EP2142352A1

EP2142352A1 - Plastic molded part and the production thereof

Info

Publication number: EP2142352A1
Application number: EP08735043A
Authority: EP
Inventors: Martin Kirschbaum; Evangelos Konstantinidis; Stefanie Brenner; Mathias PÄHL
Original assignee: SCHEER SURFACE SOLUTIONS GmbH
Current assignee: SCHEER SURFACE SOLUTIONS GmbH
Priority date: 2007-04-05
Filing date: 2008-04-05
Publication date: 2010-01-13
Also published as: WO2008122428A1; DE102007017978A1; US20100119798A1

Abstract

The invention relates to a method for the production of plastic molded parts, preferably for kitchen, sanitation, and measuring uses, wherein a preferably plate-shaped molded part is produced from a castable reaction material, the molded part so produced is cured and formed thereafter, wherein the reaction material comprises at least one organic polymer component and at least one inorganic filler material as components, and the filler material comprises an average particle size < 150µm, and the reaction material contains > 50% by weight of the inorganic filler material with respect to the mass of the cured molded part. Moreover, the invention relates to a reaction mass which can be used in a method according to the invention, and plastic molded parts which are or can be produced from such a reaction mass and/or according to such a method.

Description

description

Plastic moldings and their manufacture

The invention relates to a process for the production of plastic moldings, in particular for the kitchen, sanitary and trade fair area, a reaction mass for the production of plastic moldings as well as plastic moldings produced or producible by this process and / or from this reaction mass.

Plate-shaped plastic moldings can be used, for example, in interior design, especially in the kitchen or in the sanitary sector, as well as in the construction of buildings, in shopfitting and exhibition construction. The molded parts are used there in particular as floor, wall or worktop. Depending on the respective field of application, the molded parts differ in their shape, in their dimensions and in their composition.

The abovementioned molded parts generally have an organic polymer matrix in which inorganic and / or organic fillers are dispersed. The polymer matrix can be formed, for example, from polyester or polyacrylic resins. The inorganic fillers are generally used as flour, sand or powder, in particular quartz and cristobalite can be used.

The known from the prior art plate-shaped plastic moldings are usually cast from a reaction mass and then cured. For example, the reaction mass can be poured into temperature-regulated printing plates and cured under temperature increase and pressure. As disclosed in EP 851 808, it is thus also possible to produce molded parts in the form of composites. There, an integral plate-shaped component is described, which has a multilayer structure. The plastic moldings known from the prior art may, in order to be better cared for and scratch-resistant, contain platelet-shaped materials in a desired preferred orientation. DE 40 40 602 discloses a reaction mass which, in addition to a particulate filler having a particle size distribution of 0 to 200 μm, contains a platelet-shaped iriodin dye having a particle size of 30 μm to 200 μm, with which such molded parts can be produced.

The known from the prior art method for producing the mentioned plate-shaped plastic moldings hardly differ from each other. The plastic moldings can be sanded and polished after casting and curing, then they are usually cut to size. In this form, they are usually used without further processing or installed at customers. Any necessary adjustment must be made mechanically, for example by cutting or pledging. The cut plate-shaped plastic parts are then installed according to their purpose, for example as a kitchen worktop.

The connection of plastic parts to walls or furniture is usually done via special connection profiles. However, this can create small gaps and cracks between the plastic moldings and the profiles, in which, for example, dirt and bacteria can be stored and therefore must be laboriously sealed.

It would be desirable according to the availability of plate-shaped plastic moldings that can be easily and individually adapted to their destination and preferably also offer the possibility of a gap-free connection. The plastic moldings themselves should have a high filler content, the filler should be distributed as evenly as possible in the plastic moldings.

This object is achieved by the method according to claim 1, the reaction mass according to claim 11 and the plastic molded part according to claim 15. Preferred embodiments of the method according to the invention are set forth in the dependent claims 2 to 10. Preferred embodiments of the reaction mass of the invention and the plastic molding according to the invention can be found in claims 12 and 14 and 16 to 18. The wording of all claims is hereby incorporated by reference into the content of this description.

The inventive method is suitable for the production of plastic molded parts, in particular for the production of substantially plate-shaped plastic moldings. An inventive method is particularly suitable for the production of countertops, wall panels and floor panels, which are used in the kitchen, sanitary and trade fair area.

According to the method of the invention, a preferably plate-shaped molded part is produced from a castable reaction mass and cured. After curing, the molded part is formed. The castable reaction mass has at least one organic polymer component and at least one inorganic filler, preferably a particulate inorganic filler. The at least one filler has an average particle size of less than 150 μm, preferably less than 100 μm, in particular less than 50 μm, particularly preferably less than 30 μm. In the last-mentioned range, particle sizes between 5 μm and 10 μm are particularly preferred. In the reaction mass of the inorganic filler is contained in a proportion of> 50% by weight (based on the mass of the cured molding). Preferably, the reaction mass is converted to produce the preferably plate-shaped molded part in a mold, in particular cast, and then cured. In particular, the reaction mass can be converted into a heatable mold. The reaction mass can be heated prior to transfer to the mold, for example to a temperature of about 50 ^° C. After filling the mold, it can be heated relatively quickly to a specific curing temperature, for example about 100 ^° C. According to the invention, it may be provided that the curing of the reaction mass is assisted by an increased pressure of the mold.

After curing, the already mentioned reshaping of the molding follows. Preferably, the cured molded part is heated to at least a portion, in particular to temperatures above the Tg of the at least one organic polymer component, preferably to at least 100 ⁰ C. By supplying energy, the plastic molded part is moldable and can undergo a change in shape, in particular a plastic deformation become. After the respective molding has cooled, it retains its new shape. Preferably, this process is reversible.

In a preferred embodiment of the method according to the invention, the forming is carried out at a temperature which is below the temperature at which the molded part could melt or decompose.

Particularly preferably, the cured molding for forming to a temperature between 100 ⁰ C and 250 ⁰ C, preferably between 100 ⁰ C and 200 ⁰ C, in particular between 120 ⁰ C and 160 ° C, heated.

Surprisingly, it has been found that the plastic moldings produced from the above-mentioned reaction mass also after their curing are still easily deformable, in particular very well suited for thermal forming, despite the relatively high proportion of filler. This seems to be due to the materials used and their interaction. It is believed that the small mean particle size of the inorganic fillers in particular plays a major role here. This seems to ensure a relatively uniform temperature distribution in the interior of the molded part when heated. The risk of the occurrence of large stresses in the molded part is greatly minimized. The surface of the molded part remains essentially free of cracks during forming, as a rule no cracks are visible with the naked eye. After reshaping, therefore, the surface must at most be sanded off briefly, in most cases the reshaped plastic part can be used directly without further processing.

The reaction mass used in a process according to the invention is particularly preferably free of inorganic filler particles having a particle size> 250 μm. Preferably, it has exclusively inorganic filler particles with a particle size <100 .mu.m, in particular <50 .mu.m (optionally traces of coarser particles can not be avoided due to the production, but the proportion of these is always less than 5%, preferably less than 1%, in each case on the total amount of filler particles).

Preferably, the reaction mass has filler particles in a unimodal distribution, but bimodal or trimodal distributions may also be preferred.

In a further preferred embodiment, the reaction mass used in addition to the inorganic filler particles no further fillers such as the organic fillers mentioned above. Preferably, the reaction mass consists essentially of the at least one organic polymer component and the at least one inorganic filler and has next to at most one or more colorants and / or auxiliaries. The latter include, in particular, crosslinkers, release agents, polymerization catalysts (for example peroxides), rheological aids and dispersants, which may be present in small amounts. The auxiliaries serve in particular to improve the chemical and / or mechanical properties of the reaction mass and can be added to the needs of the respective applications. Some suitable colorants and adjuvants will be described in more detail below.

In particularly preferred embodiments of the process according to the invention, the reaction mixture according to the invention has, as rheology assistant, a silanized or non-silanized silica. The rheology aid effectively slows or even completely prevents sedimentation of the at least one inorganic filler in the reaction mass prior to curing. In particular, in the case of low-viscosity reaction materials, it is otherwise possible for there to be an unequal distribution of the filler in the molded part to be produced, which may adversely affect its properties.

The reaction mass of the invention preferably has a viscosity in the range between 5 Pa s and 60 Pa s, preferably between 15 Pa s and 45 Pa s, in particular between 20 Pa s and 30 Pa s, (in each case at 20 ⁰ C). This is essentially determined by the proportion of filler in the reaction mass, but can also be influenced by the auxiliaries mentioned.

Preferably, the cured molding is heated by means of hot air for forming. For example, the method can be carried out so that air is heated by one or more hot air devices, which is specifically directed to the molding to this at one or more certain places and to carry out a localized transformation there. In principle, however, the molded part can be heated by means of any known fluid, including by means of liquids, as long as their use leaves the plastic molded part undamaged.

Furthermore, it is also possible that the molded part is heated by radiation, for example by radiation in the infrared and / or in the microwave range.

Particularly preferably, the cured molding is heated for forming in a heated press.

For the forming of the cured plastic molding all technical forming processes, in particular those that are suitable for hot forming can be used. In particular, tensile-forming methods such as deep-drawing or bending-forming can be used according to the invention.

Due to the above-described property of the formability of the plastic moldings produced from the castable reaction mass can be produced according to the method according to the invention plate-shaped plastic moldings, which are adapted by forming individually to their destination. With particular advantage, for example, the edge of a plastic molding intended as a kitchen worktop can be shaped upwards along a wall, optionally still on site. A gap in the plane of the work surface does not occur accordingly. On a separate connection profile for sealing the wall transition can be waived if necessary. Shower trays are also particularly easy to produce according to the method according to the invention.

In accordance with the method of the invention, it is also particularly easy to produce integral plastic molded parts which have one or more have lower or trough-shaped depressions. In preferred embodiments, the one-piece plastic moldings are trough-shaped or basin-shaped. For this example, a plate can be cast, which is then subjected to a deep-drawing process, wherein it is thermally deformed and the depression or the depressions are formed.

According to the method of the invention, individually shaped plastic molded parts can be produced which can be installed directly. Alternatively, it is also possible to carry out the step of reshaping at a later time, for example only at the customer.

In a preferred embodiment of the method according to the invention, the castable reaction mass comprises an organic polymer component based on acrylic and / or methacrylic, in particular a synthetic resin based on this. Particular preference is given to methacrylate systems. The organic polymer component may comprise suitable monomers and optionally prepolymers. In a polymerization of the methacrylate system, other monomers in the form of alkyl or aryl methacrylates can be used to form copolymers. For example, copolymers with ethyl methacrylate or butyl methacrylate can be formed.

In a particularly preferred embodiment, the castable reaction mass comprises polymethylmethacrylate (PMMA) as the organic polymer component.

In addition to PMMA, further organic polymers selected from a wide range of different plastics can be used to form the polymer matrix. Examples which may be mentioned are polyester, polyacrylate and polyvinyl ester resins, but also polyurethane or epoxy resins. In principle, it does not play a decisive role for the process according to the invention which type of reaction, ie whether or not For example, radical, anionic or cationic polymerization, takes place in the formation of the polymers.

In a further preferred embodiment, the castable reaction mass contains methyl methacrylate (MMA) as the organic polymer component.

The castability of the reaction mass can be determined by the ratio of reactants to one another, for example by the ratio of PMMA to MMA, if both are contained in the reaction mass. For acrylic resins, a proportion of PMMA dissolved in MMA counteracts sedimentation of the filler particles during handling of the reaction mass. However, other known substances can be used for this purpose, e.g. fumed silica, which has already been mentioned.

At this point it is advisable to make up for the above-mentioned description of some suitable auxiliaries and colorants.

In order to increase the chemical and mechanical stability of the final product, crosslinkers may be added to the castable reaction mass. Suitable crosslinkers are known to the person skilled in the art. Preference is given to using crosslinkers as polyfunctional or polyfunctional monomers and / or polymers, in particular polyfunctional or polyfunctional acrylates or dimethacrylates, for example ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate or pentaerythritol triacrylate.

In addition to or instead of the crosslinkers, it is possible in particular to add stabilizers to the castable reaction mass. Stabilizers serve to improve the chemical properties of the organic polymer component. They increase the lifetime of the polymers and protect them from harmful influences such as oxidation, radiation heat and heat, which can occur in the application area. In particular, the addition of antioxidants and / or UV stabilizers prevents oxidation and decomposition and / or re-crosslinking of polymer chains. For this purpose, phenols, amines or phosphenes can be used.

Coloring agents in the present case are both dyes, especially organic dyes, as well as pigments. Preferably pigments are added to the castable reaction mass as colorants, since with organic dyes there is a risk that they change during or after production of the moldings and lose their color fastness. Therefore, especially inorganic pigments are of particular importance. T FarbO ₂ , iron oxide, carbon black, cobalt or ultramarine blue, as well as chromium oxide green may therefore be suitable in particular as colorants. According to the invention, the use of so-called effect pigments may also be provided, for example, rare-earth-doped strontium aluminates show intensive night lighting. Depending on the application, the colorants can be distributed uniformly or unevenly in the plastic molding.

External and / or internal plasticizers may also be included to reduce the brittleness, hardness and softening temperature of the polymers in the reaction mass and thus improve the described formability. Examples of suitable plasticizers, such as e.g. Phthalic acid esters (an external plasticizer) or long chain acrylates (an internal plasticizer) are known to those skilled in the art.

Release agents can be added to the reaction mass for improved release of the cured molding from the mold. Suitable release agents, such as e.g. Stearic acid are known in the art.

The at least one inorganic filler mentioned above is preferably a finely divided inorganic filler. Substance, in particular a filler, which is available as a natural product. For example, crystalline quartz sand precipitates in the kaolin recovery as a by-product.

In a particularly preferred embodiment of the method according to the invention, the at least one inorganic filler is selected from the group consisting of quartz, cristobalite, tridymite, corundum and mixtures thereof. Quartz and cristobalite are particularly preferred.

As further materials, the at least one inorganic filler may also include materials such as glass, alumina, granite flour, basalt flour, ceramics, particularly silicon nitride and / or silicon carbide.

Furthermore, it may be preferred that the at least one inorganic filler usable according to the invention comprises surface-coated filler particles. Thus, the surfaces of the filler particles can be silanized in order to ensure a particularly good bond to the at least one organic polymer component.

Preferably, the at least one inorganic filler has a Mohs hardness greater than or equal to 4, in particular between 5 and 9, on.

In a particularly preferred embodiment, the at least one inorganic filler is present in a proportion of 50% by weight to 85% by weight, in particular in a proportion of about 60% by weight to 70% by weight, based on the mass of the cured molding, contained in the reaction mass. Preferably, the highest possible filler content is sought.

Reaction compositions have proven to be particularly suitable for use in a process according to the invention, which are used as constituents at least one organic polymer component and at least one inorganic filler, the latter having an average particle size <30 .mu.m, in particular <20 .mu.m, more preferably between 5 .mu.m and 10 .mu.m, wherein the inorganic filler in the reaction mass in a proportion of> 50 wt .-% is included. Accordingly, such a reaction mass for the production of plastic moldings is the subject of the present invention.

The at least one filler in particular has a d90 value of 50 μm or less, in particular of 30 μm or less, particularly preferably of 25 μm or less. The d95 value of the at least one filler in a reaction mixture according to the invention is preferably 60 μm or less, in particular 45 μm or less, particularly preferably 35 μm or less.

In addition to the at least one inorganic filler, a reaction mixture according to the invention preferably has no further fillers.

With regard to the other properties of the reaction mass, reference may be made to the statements already made above, e.g. with regard to optional colorants and auxiliaries, the nature of the at least one organic polymer component, the composition of the reaction mass and the physical nature of the at least one inorganic filler.

In experiments, it has been found that the method according to the invention results in particularly high-quality results when using a reaction mass according to the invention with the characteristics mentioned. Visually visible cracks practically do not occur during forming.

As already mentioned above, the present invention also includes a plastic molding, in particular a substantially plate-shaped Plastic molding, which is produced or preparable according to the inventive method. Preferably, this is a worktop, a wall plate or a bottom plate, in particular for the kitchen, sanitary and trade fair area. The plastic molding according to the invention may also be trough-shaped or basin-shaped, as already mentioned.

An inventive substantially plate-shaped plastic molded part can be applied to a known from the prior art substructure (for example, plywood, foamed glass, polyurethane foam or with a honeycomb structure) and then forms, for example, the surface of a kitchen worktop.

The plastic molding according to the invention has a matrix which can be prepared from the above-defined at least one organic polymer component and into which the above-defined at least one inorganic filler, preferably evenly distributed, is embedded.

The plastic molding according to the invention preferably has a Mohs hardness of not more than 9, in particular between 4 and 7, preferably between 5 and 7, on.

Particularly preferably, the plastic molded part according to the invention has a preferably uniform thickness of between 2 mm and 15 mm, in particular between 4 mm and 8 mm. Particularly preferred is a thickness of about 6 mm.

A substantially plate-shaped plastic molded part according to the invention can in principle be produced in any dimensions, but preferably it has a maximum length of up to about 4.1 m and a maximum width of up to about 1.3 m. The plastic molding according to the invention particularly preferably has at least one inorganic filler which has an average particle size <30 μm, in particular <20 μm, particularly preferably between 5 μm and 10 μm. In addition to the at least one inorganic filler, it preferably has no further fillers. In particular, it is substantially free of inorganic filler particles having a particle size> 250 microns. Preferably, it has exclusively inorganic filler particles with a particle size <100 .mu.m, in particular <50 .mu.m.

The at least one inorganic filler is contained in the plastic molding in a proportion of> 50 wt .-% (based on the total mass of the plastic molding). Preferably, the proportion of the at least one inorganic filler is between 50 wt .-% and 85 wt .-%, in particular between 60 wt .-% and 70 wt .-%.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments by way of examples in conjunction with the subclaims. In this case, the individual features may be implemented individually or in combination with each other in combination without departing from the scope of the invention.

example

Castable reaction masses having the following composition were prepared:

Recipe 1:

- 36.3 wt .-% of an organic polymer component (methyl methacrylate / polymethyl methacrylate with about 25% polymer content) 0.7% by weight of a conventional crosslinking agent (trimethylolpropane trimethacrylate)

0.5% by weight of a customary peroxidic catalyst (1: 2 mixture of di (4-tert-butylcyclohexyl) peroxydicarbonate and dilauroperoxide)

61% by weight of a quartz powder as inorganic filler (Silbond 3000MST, silanized grade)

0.1% by weight of a thixotropic agent (hydrophobic silica)

- 0.2% by weight of a conventional mold release agent (stearic acid) - 1.2% by weight of a pigment (titanium oxide)

Recipe 2:

35.4% by weight of an organic polymer component (methyl methacrylate / polymethyl methacrylate with about 25% polymer content)

0.7% by weight of a conventional crosslinking agent (trimethylolpropane trimethacrylate)

- 1, 0 wt .-% of a thixotropic agent (hydrophobic silica)

0.2% by weight of a conventional mold release agent (stearic acid) 1.2.2% by weight of a pigment (titanium oxide)

Recipe 3:

35.9% by weight of an organic polymer component (methyl methacrylate / polymethyl methacrylate with about 25% polymer content)

0.7% by weight of a conventional crosslinking agent (trimethylolpropane trimethacrylate) 0.5% by weight of a customary peroxidic catalyst (1: 2 mixture of di (4-tert-butylcyclohexyl) peroxydicarbonate and dilauroperoxide)

0.5% by weight of a thixotropic agent (Aerosil R812S)

0.2% by weight of a conventional mold release agent (stearic acid) 1.2% by weight of a pigment (titanium oxide)

Recipe 4:

28.55% by weight of an organic polymer component (methyl methacrylate / polymethyl methacrylate with about 25% polymer content)

0.55% by weight of a conventional crosslinking agent (trimethylolpropane trimethacrylate)

0.4% by weight of a customary peroxidic catalyst (1: 2 mixture of di (4-tert-butylcyclohexyl) peroxydicarbonate and dilauroperoxide)

- 69 wt .-% of a quartz powder as an inorganic filler - 0.1 wt .-% of a thixotropic agent (hydrophobic silica)

0.2% by weight of a conventional mold release agent (stearic acid)

- 1, 2 wt .-% of a pigment (titanium oxide)

Recipe 5:

33.80% by weight of an organic polymer component (methyl methacrylate / polymethyl methacrylate with about 25% polymer content)

- 0.6 wt .-% of a conventional crosslinking agent (trimethylolpropane trimethacrylate) - 0.5 wt .-% of a conventional peroxidic catalyst (1: 2 mixture of di- (4-tert-butylcyclohexyl) peroxydicarbonate and dilauro peroxide )

- 63.6% by weight of corundum flour (silane-modified sepase type) 0.1% by weight of a thixotropic agent (hydrophobic silica)

0.2% by weight of a conventional mold release agent (stearic acid)

- 1, 2 wt .-% of a pigment (titanium oxide)

Reaction masses according to formulations 1 to 5 are all very easy to process. Deposition of the filler during processing was not observed.

The measured viscosities of the casting masses were:

Formulation 1: 25600 mPa-s at 2O ⁰ C

Formulation 2: 39600 mPa-s at 20 ⁰ C (high tixotrophic mass)

Recipe 3: 22800 mPa-s at 20 ° C

Recipe 4: 46100 mPa-s at 20 ⁰ C Formulation 5: 34500 mPa-s at 20 ° C

The reaction masses were filled for the production of plate-shaped moldings in a heated to about 30 ° C mold. The mold was then heated to a temperature of about 100 ⁰ C. At this temperature, the molded parts were allowed to cure under pressure. After completion of the curing and subsequent cooling of the plate-shaped moldings, the edge of the moldings was heated locally to about 150 ⁰ C and then bent by pressure forming. After cooling again, plates were obtained with a longitudinal edge projecting at a 90 "angle.

The forming was smooth and without damaging the plate-shaped moldings. The surface of the moldings showed no visible cracks in the bent area and did not have to be reworked.

Claims

claims

1. A process for the production of plastic moldings, preferably for the kitchen, sanitary and trade fair area, in which a preferably plate tenförmiges molded part is made of a castable reaction mass, the molded part thus produced is cured and the molding is formed after curing, wherein the Reaction mass as constituents comprises at least one organic polymer component and at least one inorganic filler and the filler has an average particle size <150 .mu.m, in particular <50 .mu.m, more preferably <30 .mu.m, and wherein the inorganic filler, based on the mass of the cured molding, in a proportion of> 50 wt .-% is contained in the reaction mass.

2. The method according to claim 1, characterized in that the cured molding is heated for forming in at least a portion, in particular to temperatures above the Tg of the at least one organic polymer component, preferably to at least 100 ⁰ C.

3. The method according to claim 1 or claim 2, characterized in that the cured molding for forming to a temperature between 100 ⁰ C and 250 ⁰ C, preferably between 100 ⁰ C and 200 ⁰ C, in particular between 120 ⁰ C and 160 ⁰ C. , is heated.

4. The method according to any one of the preceding claims, characterized in that the cured molding is heated for forming in a heated press or by means of hot air.

5. The method according to any one of the preceding claims, characterized in that the cured molded part is formed after curing by bending and / or deep drawing.

6. The method according to any one of the preceding claims, characterized in that the castable reaction mass comprises an organic polymer component based on acrylic and / or Methacrytbasis.

7. The method according to any one of the preceding claims, characterized in that the pourable reaction mass polymethyl methacrylate (PMMA) contains as an organic polymer component.

8. The method according to any one of the preceding claims, characterized in that the pourable reaction mass contains methyl methacrylate (MMA) as an organic polymer component.

9. The method according to any one of the preceding claims, characterized in that the inorganic filler is selected from the group consisting of quartz, cristobalite and mixtures thereof.

10. The method according to any one of the preceding claims, characterized in that the inorganic filler, based on the mass of the cured molding, in a proportion of between 50 wt .-% to 85 wt .-% is contained in the reaction mass.

11. Reaction mass for the production of plastic molded parts, in particular in a method according to one of the preceding claims, comprising as constituents at least one organic polymer component and at least one inorganic filler, wherein the at least one filler has a mean particle size large <30 microns, in particular <20 microns, more preferably between 5 microns and 10 microns, and the at least one filler, based on the mass of the cured molding, in a proportion of> 50 wt .-% in the reaction mass.

12. Reaction mass according to claim 11, characterized in that the at least one filler has a d90 value of 50 μm or less, in particular of 30 μm or less, particularly preferably of 25 μm or less.

13. Reaction mass according to claim 11 or claim 12, characterized in that the at least one filler has a d95 value of 60 μm or less, in particular of 45 μm or less, particularly preferably of 35 μm or less.

14. Reaction mass according to one of claims 11 to 13, characterized in that it has a viscosity in the range between 5 Pa s and 60 Pa s, in particular between 15 Pa s and 45 Pa s, (in each case at 20 ⁰ C).

15. Plastic molded part, in particular worktop, wall plate or base plate, preferably for the kitchen, sanitary and trade fair, with a polymer matrix, in which at least one inorganic filler is uniformly embedded embedded, in particular produced or prepared by a method according to any one of claims 1 to 10 and / or from a reaction mass according to one of claims 11 to 14.

16. Plastic molding according to claim 15, characterized in that it has a Mohs hardness between 4 and 7, preferably between 5 and 7, having.

17. Plastic molding according to claim 15 or 16, characterized in that it has a preferably uniform thickness between 2 mm and 15 mm, in particular from about 4 mm to about 8 mm.

18. Plastic molding according to one of claims 15 to 17, characterized in that the at least one inorganic filler has an average particle size <30 .mu.m, in particular <20 .mu.m, more preferably between 5 .mu.m and 10 .mu.m.