CORE FOR WRITING, DRAWING AND/OR PAINTING IMPLEMENTS AND METHOD FOR THE PRODUCTION THEREOF

Abstract

A core for writing, drawing and/or painting implements, including at least one binder, at least one wax, at least one coloring substance and at least one filler. The core is in the form of a lead core and/or colored core, the at least one binder is hyroxypropyl cellulose and the content of the at least one binder is 7 to 45 wt. %.

Claims

1-6. (canceled)

7. A core for writing, drawing and/or painting implements, comprising: at least one binder; at least one wax; at least one coloring substance; and at least one filler, wherein the core is a lead core and/or colored core, wherein the at least one binder is hydroxypropyl cellulose (HPC) and wherein the content of hydroxypropyl cellulose is 7 to 45 weight %.

8. The core according to claim 7, wherein the content of hydroxypropyl cellulose is 10 to 35 weight %.

9. The core according to claim 7, wherein the core comprises TABLE-US-00007 7 to 45 weight % HPC (binder 1) 5 to 65 weight % fillers 0.5 to 15 weight % coloring substance (pigment) 0 to 30 weight % binder 2 0 to 30 weight % wax and/or oils 0 to 15 weight % surfactant.

10. The core according to claim 7, wherein the core particularly preferably contains TABLE-US-00008 10 to 35 weight % HPC (binder) 9 to 50 weight % fillers 1.5 to 14 weight % coloring substance (pigment) 0 to 30 weight % binder 2 0 to 30 weight % wax and/or oils 0 to 10 weight % surfactant.

11. A method for producing a polymer-bound core according to claim 7, comprising forming the core by extrusion.

12. A method for producing a polymer-bound core according to claim 7, comprising the steps of: mixing and granulating all components of the core to a core granulate; extruding the core granules at a temperature in a range of 100 to 180° C. in an extruder through a mouthpiece to form endless core strands; cooling and solidifying the endless core strands; and cutting the endless core strands to a given length.

Description

[0020] The following frame examples and recipe examples are mentioned in order to show a core designed in this way more precisely.

[0021] It has been found to be beneficial when the core has

TABLE-US-00001 7 to 45 weight % HPC (binder 1) 5 to 65 weight % fillers 0.5 to 15 weight % coloring substance (pigment) 0 to 30 weight % binder 2 0 to 30 weight % wax and/or oils 0 to 15 weight % surfactant.

[0022] In particular, it is preferred when the core has

TABLE-US-00002 10 to 35 weight % HPC (binder) 9 to 50 weight % fillers 1.5 to 14 weight % coloring substance (pigment) 0 to 30 weight % binder 2 0 to 30 weight % wax and/or oils 0 to 10 weight % surfactant.

[0023] The at least one filler is advantageously a mineral filler. Fillers from the groups comprising graphite, hexagonal boron nitride, kaolin, sheet silicates, talc, chalk, barite, colored pigments and/or achromatic pigments may be mentioned as examples.

[0024] Graphite or graphite in combination with carbon black is preferred as a filler or as a coloring filler for lead cores. For colored cores, combinations of white or colorless fillers, such as hexagonal boron nitride, phyllosilicates, etc., with coloring pigments, such as azo pigments, phthalocyanines, dioxazines, quinacridones, iron oxides, carbon black, graphite, ultramarine, iron-cyan complexes have proven successful.

[0025] Binder 2, polyvinyl alcohol, polyethylene glycol and/or polyvinyl butyral may be mentioned by way of example as a further binder.

[0026] A composition for a water-soluble lead core comprises:

TABLE-US-00003 7 to 40 weight % HPC (binder 1) 5 to 70 weight % fillers 0 to 20 weight % coloring substance (pigment) 0 to 30 weight % binder 2 0 to 3 weight % wax and/or oils 0.5 to 15 weight % surfactant.

[0027] Example recipe for a lead core comprises:

TABLE-US-00004 20 weight % HPC (binder 1) 61 weight % talc 9 weight % polyethylene glycol (binder 2) 7 weight % graphite 1.5 weight % oxidized PE wax 1.5 weight % EO/PO block copolymer.

[0028] As shown in the example, graphite is used as the coloring substance for lead cores. However, a combination of graphite and carbon black can also be used.

[0029] A composition for a colored pencil core comprises:

TABLE-US-00005 7 to 45 weight % HPC (binder 1) 5 to 65 weight % fillers 0.5 to 15 weight % coloring substance (pigment) 0 to 28 weight % binder 2 0 to 30 weight % wax and/or oils 0 to 15 weight % surfactant.

[0030] Example recipe for a colored pencil core:

TABLE-US-00006 23 weight % HPC (binder 1) 56 weight % chalk 7 weight % quinacridones 14 weight % amide wax.

[0031] Colored and/or achromatic pigments can be used as coloring agents for colored cores. Examples of such pigments would be azo pigments, phthalocyanines, dioxazines, quinacridones, iron oxides, carbon black, graphite, ultramarine and iron-cyan complexes.

[0032] At least one wax from the group comprising fatty acids, stearates, montan waxes, amide waxes and paraffins can be used as the at least one wax.

[0033] The oils used can be in the form of palm oil, palm kernel oil and/or soybean oil, for example.

[0034] Surfactants can be EO/PO block polymers, ethoxylated alcohols and/or alkyl polyglycosides.

[0035] The extrusion method has proven itself as a method for producing a core according to the invention.

[0036] The core according to the invention is produced particularly by performing the following steps: [0037] mixing and granulating all recipe components of the core to a core granulate [0038] extruding the core granules at a temperature in the range of 100 to 180° C. in an extruder through a suitable mouthpiece to form endless core strands [0039] cooling and solidifying the endless core strands, and [0040] cutting the endless core strand to a given length, particularly to the required pencil length

[0041] Depending on the extrusion head, the core cross-section can take any shape—round, angular or combinations thereof. Furthermore, there is also the option to combine different core recipes in one extrusion head to form a multi-component core via multiple coextrusion.

[0042] In addition, the core granulate can be extruded into a complete lead by means of suitable coextrusion processes with other polymer-bound materials.