CORE OR CRAYON FOR WRITING AND/OR COLORING

Abstract

A core or crayon for writing and/or coloring has 15 wt % to 30 wt % of a core base material based on fat and on wax, and 40 wt % to 80 wt % of at least one filler, and 0.1 wt % to 30 wt % of at least one colorant. The core base material includes, based on the total mass of the core, 0.5 wt % to 10 wt % of aluminum distearate, 5 wt % to 20 wt % of oxidized polyethylene wax, and 5 wt %-22 wt % of at least one paraffin wax.

Claims

1. A core or crayon for writing and/or coloring, comprising: 15 wt % to 30 wt % of a core base material based on fat and on wax, the core base material having, based on a total mass of the core, 0.5 wt % to 10 wt % of aluminum distearate, 5 wt % to 20 wt % of oxidized polyethylene wax, and 5 wt %-22 wt % of at least one paraffin wax; 40 wt % to 80 wt % of at least one filler; and 0.1 wt % to 30 wt % of at least one colorant;

2. The core or crayon according to claim 1, wherein said at least one paraffin wax is at least one microparaffin wax.

3. The core or crayon according to claim 1, wherein said at least one paraffin wax has a melting point of 60° C. to 110° C.

4. The core or crayon according to claim 3, wherein said paraffin wax has a melting point of 80° C. to 85° C.

5. The core or crayon according to claim 1, wherein a fraction of said core base material is not more than 26 wt %.

6. The core or crayon according to claim 1, wherein said oxidized polyethylene wax has a melting point of 110° C. to 135° C.

7. The core or crayon according to claim 6, wherein said oxidized polyethylene wax has a melting point of 115° C. to 130° C.

8. The core or crayon according to claim 1, wherein a fraction of said aluminum distearate is 0.5 wt % to 5 wt %.

9. The core or crayon according to claim 8, wherein a fraction of said aluminum distearate is 0.5 wt % to 3 wt %.

10. The core or crayon according to claim 1, wherein a fraction of said oxidized polyethylene wax is 7 wt % to 15 wt %.

11. The core or crayon according to claim 1, wherein a fraction of said paraffin wax is 5 to 15 wt %.

12. The core or crayon according to claim 1, wherein said at least one filler includes kaolin, mica, pumice flour and/or talc.

13. The core or crayon according to claim 1, wherein said at least one colorant includes organic and/or inorganic color pigments.

14. The core or crayon according to claim 13, wherein said at least one filler and said color pigments have a mean particle size D90<40 μm.

15. The core or crayon according to claim 3, wherein said at least one microparaffin wax has a melting point of 60° C. to 110° C.

16. The core or crayon according to claim 4, wherein said at least one microparaffin wax has a melting point of 80° C. to 85° C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0023] Set out below are four example formulas for colored cores. The starting substances (totaling, e.g., 100 kg) are mixed in a mixer at 120° C. The extrusion of the core material into core strands having a diameter of around 3 to 6 mm takes place, for example, with a twin-screw extruder at a temperature of 130° C. The extrusion of 100 kg of core material takes around 1 h. Downstream of the extruder is a cooling section several meters long. The extruded core strands are separated into individual cores, which can be processed further immediately.

EXAMPLE A: Green Color Pencil Core with a Diameter of 3.3 mm

[0024]

TABLE-US-00001 Aluminum distearate (CAS No. 97404-28-9, m.p. = 2.10 wt % 140° C.).sup.1) Oxidized polyethylene wax (Licowax PED 121, CAS No. 13.00 wt %  68441-17-8, m.p. around 115° C.).sup.2) Solven Wax 170 (CAS No. 63231-60-7, m.p. around 7.40 wt % 82° C.).sup.3) Kaolin BSK-H.sup.4) 71.50 wt %  Pigment Green 7.sup.5) 2.20 wt % Titanium dioxide Kronos 2300.sup.6) 3.80 wt %

EXAMPLE B: Blue Color Pencil Core with a Diameter of 3.3 mm

[0025]

TABLE-US-00002 Aluminum distearate (CAS No. 97404-28-9, m.p. = 1.70 wt % 140° C.).sup.1) Oxidized polyethylene wax (Licowax PED 121, CAS No. 9.30 wt % 68441-17-8, m.p. around 115° C.).sup.2) Solven Wax 170 (CAS No. 63231-60-7, m.p. around 5.00 wt % 82° C.).sup.3) Compacted Talc GM10.sup.7) 80.00 wt %  Titanium dioxide Kronos 2300.sup.6) 1.00 wt % Cosmos Blue ASF.sup.8) 2.75 wt % Permanent carmine FBB.sup.9) 0.25 wt %

EXAMPLE C: Violet Color Pencil Core with a Diameter of 5.5 mm

[0026]

TABLE-US-00003 Aluminum distearate (CAS No. 97404-28-9, m.p. = 1.00 wt % 140° C.).sup.1) Oxidized polyethylene wax (Licowax PED 191, CAS No. 9.00 wt % 68441-17-8, m.p. around 120-130° C.).sup.2) Solven Wax 170 (CAS No. 63231-60-7, m.p. around 10.00 wt %  82° C.).sup.3) Kaolin Speswhite (CAS No. 1332-58-7).sup.10) 77.64 wt %  Pigment Violet 23.sup.11) 2.36 wt %

EXAMPLE D: Red Color Pencil Core with a Diameter of 3.8 mm

[0027]

TABLE-US-00004 Aluminum distearate (CAS No. 97404-28-9, m.p. =  1.00 wt % 140° C.).sup.1) Oxidized polyethylene wax (Licowax PED 191, CAS No. 13.00 wt % 68441-17-8, m.p. around 120-130° C.).sup.2) Polarwachs A75 (paraffin wax, dropping point: ISO 2176 12.00 wt % 78-82° C.).sup.12) Kaolin Speswhite (CAS No. 1332-58-7).sup.10) 69.00 wt % Pigment Red 2.sup.13)    5 wt %

[0028] The mechanical properties of the cores of the invention were investigated by conducting a drop test. In this test the cores are rolled from a height of 50 cm from a table, and drop onto a floor laid with ceramic tiles. The table below lists the experimental results for two cores of the invention as per examples A and B above and also for two comparative cores C1 (core as per example 5 from European patent application EP 2 520 442 A1) and C2 (core as per example 3 from European patent application EP 2 520 442 A1). In order to obtain a meaningful result, the drop test was carried out with 80 cores each per formula. The core breakages per core were ascertained subsequently.

TABLE-US-00005 TABLE 1 Number of core breakages Comparative Comparative per core core C1 core C2 Example A Example B 0 0 (0%)   0 (0%)   14 (17.5%)  19 (23.75%) 1 2 (2.50%) 3 (3.75%) 63 (78.75%) 54 (67.50%) 2 42 (52.50%) 38 (47.50%) 2 (2.50%) 5 (6.25%) 3 12 (15.00%) 20 (25.00%) 1 (1.25%) 2 (2.50%) 4 20 (25.00%) 12 (15.00%) 0 0 5 or more 4 (5.00%) 7 (8.75%) 0 0

[0029] In the drop test it emerged that the cores of the invention are much less susceptible to breakage. As a result, the reject rate on processing into wood-encased, sharpenable pencils is reduced, and an increase is achieved in the useful life of the pencils or crayons.

[0030] In addition, as a result of the improved mechanical properties, there is also a significant minimization of the breaking of the cores in wood-encased pencils during sharpening using mechanical hand sharpeners. A test to this effect showed a possible reduction in core breakages during sharpening from around 4% in the case of the comparative cores C1 and C2 to less than 2% in the case of cores of the invention as per examples A and B.

Manufacturer/Supplier

1) Peter Greven, D-53902 Bad Münstereifel

2) Clariant AG, D-65929 Frankfurt am Main

[0031] 3) Solven Solventes e Quimicos LTDA., St. Professora Abigal Alves Pires, 301—Ch. Nova Boa Vista—Hortolandia/SP ZIP code: 13185-071 Brazil

4) Amberger Kaolinwerke, D-92242 Hirschau

5) Clariant AG, D-65929 Frankfurt am Main

6) Kronos, D-51737 Leverkusen

7) Magnesita S.A., Bela Vista—01 31 1-000 Sao Paolo/SP

8) Toyo INK, 60870 Villers Saint Paul, France

9) Clariant AG, D-65929 Frankfurt am Main

[0032] 10) Imerys Minerals Ltd. Cornwall, PL24 2SQ, United Kingdom

11) Clariant AG, D-65929 Frankfurt am Main

[0033] 12) Wachs- u. Ceresin-Fabriken, Th. C. Tromm GmbH, Feuerstr. 7-17, D 50735 Cologne

13) Clariant AG, D-65929 Frankfurt am Main