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WRITING UTENSIL COMPRISING A PLA/PBS SHAFT BASE MATERIAL

20250326931 ยท 2025-10-23

    Inventors

    Cpc classification

    International classification

    Abstract

    A writing utensil including a lead and a shaft, wherein the lead is arranged in the shaft in a stationary manner, and the shaft has a shaft base material. The shaft base material includes the following components: 60 to 75 wt. % of a filler/fillers, 15 to 30 wt. % of a binder mixture including PLA and a second binder selected from the group of PBS and copolymers of the PBS, in particular PBSA, 0.2 to 6 wt. % of other additives such as adhesives, stabilizers, 1 to 10 wt. % of wax/waxes, and 0 to 4 wt. % of a dye, in particular a pigment.

    Claims

    1-15. (canceled)

    16. A pencil, comprising: a lead; and a shaft, wherein the lead is arranged in the shaft in a fixed manner against displacement, wherein the shaft comprises a shaft base material that comprises the following components: TABLE-US-00011 60 to 75 wt.-% filler (s); 15 to 30 wt.-% binder mixture comprising PLA and a second binder selected from the group consisting of PBS, copolymers of PBS; 0.2 to 6 wt.-% other additives; 1 to 10 wt.-% wax; and 0 to 4 wt.-% colorants.

    17. The pencil according to claim 16, wherein the second binder is PBSA.

    18. The pencil according to claim 16, wherein the other additives are adhesion promoters or stabilizers.

    19. The pencil according to claim 16, wherein the colourant is a pigment.

    20. The pencil according to claim 16, wherein the shaft base material is unfoamed.

    21. The pencil according to claim 16, wherein the filler is largely or completely organic.

    22. The pencil according to claim 16, wherein the filler is at least one of the group consisting of wood flour, wood fibers and cellulose.

    23. The pencil according to claim 16, wherein the shaft base material comprises 65 to 74 wt.-% of filler(s).

    24. The pencil according to claim 23, wherein the shaft base material comprises 67 to 73 wt.-% of filler(s).

    25. The pencil according to claim 16, wherein the binder mixture is from 15 to 25 wt.-% of the shaft base material.

    26. The pencil according to claim 16, wherein the PLA is present in the binder mixture in a weight ratio to the second binder in a range from 10:1 to 1:10.

    27. The pencil according to claim 16, wherein the other additives comprise at least one adhesion promoter that is constituted as MAH grafted polymer.

    28. The pencil according to claim 27, wherein the at least one adhesion promoter is constituted as polyester.

    29. The pencil according to claim 27, wherein 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.

    30. The pencil according to claim 27, wherein the shaft base material has a content of the at least one adhesion promoter in a range of 0.2 to 6 wt.-% related to the shaft base material.

    31. The pencil according to claim 30, wherein the shaft base material has a content of the at least one adhesion promoter in a range of 1 to 3 wt.-% related to the shaft base material.

    32. The pencil according to claim 16, wherein the shaft base material comprises 2 to 6 wt.-% of wax.

    33. The pencil according to claim 16, wherein the wax comprises a mixture of a first high-melting wax and a second wax that is low-melting compared to the first wax.

    34. The pencil according to claim 33, wherein in the mixture of the first wax and the second wax, the respective waxes are present in a range of 1 to 5 wt.-% related to the shaft base material.

    35. The pencil according to claim 34, wherein in the mixture of the first wax and the second wax, the respective waxes are present in a range of 2 to 4 wt.-% related to the shaft base material.

    36. The pencil according to claim 16, wherein the shaft base material comprises the colorant in a range of 0 to 3 wt.-% related to the shaft base material.

    37. The pencil according to claim 36, wherein the shaft base material comprises the colorant in a range of 1 to 2 wt.-% related to the shaft base material.

    38. The pencil according to claim 16, wherein the pencil is one of: a writing pencil, a painting pencil; and a cosmetic pencil.

    Description

    [0056] Further features, advantages and effects of the invention result from the following description of a preferred example of embodiment of the invention and from the appended figures. These show:

    [0057] FIG. 1 a diagrammatic representation of a pencil which is able to be sharpened.

    [0058] FIG. 1 shows in a highly diagrammatic block diagram a pencil 1 with a lead 2, a shaft 3 made of a shaft base material. Pencil 1 can be sharpened and comprises a conical region 4 in shaft 3 and lead 2, which is produced by a pencil sharpener. As a result, lead 2 is exposed. Lead 2 is arranged in shaft 3 in a fixed manner against displacement. This prevents lead 2 from slipping. Lead 2 is thus not displaced in shaft 3 when a certain degree of pressure is exerted on pencil 1 during writing. Shaft 3 comprises a material called the shaft base material. Further layers can be arranged on the shaft base material, for example decorative layers.

    [0059] The shaft base material comprises the following components:

    TABLE-US-00004 60 to 75 wt.-% filler (s) 15 to 30 wt.-% binder mixture comprising PLA and a second binder selected from the group consisting of PBS, copolymers of PBS, in particular PBSA 0.2 to 6 wt.-% other additives such as adhesion promoters, stabilisers 1 to 10 wt.-% wax (es) 0 to 4 wt.-% colourants, in particular as a pigment

    [0060] Exemplary shaft base materials are shown below.

    [0061] The production of a shaft according to the invention preferably takes place after mixing and granulating the components of the shaft base material in the extrusion process or coextrusion process as sheathing of the provided lead at approximately 150 to 200 C.

    [0062] The shape of the cross-sectional area is set in the extrusion head. After cooling, the pencil thread is cut to a certain length.

    [0063] Preferably, the wood flour, wood fibres and/or cellulose are present as particles. The particles preferably have an average particle size which can be specified as d50 in m. The designation d50=150 m means that 50% of the particles are smaller than 150 m and 50% are larger. The particle size distribution can be determined for example using a laser granulometer.

    [0064] Example 1 Painting pencil with a shaft base material comprises the following components:

    TABLE-US-00005 73 wt.-% wood flour (d50 approx. 100 m) as filler 10 wt.-% PLA (polylactide, polylactic acid, polylactic acid) in the binder mixture 10 wt.-% PBS (polybutylene succinate) in the binder mixture 1 wt.-% MAH grafted PLA (maleic acid anhydride grafted polylactide, maleic anhydride grafted polylactic acid) as other additives especially adhesion promoters 3 wt.-% stearic acid derivative wax in the wax agent 2 wt.-% EBS (distearyl ethylene diamide) in the wax agent 1 wt.-% titanium dioxide as a colourant, in particular as a pigment

    [0065] The advantage is the high filler proportion, as a result of which a largely biodegradable shaft of a pencil can be produced.

    [0066] Example 2 Writing pencil with a shaft base material comprises the following components:

    TABLE-US-00006 61.5 wt.-% wood flour (d50 approx. 35 m) as filler 10 wt.-% PLA (polylactide, polylactic acid, polylactic acid) in the binder mixture 20 wt.-% PBS (polybutylene succinate) in the binder mixture 1.5 wt.-% MAH grafted PLA (maleic acid anhydride grafted polybutylene succinate) as other additives especially adhesion promoters 1.5 wt.-% stearic acid derivative wax in the wax agent 3.5 wt.-% EBS (distearyl ethylene diamide) in the wax agent 2 wt.-% titanium dioxide as a colourant, in particular as a pigment.

    [0067] The advantage is the high filler proportion in conjunction with biodegradable binders, as a result of which a largely biodegradable shaft of a pencil can be produced.

    [0068] Example 3 Writing pencil with a shaft base material comprises the following components:

    TABLE-US-00007 60.5 wt.-% wood flour (d50 approx. 70 m) as filler 25 wt.-% PLA (polylactide, polylactic acid, polylactic acid) in the binder mixture 5 wt.-% PBS (polybutylene succinate) in the binder mixture 6 wt.-% MAH grafted PLA (maleic acid anhydride grafted polylactide, maleic anhydride grafted polylactic acid) as other additives especially adhesion promoters 1 wt.-% stearic acid derivative wax in the wax agent 1.5 wt.-% EBS (distearyl ethylene diamide) in the wax agent 1 wt.-% titanium dioxide as a colourant, in particular as a pigment.

    [0069] The advantage is the high filler proportion in conjunction with biodegradable binders, as a result of which a largely biodegradable shaft of a pencil can be produced. The adhesion promoter enables better stability.

    [0070] Example 4 Writing pencil with a shaft base material comprises the following components:

    TABLE-US-00008 71.5 wt .- % cellulose as a filler 2 wt.-% PLA (polylactide, polylactic acid, polylactic acid) in the binder mixture 20 wt.-% PBSA (poly (butylene succinate-co-butylene adipate) ) in the binder mixture 2 wt.-% MAH grafted PBSA (maleic acid anhydride grafted poly (butylene succinate-co-butylene adipate) ) as other additives especially adhesion promoters 2 wt.-% stearic acid derivative wax in the wax agent 2 wt.-% EBS (distearyl ethylene diamide) in the wax agent 0.5 wt.-% titanium dioxide as a colourant, in particular as a pigment.

    [0071] Example 5 Black cosmetic pencil with a shaft base material comprises the following components:

    TABLE-US-00009 69 wt.-% wood flour (d50 approx. 100 m) as filler 10 wt.-% PLA (polylactide, polylactic acid, polylactic acid) in the binder mixture 15 wt.-% PBS (poly (butylene succinate) in the binder mixture 1.5 wt.-% mixture 1.1 MAH grafted PLA (maleic acid anhydride grafted polylactide, maleic anhydride grafted polylactic acid) : MAH grafted PBS (maleic acid anhydride grafted polybutylene succinate) as other additives especially adhesion promoters 1 wt.-% stearic acid derivative wax in the wax agent 2.5 wt.-% EBS (distearyl ethylene diamide) in the wax agent 1 wt.-% soot as a colourant, in particular as a pigment.

    [0072] Example 6 Writing pencil with a shaft base material comprises the following components:

    TABLE-US-00010 66 wt.-% cellulose as a filler 8 wt.-% PLA (polylactide, polylactic acid, polylactic acid) in the binder mixture 15 wt.-% PBSA (poly (butylene succinate-co-butylene adipate) ) in the binder mixture 5 wt.-% MAH grafted PBSA (maleic acid anhydride grafted poly (butylene succinate-co-butylene adipate) ) as other additives especially adhesion promoters 3 wt.-% stearic acid derivative wax in the wax agent 2 wt.-% EBS (distearyl ethylene diamide) in the wax agent 1 wt.-% titanium dioxide as a colourant, in particular as a pigment.

    [0073] With these examples, shaft base materials can be produced having a high proportion of filler which is biodegradable. In addition, bio-based compostable binders are used.

    [0074] The pencil with one of the preceding examples as a shaft base material is provided in the product lines writing pencil, painting pencil and cosmetic pencil.

    LIST OF REFERENCE NUMBERS

    [0075] 1 pencil [0076] 2 lead [0077] 3 shaft [0078] 4 conical region