Sanitary tub and method for producing a sanitary tub

Description

[0001] The present invention relates to a sanitary tub according to the preamble of claim 1 and a method for producing a sanitary tub according to the preamble of claim 9.

[0002] Conventional anti-slip surfaces in sanitary areas, especially in bathtubs and shower trays of all materials, are always visible. One example is anti-slip coatings based on quartz sand particles that are incorporated / fired into the glaze. Here, the quartz sand particles are always visible and tactile. With these anti-slip types, the material is not applied over the entire surface, but rather in the form of dots / squares that alternate with the "normal" surface.

[0003] Another existing method for creating anti-slip properties is firing a coarsely ground enamel. Instead of completely grinding the enamel granules into a fine dust, coarser particles are incorporated into the liquid enamel, the emulsion. During the firing process, the coarser particles do not completely melt, resulting in a rough surface (similar to sandpaper) rather than a smooth surface. Here, too, the end result is visible, as the coarser particles refract light differently than a smoothly fired glaze / enamel.

[0004] The disadvantages of the current technology are that, firstly, the anti-slip surfaces are always visible. Furthermore, compromises must be made in terms of cleaning properties. Since both the anti-slip coating, consisting of quartz sand particles, and the coarser enamel, leave a (partially) rough surface, limescale and dirt can settle there. Cleaning is therefore not always easy.

[0005] WO 2014 / 015896 A1 discloses a sanitary device having a base body made of a metal provided with an enamel layer comprising a base layer made of a base enamel, on which a cover layer made of a covering enamel is applied in order to increase the impact resistance.

[0006] DE 10 2018 118 041 A1 discloses a sanitary tub with a tub body made of steel and an enamel coating arranged on the tub body, wherein the coating has macroscopic structures produced with a laser beam.

[0007] Based on this preliminary consideration, it is therefore the object of the present invention to provide a sanitary tub with an anti-slip surface which is easy to clean.

[0008] The invention solves this problem by providing a sanitary tub with the features of claim 1 and by a method with the features of claim 9.

[0009] According to the invention, a sanitary tub comprises a molded tub body made of sheet steel, which is provided with an enamel coating at least on one upper side. The enamel coating / glaze is provided, at least in some areas, with a slip-resistant treatment containing titanium dioxide. The terms glaze, enamel, and enamel are used synonymously in the context of the present application.

[0010] Within the scope of the present invention, titanium dioxide is preferably used in the anatase modification or in mixtures of several modifications comprising anatase. Thus, at least a portion of the titanium dioxide particles used can be in the anatase form. This modification exhibits lower surface roughness and good health compatibility. However, the use of other modifications such as brookite or rutile is also possible within the scope of the present invention, either as pure modifications or in mixtures of several modifications.

[0011] Preferably, a predominant part of the titanium dioxide particles of the coating can be rod-shaped or have a rod-shaped geometry.

[0012] In contrast to a full-surface coating, the coating is designed as a particulate-distributed coating, in which the particles are spaced apart from one another on the enamel surface. According to the invention, the degree of coverage of the enamel surface can be less than 50%, particularly preferably less than 20%, based on the coated area. Thus, in this area, less than 20% of the surface is covered by particles of the coating, and the area between the particles is uncovered.

[0013] The titanium dioxide-containing treatment exhibits a lower surface roughness compared to a silicate coating. Furthermore, depending on the modification of the titanium dioxide used, the treatment agent can preferably be transparent or alternatively white.

[0014] Titanium dioxide, particularly when used in the rutile or anatase configurations, can also serve as a brightener for the enamel substrate, particularly in the dry state of the sanitary tub, so that discolorations or defects that occur during the thermal treatment in the production of the enamel layer are covered by the use of the titanium dioxide-containing treatment.

[0015] These advantages of lower surface roughness and the brightening function are particularly in demand when used in the area of ​​sanitary bathtubs.

[0016] Another advantage of the invention is that after the agent has been applied, neutralized with water, and dried on the "normal" surface, only the titanium rods, which are firmly attached to the surface and distributed at equal intervals, remain attached.

[0017] This means that when you touch the surface of the sanitary tub with the palm of your hand, you are mostly touching the original surface, i.e. the enamel.

[0018] Further advantageous embodiments of the invention are the subject of the subclaims.

[0019] In order to achieve ideal coverage and uniform adjustment of the surface roughness, it is advantageous if the treatment agent is applied with an application quantity of up to 200 ml / m 2<, preferably 80 - 120 ml / m 2<.

[0020] To increase abrasion resistance, it may be advantageous if the treatment contains a ceramic component in addition to titanium dioxide, such as a silicon species, a silicate, and / or, in particular, obsidian. This can contribute to increasing the abrasion resistance of the treatment, but may also increase the surface roughness. Therefore, a preferred range for the obsidian content in the coating is advantageously less than 50 wt.%, preferably between 2-30 wt.%.

[0021] Furthermore, the coating may optionally comprise amorphous silicate, particularly preferably up to 30 wt.% based on the total mass of the anti-slip coating.

[0022] The distribution of the titanium dioxide in the treatment or coating area can vary by less than 30% of the average surface area weight in order to achieve the highest possible homogeneity in the distribution. The distribution refers to a particle distribution in a particulate coating. A correspondingly large measuring range, e.g. 25 cm2<, must be selected to determine the surface area weight and distribution. Furthermore, the sanitary bathtub can have a base area, a side wall and a tub rim, with the sanitary bathtub having the treatment at least in some areas in the area of ​​the base and the tub rim. The treatment can in particular be a coating. This reduces the risk of both feet and hands slipping when supporting themselves on the tub edge. Optionally, the sanitary bathtub can also be fully coated on one top surface.

[0023] Furthermore, a method according to the invention with the features of claim 9 is disclosed.

[0024] A method according to the invention for producing a sanitary tub, in particular a sanitary tub according to the invention, comprises at least the following steps: A forming a tub body from a steel sheet; B coating the tub body at least on one upper side with an enamel coating; C baking the enamel coating on the tub body at a baking temperature T1; D applying a treatment liquid, as a coating dispersion, at least in some areas to produce a transparent anti-slip effect on the enamel coating, and E washing the liquid material off the enamel coating after a contact time, characterized in that the contact time of the liquid coating dispersion (401) is between 30 and 90 seconds.

[0025] A particular manufacturing advantage in the production of the sanitary tub is that the ready-to-use sanitary tub is first produced and then provided with the titanium dioxide-containing anti-slip treatment at the factory. This treatment is carried out after the heat treatment to densify the enamel. The anti-slip coating does not require additional heating, thus preventing temperature-induced material expansion with corresponding material stresses and / or cracks, nor an unintentional phase transformation of titanium dioxide. For example, a phase transformation in titanium dioxide from anatase to a more crystalline variant of rutile is known, which occurs at 400°C–600°C.Such a transformation and the resulting material changes of the steel, the enamel and in particular the anti-slip medium are prevented in the present process, since all further manufacturing steps after step C take place well below 400°C, preferably below 200°C, and the service temperature of the sanitary tub is also well below this limit.

[0026] The process also has the advantage that thermal deformation of the basic shape of the sanitary tub, i.e. thermal warping under the influence of temperature, is virtually impossible after step C.

[0027] In particular, the temperature during the exposure time does not exceed 120°C. The application in step D and the subsequent exposure in step E are therefore not accompanied by a baking process, as is necessary, for example, when forming an enamel coating.

[0028] Advantageous embodiments of the method according to the invention are the subject of the subclaims.

[0029] According to the invention, the exposure time of the liquid coating dispersion is between 30 and 90 seconds. This exposure time represents an optimum between adjusting the surface roughness to achieve an anti-slip effect, while also ensuring that the surface roughness is not too high, which would encourage increased accumulation of dirt or the like. Furthermore, excessive exposure time can lead to discoloration of the glaze.

[0030] It is advantageous for the coating dispersion to contain at least 2 wt.%, preferably between 3 and 6 wt.%, of titanium dioxide. This concentration allows for a more controlled adjustment of the layer thickness and / or surface roughness. An excessively high concentration may, under unfavorable storage conditions or upon surface contact, lead to a spontaneous precipitation reaction of the titanium dioxide from the coating dispersion.

[0031] Better stabilization of the titanium dioxide particles in the dispersion is achieved if the coating dispersion contains glycerol, preferably at least 50% by weight. Glycerin is water-soluble and essentially stable against evaporation effects.

[0032] To increase the stability of the dispersion, the coating dispersion may also contain one or more dispersants.

[0033] One or more further components of the treatment dispersion, in particular in the form of a coating dispersion, can be selected from a class consisting of: one or more emulsifiers, one or more surfactants, a crosslinked polymer.

[0034] The crosslinked polymer can, in particular, be a thermoplastic such as EFA. Furthermore, the treatment dispersion can also contain an ethylene-propylene component, e.g., a polymer or oligomer of the aforementioned components, and / or epichlorohydrin.

[0035] The treatment dispersion is preferably washed off with water or a water-based detergent, whereby inorganic components of the dispersion, such as titanium dioxide or optionally obsidian or silicate, remain on the tank surface.

[0036] The temperature during application in step D or during the exposure time is less than the baking temperature T1, preferably less than 120°C, particularly preferably between 10-50°C, so that too rapid deposition of components on the surface is avoided.

[0037] Further advantages, features, and details of the invention will become apparent from the following description, in which an exemplary embodiment of the invention is explained in more detail with reference to the accompanying drawings. Those skilled in the art will expediently consider the features disclosed in the drawings, the description, and the claims individually and combine them into meaningful further combinations within the scope of the appended claims. In particular, there are numerous possibilities for modifying and developing these within the scope of the present claims. They show: Fig. 1 shows a sanitary tub according to the invention with several areas provided with an anti-slip coating; and Fig. 2 shows a process diagram for the production of the sanitary tub according to the invention. Fig. 1 .

[0038] Fig. 1 shows a sanitary tub 1 according to the invention with a base region 2, a side wall 3 extending obliquely at an angle of at least 75° thereto, and an edge 4 of the sanitary tub 1, which runs essentially parallel to the base region 2 and may have a bend or flange. The sanitary tub 1 is located on a support frame and can be designed as a bathtub or a shower tray.

[0039] The sanitary tub 1 has several coating areas 5, 6, 7, 8, wherein the coating is arranged at least partially in the area of ​​the bottom 2 and the edge 4.

[0040] This prevents, on the one hand, the feet from slipping on the enamel surface of the sanitary tub 1 in the area of ​​the floor 2 and, on the other hand, the hands from slipping, e.g. when leaning on the sanitary tub 1 or when getting into the sanitary tub 1.

[0041] The advantage of the anti-slip finish 5-8 is that it is completely white or transparent and does not cause any noticeable or visible changes to the smooth enamel surface. Optionally, the entire visible side of the sanitary tub 1, i.e., the area accessible from the top, can be provided with an anti-slip treatment, particularly an anti-slip coating.

[0042] The coating material offers particular advantages for sanitary tubs that are less evident or nonexistent in other applications. In particular, the factory application under controlled conditions allows for more precise adjustment of the surface roughness and layer thickness. This ensures reliable processing of the coating material during the manufacturing process.

[0043] The following method has proven particularly effective when applying the material: A defined exposure time of approximately 1 minute should be observed over the entire surface of the intended application area. Uncoated areas can be masked. However, a comprehensive coating, or at least the surfaces of the sanitary tub that come into contact with water, is also possible.

[0044] After the contact time, the coating material is rinsed off completely and neutralized. Rinsing is preferably done with water or a water-based detergent, and the mixture of water and treatment material can then be recycled.

[0045] The sanitary tub can then be dried to ensure the product is completely dry after treatment. This can preferably be done at temperatures below 120°C, at which any residual wash water evaporates.

[0046] With steel / enamel products, the following challenges arise: If the exposure time is exceeded, a color change occurs. If the exposure time is shortened, the anti-slip effect is lost.

[0047] Since the anti-slip treatment is applied to the finished product, the product should be reliably dried in a preferred further step to prevent any corrosion during delivery (particular attention should be paid to the back of the C-shaped flanged edge).

[0048] Since some of the surfaces can be very large, the process should be defined so that the exposure time is approximately the same for all surface elements. 30-90 seconds represents a preferred optimum.

[0049] Another challenge is that the material runs toward the drain during washing, so the exposure time in the areas around the drain hole can quickly exceed one minute. This can be avoided by using appropriate water pressure during washing.

[0050] The anti-slip treatment is applied to the completely finished product of a sanitary bathtub and therefore has no influence on the manufacturing processes of the actual product.

[0051] The quartz sand particles from the state of the art, on the other hand, were applied to a finished product, but the quartz sand particles had to be fired under special kiln conditions, which resulted in a separate, additional kiln firing.

[0052] Since the anti-slip coating is completely transparent or white and therefore not visible on the enamel surface, it can also be easily applied partially or over the entire surface.

[0053] Until now, only quartz sand particles could be used for anti-slip treatment on bathtubs, as the coarse enamel process was not suitable for products with surrounds. The anti-slip treatment can now also be used on bathtubs, as it is not visible whether the product is applied only to the floor or also to the walls.

[0054] The anti-slip effect is particularly pronounced when it is wet and / or subjected to pressure.

[0055] A process sequence according to the invention is described in Fig. 2 shown schematically.

[0056] In a first step 100, a tub body is formed from a steel sheet. In a step 200, the tub body is coated with an enamel coating 201, at least on one upper side. In a third step 300, the enamel coating is baked on the tub body at a baking temperature T1. This temperature can be, for example, at least 600°C.

[0057] This step produces a finished sanitary tub, which is now refined to turn the finished product into a product according to the invention.

[0058] In In a fourth step 400, a treatment liquid 401, in particular as a coating dispersion, is applied at least in some areas to produce the anti-slip titanium dioxide-containing coating of the sanitary tub according to the invention on the enamel coating.

[0059] InIn a fifth step 500, the liquid material is washed off the enamel coating after a contact time. The washing liquid can, in particular, be water. The method can also include a drying step for drying the surface of the washing liquid. The drying temperature in a sixth step 600 can, in particular, be less than 200°C, preferably less than 120°C.

[0060] In summary, a transparent or white coating is applied to the finished product, ensuring that the coating's exposure time is long enough to cause minimal visible changes to the surface. To achieve this, the medium is applied and then washed off after a defined exposure time. When washing / cleaning the surface after the defined exposure time, it is ensured that the exposure time per unit area is approximately the same.

[0061] After washing, the product is dried so that no moisture remains on the top, bottom or undercuts.

[0062] The nominal viscosity of the coating dispersion at 25°C during application can be less than 20,000 mPa*s, preferably between 6,000 and 16,000 mPa*s. Any viscometer, such as a rotational viscometer, can be used to measure the viscosity.

[0063] The particle size of the titanium dioxide particles in the coating dispersion is microscale, preferably less than 60 µm, particularly preferably less than 25 µm, in particular less than 10 µm.

[0064] The treatment agent can be applied at a rate of up to 200 ml / m 2 , preferably 80-120 ml / m 2 . The anti-slip coating can have a titanium dioxide content of at least 1.7 mg / m 2 , preferably 2-10 mg / m 2 , as an average basis weight.

[0065] The titanium dioxide particles are shaped like rods. These rods provide the anti-slip effect because they "protrude" when the treated surface is wet, thus triggering the grip effect.

[0066] The factory-adjustable deposition times, titanium dioxide concentration, and the overall formulation of the treatment or coating compound are adjusted to achieve a sliding friction coefficient for the sanitary bathtub according to the invention between 0.3 - 0.6; preferably 0.35 - 0.55, and above 0.45, rating group "C" according to the DGUV rating group. The sliding friction coefficient can preferably be determined according to DIN EN ISO 8295. List of reference symbols

[0067] 1Sanitary tub 2Floor area 3Side wall 4Edge 5Coating area or coating 6Coating area or coating 7Coating area or coating 8Coating area or coating 100Shaping a tub body 200Coating with an enamel coating 201Enamel coating 300Firing the enamel coating 400Applying an anti-slip coating liquid 401Coating liquid 500Wash off the liquid material 600Drying the tub body

Claims

1. Sanitary tub (1) having a formed tub body made of sheet steel, which is provided with an enamel coating (201) on at least one upper side, wherein an anti-slip coating (5-8) containing titanium dioxide is applied at least in some areas on the enamel coating (201), characterized in that the coating is designed as a particulate coating with a degree of coverage of the enamel surface in the coating area of less than 50%.

2. Sanitary tub according to claim 1, characterized in that the coating (5-8) in the coating area has a proportion of titanium dioxide with an average surface weight of at least 1.7 mg / m2, preferably 2-10 mg / m2.

3. Sanitary tub according to claim 1 or 2, characterized in that the coating (5-8) comprises a ceramic component, in particular obsidian, in addition to titanium dioxide.

4. Sanitary tub according to one of the preceding claims, characterized in that at least part of the titanium dioxide is in the form of brookite or, particularly preferably, anatase.

5. Sanitary tub according to one of the preceding claims, characterized in that the distribution of titanium dioxide in the coating area (5-8) varies by less than 30% of the average surface weight.

6. Sanitary tub according to one of the preceding claims, characterized in that the titanium dioxide is formed as particles, wherein a majority of the particles has a rod shape.

7. Sanitary tub according to one of the preceding claims, characterized in that the sanitary tub has a coefficient of sliding friction in the coating area for the sanitary tub according to the invention of between 0.3 and 0.6, preferably between 0.35 and 0.55, in particular between 0.45 and 0.55.

8. Sanitary tub according to one of the preceding claims, characterized in that the sanitary tub (1) has a base area (2), a side wall (3) and a tub rim (4), wherein the sanitary tub (1) has the coating (5-8) at least in some areas in the region of the base (2) and the tub rim (4).

9. Method for producing a sanitary tub, characterized by at least the following steps of: A forming (100) a tub body from a steel sheet; B coating (200) the tub body at least on one upper side with an enamel coating (201); C baking (300) the enamel coating (201) onto the tub body at a baking temperature T1; D application (400) at least in sections of a coating liquid (401), as a coating dispersion, to produce an anti-slip coating (5-8) containing titanium dioxide on the enamel coating (201), E washing off (500) the liquid material (401) from the enamel coating (201) after an exposure time, characterized in that the exposure time of the liquid coating dispersion (401) is between 30 and 90 seconds.

10. Method according to claim 9, characterized in that the coating dispersion (401) comprises at least 2% by weight, preferably between 3 and 6% by weight, of titanium dioxide.

11. Method according to one of the preceding claims 9 or 10, characterized in that the coating dispersion (401) comprises glycerin, preferably at least 50% by weight of glycerin.

12. Method according to one of the preceding claims 9 to 11, characterized in that the washing off (500) is carried out with water or a water-containing detergent.

13. Method according to one of the preceding claims 9 to 12, characterized in that the temperature during application (400) in step D or during the exposure time is less than the baking temperature T1, preferably less than 200°C, particularly preferably less than 120°C, in particular between 10 and 50°C.