EP0894118A1

EP0894118A1 - Compostable waterproof coating

Info

Publication number: EP0894118A1
Application number: EP97916448A
Authority: EP
Inventors: Ernst Grigat; Karsten-Josef Idel; Uwe Westeppe; Wolfgang Schulz-Schlitte; Winfried Pommeranz; Jürgen Lörcks; Harald Schmidt
Original assignee: Bayer AG; BioTec Biologische Naturverpackungen GmbH and Co KG
Current assignee: Bayer AG; BioTec Biologische Naturverpackungen GmbH and Co KG
Priority date: 1996-04-18
Filing date: 1997-04-07
Publication date: 1999-02-03
Also published as: JP2000508700A; CN1216568A; WO1997040111A1; AU2509397A; DE19615348A1; CA2251829A1

Abstract

The invention pertains to a compostable waterproof coating, a process for producing it and its use for coating objects.

Description

Compostable waterproof cover

The present invention relates to a compostable waterproof coating, a method for producing the same and the use of the coating for coating objects.

From an ecological point of view, for many purposes, for example, disposable tableware, one is interested in using completely biodegradable (in this application equated with compostable) materials. Paper or cardboard, for example, are ideal for this. The hydrophobization of these materials is problematic because they have to be waterproof for use, for example, as disposable tableware.

Therefore, the task was to develop a completely biodegradable coating system, which is both technically usable - mechanically producible flexible coatings with a small layer thickness - and fully biodegradable.

The task was solved by dissolving completely biodegradable polymers in suitable solvents and using this solution for spraying compostable parts. The coating is created by running the solution with subsequent evaporation of the solvent.

Suitable biodegradable polymers are aliphatic or partially aromatic polyesters, thermoplastic aliphatic or partially aromatic polyester urethanes, aliphatic or aliphatic-aromatic polyester carbonates, aliphatic polyester amides.

The following polymers are suitable:

Aliphatic or partially aromatic polyester

A) aliphatic bifunctional alcohols, preferably linear C ₂ -C ₁₀ -dialkohoien such as ethanediol, butanediol, hexanediol, particularly preferably butanediol and / or optionally cycloaliphatic bifunctional alcohols, preferably with C ₅ -C ₆ -C atoms in cycloaliphatic ring like 40111 PC17EP97 / 01723

- 2 -

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 ₁₂ -

Alkyl diols such as neopentyl glycol and, if necessary, small amounts of higher functional alcohols, preferably C ₃ -C ₁₂ alkyl polyols such as 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 terephthalic acid or isophthalic acid or naphthalenedicarboxylic 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 hydroxyvaleric 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 making up no more than 50% by weight, based on all acids.

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 _{] 2} -alkyl diols such as neopentyl glycol and additionally optionally small amounts of higher-functional alcohols, preferably C ₃ -C ₁₂ alkyl polyols such as for example 1,2,3-propanetriol or trimethylolpropane and from aliphatic bifunctional acids, preferably C ₂ -C _{] 2} -alkyldicarboxylic acids such as, for example, and preferably succinic acid or adipic acid and / or optionally aromatic bifunctional acids such as terephthalic acid or isophthalic acid or naphthalenedicarboxylic acid and additionally, if appropriate small amounts of higher 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-caprolactone or dilactide,

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 higher functional isocyanates, preferably with 1 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 bifunctional and / or higher-functional alcohols, preferably C ₃ -C ₁₂ -alkyldi- or -polyols or 5 to 8 C- Atoms in the case of cycloaliphatic alcohols, for example ethanediol, hexanediol, butanediol, cyclohexanedimethanol, and / or optionally additionally with linear and / or branched and / or cycloaliphatic bifunctional and / or higher-functional amines and / or amino alcohols with preferably 2 to 12 C atoms of the alkyl chain, e.g. Ethyl endiamine or aminoethanol, and / or optionally further modified amines or alcohols such as, for example, ethylenediaminoethanesulfonic acid, as the free acid or as a salt,

the ester fraction C) and / or D) at least 75% by weight, 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 higher-functional alcohols, preferably C ₃ -C ₁₂ -alkyl polyols such as 1,2,3-propanetriol or trimethylolpropane and from aliphatic bifunctional acids, preferably C ₂ -C ₁₂ -alkyldicarboxylic acids such as for example e and 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 higher 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 making 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 carbonic acid 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 ₂ -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, if appropriate, small amounts of higher-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 C atoms in the alkyl chain such as and preferably succinic acid or adipic acid and / or optionally aromatic bifunctional acids such as terephthalate acid or isophthalic acid or naphthalenedicarboxylic acid and, if necessary, small amounts of higher 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 and, in addition, small amounts of higher-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 higher-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 carbon atoms in the cycloaliphatic chain, preferably ώ-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 weight content of the ester structures is preferably between 30 and 70%, the content of the amide structures between 70 and 30%

The biodegradable polyesteramides according to the invention can be synthesized either by the "polyamide method" by stochiometrically mixing the starting components, if appropriate with addition of water and subsequent removal of water from the reaction mixture, or by the "polyester method" by stochiometrically mixing the starting components as well as additions of an excess of diol with esterification of the acid groups and subsequent transesterification or re-embedding of these esters. In this second case, the excess of diol is also evaporated off, in addition to water. Preference is given to synthesis by the snow-covered "polyester method" "

The polyesters, polyester urethanes, polyester carbonates or preferably polyester amides according to the invention can furthermore contain 0.1 to 5% by weight, preferably 0.1 to

1% by weight of branching agents These branching agents can be, for example, trifunctional alcohols such as trimethylolpropane or glycerol, tetrafunctional alcohols such as pentaerythritol, trifunctional carboxylic acids such as citric acid This does not hinder materials

The polycondensation can also be accelerated by using known catalysts. Both the known phosphorus compounds which 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 amidically branching products such as, for example, aminoethylaminoethanol, which both the condensate Accelerate station as well as lead to branched products (see for example DE 38 31 709)

Solvents which can be used according to the invention can be: alcohols, ketones, ethers, halogenated or halogen-free hydrocarbons or esters. Acetone, ethyl acetate, isopropanol, methanol, dichloromethane, chloroform, tetrahydrofuran or toluene are preferred. Ethanol is particularly preferred

Solvents which can be used according to the invention can also be mixtures of the solvents mentioned and mixtures including other solvents, such as water

According to the invention, the concentrations of the solutions are between 70% by weight and 1% by weight of polymer, preferably between 50% and 8% by weight of polymer, particularly preferably between 40% and 19% by weight of polymer

The coatings according to the invention can also be combined with other additives such as fillers or additives, for example

Adhesion improvers or release agents to be made with the solutions

The present invention furthermore relates to a method for waterproofing non-waterproof compostable objects by means of the coatings according to the invention, characterized in that solutions of compostable plastics are applied in accordance with the composition according to the invention and the coatings are formed therefrom. The application can take place, for example, by pouring, brushing or, preferably, spraying.

The present invention furthermore relates to a method for waterproofing non-waterproof compostable objects by means of the coatings according to the invention, characterized in that the preparation of the solutions of compostable plastics which are used for application are prepared in a suitable bonding device, preferably at temperatures above 60 ° C and immediately (in no longer than 10 minutes) to apply. This can be done discontinuously or preferably continuously. The present invention further relates to a method for waterproofing non-waterproof compostable objects by means of the coatings according to the invention, characterized in that the curing of the coatings is accelerated. This can be done, for example, by physical means, such as accelerated removal of the solvent, for example in vacuo or at elevated temperature, or, for example, by adding crystallization accelerators (nucleating agents) or, for example, by adding reactive solidifier.

The non-waterproof compostable objects can be: cellulose products such as paper or cardboard, textile structures such as fabrics or nonwovens, wood or wood-based materials, starchy materials such as starch foam with or without biodegradable polymers as blend partners, foils or molded parts made of biodegradable materials, Leather or leather materials, chitin or products made from it.

The coatings of the invention are also suitable for paper coating. The coatings according to the invention can also be used to inhibit corrosion of metals.

The present invention also relates to the finished waterproof compostable parts provided with coatings, such as, for example, disposable tableware, storage containers or coffins.

The layer thickness of the coating is generally 0.1 to 20, preferably 0.5 to 10, in particular 1 to 5 μm.

The present invention also relates to compostable temporary coverings which are intended to be removed again after a certain period of time, such as protective covers for transporting or storing objects.

The present invention also relates to compostable coatings which enable the coated material to be heat-sealed. Examples

example 1

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 with a relative solution viscosity of 2.5, measured in a 1% by weight solution

Solution in meta-cresol at 20 ° C, are dissolved in 80 g ethanol at 75 ° C. The solution is sprayed onto a bowl of starch foam and left to dry for 1 hour at room temperature.

The bowl is filled with 90 ° C warm water and the water is allowed to cool in it (approx. 1 hour). The shell is visually and in use none

Changes on.

Example 2 (comparison)

An untreated bowl - except for the coating identical to the bowl from Example 1 - is soaked within one minute when filled with 90 ° C warm water and the water runs through it.

Claims

claims

1. Compostable waterproof coating, made from a solution of 1 to 70 wt .-%, based on the polymer portion, biodegradable polymer 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 and subsequent evaporation of the solvent.

2. A coating according to claim 1, wherein the polymers used are:

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 higher-functionality alcohols and from aliphatic bifunctional acids and / or optionally aromatic bifunctional acids and additionally if appropriate small amounts of higher-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 in addition, if appropriate, small amounts of higher-functionality alcohols and from aliphatic bifunctional acids and / or optionally aromatic bifunctional acids and additionally if appropriate small amounts of higher-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 higher-functional isocyanates, optionally additionally with linear and / or branched and / or cycloaliphatic bifunctional and / or higher-functional alcohols and / or optionally additionally with linear and / or branched and / or cycloaliphatic bifunctional and / or higher functional amines and / or amino alcohols and / or optionally further modified amines or alcohols,

wherein the ester content 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 4,000 and / or possibly small amounts of branched bifunctional alcohols and additionally optionally small amounts of higher-functional alcohols and from aliphatic bifunctional acids and / or optionally aromatic bifunctional acids and additionally optionally small amounts of higher 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 making up no more than 50% by weight, based on all acids;

L) an amide component from aliphatic and / or cycloaliphatic bifunctional and / or optionally small amounts of branched bifunctional amines and additionally optionally small amounts of higher functional amines and from linear and / or cycloaliphatic bifunctional and / or optionally small amounts of branched bifunctional and / or optionally aro - Bifunctional acids and, if necessary, small amounts of higher-functionality acids or

M) from an amide component 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

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.

3. A coating according to claim 1, wherein alcohols, ketones, ethers, halogenated or halogen-free hydrocarbons or esters are used as solvents.

4. A coating according to claim 3, wherein acetone, ethyl acetate, isopropanol, methanol, dichloromethane, chloroform, tetrahydrofuran, ethanol or toluene is used.

5. A coating according to claim 4, wherein ethanol is used as a solvent.

6. Use of solutions according to claim 1 as a coating of biodegradable materials or objects.

7. Use according to claim 6 as a temporary biodegradable coating of objects.

8. Use of the coatings according to claim 6 for heat sealing the coated materials.