Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to recording or copying
material on or in which non-relief coloured images are formed
in use, which comprises a carrier coated with a sen.sitive layer
containing a chromogenic compound which is capable of reacting
with a phenol in order to give rise to a coloured print.
Numerous materials of this type are already know~.
U.S. Patent No. 3,451,33~3 granted June 24th 1969 to H.H. Baum
assignor to National Cash Register Company describes a material
containing spiropyranes which, after forming a complex with a
phenol, give rise to a print coloured by merocyanine.
U.S. Patent No. 3,67~,535 granted July 4th 1972 to
; J.H. Blose et al, assignors to National Cash Register Company
describes ~aterials based on derivatives'of triphenylmethane,
, which react with phenols to give a coloured print under the action
-I 15 of heat. Similar materials are known from U.S. Patent 2,663,654,
i granted December 22nd 1953 to C.S. Miller et al assignors to
Minnesota Mining & Manufacturing Co., wherein the chromogenic
compounds are ferric salts.
Finally, materials containing diazo compounds, which
react with free phenols to give coloured prints, are also known
from French Patent 1,336,307 (inventor A. Schaeffer), filed
July l9th 1962,delivré July 22nd 1963, Establissements
Bauchet et Cie.
All these copying or recording materials and the
processes in which they are u~ed have disadvantages which
are an obstacle to their very wide application. On the
one hand, the phenols oxidise rapidly and the copies age
quickly, and on the other hand, it is necessary to
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prevent the chromogenic compounds from reacting too rapidly
and causing the colour-forming reactions to occur prematurely.
It is therefore necessary to try to stabilise the latter in order
to prevent the premature reaction, but this stabilisation, though
necessary, is itself unsatisfactory, since it subsequently
slows down the intended print-forming reaction of the compound
and does not chemically block the reactive sites on the phenol.
The present invention makes it possible to alleviate
these disadvantages.
The invention provides recording or copying material
on or in which non-relief coloured images are formed in use
comprising a carrier coated with a layer which contains (1) a
chromogenic compound capable of reacting with a phenolic compound
to give a colour and (2) a phenylurethane derived from an
isocyanate having at least seven carbon atoms, which phenyl-
urethane is capable of producing such a phenollc compound in situ.
The phenylurethane present in the sensitive layer of
material according to -the immediately preceding paragraph results
from blocking the hydroxyl group(s) of a phenolic compound with
an isocyanate. Under the action of energy supplied to the layer,
or on coming into contact with certain phenol-releasing liquid
or gaseous fluids (such as will be described in detail further
below), the phenylurethane can libera-te the phenol which then
reacts with the chromogenic compound.
In the absence of the external energy or phenol-
releasing fluid, the phenylurethane is a very stable
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compound, with the result that the recording or copying
material according to the invention has a very high
storage stability and a greatly increased resistance to
aging. The phenols which can be used within the framework
of the invention include benzene monophenols, diphenols or
triphenols in which the benzene nucleus may be substituted or
unsuhstituted and naphthalene derivatives, specific examples
being phenol, resorcinol, pyrogallol, phloroglucinol,
2,3-dihydroxyanphthalene, and 4,4'-isopropylidene-diphenol.
As is known, phenylurethanes are obtained by
reacting an isocyanate with a phenol. The reaction can
be depicted as follows:
.
~ N = C = O + H - O ~
r ~ B - - - - - - - - - H O ---- ----- R
_ ~ N - C - O
R R'
Any isocyanates having at least seven carbon atoms may be
suitable, although it is preferable to use the simplest and most
easily avallable isocyanates, examples of which include
phenylisocyanate, tolylene-diisocyanate, naphthylene-
1,5-diisocyanate, diphenyl-
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methane-4,4'-diisocyanate, and hex~methylene-1,6-
diisocyanateO
In order to prepare the desired phenylurethane,
stoichiometric quantities of the selected reactive
isocyanate and phenol are reacted in an anhydrous and
non-reactive solvent in the presence of a known catalyst
such as a tertiary aliphatic amine,e.g. triethylamine. The
reaction product i9 then recovered, filtered, washed and
dried. The phenylurethanes thus prepared decompose
between 80 and 200C.
The chromogenic compounds used are not a critical
feature o~ the invention and may be any compounds which
can react with a phenol to give a coloured reaction product,
useful examples including indolino-spiropyranes, benzo-
lS thiazolo-spiropyranes, triphenylmethane derivatives,
ferric salts, and certain diazo compounds.
In general, the ratio by weight of the chromo-
genic compound to the phenylurethane canjbe between 0.01
and 10, but preferably between 0.1 and 1.
~0 In certain cases, it can be useful to add a
binder to the sensitive layerc Preferably, the ~inder
will be a polyvinyl alcohol, polyvinyl ester, acrylic
ester, homopolymer or copolymer of polyvinyl chloride or
any other binder normally used in coatin~ of the kind in
question. ~he phenylurethane and the chromogenic material
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may be contained in separately applied sub-layers of the
- sensitive layerO
During the decomposition of the phenylurethane
into a phenol and an isocyanate, the liberated isocyanate
may, under certain conditions escape from the layer, which
can be inconvenient. The sensitive layer therefore :
preferably contains material capable of reacting with the ~
liberated isocyanate in order to retain it in the layer, ~:.
examples of suitable materials including aliphatic,
alcohols, polyethers, hydroxylic polyesters, and all these
compounds possessing free OH groupings which can react with
. the isocyanate and are not deleterious to the quality of .
the recording or copying material.
The carriers which can be used include those ~. `
which are conventionally used in recording or copying,
such as paper, plastics materials, and metals, the binder .:
- which may be present in the layer being .~uited to the
relevant carrler.
There are several possible proces~es for u~ing
these recording or copying material~.
A first process consists of dec~.mposing the
phenylurethane present in the sensitive layer by
supplying energy, preferahly thermal energy, w~ich
decompo~es the phenylurethane to liberate the phenol,
which then reacts with the chromogenic compound.
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In order to lower the decompo~ition temperature, :.
a catalyst for the decompasition reaction may be incorpor- :
ated in the sensitive layer (or in a separate underlayer
or overlayer). In this way, it i5 possible to attain a
decomposition tempera~ure of about 80C.
Examples of suitable catalysts include ammonia, ..
alkali metal hydroxides such as sodium hydroxide, or
potassium hydroxide, aliphatic amines, preferably tertiary
aliphatic amines, of the general formula
Rl,
10~ ~ R~ whe~ein R1~ ~2 and R3 have 1 to 10
R3 carbon atoms, ~.
tertiary cycloaliphatic polyamines, Cuch as, for example,
hexamethylenetetramine, or triethylenediamine, hydroxy-
. amine~ (or aminoalcoh~ls), ~uch as, for example,
:. 15monoethanolamine, diethanolamine or triethanolamine, .:.
2-amino-1-butanol, ar tris~(hydroxyme~hyl)-aminomethane,
organic or inor~anic ammQn1um ~alts, such a.R carbonates,
bicarbonates, ~onmates, ox~lates, or benzoates, morpholine
derivatives, such a~ morpholine, ~methylmorpholine,
2,6-dimethylmorpholine, or N~aminoethyl-morpholine, metal
salts of organic acids havin~ 3 ~o 18, preferably 5 to
10, carbon atom~, pre~erred metals being tin, calcium,
lead, zlnc, and aluminium, and lead octoate, zinc octoate,
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and calcium naphthenate being especially preferred,
organo-tin salts, such as, for example, dibutyl-tin
dilaurate, and compounds or mixtures which produce ammonia
when heated, for example urea, thiourea and their derivatives,
ammonium salts which decompose when heated such as, for example,
ammonium carbonate, or ammonium benzoate, and mixtures of an
ammoniurn salt of a strong acid ~ a metal compound which, when
heated, produce ammonia or of a salt of a strong acid and a
weak base + salt of a ~eak acid and a strong base.
Thermal recording can be effected by means of
a heated print head or a number of other means well-known
in this field, the coloured print appearing wherever the
material has been heated, and thermal copying can likewise
be effected by known infrared thermocopying processes, such
as the process known under the name Thermofax.
j In the case of photocopying, the sensltive
layer, which then contains a photo-sensitive chromo~enic
', compound, may be exposed once or several times in
accordance with various known processes, in such a way that
the chromogen reacts only in selected areas with the
phenol subsequently released by heat applied to the layer
generally.
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A non-thermal process ~or utilising the
materials according to the invention consists in brin~ing
a liquid or gaseous fluid into contact with the sensitive
layer according to the invention, this fluid having the ~.
ability to liberate the phenol ~r reaction with the
chromogenic compound.
Examples of fluids which are able to react
with the phenylurethane to liberate the phenol include
ammonia (gas) or ammonia (liquid), alkali metal hydroxides
such as sodium hydroxide, or potassium hydroxide, aliphatic ~:-
pre~rabl~/
..1 amines, and ~æ~je}ab}~ tertiary aliphatic amines of the
general formula
Rl .
_ R2 ! wherein R1, R2 and R3 have 1 to 10
R3 carbon atoms, ~
tertiary cycloaliphatic polyamines, such as, for example, .~
-
hexamethylenetetramine, or triethylenediamine, hydrdxy~
amines (or aminoalcohols), such aR, for example, :;
monoethanolamine, diethanolamine, triethanolamine,
2-amino-1 butanol, or tris-(hydroxymethyl)-aminomethane,
organic or inorganic ammonium salts, such as car~onate-s,
,
bicarbonate~, formates, oxalates~ or benzoates, and
morpholine,de.~ivati.ves such as mor~holine. ~-~çthyl- :
morpholine, 2,6-dimethylmorpholine, or N-aminoe:thyl-
morpholine.
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Gaseou~ fluids are usually used only in copying,
in order to de~elop the previously image-exposed material
by known processesO If the fluid is in the li~uid form,
recordings can be made on a material according to the
invention with the aid of a stylus or an "inking" pen of
a well-known type, the ink being replaced by the liquid
in question, or the liquid can be used to develop
exposed material, as in the ca~e where the fluid i~ gaseous.
In all cases using fluids, it may be an advantage, in
order to accelerate the reaction and to dry the material,
slightly to heat the latter to a temperature above 40C
but below the thermal decomposition temperature ~ the
phenylurethane.
A particularly important application of the inven-
tion is the diazo-type process in all its forms,
~: development taking place either by heat, by a semi-wet
route or by a gaseous route with the aid of ammonia. The ` ;~
invention thus provides considerable progres~ coMpared
with the materials for the diazo-type process which are
well-known to those skilled in the art, since the
material can be stored for an indefinite length of time
without the slighte3t trace of phenol appearing in the
I layer to cause pre~ature coupling, and the quantity of
; stabilising additive3 generally used in thes~ layers aan
thus be considerably limited. In the case of the diazo-type
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process it is not necessary to employ a binder for the
layer containing the diazo compound and the phenyl-
urethane. The ratios by weight of the diazo compound
to the phenylurethane can vary between 0.3 and 3. In ~,
all cases, the fluidi3 used for development can be in the
pure form or in solution. ~'
Embodiments of the invention will now be
described in more detail in the following specific
examples. ,~
EX~MPLE 1 '~ ~
8 grams of 2,3-dihydroxynaphthalene, 100 grams ~'
of dried methyl ethyl ketone (MEK) and a fe,w drops of '- ''
triethylamine are introduced into a three-necked flask
eguipped with a stlrrer, a reflux condenser and a dropping
15 ~unnel. ~ '
1~ grams of phenyl isocyanate are added '
dropwiise wi~h the aid of the dropping funnel, whilst
stirring, the mixturP is ~eated slightly and a white '-'
precipitate is ~ormed which is filtered of~, washed with
MEK and dried. This precipitate is naphthyl-di-~phenyl-
; , urethane). ,
The following c,omposition i9 deposi~ed on a
paper base coated with a solvent barrier layer~
- 1 gram of naphthyl~di-(phenylurethane),
- 10 grams of a 10% strength ~olution o~ AXRH resin
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(a vinyl copolymer from Société Rhone Poulenc) in
tetrahydrofurane.
The deposited layer is dried at 50C.
Secondly, 0.~ gram of 1'-lsopropyl-3',3'-
dimethyl-6-nitro-8-methoxy-spiro-(2H-l-benzopyrane-2,2'-
indoline) and 10 grams of a 10% strength aqueous solution
of 4/125 P Rhodoviol (Registered Trade Mark of polyvinyl
alcohol from Societé Rhone Poulenc) are prepared in a mill. .
This composition is deposited on top o~ the
preceding layer with a Meyer rod and dried at 70C.
A stylus heated to 150C, produces thereon
a blue-black trace on a light background.
EXAMPLE 2
The procedure followed is as in Example 1 but
the 2,3-dihydroxynaphthalene is replaced by the same
amount of ll,4'-isopropylidene-diphenol (Bisphenol A) and
the phenyl isocyanate is replaced by the equivalent
stoichiometric amount of tolylene 2,1~-diisocyanate (TDI).
20 grams of bisphenol blocked with TDI, 100 grams
20 of 10% strength 4/20 Rhodoviol (Registered Trade Mark of
polyvinyl alcohol from Société Rhone-Poulenc) in water,
2 grams of crystal violet-lactone,3 grams of zinc o~ide and
10 grams of ethylene glycol are dispersed in a mill.
This composition is deposited on a carrier at a
rate of 5 g per m by means of a Meyer rod and is dried.
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A stylus heated to 150C causes a blue trace on a light
background to be produced ther~n~ ~
ExAMæLE 3- 1 ;
The procedure followed i5 as in the preceding
Examples, adding 3 mols of phenyl isocyanate to one mol
of pyrogallol. The blocked pyrogallol which precipitates
i8 collected and dri~d.
S grams of ferric stearate, 3 grams of blocked
pyrogallol, 20 grams of l~/o gtrength B 10 Rhovinal
~clen~f~r ,,
olyvinylbutyral from Societe Rhone Poulenc) in
isopropanol and 10 grams of 1,4-butanediol are vigorously
dispers~d in a ball mill. ~ ;
; After thi~ dispersion has beçn coated onto
paper, a heating head heated to 120C causes the
formation of dark mar~on traces on a white background.
ExAMæLE 4
The ~ollowing composition is prepared:
- naphthyl-di-(phenylurethane) 2.5 grams
- 4-diazo-2,5-dibuto~yphenyl-morpholine
. ~ .
a ~ chloroæincate ' 3 grams
- citric acid l.S grams
, - wa~er 175 cm
- methyl ethyl ketone 175~cm3
~his solution is depo~ited on paper at a rate
of 2 grams per m2 and is dried.
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By mean~ of exposure to ultraviolet rays under
a transparent po itive original and subsequent heating
to 140C for 20 seconds, a blue positive image of the
original is obtained.
EX~MPLE 5
The following composition is prepared:
eny~ thc~e
~; ~ - naphthyl-di-(phcnylmothane) 10 grams
- 4-diazo-2,5-dibutoxyphqnyl-morpholine 20 gram~
- citric aaid 10 grams
- ethylene glyaol ' 10 ml
- methyl ethyl ketpne 1 1.
Thi~ composition i~ then depo~ited on a paper carrier at
a rate of 20 cm3/m2 and is then dried.
After exposure under a positive, the various
sample~ are deveioped with one of the following ~olutions,
with the aid of a "semi~wet" machine-type roller developer:
-l~/o ~trength by weight aqueous sodium hydroxide solution
-20% stength aqueous monoethanolamine ~olution
-8~/o strength aqueous triethanolamine solution
-5% strength aqueQus triethylenediamine solution.
A blue image of exaellent ~uality is obtalned in
' ~ these four ca~e~.
- EXAMP~E 6
A material such as that obtained in Example 5 i~ ~;
employed. After expo~ure under a po~itive and development
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by contact with ammonia vapours in a diazo machine/ a
copy of excellent quality is likewise obtained.
ExAMæLE 7
The following composition is prepared:
- p-diethylaminobenzenediazonium fluoroborate10 g
- pyrogallol bloçked with toluene diisocyanate10 g
- citric acid 5 g
- ethanol 500 ml
- thiourea 5 g
After coating onto a paper carrier followed
by exposure through a Po9itive, the copy is developed
with the aid of a fluid, such as:
~, ~. - normal (1 N) ~mmonia solution
j - pur~ piperidine o ~
- pure ~-methylmorpholine.
A maroon-coloured image of excellent quality is
obtaine~ at ambient temperatu~e. In order to dry the
material, the latter can be heated, but the quality of
the copy i~ ~ot improved. ~
EXAMPLE 8 -
The composition of Example 7, coated in the
same manner onto a paper carrier, is employed and then
exposed thr~ugh a positive. After development in a 20~/o
strenyth aqueous ammonium bicarbonate ~olution, the carrier
25 is dried at a temperature above or equal to 50C and a
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copy of excellent ~uality is obtained.
EXAMPLE 9
0.05 g of dibutyl-tin dilaurate is added to
the compositior. of Example 1. After coating onto the paper
carrier, the same coloured trace is obtained but at a
temperature of 120C.
EY~ PLE 10
In the composition of Example 2, 1 gram of
lead octoate is added. A coloured trace is obtained which
10 has the same intensity as in Example 2 at a temperature
of 140C.
; EXAMPLE 11 ;~
- A top layer composed of: -
- 10~/o strength 4-125 Rhodoviol(polyvinyl alcohol
~, 15 from Societe Rhone Poulenc) in water 5 grams
- triethylenediamine 0.5 gram -
is coated onto the material of Example 3.
,
A dark maroon-coloured trace, which has the same
intensity as in Example 3, is obtained by means of a
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heating head heated to a temperature of 100C.
- EXAMPLE 12
;~ A top layer consisting of a 5% strength by weight
~! solution of a~nonium carbonate in polyvinyl alcohol is
- - deposited on the material of Example 4.
After exposure under a translucent original, the
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material is developed at a temperature of 120C and a
blue-coloured trace is obtainedO
EXAMPLE 13
The material obtained in Example 4 is employed.
5 The following dispersion is applied to theback thereof at
a rate of 10 g/m2: .
ground borax 5 grams
~, ground ammonium fluosilicate 15 grams
e m4r~
Rhodopas H ~olyvinyl acetate from Societe
Rhone Poulenc) 5 grams
toluene. 30 ml.
Exposure is carried out with ultra violet rays .~ .
through a translucent original and heating is then
.
carried out at 110C for about 10 seconds. A blue
positive image of the original is obtained. :. .
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