POLYMERIC MATERIAL FILM WITH REPELLENT PROPERTIES

PELLICULE A BASE D'UNE SUBSTANCE POLYMERIQUE CHASSANT LES ANIMAUX NUISIBLES

English Abstract

ABSTRACT OF THE DISCLOSURE
Garbage bags and similar articles formed of
flexible polymeric material sheet are provided with
long-lasting animal and/or insect repellent properties
by providing selected portions of the outer surface of
the film in porous form and absorbing a chemical repell-
ent into the pores.
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Claims

The embodiments of the invention in which an
exclusive property or privilege is claimed are defined as
follows:
1. A flexible film of flexible polymeric material
having a plurality of closely-spaced microscopic pores
extending part-way through the thickness of the film and
a chemical animal and/or insect repellent material absorb-
ed in said pores to impart to said film long-lasting
animal and/or insect repellent properties resistant to
environmental removal.
2. The film of claim 1 wherein said pores extend
to a depth of about 50% of the thickness of the film.
3. The film of claim 1 wherein said repellent is
methyl nonyl ketone.
4. The film of claim 1 formed into a bag structure
with said microscopic pores positioned in the exterior
surface of the bag.
5. A method for the production of flexible poly-
meric film having long lasting animal and/or insect
repellent properties resistant to environment removal,
which includes subjecting at least a selected portion of
said film to corona discharge to form a plurality of
closely spaced microscopic pores in said portion to a
depth effective to absorb a chemical animal and/or insect
repellent material therein and absorbing said chemical
material into said pores.
6. The method of claim 5 wherein said polymeric
material is polyethylene and said corona discharge is
effected at an intensity of about 38 to about 41 dynes.

7. The method of claim 5 wherein said repellent
is methyl nonyl ketone.

Description

926
FIELD OF INVENTION
~ . ... .
The present invention is directed to flexible
polymeric material film having long-lasting animal and/or
insect repellent properties, articles formed therefrom
and methods of production of the film.
BACKGROUND TO TEIE INVENTION
The use of plastic garbage bags and other
flexible polymeric material articles is widespread in the
collection and storage oE garbage in both household and
industxîal applications. It is desirable for these bags
and articles to be repulsive to cats, dogs and other
animals and insects.
Prior ~ttempts to render polymeric material
articles repellent to animals and insects have included
the surface application oE a repellent material to a non- ~
porous polymeric surface and the introduction of a -
repellent during extrusion of the film from whlch the
articles are made. These methods have not been success-
fulf since, in the case of the surface application, the
repellent is read1ly washed away or evaporated when the
film comes in con-tact with water or is exposed to the
air and sunlight, whilel in the case of extrusion, the
repellent is evaporated during the heat buildup required
for extrusion.
SUMMARY OF THE INVENTION
In~accordan~e with this invention, there iæ;
provided a polymeric mater~ial film or sheet whi~h rætains
animal and/or~inæect~repellent~properties over an extend- -
ed~period of time~and hence overcomes the prior art
, ~ , .
problems men-tioned above.
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GENERAL DESCRIPTION OF INVENTION
_ ... . . . ... _ .. _ ... _ ..
The film provided in accordance with this
invention has microporosity formed in at least part of
at least one surface of the film to a depth which is
less than the total film depth and a chemical repellen
material located in the microporous surEace.
By "microporosity" as used herein, there is
,
meant a plurality of closely-spaced pores ln the sur:Eace
which are of small dimension sufficient to absorb
chemical repellent material therein yet insufficient to
permit absorbed chemical repellent material to be
readily removed.
Since the repellent material is xetained w:ith-
in the microporosity, the repellent action is retained
for long periods until all the repellent material has
r -- evaporated from the microporosity. While a number of
di~ferent repellent materials may be used, it is preferred
to use methyl nonyl ketone. RepelIents in liquid or
. . . .
solid form may be used, as clesired.
The microporosity may be provided in the film
by exposing the areas of the film in which the micro-
porosity is to be formed to corona discharge of an inten-
sity required to penetrate the film to the required
depth. The corona discharge causes the formation of
multiple number of~closely spaced pores.
The intensity of the discharge applied to the
film depends on the thickness of film chosen, the depth
of penetration of the film desired and the polymeric
material chosen.
~ 30 ~Polyethylene is usually the polymeric mater-
; ial chosen since it is readily available and mos~
:'
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commonly used for garbage bag applications. For poly-
ethylene, the corona discharge intensity is usually in
the range of abou-t 32 to about 41 dynes, with an intensity
in the range of about 38 to about 41 being preferred.
Usually, a penetration of about 50~ of the
thickness of the film is effected.
The corona treatment of the polymeric fllm
usually is carried out on a continuous tube film at a
desired width on one or both sides of the tube during the
10 extrusion process.
Following formation of the microporosity in the
film, the chemical repellent is applied to and positioned
in the pores. The chemical repellent may be applied to and
positioned in the microporosity in any convenient manner,
such as, by wiping on spray application, or pressure
, ~ applicationl dependent on the nature of the formula-tion
used. The positioning of the chemical repellent into the
microporous surface at least partially fills the pores
and leaves a dr~ exterior. The chemical repellent slowly
20 evaporates out the pores and the film retains its effect-
; iveness as a repellent until all the repellenk material
has evaporated from the pores. The product, therefore,
retains its effectiveness over an extended period of time.
- ~ SUMMARY
The present invention, thPrefore, provides an
animal and/or lnsect repellent flexihle polymeric mater-
ial film, preEexably in a garbage bag form, which has
long repellent life, even under adverse environmental
condltions. Modi~lcations are possible withln the scope
30 of the invention.
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