A novel biodegradable additive and uses thereof

Abstract

The present invention provides a novel biodegradable additive comprising tea seed, at least one carbohydrate or derivative thereof, and at least one mineral salt, wherein the tea seed is not in the form of tea seed oil. The present invention also provides a method of preparing said additive, a biodegradable product comprising said additive such as gloves, shoes and tyres, as well as a method for producing said biodegradable product.

Description

[0001] A NOVEL BIODEGRADABLE ADDITIVE AND USES THEREOF

[0002] Field of the invention

[0003] The invention relates to a novel biodegradable additive and biodegradable products comprising thereof, such as a latex product. For example, gloves, shoes and tyres.

[0004] Background of the invention

[0005] Disposable product, especially disposable gloves are used in many applications, such as in healthcare, food service, janitorial, and more, to provide adequate protection from bacteria, viruses and other potential contaminants. However, the widespread use of conventional disposable gloves, typically made from non-biodegradable materials like nitrile, synthetic polyisoprene, neoprene, and vinyl, has raised significant environmental concerns.

[0006] The environmental impact of non-biodegradable gloves is a pressing issue, primarily due to the vast amounts of glove waste generated worldwide. These gloves can persist for decades after being disposed of in landfills, contributing to the mounting problem of plastic pollution and environmental degradation. As landfill sites continue to expand to accommodate increasing waste volumes, the ecological burden of non-biodegradable gloves becomes more pronounced.

[0007] Efforts to address this environmental challenge have led to the exploration of biodegradable materials for glove manufacturing. Biodegradable gloves offer the potential to reduce waste accumulation and minimize the long-term environmental consequences associated with non- biodegradable alternatives.

[0008] Thus, there is still a need for biodegradable materials which improve the biodegradability of traditional gloves without compromising the glove's desired properties.

[0009] Summary of the invention

[0010] In a first aspect of the invention, there is provided a biodegradable additive comprising tea seed, at least one carbohydrate or derivative thereof, and at least one mineral salt, wherein the tea seed is not in the form of tea seed oil. In some embodiments, the tea seed may be in the form of a tea seed cake, tea seed meal, tea seed powder, or tea saponin powder, preferably in the form of tea seed powder. More preferably, the tea seed may be obtained from Camellia genus, preferably from Camellia oleifera or Camellia sinensis.

[0011] In some embodiments, the carbohydrate may be a sugar, starch or cellulose. For example, the carbohydrate may be a sugar selected from one or more of a group consisting of glucose, dextrose, fructose, sucrose, lactose, maltose, galactose, trehalose, ribose, xylose, mannose, tagatose, molasses, palm sugar, and coconut sugar.

[0012] In some embodiments, the carbohydrate derivative may be selected from one or more of a group consisting of sugar alcohols / polyols (such as sorbitol, mannitol, xylitol, erythritol, maltitol, isomalt), sugar acids (such as gluconic acid, ascorbic acid, deoxyribose), amino sugars (such as glucosamine, galactosamine, N-acetylglucosamine, N-acetylgalactosamine), cellulose derivatives (such as carboxymethyl cellulose, ethyl cellulose), starch derivatives (such as modified starches, amylose and amylopectin fractions), pectin derivatives (such as pectinase- treated pectin, low methoxyl pectin), sugar phosphates (such as glucose-6-phosphate, fructose-6-phosphate), sugar sulfates (such as heparin, heparan sulfate, chondroitin sulfate) , glycolipids (such as glycosphingolipids) and glycoproteins mucins, and immunoglobulins.

[0013] In some embodiments, the mineral salt may be selected from one or more of a group consisting of nitrogen compounds (such as ammonium sulfate, ammonium nitrate, ammonium chloride, urea), phosphorus compounds (such as monopotassium phosphate, dipotassium phosphate, calcium phosphate, sodium phosphate), iron salts (such as ferrous sulfate, ferric chloride), sulfur compounds (such as sulfur, sulfate salts), magnesium salts (such as magnesium sulfate, magnesium chloride), potassium salts (such as potassium sulfate, potassium chloride), calcium salts (such as calcium carbonate, calcium sulfate, calcium chloride), sodium salts (such as sodium chloride, sodium phosphate, sodium nitrate) and the trace elements (such as copper, zinc, manganese, cobalt, molybdenum).

[0014] In a preferable embodiment, the additive comprises tea seed powder, sucrose and sodium chloride.

[0015] In some embodiments, the tea seed may be at a dosage in the range of about 65% to about 80% by weight. In some embodiments, the carbohydrate or derivative thereof may be at a dosage in the range of about 19% to about 30% by weight. In some embodiments, the mineral salt may be at a dosage in the range of about 1 % to about 5% by weight. In some embodiments, the additive may further comprise at least one supporting chemical selected from one or more of a group consisting of a dispersing agent, and an antifoam agent.

[0016] In some embodiments, the additive has a final particle size of less than 300 pm.

[0017] In some embodiments, the additive is for accelerating biodegradation of a latex product comprising the additive in landfill conditions.

[0018] In a second aspect of the invention, there is provided a method for producing the biodegradable additive according to the invention, comprising:

[0019] (a) dispersing tea seed, at least one carbohydrate or derivative thereof, at least one mineral salt and optionally at least one supporting chemical in water to form a mixture;

[0020] (b) blending said mixture for a period of time sufficient to obtain a homogenous blend; and

[0021] (c) optionally, sizing down the homogenous blend to obtain the biodegradable additive.

[0022] In a third aspect of the invention, there is provided a biodegradable product comprising the biodegradable additive according to the invention.

[0023] In some embodiments, the biodegradable product may be a latex product, preferably gloves, shoes and tyres. Preferably, the latex is one or more selected from a group consisting of natural rubber, acrylonitrile butadiene (NBR), polyisoprene and neoprene / chloroprene.

[0024] In a fourth aspect of the invention, there is provided a method for producing a biodegradable latex product, comprising integrating the biodegradable additive according to the invention into a latex compounding process.

[0025] Brief description of the drawings

[0026] Certain embodiments of the present disclosure are described more fully hereinafter with reference to the accompanying drawings.

[0027] Figure 1 shows the biodegraded mass percentage of different gloves determined by the ASTM D5511 test. Figure 2 shows the biodegraded mass percentage of different gloves determined by the ASTM

[0028] D5526 test under the condition of 35%solid content.

[0029] Figure 3 shows the biodegraded mass percentage of different gloves determined by the ASTM D5526 test under the condition of 45%solid content.

[0030] Figure 4 shows the biodegraded mass percentage of different gloves determined by the ASTM D5526 test under the condition of 60%solid content.

[0031] Detailed description of the invention

[0032] Further details of the invention will now be described with reference to the following nonlimiting examples. Unless otherwise defined herein, technical and scientific terms used in the present description have the meanings that are commonly understood by those of ordinary skill in the art.

[0033] As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0034] As used herein, the term “comprising” may include the embodiments “consisting of” and “consisting essentially of’. The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases that require the presence of the named ingredients / steps and permit the presence of other ingredients / steps. However, such description should be construed as also describing compositions, mixtures, or processes as “consisting of’ and “consisting essentially of’ the enumerated ingredients / steps, which allows the presence of only the named ingredients / steps, along with any impurities that might result therefrom, and excludes other ingredients / steps.

[0035] As used herein, the term “biodegradable” refers to being able to decay in nature environment by microorganisms such as bacteria and fungi.

[0036] A. The biodegradable additive

[0037] The present invention discloses a biodegradable additive comprising tea seed, at least one carbohydrate or derivative thereof, and at least one mineral salt, wherein the tea seed is not in the form of tea seed oil. The biodegradable additive is able to enhance the biodegradation rate of disposable products comprising it, such as gloves when discarded in landfill environments.

[0038] The first component of the biodegradable additive is tea seed which is not in the form of tea seed oil. Tea seed comprises blend of organic compounds that are easily metabolized by microbial populations commonly found in landfills, thus serving as a nutrient-rich food source for bacteria present in landfill environments. Thus, when a biodegradable product (such as a glove) comprising said additive starts to decompose, the released organic compounds serve as an abundant and readily accessible food source for bacteria. This, in turn, stimulates bacterial activity and establishes a thriving microbial community around the gloves. The increased microbial population significantly enhances the biodegradation process, leading to the rapid breakdown of the gloves into smaller, biodegradable fragments.

[0039] As used herein, “tea seed” refers to the seeds of the tea plant, Camellia genus. Preferably, tea seed used in the present invention may be obtained from Camellia oleifera or Camellia sinensis.

[0040] Camellia oleifera, commonly known as the oil tea camellia or tea-oil camellia, is abundant in regions where it is cultivated for its oil-producing seeds. This plant is native to southern China and has been cultivated for centuries for its oil-rich seeds. The primary purpose of Camellia oleifera tea seeds is the extraction of tea seed oil. On the other hand, Camellia sinensis, commonly known as the tea plant, is primarily cultivated for its leaves, which are used to produce various types of tea, including green tea, black tea, white tea, and oolong tea. Tea seeds from Camellia sinensis serve a dual purpose: plant propagation and, to a lesser extent, oil extraction. The primary focus of Camellia sinensis cultivation is the production of tea leaves for making tea beverages. While less common, tea seeds from Camellia sinensis can also be used for the extraction of tea seed oil.

[0041] In some embodiments, the tea seed may be in the form of a tea seed cake, tea seed meal, f tea seed powder, or tea seed saponin composition, preferably in the form of tea seed powder.

[0042] Tea seed cake refers to the residue obtained after initial oil extraction from tea seeds. It may generally comprise from 15 to 20% of oil, from 30 to 40% of protein, from 10 to 15% of fiber, and other nutrients such as carbohydrates and minerals.

[0043] Tea seed meal is obtained after the tea seed cake undergoes further oil extraction process. The oil content remaining in tea seed meal is lower than tea seed cake. It may generally comprise from 5 to 10% of oil, from 40 to 50% of protein, from 10 to 15% of fiber, and other nutrients such as carbohydrates and minerals.

[0044] Tea seed saponin composition is obtained by further extraction or purification from tea seed meal or tea seed powder. The tea seed saponin composition may generally comprise from 15% to 85% of saponin, and may be in the form of powder or concentrated liquid.

[0045] Tea seed powder is obtained by mechanical processing of the tea seed meal to obtain a smaller particle size. The size can vary from 80 mesh to 500 mesh depending on the requirement. The composition of tea seed powder varies depending on factors such as the source of the tea seeds, the oil extraction process, and whether any specific treatments or purification steps have been applied. Generally, the tea seed powder suitable for use in the present invention comprises the following components:

[0046] • Protein: Tea seed powder typically contains a significant amount of protein, often in the range of from 30 - 50 %. The protein content can make it a valuable nutritional supplement for various applications, including animal feed.

[0047] • Dietary Fiber: Tea seed powder contains dietary fiber, which includes both soluble and insoluble fibers. The fiber content can range from 10% to 20% or more, contributing to its potential benefits in terms of digestion and gut health.

[0048] • Carbohydrates: The carbohydrate content of tea seed powder is usually moderate and can vary from 10% to 20%, depending on the specific processing and source of the seeds.

[0049] • Lipids (Residual Oil): While tea seed powder is the by-product of oil extraction, it may still contain a small amount of residual oil, typically less than 5%. The lipid fraction includes both saturated and unsaturated fats.

[0050] • Phenolic Compounds: Tea seeds, and therefore tea seed powder, can contain various phenolic compounds, such as catechins and flavonoids. These compounds are antioxidants and may have potential health benefits.

[0051] • Anti-Nutritional Factors: Tea seed powder may contain certain anti-nutritional factors, such as tannins and saponins. Proper processing methods can help reduce these factors.

[0052] • Minerals: Tea seed powder contains essential minerals, including calcium, phosphorus, potassium, and others. These minerals can be valuable as nutrient supplements in animal feed and may benefit soil health when used as a soil conditioner. Water: The moisture content of tea seed powder can vary depending on the drying process used during production.

[0053] • Saponins: If saponins have not been entirely removed during processing, they may be present in tea seed powder. Saponins are naturally occurring compounds with foaming and detergent-like properties.

[0054] In some embodiments, the tea seed (e.g. in the form of tea seed powder) may be at a dosage in the range of from about 65% to about 80% by weight. For example, the tea seed may be at a dosage in the range of from about 70% to about 80%, from about 72% to about 80%, from about 74% to about 80%, from about 76% to about 80%, from about 65% to about 78%, from about 65% to about 75%, from about 65% to about 74%, from about 65 to about 72% by weight. The tea seed may also be at a dosage of about 65%, 66%, 67%, 68%, 69%, 70%, 71 %, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79% or 80% by weight.

[0055] The second component of the biodegradable additive is carbohydrate or derivatives thereof, which acts as a chemoattractant specifically designed to lure microorganisms, particularly bacteria towards the biodegradable product comprising the additive. This component releases chemical signals that attract and guide bacteria towards the surface of the biodegradable product. The attraction of bacteria ensures a higher concentration of microbial activity in the proximity of the biodegradable product, further optimizing the biodegradation process.

[0056] When microorganisms, especially bacteria, come into contact with carbohydrates or derivatives thereof, they metabolize these compounds as an energy source. During this metabolic process, carbohydrates are broke down into simpler substances through fermentation or respiration. As microorganisms metabolize carbohydrates, they produce various metabolic byproducts, including organic acids, alcohols, and gases like carbon dioxide and methane. These byproducts can alter the chemical composition of the surrounding environment. This alteration can in turn create concentration gradients, where certain chemicals are more concentrated in some areas than others, thus attracting microorganisms to areas where these compounds are being metabolized, leading to an increased microbial population in those regions. The increased microbial activity in areas rich in carbohydrates can accelerate the decomposition of organic waste materials in the landfill. This, in turn, it helps breaking down organic matter more efficiently, reducing the overall volume of waste and potentially mitigating odour issues associated with landfills.

[0057] In some embodiments, the carbohydrate or derivatives thereof may be one or more selected from a group consisting of sugars, starches and celluloses, preferably sugars. Examples of sugars that are suitable for use in the present invention include but not limited to glucose / dextrose, fructose, sucrose, lactose, maltose, galactose, trehalose, ribose, xylose, mannose, tagatose, molasses, palm sugar, coconut sugar or the combination thereof.

[0058] In some embodiments, the second component is a carbohydrate derivative. As used herein, “carbohydrate derivatives” refer to compounds that are derived from carbohydrates through chemical modifications or reactions. Examples of carbohydrate derivatives that are suitable for use in the present invention include but not limited to sugar alcohols / polyols (such as sorbitol, mannitol, xylitol, erythritol, maltitol, isomalt), sugar acids (such as gluconic acid, ascorbic acid, deoxyribose), amino sugars (such as glucosamine, galactosamine, N- acetylglucosamine, N-acetylgalactosamine), cellulose derivatives (such as carboxymethyl cellulose, ethyl cellulose), starch derivatives (such as modified starches, amylose and amylopectin fractions), pectin derivatives (such as pectinase-treated pectin, low methoxyl pectin), sugar phosphates (such as glucose-6-phosphate, fructose-6-phosphate), sugar sulfates (such as heparin, heparan sulfate, chondroitin sulfate) , glycolipids (such as glycosphingolipids), glycoproteins, mucins, and immunoglobulins.

[0059] In some embodiments, the carbohydrate or derivative thereof may be at a dosage in the range of from about 19% to about 30% by weight. For example, the carbohydrate or derivative thereof may be at a dosage in the range of from about 20% to about 30%, from about 22% to about 30%, from about 24% to about 30%, from about 26% to about 30%, from about 19% to about 28%, from about 19% to about 26%, from about 19% to about 24%, from about 19% to about 22% by weight. The carbohydrate or derivative thereof may also be at a dosage of about 19%, 20%, 21 %, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% or 30% by weight.

[0060] The third component of the biodegradable additive is a mineral salt which acts as a biodegradation catalyst that provides acceleration on the bacterial activity during the biodegradation process. A higher rate of bacterial activity will increase the speed of degradation process of the product comprising said additive, such as gloves.

[0061] Mineral salts can play several important functions in bacterial activity within a landfill environment. Landfills are complex ecosystems where various microorganisms, including bacteria, play crucial roles in the decomposition and stabilization of organic waste. Mineral salts can impact bacterial activity in landfills in multiples ways. For example, mineral salts can serve as a source of essential nutrients for bacteria, including elements like nitrogen, phosphorus, sulfur, and trace minerals. Bacteria require these nutrients for growth and metabolism. When mineral salts are present in sufficient quantities, they can support the proliferation of bacteria in the landfill. Mineral salts can also help buffer the pH levels in the landfill environment. Bacterial activity can alter the pH by producing acids or bases during metabolic processes. Mineral salts can help maintain a more stable pH range, which is important for the survival and activity of specific bacteria that are adapted to particular pH conditions. Bacteria need to regulate their internal osmotic pressure to survive in different environmental conditions. Mineral salts can influence the osmotic potential of the surrounding medium. Bacteria can adjust their internal solute concentrations to adapt to the osmotic conditions created by the presence of mineral salts. Some mineral salts can serve as electron acceptors or donors in bacterial metabolic processes. For example, certain bacteria can use sulfate (a mineral salt) as an electron acceptor in anaerobic respiration, facilitating the decomposition of organic matter in the landfill. Landfills may contain various pollutants and contaminants, some of which can be toxic to bacteria. Mineral salts, by interacting with these contaminants, can help mitigate their toxicity and protect bacterial populations. For example, certain salts can bind heavy metals and reduce their bioavailability to bacteria. Mineral salts can affect the water activity (aw) in the landfill environment. Bacteria require a certain range of water activity for metabolic processes. Mineral salts can influence the availability of water molecules and affect the water activity, which, in turn, can impact bacterial growth and activity. Overall, the role of mineral salts in bacterial activity in landfills is complex and context dependent. The specific effects of mineral salts on bacterial communities can vary depending on factors such as the composition of the waste, the pH of the landfill, the availability of other nutrients, and the presence of contaminants. Proper management of mineral salts in landfill environments can help optimize microbial processes for waste decomposition and minimize potential environmental impacts.

[0062] In some embodiments, examples of mineral salts that are suitable for use in the present invention include but not limited to nitrogen compounds (such as ammonium sulfate, ammonium nitrate, ammonium chloride, urea), phosphorus compounds (such as monopotassium phosphate, dipotassium phosphate, calcium phosphate, sodium phosphate), iron salts (such as ferrous sulfate, ferric chloride), sulfur compounds (such as sulfur, sulfate salts), magnesium salts (such as magnesium sulfate, magnesium chloride), potassium salts (such as potassium sulfate, potassium chloride), calcium salts (such as calcium carbonate, calcium sulfate, calcium chloride), sodium salts (such as sodium chloride, sodium phosphate, sodium nitrate) and the trace elements (copper, zinc, manganese, cobalt, molybdenum). Preferably, the mineral salt is sodium chloride. In some embodiments, the mineral salt may be at a dosage in the range of about 1 % to about 5% by weight. For example, the mineral salt may be at a dosage of 1 %, 1 .5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5% by weight.

[0063] In a preferred embodiment, the biodegradable additive comprises tea seed powder, sucrose and sodium chloride.

[0064] The biodegradable additive of the invention may be in form of a powder, emulsion, suspension or dispersion. Preferably, the biodegradable additive is in form of a stable dispersion. In some embodiments, the additive has a final particle size less than 300 pm, for example, from 0.01 pm to 300 pm, from 20 pm to 200 pm, from 20 pm to 150 pm, from 50 pm to 100 pm. It is found in the present application that once the particle size goes over 300 pm, the film formation and the physical properties of the final products (such as gloves) will be compromised.

[0065] In some embodiments, the biodegradable additive is a stable dispersion, which may further comprise one or more supporting chemicals such as a dispersing agent and an anti-foaming agent. The presence of such supporting chemicals enables the additive to be more suitable for subsequent applications, such as assisting with placing the additive into the latex compounding process in an even fashion to assure proper biodegradation. Such supporting chemicals may not be present if the additive is used in the form of a powder, and their absence will not affect the biodegradation capability of the additive powder.

[0066] Dispersing agents known in the art are suitable for use in the present invention. Such dispersing agents may be surfactants either in anionic or non-ionic types. Examples of anionic dispersing agents include but not limited to sodium dodecyl sulfate (SDS), sodium lauryl sulfate (SLS), sodium dioctyl sulfosuccinate (AOT), sodium alkylbenzene sulfonates (ABS), alkyl sulfates. Examples of non-ionic dispersing agents include but not limited to polysorbate 20 (Tween 20), polysorbate 80 (Tween 80), Triton X-100, octylphenol ethoxylates, fatty alcohol ethoxylates. Other dispersing agents such as sodium polyacrylate, polyethylene glycol, and the derivatives of sulfonates and phosphates can be used in this invention.

[0067] Anti-foaming agents that are suitable for use in the present invention are known in the art. One example of anti-foaming agents is non-silicone-based compounds. There are 3 types of nonsilicone based antifoam, which are polyglycol based, fatty acid based, and mineral oil based. Examples of polyglycol based antifoam agents include but not limited to polyethylene glycol (PEG), and polypropylene glycol (PPG). Examples of fatty acid based anti-foaming agents include but not limited to stearates and oleates. Examples of mineral oil based anti-foaming agents are hydrocarbon based oils like vegetable oils or paraffin oils.

[0068] The present invention also provides a method for producing the biodegradable additive, comprising the following steps:

[0069] (a) dispersing tea seed, at least one carbohydrate or derivative thereof, at least one mineral salt and optionally at least one supporting chemical in water to form a mixture;

[0070] (b) blending said mixture for a period of time sufficient to obtain a homogenous blend; and

[0071] (c) optionally, sizing down the homogenous blend to obtain the biodegradable additive.

[0072] In some embodiments, quality control tests may be conducted to verify the uniformity of the final additive compound throughout the blending process. One of such tests may be the measurement of particle size. There are various methods for particle size analysis, including high definition image processing, analysis of Brownian motion, gravitational settling of the particle, and light diffraction (Rayleigh and Mie diffracting) of the particles.

[0073] An additional step of sizing down would be necessary if the particle size of the homogenous blend obtained at the end of step (b) is over 300 pm. Granulation techniques known in the art may be used in the present invention, such as wet ball milling to reduce the particle size of the blend to a suitable range.

[0074] B. The biodegradable product

[0075] The present invention also provides a biodegradable product comprising the biodegradable additive according to the invention, and a preparation method thereof. In particular, the present invention provides a method for producing a biodegradable latex product, comprising integrating the biodegradable additive according to the invention into a latex compounding process.

[0076] In some embodiments, the product may be a latex product, such as gloves, shoes, and tyres. Preferably, the latex is one or more selected from a group consisting of natural rubber, acrylonitrile butadiene, polyisoprene and neoprene / chloroprene.

[0077] One advantage of the biodegradation additive of the present invention is that it can be integrated seamlessly into the latex compounding process without compromising the desired characteristics of the resulting latex products such as gloves. The resulting products (e.g., gloves) made therefrom exhibit the same desired mechanical, barrier and tactile properties, and have effectively similar shelf-lives as products without the additive, and yet, when disposed of, are able to at least partially metabolize into inert biomass by the communities of anaerobic and aerobic microorganisms commonly found in the landfill conditions.

[0078] In some embodiments, the biodegradable additive may be at a dosage in the range of about from 0.01 to 10 phr, preferably from 0.1 to 8 phr, from 0.2 to 6 phr, from 0.3 to 5 phr, from 0.4 to 4 phr, or from 0.5 to 2 phr. As used herein, the term “phr” means parts per hundred parts of rubber.

[0079] In some embodiments, the biodegradable additive of the present invention is added into the conventional latex formulation used for making gloves (i.e., the latex compounding process), which latex formulation may further comprise one or more of sulphur, activators such as zinc oxide, accelerators such as zinc dibutyldithiocarbamate (ZDBC), pigments such as titanium dioxide, opaqueness provider, anti-oxidants, surfactants such as sodium dodecyl benzene sulphonate (SDBS), and / or pH stabilizers. The latex formulation comprising the biodegradable additive then undergoes standard glove formation procedures, including dipping, curing, and drying.

[0080] The biodegradable gloves, infused with the biodegradable additive of the invention, exhibit enhanced biodegradability compared to traditional non-biodegradable gloves. The three- component synergistic action stimulates bacterial growth, attracts microbial populations, and catalyses the bacterial activity. These combined effects lead to an accelerated biodegradation process, reducing the environmental impact of disposable gloves in landfill conditions.

[0081] It should be understood that any and all embodiments of the present disclosure can be combined with technical features in any other embodiment or multiple other embodiments to obtain additional embodiments under the premise of no conflict. The invention includes such combinations resulting in further embodiments.

[0082] Examples

[0083] The examples and exemplary embodiments below are intended to be purely exemplary of the invention and should therefore not be considered to limit the invention in any way.

[0084] Example 1 : Preparation of the biodegradable additive The biodegradable additive of the present invention is prepared according to the formula as shown in the following Table 1.

[0085] Table 1. Composition of the biodegradable additive

[0086] All materials were dispersed at the indicated dosage into water, and the mixture was then stirred using a high-speed dissolver at 1500 rpm for 30 minutes to obtain a homogenous blend. The blend was subjected to a wet milling process using a horizontal bead mill until the particle size reaches a workable range. The particle size was measured by Horiba LA-960 Laser diffraction particle size analyser. The particle size of the biodegradable additive was determined as 50 pm.

[0087] Example 2: Preparation of a biodegradable glove

[0088] The biodegradable additive prepared in Example 1 was integrated seamlessly into the latex compounding process. The latex formulation is as shown in Table 2.

[0089] Table 2. Latex formulation for glove formation

[0090] Gloves were then prepared using a known standard method. Briefly, glove formers were first cleaned using chemical or physical washing, and the dried. The dried formers were dipped into a coagulant, and then let the coagulant dried on surfaces of the formers. Subsequently, the formers were dipped in the latex formulation prepared according to Table 2, thus a latex film was formed on the surfaces of the formers. The formers were then subjected to leaching to remove leachable materials, followed by glove beading. The latex film was further dried and cured before the gloves were stripped out from the formers.

[0091] Two types of gloves were obtained. One contained 0.5 phr of the additive of the present invention (low dosage), and the other one contained 1.0 phr of the additive of the present invention (high dosage). Untreated gloves were also prepared as a control.

[0092] Example 3 Determination the biodegradation performance of the gloves

[0093] The biodegradability of the gloves prepared in Example 2 were tested according to standard methods ASTM D5511 and D5526 and compared with traditional NBR gloves without the biodegradable additive of the present invention (i.e., untreated gloves obtained in Example 2). Polyethylene (PE) was used as a negative control.

[0094] ASTM D5526 is centred around determining the anaerobic biodegradation of plastic materials (such as gloves) under accelerated landfill conditions. It simulates the biological processes within landfills, assessing how untreated and treated glove break down under anaerobic conditions in a manner that replicates a landfill environment. In contrast, ASTM D5511 focuses on determining the anaerobic biodegradation of plastic materials (such as gloves) under high- solids anaerobic digestion conditions (i.e., a solid condition above 20%). It aims to evaluate the impact of untreated and treated gloves within high-solids anaerobic digestion units, assessing their decomposition and effects within these specific conditions.

[0095] The results are shown in Table 3 and Figures 1-4. For ASTM D5511 , both treated gloves (low and high dosages) showed higher mass loss as compared to untreated gloves. When the dosage of the additive increased, the biodegradability also increased from 1.8% to 4.4%. For ASTM D5526, the performance of the treated gloves were negatively correlate with the amount of solid content used in the test. Treated gloves showed highest mass biodegradation when the solid content was 35%. In other words, the biodegradation additives gave highest biodegradation performance under low solid content conditions, i.e., high humidity conditions. Thus, in all conditions tested, gloves comprising the additive of the present application exhibited significantly higher biodegradation efficiency compared with untreated gloves without such additive and the PE negative control.

[0096] Table 3. Biodegradability of gloves on Day 49 as determined by ASTM D5511 and on Day 50 as determined by ASTM D5526.

[0097] For one skilled in the art, various modifications and changes may be made to the present disclosure. Those skilled in the art should understand that any amendments, equivalent replacements, improvements, and so on, made within the spirit and principle of the present disclosure, should be covered within the scope of protection of the present disclosure.

Claims

Claims1 . A biodegradable additive comprising tea seed, at least one carbohydrate or derivative thereof, and at least one mineral salt, wherein the tea seed is not in the form of tea seed oil.

2. The biodegradable additive according to Claim 1 , wherein the tea seed is in the form of a tea seed cake, tea seed meal, tea seed powder, or tea seed saponin composition, preferably in the form of tea seed powder.

3. The biodegradable additive according to Claim 1 or 2, wherein the tea seed is obtained from Camellia genus, preferably from Camellia oleifera or Camellia sinensis.

4. The biodegradable additive according to Claim 1 , wherein the carbohydrate is a sugar, starch or cellulose.

5. The biodegradable additive according to Claim 4, wherein the sugar is selected from one or more of a group consisting of glucose, dextrose, fructose, sucrose, lactose, maltose, galactose, trehalose, ribose, xylose, mannose, tagatose, molasses, palm sugar, and coconut sugar.

6. The biodegradable additive according to Claim 1 , wherein the carbohydrate derivative is selected from one or more of a group consisting of sugar alcohols / polyols (such as sorbitol, mannitol, xylitol, erythritol, maltitol, isomalt), sugar acids (such as gluconic acid, ascorbic acid, deoxyribose), amino sugars (such as glucosamine, galactosamine, N-acetylglucosamine, N-acetylgalactosamine), cellulose derivatives (such as carboxymethyl cellulose, ethyl cellulose), starch derivatives (such as modified starches, amylose and amylopectin fractions), pectin derivatives (such as pectinase-treated pectin, low methoxyl pectin), sugar phosphates (such as glucose-6-phosphate, fructose-6-phosphate), sugar sulfates (such as heparin, heparan sulfate, chondroitin sulfate) , glycolipids (such as glycosphingolipids) and glycoproteins mucins, and immunoglobulins.

7. The biodegradable additive according to Claim 1 , wherein the mineral salt is selected from one or more of a group consisting of nitrogen compounds (such as ammonium sulfate, ammonium nitrate, ammonium chloride, urea), phosphorus compounds (such as monopotassium phosphate, dipotassium phosphate, calcium phosphate, sodium phosphate), iron salts (such as ferrous sulfate, ferric chloride), sulfur compounds (suchas sulfur, sulfate salts), magnesium salts (such as magnesium sulfate, magnesium chloride), potassium salts (such as potassium sulfate, potassium chloride), calcium salts (such as calcium carbonate, calcium sulfate, calcium chloride), sodium salts (such as sodium chloride, sodium phosphate, sodium nitrate) and the trace elements (such as copper, zinc, manganese, cobalt, molybdenum).

8. The biodegradable additive according to any one of Claims 1-7, wherein the additive comprises tea seed, sucrose and sodium chloride.

9. The biodegradable additive according to any one of Claims 1-8, wherein the tea seed is at a dosage in the range of 65-80% by weight.

10. The biodegradable additive according to any one of Claims 1-9, wherein the carbohydrate or derivative thereof is at a dosage in the range of 19-30% by weight.

11. The biodegradable additive according to any one of Claims 1-10, wherein the mineral salt is at a dosage in the range of 1-5% by weight.

12. The biodegradable additive according to any one of Claims 1-11 , wherein the additive further comprises at least one supporting chemical selected from one or more of a group consisting of a dispersing agent and an antifoam agent.

13. The biodegradable additive according to any one of Claims 1-12, wherein the additive has a final particle size less than 300 pm.

14. The biodegradable additive according to any one of Claims 1-13, wherein the additive is for accelerating biodegradation of a latex product comprising the additive in landfill conditions.

15. A method for producing the biodegradable additive according to any one of Claims 1- 14, comprising:(a) dispersing tea seed, at least one carbohydrate or derivative thereof, at least one mineral salt and optionally at least one supporting chemical in water to form a mixture;(b) blending said mixture for a period of time sufficient to obtain a homogenous blend; and(c) optionally, sizing down the homogenous blend to obtain the biodegradable additive.

16. A biodegradable product comprising the biodegradable additive according to any one of Claims 1-14.

17. The biodegradable product according to Claim 16, wherein the product is a latex product, preferably gloves, shoes and tyres.

18. The biodegradable product according to Claim 17, wherein the latex is one or more selected from a group consisting of natural rubber, acrylonitrile butadiene, polyisoprene and neoprene / chloroprene.

19. A method for producing a biodegradable latex product, comprising integrating the biodegradable additive according to any one of claims 1-14 into a latex compounding process.

20. The method according to Claim 19, wherein the latex is one or more selected from a group consisting of natural rubber, acrylonitrile butadiene, polyisoprene and neoprene / chloroprene.21 . The method according to Claim 19 or 20, wherein the biodegradable latex product is a glove.

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