A pen refill having polyhydroxybutyric acid as a binder, and a pen having the pen refill

Abstract

A pen core for a writing pen, a drawing pen, a painting pen and / or a cosmetic pen, which contains a binder, a filler, a colorant and other additives, is proposed. The pen core has the following components: 5 to 65% by weight of a binder containing polyhydroxybutyric acid and / or a copolymer of polyhydroxybutyric acid as the first polymer and a second polymer, 33 to 85% by weight of a filler containing a colorant, 2 to 33% by weight of wax or waxes, and 0 to 1% by weight of other additives such as a stabilizer and a lubricant.

Description

Technical Field

[0001] The present invention relates to a pen core for writing, drawing, painting and / or cosmetic pens, based on a biodegradable binder having the features of claim 1. The present invention also relates to a pen having such a pen core.

[0002] Pen cores for writing, drawing, painting and / or cosmetic use having polymers made from crude oil are known.

[0003] European Patent Application Publication No. 2644407 describes a polymer-bonded expandable core containing a biodegradable binder and graphite as a colorant. In some cases, the strength and line concealment of such cores, especially pencil cores, can be optimized.

[0004] Furthermore, German Patent Application Publication No. 19855325 describes a sheath for a color core or a lead core based on cellulose and a biodegradable polymer. In this case, a number of biopolymers for covering the core are described, but no suggestions are given as to how the core can be designed using such biopolymers.

[0005] Polymer-bonded color cores and graphite cores are known from International Publication No. 2010 / 006742. Such cores contain a polymer binder, wax, palm oil and a filler. Most polymer cores are composed based on crude oil products and thus directly depend on the price and supply volume of crude oil. Furthermore, cores produced based on polymers derived from crude oil consume non-renewable resources that exist in nature.

[0006] Furthermore, polymer-bonded color cores and graphite cores are known from U.S. Patent No. 2,988,784. Such cores contain a polymer binder based on cellulose esters, especially cellulose acetate, waxes, and fillers. Since these cores are indeed composed of natural raw materials, they can be completely decomposed, but most of them consist of wood, which is a naturally occurring raw material. Due to the high demand for wood, it is becoming increasingly difficult and expensive to obtain high-quality wood. In addition, the production of pens using cellulose esters places a significant burden on the gradually decreasing output of natural wood.

[0007] Accordingly, an object of the present invention is to improve a pen core for writing, drawing, and / or painting and a pen having the pen core so that the pen core forms an environmentally conscious alternative without losing the main characteristics of the pen core, such as sharpenability, color imparting property, strength, line concealment, and / or erasability.

[0008] The subject matter of the present invention is a pen core having the features of claim 1 and a pen having the features of claim 7. Preferred or advantageous embodiments of the invention result from the dependent claims and the following description.

[0009] The present invention relates to a pen core for writing pens, drawing pens, painting pens, and / or cosmetic pens, which consists of a filler, a colorant, a binder, and other additives. This pen core may be designed as a colored pen core or a pencil core.

[0010] A pen core for writing, drawing, painting, and / or cosmetic use is understood to particularly mean a pen core that is firmly incorporated into a shaft material, such as wood or an extrusion mixture as a polymer mixture, and can be sharpened. Alternatively, the pen core can also be slidably mounted in a hard case. These examples are a pencil with a wooden case and a pen core for a mechanical pencil, such as a so-called retractable pencil or a clutch pen. In this regard, the pen core particularly has an outer diameter in the range of about 0.3 mm to 6 mm.

[0011] According to the present invention, the pen refill has the following components, based on the pen refill, particularly the total weight of the pen refill: 5 to 65% by weight of a binder containing polyhydroxybutyric acid and / or a copolymer of polyhydroxybutyric acid as the first polymer and a second polymer, 33 to 85% by weight of a filler containing a colorant, 2 to 33% by weight of wax or waxes, 0 to 1% by weight of other additives such as stabilizers and lubricants and has.

[0012] According to the present invention, the binder contains polyhydroxybutyric acid. Polyhydroxybutyric acid is abbreviated as PHB and is registered with the Chemical Information Search Service under the CAS number: 26063-00-3 in particular. Depending on the number of monomers in the polymer, the properties of PHB as a polymer may vary slightly. Polyhydroxybutyric acid has thermoplastic properties and is biodegradable.

[0013] Alternatively or additionally, the binder contains a copolymer having polyhydroxybutyric acid as the first polymer. A copolymer is understood to mean, in particular, a polymer composed of exactly two polymers. The polymers of the copolymer are chemically bonded. In the case of a copolymer based on polyhydroxybutyric acid, the first polymer is polyhydroxybutyric acid. The second polymer is selected according to the requirements of the properties. Preferably, the second polymer can be produced from a bio-based source and / or is biodegradable. Most preferably, the second polymer is more flexible than polyhydroxybutyric acid.

[0014] Surprisingly, by using polyhydroxybutyric acid and / or a copolymer containing polyhydroxybutyric acid as the first polymer as a binder, a high-quality pen refill can be produced, and it has been found that polyhydroxybutyric acid forms an environmentally conscious alternative due to its biodegradability.

[0015] In one embodiment, the binder has only polyhydroxybutyric acid. In a further embodiment, the binder has only a copolymer having polyhydroxybutyric acid as the first polymer and a second polymer. In a further embodiment, the binder has a mixture from polyhydroxybutyric acid and a copolymer having polyhydroxybutyric acid as the first polymer and a second polymer.

[0016] In particular, the filler is selected from the group comprising hexagonal boron nitride, phyllosilicate, chalk, barite, colored pigments and / or achromatic pigments, or mixtures thereof. This makes it possible to produce a pen core optimized with respect to cost and mechanical properties.

[0017] The filler may additionally contain graphite and / or carbon black which act simultaneously as colorants. Preferably, in the case of a black pen core, graphite and / or carbon black are selected as the filler and colorant, either alone or as a mixture thereof. In particular, a black pen core is called a pencil core or a graphite core.

[0018] The colorant is used to impart color to the pen core, so that a colored streak is visible during writing. In particular, the colorant is selected from the group comprising titanium dioxide, zinc sulfide, colored pigments, carbon black, graphite and / or mixtures thereof. This makes it possible to select the color of the pen core.

[0019] Other additives include stabilizers and lubricants.

[0020] Stabilizers are added to the pen core to suppress the aging process of the polymer. For example, the action of heat, light, ozone and oxygen can lead to the aging process, which can be discerned as a deterioration of properties, such as a change in color.

[0021] In particular, in the case of a retractable pencil or a clutch pen, a lubricant is added to the pen core so that the pen core is not pinched and immobilized within the case. Further, the lubricant facilitates the movement of the pen on the paper surface and improves the transfer of the coloring agent of the pen core to a writing surface, such as a blackboard, paper, concrete, asphalt, or skin. In particular, the lubricant has palm oil.

[0022] In one embodiment, the copolymer has a weight ratio of polyhydroxybutyric acid as the first polymer to the second polymer in the range of 1:10 to 10:1, preferably in the range of 5:10 to 10:5, particularly based on the total weight of the binder.

[0023] In a further embodiment, the second polymer of the copolymer is poly(3-hydroxyvaleric acid). Poly(3-hydroxyvaleric acid) is particularly known as poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) and / or as PHV (CAS: 83120-66-5). This can be produced from a biological source and is biodegradable.

[0024] In particular, the binder has only a copolymer of polyhydroxybutyric acid as the first polymer and poly(3-hydroxyvaleric acid) as the second polymer in a weight ratio in the range of 1:10 to 10:1, preferably in the range of 5:10 to 10:5, particularly based on the total weight of the binder.

[0025] In particular, the binder contains a mixture from polyhydroxybutyric acid, poly(3-hydroxyvaleric acid), and / or polylactic acid. Advantageously, the binder consists of this mixture. A mixture from polymers is called a blend.

[0026] PLA is the name of polylactic acid, which can also be particularly called polylactide and / or poly lactic acid. Among other things, PLA is also registered with the Chemical Information Search Service with the CAS number 9051-89-2. Depending on the number of monomers in the polymer, the properties of PLA as a polymer may vary slightly.

[0027] PLA is a thermoplastic. PLA has the advantage that it can be manufactured from bio-based sources, so that the petroleum-based raw materials used in pens are significantly reduced or completely avoided. PLA is obtained, for example, from corn and belongs to the polyester as a synthetic polymer. Thus, pure PLA is preferably manufactured from renewable raw materials and is not based on fossil raw materials such as petroleum.

[0028] In particular, the binder contains a mixture from polyhydroxybutyric acid, poly(3-hydroxyvaleric acid) and polylactic acid. In particular, the binder contains a mixture from polyhydroxybutyric acid and poly(3-hydroxyvaleric acid). In particular, the binder contains a mixture from poly(3-hydroxyvaleric acid) and polylactic acid. In particular, the binder contains a mixture from polyhydroxybutyric acid and polylactic acid.

[0029] This enables selection in terms of properties such as abrasion resistance and mechanical strength in the case of biodegradable binders.

[0030] Other copolymers based on polyhydroxybutyric acid are also possible, broadening the range of choices with respect to various properties. For example, in addition to mechanical properties, particularly machinability, color imparting property, strength, line hiding power, erasability, etc., the manufacturing cost can also be adjusted.

[0031] In a preferred embodiment, the pen core has a binder content in the range of preferably 8 to 50% by weight, preferably in the range of 15 to 27% by weight, based on the total mass of the pen core. This has the advantage that the binder ratio can be optimized according to the manufacturing cost while simultaneously providing the mechanical properties of the pen core.

[0032] In a further embodiment, the pen core has at least one wax or a mixture of waxes as a wax mixture. The at least one wax is selected from the group consisting of fatty acids, stearates, montan wax, amide wax, carnauba wax, beeswax, paraffin, polyolefin wax, polyethylene wax, polyethylene vinyl acetate wax, and mixtures thereof. Additionally, the wax contains further additives. A plurality of different waxes can be used as the wax mixture.

[0033] Preferably, the wax has a mixture from polyethylene wax and / or polyethylene vinyl acetate wax.

[0034] Preferably, the at least one wax is selected from the group consisting of calcium stearate and / or ethylene bisstearamide (EBS). In particular, ethylene bis(stearamide) is known as the name of distearylethylenediamide and / or as EBS (especially CAS: 110 - 30 - 5). Calcium stearate (CAS: 1592 - 23 - 0) is also included as E470a in the European food additive list. In particular, additionally the wax contains Biomere from Deurex.

[0035] In a further embodiment, the pen core has a colorant content in the range of 0 to 10% by weight based on the pen core.

[0036] In a further embodiment, the pen core has the following components, in particular based on the total weight of the pen core: 8 - 50% by weight of a binder containing polyhydroxybutyric acid and / or a copolymer having polyhydroxybutyric acid as the first polymer and a second polymer, 40 - 80% by weight of a filler containing a colorant, 5 - 28% by weight of wax or waxes, 0 - 1% by weight of other additives such as stabilizers, lubricants and has.

[0037] In particular, when using a pen refill in a pen with an axis, an adhesion promoter is used. The adhesion promoter has the advantage that the pen refill is arranged in a slide-fixed manner within the axis. Therefore, even when a light pressure is applied during writing, the pen refill does not slide within the axis.

[0038] A further object of the present invention is a pen having a pen refill as described above. This pen is designed in particular as a writing pen, a drawing pen, a painting pen and / or a cosmetic pen. This pen has a pen refill and an axis, in which case the axis surrounds the pen refill, preferably concentrically and / or coaxially. The pen refill is preferably slidably fixed relative to the axis and / or arranged immovably. In particular, the pen refill is permanently and / or non-destructively fixed within the axis. Alternatively, the pen refill is slidably attached to the pen. For example, the pen is designed as a retractable pencil or a clutch pen.

[0039] Further features, advantages and effects of the present invention will become apparent from the following description of the preferred embodiments of the present invention.

[0040] The production of the pen refill according to the present invention is preferably carried out by mixing and granulating the components of the pen refill as strands of the pen refill at about 150 to 200 °C in an extrusion method or a co-extrusion method.

[0041] The shape of the cross-section of the pen refill is set by an extrusion head. When producing a pen refill for a clutch pen, further cutting of the pen refill strands to a certain length is carried out. In the case of a pen refill for a pen with an axis, the pen refill is covered with axis material as one of the further process steps.

[0042] An exemplary composition of the pen refill is shown as follows.

[0043] Example 1: A pen refill having the following components: 17.5% by weight of polyhydroxybutyric acid as a binder, 67.5% by weight of talc and / or kaolin as filler, 7% by weight of carbon black as colorant, 3% by weight of polyethylene wax as wax, 5% by weight of polyethylene vinyl acetate wax as wax.

[0044] The advantage is that the proportion of the filler combined with the biodegradable binder is high, whereby a pen core that is mostly biodegradable can be manufactured.

[0045] Example 2: Pencil lead as a pen core having the following components: 60% by weight of a copolymer from polyhydroxybutyric acid and poly(3-hydroxyvaleric acid) in a weight ratio of 2:1, advantageously corresponding to 40% by weight of polyhydroxybutyric acid and 20% by weight of poly(3-hydroxyvaleric acid) as binder, based in particular on the total weight of the binder, 34% by weight of graphite and carbon black as filler containing a colorant, in particular in a weight ratio of 1:2, 2% by weight of polyethylene wax as wax, 4% by weight of polyethylene vinyl acetate wax as wax.

[0046] The copolymer reduces the proportion of the crystalline region, reduces the wear of the pen core, and thus facilitates writing.

[0047] Example 3: A pen core having the following components: 26% by weight of polyhydroxybutyric acid as binder, 55% by weight of phyllosilicate as filler, 10% by weight of red pigment as colorant, 5% by weight of polyethylene wax as wax, 3% by weight of polyethylene vinyl acetate wax as wax, 1% by weight of palm oil as lubricant.

[0048] Example 4: A pen core having the following components: 7% by weight of poly(3-hydroxyvaleric acid) as binder, 81% by weight of graphite as a filler, 2% by weight of carbon black as a colorant, 6% by weight of ethylene bisstearamide as a wax, 4% by weight of calcium stearate as a wax.

[0049] Example 5: A pen refill having the following components: A copolymer of polyhydroxybutyric acid and poly(3-hydroxyvaleric acid), which is used as a binder, especially in a ratio of 1:4, preferably corresponding to 8% by weight of polyhydroxybutyric acid and 32% by weight of poly(3-hydroxyvaleric acid), based on the total weight of the binder, 40% by weight, 46% by weight of barite as a filler, 10% by weight of a yellow pigment as a colorant, 2% by weight of polyethylene wax as a wax, 2% by weight of calcium stearate as a wax.

[0050] Example 6: A pen refill having the following components: A mixture or blend of polyhydroxybutyric acid and polylactic acid, which is used as a binder, especially in a ratio of 3:1, preferably corresponding to 12% by weight of polyhydroxybutyric acid and 4% by weight of polylactic acid, 16% by weight, 74% by weight of hexagonal boron nitride as a filler, 5% by weight of carbon black and titanium dioxide pigment as a colorant, 4% by weight of ethylene bisstearamide as a wax, 6% by weight of polyethylene vinyl acetate wax as a wax.

[0051] Example 7: A pen refill having the following components: A mixture or blend of polyhydroxybutyric acid and polylactic acid, which is used as a binder, especially in a ratio of 27:10, preferably corresponding to 19% by weight of polyhydroxybutyric acid and 7% by weight of polylactic acid, 26% by weight, 55% by weight of layered silicate as a filler, 10% by weight of a green pigment as a colorant, 5% by weight of polyethylene wax as wax, 3% by weight of ethylene vinyl acetate wax as wax, 1% by weight of palm oil as lubricant.

[0052] Using these examples, a pen refill having a biodegradable binder can be manufactured.

Claims

1. In a pen refill for a writing pen, drawing pen, painting pen and / or cosmetic pen, which contains a binder, a filler, a colorant and other additives, the pen refill has the following components: 5 to 65% by weight of a binder containing polyhydroxybutyric acid and / or a copolymer of polyhydroxybutyric acid as the first polymer and a second polymer, 33 to 85% by weight of a filler containing a colorant, 2 to 33% by weight of wax or waxes, 0 to 1% by weight of other additives such as a stabilizer and a lubricant and is characterized by having the above. A pen refill.

2. The pen refill according to claim 1, wherein the binder is biodegradable.

3. The pen refill according to claim 1 or 2, wherein the copolymer has a weight ratio of polyhydroxybutyric acid as the first polymer to the second polymer in the range of 1:10 to 10:1, preferably in the range of 5:10 to 10:

5.

4. The pen refill according to any one of claims 1 to 3, wherein the second polymer of the copolymer contains poly(3-hydroxyvaleric acid).

5. The pen refill according to any one of claims 1 to 4, wherein the copolymer of polyhydroxybutyric acid and poly(3-hydroxyvaleric acid) as the second polymer contains a weight ratio in the range of 1:10 to 10:1, preferably in the range of 5:10 to 10:

5.

6. The pen refill according to any one of claims 1 to 5, wherein the binder contains a mixture from polyhydroxybutyric acid, poly(3-hydroxyvaleric acid) and / or polylactic acid.

7. The pen refill according to any one of claims 1 to 6, wherein the pen refill contains a binder content in the range of 8 to 50% by weight, preferably in the range of 15 to 27% by weight, based on the pen refill.

8. The pen refill according to any one of claims 1 to 7, wherein the pen refill contains a wax content in the range of 2 to 33% by weight, preferably in the range of 5 to 28% by weight, based on the pen refill.

9. The pen refill according to any one of claims 1 to 8, wherein the pen refill contains a colorant content in the range of 0 to 10% by weight, based on the pen refill.

10. A pen having the pen refill according to any one of claims 1 to 9.

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