Note: Descriptions are shown in the official language in which they were submitted.
I
FIELD OF INVENTION
The present invention relates to disinfectant
compositions that are compatible with polyvinyl-
chloride, to a polyvinyl chloride article for dopiness-
in said compositions, and to a method of disinfecting
with said compositions. More specifically, the pro-
sent invention concerns a disinfectant composition
that is a mixture of trichloroi60cyanuric acid and
cyan uric acid, which composition is the less prone to
attack containers fabricated from rigid polyvinyl-
chloride. Most specifically, the compositions herein
disclosed comprise from about 50 parts trichloroiso-
cyan uric acid to about 90 parts ~richloroisocyanuric
acid and from about 10 parts cyan uric acid to about 50
parts cyan uric acid.
BACKGROUND OF INVENTION
Polyvinyl chloride (PVC) is a resin based on the
vinyl radical (CH2-CH~) or the vinylidene radical
(SCHICK). PVC has applications for piping systems,
which accounts for 40% of the PVC market, as a build-
in construction material, as flooring, and in wall
coverings. Meat wrap enclosures axe prominent in food
packaging, with bottles and blister packs occupying a
prominent place in non-food uses. Cohen, "Polyvinyl
and Vinyl Copolymers", Modern Plastics Encyclopedia,
pages 100-108 ~1981-82) states that PVC's are comma-
gaily inert, water, corrosion, and weather resistant;
have a high strength-to-weight ratio; are tough,
dent-re~istant; are electrical and thermal insulators,
~:33~
and maintain their properties over long periods of
time. As stated in the Cohen article, several types
of PVC exist: homopolymers, which have a chlorine
content of about 56.8% by weight, chlorinated PVC,
which has a chlorine content of about 67% by weight,
and copolymers, particularly vinyl acetate
copolymers. The hither molecular weight homopolymers
have greater strength, chemical and heat resistance,
but are difficult to process, while the lower mole-
cuter weight resins are more easily manufactured but
with some sacrifice in properties. The chlorinated
PVC's have good heat deflection temperature and there-
fore have utility in residential hat water systems.
The copolymers provide easier flow at processing
temperatures, better pigment binding, a broader them-
portray range for vacuum forming, and greater
volubility.
Penn, PVC Technology (Third Edition 1970 ) India
gates at page 6 that pure, unplasticized, PVC it
resistant to most acids and alkalis, although it is
decomposed by concentrated sulfuric, nitric and
chronic acids.
Toe term "rigid PVC" is used interchangeably with
the term "unplasticized PVC" ~UPVC) to described a PVC
resin containing little or no plasticizer, but include
in stabilizer, and in most instances lubricants and
other additives. The major applications for rigid PVC
are pipe and sheet High impact rigid PVC is made by
incorporating a copolymer or by use of a modifier such
as a synthetic rubber or an acrylic in a conventional
polymer.
I
The chemical properties of rigid PVC have been
reported in the Penn reference at pages 380-383. Thus
it is seen that rigid PVC it satisfactory in hype-
shellers acid at temperatures of 20 and 60C.
Compositions containing trichloroisocyanuric acid
and cyan uric acid are known. Thus, U.S. Patent
2,988,471 to Fuchs et at. discloses a disinfectant
composition for use in the treatment of swimming
pools, the composition comprising a disinfectant
material which provides available chlorine, for
example, sodium dichlorocyanurate, dummy hypochlorite
and calcium hypochlorite, and cyan uric acid to reduce
loss of active chlorine in aqueous systems exposed to
sunlight. Consideration of compatibility with polyp
vinyl chloride is not considered in the Fuchs patent.
U.S. Patent 3,278,443 to Bright et at. discloses
bleaching compositions based on chlorinated cyan uric
acid, which compositions contain a stabilizer material
which is an ethylenically unsaturated material of the
general formula R-CH=CH-X where R is selected from the
group consisting of phenol, ethoxyphenyl, ethylene
dioxybenzyl and like moieties, and X is selected from
the group consisting of hydrogen, phenol, ethylene,
methyl, hydroxymethyl and like moieties. Cyan uric
acid is not disclosed in the Bright patent
U.S. Patent 3,413,078 to Lucite et at. discloses
a method of bleaching synthetic fibers wherein a
chlorinating agent consists of at least one N-chloxi-
noted derivative of cyan uric acid in admixture with
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33~
cyan uric acid, or at least one alkali metal hype-
chlorite or alkaline earth metal hypochlorite in
admixture with cyan uric acid. The synthetic fibers
that may be bleached according to the method of the
Lucite patent include polyvinyl chloride fibers.
A bleaching process is described in U.S. Patent
3,586,474 to Kowalski. In that process the generation
of nitrogen trichloride vapor is inhibited by a con-
elusion of from 0.01 to 0.5% by weight of the bleach
bath of a turret of a saturated fatty acid, thereby
preventing corrosion problems and eliminating expel-
soon hazards. Light stabilized chlorine compositions
are disclosed in U.S. Patent 3,253,979 to Rob son. In
the Rob son compositions, which are suitable for treat-
mint of public swimming pools, cyan uric acid is used
as a stabilizer to avoid against loss of available
chlorine due to sunlight. The cyan uric acid reacts
with free available chlorine to form N-chloroiso-
cyan uric acid or its salts, the N-chloroisocyanurates,
which N-chloro compounds do not absorb in the ultra-
violet region of sunlight and thus are not decomposed.
U.S. Patent 3,178,372 to Pomot et at, discloses
stabilized trichlorocyanuric acid compositions, where-
in one mole of tri-alkali metal sonority is incur-
prorated for every two moles of trichlorocyanuric acid.
A packaged dry bleach and disinfectant compost-
lion is disclosed in U.S. Patent 3,061,549 to Dickeys
The bleach incorporated is dichlorocyanuric acid or a
trichlorocyanuric acid, as sources of available
chlorine upon dissolution of acid in water. As
~2~3~
indicated in the '549 patent at column 1, lines 16-22,
the effects of volatile compounds resulting from
partial decomposition of the dichlorocyanuric acid or
trichlorocyanuric acid may be destructive to a great
variety of common packaging material. The dry bleach
materials of the '549 patent are stabilized by mix-
lures of manganese dioxide and cupric oxide (hopcho-
file), activated alumina, activated carbon zealots,
fuller earth, bentoni~e, activated montmorillonite,
silver phosphate, silver nitrate, mercuric nitrate,
alkali metal silicates, alkali metal hydroxides,
carbonates of potassium, rubidium, or sesame, and
alkaline earth oxides. The dry bleach package of
Dickeys comprises a glass or paper board container
having top and bottom closures, and which may be
adapted for opening in any suitable manner or by any
suitable means to dispense the bleach composition.
The stabilizing mixture is provided in a separate
porous fabric bag which is proximate to the container
for the bleach materials, but remains unmixed there-
with. According to Example I, the adsorbent was
contained within a small perforated bag of polyethy-
tone plastic, the edges of which were heat sealed/ and
suspended in the container for the dry bleach.
Stabilized trichlorocyanuric acid compositions
are also disclosed in U.S. Patent 3,108,078 to Nixon,
these compositions containing as the stabilizing agent
an olefin having a double bond containing a tertiary
carbon atom. Examples of the stabilizers of the Nixon
patent are diisobutylene, tetraisobutylene, propylene-
tetramer, and the like. U.S. Patent 4,289,815 to Lee
discloses a sealed pouch for controlled release of
~L23;l~10~
chlorinating agent, including trichlorocyanuric acid
and dichloroisocyanuric, wherein the pouch it polyp
vinyl alcohol in film form, the polyvinyl alcohol
being at least 99% hydrolyzed and having a minimum
degree of swelling in water of about 120~. At column
5, lines 23-28, it is said that the polyvinyl alcohol
pouch may be contained within another moisture carrier
bag made from polyethylene, polystyrene or polyvinyl-
chloride. The compositions contained within the
sealed pouch of the Lee patent are in dry form.
Cyan uric acid is not contained within the pouch of the
Lee patent.
U.S. Patent 4,389,325 to Erg et at, discloses the
use of porous crystalline alumino-silicate to provide
a stabilized chloroisocyanuric composition. Also of
interest is U.S. Patent 4,389,318 to Wojtowicz wherein
stabilization of the trichloroisocyanuric acid is
accomplished by including an alkali metal bicarbonate,
the molar ratio of the alkali metal bicarbonate to the
trichloroisocyanuric acid being from about 3:1 to
about 1:1. The moisture content of the dry compost-
lion it less Han about 0.2% by weight of the mixture.
It has been found that dispensers, especially
toilet cleaner dispenser articles, containing an
aqueous solution of trichloroisocyanuric acid (up to
the volubility limit thereof), which dispensers are
fabricated from rigid polyvinyl chloride, especially
high impact polyvinyl chloride, tend over time to be
discolored and to be deformed. It has alto been found
that such discoloration and deformation is essentially
avoided by inclusion of cyan uric acid.
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SUMMARY OF INVENTION
It it an object of the present invention to
provide a dispenser manufactured of rigid polyvinyl-
chloride, especially high impact polyvinyl chloride,
for dispensing a disinfectant which it a dichloroiso-
cyan uric or trichloroisocyanuric acid.
A primary object of the present invention is to
provide a dispenser fabricated from polyvinyl chloride
containing as the disinfectant material a tablet,
cake, or other solid composition consisting essential-
lye of a disinfectant agent selected from the group
consisting of alkali and alkaline earth metal
dichlorocyanurates and trichloroi60cyanuric acid, and
cyan uric acid, which composition in aqueous solution
forms within the dispenser a concentrated solution of
the disinfectant tablet materials, the polyvinyl-
chloride dispenser resisting discoloration and
deformation in such environment.
These and other objects of the present invention
will be more readily understood upon a reading of the
specif1catlon, a summary of which it provided below.
The dispenser of the present invention comprises
one or more product chambers for containing a
disinfectant tablet in tablet form, said at sinfectant
tablet consisting essentially of 50 to 90~ by weight
of a disinfectant agent selected from the group con-
sitting of alkali metal and alkaline earth metal
dichloroisocyanurates and trichloroisocyanuric acid,
and from about 10 to about 50~ cyan uric acid; liquid
~33~
inlet means disinfectant solution outlet means, which
means may be the same as the liquid inlet means; and
vent means, at least the product chamber of said disk
penner being fabricated from rigid polyvinyl chloride.
The subject invention also concerns a method of
disinfecting a reservoir such as a toilet bowl. The
method comprises in one aspect the steps of forming a
concentrated disinfectant solution within a product
chamber of a rigid polyvinyl chloride dispenser, said
concentrated disinfectant solution consisting Essex-
tidally of the dissociation products of an alkali metal
or earth metal salt of dichlorocyanurate and tracheal-
roisocyanuric acid, and cyan uric acid, the concentration
of said dissociation products therein being up to the
volubility limits thereof, and dispensing said con-
cent rated solution into a toilet bowl, the concentra-
lion of the disinfectant being from about two to about
15 ppm in the bowl water after the flush.
In another embodiment the present invention pro-
vises a reservoir cleaning dispenser for releasing
into the reservoir a disinfectant solution, the dispenser
comprising a polyvinyl chloride disinfectant chamber, means
for concentrated disinfectant solution to exit from
the disinfectant chamber, and a disinfectant composition
in solid form contained within said disinfectant
chamber, the disinfectant composition consisting Essex-
tidally of from about 50 to about 90% trichloroisocyanuric
acid and from about 10 to about 50~ cyan uric acid.
I- 8 -
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I
BRIEF DESCRIPTION OF THE DRAWINGS
,, ,, . _
Figure 1 is a perspective view of a first embody-
mint of the dispenser of the present invention.
Figure 2 is a perspective view of a second embody-
mint of the dispenser of the present invention.
Figure 3 is a cross-sectional side elevation Al
view through lines 3-3 of Figure 2.
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. I. I,
:~33~
Figure 4 it a perspective view of a dual chamber
dispenser for separately dispensing a forfeit cleaning
ablution and a second cleaning solution, which it the
disinfectant 601ution.
DESCRIPTION OF THE PREFERRED EMBODIMENT
he dispenser of the present invention is adapted
for placement within the tank of a flush toilet disk
penner containing within a product chamber a disinfect
lent tablet, cake, or other solid material, which
dispenser, particularly the product chamber, is
fabricated from rigid polyvinyl chloride. The disk
penner is adapted to release a concentrated disinfect
lent solution each the toilet is flushed, the solution
contained within the product chamber being dispensed
by gravity and/or siphonic flow. After a flush, as
the level of the tank water rises, water repenters the
product chamber of the dispenser, thereby reforming
the concentrated solution of disinfectant material.
Initially, of course, the disinfectant material it in
dry form as noted above. However, after flushing
several times, the tablet or other form of the Metro-
at readily forms the concentrated solution of Dyson-
extant material upon refilling of the toilet tank,
i.e., each time the product chamber is refilled.
The dispenser preferably comprises a product
chamber containing said disinfectant material, inlet
means for allowing tank water to enter the product
chamber, discharge means for allowing concentrated
solution to be dispensed from the product chamber in
~L~33~
response to a flush of the toilet, and vent ennui to
permit air and evolving vases from the immersed Dyson-
fectant composition to escape during the filling of
the product chamber with tank water. The inlet mean
and the outlet means may be the same.
Most preferably, the inlet and outlet means are
combined, said combined inlet/di~char~e means being in
the form of a siphon conduit. The siphon conduit pro-
fireball enters the product chamber at a point such
that the product chamber it divided into an upper
portion and a lower portion, solution contained in
said upper portion being dispensed upon the occasion
of a flush, while solution contained in said lower
portion being retained to provide a weak solution of
disinfectant immediately following refilling. The
vent conduit preferably extends from proximate the top
of the upper portion of the product chamber.
Referring to Figure 1, the dispenser 10 of the
present invention comprises a product chamber 11 have
ivy the lower portion 12 for containing a disinfectant
composition herein after described and an upper portion
14, the volume of which it essentially equal to the
volume of solution discharged from the do pouncer a
refill/di~charge pathway 30 which is an inverted
Conduit and a vent 40, which it shown to extend
from the top of the product chamber 11. Preferably,
the dispensing article herein is fabricated by
thermoforming a first thermoplastic resin substrate 22
to provide the product chamber, refill/discharge
pathway, and vent, respectively, filling the product
chamber with the disinfectant composition, and
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kiwi
securing to the back of the substrate 22 a backing
substrate 22'. Other suitable method of fabrication
can be used, for example, injection molding.
Common to the upper and lower portions of the
product chamber 11 is front wall 15, the back wall
which is the backing substrate 22', and side wall 17.
The lower portion 12 of the product chamber 11 further
comprises bottom wall 21, side wall 16, and top wall
segment 18, while the upper portion 14 of the product
chamber 11 further compare en top wall 20 and wide wall
19. The refill/discharge conduit 30 comprises a long
leg 31 and a short leg 32, the legs 31 and 32 being
arcuately joined at their uppermost portions, said
arcuate portion being designated by numeral 29, the
short leg 32 being in fluid communication with the
lower portion 12 of the product chamber 11 at the top
wall segment 18, which wall segment 18 is hereinafter
referred to as the shoulder 18. Preferably, the
uppermost portion 39 of the refillldischarge pathway
30 is at a level that is at or is slightly below that
of the top wall 20 of the upper portion 14 of the
product chamber 11.
Preferably the long leg 31 of the refolds-
charge pathway 30 comprises an end portion 33 having
an orifice 36 proximate the bottom thereof, a middle
portion 34 of larger horizontal cross-sectional area
than said end portion 33, and a top portion 35 of
progressively smaller cross-sectional aria than that
of the middle portion 34. The cross-sectiona]. area of
the short icy 32 is essentially constant through its
height, and is smaller than that of the top portion 35
I
of the long leg 31. The uppermost portion 39, which
is in transition between said top portion 39 of leg 31
and leg 32, has a decreasing cro6s-~ectional area
normal to the flow path of fluid. The product chamber
it vented by mean of conduit 40 extending from the
lap wall 20 of the upper chamber to the periphery of
the elastic substrate 22. Preferably, induce 41 it
provided to advise the consumer of the proper
placement of the dispenser 10 in the toilet tank,
which is above top wall 20 of the product chamber 11.
The disinfectant composition 25 it provided in
the lower portion I of product chamber 11 and may be
in tablet, extradite, pouch, agglomerate, briquette,
or cake farm.
Referring to Figure 2, the dispenser 110 come
proses a product chamber 111 having a lower portion of
112 and an upper portion 114; a refill/discharye
pathway 130, and a vent 140. The lower portion 112
has front wall aye, side walls 116 and await bottom
wall 121, and top wall segment aye. The upper champ
bier 114 has a front wall 115b, side walls 117b and
119, top wall 120, and bottom wall segment 118b. The
back wall which it the planar backing subfitrate 123 it
common to both upper and lower portions ox the product
chamber 111. As shown in Figure 2, the disinfectant
composition is provided in the lower portion 112 of
product chamber 111, although this is not essential.
As ought clearly shown in Figure 3, a cr~s-sec-
tonal view of the product chamber across lined 3-3 of
Figure 2, the top wall segment aye and bottom wall
- 12 -
~33~4
segment 118b extend only partially into the depth of
the product chamber normal to the backing substrate,
thus providing an elongate path or channel 156 for
fluid communication between the lower portion 112 and
upper portion 114 of the product chamber 111. The top
wall segment aye of the lower chamber 112 provides a
baffle preventing the substantial bypassing of gas
evolved from the disinfectant tablet from the lower
chamber 112 to the upper chamber 114.
The cross-sectional area of the baffle aye may
be adjusted. However, decrease in the cross-sectional
area of the baffle aye preferably is obtained by
reducing the longitudinal dimension of the baffle,
rather than the transverse dimension of the baffle.
In the dispenser shown in Figure 2, the baffle may be
a wall segment common to both the lower portion 112
and the upper portion 114. However, the particular
construction shown in Figure 2 wherein the baffle aye
and wall segment 118b are separate and join proximate
the backing substrate is more suitable for fabrication
by thermoforming.
The refill/discharge pathway 130 shown in Figure
2 it the same as that shown in Figure 1 for dispenser
10. Similarly, the vent conduit 140 is the same as
that shown in Figure 1 for dispenser 10. Figure 4
illustrates a dispenser 200 adapted for releasing into
the tank water simultaneously from Separate product
chambers aye and 211b a first cleaning solution and a
second cleaning solution, said first cleaning solution
being a detergent solution and the second cleaning
solution being the disinfectant solution. Product
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I
shimmer aye containing the detergent composition, it
the same as shown in Figure 1, while product chamber
211b is the tame as that shown in figure 2.
Typically, the dispenser of the prevent invention
release active disinfectant solution for a period of
from about 20 to about 40 days, depending on the level
of use thereof. On average, the dispenser releases
the disinfectant solution or a period of 30 days,
based upon an average of from about 8 to 12 flushes
per day. Thus, the volume ox the product chamber is
preferably from about 65 to about 85 ml, the upper
portion of the product chamber being from about 45 to
about 75 ml, the solution released by the dispenser
being contained in said upper portion. The disinfect
lent material weighs typically between about 25 to
about 45 grams active disinfectant material, and is
preferably in tablet or extradite Norm. The tablet is
about 1-1/2 inches diameter by about 1/2 inch in
thickness.
A typical dispenser as shown in Figure 2 has a
lower chamber that it about 2-1/2 inches high by
2-11/16 inches wide by about 1 inch deep, and an upper
chamber that it about 7, inches high by about 2-1/8
inches wide by about 1 inch deep. The elongate
pathway between the upper chamber and the lower
chamber it about 3/16 inch in width, measured normal
to the backing substrate.
The shoulder 18 of the dispenser illustrated in
Figure 1 for the top wall segment 118 of the dispenser
illustrated in Figure 2 Jay be slightly raised in the
- 14 -
1~30Q~
direction of the refill/discharge pathway, thereby
assuring that toe evolved gases are collected in the
refill/discharge pathway. Similarly, the top wall 20
or 120 of the upper chamber may be directed it'll
upwardly towards the vent conduit 40 or 140, respect
lively, thereby directing evolved gases out of the
product chamber.
The disinfectant material contained within the
dispenser of the present invention it, prior to use
within the toilet, in dry form, which may be portico-
late, cake, agglomerate, extradite, or other form.
Preferably, the material is in the form of a tablet or
extradite. The do infect ant composition comprises
from about 50 to 90 parts of a disinfectant agent
selected from the group consisting of alkali metal or
alkaline earth metal dichlorocyanurates, for example,
sodium dichlorocyanurate, potassium dichlorocyanurate,
and calcium dichlorocyanurate, and trichloroiso-
cyan uric acid, and from about 10 to about 50 parts
cyan uric acid. The disinfectant material may Allah
contain minor amounts of monochlorocyanurates. In
solution, a portion of the active disinfectant species
and the cyan uric acid will form ~onochlorocyanurates,
which reaction is depending upon pi of the solution.
It ha been found that a polyvinyl chloride disk
penner containing only trichloroisocyanuric is disk
colored an is deformed during quiescence periods,
that it, during period between flushes. By including
between 10 to 50 parts cyan uric acid, preferably
between 15 to 35 parts cyan uric acid in the disinfect
lent composition, it has been found that discoloration
- 15 -
3 ~330~L
and deformation of the polyvinyl chloride dispenser it
largely avoided.
Polyvinyl chloride suitable for the manufacture of
dispensers of the present invention are rigid polyp
vinyl chlorides, that is, polyvinyl chlorides having
lets than about I plasticizer. Such polyvinyl-
chloride it available as extruded sheet, and has
tensile modulus of from about 350 to about 600 psi x
10 ; tensile strength of from about 6000 to about
7500 psi and Issued impact strength of 1/8 inch piece of
from 0.4 to about 20 it lbs/in notch gate. Preferred
PVC for use in the fabrication of the subject disk
penner are the extruded high-impact PVC, that is,
those having an Xzod impact of from about 5 to 15 it
lbs/in notch gate was measured with ASTM D~56), which
PVC material it available as Carom 49 manufactured by
Goes Corporation and Genotherm~ 1008 manufactured by
American Hoechst Corporation.
Example 1
Tablets containing essentially 100% trichloroiso-
cyan uric acid and 0% cyan uric acid were placed in two
beakers containing 72 miss of water at room
temperature. The bottom portion of two dispenser of
the type shown in Figure 2 were suspended within the
trichloroisocyanuric acid solutions, as well as a
0.020 inch strip of unthermoformed polyvinyl chloride
(Blue C, American Hoechst). The samples were observed
in the solution over a 28-day period. During the
cur e of the experiment, water was added to replace
that 108s by evaporation. All test samples showed
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l~VV
discoloration and deformation, with the clear plastic
bottom portion of the dispenser showing the greatest
amount of attack by the concentrated by trichloroiso-
cyan uric solution.
Example 2
Further texts were conducted on a whole dispenser
unit of the type shown in Figure 4, the dispenser con-
twining a 28 gram tablet of 100~ trichloroisocyanuric
acid. The dispenser used in this text alto had a
second product chamber adapted to contain a surfactant
composition. However, the samples tested did not con-
lain a surfactant. The dispenser was sealed in Mobil
OPUS polypropylene over wrap. The dispenser was
manufactured from American Hoechst D'8A:PCN128 polyp
vinyl chloride.
Each of the 6 sample dispensers were placed on
test at 120~F, 95/85% relative humidity for 28 days
and 3 dispensers and subjected to three freeze-thaw
suckle
No sign of discoloration in any form was noted.
Subject ampule (6 at 120F, 95/85% relative humidity
and 3 at froth) had an average weight increase
of about Al at each test condition. All 95~85%
relative humidity samples were cut open and inspect-
Ed No product attack was observed.
12 sample dispensers were placed in toilet tanks,
6 at the water line and 6 completed submerged. In
addition, three samples were completely submerged in a
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4 liter beaker of water end 3 sample alto containing
a surfactant tablet in the detergent chamber were come
pletely submerged.
Samples tested in the toilet showed a white disk
coloration around the bottom of the disinfectant
tablet compartment as well as plastic deformation.
Reformation was also seen on the ridding backing of
the disinfectant chamber. Attack way more severe in
the completely submerged samples than in the samples
placed at the water line. All samples were examined
and no indication of plastic 60ftening was evident.
The beaker samples tested all showed discoloration and
plastic deformation in chambers containing the in-
chloroisocyanuric acid tablet. In addition, ridding
deformation was more severe in all beaker samples.
Example 3
- Dispensers of the type shown in Figure 4 Jon-
twining a blended disinfectant tablet compri~iny a
mixture of 75% trichloroi~ocyanuric acid and 25~
cyan uric acid were tested. These dispensers also
contained a detergent block composition in a second
product chamber. Six samples were placed on tests at
120F and 95F/85~ relative humidity for 28 days and 3
units were subjected to 3 freeze/thaw cycles. Half
the high temperature samples were stored siphon tubes
up; half stored siphon tubes down. No sign of disk
coloration in any form was noted. Weight loss average
for the 120F samples was 0.25% and fox the 95F/85~
relative humidity samples 0.40~ weight gamin way not-
Ed The fiamples tested for freeze-thaw showed a 0.03%
- 18 -
~33~)4
weight increase. Upon completion of the test, all
120F and 95DF/85~ relative humidity samples were cut
open. No discoloration or deformation way observed in
either the disinfectant or the ~urfactant chamber.
12 sample dispensers were placed in toilet tanks
for 28 days at room temperature, half of the samples
being at the water line and half the samples being
completely submerged. Of the water line samples, all
showed slight discoloration and deformation only on
the bottoms and corners of the disinfectant chamber.
One sample showed slight discoloration and deformation
on the ridding backing of the disinfectant comport-
mint. A granular deposit was noted at the top of the
vent port of the disinfectant compartment on all
samples placed at the water line. All completely
submerged samples showed slight discoloration and
deformation only on the bottoms and corners of the
disinfectant compartment. One sample showed slight
discoloration and deformation on the ridding in the
form of one spot. No granular deposit was seen on the
submerged samples tested.
It was concluded that the tablet containing
trichloroi~ocyanuric acid and cyan uric acid notably
minimized the plastic discoloration and deformation
noted in previous test of Examples 1 and 2. The
granular deposit was analyzed as 95% cyan uric acid and
forms when the unit undergoes static periods of at
least several days. The formation of the deposit may
be prevented by submerging the vent.
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