Flexible wood composite material

Abstract

A composite material, a method for its manufacture, and an article manufactured therefrom. The composite material includes a first component formed from a renewable polymer and a second component formed from a reinforcing material. The first component is a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, and the second component is made from particles of a hydrophilic material having a sieved size of less than 0.5 mm. The composite material further includes an elastic region to provide compostable objects and articles with flexible or semi-rigid properties in at least one dimension. Flexible composite materials can be used for thin-walled extrusions that exhibit increased flexibility or softness in the cross direction.

Description

Technical Field

[0001] The present invention relates to composite materials that can be formed into three-dimensional objects and three-dimensional articles. The materials of the present invention include a first component formed by a renewable polymer and a second component formed by a reinforcing material.

[0002] In particular, the present invention relates to a material in which the first component consists of a thermoplastic polymer selected from the group of biodegradable polyesters and their mixtures, and the second component consists of particles of a hydrophilic material. The present invention also relates to articles manufactured from the composite material and a method for manufacturing the composite material.

Background Art

[0003] Due to the increasing awareness of environmental issues and resource shortages, there is a growing interest in the use of bio-based materials in many applications. Legally, due to stricter policies, many industries are forced to search for and develop new materials from renewable resources to replace conventional materials derived from non-renewable fossil resources.

[0004] One of the most prominent challenges in recent decades has been the accumulation of plastic in the environment, particularly in the oceans. This is mainly due to waste leaking into the environment from waste disposal facilities due to inadequate waste management processes. Plastic fragments in the ocean pose a significant threat to marine animals and could ultimately lead to a catastrophic situation for marine ecosystems. In October 2018, the European Parliament approved a ban on the use of plastic cutlery, plates, cotton swabs, straws, drink stirring sticks, and balloon sticks. At the time of the decision, the EU hoped to implement the ban throughout the EU by 2021. Furthermore, for items for which there are no alternative materials (such as hamburger boxes and sandwich wrappers), a 25% reduction is required in each country by 2025. Another goal is to collect and recycle 90% of all PET bottles by 2025. Therefore, it is clear that achieving more efficient waste management processes is an urgent necessity. Meanwhile, this problem could potentially be solved, at least partially, by developing materials that decompose quickly when released into the natural environment.

[0005] To address the environmental problems caused by petroleum-derived, non-biodegradable, and single-use plastics, research is actively being conducted to develop biodegradable polymers that possess similar properties to comparable non-biodegradable plastics. This has led to the development of numerous polymers, including polylactic acid (PLA), polycaprolactone (PCL), polyhydroxybutyrate (PHB), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoic acid (PHA), and mixtures thereof. Despite their advantageous properties, particularly in terms of biodegradability, these materials decompose slowly when exposed to environmental conditions. Most commercially available biopolymers can only be used in industrial composting processes that require temperatures raised to approximately 60°C, and even then, their thickness must be less than 1.5 mm. Therefore, these materials are only suitable for thin-walled products such as carrying bags or films.

[0006] PLA is an example of a biodegradable thermoplastic synthetic polyester derived from renewable resources such as sugarcane and corn, as well as other plants, and is currently one of the most widely used bioplastics. PLA also boasts excellent durability and rigidity, and has good processability for most applications. While PLA does not decompose rapidly in low-temperature, low-humidity environments, it decomposes rapidly when exposed to high humidity and high temperatures (above 60°C). PLA biodegradation involves two processes: hydrolysis leading to low-molecular-weight oligomerization, followed by complete digestion by microorganisms. Although PLA has applications ranging from food to medical fields, its use is limited by the high cost of the polymer and its slow decomposition rate in nature.

[0007] Several studies have shown that even if the wall thickness of products using biodegradable polymers like PLA is kept to around 1 mm, biodegradation in the ocean can take an excessive amount of time (i.e., several years), raising doubts about their biodegradability in the ocean. This slow rate of degradation is strongly related to the low water absorption of pure PLA.

[0008] The development of biodegradable and compostable materials focuses on bio-based polymers and biodegradable polymers, as well as renewable resources such as forestry residues and natural fibers derived from by-products of industries such as coffee, cosmetics, and grain-based ethanol. Furthermore, agricultural fibers (such as straw) and lignin-containing materials such as hemp stalks can also be used as fillers.

[0009] For example, flexibility or elasticity is required for some applications, such as straws. This is especially true when child safety is a concern. Known PLA-derived thermoplastic composites are rigid, which prevents the formation of sharp edges and provides a sense of security.

[0010] There is a need for a material that exhibits the advantageous properties of thermoplastic / wood particle-based composites while also possessing sufficient flexibility for use, for example, in straws.

[0011] A composition of PLA, a compostable polymer, and a finely ground cellulosic material is disclosed in WO2015 / 048589. This publication describes an annealed PLA composite containing PLA and up to 30% finely ground cellulosic material, such as finely ground paper pulp. The particle size of the finely ground material ranges from 10 to 250 μm, particularly 20 to 50 μm, and has a narrow particle size distribution. According to this publication, the material is compostable and exhibits a high heat deflection temperature (HDT). However, no mechanical advantages are obtained from the addition of the finely ground material, and to avoid problems during processing and injection molding, the maximum load of the material was limited to 30%.

[0012] More composite materials are described in CN101712804A, US2013253112, US2016076014, US2002130439 and EP0319589.

[0013] The wood used in WPC is crushed, sieved, and dried before extrusion. For deck and fence contours, when a rough surface texture is acceptable or desirable, screening the wood fibers to 40 to 60 mesh provides good flow properties and facilitates mixing into the polymer matrix. For contours requiring a smooth finish, the wood is sieved through an 80 to 100 mesh screen. Fine particles passing through a 120 mesh screen are undesirable because they have poor flowability and are unevenly distributed in the polymer matrix during extrusion. Unevenly distributed wood fibers, so-called "wood spots," are a common quality issue, especially when the wood contains excessive fine particles or when the extruder is too worn to produce a uniform mixture (CN107932874A).

[0014] For example, JP4699568B2 relates to a method for manufacturing thin-walled containers having a thickness in the range of 0.3 to 0.7 mm. The polymer used in this invention is PLA, and the material may further contain inorganic fillers (1 to 28% by weight). Therefore, this invention is not applicable to materials containing natural fibers in combination with PLA. As shown in the following sections, manufacturing thin-walled products from biodegradable polymers alone will cause thermal deformation when exposed to high temperatures (e.g., above 50°C).

[0015] US10071528B2 describes an invention relating to rigid, thin-walled fiber composite products and methods for manufacturing the same. The products of this invention consist of layers having different types of fibers, including natural fibers, as reinforcing materials. The final structures have a thickness between 0.5 mm and 3 mm. This patent invention relates only to hollow and cylindrical structures and does not include biodegradable polymers as matrix materials.

[0016] CN101429328A describes an invention relating to a material that can be used to manufacture a naturally biodegradable, deep-cavity, thin-walled soft bottle for tableware, and to the soft bottle itself. The material presented in this invention consists, by weight, of 85 to 90% PLA, 9 to 14% polyethylene terephthalate (PET), and the remainder being PET additives. The bottle thickness is 0.07 to 0.09 mm. Although the authors state that the material is biodegradable, the inclusion of PET, which is known not to be biodegradable, leaves small plastic remnants. Furthermore, the inclusion of natural fibers in the material is outside the scope of this invention.

[0017] A material invention for biodegradable or compostable containers is presented in US20030216492A1 (expired). The material presented in the invention is based on starch obtained, for example, from potatoes, paper, or corn. Furthermore, the properties of the material are modified by adding wood flour or fibers (aspect ratio 1:2 to 1:8) to the starch suspension. The addition of wood fibers makes the material moldable. The molded articles are made waterproof by applying a liquid-resistant coating (such as PROTECoat, Zein®). These products can be used as cups, trays, bowls, dishes, or plates. The thickness of the articles can range from 0.001 mm to 10 mm. The invention applies only to starch-based formulations and not to extrusion applications. Although injection molding is presented as one possible conversion technique, the formulations for creating injection-molded articles contain less than 10% by weight of wood. Furthermore, coating is necessary to make this material suitable for its intended application. Other starch-based materials for thin-walled applications are described in US6168857B1 (sheets with a thickness of less than approximately 1 cm).

[0018] Based on the above facts, there is still a need for biodegradable materials that decompose at an accelerated rate under environmental conditions and can be efficiently produced using mass production machinery. [Prior art documents] [Patent Documents]

[0019] [Patent Document 1] WO2015 / 048589A1 [Patent Document 2] CN101712804A [Patent Document 3] US2013253112A [Patent Document 4] US2016076014A [Patent Document 5] US2002130439A [Patent Document 6] EP0319589

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Patent Document 11

Patent Document 12

Summary of the Invention

Problems to be Solved by the Invention

[0020] The object of the present invention is to eliminate at least part of the drawbacks of the prior art and to provide a new flexible wood composite material suitable for extrusion processing.

Means for Solving the Problems

[0021] The present invention is based on the concept of providing a composite material by combining a first component formed of a rigid thermoplastic biopolymer, a second component formed of a reinforcing material, and a third component exhibiting flexibility or elastic properties. The composite material thus obtained can be used for the production of articles having an elastic region. Such articles exhibit flexibility or semi-rigid properties in at least one dimension. The reinforcing material consists of fibers or particles formed, for example, from non-fibrillated wood particles and has a sieved size of 0.5 mm or less.

[0022] Furthermore, the produced material has a coarse surface for promoting biodegradation.

[0023] The compositions of the types shown can be produced by incorporating a third component, formed from an elastic or flexible thermoplastic biopolymer, into a composite material. In particular, the third component is selected from biopolymer materials. Such materials are exemplified by polybutylene adipate terephthalate (PBAT) and polybutylene succinate PBS. Such polymers, especially biopolymers, can be uniformly or homogeneously dispersed within the polymer of the first component.

[0024] The new material can be extruded into sheets or tubes, or into other three-dimensional products or objects that are flexible or elastic.

[0025] More specifically, the present invention is characterized primarily by what is described in the feature portion of the independent claim.

[0026] The present invention offers considerable advantages.

[0027] Therefore, this material achieves excellent compostability properties in combination with good mechanical properties. The water absorption rate of straws made of thermoplastic material, biodegradable material and wood flour disclosed herein is greater than 1% by weight, and this water absorption rate is obtained by immersing the straws in water for a period of 4 months, with the straws weighing 2 to 4 grams, having a thickness of 0.1 mm to 1 mm, a diameter of 5 mm to 15 mm, and a water absorption rate of 1 to 1.5 g / cm³. 3 This is the case where the density is such that it has a certain characteristic.

[0028] In a preferred embodiment, the manufactured material has a coarse surface that provides accelerated biodegradation. Furthermore, this material degrades more rapidly under mesothermal conditions compared to typical biodegradable polymers such as PLA and PBAT.

[0029] Products for which this material is particularly suitable have a wall thickness of approximately 1.0 mm or less, especially 0.5 mm or less. For this reason, the material is well-suited for beverage straws and thin sheets.

[0030] In one embodiment, the present invention provides a thin sheet having walls formed from a compostable material that includes a combination of an elastic biodegradable polymer forming a continuous matrix and hydrophilic material particles mixed therein that can swell within the matrix by absorbing water.

[0031] Alternatively, it is a compostable material consisting of a combination of biodegradable polymers with different elongation properties that form two separate, continuous matrices, and hydrophilic material particles that can swell within the matrices by absorbing water.

[0032] The present invention will be examined in more detail below, with further explanation and reference to the attached drawings. [Brief explanation of the drawing]

[0033] [Figure 1] Figure 1 shows an example of surface data for a sample containing 0% wood. [Figure 2] Figure 2 shows an example of surface data for a sample containing 10% wood. [Figure 3] Figure 3 shows an example of surface data for a sample containing 10% wood. [Figure 4] Figure 4 shows the decomposition of materials with various wood content in industrial compost. [Figure 5] Figure 5 shows an SEM image of an untreated sample containing 0% wood. [Figure 6] Figure 6 shows an SEM image of an untreated sample containing 10% wood. [Figure 7] Figure 7 shows an SEM image of an untreated sample containing 20% ​​wood. [Figure 8] Figure 8 shows an SEM image of a sample containing 0% wood after being immersed in water at room temperature for 4 weeks. [Figure 9] Figure 9 shows SEM images of a sample containing 10% wood after being immersed in water at room temperature for 4 weeks. [Figure 10] Figure 10 shows an SEM image of a sample containing 20% ​​wood after being immersed in water at room temperature for 4 weeks. [Figure 11] Figure 11 shows an SEM image of a sample containing 0% wood after being immersed in water at 45°C for 4 weeks. [Figure 12] Figure 12 shows an SEM image of a sample containing 10% wood after being immersed in water at 45°C for 4 weeks. [Figure 13] Figure 13 shows an SEM image of a sample containing 20% ​​wood after being immersed in water at 45°C for 4 weeks. [Figure 14] Figure 14 shows a DMTA graph from vibration measurements of a deformable composite material. [Figure 15] Figure 15 shows graphs of the progress (%) of biodegradation as a function of time based on CO2 generation for both the standard product and the test product ("Sulapac® Straw"). [Modes for carrying out the invention]

[0034] In this specification, “three-dimensional object” means an object having width, length, and height. Typically, this term refers to objects formed as sheets, plates, boards, panels, tubes, pipes, or contours. In these objects, each dimension is preferably greater than 0.1 mm.

[0035] The term "thin-walled" product refers to a product with a wall thickness of approximately 1.0 mm or less, and more specifically, a wall thickness of 0.5 mm or less and 0.2 mm or more.

[0036] In some embodiments, the thin-walled product typically has a wall thickness of about 0.3 to about 0.5 mm.

[0037] In the context of polymers, "rigid" means that either a thermoplastic or thermosetting polymer has an elongation at break of 10% or less, according to ISO 527.

[0038] An "elastic material" is a polymer whose elongation at break is greater than 100% according to ISO 527.

[0039] "Course" refers to a surface with a surface roughness (Ra) greater than 1 μm, as measured according to ISO 4287.

[0040] The term "screened" size is used to specify particles that can be sized or separated to a particular size using a screen with a mesh size corresponding to the particle sorting size.

[0041] Transition tests conducted in accordance with Regulation (EU) No. 10 / 2011 are carried out, for example, according to the EN1186-3:2002 standard, which describes the test procedure for comprehensive transition tests, or the EN13130 ​​standard, which describes the general test procedure for specific transition tests, including analytical measurements.

[0042] This technology is based on forming compositions by combining natural hydrophilic particles, particularly biomass particles, with a biodegradable polymer mixture. Suitable raw materials include lignocellulosic materials such as annual or perennial grasses, or woody materials and other crops and plants, as well as materials derived therefrom, such as pulp and fibers. In one embodiment, particles or fibers of wood or other lignocellulosic materials, such as chips or other coarse wood particles, are combined with a biodegradable polymer mixture to form a composition.

[0043] In the materials described herein, water absorption through the structure is achieved primarily by incorporating hydrophilic particles, such as finely divided wood particles like sawdust, or larger wood particles like chips, which allows the composite material to disintegrate. Elastic properties are achieved by incorporating a second polymer, an elastic component. This composite material, possessing a combination of biodegradability and flexibility, is suitable for processing, for example, by melt processing.

[0044] In one embodiment, the composite material comprises a first component formed of a polymer and a second component formed of a reinforcing material. The first component is typically a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof. The second component consists of particles of a biomass material, such as wood particles, having a sieved size of 0 to 0.5 mm.

[0045] In one embodiment, biodegradable polyester is a renewable plant-derived material that can be replenished within a period of 10 years or less, for example, from one month to five years.

[0046] In one embodiment, the first component forms the matrix of the composite, while the microstructure of the second component in the composition is discontinuous. The particles of the second component may have a random orientation, or they may be arranged in a desired orientation. The desired orientation may be a predetermined orientation.

[0047] Furthermore, the present invention relates to a product of a flexible composite material for use in thin-wall extruded biodegradable applications. The present invention also relates to materials and products.

[0048] As will be described in more detail below, in a particularly preferred embodiment, the composite material is formed into generally elongated, planar or tubular objects that exhibit increased flexibility or pliability in the transverse direction, i.e., perpendicular to the longitudinal axis of the plane. In a direction different from the thickness of the material, the manufactured articles typically exhibit minimum dimensions of at least 5 mm to 10,000 mm, and particularly 10 mm to 1,000 mm.

[0049] In one embodiment, the composite material has a weight of 1.2 g and is 34 cm long. 2 When formed into a tubular object having an outer surface, 0.01 mg / (cm) within a 30-day period using NTP. 2 ) and 0.1 mg / cm³ 2 It exhibits a water absorption rate exceeding [a certain level].

[0050] In one embodiment, the weight ratio of the thermoplastic polymer to the natural fiber particles (e.g., wood) is 35:65 to 99:1. In another embodiment, the composite comprises 1 to 60% by weight, particularly 10 to 30% by weight, of the natural fiber particles from the total weight of the thermoplastic polymer and the natural fiber particles.

[0051] In a preferred embodiment, a polylactic acid polymer (hereinafter also abbreviated as "PLA") is used as the thermoplastic polymer in the first component of the composition. The polymer may be a copolymer containing repeating units derived from other monomers such as caprolactone and glycolic acid, but preferably the polymer contains at least 80% by volume of lactic acid monomer or lactide monomer, particularly at least 90% by volume, and particularly about 95 to 100% by volume of lactic acid monomer or lactide monomer.

[0052] In a preferred embodiment, the thermoplastic polymer is selected from the group of lactide homopolymers, mixtures of lactide homopolymers and other biodegradable thermoplastic homopolymers, wherein the lactide homopolymer accounts for 5 to 99% by weight (particularly 40 to 99% by weight) and the biodegradable thermoplastic polymer accounts for 1 to 95% by weight (particularly 1 to 60% by weight), and the copolymer or block copolymer of the lactide homopolymer and any thermoplastic biodegradable polymer, wherein the repeating units are derived from lactide (particularly 5 to 99% by weight, particularly 40 to 99% by weight) and the repeating units are derived from other polymerizable materials (particularly 1 to 60% by weight).

[0053] In one embodiment, polylactic acid or polylactide (both abbreviated as "PLA") is used. A particularly preferred embodiment involves using a PLA polymer or copolymer, the PLA polymer or copolymer having a weight-average molecular weight (Mw) of about 10,000 g / mol to about 600,000 g / mol, preferably about 500,000 g / mol or less or about 400,000 g / mol or less, more preferably about 50,000 g / mol to about 300,000 g / mol or about 30,000 g / mol to about 400,000 g / mol, and most preferably about 100,000 g / mol to about 250,000 g / mol, or about 50,000 g / mol to about 200,000 g / mol.

[0054] When using PLA, it is preferable that the PLA be in a semi-crystalline or partially crystalline form. To form semi-crystalline PLA, it is preferable that at least about 90 mol% of the repeating units in the polylactide be either L- or D-lactide, and more preferably at least about 95 mol%.

[0055] Other examples of biodegradable thermoplastic polymers include polylactones, poly(lactic acid), poly(caprolactone), polyglycolides, copolymers of lactic acid and glycolic acid, and polyhydroxyalkanoates (PHA) or mixtures of PHA and polylactone.

[0056] In another embodiment, the thermoplastic polymer has a melting point in the range of about 100 to 130°C. In one embodiment, the thermoplastic polymer is polybutylene adipate terephthalate (also abbreviated as PBAT).

[0057] Thermoplastic polymers may include neat polymers in either homopolymer or copolymer form, such as random copolymers including adipic acid, 1,4-butanediol, and dimethyl terephthalate copolyesters. PBAT polymers are typically statistically biodegradable and aliphatic-aromatic copolyesters. Suitable materials are available from BASF under the trade name Ecoflex®. The polymer properties of PBATs are similar to those of PE-LDs due to their high molecular weight and long-chain branched molecular structure.

[0058] PBAT is classified as a random copolymer due to its random structure. This also means that it cannot crystallize to a considerable extent due to a significant lack of structural order. This results in several physical properties, such as a wide melting point, low modulus of elasticity and low stiffness, but high flexibility and toughness. In addition to virgin polymers, the composition may also include recycled polymer materials, particularly recycled biodegradable polymers. Furthermore, the composition may also include composites of polyesters such as fiber-reinforced PLA, ceramic materials, and glass materials (e.g., bioglass, phosphate glass).

[0059] Thermoplastic polymers can also include polybutylene succinate (PBS), a biodegradable and compostable polyester. It is produced from succinic acid and 1,4-butanediol. PBS is a crystalline polyester with a melting point of 95 to 120°C.

[0060] The thermoplastic material is preferably a biodegradable polymer (only), but non-biodegradable polymers can also be used. Examples of such polymers include polyolefins, e.g., polyethylene, polypropylene, and polyesters, e.g., poly(ethylene terephthalate) and poly(butylene terephthalate), as well as polyamides. The polymer may also be any crosslinked polymer produced in situ before processing or during the compounding process, for example, using ionizing radiation or a chemical free radical generator. Examples of such polymers include crosslinked polyesters such as polycaprolactone.

[0061] Furthermore, it is also possible to use a combination of the above-mentioned biodegradable polymer and the non-biodegradable polymer. Generally, the weight ratio of the biodegradable polymer to any non-biodegradable polymer is 100:1 to 1:100, preferably 50:50 to 100:1, and particularly 75:25 to 100:1. Preferably, the composite material has greater biodegradability than the thermoplastic material alone, and the material biodegrades more quickly or more completely.

[0062] By using additional polymer components in the first polymer material, the mechanical properties of the first component can be improved. Such mechanical properties include tear resistance.

[0063] In one embodiment, the first polymer component has a melt flow index of about 0.5 to 15 g / min, for example, 1 to 10 g / min, and especially about 1 to 3 g / min (at 190°C; 2.16 kg).

[0064] To develop materials that have the ability to decompose quickly in composting and marine environments, and possess sufficient rigidity for a wide range of applications, biodegradable reinforcing agents are further incorporated into the polymer to enhance the material's water absorption and improve its mechanical properties.

[0065] The second component is a reinforcing material containing, or essentially consisting of, woody material having a sieved size of less than 0.5 mm. Other wood particles may also be present in the second component.

[0066] Suitable natural fibers can be obtained directly from lignocellulosic materials, animals, or by-products or by-flows of industrial processes. Examples of this type of material include annual or perennial herbs, woody materials, and other crops and plants, including those belonging to the main group of Tracheobionta that have hollow stems, such as flax, hemp, jute, coir, cotton, sisal, kenaf, bamboo, reeds, horsetail, wild angelica, and pasture grasses, hay, straw, rice, soybeans, grass seeds, as well as the seed coats of grains (especially wheat, rye, and barley) and crushed coconut husks. In addition, wool, feathers, and silk can be used.

[0067] The type of wood can be freely selected from deciduous and coniferous trees, such as beech, birch, alder, aspen, poplar, oak, cedar, eucalyptus, mixed tropical hardwoods, pine, spruce, and larch. Other suitable raw materials can be used, and the wood material of the composite can also be any manufactured wood product. In a preferred embodiment, the wood material is selected from both hardwoods and conifers, particularly from hardwoods of the genus Populus, such as poplar and aspen, or from conifers of the genera Pinus and Picea.

[0068] The particles can typically be obtained from wood raw materials by cutting or chipping the raw materials. Deciduous or coniferous wood chips are preferred, such as aspen or birch chips.

[0069] In addition to wood flour, this composition includes reinforcing fibrous materials, such as cellulose fibers, such as flax or cotton seed fibers, tree bark, jute leaf or bark fibers, hemp, soybeans, bananas or coconuts, hay stem fibers (straw), rice, barley, and other crops and plants, including plants belonging to the main class of Tracheobionta that have hollow stems, and subclasses of herbaceous plants (bamboo, reeds, horsetail, wild angelica, and pasture grass).

[0070] According to the research conducted in this invention, it was found that the swelling of natural fiber particles such as wood fibers with a screen particle size of 0.5 mm or less due to water absorption has enough force to form cracks in the polymer matrix, allowing water to penetrate the material more efficiently and thus promoting the decomposition of the material. When the material decomposes, long polymer chains are broken down into short chain fragments, and ultimately decompose into natural compounds such as carbon dioxide (CO2), water, biomass, and inorganic compounds, so that no residue of plastic particles such as microplastics or residue of harmful substances remains in the environment.

[0071] Hydrophilic natural fibers or particles that swell within the matrix upon contact with water are uniformly distributed within the matrix.

[0072] In one embodiment, the hydrophilic particles (including fibers) are preferably unmodified before being mixed with the other components of the composition. "Unmodified" means that they have not been subjected to any chemical or physical treatment that permanently reduces or removes their ability to absorb moisture and water before being mixed with the other components of the composition. Thus, the hydrophilic particles in the composition retain at least 20%, preferably at least 40%, and particularly 50% or more of the water absorption capacity of the hydrophilic particles of the raw material.

[0073] As described below, particles can be dried to a low moisture content before being mixed, particularly melt-mixed, with polymer components. Such drying typically does not permanently reduce the particle's ability to absorb moisture or water from the composition.

[0074] The hydrophilic materials described herein, such as wood powder, have a screen size of less than 500 mesh (0.5 mm). As a result of producing sheets with a wall thickness of less than 0.5 mm, preferably less than 0.4 mm, the surface of the sheet becomes rough. Some of the wood powder particles have dimensions larger than the wall thickness of the manufactured sheet before extrusion. These particles are obviously forced to be oriented horizontally, but they still protrude from the surface of the sheet.

[0075] This feature allows for accelerating the decomposition rate of the composition in a wet state.

[0076] Conventional biodegradable polymers like PLA are typically biodegradable if the material thickness is less than 1 mm, but in many types of natural environments (sea, lakes, soil, etc.), the biodegradation rate is insufficient; that is, a hot and humid environment is required for decomposition. Furthermore, these biodegradable polymers do not possess sufficient mechanical properties or resistance to thermal decomposition, so their application to many uses is considerably limited.

[0077] The rate of decomposition largely depends on the surface area of ​​the material. For example, a solid product made from polylactide or polylactic acid (abbreviated as PLA) (e.g., a straw with a smooth surface) takes 5 to 10 years to decompose completely, while PLA powder with a particle size of 100 to 250 μm decomposes at a rate of approximately 3% by weight per week (completely within one year) in anaerobic sludge, for example.

[0078] In one embodiment, the composition and the articles formed therefrom have a rough (or "coarse") surface quality. For that purpose, and to achieve good mechanical performance of the extruded articles, the raw materials used in processing must be dried before processing. If the moisture content of the raw materials is too high, moisture will evaporate from the material during processing, forming holes and streaks in the product. Such undesirable holes will tear the sheet or tube extruded articles and stop production.

[0079] In one embodiment, the moisture content in the composite particles is reduced to less than 2% before processing.

[0080] A composition consisting only of the first and second components is typically rigid. The polymer of the first component is hard. According to this art, such compositions can be converted to a semi-rigid structure, either with the help of at least one additional polymer, or by mechanical treatment, by incorporating polymer-rich regions into the material, or by a combination of two or more of these.

[0081] Therefore, this composite material typically includes an elastic region in order to provide an object with flexible properties.

[0082] Such an elastic region can be achieved in several ways.

[0083] In the first embodiment, the composition comprises a third component formed of a polymer different from the polymer of the first component, the polymer of the third component capable of forming an elastic region in the material in order to impart to the composite material mechanical properties ranging from flexible to semi-rigid in at least one dimension of the object at ambient temperature.

[0084] The flexibility of the novel composition is achieved by adding an elastic biopolymer (hereinafter also referred to as the "third component") to the first component. The elastomer can be a thermoplastic polymer or a thermosetting polymer. To maintain the general relationship between the polymer and the reinforcing material, a portion of the first component, i.e., the high-temperature polymer, can be replaced with the elastic polymer, thereby maintaining at least essentially the same volume portion of the polymer in the composite material—typically, a change of ±20% in polymer volume is possible.

[0085] Typically, the third component is formed as follows: - Formed from polymers having elongation at break of 100% or more, especially 200% or more.

[0086] The third component can be formed by a polymer selected from the group of biodegradable thermoplastic polymers such as PBS and PBAT, which include natural rubber, unsaturated or saturated rubber including silicone, as well as natural or synthetic soft materials including soft gelatin, hydrogel, hydrocolloid and modified cellulose, and natural gums such as gum arabic, agar and dammar gum.

[0087] The third component, i.e., the elastic or flexible polymer, does not need to have the same melting range as the first component. Typically, the third component has a melting point outside that of the first component, and in particular, the melting point of the polymer of the third component is lower than that of the first component.

[0088] In one embodiment of the composite material according to this technology, the third component is miscible with the first component, which forms a homogeneous matrix when processed at high temperatures.

[0089] In another embodiment, the third component is immiscible with the first component and forms a phase-separated zone or region within the first component. In one embodiment, the composite material exhibits an elongation of at least 5%, for example, 7.5 to 25% (measured according to ISO 527). Typically, such elongation is achieved at 23°C.

[0090] In one embodiment, the composite material exhibits at least 25%, typically at least about 30%, and up to 40%, or even up to 50% ocean degradation (measured according to ASTM D7081) after 300 days.

[0091] Based on the above, in one embodiment of this technology, the composite material includes, is composed of, or is essentially composed of the following: - 40 to 70 parts by weight of biodegradable polyester, - 10 to 40 parts by weight of lignocellulose particles, and - 10 to 40 parts by weight of elastic biodegradable polymer, - 0.5 to 5 parts by weight of processing aid, and - 0 to 10 parts by weight of water-soluble substance.

[0092] Preferably, the elastic biodegradable polymer, together with a biodegradable rigid polymer such as polyester, constitutes the majority of the composition (i.e., more than 50% by weight of the total weight of the composition). In a particularly preferred embodiment, the elastic biodegradable polymer, together with the biodegradable polylactide, constitutes at least 60% by weight and up to 90% by weight, for example, 70 to 85% by weight, of the total weight of the composition. Generally, the elastic polymer, together with the elastic polymer, forms 5 to 50% by weight, particularly 10 to 40% by weight, for example, 15 to 30% by weight, of the total weight of the biodegradable polyester.

[0093] Further polymers or any natural water-soluble compounds can be incorporated into the composition. In one embodiment, the composition contains 3 to 30 parts by weight of a fourth component, which is a thermoplastic polymer different from that of the first and third components. Such a component can be used to achieve improved mechanical properties of the matrix polymer. The fourth polymer can also be used to modify the surface properties of the composition (e.g., the movement properties of the straw). The fourth component may also consist of a polysaccharide, which is a high molecular weight carbohydrate molecule consisting of long chains of monosaccharide units linked by glycosidic bonds, and which can be hydrolyzed to give monosaccharides or oligosaccharides such as maltodextrin or starch.

[0094] In one embodiment, the fourth component is 100 g / dm 3 It is formed by natural water-soluble substances that have a higher level of water solubility than [unspecified substance].

[0095] Based on the above, in one embodiment of the present technology, the composite material comprises, or is essentially composed of, about 40 to 70 parts by weight of polylactide, 10 to 40 parts by weight of wood particles or wood fibers having a screen size of less than 0.5 mm, 10 to 30 parts by weight of PHAT, and 0 to a maximum of 1 part by weight of wax.

[0096] This technology relates to the production of biodegradable composite articles having a rough surface by melt processing. In particular, embodiments relate to the use of a composition comprising a continuous matrix of a mixture of thermoplastic biodegradable polymers and wood particles distributed within the matrix in such a manner, especially by extrusion molding.

[0097] Thus, in one embodiment, the surface of the sheet is rough. In this specification, “course” means a surface having a surface roughness (Ra value) greater than 1 μm as measured according to ISO 4287. Such a surface is typically formed with a wood-PLA composition containing more than 10% by weight of wood, which increases water absorption.

[0098] In one embodiment, when the composite material is molded into an object, such as a tubular object, such as those of the type mentioned in the preceding paragraph, it is possible to exhibit a surface roughness greater than 1 μm as measured by ISO 4287.

[0099] On the other hand, tests have shown that surfaces formed from wood-PLA composites containing less than 10% by weight of wood particles, and having an Ra value of less than 1.0 μm as measured by ISO 4287, absorb water slowly and have a longer decomposition time.

[0100] The compounding of the first, second, and third components described above is typically carried out, for example, in an extruder, particularly a single-screw or twin-screw extruder. In the compounding process, the screw extruder profile is preferably such that its dimensions allow the wood powder to move along the screw without crushing or burning it. Thus, the channel width and thread height are selected to avoid the formation of excessive localized pressure increases that could cause the wood particles to break down. The cylinder temperature and screw rotation speed are also selected so as not to decompose the structure of the wood chips due to excessively high pressure during extrusion.

[0101] Proper temperature control is necessary when compounding wood-based composites. During mixing in an extruder, the gravitational temperature rises due to increased friction between the polymer and the wood.

[0102] In one embodiment, the processing temperature during the process is kept below 220°C to prevent thermal decomposition of natural fibers. To reduce or prevent the decomposition of polymers and natural fibers during processing, the L / D ratio of the composition is preferably at least 20:1.

[0103] Furthermore, in one embodiment, the compounding temperature is 200°C or lower. Some of the polymers used have melting points of 160°C or higher, and in this embodiment, an operating environment of 40°C is maintained.

[0104] In one embodiment, the compounding is carried out at a temperature range of 110 to 210°C, particularly 150 to 200°C.

[0105] In yet another embodiment, the barrel temperature is in the range of approximately 160 to 190°C from the hopper to the die, while the screw rotation speed is in the range of 25 to 50 rpm. These are, of course, merely indicator data, and the exact settings will vary depending on the equipment actually used.

[0106] In one embodiment, the composite material described herein can be formed by melt processing into an article having at least one wall with a total thickness of less than 0.5 mm and greater than 0.2 mm.

[0107] Fillers and additives can be added to smooth the flow of material in the extruder.

[0108] The typical content of inorganic fillers, if present, is approximately 0.1 to 40% by weight, and especially approximately 1 to 20% by weight.

[0109] Other inorganic fillers and pigments may also be present in the first composition. Further examples of inorganic fillers and pigments include calcium sulfate, barium sulfate, zinc sulfate, titanium dioxide, aluminum oxide, and aluminosilicates.

[0110] In one embodiment, the first composition comprises an inorganic filler such as talc, calcium carbonate (CaCO3), or kaolin. Silica is another filler that can be used.

[0111] In one embodiment, the composite further comprises finely divided material particles that impart color properties to the composite. The dyeing material can be selected from, for example, bio-based materials having appropriate stability at melting temperatures that can be up to 210°C.

[0112] One embodiment involves the use of other additives in the formulation of the composite. For example, maleic anhydride grafted PLA (MA-PLA) can be used to chemically bond wood fibers and a polymer matrix together. This improves the mechanical properties of the composite material and also improves the water resistance of the material based on a reduction in the number of free -OH- groups on the surface of the natural fibers. Maleic anhydride can be grafted onto all types of biodegradable polymers (such as PBAT and PCL). The amount of MA graft polymer used is 1 to 7% by weight, particularly 1 to 3% by weight.

[0113] Oleamide, wax, metal stearates (e.g., zinc and calcium), inorganic fillers (e.g., talc), and lignin can be added to formulations as processing aids to improve the processability of materials for thin-wall applications. Oleamide, wax, and metal stearates are added to reduce internal friction in the material during extrusion molding. This suppresses the material's inherent tendency to decompose thermally during processing and improves the dispersion of wood fibers in the material. In addition, the long fatty chains contained in oleamide, wax, lignin, and metal stearates can reduce the water absorption rate of the material.

[0114] Metal stearates and certain inorganic fillers such as CaCO3 can also act as acid-scavenging agents to neutralize acids released from natural fibers and polymers during processing. Lignin can also improve the mechanical properties of the composite material. Typical additions of oleamide and wax range from 0.1 to 7% by weight, while the amount of metal stearate in the composite material ranges from 0.5 to 7% by weight. The amount of inorganic filler used ranges from 0.1% to 20% by weight. The amount of lignin used ranges from 0.1% to 2% by weight.

[0115] A group of lubricants that have been found to be applicable to reduce friction are natural plant or animal waxes, such as candelilla, carnauba, and beeswax. These are primarily composed of hydrocarbons, fatty esters, alcohols, free fatty acids, and resins (e.g., triterpenoid esters). Typical addition amounts of wax range from 0.1 to 3% by weight.

[0116] In one embodiment, one or more of the additives presented above are incorporated into the composition in amounts ranging from 0.1% to a maximum of 10% by weight, particularly about 1 to 5% by weight, preferably about 3% by weight. The additive or mixture of additives is added to the mixture of biodegradable polymers and wood chips before further processing and product manufacturing.

[0117] One embodiment includes a method for producing a thin-walled composite material from at least one thermoplastic polymer having a melting point higher than 110°C, particularly higher than 130°C, and having an MFR in the range of 1 to 70 g / 10 min (190°C / 2.16 kg), particularly 3 to 6 g / 10 min. The polymer is a biodegradable polymer or a mixture of biodegradable polymers, which is mixed with natural fiber particles having a sieved size of 0.5 mm or less in a weight ratio of 99:1 to 35:65.

[0118] The mixture may also contain one or more of the aforementioned additives, for example, in a maximum content of 10% by weight, the proportion of which is subtracted from the weight of either the polymer or the natural fiber.

[0119] In one embodiment, the additive is included in an amount of up to about 5% by weight, preferably less than 3% by weight.

[0120] Before being fed into the extruder hopper, the mixture is pelletized to form granules or pellets.

[0121] For example, wood flour is unsuitable for extrusion molding of thin-walled products as is. Wood flour tends to agglomerate during feeding, hindering the uniform flow of the composite during extrusion molding and leading to the breakage of the extruded product during continuous molding. This problem was solved by compounding all the raw materials together in granular form.

[0122] In one embodiment, the composite material is manufactured by the following: - A thermoplastic polymer, or a mixture of multiple thermoplastic polymers, as disclosed in the embodiments herein, and hydrophilic material particles having a sieved size of less than 0.5 mm are combined in a melt-mixing apparatus to produce composite melt-mixed granules. - To provide an extruded product of a molten mixture by pultrusion or pulling-out through a mold or nozzle, and - Optionally, form the extruded product into a plate, sheet, or tube shape.

[0123] In one embodiment, the hydrophilic material is first combined with one polymer to provide an extruded product, which is then combined with an extruded product or pellet of other polymer materials. The mixture or material obtained by melt-mixing the components can be processed using one of the following methods. Machining, compression molding, transfer molding, injection molding, extrusion molding, rotational molding, blow molding, thermoforming, casting, forging, foam molding.

[0124] In one embodiment, a product made from a combination of biodegradable polymers (or more) and natural fibers (e.g., wood) is recycled by mechanically crushing the product and mixing the crushed material with a virgin mixture of biodegradable polymers (or more) and natural fibers at an addition rate of up to 100% by weight, particularly from 1% to 100% by weight. The mixture of crushed material and virgin material is then fed into a hopper of an extruder or injection molding machine to form a new product containing 5 to 100% by weight of recycled material.

[0125] In one embodiment, the composition may include recycled polymer materials, particularly recycled biodegradable polymers. Furthermore, the natural fibers used in the composition may be mechanically and / or chemically recycled.

[0126] Articles manufactured from the above-described compositions can be formed into thin-walled, particularly extruded, articles having flexible or elastic properties. These articles can be formed as elongated objects, such as sheets, plates, boards, panels, tubes, pipes, or contours.

[0127] In one embodiment, the product is thin-walled, i.e., has a wall thickness of 0.5 mm or less and 0.05 mm or more. It may also include a region where the wall thickness is 0.1 to 0.2 mm.

[0128] In one embodiment, the article is provided with a coating for modifying the surface of the article, if necessary. The coating can be manufactured by multi-component extrusion molding or, for example, conventional spray painting or dip coating.

[0129] In one embodiment, an article in the form of a sheet or tube is provided, which consists of, or is essentially composed of, the materials or compositions disclosed above, for example, 40 to 70 parts by weight of polylactide, 10 to 40 parts by weight of wood particles having a screen size of less than 0.5 mm, 10 to 30 parts by weight of PHAT, and 0 or up to 1 part by weight of wax. In one embodiment, the article has walls containing wood fibers or wood particles at a concentration of 10 to 30% by weight. The walls of the article contain 10 mg / dm³ of wood fibers or wood particles in a water-ethanol solution having an ethanol content of 0 to 96% by weight, particularly 5 to 95% by weight. 2 This indicates a total transition level of less than [value]. Transition testing was conducted in accordance with the EN1186-3:2002 standard.

[0130] In one embodiment, an article in the form of a container or a closed article is provided, which consists of, or is essentially composed of, the materials or compositions (or composite materials) disclosed above, for example, 40 to 70 parts by weight of polylactide, 10 to 40 parts by weight of wood particles having a screen size of less than 0.5 mm, 10 to 30 parts by weight of PHAT, and 0 to a maximum of 1 part by weight of wax. In one embodiment, the article has a wall containing wood fibers or particles at a concentration of 10 to 30% by weight. In one embodiment, the article has a wall containing wood fibers or particles at a concentration of 10 to 30% by weight. The wall of the article has a total migration level of 10 mg / dm³ to 3% by weight of acetic acid. 2 This indicates that the value is less than [value]. Transition testing is conducted in accordance with the EN1186-3:2002 standard. [Examples]

[0131] A composite containing approximately 59% polylactide, 20% wood particles with a screen size of less than 0.5 mm, 20% PBAT, and 1% wax was tested for its properties.

[0132] In some examples, the proportion of wood particles was reduced, and the relative proportion of polymer components was increased accordingly.

[0133] (decomposition) We investigated the degradation of sheets made from a composite material that can be molded into a straw shape (hereinafter also referred to as Slapak® straws) in a marine environment.

[0134] This study evaluated two potential weight loss pathways: physical degradation and biological degradation. Regarding physical degradation, no signs of such degradation were detected in this study. However, biological degradation was observed on the material surface. Furthermore, the amount of surface degradation was found to be directly proportional to the total amount of degradation occurring simultaneously in the sample. Therefore, surface degradation could be used as an indicator of the degradation rate of the Slapak® straw material.

[0135] Based on this study, after immersion in the Baltic Sea for six months, the degradation rate of a 100 μm thick, 394 mg weight sheet was 1.09 mg / day or 0.27 μm / day. Therefore, the minimum degradation rate of Slapak® straws in the Baltic Sea is expected to be 1.09 mg / day or 0.27 μm / day.

[0136] (Surface roughness) Surface roughness is directly proportional to the effective surface area. Therefore, the roughness value is a measure of the effective surface area, normalized in proportion to the area being considered.

[0137] Surface roughness was measured using a Weeko Wyko NT9100 optical profilometer. Samples with wood content of 0%, 10%, and 20%, similar to those used previously, were employed. Surface roughness was determined by measuring both sides of the sample five times, and the result was obtained as the average of 10 measurements. The difference between the inside and outside of the sample was within the margin of error. In this analysis, samples with 10% and 20% wood content, respectively, were often outside the measurement range. Nevertheless, the average values ​​obtained using this method are reliable, although the highest and lowest points could not be reliably determined.

[0138] Table 1 shows the average roughness of the samples, and Figures 1 to 3 show examples of surface data for samples containing 0%, 10%, and 20% wood, respectively.

[0139] [Table 1]

[0140] As shown in Table 1, the average roughness of materials containing wood was approximately four times and seven times higher than that of materials without wood. Therefore, it can be concluded that increasing the wood content increases the effective surface area and improves the decomposition rate of the product.

[0141] Using the same samples as in the previous study, the water absorption rate of the materials was investigated as a function of wood content. The materials investigated were similar in terms of polymer composition. This study was conducted using three parallel samples, and the reported results are average values. Before weighing, the samples were dried on paper to remove any excess moisture on top of the samples. The test results are shown in Table 2.

[0142] [Table 2]

[0143] As can be seen from Table 2, the higher the wood content, the more moisture is absorbed by the material. Furthermore, samples containing wood have significantly higher moisture content than samples without wood. Table 3 shows the decomposition of samples with different wood content. Under industrial composting conditions, decomposition occurs efficiently with sufficiently small wall thicknesses, so wood content does not significantly affect the decomposition rate detected on a timescale of several weeks. Nevertheless, material decomposition is faster with higher wood content, as shown in Figure 4, which illustrates the decomposition of materials with different wood content within three weeks in an industrial composting environment.

[0144] [Table 3]

[0145] (The effects of water) As previously shown, the amount of water absorbed by a material increases as a function of its wood content. Additionally, wood is known to swell when in contact with water. When this material is brought into contact with water, the wood particles within the matrix begin to swell. This swelling causes microscopic cracks to form throughout the material, starting from the surface. These microscopic cracks are shown in the following SEM images.

[0146] When cracks appear on the surface, the surface area increases further. In materials that do not contain wood, cracks cannot be detected at any temperature. In a sample containing 10% wood, the small beginnings of cracks can be detected photographically. In a sample containing 20% ​​wood, cracks are easily detectable.

[0147] The examination was performed using a Zeiss Sigma VP scanning electron microscope (SEM) with a secondary electron (SE) detector at an acceleration voltage of 2kV.

[0148] The described materials are the same as before, containing 0%, 10%, and 20% wood. Samples were stored in water for one month and then dried at room temperature after treatment. Samples used for reference were stored in a standard storage environment at normal temperature and humidity.

[0149] Figures 5 to 7 are SEM images of the untreated surface of samples containing 0%, 10%, and 20% wood, respectively. Figures 8 to 10 are SEM images of the same samples after immersion in water at room temperature for 4 weeks. Figures 11 to 13 are SEM images of the same samples after immersion in water at 45°C for 4 weeks.

[0150] These figures clearly show the stress cracking in the wood grain samples after swelling.

[0151] Table 4 shows the properties of typical materials. Thermal properties were investigated using a TA Q2000 differential scanning calorimeter (DSC) at heating temperatures of 20°C / min and 5°C / min, and the results were found to be the same. Mechanical values ​​were investigated using a TA Q800 dynamic mechanical analysis (DMA) with a force ramp at 3 N / min.

[0152] [Table 4]

[0153] (Effect of cavities in the wood composite matrix) Natural fibers are all highly hydrophilic materials and are strongly affected by water. Water molecules enter the free spaces of fine voids and rapidly diffuse along the fiber matrix interface. When exposed to moisture, the fiber-matrix interface degrades, significantly reducing its mechanical properties. Moisture affects the fiber / biopolymer bonding regions or interface regions, as well as the fibers themselves, leading to a weakening of the overall performance of the composite. Macroscopic and microscopic changes confirm a decrease in the tensile strength of the composite due to degradation. The tensile properties of PLA / wood composites decrease when samples are exposed to natural weathering conditions.

[0154] Table 5 shows the mechanical weakening of wood composite materials containing 20% ​​wood particles after immersion in water at room temperature and 45°C (for a period of up to 30 days).

[0155] As can be seen, in both cases, the Young's modulus decreases. When immersed at room temperature, no significant change is observed in elongation or stress during braking. A decrease in Young's modulus indicates that the material has lost its elasticity and become more brittle.

[0156] [Table 5]

[0157] (Thermoforming) The elongation at break under tensile stress is relatively low for PLA, at 4-8%, and rapid increases in tension during processing can cause structural failure; therefore, good tension control during sheet handling is important. Because the toughness of PLA increases with orientation, thermoformed parts are less brittle than PLA sheets, and the elongation at break under tensile stress can increase from 4-8% of the sheet to approximately 40%. Areas with weaker orientation tend to be more brittle than the rest of the thermoformed part.

[0158] This material exhibits significant elongation even in these regions. An edge preheater is necessary to prevent the sheet from cracking. The edge preheater is set to approximately 190°C.

[0159] Contact heating edge preheaters are typically set to below 100°C. The optimal thermoforming temperature for this material was found to be approximately 70°C, at which point the elongation during braking was approximately 350%, which was the limit of the measuring instrument used.

[0160] The thermoformability of this material is described below. Sheets manufactured before thermoforming may have a maximum thickness of 5 mm, while the thickness after processing is between 0.2 mm and 1 mm.

[0161] (Deformation control of wood composite materials) As previously shown, conventional wood composites were extremely rigid. This material, which includes a flexible thermoplastic resin component, can be freely deformed at a moderate temperature. The braking elongation of this material averages 9.7% at room temperature. Vibration measurements of the study material with a 20% wood content were performed using a TA Q800 DSC. Measurements were performed with a temperature ramp of 3°C / min, a frequency of 1 Hz, and a strain of 1%. Figure 14 shows the storage modulus (G'), loss modulus (G''), and tangent delta as functions of temperature.

[0162] While tracking the "loss modulus" in vibration measurements, it is possible to analyze the liquid-like behavior of the material. In this case, below 50°C, solid (elastic) properties are dominant. This is evident from the very high Young's modulus and small elongation during braking. When the material is heated, a decrease in storage modulus and an increase in loss modulus are detected. In this region (approximately 60 to 70°C), the material possesses properties ranging from a freely deformable viscotic (viscous) liquid to an elastic solid that returns to its shape after deformation. By appropriately combining these properties, the material can be stretched to an elongation rate of over 300% before braking. Above 70°C, the loss modulus decreases, the material loses its elastic strength, and begins to behave like a viscous liquid.

[0163] The same phenomenon can be seen in Table 6, which shows the values ​​of elongation and stress during braking at different temperatures, along with Young's modulus.

[0164] This phenomenon gives the material unique properties when considering the deformation of composite materials at a certain temperature. The elongation value during braking remains constant (the limit of the equipment) from 60°C to approximately 100°C. Measurements of stress and vibration during braking show that above 70°C, the liquid properties of the material become dominant, and the ability to control deformation decreases significantly. At 140°C, the solid properties, along with the stress value during braking, decrease significantly, the influence of gravity becomes large, and reliable detection of properties becomes impossible.

[0165] [Table 6]

[0166] (ocean decomposition) Further marine disintegration tests were conducted on this composite material, and the results are shown in Table 7.

[0167] [Table 7]

[0168] Figure 15 also shows a graph of the ocean decomposition of the two products over 350 days based on CO2 emissions according to ASTMD7081.

[0169] As can be seen from the figure, the reference sample made of cellulose achieved a biodegradation rate of 78.2% during the test period. The biodegradation rate of the test product, "Slapak® Straw," also slowly increased, reaching approximately 40% (39.9%) after 350 days.

[0170] In the second test, the biodegradability of pure PLA (polylactic acid) was compared with that of wood over a 210-day period, in accordance with ASTM D7081. The results are shown in Table 8.

[0171] [Table 8]

[0172] As can be seen, while PLA decomposes at a rate of 16.9 mg and wood at 13.2 mg, this composite material decomposes at a rate of 38.1 mg or more. This indicates that the combination decomposes faster than each component individually.

Claims

1. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

2. The method according to claim 1, wherein the compounded molten mixture is prepared by the following method: Machining, compression molding, transfer molding, injection molding, extrusion molding, rotational molding, blow molding, thermoforming, casting, forging, and foam molding. A method of processing using at least one of the following methods.

3. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The third component, together with the first component, constitutes more than 50% by weight of the total weight of the composite material. - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

4. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The thermoplastic polymer is selected from the group consisting of lactide homopolymers, mixtures of lactide homopolymers and other biodegradable thermoplastic homopolymers (containing 5 to 99% by weight or 40 to 99% by weight of lactide homopolymer and 1 to 95% by weight or 1 to 60% by weight of biodegradable thermoplastic polymer), and copolymers of lactide homopolymers and any thermoplastic biodegradable polymer (containing 5 to 99% by weight or 40 to 99% by weight of repeating units derived from lactide and 1 to 95% by weight or 1 to 60% by weight of repeating units derived from other polymerizable materials). - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

5. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The aforementioned composite material has a surface roughness exceeding 1 μm as measured according to ISO 4287. - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

6. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The composite material can be melt-processed into a molded article having at least one wall with a total thickness of less than 0.5 mm and greater than 0.2 mm. - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

7. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The biodegradable polyester is selected from lactide or lactic acid copolymers containing units derived from polylactide, poly(lactic acid), and other monomers, and the biodegradable polyester contains at least 80% by volume of lactide or lactic acid monomers. - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

8. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The biodegradable thermoplastic polymer comprises a polymer selected from the group consisting of polylactone, poly(lactic acid), poly(caprolactone), polyglycolides, copolymers of lactic acid and glycolic acid, polyhydroxyalkanoates (PHAs), and mixtures of PHAs and polylactones, wherein the biodegradable thermoplastic polymer has a melting point in the range of 100 to 130°C as measured by differential scanning calorimetry (DSC 10°C / min). - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

9. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The processing additive comprises one or more additives selected from the group consisting of metal stearate, maleic anhydride graft biodegradable polymer, oleamide, erucamide, fatty acids, synthetic waxes, natural vegetable waxes, animal waxes, lignin, and mixtures thereof. - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

10. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The composite material can be melted at a maximum temperature of 180°C. - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

11. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The composite material exhibits an elongation of at least 5% (measured according to ISO 527), - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

12. A method for producing a composite material that can be thermoformed into a three-dimensional object, comprising a first component formed from a renewable polymer and a second component which is a reinforcing material, - The first component comprises a thermoplastic polymer selected from the group consisting of biodegradable polyesters and mixtures thereof, - The second component comprises lignocellulose particles of a hydrophilic material, having a sieved size of less than 0.5 mm. The aforementioned composite material further, - A third component formed of a polymer different from the polymer of the first component, wherein the polymer of the third component is capable of forming an elastic region in at least one dimension for providing an object having flexible or semi-rigid properties, The composite material comprises 30 to 70 parts by weight of the first component; 10 to 40 parts by weight of the second component; 10 to 40 parts by weight of the third component; and 0.1 to 5 parts by weight of a processing additive. The third component is formed from polybutylene adipate terephthalate (PBAT), The composite material exhibited at least 25% marine disintegration (measured according to ASTM D7081) after 300 days. - A step of compounding molten mixed granules by blending the thermoplastic polymer of the first component, the third component, and the second component in a melt-mixing apparatus at a temperature range of 110 to 210°C or 150 to 200°C. - The step of providing an extruded product of a molten mixture by pultrusion or pull-out through a mold or nozzle, - Optionally, a step of forming the extruded product into a plate, sheet, or tube shape. A method for manufacturing composite materials, including

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