LÁPIS, HASTE, E, PROCESSO PARA PRODUÇÃO DO LÁPIS E / OU DA HASTE

Abstract

Pencil (1) having a shaft (3), wherein the shaft (3) comprises a shaft base material having a base formulation, wherein the base formulation comprises 50% to 80% by weight of PLA, PLA copolymer and / or PLA blend, 20% to 50% by weight of further polymers, plasticizers, waxes / lubricants, further additives such as adhesion promoters, stabilizers etc., colorants, in particular pigments, organic and / or inorganic fillers as shaft fillers, wherein the shaft base material is foamed and / or comprises pores.

Description

24 PENCIL, STEM, AND PROCESS FOR PRODUCING THE PENCIL AND / OR STEM

[001] The invention relates to a pencil with the characteristics of the preamble to claim 1. In addition, the invention relates to a shaft for writing instruments, painting instruments, drawing instruments and / or cosmetic pencils, as claimed in claim 12, and to a process for producing the pencil and / or shaft with the characteristics of claim 13.

[002] Pencils with wooden casings, in which the graphite lead is encased or coated with naturally grown wood, have been known for a long time. In recent years, the price of high-quality wood has increased due to a lack of wood availability, which has a direct effect on the production costs of pencils. In addition, relatively large natural wood resources are being consumed for pencil production.

[003] In response to this, the production of graphite lead pencils or graphite lead casings and graphite leads from polymers by extrusion has become widespread. Polystyrene (PS) is an example of a base polymer for the base material of the rod. Polystyrene has the advantages of good availability, easy processability and good mechanical properties for the resulting rod.

[004] In this context, the document published DE 10 2008 034 013 B4 proposes the use of a wood substitute material for the shaft of a pencil, where the wood substitute material is based on a polymeric binder.

[005] An extruded pencil of this type is also known, for example, from document EP 0 505 262 B1, which undoubtedly constitutes the closest state of the art. The pencil described consists of expanded polystyrene in the casing and a flexible graphite lead coated with polystyrene. Petition 870250083425, dated 09 / 16 / 2025, page 42 / 65 / 24

[006] The objective of the present invention is to propose a pencil that constitutes a sustainable alternative to the prior art, in which, at the same time, the functional characteristics of the pencil, in particular the sharpenability and resistance to bending, must be maintained. This objective is achieved by means of a pencil with the characteristics of claim 1, a shaft for writing instruments, painting instruments, drawing instruments and / or cosmetic pencils, as claimed in claim 12, and a process for producing the pencil and / or shaft with the characteristics of claim 13. The preferred or advantageous embodiments of the invention are defined in the dependent claims, in the description below, as well as in the accompanying drawing.

[007] The object of the invention is a pencil, in which the pencil has a shaft.

[008] Optionally, the pencil has a graphite lead, wherein the shaft preferably surrounds the graphite lead concentrically and / or coaxially and wherein the graphite lead is arranged with the shaft in a manner that is resistant to displacement and / or non-displaceable. In particular, the graphite lead is permanently and inextricably fixed to the shaft and / or cannot be detached without being destroyed. As an example, the graphite lead may optionally be bonded to the shaft by means of intermediate layers in such a way that there is material bonding, forced fitting and / or interlocking.

[009] In particular, the pencil is constructed as a right cylinder, wherein the area of ​​the base of the cylinder or the area of ​​the cross-section may, for example, be round, oval, triangular, quadrangular, pentagonal, hexagonal or polygonal. Alternatively, the pencil may be twisted or bent into shape.

[0010] In particular, the pencil can be sharpened. For example, it can be sharpened with a pencil sharpener, for example, a colored pencil sharpener, a graphite lead pencil sharpener, a sharpening machine. Petition 870250083425, dated 09 / 16 / 2025, page 43 / 65 / 24 pointing or a cosmetic pencil sharpener, in which a conical pencil point is created or remade by removing material separated from the shaft and graphite lead.

[0011] The rod has a rod base material, wherein preferably at least 60% by weight, preferably at least 80% by weight, and in particular at least 98% by weight or even 100% by weight of the rod consists of the rod base material. Alternatively or additionally, preferably at least 80% of the cross-sectional area, preferably at least 90% of the cross-sectional area, and in particular at least 98% of the cross-sectional area or even 99% of the cross-sectional area is formed by the rod base material. In particular, the rod base material is in a foamy and porous form.

[0012] In particular, the rod has a rod body produced from the base material of the rod. The rod body has an annular cross-section, for example, in the form of a circular ring. In particular, the inner contour may be circular and / or the outer contour may have any configuration, for example, round, oval, triangular, quadrangular, pentagonal, hexagonal or polygonal.

[0013] In the context of the invention, it is proposed that the base material of the rod be produced in two stages. In a first stage, the components of the base formulation are mixed. A base mixture with the base formulation is formed. In a second stage, the base mixture with the base formulation is mixed with a foaming additive. A production mixture is formed. The production mixture is thermally heated above the decomposition temperature of the foaming additives and molded into the rod. The base material of the rod is produced. The base material of the rod is foamed and / or contains pores. The gaseous components of the base material of the rod can be ignored in the total weight of the base material of the rod. The ratios of the components in the base formulation are substantially retained in the base material of the rod. Petition 870250083425, dated 09 / 16 / 2025, page 44 / 65 / 24

[0014] The basic formulation comprises: 80% by weight of PLA and / or PLA copolymer, 50% by weight of other polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, etc., colorants, in particular pigments, organic and / or inorganic fillers.

[0015] In addition to olefins, the term “additional polymers” may also include polybutylene succinate (PBS). In particular, the proportion of PBS is less than 8% by weight, preferably less than 5% by weight, in particular 0% by weight. The base formulation may be PBS-free.

[0016] In particular, the basic formulation comprises the following proportions of the components: 80% by weight PLA and / or PLA copolymer, 10% by weight polybutylene succinate (PBS), 25% by weight other polymers 0.1 to 25% by weight of plasticizers to 10% by weight of waxes / lubricants 0.1 to 10% by weight of other additives, such as adhesion promoters, stabilizers, etc.; 10% by weight of colorants, especially pigments; 40% by weight of organic and / or inorganic fillers such as rod fillers.

[0017] To produce the shaft of a pencil or writing instrument, painting instrument, drawing instrument and / or cosmetic pencil, the components of the base formulation are mixed and, as the base mixture of the base formulation, mixed with foaming additives and foamed and molded as the production mixture. The base material of the shaft is produced. The foaming additives in this sense are preferably added to the base mixture of the base formulation in situ at the final extrusion, in order to obtain Petition 870250083425, dated 09 / 16 / 2025, page 45 / 65 / 24 specifically its action only during the modeling of the final product.

[0018] To produce the base material for the rod, a production mixture is used. The production mixture has the following components: 99% by weight of the base mixture with the base formulation containing 10% by weight of foaming additives.

[0019] The proportion of foaming additives used depends, on the one hand, on the content of at least one reactive component in the additive and, on the other hand, on the desired reduction in the density of the final product. In addition, specific process parameters (temperature, pressure, melt viscosity, residence time of the polymer in the extruder or injection molding unit, etc.) further determine this content.

[0020] The foaming additives are no longer contained in the final product in their original form because they have been deliberately thermally decomposed and an expanding gas has been released, which forms foam in the base mixture with the base formulation. This results in pores in the plastic mass due to the use of foaming additives. The entire base mixture of the base formulation is foamed, so that, due to the foam formation, the details regarding the ratios of the base formulation components, such as percentages, do not undergo significant changes. PLA / PLA copolymer

[0021] PLA is a designation for polylactic acid, which in particular can be called polylactide. In particular, PLA is also registered with the Chemical Abstracts Service under CAS number 9051-89-2. The properties of PLA as a polymer can vary somewhat depending on the number of monomers in the polymer. PLA can also be present as a PLA copolymer or a PLA blend. The PLA copolymer contains PLA as the first component and contains a polymer with which the PLA is copolymerized as the second component. The second component can be isolated or comprise a mixture of, for example, monomers. Petition 870250083425, dated 09 / 16 / 2025, page 46 / 65 / 24 example, polyvinyl alcohol (PVA), polycaprolactone (PCL), polyethylene glycol (PEG), etc. Finally, PLA blends can be used, in which PLA is mixed as a polymer with other polymers, for example, polyolefins, for example, polyethylene, as a PLA blend. PLA may be present as PLA, PLA copolymer, PLA blend and mixtures thereof.

[0022] PLA, PLA copolymer and / or PLA blend is present in a range of 50 to 80% by weight, preferably 55 to 70%, relative to the base material of the rod.

[0023] One consideration of the invention is that the base polymers used until now, in particular polystyrene or polystyrene-based polymers, are produced from petroleum-based starting materials. Consumer concerns regarding the use of such petroleum-based raw materials are increasing because, on the one hand, petroleum resources need to be used for this purpose and, on the other hand, the resulting material cannot be compostable or is hardly compostable. Both properties go against the current trend of promoting sustainable and / or environmentally friendly products. In contrast, the invention proposes the use of PLA (polylactide polymers) as the base polymer, so that the use of petroleum-based raw materials in the pencil is significantly reduced or completely avoided.PLA, also known generically as polylactic acid, is obtained, for example, from renewable natural raw materials, such as corn, and belongs to the polyesters as a synthetic polymer. Thus, pure PLA is preferably produced from renewable raw materials and is not based on fossil raw materials, such as petroleum, for example.

[0024] In addition, PLA can be composted and, in particular in industrial composting units, can be decomposed within a manageable period of time, in particular less than 12 weeks, by Petition 870250083425, dated 16 / 09 / 2025, page 47 / 65 / 24 example, in harmless end products, in particular according to EN 14995 or EN 13432 standards, where other similar standards may define other conditions and time periods. Industrial composting conditions are necessary for the composting or decomposition of PLA, i.e., controlled temperature and humidity conditions, in the presence of microorganisms. As an example, in this case, temperatures should be between 55 and 70°C. Through industrial composting, it is possible to decompose the pencil shaft, according to the standard, into harmless end products and describe it as biodegradable. Special PLA copolymers and / or additional polymers may have a specific additional influence on biodegradable behavior.

[0025] The mechanical properties of PLA can be adjusted to those of known polystyrene through additives. The proposed composition of the base material for the shaft allows the production of a shaft that possesses the necessary properties for pencils, such as sharpenability, adhesion, mechanical, thermal and chemical stability. In this way, PLA constitutes a sustainable alternative to the base polymers used until now for the production of pencil shafts.

[0026] It has been shown to be particularly advantageous in the selection of PLAs that, in particular in comparison with other plastics, the original properties, such as sharpenability, tear resistance and touch, for example, are not altered in a negative way compared with the polymers of the prior art. In this way, PLA in the aforementioned foamed formulation constitutes a valuable and sustainable substitute for the polymers known until now.

[0027] In particular, the base material of the rod is configured as a PLA blend and / or PLA copolymer. In the PLA blend, PLA is mixed with one or more polymers. In the PLA copolymer, PLA is polymerized with another polymer. Petition 870250083425, dated 09 / 16 / 2025, page 48 / 65 / 24

[0028] PLA blends can be compatible blends with polyethylene glycol (PEG) and polypropylene glycol (PPG), for example, which in this case increase the flexibility of PLA, which is brittle on its own. However, incompatible blends, for example with polyolefins (polyethylene PE, polypropylene PP), are also possible to obtain specific properties. These are preferably produced from biological and sustainable sources, such as bioethanol or hydrogenated vegetable oils.

[0029] The biopolymer polybutylene succinate (PBS) can also be blended with the above polymers in the PLA / PLA copolymer. The PBS content here is 0 to 10% by weight, preferably with a proportion of less than or equal to 5% by weight, preferably less than or equal to 3% by weight and, in particular, less than or equal to 1% by weight, relative to the base material of the rod. This has the advantage that the brittle properties of PLAs are somewhat reduced by mixing with PBS.This means that the proportion of plasticizers can be reduced.

[0030] The other polymers in the PLA blend or PLA copolymer are present in the range of 0 to 30% by weight, preferably 5 to 20% by weight, particularly preferably 7 to 15% by weight, relative to the base material of the rod. Plasticizers

[0031] In particular, the base material of the rod has one or more plasticizers. In addition to copolymerization into a polymer (internal plasticization), plasticizers can also be introduced in a solid, polymeric form or as a specific, oily, viscous substance into the base formulation (external plasticization). As a rule, the plasticizing action here is obtained by heat treatment during granulation or extrusion.

[0032] In particular, polymeric plasticizers based on polyadipate may be mentioned (for example, polybutylene adipate terephthalate (PBAT) (CAS 60961-73-1), but also other types of Petition 870250083425, dated 09 / 16 / 2025, page 49 / 65 / 24 elastic polymers, such as types of polyethylene, for example, or, in general, TPEs.

[0033] Other external plasticizers include epoxidized vegetable oils, such as epoxidized soybean oil (ESBO) (CAS: 801307-8), but also citrate esters, such as acetyltributyl citrate (ATBC) (CAS: 77-90-7). In addition, glycine triacetate (GTA) and diethylhexyl adipate (DOA) may be used alone or in combination with the aforementioned plasticizers. The plasticizers are present in a range of 0.1 to 25% by weight, preferably 5 to 20% by weight, particularly preferably 7 to 15% by weight, relative to the base material of the rod. Waxes, lubricants

[0034] To obtain adequate processability and produce specific material properties, different waxes and lubricants are optionally added as a mixture. Among others, these may be PE waxes (grafted with maleic acid anhydride, for example), amide waxes, fatty acids such as stearic acid and palmitic acid, for example, mountain waxes, stearates (for example, Ca stearate), fatty acid esters, paraffin waxes, but also oils and fats such as palm oil, for example. The content of these auxiliary agents is between 0 and 10% by weight, preferably between 1 and 5% by weight.

[0035] For sharpening ability, it is advantageous that at least one wax be selected from the group of waxes comprising amide waxes, fatty acids such as stearic acid and palmitic acid, for example, mountain waxes, stearates, fatty acid esters, paraffin waxes. In addition, the wax is composed of ethylene bis-stearamide, stearic acid, calcium stearate, polyethylene wax, polyethylene wax grafted with maleic acid anhydride. Other additives

[0036] Other additives are used for different purposes. Petition 870250083425, dated 09 / 16 / 2025, page 50 / 65 / 24 depending on the rest of the formulation. Thus, adhesion promoters are used to join incompatible polymers, but possibly also as filler materials. An example here is the coupling of PLAs with the aid of a polyester grafted with maleic acid anhydride. In addition, various stabilizers and / or nucleating agents may be added. The amount of other additives depends on the quality and quantity of the other components and is between 0 and 10% by weight, preferably between 1 and 5% by weight. Dye

[0037] Dyes are used to adjust the desired aesthetic color effect and should provide the base material of the rod, on the one hand, with natural colors similar to wood (shades of brown) or, on the other hand, with deliberately contrasting colors (black in cosmetic pencils). Preferably, thermally stable and physiologically suitable organic and / or inorganic pigments are used for this purpose, such as titanium dioxide, iron oxide, azo pigments, etc. To lighten the shade, it has proven advantageous for the white pigment to be titanium dioxide (TiO2). To adjust the desired shade, it is advantageous for the base material of the rod to contain 0.1 to 10% by weight of colored pigment, for example, iron oxide pigment, as part of the dye. The exact content depends on the desired color and the color-producing components (e.g., filler materials) that are already present.

[0038] There are dyes that also constitute filler materials, such as graphite or carbon black, for example. The proportions of the filler materials in the rod are valid for colored filler materials. Filling materials

[0039] In a preferred alternative or implementation of the invention, at least a portion of the rod filler material is selected Petition 870250083425, dated 16 / 09 / 2025, page 51 / 65 / 24, to be an inorganic filler material. By selecting the inorganic filler material, the strength, brittleness, and sliding properties during sharpening can be adjusted, but the material costs can also be reduced correspondingly. Preferably, at least one inorganic filler material is from the group formed by phyllosilicates, in particular soapstone, talc, clay, kaolin, calcium carbonate, but also chalk, boron nitride, graphite, or a mixture thereof. Organic fillers such as wood flour and / or powdered cellulose are preferably used because, on the one hand, they are inexpensive and promote resemblance to wood, but, on the other hand, they also increase the proportion of biodegradable and renewable components in the formulation.

[0040] The filler material of the rod is preferably present in the range of 0 to 40% by weight, preferably 3 to 20% by weight, particularly preferably 4 to 13% by weight, in relation to the base material of the rod.

[0041] In a preferred embodiment of the invention, at least most or even all of the rod filler material is selected to be an organic filler material. For the rod to have a wood-like character, preferably the organic filler material is selected from the group comprising wood and / or cellulose. As an example, wood flour can be used during manufacturing. For sharpening ability, it is particularly advantageous that at least one organic filler material is formed from filler material particles with a maximum particle size of 250 µm, in particular a maximum of 100 µm.

[0042] In a preferred embodiment of the invention, at least most or even all of the rod filler material is selected to be a mixture of inorganic and organic filler materials. Petition 870250083425, dated 09 / 16 / 2025, pages 52 / 65 / 24 described above.

[0043] In particular, the base material of the rod is free of dyes. Alternatively, the base material of the rod has 1 to 3% by weight of white pigment as part of the dye to lighten the shade of the base material of the rod. Foaming agents

[0044] The base formulation, in particular the PLA and the polymer phase with the other additives, is foamed with foaming additives. In the final state, the base material of the foam rod has pores that make the main body of the rod lightweight and capable of being sharpened.

[0045] In this sense, foaming additives are mixed into the base formulation and distributed homogeneously, especially in the extruder or during injection molding. During melting in the extruder cylinder, when the respective decomposition point of the foaming additive is reached, a defined quantity of gas is released, which is dispersed in the liquid phase of the plastic mixture. When the molten plastic mass exits the machine and when the extruded rod enters a cooling and calibration device, the plastic matrix freezes and fixes the gas bubbles in the rod's base material.

[0046] Preferably, the process is carried out in such a way that the pores are formed homogeneously throughout the base material of the rod, in particular in PLA and other optional polymers, and the pores cannot be seen on the surface of the rod. Alternatively, the base material of the rod with added foaming additives is coated with a decorative layer without foaming additives, so that the surface of the base material of the rod is free of pores. In this sense, the decorative layer is ideally formed from polymers that are identical or at least compatible with the base material of the rod, so that sufficient adhesion is produced.

[0047] On the one hand, the pores reduce the weight and polymer consumption. On the other hand, the base material of the PLA rod becomes more Petition 870250083425, dated 09 / 16 / 2025, page 53 / 65 / 24 elastic, so the use of plasticizers can be reduced. Furthermore, due to the pores, the resulting pencil shaft base material can be sharpened more easily with conventional sharpeners. In addition, the reduction in density reduces the amount of material in the shaft base material and reduces costs. In this sense, densities of less than 1 g / cm3 are obtained. The addition of foaming agents implies the presence of pores in the extruded shaft base material. The amount of foaming agents required depends on many factors, such as the polymer ratio, the amount of filler material, the residence time and residence temperature of the shaft base material in the extruder, etc., and is adjusted between 1 and 10% by weight, preferably between 2 and 6%.As a rule, foaming agents in this sense are added to the base formulation as what are known as standard mixtures (substance(s) or reagent(s) incorporated into a support material, usually a polymer) of the base formulation, in order to ensure adequate miscibility. In this sense, physiologically harmless substances from the carbonate and / or citrate group are preferably used, which mainly produce CO2 as gas and do not leave any reaction residues that are hazardous and / or harmful to health. The foaming agents that can be used here comprise carbonates or citrates. Examples of carbonates are ammonium carbonate and alkaline carbonates, such as sodium carbonate and potassium carbonate. Ammonium carbonate can be produced by adding calcium carbonate along with ammonium sulfate. Ammonium citrate, alkaline citrates, such as sodium citrate, potassium citrate, can be used as citrates.

[0048] In a preferred embodiment of the invention, a large portion of the components are below the threshold conditions for the described industrial biocomposting capacity of PLAs and, therefore, are co-compostable or are bio-based from the outset or even from the outset. Petition 870250083425, dated 09 / 16 / 2025, page 54 / 65 / 24 natural, so they do not need to be composted. This means that the base material of the stem can be biologically decomposed on an industrial scale or disposed of harmlessly. Particularly preferably, all components are below these limits.

[0049] In another possible embodiment of the invention, an adhesion promoter layer is disposed between the graphite lead and the rod. The adhesion promoter layer improves the bond between the rod and the graphite lead, so that, on the one hand, the sharpening capacity is improved and, on the other hand, the fixation of the graphite lead to the rod is ensured. In particular, this option is used when mutually incompatible polymers are used in the rod and the graphite lead. Preferably, polylactic acid wax grafted with maleic acid anhydride and / or an identical graft with another polyester is used as the adhesion promoter.

[0050] In another preferred embodiment of the invention, the graphite lead is also produced based on PLA. In particular, the graphite lead has PLA as the binder. Preferably, the graphite lead is formed from the components described in document DE 10 2013 016 355 A1, the description of which is incorporated herein by reference.

[0051] In particular, the graphite mine has a graphite mine base material. The graphite mine base material is crucial for industrial composting. The graphite mine base material contains at least one binder with 10 to 40% by weight of PLA. In particular, the graphite mine base material has the following components: 40% by weight PLA, 80% by weight graphite mine filler material, 20% by weight waxes / lubricants, 10% by weight additives such as plasticizers, stabilizers, adhesion promoters, for example. Petition 870250083425, dated 09 / 16 / 2025, page 55 / 65 / 24

[0052] The proportion of polylactic acid in the composition of graphite mine is in the range of 10 to 60% by weight, preferably in the range of 10 to 40% by weight and particularly preferably in the range of 10 to 25% by weight.

[0053] It has been shown to be particularly advantageous that the polymer-bonded graphite mine contains 60% by weight of polylactic acid, 25% by weight of wax, 70% by weight of graphite mine filler materials, 5% by weight of palm oil, and 30% by weight of dye.

[0054] It has been shown to be successful if at least one wax from the graphite mine is from the group comprising fatty acids, stearates, montana waxes, amide waxes and paraffins. Mixtures of two or more waxes may also be used.

[0055] Particularly preferable in this respect, at least one wax is calcium stearate and / or an ethylene-bis-stearamide (EBS) and / or PE wax. Very good results have been obtained using ethylene-bis-stearamide (EBS) on colored pencil graphite leads. Very good results have been obtained using calcium stearate on black pencil graphite leads.

[0056] Advantageously, at least one filler material from the graphite mine is formed by at least one filler material from the group comprising graphite, hexagonal boron nitride, talc, soapstone, phyllosilicates (clays, kaolins), chalk.

[0057] For graphite leads for black pencils, in particular, graphite or graphite in combination with carbon black is particularly preferred as a color-producing filler material which, due to its high content, also constitutes the filler material. For graphite leads for colored pencils, Petition 870250083425, dated 09 / 16 / 2025, page 56 / 65 / 24 combinations of white or colorless filler materials, such as talc, phyllosilicates, hexagonal boron nitride, etc., with color-producing pigments, such as azo pigments, phthalocyanines, dioxazines, quinacridones, iron oxides, carbon black, graphite, ultramarine, and iron cyanocomplexes, have been successful.

[0058] There are dyes that constitute a graphite mine filler material at the same time. The proportions for colored graphite mine fillers are the same as for graphite mine fillers.

[0059] As an example, the filler material for the graphite lead is selected from the group consisting of phyllosilicate and talc (colored pencils) and graphite (black pencils).

[0060] In a preferred embodiment of the invention, the rod base material and the graphite mine base material are joined directly. In particular, they are joined in a way that bonds materials. An intermediate layer can be advantageously dispensed with by selecting PLA for the two base materials, because these identical polymers can bond to each other without additional intervention. Thus, by selecting identical base materials, the bond-promoting layer can be dispensed with and, moreover, a stable bond can be formed.

[0061] In particular, the components of the graphite mine are below the threshold conditions for the industrial biocompostability of PLAs and are therefore also co-decomposable or bio-based, as described above.

[0062] In another embodiment of the invention, the pencil is constructed as a writing pencil and / or a painting pencil and / or a cosmetic pencil. In particular, it can be produced as a black pencil or as a colored pencil.

[0063] A rod for writing instruments, instruments of Petition 870250083425, dated 09 / 16 / 2025, page 57 / 65 / 24. Painting, drawing instruments and / or cosmetic pencils constitute another subject matter of the invention. Drawing instruments are, for example, constructed as pen holders. Ballpoint pens or mechanical pencils with movable graphite leads, whose shaft can be produced from the base material of the shaft with the base formulation, are considered writing instruments.

[0064] In particular, the base material for the rod for drawing instruments can be constructed as described above. In particular, the base formulation for the base material of the rod is constructed and / or produced in the same manner.

[0065] In particular, the rod for writing instruments, painting instruments, drawing instruments and / or cosmetic pencils has a rod base material with a base formulation, wherein the base formulation comprises 80% by weight of PLA, PLA copolymer and / or PLA mixture to 50% by weight of other polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, etc., colorants, in particular pigments, organic and / or inorganic fillers, as rod fillers.

[0066] The base material of the stem is foamed and / or contains pores.

[0067] The shaft for writing instruments, painting instruments, drawing instruments and / or cosmetic pencils contains a shaft base material with the same properties as the shaft base material described above.

[0068] A process for producing the pencil and / or the rod as described above or according to one of the preceding claims constitutes another subject matter of the invention. In particular, the rod is applied to the graphite lead by primary molding. In particular, extrusion, injection molding or pressing can be used as primary molding processes. Petition 870250083425, dated 09 / 16 / 2025, page 58 / 65 / 24

[0069] Production by extrusion can be carried out in a single stage or in two stages. In the case of single-stage production, all components of the pencil (graphite lead, any adhesion promoter layer, shaft base material and decoration) are thermoplastically molded to a near-final shape in a single tool, and the geometry is frozen during subsequent cooling processes.

[0070] In the case of two-stage extrusion, the graphite lead is first molded along with – if necessary – the optional adhesion promoter which is already located concentrically on the graphite lead. In a further variation, the latter can also be applied first to the base material of the rod. In a second stage and with an additional tool, the graphite lead rod obtained in this way is then coated with the base material of the rod and the decoration. After that, the procedure is identical to that of the single-stage variation.

[0071] Other features, advantages and effects of the invention will be evident from the following description of preferred exemplary embodiments of the invention. In the figures: Figure 1 shows a diagrammatic view of a pencil as an exemplary embodiment of the invention; Figure 2 shows a diagrammatic view of another pencil as a further exemplary embodiment of the invention; Figure 3 shows a diagrammatic view of a rod as an exemplary embodiment of the invention.

[0072] Figure 1 shows a diagrammatic longitudinal section of a pencil 1, wherein the pencil 1 is constructed, for example, as a writing pencil, painting pencil, cosmetic pencil, black pencil or similar.

[0073] Pencil 1 has a graphite lead 2 and a shaft 3, wherein the graphite lead 2 is arranged in the shaft in such a way that it is fixed against displacement relative to the shaft 3. In the exemplary embodiment, the lead of Petition 870250083425, dated 09 / 16 / 2025, page 59 / 65 / 24 graphite 2 is arranged coaxially and / or concentrically in pencil 1. Pencil 1 is of cylindrical construction, where its base area or cross-sectional area can, for example, be circular, polygonal, oval, etc. In cross-section, the graphite lead 2 has a circular construction, for example. The rod 3 has the outer contour of pencil 1 and the inner contour of graphite lead 2.

[0074] Pencil 1 is sharpenable and has a conical tip 4 on one side, wherein a conical section of the rod 5 of rod 3 transitions into a conical section of the graphite lead 6 of graphite lead 2. The conical section of the graphite lead 6 forms the tip of pencil 1. The conical tip 4 can, for example, be produced by a separation or cutting procedure using a sharpener.

[0075] Rod 3 has a rod base material, wherein rod 3 is formed primarily from the rod base material. Optionally, pencil 1 may have other layers; in particular, an adhesion promoter layer 7, which forms an intermediate layer, may be disposed between the graphite lead 2 and the rod 3 in pencil 1. Alternatively or additionally, a decorative layer 8 may be disposed on the outer circumference of rod 3.

[0076] It is planned that the base material of the rod will be produced using PLA. Exemplary compositions are provided below: Example 1: Pencil or rod with a base material that has the following base formulation: 80% PLA by weight 2.5% by weight calcium stearate as wax, 1% by weight PE wax as wax, 15% by weight epoxidized vegetable oil as plasticizer, 0.5% by weight iron oxide pigment as colorant, 1% by weight TiO2 as colorant.

[0077] The following is added for foaming: Petition 870250083425, dated 09 / 16 / 2025, pages 60 / 65 / 24 Polymeric compound with 5% by weight, containing the reactive components sodium bicarbonate / citric acid as carbonate-based foaming additives.

[0078] Ex. 1 demonstrates a filler-free stem with high porosity and also high compostability or a high proportion of sustainable raw materials.

[0079] Example 2: Pencil shaft or writing instrument with shaft base material that has the following base formulation as a PLA mixture produced from PLA and PE: 65% PLA by weight 5% by weight of PE as an additional polymer. 5% by weight of PBAT as a plasticizer 10% by weight of ATBC as a plasticizer 2.5% by weight of PE wax grafted with MAH as an adhesion promoter. 1% by weight of MAH grafted onto PLA as an adhesion promoter. 10% by weight of wood flour as an organic filler material, as a stem filler material. 1.5% by weight of TiO2 as a colorant.

[0080] The following is added for foaming: Polymeric compound with 2% by weight, containing the reactive components sodium bicarbonate / citric acid as carbonate-based foaming additives.

[0081] Ex. 2 is a wood-like rod with medium porosity. The 10% by weight wood content enhances sharpening capacity, as does the proportion of natural and renewable raw materials in the formulation.

[0082] Example 3: Pencil or rod with base material of the rod that Petition 870250083425, dated 09 / 16 / 2025, page 61 / 65 / 24, has the following base formulation as a PLA mixture produced from PLA and PBS: 69% PLA by weight 6% by weight of PBS as an additional polymer. 4% by weight of talc as a filler material for the stem. 5% by weight of epoxidized vegetable oil as a plasticizer. 10% by weight of ATBC as a plasticizer 2.2% by weight of stearic acid as wax 2.2% by weight of calcium stearate as wax 0.3% by weight of iron oxide pigment as a colorant. 1.3% by weight of TiO2 as a colorant.

[0083] The following is added for foaming: Polymeric compound with 2% by weight, containing the reactive component sodium bicarbonate as a carbonate-based foaming additive.

[0084] Ex. 3 provides a highly elastic rod with a medium degree of foaming.

[0085] Example 4: Pencil or rod with a base material that has the following base formulation: 55% PLA by weight 10% by weight of PBAT as a plasticizer 7% by weight of epoxidized vegetable oil as a plasticizer. 2% by weight of ethylene bis-stearamide as a lubricant. 2% by weight of PE wax as wax 2.5% by weight of MAH grafted onto PLA as an adhesion promoter. 20% by weight of wood flour as an inorganic filler material, as a filler material for the rod. 0.1% by weight of iron oxide pigment as a colorant. Petition 870250083425, dated 09 / 16 / 2025, page 62 / 65 / 24 1.4% by weight of TiO2 as a colorant.

[0086] The following is added for foaming: Polymeric compound with 4% by weight, containing the reactive components sodium bicarbonate / citric acid as carbonate-based foaming additives.

[0087] Ex. 4 provides a significantly more filled rod with high porosity.

[0088] Example 5: Cosmetic pencil or shaft with shaft base material having the following base formulation as a mixture of PLA and PE: 45% PLA by weight 15% by weight of PE as an additional polymer. 20% by weight of PBAT as a plasticizer 4% by weight of epoxidized vegetable oil as a plasticizer. 2% by weight of ATBC as a plasticizer 2% by weight of ethylene bis-stearamide as a lubricant. 1% by weight of calcium stearate as wax 10% by weight of chalk as an inorganic filler material, as a filler material for the rod. 1% by weight of carbon black as a colorant

[0089] The following is added for foaming: A 4.5% by weight polymeric compound containing the reactive components sodium bicarbonate / citric acid as carbonate-based foaming additives.

[0090] Ex. 5 provides a black, sharpenable cosmetic pencil with a high content of polymeric plasticizer.

[0091] While figure 1 shows a pencil 1 with a PLA-based shaft 3 and a conventional graphite lead 2, wherein the adhesion promoter layer 7 is disposed between the graphite lead 2 and the shaft 3, the Petition 870250083425, dated 09 / 16 / 2025, page 63 / 65 / 24 figure 2 shows a different illustrative modality.

[0092] In the exemplary embodiment of figure 2, graphite mine 2 is also produced from PLA, and it has a base material of graphite mine that contains at least 10% PLA.

[0093] Exemplary compositions are provided below: Example 1: Black pencil graphite lead 10 to 60% by weight polylactide 2 to 25% by weight wax 5% by weight palm oil Remainder graphite

[0094] Graphite is used in the examples as a dye for black pencil graphite leads. However, a combination of graphite and carbon black can also be used.

[0095] A composition for colored pencil graphite leads comprises: 60% by weight polylactic acid, 25% by weight wax, 30% by weight dye. Remaining filler materials.

[0096] Colored and / or uncolored pigments can be used as color-producing agents in colored pencil graphite leads. Examples of such pigments include, among others, azo pigments, phthalocyanines, dioxazines, quinacridones, iron oxides, carbon black, graphite, ultramarine and iron cyanocomplexes.

[0097] Advantageously, in the exemplary embodiment of figure 2, the adhesion promoter layer 7 can be dispensed with, since both base materials are PLA-based and, as the components are of the same type, they can bond extremely well in order to join and interconnect materials without the adhesion promoter layer 7. Petition 870250083425, dated 09 / 16 / 2025, pages 64 / 65 / 24

[0098] In the case of pencil 1 in Figure 1, at least the rod 2 is compostable. Although the additional components may be more difficult to compostable, this exemplary embodiment constitutes a major step towards a sustainable alternative for pencil 1. In the exemplary embodiment of Figure 2, both the rod 2 and the graphite lead 3 are compostable, so this pencil 1 constitutes a sustainable alternative.

[0099] Figure 3 diagrammatically shows a rod 3 produced from the base material of the rod with a void 9. A movable and interchangeable graphite lead can be inserted into the void. Preferably, the tip can move in the void, as is the case, for example, with a ballpoint pen. The rod 3 can constitute a section. Additional functional ends to limit the movement of the rod, such as a tip or push button, can be mounted on the ends of the rod 3.For example, stem 3 can be configured as a portion of a stem 3 from a writing pencil, drawing pencil, ballpoint pen, cosmetic pencil, black pencil, retractable pencil, or similar. Alternatively or additionally, a decorative layer 8 can be arranged on the outer circumference of stem 3.

[00100] List of reference symbols pencil graphite lead conical tip conical tip section conical tip section of graphite lead adhesion promoter layer decorative layer void Petition 870250083425, dated 09 / 16 / 2025, page 65 / 65

Claims

1 / 4 CLAIMS 1. Pencil (1), characterized in that with a shaft (3), wherein the shaft (3) has a shaft base material with a base formulation, wherein the base formulation comprises 50 to 80% by weight of PLA, PLA copolymer and / or PLA mixture, 20 to 50% by weight of other polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, etc., colorants, in particular pigments, organic and / or inorganic fillers, as shaft fillers, wherein the shaft base material is foamed and / or contains pores.

2. Pencil (1) according to claim 1, characterized in that a production mixture is used for the production of the base material of the shaft, wherein the production mixture contains 90 to 99% by weight of the base mixture with the base formulation 1 to 10% by weight of foaming additives.

3. Pencil (1) according to claim 1 to 2, characterized in that the base formulation comprises the following proportions of the components: 50 to 80% by weight of PLA, PLA copolymer and / or PLA mixture 0 to 10% by weight of polybutylene succinate (PBS) 0 to 25% by weight of other polymers, in addition to PBS 0 to 25% by weight of plasticizers 0 to 10% by weight of waxes / lubricants 0 to 10% by weight of other additives, such as adhesion promoters, stabilizers, etc. Petition 870250083425, dated 09 / 16 / 2025, page 35 / 65 2 / 4 0 to 10% by weight of colorants, especially pigments 0 to 40% by weight of organic and / or inorganic fillers as fillers for the shaft.

4. Pencil (1) according to any of the preceding claims, characterized in that the PLA is bio-based and / or at least most or all of the filler material of the shaft is organic.

5. Pencil (1) according to any of the preceding claims, characterized in that the filler material of the shaft is selected from the group comprising wood and cellulose.

6. Pencil (1) according to any of the preceding claims, characterized in that the filler material of the shaft comprises an inorganic filler material component, wherein the inorganic filler material component is preferably from the group formed by phyllosilicates, in particular soapstone, clay, kaolin, talc and / or chalk, graphite, boron nitride.

7. Pencil (1) according to any of the preceding claims, characterized in that the pencil has a graphite lead, wherein the graphite lead is arranged in the pencil and / or in the shaft in a manner that is resistant to displacement.

8. Pencil (1) according to claim 7, characterized in that an adhesion promoter layer (7) is disposed between the graphite lead (2) and the shaft (3).

9. Pencil (1) according to claim 7 or 8, characterized in that the graphite lead (2) contains a graphite lead base material, wherein the graphite lead base material contains at least one binder with 10 to 40% by weight of PLA.

10. Pencil (1) according to claim 9, characterized Petition 870250083425, dated 09 / 16 / 2025, page 36 / 65 3 / 4 by the fact that the base material of the shaft and the base material of the graphite lead are directly joined without a separate adhesion promoter layer.

11. Pencil (1) according to any of the preceding claims, characterized in that it is constructed as a writing pencil and / or a painting pencil and / or as a cosmetic pencil.

12. Stem (3), characterized in that it is for writing instruments, painting instruments, drawing instruments and / or cosmetic pencils, wherein the stem (3) has a stem base material with a base formulation, wherein the base formulation comprises 50 to 80% by weight of PLA, PLA copolymer and / or PLA mixture, 20 to 50% by weight of other polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, etc., colorants, in particular pigments, organic and / or inorganic fillers, as stem fillers, wherein the stem base material is foamed and / or contains pores.

13. Process for producing the pencil (1) as defined in any of claims 1 to 11 and / or the shaft as defined in claim 12, characterized in that a base mixture with the base formulation and foaming additives are mixed and heat-treated to produce the foamed shaft material, wherein the base formulation comprises 50 to 80% by weight of PLA, PLA copolymer and / or PLA mixture, 20 to 50% by weight of other polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, etc., colorants, in particular pigments, organic and / or inorganic filler materials, as shaft filler materials. Petition 870250083425, dated 09 / 16 / 2025, page 38 / 65

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