EP4473041A1

EP4473041A1 - A polymer composition

Info

Publication number: EP4473041A1
Application number: EP23721610.6A
Authority: EP
Inventors: Florian Diehl; Barbara Gall
Original assignee: UPM Kymmene Oy
Current assignee: UPM Kymmene Oy
Priority date: 2023-04-20
Filing date: 2023-04-20
Publication date: 2024-12-11
Also published as: KR20260007579A; MX2025012416A; WO2024217683A1; CN120958067A; AU2023444525A1

Abstract

A polymer composition is disclosed. The polymer composition is made by using at least one polymer and a lignin-based filler prepared from lignin subjected to hydrothermal carbonization treatment. The amount of filler in the polymer composition is 5 – 50 phr, and the total biogenic carbon content of the polymer composition is 4 – 100 %. Further is disclosed a cured polymer composition and an article comprising the cured polymer composition.

Description

A POLYMER COMPOSITION

FIELD OF THE INVENTION

The present disclosure relates to a polymer composition . Further, the present disclosure relates to a cured polymer composition compri sing the polymer composition as disclosed in the current disclosure . Further, the present disclosure relates to an article comprising the polymer composition or the cured polymer composition as disclosed in the current disclosure .

BACKGROUND OF THE INVENTION

The fashion industry makes up for 10 % of the global greenhouse gas emis sions . This is more than international flights and shipping combined . Di f ferent fossil-based rubber or polymer-based compositions are being used in fashion industry, such as in shoe sole making . There is an ongoing need to find sustainable solutions for di f ferent applications to reduce emissions .

SUMMARY

A polymer composition is disclosed . The polymer composition is made by using at least one polymer and a filler, wherein :

- the amount of filler in the polymer composition is 5 - 50 phr ;

- the filler is a lignin-based filler prepared from lignin subj ected to hydrothermal carboni zation treatment ;

- the polymer is selected from ethylene-vinyl acetate , ethylene-vinyl acetate copolymer, polyurethane , thermoplastic polyurethane , polyethylene , polypropylene , polyolefin elastomer, olefin block copolymer, ethylene propylene diene monomer rubber, or any combination or mixture thereof ; and

- the total biogenic carbon content of the polymer composition is 4 - 100 % as determined according to standard ASTM D6866-22 .

Further, is disclosed a cured polymer composition comprising the polymer composition as disclosed in the present disclosure .

Further is disclosed an article comprising the polymer composition or the cured polymer composition as disclosed in the current disclosure .

DETAILED DESCRIPTION

- the amount of filler in the polymer composition is 5 - 50 phr ;

Further is disclosed a cured polymer composition comprising the polymer composition as disclosed in the current disclosure . In one embodiment , the polymer composition is a cured polymer composition .

Further is disclosed an article comprising the polymer composition or the cured polymer composition as disclosed in the current disclosure . The article may be a shoe sole, a midsoles, an outsoles, unisole, an insoles, a monobloc sandal, a flip flop, a full EVA footwear, a sportive article, a seal, a hose, a gasket, a foam, a foam mattress, or an automotive part.

The amount of polymer in the polymer composition may be 50 - 90 weight-%, or 55 - 85 weight-%, or 60 - 80 weight-%, based on the total weight of the polymer composition .

The amount of filler in the polymer composition may be 5 - 50 phr, or 10 - 45 phr, or 15 - 40 phr .

The term "phr" refers to "parts per hundred rubber". Parts per hundred rubber is a measure commonly used by rubber chemists to depict what amount of certain ingredients are needed in a composition. The term "phr" may be taken to refer to the amount of (all) the polymer (s) that are used in the polymer composition as disclosed in the current disclosure.

The at least one polymer may be derived from a fossil resource or from a biobased resource. All of the polymers used in the polymer composition may be derived either from a fossil source or from a biobased source. Alternatively, polymers from both fossil sources and biobased sources may be used in the polymer composition.

In one embodiment, the polymer (s) used in the polymer composition is (are) derived from (a) fossil resource (s) and the total biogenic carbon content of the polymer composition may be 4 - 40 %, or 6 - 35 %, or 8 - 30 %, as determined according to standard ASTM D6866- 22. Alternatively, at least one polymer may be derived from (a) biobased resource (s) and the total biogenic carbon content of the polymer composition may be 4 - 100 % , or 6 - 90 %, or 8 - 80 %, or 10 - 70 % as determined according to standard ASTM D6866-22.

The polymer is selected from ethylene-vinyl acetate, ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane, polyethylene, polypropylene, polyolefin elastomer, olefin block copolymer, ethylene propylene diene monomer rubber, or any combination or mixture thereof. The polymer may be selected from ethylene-vinyl acetate, ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane. The polymer may be any one of ethylene-vinyl acetate, ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane, polyethylene, polypropylene, polyolefin elastomer, olefin block copolymer, ethylene propylene diene monomer rubber. The polymer may be any one of ethylene-vinyl acetate, ethylenevinyl acetate copolymer, polyurethane, thermoplastic polyurethane, polyolefin elastomer, olefin block copolymer, ethylene propylene diene monomer rubber. Any combination or mixture of the above polymers may also be used .

The polymer composition may be prepared by using at least one polymer and the filler. Further components or materials, such as additives, lubricants, stabilizers, antioxidants, curing agents, blowing agents, etc., may also be used for preparing the polymer composition. In one embodiment, combining the at least one polymer and the filler comprises also combining one or more additives, lubricants, stabilizers, antioxidants, curing agents, and/or blowing agents, to form the polymer composition.

When preparing the polymer composition, a so- called masterbatch may first be prepared by using the at least one polymer and the filler. The masterbatch may be prepared by mixing the polymer and the filler at an elevated temperature. Also other additives, lubricants, stabilizer, antioxidants, curing agents, blowing agents, etc. as needed may be included in the masterbatch. A masterbatch is generally considered a solid product (normally of plastic, rubber, or elastomer) in which pigments or fillers are optimally dispersed at high concentration in a carrier material. The carrier material is compatible with the main plastic in which it will be blended during molding, whereby the final plastic product, i.e. the polymer composition, obtains the color or properties from the masterbatch.

Alternatively, the polymer composition may be directly compounded at an elevated temperature from the polymer and the filler. Also other additives, lubricants, stabilizers, antioxidants, curing agents, blowing agents, etc. as needed may be directly compounded with the polymer and the filler.

The temperature used when combining the at least one polymer and the filler may vary depending on the type of polymer used. The suitable temperature to be used for each polymer is readily available to the person skilled in the art. Also the polymer providers define suitable processing temperatures for different polymers. Generally, temperatures of e.g 20 - 350 °C, or 40 - 330 °C, or 70 - 300 °C, or 120 - 280 °C, or 150 - 250 °C, may be used.

The polymer composition may be further cured at an elevated in a subsequent step after mixing of the at least one polymer and the filler.

The polymer composition may be non-expanded or expanded. In one embodiment, the polymer composition is a non-expanded polymer composition, and the density of the non-expanded polymer composition is 0.7 - 1.3 g/cm³ , or 0.8 - 1.2 g/cm³, or 0.9 - 1.1 g/cm³ according to ASTM D792-20. In one embodiment, the polymer composition is an expanded polymer composition.

When the polymer composition is expanded it may be taken to have the form of a foam. The expanded polymer composition may be formed by introducing pockets of air or gas (e.g. CO2) into the polymer composition when being prepared. E.g. blowing agent (s) may be used to expand the polymer composition in order to cause it to foam. Polymer foaming is a process where gas filled cells, bubbles, are introduced to the material structure. With foaming, density of a material can be reduced as less material is consumed. In addition, density of the foam can be controlled, and a broad range of densities can be produced based on the product requirements. This results in reduction of weight and material costs. The expanded polymer composition may also be known as or called foamed polymer composition or polymer foam.

In one embodiment, no additional foaming agent and/or filler other than the lignin-based filler is used for making the expanded polymer composition. In one embodiment, no additional foaming agent and/or filler other than the lignin-based filler is used for making the polymer composition.

The total organic carbon content of the polymer composition may be 90 - 100 %, or 93 - 99 %, or 96 - 98 % as determined according to DIN EN 15936:2012-11. The term "total organic carbon (TOC) " may be taken as the amount of carbon found in an organic compound or in this case in the polymer composition.

The polymer composition may comprise ash in a total amount of 0.1 - 7.5 % , or 0.3 - 7.0 % , or 0.5 - 6 % , or 1.0 - 5.0 %, or 1.5 - 3.0% as determined according to DIN 51719:1997-07.

The amount of renewable materials in the polymer composition may be 5 - 100 %, or 10 - 95 %, or 15 - 90 %, or 20 - 85 %.

The filler used to make the polymer composition is a lignin-based filler prepared from lignin subjected to hydrothermal carbonization treatment (HTC) . The hydrothermal carbonization treatment of lignin refers to a thermochemical conversion process of lignin-containing material in an aqueous suspension. Hydrothermal carbonization treatment of lignin produces lignin derivatives having high carbon content and functional groups.

Lignin is a biopolymer, that is a key structural material in the supporting tissues of most living plants. It is a renewable material which can be used in several applications. The lignin may be derived from any suitable source. The lignin may be derived from e.g. wood, such as hardwood, softwood, broadleaf wood, or their combination, or from any other biomass such as sugarcane. The wood may originate from e.g. pine, poplar, beech, aspen, spruce, eucalyptus, ash, or birch. The wood may also be any combination or mixture of these.

In one embodiment, the lignin-based filler is prepared from lignin derived from enzymatic hydrolysis process and/or from a Kraft process and subjected to the hydrothermal carbonization treatment. In one embodiment, the lignin-based filler is prepared from lignin derived from enzymatic hydrolysis process and subjected to the hydrothermal carbonization treatment. In one embodiment, the lignin-based filler is prepared from lignin derived from a Kraft process and subjected to the hydrothermal carbonization treatment.

In one embodiment, the enzymatic hydrolysis process comprises enzymatic hydrolysis of a plant-based feedstock, such as a wood-based feedstock. In one embodiment, the enzymatic hydrolysis process comprises enzymatic hydrolysis of cellulose. In one embodiment, the lignin-based filler is prepared from lignin derived from pulping of wood, e.g. Kraft lignin.

The lignin-based filler may be prepared as disclosed below. The lignin to be used may be derived from e.g. a process wherein the lignin is formed in enzymatic hydrolysis of lignocellulosic feedstock or the lignin may be derived from a Kraft process. Also other lignin sources may be used.

In one embodiment, the starting material for preparing the lignin-based filler is lignin taken from enzymatic hydrolysis process. Enzymatic hydrolysis is a process, wherein enzyme (s) assist (s) in cleaving bonds in molecules with the addition of elements of water. In one embodiment, the enzymatic hydrolysis comprises enzymatic hydrolysis of cellulose. In one embodiment, the lignin-based filler is prepared from lignin derived from enzymatic hydrolysis process that is subjected to hydrothermal carbonization treatment.

The inventors surprisingly found out that when e.g. lignin from enzymatic hydrolysis process is used for producing the lignin-based filler, one is able to lower the ash content of the lignin-based filler. The lower ash content has the added utility of e.g. higher purity of the lignin-based filler.

The lignin may originate from second-generation biomass. The second-generation (2G) biomass may be taken to refer to non-edible and non-food biomass. Contrary to the term second-generation biomass, the first- generation biomass is to be taken as edible biomass.

The derived lignin may be dissolved in alkaline solution, such as NaOH. The dissolution may be accomplished by heating the mixture of lignin and alkaline solution to about 80 °C, adjusting the pH to a value above 7, such as 9 - 11, and mixing the mixture of lignin and alkaline solution for a predetermined time. The mixing time may be continued for about 2 - 3 hours. The exact pH value is determined based on the grade target of the product.

The dissolved lignin may then be subjected to hydrothermal carbonization treatment (HTC) .

The hydrothermal carbonization treatment may take place in a reactor (HTC reactor) , or if needed, in several parallel reactors, working in a batchwise manner. The dissolved lignin may be pre-heated before being entered in the HTC reactor (s) . The temperature in the HTC reactor (s) may be 150 - 250 °C and the pressure may be 20 - 30 bar. The residence time in the HTC reactor (s) may be about three to six hours. In the HTC reactor, the lignin is carbonized, whereby a stabilized lignin derivative with a high specific surface area may be precipitated. The formed slurry comprising the carbonized lignin may then be removed and cooled. Consequently, a slurry comprising lignin-based filler is formed.

The slurry comprising lignin-based filler may be fed to a separation unit, wherein the precipitated lignin may be separated from the slurry. The separated lignin-based filler may be dried and recovered. Before drying, the lignin-based filler may be, if needed, washed. The recovered lignin-based filler may be treated further, e.g. crushed, dried further, milled etc. before using as the lignin-based filler. The thus formed lignin-based filler is a renewable and a biobased filler .

During the above-described process lignin polymers are connected to each other. Thus, the ligninbased filler may be considered to comprise or consist of lignin polymers that are linked together. Lignin polymers that are connected or linked together may not be soluble anymore. However, smaller lignin polymer chains still remain soluble and thus can be subjected to standard analytical techniques like size exclusion chromatography or nuclear magnetic resonance spectroscopy (NMR spectroscopy) , which require the analyte to be dissolved in a solvent. Thus, different properties of the soluble fraction of the lignin-based filler may be determined.

The colour of the polymer composition may vary from brown to black. The color of the polymer composition may be represented by an L value of at most 35, an a value of at most 10, and a b value of at most 15 as determined by DIN EN ISO/CIE 11664-1:2020-03.

In one embodiment, the color of the polymer composition is represented by an L value of at most 35, or at most 30, or at most 25, or at most 23, or at most 20, or at most 15, or at most 10. In one embodiment, the color of the polymer composition is represented by an a value of at most 10, or at most 8, or at most 7, or at most 6, or at most 5, or at most 4.8, or at most 4.5, or at most 4.3. In one embodiment, the color of the polymer composition is represented by a b value of at most 15, or at most 12, or at most 10, or at most 8, or at most 7, or at most 6.5, or at most 6.3 or at most 6.1.

In one embodiment, the color of the polymer composition is represented by an L value of at least 2, or at least 4. In one embodiment, the color of the polymer composition is represented by an a value of at least 0.5, or at least 1, or at least 2, or at least 3, or at least 4, or at least 6, or at least 8, or at least 10. In one embodiment, the color of the polymer composition is represented by a b value of at least 0.5, or at least 1, or at least 2, or at least 3, or at least 4, or at least 6, or at least 8, or at least 10.

In one embodiment, the color of the polymer composition is represented by an L value of at most 35, or at most 30, or at most 25, or at most 23, or at most 20, or at most 15, or at most 10; and an a value of at most 10, or at most 8, or at most 7, or at most 6, or at most 5, or at most 4.8, or at most 4.5, or at most 4.3; and a b value of at most 15, or at most 12, or at most 10, or at most 8, or at most 7, or at most 6.5, or at most 6.3 or at most 6.1.

In one embodiment, the color of the polymer composition is represented by an L value of at least 2, or at least 4; and an a value of at least 0.5, at least 1, or at least 2, or at least 3, or at least 4, or at least 6, or at least 8, or at least 10; and a b value of at least 0.5, at least 1, or at least 2, or at least 3, or at least 4, or at least 6, or at least 8, or at least 10.

In one embodiment, the polymer composition does not include any additional colouring agent other than the lignin-based filler.

The color of the lignin-based filler may vary from brown to black. In one embodiment, the color of the ligninbased filler is represented by an L value of at most 50, or at most 45, or at most 40. In one embodiment, the color of the lignin-based filler is represented by an a value of at most 15, or at most 13, or at most 11. In one embodiment, the color of the lignin-based filler is represented by a b value of at most 22, or at most 20, or at most 18.

In one embodiment, the color of the ligninbased filler is represented by an L value of at least 25, or at least 30. In one embodiment, the color of the lignin-based filler is represented by an a value of at least 7, or at least 8, or at least 9. In one embodiment, the color of the lignin-based filler is represented by a b value of at least 11, or at least 13, or at least 15.

In one embodiment, the color of the ligninbased filler is represented by an L value of at most 50, or at most 45, or at most 40; and an a value of at most 15, or at most 13, or at most 11; and a b value of at most 22, or at most 20, or at most 18.

In one embodiment, the color of the ligninbased filler is represented by an L value of at least 25, or at least 30; and an a value of at least 7, or at least 8, or at least 9; and a b value of at least 11, or at least 13, or at least 15.

The L, a, and b values indicates values for the color of the polymer composition or the lignin-based filler, respectively. These values may be determined by DIN EN ISO/CIE 11664-1 : 2020-03and may be measured by any device, which allows measurement of the CIELab color space. The use of the lignin-based filler may result in a black colored polymer composition. The polymer composition has the added utility that no other colorants or pigments are needed to achieve the desired color of the polymer composition. The ( cured) polymer composition as disclosed in the current disclosure has the added utility of having a high bio-based content and thus may be used to replace many fossil-based polymer compositions for different applications . The ( cured) polymer composition thus may have a high renewable share of its components . The ( cured) polymer composition has the added utility of being a sustainable polymer composition, the use of which may reduce emissions compared to fossil-based polymer compositions . The ( cured) polymer composition has the added utility of having a low density and thus being a light-weight material . Further, the ( cured) polymer composition has the added utility of having a colour from brown to black without having to add any ( fossi lbased) colouring agents .

EXAMPLES

Reference will now be made in detail to the embodiments of the present disclosure .

The description below discloses some embodiments in such a detail that a person skilled in the art is able to uti li ze the method based on the di sclosure . Not all steps of the embodiments are discussed in detail , as many of the steps will be obvious for the person skilled in the art based on this disclosure .

Example 1 - Producing a cured polymer composition

In this example cured polymer compositions were produced . The purpose was to evaluate the performance of using the renewable lignin-based filler ( LBF) in di fferent polymer compositions . Comparative examples were prepared by using calcium carbonate in polymer compositions instead of the lignin-based filler .

The lignin-based filler was prepared by following the description provided above in the current speci fication by using lignin material from enzymatic hydrolysi s process o f beech wood or from a combination of beech wood and sugarcane and subj ected to hydrothermal carboni zation treatment .

The curable polymer compositions were prepared in an internal mixer model TMI 0 . 6 from ERMAFA Sondermaschinen- und Anlagenbau GmbH at a temperature of 120 ° C and subsequently laminated by a two-roll mil l model LaboWal z W150 from Vogt Labormaschinen GmbH . Thereafter they were pressed and cured in a hydraulic press model LP3000 600kN from MonTech

Werkstof fprufmaschinen GmbH at 180 ° C for 10 minutes to produce sheets , which were then evaluated for various properties .

The compounds used to prepare the polymer compositions and the properties measured are presented in the below table 1 :

Table 1 . Cured non-expanded polymer compositions

*EVA 1 = ethylene vinyl acetate copolymer ( fossil-based,

EVA3019PE from Braskem)

* *EVA 2 = Ethylene-Vinyl Acetate (EVA) copolymer, with high vinyl-acetate content ( fossil-based, HM728 from Braskem)

* * *EVA 3 = Ethylene-Vinyl Acetate (EVA) copolymer with renewable ethylene from sugar cane . The minimum biobased content of thi s grade i s 70 % , determined according to ASTM D6866 (plant-based, SVT2180 from Braskem)

In an otherwise similar manner as above presented was also cured expanded polymer compositions were prepared . The polymer composition was expanded by using the blowing agent azodicarbonamide that forms nitrogen, carbon monoxide , carbon dioxide , and ammonia gases during thermal decomposition, which result in the foaming of the polymer composition .

Table 2 . Cured expanded polymer compositions

*EVA 1 = ethylene vinyl acetate copolymer ( fossil-based,

EVA3019PE from Braskem)

From the above results one may see that a polymer composition with high biobased share together with good performance may be prepared . The polymer compositions formed by using the lignin-based filler further has a light weight ( low density) and a colour varying from brown to black .

It is obvious to a person skil led in the art that with the advancement of technology, the basic idea may be implemented in various ways . The embodiments are thus not limited to the examples described above ; instead they may vary within the scope of the claims .

The embodiments described hereinbefore may be used in any combination with each other . Several of the embodiments may be combined together to form a further embodiment . A polymer composition, a cured polymer composition, and an article as disclosed herein, may comprise at least one of the embodiments described hereinbefore . It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments . The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be understood that reference to 'an' item refers to one or more of those items. The term "comprising" is used in this specification to mean including the feature (s) or act(s) followed thereafter, without excluding the presence of one or more additional features or acts.

Claims

1. A polymer composition, wherein the polymer composition is made by using at least one polymer and a filler, wherein:

- the amount of filler in the polymer composition is 5 - 50 phr;

- the filler is a lignin-based filler prepared from lignin subjected to hydrothermal carbonization treatment ;

- the polymer is selected from ethylene-vinyl acetate, ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane, polyethylene, polypropylene, polyolefin elastomer, olefin block copolymer, ethylene propylene diene monomer rubber, or any combination or mixture thereof; and

- the total biogenic carbon content of the polymer composition is 4 - 100 % as determined according to standard ASTM D6866-22.

2. The polymer composition of any one of the preceding claims, wherein the amount of filler in the polymer composition is 10 - 45 phr, or 15 - 40 phr.

3. The polymer composition of any one of the preceding claims, wherein the polymer (s) used in the polymer composition is (are) derived from (a) fossil resource (s) and the total biogenic carbon content of the polymer composition is 4 - 40 %, or 6 - 35 %, or 8 - 30 % as determined according to standard ASTM D6866-22.

4. The polymer composition of any one of the preceding claims, wherein at least one polymer is derived from (a) biobased resource (s) and the total biogenic carbon content of the polymer composition is 4 - 100 %, or 6 - 90 %, or 8 - 80 %, or 10 - 70 % as determined according to standard ASTM D6866-22.

5. The polymer composition of any one of the preceding claims, wherein the polymer composition is a non-expanded polymer composition, and the density of the non-expanded polymer composition is 0.7 - 1.3 g/cm³, or

0.8 - 1.2 g/cm³, or 0.9 1.1 g/cm³ according to ASTM D792-20.

6. The polymer composition of any one of the preceding claims, wherein the total organic carbon content of the polymer composition is 90 - 100 %, or 93 - 99 %, or 96 - 98 % as determined according to DIN EN 15936:2012-11.

7. The polymer composition of any one of the preceding claims, wherein the polymer composition comprises ash in a total amount of 0.1 - 7.5 %, or 0.3 - 7.0 %, or 0.5 - 6 %, or 1.0 - 5.0 %, or 1.5 - 3.0% as determined according to DIN 51719:1997-07.

8. The polymer composition of any one of the preceding claims, wherein the lignin originates from second generation biomass.

9. The polymer composition of any one of the preceding claims, wherein the colour of the polymer composition varies from brown to black.

10. The polymer composition of any one of the preceding claims, wherein the polymer composition is an expanded polymer composition.

11. The polymer composition of any one of the preceding claims, wherein no additional foaming agent and/or filler other than the lignin-based filler is used for making the polymer composition.

12. A cured polymer composition, wherein the cured polymer composition comprises the polymer composition of any one of claims 1 - 11.

13. An article comprising the polymer composition of any one of claims 1 - 11 or the cured polymer composition of claim 12.

14. The article of claim 13, wherein the article is a shoe sole, a midsoles, an outsoles, unisole, an insoles, a monobloc sandal, a flip flop, a full EVA footwear, a sportive article, a seal, a hose, a gasket, a foam, a foam mattress, or an automotive part.