Pencil, barrel, and method for manufacturing

Abstract

A pencil (1) having a shaft (3), the shaft (3) having a shaft base material having a basic formulation, the basic formulation comprising 50-80% by weight of PLA, PLA copolymer and / or PLA blend, 20-50% by weight of further polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, etc., colorants, especially pigments, organic and / or inorganic fillers as shaft fillers, and the shaft base material being foamed and / or having pores.

Description

Technical Field

[0001] The present invention relates to a pencil having the features of the preamble of claim 1. The present invention further relates to a shaft for writing implements, drawing implements, drafting implements and / or cosmetic pencils according to claim 12, and to a method for manufacturing a pencil and / or a shaft having the features of claim 13.

[0002] Wooden pencils with cores surrounded or coated by natural wood have been known for a long time. In recent years, due to the shortage of available wood, the price of high-quality wood has been rising, which has a direct impact on the manufacturing cost of pencils. In addition, a relatively large amount of natural wood resources are required to manufacture pencils.

[0003] In contrast, the production of pencils or core coatings and cores by extrusion from polymers is spreading. As the basic polymer for the shaft substrate, for example, polystyrene (PS) is used. Polystyrene has the advantages of being easily available, easy to process, and having good mechanical properties of the resulting shaft.

[0004] Under such circumstances, German Patent Invention No. 102008034013 proposes the use of a wood substitute material for the shaft of a pencil, which is based on a polymer binder.

[0005] Such extruded pencils are also known, for example, from European Patent No. 0505262, which is probably the closest prior art. The pencil described in this specification consists of foamed polystyrene in the coating and a flexible polystyrene-bonded core.

[0006] The object of the present invention is to propose a pencil that is a sustainable alternative to the prior art, while simultaneously maintaining its usability, particularly its sharpness and bending strength. This object is addressed by a pencil having the features of claim 1, a shaft for a writing instrument, drawing instrument, drafting instrument and / or cosmetic pencil as described in claim 12, and a method for manufacturing a pencil and / or shaft having the features of claim 13. Preferred or advantageous embodiments of the present invention will become apparent from the dependent claims, the following description and the accompanying drawings.

[0007] The subject of this invention is a pencil, which has a barrel.

[0008] Optionally, the pencil has a lead, and the barrel preferably surrounds the lead concentrically and / or coaxially, and the lead is positioned with the barrel so as not to move relative to each other and / or immovably. In particular, the lead is permanently and inseparably fixed within the barrel and / or cannot be separated without destruction. For example, the lead may be coupled to the barrel materially, forcefully, and / or by form, possibly via an intermediate layer.

[0009] The pencil is formed particularly as a straight column, and the base or cross-section of the column may be formed in the shape of, for example, a circle, ellipse, triangle, square, pentagon, hexagon, or polygon. Alternatively, the pencil may be twisted or bent in shape.

[0010] Pencils are specifically designed to be sharpened. For example, a pencil can be sharpened using a pencil sharpener, such as a colored pencil sharpener, pencil sharpener, sharpener, or cosmetic pencil sharpener, in which case the conical tip of the pencil can be created or modified by separating and removing the material from the shaft and lead.

[0011] The shaft has a shaft base material, and the shaft preferably consists of at least 60% by weight, preferably at least 80% by weight, particularly at least 98% by weight, or even more than 100% by weight of the shaft base material. Alternatively or supplementally, the cross-sectional area of ​​the shaft preferably has the shaft base material covering at least 80% of the cross-sectional area, preferably at least 90% of the cross-sectional area, particularly at least 98% of the cross-sectional area, or even more than 99% of the cross-sectional area. In particular, the shaft base material exists in a foamed, porous form.

[0012] In particular, the shaft has a shaft body made of a shaft base material. The shaft body is formed in an annular shape, for example, a ring shape, when viewed in cross-section. In particular, the inner contour can be circular, and / or the outer contour can be formed arbitrarily, for example, circular, elliptical, triangular, quadrilateral, pentagonal, hexagonal, or polygonal.

[0013] Within the scope of the present invention, it is proposed to manufacture the shaft base material in two steps. In the first step, the components of the basic formulation are mixed. A basic mixture having the basic formulation is obtained. In the second step, the basic mixture having the basic formulation is mixed with a foaming additive. A manufacturing mixture is obtained. The manufacturing mixture is heated by heat above the decomposition temperature of the foaming additive to form the shape of a shaft. A shaft base material is obtained. The shaft base material is foamed and has pores. The gaseous components of the shaft base material can be ignored in terms of the total weight of the shaft base material. The ratio of the components of the basic formulation is substantially maintained in the shaft base material.

[0014] The basic formula is: 50-80% by weight of PLA and / or PLA copolymer 20-50% by weight of further polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, colorants, especially pigments, and organic and / or inorganic fillers. Includes.

[0015] Further polymers may include polybutylene succinate (PBS) in addition to olefins. In particular, the proportion of PBS is less than 8% by weight, preferably less than 5% by weight, and especially 0% by weight. The basic formulation does not need to contain PBS.

[0016] In particular, the basic formulation consists of the following components in the following proportions: 50-80% by weight of PLA and / or PLA copolymer 0-10% by weight of polybutylene succinate (PBS) 0-25% by weight of additional polymer 0.1 to 25% by weight of plasticizer 0-10% by weight of wax / lubricant 0.1 to 10% by weight of other additives, such as adhesion promoters, stabilizers, etc. 0-10% by weight of colorants, especially pigments. 0-40% by weight of organic and / or inorganic fillers as shaft fillers. Includes.

[0017] To manufacture the shafts of pencils or writing instruments, drawing instruments, drafting instruments, and / or cosmetic pencils, the components of a basic formulation are mixed, a foaming additive is mixed with the basic mixture of the basic formulation, the mixture is foamed as a manufacturing mixture, and then molded. A shaft base material is obtained. In this case, the foaming additive is preferably added in situ to the basic mixture of the basic formulation at the time of final extrusion so that its effect is achieved only when the final product is molded.

[0018] A manufacturing mixture is used to produce the shaft base material.

[0019] The manufacturing mixture consists of the following components: Basic mixture having a basic composition of 90-99% by weight. 1-10% by weight of foaming additive It holds.

[0020] The proportion of foaming additives used is determined, on the one hand, by the content of at least one reactive component in the additive, and on the other hand by the desired density reduction in the final product. Furthermore, this content is further determined by specific method parameters (such as temperature, pressure, melt viscosity, and polymer residence time in the extruder or injection molding apparatus).

[0021] The blowing additive is intentionally thermally decomposed to release an expanding gas that foams the basic mixture of the base formulation and is thus no longer present in the final product in its original form. Accordingly, pores remain in the plastic mass, suggesting the use of a foam additive. Since the entire basic mixture of the base formulation is foamed, the ratio specified in weight percent of the components of the base formulation does not change significantly due to foaming.

[0022] PLA / PLA copolymer PLA is the name for polylactic acid and is sometimes referred to specifically as polylactide and / or polylactic acid. In particular, PLA is also registered with the Chemical Abstracts Service under the CAS number: 9051-89-2. The properties of PLA as a polymer may vary somewhat depending on the number of monomers in the polymer. PLA may exist as a PLA copolymer or a PLA blend. A PLA copolymer contains PLA as a first component and a polymer in which PLA is copolymerized as a second component. The second component may contain, for example, polyvinyl alcohol (PVA), polycaprolactone (PCL), polyethylene glycol (PEG), etc. alone or as a mixture. Additionally, a PLA blend can be used, in which case the polymer PLA is mixed as a PLA blend with other polymers, such as polyolefins, such as polyethylene. PLA can exist as PLA, PLA copolymers, PLA blends, and mixtures thereof.

[0023] PLA, PLA copolymers and / or PLA blends are present in the range of 50 to 80% by weight, preferably 55 to 70% by weight, based on the axial substrate.

[0024] Herein lies the consideration of the present invention, which concerns the fact that the basic polymers used to date, particularly polystyrene or polystyrene-based polymers, are manufactured from petroleum-based starting materials. Consumer concerns about the use of such petroleum-based starting materials are growing. This is because, on the one hand, petroleum resources must be utilized for their production, and on the other hand, the resulting materials are not compostable at all or very little. Both of these characteristics contradict the current trend to demand sustainable and / or environmentally friendly products. In response, the present invention proposes the use of PLA (polylactide polymer) as the basic polymer. This significantly reduces or completely avoids the use of petroleum-based raw materials in pencils. PLA, also commonly called polylactic acid, is obtained, for example, from renewable natural raw materials, such as corn, and belongs to the polyester class as a synthetic polymer. Therefore, pure PLA is preferably manufactured from renewable raw materials and is not based on fossil raw materials, such as petroleum.

[0025] In addition, PLA is compostable, and can be broken down into harmless final products, particularly in industrial composting plants, in accordance with EN 14995 or EN 13432 standards, especially within a manageable period of less than 12 weeks, and other similar standards may specify other conditions and periods. Composting or decomposition of PLA requires industrial composting conditions in the presence of microorganisms, i.e., controlled temperature and humidity conditions. For example, in this case, the temperature must be 55-70°C. Using industrial composting, it is possible to decompose the pencil shaft into harmless final products in accordance with standards, and this can be called biodegradable. In this case, the biodegradation behavior can be further intentionally influenced by special copolymers and / or additional polymers of PLA.

[0026] The mechanical properties of PLA can be adapted to the known mechanical properties of polystyrene by additives. The proposed composition of the shaft substrate enables the production of shafts having the properties required for the pencil in terms of machinability, grip, mechanical, thermal and chemical stability. Thereby, PLA becomes a sustainable alternative to the basic polymers that have been used hitherto for the production of pencil shafts.

[0027] When selecting PLA, it has been found to be particularly advantageous that the original properties, such as machinability, breaking strength, and tactile feel, do not change unfavorably compared to polymers according to the prior art, especially when compared to other plastics. Thereby, the PLA in the above foam formulation becomes a completely equivalent and sustainable substitute for the polymers known hitherto.

[0028] In particular, the shaft substrate is formed as a PLA blend and / or a PLA copolymer. In the case of a PLA blend, PLA is mixed with one or more polymers. In the case of a PLA copolymer, PLA is polymerized with a further polymer.

[0029] The PLA blend may be, for example, a compatible mixture with polyethylene glycol (PEG) and polypropylene glycol (PPG), in which case the flexibility of the inherently brittle PLA is increased. However, in order to obtain the desired properties, incompatible mixtures with, for example, polyolefins (polyethylene PE, polypropylene PP) are also conceivable. These are preferably produced from biological sustainable sources, such as bioethanol or hydrogenated vegetable oils.

[0030] Similarly, the biopolymer polybutylene succinate (PBS) can be mixed with the above-mentioned further polymers into the PLA / PLA copolymer. Here, the content of PBS is in a proportion of 0 to 10% by weight, preferably 5% by weight or less, preferably 3% by weight or less, particularly 1% by weight or less, based on the shaft substrate. This has the advantage that the brittleness of PLA is somewhat reduced by mixing PBS. Thereby, the proportion of the plasticizer can be reduced.

[0031] Further polymers of the PLA blend or PLA copolymer are present in the range of 0 to 30% by weight, preferably 5 to 20% by weight, and particularly preferably 7 to 15% by weight, relative to the axial substrate.

[0032] plasticizer In particular, the shaft base material contains one or more plasticizers. Besides copolymerization within the polymer (internal plasticization), the plasticizer can also be introduced into the basic formulation in solid polymer form or as a special oily viscous substance (external plasticization). In this case, the plasticizing effect is typically controlled by temperature treatment during granulation or extrusion.

[0033] In particular, not only polyadipic acid-based polymer plasticizers (e.g., polybutylene adipate terephthalate (PBAT) (CAS: 60961-73-1)) but also other types of elastic polymers, such as polyethylene types, or generally TPEs, can be mentioned.

[0034] Further external plasticizers include epoxidized vegetable oils, such as epoxidized soybean oil (ESBO) (CAS: 8013-07-8), and even citrate esters, such as acetyl tributyl citrate (ATBC) (CAS: 77-90-7). Additionally, glycerin triacetic acid (GTA) and diethylhexyl adipate (DOA) can be used individually or in combination with the above plasticizers. The plasticizer is present in an amount of 0.1 to 25% by weight, preferably 5 to 20% by weight, and particularly preferably 7 to 15% by weight, relative to the axial substrate.

[0035] wax, lubricant To achieve appropriate processability and to adjust material-specific properties, various waxes and lubricants are optionally used as a mixture. These may include PE wax (e.g., grafted with maleic anhydride), amide wax, fatty acids, such as stearic acid and palmitic acid, montan wax, stearate (e.g., calcium stearate), fatty acid esters, paraffin wax, and even oils and fats, such as palm oil. The content of these additives is in the range of 0 to 10% by weight, preferably 1 to 5% by weight.

[0036] For good grinding properties, it is advantageous that at least one wax is selected from the group of waxes including amide waxes, fatty acids such as stearic acid and palmitic acid, montan wax, stearate, fatty acid esters, and paraffin wax. Furthermore, the wax may include ethylene bis-stearamide, stearic acid, calcium stearate, polyethylene wax, and maleic anhydride-grafted polyethylene wax.

[0037] Other additives Other additives are used for various purposes depending on the remaining formulation. Therefore, adhesion promoters are used not only to bond incompatible polymers together, but also, in some cases, as fillers. An example here is the coupling of PLA with maleic anhydride-grafted polyester. Furthermore, various stabilizers and / or nucleating agents can also be added. The content of other additives depends on the properties and amount of the remaining components, and is typically 0-10% by weight, preferably 1-5% by weight.

[0038] Coloring agents The colorants help to adjust the desired aesthetic color effect, and it is desirable that the barrel base material be adjusted to be natural and wood-like (brown tones) on the one hand, or even more deliberately contrasting (black in the case of cosmetic pencils) on the other hand. In this case, preferably, correspondingly thermally stable and physiologically appropriate organic and / or inorganic pigments, such as titanium dioxide, iron oxide, azo pigments, etc., are used. To lighten the tone, it has been found to be advantageous if the white pigment is formed from titanium dioxide (TiO2). To adjust the desired tone, it is advantageous that the barrel base material contains 0.1 to 10% by weight of a colored coloring pigment, such as an iron oxide pigment, as part of the colorant. The exact content depends on the desired color and any existing coloring components (e.g., fillers).

[0039] There are also colorants that act as fillers, such as graphite or carbon black. For colored fillers, the proportion of the shaft filler is applied.

[0040] filling material In preferred alternative or advanced forms of the present invention, the shaft filler is intended to be selected at least partially from inorganic fillers. The selection of inorganic fillers allows for adjustment of properties such as strength, brittleness, and sliding properties when cutting, as well as a corresponding reduction in material costs. Preferably, at least one inorganic filler is formed from the group of layered silicates, particularly steatite, talc, clay, kaolin, calcium carbonate, and even chalk, boron nitride, graphite, or mixtures thereof. Organic fillers such as wood flour and / or cellulose powder are preferably used. This is because organic fillers are inexpensive, increase similarity to wood, and further increase the proportion of biodegradable and renewable components in the formulation.

[0041] The shaft filler is present in an amount of 0 to 40% by weight, preferably 3 to 20% by weight, and particularly preferably 4 to 13% by weight relative to the shaft base material.

[0042] In a preferred development of the present invention, the shaft filler is selected as an organic filler, at least largely or even entirely. To give the shaft a wood-like appearance, the organic filler is preferably selected from the group including wood and / or cellulose. For example, wood powder can be used in the production. For machinability, it is particularly advantageous that at least one of the organic fillers is formed from filler particles with a maximum particle size of 250 μm, and especially 100 μm.

[0043] In a preferred evolution of the present invention, the shaft filler is selected as a mixture of the aforementioned inorganic and organic fillers, at least in part or even entirely.

[0044] In particular, the shaft substrate does not contain any colorants. Alternatively, the shaft substrate may have 1-3% by weight of white pigment as part of the colorants to lighten the color tone of the shaft substrate.

[0045] Foam additives The foaming additive causes the polymer phase, which includes the basic formulation, particularly PLA, and further additives, to foam. As a result, the foamed shaft base material has pores in its final state, and these pores make the shaft body lighter and easier to machine.

[0046] In this case, the foaming additive is mixed into the base compound, particularly in the extruder or during injection molding, and uniformly dispersed. As the mixture melts together in the extruder cylinder, a specified amount of gas is released when each foaming additive reaches its decomposition point, and this gas disperses into the liquid phase of the plastic mixture. As the molten plastic mass exits the machine and the extruded strands enter the cooling and calibration device, the plastic matrix freezes and the gas bubbles are fixed in the axial substrate.

[0047] Preferably, the process is carried out so that pores are uniformly formed throughout the shaft substrate, particularly in the PLA and optionally further polymers, and so that no pores are visible on the shaft surface. Alternatively, the shaft substrate mixed with the foaming additive is coated with a decorative layer that does not contain the foaming additive so that the surface of the shaft substrate does not have pores. In this case, the decorative layer is ideally formed from the same or at least compatible polymer as the shaft substrate to ensure sufficient adhesion.

[0048] On the one hand, the pores reduce weight and polymer consumption. On the other hand, the PLA shaft base material becomes more elastic, allowing for reduced use of plasticizers. Furthermore, due to the pores, the resulting pencil shaft base material can be sharpened more easily with conventional sharpeners. In addition, the reduced density decreases the amount of material used for the shaft base material, lowering costs. In this case, 1 g / cm³ 3A density of less than is achieved. The presence of pores in the extruded shaft substrate suggests the addition of a foaming additive. The required amount of foaming additive is determined by many factors, such as the proportion of polymer, the amount of filler, the residence time and residence temperature of the shaft substrate in the extruder, and is adjusted to 1 to 10% by weight, preferably 2 to 6%. Here, the foaming additive is usually added to the basic formulation as a so-called masterbatch (carrier material, usually an active or reactive substance incorporated into the polymer) to ensure proper miscibility. In this case, preferably, physiologically harmless active substances from the group of carbonates and / or citrates are used, which generally release CO2 as a gas and do not leave hazardous and / or harmful reaction residues. The foaming additive in this case includes carbonates or citrates. As carbonates, for example, ammonium carbonate, alkaline carbonates such as sodium carbonate and potassium carbonate can be used. Ammonium carbonate can also be produced by adding calcium carbonate together with ammonium sulfate. As citrates, ammonium citrate, alkaline citrates, such as sodium citrate and potassium citrate, can be used.

[0049] In a preferred embodiment of the present invention, the majority of the components are intended to be compostable, or are bio-based from the outset, or even naturally derived, under the boundary conditions of industrial biological compostability described for PLA, and therefore do not require composting. This achieves that the shaft material as a whole can be at least industrially biodegradable or disposed of without releasing harmful substances. Particularly preferably, all components of the pencil are subject to this condition.

[0050] In a possible development of the present invention, an adhesion-promoting layer is placed between the core and the shaft. The adhesion-promoting layer improves the bond between the shaft and the core, thereby improving machinability and ensuring secure fixation of the core within the shaft. This option is particularly useful when polymers that are not compatible with each other are used for the shaft and the core. Preferably, the adhesion promoter in the adhesion-promoting layer is the same graft as maleic anhydride-grafted polylactic acid wax and / or other polyesters.

[0051] In a preferred evolution of the present invention, the core is also manufactured using PLA as a base. In particular, the core has PLA as a binder. Preferably, the core is formed from components as described in German Patent Application Publication No. 102013016355, which is incorporated herein by reference.

[0052] In particular, the core has a core base material. The core base material is crucial for industrial composting. The core base material has at least one binder containing 10-40% by weight of PLA. In particular, the core base material has the following components: 10-40% by weight of PLA 30-80% by weight of core filling material 0-20% by weight of wax / lubricant 0-10% by weight of additives, such as plasticizers, stabilizers, and adhesion promoters. It holds.

[0053] The proportion of polylactide in the core composition 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.

[0054] The core, bonded with polymer, 10-60% by weight of polylactide 2-25% by weight of wax 15-70% by weight of core filling material 0-5% by weight of palm oil 0-30% by weight of coloring agent It was found that having [this] is advantageous.

[0055] It has been demonstrated that the wick is effective if at least one of the waxes is from the group including fatty acids, stearate, montan wax, amide wax, and paraffin. Mixtures of two or more waxes are also usable.

[0056] In this case, it is particularly preferable that at least one of the waxes is calcium stearate and / or ethylene bis-stearamide (EBS) and / or PE wax. Very good results were achieved in colored pencil leads (Farbminen) when ethylene bis-stearamide (EBS) was used. Very good results were achieved when calcium stearate was used in pencil leads (Bleiminen).

[0057] Advantageously, at least one core filler of the core consists of at least one filler from the group including graphite, hexagonal boron nitride, talc, steatite, layered silicates (clay, kaolin), and chalk.

[0058] In this case, for the pencil lead, graphite combined with graphite or carbon black is particularly preferred as a coloring filler, as its high content allows it to function as a filler as well. For colored pencil leads, it has been demonstrated that combinations of white or colorless fillers, such as talc, layered silicates, or hexagonal boron nitride, and coloring pigments, such as azo pigments, phthalocyanine, dioxazine, quinacridone, iron oxide, carbon black, graphite, ultramarine, and iron cyano complexes are effective.

[0059] There are colorants that also serve as core fillers. For colored core fillers, the proportion of the core filler material is applied.

[0060] For example, the core filler is selected from the group including layered silicates and talc (colored pencils) and graphite (pencils).

[0061] In a preferred development of the present invention, the shaft substrate and the core substrate are directly bonded to each other. In particular, they are bonded to each other materially. By selecting PLA for both substrates, an intermediate layer can be advantageously omitted, as these homogeneous polymers can adhere to each other without further treatment. Thus, by selecting homogeneous substrates, an adhesion-promoting layer can be omitted, and a stable bond can be constructed.

[0062] In particular, the core components, under the boundary conditions of PLA's industrial biological compostability, are similarly and simultaneously decomposable or bio-based, as already mentioned.

[0063] In a preferred configuration of the present invention, the pencil is formed as a writing pencil and / or a drawing pencil and / or a cosmetic pencil. In particular, this can be realized as a pencil or a colored pencil.

[0064] Further applications of the present invention include shafts for writing instruments, drawing instruments, drafting instruments, and / or cosmetic pencils. Drafting instruments are formed, for example, as pencil holders. Writing instruments also include ballpoint pens or mechanical pencils (Fallstifte) with a movable lead, the shafts of which can be manufactured from a shaft base material containing a basic compound.

[0065] In particular, shaft base materials for drafting tools can be formed as described above. Specifically, the basic formulations of shaft base materials are formed and / or manufactured in the same manner.

[0066] In particular, the shafts for writing instruments, drawing instruments, drafting instruments and / or cosmetic pencils have a shaft base material containing a basic compound, the basic compound is 50–80% by weight of PLA, PLA copolymer and / or PLA blend 20-50% by weight of further polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, colorants, especially pigments, and organic and / or inorganic fillers as shaft fillers. It includes the following. The shaft base material is foamed and / or has pores.

[0067] The shafts for writing instruments, drawing instruments, drafting instruments, and / or cosmetic pencils have shaft materials having the same properties as the shaft materials described above.

[0068] Further application of the present invention relates to a method for manufacturing a pencil and / or barrel as described above or as described in any one of the prior claims. It is particularly intended that the barrel be applied to the lead by primary molding. As the primary molding method, extrusion molding, injection molding or press molding can be used in particular.

[0069] Manufacturing using extrusion molding can be carried out in one or two stages. In one-stage manufacturing, all components of the pencil (lead, possibly an adhesion-promoting layer, barrel base material, and decoration) are thermoplastically molded to the final contour within a single tool, and the shape is then fixed during the subsequent cooling process.

[0070] In the two-stage extrusion process, the core is first formed, along with any adhesive promoter already concentrically present on the core, if necessary. The latter can also be applied together with the shaft base material in a further variation. The resulting core strand is then covered with the shaft base material and decoration in an additional tool during the second step. The subsequent process steps are again identical to those of the one-stage variation.

[0071] Further features, advantages, and effects of the present invention will become apparent from the following description of preferred embodiments of the present invention. [Brief explanation of the drawing]

[0072] [Figure 1] This is a schematic diagram of a pencil as an embodiment of the present invention. [Figure 2] This is a schematic diagram of a further pencil as a further embodiment of the present invention. [Figure 3] This is a schematic diagram of a shaft made of a shaft base material having a hollow chamber.

[0073] Figure 1 shows a schematic longitudinal section of pencil 1, which is formed as, for example, a writing pencil, a drawing pencil, a cosmetic pencil, or a pencil.

[0074] The pencil 1 has a lead 2 and a shaft 3, and the lead 2 is positioned within the shaft so as not to move relative to the shaft 3. In this embodiment, the lead 2 is positioned coaxially and / or concentrically within the pencil 1. The pencil 1 is formed in a columnar shape, and its base or cross-section may be formed in the shape of, for example, a circle, polygon, or ellipse. The lead 2 has a cross-section that is, for example, circular. The shaft 3 has an outer contour of the pencil 1 and an inner contour of the lead 2.

[0075] The pencil 1 is formed to be sharpened and has a tip cone 4 on one side, where the shaft cone section 5 of the shaft 3 transitions into the lead cone section 6 of the lead 2. The lead cone section 6 forms the tip of the pencil 1. The tip cone 4 can be formed, for example, by separation or cutting using a sharpener.

[0076] The shaft 3 has a shaft base material, and the majority of the shaft 3 is formed from the shaft base material. Optionally, the pencil 1 may have further layers, in particular, an adhesion-promoting layer 7 forming an intermediate layer may be placed between the lead 2 and the shaft 3 of the pencil 1. Alternatively or additionally, a decorative layer 8 may be placed on the outer circumference of the shaft 3.

[0077] The shaft base material is intended to be manufactured using PLA as the base material. An example composition is given below: Example 1: A pencil or barrel having a barrel base material with the following basic composition: 80% PLA 2.5% by weight of calcium stearate as wax. 1% by weight of PE wax as a wax. 15% by weight of epoxidized vegetable oil as a plasticizer. 0.5% by weight of iron oxide pigment as a coloring agent. 1% by weight of TiO2 as a coloring agent

[0078] Add the following to induce foaming: A polymer compound containing 5% by weight of sodium bicarbonate / citric acid, a carbonate-based foaming additive, as a reactive component.

[0079] Example 1 shows a filler-free shaft with high porosity and similarly high compostability, or a high proportion of sustainable raw materials.

[0080] Example 2: A pencil or writing instrument barrel having a barrel base material having the following basic composition as a PLA blend consisting of PLA and PE: 65% PLA 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 MAH-grafted PE wax as an adhesion promoter. 1% by weight of MAH grafted PLA as an adhesion promoter 10% by weight of wood powder, an organic filler used as a shaft filler. 1.5% by weight of TiO2 as a coloring agent

[0081] Add the following to induce foaming: A polymer compound containing 2% by weight of sodium bicarbonate / citric acid, which is a carbonate-based foaming additive, as a reactive component.

[0082] Example 2 is a wood-like shaft with moderate porosity. A 10% by weight wood content supports the proportion of natural, renewable raw materials in the mixture and its machinability.

[0083] Example 3: A pencil or barrel having a barrel base material with the following basic formulation as a PLA blend consisting of PLA and PBS: 69% PLA 6% by weight of PBS as a further polymer 4% by weight of talc as a shaft filler. 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 a wax 2.2% by weight of calcium stearate as wax. 0.3% by weight of iron oxide pigment as a coloring agent. 1.3% by weight of TiO2 as a coloring agent

[0084] Add the following to induce foaming: A polymer compound containing 2% by weight of sodium bicarbonate, a carbonate-based foaming additive, as a reactive component.

[0085] Example 3 represents a more elastic shaft with a moderate degree of foaming.

[0086] Example 4: A pencil or barrel having a barrel base material with the following basic composition: 55% PLA 10% by weight of PBAT as a plasticizer 7% by weight of epoxidized vegetable oil as a plasticizer 2% by weight of ethylene bisstearamide as a lubricant 2% by weight of PE wax as a wax. 2.5% by weight of MAH grafted PLA as an adhesion promoter. 20% by weight of wood powder, an inorganic filler used as a shaft filler. 0.1% by weight of iron oxide pigment as a coloring agent. 1.4% by weight of TiO2 as a coloring agent

[0087] Add the following to induce foaming: A polymer compound containing 4% by weight of sodium bicarbonate / citric acid, a carbonate-based foaming additive, as a reactive component.

[0088] Example 4 represents a shaft with high porosity, which is clearly more densely packed.

[0089] Example 5: A cosmetic pencil or barrel having a barrel base material with the following basic formulation as a PLA blend with PE: 45% by weight PLA 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 bisstearamide as a lubricant 1% by weight of calcium stearate as wax 10% by weight of chalk, an inorganic filler used as a shaft filler. 1% by weight of carbon black as a coloring agent

[0090] Add the following to induce foaming: A polymer compound containing 4.5% by weight of sodium bicarbonate / citric acid, which is a carbonate-based foaming additive, as a reactive component.

[0091] Example 5 represents a black-colored, sharpenable cosmetic pencil with high polymer plasticity.

[0092] Figure 1 shows a pencil 1 having a PLA-based shaft 3 and a conventional lead 2, with an adhesion promoting layer 7 placed between the lead 2 and the shaft 3, whereas Figure 2 shows a modified embodiment.

[0093] In the embodiment shown in Figure 2, core 2 is similarly manufactured on a PLA base, and it has a core substrate having at least 10% PLA.

[0094] An example composition is shown below: Example 1: Pencil lead 10-60% by weight of polylactide 2-25% by weight of wax 0-5% by weight of palm oil Remaining graphite

[0095] As shown in the example, graphite is used as a coloring agent for pencil leads. However, a combination of graphite and carbon black can also be used.

[0096] The composition for colored pencil leads includes the following: 10-60% by weight of polylactide 2-25% by weight of wax 1-30% by weight of coloring agent remaining filler

[0097] In the case of colored pencil leads, colored and / or colorless pigments can be used as means of coloring. Examples of such pigments include azo pigments, phthalocyanines, dioxazines, quinacridones, iron oxides, carbon black, graphite, ultramarine, and iron cyano complexes.

[0098] In the embodiment shown in Figure 2, the adhesion promoter layer 7 can be advantageously omitted. This is because both substrates are PLA-based and, due to their similar components, can bond together excellently materially and morphologically without the adhesion promoter layer 7.

[0099] In the case of pencil 1 in Figure 1, at least the shaft 2 is compostable. Therefore, even if composting of further components may be more difficult, this embodiment represents a significant step towards a sustainable alternative to pencil 1. In the embodiment in Figure 2, both the shaft 2 and the lead 3 are formed to be compostable, making this pencil 1 a sustainable alternative.

[0100] Figure 3 schematically shows a shaft 3 made of a shaft base material having a hollow chamber 9. A replaceable movable lead can be inserted into the hollow chamber. Preferably, the lead can move within the hollow chamber, for example, in the case of a ballpoint pen. The shaft 3 may represent only a part. Additional functional ends, such as tips or push heads, can be attached to both ends of the shaft 3 to restrict the movement of the lead. The shaft 3 can be formed as part of a shaft 3 for, for example, a writing pencil, drawing pencil, ballpoint pen, cosmetic pencil, pencil, mechanical pencil (Druckfallstift), etc. Alternatively or additionally, a decorative layer 8 can be placed on the outer circumference of the shaft 3. [Explanation of symbols]

[0101] 1 Pencil 2 cores 3 axes 4. Conical tip 5-axis cone section 6-core cone section 7 Adhesion promotion layer 8. Decorative layer 9 Hollow chamber

Claims

1. Pencil (1), It has an axis (3), The shaft (3) has a shaft base material having a basic composition, The aforementioned basic formulation 50–80% by weight of PLA, PLA copolymer and / or PLA blend, 20-50% by weight of further polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, colorants, especially pigments, and organic and / or inorganic fillers as shaft fillers. Includes, The shaft base material is foamed and / or has pores, Pencil (1).

2. A manufacturing mixture is used to manufacture the aforementioned shaft substrate, and the manufacturing mixture is A basic mixture having the above basic composition in an amount of 90 to 99% by weight, 1-10% by weight of foaming additive A pencil (1) according to claim 1, characterized by having the following features.

3. The above basic formulation consists of the following components in the following proportions: 50–80% by weight of PLA, PLA copolymer and / or PLA blend 0-10% by weight of polybutylene succinate (PBS) 0-25% by weight of further polymers other than PBS 0-25% by weight of plasticizer 0-10% by weight of wax / lubricant 0-10% by weight of other additives, such as adhesion promoters, stabilizers, etc. 0-10% by weight of colorants, especially pigments. 0-40% by weight of organic and / or inorganic fillers as shaft fillers. A pencil (1) according to claim 1 or 2, characterized by containing the following.

4. A pencil (1) according to any one of claims 1 to 3, characterized in that the PLA is bio-based and / or the shaft filler is at least largely or completely organic.

5. The pencil (1) according to any one of claims 1 to 4, characterized in that the shaft filler is selected from the group including wood and cellulose.

6. The pencil (1) according to any one of claims 1 to 5, characterized in that the shaft filler contains an inorganic filler component, and the inorganic filler component is preferably formed from the group including layered silicates, particularly steatite, clay, kaolin, and talc, and / or chalk, graphite, and boron nitride.

7. The pencil (1) according to any one of claims 1 to 6, characterized in that the pencil has a lead and the lead is arranged so as not to move within the pencil and / or shaft.

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

9. The pencil (1) according to claim 7 or 8, characterized in that the lead (2) has a lead base material, and the lead base material has at least one binder containing 10 to 40% by weight of PLA.

10. The pencil (1) according to claim 9, characterized in that the shaft base material and the core base material are directly bonded to each other without a separate adhesion promoting layer.

11. A pencil (1) according to any one of claims 1 to 10, characterized in that it is formed as a writing pencil and / or a drawing pencil and / or a cosmetic pencil.

12. A shaft (3) for writing instruments, drawing instruments, drafting instruments and / or cosmetic pencils, wherein the shaft (3) has a shaft base material having a basic composition, The aforementioned basic formulation 50–80% by weight of PLA, PLA copolymer and / or PLA blend, 20-50% by weight of further polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, colorants, especially pigments, and organic and / or inorganic fillers as shaft fillers. Includes, The shaft base material is foamed and / or has pores, Axis (3).

13. A method for manufacturing a pencil (1) according to any one of claims 1 to 11 and / or a shaft according to claim 12, comprising mixing a basic mixture having the basic composition and a foaming additive to produce a foamed shaft material, and heat-treating the mixture, wherein the basic composition is 50–80% by weight of PLA, PLA copolymer and / or PLA blend, 20-50% by weight of further polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, colorants, especially pigments, and organic and / or inorganic fillers as shaft fillers. A method characterized by including

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