1、 ISO 2017 Imaging materials Colour reflection prints Test method for ozone gas fading stability Matriaux pour limage Tirages par rflexion en couleurs Mthode dessai de la stabilit de la dcoloration lozone INTERNATIONAL STANDARD ISO 18941 Second edition 2017-07 Reference number ISO 18941:2017(E) ISO 1
2、8941:2017(E)ii ISO 2017 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopyi
3、ng, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749
4、01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO 18941:2017(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 Terms and definitions . 1 4 Requirements 3 5 Target selection . 3 6 Measurements . 4 6.1 Use of replicates and reference samples. 4 6.2 Holding and measurement c
5、onditions . 4 6.3 Measured attributes . 5 6.3.1 Definition of density terms . 5 6.3.2 Density attributes to be measured . 5 6.3.3 Definitions of colorimetry terms . 6 6.3.4 Colorimetry values to be measured 6 7 Calculations and computations . 6 7.1 Computation of densitometric attributes 6 7.2 Densi
6、ty change in d minpatches 6 7.3 Percentage density change in primary colour patches 6 7.4 Percentage density change in secondary (mixed) colour patches . 6 7.5 Percentage density change in composite neutral patch 6 7.6 Colour balance shift in composite neutral patch . 7 7.7 Colour balance shift in s
7、econdary (mixed) colour patches 7 7.8 Colour balance in d minpatches by colorimetry 7 7.9 Effects of colorant fading and stain formation on colour photographs . 7 8 Test methods Gas fading (ozone) . 7 8.1 General . 7 8.2 Apparatus 8 8.3 Test procedure 15 9 Test environment conditions 16 9.1 Humidity
8、 control calibration .16 9.2 Relative humidity .16 9.3 Temperature .16 9.4 Ozone concentration .16 10 Test report 17 10.1 General reporting requirements .17 10.2 Ozone test reporting .17 Annex A (informative) Method for interpolation .19 Annex B (normative) Reciprocity considerations .20 Bibliograph
9、y .22 ISO 2017 All rights reserved iii Contents Page ISO 18941:2017(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 techn
10、ical 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
11、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 need
12、ed for the different types of ISO documents 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). Attention is drawn to the possibility that some of the elements of this document may be the subject of pate
13、nt rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents). Any trade name u
14、sed in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to t
15、he World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: w w w . i s o .org/ iso/ foreword .html. This document was prepared by Technical Committee ISO/TC 42, Photography. This second edition cancels and replaces the first edition (ISO 18941:2011),
16、 which has been technically revised.iv ISO 2017 All rights reserved ISO 18941:2017(E) Introduction In image permanence testing, there are four environmental variables known to affect the stability of a photographic image: heat, light, moisture and air pollution, such as ozone 131415161718192021 2223
17、242526 . Although natural ageing under “real-world” environmental levels of these variables is considered the only certain test for image permanence, the high stability of most modern photographic products makes testing under ambient conditions too lengthy a process to be of practical use. Thus, a w
18、idely used alternative to natural ageing is accelerated ageing, whereby a sample specimen is exposed to each environmental variable individually and at levels considerably greater than ambient, forcing degradation of the image by that single factor in a far shorter length of time. This document cove
19、rs the equipment, methods and procedures for generating a known ozone exposure and the subsequent measurement and quantification of the amount of change produced within a photographic image due to that exposure. It is important to note that if predictions of absolute product longevity are of concern
20、 to the experimenter, then further knowledge needs to be gained regarding the reciprocal behaviour of the test product under the experimental accelerated ozone conditions. See Annex B for more information on reciprocity. Additionally, there are other known variables in an ozone test setup that can a
21、ffect the rate at which an image will degrade in the presence of ozone. These include air flow over the sample, the nature of the chemical reaction that is occurring, the relative quantities of the reactants (ozone and colorant molecules) and the humidity content and the pH of the image recording la
22、yer. Each of these variables can affect the reciprocal response and needs to be understood for a clear analysis of the accelerated data. In some products, such as most dyes on swellable inkjet media and in silver halide products in gelatine, the ozone reaction can be considered to be “diffusion-cont
23、rolled,” whereby ozone first needs to permeate a protective surrounding matrix before coming in contact with a colorant molecule and reacting. Further, the reacted components then need to be desorbed and removed from the surface before fresh, unreacted molecules can again diffuse, adsorb and react.
24、In this type of process, a simple increase in ozone concentration might or might not yield a proportional increase in reaction rate as diffusion, adsorption and, in some cases, desorption may be the dominant factor controlling the rate of reaction. The relative quantities of the reactants (ozone and
25、 colorant) will also affect the rate of reaction and reciprocal behaviour. Under the assumed ambient conditions, a photographic image would undoubtedly contain a vast excess of colorant molecules relative to the local concentration of ozone molecules in the air. Here, ozone would likely be the limit
26、ing factor controlling the rate of reaction and, in the absence of other controlling factors, an increase in ozone concentration will produce a proportional increase in the rate of reaction. At some precise ozone concentration, the quantity of reactants would be equal and the reaction would proceed
27、at a maximum rate. At this point, however, a further increase in ozone concentration would not accelerate the reaction rate, causing a failure in the reciprocal relationship that is required for converting accelerated data into predictions of ambient performance. For this reason, if product longevit
28、y predictions are to be made, this ozone concentration needs to be determined and never exceeded during testing. This document has been primarily developed via testing with inkjet images on porous “instant-dry” photographic media, which have been shown to be susceptible to fading by oxidative gases
29、present in polluted ambient air 1314192021 . While many chemical species may be present in polluted air, it has been shown that most of the fade observed for current inkjet systems can be explained by oxidation by ozone 212728 . Additionally, this method may reasonably be used for colour photographi
30、c images made with other digital and traditional “continuous-tone” photographic materials such as chromogenic silver halide, silver dye-bleach, dye transfer 26 , dye-diffusion-transfer “instant” and other similar systems. However, since these systems have, in general, been shown to be much less sens
31、itive to oxidative degradation by ozone, relatively small levels of image degradation with this accelerated test method may not be realized within the typical duration of such a test for these imaging systems. High levels of ozone, often found outside major metropolitan areas in summer months, toget
32、her with high levels of humidity, will greatly accelerate the fade. Since ozone is a highly reactive gas, storage of photographs in any kind of gas-impermeable enclosure, such as framed behind glass or in an album, ISO 2017 All rights reserved v ISO 18941:2017(E) will greatly reduce image degradatio
33、n due to ozone. This method therefore relates primarily to the display of unprotected photographs.vi ISO 2017 All rights reserved INTERNATIONAL ST ANDARD ISO 18941:2017(E) Imaging materials Colour reflection prints Test method for ozone gas fading stability 1 Scope This document describes the equipm
34、ent, methods and procedures for generating a known ozone exposure and the subsequent measurement and quantification of the amount of change produced within both digitally printed hardcopy images and traditional analogue photographic colour print images due to that exposure. The test method described
35、 in this document uses increased levels of ozone to achieve an accelerated test. If the principal “gas fading” mechanism for a system is not ozone, this method might not be suitable and might give misleading results as to resistance of the test image to polluted air. 2 Normative references The follo
36、wing 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 5-
37、3, Photography and graphic technology Density measurements Part 3: Spectral conditions ISO 5-4, Photography and graphic technology Density measurements Part 4: Geometric conditions for reflection density ISO 1431-3, Rubber, vulcanized or thermoplastic Resistance to ozone cracking Part 3: Reference a
38、nd alternative methods for determining the ozone concentration in laboratory test chambers ISO 13655, Graphic technology Spectral measurement and colorimetric computation for graphic arts images ISO 18913, Imaging materials Permanence Vocabulary ISO 18944, Imaging materials Reflection colour photogr
39、aphic prints Test print construction and measurement 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 18913 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia:
40、 available at h t t p :/ www .electropedia .org/ ISO Online browsing platform: available at h t t p :/ www .iso .org/ obp 3.1 air/gas mixture of atmospheric air and ozone inside the test chamber 3.2 volume turnover complete replacement of the air/gas (3.1) volume within the test chamber ISO 2017 All
41、 rights reserved 1 ISO 18941:2017(E) 3.3 volumetric turnover rate rate at which volume turnover (3.2) occurs 3.4 agitation degree to which air/gas (3.1) is circulated within the chamber resulting in a mixing of the air/gas at the surface of the test sample to overcome concentration gradients Note 1
42、to entry: Agitation can be directly related to flow rate but inversely related to volume turnover (3.2). For a given incoming gas-flow velocity, the actual flow across the samples, and therefore the agitation, can be affected by chamber volume, with, for example, larger chamber volumes resulting in
43、lower flow over the samples. Agitation of air/gas is important to ensure mixing so that any reaction by-products are carried away from the test samples. 3.5 air velocity at sample rate of flow of air/gas (3.1) across the sample plane, as opposed to the flow of air/gas within the chamber volume, or w
44、ithin the entering or exiting ports Note 1 to entry: Expressed in reciprocal milliseconds (ms 1 ). 3.6 effective concentration concentration of ozone as experienced by the test object Note 1 to entry: Concentration that results in a specific change in a specific sample after exposure for a specific
45、time. 3.7 closed-loop system system in which the air/gas (3.1) volume is recirculated within the test chamber, with ozone added as needed to maintain the desired aim concentration 3.8 open-loop system system where the air/gas (3.1) volume continually enters, flows through and exits the system with n
46、o recirculation 3.9 ideal mixing sufficient agitation (3.4) that results in uniform concentration throughout the chamber, such that no localized concentration gradients exist across the test samples 3.10 operational control point set point for equilibrium conditions measured at one or more sensor lo
47、cations in an exposure device SOURCE: ASTM G113 3.11 operational fluctuations positive and negative deviations from the setting of the sensor at the operational control set point during equilibrium conditions in a laboratory-accelerated weathering device Note 1 to entry: Operational fluctuations are
48、 the result of unavoidable machine variables and do not include measurement uncertainty. Operational fluctuations apply only at the location of the control sensor and do not imply uniformity of conditions throughout the test chamber. SOURCE: ASTM G1132 ISO 2017 All rights reserved ISO 18941:2017(E)
49、3.12 operational uniformity range around the operational control point (3.10) for measured parameters within the intended exposure area, within the limits of intended operational range SOURCE: ASTM G113 3.13 uncertainty (of measurement) parameter, associated with the result of a measurement, that characterizes the dispersion of the values that could be reasonably attributed to the measurement Note 1 to entry: The parameter might be, for example, a standa
