Industrial plasticine and its uses

Abstract

Main claim: A plasticine consisting of at least a binder and a filler, characterized in that the plasticine contains at least one surfactant.

Description

[Technical field]

[0001] The present invention relates to plasticine or technical plasticine and its uses.

[0002] Plasticines or clays for moulding and modelling are known in principle, where, for example, mixtures are used which consist of mineral-based and organic fillers and binders.

[0003] Such plasticine or clay or styling clay is used in modelling automobiles.

[0004] Clays for the design process of car manufacturers must have several properties / parameters to obtain a satisfactory working result. To create a model, the clay is first heated to a temperature of about 60° C. in a heated oven and then applied manually or mechanically to the substrate. To make this possible, such materials must be plastically deformable and have a low penetration hardness. After application of the clay to the substrate, the clay starts to cool and with it the hardness increases. This increase in hardness is caused by components of the clay that undergo a phase transition from liquid to solid between 60° C. and room temperature. Such components can be present as wax and / or petrolatum. For example, when the solidification range of the wax is reached during the cooling of the clay, the wax at the surface starts to become more and more brittle. This change can be confirmed by removing a sample from the oven at 60° C. and kneading it by hand until noticeable crack formation occurs on the surface. The drawback here is that it seems that the superficially brittle clay can no longer be applied to the substrate or model to obtain a homogeneous layer.

[0005] This period of possible treatment is called the time window of application or duration of malleability.

[0006] The further processing step of the clay, now cooled to room temperature, is cutting. This is done first mechanically by milling and then manually, with increasingly finer planers, scrapers and blades made of spring steel. To enable the cutting process, the clay must have a high penetration hardness at room temperature. In particular, fine machining with blades reveals disruptive properties. For example, when the blade is repeatedly drawn over the clay surface, the chips already removed penetrate into the surface. So-called "smears" occur, which occur with different frequency and magnitude depending on the clay used and have an unfavorable effect on the surface quality.

[0007] When used in the design laboratory, the time the clay remains in the heating cabinet varies and processing is already possible after a heating phase of several hours. Small portions of clay for further processing of models are stored in the heating cabinet for several weeks. It is therefore important that the clay has good storage stability at 60°C, i.e. it should not show any exudation of the liquid phase, should not form a skin on the surface and the change in penetration hardness should be slight.

[0008] For example, from German Utility Model No. 29720344 clays for design modelling are known which contain hollow microspheres in addition to zinc soap as a filler for imparting consistency, kaolin as a filler, vaseline, microwax, paraffin, white oil and colouring agents. A disadvantage of such clays according to the prior art is that they show an increased viscosity at low temperatures if the application time period is too short, and furthermore the chips resulting from the removal machining of the model have a tendency to smear.

[0009] The object of the present invention is therefore to create a plasticine or a technical plasticine that does not have the aforementioned drawbacks, in particular a plasticine that exhibits low viscosity at low temperatures and at the same time reduces the number and size of chips that show smearing, without impairing the good properties of plasticine such as low penetration hardness, good layer adhesion during application and a wide time range during application (= malleability), thereby contributing to their improvement.

[0010] The above-mentioned problem is solved by the features contained in claims 1, 9 and 10. Advantageous configurations and developments of the material according to the invention are contained in the further claims.

[0011] Surprisingly, it has been found that by adding a surfactant as a component of the plasticine, the penetration hardness can be reduced and the time range of the application process can be extended. Here, it has been found that the problem posed is solved if the proportion of surfactant in the plasticine is 0.1-4.0% by weight. In a preferred embodiment, 0.15-3.0% by weight of surfactant is contained in the plasticine. A content of 0.20% by weight to 2.00% by weight is particularly preferred. Surprisingly, it has been found that the effect of the surfactant used can be observed over the entire range.

[0012] For example, a low penetration hardness at 60° C. means that the plasticine flows more easily when applied and therefore less force is required to distribute.

[0013] Illustrative examples of the surfactant include nonionic surfactants such as 1-hexadecanol, esters of myristic acid and myristyl alcohol, (C16-C18) fatty alcohol polyglycol ethers, polyglycerol distearate, and / or oxyethylated polyglycerol stearate.

[0014] In general, the surfactants used according to the invention are included in the general concept of amphiphilic molecules having at least one hydrophobic region and at least one hydrophilic region. The hydrophobic region of the surfactant consists of an alkyl group having 8 to 34, in particular 14 to 18, carbon atoms. This region can belong to a carboxylic acid or an alkanol.

[0015] In the hydrophilic region, such as in the non-ionic surfactants listed above, alcohol, carboxylic acid ester and / or ether groups are present, which may be derived from fatty acids or fatty alcohols, or even from glycerin or ethyl glycol.

[0016] It is also possible to use other nonionic, anionic, cationic and / or amphoteric surfactants with different hydrophilic regions, in which case the hydrophilic regions of these surfactants are present in the following configuration:

[0017] 1) Nonionic surfactants: containing alcohols, carboxylic acid esters, amides or ethers derived from fatty alcohols, fatty acids, glycerin, ethylene glycol, propylene glycol or glycosides; 2) Anionic surfactants: including carboxylates, sulfonates, sulfates and phosphates; 3) Cationic surfactants: including quaternary ammonium compounds; 4) Amphoteric surfactants: including quaternary ammonium compounds, carboxylates, sulfonates, sulfates, sulfoacetates and / or amidobetaines;

[0018] Exemplary individual surfactant classes include the following: - Non-ionic surfactants: sucrose stearate and - N-(2-hydroxyethyl) coconut fatty acid amide; - Anionic surfactants: sodium palmityl sulfate and sodium tetradecene sulfonate; - Cationic surfactant: distearyl dimethyl ammonium chloride; - Amphoteric surfactants: coconut amidopropyl betaine and disodium cocoamphodiacetate;

[0019] Surprisingly, it has been found that the surfactants of the surfactant group can be used in mixtures with one another within the scope of the claims.

[0020] It has proven to be advantageous if the hardness of the plasticine is low and the application time window is wide, in which case the wax and / or oil content can also be reduced. As a result, the hardness of the plasticine is increased again to the normally desired level, while the application time window remains almost unaffected. However, it has also surprisingly been found that the viscosity of the cooled material is reduced, which in turn has a positive effect on the reduction of so-called "smearing".

[0021] The binders used can be present as waxes, such as microwaxes or paraffin waxes, as petrolatum, as oils, such as paraffin oil, and also as mixtures of the aforementioned substances.

[0022] The proportion of the binder is from 10 to 60% by weight, preferably from 12 to 55% by weight, and particularly preferably from 15 to 50% by weight.

[0023] As fillers, substantially inorganic and / or organic fillers can be used, such as cellulose particles, native starch, talc, aluminum hydroxide, alumina, sulfur, diatomaceous earth and / or clay powders, which have a particle size of <250 μm, preferably less than 100 μm. As further fillers, inorganic or organic salts of the metals calcium, zinc, tin, magnesium or barium, such as, for example, calcium carbonate, calcium stearate, zinc oxide, zinc oleate, zinc oxide, magnesium carbonate or barium sulfate, and mixtures of these salts can be used.

[0024] Furthermore, so-called lightweight fillers can also be used or mixed as fillers. Examples of lightweight fillers are hollow spheres, in particular hollow glass microspheres, for example from 3M or PQ-Corporation. Depending on the content of the lightweight fillers, the desired density can be adjusted, which is advantageously in the range of 0.3 to 1.1 g / ml. The size of the commercially available lightweight fillers can also be freely selected, which is advantageously in the range of 5 to 400 μm. As further fillers, luster agents, metal effect pigments, pearlescent pigments or mixtures of these substances can be present, whereby, for example, certain optical effects are achieved.

[0025] As colorants, dyes or powdered pigments can be used. Several possible color pigment options include iron oxide, iron hydroxide, carbon black, organic pigments and / or titanium dioxide.

[0026] The present invention will now be described in more detail with reference to some configuration and formulation examples.

[0027] [Table 1-1] [Table 1-2]

[0028] The desired consistency of the material can be easily adjusted by varying the binder content.

[0029] [Table 2]

[0030] The invention is explained in more detail with the help of the following table.

[0031] [Table 3]

[0032] The method for measuring penetration hardness is standardized by the American Society for Testing and Materials (ASTM D 1321-16a / ASTM D 937-07(2019)). There are also corresponding standards in other countries, such as the British Standard BS EN 1426:2015-07-31 and DIN 51579:2010-03.

[0033] As can be seen from Table 1, the penetration hardness of the material according to the invention with a surfactant component was found to be lower than that of the material of the same composition without the surfactant. A lower penetration hardness at 60° C. means that the Plasticine flows more easily when applied and less force is required to distribute it on the model.

[0034] [Table 4]

[0035] Malleability or duration of malleability is understood to mean the time range during application during which the plasticine can be worked or applied to a model.

[0036] There is no standardized mechanical test for the measurement of malleability, but there is a tactile test. For this, the materials to be compared are heated to 60°C. Then, two samples of the same size are taken in each hand and slowly kneaded. If the materials differ in terms of the time range of their application, this test shows this by the difference in the length of time until the materials become superficially brittle or crack.

[0037] The increased application time window allows the user to remove larger quantities of plasticine from the oven, saving time and money. This increased time window advantage can also be considered a major advantage in machining, where heated plasticine must be transported over long distances in tubes or other delivery systems.

[0038] A method for producing such a modeling material is described below.

[0039] Step 1 : A binder or binder mixture is prepared and mixed at a temperature above room temperature until homogeneous. Step 2 : Add surfactant and mix until uniform. Step 3 : Add fillers and dyes and mix again until material is uniform. Step 4 : Add the lightweight fillers and mix again until uniform. Step 5 Optionally, the material is degassed under vacuum.

[0040] The plasticine according to the invention is used for the production of design models for automobile manufacturing. Such design models are produced up to a scale of 1:1. The application of such material can be carried out, on the one hand, by hand, but on the other hand, by machine. In both types of application, it has proven advantageous if the plasticine contains a certain proportion of surfactant. Especially in mechanical application, it has surprisingly been possible to see improvements during further processing of the base model. Further processing includes, for example, the removal of excess plasticine material by a cutting process in milling.

Claims

1. A plasticine comprising at least a binder and a filler, the binder comprises wax and / or petrolatum; the plasticine comprises at least one surfactant, A plasticine, characterized in that the content of the surfactant in the plasticine is 0.10 to 4.0% by weight.

2. 2. The plasticine according to claim 1, wherein the content of said surfactant in said plasticine is 0.15 to 3.0% by weight.

3. the surfactant is from the group of amphiphilic molecules, the amphiphilic molecule has a hydrophobic region and at least one hydrophilic region; Plasticine according to claim 1 or 2, characterized in that the hydrophobic region of the surfactant consists of an alkyl group containing from 8 to 34 carbon atoms.

4. Plasticine according to any one of claims 1 to 3, characterized in that the hydrophobic region of the surfactant consists of an alkyl group containing from 14 to 18 carbon atoms.

5. 5. Plasticine according to claim 1, characterized in that the surfactant is present as a nonionic, anionic, cationic and / or amphoteric surfactant.

6. The surfactant has a hydrophilic region, the hydrophilic region of the nonionic surfactant comprises an alcohol, a carboxylic acid ester, an amide or an ether derived from a fatty alcohol, a fatty acid, glycerin, ethylene glycol, propylene glycol or a glycoside; the hydrophilic region of the anionic surfactant comprises carboxylates, sulfonates, sulfates and phosphates; the hydrophilic region of the cationic surfactant comprises a quaternary ammonium compound; 6. Plasticine according to claim 5, characterized in that the hydrophilic region of the amphoteric surfactant comprises a quaternary ammonium compound, a carboxylate, a sulfonate, a sulfate, a sulfoacetate and / or an amidobetaine.

7. The plasticine is 10 to 60% by weight of said binder, 0.1 to 4% by weight of said surfactant, 30 to 85% by weight of said filler, 0-10% by weight of a colorant, and 0-20% by weight of other additives The plasticine of claim 1, comprising:

8. 2. Use of the plasticine according to claim 1 for producing design models in automobile manufacturing.

9. 2. Use of the plasticine according to claim 1 for producing design models in automobile manufacturing, said models being produced by mechanical application of the plasticine and mechanical removal of excess clay.

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