Note: Descriptions are shown in the official language in which they were submitted.
CA 02339738 2001-02-06
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O.Z. 0050/49256
polymers and plastics with long-lasting odor and the nse thexeof
The iuvexltion relates to a prooess for preparing odorant polymers and
plastics, to
the odorant polymer or the odorant plastic itsel.~, and also to a moldiu"
composition
and an article which comprise tbie odoxant polymer yr the odorant plastic.
For some time the prior art has included efforts to prepare odorant plastics.
Considerable practical problems arise here, If the intended plastic is mixed
with the
required amount of a desired odorant, such as a perfiune, and the mixture is
then
processed to give moldings, most of the odorant evaporates or is thermally
degraded. In. relation to the proportion of the odorant which actually
remai~as
within the plastic, there is also the risk that the odorant will separate out
from the
plastic once the latter has cooled and solidified. This results in z~.~ation
of the
odorant to the surface of the solidified plastic, giving the surface a
"greasy",
2 0 unsightly and disfigured appearance. This process also inevitably results
in high
losses of the expensive odorant.
In order to eliminate these disadvantages, it is known in the prior art, via
DE-A-16 94 055, that a silicon dioxide powder as carrier material can be nixed
2 5 with a liquid odorant until the resultant mixture forans small clumps.
Further
silicon dioxide powder with a lower apparoat density than the silicon dioxide
initially used is added to these clumps, giviur~g small clumps of dimensions
not
greater than 0.45 mm. These are then mixed with the plastic.
3 0 A disadvantage of this process is that the plastic processed in this way
comprises
an iuorgaztic solid which can adversely affect the physical properties of tlae
plastic,
for example impact strength and transparency,
DE-A-37 21 91.6 begins with pulverulent porous carrier materials whose origin
35 may be either inorganic or oro r;c, in the form of plastics or of plastics
mixtures.
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The desixed odorant is adsorbed onto the porous carrier material and mixed
with a
plastic for further processing by, for example, extrusion.
During the processing of the plastics the odorant diffuses into the polymer
mats.
S A disadvantage here is that this difhisioa of the odorant into the polymer
matrix
during processing can also lead to loss of the odorant, since the poxosxty of
the
particular carrier material means that the odozant is adsorbed in the pores of
the
cazrier, rather than absorbed.
It is an object o~ the present invention, taking this prior art as a starting
point, to
pro~ride a process which allows cost-effective preparation of odorant
polymers, in
particular of odorant plastics with long lasting vdvr, and to pmvide these
odorant
polymers and this odorant plastic.
We have found that this object is achieved by means of a process in which a
comminuted or fizu'r-particle first polymer material, in particular a plastic,
is mixed
with a desired odorant, allowed to swell for a predetermined period, and then
further processed under a predetermined pressure and at a predetermined
temperature. Since the comminuted or one particle first polymer maxeza,al is
raiaced
2 0 and allowed to swell with the desired odorant ~or a predetermined period,
the
odorant can enter into every one o~ the particles of the first polymer
material. The
polymer particles are genuinely loaded with the odorant. Correspondingly, for
the
purposes of the present invention swelling is the absorption of the odorant
into the
polymer zzratrix or, respectively, the polymer network of the first polymer,
which is
2 5 used as a carrier. A precondition for this is that the distribution of the
odorant in
the first polymer material is uniform. In the case of maeroporous materials -
as in
the prior art - what is obtained is merely pores charged with odorant, without
any
loading of the polyznez skeleton. If the odorant has sufficient thermal
stability, the
resultant odorant polymer or plastic can be further processed in a usual
manner by
3 0 melting followed by homogenization. Particular further processing methods
for
odoraats of relatively low thermal stability are given ax a later stage in
this text.
In one preferred embodiment of the process of the invention, after the first
polymer
material has been. allowed to swell with the odorant it may be mzxed with a
second
3 5 plastic and then melted and then homogenized This gives a compact material
which comprises the odorant polymer material together with the second plastic,
the
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macroscopic distribution being approximately uniform. For the purposes of the
present invention, the frst aztd second material are difr'erentiated by
referring to the
first as the polymer material, the carrier material, and the second as the
plastic, the
objective here being to make it clear that the first polymer material may be,
but
does not have to be, a thermoplastic.
The second plastic may likewise have been comminuted, but this is not an
essential
requirement.
The furst polymer material and the second plastic may be identical or differ
from
one another. If the fast polymer material is identical with the second
plastic, then
for the purposes of the present invention the second plastic may also be a
polymer
material which is not a plastic. ?his method gives an odoraat polymer. If the
first
polymer material, which serves as actual carrier material fox the odorant,
dicers
1 S Cxom the second plastic, the first polymer ~onaterial in particular
comprises a plastic
in the form of a particulate, crosslinked plastic ox of an, elastomer, which
may also
have rubbery properties, with a glass transition temperature ?g below the
glass
transition temperature ?g of the second plastic, preferably 0°C or
below,
particularly preferably below -10°C.
The way in which fast polymer materials of this type can be saxutated with the
particular odorants used is that they ,form a microscopically small network
which
absorbs the odorants, whereupon the odorants swell the network. ?he odorant
used
may be as odorant oil. A par4,culax use of the polymers or plastics prepared
by the
2 5 process of the ~iz~vention becomes possible if the odorants used comprise
pherozz~oncs and/or ecomones. Plaques coated or saturated with pheromones have
hitherto been used with promising results fox contcollizxg izxsects. Since
pheromone
daps of this type are mostly e~onployed iua the open, these products are
exposed to
weathering and therefore have to be frequently replaced since the active
ingredient
3 0 is leached out. By employing the process of the invention it is possible
to
incorporate these odorants into the particular plastic provided so that the
odorants
are protected from the effects of weathering and can be used in the form of
boards,
plaques, or other moldings with a lasting odor. The process of the invention
for
preparing odorant polymers or plastics is therefore not restricted to those
polymers
35 or plastics providing an odor detectable by the human smell, but also
encompasses
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-4-
odorant polymers or plastics whose odor can be detected only by the ser~sztive
olfactory systems of animals, in particular of insects.
The mixing of the first polymer material with this odorant ox odorant oil may
be
carried out in a closed container. This ensures that all of the odorant oil is
available
for the loading of the first polymer material, rather tbiaz~. being dissipated
into the
environment. IJxamples of utaterials suitable for preparing the powder of the
first
polymer maxerial aze spray-dried dispersions of polymer or of plastic.
Depending on the nature of the odoxant used, nn particular on its thermal
stability,
the $~st operation consisting of mixing the first polymer material in powder
form
with the odoxant and allowing it to swell may be followed, in the feather
operation
to form the odorant polymer or plastic, by process modifications individually
matched. to the odorant. The sewed plastic heze racy be used iu~ ground,
powder, or
pellet form.
In the case of odorants with very low thermal stability, the method of further
processing may be thax once the first polymer material has been allowed to
swell it
is mixed with the second plastic at high pressure at about room temperature or
by
2 0 way of slight heating to below the glass transition temperature Tg of the
second
plastic, preferably to just below Tg. The second plastic material used is then
preferably one which melts at a low tempeiatiue, the phe~ao~nenon of cold flow
being utilized. The second plastic may be the same as the fast polymer
material but
may also differ therefrom. A procedure such as that described is particularly
2 S suitable for pheromones or ecomones in general.
In the case of odorants which have little or no sensitivity to high
temperatures,
once the first polymer material has been allowed to swell it may be mixed with
the
second plastic again. at high pressure and wifih heating to a temperature
which is
3 0 above the glass transition temperature Tg either of the fxxst polymer
material or of
the second plastic, preferably just above Tg in each case.
however, in the case of odorants which have no particular sensitivity to high
temperatures it is quite possible to provide conventional pressure conditions
and
3 5 temperature conditions duzizag processing, e.g_ by extrusion. The mi~cture
of the
udorant-loaded first polymer powder and the second plastic, e.g_ in the fozxn
of
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-5-
pellets, may then be melted and homogenized in a mixing assembly at
atmospheric
pressure and at an elevated temperature. The melting iu~ the mixing assembly
may,
for example, be carried out in an extruder or kaeader. After homogenization,
the
resultant melt may be peIletized and further processed by the usual methods of
processing for thermoplastic molding compositions.
Materials preferably used as first polymer matezxal are thermoplastics,
thermoplastic elastomers, graft rubber, polymers based on renewable rave
materials, or polymers or polymer ~nixtut~.c based on starch. It is
particularly
preferable for the first polymer material to be selected from polylactic acid,
as an
example of a polymer based on renerwable zaw materials, polyurethanes,
polyamides, polyesters, or polybutylene terephthalatas, or polymers,
copolymers,
block polymers, triblock copolymers, or graft copolymers of styrene,
butadiene,
a.erylonitrile, (meth)acrylate, or acrylic esters. The abovementioned
materials axe
also suitable for use as second pl,as~tic, and in that case it is also
possible to use
mvchires of these with polycarbonates. Examples of the abovementioned
polymers,
copolymers or triblock copolymers are polystyrene (PS), in particular here
impact-
modified polystyrene, polybutadiene, polyacrylates, polymethyl methacrylates
(PM1VIA), acrylonitrile-butadiene-styrene copolymers (ABS), acrylonitrile-
styrene-
2 0 acrylate copolymers (ASA), styrene-acrylonitrile copolymers (SAN), styrene-
butadiene copolymers (SBR), acrylonitrile-butadiene copolyzz~ers (NBR), and
styrene-butadiene-styrene triblock copolymers (SBS). Good results are also
achieved using ground superabsorber material.
2 5 The first polymer material may be in the form of a devvatered erziulsion
polymer,
for example, obtained either by spray dzyiuug or by coagulation and drying.
Fine-
particle polymer powders obtained by precipitation from solutions axe also
highly
suitable as first polymer material.
3 0 The invention also provides the odorant polymer or the odorant plastic
itself,
obtained by the process of the invention. For sir~aplxcity, the text below
refers to
odorarrt plastics, and this is intended to include the possibility that the
materials
used produce an odorant polymer which is not a plastic. The odorant plastic
may
be in pellet form and an example of its use is in defense against animals. For
the
3 5 pu~rposcs of the present invention, animals may be pests, in particular
including
insects. ~lowever, defense against animals includes the repelling of domestic
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-6-
animals, such as dogs, cats and other small aninnals from places which they
would
like to foul but where this fouling is undesirable. Pellets made from the
odorant
plastic m,ay preferably be used here, and particularly preferably pellets made
from
biodegradable plastics and loaded with the appropriate odorants which are
known
per se and repel the animals. Examples of these biodegradable plastics are
polymers based on renewable raw materials, for example polylactic acid, and
polymers and polymer mixtures based on starch or based on synthetic materials,
for example based on polyestcrunides or on branched polyesters. The advantage
of
using the odorant plastic of the invention is that the active ingredient is
dissipated
over a long period and cannot be removed from the plastic even by rain.
The invention farther relates to a molding composition which comprises an
odorant
polymer of this type or an odorant plastic of this type. Depending on the
propor6ion
of odorant in the finished plastic, which may be in the form of pellets, for
example,
I5 Ibis may also be used as a masterbatch. The relatively high proportion of
odorant
may be achieved, for example, by altering the mixing ratio of first polymer
material and second plastic.
z
Tha iunvention also relates to tha use of the ~oaolding composition which
comprises
2 0 an odorant polymer or an odorant plastic, or the use of the odorant
polymer or
plastic itself for altering and/or improving the odor properties of articles.
There is a
wide variety of applications available here, and particular advantage is given
by
those which conceal the unavoidable unpleasant intrinsic odors of plastics in
a
wide variety of applications. An, example which may be mentioned here is the
2 5 interior of zzxotor vehicles in which components produced from plastic,
for example
dashboard. supports, center consoles, trim firms, etc. can have a strong odor
of the
plastic when they are new. l~'sing the odorant plastics or the molding
cozxxpositions
prepared therefrom, this unpleasant odor can be concealed. Since the skilled
worker is aware of a very broad range of very varied odorants, all of which
can be
3 0 incorporated into the plastic by the process of the invention, a varied
range of
possibilities is available to automobile manufacturers. Examples which may be
mentioned here are plastics with the odor of leather, fresh air, flowers,
forest or
perfume.
35 Azzother possible application consists in concealing unpleasant intrinsic
odors of
construction materials, for example in the window :frame sector or the
baseboard
CA 02339738 2001-02-06
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sector. Flere, too, in the first weeks ai~er completion the intrinsic odors
occurring
are regarded as unpleasant and may be concealed, for example using a citrus
odor.
Other articles manufactured from plastic, such as vacuum cleaner housings or
plastic parts in refrigerators, may have an unpleasant odor of the plastic
from
which they have been produced, such as an ABS plastic or an impact-modified
polystyrene. These odors, too, may be concealed by a wide variety of desired
'types
of odor, using odorant plastics.
fhe invention also pro~~rides an article which cozz~.px~ises the odorant
poly~aer or the
odorant plastic and/or comprises the molding composition in v~rhich the
odorant
polymer or the odoraat plastic is present. This article may be a plastic part
or a
semifinished product, fox example as injection molded article, or a film,
sheet,
pipe, or profile. ?here are many uses for the article, which has at least some
inbuilt
odor due to the odorant polymer or plastic present therein. Firstly, it may be
used
for the uses described above for the odorant polymer or the odorant plastic
and for
the molding composition which comprises the odorant polymer or odorant
plastic.
Secondly, however, it may be used for imiprovxng room air quality. It then
acts as
an odor dispenser, and it is advisable here to avoid any excessive proportion
of the
2 0 odorant present in the plastic, so that the article generates an odor
which is discrete
and only just detectable when in use in office areas or other liming areas,
I~owe~rer,
a higher proportion of the odorant znay be indicated if the article used as
odor
dispenser as employed in the sanitary sector. If the article has been produced
by
injection molding, it may advantageously be given any desired shape. For
example,
it is possible tv produce lemons with the odor of lemons or coniferous trees
which
give out an odor of spruce needles, or any desired other article with its
associated
odor characteristics. These odorant articles are therefore also suitable as
decorative
articles.
3 0 Another possibility is to incorporate the odorant plastic into articles in
daily use,
such as household articles, telephones, computer casings, etc. The
corresponding
odorants may be selected so as to provide a motivation to purchase, or to
generate
a general feeling of wellbeing, or else even to increase the ability to
concentrate. It
is also possible for promotional items, such as ballpoint pens or other small
products, to be provided with a customer-specific odor, these articles
comprising
the odorant plastic or the molding composition which comprises the odorant
CA 02339738 2001-02-06
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_g_
plastic. In addition, it is possible to produce odorant gz~eeti~g cards, CD
packaging,
cassette packaging, telephone cards, or chip cards.
If the articles are produced in the form of sheeting, they may be used as
packaging
films, as self adhesive odorant labels for refrigerators, for example to
eliminate
fishy odors, or ~or wardrobes or other storage boxes. It should be emphasized
that
the selection of the appropriate odozant also allows long lasting defense
against
pests. For the purposes of the present invention, the term. pest has a ode
meaning,
including insects and also small animals, such as mice, rats, martens, etc.
Use of
the appropriate odorants permits appropriate repellent cable-insulation
materials to
be used in electrical engineering. It is not just cable-insulating material
which may
be brought into considezation here, but any construction material liable to
attack by
small animzls. Tm relation to the defense required against insect pests,
mosquitoes
and ants are worthy of consideration, as are various uxoth species.
Examples of the uses mentioned for the odorant plastic, or the molding
cobaposition or article comprising the odorant plastic are so varied that they
can
only be illustrated here by way of example. 'The use can also be extended to
any
desired other sectors of daily life. For example, selection of a suitable
odorant
2 0 plastic also permits the production oftoys with a variety of aromas.
The invention will be described in more detail below by way o~ examples.
Exa~mnle 1:
The fast polymer material is composed of a spray-ckied polybutadieue and
polyaczylaxe rubber. 200 g of this dried rubber eras placed in a 1 000 ml
screw top
glass container and mixed with 10 or 20% of the odorant citral or citronellol.
1"he
glass containers were then rolled on a roller bed for 48 h. This mixed the
odorant
3 0 uniformly into the rubber.
The rubber treated in this way was blended firstly with a styrene-
acrylonitrile
polymer with a melt index MVI (220°/10 kg) of 62 g/10 min, at a
concentration of
10 or 20%, and secondly with nylon-6 with a melt index MVI (275°/5 kg)
of
120 g/10 min, in the same mixing ratio. Then each rubber-pellets mixture was
CA 02339738 2001-02-06
O.Z. 0050/49256
-9-
compounded in an extruder with contrarotating screws. The machine parameters
here were set as follows:
Screw rotai~on rate: 200 rpxb,
Temperatures: Feed: 30°C,
Processing unit: 220°C
Throughput: 1.5 kg/h
The expe~nents carried out under Exanrplo 1 are shown in Table 1.
Example 2
In this example the first polymer material is composed of a graft r Libber
dried in a
fluidized-bed dryer and prepared as described in DE B-24 27 960. lviaSO4 waS
used for precipitation, fohowed by preliminary dewatering to a water content
of
about 28% by centnifi~,ging. 100 parts of this graft zubbez- were treated with
25 parts
of citronellol and xx~ixed as described in Example 1.
40 parts of the graft rubber pretreated in this way were intizxxately mixed
with
60 parts of a sf"yrene-acryIonitrile copolymer melt (SAID at 230°C in
an extruder
2 0 with eorotating screws. The acrylonitrile content in. the SAN molt was
35%. This
gave a melt with a strong lemon odor, and the melt was used to produce
u~oldings,
such as plaques and bars, which continued to have a strong Iemon odor. Films
were
also produced
2 5 The resultant nxoldings were subjected to an odor test at intervals of a
number of
months. Even after a storage time of 10 months here, it was still possible to
detect
a pronounced lemon odor.
Example 2a:
The mixture of Example 2 made from the graft rubber and tlae citronellol was
mixed with SAN in such a way that only about 30% of the odorant-saturated
graft
robber was present iua the finished mixture. This miacture, too, had a strong
lemon
odor.
CA 02339738 2001-02-06
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~ - 10-
The odor test was again undertaken over a period of a cumber of months. After
months here there was still a discrete, pleasant fruity odor.
Examples ~1 to 2-T:
5
Odorant plastics of the invention were prepared as described in Example 2 from
other polymer materials and plastics gives in. Table 2, using the odorants
also
given in that table.
CA 02339738 2001-02-06
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CA 02339738 2001-02-06
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CA 02339738 2001-02-06
-13-
Table 2a:
Odoz~nt Chemical name
HASF trade name
Nerolidol 3,7,11-Trimethyldodecatrien-3-of
Ph of 3 7 l I 15-Tetrameth lhexadec-2-en-I-of
1~ drox ciol 3,7-Dimeth loctane-I,7-diol
Gerany l
acetate Mixdnre of 70% geranyl acetate
and 30%
neryl acetate
Alfa-Ionon 100 4-(2,6,6-T~ixnethyl-2-cyclohexen-1-yl)-3-
buten 2-one
Exa.~oaple 3
The materials and odorants given in Table 3 were used to repeat the
preparation of
the z~uixti~re of Example 1 ~rom the giaft rubber and the odorant oil. The
materials
mentioned under 3-11 to 3-I4 are fully biodegradable polymers. The odorants
used
are sensitive to high temperatures,
~0
Once each odorant had been nn~ixed into the first polymer material, this
material
'was uvxed with each of the pulverulent or pelletized plastic given and
compressed
into a mold under nudld conditions, with heating to just above the glass
transition
temperature Tg of the thermoplastic used.
As an alternative to this, the mixtures resulting from the first polymer
material and
the second plastic were processed between heated rolls to give fxlzns.
In these versions of the process the processing temperatures selected were
below
2 0 the usual temperatures for extrusion, the extent about 50 to 150°C.
CA 02339738 2001-02-06
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CA 02339738 2001-02-06
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