Writing instruments including PLA / PBS barrel base material

Abstract

A writing instrument (1) comprising a core (2) and a shaft (3), wherein the core (2) is arranged so as to be difficult to be displaced within the shaft (3), the shaft (3) has a shaft base material, and the shaft base material comprises the following components: 60 to 75% by weight of a filler, 15 to 30% by weight of a binder mixture, the binder mixture comprising PLA and a second binder selected from the group consisting of PBS, a copolymer of PBS, particularly PBSA, 0.2 to 6% by weight of other additives such as an adhesion promoter, a stabilizer, 1 to 10% by weight of a wax, 0 to 4% by weight of a colorant, particularly a pigment, the writing instrument (1).

Description

Technical Field

[0001] The present invention relates to a writing instrument having the features of the superordinate concept of claim 1.

[0002] Writing instruments having a wooden shaft have been known for a long time. The price of wood has risen in the past, which has increased the manufacturing cost. Therefore, a manufacturing method of coating the core with a polymer by extrusion molding has been developed. As the base polymer of the shaft material, for example, polystyrene (PS) is used. Polystyrene has the advantages of being easily available, easy to process, and having good mechanical properties of the obtained shaft. Polystyrene has the disadvantage of not being biodegradable.

[0003] From such a background, in German Patent Invention No. 102008034013, it has been proposed to use a wood substitute for the shaft of a writing instrument, and this wood substitute is based on a polymer binder.

[0004] Such a writing instrument by extrusion molding is also known, for example, from European Patent No. 0505262, which is the closest prior art. The writing instrument described in this document consists of a foamed polystyrene sheath and a flexible polystyrene bonded core.

[0005] The object of the present invention is to propose a writing instrument that is a sustainable alternative to the prior art, and at the same time, it is required that the use characteristics of the writing instrument, particularly the shaving property and bending strength, be maintained. The above object is solved by a writing instrument having the features of claim 1. The preferred or advantageous embodiments of the present invention are apparent from the dependent claims, the following description, and the attached drawings.

[0006] The subject of the present invention is a writing instrument having a core and a barrel, wherein the barrel preferably concentrically and / or coaxially surrounds the core, and the core is positioned to be unlikely to and / or not likely to be misaligned with the barrel. In particular, the core is permanently fixed within the barrel so as not to be removable and / or cannot be removed without destruction. For example, the core is coupled to the barrel by material connection, friction connection and / or shape connection, optionally via an intermediate layer. The barrel is positioned around the core. The barrel serves to support and protect the core and has a larger diameter than the core. This allows the user to grip the barrel with their fingers and operate the writing instrument well. The barrel has a material referred to as the barrel base material. Further layers, such as a decorative layer, may be disposed on the barrel base material.

[0007] The writing instrument is formed in particular as a right-circular cylinder, and the base or cross-section of the cylinder may be formed in the shape of, for example, a circle, an ellipse, a triangle, a square, a pentagon, a hexagon, or a polygon. The writing instrument may also have a twisted or curved shape.

[0008] Writing instruments are specifically designed to be sharpenable. For example, a writing instrument can be sharpened with a writing instrument sharpener, such as a colored writing instrument sharpener, pencil sharpener, sharpener, or cosmetic pencil sharpener, in which case a new conical tip of the writing instrument can be created or shaped by cutting and removing material from the barrel and lead. A writing instrument is described as "sharpenable" if a person can apply moderate force by hand to cut and remove material from the writing instrument with a blade inside the housing, thereby creating a conical tip.

[0009] The shaft has a shaft base material, and the shaft preferably consists of at least 60% by weight, advantageously at least 80% by weight, particularly at least 98% by weight, or even more than 100% by weight of the shaft base material. Alternatively, the cross-section of the shaft preferably has the shaft base material covering at least 80% of the cross-section, advantageously at least 90% of the cross-section, particularly at least 98% of the cross-section, or even more than 100% of the cross-section.

[0010] In particular, the shaft has a shaft body made of a shaft base material. The shaft body has a ring-shaped cross-section, for example, an annular shape. In particular, the inner contour is formed to be circular, and / or the outer contour may be arbitrarily formed to be, for example, circular, elliptical, triangular, quadrilateral, pentagonal, hexagonal, or polygonal.

[0011] In this invention, it is proposed that the shaft base material contains the following components relative to the shaft base material, particularly in relation to the total weight of the shaft base material: The shaft base material has the following components: 60-75% by weight of filler, A binder mixture comprising 15-30% by weight, wherein the binder mixture comprises PLA and a second binder selected from the group consisting of PBS, PBS copolymers, and especially PBSA, 0.2-6% by weight of other additives, e.g., adhesion promoters, stabilizers, 1-10% by weight of wax, A coloring agent in an amount of 0-4% by weight, particularly a coloring agent as a pigment.

[0012] In particular, the shaft substrate has a filler content exceeding 60% by weight, which is considered a high proportion. The shaft substrate may also have a mixture of multiple fillers. The shaft substrate has 60-75% by weight of a single filler or a mixture of fillers. These can be selected from biodegradable materials. Furthermore, since the use of binders is reduced by the filler content, costs can be reduced depending on the filler content.

[0013] In particular, the shaft base material does not contain any chemical additives that release gas through thermal decomposition, nor does the molten material physically foam due to gas introduction during extrusion molding. Preferably, the shaft base material is not foamed. However, at the processing temperature used, the formation of very small bubbles within the shaft base material due to the volatile components of each starting material cannot be completely eliminated.

[0014] In particular, the filler material has the advantage that, because the shaft is not flexible, a hard and brittle high-quality core is supported by the shaft base material in a way that prevents breakage.

[0015] Furthermore, the axial substrate has a binder mixture consisting of PLA and at least one second binder. PLA also includes PLA blends or PLA compounds in particular. PLA is an abbreviation for polylactic acid, which can be specifically called polylactide and / or polylactic acid. In particular, PLA is also registered with the Chemical Abstracts Service under the name CAS number 9051-89-2. Depending on the number of monomers in the polymer, the properties of PLA as a polymer may vary somewhat.

[0016] PLA is a thermoplastic resin. PLA has the advantage of being bio-based, which significantly reduces or completely eliminates the use of petroleum-based raw materials in writing instruments. PLA is obtained, for example, from corn and belongs to the polyester group as a synthetic polymer. Therefore, pure PLA is preferably produced from renewable raw materials and is not based on fossil raw materials such as petroleum.

[0017] Furthermore, PLA is compostable, and in industrial composting plants in particular, it can be broken down into harmless final products within a manageable period, for example, within 12 weeks. This is done in accordance with standards EN 14995 or EN 13432, although other similar standards may specify different conditions and periods. Composting and decomposition of PLA requires industrial composting conditions, namely controlled temperature and humidity conditions in the presence of microorganisms. For example, in this case, the temperature must be 55-70°C. Industrial composting allows for the decomposition of standard-compliant writing instrument barrels into harmless final products, which can be described as biodegradable.

[0018] The PLA-based binder mixture has at least one second binder as a second component, which is selected from the group consisting of PBS, copolymers of PBS, and especially PBSA. Here, PBS is the name for polybutylene succinate (e.g., CAS: 25777-14-4). Here, PBSA is the name for poly(butylene succinate-co-butylene adipate) (e.g., CAS: 67423-06-7). Depending on the number of monomers in the polymer, the properties of the polymer may differ somewhat. PBS and PBSA are more biodegradable than PLA. Both exhibit thermoplasticity. The starting materials for polymerization can be prepared from glucose or fructose. In this way, PBS and PBSA can be prepared on a bio-based basis.

[0019] Furthermore, the shaft substrate may contain other additives. Such additives include adhesion promoters and stabilizers. Adhesion promoters are preferably used to enhance the adhesion between the filler and the binder mixture. Adhesion promoters can also be used to enhance the adhesion of the core within the shaft substrate. An example of an adhesion promoter is a maleic anhydride grafted polymer selected from the group of polyesters, including PLA, PBS, and PBSA.

[0020] Stabilizers are added to reduce the aging process of polymers. For example, aging is caused by the effects of heat, light, ozone, and oxygen, which is visible in the degradation of properties, such as changes in color.

[0021] Furthermore, the barrel base material has at least one wax. The barrel base material may also have a mixture of multiple waxes. The barrel base material has 1 to 10% by weight of a single wax or a mixture of waxes. In particular, the wax helps to adjust the extrudeability, for example, by improving the flow behavior and / or adjusting the machinability. In particular, easier material removal from the barrel and core can be achieved, thereby producing a conical tip for the writing instrument. The wax can act as an aid in extrusion molding (improving flow properties, reducing wall adhesion of molten material to machine parts and / or tool parts), but it can also have a favorable effect on the material structure for machining. This is especially important when the user manually grinds the writing instrument using a grinding machine.

[0022] In particular, at least one wax has a melting point such that it exists as a liquid in the extruder and can affect the flow behavior of the molten material and / or heated shaft substrate.

[0023] Furthermore, the shaft substrate preferably contains a colorant. These are used in particular to lighten the color tone of the shaft substrate. To lighten the color tone, it has been found to be advantageous to use a white pigment, for example, titanium dioxide (TiO2).

[0024] The proposed barrel base material composition enables the manufacture of barrels possessing the necessary properties for writing instruments, such as machinability, grip, and mechanical, thermal, and chemical stability. Therefore, the binder mixture serves as a sustainable alternative to the base polymers that have been used to manufacture writing instrument barrels.

[0025] When binder mixtures are selected, a particular advantage is that their original properties, such as machinability, tensile strength, and tactile feel, do not deteriorate compared to prior art polymers, especially when compared to other plastics. Therefore, binder mixtures represent a valuable sustainable alternative to conventionally known polymers.

[0026] In a preferred embodiment of the filler, the filler is selected from the group including wood powder, wood fiber and / or cellulose. One form of wood powder is called lignocellulose. Lignocellulose has the lignin of wood in cellulose. Lignocellulose can be produced from wood by mechanical grinding, especially as wood pulp, pressure groundwood pulp, wood chips, etc. These fillers are bio-based and / or biodegradable and are available at low cost. In particular, the filler can contain additional substances in addition to wood powder, wood fiber and / or cellulose.

[0027] In a further embodiment, the shaft base material has a mixture of fillers. In particular, mixtures of organic fillers with additional organic and / or inorganic substances such as talc, chalk, kaolin, etc. can be mentioned.

[0028] In one embodiment, the filler is at least mostly or completely organic. For example, in order for the filler to be expressed as completely organic, it can consist entirely of wood powder, wood fiber, cellulose and mixtures thereof.

[0029] In a further embodiment, in addition to organic fillers such as wood powder, wood fiber and / or cellulose, additional inorganic fillers can be present as a mixture with the organic fillers. The inorganic filler is present in the mixture of fillers in a range of more than 0% by weight to 10% by weight based on the weight of the filler. The organic filler is present in the mixture of fillers in a large proportion of 90% by weight or more based on the weight of the filler. Thus, the filler is generally organic.

[0030] In a further embodiment, the shaft base material contains the filler in a content range of 60 to 75% by weight, preferably 68 to 73% by weight, based on the shaft base material. This enables a high filler ratio.

[0031] In the first possible alternative form, the binder mixture comprises PLA, a second binder, and a further binder. In the second possible alternative form, the binder mixture consists of PLA and the second binder, or substantially consists of these.

[0032] In a further embodiment, the binder mixture is selected in the range of 17–27% by weight, preferably 19–23% by weight, relative to the axial substrate. The proportion of the binder is selected in particular so that a suitable flexural strength and modulus is achieved to support a hard and brittle but high-quality core within the axial substrate in a state that withstands breakage. This has the advantage that the axial substrate is optimized with respect to its mechanical properties.

[0033] In one preferred development, the binder mixture has only a second binder in addition to PLA. Alternatively, the binder mixture consists of PLA and a second binder, or the binder mixture consists substantially of PLA and a second binder. The PLA is present in a weight ratio of 10:1 to 1:10 relative to the second binder.

[0034] This has the advantage that the properties of the PLA-containing compound can be modified by a second binder in the binder mixture. For example, by adding PBS or PBSA, biodegradability can be increased. Mechanical and / or elastic properties can be optimized. Raw material costs can be optimized.

[0035] In one preferred development, the other additives include an adhesion promoter, which improves the adhesion between the filler and the binder mixture.

[0036] In one preferred development, the adhesion promoter includes an MAH-grafted polymer selected from the group of polyesters, particularly PLA, PBS, PBSA, and mixtures thereof. Here, MAH is an abbreviation for maleic anhydride, and also specifically refers to maleic anhydride (CAS: 108-31-6). MAH-grafted PLA can be specifically referred to as maleic anhydride-grafted polylactic acid and / or maleic anhydride-grafted polylactic acid.

[0037] MAH-grafted PBS can be specifically referred to as maleic anhydride-grafted polybutylene succinate. MAH-grafted PBSA can be specifically referred to as maleic anhydride-grafted poly(butylene succinate-co-butylene adipate). In one embodiment, the adhesion promoter includes a mixture of MAH-grafted PLA, MAH-grafted PBS, and MAH-grafted PBSA. This mixture of MAH-grafted PLA, MAH-grafted PBS, and MAH-grafted PBSA can exist in different ratios. The presence of MAH in the adhesion promoter allows the promoter to react with the filler, on the one hand, via esterification of OH groups, and on the other hand, to integrate unimpeded into the primary matrix of the polymer via a similar base polymer.

[0038] In one preferred development, the axial substrate contains an adhesion promoter in an amount of 0.2 to 6% by weight, preferably 1 to 3% by weight, relative to the total weight of the axial substrate. The exact content of the adhesion promoter is determined by various factors, particularly the degree of grafting with the MAH and the steric accessibility of the functional groups.

[0039] In a further embodiment, at least one wax is suitable for adjusting the extrudeability and / or machinability of the shaft substrate.

[0040] In one preferred embodiment, at least one wax is selected from the group comprising stearic acid wax and stearic acid derivatives; palmitic acid wax and palmitic acid derivatives; silicone wax; EBS; polyolefin wax, e.g., oxidized, non-oxidized polyethylene wax and / or oxidized, non-oxidized polypropylene wax; and mixtures thereof. Distearyl ethylenediamide is specifically known as ethylenebis(stearoamide) and / or EBS (CAS: 110-30-5).

[0041] If the properties of a single wax do not ensure a satisfactory operating point with respect to the extrudeability and machinability of the axial substrate, a mixture of several different waxes is preferably used.

[0042] Preferably, such a first high-melting-point wax, which improves extrudeability, is blended with at least one additional wax, such as a relatively low-melting-point wax, which improves machinability.

[0043] The first wax has a melting point, for example, above 100°C. This improves the flow behavior of the molten material, allowing the heated shaft substrate to flow more smoothly out of the extruder. The first wax is selected from the group including EBS, polyolefin waxes, such as oxidized and non-oxidized polyethylene waxes and / or oxidized and non-oxidized polypropylene waxes, and mixtures thereof.

[0044] The additional wax has a melting point below 100°C, for example. This has the advantage of making the pencil sharpening process easier. The additional wax is selected from the group that includes stearic acid wax and stearic acid derivatives; palmitic acid wax and palmitic acid derivatives; silicone wax and mixtures thereof.

[0045] The proportion of wax is preferably in the range of 1 to 10% by weight, more preferably in the range of 2 to 6% by weight, relative to the total weight of the shaft substrate. The wax can exist as a mixture of at least two types of wax. In particular, in the case of a mixture of a first wax and an additional wax, each of these waxes is present in the range of 1 to 5% by weight, more preferably in the range of 2 to 4% by weight, relative to the total weight of the shaft substrate.

[0046] In a further embodiment, the colorant is in the range of 0 to 3% by weight, preferably 0 to 2% by weight. The colorant has the function of brightening the relatively dark base color of the polymer-filler mixture and giving it a uniform and natural hue. By changing the content, natural variations in the filler can also be further compensated for.

[0047] In a preferred evolution of the present invention, the core is manufactured on a PLA 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, the disclosures of which are incorporated herein by reference.

[0048] In particular, the core has a core base material, and 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.

[0049] The proportion of polylactic acid in the core material 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.

[0050] The core material is as follows: 10-60% by weight of polylactic acid, 2-25% by weight of wax, 15-70% by weight of filler, especially core filler, 0-5% by weight of palm oil, 0-30% by weight of coloring agent It was found to be advantageous when one possesses [the necessary trait].

[0051] In a preferred evolution 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 by material bonding. By selecting PLA for the two substrates, these similar polymers can be bonded to each other without further measures, and thus, an intermediate layer can be advantageously omitted. Thus, by selecting similar substrates, an adhesion promoter layer can be omitted, and a stable composite material can be constructed.

[0052] In particular, the organic components of the core are either similarly decomposable under the boundary conditions of industrial biological composting of PLA, or are bio-based as already mentioned above.

[0053] In a further embodiment, the writing instrument is formed to be used as a writing instrument and / or a drawing instrument and / or a cosmetic pencil.

[0054] Further features, advantages, and effects of the present invention will become apparent from the following description of preferred embodiments of the present invention and from the accompanying drawings. [Brief explanation of the drawing]

[0055] [Figure 1] This is a schematic diagram of a writing instrument with sharpening properties.

[0056] Figure 1 shows a very schematic block diagram of a writing instrument 1, which comprises a lead 2 and a shaft 3 made of a shaft base material. The writing instrument 1 is sharpenable and has a conical region 4 in the shaft 3 and lead 2 that is created by a sharpening machine. As a result, the lead 2 is exposed. The lead 2 is positioned within the shaft 3 to prevent displacement. This prevents the lead 2 from slipping. Therefore, even if some pressure is applied to the writing instrument 1 during writing, the lead 2 will not shift position within the shaft 3. The shaft 3 has a material called the shaft base material. Further layers, such as a decorative layer, may be placed on the shaft base material.

[0057] The shaft base material has the following components: 60-75% by weight of filler, A binder mixture comprising 15-30% by weight, wherein the binder mixture comprises PLA and a second binder selected from the group consisting of PBS, PBS copolymers, and especially PBSA, 0.2-6% by weight of other additives, e.g., adhesion promoters, stabilizers, 1-10% by weight of wax, A coloring agent in an amount of 0-4% by weight, particularly a coloring agent as a pigment.

[0058] An exemplary shaft substrate is shown below.

[0059] The manufacturing of the shaft according to the present invention is preferably carried out at about 150-200°C, after mixing and granulating the components of the shaft base material by extrusion molding or co-extrusion molding as a coating for the provided core.

[0060] The cross-sectional shape is set by the extrusion head. After cooling, the rod-shaped writing instrument is cut to a predetermined length.

[0061] Advantageously, wood flour, wood fibers, and / or cellulose exist as particles. The particles preferably have an average particle size that can be expressed as d50 in μm units. The notation d50 = 150 μm means that 50% of the particles are smaller than 150 μm and 50% are larger. The particle size distribution can be determined, for example, using a laser granulometer.

[0062] Example 1: A drawing pen with a barrel base material has the following components: 73% by weight of wood powder (d50 approximately 100 μm) as a filler. 10% by weight of PLA (polylactic acid) in the binder mixture 10% by weight of PBS (polybutylene succinate) in the binder mixture 1% by weight of other additives, particularly MAH-grafted PLA (maleic anhydride-grafted polylactic acid, maleic anhydride-grafted polylactic acid) as an adhesion promoter. 3% by weight of stearic acid derivative wax in the waxing agent 2% by weight of EBS (distearyl ethylenediamide) in the wax 1% by weight of titanium dioxide as a coloring agent, especially as a pigment.

[0063] The advantage lies in the high proportion of filler material, which allows for the manufacture of writing instrument barrels that are generally biodegradable.

[0064] Example 2: A writing instrument with a shaft base material has the following components: 61.5% by weight of wood powder (d50 approximately 35 μm) as a filler. 10% by weight of PLA (polylactic acid) in the binder mixture 20% by weight of PBS (polybutylene succinate) in the binder mixture 1.5% by weight of other additives, particularly MAH-grafted PBS (maleic anhydride-grafted polybutylene succinate) as an adhesion promoter. 1.5% by weight of stearic acid derivative wax in the waxing agent. 3.5% by weight of EBS (distearyl ethylenediamide) in the waxing agent 2% by weight of titanium dioxide as a coloring agent, especially as a pigment.

[0065] The advantage lies in the high proportion of filler combined with a biodegradable binder, which in turn allows for the manufacture of writing instrument barrels that are largely biodegradable.

[0066] Example 3: A writing instrument with a shaft base material has the following components: 60.5% by weight of wood powder (d50 approximately 70 μm) as a filler. 25% by weight of PLA (polylactic acid) in the binder mixture 5% by weight of PBS (polybutylene succinate) in the binder mixture 6% by weight of other additives, particularly MAH-grafted PLA (maleic anhydride-grafted polylactic acid, maleic anhydride-grafted polylactic acid) as adhesion promoters. 1% by weight of stearic acid derivative wax in the waxing agent 1.5% by weight of EBS (distearyl ethylenediamide) in the waxing agent 1% by weight of titanium dioxide as a coloring agent, especially as a pigment.

[0067] The advantage lies in the high proportion of filler combined with a biodegradable binder, which allows for the manufacture of writing instrument barrels that are largely biodegradable. Adhesion promoters enable even greater stability.

[0068] Example 4: A writing instrument with a shaft base material has the following components: 71.5% by weight of cellulose as a filler. 2% by weight of PLA (polylactic acid) in the binder mixture 20% by weight of PBSA (poly(butylene succinate-co-butylene adipate)) in the binder mixture 2% by weight of other additives, in particular MAH-grafted PBSA (maleic anhydride-grafted poly(butylene succinate-co-butylene adipate)) as an adhesion promoter. 2% by weight of stearic acid derivative wax in the waxing agent 2% by weight of EBS (distearyl ethylenediamide) in the wax 0.5% by weight of titanium dioxide as a coloring agent, especially as a pigment.

[0069] Example 5 A black cosmetic pencil with a shaft base material has the following components: 69% by weight of wood powder (d50 100μm) as a filler. 10% by weight of PLA (polylactic acid) in the binder mixture 15% by weight of PBS (polybutylene succinate) in the binder mixture A mixture of 1.5% by weight of other additives, particularly as an adhesion promoter, consisting of MAH-grafted PLA (maleic anhydride-grafted polylactic acid, maleic anhydride-grafted polylactic acid):MAH-grafted PBS (maleic anhydride-grafted polybutylene succinate) = 1:1. 1% by weight of stearic acid derivative wax in the waxing agent 2.5% by weight of EBS (distearyl ethylenediamide) in the waxing agent 1% by weight of carbon black as a coloring agent, especially as a pigment.

[0070] Example 6: A writing instrument with a shaft base material has the following components: 66% by weight of cellulose as a filler. 8% by weight of PLA (polylactic acid) in the binder mixture 15% by weight of PBSA (poly(butylene succinate-co-butylene adipate)) in the binder mixture 5% by weight of other additives, in particular MAH-grafted PBSA (maleic anhydride-grafted poly(butylene succinate-co-butylene adipate)) as an adhesion promoter. 3% by weight of stearic acid derivative wax in the waxing agent 2% by weight of EBS (distearyl ethylenediamide) in the wax 1% by weight of titanium dioxide as a coloring agent, especially as a pigment.

[0071] These examples demonstrate that it is possible to manufacture shaft substrates containing a high proportion of biodegradable fillers. Furthermore, a bio-based compostable binder is used.

[0072] Writing instruments using any of the aforementioned examples as the barrel material are offered in product lines such as writing instruments, drawing instruments, and cosmetic pencils. [Explanation of Symbols]

[0073] 1 writing implements 2 cores 3 axes 4. Conical Region

Claims

1. A writing instrument (1) comprising a lead (2) and a barrel (3), In a writing instrument (1), the lead (2) is positioned within the shaft (3) in such a way that it is less likely to shift position. The shaft (3) has a shaft base material, and the shaft base material has the following components: 60-75% by weight of filler, A binder mixture comprising 15 to 30% by weight, wherein the binder mixture comprises PLA and a second binder selected from the group consisting of PBS and PBSA. 0.2 to 6% by weight of other additives, 1-10% by weight of wax, 0-4% by weight of coloring agent Includes, The filler is selected from the group consisting of wood powder, wood fibers and / or cellulose. In the binder mixture, the PLA is present in a weight ratio of 10:1 to 1:10 relative to the second binder, and A writing instrument (1) characterized in that the wax comprises a first high-melting-point wax and an additional wax having a lower melting point, wherein the additional wax has a melting point below 100°C.

2. The writing instrument (1) according to claim 1, characterized in that the shaft base material is not foamed.

3. The writing instrument (1) according to claim 1 or 2, characterized in that the filler is at least largely or entirely organic.

4. The writing instrument (1) according to claim 1, characterized in that the shaft base material contains 65 to 74% by weight of filler.

5. The writing instrument (1) according to claim 1, characterized in that the binder mixture is selected in an amount of 15 to 25% by weight of the shaft base material.

6. The writing instrument (1) according to claim 1, characterized in that the other additive comprises at least one adhesion promoter, the adhesion promoter being formed as an MAH grafted polymer.

7. The writing instrument (1) according to claim 6, characterized in that the at least one adhesion promoter is selected from the group comprising MAH-grafted PLA, MAH-grafted PBS, MAH-grafted PBSA, and mixtures thereof.

8. The writing instrument (1) according to claim 6 or 7, characterized in that the shaft base material contains at least one adhesion promoter in an amount ranging from 0.2 to 6% by weight relative to the shaft base material.

9. The writing instrument (1) according to claim 1, characterized in that the shaft base material contains 2 to 6% by weight of wax.

10. The writing instrument (1) according to claim 1, characterized in that, in the case of a mixture of the first wax and the additional wax, each of the waxes is present in an amount of 1 to 5% by weight relative to the shaft base material.

11. The writing instrument (1) according to claim 1, characterized in that the shaft base material contains the coloring agent in an amount of 0 to 3% by weight relative to the shaft base material.

12. The writing instrument (1) according to claim 1, characterized in that the writing instrument (1) is formed as a writing instrument for writing and / or drawing and / or a cosmetic pencil.

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