[0001] The present invention relates to novel color developers for use in carbonless copy
papers (CCP) and thermal imaging papers (TP) which will produce a stable intense mark
when placed in contact with colorless dye precursors. The present invention also relates
to record material sheets bearing a coating which contains such novel color developers.
[0002] Pressure-sensitive or heat-sensitive recording papers rely on two components to form
color. One component is a colorless or slightly colored dyestuff or color precursor.
The other component is an acidic material or color developer which is capable of forming
a color by reaction with the dyestuff or color precursor. Marking of the recording
papers is effected by pressure or heat which transfers one reactant to the other.
[0003] Pressure-sensitive recording material consists, for example, of at least one pair
of sheets which contain at least one dyestuff or color precursor, dissolved in an
organic solvent, and a color developer. The dyestuff or color precursor effects a
colored marking at those points where it comes into contact with the color developer.
[0004] In order to prevent the color precursors contained in the pressure-sensitive recording
material from becoming active prematurely, they are usually separated from the developer.
This can advantageously be accomplished by incorporating the color precursors in foam
like, sponge-like, or honeycomb-like structures. Preferably, the color formers are
enclosed in microcapsules which usually can be ruptured by pressure.
[0005] In a common method of manufacture of pressure-sensitive recording papers, better
known as carbonless copy papers, a layer of pressure-rupturable microcapsules containing
a solution of colorless or slightly colored dyestuff or color precursor, is normally
coated on the backside of the front sheet of paper of a carbonless copy paper set.
This coated backside is known as the CB coating. In order to develop an image or copy,
the CB coating must be mated with a paper containing a coating of suitable color developer
on its front. This coated front color developer coating is called the CF coating.
Marking of the pressure-sensitive recording papers is effecting by rupturing the capsules
in the CB coating by means of pressure to cause the dyestuff precursor solution to
be exuded onto the front of the mated sheet below it. The colorless or slightly colored
dyestuff, or dyestuff precursor, then reacts with the color developer in the areas
at which the pressure was applied, thereby affecting the colored marking. Such mechanism
or the producing technique of pressure-sensitive recording papers is well known.
[0006] Various developers for use in thermoreactive recording material are also well known.
Thermoreactive recording material usually contains at least one carrier, one color
precursor, one solid developer and, optionally, also a binder. The thermoreactive
recording systems comprise, for example, heat-sensitive recording and copying materials
and papers. These systems are used, for example, for recording information, e.g.,
in electronic computers, teleprinters or telewriters, or in recording and measuring
instruments. The image (mark) formation can also be effected manually with a heated
pen. Laser beams can also be used to produce heat-induced marks. The thermoreactive
recording material can be so composed that the color presursor is dispersed or dissolved
in one binder layer and the developer is dissolved or dispersed in the binder in a
second layer. Another possibility consists in dispersing both the color precursor
and the developer in one layer. By means of heat, the binder is softened at specific
areas and the color precursor comes into contact with the developer at those points
where heat is applied and the desired color develops at once.
[0007] Color precursors are well known to those experienced in the field and any such color
former may be used in conjunction with the present invention, e.g., those belonging
to the classes of the phthalides, fluoranes, spiropyranes, azomethines, triarylmethane-leuco
dyes, of the substituted phenoxazines or phenothiazines, and of the chromeno or chromane
color formers. Examples of such suitable color precursors are: crystal violet lactone,
3,3-(bisamino-phenyl)-phthalides, 3,3-(bisubstituted indolyl)-phthalides, 3-(aminophenyl)-3-indolylphthalides,
6-diaalkylamino-2-n-octylaminofluoranes, 6-dialkylamino-2-arylaminofluoranes, 6-dialkylamino-3-methyl-2-arylaminofluoranes,
6-dialkylamino-2- or 3-lower alkylfluoranes, 6-dialkylamino-2-dibenzylaminofluoranes,
6-dialkylamino-2-dibenzylaminofluoranes, 6-diethylamino-1,3-dimethylfluoranes, the
lactonexanthenes, the leucoauramines, the 2-(omega substituted vinylene)-3,3-disubstituted-3-1-1-indoles,
1,3,3-trialkylindolinospirans, bis-(aminophenyl)-furyl-, phenyl- or carbazolylmethanes,
or benzoyl-leucomethylene blue.
[0008] Known color developers for use in such pressure-sensitive or heat-sensitive recording
papers have included:
(1) novolac phenolic resins made by acid catalyzed condensation of phenol, recorcinol,
pyrogallol, cresols, xylenols, or alkyl phenols such as p-tertiary butyl phenol, with
aldehydes such as formaldehyde, acetaldehyde, benzaldehyde, and butyraldehyde;
(2) Metal salts of aromatic carboxylic acids with an OH group at the ortho position,
such as zinc salts of salicylic acid, 3,5-di-tert-butyl salicylic acid, octyl salicylic
acid, and 1-hydroxy-2-naphthoic acid, and
(3) acid-treated clays such as kaolinites and attapulgites.
[0009] The search has continued for other developers having high developing power, rapid
developing speed, good light resistance and time stability. Examples of some colored
developers which have been developed in the past which are somewhat related to those
of the present invention are disclosed in U. S. Patent 4,291,901 to Petitpierre and
Japanese patent disclosure 1979-111905.
[0010] Accordingly, it is an object of the present invention to provide a novel color developer
for use in pressure-sensitive or heat-sensitive recording papers.
[0011] It is another object of the present invention to provide an improved record sheet
coated with such a novel color developer.
[0012] A further object of the present invention to provide such a color developer with
excellent color developing properties.
[0013] These and other objects of the present invention are obtained by means of the novel
color developers of the present invention which are, in part, N-monosubstituted sulfonamides
which contain at least one electron-withdrawing group. The simple sulfonamides and
n-monoalkyl sulfonamides (RSO₂NH₂ and RSO₂NHR' respectively) have acidities that are
too weak for these materials to be very useful as primary color developers. They are
useful as film modifiers and/or secondary color developers. However, the addition
of an electron-withdrawing group not more than five (5) atoms from the NH group on
the sulfonamide increases its acidity (via the inductive effect), and makes the sulfonamides
suitable for use as primary color developers. Where applicable, the pK
a (-log K
a, where K
a is the acid dissociation constant) of the sulfonylamide (-SO₂-NH-) group should be
in the range of 9.5 to 2.5, and preferably in the range of 8 to 4. Suitable electron-withdrawing
groups are those substituents which possess positive Hammett or Taft constants. The
novel color developers can also be N-monosubstituted, N'-mono or di-substituted sulfamides
[R'''(R
o")-N-SO₂NHR
o']. Again for the reasons stated above, an electron-withdrawing group must be no more
than 5 atoms from the NH group.
[0014] The maximum color developing potential is realized when these N-monosubstituted sulfonamides
or N,N'-substituted sulfamides are used in conjunction with some source of metal or
metal compound. Specifically, the sulfonamines or sulfamides may be
(1) mixed with or dissolved in an organic metal salt such as zinc oleate, zinc octoate,
and zinc acetate,
(2) precipitated onto a metal oxide hydroxide, or carbonate such as zinc oxide, zinc
hydroxide, or zinc carbonate,
(3) co-precipitated from water with soluble metal salts like zinc chloride, zinc ammonium
chloride, or zinc sulfate, or
(4) chemically modified by a metal so as to incorporate the metal into the sulfonamide
or sulfamide molecules.
[0015] The latter will take the form of organic acid salt formation by reacting either an
extra

group or a COOX group in the sulfonamide or sulfamide with a basic metal oxide or
carbonate. The salt may also be formed by reaction of alkali salt of the sulfonamide
(or sulfamide) with a soluble acidic metal salt such as zinc sulfate. The above examples
are restricted to zinc for the sake of being concise. Other metals such as aluminium,
barium, bismuth, calcium, cerium, cesium, lithium, magnesium, tin, and titanium may
be used in place of zinc.
[0016] The present invention comprehends all compounds which include a sulfonylamide (-SO₂NH-)
group and also include an electron-withdrawing atom or moiety within five atoms of
the NH group. However, the compound must be free of any basic group, for example,
epoxy or NH₂. Any additional NH groups within the compound must be no more than one
carbon away from an SO₂ group, or to a C=O, C≡N, or NO₂ group. The present invention
further excludes such compounds in which the electron-withdrawing group is a carboxy
phenyl group connected through the nitrogen atom of the sulfonylamide group or in
which the sole electron-withdrawing group is a carboxyphenyl group. Also excluded
are compounds having a hydroxy group on the opposite side of the amide from the sulfonyl
group of the sulfonylamide grouping.
[0017] Particularly preferred sulfonylamide compounds in accordance with the present invention
have electron withdrawing groups on both sides of the sulfonylamide grouping.
[0018] Subject to the above conditions, the electron withdrawing group can be any of the
following: -NO₂, -SO₂R, -CN, -SO₂Ar, -COOH, -SO₂NH₂, -SO₂NHR, -SO₂NR₂, -F, -Cl, -Br,
-I, -OAr, -COOR, -COOAr, -OR, -OH, -SR, -SH, -COR, -COAr, -C≡CR, -Ar, -CH=CR₂, wherein
R is an alkyl group of up to 18 carbon atoms, preferably 3-8 carbon atoms, and Ar
is an aryl group, preferably phenyl or naphthyl. The R and Ar groups may be optionally
substituted as long as the above conditions are met.
[0019] Particularly useful compounds for use as color developers in accordance with the
present invention are N-monosubstituted sulfonamides represented by formula

where R¹ and R² are alkyl (branched or linear), preferably with no more than 18 carbon
atoms and most preferably with 3-8 carbon atoms, aryl, preferably phenyl or naphthyl,
or a combination of both, each of which may be substituted or unsubstituted, said
substituents, if any, being any group other than a basic group, such as epoxy or NH₂,
and if -NH- it must be no more than one carbon atom away from a SO₂, C=O, C≡N or NO₂
group:
G is an electron withdrawing group as defined above and is not more than five atoms
away from the -NH- group, with the proviso that G is not -OH or -SH when n is 1 and
with the further proviso that -(R²)
n-G is not

and
n is 0 or 1.
[0020] Other sulfonamides useful in the practice of the present invention are those in accordance
with formula

wherein n, R¹, R² and G are as defined above with the proviso that R¹ is not

and with the further proviso that G is not COOH in formula II when all of the following
three conditions apply: R² is aryl, n is 1, and R¹ does not comprehend or include
an electron-withdrawing group (as defined above for G) within 5 atoms of the NH group.
[0021] Analogous to the sulfonamides above, the N-monosubstituted, N'-mono or di-substituted
sulfamide color developers, which are also particularly useful in accordance with
the present invention, are represented by formula III below:

where R², G and n are as defined above and R³ and R⁴ are as defined above for R¹
and R² although one of R³ and R⁴ may be H; furthermore, when one of R³ and R⁴ is H,
the other may be an electron withdrawing group as defined above for G.
[0022] The usefulness of the N-monosubstituted sulfonamides as color developers is enhanced
further by placing electron-withdrawing groups on both sides of the sulfamoyl group.
Preferred such compounds useful in the practice of the present invention are represented
by formula IV:

wherein n, R² and G are as defined above and G' is an electron withdrawing group
as defined above with respect to G.
[0023] While the substituents with respect to formulae I-IV and the remainder of the generic
formula as discussed above may include any functional group not specifically proscribed,
it particularly may include additional -SO₂NH-, alkyl, aryl and electron withdrawing
(as defined above for G) groups, and may, in fact, be a polymer containing repeating
units of any of the above.
[0024] Examples of compounds within formula (I) are as follows:

[0025] With respect to examples of compounds of formula (II), it should be noted that in
Japanese patent disclosure 1979-111905, comparative compound example 3, i.e. N-(octadecyl)-o-carboxybenzene
sulfonamide, is taught as being a poor developer, particularly in comparison with
the anthranilic developers disclosed by the Japanese patent. It has surprisingly been
discovered, however, that the addition of another electron withdrawing group, this
time on the nitrogen side of the sulfonamide, further increases the color developing
property and such compounds thus become preferred compounds of the present invention.
Examples of compounds in formula (II) including the above described preferred compounds
are as follows:

[0026] With respect to all of the above acids, the preferred form is that of the metal salt,
particularly an alkaline earth metal salt, and more particularly a zinc salt.
[0027] Examples of formula (III) are:

[0028] With respect to compounds under formula (IV), note the compounds already set forth
hereinabove as examples under formula (II).
[0029] In addition to the above formulas, an infinite number of polyfunctional molecules
can be synthesized. However, the functional group or repeating unit in each of these
molecules would still be a N-monosubstituted sulfonamide or sulfamide as depicted
in formulas (I) through (IV). For instance, the polysulfonamides prepared from aromatic
disulfonyl chlorides and aromatic diamines, such as polycondensate of benzene disulfonyl
chloride and p,p'-diaminodiphenylmethane (also called methylene dianiline):

With respect to the above reaction scheme, the molecular weight can be controlled
by carboxymethoxybenzene sulfonyl chloride as a reaction terminator. Another such
a polycondensate is the product of a mild, selective hydrolysis of the methyl esters
of the reaction product of two moles carboxymethoxy benzene sulfonyl chloride (CBC
from Sherwin-Williams Co.) with trimethylene glycol di-p-aminobenzoate (Polacure
740M from Polaroid Corporation),
trimethylene bis (N-o-carboxylphenylsulfonyl)-p-aminobenzoate

An even superior compound is the complex of mixed zinc salt that results from reacting
the above compound with more basic zinc salts.
[0030] The synthesis of all of the above compounds is quite straightforward. They are prepared
by reacting the appropriate sulfonyl (or sulfamoyl) chloride with an amine, amide,
or sulfonamide. The reaction (for amines) can be performed in an aqueous solution
or suspension by using the Schotten-Baumann technique with sodium carbonate as base
(see Scheifele and D. F. Detar,
Org. Syn. Coll. Vol. 4, 34 (1963)). Alternatively, the reaction (for amides and sulfonamides) may
be performed in an inert solvent such as acetonitrile (see E. Muller, ed.
Methoden der Organischer Chemie (Houben-Weyl), vol. 9, 4th ed., Georg Thieme Verlag, Stuttgart, West Germany, pp.
398-404, 605-648 (1955)).
[0031] The following compounds are further examples of the present invention:

[0032] It should be noted that the most preferred electron withdrawing groups (G and G')
are -SO₂R; -COOH; -OR; -COOR; -COR; -NO₂; -CN; and the halides. The most preferred
set of electron-withdrawing groups are -SO₂R; -COOH; -OR; -COOR; and -COR.
[0033] The following preparative example shows a method of synthesis of one of the compounds
used in the present invention. It should be understood that all of the other compounds
can be made by analogous synthesis or in manners which are already known to the prior
art, or could be derived from methods known to the prior art without undue experimentation.
Throughout all of the present examples and claims all percentages are by weight unless
otherwise indicated.
Preparative Example - Preparation of N-(p-n-butylphenyl)-o-carboxybenzene sulfonamide
[0034]

[0035] The first stage of the reaction (as shown in reaction scheme I hereinabove) is carried
out by dissolving 254.4 g (2.4 moles) of sodium carbonate (granular, 99+%, ACS reagent
grade) in 1.5 liters of water. The solution is heated to 50°C, and at 50°C-60°C, 149.2
g or 157 ml (1 mole) of p-n-butylaniline (97% purity) and 281.6 g of carbomethoxybenzene
sulfonyl chloride (commercially available under the name CBC) are added alternately
in five portions each. The dual additions of the five portions of each reactant are
timed at approximately 5 minute intervals. That is, 31.6 ml of butylaniline is added
and followed directly by the addition of 56.32 g of CBC. After 5 minutes have passed,
the next portions are added again in immediate succession, i.e., 31.6 ml butylaniline
followed by 56.32 g CBC. This continues until all five portions of each reactant have
been added. Sodium hydroxide may be added in case carbon dioxide is evolved which
occurs if an insufficient amount of sodium carbonate is present.
[0036] After all of the reactants have been added, the temperature is raised to 80°C and
held for 25 minutes, and the mixture then cooled to room temperature.

[0037] Reaction scheme II is carried out by slowly adding the cooled reaction mixture into
a 4 liter beaker containing 250 ml water and 300 ml of hydrochloric acid (37%), and
equipped with an efficient stirrer, taking care that the mixture does not foam over.
The dispersion is chilled in a refrigerator over night. The crude N-(p-n-butylphenyl)-o-carbomethoxy
benzene sulfonamide settles on the bottom of the beaker as a brownish, viscous mass.
The water layer is poured off and replaced by a solution of 80g sodium hydroxide in
1.5 liter of water. The resulting solution is heated for 2 hours at 85°C to hydrolize
the methyl ester (reaction scheme III).

[0038] The solution is filtered at room temperature to remove a very small amount of black
precipitate. The solution is again poured into a 4 liter beaker containing 250 ml
water and 300 ml hydrochloric acid (37%). (Reaction scheme IV)

[0039] The product is isolated by filtration using a Buchner funnel, and is washed with
water on the filter. The filtrate is allowed to air dry, and then pulverized to a
light brown to beige powder. The yield is approximately 90% (based on butylaniline)
and purity is approximately 96%. The procedue could be simplified by consolidating
reactions I and III, as well as II and IV, thereby avoiding the difficult to handle
methyl ester. The procedure is an adaptation of the related preparation of p-toluenesulfonyl
anthranilic acid as submitted by H. J. Scheifele, Jr. and D. F. DeTar in
Organic Synthesis, Collective, volume 4, p. 37 (1963).
[0040] The following examples show methods of formulating coatings containing the developers
of the present invention for application to pressure-sensitive recording papers. The
coatings are formulated to be porous. This permeability is usually obtained through
the use of fillers, such as aluminum oxide, zinc oxide, silicon dioxide, clay or organic
thixotropes. The binders are predominantly saturated aliphatic or aromatic compounds.
The number of extraneous, organic, polar groups in the final, dried coating are kept
to an absolute minimum. Acid groups and their metal salts are the notable exceptions.
The color developer should be the predominant, non-fugitive, polar material in the
CF coating. For example, in the moisture set ink below, the full color developing
potential appears only after the solvents (diethylene glycol, triacetin, and absorbed
water) leave the film during the setting process. It will be understood that other
fillers, binders and solvents can be used to complete the compositions of the present
invention, all as are conventional in this art and well known.
Example 1 - An Aqueous Coating
[0041] 5.4% trimethylene bis(N-(o-carboxylphenylsulfonyl)-p-aminobenzoate) was added to
3.7% ammonium hydroxide in 26% aqueous solution and 50% water, and mixed until completely
dissolved. Thereupon 10% Pencoate RBB 725 (an oxidized starch from Penick and Ford,
Division of Pacific Resins and Chemicals, Inc.), 1% zinc ammonium chloride and 30%
zinc oxide were added and mixed thoroughly in a high speed mixer or mill.
[0042] As an alternative to the above approach of incorporation, the sulfonamide (or its
zinc salt) may be pulverized in a ball mill, and then simply mixed with the rest of
the components. If zinc salt is used, then the ZnO may be replaced by hydrated alumina.
Example 2 - A Letterpress Coating - Moisture Set Ink
[0043] A kettle was charged with 24.7% diethylene glycol and 24.7% triacetin (glyceryl triacetate).
5% Lacros 294 (an acid modified rosin resin from Crosby Chemicals, Inc.) was added
and heated to 95°C for 30 minutes or until dissolved. Thereupon, 30.0% n-butyl-N-(-o-carboxyphenylsulfonyl)-p-aminobenzoate
was added and, upon dissolution, 4.0% Kadox 15 (zinc oxide - chemical grade from New
Jersey Zinc Co.) was added. The temperature was maintained at 100-105°C for one hour,
although a longer heating period may be required for more inert grades of ZnO. 5.0%
diethylene glycol monostearate, 5.0% zinc octoate and 0.1% benzotriazole were added
in quick succession and cooled to 65°C. Then 1.5% (or less, if preferred) Crayvalac
SF (organic thixotrope from Cra-Vac Indsutries, Inc.) was added and dispersed thoroughly
with a high speed mixer, and drained through a mesh filter. The active ingredient
is the zinc salt n-butyl-N-(-o-carboxyphenylsulfonyl)-p-aminobenzoate.
Example 3 - A Flexo-Gravure Coating
[0044] 10% trimethylene bis (N-o-carboxyphenylsulfonyl)-p-aminobenzoate) and 16.0% Lacros
294 were dissolved in 62% ethyl alcohol. To this solution, 10.0% zinc octoate (18%
Zn) were added while stirring. Into this clear solution were dispersed 2.0% Alumina
Oxide C (fumed aluminum oxide from Degussa Corp.) or 2.0% fumed silica (trade name
"Aerosil" 200 or R 972 from Degussa Corp.).
Example 4 - Transfer Litho (Letterpress) Ink
[0045] A mixture of 37.0% mineral seal oil and 30.3% zinc octoate (96% pure with remainder
as mineral seal oil) is heated to 100°C and then 10.2% zinc resinate (Poly Tac 100
from Reichold Chemicals Inc.) is added. After a clear solution is obtained, 18% N-(p-n-butylphenyl)-o-carboxybenzene
sulfonamide prepared by the method of the preparative example above, is added. 2.2%
zinc oxide (Kadox 15 from New Jersey Zinc Co.) is dispersed into the solution and
the solution is heated for 1-1/2 hours at 100-117°C. The mixture is cooled down to
80°C and 1.5% Cravalac SF is dispersed with a high speed mixer. If the texture of
the ink is too coarse, the ink is passed through a 3-roll mill. The color developer
is present in the form of a fine dispersion.
Examples 5 and 6
[0046] Following the same general procedure as set forth in example 4, other transfer litho
(letterpress) inks can be made using different sulfonamides. Two examples of same
showing the relative amounts of components are set forth hereinbelow in Table 1:

[0047] The color developers in 5 and 6 are present in solution.
[0048] Table 2 shows the color developing power of the products of examples 4, 5 and 6,
as compared to a commercial product:

Example 7 - Comparative Example
[0049] The following is a comparison proving the superiority of the compounds of the present
invention to those of comparative compound 3 in Japanese patent application 1979-111905.
1(a) 10 g zinc salt of N-(4-dodecylphenyl)-o-carboxybenzenesulfonamide was dissolved
in 50 ml of ethyl acetate, as described in "Application 1" of JP 1979-111905. This
solution was applied to 11 lb. paper stock (41g/m²) at a coating weight of 0.2 g/m².
The resulting CF1 sheet was mated with commercial NCR CB paper (15#), and the 2-ply
formset was fed through a mini-calander set at 30 psi pressure to produce 37 kg/cm.
After one hour, the image intensity was measured on a BNL-2 Opacimeter from Technidyne
Corporation as reflectance percent of the imaged area relative to the sheet.
1(b) A CF2 was made and tested as above except the coating solution contained 10g
N-(4-dodecylphenyl)-o-carboxybenzenesulfonamide and 10g zinc octoate in 50 ml ethyl
acetate.
2(a) The above procedure 1(a) was repeated using the zinc salt of N-(octadecyl)-o-carboxybenzenesulfonamide
as the color developer to produce CF3.
2(b) A CF4 sheet was prepared as in 1(b) except N-(octadecyl)-o-carboxybenzenesulfonamide
was used as the color developer.
[0050] Results: A low reflectance value, R, represents an intense image.

[0051] The preferred color developer is significantly better than the comparative compound
3.
[0052] It will be obvious to those skilled in the art that various changes may be made without
departing from the scope of the invention and the invention is not to be considered
limited to what is described in the specification.
1. In a pressure-sensitive or heat-sensitive recording material including a dye precursor
and a color developer, the improvement wherein said color developer is a compound
including a sulfonylamide (-SO₂NH-) and also including an electron-withdrawing atom
or moiety within five atoms of the nitrogen atom of said sulfonylamide group, said
compound being free of any basic group, with any additional NH groups being no more
than one carbon atom away from an SO₂, C=O, C≡N or NO₂ group, with the proviso that
the electron-withdrawing group is not a carboxyphenyl group connected through the
nitrogen atom of the sulfonylamide group, with the further proviso that the sole electron-withdrawing
group is not a carboxphenyl group and with the further proviso that the electron-withdrawing
group is not a hydroxy group on the opposite side of the amide from the sulfonyl group
of the sulfonylamide group.
2. A recording material in accordance with claim 1, wherein, subject to the provisos
of claim 1, said electron-withdrawing group is selected from the group consisting
of -NO₂, -SO₂R, -CN, -SO₂Ar, -COOH, -SO₂NH₂, -SO₂NHR, -SO₂NR₂, -F, -Cl, -Br, -I, -OAr,
-COOR, -COOAr, -OR, -OH, -SR, -SH, -COR, -COAr, -C≡CR, -Ar, -CH=CR₂, wherein R is
an optionally substituted alkyl group and Ar is an optionally substituted aryl group.
3. A recording material in accordance with claim 1, wherein said compound has electron-withdrawing
groups on both sides of the sulfonylamide grouping.
4. A recording material in accordance with claim 1, wherein said compound is:
an N-monosubstituted sulfonamide of the formula -

in which R¹ and R² are alkyl, aryl or a combination of alkyl and aryl, each being
substituted or unsubstituted, said substituents, if any, being any group other than
a basic group and, if -NH-, no more than one carbon atom away from a SO₂, C=O, C≡N
or NO₂ group,
G is an electron-withdrawing group selected from the group consisting of -NO₂, -SO₂R,
-CN, -SO₂Ar, -COOH, -SO₂NH₂, -SO₂NHR, -SO₂NR₂, -F, -Cl, -Br, -I, -OAr, -COOR, -COOAr,
-OR, -OH, -SR, -SH, -COR, -COAr, -C≡CR, -Ar, -CH=CR₂, wherein R is an optionally substituted
alkyl group and Ar is an optionally substituted aryl group, G being not more than
five atoms away from the amide group of the sulfonylamide grouping, with the proviso
that G is not -OH or -SH when n is 1 and with the further proviso that -(R²)
n-G is not

, and
n is 0 or 1;
a sulfonamide of the formula -

in which, R¹, R² and G are as defined above, with the proviso that R¹ is not

, and with the further proviso that G is not COOH when all of the following three
conditions apply; R² is aryl, n is 1, and R¹ does not comprehend or include an electron-withdrawing
group within five atoms of the amide group of the sulfonylamide grouping;
an N-mono-substituted, N'-mono or di-substituted sulfamide of the formula

in which R², G and n are as defined above, and R³ and R⁴ are as defined for R¹ and
R² or one of R³ and R⁴ is H, and further in which, when one of R³ and R⁴ is H, the
other may be an electron-withdrawing group as defined above for G;
an N-monosubstituted sulfonamide having electron withdrawing groups on both sides
of the sulfamoyl group, of the formula -

in which n, R² and G are as defined above and G¹ is an electron-withdrawing group
as defined above with respect to G; or
a polyfunctional molecule in which each functional group or the repeating unit is
an N-monosubstituted sulfonamide or sulfamide depicted in formulas (I) through (IV).
5. A recording material in accordance with claim 1, wherein said compound is selected
from the group consisting of:
N-(phenylsulfonyl)-p-toluenesulfonamide
N-phenyl-benzene sulfonamide
C3-8 alkyl-N-(phenylsulfonyl)-p-aminobenzoate
N-α-(p-toluenesulfonyl)-DL-phenylalanine
N-(carboxymethyl)-p-toluenesulfonamide
N-[o-(p-toluenesulfonamido) phenyl]-p-toluenesulfonamide
C3-8alkyl-N-(o-carboxyphenylsulfonyl)-p-amino-benzoate
N-(o-carboxyphenylsulfonyl)-4-aminobenzophenone
N-(o-carboxyphenylsulfonyl)4-aminobenzenesulfonamide
N-(4-C1-18 alkylphenyl)-o-carboxybenzenesulfonamide
N-2(2,4-diC3-8 alkylphenyl)-o-carboxybenzenesulfonamide
N-(diC1-8 alkylsulfamoyl)-p-toluenesulfonamide
N-phenyl-N'-C1-8 alkylsulfamide
N-benzoyl-N'-C1-8 alkylsulfamide
N-phenyl-N', N'-diC1-8 alkylsulfamide
N-(diC1-8 alkylsulfamoyl)-α-aminophenylacetic acid
N-(o-(N' ,N'-diC1-3alkylsulfamoylamido)-phenyl-diC1-8alkylsulfamide trimethylene bis (N-o-carboxylphenylsulfonyl)-p-aminobenzoate
N-toluenesulfonyl-α-aminophenylacetic acid
N-phenylsulfonyl-α-aminophenylacetic acid
N-(m-carboxybenzoyl)-p-toluenesulfonamide
N-(m-carboxybenzoyl)-benzenesulfonamide
N-(m-carboxybenzoyl)-N',N'-dimethylsulfamide
N-(o-carboxybenzoyl)-p-toluenesulfonamide
N-(o-carboxybenzoyl-benzenesulfonamide
N-(o-carboxybenzoyl)-N',N'-dimethylsulfamide
N-(m-nitrobenzoyl)-p-toluene sulfonamide
N-(m-nitrobenzoyl)-benzenesulfonamide
N-(m-nitrobenzoyl)-N',N'-dimethylsulfamide
N-(p-nitrobenzoyl)-p-toluenesulfonamide
N-(p-nitrobenzoyl)-benzenesulfonamide
N-(p-nitrobenzoyl)-N', N'-dimethylsulfamide
N-(phenylsulfonyl)-benzenesulfonamide; and
4,4'-oxybis[N-(phenylsulfonyl)-benzenesulfonamide].
6. In a color developer solution for coating onto sheet material to make pressure-sensitive
or heat-sensitive recording material, containing a color developer compound, a solvent,
and other additives to permit coating, the improvement wherein said color developer
compound is a compound including a sulfonylamide (-SO₂NH-) and also including an
electron-withdrawing atom or moiety within five atoms of the nitrogen atom of said
sulfonylamide group, said compound being free of any basic group, with any additional
NH groups being no more than one carbon atom away from any SO₂, C=O, C≡N or NO₂ group,
with the proviso that the electron-withdrawing group is not a carboxyphenyl group
connected through the nitrogen atom of the sulfonylamide group, with the further proviso
that the sole electron-withdrawing group is not a carboxyphenyl group and with the
further proviso that the electron-withdrawing group is not a hydroxy group on the
opposite side of the amide from the sulfonyl group of the sulfonylamide group.
7. A color developer solution in accordance with claim 6, wherein, subject to the
proviso of claim 6, said electron-withdrawing group is selected from the group consisting
of -NO₂, -SO₂R, -CN, -SO₂Ar, -COOH, -SO₂NH₂, -SO₂NHR, -SO₂NR₂, -F, -Cl, -Br, -I, -OAr,
-COOR, -COOAr, -OR, -OH, -SR, -SH, -COR, -COAr, -C≡CR, -Ar, -CH=CR₂, wherein R is
an optionally substituted alkyl group and Ar is an optionally substituted aryl group.
8. A color developer solution in accordance with claim 6, wherein said compound has
electron-withdrawing groups on both sides of the sulfonylamide grouping.
9. A color developer solution in accordance with claim 6, wherein said compound is:
an N-monosubstituted sulfonamide of the formula -

in which R¹ and R² are alkyl, aryl or a combination of alkyl and aryl, each being
substituted or unsubstituted, said substitutents, if any, being any group other than
a basic group and, if -NH; no more than one carbon atom away from a SO₂, C=O, C≡N
or NO₂ group,
G is an electron-withdrawing group selected from the group consisting of -NO₂, -SO₂R,
-CN, -SO₂Ar, -COOH, -SO₂NH₂, -SO₂NHR, -SO₂NR₂, -F, -Cl, -Br, -I, -OAr, -COOR, -COOAr,
-OR, -OH, -SR, -SH, -COR, -COAr, -C≡CR, -Ar, -CH=CR₂, wherein R is an optionally substituted
alkyl group and Ar is an optionally substituted aryl group, G being not more than
five atoms away from the amide group of the sulfonylamide grouping, with the proviso
that G is not -OH or -SH when n is 1 and with the further proviso that -(R²)
n-G is not

, and
n is 0 or 1;
a sulfonamide of the formula -

in which, R¹, R² and G are as defined above, with the proviso that R¹ is not

, and with the further proviso that G is not COOH when all of the following three
conditions apply; R² is aryl, n is 1, and R¹ does not comprehend or include an electron-withdrawing
group within five atoms of the amide group of the sulfonylamide grouping;
an N-mono-substituted, N'-mono or di-substituted sulfamide of the formula

in which R², G and n are as defined above, and R³ and R⁴ are as defined for R¹ and
R² or one of R³ and R⁴ is H, and further in which, when one of R³ and R⁴ is H, the
other may be an electron-withdrawing group as defined above for G;
an N-monosubstituted sulfonamide having electron withdrawing groups on both sides
of the sulfamoyl group, of the formula -

in which n, R² and G are as defined above and G¹ is an electron-withdrawing group
as defined above with respect to G; or
a polyfunctional molecule in which each functional group or the repeating unit is
an N-monosubstituted sulfonamide or sulfamide depicted in formulas (I) through (IV).
10. A color developer solution in accordance with claim 6, wherein said compound is
selected from the group consisting of:
N-(phenylsulfonyl)-p-toluenesulfonamide
N-phenyl-benzene sulfonamide
C3-8 alkyl-N-(phenylsulfonyl)-p-aminobenzoate
N-α-(p-toluenesulfonyl)-DL-phenylalanine
N-(carboxymethyl)-p-toluenesulfonamide
N-[o-(p-toluenesulfonamido) phenyl]-p-toluenesulfonamide
C3-8 alkyl-N-(o-carboxyphenylsulfonyl)-p-amino-benzoate
N-(o-carboxyphenylsulfonyl)-4-aminobenzophenone
N-(o-carboxyphenylsulfonyl)4-aminobenzenesulfonamide
N-(4-C1-18 alkylphenyl)-o-carboxybenzenesulfonamide
N-2(2,4-diC3-8 alkylphenyl)-o-carboxybenzenesulfonamide
N-(diC1-8 alkylsulfamoyl)-p-toluenesulfonamide
N-phenyl-N'-C1-8 alkylsulfamide
N-benzoyl-N'-C1-8 alkylsulfamide
N-phenyl-N',N'-diC1-8 alkylsulfamide
N-diC1-8 alkylsulfamoyl)-α-aminophenylacetic acid
N-(o-(N',N'-diC1-3alkylsulfamoylamido)-phenyl-diC1-8alkylsulfamide trimethylene bis (N-o-carboxylphenylsulfonyl)-p-aminobenzoate
N-toluenesulfonyl-α-aminophenylacetic acid
N-phenylsulfonyl-α-aminophenylacetic acid
N-(m-carboxybenzoyl)-p-toluenesulfonamide
N-(m-carboxybenzoyl)-benzenesulfonamide
N-(m-carboxybenzoyl)-N',N'-dimethylsulfamide
N-(o-carboxybenzoyl)-p-toluenesulfonamide
N-(o-carboxybenzoyl)-benzenesulfonamide
N-(o-carboxybenzoyl)-N', N'-dimethylsulfamide
N-(m-nitrobenzoyl)-p-toluene sulfonamide
11. In the method of producing a colored marking by causing a dye precursor to come
into contact with a color developer, the improvement wherein said color developer
is a compound including a sulfonylamide (-SO₂NH-) and also including an electron-withdrawing
atom or moiety within five atoms of the nitrogen atom of said sulfonylamide group,
said compound being free of any basic group, with any additional NH groups being no
more than one carbon atom away from an SO₂, C=O, C≡N or NO₂ group, with the proviso
that the electron-withdrawing group is not a carboxyphenyl group connected through
the nitrogen atom of the sulfonylamide group, with the further proviso that the sole
electron-withdrawing group is not a carboxyphenyl group and with the further proviso
that the electron-withdrawing group is not a hydroxy group on the opposite side of
the amide from the sulfonyl group of the sulfonylamide group.
12. A method in accordance with claim 11, wherein, subject to the provisos of claim
11, said electron- withdrawing group is selected from the group consisting of -NO₂,
SO₂R, -CN, -SO₂Ar, -COOH, -SO₂NH₂, -SO₂NHR, -SO₂NR₂, -F, -Cl, -Br, -I, -OAr, -COOR,
-COOAr, -OR, -OH, -SR, -SH, -COR, -COAr, -C≡CR, -Ar, -CH=CR₂, wherein R is an optionally
substituted alkyl group and Ar is an optionally substituted aryl group.
13. A method in accordance with claim 11, wherein said compound has electron-withdrawing
groups on both sides of the sulfonylamide grouping.
14. A method in accordance with claim 11, wherein said compound is:
an N-monosubstituted sulfonamide of the formula -

in which R¹ and R² are alkyl, aryl or a combination of alkyl and aryl, each being
substituted or unsubstituted, said substituents, if any, being any group other than
a basic group and, if -NH; no more than one carbon atom away from a SO₂, C=O, C≡N
or NO₂ group,
G is an electron-withdrawing group selected from the group consisting of -NO₂, -SO₂R,
-CN, -SO₂Ar, -COOH, -SO₂NH₂, -SO₂NHR, -SO₂NR₂, -F, -Cl, -Br, -I, -OAr, -COOR, -COOAr,
-OR, -OH, -SR, -SH, -COR, -COAr, -C≡CR, -Ar, -CH=CR₂, wherein R is an optionally substituted
alkyl group and Ar is an optionally substituted aryl group, G being not more than
five atoms away from the amide group of the sulfonylamide grouping, with the proviso
that G is not -OH or -SH when n is 1 and with the further proviso that -(R²)
n-G is not

, and
n is 0 or 1;
a sulfonamide of the formula -

in which, R¹, R² and G are as defined above, with the proviso that R¹ is not

, and with the further proviso that G is not COOH when all of the following three
conditions apply; R² is aryl, n is 1, and R¹ does not comprehend or include an electron-withdrawing
group within five atoms of the amide group of the sulfonylamide grouping;
an N-mono-substituted, N'-mono or di-substituted sulfamide of the formula

in which R², G and n are as defined above, and R³ and R⁴ are as defined for R¹ and
R² or one of R³ and R⁴ is H, and further in which, when one of R³ and R⁴ is H, the
other may be an electron-withdrawing group as defined above for G;
an N-monosubstituted sulfonamide having electron withdrawing groups on both sides
of the sulfamoyl group, of the formula -

in which n, R² and G are as defined above and G¹ is an electron-withdrawing group
as defined above with respect to G; or
a polyfunctional molecule in which each functional group or the repeating unit is
an N-monosubstituted sulfonamide or sulfamide depicted in formulas (I) through (IV).
15. A method in accordance with claim 11, wherein said compound is selected from the
group consisting of:
N-(phenylsulfonyl)-p-toluenesulfonamide
N-phenyl-benzene sulfonamide
C3-8 alkyl-N-(phenylsulfonyl)-p-aminobenzoate
N-α-(p-toluenesulfonyl)-DL-phenylalanine
N-(carboxymethyl)-p-toluenesulfonamide
N-[o-(p-toluenesulfonamido) phenyl]-p-toluenesulfonamide
C3-8 alkyl-N-(o-carboxyphenylsulfonyl)-p-amino-benzoate
N-(o-carboxyphenylsulfonyl)-4-aminobenzophenone
N-(o-carboxyphenylsulfonyl)4-aminobenzenesulfonamide
N-(4-C1-18 alkylphenyl)-o-carboxybenzenesulfonamide
N-2(2,4-diC3-8 alkylphenyl)-o-carboxybenzenesulfonamide
N-(diC1-8 alkylsulfamoyl)-p-toluenesulfonamide
N-phenyl-N'-C1-8 alkylsulfamide
N-benzoyl-N'-C1-8 alkylsulfamide
N-phenyl-N',N'-diC1-8 alkylsulfamide
N-diC1-8 alkylsulfamoyl)-α-aminophenylacetic acid
N-(o-(N',N'-diC1-3alkylsulfamoylamido)-phenyl-diC1-8alkylsulfamide
trimethylene bis (N-o-carboxylphenylsulfonyl)-p-aminobenzoate
N-toluenesulfonyl-α-aminophenylacetic acid
N-phenylsulfonyl-α-aminophenylacetic acid
N-(m-carboxybenzoyl)-p-toluenesulfonamide
N-(,-carboxybenzoyl)-benzenesulfonamide
N-(m-carboxybenzoyl)-N',N'-dimethylsulfamide
N-(o-carboxybenzoyl)-p-toluenesulfonamide
N-(o-carboxybenzoyl-benzenesulfonamide
N-(o-carboxybenzoyl)-N',N'-dimethylsulfamide
N-(m-nitrobenzoyl)-p-toluene sulfonamide
N-(m-nitrobenzoyl)-benzenesulfonamide
N-(m-nitrobenzoyl)-N',N'-dimethylsulfamide
N-(p-nitrobenzoyl)-p-toluenesulfonamide
N-(p-nitrobenzoyl)-benzenesulfonamide
N-(p-nitrobenzoyl)-N',N'-dimethylsulfamide
N-(phenylsulfonyl)-benzenesulfonamide; and
4,4'-oxybis[N-(phenylsulfonyl)-benzenesulfonamide].
Amended claims in accordance with Rule 86(2) EPC.
1. A color developer composition for coating onto sheet material to make pressure-sensitive
or heat-sensitive recording material, containing a color developer compound, a solvent,
and other additives to permit coating, characterised in that said color developer
compound is a compound including a sulfonylamide (-SO₂NH-) group and also including
an electron-withdrawing atom or moiety within five atoms of the nitrogen atom of said
sulfonylamide group, said compound being free of any basic group, with any additional
NH groups being no more than one carbon atom away from an SO₂, C=O, C≡N or NO₂ group,
with the proviso that the electron withdrawing group is not a carboxyphenyl group
connected through the nitrogen atom of the sulfonylamide group, with the further proviso
that the sole electron-withdrawing group is not a carboxyphenyl group and with the
further proviso that said compound does not include a -CHOH- group directly connected
to a nitrogen atom.
2. A color developer composition in accordance with Claim 1, wherein, subject to the
provisos thereof said electron-withdrawing group is selected from the group consisting
-NO₂, -SO₂R, -CN, -SO₂Ar, -COOH, -SO₂NH₂, -SO₂NHR, -SO₂NR₂, -F, -Cl, -Br, -I, -OAr,
-COOR, -COOAr, -OR, -OH, -SR, -SH, -COR, -COAr, -C≡CR, -Ar, -CH=CR₂, wherein R is
an optionally substituted alkyl group and Ar is an optionally substituted aryl group.
3. A color developer composition in accordance with Claim 1, wherein said compound
has electron-withdrawing groups on both sides of the sulfonylamide grouping.
4. A color developer composition in accordance with Claim 1 wherein, subject to the
provisos thereof, said compound is :
an N-monosubstituted sulfonamide of the formula -

in which R¹ and R² are alkyl, aryl or a combination of alkyl and aryl, each being
substituted or unsubstituted, said substituents, if any, being any group other than
a basic group and, if -NH-, no more than one carbon atom away from a SO₂, C=O, C≡N
or NO₂ group,
G is an electron-withdrawing group selected from the group consisting of -NO₂, -SO₂R,
-CN, -SO₂Ar, -COOH, -SO₂NH₂, -SO₂NHR, -SO₂NR₂, -F, -Cl, -Br, -I, -OAr, -COOR, -COOAr,
-OR, -OH, -SR, -SH, -COR, -COAr, -C≡CR, -Ar, -CH=CR₂, wherein R is an optionally substituted
alkyl group and Ar is an optionally substituted aryl group, G being not more than
five atoms away from the amide group of the sulfonylamide grouping, with the proviso
that G is not -OH or -SH when n is 1 and with the further proviso that -(R²)n-G is not

, and
n is 0 or 1;
a sulfonamide of the formula -

in which, R¹, R² and G are as defined above, with the proviso that R¹ is not

, and with the further proviso that G is not COOH when all of the following three
conditions apply; R² is aryl, n is 1, and R¹ does not comprehend or include an electron-withdrawing
group within five atoms of the amide group of the sulfonylamide grouping;
an N-mono-substituted, N'-mono or di-substituted sulfamide of the formula

in which R², G and n are as defined above, and R³ and R⁴ are as defined for R¹ and
R² or one of R³ and R⁴ is H, and further in which, when one of R³ and R⁴ is H, the
other may be an electron-withdrawing group as defined above for G;
an N-monosubstituted sulfonamide having electron withdrawing groups on both sides
of the sulfamoyl group, of the formula -

in which n, R² and G are as defined above and G¹ is an electron-withdrawing group
as defined above with respect to G; or
a polyfunctional molecule in which each functional group or the repeating unit is
an N-monosubstituted sulfonamide or sulfamide depicted in formulas (I) through (IV).
5. A color developer composition in accordance with Claim 1, wherein said compound
is selected from the group consisting of:
N-(phenylsulfonyl)-p-toluenesulfonamide
N-phenyl-benzene sulfonamide
C3-8 alkyl-N-(phenylsulfonyl)-p-aminobenzoate
N-α-(p-toluenesulfonyl)-DL-phenylalanine
N-(carboxymethyl)-p-toluenesulfonamide
N-[o-(p-toluenesulfonamido) phenyl]-p-toluenesulfonamide
C3-8 alkyl-N-(o-carboxyphenylsulfonyl)-p-amino-benzoate
N-(o-carboxyphenylsulfonyl)-4-aminobenzophenone
N-(o-carboxyphenylsulfonyl)4-aminobenzenesulfonamide
N-(4-C1-18 alkylphenyl)-o-carboxybenzenesulfonamide
N-2(2,4-diC3-8 alkylphenyl)-o-carboxybenzenesulfonamide
N-(diC1-8 alkylsulfamoyl)-p-toluenesulfonamide
N-phenyl-N'-C1-8 alkylsulfamide
N-benzoyl-N'-C1-8 alkylsulfamide
N-phenyl-N', N'-diC1-8 alkylsulfamide
N-(diC1-8 alkylsulfamoyl)-α-aminophenylacetic acid
N-(o-(N' ,N'-diC1-3alkylsulfamoylamido)-phenyl-diC1-8alkylsulfamide trimethylene bis (N-o-carboxylphenylsulfonyl)-p-aminobenzoate
N-toluenesulfonyl-α-aminophenylacetic acid
N-phenylsulfonyl-α-aminophenylacetic acid
N-(m-carboxybenzoyl)-p-toluenesulfonamide
N-(m-carboxybenzoyl)-benzenesulfonamide
N-(m-carboxybenzoyl)-N',N'-dimethylsulfamide
N-(o-carboxybenzoyl)-p-toluenesulfonamide
N-(o-carboxybenzoyl)-benzenesulfonamide
N-(o-carboxybenzoyl)-N',N'-dimethylsulfamide
N-(m-nitrobenzoyl)-p-toluene sulfonamide