Elastomeric composition and articles comprising the composition

Abstract

The invention relates to compositions comprising an elastomeric polymer and 50 phr (parts per 100 parts of the polymer) or more of HTC lignin, wherein the HTC lignin has a D90 particle size as determined by ISO 13320:2020 of 5 µm or greater and an STSA surface area of ​​40 m2 / g or less as determined by ASTM D 6556-14. The invention also relates to an article comprising the composition and use of the composition in a gas barrier.

Description

Title of the invention: Elastomeric composition and articles comprising the composition

[0001] The present invention relates to a composition comprising an elastomeric polymer and hydrothermally treated lignin, articles comprising it and the use of the composition in a gas barrier.

[0002] Context

[0003] Carbon black is widely used as a filler for rubber articles, such as tires. However, carbon black is generally produced from fossil materials and is therefore not a sustainable material. To produce rubber articles on a more sustainable and environmentally friendly basis, many attempts have been made to replace carbon black with renewable materials such as lignin. However, to date, these attempts have not led to satisfactory rubber compositions and the corresponding products have not been commercialized on a large scale.

[0004] WO 2016 / 185351 discloses a compound for a puncture-resistant product comprising kraft lignin. Other uses of lignin in rubber mixtures are disclosed in WO 2020 / 140155 and in Aini et al., Front. Mater. 6 (2020) 329.

[0005] EP 3243877 discloses a tire comprising hydrothermally carbonized lignin. Hydrothermally treated lignin (also known as HTC lignin) is derived from lignin by thermochemical conversion in the presence of water (see e.g., Correa et al., Materials 11 (2018) 1568). The HTC lignin of EP 3243877 has a specific surface area of ​​less than 150 m2 / g. It is stated that the HTC lignin may be used in an amount of 75% by weight of the total rubber composition. For off-tread samples containing 46 phr (parts per 100 parts of rubber), EP 3243877 suggests that the tanô of the rubber composition containing HTC lignin is lower than that of a rubber composition containing carbon black. Other advantages are claimed with regard to tensile strength. No mention is made of air and gas permeability.

[0006] WO 2020 / 202125 discloses an inner coating comprising HTC lignin as a partial replacement for carbon black. WO 2020 / 202125 suggests the use of 15-45 phr of HTC lignin, preferably having a specific surface area of ​​30-55 m2 / g, D50 of 1-4pm and D90 of 5-8pm. Compared to carbon black and a combination of carbon black and kraft lignin (see WO 2016 / 185351 above), a rubber blend containing carbon black and 30 phr of HTC lignin is found to have improved oxygen impermeability with no change in M300%.

[0007] EP A 3974470 discloses compositions comprising halobutyl rubber and 50 to 90 phr of certain HTC lignin fillers having a STSA specific surface area of ​​10 to 50 m2 / g. The use of these fillers reduces gas permeability by 15% or less compared to carbon black. Summary of the invention

[0008] The present invention provides a composition having reduced gas permeability and other advantageous properties. The composition according to the invention is particularly advantageous when used in a gas barrier or in articles requiring gas barrier properties such as pipes, membranes, hollow articles and tires. The composition is particularly useful for use in internal coatings for tires or as such.

[0009] The composition according to the present invention comprises an elastomeric polymer and HTC lignin. The HTC lignin is present in an amount of 50 phr (parts per 100 parts of the polymer) or more. Preferably, the HTC lignin has a D90 particle size as determined by ISO 13320 of 5 pm or more and a specific surface area of ​​40 m2 / g or less as determined by ASTM D 6556-14.

[0010] It has been surprisingly discovered that the composition according to the present invention can significantly improve several properties of Telastomer containing the composition, including gas permeability.

[0011] According to various embodiments, the composition has the following characteristics, where appropriate combined:

[0012] - the elastomeric polymer is a halobutyl rubber;

[0013] - HTC lignin is present in an amount of 60 to 100 phr, preferably 90 phr or more;

[0014] - HTC lignin has an STSA surface area as determined by ASTM D 6556-14 less than 30, preferably less than 25, more preferably less than 20, even more preferably less than 15 and most preferably less than 10 m2 / g or less;

[0015] - HTC lignin is present in an amount of 90 phr or more and has a surface area specific of 10 m2 / g or less;

[0016] - D90 is 15 pm or more.

[0017] An article is provided comprising the composition as presented above. According to various embodiments, the article is a tire, a puncture-proof product or a re- inner garment.

[0018] It is proposed to use a composition as above in a gas barrier. Detailed description

[0019] The polymer of the present invention is an elastomer including rubbers and polymer rubber blends and composites.

[0020] The composition of the invention may comprise many types of elastomers, such as styrene-butadiene polymers and block polymers, polyisoprene, natural rubbers, polybutadiene, ethylene propylene rubber, silicone elastomers, fluoroelastomers, polyurethane elastomers and nitrile rubbers. Styrene butadiene (SBR) and butadiene (BR) are the most common rubber polymers in the tire industry. The composition of the invention may comprise one or more elastomers.

[0021] The elastomer of the present invention may be any elastomer including natural and synthetic rubber. The rubber as used herein is a diene polymer or diene-containing copolymer derived from butadiene, isobutylene, and isoprene. Copolymers of isobutylene and isoprene (also known as butyl rubber) are particularly preferred, as are the corresponding halogenated rubbers also known as halobutyl rubbers.

[0022] Butyl rubber is a synthetic copolymer of isobutylene (usually 98-99% by weight) and isoprene (usually 1-2% by weight). It is characterized by its very low unsaturation level and has distinct chemical and physical properties. Butyl rubber has low gas permeability and high chemical resistance.

[0023] Butyl rubber is usually produced by the cationic copolymerization of isobutylene with isoprene in the presence of a Friedel-Crafts catalyst at low temperature, for example around -100°C or -90°C. Halogenated butyl rubber can then be produced, for example, by reacting a solution of butyl rubber in hexane with elemental bromine or chlorine.

[0024] Halogenated butyl rubber can be obtained by halogenating butyl rubbers during or after polymerization. Chloro- and bromo-butyl rubbers exhibit improved compatibility with other polymers and faster cure rates than butyl rubber. The allylic C-Br or C-Cl bonds facilitate vulcanization and allow for a cure chemistry that is fundamentally different from other elastomers that rely on the reactivity of allylic C-H bonds. Halobutyl rubbers can, for example, be cured by ZnO alone, producing vulcanizates in the absence of sulfur. This cure chemistry distinct can for example facilitate co-vulcanization with other rubbers, such as natural rubber (NR) or styrene-butadiene rubber.

[0025] The halogenated butyl rubbers for use in the present formulations may comprise copolymers of isobutylene (e.g., 95-99.5 wt. %, or preferably 98-99 wt. %) and isoprene (e.g., 0.5-5 wt. %, 0.3-6 wt. %, or 1-2 wt. %, based on the total weight of monomers). The chlorobutyl rubber may, for example, contain chlorine in an amount of about 0.1 to about 6 wt. %, or about 0.8 to about 15 wt. % (based on the weight of the polymer). The bromobutyl rubber may, for example, contain bromine in an amount of about 0.1 to about 15 wt. % or about 1 to about 6 wt. % (based on the weight of the polymer). In halogenated butyl rubbers, the halogen content is limited by the isoprene content, and further limited by the fact that only a portion of the double bonds are halogenated.In a typical halobutyl rubber, 60% of the double bonds may have an allylic halogen substituent.

[0026] In a preferred embodiment, the rubber blend comprises halobutyl rubber, which may contain at least one other diene rubber. In a particularly preferred embodiment, the rubber blend comprises from 31 to 100 phr of at least one halobutyl rubber and from 0 to 69 phr of at least one other diene rubber. In the case of internal coatings, a polymer derived from isobutene and para-bromo methylstyrene is preferred. In such polymers, high bromomethyl styrene concentrations (e.g., 40 to 60 mol %, especially 50 mol %) are particularly preferred. One such commercial polymer is Exxpro™ 3563 from Exxon Mobile.

[0027] The other diene rubber may be selected from the group consisting of natural rubber, butyl rubber, polybutadiene rubber, styrene-butadiene copolymer, synthetic polyisoprene, natural polyisoprene, styrene-isoprene copolymer, styrene-isoprene-butadiene terpolymer, solution polymerized styrene-butadiene rubber and emulsion polymerized styrene-butadiene rubber and / or ethylene-propylene-diene rubber.

[0028] The rubber components may be functionalized. This functionalization uses hydroxy groups and / or epoxy groups and / or siloxane groups and / or amino groups and / or phthalocyanine groups and / or aminosiloxane groups and / or carboxy groups and / or other functionalization systems which may enter into chemical bonding with the light-colored fillers used.

[0029] Fillers are used to improve the mechanical properties of elastomers and vulcanized or crosslinked elastomers and rubbers. Typical examples are carbon black and silica. In the tire and rubber manufacturing industries, the Carbon black and silica are widely used as fillers. Approximately 93% of carbon black is used in rubber formulation and is often classified into two main categories: mechanical rubber articles (i.e., automotive hoses and belts) and tires.

[0030] The feedstock of the present invention comprises hydrothermally carbonized lignin, also known as HTC lignin. Lignin is the second most important natural resource. It is an aromatic polymer that holds cellulose and hemicellulose together in plants, strengthens cell walls, and protects plants from pests and diseases. The complex structure of amorphous lignin is formed by the attachment of different functional groups such as methoxyl, phenolic, hydroxyl, and carbonyl groups. A huge amount of lignin byproduct is produced by the paper and pulp industries, and about 98% of it is usually burned to generate energy or just discarded in a landfill.

[0031] Hydrothermal carbonization is a thermochemical process in which biomass is treated under pressure and in the presence of hot water and / or steam. In contrast to pyrolysis, biomass decomposes incompletely during HTC and the products are a solid carbon-rich material, a gaseous phase mainly composed of CO2, water and water-soluble compounds.

[0032] HTC lignin can be prepared from any type of lignin containing raw material such as lignin-containing waste as well as lignin in solid or dissolved form and mixtures thereof. A high lignin content of 60 wt% or more, preferably 80 wt% or more or more preferably 90 wt% in the raw material is preferred.

[0033] Preferred lignin-containing feedstocks are black liquor from the digestion of woody biomass or solids prepared therefrom, solids from the enzymatic hydrolysis of woody biomass, black liquor from the digestion of woody biomass with sulfites (lignosulfonates), or solids or liquids prepared from the digestion of woody biomass with solvents (e.g., organosolv lignin). In a preferred embodiment of the present invention, lignin is derived as a side stream in the enzymatic hydrolysis of a lignocellulosic feedstock. This preferred feedstock is also known as EH lignin.

[0034] The lignin-containing biomass may be selected from a group consisting of kraft lignin, steam cracking lignin, biorefinery lignin, supercritical separation lignin, hydrolysis lignin, flash precipitation lignin, lignin from biomass, lignin from alkaline pulping processes, lignin from soda process, lignin from organosolv pulping, lignin from from an alkaline process, lignin from an enzymatic hydrolysis process, and any combination thereof. In one embodiment, the lignin is wood-based lignin. The lignin may be derived from softwood, hardwood, annual plants, or any combination thereof.

[0035] "Kraft lignin" is lignin that is derived from kraft black liquor. Black liquor is an alkaline aqueous solution of lignin residues, hemicellulose, and inorganic chemicals used in a kraft pulping process. The black liquor from the pulping process includes components from different softwood and hardwood species in various proportions. Kraft lignin can be separated from the black liquor by various techniques including, for example, precipitation and filtration.

[0036] The term "flash-precipitated lignin" is to be understood as lignin that has been precipitated from black liquor in a continuous process, by reducing the pH of a black liquor stream, under the influence of an overpressure of 200 - 1000 kPa, to the lignin precipitation level, using a carbon dioxide-based acidifying agent, preferably carbon dioxide, and suddenly releasing the pressure to precipitate the lignin. Flash-precipitated lignin particles, having a diameter of less than 2 pm, form agglomerates that can be separated from the black liquor, for example by filtration.

[0037] Lignin can be derived from an organosolv process. Organosolv is a pulping technique that uses an organic solvent to solubilize lignin and hemicellulose.

[0038] Lignin may be slurried or dissolved for hydrothermal conversion. Preferably, the lignin is dissolved in an alkaline solution, such as NaOH. Dissolution may be accomplished by heating the mixture of lignin and alkaline solution to about 80°C, adjusting the pH to a value greater than 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 product quality target.

[0039] The slurry may be subjected directly to hydrothermal treatment or supplied to a separation unit, in which the precipitated lignin may be separated from the slurry.

[0040] The hydrothermal carbonization treatment can be carried out in one reactor (HTC reactor), or if necessary, in several parallel reactors, working in a discontinuous manner. The dissolved lignin can be preheated before being introduced into the HTC reactor(s). The temperature in the HTC reactor(s) can be 150 - 250 °C and the pressure can be 20 - 30 bar. The residence time in the HTC reactor(s) can be about three to six hours. In the HTC reactor, the lignin is carbonized, whereby a stabilized lignin derivative having a high specific surface area can be precipitated. The formed slurry comprising the carbonized lignin can then be removed and cooled.

[0041] The lignin-containing raw material, preferably in the form of a lignin solution, is subjected to a hydrothermal carbonization (HTC) process. For example, HTC lignin may be obtained by heating a lignin-containing raw material in the presence of water at temperatures between 150°C and 350°C, preferably between 150°C and 250°C under autogenous pressure, usually 10 to 40 bar. The heat treatment may be maintained for 30 minutes and up to 8 hours or more. Preferably, the treatment is completed in 1 to 6 hours or more preferably, in 2 to 4 hours.

[0042] For hydrothermal carbonization of raw materials containing lignin, it is preferable that at least a portion of the lignin is dissolved. Such partial or complete dissolution can be achieved by adjusting the pH to a value >7, preferably >9 and more preferably >10. A pH between 10 and 12, preferably between 10 and 11 before the HTC treatment has a favorable impact on the particle size distribution for use according to the present invention. In a preferred embodiment, the lignin for the hydrothermal treatment is in solution.

[0043] Dissolution may also be facilitated by increasing the temperature to more than 50°, for example between 70 and 90°C and preferably to 80°C. The dissolution conditions must be maintained for at least 5 minutes, more preferably at least 10 minutes, more preferably at least 15 minutes, particularly preferably at least 30 minutes, in particular at least 45 minutes but less than 300 minutes.

[0044] For the present invention, it is not necessary that all of the lignin is dissolved in the liquid. Advantageously, however, more than 50%, particularly preferably more than 60%, even more preferably more than 70%, particularly preferably more than 80%, in particular more than 90% of the lignin is dissolved in the liquid.

[0045] In a particularly preferred embodiment, the mixture of at least partially dissolved lignin also comprises at least one crosslinking agent capable of reacting with the functional groups of the lignin. These crosslinking agents may have aldehyde, carboxylic acid, epoxy, hydroxyl, isocyanate groups or other functional groups. The functional group of the crosslinking agent must be capable of reacting twice with the functional groups of the lignin. If the functional group can only react once, the crosslinking agent must contain at least two of these groups. Aldehydes, and in particular formaldehyde, are preferred. The crosslinking agent may be added in the step of dissolution and / or the HTC step. The reaction of the crosslinking agent with lignin may also be an intermediate step between the dissolution and HTC steps and it may be necessary to adjust the pH to carry out the reaction.

[0046] The crosslinking agent should be used in excess of the crosslinkable groups of the lignin. Such an excess may mean 1.5, 2 or even 4 times more. Amounts beyond 4 times more are unnecessary and are therefore not economically advisable. Typical amounts are less than 40, less than 35 or preferably less than 25% by weight based on the weight of the lignin. Specifically, in the case of formaldehyde, the amount may be reduced to less than 10 or even less than 5% by weight.

[0047] The amount and type of the crosslinking agent helps to adjust the specific surface area of ​​the product obtained in the HTC step. The use of the crosslinking agent increases the specific surface area of ​​the HTC lignin, whereby the surface area also generally increases with an increase in the crosslinking agent.

[0048] The HTC lignin for use in the present invention has a D90 particle size of 5 pm or more, as determined by laser diffraction according to ISO 13320:2020. The D90 particle size of the HTC lignin is preferably 8 pm or more, such as 10 pm or more. Particularly preferred D90 values ​​are 20 pm or more, or even 30 pm or more.

[0049] In the measurement according to ISO 13320:20, the HTC lignin is suspended in distilled water and the particle size distribution is measured with laser diffraction. Before and / or during the measurement of the particle size distribution, the sample to be measured is dispersed by ultrasound, until a stable particle size distribution is obtained over several measurements.

[0050] The particle size distribution may be influenced by certain process parameters. For example, particle size control may be achieved by adjusting the solids content of the feedstock, the pH of the feedstock, the inorganic ion concentration of the feedstock, and the temperature and residence time during the hydrothermal treatment. Advantageously, the solids concentration of the feedstock does not exceed 40% by weight (based on the feedstock), is preferably not greater than 20% by weight, and most preferably not less than 10% by weight. The pH is advantageously 7 or higher, such as 8.5 or higher, or even 11 or higher.The conductivity of the inorganic ions is measured at a value between 10 mS / cm and 200 mS / cm, preferably between 10 mS / cm and 150 mS / cm, more preferably between 10 mS / cm and 50 mS / cm, even more preferably between 10 mS / cm and 40 mS / cm, particularly preferably between 10 mS / cm and 25 mS / cm (determined as the conductance of the measuring probe of the PCE-PHD 1 between 20 °C and 25 °C). The temperature of the hydrothermal treatment can be limited to a maximum value between . 200°C and 250°C, preferably with a maximum value between 210°C and 245°C. Residence times between 1 minute and 6 hours, such as between 30 minutes and 4 hours or 1 and 3 hours are also useful. The above measures can also be adopted in combination.

[0051] If necessary, the particle size can also be adjusted by separating or mixing different HTC lignin materials. Gravity separation in a liquid or gaseous medium is a suitable method. Separation devices are well known to those skilled in the art. Examples include cyclones, particularly hydrocyclones in the case of liquids, centrifuges or separators (air separators). However, the present invention is not limited to the use of specific devices. Any devices that allow separation can be used, for example, fluidized bed devices, sieves, etc. Different types of separation can also be combined.

[0052] The obtained HTC line has an STSA of 40 m2 / g or less, more preferably 30 m2 / g or less, such as 25, 20, 15 or 10 m2 / g or less. The STSA surface area is determined according to ASTM D 6556-14. STSA (Statistical Thickness Surface Area) is an indication of the external surface area of ​​the HTC lignin particles.

[0053] Advantageously, the BET specific surface area of ​​the present HTC lignin deviates only by a maximum of 20%, preferably by a maximum of 15%, more preferably by a maximum of 10% from the STSA surface area. The BET specific surface area is determined as the total specific surface area of ​​the external and internal surface, by means of nitrogen absorption by the particles according to Brunauer, Emmett and Teller. A method for determining the BET surface area is also disclosed in ASTM D 6556-14.

[0054] The composition according to the invention may further include curing activators or dispersing agents, such as stearic acid (as exemplified), as well as other processing aids such as, for example, naphthenic oil. A processing aid, emulsifier or dispersing agent may, for example, be an ammonium or alkali metal salt of C12 to C24 fatty acids, such as ammonium, sodium or potassium salts of oleic acid, palmitic acid, stearic acid or linoleic acid. Alternative dispersing agents include ammonium and alkali metal salts of polyethoxylated sulfates of C6 to C20 alkyl alcohols, or polyethoxylated alkylphenoxy ethanols, and acid esters (phthalic, adipinic, phosphoric, for example, at loadings of 5-15 and 5-30 phr). Suitable amounts of the emulsifier may be, for example, about 0.1 to about 15 phr, or about 0.1 to about 5 phr.

[0055] The HTC lignin and other optional components are incorporated into the elastomer according to known methods as described for example in ASTM D3182 - 21b. The amount of HTC lignin is 50 phr or more, preferably 60 to 100 phr and most preferably 90 phr or more.

[0056] The compositions according to the invention may be formulated with the assistance of vulcanization reagents, activators, catalysts or accelerators, such as ZnO and / or sulfur and / or accelerator-activators and / or sulfur donors / accelerators such as: thiazoles, sulfenamides, guanidines, dithiocarbamates and thiuram sulfides; for example, thiocarbamyls, dithiocarbamyls, alkoxythio carbonyls, dialkylthio phosphoryls, diamino-2,4,6-triazinyls, thiuram xanthates and / or alkylphenols. A preferred thiazole is dibenzothiazyl disulfide (MBTS) and a preferred thiuram is tetramethyl thiuram monosulfide (TMTM). A preferred alkylphenol is poly-tert-amylphenol disulfide. When used, suitable accelerators may be added, for example, in an amount of about 0.1 to about 10 phr or about 0.1 to about 5 phr.

[0057] The composition according to the invention is advantageous for the manufacture of technical rubber articles, such as belts, transmission belts and hoses. It is particularly advantageous in rubber articles requiring gas impermeability, such as hoses. Its unique properties are particularly advantageous in internal coatings.

[0058] An inner liner is an inner layer of rubber used in tubeless tires, i.e., tires that are without an inner tube, in order to ensure their sealing under the pressure of the air contained inside the tire cavity. The inner liner must ensure that the oxygen in the air filling remains, as much as possible, confined inside the cavity and does not extend into parts of the tire, thus leading to a degradation phenomenon. The material of the inner liner must therefore have exceptional gas barrier properties. Furthermore, it must have these properties at a minimum thickness, since increasing the thickness entails a series of disadvantages with respect to the increase in weight and a compromise with respect to rolling resistance.

[0059] Preferably, the composition of the present invention is an inner coating comprising HTC lignin and a halobutyl rubber. Examples

[0060] Samples A, B, D and F (comparative) and samples C, E and G (according to the invention) were prepared on the basis of the compositions in Table 1. The components in powder and oil form were added to the polymer and then mixed for 7 minutes (with deceleration), in an internal Banbury mixer having a chamber volume of 1600 cm3 set at 40 °C and 60 rpm (filling factor of 70%). The hardeners were then added and mixing continued for 4 minutes. 0.5 mm thick sheets were formed and cured at 170 °C for 35 minutes. The sheets were tested as described below.

[0061] Air permeability was evaluated according to ASTM D1434-82(09)el, using a LabThink VAC-V1 gas permeability tester. The nitrogen transmission rate at 23°C was determined over a 38.48 cm2 sample test area.

[0062] Tensile properties were determined according to ASTM D412-16 at 23°C and 100°C. The samples were conditioned at 100°C for 30 minutes inside the climatic chamber maintained at 100°C before testing.

[0063] Compression set was measured after 24 hours at 70°C according to ISO 815-1. Density was measured according to ASTM D297.

[0064] [Tables 1] Specific surface area [m2 / g] D90 [pm ] A [phr] B [phr] C [phr] D [phr] E [phr] F [phr] G [phr] comp comp inv. comp inv. comp inv. Bromobutyl rubber 2244 (Exxon) 80 80 80 80 80 80 80 Natural rubber CV60 20 20 20 20 20 20 20 Naphthenic oil 10 10 10 10 10 10 10 Norsolene S95 4 4 4 4 4 4 4 MgO 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Stearic acid 2 2 2 2 2 2 ZnO 1 1 1 1 1 1 1 Sulfur 1.5 1.5 1.5 1.5 1.5 1.5 1.5 MBTS 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Carbon black N660 30 60 Carbon black N990 8 60 90 HTC 1000 10 15.9 60 90 HTC 4000 34 6.3 60 Air permeability [cmVm2 24h 0.1 MPa] 89.2 64.6 59.5 75.4 56.1 66.6 46.6 Air permeability in % relative to carbon black 100 92 100 74 100 70 M100 % 23°C [MPa] 0.27 1.34 1.60 0.59 1.21 0.88 1.95 M100 % 100°C [MPa] 0.23 0.9 1.47 0.45 1.09 0.79 1.63 M300% 23°C [MPa] 0.47 5.37 4.63 1.71 2.99 2.91 3.69 M300% 100°C [MPa] 0.45 3.16 3.28 1.26 1.95 2.19 2.30 Compression set [%] 37.0 28.4 17.6 39.3 22.4 33.3 16.5 Density [g / cm3] 0.948 1.130 1.05 3 1.132 1.05 0 1.190 1.08 2

[0065] The data show that the compositions according to the present invention result in lower gas permeability, compared to carbon black of comparative specific surface area. In particular, at a loading of 60 phr, the air permeability is reduced by 8 and 26%, respectively. At a loading of 90 phr, the reduction amounts to 30%. This is unexpected, since the prior art suggests much lower loadings (< 45 phr) and requires carbon black as a supplemental filler, or reports more modest reductions. Furthermore, it is noted that the effect on air permeability is particularly advantageous if the specific surface area is low and the loading is high. It is further noted that the compositions of the invention exhibit better M100% and M300% characteristics, particularly at elevated temperatures. Another advantageous property of the compositions is reduced compression set.Yet another advantage comes from the reduced density, which allows for products with reduced gas permeability at a lower weight.

Claims

Claims

1. A composition comprising an elastomeric polymer and 50 phr (parts per 100 parts of the polymer) or more of HTC lignin, wherein the HTC lignin has a D90 particle size as determined by ISO 13320:2020 of 5 pm or more and an STSA surface area of ​​10 m2 / g or less as determined by ASTM D 6556-14.

2. The composition of claim 1, wherein the elastomeric polymer is a halobutyl rubber.

3. A composition according to any preceding claim, wherein the HTC lignin is present in an amount of 60 to 100 phr.

4. A composition according to any preceding claim, wherein the HTC lignin is present in an amount of 90 phr or more.

5. A composition according to any preceding claim, wherein the D90 is 15 pm or more.

6. An article comprising the composition of any preceding claim.

7. An article according to claim 6, which article is a tire, a puncture sealant or an inner liner.

8. Use of a composition according to any one of claims 1 to 5 in a gas barrier.