WO2025087487A1 - Curable casting compound for production of moulded plastics articles - Google Patents

Abstract

The invention relates to a curable casting compound for production of moulded plastics articles, especially of sanitary or kitchen products, having an antimicrobial, in particular antiviral, surface, comprising a binder composition, especially comprising a liquid monomeric acrylate component, and at least one filler composition, especially comprising quartz, wherein at least one hydrophobic monomer composition having at least one organosiloxane functionalized with at least one unsaturated group is present in the casting compound with a proportion by weight based on the total mass of the curable casting compound of 0.001% by weight or more, especially 0.01% by weight or more, preferably 0.05% by weight or more, especially 0.1% by weight or more, preferably 0.185% by weight or more, and 10% by weight or less, especially 5% by weight or less, preferably 2.5% by weight or less, especially 2% by weight or less, preferably 1% by weight or less, especially 0.5% by weight or less, especially 0.25% by weight or less, preferably 0.210% by weight or less.

Description

Curable casting compound for the production of plastic molded parts

The invention relates to a curable casting compound for producing plastic molded parts, in particular sanitary or kitchen products, with an antimicrobial, in particular antiviral, surface, comprising a binder composition, in particular comprising a liquid monomeric acrylate component, and at least one filler composition, in particular comprising quartz.

The invention further relates to a use of a casting compound for producing a plastic molded part with an antimicrobial, in particular antiviral, surface.

The invention further relates to a plastic molded part produced with a cured casting compound with an antimicrobial, in particular antiviral, surface.

The invention further relates to the use of at least one organosiloxane functionalized with at least one unsaturated group in a curable casting compound for inactivating microorganisms, in particular viruses.

Curable casting compounds are used to produce plastic molded parts, particularly in the sanitary or kitchen sector, such as kitchen sinks, countertops, bathtubs, washbasins, or the like. The curable casting compounds typically comprise a binder material and a filler material to improve the mechanical properties of the plastic molded parts, as is known, for example, from DE 38 32 351 A1 or WO 2005/071000 A1. However, such curable casting compounds have the disadvantage that the surfaces of plastic molded parts produced therewith are difficult to clean, thus resulting in poor surface cleanability. This is problematic from a hygiene perspective, as the poor cleanability also promotes potential microbial growth. EP 3 959 980 A1 further discloses a heat-curable casting compound comprising a polymeric binder and filler particles incorporated therein, wherein the casting compound contains at least one essential oil.

A disadvantage of this approach is that the antibacterial components are not chemically fixed in the incorporated material matrix and are therefore susceptible to migration. This poses a risk that, for example, the organoleptic properties of foodstuffs may be impaired upon contact with plastic moldings manufactured in this way. Furthermore, there is also a risk of contact allergic reactions in users of the plastic molding.

An object of the present invention is therefore to provide a curable casting compound and a plastic molded part which have antimicrobial properties that at least reduce, if not completely eliminate, contamination of food and allergic reactions of users upon contact.

Another object of the present invention is to provide an alternative curable casting compound and an alternative plastic molded part.

In one embodiment, the present invention achieves the above-mentioned objects in a curable casting compound for producing plastic molded parts, in particular sanitary or kitchen products, with an antimicrobial, in particular antiviral, surface, comprising a binder composition, in particular comprising a liquid monomeric acrylate component and at least one filler composition, in particular comprising quartz, in that at least one hydrophobic monomer composition with at least one organosiloxane functionalized with at least one unsaturated group is contained in the casting compound with a weight fraction based to the total mass of the curable casting compound of 0.001 wt.% or more, in particular 0.01 wt.% or more, preferably 0.05 wt.% or more, in particular 0.1 wt.% or more, preferably 0.185 wt.% or more and 10 wt.% or less, in particular 5 wt.% or less, preferably 2.5 wt.% or less, in particular 2 wt.% or less, preferably 1 wt.% or less, in particular 0.5 wt.% or less, in particular 0.25 wt.% or less, preferably 0.210 wt.% or less.

In one embodiment, the invention achieves the above-mentioned objects by using a casting compound according to one of claims 1-7 for producing a plastic molded part with an antimicrobial, in particular antiviral, surface.

In one embodiment, the invention achieves the above-mentioned objects with a plastic molded part produced with a cured casting compound according to one of claims 1-7 with an antimicrobial, in particular antiviral, surface.

In one embodiment, the invention achieves the above-mentioned objects by using at least one organosiloxane functionalized with at least one unsaturated group for inactivating microorganisms, in particular viruses, on a surface of a plastic molding, wherein the organosiloxane is introduced into a curable casting compound according to one of claims 1-7, with which the plastic molding is produced.

One of the advantages achieved is that an antimicrobial, in particular antibacterial and/or antiviral, effect can be provided with a curable casting compound in a plastic molded part, in which the active substance is chemically fixed in the material of the plastic molded part and the effect is not based on the release of substances that are at least partially toxic to bacteria and/or viruses, which at least reduces, if not completely eliminates, any impairment of food and allergic reactions of users upon contact with the surface of the plastic molded part. Further features, advantages and further embodiments of the invention are described below or will become apparent thereby.

According to an advantageous development of the invention, the binder composition has a weight fraction of 10 wt.% or more, in particular 15 wt.% or more, preferably 20 wt.% or more, and 50 wt.% or less, preferably 40 wt.% or less, in particular 30 wt.% or less, preferably 25 wt.% or less, of the total mass of the casting compound. The advantage of this is sufficient binding capacity of the components of the casting compound.

According to a further advantageous development of the invention, the filler composition has a weight fraction of 40 wt.% or more, in particular 50 wt.% or more, preferably 60 wt.% or more, in particular 70 wt.% or more, and 90 wt.% or less, preferably 85 wt.% or less, in particular 80 wt.% or less, preferably 75 wt.% or less, of the total mass of the casting compound. The advantage of this is sufficient strength of a plastic molded part produced with the casting compound.

According to a further advantageous development of the invention, the binder composition comprises a liquid monomeric acrylate component in a proportion of 70 wt.% or more, preferably 80 wt.% or more and 90 wt.% or less, in particular 85 wt.% or less, based on the proportion of the binder composition. The advantage of this is that it can be polymerized to form a polyacrylate upon curing during the production of a plastic molded part. To increase the viscosity of the curable casting compound, a proportion of a prepolymerized acrylate component can be added to the monomeric acrylate; for example, prepolymerized polymethyl methacrylate PMMA can be added to the monomer methyl methacrylate.

According to a further advantageous development of the invention, at least one crosslinker is contained in the casting compound in a proportion of 0.1 wt.% or more, preferably 0.5 wt.% or more, in particular 0.8 wt.% or more, in particular 1 wt.% or more, preferably 1.5 wt.% or more, preferably 5 wt.% or more, preferably 7.5 wt.% or more, in particular 10 wt.% or more and 20 wt.% or less, in particular 17.5 wt.% or less, in particular 15 wt.% or less, in particular 10 wt.% or less, based on the total mass of the casting compound. This enables sufficient hardness of a plastic molded part produced with the casting compound.

wobei According to a further advantageous development of the invention, the organosiloxane functionalized with at least one unsaturated group has the formula:

where

- R ¹ are identical or different aliphatic or aromatic hydrocarbon radicals,

- R ² CH2CH ₂ O(CR ⁴ R ⁵ )XOH, where

- R ⁴ and R ⁵ may be identical or different radicals and each represent a hydrogen or alkyl radical, branched or unbranched, with up to a total of 12 carbon atoms and x has a value of 2 to 11,

- R ³ is equal to R ² or R ¹ ,

- a equals 1 to 50 and

- b is equal to 0 to 500.

wobei R⁴ und R⁵ gleiche oder verschiedene Reste sein können und jeweils einen H- oder Alkylrest, verzweigt oder unverzweigt, mit bis zu insgesamt 12 C-Atomen bedeuten und x einen Wert von 2 bis 11 hat, in Gegenwart eines an sich bekannten Hydrosilylierungskatalysators (Platin- oder Rhodiumkatalysator) anlagert. Bevorzugte Beispiele für die Reste R⁴ und R⁵ sind Wasserstoff und Alkylreste von C1 bis C8. Insbesondere bevorzugt ist R⁴ = R⁵ = Wasserstoff, x ist vorzugsweise 2 bis 6. Insbesondere bevorzugt ist x = 4. The advantage of this is that the organosiloxane has at least one unsaturated group and can be prepared easily and inexpensively. The skilled worker knows from his or her technical knowledge that the compounds are present in the form of a mixture with a distribution governed essentially by statistical laws. The values for the indices a and b are therefore, in particular, average values. The organosiloxanyl derivatives are easily accessible via transition-metal-catalyzed hydrosilylation reactions of organosiloxanyl derivatives on alkanediol moieties. novinylether. They can be prepared, for example, in a simple manner by reacting hydrogen-functional siloxanes of the above formula with R ² = H and where the other indices have the above-mentioned meaning, with alkanediol monovinyl ethers of the general formula

where R ⁴ and R ⁵ can be identical or different radicals and each represents a hydrogen or alkyl radical, branched or unbranched, having up to a total of 12 carbon atoms, and x has a value of 2 to 11, in the presence of a known hydrosilylation catalyst (platinum or rhodium catalyst). Preferred examples of the radicals R ⁴ and R ⁵ are hydrogen and alkyl radicals from C1 to C8. Particularly preferably, R ⁴ = R ⁵ = hydrogen, and x is preferably 2 to 6. Particularly preferably, x = 4.

Furthermore, EP 0 819 719 A2 is hereby incorporated by reference, in particular also all compounds and derivatives of the organosiloxanes disclosed in EP 0 819 719 A2 and their preparation processes, preferably the structures for organosiloxanes disclosed therein as examples, in particular in Examples 1-7.

According to a further advantageous development of the invention, the at least one unsaturated group comprises the acrylate group. The advantage of this is that optimal compatibility with the binder can be achieved.

According to a further advantageous development of the invention, the plastic molded part is a sink, a kitchen basin, and/or a worktop. The advantage of this is the simple and practical use of the plastic molded part in sanitary and/or kitchen areas. Further important features and advantages of the invention emerge from the subclaims and from the following explanation.

It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

Preferred embodiments and embodiments of the invention are explained in more detail in the following description.

It has been found that the use according to the invention of an organosiloxane functionalized with at least one unsaturated group enables an improvement in the antimicrobial, in particular the antibacterial and/or antiviral, properties of the surface of a plastic molded part.

Comparison example 1

A previously known curable casting compound is produced by mixing a binder material with a filler material. The binder material is obtained by dissolving PMMA in MMA such that the binder material contains 19 wt.% PMMA and 81 wt.% MMA. Trimethylolpropane trimethacrylate (TRIM) is also added as a crosslinker.

The filler material here includes a type of granular quartz material Granucol® (Gebrüder Dorfner GmbH & Co., Hirschau):

Granucol® white 2/9 (average particle size 330 micrometers)

The filler material is then added to the binder material and mixed homogeneously. A peroxide mixture is then added to the curable casting compound to adjust the polymerization and curing of the casting compound. Such a peroxide mixture can, for example, include di-(4-tert-butylcyclohexyl) peroxydicarbonate and/or dilauroyl peroxide. Alternatively, or the binder additionally comprises one or more crosslinking agents. Suitable crosslinking agents include, for example, substances from the group of aliphatic or aromatic di-, tri-, or multifunctional acrylates 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 acrylates or methacrylates and/or combinations thereof.

In addition, Heucodur HD952 was added as a color pigment.

The composition of the curable casting compound according to Comparative Example 1 is shown in the following Table 1, where the contents of the individual components are given in percent by weight.

Table 1

The peroxide mixture can essentially consist of a mixture of dilauroyl peroxide and di-(4-tert-butylcyclohexyl)peroxydicarbonate in a weight ratio of 1.5:1.

The hardenable casting compound is then placed into a mold for a plastic molded part in the shape of a kitchen sink and polymerized under the influence of heat.

Typically, the estimated mean half-life of coronaviruses on such plastic surfaces is 6.8 hours. Example 1

A casting compound according to the invention is produced, the composition of which largely corresponds to the curable casting compound according to Comparative Example 1, with a binder amount of 0.20 wt.% being added in exchange for a corresponding amount of Tegomer V-Si 7255. The remaining material contents are kept the same.

The composition of the curable casting compound according to Example 1 is shown in the following Table 2, where the contents of the individual components are given in percent by weight.

Table 2

The hardenable casting compound produced in this way is then placed into a casting mold for a kitchen sink and polymerized under the influence of heat.

A sample piece is taken from the manufactured kitchen sink.

To investigate the antimicrobial, especially the antiviral, effect, the following procedure is now used:

Initially, a high-titer suspension of feline coronavirus was prepared (109 PFU/ml). Solutions with concentrations of 109 PFU/ml, 106 PFU/ml, and 104 PFU/ml were used for the experiments. 50 μl of each solution were used. The suspension was spread over an area of 1 ^cm² and left at room temperature (approximately 21°C). Both a sample from Example 1 and a glass surface (reference material) were used. At time 0 (virus application) and after defined time intervals (1 h, 4 h, 8 h, 24 h, 48 h; at approximately 21°C), the viruses were analyzed for their infectivity in cell culture using the TCID50 assay, using CPE as the endpoint. All tests were performed in quadruplicate.

Figures 1-3 show the stability of SARS-CoV-2 on the surfaces mentioned. Figure 1 shows a comparison of the survival time of coronaviruses on the sample according to Example 1 and on a glass surface at an initial concentration of the feline coronavirus of 10 ⁹ CFU/ml. Figure 2 shows a comparison of the survival time of coronaviruses on the sample according to Example 1 and on a glass surface at an initial concentration of the feline coronavirus of 10 ⁶ CFU/ml, and Figure 3 shows a similar comparison of the survival time of coronaviruses on the sample according to Example 1 and on a glass surface at an initial concentration of the feline coronavirus of 10 ⁴ CFU/ml.

From Figure 1 it can be seen that, starting from an initial concentration of 10 ⁹ CFU/ml, after just 1 hour of incubation, compared to the glass surface, only approximately 4/7 = 57% of the coronaviruses are still present on the plastic surface or the surface of the plastic molded part according to Example 1. After 4 hours, approximately 3/6 = 50% are still present, after 8 hours approximately 2/5.5 = 36%, after 24 hours approximately 1.5/5 = 30% and after 48 hours approximately 1/4.8 = 20% of the coronaviruses are still present on the plastic surface or the surface of the plastic molded part according to Example 1.

Figure 2 shows that, starting from an initial concentration of 10 ⁶ CFU/ml, after just 1 hour of incubation, only approximately 3/5.25 = 57% of the coronaviruses are still present on the plastic surface or the surface of the plastic molded part according to Example 1 compared to the glass surface. After 4 hours, approximately 2/4.75 = 42% remain, after 8 hours approximately 1.75/4.5 = 39%, after 24 hours 1.5/3.9 = 38%, and after 48 hours approximately 0.3/3.8 = 8% of the coronaviruses are present on the plastic surface or the surface of the plastic molded part according to Example 1.

Figure 3 shows that, starting from an initial concentration of 10 ⁴ CFU/ml, after just 1 hour of incubation, compared to the glass surface, only approximately 2/3 = 67% of the coronaviruses are still present on the plastic surface or the surface of the plastic molded part according to Example 1. After 4 hours, approximately 1/2.5 = 40% of the coronaviruses are still present on the plastic surface or the surface of the plastic molded part according to Example 1. At times of 8, 24, and 48 hours, no viruses are present or detectable on the surface of the plastic molded part according to Example 1.

It is known that the longest half-lives for coronaviruses have been determined for stainless steel and plastic. The estimated average half-life of coronaviruses is approximately 5.6 hours on stainless steel and—as already mentioned—6.8 hours on plastic. For the surface of the sample according to Example 1, the average half-life was 1 hour. Thus, the surface according to Example 1 leads to a significant reduction in the half-life of coronaviruses compared to other surfaces such as stainless steel, plastic, or glass.

The experiments conducted clearly demonstrated that even high concentrations of coronaviruses have a half-life of less than one hour on the surface of a sample according to Example 1. The experiments conducted further demonstrate that the mortality rate of coronaviruses on a surface of a sample according to Example 1 is significantly higher than on a glass surface.

The result shows that the addition of one or more functionalized organosiloxanes significantly increases the mortality rate of viruses in particular. The kitchen sinks produced with the curable casting compound according to one embodiment of the present invention exhibit no impairment in their mechanical or optical properties compared to the curable casting compound obtained in the comparative example. The effect of the antimicrobial effect, in particular the antibacterial and/or antiviral effect, thus occurs when one or more functionalized organosiloxanes are used according to the invention.

In summary, at least one of the embodiments of the invention may have at least one of the following advantages and/or at least one of the following features:

Antimicrobial, particularly antibacterial and/or antiviral, effect.

Chemical fixation of one or more functionalized organosiloxanes in the material matrix.

The antimicrobial, in particular antibacterial and/or antiviral, effect is not based on the release of substances that are at least partially toxic to bacteria and/or viruses.

Although the present invention has been described using preferred embodiments, it is not limited thereto but can be modified in many ways.

Claims

Claims 1. A curable casting compound for producing plastic molded parts, in particular sanitary or kitchen products, with an antimicrobial, in particular antiviral, surface, comprising a binder composition, in particular comprising a liquid monomeric acrylate component, and at least one filler composition, in particular comprising quartz, characterized in that at least one hydrophobic monomer composition with at least one organosiloxane functionalized with at least one unsaturated group is contained in the casting compound with a weight fraction based on the total mass of the curable casting compound of 0.001 wt.% or more, in particular 0.01 wt.% or more, preferably 0.05 wt.% or more, in particular 0.1 wt.% or more, preferably 0.185 wt.% or more and 10 wt.% or less, in particular 5 wt.% or less, preferably 2.5 wt.% or less, in particular 2 wt.% or less, preferably 1 wt.% or less, in particular 0.5 wt.% or less, in particular 0.25 wt.% or less, preferably 0.210 wt% or less. 2. Curable casting compound according to claim 1, characterized in that the binder composition has a weight proportion of 10 wt.% or more, in particular 15 wt.% or more, preferably 20 wt.% or more and 50 wt.% or less, preferably 40 wt.% or less, in particular 30 wt.% or less, preferably 25 wt.% or less of the total mass of the casting compound. 3. Curable casting compound according to one of claims 1-2, characterized in that the filler composition has a weight fraction of 40 wt.% or more, in particular 50 wt.% or more, preferably 60 wt.% or more, in particular 70 wt.% or more and 90 wt.% or less, preferably 85 wt.% or less, in particular 80 wt.% or less, preferably 75 wt.% or less of the total mass of the casting compound. 4. Curable casting compound according to one of claims 1-3, characterized in that the binder composition comprises a liquid monomeric acrylate component in a proportion of 70 wt.% or more, preferably 80 wt.% or more and 90 wt.% or less, in particular 85 wt.% or less, based on the proportion of the binder composition. 5. Curable casting compound according to one of claims 1-4, characterized in that at least one crosslinker is contained in the casting compound in a proportion of 0.1 wt.% or more, preferably 0.5 wt.% or more, in particular 0.8 wt.% or more, in particular 1 wt.% or more, preferably 1.5 wt.% or more, preferably 5 wt.% or more, preferably 7.5 wt.% or more, in particular 10 wt.% or more and 20 wt.% or less, in particular 17.5 wt.% or less, in particular 15 wt.% or less, in particular 10 wt.% or less, based on the total mass of the casting compound. 6. Curable casting compound according to one of claims 1-5, characterized in that the organosiloxane functionalized with at least one unsaturated group has the formula:

where - R ¹ are identical or different aliphatic or aromatic hydrocarbon radicals, - R ² CH2CH ₂ O(CR ⁴ R ⁵ )XOH, where - R ⁴ and R ⁵ can be identical or different radicals and each represents a branched or unbranched alkyl radical with up to a total of 12 C atoms and x has a value of 2 to 11, - R ³ is equal to R ² or R ¹ , - a equals 1 to 50 and - b is equal to 0 to 500. 7. Curable casting compound according to one of claims 1-6, characterized in that the at least one unsaturated group comprises the group of acrylates. 8. Use of a casting compound according to any one of claims 1-7 for producing a plastic molded part with an antimicrobial, in particular antiviral, surface. 9. Plastic molded part, produced with a cured casting compound according to one of claims 1-7, with an antimicrobial, in particular antiviral, surface. 10. Plastic molded part according to claim 9, characterized in that the Plastic molded part is a sink, a wash basin and/or a worktop. 11. Use of at least one organosiloxane functionalized with at least one unsaturated group for inactivating microorganisms, in particular viruses, on a surface of a plastic molded part, wherein the organosiloxane is incorporated into a curable casting compound according to any one of claims 1-7, with which the plastic molded part is produced.