ISO 9718:1995

INTERNATIONAL
IS0
STANDARD
Second edition
1995-11-15
Photography - Processed vesicular
photographic film - Specifications for
stability
Photographie - Film pho tographique v&iculaire trait6 - Spkcifica tions
relatives 9 la s tabi/@
Reference number
IS0 9718:1995(E)
IS0 9718:1995(E)
Contents
Page
Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Normative
. . . . . . . . . . . . . . . . . . . . . . . .~.
3 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D . . . .
................................. ...................................
4 Safety and hazards
............................ .......................... 3
5 Requirements for film base
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Requirements for processed film
7 Requirements for the emulsion and backing layers of processed
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~.
film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8 Requirements for image stability
............................................................................
9 Test methods
................................................................
10 Image test methods
......................................................
11 Classification for reporting
Annexes
A Preparation of standard solution of tetrabutylammonium
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
hydroxide . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
B Microfilm image quality
. . . 14
C Distinction between film storage copies and work copies
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
D Effects of heat and pressure
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
E Effects of high humidity . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
F Light-fading of vesicular images
G Corrosiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*.
..................................................................... 19
H Bibliography .
0 IS0 1995
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publrsher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
0 IS0
IS0 9718:1995(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
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 International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 9718 was prepared by Technical Committee
ISO/TC 42, Photography.
This second edition cancels and replaces the first edition
(IS0 9718:1991), which has been technically revised.
Annex A forms an integral part of this International Standard. Annexes B,
C, D, E, F, G and H are for information only.
. . .
III
0 IS0
IS0 9718:1995(E)
Introduction
Since 1930, great advances have been made in the use of photographic
films for the preservation of records. The preservation of records on film
by national, state and municipal governments, by banks, insurance com-
panies, industry and other enterprises, has been stimulated by recognition
of the resultant economies in storage space, organization, accessibility and
ease of reproduction. The safe-keeping of pictorial film records having le-
gal, scientific, industrial, medical, historical, military or other values has
also become increasingly important.
The use of film for records having long-term values necessitated the de-
velopment of International Standards to specify the characteristics of film
suitable for this purpose. IS0 10602 specifies the requirements for silver-
gelatin films which are suitable for storage. This International Standard (for
vesicular film) and IS0 8225 (for diazo film) give the requirements for
photographic duplicate films suitable for storage.
The term “archival film” has been discontinued and the new concept of
“life expectancy” is introduced. Film life is classified by the LE or life ex-
pectancy rating as defined in this International Standard. For example,
LE-100 represents film with a life expectancy of 100 years when stored
under extended-term storage conditions specified in IS0 5466.
Criteria for properties of LE-10 and LE-100 vesicular films are based upon
the dark-ageing stability of Dmin processed areas. Different dark-incubation
tests are specified for LE-I 0 and LE-100 films but all other properties and
processing requirements are identical.
In addition to tests to ensure that the density of D,ir, areas does not in-
crease to unacceptable levels during storage, a test is also specified on
high-density areas. This is to guard against the possibility of vesicle (or
bubble) collapse during storage. This test has to be carried out at tem-
peratures below the softening point of the image binder, as tests above
this temperature have no practical meaning (see references [I, 21. How-
ever, to give confidence of acceptable image stability, the permissible
density change was made very small at the measurement error of the
densitometer. Both LE-I 0 and LE-100 vesicular films must meet the same
requirement.
It is recognized that vesicular images may show density changes after
exposure to light. However, this International Standard covers only films
used as storage copies, not as work copies (as defined in annex C). The
light-fading requirements specified in this International Standard ensure
satisfactory behaviour for storage copies which are not intended to be
subjected to frequent light exposure.
In addition to the characterization of films with respect to their expected
storage life, vesicular films are also separated into two classes (A and B);
these classes are dependent upon their intended use. Class A films are
those which retain density in both the visual and actinic region (printing)
after storage. Such films can be viewed directly or reprinted onto ultra-
iv
0 IS0
IS0 9718:1995(E)
violet (UV)-sensitive materials. However, some films are not intended to
be reprinted onto UV-sensitive materials. Such films require only visual
capabilities after storage and are designated as Class B films. Obviously,
both Class A and Class B films can fall into the LE-10 and LE-100 cat-
egories. The requirements for Class A and Class B films are identical, with
the exception of change in the D,i” area after dark-ageing and after light-
fading.
Everyone concerned with the preservation of records on photographic film
should realize that specifying the chemical and physical characteristics of
the material does not, by itself, assure satisfactory behaviour. It is also
essential to provide the correct storage temperature and humidity, and
protection from the hazards of fire, water, light and certain atmospheric
pollutants. Conditions for the storage of record films are specified in
IS0 5466 and IS0 10214.
This intentionally left blank
page
IS0 9718:1995(E)
INTERNATIONAL STANDARD 0 IS0
- Processed vesicular photographic
Photography
- Specifications for stability
film
cation, the editions indicated were valid. All standards
1 Scope
are subject to revision, and parties to agreements
based on this International Standard are encouraged
1.1 This International Standard establishes specifi-
to investigate the possibility of applying the most re-
cations for the stability of polyester-base safety film
cent editions of the standards indicated below.
which has a heat-processed vesicular photographic
Members of IEC and IS0 maintain registers of cur-
image formed by nitrogen bubbles. It covers photo-
rently valid International Standards.
graphic film intended for LE-10 and LE-100 records.
IS0 5-l : 1984, Photography - Density measurements
- Part 1: Terms, symbols and notations.
1.2 This International Standard applies to photo-
graphic film in which the image layer is a discrete
IS0 5-2: 1991, Photography - Density measurements
layer attached to a transparent support.
- Part 2: Geometric conditions for transmission
density.
1.3 It applies to roll film and sheet film.
IS0 5-3:1995, Photography - Density measurements
- Part 3: Spectral conditions.
1.4 This International Standard characterizes only
the inherent keeping behaviour of the film. However,
IS0 527-3: 1995, Plastics - Determination of tensile
the suitability of a film record after extended storage
properties - Part 3: Test conditions for films and
depends on both the inherent ageing characteristics
sheets.
of the film and the original image quality. The latter is
discussed in annex B.
IS0 543:1990, Photography - Photographic films -
Specifications for safety film.
1.5 This International Standard applies only to
IS0 5466:1992, Photography - Processed safety
vesicular photographic film intended and used as
photographic films - Storage practices.
LE-10 and LE-100 storage copies. It does not apply to
vesicular film records intended and used as “work”
IS0 6077:1993, Photography - Photographic films
or “use” copies (as discussed in annex C). Most film
and papers -
Wedge test for brittleness.
records used in libraries are work copies and have to
be durable. LE-10 and LE-100 storage copies should
IS0 8225: 1995, Photography - Ammonia-processed
be stored in accordance with IS0 5466 and
diazo photographic film
- Specifications for stability.
IS0 10214. The effects of heat and pressure are
discussed in annex D and those of high humidity in
IS0 10214:1991, Photography - Processed photo-
annex E.
graphic materials -
Filing enclosures for storage.
IS0 10602: 1995, Photography - Processed silver-
2 Normative references
gelatin type black-and-white film - Specifications for
stability.
The following standards contain provisions which,
through reference in this text, constitute provisions
of this International Standard. At the time of publi-

0 IS0
IS0 9718:1995(E)
3.11 safety poly(ethylene terephthalate) base:
3 Definitions
Film base composed mainly of a polymer of ethylene
glycol and terephthalic acid.
For the purposes of this International Standard, the
following definitions apply.
3.12 density: Degree of light absorption, reflection
or scattering characteristics of a photographic image,
3.1 archival medium: Recording material that can
expressed as the logarithm to the base 10 of the ratio
be expected to retain information for ever so that it
of incident radiant flux to the transmitted, reflected
can be retrieved without significant loss when prop-
or scattered flux. (See IS0 5-3.)
erly stored.
NOTE 1 There is, however, no such material and it is not 3.13 printing density: Density of a processed
a term to be used in International Standards or system
photographic image in which the incident and trans-
specifications.
mitted radiant flux are evaluated by a receiver having
the same spectral response as the photographic ma-
3.2 life expectancy (LE): Length of time that infor-
terial on which the sample is to be printed, and the
mation is predicted to be retrievable in a system un-
incident radiant flux has the same spectral e,nergy
der extended-term storage conditions.
distribution as the printing light source.
NOTE 2 However, the actual useful life of film is very
3.14 visual diffuse density: Density of a processed
dependent upon the existing storage conditions (see
photographic image in which the incident and the
IS0 5466 and IS0 10214).
transmitted or reflected radiant flux are evaluated by
the human eye, or by a receiver having the same
Rating for the “life
3.3 LE designation:
,
spectral response as the human eye.
expectancy” of recording materials and associated
retrieval systems. The number following the LE sym-
3.15 projection density: Density of a processed
bol is a prediction of the minimum life expectancy, in
photographic image in which the angular distribution
years, for which information can be retrieved without
of the incident and transmitted radiant flux are equal
significant loss when stored under extended-term
and specified.
storage conditions.
NOTE 4 For microfilm applications, the angular distri-
For example, LE-100 indicates that information
NOTE 3
bution is a nominal half-angle of 6,4”, which corresponds to
can be retrieved for at least 100 years’ storage.
an f-number of f/4,5 and simulates a microfilm reader.
Storage
3.4 extended-term storage conditions:
conditions suitable for the preservation of recorded
4 Safety and hazards
information having permanent value.
Storage
3.5 medium-term storage conditions:
4.1 Hazard warnings
recorded
conditions suitable for the preservation of
information for a minimum of 10 years. Some of the chemicals specified in the test pro-
cedures are caustic, toxic or otherwise hazardous.
3.6 film base: Plastic support for the emulsion and Safe laboratory practice for the handling of chemicals
backing layers. requires the use of safety glasses or goggles, rubber
gloves and other protective apparel such as face
lsion layer(s): Image or im age-f0 rming masks or aprons where appropriate. Specific danger
37 . emu
Ims, papers and plates
laye r(s) of photographic fi notices are given in the text and footnotes for par-
ticularly dangerous materials, but normal precautions
3.8 Class A films: Films which are usable both vis- are required during the performance of any chemical
ually and for printing onto ultraviolet-sensitive ma- procedure at all times. The first time that a hazardous
material is noted in the test procedure section, the
terials.
hazard will be indicated by the word “DANGER” fol-
3.9 Class B films: Films which are usable visually lowed by a symbol consisting of angle brackets “( )”
but do not have any density requirements for printing containing a letter which designates the specific haz-
onto ultraviolet-sensitive materials. ard. A double bracket ‘I(( ))” will be used for particu-
larly perilous situations. In subsequent statements
3.10 safety photographic film: Photographic film involving handling of these hazardous materials, only
which passes the ignition time test and burning time the hazard symbol consisting of the brackets and
letter(s) will be displayed. Furthermore, for a given
test as specified in IS0 543.
0 IS0
IS0 9718:1995(E)
material, the hazard symbol will be used only once in 4.3 Safety precautions
a single paragraph.
All pipette operations shall be performed with a
pipette bulb or plunger pipette.
Detailed warnings for handling chemicals and their
diluted solutions are beyond the scope of this Inter-
Safety glasses shall be worn for all laboratory
national Standard.
work.
Employers shall provide training and health and
safety information in conformance with legal re- 5 Requirements for film base
quirements.
The base used for record film, as specified in this
International Standard, shall be of a safety polyester
The hazard symbol system used in this International
[i.e. poly(ethylene terephthalate)] and can be identi-
Standard is intended to provide information to the
fied by the method described in 9.1.
users and is not meant for compliance with any legal
requirements for labelling as these vary from country
Some films on polyester base can have a maximum
to country.
LE rating of 500.
It is strongly recommended that anyone using
6 Requirements for processed film
these chemicals obtain from the manufacturer
pertinent information about the hazards, hand-
ling, use and disposal of these chemicals.
6.1 Safety film
The film shall meet the requirements specified in
IS0 543.
6.2 Amount of free acid
4.2 Hazard information code system
The polyester base shall not have an amount of free
acid greater than the equivalent of I,0 ml of
Harmful if inhaled. Avoid breathing dust,
(B)
0,l mol/l sodium hydroxide solution per gram of film.
vapour, mist or gas. Use only with ad-
The amount of free acid shall be measured in accord-
equate ventilation.
ance with 9.3.
Harmful if contact occurs. Avoid contact
(c>
The volume of 0,l mol/l sodium hydroxide equivalent
with eyes, skin or clothing. Wash thor-
to the amount of free acid of the processed film shall
oughly after handling.
not increase more than 0,5 ml over its original value
Harmful if swallowed. Wash thoroughly
6)
after the accelerated ageing described in 9.2.
after handling. If swallowed, obtain med-
ical attention immediately.
6.3 Tensile properties and loss in tensile
properties
May be fatal if swallowed. If swallowed,
KS))
obtain medical attention immediately.
The film samples shall be processed and dried under
the conditions used for the film records. Processed
Will burn. Keep away from heat, sparks
(F)
films shall be tested for tensile properties as de-
and open flame. Use with adequate venti-
scribed in 9.4 and shall have a tensile stress and
lation ?
elongation at break as specified in table 1 (unheated
Oxidizer. Contact with other material may film). The loss in tensile properties after accelerated
(0)
cause fire. Do not store near combustible ageing as described in 9.2 shall not exceed the per-
materials. centage specified in table 1 (heated film).
1) The flammable warning symbol (F) will not be used for quantities of common solvents under 1 Iitre.

0 IS0
IS0 9718:1995(E)
7.4 Thermal sticking
Table 1 - Limits for tensile properties and loss
Processed film shall show no evidence of blocking
in tensile properties on accelerated ageing of
(sticking), delamination or surface damage at high
polyester-base film
temperature when tested before and after acceler-
ated ageing as specified in 9.2. Thermal sticking shall
Tensile
Elongation
Film type stress at
be tested as specified in 9.8. A slight sticking of film
at break
break
to glass which does not result in physical damage
shall be acceptable.
Unheated film
Minimum permissible 140 MPal) 75 %
tensile properties
Heated film
8 Requirements for image stability
Maximum permissible 15 % 30 %
loss in tensile properties
compared with unheated
8.1 Proper development
film
Processed film shall not show a projection density
1) 1 MPa=lO”N/m*
decrease greater than 20 % when tested as specified
in 10.2.
7 Requirements for the emulsion
and backing layers of processed film 8.2 Residual diazonium salt test
Processed film shall not show a density decrease
7.1 Layer adhesion
greater than 0,l when tested as specified in 10.3.
7.1 .I Tape-stripping adhesion
8.3 Image stability: Light-fading
The processed film shall not show any removal of the
Low-density and high-density patches (see table2) of
emulsion layer or backing layer when tested as de-
the processed film shall be tested in a light-exposure
scribed in 9.5.
apparatus as specified in 10.4. After testing, patches
with low printing and low projection densities shall
7.1.2 Humidity-cycling adhesion
have a density of 0,7 or less. The difference between
densities for patches with high and low printing den-
The emulsion layer or backing layer of the processed
sities shall be 0,8 or greater and that between patches
film shall not show separation or cracking that can
with high and low projection densities shall be I,4 or
impair its intended use, when tested as described in
greater (see table2). These density requirements shall
96 . .
apply to both projection and printing densities for
Class A films and to projection densities only for
Class B films (see annex E). The same density re-
7.2 Blocking
quirements shall apply for both LE-10 and LE-100
films.
Processed film shall show no evidence of blocking
(sticking), delamination or surface damage when
tested as described in 9.7. A slight sticking of the film
Table 2 - Limits for change in image density
samples that does not result in physical damage or a
after light-fading test
change in surface gloss shall be acceptable.
1 Pp;,” 1 Pymi;n
Vesicular density levels
7.3 Binder stability
Original
Low density
< 0,4 < 0,4
Processed film shall not exceed a 1 mm increase in
High density - low density
> 0,8 > I,4
brittleness after accelerated ageing as specified in
9.2. Brittleness shall be determined at 50 % relative
Final
humidity and shall be tested in accordance with
Low density
< 0,7 < 0,7
High density - low density
IS0 6077. Films shall be tested preferably in low-
> 018 3 I,4
density areas.
0 IS0
IS0 9718:1995(E)
8.4 Image stability: Dark-ageing of 9.2 Accelerated ageing conditions
minimum-density area
Processed film shall be subjected to accelerated age-
ing conditions to meet the requirements for increase
Minimum-density patches of the processed film shal
in the amount of free acid, loss in tensile properties,
be incubated as specified in 10.5 using the two con
binder stability and thermal sticking.
ditions specified for either LE-10 or LE-100 films. Afte
incubation under each of the two conditions, the
The test specimens shall be conditioned at
density patches with low printing and low projection
(23 + 1) “C and (50 + 2) % relative humidity for at
densities shall have a density of 0,6 or less. These
least-l 5 h. After conditioning, place the specimens in
density requirements shall apply to both projection
a moisture-proof
envelope and heat-seal the
and printing densities for Class A films, and to pro-
envelope *I. To prevent sticking between adjacent
jection density only for Class B films.
specimens, it may be necessary to interleave them
with aluminium foil. Ensure a high ratio of film to air
volume by squeezing out excess air prior to heat-
8.5 Image stability: Dark-ageing of vesicular
sealing. Use a separate envelope for each film sam-
image
ple. Heat the envelopes in an oven for 72 h at
(100 + 2) “C 3).
A density patch having a projection density of 2,0 shall
be incubated as specified in 10.6. After incubation, the
An alternative method of incubating the specimens in
projection density shall not show a density change a closed environment is by placing them in 25 mm
greater than + 0,03. This density requirement shall borosilicate glass tubes (see reference [5]). Each tube
-
apply for both LE-10 and LE-100 films. shall have two flanged sections separated by a gasket
to provide a moisture seal41 and shall be held together
by a metal clamp. Sufficient film specimens shall be
used to provide a high ratio of film to air volume.
9 Test methods
NOTE 5
In the subsequent text, samples subjected to
these accelerated ageing conditions are designated “heated
film”. Comparison samples kept under room conditions are
9.1 Identification of film base designated “unheated film”.
Remove all emulsion and backing layers from a sam-
ple of the unknown film by scraping. Then remove all
9.3 Determination of the amount of free acid
sublayers by scraping. Prepare a sample of the base
material by scuffing the surface with a suitable tool
such as a razor blade. The general procedure is to 9.3.1 Specimen preparation
move the scuffing device back and forth over the
sample manually while exerting a very slight pressure. Measurements shall be made on two unheated and
This removes the top layer of the base as a very fine two heated specimens of imaged film that weigh ap-
proximately 1 g to 2 g each. Weigh the specimens to
dust. Carefully brush this into a mortar.
the nearest 0,Ol g. Heat the films in accordance with
Mix the sample with about 100 times its mass of
9.2. Remove all coatings from the film base by scrap-
potassium bromide, previously ground to about
ing. Cut each specimen into small pieces and accu-
75 pm. Prepare a strip or pellet as described in refer-
rately weigh it prior to dissolving it in the appropriate
ence [3].
solvents.
Obtain an infrared absorption curve from the prepared
strip or pellet by means of an infrared absorption
9.3.2 Solution preparation
spectrometer. By comparing the infrared absorption
curve for the unknown with curves for known Immerse the specimens in 30 ml of a 70/30 (m/m)
polymers, the identity of the unknown can be estab- mixture of purified ecresoI/chloroform (DANGER:
lished (see reference [4]).
w cc> 6)).
2) A suitable moisture-proof envelope is a metal foil bag that is coated on the inside with polyethylene for heat-sealing.
3) Incubation is accomplished in a closed environment to prevent escape of any acid that may be produced during incubation.
Such acid may catalyse further film base degradation.
4) A suitable inert gasket can be made from polytetrafluoroethylene.
0 IS0
IS0 9718:1995(E)
WARNING - Chloroform is harmful if inhaled. is the concentration, in moles per litre, of
Avoid breathing vapour, mist or gas. Use with the titrant;
adequate ventilation. If inhaled, move to fresh air.
m is the mass, in grams, of the specimen.
Contact should be avoided between chloroform
and the eyes, skin or clothing. In case of contact,
Carry out the titration in duplicate on separately pre-
obtain medical attention immediately.
pared solutions. The average amount of free acid for
the unheated and heated film specimens shall be cal-
o-Cresol is toxic if swallowed. Contact should be
culated and reported separately.
avoided between o-cresol and the eyes, skin or
clothing. Wash after handling. In case of contact,
flush eyes and skin thoroughly with water. Obtain
9.4 Tensile property test for processed film
medical attention immediately.
9.4.1 Specimen preparation
Take care to dispose of chloroform and o-cresol in
accordance with national and local hazardous
Processed film already in 16 mm format may be
waste disposal regulations.
tested in this width. In the case of perforated 16 mm
film, specimens shall be cut from between the per-
Dissolve the polyester support by heating it at
forations. Film in other sizes shall be cut into sections
(93 + 2) “C for 30 min or until the specimen has dis-
-
15 mm to 16 mm wide and at least 150 mm long,
solved. Precautions should be taken to prevent ex-
using a sharp tool that does not nick the edges of the
cessive evaporation of the solvent. Cool the dissolved
specimen. Five specimens are required for the un-
specimens to room temperature.
heated film and five specimens for the heated film.
The specimens to be heated and the control speci-
9.3.3 Titration
mens shall be cut alternately and contiguously from
a single piece of film. The thickness of each specimen
Titrate the polyester solution potentiometrically with
shall be measured with a suitable gauge to the near-
standardized 0,l mol/l tetrabutylammonium hydroxide
est 0,002 mm and the width to the nearest 0,l mm.
using an automatic recording titrimeter and a
glass/calomel electrode system. The electrodes
9.4.2 Accelerated ageing
shall have been preconditioned for 24 h in the
o-cresoI/chIoroform solvent mixture ((B) (C) (S)) to
Five specimens shall be subjected to accelerated
prevent excessive instrumentation noise.
ageing as described in 9.2.
During titration, the burette tip shall be immersed into
the solution as far as possible, and shall also be as far
9.4.3 Conditioning
from the electrodes as is practical. The stirring rate
shall be as rapid as can be maintained without causing
All specimens, both unheated and heated, shall be
bubbles. Also titrate 30 ml of a blank solution which
conditioned at (23 + 1) “C and at (50 + 2) % relative
has been heated for the same length of time as the
humidity for at least 15 h. This can be accomplished
polyester solution. Details of the preparation of stan-
by means of an air-conditioned room or an air-con-
dardized tetrabutylammonium hydroxide are given in
ditioned cabinet. The specimens shall be supported in
annex A.
such a way as to perrnit free circulation of air around
the film and the linear air velocity shall be at least
9.3.4 Calculation
150 mm/s.
The amount of free acid, A, expressed in equivalent
9.4.4 Procedure
millilitres of 0,l mol/l sodium hydroxide per gram of
film base, is calculated as follows for each specimen:
The film specimens shall not be removed from the
conditioning atmosphere for testing. The tensile
A (‘, - vBkT
=
stress and percent elongation at break of unheated
0,lm
and heated film specimens shall be tested alternately
by means of a tensile machine, as specified in
where
IS0 527-3.
is the volume, in millilitres, of titrant used
VS
The initial grip separation shall be 100 mm and the
for the specimen;
rate of grip separation shall be 50 mm/min. The
is the volume, in millilitres, of titrant used tensile stress and elongation at break shall be calcu-
for the blank; lated separately for the unheated and heated film.

d
0 IS0
IS0 9718:1995(E)
9.6 Humidity-cycling adhesion test
9.5 Tape-stripping adhesion test
9.6.1
Specimen preparation
9.5.1 Specimen preparation
Two specimens of processed film shall be selected
from an area of high density. The specimens should
dimensions of the processed film
Although the
be 50 mm x 50 mm or 50 mm long x the film width
specimen are not critical, one dimension shall be at
where the size of the film permits, but the dimensions
least 150 mm. Four specimens shall be used for the
are not critical provided all specimens are of uniform
emulsion surface and four specimens for the backing
size.
layer, if present.
9.6.2 Procedure
Mount the test specimens in a specimen rack and
9.5.2 Conditioning
place them in a glass laboratory desiccator jar in such
a way that they are freely exposed to the required
Specimens shall be conditioned as described in 9.4.3.
conditioning atmosphere. Place the jar in a forced-air
circulating oven for 8 h at (50 + 2) “C. The atmos-
phere within the jar shall be maintained at 96 % rela-
9.5.3 Procedure tive humidity, which can be obtained by keeping a
saturated solution of potassium sulfate in water (see
The film specimens shall not be removed from the reference [6]) in the bottom of the jar5). Take care to
conditioning atmosphere for testing. Apply a strip of ensure that the saturated solution contains an excess
pressure-sensitive plastic-base adhesive tape about of undissolved crystals at 50 “C. The undissolved
150 mm long to the surface of the processed film. crystals shall be completely covered by a layer of
Press the tape down with thumb pressure to ensure saturated salt solution and the surface area of the
adequate contact, leaving enough tape at one end to solution should be as large as practical. The jar and
grasp. No portion of the tape shall extend to the salt solution shall be kept at 50 “C for at least 20 h
edges of the film specimens or extend to film perfor- prior to use to ensure adequate equilibrium.
ations. Hold the specimen firmly on a flat surface and
After 8 h, place the specimens and specimen rack for
remove the tape rapidly from the film surface. This
16 h in a second desiccator jar that is also in the same
shall be accomplished by peeling the tape back on it-
oven. The atmosphere within the second jar shall be
self and pulling the end so that it is removed from the
maintained at 11 % relative humidity, which can be
film at an angle of approximately 180”. Removal by the
obtained by keeping a saturated solution of lithium
tape of any portion of the surface layer on any of the
chloride in water (see reference [6]) in the bottom of
specimens shall be considered failure.
the jar 5).
The results of the tape-stripping test may be very de-
Time periods of 8 h at the high humidity and 16 h at
pendent upon the adhesive tape used if the bonding
the low humidity constitute one cycle? Each film
force between it and the particular film surface under
specimen shall be subjected to 12 humidity cycles.
test is not sufficiently high. For this reason, a mini-
After this, remove the film specimens from the
mum bonding force is specified for this test. This
specimen rack and examine the emulsion and any
bonding force shall be determined by applying the
backing layer for any evidence of peeling, flaking or
adhesive tape to the film surface in the same manner
cracking produced as a result of the humidity-cycling
as described in the tape-stripping test. The tape shall
treatment.
be rapidly peeled back from the film surface at an
angle of approximately 180”. The peelback force re-
NOTE 6 Films may sometimes exhibit what appear to be
quired to separate the tape from the film shall be
small pinholes in the image after processing. These can be
measured by a suitable device such as a strain gauge
caused by dirt or dust particles on the emulsion surface at
or spring scale capable of reading the maximum force
the time the raw film is exposed and should not be con-
used. A bonding force of at least 0,9 N per millimetre
fused with holes or cracks in the emulsion layer. The exist-
ence of such clear spots in the image prior to humidity
of tape width is required.
5) The relative humidity is based on the normal vapour pressure of the salt solution but the relative humidity tolerances cannot
be specified.
morning and in the
6) This can be most easily accomplished by placing the specimens in the 96 % relative humidity jar in the
11 % relative humidity jar in the evening.
0 IS0
IS0 9718:1995(E)
cycling should be noted so that their presence does not lead mens as specified in 9.2. A specimen 50 mm
to a false interpretation of adhesion weakness.
x 50 mm is convenient, but the dimensions are not
critical.
The film shall be examined under magnification and
lighting conditions that are normal for the end use of Place the specimen between two smooth uncoated
the product. During an interruption in the cycling pro- glass plates that have dimensions slightly larger than
the film specimens shall be kept at the specimen, under a uniform pressure of 35 kPa.
cedure,
(50 + 2) “C and 11 % relative humidity. This can be accomplished by placing a weight on the
upper glass plate, the dimensions of the weight being
greater than that of the specimen. Put each glass-
9.7 Blocking test
plate/film sandwich in a forced-air circulating oven for
1 h at (65 + 2) “C.
At least five specimens of processed film shall be
humidity and
conditioned at 62 % relative
Remove the glass-plate/film sandwich from the oven
(40 + 2) “C. The preferred specimen size is
and allow it to cool. After removal of the glass plates,
50 mm x 50 mm but the dimensions are not critical
examine the film for evidence of blocking (sticking),
provided all specimens are of uniform size. Place the
film delamination and surface damage.
specimens in a glass laboratory desiccator jar so that
they are freely exposed to the required conditioning
10 Image test methods
atmosphere for at least 15 h. Place the jar containing
the specimens in a forced-air circulating oven at
humidity of approximately 10.1 Densitometry
(40 + 2) “C. A relative
62 &an be obtained by keeping a saturated solution
Image density shall be measured in accordance with
of sodium nitrite (see reference [7]) in water at the
10.1.1 and 10.1.2.
bottom of the jar @. Take care to ensure that the satu-
rated solution contains an excess of undissolved
10.1.1 Projection density
crystals at 40 “C. The undissolved crystals shall be
completely covered by a layer of saturated salt sol-
Projection visual diffuse transmission density shall be
ution and the surface area of the solution should be
measured as specified for the f/4,5 type in IS0 5-1,
as large as is practical. The jar and salt solution shall
IS0 5-2 and IS0 5-3, designated as D, (6,4”; SH: 6,4”;
be kept at 40 “C for at least 20 h prior to use to en-
VI
sure adequate equilibrium. T-
After moisture equilibrium is attained, remove the jar
10.1.2 Printing density
from the oven. Without removing the film specimens
from the jar, stack at least five film specimens so that
Printing transmission density shall be determined as
the emulsion surface of one specimen is against the
specified for IS0 Type 1 density in IS0 5-1, IS0 5-2
back surface of the adjacent specimen. Place the
and IS0 5-3, designated as DT (90’ opal; SH: stack under a uniform pressure of 35 kPa. This can be
accomplished by placing a weight on the film stack,
10.2 Proper development test
the dimensions of the weight being greater than
those of the film specimens. The jar containing the
Measurements shall be made on processed vesicular
weighted stack shall be put back into the forced-air
film having a projection density equal to I,8 or greater.
circulating oven for 3 days at 40 “C.
The projection density shall be measured as specified
Alternatively, the temperature and humidity conditions
in 10.1 .I. Subject the film to a dark incubation of 3 h
can be achieved by means of air-conditioned cabinets
at (65 k 2)“C in an open air oven.
or air-conditioned rooms.
Measure the projection density. Express any density
Remove the film stack from the oven and allow it to
decrease as a percentage of the original projection
cool. Individually remove the film specimens from the
density.
stack and observe each for evidence of film blocking
(sticking) (see 7.2).
IO.3 Residual diazonium salt test
area of the processed vesicular film shall be
9.8 Thermal sticking test
A Drnin
read for printing density as specified in 10.1.2. Place
the specimen at a distance of 100 mm from a
Measurements shall be made on two unheated
100 W clear incandescent lamp without a reflector for
specimens of processed film and two heated speci-

0 IS0 IS0 9718:1995(E)
10.5.2 Procedure
a IO-min exposure. The density of the identified area
shall be read again for printing density.
Condition the film at (50 + 2) % relative humidity as
-
specified in 9.4.3. One specimen of medium-term
IO.4 Image stability: Light-fading test
films shall be heated for 30 days at 50 “C and 50 %
relative humidity, and a second specimen for 2 days
10.4.1 Specimens
at 70 “C and 50 % relative humidity. One specimen
of long-term films shall be heated for 40 days at
Measurements shall be made on low-density and
65 “C and 50 % relative humidity and a second speci-
high-density areas of two specimens of the processed
men for 6 days at 80 “C and 50 % relative humidity.
test film. Class A films shall be measured for printing
density as specified in 10.12, and for projection den-
Incubation at two temperatures is required to verify
sity as specified in 10.1 .I. Class B films shall be
that the temperature dependence of the D,i” increase
measured only for projection density. The low-density
allows predictable extrapolation to room-temperature
and the high-density areas shall conform to the values
conditions. However, for films that have been pre-
specified in table 2.
viously tested and do not contain new polymeric
binders, a single incubation temperature is sufficient.
In such cases, medium-term films shall be tested for
10.4.2 Light-exposure apparatus
2 days at 70 “C and 50 % relative humidity, and long-
a ca rbon
The light-exposure apparatus shall contain
term films for 21 days at 70 “C and 50 % relative hu-
#crate s on
arc of the solenoid-activated type which op
midity.
a potential of 120 V to 145 V at 15 A. The arc shall be
All incubations shall be carried out in a humidity-
enclosed in a borosilicate glass globe which filters out
controlled oven or in a glass desiccator jar containing
wavelengths below 275 nm. The film plane surface
a salt solution which provides 50 % relative humidity
shall have an irradiance of I,7 W/mm*, 5 W/mm* and
at the incubation temperature. Precautions to be fol-
2 W/mm* at wavelengths of 358 nm, 386 nm and
lowed in using a desiccator jar are specified in 9.6.2.
416 nm respectively, and 0,25 W/mm* for the rest of
The density of the low-density areas shall be meas-
the spectrum 7).
ured using the appropriate methods specified in 10.1.
10.4.3 Procedure
The density increase shall conform to the level speci-
fied in 8.4.
Insert the specimens in the light-exposure apparatus.
Position the holders in the light-exposure apparatus
10.6 Image stability: Dark-ageing of
so that the emulsion side of the specimens is facing
vesicular image
the arc. Expose the film for 8 h with the light-
exposure apparatus operating between 40 % and
Measurements shall be made on a projection-density
50 % relative humidity and at a temperature between
patch of 2,0 measured as specified in 10.1 .I.
50 “C and 55 “C. Measure the density values of the
low-density and high-density areas using the appro-
Condition the film at (50 + 2) % relative humidity as
priate methods specified in 10.1.
specified in 9.4.3. Both LE-10 and LE-100 films shall
be heated for 50 days at 45 “C and 50 % relative hu-
10.5 Image stability: Dark-ageing of
midity in a humidity-controlled oven or in a glass
minimum-density area desiccator jar containing a salt solution which provides
50 % relative humidity. Remeasure the projection
density.
10.5.1 Specimens
The projection density change shall conform to the
Measurements shall be made on a minimum-density
level specified in 8.5.
area of three specimens of the processed test film.
Class A films shall be tested using a pair of speci-
mens measured for printing density as specified in
11 Classification for reporting
10.1.2, and another pair of specimens shall be meas-
Vesicular films shall be classified as LE-10 or LE-100
ured for projection density as specified in 10.1 .I.
film, depending upon their useful life. This is deter-
Class B films shall be tested using only specimens
measured for projection density. mined by conformance to the test requirements
7) Details on the availability of such a carbon arc light source may be obtained from the Secretariat of ISO/TC 42. (Sources
with equivalent emission may be used.)

0 IS0
IS0 9718:1995(E)
shall be classified as Class B films if they meet pro-
specified in 8.4 for the dark-ageing of minimum-
density area. All other property requirements are the jection requirements only. This is determined by con-
formance to the light-fading test requirements
same.
specified in 8.3 and to the dark-ageing test require-
Vesicular films shall be classified as Class A films if
ments specified in 8.4. Other property requirement
...