U.S. patent number 3,841,872 [Application Number 05/293,698] was granted by the patent office on 1974-10-15 for hydrophilic-colloid silver halide emulsion hardened with a bisvinylsulfonyl compound.
This patent grant is currently assigned to Eastman Kodak Company. Invention is credited to Donald M. Burness, Robert A. Silverman.
United States Patent |
3,841,872 |
Burness , et al. |
October 15, 1974 |
HYDROPHILIC-COLLOID SILVER HALIDE EMULSION HARDENED WITH A
BISVINYLSULFONYL COMPOUND
Abstract
Photographic elements are disclosed containing a hydrophilic
colloid layer hardened with a compound having two vinylsulfonyl
radicals coupled through a divalent hydrocarbon radical chosen from
the group consisting of (1) an aliphatic radical having from 1 to 6
carbon atoms, (2) --X--Y--X-- in which X is an alkylene group
having 1 or 2 carbon atoms and Y is a phenylene group and (3) a
phenyl-substituted methylene group. The compounds may be utilized
generally in hardenable hydrophilic colloid compositions. Except
for those compounds incorporating an alkylene divalent hydrocarbon
radical, the hardeners are new compounds.
Inventors: |
Burness; Donald M. (Rochester,
NY), Silverman; Robert A. (Rochester, NY) |
Assignee: |
Eastman Kodak Company
(Rochester, NY)
|
Family
ID: |
23130172 |
Appl.
No.: |
05/293,698 |
Filed: |
September 29, 1972 |
Current U.S.
Class: |
430/415; 527/201;
568/28; 568/46; 430/451; 530/354; 568/32; 106/154.11 |
Current CPC
Class: |
G03C
1/30 (20130101); C07C 317/10 (20130101) |
Current International
Class: |
C07C
317/10 (20060101); C07C 317/00 (20060101); G03C
1/30 (20060101); G03c 001/30 () |
Field of
Search: |
;96/111,67 ;260/117,67A
;106/125 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Klein; David
Assistant Examiner: Louie, Jr.; Won H.
Attorney, Agent or Firm: Lewis; John T.
Claims
What is claimed is:
1. A photographic element comprising a support and at least one
radiation-sensitive hydrophilic colloid layer containing silver
halide and at least one hydrophilic colloid layer hardened with a
compound having two vinylsulfonyl radicals coupled through a
divalent hydrocarbon radical chosen from the group consisting
of:
a. an unsubstituted alkyl or an unsubstituted alkylene radical
having from 1 to 6 carbon atoms,
b. --X--Y--X-- in which X is an unsubstituted alkylene group having
1 or 2 carbon atoms and Y is an unsubstituted phenylene group,
and
c. phenyl-substituted methylene.
2. A photographic element according to claim 1 in which said layer
contains from 0.5 to 6 percent by weight of said hardener based on
the weight of hardenable colloid present in said layer.
3. A photographic element according to claim 1 in which said layer
contains from 1 to 3 percent by weight of said hardener based on
the weight of hardenable colloid present in said layer.
4. A photographic element according to claim 1 in which said layer
contains gelatin.
5. A photographic element according to claim 1 in which X is an
unsubstituted methylene.
6. A photographic element according to claim 1 in which said
hydrophilic colloid is hardened with
1,3-bis(vinylsulfonyl)propane.
7. A photographic element according to claim 1 in which said
hydrocarbon radical is an unsubstituted alkylene radical.
8. A photographic element comprising a support and at least one
radiation-sensitive silver halide-containing gelatin layer hardened
with a compound having the structural formula:
CH.sub.2 =CHSO.sub.2 --A--SO.sub.2 CH=CH.sub.2
in which A is chosen from the group consisting of
a. an unsubstituted alkyl or an unsubstituted alkylene radical
having from 1 to 6 carbon atoms;
b. --X--Y--X-- in which X is an unsubstituted alkylene group having
1 or 2 carbon atoms and Y is an unsubstituted phenylene group;
and
c. phenyl-substituted methylene.
Description
This invention relates to hydrophilic colloid compositions and to
photographic elements containing at least one hydrophilic colloid
layer hardened with a compound having two vinylsulfonyl radicals
linked by a divalent hydrocarbon radical containing an aliphatic
linking moiety. Additionally, this invention relates to novel
compounds of this type useful as hardeners.
In the photographic arts, hydrophilic colloids--typically refined
gelatins--have been used to suspend silver halide grains and
thereby to form radiation-sensitive compositions which when coated
onto suitable supports are capable of forming photographic
elements. Typically, a variety of addenda is employed to alter the
properties of both the gelatin and the silver halide grains. It has
been recognized previously in the art that, without special
modifiers, hydrophilic colloids such as gelatins ingest large
quantities of water when brought into contact with aqueous
solutions, causing appreciable swelling, and are easily abraded.
Also, unmodified gelatin coatings tend to melt at relatively low
temperatures, thereby limiting their temperature range of utility.
To alter these deficiencies of unmodified photographic gelatins, it
has heretofore been recognized that certain addenda generically
designated as "hardener addenda" or simply "hardeners" may be
incorporated into radiation-sensitive compositions and coatings to
obviate at least one of the above undesirable gelatin
characteristics.
In order to serve the needs of the photographic arts, it is
desirable not only that a hardener ameliorate the deficiencies of
gelatins as noted above, but that the hardener meet certain
additional practical criteria. For example, the hardener should
cause hardening or setting of the emulsion sufficiently slowly to
permit coating of the photographic emulsion onto a support, but it
should not set up so slowly that after-hardening takes place; i.e.,
the emulsion continues to harden undesirably during storage of a
fabricated photographic element. Also, the hardener should possess
sufficiently low levels of toxicity so as not to pose a significant
hazard to manufacturing personnel. Further, the hardener should not
undesirably reduce nor interfere with the desired photographic
properties of the element into which it is incorporated. For
example, the hardener should not contribute to the reduction of
silver halide to produce fogging of a photographic emulsion or
coating. These criteria for hardeners are all the more challenging
when it is borne in mind that the compositions of photographic
gelatins are themselves not fully understood and that the
mechanisms are not entirely appreciated.
In addition to the above considerations, it must be recognized that
the hardener is only a part of what typically is a comparatively
complex photographic system. For example, in addition to the
radiation-sensitive silver halide and the gelatin to be hardened,
photographic emulsions typically contain numerous additional
addenda. With so many criteria being applied to hardeners and in
view of the complexity of photographic emulsions, it is not then
surprising that there is presently no known way of predicting the
suitability of significantly differing types of compounds as
hardeners in photographic emulsions, and the art has relied upon
empirical methods to discover new types of hardeners.
Divinylsulfone has been heretofore recognized as an effective
gelatin hardener, but its use has been curtailed by its undesirable
toxicity. Heyna, in U.S. Pat. No. 2,994,611 issued Aug. 1, 1961,
discloses the use of bis(vinylsulfonyl)aryl and
bis(vinylsulfonylanilide)aryl hardeners with proteins. Ryan, in
U.S. Pat. No. 3,132,945 issued May 14, 1964, teaches the use of
monovinylsulfonyll acyclic aliphatic gelatin ballasts to facilitate
silver halide dispersion. Feldman, in U.S. Pat. No. 3,068,123
issued Dec. 11, 1962, teaches the reaction of
bis(vinylsulfonyl)alkylene compounds with glycols to produce agents
capable of imparting crease resistance to textiles. Welch, in U.S.
Pat. No. 3,202,474 issued Aug. 24, 1965, teaches the reaction of
divinylsulfone with formaldehyde in controlled proportions to
produce novel crosslinked and partially esterified cellulose
textiles of improved resistance to stretching and shrinking. Other
compounds having bis(vinylsulfonyl) moieties joined through a
divalent radical having one or more hetero atoms such as oxygen or
nitrogen have been used as hardeners in photographic applications
as illustrated by Burness in U.S. Pat. No. 3,539,644 issued Nov.
10, 1970.
In one aspect, the present invention is directed to a composition
comprised of a hardenable hydrophilic colloid and an amount
sufficient to produce hardening of a compound having two
vinylsulfonyl radicals coupled through a divalent hydrocarbon
radical chosen from the group consisting of (1) an aliphatic
radical having from 1 to 6 carbon atoms, (2) --X--Y--X-- in which X
is an alkylene group having 1 or 2 carbon atoms and Y is a
phenylene group, and (3) a phenyl-substituted methylene group.
In another aspect, the present invention is directed to a
photographic element containing a radiation-sensitive layer of a
hardenable hydrophilic colloid as set forth above.
In still another aspect, the present invention is directed to
compounds having the structural formula:
CH.sub.2 =CHSO.sub.2 --A--SO.sub.2 CH=CH.sub.2
in which A is chosen from the class consisting of (1) alkenylene in
which the alkenylene group has from 2 to 6 carbon atoms; (2)
--X--Y--X-- in which X is an alkylene group having 1 or 2 carbon
atoms and Y is a phenylene group; and (3) a phenyl-substituted
methylene group.
It has been discovered quite unexpectedly that bis(vinylsulfonyl)
compounds having a divalent hydrocarbon linking radical containing
an aliphatic moiety, as hereinafter more specifically defined, are
capable of being utilized as hardeners for hydrophilic colloids
and, specifically, are useful as hardeners for radiation-sensitive
hydrophilic colloid layers, such as radiation-sensitive silver
halide-containing gelatin layers, utilized in photographic
elements. The bis(vinylsulfonyl) compounds of this invention harden
hydrophilic colloids to reduce swelling and abrasion thereof. The
hardeners of the present invention are particularly useful, since
they do not harden hydrophilic colloids so rapidly as to interfere
with their being coated onto a support, yet they are free from
undesirable afterhardening characteristics. At the same time,
colloids hardened with the bis(vinylsulfonyl) compounds utilized in
the practice of this invention do not pose a hazard to
manufacturing personnel as compared with divinylsulfone hardener,
for example. It is a particularly useful discovery that the
bis(vinylsulfonyl) compounds of this invention are compatible with
radiation-sensitive hardenable colloids, such as photographic
emulsions.
One class of hardeners having divalent hydrocarbon linking radicals
joining two vinylsulfonyl groups and containing an aliphatic
linking moiety according to this invention is
bis(vinylsulfonyl)alkylene hardeners.
Exemplary preferred hardeners of this class are
1,1-bis(vinylsulfonyl)methane, 1,2-bis(vinylsulfonyl)ethane,
1,1-bis(vinylsulfonyl)ethane, 2,2-bis(vinylsulfonyl)propane,
1,1-bis(vinylsulfonyl)propane, 1,3-bis(vinylsulfonyl)propane,
1,4-bis(vinylsulfonyl)butane, 1,5-bis(vinylsulfonyl)pentane, and
1,6-bis(vinylsulfonyl)hexane. It is recognized that compounds of
this general class have been heretofore known to the art, as taught
by Feldman, for example. However, this class of compounds has never
previously been recognized to possess useful hardening
properties.
In addition to the above compounds useful as hardeners according to
this invention, certain novel compounds have been discovered which
have useful hardening properties. One such class of novel compounds
is that containing two vinylsulfonyl radicals joined by a divalent
hydrocarbon linking radical which is an alkenylene having from 2 to
6 carbon atoms. Exemplary of suitable bis(vinylsulfonyl)alkenes are
1,4-bis(vinylsulfonyl)-2-butene, 1,5-bis(vinylsulfonyl)-2-pentene,
1,6-bis(vinylsulfonyl)-2-hexene and
1,6-bis(vinylsulfonyl)-3-hexene. An additional class of novel
hardening compounds is that in which the two vinylsulfonyl groups
are linked by a divalent hydrocarbon radical identified by the
formula --X--Y--X-- in which X is in each occurrence an alkylene
radical having 1 or 2 carbon atoms and Y is a phenylene group.
Exemplary of this class of compounds are
.alpha.,.alpha.'-bis(vinylsulfonyl)xylene and
bis(2-vinylsulfonylethyl)-benzene. Still another useful hardener
within the contemplation of this invention is
.alpha.,.alpha.-bis(vinylsulfonyl)toluene.
The compounds useful in the practice of this invention may be
prepared by procedures generally known to the art, such as, for
example, by the oxidation of the corresponding sulfides to sulfones
as described by Schultz et al, in J. Org. Chem., 28, 1140 (1963),
and by other methods generally known to the art, such as those
described more fully in U.S. Pat. Nos. 3,005,852 issued Oct. 24,
1961, and 3,006,962 and 3,006,963 issued Oct. 31, 1961. The
compounds are preferably prepared according to the procedures set
forth in the examples.
The hydrophilic colloids which are hardenable by the above
bis(vinylsulfonyl) compounds can be formed from one or more
hydrophilic, water-permeable, colloid-forming, natural or synthetic
polymers. Specific polymers which can be hardened according to the
practice of this invention include hardenable polymers such as
gelatin, colloidal albumin, acid- or water-soluble vinyl polymers,
cellulose derivatives, proteins, various polyacrylamides, dispersed
polymerized vinyl compounds, particularly those which increase the
dimensional stability of photographic materials as exemplified by
amine-containing polymers of alkyl acrylates, methacrylates,
acrylic acid, sulfoalkyl acrylates and methacrylates, acrylic
acid-acrylate copolymers, and the like. Suitable synthetic polymers
include those described, for example, in U.S. Pat. Nos. 3,142,568
by Nottorf issued July 28, 1964, 3,193,386 by White issued July 6,
1965, 3,062,674 by Houck et al., issued Nov. 6, 1962, 3,220,844 by
Houck et al., issued Nov. 30, 1965, 3,287,289 by Ream et al.,
issued Nov. 22, 1966, 3,411,911 by Dykstra issued Nov. 19, 1968,
and 3,488,708 by Smith issued Jan. 6, 1970, and Canadian Pat. No.
774,054 by Dykstra. The use of hardeners of this invention with
polymers having active ketomethylene groups, as described in Smith,
U.S. Pat. No. 3,488,708, cited above, is the separate invention of
Osterhoudt and Smith disclosed in concurrently filed patent
application U.S. Ser. No. 293,695, titled "Photographic Element
Comprising a Vinylsulfonyl Crosslinked Polymer Having Active
Ketomethylene Groups."
The hydrophilic colloid to be hardened is typically utilized as a
layer or coating on a support. A wide variety of supports, such as
polymeric film, wood, metal, glass and the like, may be utilized to
form hydrophilic colloid-coated elements according to this
invention. Where a photographic element is contemplated, the
support can take such forms as those set forth in paragraph X of
Product Licensing Index, Vol. 92, December, 1971, publication
9,232, page 108.
Where the hydrophilic colloid is to be utilized in combination with
a support to form a photographic element, it will contain in or on
it a radiation-sensitive material. This material can be
panchromatic or orthochromatic material, sensitive only to X-rays
or sensitive to selected portions of the electromagnetic spectrum.
In one form of the invention, the radiation-sensitive portion of
the photographic element can contain a single, unitary hydrophilic
colloid layer having dispersed therein the radiation-sensitive
material, together with photographic addenda to form a photographic
emulsion layer or coating. In alternative forms, the
radiation-sensitive portion of the photographic element can
comprise a plurality of layers with the radiation-sensitive
material or materials being contained in some or all of the layers.
For example, as is characteristic of color photography, a plurality
of layers can be present, sensitized within separate segments of
the visible spectrum.
Suitable radiation-sensitive colloid compositions which can be
employed in practicing this invention are sensitive to
electromagnetic radiation and include such diverse materials as
silver salt, zinc oxide, photosensitive polycarbonate resins and
the like. Silver halides are preferred radiation-sensitive
materials and are preferably associated with a colloid dispersion
vehicle to form an emulsion coating or layer. Specific preferred
silver halide-containing photographic emulsions and processes for
their preparation and use are disclosed in paragraph I of Product
Licensing Index, Vol. 92, December, 1971, publication 9,232, page
107. The radiation-sensitive colloids can additionally include a
variety of conventional photographic addenda, such as development
modifiers, antifoggants, plasticizers and lubricants, brighteners,
spectral-sensitization agents and color-forming materials, as set
forth in paragraphs IV, V, XI, XIV, XV and XXII, respectively of
Product Licensing Index, Vol. 92, December, 1971, publication
9,232, pages 107-110. While it is contemplated that the compounds
utilized in the practice of this invention may serve as the sole
hardener present, it is appreciated that other conventional
hardeners may also be incorporated into the hydrophilic colloid,
such as those set forth, for example, in paragraph VII of Product
Licensing Index, Vol. 92, December, 1971, publication 9,232, pages
107-108.
While a wide range of concentrations of the bis(vinylsulfonyl)
compounds described herein is effective to harden, a particularly
effective concentration is from about 0.5 to about 6 percent by
weight, based on the weight of the hardenable material present.
This does not include the weight of water present in the colloid.
In a preferred range, it has been found that about 1 percent to
about 3 percent by weight, based on the weight of hardenable
material, is particularly effective in achieving superior
hardening.
In order to achieve uniform hardening activity, it is preferred to
disperse uniformly the bis(vinylsulfonyl) compounds in the
hydrophilic colloid to be modified. According to one technique,
referred to as forehardening, the hardener compound is dissolved in
a volatile solvent, such as a lower alkyl alcohol, acetone, etc.,
and the solution is uniformly blended with the hydrophilic colloid
to be modified. Typically, the hydrophilic colloid has at this
stage an amount of water associated therewith which is in excess of
that ultimately desired. Immediately after blending, the colloid is
deposited on a suitable support to form a layer or coating. The
colloid is then hardened on the support and such volatile solvent
and/or dispersants as are associated with the colloid and
2-haloethylsulfonyl compound solution are removed by evaporation
either at ambient or elevated temperatures, typically below about
100.degree. C.
It is also contemplated that the hardener compounds of this
invention may be associated with hydrophilic colloids after they
have been positioned on supports as coatings or layers. The support
bearing a hydrophilic colloid coating to be hardened may be
immersed in a solution containing the 2-haloethylsulfonyl compound
therein so that the solution either surface-hardens the colloid
layer or permeates and uniformly hardens the colloid layer. This
hardening technique, referred to as prehardening, finds particular
utility in hardening certain photographic elements after exposure
but before processing to form the photographic image. In this way,
a level of hardening can be imparted to the photographic element
that might be objectionable in storage and use prior to exposure,
but which is quite advantageous in preventing damage to the colloid
layer of the photographic element during processing.
The following examples are included for a further understanding of
the invention.
EXAMPLE 1
Bis(vinylsulfonyl)methane
a. Bis(2-hydroxyethylsulfonyl)methane
Bis(2-hydroxyethylthio)methane prepared from the well-known
acid-catalyzed reaction of formaldehyde and 2-mercaptoethanol
produced a colorless solid of m.p. 71.5.degree.-77.degree. C.
b. Bis(2-chloroethylsulfonyl)methane
A solution of 22 g. of diol and 0.6 g. of N,N-dimethylformamide in
240 ml. of acetonitrile was heated to reflux and 22.9 g. of thionyl
chloride were added slowly during 40 minutes. After a 3-hour reflux
period, the solution was treated with charcoal and filtered, and
the solvent was evaporated at 40.degree. C. to yield a semisolid.
Recrystallization from n-propanol and then 3:1 toluene-ligroine
produced 7.5 g. of colorless solid; m.p. 108.degree.-109.5.degree.
C.
c. Bis(vinylsulfonyl)methane
To a solution of 24.2 g. of the dichloride in 200 ml. of dry ethyl
acetate containing 0.2 g. of hydroquinone was added at
0.degree.-5.degree. C. a solution of 18.2 g. of triethylamine in 30
ml. of ethyl acetate. After several hours the mixture was filtered
and the filtrate concentrated at 25.degree. C. to give 67 g. of a
nearly colorless 25 percent solution of
bis(vinylsulfonyl)methane.
EXAMPLE 2
1,3-bis(vinylsulfonyl)propane
a. 1,3-Bis(2-hydroxyethylthio)propane
The sodium mercaptide of 2-mercaptoethanol was made by reacting 1
mole each of sodium methoxide and 2-mercaptoethanol in dry methanol
under a nitrogen atmosphere. To this solution, 0.5 mole of
1,3-dichloropropane was added and the mixture was refluxed for 1
hour and filtered. The methanol filtrate was evaporated on a flash
evaporator and traces of 2-mercaptoethanol were distilled off at
high vacuum at room temperature. The yellow, oily residue was
extracted with acetone, the solution filtered, and the acetone
evaporated to give a 95 percent yield of the crude product.
b. 1,3-Bis(2-hydroxyethylsulfonyl)propane
Schultz, Freyermuth and Buc's method as described in J. Org. Chem.,
28, 1140 (1963), for the oxidation of sulfides to sulfones was
used. A mixture of 0.56 mole of 1,3-bis(2-hydroxyethylthio)propane
and tungstic acid (0.6 g.) catalyst solution was warmed to
63.degree. C. and 2.04 moles of 30 percent hydrogen peroxide were
added dropwise, keeping the temperature at 63.degree.-70.degree. C.
After addition was completed, the solution was cooled to room
temperature. The white solid formed was collected and
recrystallized from hot water; yield 71.4 g. (49 percent); m.p.
158.degree.-161.degree. C.
c. 1,3-Bis(2-chloroethylsulfonyl)propane
1,3-Bis(2-hydroxyethylsulfonyl)propane (71.4 g., 0.274 mole) was
suspended in 900 ml. of dry ethyl acetate and 2 ml. of
N,N-dimethylformamide. The mixture was heated to reflux and 71.8 g.
(0.603 mole) of thionyl chloride were dropped in within 1.5 hours
and the mixture was refluxed for another 4.5 hours. The cooled
reaction mixture was filtered and the resulting solid was washed
successively with ethyl acetate and ethanol and then digested in
hot alcohol for 1 hour. There were obtained 74.5 g. (90.2 percent)
of 1,3-bis(2-chloroethylsulfonyl)propane; m.p.
142.degree.-146.degree. C.
d. 1,3-Bis(vinylsulfonyl)propane
1,3-Bis(2chloroethylsulfonyl)propane (74.5 g., 0.249 mole) was
suspended in 2,300 ml. of ethyl acetate containing 0.12 g.
hydroquinone. Triethylamine (50.7 g., 0.50 mole) was dropped in
with stirring, within 10 minutes at 25.degree. C. The resulting
mixture was stirred at 25.degree. C. for 20 hours. The amine salt
was filtered off and the ethyl acetate solution evaporated at
30.degree. C. The tan-colored solid was washed with water, then
recrystallized from ethanol; yield 32.8 g. (59 percent); m.p.
60.degree.-63.degree. C.
Anal. Calc'd. for C.sub.7 H.sub.12 O.sub.4 S.sub.2 : C, 37.5; H,
5.4; S, 28.5 Found: C, 37.6; H, 5.0; S, 28.5
EXAMPLE 3
1,2-bis(vinylsulfonyl)ethane
A method similar to that of Example 2 was utilized except that
1,2dichloroethane was substituted for 1,3-dichloropropane. The
yield was 76 percent upon recrystallization from ethanol. The
melting point of the product was 122.degree.-5.degree. C.
Anal. Calc'd. for C.sub.6 H.sub.10 O.sub.4 S.sub.2 : C, 34.3; H,
4.8; S, 30.5 Found: C, 34.7; H, 4.9; S, 30.9
EXAMPLE 4
1,4-bis(vinylsulfonyl)butane
A method similar to that of Example 2 was utilized except that
1,4-dichlorobutane was substituted for 1,3-dichloropropane. The
yield was 87.2 percent upon recrystallization from ethanol. The
melting point of the product is 96.degree.-102.degree. C.
Anal. Calc'd. for C.sub.8 H.sub.14 O.sub.4 S.sub.2 : C, 40.3; H,
5.9; S, 26.9 Found: C, 40.2; H, 5.8; S, 26.9
EXAMPLE 5
1,5-bis(vinylsulfonyl)pentane
A method similar to that of Example 2 was utilized except that
1,5-dichloropentane was substituted for 1,3-dichloropropane. The
yield was 27.4 percent upon recrystallization from ethanol. The
melting point of the product was 49.degree.-52.degree. C. The nmr
spectrum confirmed the structure.
EXAMPLE 6
2,2-bis(vinylsulfonyl)propane
This compound was prepared from
2,2-bis(2-chloroethylsulfonyl)propane as described by J. Buchi et
al, in Helv. Chim. Acta, 42, 1368 (1959), by the procedure of
Example V(c). Removal of the solvent and recrystallization from
ether-ethanol produced pure, colorless needles; m.p.
121.degree.-122.5.degree. C. (Buchi et al., report m.p. 123.degree.
C.)
EXAMPLE 7
1,1-bis(vinylsulfonyl)ethane
This hardening compound was prepared from
1,1-bis(2-chloroethylsulfonyl)ethane as in Example 2 but with a
reaction time of 3.5 hours. The product, after evaporation of the
solvent, was noncrystalline. The infrared and nmr spectra were
compatible with the expected compound.
EXAMPLE 8
trans-1,4-Bis(vinylsulfonyl)butene
This compound was prepared from
1,4-bis(2-chloroethylsulfonyl)-2-butene by the method of Example
2-d. It consisted of needlelike crystals having a m.p.
120.degree.-125.degree. C.
Anal. Calc'd. for C.sub.8 H.sub.12 O.sub.4 S.sub.2 : C, 40.6; H,
5.1; S, 27.1 Found: C, 40.9; H, 5.3; S, 27.5
EXAMPLE 9
.alpha.,.alpha.'-bis(vinylsulfonyl)-p-xylene
A suspension consisting of 21.2 g. of
.alpha.,.alpha.'-bis(2-chloroethylsulfonyl)-p-xylene (prepared from
p-xylylene dichloride as in Example 1), 25 ml. of triethylamine,
0.05 g. of hydroquinone and 400 ml. of ethyl
acetate-N,N-dimethylformamide (1:1 v./v.) were stirred at
25.degree. C. for 20 hours and filtered. The filtrate was
evaporated to 150 ml. volume, poured into water and the white solid
isolated and recrystallized from methanol and ethyl acetate; m.p.
207.degree.-212.degree. C.
Anal. Calc'd. for C.sub.12 H.sub.14 O.sub.4 S.sub.2 : C, 50.3; H,
4.9 Found: C, 50.6; H, 5.1
EXAMPLE 10
.alpha.,.alpha.-bis(vinylsulfonyl)toluene
This compound was prepared from
.alpha.,.alpha.-bis(2-chloroethylsulfonyl)toluene which is prepared
as follows:
.alpha.,.alpha.-Bis(2-chloroethylthio)toluene was first obtained
from a solution of 10.5 g. of benzaldehyde and 19.2 g. of
2-chloroethanethiol in ether which was saturated with hydrogen
chloride at a reaction temperature of -10.degree. to -15.degree. C.
After 18 hours at 6.degree. C., the ether was evaporated and
replaced with benzene. The solution was cooled, filtered,
neutralized with aqueous sodium bicarbonate and evaporated to give
a colorless intermediate product. The nmr spectrum conformed to the
expected structure.
.alpha.,.alpha.-Bis(vinylsulfonyl)toluene was next obtained when
oxidation of the first-formed product was effected with
m-chloroperbenzoic acid. The reaction temperature was held at
25.degree.-30.degree. C. for 4.5 hours after the addition. After
filtration of the cold (-5.degree. C.) reaction mixture, the
chloroform solution was evaporated at 40.degree. C. to dryness.
After recrystallization from benzene and then methanol, a colorless
solid was obtained having a melting point of from
97.degree.-99.degree. C.
Anal. Calc'd. for C.sub.11 H.sub.12 O.sub.4 S.sub.2 : C, 48.5; H,
4.4; S, 23.5 Found: C, 48.8; H, 4.6; S, 23.4
EXAMPLE 11
Portions of the compounds prepared in the preceding examples were
added to separate portions of high-speed silver bromoiodide
emulsion which was panchromatically sensitized with a cyanine dye.
These portions are set forth as percent-by-weight based on the
weight of dry gelatin (i.e., without including water in the
weight). Each emulsion sample was coated on a cellulose acetate
film support at a coverage of 459 mg. of silver and 1,040 mg. of
gelatin/ft..sup.2 and dried.
A sample of each film coating was tested for hardness, after a
3-day incubation at 28.degree. C. and 50 percent relative humidity,
by immersing in water at 25.degree. C. for 3 minutes and then
calculating the percentage of swell of the emulsion after measuring
the thickness of the swollen samples.
The results of these hardness tests are presented in Table 1. It
can be seen that in each instance the hardener significantly
reduced the amount of swelling of the gelatin. With only 1 percent
hardener present, the swell was in all cases reduced to less than
60 percent of its original value. With 3 percent hardener the swell
was in all cases less than 40 percent, and with 6 percent hardener
the swell was 35 percent or less.
Table 1
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Sample Swell Percentage Swell Example Control Swell 1%* 3%* 6%* 1%*
3%* 6%*
__________________________________________________________________________
1 750 360 250 210 48 33 28 2 710 400 200 210 57 28 30 3 700 330 210
190 47 30 27 4 720 350 270 230 49 37 32 5 720 410 280 250 57 39 35
6 810 370 260 240 46 32 30 7 830 400 290 230 48 35 28 8 800 320 230
210 40 29 26 9 890 390 ** ** 44 ** ** 10 810 440 280 280 54 35 35
12 690 340 250 210 49 36 30 13 690 360 260 200 52 38 29 14 660 530
410 340 80 62 51.5 15 680 440 ** 310 65 ** 46 16 750 450 350 ** 60
47 **
__________________________________________________________________________
*percentage of hardener based on weight percentage of dry gelatin
(excluding water) **not run
EXAMPLES 12-16
Comparative Testing
For purposes of comparison, five hardeners heretofore known to the
art were tested directly against the hardeners useful in the
practice of this invention, using the hardening testing procedures
of Example 11. The five hardeners are as follows:
Example Prior-Art Hardener ______________________________________
12 bis(2-vinylsulfonylethyl)ether 13
bis(2-vinylsulfonylmethyl)ether 14
N,N'-bis(2-vinylsulfonylethyl)piperazine-bis(methoperchlorate) 15
divinylsulfone 16 4,6-dimethyl-1,3-divinylsulfonyl benzene
______________________________________
The results of testing the conventional hardeners are set forth in
Table 1 also. Whereas hardeners according to this invention are in
all instances capable of reducing swelling to less than 60 percent
of that of the unhardened gelatin when present in concentrations of
only 1 percent, it can be seen that, except for the conventional
bis(vinylsulfonylalkyl)ether hardeners, none of the conventional
hardeners was capable of reducing swell to below 60 percent at
concentrations of 1 percent. Similar comparative hardening
characteristics were noted at higher concentrations. It is
particularly to be noted that the bis(vinylsulfonyl)alkene hardener
of Example 8 was more effective as a hardener than any of the
conventional hardeners in comparable concentration ranges. It is
also to be noted that the bis(vinylsulfonyl)alkylbenzene hardener
of Example 9 and the .alpha.,.alpha.-bis(vinylsulfonyl)toluene
hardener of Example 10 were significantly more effective than the
bis(vinylsulfonyl)benzene hardener of Example 16.
Example 17
A comparison of the hardening efficiency of one of the
representative hardeners of this invention,
1,3-bis(vinylsulfonyl)propane (Example 2), with that of two of the
most active compounds of the prior art, divinylsulfone (Example 15)
and bis(vinylsulfonylmethyl)ether (Example 13). Gelatin coatings
were prepared, each containing one of the noted hardeners,
sol-dried, and aged 1 day under ambient conditions. After 24 hours
at 50 percent R.H., the samples were sealed in bags and incubated
at 49.degree. C. for 72 hours. The films were then immersed in a
40.degree. C. water bath and allowed to swell. An Instron Tensile
Tester was used to measure the tensile strength of the films.
Utilizing the theory of rubber-like elasticity and the tensile
strength, it was possible to calculate the number of cross-links
per gram of dry gelatin. The maximum number of cross-links that
could be present was calculated knowing the concentration of
hardener added to the film and determining the reaction sites
within the gelatin utilizing a Beckman Amino Acid Analyzer. The
results obtained are set forth below in Table 2.
Table 2 ______________________________________ Compound by Hardener
Concentration Crosslinking Example No. (based on weight of dry
Efficiency gelatin) ______________________________________ 2 3.74%
99% 15 3.88% 38% 13 3.75% 68%
______________________________________
EXAMPLE 18
The hydrolytic stability of the crosslinks formed with
1,3-bis(vinylsulfonyl)propane (Example 2) was compared with that of
other hardeners, e.g., dialdehydes and bisaziridines. Samples of
both sol-dried and gel-dried films were examined over the range of
10.degree.-90.degree. C. in an Instron Tensile Tester, as noted in
the preceding example. Results showed that the crosslinks formed
with the compound of Example 2 were the most stable and the films
had a higher tensile strength than those containing other
hardeners.
The invention has been described in detail with particular
reference to preferred embodiments thereof, but it will be
understood that variation and modifications can be effected within
the spirit and scope of the invention.
* * * * *