Uses of bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate as a plasticizer in surface coatings

Abstract

This invention relates to a multilayer surface covering having one layer derived from a filler-containing PVC plastisol and another layer derived from an unfiller-free PVC plastisol, both containing a plasticizer composition comprising bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate. This surface covering can be used as a floor covering or as artificial leather.

Description

Technical Field

[0001] This invention relates to a multilayer surface covering having at least one layer derived from a filler-containing PVC plastisol and another layer derived from an unfiller-free PVC plastisol, both containing a plasticizer composition comprising bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (hereinafter also referred to as 1,4-DEHCH). This surface covering can be used as a floor covering or as artificial leather. Background Technology

[0002] Multilayer surface coverings, particularly floor coverings and artificial leather, are known and produced on an industrial scale. These surface coverings consist of multiple layers. At least some of these layers are primarily composed of polyvinyl chloride (PVC), to which plasticizers must be added to improve properties such as stretchability and processability. The most well-known PVC plasticizer in Europe is diisononyl phthalate (DINP), which is also considered the standard for applications in floor coverings and artificial leather. DINP is characterized by acceptable gelling properties, moderate viscosity, and, in particular, low volatility. Low volatility is especially important in the aforementioned applications to reduce emissions during manufacturing or in the final product. Due to the high processing temperatures, during the manufacture of flexible PVC products, at least some of the plasticizer will evaporate, then condense and / or drip at cooler sites, leading to contamination. This necessitates periodic production shutdowns, resulting in economic losses.

[0003] Although DINP is a global standard, phthalate-free plasticizers are increasingly used due to market demand (see US2016 / 0326346A1). One of the most important phthalate-free plasticizers is diisononyl cyclohexane-1,2-dicarboxylate (1,2-DINCH). Terephthalates, such as di-2-ethylhexyl terephthalate (DEHT or DOTP), are also potential large-volume alternatives to phthalates, or especially DINP, but they have repeatedly faced acceptance issues in the public eye because they belong to the phthalate family. However, both classes of plasticizers have lower gelation rates and higher volatility compared to DINP. To compensate for these gelation weaknesses, fast-setting agents must be added. However, fast-setting agents are generally more volatile, thus increasing the process volatility of the overall plasticizer composition. Furthermore, the additional use of fast-setting agents increases formulation costs, as they are typically more expensive. Summary of the Invention

[0004] The object of the present invention is to provide a multilayer surface coating in which an advantageous plasticizer composition is included in an existing PVC plastisol layer.

[0005] This objective can be achieved by the multilayer surface coating according to claim 1. Preferred embodiments of the invention are given in the dependent claims. Such a surface coating is a multilayer surface coating having at least one layer derived from a filler-containing PVC plasticizer comprising a composition of PVC, filler, and plasticizer, and at least one layer derived from a filler-free PVC plasticizer comprising a composition of PVC and plasticizer, characterized in that the plasticizer compositions in the filler-containing PVC plasticizer and the filler-free PVC plasticizer each contain bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (1,4-DEHCH).

[0006] When used in plastisols, the plasticizer compositions according to the invention produce improved overall properties compared to other cyclohexane dicarboxylic acid esters or mixtures thereof. Therefore, the desired DINP gelation speed can be achieved even without the addition of a fast-setting agent. Furthermore, plastisols with the plasticizer compositions according to the invention exhibit significantly reduced viscosity compared to plastisols containing DINP, resulting in faster or easier application and / or potentially lower formulation costs due to the possibility of increased filler content. The increased gelation speed compared to other cyclohexane dicarboxylic acid esters (e.g., 1,4-DINCH, 1,2-DINCH, 1,2-DEHCH) can lead to higher processing speeds or lower energy consumption during processing.

[0007] Within the scope of this invention, the phrase "layers derived from" refers to the respective layers obtained from the corresponding plastisol compositions. For the manufacture of surface coatings according to the invention, the plastisol provided herein is used in liquid or flowable form, applied layer by layer by a coating method, and then repeatedly pre-gelled at temperatures (100-150°C) insufficient for complete gelation or foaming. This pre-dries the layers and allows the application of the next layer, and in a final step, the final product is processed at a temperature of 160–230°C, for example, in a so-called "gelation tunnel." In this step, foaming and "bonding" of the individual layers also occur.

[0008] In principle, the layers of the surface covering according to the invention can be arranged in any order. However, it is preferred according to the invention that the layer derived from the filled PVC plastisol is arranged below the layer derived from the unfilled PVC plastisol. Between these two layers derived from the filled PVC plastisol and the unfilled PVC plastisol, one or more additional layers and / or carrier materials, such as polyester fabric, glass nonwoven fabric, paper, or paperboard, may exist. The carrier material may also preferably be located at a position within the filled layer.

[0009] Filler-containing PVC plastisol contains a composition of fillers and plasticizers in addition to PVC. Different types of PVC can be used as the PVC used in the filler-containing PVC plastisol. Preferably, the PVC in the filler-containing PVC plastisol is paste-grade PVC, extender-grade PVC, or a mixture of two or more of the aforementioned PVC types. In an alternative embodiment, the PVC is a mixture of two or more paste-grade PVCs.

[0010] The difference between paste-grade PVC and blended PVC typically lies in the production method and the resulting PVC particle size. Paste-grade PVC can be produced through emulsion polymerization or micro-suspension polymerization, resulting in PVC particles with a typical particle size of 1 to 40 μm. Blended PVC can be produced through suspension polymerization. The resulting agglomerated PVC particles typically have a particle size of 80 to 200 μm. Furthermore, adding blended PVC can reduce the viscosity level of the plastisol, even at low plasticizer contents, thereby making the plastisol easier to coat.

[0011] The exact composition is variable in principle and can be customized according to the corresponding application. For the surface coating according to the invention, it is preferred that the filler-containing PVC plastisol contains a plasticizer composition in a ratio of 35-80 parts by weight / 100 parts by weight, preferably 40-75 parts by weight / 100 parts by weight of PVC. The plasticizer composition comprises bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (1,4-DEHCH), but may also contain one or more other plasticizers. The corresponding plasticizers are known to those skilled in the art. The plasticizer composition contains 1,4-DEHCH, particularly in a ratio of at least 50% by weight, preferably at least 65% by weight, more preferably at least 80% by weight, each based on the entire plasticizer composition. In a particularly preferred embodiment, the plasticizer composition for the filler-containing PVC plastisol consists only of 1,4-DEHCH.

[0012] The filler-containing PVC plastisol used in the multilayer surface coverings according to the invention preferably contains filler in a ratio of 50-200 parts by weight / 100 parts by weight of PVC, more preferably 70-180 parts by weight / 100 parts by weight of PVC, and particularly preferably 85-170 parts by weight / 100 parts by weight of PVC. Suitable fillers for surface coverings are known to those skilled in the art. Preferred fillers that can be used in the filler-containing PVC plastisol within the scope of the invention are calcium carbonate, magnesium carbonate, clay, calcium silicate, talc, calcium sulfate, calcium oxide, magnesium oxide, aluminum silicate, dolomite, silica, and diatomaceous earth. Calcium carbonate and magnesium carbonate are particularly preferred.

[0013] In addition to the contents mentioned above, filler-containing PVC plastisols may also contain additives. Examples of additional additives include rheology modifiers, which reduce the viscosity of the plastisol; epoxidized vegetable oils, such as epoxidized soybean oil (ESBO) as a co-stabilizer; and heat stabilizers or degassing agents, which reduce surface tension to facilitate the removal of air bubbles generated in the plastisol during production. Examples of rheology modifiers are products available under the trade names VISCOBYK®-5120, VISCOBYK®-5130, and VISCOBYK®-4041. Known degassing agents are methylalkyl polysiloxanes (e.g., available under the trade name BYK®-3105) or polyalkylene derivatives (e.g., available under the trade name BYK®-3155). Preferred degassing agents are silicone-free. Suitable heat stabilizers are lead salts, organotin compounds, barium / zinc compounds, cadmium or zinc compounds, calcium / zinc stabilizers, and organic-based stabilizers (so-called OBS). Preferred heat stabilizers are barium / zinc compounds, calcium / zinc stabilizers, and organic-based stabilizers (so-called OBS). Additives may be individually included in the plastisol at a maximum of 15 parts by weight per 100 parts by weight of PVC.

[0014] The multilayer surface covering may also include a carrier material. Different materials can be used as the carrier material for the surface covering described herein. Preferably, the carrier material for the multilayer surface covering consists of polyester fabric, glass nonwoven fabric, paper, or paperboard. If a carrier material is present, it is coated with a filler-containing PVC plastisol at least on its top side, i.e., one side. This particularly relates to paper and paperboard. Through this coating, the flowable plastisol composition penetrates into the structure of the carrier material. Therefore, in the sense of the invention, the carrier material belongs to a layer derived from the filler-containing PVC plastisol. The carrier material is preferably coated with filler-containing PVC plastisol on both sides, i.e., the top and bottom sides, which can also be done in one step. Thus, the carrier material is impregnated or soaked with the filler-containing PVC plastisol. The carrier material is then contained in the layer derived from the filler-containing PVC plastisol.

[0015] Fillerless PVC plastisol contains at least a plasticizer composition in addition to PVC. As the name suggests, fillerless PVC plastisol does not contain fillers, i.e., there are no substances that can be considered fillers. The layer obtained from fillerless PVC plastisol is preferably transparent. Different types of PVC can be used as the PVC in fillerless PVC plastisol. The PVC in fillerless PVC plastisol is preferably paste-grade PVC, blend-grade PVC, or a mixture of two or more of said PVC types. In an alternative embodiment, the PVC is a mixture of two or more paste-grade PVCs. The definitions and differences between paste-grade PVC and blend-grade PVC have been explained above.

[0016] For fillerless PVC plastisol, it is preferable that it comprises at least one paste-grade PVC and at least one blend-grade PVC. The amounts of paste-grade PVC and blend-grade PVC can vary widely to match the requirements of their respective applications. In a preferred embodiment, the content of paste-grade PVC is 40-80% by weight, and the content of blend-grade PVC is 20-60% by weight, each based on the total amount of PVC in the fillerless PVC plastisol. Needless to say, the amounts of paste-grade PVC and blend-grade PVC must be summed to 100% by weight.

[0017] The composition of fillerless PVC plastisol is, in principle, variable and can be customized according to the corresponding application. For the surface coatings according to the invention, it is preferred that the fillerless PVC plastisol comprises a plasticizer composition containing 1,4-DEHCH at a ratio of 15-40 parts by weight per 100 parts by weight of PVC. The plasticizer composition comprises bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (1,4-DEHCH), but may also contain one or more other plasticizers. The corresponding plasticizers are known to those skilled in the art. 1,4-DEHCH is particularly included in the plasticizer composition at a ratio of at least 50% by weight, preferably at least 65% by weight, more preferably at least 80% by weight, each based on the entire plasticizer composition. According to the invention, it is preferred that the plasticizer composition for fillerless PVC plastisol also contains a rapid gelling agent in addition to 1,4-DEHCH. The rapid gelling agent may be present in the fillerless PVC plastisol at a ratio of up to 15 parts by weight per 100 parts by weight of PVC. Suitable fast-setting agents are ethylene glycol dibenzoate, dibutyl terephthalate or dipentyl terephthalate, 2-ethylhexyl benzoate, isononyl benzoate or isodecanyl benzoate, tributyl citrate, acetyl tributyl citrate or hydrogenated phthalates or terephthalates having C4 to C7 alkyl chains.

[0018] In addition to the contents mentioned, unfilled PVC plastisol may also contain additives. Examples of added additives are rheology modifiers, which reduce the viscosity of the plastisol. Known examples of rheology modifiers are products available under the trade names VISCOBYK®-5120, VISCOBYK®-5130, and VISCOBYK®-4041. The additives can be included in the unfilled PVC plastisol at a ratio of 3-12, preferably 4-10 parts by weight per 100 parts by weight of PVC.

[0019] Furthermore, the fillerless PVC plastisol may contain one or more heat stabilizers. Suitable heat stabilizers are lead salts, organotin compounds, barium / zinc compounds, cadmium or zinc compounds, calcium / zinc stabilizers, and organic-based stabilizers (so-called OBS). Preferred heat stabilizers are barium / zinc compounds, calcium / zinc stabilizers, and organic-based stabilizers (so-called OBS). The proportion of the one or more stabilizers in the fillerless PVC plastisol is preferably 1-4 parts by weight per 100 parts by weight of PVC.

[0020] In addition to the layers already mentioned, the multilayer surface covering according to the invention can have further layers. Therefore, the surface covering can have an additional foamed layer on the back side derived from foamable PVC plastisol. Such a layer can improve acoustic properties. In the case of floor coverings, this layer derived from foamable PVC plastisol can be used to attenuate walking noise.

[0021] The additional foaming layer derived from expandable PVC plastisol specifically comprises PVC, a plasticizer composition containing at least cyclohexane-1,4-dicarboxylic acid bis(2-ethylhexyl) ester (1,4-DEHCH), one or more fillers, a foaming agent, a catalyst, and optionally one or more additional additives. The plasticizer composition of the additional foaming layer derived from expandable PVC plastisol may additionally comprise a rapid gelling agent. Suitable rapid gelling agents are dibenzoyl diol ester, dibutyl terephthalate or diamyl terephthalate, 2-ethylhexyl benzoate, isononyl benzoate or isodecanyl benzoate, tributyl citrate, acetyl tributyl citrate, or hydrogenated phthalates or terephthalates having C4 to C7 alkyl chains.

[0022] The composition of the additional foaming layer derived from expandable PVC plastisol is, in principle, variable and can be customized according to the specific application. Preferably, for the surface covering according to the invention, the additional layer derived from the foamable PVC plastisol contains a plasticizer composition at a ratio of 40-80 parts by weight / 100 parts by weight of PVC, said plasticizer composition containing 1,4-DEHCH. The additional layer of foamable PVC plastisol may further contain filler at a ratio of 70-200 parts by weight / 100 parts by weight of PVC.

[0023] To achieve the desired foaming, one or more foaming agents can be used. The foaming agent decomposes, thereby producing gases (bubbles) that cause foaming. Known foaming agents include, for example, azodicarbonamide, carbonates, bicarbonates, or oxobis(benzenesulfonyl)hydrazine (OBSH). Foaming agents must generally be used in only relatively small amounts. However, in principle, the amount of foaming agent is related to the desired degree of foaming. Additional foaming layers derived from foamable PVC plastisol contain a foaming agent at a ratio of 2-5 parts by weight per 100 parts by weight of PVC.

[0024] According to the present invention, the decomposition of the foaming agent can be catalyzed by a so-called catalyst. Zinc-containing compounds are commonly used as catalysts. Suitable catalysts are, for example, ZnO, ZnBO3, and zinc salts such as zinc octoate, NaZn, KZn, or MgZn compounds. The amount of catalyst used is usually small, but the type and amount have a decisive influence on the decomposition rate of the foaming agent and therefore on the amount of bubbles formed during the time-limited foaming process that leads to foaming. Therefore, the additional layer of foamed PVC plastisol can preferably contain a catalyst at a ratio of 1-5 parts by weight per 100 parts by weight of PVC.

[0025] In addition to the contents mentioned, the additional foaming layer derived from expandable PVC plastisol may also contain additives. Examples of such additives are rheology modifiers, which can reduce the viscosity of the plastisol. Examples of rheology modifiers are products available under the trade names VISCOBYK®-5120, VISCOBYK®-5130, and VISCOBYK®-4041. This additive can be included in the expandable PVC plastisol at a ratio of 4-10 parts by weight per 100 parts by weight of PVC.

[0026] Optionally, instead of the aforementioned chemically decomposing foaming agents, additional foam layers can be created by mechanical foaming, i.e., by incorporating air. In this case, instead of catalysts and foaming agents, so-called foam stabilizers are added to the corresponding plastisol, which prevent the introduced air from escaping and the foam from shrinking. Such compounds, typically based on silicones or soaps, are known to those skilled in the art, for example, under the trade names “BYK® 8070” or BYK® 8020. In a particularly preferred embodiment, this mechanical foam can also be used to impregnate a carrier material.

[0027] In a preferred embodiment of the invention, the multilayer surface covering according to the invention has a decorative feature. In the context of the invention, decoration refers to visual and / or tactile design, for example, by introducing (printed) inks and / or embossing patterns. Such decoration can be applied and / or embossed onto a layer derived from filler-containing PVC. However, an additional, optionally foamed, decorative layer derived from PVC plastisol may also be present, on which the decoration is applied and / or embossed. The additional, optionally foamed decorative layer derived from foamable PVC plastisol particularly comprises PVC, a plasticizer composition containing at least cyclohexane-1,4-dicarboxylic acid bis(2-ethylhexyl) ester, fillers, and optionally a foaming agent, a blowing agent, and / or one or more additives.

[0028] In a particularly preferred embodiment of the invention, the multilayer surface coating comprises a carrier material, at least one layer derived from a filler-containing PVC plastisol comprising a composition of PVC, filler, and plasticizer, at least one layer derived from an unfiller-containing PVC plastisol comprising a composition of PVC and plasticizer, and at least one foaming layer comprising a foamable PVC plastisol comprising PVC, a plasticizer composition, filler, a foaming agent, and a catalyst. All plasticizer compositions of the PVC plastisols used each contain bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (1,4-DEHCH). In a particularly preferred embodiment, the multilayer surface coating further comprises an additional scratch-resistant layer, preferably composed of polyurethane or polyacrylate and being translucent (transparent).

[0029] Very particularly preferred, the multilayer surface coating includes an additional filler layer, particularly a foamed layer, between the unfilled layer and the filler layer, on which the decoration is applied. The application of decorative inks can, for example, be carried out in one or more steps using screen printing rollers (each color separately). Here, the principle of chemical inhibition is often applied; the printing ink, which may also be a colored PVC plastisol, can be supplemented with an inhibitor solution, which prevents or slows the decomposition of the foaming agent at the site of application by chemical complexation of the catalyst, resulting in no or only slight foaming at that location. Suitable inhibitors are commercially available, for example, based on benzotriazoles or thioureas. Attached Figure Description

[0030] For the surface covering according to the invention, a specific layer sequence is preferred. These layer sequences can also be... Figure 1 , Figure 2 and Figure 3 As can be seen in the exemplary illustrations. In the basic implementation (see...) Figure 1 In this embodiment, the multilayer surface coating comprises at least one layer (2) derived from a filler-containing PVC plastisol and at least one layer (1) derived from an unfiller-containing PVC plastisol, which is preferably transparent. The at least one preferably transparent layer (1) derived from an unfiller-containing PVC plastisol is disposed above the at least one layer (2) derived from the filler-containing PVC plastisol.

[0031] Figure 2A preferred embodiment is shown, wherein, in addition to the at least one preferably light-transmitting or transparent layer (1) derived from unfilled PVC plastisol and the at least one layer (2) derived from filled PVC plastisol, there is also a carrier material (3) and a foamed layer (4) derived from expandable PVC plastisol. In this embodiment, the carrier material (3) is coated with filled PVC plastisol on both sides and is therefore located within the at least one layer (2) derived from filled PVC plastisol. The foamed layer (4) derived from expandable PVC plastisol is then arranged below the layer (2). It is also conceivable that the carrier material is coated with filled PVC plastisol only on the top side. The carrier material is then directly adjacent to the foamed layer (4) derived from expandable PVC plastisol.

[0032] Figure 3 A further preferred embodiment is shown, wherein an optional foamed decorative layer (5) is additionally present. Visual (color) and / or tactile (e.g., embossed pattern) decoration (6) is then applied to this layer. Here, the decorative layer (5) is disposed between the at least one layer (2) derived from a filler-containing PVC plastisol and the at least one preferably transparent layer (1) derived from an unfiller-free PVC plastisol.

[0033] In a particularly preferred embodiment, a scratch-resistant layer, preferably made of polyurethane or polyacrylate, is further applied to the preferably translucent or transparent layer derived from unfilled PVC plastisol to improve scratch and abrasion resistance. Such a layer is not shown in the figure.

[0034] The multilayer surface coating according to the invention can be manufactured in a manner known to those skilled in the art by applying layer by layer a still-flowable plastisol, optionally with intermediate drying, for example by means of rollers / gelling rollers heated to about 100 to 140°C, which results in partial gelation, i.e., incomplete gelation, so that the next layer can be applied without causing the plastisol to fuse together. Optional intermediate drying can be carried out, for example, with a so-called gelling roller, i.e., a roller heated to the desired temperature.

[0035] Multi-layer surface coverings can be used in a variety of applications. In a particularly preferred embodiment of the invention, the surface covering is floor covering or artificial leather and is used for the corresponding application. Detailed Implementation

[0036] The present invention will now be explained with reference to the embodiments. However, these embodiments are merely illustrative and should not be construed as limiting.

[0037] Example 1 - Preparation of Plasticized Sol

[0038] Prepare PVC plastisol, such as for example, to produce a topcoat film (filler-free layer) for floor coverings. The amounts in the plastisol formulation are given in parts by weight (phr). Formulations are shown in Table 1.

[0039] Table 1: Plaster Formulation

[0040] phr PVC (Vestolit P 1430 K70–Ultra; derived from Vestolit) 100 Plasticizers or plasticizer mixtures 50 Epoxidized soybean oil was used as a stabilizer (Edenol D81, obtained from Emery Oleochemicals). 3 Ca / Zn-based heat stabilizer (Reagens SLX 781) 2

[0041] First, weigh the liquid, then the powdered components, into a PE beaker. Manually stir the mixture with a spatula to remove any unwetted powder. Then, clamp the mixing beaker into the holder of the dissolving stirrer. After turning on the stirrer, slowly increase the speed to approximately 2000 rpm. Simultaneously, carefully degas the plastisol. For this, adjust the pressure to below 20 mbar. Once the plastisol reaches a temperature of approximately 30°C, reduce the speed to approximately 350 rpm. From there, degas the plastisol for 9 minutes at this speed and below 20 mbar. This ensures that premature partial gelation does not occur during the homogenization of the plastisol.

[0042] The following plasticizers or mixtures of the following plasticizers are used in plastisol:

[0043] 1,4-DEHCH = cyclohexane-1,4-dicarboxylic acid bis(2-ethylhexyl) ester (according to the present invention, Hanwha Chemical Corp., South Korea)

[0044] 1,2-DEHCH = cyclohexane-1,2-dicarboxylic acid bis(2-ethylhexyl) ester (Nan Ya, Taiwan Province, China)

[0045] DINP = diisononyl phthalate (VESTINOL 9, from Evonik Operations GmbH)

[0046] 1,2-DINCH = diisononyl 1,2-cyclohexanedicarboxylate (ELATUR CH, Evonik Operations GmbH)

[0047] 1,4-DINCH=1,4-cyclohexanedicarboxylate diisononyl terephthalate (prepared by hydrogenation of diisononyl terephthalate ring)

[0048] DOTP = Dioctyl terephthalate (Eastman 168, from Eastman, USA)

[0049] DPT = diamyl terephthalate (Elatur DPT, from Evonik Operations GmbH)

[0050] 2088 = Benzoflex 2088 (a mixture of ethylene glycol dibenzoate, obtained from Eastman, USA)

[0051] Example 2 - Determination of the viscosity of plastisol

[0052] The viscosity of the plastisol prepared in Example 1 was measured using a Physica MCR 101 rheometer (obtained from Anton Paar Germany GmbH) with the aid of relevant software, employing a rotation mode and a CC27 measurement system. Measurements were performed after the plastisol had been tempered at 25°C for 24 hours following its preparation.

[0053] The following points were involved during the measurement:

[0054] - Pre-shear 100 s -1 The measurement will be recorded for a period of 60 seconds.

[0055] - Shear rate from 200s -1 Dropped to 0.1s -1 Thirty measurement points were recorded, with each measurement lasting for 10 seconds.

[0056] Measurements were performed at room temperature. Determination was made in each case at 100 seconds. -1 The viscosity obtained at the shear rate.

[0057] Table 2 lists the results of viscosity measurements for the plastisols prepared in Example 1, each containing a given plasticizer or mixture of plasticizers.

[0058] Example 3 - Gelation Properties

[0059] The gelling properties of the plastisol were studied using a plate-to-plate measurement system (PP25) in oscillating mode on a Physica MCR 101 (obtained from Anton Paar), operated under shear stress control. An additional temperature control hood was attached to the equipment to achieve the best possible heat distribution. The following measurement parameters were set:

[0060] Mode: Temperature-gradient (linear temperature slope)

[0061] Starting temperature: 25℃

[0062] Finishing temperature: 180℃

[0063] Heating / cooling rate: 5K / min

[0064] Oscillation frequency: 4-0.1Hz ramp (logarithmic)

[0065] Angular frequency Ω: 10s -1

[0066] Number of measurement points: 63

[0067] Measurement duration: 0.5 minutes

[0068] Automatic gap tracking

[0069] Duration of constant measurement point

[0070] Gap width 0.5mm

[0071] Measurement process:

[0072] Using a spatula, apply a few drops of the plastisol to be measured onto the lower plate of the measuring system without air bubbles. Note that after the measuring system is closed, some plastisol swells uniformly out of the measuring system (within approximately 6 mm of the surrounding area). Then, place the temperature control hood over the sample and begin the measurement. Here, the so-called complex viscosity of the plastisol is determined as a function of temperature. A sudden and strong increase in complex viscosity can identify the onset of the gelation process. The earlier this viscosity increase begins, the better the gelling ability of the system. The temperature at which the complex viscosity of each plastisol is measured to 1000 Pa·s is determined by interpolation from the resulting measurement curves. The results are listed in Table 2.

[0073] Example 4 - Thin Film Fabrication

[0074] The plastisol prepared in Example 1 was processed into a 1 mm thick film.

[0075] To this end, firstly, high-gloss release paper (obtained from Sappi, Italy) was cut to a size of 30×44cm and placed in the clamping frame of the LTSV coating apparatus of the Mathis oven. The clamping frame was then placed on a guide frame, and the Mathis oven (LTF type) was set to 200°C. After reaching this temperature, the frame was preheated. Next, a doctor blade was placed in the clamping apparatus, and the blade gap was adjusted through preliminary experiments to achieve a film thickness of 1mm (+ / -0.05mm) after gelation. The plastisol was then applied to the clamped release paper using the doctor blade (speed 3m / min). The doctor blade was then removed, and the clamping frame was moved into the oven. After gelation (2 minutes at 200°C), the frame was removed from the oven again, and after cooling, the film was removed from the paper.

[0076] Example 5 - Cold Flexibility by Means of Glass Transition Temperature (DSC)

[0077] For measurement, a small circle (Ø4.5 mm) was punched from the PVC film of the respective plastisol prepared according to Example 4. The sample was measured under nitrogen in an aluminum crucible (perforated crucible lid) using a DSC1 obtained from Mettler Toledo, with the following settings:

[0078] Drying gas nitrogen: approximately 45 N / ml / min (= standard ml / min)

[0079] Nitrogen gas (purge gas): approximately 180 N / min

[0080] Cooling: Liquid nitrogen (with an additional container at 1.5 bar)

[0081] method:

[0082] [1] 25.0 to 120.0 °C, 25.0 K / min

[0083] [2] 120.0℃, isothermal for 5.00 minutes

[0084] [3] 120.0℃ to -50.0℃; 25.0K / min

[0085] [4] -50.0 to -120.0℃, 10.0 K / min

[0086] [5] -120.0℃, 3.00 minutes isothermal

[0087] [6] -120 to 50.0℃, 10.0K / min

[0088] Start simultaneously

[0089] Different temperature ramps eliminate the thermal history of the samples, thus contributing to higher reproducibility of results. For the glass transition, the peak-to-maximum value of the first derivative of the ramp [6] was evaluated. The obtained heat flux was plotted as a function of the measured temperature.

[0090] Example 6 - Volatility of Plasticizers in Films

[0091] Three circles for each sample were punched out from the PVC film prepared in Example 4 using a punch (circular; diameter: 5 cm). The samples were then conditioned in a desiccator for 16 hours.

[0092] The sample circle was weighed on an analytical balance, placed in a wire basket, and sealed with clamps.

[0093] Place 130ml of activated carbon into a 1L high tin can. First, place the first wire basket containing the sample on top of the activated carbon, and then place another 130ml of activated carbon on top of the sample circle. In this way, the tin can is filled with a total of 520ml of activated carbon and three wire baskets containing samples, layer by layer. Finally, fill the top layer with another 130ml of activated carbon.

[0094] The perforated lids of the galvanized iron cans were placed on the cans without pressure. The filled galvanized iron cans were placed in a temperature-controlled chamber set to 120°C, ensuring the ventilation fan inside the chamber was not blocked and the cans did not touch each other. The air exchange and exhaust valves were set to 10% respectively. After 72 hours at 120°C, the cans were removed from the chamber again, cooled, and then each sample was removed from the basket, adjusted in a desiccator for another 16 hours, and then re-weighed on an analytical balance. The obtained mass difference was due to the loss of plasticizer. The average of the three mass differences for each case was calculated, and the percentage of plasticizer loss was calculated. The results are listed in Table 2.

[0095] Example 7 - Determination of Shore A Hardness of Thin Films

[0096] To determine the Shore hardness, the plasticized sol prepared as in Example 1 was poured into a circular stainless steel mold with a diameter of 42 mm (weight: 20 g). The paste was then allowed to gel in the mold at 200°C for 25 minutes in a circulating air drying cabinet. After cooling, the sample was removed and conditioned in an air-conditioned room (25°C) for at least 16 hours before measurement. The obtained sample thickness was approximately 12 mm.

[0097] Hardness measurements were performed according to DIN 53 505 using a Shore A measuring device from Zwick-Roell, with the measurement read after 3 seconds in each case. Measurements were taken at three different locations on each specimen, and the average value was calculated. The results are listed in Table 2.

[0098] Table 2: Measurement results of Examples 2, 3, 5, 6 and 7

[0099]

[0100] The results in Table 2 can be summarized as follows:

[0101] - The viscosity of the plasticizer 1,4-DEHCH according to the invention is significantly lower than that of DINP. This allows for higher filler density (more filler) and / or eliminates the need for viscosity reducers. This is advantageous because it saves on the additional costs associated with using viscosity reducers (e.g., the cost of the substance, the cost of additional containers for storing the substance) and avoids additional potential problems caused by the evaporation of viscosity reducers, which are typically highly volatile. Alternatively, the high efficiency, expressed as a significantly lower Shore hardness, can save on plasticizers and thus further reduce emissions.

[0102] - The glass transition temperature (Tg) of the film prepared according to Example 4 using 1,4-DEHCH as a plasticizer g It is comparable to films using DINP as a plasticizer.

[0103] - The 1,4-DEHCH according to the invention has the same gelling properties as DINP according to Example 3, even without the addition of a fast-setting gelling agent. Other plasticizers, 1,2-DINCH, DOTP, and 1,4-DINCH, can only be adjusted to comparable gelling properties by means of a fast-setting gelling agent (here: DPT). However, this also increases volatility (Example 6), i.e., deteriorates.

[0104] - Although 1,4-DINCH exhibits the lowest volatility of all the mixtures, it still possesses low viscosity and optimal cold toughening (Example 5), but other properties such as gelling (Example 3) deteriorate significantly. It is not possible to apply this to just one parameter; rather, the overall performance of various parameters must be considered.

[0105] Among all alternatives to DINP, the plasticizer 1,4-DEHCH according to the present invention exhibits the best overall performance in terms of gelation, volatility, and effects (Shore hardness, viscosity, cold flexibility). Furthermore, it eliminates the need for a fast-setting agent, which is advantageous for the reasons stated above.

Claims

1. A multilayer surface coating comprising at least one layer derived from a filler-containing PVC plastisol, said filler-containing PVC plastisol comprising a composition of PVC, filler, and plasticizer, and at least one layer derived from an unfiller-free PVC plastisol, said unfiller-free PVC plastisol comprising a composition of PVC and plasticizer, characterized in that, The plasticizer compositions in the filled PVC plastisol and the unfilled PVC plastisol each contain bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate.

2. The multilayer surface covering according to claim 1, wherein the PVC in the filler-containing PVC plastisol and the filler-free PVC plastisol are, in each case, paste-grade PVC, blend-grade PVC, or a mixture thereof.

3. The multilayer surface coating according to claim 2, wherein the filler-free PVC plastisol contains at least one paste-grade PVC and at least one blend-grade PVC.

4. The multilayer surface covering according to any one of claims 1-3, wherein the filler-free PVC plastisol contains a plasticizer composition in a ratio of 15-40 parts by weight to 100 parts by weight of PVC.

5. The multilayer surface covering according to any one of claims 1-3, wherein the filler-containing PVC plastisol contains a plasticizer composition in a ratio of 35-80 parts by weight to 100 parts by weight of PVC.

6. The multilayer surface covering according to any one of claims 1-3, wherein the filler-containing PVC plastisol contains filler in a ratio of 50-200 parts by weight to 100 parts by weight of PVC.

7. The multilayer surface covering according to any one of claims 1-3, wherein the multilayer surface covering comprises at least one carrier material coated with a filler-containing PVC plastisol on one or both sides of the carrier material.

8. The multilayer surface covering according to claim 7, wherein the carrier material is composed of polyester fabric, glass nonwoven fabric, paper or cardboard.

9. The multilayer surface covering according to any one of claims 1-3, wherein the surface covering has an additional foaming layer on the back side derived from foamable PVC plastisol.

10. The multilayer surface coating of claim 9, wherein the foamable PVC plastisol comprises PVC, a plasticizer composition, fillers, a foaming agent and a catalyst, and optionally additives for reducing viscosity.

11. The multilayer surface covering according to claim 9, wherein the additional foaming layer derived from foamable PVC plastisol contains filler in a ratio of 70-200 parts by weight of PVC to 100 parts by weight of PVC.

12. The multilayer surface covering according to claim 9, wherein the additional foaming layer derived from foamable PVC plastisol contains a plasticizer in a ratio of 40-80 parts by weight to 100 parts by weight of PVC.

13. The multilayer surface coating according to claim 9, wherein the multilayer surface coating comprises a carrier material, at least one layer derived from a filler-containing PVC plastisol, the filler-containing PVC plastisol comprising a composition of PVC, filler, and plasticizer, at least one layer derived from an unfiller-free PVC plastisol, the unfiller-free PVC plastisol comprising a composition of PVC and plasticizer, and at least one foaming layer derived from an expandable PVC plastisol, the expandable PVC plastisol comprising PVC, a plasticizer composition, filler, foaming agent, and catalyst, characterized in that, The plasticizer compositions in all the PVC plastisols used each contain cyclohexane-1,4-dicarboxylic acid bis(2-ethylhexyl) ester.

14. The multilayer surface covering of claim 13, wherein the multilayer surface covering further comprises a scratch-resistant layer.

15. The multilayer surface covering of claim 14, wherein the scratch-resistant layer is composed of polyurethane or polyacrylate and is transparent.

16. Use of the multilayer surface covering according to any one of claims 1-15 as a floor covering or as artificial leather.

Images