LEAD, CHALK OR COLOR TABLET FOR WRITING, DRAWING AND/OR COSMETICS PURPOSES, PENCIL CONTAINING A LEAD, AND METHOD FOR PRODUCING A LEAD, CHALK OR COLOR TABLET

Abstract

A lead or chalk or color tablet for writing, drawing and/or cosmetics purposes, contains at least one sugar and/or sugar alcohol and/or pentaerythritol, at least one cellulose derivative and/or starch derivative and at least one surfactant. The at least one surfactant is selected from the group of sulfuric acid fatty acid ester salts and/or fatty acid sulfoalkyl esters and/or ethoxylated forms of alkali metal fatty acid sulfates. A pencil having such a lead and to a method for producing a lead or chalk or color tablet are also provided.

Claims

1. A lead or chalk or color tablet for at least one of writing, drawing or cosmetics purposes, comprising: at least one of at least one sugar or sugar alcohol or pentaerythritol; at least one of at least one cellulose derivative or starch derivative; and at least one surfactant selected from the group consisting of sulfuric acid fatty acid ester salts, fatty acid sulfoalkyl esters and ethoxylated forms of alkali metal fatty acid sulfates.

2. The lead or chalk or color tablet according to claim 1, which further comprises providing at least one of sodium lauryl sulfate, potassium lauryl sulfate, ammonium lauryl sulfate, sodium cocoyl isethionate, sodium myreth sulfate or sodium dodecylpoly(oxyethylene) sulfate as the surfactant.

3. The lead or chalk or color tablet according to claim 1, which further comprises providing at least one of sucrose or xylose as the sugar.

4. The lead or chalk or color tablet according to claim 1, which further comprises providing mannitol, sorbitol, xylitol, adonitol, arabitol, dulcitol or threitol as the sugar alcohol.

5. The lead or chalk or color tablet according to claim 1, which further comprises providing at least one of sodium carboxymethylcellulose or carboxymethyl starch or sodium carboxymethyl starch as at least one of the cellulose derivative or starch derivative.

6. The lead or chalk or color tablet according to claim 1, which further comprises providing from 1 to 30% by weight of the surfactant.

7. The lead or chalk or color tablet according to claim 1, which further comprises providing from 1 to 25% by weight of the surfactant.

8. The lead or chalk or color tablet according to claim 1, which further comprises providing from 4 to 40% by weight of at least one of the sugar or sugar alcohol or pentaerythritol.

9. The lead or chalk or color tablet according to claim 1, which further comprises providing from 4 to 30% by weight of at least one of the sugar or sugar alcohol or pentaerythritol.

10. The lead or chalk or color tablet according to claim 1, which further comprises providing from 0.5 to 25% by weight of at least one of the cellulose derivative or starch derivative.

11. The lead or chalk or color tablet according to claim 1, which further comprises providing from 0.5 to 18% by weight of at least one of the cellulose derivative or starch derivative.

12. The lead or chalk or color tablet according to claim 1, which further comprises providing at least one filler at a fraction of from 30 to 80% by weight.

13. The lead or chalk or color tablet according to claim 1, which further comprises providing at least one filler at a fraction of from 40 to 70% by weight.

14. The lead or chalk or color tablet according to claim 12, which further comprises selecting the filler from at least one of the group consisting of talc, kaolin, pumice powder, calcium carbonate, barium sulfate, mica and titanium dioxide.

15. The lead or chalk or color tablet according to claim 13, which further comprises selecting the filler from at least one of the group consisting of talc, kaolin, pumice powder, calcium carbonate, barium sulfate, mica and titanium dioxide.

16. The lead or chalk or color tablet according to claim 1, which further comprises providing at least one fatty or waxy substance.

17. The lead or chalk or color tablet according to claim 16, which further comprises providing the at least one fatty or waxy substance at a fraction of from 0.1 to 30% by weight.

18. The lead or chalk or color tablet according to claim 16, wherein the at least one fatty or waxy substance contains at least one of a fatty acid or a fatty acid derivative or a wax.

19. The lead or chalk or color tablet according to claim 17, wherein the at least one fatty or waxy substance contains at least one of a fatty acid or a fatty acid derivative or a wax.

20. The lead or chalk or color tablet according to claim 1, which further comprises at least one colorant.

21. The lead or chalk or color tablet according to claim 20, wherein the at least one colorant is at least one of an inorganic or organic pigment.

22. The lead or chalk or color tablet according to claim 20, which further comprises providing the at least one colorant at a fraction of from 0.5 to 20% by weight.

23. The lead or chalk or color tablet according to claim 13, which further comprises providing at least one of at least one inorganic or organic pigment and at least one water-soluble dye.

24. A pencil, comprising a lead according to claim 1.

25. The pencil according to claim 24, which further comprises a sheathing composed of wood or a wood substitute material.

26. A method for producing a lead or a chalk or a color tablet for at least one of writing, drawing or cosmetics purposes, the method comprising the following steps: providing at least one of at least one sugar or sugar alcohol or pentaerythritol; providing at least one of at least one cellulose derivative or starch derivative; providing at least one surfactant selected from the group consisting of sulfuric acid fatty acid ester salts, fatty acid sulfoalkyl esters and ethoxylated forms of alkali metal fatty acid sulfates; thermoplastically processing the at least one of at least one sugar or sugar alcohol or pentaerythritol, the at least one of at least one cellulose derivative or starch derivative and the at least one surfactant at an elevated temperature bringing about a softening of at least one of the sugar or sugar alcohol or of the pentaerythritol and obtaining a lead base composition; and extruding the lead base composition to give at least one of leads or chalk strands or shaping the lead base composition to give color tablets.

27. The method according to claim 26, which further comprises: adding water being jointly mixed with the at least one of at least one sugar or sugar alcohol or pentaerythritol, the at least one of at least one cellulose derivative or starch derivative and the at least one surfactant; and reducing a fraction of the water to at most 2% by weight during the thermoplastic processing.

Description

DESCRIPTION OF THE INVENTION

[0028] Four exemplary recipes for a lead are listed below. The starting substances or raw materials are first mixed at a temperature of from 80 to 150 C. in a high-speed mixer or in an extruder. In order to quicken the mixing or homogenization process, a water fraction of from 15 to 20% by weight is added and is evaporated up to a residual moisture of not more than 2% by weight during the mixing operation in the high-speed mixer or extruder. The lead base composition which is obtained is extruded at about from 140 to 180 C. in a screw extruder and then cut to length to give leads. The leads or chalks thus produced have a diameter of between 2.6 and 6.0 mm.

Example 1

Aquarellable Green Colored Lead or Aquarellable Green Chalk:

[0029]

TABLE-US-00001 Mannitol 6.0% by weight NaCMC.sup.1) 4.0% by weight Sodium cocoyl isethionate 20.0% by weight (CAS 61789-32-0) Kaolin 56.4% by weight Titanium dioxide 5.0% by weight Pigment Yellow 3 1.8% by weight Pigment Yellow 1 0.9% by weight Pigment Blue 15 1.35% by weight Pigment Green 7 4.55% by weight

[0030] A lead or chalk or a pencil containing a lead having a composition in line with Example 1 has a very good processability or extrudability. This can be attributed in particular to the use of mannitol as sugar alcohol and to the high fraction of 20% by weight of the surfactant used (sodium cocoyl isethionate). Furthermore, the lead exhibits an excellent aquarellability and lightfastness.

Example 2

Aquarellable Blue Colored Lead or Aquarellable Blue Chalk:

[0031]

TABLE-US-00002 Sorbitol 6.7% by weight Carboxymethyl starch.sup.2) 4.5% by weight Sodium myreth sulfate 10.0% by weight (CAS 25446-80-4) Hydrocarbon wax 6.8% by weight Pumice powder 63.2% by weight Titanium dioxide 1.0% by weight Pigment Blue 15 7.2% by weight Pigment Red 146 0.6% by weight

[0032] In the case of a lead or chalk or a pencil containing a lead having a composition in line with Example 2, the fraction of surfactant, sodium myreth sulfate in this case, was reduced as compared to Example 1. Nevertheless, a sufficiently good processability and extrudability with comparable aquarellability and lightfastness is also apparent in the production of the lead.

Example 3

Aquarellable Red Colored Lead or Aquarellable Red Chalk:

[0033]

TABLE-US-00003 Xylitol 7.0% by weight Carboxymethyl starch.sup.2) 5.0% by weight Sodium lauryl sulfoacetate 8.0% by weight (CAS 1847-58-1) Sorbitan monostearate 8.0% by weight Talc 62.6% by weight Titanium dioxide 1.0% by weight Pigment Red 254 7.0% by weight Pigment Yellow 3 1.4% by weight

[0034] In the case of a lead or chalk or a pencil containing a lead having a composition in line with Example 3, the surfactant used was sodium lauryl sulfoacetate and its fraction was further reduced as compared to Examples 1 and 2, specifically to 8% by weight. However, aquarellability and lightfastness and also processability are also still satisfactory in this case.

Example 4

Aquarellable Orange Colored Lead or Aquarellable Orange Chalk:

[0035]

TABLE-US-00004 Mannitol 17.4% by weight Carboxymethyl starch.sup.2) 2.3% by weight Sodium lauryl sulfate 15.0% by weight (CAS 151-21-3) Hydrocarbon wax 4.3% by weight Kaolin 50.6% by weight Titanium dioxide 6.0% by weight Pigment Yellow 74 3.6% by weight Pigment Orange 34 0.8% by weight

[0036] In the case of a lead or chalk or a pencil containing a lead having a composition in line with Example 4, the surfactant used was sodium lauryl sulfate. Such a lead or chalk exhibits in particular a good aquarellability.

[0037] Product Names/Manufacturers:

1) Dow Wolff Cellulosics GmbH, 29699 Bornlitz, Germany

2) Sdstrke GmbH, 86529 Schrobenhausen, Germany