Note: Descriptions are shown in the official language in which they were submitted.
10471~Z;~
According to the present invention there is provided
a method of producing a hardened gelatin layer which com-
prises treating an aqueous gelatin solution with an aqueous
solution of a compound of the formula
(I) j _ ~ Z
where X is a halogen atom, Y is a hydrogen or a halogen atom,
Z is an anion and R is an alkyl, aralkyl, or aroylalkyl group,
or a group of the formula
X
(II) z ~ ~ (C~2)n
where X, Y and Z have the meanings assigned to them above
and n is an integer of 2 to 12.
When the compound of use in the present invention is a
mono(2-halopyridinium) salt, Y is preferably a halogen atom
in the 2 or 4 positions.
; 1-5 Further in regard to the mono(2-halopyridinium) salt
particularly useful compounds are those wherein R is methyl,
phenylethyl and benzoylmethyl.
- 2 -
10478Z2
Particularly preferred compounds are those wherein
X is c'nlorine or bromine.
When the compound Or use in the present invention is a
bis(2-halopyridinium) salt preferred compounds have the
S for~ula
(III) ~ ~ -(C~2)n N ~ l 2 Z
where X and n have the meanings assigned to them above.
In compounds of the above formula (III) it is preferred
that n is 3-8.
Particularly preferred compounds are compounds of ~~
the above formula (III) wherein X is a chlorine atom.
Examples of anions are chloride, perchlorate and fluoro-
borate. The preferred anions since they render the compounds
more stable are perchlorate and fluoroborate.
The method of the present invention finds particular
use as a step in the preparation of photographic
silver halide materials and according to a preferred
embodi~ent of the present invention in a process for
the production of a gelatino silver halide photographic
material there is provided the steps of treating an
aaueous ~elatino silver halide emulsion with an aqueous
solution of a co~pound of fo~nula I or III and then
coating the aqueous emulsion as a layer on a photobase.
104782Z
Prele-~6bly rom 0.1 g -to 50 g o~ th~ com~ound of
formuia I per 100 g of gelatin in tlle solution are used
in the method of the present inventlon,
The compowlds of formula(I)may be prcpared by
quaternizing a halopyridine with the appropriate alkylating
agent,
Compounds of for~ula(III)may be prepared by
quaternizing pyridine wi'ch an a ,~ dihaloallsane, oxidising
with alkaline potassium ferricyanide and then treating
the bis-pyridone so formed with phosphoryl chloride,
~ .
2-Chloropyridine 6~ and 6,5 g dimethyl sulphate were
mixed and warmed on a ~Jater bath until a vigorous reaction
began, When the initial reaction 'nad subsided, the
mlxture was heated on a 3team bath for 1 hour gi~ing a
yellow viscous product. Any excess dimethyl ~ulphate was
removed by washing with ether then the residue was dissolved
in a minimum of cold waterD A solution of 10 g sodium
perchlorate in 10 ml water was added slowiy with stirring
and the white precipitate which formed was filtered, The
product was suspended in 50 ml cold water, filtered
and then dried over P205, ~,p, 199 - 202, Yields 4,2g,
... ..
~ Preparation of 1,l'trimethylene-bis-(2-chloropyridinium
; perchlorate).
1,3 Di-bromopropane 20,2 g and 17 g pyrldine were
warmed carefully on a water-bath, (A cold-water bath
was needed to control the reaction once it had begun).
After the reaction had subsided the mixture was heated
-- 4 --
1047~Z
for 15 mins, orl a steam-bath then cooled, dry ether added
and the solid filteredO The product was recrystallised
from eth-Inol to give 24,~ g l,l'-trimethylene bis-pyridinium
chloride m.p, 241-3,
18 g of the sa]t was dissolved in a srnall quantity of
water and mi~ed with a saturated solution of 66 g K3 Fe(CN)6
in water. The solution was cooled in ice-water and 60 ml
of 40% NaOH added dropwise keeping temperature at
about 10C. The mixture was left overnight at room
10 - temperature then neutralised ~Jith acetic acid and extracted
with chlorofor~, The dried chloroform solution ~as
evaporated and -the residue recrystallised from benzene to
give 4~8 g l,l'trimethylene bis(2-pyridone), m.p. 132,
4,6 g of the bis-pyridone and 30 g phosphoryl chloride
was refluxed for 2 hours, then the excess POCl3 removed
under vaccum, The solid was dissolved in 50 ml cold water
and a solution of lO g NaC104 in lO ml water added with
stirringO The solid ~las filtered, washed wi-th water and
recrystallised from acetone/water, adding a little ether
to induce crystallisation,
Yield of l,l'trlmethylene bis(2-chloropyridinium~
perchlorate 4,9 g m.p, 282~3,
The following compounds of formula I were prepared
in a mar.rer similar to that used to prepare 2-chloro-1-
methyl-pyridinium perchlorate which ~s hereir~after
referred to as co~pound l,
, , . . . ., . , . .. , .. , .. . . . . . . ... . .. . . . . , ., ~ ...
- , ~ .
,
78ZZ
- -- Conpouncl 2 2-bror~o-1-me-thyl pyridinium perchlorate
3 2-icdo-1-methyl uyridinium iodide
" 4 2,6~dlchloro-1-methyl pyridinium
perchlorate
2,6-clibromo-1 methyl pyridinium
perchlorate
" 6 2,4-dichioro-1-met~yl pyridinium
perchlorate
" 7 2-chloro-1-(2 phenylethyl) p~Jridinium
bromide
" 8 2-bromo-I-benzoylmethyl pyridinium bromide
9 1,1'-trimethylene-bis-(2-chloropyridinium
perchlorate)
" 10 1,1'-octamethylene-b.is-(2-chloropyridinium
perchlorate), prepared in a manner similar
to that used to prepare compound 9.
`
10 EX~MPLE
The compounds were tested by the scratch resistance
method This involves drawing a loaded stylus across a
swollen gelatin layer, and determining the minimum weight
required to scratch the surface.
~5 The aqueous~gelatin coating solutions were made up
. .
as follows:-
Gelatin 17.5 g in water 150 ml soaked for 20minutes and melted out at 60 for 10 minutes. The pH
of this gelatin solution was ad~usted to 6.5. Each test
compound, 0~00125 moles, was dissolved in ethanol 25 ml~
water 35 ml, and added to separate portions of the
.
- ' - .. .. ... ,. . , , , , , . ...
'',
1~47822
gelatin solution, The p~l of the gelatin solu-tions was
readJusted to 6.5 and made up -to 250 mls wi-th water, 200
thick coa-tings were made with a doctor bar on film base
and dried in a fan assisted drying cabinet withou-t heat,
The coatings ~ere kep-t at 22C, 50% ~I and 43C~
6~o RH~ Scratch measurements were r.~ade after ~O minu-tes
soaXing in water a-t 20C,
The results obtained are sho~m ln the acoomp~nying
Table,
--
~047822
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