Composite material and use thereof, and process for production thereof

Abstract

The invention relates to a composite material for writing, drawing and / or painting tools, cosmetic articles or articles from the craftwork sector and elements therefor, at least consisting of at least one polymeric binder, at least one organic filler, at least two waxes, at least one adhesion promoter, at least one inorganic filler, characterized in that the composite material includes at least two waxes, in that the at least two waxes have different melting points from one another, and in that the composite material has the following composition: organic filler... 15-45 wt%; adhesion promoter... 0.2-1.5 wt%; wax 1... >0.4-1.6 wt%; wax 2... 0.4-1.6 wt.%; inorganic filler... 0.2-3 wt%; first polymeric binder... 4-20 wt%; second polymeric binder... remainder to 100 wt%.

Description

Composite material and its uses as well as methods for its production Description

[0001] The invention relates to a composite material and its use for writing, drawing or painting instruments, cosmetic and / or hobby and creative articles, or accessories, as well as elements thereof, such as pencils, colored pencils, sharpeners; sharpener boxes, caps or cosmetic pencils with color-emitting leads, as well as various types of pencils with leads made of, for example, eraser material, lead casings, shafts, ink reservoirs, spatulas or containers for modeling clay.

[0002] Furthermore, the invention relates to a method for producing the composite material.

[0003] Consumer goods and their components made of composite materials, as well as the processes for their production using injection molding, are generally known.

[0004] It is also generally known to replace products and elements for products made of pure wood or pure plastic with composite materials.

[0005] Due to the lack of availability of wood, the price increase especially for high-quality woods and a related increase in manufacturing costs in conjunction with the relatively high consumption of natural wood resources, the production of a mine covering made of wood-plastic composite material is known from DE102008034013A1. The disadvantage here is that this wood substitute material and its use can only be employed in extrusion.

[0006] Furthermore, patent US2988784 discloses the manufacture of a sheathed mine using wood substitute materials. A disadvantage of manufacturing such a writing instrument using the injection molding process described above is that the composite material does not completely fill the mold. As explained in the document, this type of material is better suited for use in extrusion technology.

[0007] Patent DE 600 34 108 T2 discloses a method for producing pen casings by co-extrusion, wherein the casing consists of thermoplastic material. Although the use of pure plastic is known in principle, the formula mentioned in this document would also have to be adapted for use in injection molding in order to completely fill the injection molds. Regardless, it remains disadvantageous to manufacture such pens from pure plastic using injection molding processes, as the aim is to keep the proportion of plastics in consumer goods as low as possible.

[0008] It is therefore an object of the present invention to create a wood-plastic composite material which does not have the aforementioned disadvantages.

[0009] The object of the invention is therefore to create a wood-plastic composite material that has improved flowability with the highest possible wood content.

[0010] Furthermore, the object of the invention is to create a wood-plastic composite material that enables its use in injection molding, thereby allowing more complex and / or longer flow geometries to be processed.

[0011] It has been shown that a simple increase in temperature during the processing of the composite material can at least partially improve flowability, but this would lead to the burning or denaturation of the wood flour content / organic fillers in the composite mass.

[0012] The problem is solved by the features mentioned in claim 1. Further solution features are found in the dependent claims.

[0013] Furthermore, the problem is solved by the method encompassed in claim 9.

[0014] Claims 10 and 11 claim the use of such a wood-plastic composite material according to the invention.

[0015] Surprisingly, it has been shown that a composite material for writing, drawing and / or painting instruments, cosmetics or hobby and creative items, as well as related components, is particularly suitable if it consists of at least one polymeric binder, at least one organic filler, at least two waxes, and at least one The adhesion promoter consists of at least one inorganic filler and the at least two waxes have different melting points.

[0016] A composite material designed according to the invention consists of organic filler . 15-45 wt.% Bonding agent . 0.2-1.5 wt. % Wax 1 . 0.4-1.6 wt. % Wax 2 . 0.4-1.6 wt. % Inorganic filler . 0.2-3 wt.% First polymeric binder. 4-20 wt.% Second polymeric binder. Remainder to 100 wt.%.

[0017] In this case, at least the first polymeric binder is in the form of polyethylene (PE) and at least the second polymeric binder is in the form of polypropylene (PP).

[0018] The at least two waxes are present as stearic acid / derivative and ethylene bis-stearamide (EBS). It should be noted that stearic acid is usually found in industrial applications as a mixture of stearic and palmitic acids. The two waxes have different melting points. In this case, the melting point of one wax is above 100°C and the other below 100°C. Specifically, the melting point of EBS is approximately 140°C and the melting point of stearic acid / derivative is approximately 65°C.

[0019] It has been surprisingly shown that the wax mixture significantly reduces the internal and external friction of the polymer melt. This ensures the necessary flowability for an injection molding process.

[0020] The ratio of stearic acid to EBS is in the range of 1:4 to 4:1. A ratio of stearic acid to EBS in the range of 1:3 to 3:1 has proven advantageous. A ratio of stearic acid to EBS of 1:2 to 2:1 is particularly advantageous.

[0021] Wood and / or cellulose are used as at least one organic filler. This filler contains at least one organic filler particle with a mean particle size of <250 pm, in particular <150 pm.

[0022] For bonding wood and polymer, an adhesion promoter has proven effective. Maleic anhydride (MAH)-grafted polyolefin and / or polyolefin wax are present as at least one of the adhesion promoters.

[0023] The components of the wood-plastic composite are compounded in an extruder during the manufacturing process. It has proven advantageous to perform this compounding on a two-screw co-rotating extruder followed by underwater or strand pelletizing.

[0024] This composite material is used in injection molding to manufacture writing, drawing and / or painting instruments, cosmetic items or hobby and creative items, such as spatulas or containers for modeling clay, as well as to manufacture elements for these items, and is preferably fed to the injection molding tool in the form of granules.

[0025] Wood-plastic composites are used to manufacture articles using injection molding. Examples include writing, drawing, and / or painting instruments, as well as cosmetics and hobby / creative items.

[0026] The invention will be explained in more detail by the following framework examples and recipe examples. Example 1: organic filler . 15-45 wt.% Bonding agent . 0.2-1.5 wt. % Wax 1 . 0.4-1.6 wt. % Wax 2 . 0.4-1.6 wt. % Inorganic filler . 0.2-3 wt.% Additive(s) . 0 - 3 wt.% First polymeric binder. 4-20 wt.% Second polymeric binder. Remainder to 100 wt.% Example 2: organic filler . 18-40 wt.% Bonding agent . 0.3-1.3 wt. % Wax 1 . 0.5-1.3 wt. % Wax 2.0.5–1.3 wt. % Inorganic filler . 0.3-2 wt.% Additive(s) . 0 - 5 wt.% First polymeric binder. 5-18 wt.% Second polymeric binder. Remainder per 100 wt. % Recipe example 1: Wood flour . 30 wt. % MAP / PE adhesion promoter . 0.4 wt. % Wax 1 - EBS . 0.8 wt. % Wax 2 - Stearic acid / derivative . 0.8 wt. % TiO2 . 0.4 wt. % PE . 9 wt. % PP. Remainder per 100 wt. % This example formulation shows that the two wax components have different melting points. Specifically, EBS has a melting point of approximately 140°C and the stearic acid / derivative has a melting point of approximately 65°C. Recipe example 2: Wood flour . 40 wt. % MAP / PE adhesion promoter . 0.8 wt. % Wax 1 - EBS . 1.0 wt. % Wax 2 - Stearic acid / derivative . 2 wt. % TiO2 . 0.4 wt. % UV stabilizer . 0.5 wt. % PE . 11 wt. % PP. Remainder per 100 wt. %

[0027] The organic fillers are made from wood, wood flour and / or cellulose, or derivatives thereof. The maximum particle size is 250 pm. A maximum particle size of 100 pm is advantageous.

[0028] To adjust the brittleness, mechanical properties and optical design, it is advantageous that at least one inorganic filler from the group of The fillers selected include layered silicates, calcium sulfate, calcium carbonate, boron nitride, soapstone, and / or graphite.

[0029] To lighten the color, an additional organic filler can be used. Titanium dioxide (TiO2), for example, has proven advantageous as a color pigment. To achieve the desired color, it is beneficial if the composite material contains 0.1 to 5 wt% colored pigment.

[0030] In order to achieve specific properties and meet special requirements, such as surface finish, feel or UV resistance, it is advantageous that at least one additive is chosen from the group of additives including lubricants, plasticizers, surfactants, thermal stabilizers, and UV stabilizers.

Claims

Patent claims 1) Composite material for writing, drawing and / or painting instruments, cosmetics or articles from the Hobby and creative applications, as well as elements thereof, consisting at least of: at least one polymeric binder, at least one organic filler, at least two waxes, at least one adhesion promoter, at least one inorganic filler, characterized in that the composite material has at least two waxes, that the at least two waxes have different melting points, and that the composite material is composed as follows: organic filler . 15-45 wt.% Bonding agent . 0.2-1.5 wt. % Wax 1 . 0.4-1.6 wt. % Wax 2 . 0.4-1.6 wt. % Inorganic filler . 0.2-3 wt.% First polymeric binder. 4-20 wt.% Second polymeric binder. Remainder to 100 wt.% 2) Composite material according to claim 1, characterized in that the at least first polymeric binder is in the form of polyethylene (PE) and the at least second polymeric binder is in the form of polypropylene (PP). 3) Composite material according to claim 1, characterized in that at least one wax has a melting point above 100°C and at least one wax has a melting point below 100°C. 4) Composite material according to claim 1 or 2, characterized in that, that the at least two waxes are present as stearic acid or stearic acid derivative and ethylene bis-stearamide (EBS). 5) Composite material according to at least one of the preceding claims, characterized in that the ratio of stearic acid or stearic acid derivative and EBS is in the range of 1:4 to 4:

1. 6) Composite material according to at least one of the preceding claims, characterized in that the ratio of stearic acid or stearic acid derivative and EBS is in the range of 1:2 to 2:

1. 7) Composite material according to at least one of the preceding claims, characterized in that the at least one organic filler is formed from filler particles with an average particle size of < 250 pm, in particular of < 150 pm. 8) Composite material according to claim 1 or 6, characterized in that the at least one organic filler is formed from wood and / or cellulose. 9) Composite material according to claim 1, characterized in that the at least one adhesion promoter is a maleic anhydride (MAH) grafted polyolefin and / or polyolefin wax. 10) Method for producing a composite material according to claim 1, characterized in that the components are compounded on an extruder. 11) Method for manufacturing a writing, drawing and / or painting device and an element thereof, characterized in that the manufacturing method comprises an injection molding process. 12) Use of a composite material according to claim 1 for the manufacture of articles by injection molding. 13) Use of a composite material according to claim 1 for the manufacture of writing, drawing and / or painting instruments, as well as cosmetic articles or articles from the hobby and creative sector.