|
INTERNATIONAL ISO
STANDARD 20427
First edition
2023-11
Pigments and extenders — Dispersion
procedure for sedimentation-based
particle sizing of suspended pigment
or extender with liquid sedimentation
methods
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: [email protected]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles of dispersion. 3
4.1 Principles of ultrasonic dispersion . 3
4.2 Principle of wet jet mill dispersion . 3
4.3 Principle of shaker-based dispersion . 3
5 Principles of sedimentation-based techniques for particle size analysis .4
5.1 Stokesian sedimentation analysis . 4
5.2 Disk-type centrifuges . 4
5.3 Cuvette-type centrifuges . . 4
5.4 Gravitation-based sedimentation methods . 4
5.5 Centrifugal field-flow fractionation method . 5
6 Apparatus . 5
7 Settings for dispersion .7
7.1 Procedure of ultrasonic dispersion using a probe-type sonicator . 7
7.2 Procedure of ultrasonic dispersion using a bath-type sonicator . 8
7.3 Procedure of shaker-based dispersion . 8
8 Dispersion procedure . 9
8.1 General . 9
8.2 Sampling for dispersion. 9
8.3 Reagents . 9
8.4 Recommendations for sample preparation. 10
9 Sampling .10
10 Measurement and expression of results .10
11 Test report .10
Annex A (normative) Protocol for the determination of energy input .12
Annex B (informative) Limits for ultrasonic dispersion procedure .15
Annex C (informative) Procedures for dispersion of TiO pigments .16
Annex D (informative) Procedure for dispersion of CaCO with wet jet milling .17
Annex E (informative) Procedure for the dispersion of Fe O with an ultrasonic probe .18
2 3
Annex F (informative) Procedure for dispersion of carbon black .19
Annex G (informative) General procedure for dispersion of pigment or extender .20
Bibliography .22
iii
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 256, Pigments, dyestuffs and extenders.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
INTERNATIONAL STANDARD ISO 20427:2023(E)
Pigments and extenders — Dispersion procedure for
sedimentation-based particle sizing of suspended pigment
or extender with liquid sedimentation methods
1 Scope
This document specifies sample preparation methods to determine the size distribution of separate
particles of a single pigment or extender, which is dispersed in a liquid by application of a standardized
dispersion procedure, using an ultrasonic device, shaker device or wet jet mill.
The sample preparation methods described are optimized for measurements carried out with a particle
sizing technique based on sedimentation. This technique relies on particle migration due to gravitation
or centrifugal forces and requires a density contrast between the particles and the liquid phase.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 3696, Water for analytical laboratory use — Specification and test methods
ISO 9276-1, Representation of results of particle size analysis — Part 1: Graphical representation
ISO 13317-1, Determination of particle size distribution by gravitational liquid sedimentation methods —
Part 1: General principles and guidelines
ISO 13317-2, Determination of particle size distribution by gravitational liquid sedimentation methods —
Part 2: Fixed pipette method
ISO 13317-3, Determination of particle size distribution by gravitational liquid sedimentation methods —
Part 3: X-ray gravitational technique
ISO 13317-4, Determination of particle size distribution by gravitational liquid sedimentation methods —
Part 4: Balance method
ISO 13318-1:2001, Determination of particle size distribution by centrifugal liquid sedimentation methods
— Part 1: General principles and guidelines
ISO 13318-2, Determination of particle size distribution by centrifugal liquid sedimentation methods —
Part 2: Photocentrifuge method
ISO 13318-3, Determination of particle size distribution by centrifugal liquid sedimentation methods —
Part 3: Centrifugal X-ray method
ISO 15528, Paints, varnishes and raw materials for paints and varnishes — Sampling
ASTM D5965, Standard Test Methods for Density of Coating Powders
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
nanoscale
length range from approximately 1 nm to 100 nm
Note 1 to entry: Properties that are not extrapolations from a larger size are predominantly exhibited in this size
range. For such properties, the size limits are considered approximate.
Note 2 to entry: The lower limit in this definition (approximately 1 nm) is introduced to avoid single and
small groups of atoms from being designated as nano-objects or elements of nanostructures, which can be
implied by the absence of a lower limit.
[SOURCE: ISO 80004-1:2023, 3.1.1 — modified, notes 1 and 2 to entry have been added.]
3.2
nanoparticle
nano-object with all external dimensions in the nanoscale (3.1) where the lengths of the longest and the
shortest axes of the nano-object do not differ significantly
Note 1 to entry: If the dimensions differ significantly (typically by more than three times), terms such as
nanofibre or nanoplate may are preferred to the term nanoparticle.
[SOURCE: ISO 80004-1:2023, 3.3.4, modified — "where the lengths of the longest and the shortest axes
of the nano-object do not differ significantly" has been added to the definition.]
3.3
agglomerate
collection of weakly or medium strongly bound particles where the resulting external surface area is
similar to the sum of the surface areas of the individual components
Note 1 to entry: The forces holding an agglomerate together are weak forces, for example van der Waals or simple
physical entanglement.
Note 2 to entry: Agglomerates are also termed secondary particles and the original source particles are termed
primary particles (3.5).
[SOURCE: ISO 80004-1:2023, 3.2.4]
3.4
aggregate
particle comprising strongly bonded or fused particles where the resulting external surface area is
significantly smaller than the sum of surface areas of the individual components
Note 1 to entry: The forces holding an aggregate together are strong forces, for example covalent or ionic bonds,
or those resulting from sintering or complex physical entanglement, or otherwise combined former primary
particles (3.5).
Note 2 to entry: Aggregates are
...