Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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I
FILE~ ;,, 7
T~. " ~ ,LJ''.i._
Compostable and melt-processable foams
Foamed, melt-processable plastics are known (c.~ Rompp Chemielexikon, "Schaum-
kunststoffe" entry, volume 5, 9th edition, Thieme Verlag 1992). They are obtained
S inter alia by the use of blowing agents (c.~ Rompp Chemielexikon, "Blahmittel" entry, volume 1, 9th edition, Thieme Verlag 1990).
The object has now arisen of producing completely compostable articles resistant to
water and water vapour having a low density. This object has been achieved by
10 processing certain completely compostable polymers resistant to water and water
vapour by means of suitable blowing agents to yield the required articles, preferably
in a melt processing production process.
The present invention accordingly provides foamed mouldings produced from
15 polymers selected from the group of aliphatic or partially aromatic polyesters,
thermoplastic aliphatic or partially aromatic polyesterurethanes, aliphatic or aliphatic-
aromatic polyestercarbonates and aliphatic polyesteramides, which are mixed withblowing agents and melt processed.
20 The present invention furthermore provides a process for the production of the
articles according to the invention.
The present invention furthermore provides the use of certain completely compost-
able polymers resistant to water and water vapour for the production of foamed
25 mouldings.
The following polymers are suitable:
Aliphatic or partially aromatic polyesters prepared from
A) aliphatic difunctional alcohols, preferably linear C2-C1O dialcohols, such as for
example ethanediol, butanediol, hexanediol, particularly preferably butanediol
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and/or optionally cycloaliphatic difunctional alcohols, preferably having C5-C6
C atoms in the cycloaliphatic ring, such as for example cyclohexane-
dimethanol and/or, partially or entirely instead of the diols, monomeric or
oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydro-
furan or copolymers thereof having molecular weights of up to 4000,
preferably of up to 1000, and/or optionally small quantities of branched,
difunctional alcohols, preferably C3-C,2 alkyldiols, such as for example
neopentyl glycol and additionally optionally small quantities of more highly
functional alcohols, preferably C3-C12 alkylpolyols, such as for example 1,2,3-
propanetriol or trimethylolpropane and from aliphatic, difunctional acids,
preferably C2-C,2 alkyldicarboxylic acids, such as for example and preferably
succinic acid or adipic acid and/or optionally aromatic difunctional acids,
such as for example terephthalic acid or isophthalic acid or n~rhth~lenedi-
carboxylic acid and additionally optionally small quantities of more highly
functional acids, such as for example trimellitic acid or
B) from acid- and alcohol-functionalised structural units, preferably having 2 to
12 C atoms in the alkyl chain, for example hydroxybutyric acid or hydroxy-
valeric acid or lactic acid, or the derivatives thereof, for example ~-capro-
lactone or dilactide,
or a mixture and/or a copolymer of A and B,
wherein the aromatic acids constitute a fraction of no more than 50 wt.%, relative
25 to all the acids.
All the acids may also be used in the form of derivatives, such as for example acid
chlorides or esters, both as monomeric and as oligomeric esters;
30 Aliphatic or partially aromatic polyesterurethanes prepared from
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C) aliphatic difunctional alcohols, preferably linear C2-C~0 dialcohols, such as for
example ethanediol, butanediol, hexanediol, particularly preferably butanediol
and/or optionally cycloaliphatic difunctional alcohols, preferably having a C5-
C6 cyclo~liph~tic ring, such as for exarnple cyclohex~ne~limethanol and/or,
S partially or entirely instead of the diols, monomeric or oligomeric polyols
based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers
thereof having molecular weights of up to 4000, preferably of up to 1000,
and/or optionally small quantities of branched, difunctional alcohols,
preferably C3-C,2 alkyldiols, such as for example neopentyl glycol and
additionally optionally small quantities of more highly functional alcohols,
preferably C3-C~2 alkylpolyols, such as for example 1,2,3-propall~l.;ol or
trimethylolpropane and from aliphatic, difunctional acids, preferably C2-CI2
alkyldicarboxylic acids, such as for example and preferably succinic acid or
adipic acid and/or optionally aromatic difunctional acids, such as for example
terephthalic acid or isophthalic acid or naphthalenedicarboxylic acid and
additionally optionally small quantities of more highly functional acids, such
as for example trimellitic acid or
D) from acid- and alcohol-functionalised structural units, preferably having 2 to
12 C atoms in the alkyl chain, for example hydroxybutyric acid or hydroxy-
valeric acid or lactic acid, or the derivatives thereof, for example ~-capro-
lactone or dilactide,
or a mixture and/or a copolymer of C and D,
wherein the aromatic acids constitute a fraction of no more than 50 wt.%, relative
to all the acids.
All the acids may also be used in the form of derivatives, such as for example acid
chlorides or esters, both as monomeric and as oligomeric esters;
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E) from the reaction product of C and/or D with aliphatic and/or cycloaliphatic
difunctional and additionally optionally more highly functional isocyanates,
preferably having I to 12 C atoms or 5 to 8 C atoms in the case of
cycloaliphatic isocyanates, for example tetramethylene diisocyanate,
hexamethylene diisocyanate, isophorone diisocyanate, optionally additionally
with linear and/or branched and/or cycloaliphatic difunctional and/or more
highly functional alcohols, preferably C3-C,2 alkyldi- or polyols or 5 to 8 C
atoms in the case of cycloaliphatic alcohols, for example ethanediol,
hex~n~-liol, butanediol, cyclohPx~ne~limethanol, and/or optionally additionally
with linear and/or branched and/or cyclo~liph~tic difunctional and/or more
highly functional amines and/or aminoalcohols preferably having 2 to 12 C
atoms in the alkyl chain, for example ethylen~di~mine or aminoethanol,
and/or optionally further modified amines or alcohols, such as for example
ethylçne~ min~ethanesulfonic acid, as the free acid or the salt,
wherein the ester fraction C) and/or D) amounts to at least 75 wt.%, relative to the
sum of C), D) and E), wherein, in the polymer structure typical of polyurethanesoptionally comprising soft segments C) and D) and hard segments E), a completelyrandom distribution of the raw materials in the polymer is not to be expected;
Aliphatic or aliphatic-aromatic polyestercarbonates prepared from
F) aliphatic difunctional alcohols, preferably linear C2-C10 dialcohols, such as for
example ethanediol, butanediol, hexanediol, particularly preferably butanediol
and/or optionally cycloaliphatic difunctional alcohols, preferably having 5 to
8 C atoms in the cycloaliphatic ring, such as for example cyclohexanedimeth-
anol and/or, partially or entirely instead of the diols, monomeric or oligo-
meric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or
copolymers thereof having molecular weights of up to 4000, preferably of up
to 1000, and/or optionally small quantities of branched, difunctional alcohols,
preferably C3-C12 alkyldiols, such as for example neopentyl glycol and
additionally optionally small quantities of more highly functional alcohols,
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preferably C3-CI2 alkylpolyols, such as for example 1,2,3-propanetriol or
trimethylolpropane and from aliphatic, difunctional acids, preferably C2-CI2
alkyldicarboxylic acids, such as for example and preferably succinic acid or
adipic acid and/or optionally aromatic difunctional acids, such as for example
S terephthalic acid or isophthalic acid or n~phth~lenedicarboxylic acid and
additionally optionally small quantities of more highly functional acids, such
as for example trimellitic acid or
G) from acid- and alcohol-functionalised structural units, preferably having 2 to
12 C atoms in the alkyl chain, for example hydroxybutyric acid or hydroxy-
valeric acid or lactic acid, or the derivatives thereof, for example ~-capro-
lactone or dilactide,
or a mixture and/or a copolymer of F and G,
wherein the aromatic acids constitute a fraction of no more than 50 wt.%, relative
to all the acids.
All the acids may also be used in the form of derivatives, such as for example acid
chlorides or esters, both as monomeric and as oligomeric esters;
H) a carbonate fraction which is produced from aromatic difunctional phenols,
preferably bisphenol A, and carbonate donors, preferably phosgene, or a
carbonate fraction which is produced from aliphatic carbonic acid esters or
the derivatives thereof, such as chlorocarbonic acid esters or aliphatic
carboxylic acids or the derivatives thereof, such as for example salts and
carbonate donors, for example phosgene.
The ester fraction F) and/or G) must amount to at least 70 wt.%, relative to the sum
of F), G) and H);
Aliphatic or partially aromatic polyesteramides plel)aled from
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I) aliphatic difunctional alcohols, preferably linear C2-C~0 dialcohols, such as for
example ethanediol, butanediol, hex~ne~liol, particularly preferably butanediol
and/or optionally cyclo~liph~tic difunctional alcohols, preferably having 5 to
8 carbon atoms, such as for example cyclohex~n~.1imethanol and/or, partially
or entirely instead of the diols, monomeric or oligomeric polyols based on
ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof
having molecular weights of up to 4000, preferably of up to 1000, and/or
optionally small quantities of branched, difunctional alcohols, preferably C3-
C,2 alkyldiols, such as for example neopentyl glycol and additionally
optionally small quantities of more highly functional alcohols, preferably C3-
C,2 alkylpolyols, such as for example 1,2,3-propanetriol or trimethylolplopalle
and from aliphatic, difunctional acids, preferably having 2 to 12 C atoms in
the alkyl chain, such as for example and preferably succinic acid or adipic
acid and/or optionally aromatic difunctional acids, such as for example
terephthalic acid or isophthalic acid or naphthalenedicarboxylic acid and
additionally optionally small quantities of more highly functional acids, such
as for example trimellitic acid or
K) from acid- and alcohol-functionalised structural units, preferably having 2 to
12 C atoms in the carbon chain, for example hydroxybutyric acid or hydroxy-
valeric acid or lactic acid, or the derivatives thereof, for example ~-capro-
lactone or dilactide,
or a mixture and/or a copolymer of I) and K),
wherein the aromatic acids constitute a fraction of no more than 50 wt.%, relative
to all the acids.
All the acids may also be used in the form of derivatives, such as for example acid
chlorides or esters, both as monomeric and as oligomeric esters;
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L) an amide fraction prepared from aliphatic and/or cyclo~liph~tic difunctional
and/or optionally small quantities of branched difunctional ~mines, linear
aliphatic C2-C~0 diamines being preferred, and additionally optionally small
quantities of more highly functional amines, hexamethylene~i~mine,
S isophorone~ mine being preferred among the amines and hexamethylene-
diamine being particularly preferred, and from linear and/or cycloaliphatic
difunctional acids, preferably having 2 to 12 C atoms in the alkyl chain or a
C5-C6 ring in the case of cyclo~lirh~tic acids, preferably adipic acid and/or
optionally small quantities of branched, difunctional and/or optionally
aromatic difunctional acids, such as for example terephthalic acid or
isophthalic acid or naphthalenedicarboxylic acid and additionally optionally
small quantities of more highly functional acids, preferably having 2 to 10 C
atoms or
15 M) from an amide fraction prl pal~d from acid- and amine-functionalised
structural units, preferably having 4 to 20 C atoms in the cycloaliphatic chain,preferably ci)-laurolactam and ~-caprolactam, particularly preferably ~-
caprolactam,
or a mixture of L) and M) as the amide fraction.
The ester fraction I) and/or K) must amount to at least 30 wt.%, relative to the sum
of I), K), L) and M). The fraction by weight of the ester structures is preferably
between 30 and 70%, the fraction of the amide structures between 70 and 30%.
The biodegradable polyesteramides according to the invention may be syntheci.~e~l
both in accordance with the "polyamide method" by stoichiometric mixing of the
starting components optionally with the addition of water and subsequent removalof water from the reaction mixture and in accordance with the "polyester method"by stoichiometric mixing of the starting components together with the addition of an
excess of diol with esterification of the acid groups and subsequent tr~n~esterification
or transamidation of these esters. In this second case, the excess of diol is distilled
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off again together with the water. Synthesis in accordance with the deseribed
"polyester method" is preferred.
The polyesters, polyesterurethanes, polye~lelc~l.onates or preferably polyesteramides
5 according to the invention may furthermore contain 0.1 to 5 wt.%, preferably 0.1 to
1 wt.% of br~nching agents. These branching agents may be, for exarnple,
trifunctional alcohols, such as trimethylolpropane or glycerol, tetrafunctional alcohols
such as pentaerythritol, trifunctional carboxylic acids such as citrie aeid. Thebr~nrhing agents inerease the melt viseosity of the polye~le.dll,ides aeeording to the
10 invention to sueh an extent that extrusion blow moulding is possible with these
polymers. Biodegradation of these materials is not hindered as a eonsequence.
Polycon(ien~tion may furthermore be accelerated by the use of known catalysts.
Possible catalysts for accelerating polycon~en~tion are not only known phosphorus
15 compounds, which accelerate polyamide synthesis, and acidic or organometallic esterification catalysts, but also combinations of the two types.
Care must be taken to ensure that the catalysts have a negative effect neither on
biodegradability or compostability nor on the quality of the resultant compost.
Polycondensation to yield polyesteramides may furthermore be influenced by the use
of lysine, lysine derivatives or other amide br~n~hing products, such as for example
aminoethylaminoethanol, which both accelerate contlen~tion and give rise to
branched products (c.~ for example DE 38 31 709).
The completely compostable polyesterurethanes, polyesters, polye~l~rc~l,onates and
polyesteramides according to the invention may be provided with fillers and
reinforcing materials and/or with processing auxiliaries, such as for example
nucleating auxiliaries, mould release auxiliaries or stabilisers, wherein care must be
30 taken to ensure that complete compostability is not impaired or the rem~iningsubstances, for example mineral auxiliaries, are innocuous in the compost.
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Fillers and reinforcing materials suitable according to the invention may be minerals,
such as for example kaolin, chalk, gypsum (a or ~3 modification), lime or talc or
natural substances, such as for example starch or modified starch, cellulose or
cellulose derivatives or cellulose products, wood flour or natural fibres, such as for
5 example hemp, flax, rape or ramie.
The completely compostable polyesterurethanes, polyestercarbonates and polyester-
amides according to the invention may also be mixed with further blend components,
wherein care must be taken to ensure that complete compostability is not inlpailed
10 or the rem~ining substances, for example mineral auxiliaries, are innocuous in the
compost.
Blowing agents usable according to the invention may be substances which are
gaseous under melt processing conditions, for example compounds which elimin~te
15 nitrogen, water or carbon dioxide, vaporisable compounds or reaction products of
two or more compounds which are gaseous under melt processing conditions.
The group of blowing agents elimin~ting gaseous subst~nre~, for example nitrogen,
water or carbon dioxide under melt processing conditions includes, for example, azo
20 compounds, such as for example and preferably hydrazides, such as for example and
particularly preferably toluenesulfonic acid hydrazide, or carbonates, such as for
example calcium carbonate or sodium carbonate or preferably hydrogen carbonates,among these preferably sodium hydrogen carbonate, or mineral salts which elimin~te
water.
The group of blowing agents con~i~ting of vaporisable compounds includes, for
example, pentane, cyclopentane or C, halogenated hydrocarbons.
The group of reaction products of two or more compounds, which are gaseous under30 melt processing conditions, includes for example and preferably mixtures of acids,
among the acids preferably lactic acid, oxalic acid and particularly preferably citric
acid, and CO2 donors, such as for example carbonates and bicarbonates.
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The blowing agents are generally used in a quantity of 0.1 to 30, preferably of 0.5
to 15, particularly preferably of 1 to 8 wt.%, relative to the entire llli~Ule.
The present invention furthermore provides a process for the production of the
S articles according to the invention, characterised in that the lllixlufe of the completely
compostable polymers resistant to water and water vapour according to the invention
is mixed with the blowing agents and the mixture is melt processed. Melt processing
may comprise extrusion, for example to yield foamed profiles. Melt processing may
also c~lllpl,se injection moulding to yield foamed mo~ inEs, such as for example10 dishes or cups. Melt processing may also comprise vigorous mixing below the
foaming telllyel~ule, for example in a kne~(lçr, and subsequent heat treatment at
above the foaming temperature to yield components, such as for example semi-
finished products.
lS The present invention furthermore provides the use of the completely compostable
polymers resistant to water and water vapour according to the invention for the
production of foamed mouldings.
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Examples
Example 1
A biodegradable polyesteramide comprising a 60 wt.% fraction of polycaprolactam
and a 40 wt.% fraction of an ester of adipic acid and butanediol (relative solution
viscosity: 2.5, measured on a 1 wt.% solution in meta-cresol at 20~C) is extruded at
145~C with 5 wt.% (relative to the entire ~ lu~e) of tol~len~s.llfonic acid hydrazide.
A foamed extrudate having a bulk density of 0.6 g/cm3 is obtained.
Example 2
20 g of a biodegradable polyesteramide comprising a 60 wt.% fraction of polycapro-
lactam and a 40 wt.% fraction of an ester of adipic acid and butanediol (relative
solution viscosity: 2.5, measured on a 1 wt.% solution in meta-cresol at 20~C) are
intim~tely mixed with 1 g of azodicarbonamide at 150~C in a kne?~er, transferredinto an open, heat-resistant mould and then heated for 30 minutes at 200~C in anoven. A coarse-cell foam having a bulk density of 0.07 g/cm3 is obtained.
Example 3
A biodegradable polyesteramide comprising a 60 wt.% fraction of polycaprolactam
and a 40 wt.% fraction of an ester of adipic acid and butanediol (relative solution
viscosity: 2.5, measured on a 1 wt.% solution in meta-cresol at 20~C) is extruded at
135~C with 0.5 wt.% (relative to the entire mixture) of sodium hydrogen carbonate.
A foamed extrudate having a bulk density of 0.7 g/cm3 is obtained.
