Pencil, shaft and process for production thereof

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

[0001] Pin, shaft and method for manufacturing

[0002] The invention relates to a pen having the features of the preamble of claim 1. The invention further relates to a shaft for writing instruments, painting instruments, drawing instruments and / or cosmetic pencils according to claim 12 and to a method for producing the pen and / or the shaft having the features of claim 13.

[0003] Wood-cased pencils, in which the lead is surrounded or encased in naturally grown wood, have long been known. In recent years, the price of high-quality wood has been rising due to the lack of wood availability, which directly impacts the production costs of the pencils. Furthermore, comparatively large natural wood reserves are required for pencil production.

[0004] In response, the production of pencils, or rather lead casings and leads, by extrusion from polymers has become widespread. Polystyrene (PS), for example, is used as the base polymer for the shaft material. Polystyrene has the advantages of good availability, easy processing, and good mechanical properties of the resulting shaft.

[0005] Against this background, the document DE 10 2008 034 013 B4 proposes the use of a wood substitute for the shaft of a pencil, whereby the wood substitute is based on a polymeric binder.

[0006] Such an extruded pencil is also known, for example, from EP 0 505 262 B1, which arguably represents the closest prior art. The pencil described therein consists of a foamed polystyrene casing and a flexible polystyrene-bonded lead.

[0007] It is an object of the present invention to propose a pencil that represents a sustainable alternative to the prior art, while simultaneously retaining the performance characteristics of the pencil, in particular its sharpenability and flexural strength. This object is achieved by a pencil having the features of claim 1, a shaft for writing instruments, painting instruments, drawing instruments, and / or cosmetic pencils according to claim 12, and a method for producing the pencil and / or the shaft having the features of claim 13. Preferred or advantageous embodiments of the invention emerge from the subclaims, the following description, and the attached figure.

[0008] The subject of the invention is a pen, wherein the pen has a shaft.

[0009] Optionally, the pen has a lead, wherein the shaft preferably surrounds the lead concentrically and / or coaxially, and wherein the lead and the shaft are arranged in a manner that is fixed and / or immovable relative to each other. In particular, the lead is permanently fixed in the shaft and / or cannot be removed without damage. For example, the lead may be connected to the shaft via intermediate layers in a material-to-material, force-to-fit, and / or form-fitting manner.

[0010] The pin is designed, in particular, as a straight cylinder, whereby the cylinder base or cross-sectional area can be round, oval, triangular, quadrangular, pentagonal, hexagonal, or polygonal, for example. Alternatively, the pin can be twisted or flexed.

[0011] The pencil is designed to be sharpenable. For example, it can be sharpened with a pencil sharpener, such as a colored pencil sharpener, pencil sharpener, machine sharpener, or cosmetic pencil sharpener. A conical tip can be created or reworked by removing material from the shaft and the lead.

[0012] The shaft comprises a shaft base material, wherein the shaft preferably consists of at least 60 wt.%, preferably at least 80 wt.%, and in particular at least 98 wt.% or even 100 wt.% of the shaft base material. Alternatively or additionally, the cross-sectional area of ​​the shaft preferably comprises the shaft base material 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. In particular, the shaft base material is in a foamed, porous form.

[0013] In particular, the shaft has a shaft body made of the shaft base material. The shaft body has a ring-shaped cross-section, for example, a circular ring. In particular, the inner contour can be circular and / or the outer contour can be of any shape, e.g., round, oval, triangular, quadrangular, pentagonal, hexagonal, or polygonal.

[0014] Within the scope of the invention, it is proposed that the shaft base material be produced in two steps. In a first step, the components of the basic formulation are mixed. This creates a base mixture containing the basic formulation. In a second step, the base mixture is mixed with the basic formulation and a foaming additive. This creates a production mixture. The production mixture is thermally heated above the decomposition temperature of the foaming additives and formed into the shape of the shaft. This creates the shaft base material. The shaft base material is foamed and has pores. The gaseous components of the shaft base material can be neglected in relation to the total weight of the shaft base material. The ratio of the components of the basic formulation largely remains the same in the shaft base material.

[0015] The basic recipe includes:

[0016] 50 to 80 wt% PLA and / or PLA copolymer

[0017] 20 to 50 wt.% other polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, etc., colorants, especially pigments, organic and / or inorganic fillers.

[0018] In addition to olefin, other polymers may also include polybutylene succinate (PBS). In particular, the PBS content is less than 8 wt.%, preferably less than 5 wt.%, and especially 0 wt.%. The basic formulation may be PBS-free.

[0019] In particular, the basic formulation comprises the following proportions of the components: 50 to 80 wt.% PLA and / or PLA copolymer

[0020] 0 to 10 wt.% polybutylene succinate (PBS)

[0021] 0 to 25 wt.% other polymers

[0022] 0.1 to 25 wt.% plasticizer

[0023] 0 to 10 wt.% waxes / lubricants

[0024] 0.1 to 10 wt.% other additives such as adhesion promoters, stabilizers, etc.

[0025] 0 to 10 wt% colorants, especially pigments

[0026] 0 to 40 wt.% organic and / or inorganic fillers as

[0027] Shaft fillers

[0028] To produce the shaft of a pen or writing instrument, painting instrument, drawing instrument, and / or cosmetic pencil, the components of the basic formulation are mixed and blended with foaming additives as the base mixture of the basic formulation. The foaming additives are then foamed and shaped as the manufacturing mixture. The shaft base material is created. The foaming additives are preferably added in situ to the base mixture of the basic formulation during the final extrusion process, so that their effect is only achieved during the shaping of the final product.

[0029] A manufacturing mixture is used to produce the shaft base material.

[0030] The manufacturing mixture contains the following components:

[0031] 90 to 99 wt. % base mixture with the basic recipe

[0032] 1 to 10 wt. % foaming additives

[0033] The proportion of foaming additives used depends on the content of at least one reactive component in the additive, as well as on the desired density reduction in the final product. Specific process parameters (temperature, pressure, melt viscosity, polymer residence time in the extruder or injection molding system, etc.) also determine this content.

[0034] The foaming additives are no longer present in their original form in the final product, as they undergo targeted thermal decomposition and release an expanding gas that foams the base mixture of the basic formulation. This leaves pores in the plastic mass, indicating the use of foaming additives. The entire base mixture of the basic formulation is foamed, so the foaming process does not significantly alter the stated ratios in weight percent of the components of the basic formulation.

[0035] PLA / PLA copolymer

[0036] PLA is the name for polylactic acid, which can specifically be referred to as polylactide and / or polylactic acid. PLA is specifically registered with the Chemical Abstracts Service under the number CAS: 9051-89-2. Depending on the number of monomers in the polymer, the properties of PLA as a polymer can vary slightly. PLA can also be present as a PLA copolymer or PLA blend. The PLA copolymer has PLA as its first component and a polymer with which the PLA is copolymerised as its second component. The second component can be alone or a mixture of, for example, polyvinyl alcohols (PVA), polycaprolactones (PCL), polyethylene glycol (PEG), etc. PLA blends can also be used, in which PLA as a polymer is mixed with other polymers, e.g. polyolefins, e.g. polyethylene, as a PLA blend. PLA can be present as PLA, PLA copolymer, PLA blend, or mixtures thereof.

[0037] The PLA, PLA copolymer and / or PLA blend is present in the range 50 to 80 wt.%, preferably 55 to 70 wt.% based on the shaft base material.

[0038] One consideration of the invention is that the base polymers used to date, in particular polystyrene or polystyrene-based polymers, are made from petroleum-based starting materials. Consumer reservations about the use of such petroleum-based starting materials are increasing because, on the one hand, petroleum resources must be used for them and, on the other hand, the resulting material is not or hardly compostable. Both properties contradict the current trend towards promoting sustainable and / or environmentally conscious products. Instead, the invention proposes using PLA (polylactide polymers) as the base polymer, so that the use of petroleum-based raw materials in the pen is significantly reduced or completely avoided. PLA, also commonly called polylactic acid, is obtained from renewable natural resources such as corn, and as a synthetic polymer belongs to the polyesters.Thus, pure PLA is preferably made from renewable raw materials and is not based on fossil raw materials such as petroleum.

[0039] In addition, PLA is compostable and can be broken down into harmless end products within a reasonable period of time, particularly in an industrial composting facility, in particular less than, for example, 12 weeks, in accordance with the EN 14995 or EN 13432 standards, although other similar standards may define different conditions and time periods. Composting or degrading PLA requires industrial composting conditions, i.e. controlled temperature and humidity conditions in the presence of microorganisms. For example, temperatures must be between 55 and 70°C. Using industrial composting, it is possible to break down the pen barrel into harmless end products according to the standard and to describe this as biodegradable. Special PLA copolymers and / or additional polymers can specifically influence the biological degradation behavior.

[0040] The mechanical properties of PLA can be adjusted to those of the well-known polystyrene through additives. The proposed composition of the barrel base material allows the production of a barrel that exhibits the properties required for pencils: sharpenability, grip, mechanical, thermal, and chemical stability. PLA thus represents a sustainable alternative to the base polymers previously used for the production of the barrel.

[0041] A particularly advantageous aspect of choosing PLA has been shown to be that, especially compared to other plastics, the original properties, such as sharpenability, fracture strength, and haptic properties, are not adversely affected by the state-of-the-art polymers. Thus, PLA in the aforementioned and foamed formulation represents a fully functional, sustainable substitute for previously known polymers. In particular, the base material for the shaft is formed as a PLA blend and / or PLA copolymer. In a PLA blend, the PLA is mixed with one or more polymers. In a PLA copolymer, the PLA is polymerized with another polymer.

[0042] PLA blends can be compatible mixtures with, for example, polyethylene glycol (PEG) and polypropylene glycol (PPG), which in this case increase the flexibility of the inherently brittle PLA. However, incompatible blends with, for example, polyolefins (polyethylene PE, polypropylene PP) are also available to achieve specific properties. These are preferably produced from biological, sustainable sources, such as bioethanol or hydrogenated vegetable oils.

[0043] The biopolymer polybutylene succinate (PBS) can also be blended with the other polymers mentioned above into the PLA / PLA copolymer. The PBS content is 0 to 10 wt.%, preferably less than or equal to 5 wt.%, preferably less than or equal to 3 wt.%, and especially less than or equal to 1 wt.%, based on the base material of the shaft. This has the advantage that the brittle properties of PLA are somewhat reduced by the addition of PBS. This allows the amount of plasticizer to be reduced.

[0044] The other polymers of the PLA blend or PLA copolymer are present in the range 0 to 30 wt.%, preferably 5 to 20 wt.%, particularly preferably 7 to 15 wt.%, based on the shaft base material.

[0045] plasticizers

[0046] In particular, the base material of the upper contains one or more plasticizers. In addition to copolymerization in a polymer (internal plasticization), the plasticizers can also be incorporated into the base formulation in solid, polymeric form or as a specific, oily, viscous substance (external plasticization). The plasticizing effect is usually adjusted by temperature treatment during granulation or extrusion.

[0047] In particular, polymeric plasticizers based on polyadiapate (e.g. polybutylene adipate terephthalate (PBAT) (CAS: 60961-73-1 ) should be mentioned, but also other elastic polymer types such as polyethylene types or TPEs in general.

[0048] Other external plasticizers include epoxidized vegetable oils such as epoxidized soybean oil (ESBO) (CAS: 8013-07-8), as well as citrate esters such as acetyl tributyl citrate (ATBC) (CAS: 77-90-7). Glycerol triacetate (GTA) and diethylhexyl adipate (DOA) can also be used individually, or the aforementioned plasticizers can be used in combination. The plasticizers are present in the range of 0.1 to 25 wt.%, preferably 5 to 20 wt.%, particularly preferably 7 to 15 wt.%, based on the shaft base material.

[0049] Waxes, lubricants

[0050] To achieve suitable processability and to adjust material-specific properties, various waxes and lubricants are optionally used as a mixture. These can include, among others, PE waxes (e.g., with maleic anhydride grafting), amide waxes, fatty acids such as stearic acid and palmitic acid, montan waxes, stearates (e.g., Ca stearate), fatty acid esters, paraffin waxes, and also oils and fats such as palm oil. The content of these additives ranges between 0 and 10 wt.%, preferably between 1 and 5 wt.%.

[0051] For sharpenability, it is advantageous for the at least one wax to be selected from the group of waxes comprising amide waxes, fatty acids such as stearic acid and palmitic acid, montan waxes, stearates, fatty acid esters, and paraffin waxes. Additionally, the wax includes ethylene bisstearamide, stearic acid, calcium stearate, polyethylene wax, and maleic anhydride-grafted polyethylene wax.

[0052] Other additives

[0053] Other additives are used for different purposes depending on the remaining formulation. For example, adhesion promoters are used to bond incompatible polymers to each other, but also to any fillers. An example of this is the coupling of PLA with a maleic anhydrite-grafted polyester. Furthermore, various stabilizers and / or nucleating agents can be added. The content of other additives depends qualitatively and quantitatively on the remaining components and is between 0 and 10 wt.%, preferably between 1 and 5 wt.%.

[0054] Colorants

[0055] Colorants are used to achieve the desired aesthetic color effect and should give the base material a natural, wood-like appearance (brown tones) or a deliberately contrasting color (black in the case of cosmetic pencils). Thermally stable and physiologically suitable organic and / or inorganic pigments such as titanium dioxide, iron oxide, azo pigments, etc. are preferred. To lighten the color, it has proven advantageous if the white pigment is made of titanium dioxide (TiO2). To achieve the desired color, it is advantageous if the base material contains 0.1 to 10 wt.% of a colored pigment, e.g. iron oxide pigment, as part of the colorant. The exact content depends on the desired color and the color-imparting components already present (e.g. fillers).

[0056] There are colorants that also serve as fillers, such as graphite or carbon black. For colored fillers, the proportions of the shaft fillers apply.

[0057] Fillers

[0058] In a preferred alternative or development of the invention, the shaft filler is at least partially selected from an inorganic filler. By choosing the inorganic filler, for example, the strength, brittleness and sliding properties during sharpening can be adjusted, but the material costs can also be reduced accordingly. It is preferred that the at least one inorganic filler is formed from the group of layered silicates, in particular soapstone, talc, clay, kaolin, calcium carbonate, but also from chalk, boron nitride, graphite, or a mixture thereof. Organic fillers such as wood and / or cellulose flours are preferred because, on the one hand, they are inexpensive and promote wood similarity, and on the other hand, they also increase the proportion of biodegradable and renewable components in the formulation. The shaft filler is in the range 0 to 40 wt. %, preferably 3 to 20 wt.-%, particularly preferably 4 to 13 wt.% based on the shaft base material.

[0059] In a preferred embodiment of the invention, the shaft filler is at least largely or even entirely selected as an organic filler. To give the shaft a wood-like character, it is preferred that the organic filler be selected from the group comprising wood and / or cellulose. For example, wood flour can be used in production. For sharpenability, it is particularly advantageous if the at least one organic filler is formed from filler particles with a maximum particle size of 250 μm, in particular of a maximum of 100 μm.

[0060] In a preferred development of the invention, the shaft filler is selected at least largely or even completely as a mixture of the previously described inorganic and organic filler.

[0061] In particular, the base material is colorant-free. Alternatively, the base material contains 1 to 3 wt.% white pigment as part of the colorant to lighten the color of the base material.

[0062] Foam additives

[0063] The foaming additives foam the base formulation, particularly the PLA and the polymer phase, with the additional additives. This results in the foamed shaft base material having pores in its final state, making the shaft base lightweight and easy to sharpen.

[0064] The foaming additives are mixed into the base formulation, particularly during extrusion or injection molding, and distributed homogeneously. During the melting process in the extruder barrel, when the foaming additive reaches its decomposition point, a defined amount of gas is released, which is dispersed in the liquid phase of the plastic mixture. As the molten plastic mass exits the machine and the extruded strand enters a cooling and calibration device, the plastic matrix freezes, locking the gas bubbles in the shaft base material.

[0065] Preferably, the process is conducted in such a way that the pores form homogeneously throughout the entire shaft base material, especially in the PLA and any other polymers, and the pores are not visible on the shaft surface. Alternatively, the shaft base material, which has been treated with foaming additives, is coated with a decorative layer without foaming additives to ensure that the surface of the shaft base material is pore-free. The decorative layer is ideally made of polymers identical to or at least compatible with the shaft base material, ensuring sufficient adhesion.

[0066] Firstly, the pores reduce weight and polymer consumption. Secondly, the PLA shaft material becomes more elastic, thus reducing the use of plasticizer. Furthermore, the resulting pencil's shaft material can be sharpened more easily with conventional sharpeners thanks to the pores. Furthermore, the density reduction reduces the use of shaft material and lowers costs. Densities below 1 g / cm³ are achieved. 3achieved. The presence of pores in the extruded shaft base material indicates the addition of foam additives. The required amount of foaming additives depends on many factors, such as the polymer content, filler quantity, residence time and temperature of the shaft base material in the extruder, etc., and is set between 1 and 10 wt.%, preferably between 2 and 6%. The foaming additives are generally added to the basic formulation as so-called masterbatches (active ingredient(s) or reactive substance(s) embedded in a carrier material, usually a polymer) to ensure adequate miscibility. Physiologically harmless active ingredients from the group of carbonates and / or citrates are preferably used, which predominantly release CO2 as gas and do not leave behind any dangerous and / or harmful reaction residues. The foam additives comprise carbonates or citrates. Carbonates can be, for example,Ammonium carbonate and alkali carbonate, such as sodium carbonate and potassium carbonate, can be used. Ammonium carbonate can also be produced by adding calcium carbonate and ammonium sulfate. Citrates that can be used include ammonium citrate and alkali citrates, such as sodium citrate and potassium citrate.

[0067] In a preferred embodiment of the invention, it is provided that a majority of the components, under the conditions of the described industrial biological compostability of PLA, are also compostable, or are bio-based from the outset, or are of natural origin, so that they do not need to be composted. This ensures that the shaft base material in its entirety can at least be industrially biodegraded or disposed of in a pollutant-neutral manner. Particularly preferably, all components of the pen are subject to this condition.

[0068] In a possible further development of the invention, a bonding layer is arranged between the lead and the shaft. The bonding layer improves the bond between the shaft and the lead, thus improving sharpenability and ensuring the lead is firmly fixed in the shaft. This option is particularly useful when incompatible polymers are used in the shaft and lead. Maleic anhydride-grafted polylactic acid wax and / or an identical grafting with another polyester is preferably used as the bonding agent in the bonding layer.

[0069] In a preferred embodiment of the invention, the lead is also made from PLA. In particular, the lead contains PLA as a binding agent. The lead is preferably formed from the components described in the document DE 10 2013 016 355 A1, the disclosure of which is incorporated into the description by reference.

[0070] In particular, the mine comprises a base material. The base material is crucial for industrial composting. The base material comprises at least one binder containing 10–40 wt.% PLA. In particular, the base material comprises the following components:

[0071] 10 - 40 wt% PLA

[0072] 30 - 80 wt% lead filler 0 - 20 wt% waxes / lubricants

[0073] 0-10 wt.% additives such as plasticizers, stabilizers,

[0074] Adhesion promoter

[0075] The polylactide content of the lead composition is in the range of 10 - 60 wt.%, preferably in a range of 10 to 40 wt.% and particularly preferably in the range of 10 - 25 wt.%.

[0076] It has proven advantageous if the polymer-bonded lead

[0077] 10 to 60 wt.% polylactide

[0078] 2 to 25 wt% wax

[0079] 15 to 70 wt.% lead fillers

[0080] 0 to 5% by weight palm oil

[0081] 0 to 30 wt.% colorant.

[0082] It has proven effective if at least one of the waxes in the lead is one from the group consisting of fatty acids, stearates, montan waxes, amide waxes, and paraffins. Mixtures of two or more waxes can also be used.

[0083] It is particularly preferred if the at least one wax is calcium stearate and / or ethylene bisstearamide (EBS) and / or PE wax. Very good results have been achieved with the use of ethylene bisstearamide (EBS) in colored leads. Very good results have been achieved with the use of calcium stearate in lead leads.

[0084] Advantageously, the at least one lead filler of the lead consists of at least one filler from the group comprising graphite, hexagonal boron nitride, talc, soapstone, layered silicates (clays, kaolins), chalk.

[0085] For pencil leads, graphite or graphite combined with carbon black is particularly preferred as a coloring filler, which, due to its high carbon content, also serves as the filler. For colored pencil leads, combinations of white or colorless fillers, such as talc, phyllosilicates, hexagonal boron nitride, etc., with coloring pigments, such as azo pigments, phthalocyanines, dioxazines, quinacridones, iron oxides, carbon black, graphite, ultramarine, and iron cyanide complexes, have proven successful.

[0086] There are colorants that also serve as lead fillers. For colored lead fillers, the proportions of the lead fillers apply.

[0087] For example, the filler for the lead is chosen from the group comprising layered silicate and talc (colored pencil) and graphite (pencil).

[0088] In a preferred embodiment of the invention, the shaft base material and the lead base material are directly bonded to one another. In particular, they are bonded together by a material bond. By choosing PLA for the two base materials, an intermediate layer can advantageously be omitted, since these similar polymers can adhere to one another without any additional measures. Thus, by selecting similar base materials, the adhesion promoter layer can be omitted and a stable bond can be created.

[0089] In particular, the components of the mine are also biodegradable under the conditions of industrial biological compostability of PLA or are bio-based, as previously described.

[0090] In a preferred embodiment of the invention, the pen is designed as a writing pen and / or a painting pen and / or a cosmetic pen. In particular, it can be realized as a pencil or a colored pencil.

[0091] Another subject of the invention is a shaft for writing instruments, painting instruments, drawing instruments, and / or cosmetic pencils. The drawing instruments are designed, for example, as pen holders. Writing instruments also include ballpoint pens or drop-action pencils with a movable lead, the shafts of which can be manufactured from the shaft base material using the basic formulation.

[0092] In particular, the shaft base material for drawing instruments can be designed as described above. In particular, the basic formulation of the shaft base material is designed and / or manufactured in the same way.

[0093] In particular, the shaft for writing instruments, painting instruments, drawing instruments and / or cosmetic pencils has a shaft base material with a basic formulation, wherein the basic formulation

[0094] 50 to 80 wt.% PLA, PLA copolymer and / or PLA blend

[0095] 20 to 50 wt.% of other polymers, plasticizers, waxes / lubricants, other additives such as adhesion promoters, stabilizers, etc., colorants, especially pigments, organic and / or inorganic fillers as shaft fillers. The shaft base material is foamed and / or has pores.

[0096] The shaft for writing instruments, painting instruments, drawing instruments and / or cosmetic pencils has a shaft base material with the same properties as the previously described shaft base material.

[0097] Another subject of the invention relates to a method for producing the pencil and / or the shaft, as described above or according to one of the preceding claims. In particular, it is provided that the shaft is applied to the lead by a primary forming process. Extrusion, injection molding, or pressing can be used as primary forming processes.

[0098] Production by extrusion can be carried out in either a single or two-stage process. In single-stage production, all pen components (lead, adhesive layer (if applicable), barrel base material, and decorations) are thermoplastically formed in a single tool to near-net-shape, and the geometry is frozen in subsequent cooling processes.

[0099] In two-stage extrusion, the lead is first formed and, if necessary, the bonding agent, which is concentrically applied to the lead, is then applied. In another variation, the bonding agent can also be applied together with the shaft base material. The resulting lead strand is then coated with the shaft base material and the decorations in a second step and in an additional tool. After that, the process is identical to the single-stage version.

[0100] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These show:

[0101] Figure 1 is a schematic representation of a pen as an embodiment of the invention;

[0102] Figure 2 is a schematic representation of another pin as a further embodiment of the invention.

[0103] Figure 1 shows a schematic longitudinal section of a pen 1, wherein the pen 1 is designed, for example, as a writing pen, painting pen, cosmetic pen, pencil or the like.

[0104] The pen 1 has a lead 2 and a shaft 3, wherein the lead 2 is arranged in the shaft so as to be fixed relative to the shaft 3. In the exemplary embodiment, the lead 2 is arranged coaxially and / or concentrically in the pen 1. The pen 1 is cylindrical, whereby its base or cross-sectional area can be circular, polygonal, oval, etc., for example. The lead 2 has a circular cross-section, for example. The shaft 3 has the outer contour of the pen 1 and the inner contour of the lead 2.

[0105] The pencil 1 is designed to be sharpenable and has a pointed cone 4 on one side, with a shaft cone section 5 from the shaft 3 merging into a lead cone section 6 from the lead 2. The lead cone section 6 forms the tip of the pencil 1. The pointed cone 4 can be produced, for example, by separating or machining with a sharpener.

[0106] The shaft 3 has a shaft base material, with the shaft 3 being formed largely from the shaft base material. Optionally, the pen 1 can have additional layers; in particular, an adhesion promoter layer 7 can be arranged between the lead 2 and the shaft 3 in the pen 1, forming an intermediate layer. Alternatively or additionally, a decorative layer 8 can be arranged on the outer circumference of the shaft 3.

[0107] The shaft base material is intended to be made from PLA. Examples of compositions are listed below:

[0108] Example 1 : Pin or shaft with shaft base material that has the following basic formulation:

[0109] 80 wt% PLA

[0110] 2.5% w / w calcium stearate as wax

[0111] 1 wt.% PE wax as wax

[0112] 15 wt.% epoxidized vegetable oil as plasticizer

[0113] 0.5 wt.% iron oxide pigment as colorant

[0114] 1 wt.% TiO2 as colorant

[0115] For foaming, add:

[0116] 5 wt.% polymer compound, containing as reactive components

[0117] Sodium bicarbonate / citric acid as carbonate-based foaming additives

[0118] Example 1 shows a filler-free shaft with high porosity and equally high compostability or with a high proportion of sustainable raw materials.

[0119] Example 2: Pen or writing instrument barrel with barrel base material that has the following basic formulation as a PLA blend of PLA and PE:

[0120] 65 wt% PLA

[0121] 5 wt.% PE as additional polymer 5 wt.% PBAT as plasticizer

[0122] 10 wt.% ATBC as plasticizer

[0123] 2.5 wt.% MAH grafted PE wax as adhesion promoter

[0124] 1 wt.% MAH grafted PLA as adhesion promoter

[0125] 10 wt.% wood flour as organic filler as

[0126] Shaft filler

[0127] 1.5% by weight TiO2 as colorant

[0128] For foaming, add:

[0129] 2 wt.% polymeric compound containing as reactive components sodium bicarbonate / citric acid as carbonate-based foaming additives

[0130] Example 2 is a wood-like shaft with medium porosity. The 10% wood content supports sharpenability and the proportion of natural, renewable raw materials in the formulation.

[0131] Example 3: Pen or shaft with shaft base material that has the following basic formulation as a PLA blend of PLA and PBS:

[0132] 69 wt% PLA

[0133] 6 wt.% PBS as additional polymer

[0134] 4 wt.% talc as shaft filler

[0135] 5 wt.% epoxidized vegetable oil as plasticizer

[0136] 10 wt.% ATBC as plasticizer

[0137] 2.2 wt% stearic acid as wax

[0138] 2.2% w / w calcium stearate as wax

[0139] 0.3 wt.% iron oxide pigment as colorant

[0140] 1.3 wt% TiO2 as colorant

[0141] For foaming, add:

[0142] 2 wt.% polymer compound, containing as reactive components

[0143] Sodium bicarbonate as a carbonate-based foaming additive Example 3 produces a more elastic shaft with a medium degree of foaming.

[0144] Example 4: Pen or shaft with shaft base material that has the following basic formulation:

[0145] 55 wt% PLA

[0146] 10 wt.% PBAT as plasticizer

[0147] 7 wt.% epoxidized plant c as plasticizer

[0148] 2 wt.% ethylene-bis-stearam ide as lubricant

[0149] 2 wt.% PE wax as wax

[0150] 2.5 wt% MAH grafted PLA as adhesion promoter

[0151] 20 wt.% wood flour as inorganic filler as

[0152] Shaft filler

[0153] 0.1 wt.% iron oxide pigment as colorant

[0154] 1.4% by weight TiO2 as colorant

[0155] For foaming, add:

[0156] 4 wt.% polymer compound, containing as reactive components

[0157] Sodium bicarbonate / citric acid as carbonate-based foaming additives

[0158] Example 4 shows a significantly more highly filled shaft with high porosity.

[0159] Example 5: Cosmetic pencil or barrel with barrel base material that has the following basic formulation as a PLA blend with PE:

[0160] 45 wt% PLA

[0161] 15 wt.% PE as additional polymer

[0162] 20 wt.% PBAT as plasticizer

[0163] 4 wt.% epoxidized vegetable oil as plasticizer

[0164] 2 wt.% ATBC as plasticizer

[0165] 2 wt.% ethylene-bis-stearam ide as lubricant

[0166] 1 wt.% calcium stearate as wax

[0167] 10 wt.% chalk as inorganic filler as shaft filler

[0168] 1 wt.% carbon black as colorant

[0169] For foaming, add:

[0170] 4.5 wt.% polymeric compound containing as reactive components sodium bicarbonate / citric acid as carbonate-based foaming additives

[0171] Example 5 represents a black colored and sharpenable cosmetic pencil with high polymer plasticization.

[0172] While Figure 1 shows a pen 1 with a PLA-based shaft 3 and a conventional lead 2, with the adhesion promoter layer 7 arranged between the lead 2 and the shaft 3, Figure 2 shows a modified embodiment.

[0173] In the embodiment in Figure 2, the lead 2 is also made on the basis of PLA, wherein it has a lead base material which contains at least 10% PLA.

[0174] Example compositions are shown below:

[0175] Example 1 : Pencil lead

[0176] 10 to 60 wt.% polylactide

[0177] 2 to 25 wt% wax

[0178] 0 to 5% by weight palm oil

[0179] Graphite residue

[0180] As shown in the examples, graphite is used as a colorant for pencil leads. However, a combination of graphite and carbon black can also be used.

[0181] A composition for a colored pencil lead includes:

[0182] 10 to 60 wt% polylactide 2 to 25 wt% wax

[0183] 1 to 30 wt% colorant

[0184] Rest fillers

[0185] Colored and / or achromatic pigments can be used as colorants in colored leads. Examples of such pigments include azo pigments, phthalocyanines, dioxazines, quinacridones, iron oxides, carbon black, graphite, ultramarine, and iron cyanide complexes.

[0186] In the embodiment in Figure 2, the adhesion promoter layer 7 can advantageously be dispensed with, since both base materials are PLA-based and, due to the similar components, can bond excellently in a material-locking and / or form-locking manner without the adhesion promoter layer 7.

[0187] In the pen 1 shown in Figure 1, at least the shaft 2 is compostable. Even though the other components may be more difficult to compost, this embodiment represents a major step toward a sustainable alternative for the pen 1. In the embodiment shown in Figure 2, both the shaft 2 and the refill 3 are compostable, making this pen 1 a sustainable alternative.

[0188] Figure 3 schematically shows a shaft 3 made of the shaft base material with a cavity 9. A replaceable, movable refill can be inserted into the cavity. The refill can preferably move within the cavity, as in a ballpoint pen, for example. The shaft 3 can represent a section. Additional functional ends for limiting the movement of the refill, such as a tip or a print head, can be mounted at the ends of the shaft 3. The shaft 3 can, for example, be formed as part of a shaft 3 of a writing pen, crayon, ballpoint pen, cosmetic pencil, pencil, push-pull pen, or the like. Alternatively or additionally, a decorative layer 8 can be arranged on the outer circumference of the shaft 3. List of Reference Symbols

[0189] 1 pen

[0190] 2 Mine 3 Shaft

[0191] 4 pointed cone

[0192] 5 Shank taper section

[0193] 6 Lead cone section

[0194] 7 Adhesion promoter layer 8 Decorative layer

[0195] 9 Cavity

Claims

Patent claims:

1. Pen (1) with a shaft (3), wherein the shaft (3) has a shaft base material with a basic formulation, wherein the basic formulation 50 to 80 wt.% PLA, PLA copolymer and / or PLA blend 20 to 50 wt.% of further 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 has pores.

2. Pin (1) according to claim 1, characterized in that a manufacturing mixture is used to produce the shaft base material, wherein the manufacturing mixture 90 to 99 wt.% base mixture with the basic recipe, 1 to 10 wt.% foaming additives.

3. Stick (1) according to one of claims 1 to 2, characterized in that the basic formulation comprises the following proportions of the components: 50 to 80 wt.% PLA, PLA copolymer and / or PLA blend 0 to 10 wt.% polybutylene succinate (PBS) 0 to 25 wt.% other polymers, except PBS 0 to 25 wt.% plasticizer 0 to 10 wt.% waxes / lubricants 0 to 10 wt.% other additives such as adhesion promoters, stabilizers, etc. 0 to 10 wt% colorants, especially pigments 0 to 40 wt.% organic and / or inorganic fillers as Shaft fillers.

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

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

6. Pen (1) according to one of the preceding claims, characterized in that the shaft filler comprises an inorganic filler component, wherein the inorganic filler component is preferably formed from the group comprising layered silicates, in particular soapstone, clay, kaolin, talc and / or chalk, graphite, boron nitride.

7. Pen (1) according to one of the preceding claims, characterized in that the pen has a lead, wherein the lead is arranged in the pen and / or shaft in a displacement-proof manner. 8 Pen (1) according to claim 7, characterized in that an adhesion promoter layer (7) is arranged between the lead (2) and the shaft (3).

9. Pen (1) according to one of the preceding claims 7 or 8, characterized in that the lead (2) has a lead base material, wherein the lead base material has at least one binder with 10 - 40 wt.% PLA.

10. Pen (1) according to claim 9, characterized in that the shaft base material and the lead base material are directly connected to one another without a separate adhesion promoter layer.

11. Pen (1) according to one of the preceding claims, characterized in that it is designed as a writing and / or painting pen and / or as a cosmetic pen.

12. Shaft (3) for writing instruments, painting instruments, drawing instruments and / or cosmetic pencils, wherein the shaft (3) comprises a shaft base material with a basic formulation, wherein the basic formulation 50 to 80 wt.% PLA, PLA copolymer and / or PLA blend 20 to 50 wt.% of further 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 has pores.

13. A method for producing the pin (1) according to one of claims 1 to 11 and / or the shaft according to claim 12, characterized in that a base mixture with the base recipe and the foaming additives for producing the foamed shaft material are mixed and thermally treated, wherein the base recipe 50 to 80 wt.% PLA, PLA copolymer and / or PLA blend 20 to 50 wt.% 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.

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