CURABLE CASTING COMPOUND FOR THE MANUFACTURE OF MOLDED PLASTICS

Abstract

The invention relates to a curable casting compound for the manufacture of molded plastics, comprising a binder component composition and a composition of the filler component, wherein the filler component composition comprise at least one magnetic metal oxide, in particular magnetite, in a proportion of 1 to 100 percent by weight, in relation to the total mass of the composition of the filler component.

Claims

1. A curable casting compound for the manufacture of molded plastics comprising a binder component composition and a composition of the filler component, characterized in that the composition of the filler component comprises at least one magnetic metal oxide, in particular magnetite, in a proportion from 1 to 100 percent by weight, in relation to the total mass of the composition of the filler component.

2. The curable casting compound according to claim 1, characterized in that at least one magnetic metal oxide has a proportion of at least 50 percent by weight in relation to the total mass of the composition of the filler component.

3. The curable casting compound according to claim 1, characterized in that the at least one magnetic metal oxide has a proportion of between 15 and 50 per-cent by weight, preferably between 20 and 40 percent by weight, in particular be-tween 25 and 30 percent by weight, in relation to the total mass of the composition of the filler component.

4. The curable casting compound according to claim 1, characterized in that the at least one magnetic metal oxide is provided in the form of granular magnetite.

5. The curable casting compound according to claim 4, characterized in that the granular magnetite has an average diameter between 100 and 500 microns, preferably between 200 and 400 microns, more preferably between 250 and 350 microns.

6. The curable casting compound according to claim 1, characterized in that the binder component composition comprises at least a portion of a liquid monomeric acrylate.

7. The curable casting compound according to claim 1, characterized in that the composition of the filler component comprises a proportion of a peroxide mixture.

8. The curable casting compound according to claim 1, characterized in that the curable casting compound has a colorant material composition of 0.1 percent by weight to 20 percent by weight, in particular of 0.5 percent by weight to 10 percent by weight, in particular of 1 percent by weight to 5 percent by weight.

9. Use of a curable casting compound according to claim 1, for the manufacture of a molded plastic for the kitchen and/or sanitary sector, in particular kitchen sinks and countertops for kitchens.

10. Molded plastic manufactured using the curable molding compound according to claim 1, in particular by means of a casting process.

11. A securing system (10) comprising a molded plastic (1) according to claim 10 and at least one magnetic or magnetizable accessory element (2, 3) for securing to the molded plastic (1) by means of magnetic force.

12. The securing system according to claim 11, characterized in that the accessory element (2, 3) comprises at least one magnetic element (2a, 3a), which is connected to the accessory element, in particular by means of an adhesive connection.

Description

[0029] In the Figures

[0030] FIG. 1 shows the pull-off force perpendicular and in parallel to a sample plate of a molded plastic according to one embodiment of this invention; and

[0031] FIG. 2 shows a schematic representation of a securing system according to one embodiment of this invention.

[0032] It became evident that when metal oxides with magnetic properties are used in accordance with the invention, even at low final concentrations in the range of 1.0 percent by weight, in particular more than 3.0 percent by weight, preferably more than 5.0 percent by weight in the curable casting compound, a considerable magnetic force can be provided in conjunction with commercially available magnets.

COMPARATIVE EXAMPLE

[0033] A curable casting compound is prepared by adding a filler material to a binder material according to EP 1 487 906 A1, which is hereby incorporated by explicit reference. The binder material is essentially obtained by dissolving PMMA in MMA, wherein a demolding agent and crosslinking monomers are added. A binder syrup is obtained in that way.

[0034] The filler material comprises granular quartz material Granucol® (Gebrüder Dorfner GmbH & Co., Hirschau) and magnetite (LKAB Minerals GmbH). The types of Granucol® and magnetite listed below were used: [0035] Granucol® white 2/9 (mean grain size 330 microns) [0036] Magnetite (mean diameter 300 microns)

[0037] If, in particular, different Granucol® grades are used, which can be colored differently, a particularly attractive granite decor appearance can be achieved.

[0038] The filler material is now added to the binder material and homogeneously mixed therewith. Furthermore, a color material mixture is added to the curable casting compound to adjust the desired color of the later molded plastic.

[0039] The casting compound is then thermally cured by means of free-radical polymerization.

[0040] In addition, the binder may also comprise one or more cross-linking agents. Cross-linking agents are, for instance, substances from the group of aliphatic or aromatic di-, tri- or multifunctional acylates or methacrylates and/or epoxy acrylates or methacrylates and/or aliphatic or aromatic di-, tri- or multifunctional urethane acrylates or methacrylates and/or di-, tri- or multifunctional polyester acylates or methacrylates and/or di-, tri- or multifunctional silicone acrylates or methacrylates, silicone urethane acrylates or methacrylates and silicone polyester acrylates or methacrylates, or combinations thereof.

[0041] The composition of the curable casting compound according to a comparative example is again shown in general form in Table 1 below, wherein the contents of the individual components are specified in percent by weight.

TABLE-US-00001 TABLE 1 Composition of the comparative example: Component Percent by weight Binder* (PMMA in MMA) 23.07 *(PMMA: approx. 19 percent by weight, MMA: approx. 81 percent by weight) Trimethylolpropane trimethacrylate 1.89 Peroxide mixture 0.60 Heucodur ® HD952 1.66 Iriodin ® 163 0.18 Granucol ® white 2/9 72.60 Total 100.00

[0042] As mentioned above, the curable casting compound is then placed in a casting mold for a kitchen sink and polymerized by being exposed to heat.

[0043] A sample plate is cut out of the kitchen sink and a predetermined pull-off element comprising a permanent magnet having a magnetic flux density of about 350 mT, which is provided with a hook, is used to measure the pull-off force both perpendicular to the sample plate and in parallel to the sample plate. A manual force gauge model I-FGA 08 by Induk GmbH was used to measure the pull-off force.

[0044] The molded plastic manufactured in this way according to the comparative example does not contain any magnetite (FIG. 1, Magnetite: 0 percent by weight). It was impossible to determine any magnetic properties, i.e., the respective pull-off forces are 0 N according to FIG. 1.

Examples 1 to 6

[0045] A casting compound according to the invention is manufactured, the composition of which largely matches the curable casting compound of the comparative example, wherein essentially a quantity of magnetite (company LKAB Minerals GmbH) is added as a replacement of a matching quantity of Granucol® and, in the case of higher contents of magnetite, additionally also as a replacement of quantities of further components.

[0046] The composition of the curable casting compound for Examples 1 to 6 is shown in Table 2 below, wherein the contents of the individual components are specified in percent by weight, in each case in relation to 100 kg of curable casting compound.

TABLE-US-00002 TABLE 2 Composition of the casting compound modified using magnetite: Content of magnetite filler in percent by weight 5 10 20 40 80 100 Component Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Binder* 23.64 22.20 21.18 18.40 17.40 13.27 (PMMA in MMA) *(PMMA: approx. 19 percent by weight, MMA: approx. 81 percent by weight) Trimethylolpropane 1.91 1.92 1.91 1.89 1.89 1.24 trimethacrylate Peroxide mixture 0.60 0.56 0.56 0.49 0.47 0.35 Heucodur ® HD952 1.66 1.69 1.72 1.78 1.80 1.13 Iriodin ® 163 0.18 0.19 0.19 0.20 0.20 0.13 Granucol ® white 2/9 68.37 66.00 59.44 46.14 15.34 0.00 Magnetite (d50, approx. 300 μm) 3.64 7.44 15.00 31.10 62.90 83.88 Total 100.00 100.00 100.00 100.00 100.00 100.00

[0047] As described for the curable casting compound according to the comparative example, the curable casting compound according to Examples 1 to 6 is used to produce one kitchen sink each.

[0048] A sample plate is again cut out of the kitchen sink and a predetermined pull-off element comprising a permanent magnet having a magnetic flux density of about 350 mT, which is provided with a hook, is used to measure the pull-off force both perpendicular to the sample plate and in parallel to the sample plate. A manual force gauge model I-FGA 08 by Induk GmbH was used to measure the pull-off force.

[0049] In the molded plastics manufactured in that way according to Examples 1 to 6, the magnetite content was increased with every increment of the numbering of the examples. The respective pull-off forces are shown in FIG. 1 and show an increase of the respective pull-off forces with increasing magnetite content, in particular these show a substantially linear increase of the pull-off forces perpendicular to the sample plate with respect to a matching increase of the magnetite content.

[0050] As a result, it can be noted that even for a small amount of magnetite, relevant pull-off forces can be achieved, such that matching “counter elements” or accessories that are to be held on the sink by means of magnetic force can be detachably positioned there compared to the test example.

[0051] The results thus show that the addition of magnetic metal oxides, in particular magnetite, to the curable casting compound, especially as a replacement of the dye(s), results in the provision of a magnetic curable casting compound and thus in a magnetic or magnetizable molded plastic.

[0052] The molded plastic components, such as kitchen sinks or the like, manufactured using the curable casting compound according to one embodiment of this invention exhibit magnetic properties that are sufficient to securely and detachably secure matching components by means of magnetic force, compared to the curable casting compound obtained in the comparative example.

[0053] The effect of providing magnetic properties thus occurs with the use of magnetic metal oxides, in particular magnetite, according to the invention.

[0054] FIG. 2 shows a schematic representation of a securing system according to one embodiment of this invention.

[0055] FIG. 2 shows a cross-sectional view of a sink 1 having magnetic properties according to embodiments of the invention. An accessory element in the form of a sink brush 2, which has a permanent magnet 2a in its head, can be attached to a side wall 1a of the sink 1 by means of magnetic force. A further accessory element in the form of a basket 3, for instance for storing a detergent bottle or the like, is made of plastic. By means of a magnetic adhesive strip 3a applied to the back of the basket 3, the basket 3 can then be attached to the side wall 1a of the sink 1.

[0056] In summary, at least one of the embodiments of the invention has at least one of the advantages listed below: [0057] improved flexibility in securing additional components on molded plastics. [0058] low application quantity of the required active additive (metal oxide, especially magnetite) and thus low material input costs. [0059] high flexibility with regard to the visual design of surfaces. [0060] simple, inexpensive manufacture. [0061] easy workability.

[0062] Although this invention has been described with reference to preferred exemplary embodiments, it is not limited thereto and can be modified in a variety of ways.

LIST OF REFERENCE NUMERALS

[0063] 1 sink [0064] 1a shell [0065] 2 sink brush [0066] 2a permanent magnet [0067] 3 basket [0068] 3a adhesive magnetic strips [0069] 10 sink system