ISO 5794-3:2011

INTERNATIONAL  ISO
STANDARD 5794-3
First edition
2011-08-01
Rubber compounding ingredients —
Silica, precipitated, hydrated —
Part 3:
Evaluation procedures in a blend of
solution styrene-butadiene rubber
(S-SBR) and butadiene rubber (BR)
Ingrédients de mélange du caoutchouc — Silices hydratées
précipitées — Partie 3: Méthodes d’évaluation dans un mélange de
solution de caoutchouc styrène-butadiène (S-SBR) et butadiène (BR)
Reference number
ISO 5794-3:2011(E)
©
 ISO 2011

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ISO 5794-3:2011(E)
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©  ISO 2011
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Published in Switzerland
ii © ISO 2011 – All rights reserved

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ISO 5794-3:2011(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 5794-3 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee
SC 3, Raw materials (including latex) for use in the rubber industry.
ISO 5794 consists of the following parts, under the general title Rubber compounding ingredients — Silica,
precipitated, hydrated:
—  Part 1: Non-rubber tests
—  Part 2: Evaluation procedures in styrene-butadiene rubber
—  Part 3: Evaluation procedures in a blend of solution styrene-butadiene rubber (S-SBR) and butadiene
rubber (BR)
© ISO 2011 – All rights reserved  iii

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INTERNATIONAL STANDARD ISO 5794-3:2011(E)
Rubber compounding ingredients — Silica, precipitated,
hydrated —
Part 3:
Evaluation procedures in a blend of solution styrene-butadiene
rubber (S-SBR) and butadiene rubber (BR)
WARNING — Persons using this part of ISO 5794 should be familiar with normal laboratory practice.
This International Standard does not purport to address all of the safety problems, if any, associated
with its use. It is the responsibility of the user to establish appropriate safety and health practices and
to ensure compliance with any national regulatory conditions.
1 Scope
This part of ISO 5794 specifies the test formulation, equipment, procedure and test methods for determining
the physical properties of precipitated hydrated silica in a compound based on a blend of solution styrene-
butadiene and butadiene rubber. The formulation can be regarded as a model compound for silica-based
passenger car tyre treads.
[2]
NOTE 1  ISO 5794-2  specifies the test formulation, equipment, procedure and test methods for determining the
physical properties of precipitated hydrated silica in a styrene-butadiene rubber mix.
[1]
NOTE 2  ISO 5794-1  specifies methods for chemical analysis of precipitated hydrated silica, describes its physical
and chemical properties, and classifies silicas with respect to their specific surface area obtained by nitrogen adsorption.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 37, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties
ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD
and 100 IRHD)
ISO 289-1, Rubber, unvulcanized — Determinations using a shearing-disc viscometer — Part 1: Determination
of Mooney viscosity
ISO 2393, Rubber test mixes — Preparation, mixing and vulcanization — Equipment and procedures
ISO 3417, Rubber — Measurement of vulcanization characteristics with the oscillating disc curemeter
ISO 6502, Rubber — Guide to the use of curemeters
3 Test formulation
The standard formulation is given in Table 1. The formulation shall be used for any type of silica precipitated
for its evaluation.
International or national standard chemicals shall be used if available. Materials used shall be chemically
equivalent to those indicated in Table 1.
For interlaboratory comparisons, the same type of S-SBR and BR shall be used.
© ISO 2011 – All rights reserved  1

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ISO 5794-3:2011(E)
4 Procedure
4.1 Equipment and procedure
4.1.1 General
Equipment and procedure for preparation, mixing and vulcanization shall be in accordance with ISO 2393. The
1)
following procedure is an example which has been found suitable for a 1,5 l internal mixer of the Banbury  type.
4.1.2 First stage
—  Filling factor: 0,74.
—  Rotational speed: 70 r/min.
—  Starting temperature: 80 °C.
—  Friction: 1:1,11.
—  Ram pressure: 0,55 MPa.
The first stage procedure is given in a) to j) herafter.
  Duration
min
a)  Add polymers. 0,0 to 0,5
b)  Add half of the silica, carbon black/silane, ZnO, stearic acid, oil. 0,5 to 1,5
c)  Clean. 1,5
d)  Add half of the silica, antioxidant, wax. 1,5 to 3,5
e)  Clean. 3,5
f)  Mix and adjust rotational speed if required to reach discharge temperature. 3,5 to 5,0
g)  Discharge batch (batch temperature: 155 °C to 165 °C). 5,0
h)  Transfer to mill.
i)  Band for 45 s using a clearance of 4 mm between the rolls.
j)  Store compound for 24 h at room temperature before pro
...