|
4656-1
STANDARD
Third edi tion
1992-12-15
Rubber compounding ingredients - Carbon
black - Determination of dibutyl phthalate
absorption number -
Part 1:
Method using absorptometer
Ingredients de melange du caoutchouc - Noir de carbone -
Determination de I’indice d’absorption de phtalate de dibutyle -
Partie 1: Mthode A l’absorptiometre
PS
.-
Reference number
-- ISO 4656-1: 1992( E)
- -----__
--.--.-_.~. ___
---------------------- Page: 1 ----------------------
ISO 4656=1:1992(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. Esch 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, govern-
mental 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.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an Inter-
national Standard requires approval by at least 75 % of the member
bodies casting a vote.
International Standard ISO 4656-1 was prepared by Technical Committee
ISO/TC 45, Rubber and rubber products, Sub-Committee SC 3, Raw ma-
terials (including latex) for use in the rubber industry.
This third edition cancels and replaces the second edition
(ISO 4656-1:1985), of which it constitutes an editorial revision.
ISO 4656 consists of the following Parts, under the general title Rubber
compounding ingredienfs - Carbon black - Determination of dibutyl
phthalate absorption number:
- Part 1: Method using absorptometer
- Part 2: Mefhod using piastograph or plasticorder
Annexes A and B form an integral part of this patt of ISO 4656.
0 ISO 1992
All rights reserved. No part of this publication may be reproduced or utilized in any form
or by any means, electronie or mechanical, including photocopying and microfilm, without
Permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
---------------------- Page: 2 ----------------------
ISO 4656~1:1992(E)
Introduction
The degree of aggregation of carbon black particles affects the
vulcanizate and other properties of rubber mixes in which the black is
incorporated. The space between the agglomerates of carbon black is
dependent on the degree of aggregation of the black particles. The vol-
ume of this space may be estimated from the volume of dibutyl phthalate
absorbed by a given mass of carbon black. The dibutyl phthalate ab-
sorption is therefore an indication of the degree of aggregation of the
carbon black.
---------------------- Page: 3 ----------------------
This page intentionally left blank
---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 465691:1992(E)
Rubber compounding ingredients - Carbon black -
Determination of dibutyl phthalate absorption number -
Part 1:
Method using absorptometer
WARNING - The use of this part of ISO 4656 may involve hazardous materials, operations and
equipment. lt does not purport to address all of the safety Problems assoclated with lts use. lt is the
responsibility of the user of this part of ISO 4656 to establish appropriate safety and health practices
and determine the applicability of regulatory Iimitations Prior to use.
IEC and ISO maintain registers of currently valid
1 Scope
International Standards.
This patt of ISO 4656 specifies a method using an
ISO 1126:1992, Rubber compounding ingredients -
absorptometer for the determination of the dibutyl
Carbon black - Determination of loss on heating.
phthalate absorption number of carbon black for use
in the rubber industry.
ISO 6809:1989, Rubber compounding ingredients -
Carbon black - Standard reference blacks.
NOTE 1 ISO 4656-2: 1991, Rubber compounding ingredi-
- Determination of dibutyl phthalate
ents - Carbon black
absorption number - Part 2: Method using plastograph
or plasticorder, specifies a method based on the use of a
3 Principle
plastograph or plasticorder.
Dibutyl phthalate is added to a test Portion of the
carbon black which is kept in motion by means of
rotating blades. As the liquid is added, the mixture
changes from a free-flowing powder to a semi-
plastic mass. The end-point for the determination is
reached when the torque resulting from this Change
2 Normative references
in viscous properties attains a pre-set value, cali-
brated from a torque curve.
The following Standards contain provisions which,
through reference in this text, constitute provisions
of this part of ISO 4656. At the time of publication,
4 Reagent
the editions indicated were valid. All Standards are
subject to revision, and Parties to agreements based
on this part of ISO 4656 are encouraged to investi-
1,045 Mg/m3 to
gate the possibility of applying the most recent edi- 4.1 Dibutyl phthaiate,
Q25
tions of the Standards indicated below. Members of 1,050 Mg/m3.
1
---------------------- Page: 5 ----------------------
ISO 4656=1:1992(E)
lt is recommended that the dibutyl phthalate and
5 Apparatus
apparatus be allowed to stand in the test room long
enough to resch ambient temperature.
5.1 Absorptometerl),
type A or type B (see
annex A), consisting of the elements given in 5.1.1
to 5.1.4.
8 Procedure
5.1 .l Mixing chamber.
8.1 Checking the absorptometer and
constant-rate burette
51.2 Motor-driven rotors, which fit into the mixing
chamber (5.1.1) and rotate at a frequency of
Proceed as described in annexes A and B.
2,08 Hz.
8.2 Calibration of the absorptometer
51.3 Torque-sensing device, consisting of a spring
and a dashpot having a damper control valve oper-
Follow the procedure specified in 8.3 and 8.4, using
ating a torque-Iimit switch which automatically Stops
Standard reference blacks as indicated in ISO 6809.
the rotors (5.1.2) and the burette (5.1.4) when a pre-
selected torque is reached. Instructions for checking
NOTE 2 Some machines, particularly those with highly
and adjusting the settings are given in annex A.
polished rotors and chambers, may give high and incon-
sistent results fec N 650, N 660 and N 683 blacks because
of erratic torque development near the end-point. Some-
5.1.4 Constant-rate burette, pre-set to deliver
times no end-point is obtained at all. In these cases, it is
dibutyl phthalate at a rate of
recommended that such blacks be pulverized before
4,0 cm3/min + 0,024 cm3/min. Instructions for
weighing out the test portion.
checking theburette are given in annex B.
Alternatively, the spring tension may be reduced and/or
the damper valve opened further. If such changes are
5.2 Wen, gravity convection type, capable of being
made, it will be necessary to recalibrate the apparatus
maintained at 105 ‘C + 2 “C or 125 “C + 2 “C.
- -
using all the reference blacks.
In some cases, the correct value may be obtained by us-
5.3 Balance, accurate to 0,Ol g.
ing a torque-limit setting of less than 5 (see 8.4.2).
Work is in progress from which it may be possible to re-
5.4 Desiccator.
commend a suitable chamber specification to avoid these
Problems.
5.5 Apparatus capable of pulverizihg carbon
Esch Standard reference black shall be tested a
black2), if pulverizing is found to be necessary (see
sufficient number of times to establish firm meas-
8.2, note 2).
ured values.
5.6 Spatula. If, after checking and adjustment, an apparatus is
still found to give values outside the accepted
ranges, the regression of the Standard values on the
6 Sample preparation
measured values shall be calculated by the method
of least squares. Alternatively, a graph of observed
Dry an amount of the Sample of carbon black suffi-
versus accepted values may be plotted.
cient for at least three test portions (see 8.3) for 1 h
The test values of subsequent samples shall be
in the oven (5.2), maintained at 105 “C + 2 “C or
corrected by applying the appropriate equation or
125 “C + 2 “C, as specified in ISO 1126. Allow to
graph.
cool toambient temperature in the desiccator (5.4).
Keep the dried Sample in the desiccator until ready
The Standard reference blacks shall be retested
for testing.
periodically and if necessary new equations shall be
calculated or a new graph shall be plotted.
7 Conditions of test
8.3 Test Portion
The test should preferably be carried out at ambient
conditions of either 23 “C k 2 “C and (50 & 5) %
Weigh, to the nearest 0,02 g, a mass of the dried
relative humidity or 27 “C + 2 “C and (65 If- 5) %
Sample of carbon black in accordance with table 1.
relative humidity.
1) This apparatus is available commercially. Details may be obtained from the Secretariat of ISO/TC 45/SC 3.
2) A coffee bean grinder is suitable.
2
---------------------- Page: 6 ----------------------
ISO 4656.1 :1992(E)
8.4.7 Dismantle the mixing chamber, and clean the
blades of the rotor (5.1.2) and the mixing chamber
Table 1 - Mass of test Portion
with the spatula (5.6).
Mass of test
Portion
NOTE 3 The cleaning process may be simplified by
Type of carbon black
adding some dry black and operating the absorptometer
g before dismantling, while the burette is re-filling.
N 472 15
8.4.8 Re-assemble the mixing chamber.
N 630, N 642 and N 700 series, exc
...