EP0894113A2

EP0894113A2 - Compostable and thermoplastically processable foams

Info

Publication number: EP0894113A2
Application number: EP97916447A
Authority: EP
Inventors: Ernst Grigat; Hanns Peter MÜLLER; Wolfgang Schulz-Schlitte
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1996-04-18
Filing date: 1997-04-07
Publication date: 1999-02-03
Also published as: JP2000508698A; CA2251932A1; WO1997040091A3; NZ332356A; AU728971B2; CN1216558A; DE19615356A1; WO1997040091A2; AU2509297A

Abstract

The invention relates to foamed mouldings produced from polymers selected from the group of aliphatic or partially aromatic polyesters, thermoplastic aliphatic or partially aromatic polyester urethanes, aliphatic or aliphatic-aromatic polyester carbonates and aliphatic polyester amides which are mixed with blowing agents and thermoplastically processed. The invention also relates to a process for producing the objects of the invention.

Description

Compostable and thermoplastically processable foams

Foamed thermoplastically processable plastics are known (see Rompp chemistry lexicon, keyword "foam plastics" Vol 5, 9 edition, Thieme Verlag

1992) Among other things, they can be obtained by using blowing agents (see Rompp chemistry lexicon, keyword "blowing agent", Vol 1, 9 edition, Thieme Verlag 1990)

The task now was to produce completely compostable, water- and steam-resistant objects with a low density

Task in that certain completely compostable, water- and water vapor-resistant polymers were processed into suitable articles using suitable blowing agents, preferably in a thermoplastic production process

The invention thus relates to foamed moldings produced from polymers selected from the group of the aliphatic or partially aromatic

Polyesters, thermoplastic aliphatic or partially aromatic polyester urethanes, aliphatic or aliphatic-aromatic polyester carbonates and aliphatic polyester amides, which are mixed with blowing agents and processed thermoplastic

The invention also relates to a method for producing the objects according to the invention

The invention furthermore relates to the use of certain completely compostable, water- and steam-resistant polymers for the production of foamed moldings

The following polymers are suitable

Aliphatic or partially aromatic polyester

A) aliphatic bifunctional alcohols, preferably linear C ₂ -C ₁₀ dialcohols such as ethanediol, butanediol, hexanediol, particularly preferably butanediol and / or optionally cycloaliphatic bifunctional alcohols, preferably with C ₅ -C ₆ C atoms in the cycloaliphatic ring like for example cyclohexanedimethanol and / or partially or completely instead of the diols monomeric or oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights up to 4000, preferably up to 1000, and / or optionally small amounts of branched bifunctional alcohols, preferably C ₃ - C _{] 2} -

Alkyl diols such as, for example, neopentyl glycol and, if appropriate, small amounts of high-functional alcohols, preferably C ₃ -C ₁₂ -alkyl polyols such as, for example, 1,2,3-propanetriol or trimethylol propane, and from aliphatic bifunctional acids, preferably C ₂ -C ₁₂ -alkyl dicarboxylic acids such as and preferably succinic acid or

Adipic acid and / or optionally aromatic bifunctional acids such as, for example, terephthalic acid or isophthalic acid or naphthandedicarboxylic acid and additionally optionally small amounts of higher-functional acids such as trimellitic acid or

B) from acid and alcohol functionalized building blocks, preferably with 2 to

12 carbon atoms in the alkyl chain, for example hydroxybutyric acid or hydroxy valeric acid or lactic acid, or their derivatives, for example ε-caprolactone or dilactide,

or a mixture and / or a copolymer of A and B,

the aromatic acids not more than 50% by weight, based on all

Acid, make out

All acids can also be used in the form of derivatives such as acid chlorides or esters, both as monomeric and as oligomeric esters,

Aliphatic or partially aromatic polyester urethanes

C) aliphatic bifunctional alcohols, preferably linear C ₂ -C ₁₀ dialcohols such as ethanediol, butanediol, hexanediol, particularly preferably butanediol and / or optionally cycloaliphatic bifunctional alcohols, preferably with a C ₅ -C ₆ cycloaliphatic ring such as for example ¬ as cyclohexanedimethanol and / or partially or completely instead of the diols monomeric or oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights up to 4000, preferably up to 1000, and / or optionally small amounts of branched bifunctional alcohols, preferably C ₃ -C ₁₂ -alkyldiols such as neopentyl glycol and additionally optionally small amounts of high-functional alcohols, preferably C ₃ -C _{] 2} -alkyl polyols such as for example 1,2,3-propanetriol or trimethylolpropane and from aliphatic bifunctional acids, preferably C ₂ -C ₁₂ -alkyldicarboxylic acids such as, for example, and preferably succinic acid or adipic acid and / or optionally aromatic bifunctional acids such as, for example, terephthalic acid or isophthalic acid or naphthalene dicarboxylic acid and additionally, if appropriate, low Amounts of highly functional acids such as trimellitic acid or

D) from acid- and alcohol-functionalized building blocks, preferably with 2 to 12 carbon atoms in the alkyl chain, for example hydroxybutyric acid or hydroxyvaleric acid or lactic acid, or their derivatives, for example ε-caproiactone or dilactide,

or a mixture and / or a copolymer of C and D,

the aromatic acids make up no more than 50% by weight, based on all acids

E) from the reaction product of C and / or D with aliphatic and / or cycloaliphatic bifunctional and additionally optionally higher functional isocyanates, preferably with 1 to 12 C atoms or 5 to 8 C atoms in the case of cycloaliphatic isocyanates, for example tetramethyl Lene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, optionally with additional linear and / or branched and / or cycloaliphatic bifunctional and / or highly functional alcohols, preferably C ₃ -C ₁₂ alkyldi- or polyols or 5 to 8 carbon atoms in the case of cycloaliphatic alcohols, e.g. ethanediol, hexanediol, butanediol, cyclohexanedimethanol, and / or optionally additionally with linear and / or branched and / or cycloaliphatic bifunctional and / or highly functional amines and / or amino alcohols with preferably 2 to 12 C atoms of the alkyl chain, e.g. ethylenediamine or aminoethanol, and / or optionally further modified amines or alcohols such as, for example, ethylenediaminoethanesulfonic acid, as the free acid or as a salt,

wherein the ester content C) and / or D) at least 75 wt .-%, based on the

The sum of C), D) and E) is, where in the case of polymer typical for polyurethane, optionally made of soft segments C) and D) and of hard segments

E) a complete statistical distribution of the raw materials in the polymer is not expected,

Aliphatic or aliphatic-aromatic polyester carbonates

F) aliphatic bifunctional alcohols, preferably linear C ₂ -C ₁₀ dialcohols such as, for example, ethanediol, butanediol, hexanediol, particularly preferably butanediol and / or optionally cycloaliphatic bifunctional alcohols, preferably having 5 to 8 carbon atoms in the cycloaliphatic ring, such as cyclohexanedimethanol and / or partially or completely instead of the diols, monomeric or oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights up to 4000, preferably up to 1000, and / or optionally small amounts of branched bifunctional alcohols, preferably C ₃ -C ₁₂ -alkyldiols such as neopentylglycol and additionally optionally small amounts of high-functional alcohols, preferably C ₃ -C ₁₂ -alkyl polyols such as 1,2,3-propanπol or trimethylolpropane and from aliphatic bifunctional acids, preferably C ₂ -C ₁₂ -alkyldicarboxylic acids such as un d preferably succinic acid or adipic acid and / or optionally aromatic bifunctional acids such as, for example, terephthalic acid or isophthalic acid or naphthalenedicarboxylic acid and additionally optionally small amounts of high-functional acids such as trimellitic acid or

G) from acid- and alcohol-functionalized building blocks, preferably with 2 to 12 carbon atoms in the alkyl chain, for example hydroxybutyric acid or

Hydroxyvaleric acid or lactic acid, or their derivatives, for example ε-caprolactone or dilactide, or a mixture and / or a copolymer of F and G,

the aromatic acids make up no more than 50% by weight, based on all acids

H) a carbo fraction which is prepared from aromatic bifunctional phenols, preferably bisphenol-A, and carbonate donors, for example phosgene, or a carbonate fraction which is obtained from aliphatic carboxylic esters or their derivatives such as chlorocarbonic acid esters or aliphatic carboxylic acids or their derivatives like for example

Salts and carbonate donors, for example phosgene, is produced

The ester fraction F) and / or G) must be at least 70% by weight, based on the sum of F), G) and H),

Aliphatic or partially aromatic polyester amides

I) aliphatic bifunctional alcohols, preferably linear C -, - C ₁₀ -

Dialcohols such as ethanediol, butanediol, hexanediol, particularly preferably butanediol and / or optionally cycloaliphatic bifunctional alcohols, preferably having 5 to 8 carbon atoms such as cyclohexanedimethanol and / or partially or completely instead of the diols, monomeric or oligomeric polyols based on ethylene glycol,

Propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights up to 4000, preferably up to 1000, and / or optionally small amounts of branched bifunctional alcohols, preferably C ₃ -C ₁₂ -alkyldiols such as neopentyl glycol and additionally optionally small amounts of high-functional alcohols, preferably C ₃ -

C ₁₂ alkyl polyols such as 1,2,3-propanetriol or trimethylol propane and from aliphatic bifunctional acids, preferably 2 to 12 carbon atoms in the alkyl chain such as and preferably succinic acid or adipic acid and / or optionally aromatic bifunctional acids such as terephthalic acid or isophthalic acidic or naphthalenedicarboxylic acid and, if appropriate, small amounts of highly functional acids such as trimellitic acid or

K) from acid- and alcohol-functionalized building blocks, preferably with 2 to 12 carbon atoms in the carbon chain, for example hydroxybutyric acid or hydroxyvaleric acid or lactic acid, or their derivatives, for example ε-caprolactone or dilactide,

or a mixture and / or a copolymer of I) and K),

the aromatic acids making up no more than 50% by weight, based on all acids

L) an amide fraction of aliphatic and / or cycloaliphatic bifunctional and / or optionally small amounts of branched bifunctional amines, linear aliphatic C ₂ -C _{] 0} -diamines are preferred, and additionally optionally small amounts of high-functional amines are preferred among the amines Hexamethylene diamine, isophorone diamine and particularly preferably hexamethylene diamine, and from linear and / or cycloaliphatic bifunctional acids, preferably with 2 to 12 carbon atoms in the alkyl chain or C ₅ -C ₆ ring in the case of cycloaliphatic acids, preferably adipic acid and / or optionally small amounts of branched bifunctional and / or optionally aromatic bifunctional acids such as, for example, terephthalic acid or isophthalic acid or naphthalenedicarboxylic acid and additionally optionally small amounts of high-functional acids, preferably with 2 to 10 carbon atoms or

M) from an amide portion of acid and amine functionalized building blocks, preferably with 4 to 20 C atoms in the cycloaliphatic chain, preferably bevorzugt-laurolactam and ε-caprolactam, particularly preferably ε-caprolactam,

or a mixture of L) and M) as an amide component The ester content I) and / or K) must be at least 30% by weight, based on the sum of I), K), L) and M). The proportion by weight of the ester structures is preferably between 30 and 70%, the proportion of the amide structures between 70 and 30%.

The biodegradable polyesteramides according to the invention can be synthesized either by the "polyamide method" by stoichiometric mixing of the starting components, if appropriate with the addition of water and subsequent removal of water from the reaction mixture, or by the "polyester method" by stoichiometric mixing of the starting components and additions of an excess of diol with esterification of the acid groups and subsequent transesterification or transamidation of these esters. In this second case, the excess diol is distilled off in addition to water. Preference is given to synthesis by the "polyester method" described.

The polyesters, polyester urethanes, polyester carbonates or preferably polyester amides according to the invention can furthermore 0.1 to 5 wt .-%, preferably 0.1 to

1 wt .-% of branching contain. These branchers can e.g. trifunctional alcohols such as trimethylolpropane or glycerol, tetrafunctional alcohols such as pentaerythritol, trifunctional carboxylic acids such as citric acid. The branching agents increase the melt viscosity of the polyester amides according to the invention to such an extent that extrusion blow molding with these polymers is possible. This does not hinder the biodegradation of these materials.

The polycondensation can also be accelerated by using known catalysts. Both the known phosphorus compounds that accelerate polyamide synthesis and acidic or organometallic catalysts for the esterification, as well as combinations of the two, are used

Acceleration of polycondensation possible.

Care must be taken to ensure that the catalysts do not adversely affect the biodegradability or compostability or the quality of the resulting compost.

Furthermore, the polycondensation to polyester amides can be influenced by the use of lysine, lysine derivatives or other amidic branching products such as aminoethylaminoethanol, which both the condensate Accelerate sation as well as lead to branched products (see for example DE 38 31 709).

The fully compostable polyester urethanes, polyesters, polyester carbonates and polyester amides according to the invention can be equipped with fillers and reinforcing materials and / or with processing aids such as, for example, nucleation aids, mold release aids or stabilizers, it being important to ensure that the complete compostability is not impaired or the remaining ones Substances, such as mineral aids, are harmless in the compost.

Fillers and reinforcing materials suitable according to the invention can be minerals such as kaolin, chalk, gypsum (α- or β-modification), lime or talc or natural substances such as starch or modified starch, cellulose or cellulose derivatives or cellulose products, wood flour or natural fibers such as hemp, Flax, rapeseed or ramie.

The completely compostable polyester urethanes, polyester carbonates and polyester amides according to the invention can also be mixed with other blend partners, it being important to ensure that the full compostability is not impaired or that the remaining substances, for example mineral auxiliaries, are harmless in the compost.

Blowing agents which can be used according to the invention can be thermoplastic

Processing conditions of gaseous substances, for example nitrogen, water or compounds which release carbon dioxide, vaporizable compounds or reaction products of several compounds which are gaseous under thermoplastic processing conditions.

The group of blowing agents which release gaseous substances, for example nitrogen, water or carbon dioxide, under thermoplastic processing conditions includes, for example, azo 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, such as sodium hydrogen carbonate, or water-releasing mineral salts. The group of blowing agents, which consist of vaporizable compounds, includes, for example, pentane, cyclopentane or C, -halohydrocarbons

The group of reaction products consisting of several compounds which are gaseous under thermoplastic processing conditions includes, for example and preferably, mixtures of acids, among the acids preferably lactic acid,

Oxalic acid and particularly preferably citric acid and CO ₂ donors such as carbonates and bicarbonates

The blowing agents are generally used in an amount of 0.1 to 30, preferably 0.5 to 15, particularly preferably 1 to 8% by weight, based on the mixture as a whole

The invention furthermore relates to a process for producing the articles according to the invention, characterized in that the mixture of the completely compostable, water- and steam-resistant polymers according to the invention is mixed with the blowing agents and the mixture is processed thermoplastic. The thermoplastic processing can be extrusion, for example foamed profiles The thermoplastic processing can also be injection molded into foamed moldings such as bowls or cups. The thermoplastic processing can also be intensive mixing below the foaming temperature, for example on a kneader, and subsequent tempering above the foaming temperature to parts such as semi-finished products

The invention furthermore relates to the use of the fully compostable, water- and steam-resistant polymers according to the invention for the production of foamed moldings

Examples

example 1

A biodegradable polyester amide composed of 60% by weight of polycaprolactam and 40% by weight of an ester of adipic acid and butanediol (relative solution viscosity: 2.5, measured on a 1% by weight solution in meta-

Cresol at 20 ° C.) is extruded with 5% by weight (based on the entire mixture) of toluenesulfonic acid hydrazide at 145 ° C. A foamed extrudate with a bulk density of 0.6 g / cm ^{3 is obtained}

Example 2

20 g of a biodegradable polyester amide composed of 60% by weight of polycaprolactam and 40% by weight of an ester of adipic acid and butanediol (relative solution viscosity 2.5, measured on a 1% strength solution in meta-cresol at 20 ° C) are intimately mixed with 1 g of azodicarbonamide at 150 ° C in a kneader, placed in an open temperature-resistant mold and then heated in an oven for 30 minutes at 200 ° C. A coarse-pored foam with a bulk density of 0.07 g / cm is obtained

Example 3

A biodegradable polyester amide composed of 60% by weight of polycaprolactan and 40% by weight of an ester of adipic acid and butanediol (relative solution viscosity 2.5, measured on a 1% by weight solution in meta-cresol at 20 ° C.) is also included 0.5% by weight (based on the entire mixture) of sodium hydrogen carbonate extruded at 135 ° C. A foamed extrudate with a bulk density of 0.7 g / cm is obtained

Claims

claims

1. Foamed moldings, produced from biodegradable polymers selected from the group of aliphatic or partially aromatic polyesters, thermoplastic aliphatic or partially aromatic polyester urethanes, aliphatic or aliphatic-aromatic polyester carbonates, aliphatic polyester amides, with blowing agents and optionally conventional Additives mixed and processed thermoplastic.

2. Foamed molded articles according to claim 1, the polymers used being:

Aliphatic or partially aromatic polyester

A) aliphatic bifunctional alcohols and / or optionally cycloaliphatic bifunctional alcohols and / or partially or completely instead of the diols monomeric or oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights of up to 4000 and / or small amounts of branched bifunctional alcohols and in addition, if appropriate, small amounts of high-functionality alcohols and of aliphatic bifunctional acids and / or if appropriate aromatic bifunctional acids and additionally if appropriate small amounts of high-functionality acids

Acids or

B) from acid- and alcohol-functionalized building blocks or their derivatives,

or a mixture and / or a copolymer of A and B,

the aromatic acids making up no more than 50% by weight, based on all acids;

Aliphatic or partially aromatic polyester urethanes C) aliphatic bifunctional alcohols and / or optionally cycloaliphatic bifunctional alcohols and / or partially or completely instead of the diols monomeric or oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights of up to 4000 and / or small amounts of branched bifunctional alcohols and additionally optionally small amounts of high-functionality alcohols and from aliphatic bifunctional acids and / or optionally aromatic bifunctional acids and additionally optionally small amounts of high-functionality acids

Acids or

D) from acid and alcohol functionalized building blocks or their derivatives,

or a mixture and / or a copolymer of C and D,

the aromatic acids making up no more than 50% by weight, based on all acids,

E) from the reaction product of C and / or D with aliphatic and / or cycloaliphatic bifunctional and additionally optionally high-functional isocyanates, optionally additionally with linear and / or branched and / or cycloaliphatic bifunctional and / or highly functional alcohols and / or optionally additionally with linear ones and / or branched and / or cycloaliphatic bifunctional and / or highly functional amines and / or amino alcohols and / or optionally further modified amines or alcohols,

wherein the ester fraction C) and / or D) is at least 75% by weight, based on the sum of C), D) and E),

Aliphatic or aliphatic-aromatic polyester carbonates

F) aliphatic bifunctional alcohols and / or optionally cycloaliphatic bifunctional alcohols and / or partially or completely, instead of the diols, monomeric or oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights of up to 4000 and / or possibly small amounts of branched bifunctional alcohols and additionally optionally small amounts of high-functionality alcohols and from aliphatic bifunctional acids and / or optionally aromatic bifunctional acids and additionally optionally small amounts of high-functional acids or

G) from acid and alcohol functionalized building blocks or their

Derivatives,

or a mixture and / or a copolymer of F and G,

the aromatic acids making up no more than 50% by weight, based on all acids;

H) a carbo fraction which is produced from aromatic bifunctional phenols and carbonate donors or a carbonate fraction which is produced from aliphatic carbonic acid esters or their derivatives or aliphatic carboxylic acids or their derivatives and carbonate donors,

wherein the ester fraction F) and / or G) is at least 70% by weight, based on the sum of F), G) and H);

Aliphatic or partially aromatic polyester amides

I) aliphatic bifunctional alcohols and / or optionally cycloaliphatic bifunctional alcohols and / or partially or completely instead of the diols monomeric or oligomeric polyols based on ethylene glycol, propylene glycol, tetrahydrofuran or copolymers thereof with molecular weights of up to 4000 and / or optionally small amounts of branched bifunctional alcohols ¬ fetch and, if necessary, small amounts of higher functional alcohols and aliphatic bifunctional acids and / or optionally aromatic bifunctional acids and additionally optionally small amounts of higher functional acids or

K) from acid- and alcohol-functionalized building blocks or their derivatives,

or a mixture and / or a copolymer of I) and K),

the aromatic acids make up no more than 50% by weight, based on all acids,

L) an amide portion of aliphatic and / or cycloaliphatic bifunctional and / or optionally small amounts of branched bifunctional amines and additionally optionally small amounts of higher functional amines and of linear and / or cycloaliphatic bifunctional and / or optionally small amounts of branched bifunctional and / or optionally aro - Matic bifunctional acids and additionally, if necessary, small amounts of highly functional acids or

M) from an amide portion from acid and amine functionalized building blocks,

or a mixture of L) and M) as an amide component, wherein

the ester content I) and / or K) at least 30% by weight, based on the

The sum of I), K), L) and M) is and where all acids can also be used in the form of derivatives, both as monomeric and as oligomeric esters

A process for the production of foamed molded articles according to claim 1, wherein the biodegradable polymers are mixed with the blowing agents and the mixture is processed thermoplastic 4. Use of biodegradable polymers according to claim 1 and

2 for the production of foamed moldings using blowing agents.