[0001] Devices which allow for the total or partial release of an active agent from an aerosol
dispenser are known. Examples of these devices may be found in the Handbook of Aerosol
Technology by P.S. Sanders, 2nd Ed., page 85, Editor Krieger, 1979).
[0002] The main disadvantage of the total-release aerosol dispensers is their immediate
actuation which exposes the operator to the contents of the containers.
[0003] Some attempts for delayed release of the content of various containers were made
previously to prevent direct contact of the operator with the content of the container.
The resulting devices are mostly applicable and/or suitable for specific purpose only.
[0004] Dispensers with delayed opening of a water soluble seal which dissolves when coming
in contact with water in the washing machine are described in USP 3,399,806. USP 3,800,878
describes a fire extinquisher utilizing an eutectic material in conjunction with an
auxiliary seal that isolates the eutectic material from the pressurized fluid of the
container. The eutectic material melts in response to an increase in ambient temperature.
After complete melting of the eutectic material the auxiliary seal is opened by the
pressure within the container thereby permitting release of the fluid. It is rather
dangerous to employ together such actuation stimuli as heat and pressure because the
heat increases the pressure in the container which may explode.
[0005] The present invention provides a simple, inexpensive, effective, practical and easy
to handle means for delayed actuation. It is generally applicable and independent
from external factors such as aqueous medium or heat. It provides a time delayed release
for all kinds of total-release aerosol dispensers such as foggers, fumigators, insecticidal
sprays and bombs, paint capsules, gas bombs, aerosols, oven cleaners, tear gas granades,
smoke grenades and explosives, and is particularly appropriate for distribution of
pesticides, mote particularly of insecticides.
[0006] The time delayed release of the aerosol dispenser of the invention is obtained with
the aid of a material sealing the exit conduit of the dispenser and which material
is susceptible to removal by the content of the dispenser's container. The sealing
material is removed, with delay over a predeterminable period of time by the contents
of the container upon mechanical actuation of the valve.
[0007] The sealing material may be in removable association with the valve, valve stem or
actuator of said dispenser. After removal of the sealing material the content of the
container is released.
[0008] The removal of sealing material may be obtained through the pressure executed by
the contents of the dispenser on the sealing material after actuation of the valve,
by dissolution of the sealing material in, or disintegration of such sealing material
by the contents of the container after actuation of the valve, or by a combination
of such factors.
[0009] A wide variety of valves, valve stems, actuators and containers of total-release
aerosol dispensers are known. Essentially all such dispensers may be adapted in accordance
with the present invention.
[0010] In a preferred embodiment of the invention, the actuator is in the form of a so-called"overcap".
Overcaps have the dual function of protecting the valve of an aerosol dispenser during
storage and of actuating said valve, when inverted and remounted onto the dispenser
(see USP 4 426 025).
[0011] The sealing material can be any material which can be placed in the conduit or on
the orifice of the valve, valve stem, the actuator or between them and can be removed
after actuation of the valve under the influence of the container's content.
[0012] Suitable sealing material may be any material removable under the pressure of the
container's content after actuation and may for example be in foil form or have a
soft plastic consistency.
[0013] Examples of sealing materials suitable for use in the present invention are adhesive
or insulation tapes, e.g. tapes known under the trade names Scotch® 810, Scotct® CW
715 44AAV 4152, R-Tape® (CP-PAN) and Silver ClotH® Tape, preferably Scotch® 810 or
Silver Cloth® Tape; polyolefins and natural and synthetic resins such as polyvinylchloride,
polypropylene, ethylene ethyl acrylates, ethylene vinyl acetate, polyvinyl acetate,
polyvinyl alcohol, butyl acrylate, rubbers and elastomers, polyisoprene, polystyrene,
polyvinyl acetal, polyvinyl ethyl ether, polyethylene and similar materials, e.g.
low density polyethylene foils formulated with paraffin wax, such as the laboratory
films available from American Can Corp. under the trade name Parafilm® , preferably
such films of 0.010 to 0.015 inches thickness; sealants; greases such as silicone
grease; waxes.
[0014] The natural and synthetic resins may either be used alone or may be, and preferably
are, employed in combination with a plasticizer and optionally other formulating agents
such as dyes.
[0015] Sealing materials particularly suitable for use in the present invention are selected
from adhesive or insulation tapes, laboratory films such as those known as Parafilm®
, and natural or synthetic resins (such as rubbers, polyisoprenes or other aliphatic
hydrocarbon resins, wood resins and the like).
[0016] Examples of resins particularly suitable for use as sealing agent are wood resins,
e.g. wood resins having a softening point of more than 85°C, e.g. in the range of
90 to 105°C, such as low molecular weight aliphatic hydrocarbon resins derived mainly
from dienes and other reactive olefin monomers, e.g. those known under the trade name
Piccopale® resins (particularly Piccopale 100-SF, available from Hercules Inc., Wilmington);
and ethylene vinyl acetate (EVA) based resins, such as the EVA-wax-resin compositions
known as Neytac® resins (available from Neville Chemical Company) e.g. Nevtad®100
and Super Nevta® 99.
[0017] Examples of plasticizers suitable for use in the resin combinations are phthalates
and adipates, e.g. dibutyl phthalate, dicyclohexyl- phthalate, diethyl phthalate,
diisodecylphthalate, dimethyl phthalate, diphenyl phthalate, dioctyl phthalate, dioctyl
adipate, butyl benzyl phthalate, diundecyl hthalate, the dialkyl phthtalate known
under the trade name Santicizer® 711, the dialkyl adipate known under the trade name
Santicizer® 97 and polymeric type plasticizers such as Santicizer® 261, 409, 411,
412,,429, 480, 481, 482, 334 F, 79TM- trimellitate type, particularly suitable plasticizers
are dioctyl phthalate (DOP), butyl benzyl phthalate (Santicizer® 160; BBP) and dioctyl
adipate (DOA).
[0018] The most appropriate sealing materials for use in this invention are laboratory films
such as those known as Parafilr® and referred to herein above, particularly such films
having a thickness of 0.005 - 0.015, more preferably of 0.01 - 0.015 inches, and resin
/plasticizer combinations mixed in a weignt ratio from 50:50 to 90:10, preferably
from 70:30 to 90:10. Particularly suitable resin/plasticizer combinations comprise
from 75-85% by weight of resin and 15 to 25% by weight of plasticizer. They may additionally
comprise formulating agents, e.g. 1 part for.100 parts resin/plasticizer combination.
A preferred example of formulation comprises from 79-82% by weight of resin, 17-22%
by weight of plasticizer, the balance being formulating agents such as dyes, e.g.
fluorescent dyes such as fluorescent orange, fluorescent yellow, fluorescent blue,
fluorescent red and fluorescent black.
[0019] The sealing material can be placed at any place of the exit conduit allowing sealing
of the terminal orifice of the aerosol dispenser; it may be placed in the conduit
or on the orifice of the valve, valve stem or actuator and in some instances it may
also cover the surroundings thereof. The valve, valve stem and actuator may have any
size or shape; it is only necessary to secure that the amount of sealing material
employed is sufficient to completely block the terminal orifice of the aerosol dispenser.
[0020] The sealing material may be introduced at the desired place of the exit conduit (valve-,
valve stem-, or actuator orifice or conduit) by known techniques, e.g. manually, by
injection, hot molding, dip-coating, coating or other techniques well known in the
art.
[0021] These and other features and objects of the present invention will become more apparent
from the following description taken in conjunction with the accompanying drawings
wherein:
Fig. 1 is a schematic drawing of sectional view, illustrating one preferred embodiment
of this invention, i.e. a total release overcap wherein the sealing material is placed
either "on" or "in" the orifice of the overcap (serving as actuator).
Fig. 2 is a schematic drawing of sectional view, illustrating an other preferred embodiment
of this invention, i.e. an aerosol valve wherein the sealing material is placed either
"on" or "in" the orifice of the valve stem. The actuator is not shown, nor are details
drawn from the valve. For more details see for example, Handbook of Aerosol Technology,
supra.
Fig. 3 is a schematic drawing of sectional view, illustrating another preferred embodiment
of this invention, i.e. a button-lock actuator wherein the sealing material is placed
either "on" or "in" the orifice of the button-lock actuator.
[0022] Referring to Fig. 1, the total release overcap is shown with the sealing material
placed either "on" or "in" 2 the orifice 3 of the overcap. Fig. lA is a plan view
of the top of the overcap; Fig. 1B is a side sectional view of said overcap and Fig.
1C is enlarged view of the middle section of the overcap in a position in which it
is used for delayed actuation.
[0023] In operation, the cap which normally serves as a cover for shipping or storing is
inverted to actuate the valve of the can. Thereupon the content of the container interacts
with the sealing material (by pressure or solvent effects) and begins to actuate such
material until it is displaced. Only then the content of the can is released.
[0024] Referring now to Fig. 2, the aerosol valve (Handbook of Aerosol Technology, supra
at 85) is shown with the material susceptible to the container's content placed either
"on" 4 or "in" 5 the valve stem 6 of the aerosol valve assembly. Fig. 2 is a side
sectional view of the aerosol valve assembly showing the stem 6, body of the valve
7, diptube 8 and mounting cup 9.
[0025] In operation, whenever the actuator (not shown) attached to the valve stem of the
container is engaged, the content of the container interacts with the sealing material
placed "in" or "on" the valve stem and begins to actuate such material until it is
displaced. After removal of the sealing material the content of the can is released.
[0026] Referring now to Fig. 3, the button-lock actuator (Handbook of Aerosol Technology,
supra at 111) isshown with the seaiing material placed either "on" 10 or "in" 11 the
orifice 12 of the actuator.
[0027] Fig. 3A is a side sectional view of the actuator and Fig. 3B is an enlarged view
of the middle section thereof.
[0028] In operation, whenever the actuator attached to the valve stem of the container is
engaged, the content of the container interacts with the sealing material placed "in"
or "on" the orifice of the actuator and begins to affect such material until it is
displaced. The content of the can is only released with time delay, i.e. after expiration
of the time required for the removal of the sealing material.
[0029] The sealing materials are either placed between the valve and the actuator, or built
"in" or "on" the actuator or the valve stem of the total-release container. The delayed
actuation is triggered by engaging the actuator (i.e. by opening the valve). The container's
content begins then to affect the sealing material, which results finally - after
a predeterminable period of time - in the removal of such sealing material and allows
thereupon the delayed total-release of the contents of the aerosol dispenser. The
delay in time depends on the type and amount of sealing material used and on the contents
of the container.
[0030] The sealing material can be placed either "in" or "on" the valve, preferably valve
stem, into the stem orifice(s), if there are any, in the wall of the stem or in the
stem seat (spring cap). The details describing the different
types of valves, valve stems and various other parts thereof can be found in Handbook
of Aerosol Technology, supra, pp. 85-111.
[0031] Similarly, the sealing material can be placed "in" or "on" the actuator or overcap
of any size or shape. Actuators and their functions are generally described in Handbook
of Aerosol Technology, supra, pp. 111-114.
[0032] The orifice can be of various shapes and sizes. Such orifices are made in conventional
manner.
[0033] The current invention is useful for any kind of administration and total-release
of harmful, hazardous, noxious or unpleasant contents of various containers and similar
devices to the surrounding environment, which administration could be otherwise harmful,
un-
: pleasant, impractical or risky to the operator of such device. In such situations,
time is needed to get away from the container before it releases its contents.
[0034] The device of this application allows the application of various pesticides, fumigating
agents, even hazardous materials which normally cannot be applied without safety hazards,
without complicated health protections such as masks, respirators, special clothes,
etc. Sometimes, such materials cannot be applied at all without substantial health
risk to the operator.
[0035] Utilizing this invention, the operator of a device containing any kind of harmful
substance installs the device in the appropriate place, engages the actuator, valve
or other triggering unit and leaves. The sealing material now comes in contact with
the contents of the container which slowly acts onto the sealing material which is
susceptible to that content. In due time (controlled by choice of materials, thickness,
formulation, dimensions and location), such material fatigues and is displaced thus
opening the terminal orifice in the system and allows the content of the container
to be released to the environment.
[0036] The device of this invention can be similarly used to activate fire extinguishers
in a case of unattended fire, tranquilize wild animals or disturbed or violent people
without endangering personnel, administer various detoxicants, disinfectants, anesthetic
agents and other agents of a similar type. The uses such as a landing area marker
or a rescue markersite is also possible.
[0037] The following examples are intended to illustrate the current invention. They are
not to be interpreted as limiting the current invention to the material appearing
in the examples.
Example 1: Delayed Actuation-Unformulated Materials
[0038] This example illustrates a delayed actuation using containers with various contents
and unformulated sealing materials susceptible to actuation.
I. Adhesive-Tapes
[0039] An adhesive disk of the materials listed below was placed over/on an exit orifice
of total release actuator of pressurized insecticide/ solvent containg room fogger.
Then the actuator was engaged and the time delay measured in which the actual release
from the container occurred.

[0040] Depending on the tape material, the solvent and/or pressure from the fogger was able
to disintegrate the tape within 1.5 to 3 seconds.
II. Greases
[0041] Grease was placed in the valve stem of the aerosol container, the valve was opened
and the time delay of the actuation was measured.

[0042] The pressure of the aerosol was able to push through the orifice the grease in approximately
1 second. By changing the softness of the grease employed, it is possible to regulate
the time delay on release.
III. Parafïlm ®
[0043] A piece of Parafilm® of various thicknesses was placed at the interface of a valve
stem and actuator of the generally available insecticidal total-release bomb fogger
and the delayed actuation was measured.

[0044] By changing the thickness of the material, it is possible to regulate the time delay
on release.
IV. Polyethylene
IV. Polyethylene
[0045] High density polyethylene film (3/1000 inches) was installed at the interface of
the valve and actuator of room fogger and the time delay measured.

[0046] Polyethylene material did not rupture, dissolve or disintegrate for at least 60 minutes
of the experiment.
V. Other Materials
[0047] Using the procedure of sections I-IV of this example, the time delay of other types
of containers and other materials are determined.
Example 2: Delayed Actuation-Formulated Materials
[0048] This example illustrates a delayed actuation using various containers, actuating
agents and formulated materials susceptible to actuation.
I. Polymer Resins/Plasticizers
[0049] Combinations of polymer resins/plasticizers (Formulation) have been prepared in the
formulations listed below:

D.O.A. means dioctyl adipate; FD&C means Food, Drugs & Cosmetics.
[0050] All formulations prepared according to the above schedule were heated until molten,
then placed on and over the orifice at the underside of the fogger actuators (20 of
each formula). The formulations were allowed to cool to an ambient temperature. Then
the actuator was engaged and time delay measured in which the actual release from
the container occurred.
[0051] Fogger actuators used in this example were a standard button-lock type (total release
* 01-3686) obtained from Precision Valve Corp., Yonkers, N.Y., an overcap (total release
overcap # C82-0118-00) obtained from Seaquist, Division of Pittway Corp., Cary, 11.,
and a fogger actuator cap from Seaquist. ( #means catalogue number.)

[0052] The above formulations produced a small resin worm which passed through the fogger
actuator until all of the resin/plasticizer formulation which blocked the orifice
was expelled. Due to solvent and/or pressure effects on the resin/plasticizer formulation,
the formulation ruptured and allowed for total-release of the contents of the fogger.
II. Polymer Resins/Plasticizers
a. In these formulations the ratio of plasticizer v. polymer resin were as follows:
[0053]

[0054] These formulations were inserted in an amount from 0.010-0.002 g, into the bottom
side orifice of a button-lock actuator and in Seaquist cap actuators. The time delay
of total-release was measured after the actuator was engaged.
Button-Lock Actuator
[0055]

Seaquist Cap Actuator
[0056]

b. Other formulations in amount 0.001-0.100 g are inserted into an orifice of any
actuator depending on formula ratio.
III. Other Formulations
[0057] Following the above procedure, the other combination formulations are prepared and
tested for time delayed actuation of total-release containers of various types.
Example 3: Formulations Process
[0058] Formulations useful for delayed actuation were prepared by mixing the D.O.A. with
fluorescent dye, for example fluorescent orange or fluorescent yellow or with blue,
red, black or other dye pigments. The mixture was heated up to 100°C. Then, the polymer
resin was added and the whole mixture was heated up to 100°C again until it was molten
and homogenous. In the molten stage it was applied to the actuator, valve stem, valve
or orifice therein.
1. A continuous aerosol dispenser having a container with a valve stem, valve and
continuous valve actuator for discharging the container contents through a terminal
orifice of the dispenser, characterized in that its exit conduit is sealed by a material
susceptible to removal, after a predeterminable period of time, by the contents of
the container upon mechanical actuation of the valve, thereby delaying the release
of the container content for such preaeterminable period of time.
2. The device of claim 1 wherein the sealing material is selected from the group consisting
of polyethylene, laboratory foil and a formulated combination of resin and plasticizer.
3. The device of claim 2, wherein the laboratory foil is a low density polyethylene
foil formulated with paraffin wax.
4. The device of claim 2, wherein the sealing material is a formulated combination
of polymer resin and plasticizer, such formulation comprising the resin and plasticizer
in a weight ratio of from 50:50 to 90:10.
5. The device of claim 4, wherein the sealing material is a formulation comprising
from 79 to 82% by weight of resin, from 17% to 20% by weight of placticizer, the balance
being formulating agents.
6. The device of claim 4 or 5, wherein the plasticizer is a phthalate or adipate.
7. The device of any one of claims 1 to 6, wherein the sealing material is at the
interface of the valve and valve actuator.
8. The device of any one of claims 1 to 6, wherein the sealing material is in removable
association with the valve stem.
9. The device of any one of claims 1 to 6, wherein the sealing material is in removable
association with the valve actuator.
10. The device of claim 9, wherein the actuator is in the form of an overcap.
11. A method for delaying the release of the contents of a continuous aerosol dispenser,
which comprises placing a material sealing the exit conduit of the dispenser in contact
with the contents of the dispenser's container by engaging a valve of the dispenser,
and removing such sealing material with the aid of said contents over a predeterminable
period of time.