Writing instrument containing a PLA / PBS shaft substrate

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 characteristics 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, thereby increasing 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 resulting shaft. Polystyrene has the disadvantage of not being biodegradable.

[0003] Against this background, German Patent Invention No. 102008034013 proposes using 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 from, for example, 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 usage characteristics of the writing instrument, especially the shaving property and bending strength, be maintained. The above object is solved by a writing instrument having the characteristics of claim 1. The preferred or advantageous embodiments of the present invention are apparent from the dependent claims, the following description, and the accompanying drawings.

[0006] The subject of the present invention is a writing instrument, which has a core and a shaft, the shaft preferably surrounding the core concentrically and / or coaxially, and the core is arranged so as to be difficult to be displaced relative to the shaft and / or not to be displaced. In particular, the core is permanently fixed in the shaft so as not to be removable and / or cannot be removed without being destroyed. For example, the core is connected to the shaft by material connection, friction connection and / or shape connection via an intermediate layer if necessary. The shaft is arranged around the core. The shaft serves to support and protect the core and has a larger diameter than the core. Thereby, the shaft can be grasped with fingers and the writing instrument can be operated well. The shaft has a material called a shaft base material. A further layer, such as a decorative layer, may be arranged on the shaft base material.

[0007] The writing instrument is particularly formed as a straight cylinder, and the bottom surface or cross-section of the cylinder may be formed, for example, in a circular, elliptical, triangular, quadrangular, pentagonal, hexagonal or polygonal shape. Also, the writing instrument can have a twisted or bent shape.

[0008] The writing instrument is particularly formed so as to have a sharpening property. For example, the writing instrument can be sharpened with a writing instrument sharpener, such as a colored writing instrument sharpener, a pencil sharpener, a sharpener or a cosmetic pencil sharpener. At this time, a conical tip of the writing instrument can be newly generated or processed by cutting and removing material from the shaft and the core. When a person can apply an appropriate force by hand to cut and remove the material of the writing instrument with a blade in the housing, thereby generating a conical tip, the writing instrument is said to "have a sharpening property".

[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 100% by weight of the shaft base material. Alternatively or in addition thereto, the cross-section of the shaft has the shaft base material, preferably 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 100% of the cross-section.

[0010] In particular, the shaft has a shaft body composed 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 in a circular shape, and / or the outer contour may be arbitrarily formed, for example, in a circular, elliptical, triangular, quadrangular, pentagonal, hexagonal or polygonal shape.

[0011] In the present invention, it is proposed that the shaft base material contains the following components with respect to the shaft base material, particularly with respect to the total weight of the shaft base material: The shaft base material has the following components: 60 to 75% by weight of a filler, 15 to 30% by weight of a binder mixture, the binder mixture containing 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 colorant as a pigment.

[0012] In particular, the shaft base material has a proportion of filler exceeding 60% by weight, which corresponds to a high proportion. The shaft base material can also have a mixture of a plurality of fillers. The shaft base material has 60 to 75% by weight of a single filler or a mixture of fillers. These can be selected from biodegradable materials. Furthermore, since the use of the binder is reduced by the filler, the cost can be reduced by the proportion of the filler.

[0013] In particular, the shaft base material does not contain an additive material of a chemical additive that releases gas by thermal decomposition, and the melt does not physically foam by gas introduction during extrusion molding. The shaft base material is preferably not foamed. However, at the processing temperature used, slight bubble formation in the shaft base material due to the volatile components of each starting material is not excluded.

[0014] In particular, in the filler portion, since the shaft is not flexible, there is also an advantage that a hard and brittle high-quality core is supported by the shaft base material in a state resistant to breakage.

[0015] Furthermore, the shaft substrate has a binder mixture composed of PLA and at least one second binder. PLA includes, in particular, PLA blends or PLA compounds. PLA is an abbreviation for polylactic acid, which can also be referred to particularly as polylactide and / or polylactic acid. In particular, PLA is also registered with the Chemical Abstracts Service under the name with 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 that it can be produced from bio-based sources, which significantly reduces or completely prevents the use of petroleum-based raw materials in writing instruments. PLA is obtained, for example, from corn and belongs to the polyesters as synthetic polymers. Thus, 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 can decompose into harmless end products, particularly in industrial composting plants, within a manageable period, for example within 12 weeks. This is carried out particularly in accordance with the standards EN 14995 or EN 13432, but other similar standards can define other conditions and periods. The composting and decomposition of PLA require industrial composting conditions, i.e., the control of temperature and humidity conditions in the presence of microorganisms. For example, in this case, the temperature must be between 55 and 70 °C. Industrial composting can decompose the shaft of a writing instrument compliant with the standard into harmless end products, which can be represented as biodegradability.

[0018] The PLA-based binder mixture has at least one second binder as the second component, which is selected from the group consisting of PBS, copolymers of PBS, especially PBSA. Here, PBS is the name representing polybutylene succinate (e.g., CAS: 25777-14-4). Here, PBSA is the name representing 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 vary somewhat. PBS and PBSA are more biodegradable than PLA. Both show thermoplasticity in the same way. The starting materials for polymerization can be produced from glucose or fructose. In this way, PBS and PBSA can be produced in a bio-based manner.

[0019] Furthermore, the shaft substrate has other additives. The group of such additives includes adhesion promoters, stabilizers, etc. The adhesion promoter is preferably used to enhance the adhesion between the filler and the binder mixture. The adhesion promoter can also be used to enhance the adhesion of the core within the shaft substrate. An example of the adhesion promoter is a maleic anhydride-grafted polymer selected from the group of polyesters including PLA, PBS, PBSA, etc.

[0020] The stabilizer is added to reduce the aging process of the polymer. For example, the aging process is caused by the effects of heat, light, ozone, and oxygen, which is visually recognized as, for example, a change in color tone in the deterioration of properties.

[0021] Furthermore, the shaft substrate has at least one wax. The shaft substrate can also have a mixture of multiple waxes. The shaft substrate has 1 to 10% by weight of a single wax or a mixture of waxes. In particular, the wax helps in adjusting the extrusion formability, for example, improving the flow behavior and / or adjusting the machinability. In particular, easier material removal from the shaft and the core is achieved, thereby enabling the production of the conical tip of the writing instrument. The wax can serve as an extrusion aid (improving the flow characteristics, reducing the wall adhesion of the melt to the mechanical parts and / or tool parts), but can also have a favorable impact on the material structure regarding machining. This is particularly important during the process where the user manually sharpens the writing instrument using a sharpener.

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

[0023] Furthermore, the shaft substrate preferably has a colorant. These are particularly used to brighten the color tone of the shaft substrate. It has been found advantageous to use a white pigment consisting of, for example, titanium dioxide (TiO2) to brighten the color tone.

[0024] The proposed composition of the shaft substrate enables the production of a shaft with the necessary properties for a writing instrument, such as machinability, grip, mechanical, thermal, and chemical stability. Therefore, the binder mixture becomes a sustainable alternative to the base polymers that have been used for the production of writing instrument shafts so far.

[0025] When the binder mixture is selected, it has been found particularly advantageous that the original properties, such as machinability, breaking strength, touch feeling, etc., do not deteriorate compared to the polymers of the prior art, especially when compared to other plastics. Therefore, the binder mixture becomes a valuable sustainable alternative to the conventionally known polymers.

[0026] In a preferred embodiment of the filler, the filler is selected from the group including wood powder, wood fibers 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 fibers and / or cellulose.

[0027] In a further embodiment, the shaft substrate 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, for the filler to be expressed as completely organic, it can consist entirely of wood powder, wood fibers, cellulose and mixtures thereof.

[0029] In a further embodiment, in addition to organic fillers such as wood powder, wood fibers 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 the range of more than 0 wt% to 10 wt% based on the weight of the filler. The organic filler is present in the mixture of fillers in a large proportion of 90 wt% or more based on the weight of the filler. Thus, the filler is generally organic.

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

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

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

[0033] In a preferred further development, the binder mixture has only a second binder in addition to PLA. Alternatively or in addition thereto, the binder mixture consists of or consists essentially of PLA and a second binder. PLA is present in a weight ratio of 10:1 to 1:10 with respect to the second binder.

[0034] This has the advantage that the properties of the compound containing PLA can be changed by the second binder in the binder mixture. For example, by adding PBS or PBSA, biodegradability can be enhanced. Mechanical and / or elastic properties can be optimized. The raw material cost can be optimized.

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

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

[0037] MAH-grafted PBS can particularly be referred to as maleic anhydride-grafted polybutylene succinate. MAH-grafted PBSA can particularly be referred to as maleic anhydride-grafted poly(butylene succinate-co-butylene adipate). In one embodiment, the adhesion promoter contains 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 be present in different ratios. The presence of MAH in the adhesion promoter enables the adhesion promoter to react with the filler via esterification of the OH groups on the one hand and to be integrated into the polymer primary matrix without hindrance via a similar base polymer on the other hand.

[0038] In a preferred development form, the shaft substrate has the adhesion promoter in a content in the range of 0.2 to 6% by weight, preferably in the range of 1 to 3% by weight, based particularly on the total weight of the shaft substrate. The exact content of the adhesion promoter is determined by various factors, particularly the degree of grafting with MAH and the steric accessibility of the functional groups.

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

[0040] In a preferred embodiment, at least one wax is selected from the group consisting of stearic acid wax and stearic acid derivatives; palmitic acid wax and palmitic acid derivatives, silicone wax, EBS, polyolefin waxes such as oxidized and non-oxidized polyethylene waxes and / or oxidized and non-oxidized polypropylene waxes, and mixtures thereof. Distearylethylenediamide is in particular the name of ethylene bis(stearamide) and / or is known as EBS (CAS: 110-30-5).

[0041] If the properties of a single wax cannot ensure a satisfactory operating point with respect to the extrudability and machinability of the shaft substrate, preferably a mixture of a plurality of different waxes is used.

[0042] Preferably, such a first high melting point wax that improves extrudability is blended with at least one additional wax of such a relatively low melting point that improves machinability.

[0043] The first wax has a melting point, for example, exceeding 100 °C. This improves the flow behavior of the melt, and the heated shaft substrate flows out of the extruder better. The first wax is in particular selected from the group consisting of 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, for example, below 100 °C. This has the advantage that in this way the sharpening process of the pencil becomes easier. The additional wax is in particular selected from the group consisting of 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, preferably 2 to 6% by weight, based on the total weight of the shaft substrate. The wax can be present as a mixture of at least two types of waxes. 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, preferably 2 to 4% by weight, based on 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 lightening the relatively dark basic color of the polymer - filler mixture and providing a uniform and natural color tone. By changing the content, it is also possible to further compensate for the natural variations of the filler.

[0047] In a preferred development of the present invention, the core is manufactured based on PLA. 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 disclosure content of which is incorporated herein by reference ( "incorporated by reference").

[0048] In particular, the core has a core substrate, and the core substrate has the following components: 10 to 40% by weight of PLA, 30 to 80% by weight of core filler, 0 to 20% by weight of wax / lubricant, 0 to 10% by weight of additives, such as plasticizers, stabilizers, adhesion promoters.

[0049] The proportion of polylactic acid in the core substrate is in the range of 10 to 60% by weight, preferably 10 to 40% by weight, and particularly preferably 10 to 25% by weight.

[0050] The core substrate is as follows: 10 to 60% by weight of polylactic acid, 2 to 25% by weight of wax, 15 to 70% by weight of filler, particularly core filler, 0 to 5% by weight of palm oil, A colorant of 0 to 30% by weight has been found to be advantageous.

[0051] In a preferred development of the invention, the shaft substrate and the core substrate are directly joined to each other. In particular, they are joined to each other by a material connection. By selecting PLA for the two substrates, these similar polymers can adhere to each other without further measures, so that advantageously the intermediate layer can be omitted. In this way, the adhesion promoter layer can be omitted by the selection of similar substrates, and furthermore a stable composite material can be constructed.

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

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

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

Brief Description of the Drawings

[0055]

Figure 1

[0056] Figure 1 shows a very schematic block diagram of the writing instrument 1, which includes a refill 2 and a shaft 3 composed of a shaft base material. The writing instrument 1 has a sharpening property and has a conical region 4 generated by a sharpener in the shaft 3 and the refill 2. As a result, the refill 2 is exposed. The refill 2 is arranged in the shaft 3 so as not to be easily displaced. This prevents the refill 2 from slipping. Therefore, even if a slight pressure is applied to the writing instrument 1 during writing, the refill 2 does not shift within the shaft 3. The shaft 3 has a material called a shaft base material. A further layer such as a decorative layer may be arranged on the shaft base material.

[0057] The shaft base material has the following components: 60 to 75% by weight of a filler, 15 to 30% by weight of a binder mixture, where the binder mixture includes PLA and a second binder selected from the group consisting of PBS, a copolymer of PBS, and particularly PBSA, 0.2 to 6% by weight of other additives such as an adhesion promoter and a stabilizer, 1 to 10% by weight of wax, 0 to 4% by weight of a colorant, particularly a colorant as a pigment.

[0058] Exemplary shaft base materials are shown below.

[0059] The production of the shaft according to the present invention is preferably carried out at about 150 to 200 °C after mixing and granulating each component of the shaft base material by an extrusion molding method or a co-extrusion molding method as a coating for the provided refill.

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

[0061] Advantageously, the wood flour, wood fibers and / or cellulose are present as particles. The particles preferably have an average particle size that can be indicated as d50 in μm. 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 writing instrument with a shaft substrate has the following components: 73 wt% of wood flour (d50 about 100 μm) as a filler 10 wt% of PLA (polylactic acid) in a binder mixture 10 wt% of PBS (polybutylene succinate) in a binder mixture 1 wt% of other additives, in particular MAH-grafted PLA (maleic anhydride-grafted polylactic acid, maleic anhydride grafted polylactic acid) as an adhesion promoter 3 wt% of stearic acid derivative wax in a wax agent 2 wt% of EBS (distearyl ethylenediamide) in a wax agent 1 wt% of titanium dioxide as a colorant, in particular as a pigment.

[0063] The advantage is the high proportion of filler, and as a result, a shaft of the writing instrument that is generally biodegradable can be produced.

[0064] Example 2 A writing instrument with a shaft substrate has the following components: 61.5 wt% of wood flour (d50 about 35 μm) as a filler 10 wt% of PLA (polylactic acid) in a binder mixture 20 wt% of PBS (polybutylene succinate) in a binder mixture 1.5 wt% of other additives, in particular MAH-grafted PBS (maleic anhydride-grafted polybutylene succinate) as an adhesion promoter 1.5 wt% of stearic acid derivative wax in a wax agent 3.5 wt% of EBS (distearyl ethylene diamide) in the wax agent 2 wt% of titanium dioxide as a colorant, particularly as a pigment

[0065] The advantage is a high proportion of filler combined with a biodegradable binder, and as a result, a pen shaft that is generally biodegradable can be manufactured.

[0066] Example 3 The writing pen having a shaft substrate has the following components: 60.5 wt% of wood powder (d50 about 70 μm) as a filler 25 wt% of PLA (polylactic acid) in the binder mixture 5 wt% of PBS (polybutylene succinate) in the binder mixture 6 wt% of other additives, particularly MAH-grafted PLA (maleic anhydride-grafted polylactic acid, maleic anhydride grafted polylactic acid) as an adhesion promoter 1 wt% of stearic acid derivative wax in the wax agent 1.5 wt% of EBS (distearyl ethylene diamide) in the wax agent 1 wt% of titanium dioxide as a colorant, particularly as a pigment

[0067] The advantage is a high proportion of filler combined with a biodegradable binder, and as a result, a pen shaft that is generally biodegradable can be manufactured. The adhesion promoter enables better stability.

[0068] Example 4 The writing pen having a shaft substrate has the following components: 71.5 wt% of cellulose as a filler 2 wt% of PLA (polylactic acid) in the binder mixture 20 wt% 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 a wax agent 2% by weight of EBS (distearyl ethylenediamide) in a wax agent 0.5% by weight of titanium dioxide as a colorant, in particular as a pigment.

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

[0070] Example 6 A writing instrument with a shaft substrate has the following components: 66% by weight of cellulose as a filler 8% by weight of PLA (polylactic acid) in a binder mixture 15% by weight of PBSA (poly(butylene succinate-co-butylene adipate)) in a 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 a wax agent 2 wt% of EBS (distearylethylenediamide) in the wax agent 1 wt% of titanium dioxide as a colorant, particularly as a pigment

[0071] By these examples, a shaft base material containing a high proportion of biodegradable filler can be manufactured. Further, a bio-based compostable binder is used.

[0072] Writing instruments using any of the above examples as the shaft base material are provided in product lines such as writing writing instruments, drawing writing instruments, and cosmetic pencils.

Explanation of symbols

[0073] 1 Writing instrument 2 Core 3 Shaft 4 Conical region

Claims

1. A writing instrument (1) comprising a core (2) and a shaft (3), wherein the core (2) is arranged in the shaft (3) so as to be difficult to be displaced, in the writing instrument (1). 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, in particular PBSA, 0.2 to 6% by weight of other additives, such as an adhesion promoter, a stabilizer, 1 to 10% by weight of wax, 0 to 4% by weight of a colorant, in particular a pigment characterized by comprising, the writing instrument (1).

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 mostly or completely organic.

4. The writing instrument (1) according to any one of claims 1 to 3, characterized in that the filler is selected from the group consisting of wood powder, wood fiber and / or cellulose.

5. The writing instrument (1) according to any one of claims 1 to 4, characterized in that the shaft base material contains 65 to 74% by weight, preferably 67 to 73% by weight of a filler.

6. The writing instrument (1) according to any one of claims 1 to 5, characterized in that the binder mixture is selected in the range of 15 to 25% by weight of the shaft base material.

7. The writing instrument (1) according to any one of claims 1 to 6, characterized in that in the binder mixture, the PLA is present in a weight ratio of 10:1 to 1:10 with respect to the second binder.

8. The writing instrument (1) according to any one of claims 1 to 7, characterized in that the other additive contains at least one adhesion promoter, and the adhesion promoter is formed as a MAH-grafted polymer, preferably as a polyester.

9. The writing instrument (1) according to claim 8, characterized in that the at least one adhesion promoter is selected from the group consisting of MAH-grafted PLA, MAH-grafted PBS, MAH-grafted PBSA, and mixtures thereof.

10. The writing instrument (1) according to claim 8 or 9, characterized in that the shaft base material contains at least one adhesion promoter in a content range of 0.2 to 6% by weight, preferably 1 to 3% by weight, with respect to the shaft base material.

11. The writing instrument (1) according to any one of claims 1 to 10, characterized in that the shaft base material contains 2 to 6% by weight of wax.

12. The writing instrument (1) according to any one of claims 1 to 11, characterized in that the wax contains a first high melting point wax and an additional wax having a lower melting point than this.

13. In the case of the mixture of the first wax and the additional wax, each of the waxes is present in a range of 1 to 5% by weight, preferably 2 to 4% by weight, with respect to the shaft base material. The writing instrument (1) according to claim 12, characterized by this.

14. The writing instrument (1) according to any one of claims 1 to 13, characterized in that the shaft base material contains the colorant in a range of 0 to 3% by weight, preferably 1 to 2% by weight, with respect to the shaft base material.

15. The writing instrument (1) according to any one of claims 1 to 14, characterized in that the writing instrument (1) is formed as a writing and / or drawing instrument and / or a cosmetic pencil.

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