DE102017128847A1 - Biodegradable footwear based on polylactic acid - Google Patents

Abstract

The present invention relates to a footwear comprising a shoe sole (S) comprising at least an upper (1) and a lower layer (2), wherein the upper layer (1) consists of a particle foam containing more than 50 wt .-% polylactic acid , based on the total mass of the particle foam in the upper layer (1), and the upper (1) and the lower layer (2) are interconnected.

Description

The present invention relates to a footwear comprising a shoe sole (S) comprising at least an upper (1) and a lower layer (2), wherein the upper layer (1) consists of a particle foam containing more than 50 wt .-% polylactic acid , based on the total mass of the particle foam in the upper layer (1), and the upper (1) and the lower layer (2) are interconnected.

Furthermore, the invention relates to the use of an expandable and the use of an expanded polylactic acid-containing granules for the production of shoe soles (S).

In the literature, the use of biodegradable foams based on polyesters for the production of shoe soles has already been described.

So revealed the WO 2015/052020 A1 The use of expanded foam particles for the production of shoe soles The expanded foam particles are produced from a granulate containing at least one biodegradable polyester. The biodegradable polyester is obtainable by polycondensation of 40 to 60 mol% of a succinic acid, adipic acid, azelaic acid, sebacic acid, brassylic acid or their respective ester-forming derivatives or mixtures thereof, 40 to 60 mol% of a terephthalic acid or its ester-forming derivatives, 98.5 to 100 mole% of 1,4-butanediol or 1,3-propanediol or mixtures thereof and 0.05 to 1.5% by weight of one or more compounds selected from the group consisting of a compound having at least three for ester formation groups, a di- or polyfunctional isocyanate or a di- or polyfunctional epoxide. The foam particles can be used to produce molded parts which can be used, for example, in the sports and leisure sector, in the packaging and automotive industries as well as for technical applications. The disadvantage is that the educts from which the biodegradable polyester according to WO 2015/052020 A1 all are based on the raw material petroleum. At the present time, however, it is desirable in the chemical industry to replace crude oil as a raw material with renewable raw materials.

The WO 2015/052019 A1 discloses shoe soles containing expanded foam particles. The expanded foam particles are made from granules containing a polyester blend composed of biodegradable polyesters based on aliphatic or aliphatic and aromatic dicarboxylic acids and aliphatic diols and polylactic acid. The WO 2015/052019 A1 points out that a maximum of 50% by weight of polylactic acid may be present in the polyester mixture. The WO 2015/052019 A1 states that the biodegradable polyester component should form the continuous phase to guarantee a process capable of processing. For this reason, included in the WO 2015/052019 A1 For the production of shoe soles disclosed polyester mixtures preferably only 10 to 30 wt .-% polylactic acid, based on the total weight of the polyester mixture.

The foam particles disclosed in the prior art for the production of shoe soles therefore have a maximum of 50% by weight of polylactic acid. For example, polylactic acid is derived from corn starch and is therefore based on renewable raw materials.

The object of the present invention is to provide a footwear comprising a shoe sole which has an increased proportion of polylactic acid and for the production of which larger quantities of renewable raw materials can thus be used. The shoe sole should also have a low weight and a perfect fit and also be biodegradable. In addition, it should be convenient and easy and inexpensive to produce.

The object is achieved by a footwear comprising a shoe sole (S) comprising at least an upper layer (1) and a lower layer (2), wherein the upper layer (1) consists of a particle foam which has more than 50 wt % Polylactic acid, based on the total mass of the particle foam in the upper layer (1), and the upper layer (1) and the lower layer (2) are bonded together.

It has surprisingly been found that in the footwear according to the invention shoe soles (S) can be used, which consist of a particle foam containing more than 50 wt .-% polylactic acid. The footwear according to the invention is also particularly light; the shoe soles (S) have only a weight between 20 and 30 g. In addition, the shoe soles (S) have a comfortable warm and soft surface for the foot.

Another advantage of the shoe sole (S) of the footwear according to the invention is its flexibility. It adapts optimally to the foot of the wearer, which is why the footwear according to the invention is perceived by the wearer as very comfortable when worn.

In addition, the particle foam constituting the upper layer (1) of the shoe sole (S) according to the invention has an increased rigidity and thus an increased stability compared to, for example, a particle foam containing more than 50% by weight of polypropylene carbonate.

In addition, on the shoe sole (S), which consists of a polylactic acid-based particle foam, a holding means (3) for receiving the foot can be easily attached, for example by welding or gluing.

An additional advantage is that the polylactic acid used to produce the footwear according to the invention is obtained from corn starch and is thus based on renewable raw materials.

Furthermore, the footwear according to the invention is biodegradable due to the high polylactic acid content, that is, it complies with DIN EN 13432 and has a percentage biodegradation of at least 90%.

In addition, the footwear or shoe sole (S) according to the invention is very low in their production, which makes them suitable, for example, for applications in the hotel industry, where they can be disposed of environmentally friendly after a single use or after a short period of use.

For the purposes of the present invention, the feature "biodegradable" for a substance or a substance mixture is fulfilled if this substance or the substance mixture according to DIN EN 13432 has a percentage degree of biodegradation of at least 90%.

In general, biodegradability causes the footwear to disintegrate in a reasonable and detectable period of time. Degradation can be effected enzymatically, hydrolytically, oxidatively and / or by the action of electromagnetic radiation, for example UV radiation, and is usually effected for the most part by the action of microorganisms such as bacteria, yeasts, fungi and algae. The biodegradability can be quantified, for example, by mixing the footwear with compost and storing it for a certain period of time. For example, according to DIN EN 13432, CO ₂ -free air is allowed to flow through matured compost during composting. The compost is subjected to a defined temperature program. Here, the biodegradability is determined by the ratio of the net CO ₂ release of the sample (after subtraction of CO ₂ release by the compost without sample) to the maximum CO ₂ release of the sample (calculated from the carbon content of the sample) as a percentage defined as biodegradation. Biodegradable footwear usually shows after a few days of composting significant signs of degradation such as fungal growth, crack and hole formation.

Other methods of determining biodegradability are described, for example, in ASTM D 5338 and ASTM D 6400-4.

In the context of the present invention, "footwear" is understood as any type of covering of the feet of a person. This can include both shoes and stockings. Preferably, it is shoes. Particularly preferred are slippers, beach sandals or flip-flops.

The footwear according to the invention comprises a shoe sole (S).

Under a "shoe sole (S)" is understood in the context of the present invention, the tread of a shoe, so the part of the shoe, which is in direct contact with the ground.

The shoe sole (S) comprises at least one upper layer (1) and at least one lower layer (2).

But it is also conceivable that the shoe sole (S) additionally contains additional layers.

In 1 is a cross section through a shoe sole (S) shown. The shoe sole (S) comprises an upper layer (1) and a lower layer (2). Both the upper layer (1) and the lower layer (2) have a bottom (1u or 2u) and a top (1o or 2o). Preferably, the lower side (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2) are connected to each other.

Upper layer (1)

The upper layer (1) consists of a particle foam containing more than 50 wt .-% polylactic acid, based on the total mass of the particle foam in the upper layer (1).

Particle foams, which are also referred to as particle foams, have long been known. In general, they are obtainable by welding prefoamed foam particles of expandable, thermoplastic polymer granules, which may optionally contain fillers.

1. i) 60 bis 98,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), Polymilchsäure,
2. ii) 1 bis 39,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen,
3. iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, und
4. iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,

enthält.The upper layer (1) of the shoe sole (S) is preferably made of a particle foam, the

1. i) from 60 to 98.9% by weight, based on the total weight of components i) to iii), of polylactic acid,
2. ii) from 1 to 39.9% by weight, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds,
3. iii) from 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and
4. iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,

contains.

1. i) 60 bis 98,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), Polymilchsäure,
2. ii) 1 bis 39,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen,
3. iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, und
4. iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,

enthält.The subject of the present invention is therefore also a footwear, characterized in that the upper layer (1) consists of a particle foam which

1. i) from 60 to 98.9% by weight, based on the total weight of components i) to iii), of polylactic acid,
2. ii) from 1 to 39.9% by weight, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds,
3. iii) from 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and
4. iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,

contains.

1. i) 65 bis 79,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), Polymilchsäure,
2. ii) 20 bis 34,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen,
3. iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, und
4. iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,

enthält.The upper layer (1) of the shoe sole (S) very particularly preferably consists of a particle foam which

1. i) from 65 to 79.9% by weight, based on the total weight of components i) to iii), of polylactic acid,
2. ii) from 20 to 34.9% by weight, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds,
3. iii) from 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and
4. iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,

contains.

1. i) 55 bis 98,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), Polymilchsäure,
2. ii) 1 bis 44,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen,
3. iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, und
4. iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,

enthält.In an alternative embodiment, the upper layer (1) of the shoe sole (S) consists of a particle foam, the

1. i) from 55 to 98.9% by weight, based on the total weight of components i) to iii), of polylactic acid,
2. ii) from 1 to 44.9% by weight, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds,
3. iii) from 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and
4. iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,

contains.

The sum of the wt .-% of components i) to iv) generally gives 100 wt .-%.

• - einer Schmelzvolumenrate (MVR) bei 190 °C und 2,16 kg nach ISO 1133 von 0,5 bis 15 ml/10 Minuten, bevorzugt von 1 bis 9 ml/10 Minuten, besonders bevorzugt von 2 bis 8 ml/10 Minuten,
• - einem Schmelzpunkt (T_m) unter 180 °C,
• - einem Glaspunkt (T_g) größer 40 °C,
• - einem Wassergehalt von kleiner 1000 ppm,
• - einem Monomeren-Restgehalt (Lactid) von kleiner 0,3 %,
• - einem Molekulargewicht von größer 50 000 Dalton.

As component i), preference is given to using polylactic acid having the following property profile:

• - a melt volume rate (MVR) at 190 ° C and 2.16 kg after ISO 1133 from 0.5 to 15 ml / 10 minutes, preferably from 1 to 9 ml / 10 minutes, more preferably from 2 to 8 ml / 10 minutes,
• a melting point (T _m ) below 180 ° C,
• a glass point (T _g ) greater than 40 ° C,
• - a water content of less than 1000 ppm,
• a residual monomer content (lactide) of less than 0.3%,
• a molecular weight greater than 50,000 daltons.

Preferred are polylactic acids, for example, from Nature Works ^® the Ingeo ^® 2002 D, D 4032, D 4042, D 4043, D 4044, D 8252, D 3251, D 4060 and D 8051 and especially 8052 and D.

For the production of the footwear according to the invention are in particular polylactic acids with a MVR after ISO 1133 (190 ° C / 2.16 kg) of 5 to 8 ml / 10 minutes proved to be advantageous.

Particularly suitable are polylactic acids having the above-mentioned MVR range and / or an onset temperature in the cold crystallization in the range of 80 ° C to 125 ° C, preferably at 90 ° C to 115 ° C and particularly preferably at 95 ° C. to 105 ° C., measured by means of DSC (differential scanning calorimetry) at a heating rate of 20 K / min (measuring range: -60 ° C. to 220 ° C., Mettler DSC 30 with a TC15 / TA controller, Mettler-Toledo AG) ,

It has been found that most of the polylactic acid types available on the market have an onset temperature in the cold crystallization of below 80 ° C. under the abovementioned conditions. A comparison of the polylactic acid (PLA) types NatureWorks ^® 8052 D and 4044 D to the different crystallization behavior of the granulates prepared therefrom illustrate (s. Table). The table shows DSC measurements of expandable granules of two types of PLA, each nucleated with 0.3% by weight of talc and loaded with 5.7% by weight of n-pentane propellant.

Table: DSC data at a heating rate of 20 K / min (measuring range -60 ° C to 220 ° C) example T _g (glass transition temperature) T _c -Oset T _c (cold crystallization) T _m (melting point) PLA 4042 D 42.4 ° C 71.8 ° C 82.5 ° C 155.6 ° C PLA 8052 D 41.1 ° C 94.7 ° C 106.9 ° C 147.6 ° C

The expandable granules generally have a crystalline content of only a few percent after preparation; So they are mostly amorphous. An increased onset temperature in the cold crystallization in the range of 80 ° C to 125 ° C, preferably at 90 ° C to 115 ° C and particularly preferably at 95 ° C to 105 ° C favors foaming with water vapor. Kristallisierneigung and foaming behavior of the expandable granules are matched with PLA types such as NatureWorks ^® 8052 D optimally.

As component ii) it is preferred to use aliphatic or partially aromatic (aliphatic-aromatic) polyesters:

As component ii) pure aliphatic polyesters are suitable. Among aliphatic polyesters are polyesters of aliphatic C ₂ -C ₁₂ alkanediols and C ₄ -C ₃₆ aliphatic alkanedicarboxylic acids such as polybutylene succinate (PBS), polybutylene adipate (PBA), polybutylene succinate adipate (PBSA), polybutylene succinate sebacate (PBSSe), polybutylene sebacate adipate (PBSeA), polybutylene sebacate (PBSe), polyhydroxybutyric acid (PHB), polyhydroxyalkanoates (PHA) or corresponding polyesteramides. The aliphatic polyesters are marketed by Showa Highpolymers under the name Bionolle and by Mitsubishi under the name GSPIa. Recent developments are in the EP08165370.1 described. Polybutylene succinate (PBS) for example, has a glass transition point _(Tg) of - 32 ° C and a melting point (T _m) of 115 ° C.

The aliphatic polyesters usually have viscosity numbers DIN 53726 from 150 to 320 cm ³ / g and preferably from 150 to 250 cm ³ / g.

The melt volume rate (MVR) according to EN ISO 1133 (190 ° C, 2.16 kg weight) is generally 0.1 to 70 cm ^3/10 minutes, preferably from 0.8 to 70 cm ^3/10 minutes and more preferably from 1 to 60 cm ^3/10 minutes.

The acid numbers according to DIN EN 12634 are generally from 0.01 to 1.2 mg KOH / g, preferably from 0.01 to 1.0 mg KOH / g and more preferably from 0.01 to 0.7 mg KOH / g ,

Partaromatic polyesters which are also suitable as component ii) consist of aliphatic diols and aliphatic and aromatic dicarboxylic acids. Suitable partially aromatic polyesters include linear non-chain extended polyesters ( WO 92/09654 ). In particular, aliphatic / aromatic polyesters of butanediol, terephthalic acid and C ₄ -C ₁₈ aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid and brassylic acid (for example as in WO 2006/097353 to 56 described) suitable mixing partners. Examples of partially aromatic polyesters are polybutylene adipate terephthalate (PBAT), polybutylene sebacate-co-terephthalate (PBSeT) and polybutylene-2,5-furandicarboxylate-co-sebacate (PBSeF). Polybutylene adipate terephthalate (PBAT) for example, has a glass transition point _(Tg) of - 28 ° C and a melting point (T _m) from 115 to 120 ° C. Chain-extended and / or branched partially aromatic polyesters are preferably used as component ii). Mixtures of different partially aromatic polyesters are also possible.

1. a) 40 bis 70 Mol-%, bezogen auf die Komponenten a) bis b), eines oder mehrerer Dicarbonsäurederivate oder Dicarbonsäuren ausgewählt aus der Gruppe bestehend aus: Bernsteinsäure, Adipinsäure, Sebazinsäure, Azelainsäure und Brassylsäure,
2. b) 30 bis 60 Mol-%, bezogen auf die Komponenten a) bis b), eines Terephthalsäurederivats,
3. c) 98 bis 102 Mol-%, bezogen auf die Komponenten a) bis b), eines C₂-C₈-Alkylendiols oder C₂-C₆-Oxyalkylendiols,
4. d) 0 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten a) bis c), eines Kettenverlängerers und/oder Vernetzers ausgewählt aus der Gruppe bestehend aus einem di- oder polyfunktionellen Isocyanat, Isocyanurat, Oxazolin, Epoxid, Peroxid, Carbonsäureanhydrid und/oder einem mindestens trifunktionellen Alkohol oder einer mindestens trifunktionellen Carbonsäure,

enthalten.Preferred as component ii) are biodegradable, aliphatic-aromatic polyesters which

1. a) 40 to 70 mol%, based on components a) to b), of one or more dicarboxylic acid derivatives or dicarboxylic acids selected from the group consisting of: succinic acid, adipic acid, sebacic acid, azelaic acid and brassylic acid,
2. b) 30 to 60 mol%, based on components a) to b), of a terephthalic acid derivative,
3. c) 98 to 102 mol%, based on components a) to b), of a C ₂ -C ₈ -alkylenediol or C ₂ -C ₆ -oxyalkylenediol,
4. d) 0 to 2 wt .-%, based on the total weight of components a) to c), of a chain extender and / or crosslinker selected from the group consisting of a di- or polyfunctional isocyanate, isocyanurate, oxazoline, epoxide, peroxide, carboxylic anhydride and / or an at least trifunctional alcohol or an at least trifunctional carboxylic acid,

contain.

1. a) 50 bis 65 und insbesondere 58 Mol-%, bezogen auf die Komponenten a) bis b), eines oder mehrerer Dicarbonsäurederivate oder Dicarbonsäuren ausgewählt aus der Gruppe bestehend aus Bernsteinsäure, Azelainsäure, Brassylsäure und vorzugsweise Adipinsäure, insbesondere bevorzugt Sebazinsäure,
2. b) 35 bis 50 und insbesondere 42 Mol-%, bezogen auf die Komponenten a) bis b), eines Terephthalsäurederivats,
3. c) 98 bis 102 Mol-%, bezogen auf die Komponenten a) bis b), 1,4-Butandiol und
4. d) 0 bis 2 Gew.-%, vorzugsweise 0,01 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten a) bis c), eines Kettenverlängerers und/oder Vernetzers ausgewählt aus der Gruppe bestehend aus: einem polyfunktionellen Isocyanat, Isocyanurat, Oxazolin, Carbonsäureanhydrid wie Maleinsäureanhydrid, Epoxid (insbesondere eines epoxidhaltigen Poly(meth)acrylats) und/oder einem mindestens trifunktionellen Alkohol oder einer mindestens trifunktionellen Carbonsäure

enthalten.As component ii) more preferred are biodegradable, aliphatic-aromatic polyesters which

1. a) 50 to 65 and in particular 58 mol%, based on the components a) to b), of one or more dicarboxylic acid derivatives or dicarboxylic acids selected from the group consisting of succinic acid, azelaic acid, brassylic acid and preferably adipic acid, particularly preferably sebacic acid,
2. b) from 35 to 50 and in particular 42 mol%, based on components a) to b), of a terephthalic acid derivative,
3. c) 98 to 102 mol%, based on the components a) to b), 1,4-butanediol and
4. d) 0 to 2% by weight, preferably 0.01 to 2% by weight, based on the total weight of components a) to c), of a chain extender and / or crosslinker selected from the group consisting of: a polyfunctional isocyanate, Isocyanurate, oxazoline, carboxylic anhydride such as maleic anhydride, epoxide (in particular an epoxy-containing poly (meth) acrylate) and / or an at least trifunctional alcohol or an at least trifunctional carboxylic acid

contain.

As aliphatic dicarboxylic acids are preferably succinic acid, adipic acid and particularly preferably sebacic acid.

1. a) 90 bis 99,5 Mol-%, bezogen auf die Komponenten a) bis b), Bernsteinsäure,
2. b) 0,5 bis 10 Mol-%, bezogen auf die Komponenten a) bis b), einer oder mehrerer C₈-C₂₀-Dicarbonsäuren,
3. c) 98 bis 102 Mol-%, bezogen auf die Komponenten a) bis b), 1,3-Propandiol oder 1,4-Butandiol

enthalten.Therefore, preferred as component ii) are also polyesters which

1. a) from 90 to 99.5 mol%, based on components a) to b), succinic acid,
2. b) 0.5 to 10 mol%, based on components a) to b), of one or more C ₈ -C ₂₀ dicarboxylic acids,
3. c) 98 to 102 mol%, based on the components a) to b), 1,3-propanediol or 1,4-butanediol

contain.

1. a) 90 bis 99,5 Mol-%, bezogen auf die Komponenten a) bis b), Bernsteinsäure,
2. b) 0,5 bis 10 Mol-%, bezogen auf die Komponenten a) bis b), Terephthalsäure, Azelainsäure, Sebacinsäure und/oder Brassylsäure,
3. c) 98 bis 102 Mol-%, bezogen auf die Komponenten a) bis b), 1,3-Propandiol oder 1,4-Butandiol und
4. d) 0,01 bis 5 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten a) bis c), eines Kettenverlängerers und/oder Vernetzers ausgewählt aus der Gruppe bestehend aus einem polyfunktionellen Isocyanat, Isocyanurat, Oxazolin, Epoxid (insbesondere einem epoxidhaltigen Poly(meth)acrylat), einem mindestens trifunktionellen Alkohol oder einer mindestens trifunktionellen Carbonsäure

enthalten.As component ii) more preferred are polyesters which

1. a) from 90 to 99.5 mol%, based on components a) to b), succinic acid,
2. b) 0.5 to 10 mol%, based on the components a) to b), terephthalic acid, azelaic acid, sebacic acid and / or brassylic acid,
3. c) 98 to 102 mol%, based on the components a) to b), 1,3-propanediol or 1,4-butanediol and
4. d) from 0.01 to 5% by weight, based on the total weight of components a) to c), of a chain extender and / or crosslinker selected from the group consisting of a polyfunctional isocyanate, isocyanurate, oxazoline, epoxide (in particular an epoxide-containing poly (meth) acrylate), an at least trifunctional alcohol or an at least trifunctional carboxylic acid

contain.

The synthesis of the described component ii) is carried out according to the in WO-A 92/09654 . WO-A 96/15173 or preferably in WO-A 09/127555 and WO-A 09/127556 described method, preferably in a two-stage Reaktionskaskasde. First, the dicarboxylic acid derivatives are reacted together with the diol in the presence of a transesterification catalyst to form a prepolyester. This prepolyester generally has a viscosity number (CV) of 50 to 100 ml / g, preferably from 60 to 80 ml / g. The catalysts used are usually zinc, aluminum and in particular titanium catalysts. Titanium catalysts such as tetra (isopropyl) orthotitanate and in particular tetrabutyl orthotitanate (TBOT) have the advantage over the tin, antimony, cobalt and lead catalysts commonly used in the literature, such as tin dioctanate, that residual amounts of the catalyst or secondary products of the catalyst remaining in the product are less toxic are. This fact is particularly important in the case of biodegradable polyesters, since they can go directly into the environment via composting.

Component ii) is then used in a second step after the in WO-A 96/15173 and EP-A 488 617 prepared method described. The prepolyester is reacted with chain extenders, for example with diisocyanates or with epoxy-containing polymethacrylates in a chain extension reaction to give a polyester having a VZ of 50 to 450 mL / g, preferably from 80 to 250 mL / g.

In general, 0.01 to 2 wt .-%, preferably 0.1 to 1.0 wt .-% and particularly preferably 0.1 to 0.3 wt .-%, based on the total weight of components i) to iii), a crosslinker and / or chain extender selected from the group consisting of: a polyfunctional isocyanate, isocyanurate, oxazoline, epoxide, peroxide, carboxylic anhydride, an at least trifunctional alcohol or an at least trifunctional carboxylic acid. Suitable chain extenders are polyfunctional and in particular difunctional isocyanates, isocyanurates, oxazolines, carboxylic anhydride or epoxides.

Chain extenders and alcohols or carboxylic acid derivatives having at least three functional groups can also be understood as crosslinkers. Particularly preferred compounds have three to six functional groups. Examples include: tartaric acid, citric acid, malic acid, trimethylolpropane, Trimethylolethane, pentaerythritol, polyether triols and glycerol, trimesic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid and pyromellitic dianhydride. Preference is given to polyols such as trimethylolpropane, pentaerythritol and in particular glycerol. Using chain extenders and crosslinkers, biodegradable polyesters with a structural viscosity can be built up. The rheological behavior of the melts improves and the biodegradable polyesters are easier to process. The chain extenders are shear-thinning, that is, the viscosity at higher shear rates is lower.

Component ii) generally has a number average molecular weight (M _n ) in the range from 5000 to 100 000 g / mol, in particular in the range from 10 000 to 75 000 g / mol, preferably in the range from 15000 to 38000 g / mol, a weight-average molecular weight (M _w ) of from 30,000 to 300,000 g / mol, preferably from 60,000 to 200,000 g / mol, and an M _w / M _n ratio of from 1 to 6, preferably from 2 to 4. The viscosity number is between 50 and 450 g / mL, preferably between 80 to 250 g / mL (measured in o-dichlorobenzene / phenol (weight ratio 50/50)). The melting point is in the range of 85 to 150, preferably in the range of 95 to 140 ° C.

Component ii) may have hydroxyl and / or carboxyl end groups in any ratio.

If component ii) is a partially aromatic polyester, it can also be end-group-modified. For example, OH end groups can be acid-modified by reaction with phthalic acid, phthalic anhydride, trimellitic acid, trimellitic anhydride, pyromellitic acid or pyromellitic anhydride. Component ii) preferably has an acid number of less than 1.5 mg KOH / g.

The biodegradable component ii) may contain further ingredients known to the person skilled in the art but not essential to the invention. For example, the customary in plastics additives such as stabilizers, nucleating agents, lubricants and release agents such as stearates (especially calcium stearate), plasticizers (plasticizers) such as citric acid esters (especially acetyltributylcitrate), glyceric acid esters such as triacetylglycerol or ethylene glycol derivatives, surfactants such as polysorbates, palmitates or laurates, waxes such as beeswax or beeswax esters, antistatic agents, UV absorbers, UV stabilizers, antifoggers or dyes. The additives are used in concentrations of 0 to 5 wt .-%, in particular 0.1 to 2 wt .-% based on the component ii). Plasticizers may be present in 0.1 to 10% by weight in component ii).

Component iii) is described in more detail below.

Component iii) is, in particular, epoxy group-containing copolymers based on styrene, acrylate and / or methacrylic acid ester. The epoxy group-bearing units are preferably glycidyl (meth) acrylates. Copolymers having a glycidyl methacrylate content of greater than 20, particularly preferably greater than 30 and especially preferably greater than 50% by weight, of the copolymer have proven to be advantageous. The epoxy equivalent weight (EEW) in these polymers is preferably 150 to 3000, and more preferably 200 to 500 g / equivalent. The weight average molecular weight M _{w of} the polymers is preferably from 2000 to 25000 g / mol, in particular from 3000 to 8000 g / mol. The number-average molecular weight M _{n of} the polymers is preferably 400 to 6000 g / mol, in particular 1000 to 4000 g / mol. The polydispersity (Q) is generally between 1.5 and 5. The epoxy-containing copolymers of the above type are sold for example by BASF Resins BV under the trademark Joncryl ^® ADR. Particularly suitable as a chain is Joncryl ^® ADR 4368th

Component iv) is understood in particular to be one or more of the following additives: stabilizer, nucleating agent, lubricant and release agent, surfactant, wax, antistatic agent, antifogging agent, dye, pigment, UV absorber, UV stabilizer or another plastic additive. Particularly preferred is the use of 0.5 to 1 wt .-%, based on the components i) and iii) of a nucleating agent.

By nucleating agent is meant in particular talc, chalk, carbon black, graphite, calcium or zinc stearate, poly-D-lactic acid, N, N'-ethylene-bis-12-hydroxystearamide or polyglycolic acid. Particularly preferred is talc as nucleating agent.

The upper layer (1) of the shoe sole (S) preferably has a thickness in the range of 0.1 to 2.5 cm, more preferably 0.2 to 2 cm, and most preferably 0.2 to 1.5 cm ,

The subject of the present invention is therefore also a footwear, characterized in that the upper layer (1) has a thickness in the range of 0.1 to 2.5 cm.

In one embodiment of the present invention, a textile fabric is fixed on the upper side (10) of the upper layer (1) by partial melting and subsequent cooling.

The subject of the present invention is therefore also a footwear, characterized in that on the upper side (10) of the upper layer (1) a textile fabric is fixed by partial melting and subsequent cooling.

The textile fabric is preferably made of synthetic fibers such as polyacrylic, polyamide and / or polyester fibers. But it can also be natural materials such as cellulose, viscose, cotton, linen, Hauf and / or leather are used. The textile fabric can serve optical purposes, but it is also possible that it fulfills certain functions. It may be, for example, warming, slip-resistant and / or water-repellent.

On the upper side (10) of the upper layer (1) of the shoe sole (S) there is preferably arranged a retaining means (3) for receiving a foot.

The subject of the present invention is therefore also a footwear, characterized in that a retaining means (3) for receiving a foot is arranged on an upper side (10) of the upper layer (1).

In the 2 . 3 and 4 the views are shown on footwear with various holding means (3) according to the invention.

In an embodiment of the present invention, the upper layer (10) of the shoe sole (S) has at least one hole (4) through which the holding means (3) is partially carried.

The subject of the present invention is therefore also a footwear, characterized in that the upper layer (1) has at least one hole (4) through which the holding means (3) is partially carried.

In another embodiment, the top layer (1) does not include holes or more than one hole (4).

In 5 a top view of the upper layer (1o) of a shoe sole (S) with two holes (4) through which the holding means (3) can be partially performed.

Lower layer (2)

The footwear according to the invention comprising a shoe sole (S) comprises at least an upper layer (1) and a lower layer (2).

The lower layer (2) preferably consists of a particle foam which contains more than 50% by weight of polylactic acid, based on the total mass of the particle foam in the lower layer (2).

1. i) 60 bis 98,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), Polymilchsäure,
2. ii) 1 bis 39,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen,
3. iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, und
4. iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,

enthält.Particularly preferably, the lower layer (2) of the shoe sole (S) consists of a particle foam, the

1. i) from 60 to 98.9% by weight, based on the total weight of components i) to iii), of polylactic acid,
2. ii) from 1 to 39.9% by weight, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds,
3. iii) from 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and
4. iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,

contains.

1. i) 60 bis 98,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), Polymilchsäure,
2. ii) 1 bis 39,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen,
3. iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, und
4. iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,

enthält.The subject of the present invention is therefore also a footwear, characterized in that the lower layer (2) consists of a particle foam, the

1. i) from 60 to 98.9% by weight, based on the total weight of components i) to iii), of polylactic acid,
2. ii) from 1 to 39.9% by weight, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds,
3. iii) from 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and
4. iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,

contains.

1. i) 65 bis 79,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), Polymilchsäure,
2. ii) 20 bis 34,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen,
3. iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, und
4. iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,

enthält.Most preferably, the lower layer (2) of the shoe sole (S) consists of a particle foam, the

1. i) from 65 to 79.9% by weight, based on the total weight of components i) to iii), of polylactic acid,
2. ii) from 20 to 34.9% by weight, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds,
3. iii) from 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and
4. iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,

contains.

1. i) 55 bis 98,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), Polymilchsäure,
2. ii) 1 bis 44,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen,
3. iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, und
4. iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,

enthält.In an alternative embodiment, the lower layer (2) consists of a particle foam, the

1. i) from 55 to 98.9% by weight, based on the total weight of components i) to iii), of polylactic acid,
2. ii) from 1 to 44.9% by weight, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds,
3. iii) from 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and
4. iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,

contains.

In the context of the present invention, it is particularly preferred that the lower layer (2) consists of the same particle foam as the upper layer (1).

The subject of the present invention is thus also a footwear, characterized in that the lower layer (2) consists of the same particle foam as the upper layer (1).

The lower layer (2) of the shoe sole (S) preferably has a thickness in the range of 0.1 to 2.5 cm, more preferably from 0.2 to 2 cm and most preferably from 0.2 to 1.5 cm ,

Joining the upper layer (1) to the lower layer (2)

The upper layer (1) and the lower layer (2) of the shoe sole (S) are connected together.

Preferably, the upper layer (1) and the lower layer (2) are welded or glued together.

The subject of the present invention is therefore also a footwear, characterized in that the upper layer (1) and the lower layer (2) are welded or glued together.

Particularly preferably, the underside (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2) are welded or glued together.

The performance of welding as such is known to those skilled in the art. The effect of welding is achieved on the surfaces to be welded (1u) and (2o) by exposing the respective surfaces to a heat source. The corresponding heat sources or devices are also known to the person skilled in the art.

Preferably, the underside (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2) are connected to one another after completion of the welding operation by a weld seam (5).

The weld seam (5) preferably has a thickness of 0.01 to 0.5 mm, particularly preferably 0.1 to 0.3 mm.

6 shows a cross section through a shoe sole (S) with a weld (5). The weld seam (5) preferably forms between the underside (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2).

Alternatively, the upper layer (1) and the lower layer (2) may be bonded together. It is clear to a person skilled in the art that the lower side (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2) are glued together.

The implementation of gluing as such is known in the art.

Dispersion adhesives are preferably used in the context of the present invention, more preferably biodegradable dispersion adhesives. For example, from BASF is used as biodegradable adhesive of the dispersion Epotal P100 ^® ECO.

Preferably, the lower surface (1u) of the upper layer (1) and the upper surface (2o) of the lower layer (2) are bonded together by an adhesive layer (6) after completion of the bonding operation.

The adhesive layer (6) preferably has a thickness of 0.01 to 0.5 mm, particularly preferably 0.1 to 0.3 mm.

The subject of the present invention is thus also a footwear, characterized in that the underside (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2) are connected by a weld (5) or an adhesive layer (6) are.

Holding means (3)

On a top side (10) of the upper layer (1), a retaining means (3) for receiving a foot is preferably arranged.

The 2 to 4 show the top view footwear according to the invention with different holding means (3).

Holding means (3) for receiving a foot as such are known in the art. The holding means (3) serves to hold the foot of the wearer on the shoe sole (S), so that the footwear is not detached from the foot during wear.

The holding means (3) is preferably selected from the group consisting of a diagonal strap attachment with toe bridge (3 a) ( 2 ), a tether (3b) ( 3 ) and a front cap (3c) ( 4 ).

The subject of the present invention is therefore also a footwear, characterized in that the holding means (3) is selected from the group consisting of a diagonal strap attachment with toe bridge (3a), a tether (3b) and a toe cap (3c).

Preferably, the holding means (3) is partially fixed between the lower side (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2).

The subject of the present invention is therefore also a footwear, characterized in that the holding means (3) is partially fixed between the underside (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2).

In 5 there is shown an embodiment of the present invention in which the upper layer (1) has two holes (4) through which the holding means (3) can be partially carried.

In the context of the present invention it is preferred that the upper layer (1) of the shoe sole (S) has at least one hole (4) through which the holding means (3) is partially carried.

But it is also possible that the upper layer (1) has no hole (4) or more than one hole (4).

For example, when the holding means (3) is a diagonal strap attachment with a toe bridge (3a), the upper layer (1) may have three holes (4) through which the holding means (3) is partially made.

If the upper layer (1) has holes (4), the holding means (3) is partially guided through these holes (4) and anchored on the underside (1u) of the upper layer.

In a further embodiment, the holding means (3) is partially glued to the underside (1u) of the upper layer (1).

The subject of the present invention is therefore also a footwear, characterized in that the holding means (3) is partially glued to the underside (1u) of the upper layer (1).

Sticking as such is known to the person skilled in the art.

For adhering the holding means (3), preference is given to using dispersion adhesives, more preferably biodegradable dispersion adhesives. For example, from BASF is used as biodegradable adhesive of the dispersion Epotal P100 ^® ECO.

7 shows the side view of a footwear, in which the holding means (3) on the underside (1u) of the upper layer (1) is glued.

In a further embodiment, the upper layer (1) has a hole (4) through which the holding means (3) is partially carried. At the same time, the holding means (3) is also partially adhered to the underside (1u) of the upper layer (1). Such an embodiment is in 2 shown.

After joining the upper layer (1) and the lower layer (2), the holding means (3) is preferably partially fixed in the weld (5) or the adhesive layer (6).

The subject of the present invention is thus also a footwear, characterized in that the holding means (3) is partially fixed in the weld (5) or the adhesive layer (6).

The holding means (3) are preferably a textile fabric, a plastic and / or leather. In addition to the purpose of receiving a foot, the retaining means (3) also has an additional decorative purpose.

Expandable polylactic acid-containing granules

1. i) 60 bis 98,9 Gew.-% Polymilchsäure, bezogen auf das Gesamtgewicht der Komponenten i) bis iii),
2. ii) 1 bis 39,9 Gew.-% mindestens eines Polyesters auf Basis von aliphatischen und aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen, bezogen auf das Gesamtgewicht der Komponenten i) bis iii),
3. iii) 0,1 bis 2 Gew.-% eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), und
4. iv) 0 bis 10 Gew.-% eines oder mehrerer Additive, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), und einen Anteil von
5. v) 3 bis 7 Gew.-% eines organischen Treibmittels,

zur Herstellung von Schuhsohlen (S).Another object of the invention relates to the use of an expandable polylactic acid-containing granules, having a solids content of 93 to 97 wt .-%, comprising:

1. i) 60 to 98.9% by weight of polylactic acid, based on the total weight of components i) to iii),
2. ii) from 1 to 39.9% by weight of at least one polyester based on aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds, based on the total weight of components i) to iii),
3. iii) 0.1 to 2 wt .-% of an epoxy group-containing copolymer based on styrene, acrylic acid ester and / or methacrylic acid ester, based on the total weight of components i) to iii), and
4. iv) 0 to 10 wt .-% of one or more additives, based on the total weight of components i) to iii), and a proportion of
5. v) 3 to 7% by weight of an organic blowing agent,

for the production of soles (S).

1. i) 65 bis 79,9 Gew.-% Polymilchsäure, bezogen auf das Gesamtgewicht der Komponenten i) bis iii),
2. ii) 20 bis 34,9 Gew.-% mindestens eines Polyesters auf Basis von aliphatischen und aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen, bezogen auf das Gesamtgewicht der Komponenten i) bis iii),
3. iii) 0,1 bis 2 Gew.-% eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), und
4. iv) 0 bis 10 Gew.-% eines oder mehrerer Additive, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), und einen Anteil von
5. v) 3 bis 7 Gew.-% eines organischen Treibmittels,

zur Herstellung von Schuhsohlen (S).Another object of the invention preferably relates to the use of an expandable polylactic acid-containing granules, having a solids content of 93 to 97 wt .-%, comprising:

1. i) from 65 to 79.9% by weight of polylactic acid, based on the total weight of components i) to iii),
2. ii) from 20 to 34.9% by weight of at least one polyester based on aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds, based on the total weight of components i) to iii),
3. iii) 0.1 to 2 wt .-% of an epoxy group-containing copolymer based on styrene, acrylic acid ester and / or methacrylic acid ester, based on the total weight of components i) to iii), and
4. iv) 0 to 10 wt .-% of one or more additives, based on the total weight of components i) to iii), and a proportion of
5. v) 3 to 7% by weight of an organic blowing agent,

for the production of soles (S).

1. i) 55 bis 98,9 Gew.-% Polymilchsäure, bezogen auf das Gesamtgewicht der Komponenten i) bis iii),
2. ii) 1 bis 44,9 Gew.-% mindestens eines Polyesters auf Basis von aliphatischen und aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen, bezogen auf das Gesamtgewicht der Komponenten i) bis iii),
3. iii) 0,1 bis 2 Gew.-% eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), und
4. iv) 0 bis 10 Gew.-% eines oder mehrerer Additive, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), und einem Anteil von
5. v) 3 bis 7 Gew.-% eines organischen Treibmittels,

zur Herstellung von Schuhsohlen (S).In a further embodiment, the invention relates to the use of an expandable polylactic acid-containing granules having a solids content of 93 to 97 wt .-%, comprising:

1. i) from 55 to 98.9% by weight of polylactic acid, based on the total weight of components i) to iii),
2. ii) from 1 to 44.9% by weight of at least one polyester based on aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds, based on the total weight of components i) to iii),
3. iii) 0.1 to 2 wt .-% of an epoxy group-containing copolymer based on styrene, acrylic acid ester and / or methacrylic acid ester, based on the total weight of components i) to iii), and
4. iv) 0 to 10 wt .-% of one or more additives, based on the total weight of components i) to iii), and a proportion of
5. v) 3 to 7% by weight of an organic blowing agent,

for the production of soles (S).

Suitable blowing agents in accordance with component v) are the physical blowing agents conventionally used in expanded polystyrene (EPS), such as aliphatic hydrocarbons having 2 to 7 carbon atoms, alcohols, ketones, ethers, amides or halogenated hydrocarbons. Preference is given to using isobutane, n-butane, n-pentane and in particular isopentane. Further preferred are mixtures of n-pentane and iso-pentane.

The amount of blowing agent added is chosen such that the expandable granules have an expansion capacity a, defined as bulk density before pre-foaming of 500 to 800 and preferably 580 to 750 kg / m ³ and a bulk density after pre-foaming of at most 125, preferably from 8 to 100 kg / m ³ , have.

Processes for the production of expandable polylactic acid-containing granules are known to the person skilled in the art and are described, for example, in US Pat WO 2011/086030 A2 described.

1. 1) Aufschmelzen und Einmischen der Komponenten i) 60 bis 98,9 Gew.-% Polymilchsäure, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), ii) 1 bis 39,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen, iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, crylsäureester und/oder Methacrylsäureester und iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,
2. 2) Einmischen von v) 3 bis 7 Gew.-% bezogen auf die Komponenten i) bis iv) eines organischen Treibmittels in die Polymerschmelze aus Schritt 1) mittels eines statischen oder dynamischen Mischers bei einer Temperatur von mindestens 140°C,
3. 3) Austrag der treibmittelhaltigen Schmelze aus Schritt 2) durch eine Düsenplatte mit Bohrungen, deren Durchmesser am Düsenaustritt höchstens 0,3 bis 2 mm beträgt und
4. 4) Granulieren der treibmittelhaltigen Schmelze aus Schritt 3) direkt hinter der Düsenplatte unter Wasser bei einem Druck im Bereich von 1 bis 20 bar.

A process for producing expandable polylactic acid-containing granules may preferably comprise steps 1) to 4):

1. 1) melting and mixing the components i) 60 to 98.9 wt .-% polylactic acid, based on the total weight of components i) to iii), ii) 1 to 39.9 wt .-%, based on the total weight of the components i) to iii), at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds, iii) 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing Copolymers based on styrene, crylic acid ester and / or methacrylic acid ester and iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,
2. 2) mixing v) 3 to 7 wt .-% based on the components i) to iv) of an organic blowing agent in the polymer melt from step 1) by means of a static or dynamic mixer at a temperature of at least 140 ° C,
3. 3) discharge of blowing agent-containing melt from step 2) through a nozzle plate with holes whose diameter at the nozzle exit is at most 0.3 to 2 mm and
4. 4) Granulating the blowing agent-containing melt from step 3) directly behind the nozzle plate under water at a pressure in the range of 1 to 20 bar.

1. 1) Aufschmelzen und Einmischen der Komponenten i) 65 bis 79,9 Gew.-% Polymilchsäure, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), ii) 20 bis 34,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen, iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester und iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,
2. 2) Einmischen von v) 3 bis 7 Gew.-% bezogen auf die Komponenten i) bis iv) eines organischen Treibmittels in die Polymerschmelze aus Schritt 1) mittels eines statischen oder dynamischen Mischers bei einer Temperatur von mindestens 140°C,
3. 3) Austrag der treibmittelhaltigen Schmelze aus Schritt 2) durch eine Düsenplatte mit Bohrungen, deren Durchmesser am Düsenaustritt höchstens 0,3 bis 2 mm beträgt und
4. 4) Granulieren der treibmittelhaltigen Schmelze aus Schritt 3) direkt hinter der Düsenplatte unter Wasser bei einem Druck im Bereich von 1 bis 20 bar.

A process for producing expandable polylactic acid-containing granules may particularly preferably comprise steps 1) to 4):

1. 1) melting and blending the components i) 65 to 79.9 wt .-% polylactic acid, based on the total weight of components i) to iii), ii) 20 to 34.9 wt .-%, based on the total weight of the components i) to iii), at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds, iii) 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing Copolymers based on styrene, acrylic esters and / or methacrylates and iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,
2. 2) mixing v) 3 to 7 wt .-% based on the components i) to iv) of an organic blowing agent in the polymer melt from step 1) by means of a static or dynamic mixer at a temperature of at least 140 ° C,
3. 3) discharge of blowing agent-containing melt from step 2) through a nozzle plate with holes whose diameter at the nozzle exit is at most 0.3 to 2 mm and
4. 4) Granulating the blowing agent-containing melt from step 3) directly behind the nozzle plate under water at a pressure in the range of 1 to 20 bar.

1. 1) Aufschmelzen und Einmischen der Komponenten i) 55 bis 98,9 Gew.-% Polymilchsäure, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), ii) 1 bis 44,9 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen, iii) 0,1 bis 2 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester und iv) 0 bis 10 Gew.-%, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), eines oder mehrerer Additive,
2. 2) Einmischen von v) 3 bis 7 Gew.-% bezogen auf die Komponenten i) bis iv) eines organischen Treibmittels in die Polymerschmelze ausSchritt 1) mittels eines statischen oder dynamischen Mischers bei einer Temperatur von mindestens 140°C,
3. 3) Austrag der treibmittelhaltigen Schmelze aus Schritt 2) durch eine Düsenplatte mit Bohrungen, deren Durchmesser am Düsenaustritt höchstens 0,3 bis 2 mm beträgt und
4. 4) Granulieren der treibmittelhaltigen Schmelze aus Schritt 3) direkt hinter der Düsenplatte unter Wasser bei einem Druck im Bereich von 1 bis 20 bar.

A further embodiment of a process for producing expandable polylactic acid-containing granules may preferably comprise steps 1) to 4):

1. 1) melting and mixing of the components i) 55 to 98.9 wt .-% polylactic acid, based on the total weight of components i) to iii), ii) 1 to 44.9 wt .-%, based on the total weight of the components i) to iii), at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds, iii) 0.1 to 2% by weight, based on the total weight of components i) to iii), of an epoxide group-containing Copolymers based on styrene, acrylic esters and / or methacrylates and iv) 0 to 10% by weight, based on the total weight of components i) to iii), of one or more additives,
2. 2) mixing v) 3 to 7% by weight, based on the components i) to iv), of an organic blowing agent into the polymer melt from step 1) by means of a static or dynamic mixer at a temperature of at least 140 ° C.,
3. 3) discharge of blowing agent-containing melt from step 2) through a nozzle plate with holes whose diameter at the nozzle exit is at most 0.3 to 2 mm and
4. 4) Granulating the blowing agent-containing melt from step 3) directly behind the nozzle plate under water at a pressure in the range of 1 to 20 bar.

To improve processability, the finished expandable granules may be coated by glycerol esters, antistatic agents or anticaking agents.

The expandable granules used according to the invention can be prefoamed in a first step by means of physical input such as hot air, water vapor, microwave or IR radiation to foam particles having a density in the range of 8 to 100 kg / m3 and in a second step in a closed mold into particle moldings be welded.

Expanded polylactic acid-containing granules

1. i) 60 bis 98,9 Gew.-% Polymilchsäure, bezogen auf das Gesamtgewicht der Komponenten i) bis iii),
2. ii) 1 bis 39,9 Gew.-%, mindestens eines Polyesters auf Basis von aliphatischen und/oder aromatischen Dicarbonsäuren und aliphatischen Dihydroxyverbindungen, bezogen auf das Gesamtgewicht der Komponenten i) bis iii),
3. iii) 0,1 bis 2 Gew.-% eines Epoxidgruppen-haltigen Copolymers auf Basis von Styrol, Acrylsäureester und/oder Methacrylsäureester, bezogen auf das Gesamtgewicht der Komponenten i) bis iii), und
4. iv) 0 bis 10 Gew.-% eines oder mehrerer Additive, bezogen auf das Gesamtgewicht der Komponenten i) bis iii);

und einem Anteil von v) 0 bis 15 Gew.-% eines organischen Treibmittels,
zur Herstellung von Schuhsohlen (S).Another object of the invention relates to the use of an expanded polylactic acid-containing granules, having a solids content of 85 to 100 wt .-%, comprising:

1. i) 60 to 98.9% by weight of polylactic acid, based on the total weight of components i) to iii),
2. ii) from 1 to 39.9% by weight, of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds, based on the total weight of components i) to iii),
3. iii) 0.1 to 2 wt .-% of an epoxy group-containing copolymer based on styrene, acrylic acid ester and / or methacrylic acid ester, based on the total weight of components i) to iii), and
4. iv) 0 to 10% by weight of one or more additives, based on the total weight of components i) to iii);

and a proportion of v) 0 to 15% by weight of an organic blowing agent,
for the production of soles (S).

The expanded granules used according to the invention can be in a closed form by means of physical input such as hot air, water vapor, microwave or IR radiation to particle moldings having a density in the range of 20 to 200 kg / m ³ , preferably prefoamed with a density in the range of 25 to 50 kg / m ³ , to be welded.

The following examples are intended to further illustrate the present invention without, however, limiting the present invention thereto.

Examples:

Various particle foams of polylactic acid (PLA) and / or polypropylene carbonate (PPC) are produced and their modulus of elasticity is determined.

The amounts of polylactic acid (PLA) and / or polypropylene carbonate (PPC) used and the modulus of elasticity of the particle foams produced are shown in Table 1 below. Table 1 example E1 V1 V2 Polylactic acid (PLA) [wt%] 100 50 0 Polypropylene carbonate (PPC) [% by weight] 0 50 100 E-modulus [MPa] 3600 2000 600

As can be seen from Table 1, a particle foam containing 100 wt .-% polylactic acid, a significantly higher modulus of elasticity than a particle foam, the 50 wt .-% polylactic acid and 50 wt .-% polypropylene carbonate or 100 wt. - contains% polypropylene carbonate. This means that the particle foam containing 100% by weight of polylactic acid is significantly stiffer and therefore more stable than a particle foam containing 50% by weight of polylactic acid and 50% by weight of polypropylene carbonate or 100% by weight of polypropylene carbonate.

LIST OF REFERENCE NUMBERS

S

sole

1

upper layer of the shoe sole

1o

Top of the upper layer

1u

Bottom of the upper layer

2

lower layer of the shoe sole

2o

Top of the lower layer

2u

Bottom of the lower layer

3

Holding means (for receiving the foot)

3a

Oblique belt attachment with toe bridge

3b

tether

3c

toecap

4

Hole for the passage of the holding means (3)

5

Weld

• 1 shows the cross section through a shoe sole (S).
• 2 shows the view of a footwear with oblique strap attachment (3a) with thong.
• 3 shows the top view of a footwear with straps (3b).
• 4 shows the top view of a footwear with a toe cap (3c).
• 5 shows the top view of the upper layer of the shoe sole (1) with holes for anchoring.
• 6 shows a cross section through a shoe sole (S) with a weld (5).
• 7 shows the side view of a footwear, in which the holding means (3) on the underside (1u) of the upper layer (1) is glued.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2015/052020 A1 [0004]
• WO 2015/052019 A1 [0005]
• EP 08165370 [0040]
• WO 9209654 [0044]
• WO 2006/097353 [0044]
• WO 92/09654 A [0050]
• WO 96/15173 A [0050, 0051]
• WO 09/127555 A [0050]
• WO 09/127556 A [0050]
• EP 488617A [0051]
• WO 2011/086030 A2 [0123]

Cited non-patent literature

• ISO 1133 [0032, 0034]
• DIN 53726 [0041]

Claims (16)

Footwear comprising a shoe sole (S) comprising at least an upper layer (1) and a lower layer (2), wherein the upper layer (1) consists of a particle foam, the more than 50 wt .-% polylactic acid, based on contains the total mass of the particle foam in the upper layer (1), and the upper layer (1) and the lower layer (2) are bonded together. Footwear according to Claim 1 , characterized in that the upper layer (1) consists of a particle foam which i) 60 to 98.9 wt .-%, based on the total weight of components i) to iii), polylactic acid, ii) 1 to 39.9 Wt .-%, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds, iii) 0.1 to 2 wt .-%, based on the total weight of Components i) to iii), an epoxy group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and iv) 0 to 10 wt .-%, based on the total weight of components i) to iii) of one or more additives , contains. Footwear according to Claim 1 or 2 , characterized in that on a top (1o) of the upper layer (1) a holding means (3) for receiving a foot is arranged. Footwear according to Claim 3 , characterized in that the holding means (3) is partially fixed between the lower side (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2). Footwear according to Claim 3 or 4 , characterized in that the holding means (3) is selected from the group consisting of a diagonal strap attachment with toe bridge (3a), a holding strap (3b) and a front cap (3c). Footwear according to one of Claims 3 to 6 Characterized in that the upper layer (1) at least one hole (4) through which the holding means (3) is partially carried out. Footwear according to one of Claims 1 to 6 , characterized in that the lower layer (2) consists of a particle foam which i) 60 to 98.9 wt .-%, based on the total weight of components i) to iii), polylactic acid, ii) 1 to 39.9 Wt .-%, based on the total weight of components i) to iii), of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds, iii) 0.1 to 2 wt .-%, based on the total weight of Components i) to iii), an epoxy group-containing copolymer based on styrene, acrylic ester and / or methacrylic acid ester, and iv) 0 to 10 wt .-%, based on the total weight of components i) to iii) of one or more additives , contains. Footwear according to one of Claims 1 to 7 , characterized in that the lower layer (2) consists of the same particle foam as the upper layer (1). Footwear according to one of Claims 1 to 8th , characterized in that the upper layer (1) and the lower layer (2) are welded or glued together. Footwear according to one of Claims 1 to 9 , characterized in that the underside (1u) of the upper layer (1) and the upper side (2o) of the lower layer (2) by a weld (5) or an adhesive layer (6) are connected. Footwear according to one of Claims 1 to 10 , characterized in that the holding means (3) is partially fixed in the weld seam (5) or the adhesive layer (6). Footwear according to one of Claims 1 to 11 , characterized in that on the upper side (1o) of the upper layer (1) a textile fabric is fixed by partial melting and subsequent cooling. Footwear according to one of Claims 1 to 12 , characterized in that the upper layer (1) has a thickness in the range of 0.1 to 2.5 cm. Footwear according to one of Claims 3 to 6 Characterized in that the retaining means (3) partially on the underside (1u) of the upper layer (1) is glued. Use of an expandable polylactic acid-containing granules, having a solids content of 93 to 97 wt .-%, comprising: i) 60 to 98.9% by weight of polylactic acid, based on the total weight of components i) to iii), ii) from 1 to 39.9% by weight, of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds, based on the total weight of components i) to iii), iii) 0.1 to 2 wt .-% of an epoxy group-containing copolymer based on styrene, acrylic acid ester and / or methacrylic acid ester, based on the total weight of components i) to iii), and iv) 0 to 10% by weight of one or more additives, based on the total weight of components i) to iii); and a proportion of v) from 3 to 7% by weight of an organic blowing agent, for the production of soles (S). Use of an expanded polylactic acid-containing granules, having a solids content of 85 to 100 wt .-%, comprising: i) 60 to 98.9% by weight of polylactic acid, based on the total weight of components i) to iii), ii) from 1 to 39.9% by weight, of at least one polyester based on aliphatic and / or aromatic dicarboxylic acids and aliphatic dihydroxy compounds, based on the total weight of components i) to iii), iii) 0.1 to 2 wt .-% of an epoxy group-containing copolymer based on styrene, acrylic acid ester and / or methacrylic acid ester, based on the total weight of components i) to iii), and iv) 0 to 10% by weight of one or more additives, based on the total weight of components i) to iii); and a proportion of v) 0 to 15% by weight of an organic blowing agent, for the production of soles (S).

Images