatty acids or silicones can be treated at the technologically favorable points of the Herstellungsprozosses (eg after the Trocknungs.stufe in traditional processes or in granulation at the spray head of the granulator) added. When applying the method according to the invention, the following advantages result:

- Optimal dosage and proportioning of free-flowing rubber crumb

- Increasing the siliceous content in the rubber mixture

- Improvement of the processing and vulcanization behavior of the rubber compound

- Improvement of the utility value properties of the rubber materials (eg dynamic load capacity). The invention will be explained below with reference to exemplary embodiments.

Ausführungsboispiele

Bolsplol 1

Rubber crumbs after the SBR precursor are precoated in a single-fluid vortex mixer with phosphoric-slag powder, with the enrolled slug-gong being about 5%. Dio obtained mixture is packed in paper bags with PC inlay. The subsequent vulcanization resulted in an improvement in the processing and vulcanization behavior (e.g., cure and cure time, scorch seal, reaction rate) (Table 1) and the specific properties of the vulcanizates, such as elongation, Shore hardness, tensile strength, and Weitcrreißwlderstand (Table 2).

Table 1: Processing and vulcanization rates SBR rubber without treatment

Gowlchts- TJ ta- too " Rhoometer test at 150 "C M || R Rheometer test at 150 Mim N ⁰ C N kc mi, Mooneyprüfung boi parts Time Time Zoit RE RE RE RE min at _{+ 4} ts-Zoit ⁰ C 12O ⁰ C silica min min min ml M _L 100 at min per 100 parts RE 63 RE 67 47 51 0.221 ME ° C 12O ⁰ C 35.8 rubber 6.4 7.6 25.4 60 66 41 46 0.230 43 min 29.7 0 5.4 6.9 28.1 16 58 16 60 35 39 0,302 51 27.4 23.4 15 4.5 5.8 34.6 19 54 20 55 29 34 0.374 65 23.3 18.3 30 2.9 5.0 43.8 23 with phosphorus sack (5%) 21 49 26 78 19.1 13.1 45 SBR rubber after treatment 4.4 25 21 '12,6 weight t "r 23. tcilo Time kc Mooneyprüfung silica min min M _L i ₊ 4 tb-Zoit per 100 parts at rubber 21.1 0.252 100 0 25.3 0,278 ME 15 29.8 0.344 36 30 38.1 0.408 45 45 47.6 0.424 58 60 69 76

Table 2: Physical-mechanical property values SBR-Kauischukohne treatment

Gowichtsteile silica T t F D H W per 100 ToNu rubber ⁰ C min MPa % Sh N / mm 0 150 25 2.8 231 41 2.1 15 150 30 4.4 335 56 3.7 30 150 35 5.6 357 64 4.0 45 150 45 6.8 384 75 3.5

SBR rubber after treatment with phosphorus slag (5%)

Parts by weight of silica T

per 100 parts of rubber ⁰ C

min

F MPa

H ShA

W N / mm

150 150 150 150 150

20 25 30 40 50

3.8 4.8 6.4 7.7 8.1

45 59 65 75 78

3.4

6.8

9.1

10.8

10.0

Example 2

SBR granules of various particle sizes (1-10 mm) are mixed in a fluidized bed with phosphorus slag (5%) containing 50% stearic acid and then packed in PE sacks. The advantages of the very good dosing and portioning properties of the free-flowing rubber crumb, such as the good processing and vulcanization behavior of the rubber mixture, are retained as in Example 1. By using a phosphorus slag / stearic acid adduct in the preparation of the Rieoelfähigon rubber to an improvement in the distribution of the silica in the rubber mixture with an increase in the tensile strength and the tear propagation resistance is achieved (Table 3). A further dosage of Steariniiäure in the formulation design with Gumrniwerkatoffen need not be considered. By the

Use of phosphorus slag / Stearinsäuro adduct, a reduction in the amount of stearic acid is possible because the otherwise required according to formulation Übordosiorung to Ausgloich the losses due to insufficient homogenization is not orforclorlich.

Table 2: Physico-mechanical equivalency values

Gewii / it ^c "..ilG silica per 100 parts of rubber

Variant SBR rubber

F MPa

H ShA

W N / mm

without a treaty 150

after treatment with phosphor slag 150

after treatment 150

with a phosphorus slag /

Stearic acid adduct (50/50) (5%)

35 5.6 357 64 4.0 30 6.4 367 65 9.1

10.2

441

65

12.3

Claims (2)

1. A process for the production of free-flowing rubber beds for the production of Tecnnischen rubber articles by a surface treatment of rubber crumb, characterized in that rubber crumbs with SiCVialiigen compounds of grain size 20 to 200mm, which C, Al, Fe, Ti, Mo, V and / or other inorganic Materials in elemental and / or oxidative form can be treated, whereby a mass ratio of rubber / SiO 2 -containing compound of 200 to 10: 1 is maintained. 2. The method according to claim 1, gekonnzeichnet characterized in that the SiO ₂ -haltigon compounds with hydrophobic substances such. For example, oils, fatty acids or silicones have been additionally treated.