DE2312666A1 - MATERIAL FROM RUBBER WASTE, IN PARTICULAR FROM TIRE SCRAPS - Google Patents

Description

Bayer Aktiengesellschaft

Central area

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and licenses

509 Leverkusen, Bayerwerk

Mr / Gr

f March 3, 1973

Material made from rubber waste, in particular from shredded tires

The present invention is directed to a material made from rubber waste, in particular from shredded tires and made of elastomeric plastics as a binder. Although materials of this type have been known for a long time they have not yet found a wide field of application because they have many shortcomings.

On the other hand, rubber waste is accumulating in ever larger quantities, especially old vehicle tires such as car, motorcycle, airplane, bicycle tires, etc. The destruction of this old rubber, For which there has not yet been sufficient use, creates particular difficulties in terms of environmental protection. In the previous materials, in which tire chips are contained, these are used as a filler in solid elastomer plastics embedded. Such materials are void-free and their property profile is largely similar to that of plastic certainly. With these materials, the size of the rubber particles does not normally exceed the volume of about 0.5 cm, the majority of the particles being significantly smaller. The rubber chips for this are usually obtained from the old rubber peeled off during the retreading process of car tires by crushing it.

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The disadvantage here is that car tires with wire inserts do not up to the rubber chip size that has been used up to now could be crushed and therefore not usable. In addition, these materials are in the process of being manufactured relatively expensive and because of the dense packing of the Rubber parts are also relatively heavy.

The object of the present invention is therefore to provide a material based on rubber waste, in particular from To create shredded tires, which also includes the recovery of Old rubber, which contains steel wire or other inlays, enables , and being this material due to its structure both technically and in terms of price a broader field of application is open than the previously known, comparable materials.

According to the invention, this object is achieved by a material solved, which is characterized in that the individual rubber chips. a volume ranging from 0.1 cm to '

3 3 3

100 cm with a predominant proportion of 1 cm to 20 cm, and that the binder has a cellular structure and the voids between the rubbers are only partially carved fills out.

By using larger rubber particles than before according to the invention, excessive shredding is saved. At the same time, these larger particles allow metal wire inserts, textile inserts, etc. in the rubber waste all can remain. They are crushed with the appropriate machines at the same time as the rubber particles. The bigger ones

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Particles ensure larger cavities between the individual chips, so that the volume weight is lower. If you have a material with a higher density, it is easily possible to compress it during manufacture by applying pressure. This application of pressure has the further advantage that the material experiences a certain prestress, which is noticeable in its blasticity properties. Because of the lower specific surface area of the rubber chips, the maximum amount of binding agent required for wrapping and thus binding the rubber chips can be reduced in comparison with the much smaller chips used up to now, as it is directly dependent on the specific surface area, which is known to increase with the chip size decreases. The use of binders with a cellular structure to connect the individual rubber chips has the advantage that relatively small amounts of binder by weight are required, so that the total weight of the material is also kept low as a result. It is particularly advantageous that the binding agent only partially fills the cavities between the rubber slots. In this way it is achieved that the material is gas and liquid permeable.

This results in a wide range of applications, starting as a filler or insulating material, through to use as filter material up to the substructure for paths and squares, be it by direct application as a layer or in form of prefabricated panels.

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According to a particular embodiment of the material according to the invention, the proportion of the binder is 5 % to 15%, based on the dry density of the rubber chips. With this relatively small amount of binder, a particularly favorable ratio of the remaining cavities to the space of the material occupied by the rubber chips is guaranteed.

A variety of commercially available adhesives that show a cell structure after they have set are suitable as binders.

In the context of the invention, materials have proven to be particularly favorable whose binder consists of a light- curing isocyanate or polyisocyanate.

The isocyanate or polyisocyanate reacts with water and crosslinks to form urea, with carbon dioxide being split off. The amount of water required for the hardening process is taken from the air. If you want to increase the cell structure in the binder, moisten the rubber chips with an appropriate amount of water. The vigorous evolution of CO ₂ that occurs during the reaction causes the binder to foam before it hardens. By using the large-volume rubber chips and the resulting large cavities, the foam formed from the binder is given the opportunity to develop freely, so that the ratio of the amount of binder to the foam volume and thus to the adhesive surface between foam and rubber chips are very favorable can. With the low amounts of binder in question, the foam fills only part of the cavities, so that no foaming pressures occur. By using different

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Like isocyanates or polyisocyanates, the elasticity of the binder can be influenced.

According to an alternative embodiment, the binder consists of a two-component polyurethane. For example polyisocyanate is reacted with a polyol to form polyurethane. By using two components you can better influence the reaction time and the elasticity.

According to a particular embodiment, the material according to the invention is characterized by the content of non-rubber-like comminuted waste materials. These can be, for example:

Tissue, foil, flexible foam, thermoplastic, glass waste etc. in shredded form.

According to another embodiment, the material has reinforcements made of coarse-meshed fabrics and / or fiber material. As a result, an aieotropic or isotropic reinforcement of the material is achieved.

The properties of the material according to the invention can be varied within wide limits, because they are dependent on many parameters, such as, for. B. the density, the binder, the shape, size, grain distribution uad surface properties of the rubber chips, type and proportion of binder, type, amount and size of any fillers used and the type and arrangement of possible reinforcements.

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This large number of parameters makes it possible to adapt the material properties to the requirements of special applications within certain limits. A gun stiger range for the bulk density is between about 450 and 850 kg / nr. ⁵ The compressive strength at 10% deformation is between 1 and 10 kp / cra ² . The tensile strength at 1 % deformation is between 0.3 and 3 kp / cm. the shear strength at a shear angle of 4.5 ° between about 0.5 and 4 kp / cm. The coefficient of thermal conductivity was determined between 0.08 and 0.2 kcal / mh ⁰ C.

The previous areas of application for materials containing rubber chips were primarily limited to relatively thin-layer coverings on sports hall floors, running tracks, play areas and the like. A particular disadvantage was the complete or low impermeability to water. As a sub-layer or sub-layer for sidewalks or other surfaces, the material was also not well received for reasons of price. But the lack of water permeability also played a decisive role in these areas of application.

It is now the merit of the present invention to have recognized that a material from rubber chips and binding agents can also be produced in a highly water-permeable form. The material is weather and frost resistant. It is precisely these properties that open up new areas of application for the material according to the invention. Up to now, if the subsoil was susceptible to frost, it was usually necessary to create a frost-free subsoil by replacing the soil. A more or less mechanically or chemically strengthened intermediate layer was required.

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The material according to the invention as a remodeling layer for paths or spaces, especially for areas used for sports, is characterized by a layered combination with a top covering. The substructure layer can have a thickness of 5 to 20 cm.

Because of the low levels compared to mineral sub-base layers When the materials according to the invention are used as the substructure layer, the thermal conductivity becomes frost penetration prevented or reduced in the subsoil. In addition, the water permeability of the material allows vertical drainage. Furthermore, due to the load-distributing effect of the layer, a bound base layer can be dispensed with or these can be made thinner.

The substructure layer preferably consists of individual panels. These are particularly important for small ones Space advantageous for reasons of cost.

According to a further particular embodiment, the substructure layer or plates have recesses for heating lines on. The arrangement of heating lines, for example in the form of a water heater or an electric heater, has the advantage that the surface can be kept free of snow and ice. Due to the low thermal conductivity of the material are greater heat losses in the subsurface prevented.

In order to keep the subsurface free of water, the invention provides that a watertight layer underneath the sub-structure

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Slide is arranged. This ensures that the layer through which consists of the inventive material "Under Construction passing water accumulates on the film, and z. Page can be removed. The film loading, for example, is of a suitable weather-resistant plastic.

Furthermore, when fastening paths and squares with the material according to the invention, no lateral delimiting elements are required, since evasion of the base layer and erosion at the edges of the sub-base layer as a result of the tensile and shear strength of the material is prevented. When used for areas used for sport, by setting the elasticity of the material accordingly, good running properties can be achieved even with rigid or hard top coverings as a result of the cushioning effect. The usual thickness of elastomeric top coverings can be reduced when using the substructure layer described compared to previous fastenings while maintaining the same elasticity behavior.

If the material according to the invention is used in the form of individual plates which are placed next to one another, one can glue the panels together; However, it is important to ensure that 'the glued areas are designed in such a way that that there are no water barriers.

The panels can have overlapping or overlapping edges be provided interlocking profiles.

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The production of these panels can be carried out discontinuously in Forming or pressing are done. However, it can also be carried out continuously, for example on double conveyor belts be carried out by making an endless profile that is cut to appropriate sections of the desired length is cut to length. In this continuous production it is necessary to use binders that set quickly used or admixed with accelerator additives.

The panel size depends on the manufacturing process and also on the dimensions of the building in question and the laying method. It should preferably be in the range from about 0.15 to 4 m.

If the layer is produced using the in-situ installation process, so First, a mixture of rubber chips and binding agent is produced and poured onto the surface to be fastened, distributed there and by shaking or weighing down condensed; then it hardens. The moisture-curing isocyanates are particularly suitable for this process suitable as a binder.

There are no restrictions on the type of top coverings that can be laid on top of the sub-layer. Rigid coverings, such as B. Concrete slabs can be attached directly to the layer. This can be done mechanically, e.g. B. with With the help of the well-known Dachsteinauflager, or by gluing. Care must only be taken that the joints between the panels are wide enough to allow the rainwater to drain into the sub-layer.

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If you want to use the material as a sub- layer for rubber-elastic or plastic coverings, the surface cavities must be reduced. For this purpose, for example, “casting compounds or fillers made from small rubber chips and elastomeric” binders are suitable. The water permeability of the surface can be regulated via the binder content and the size of the rubber chips. The material can also be manufactured during manufacture in such a way that a fine layer is provided as the surface.

The material according to the invention is shown in various embodiments in a drawing:

Show it:

Figure 1 shows a cross section through the material layer,

Figure 2 shows a cross section through the material layer with a fine-grained surface layer

FIG. 3 shows a cross section through the material layer with a fabric insert and a solid top covering

FIG. 4 shows a cross section through the material layer with long fiber material as an insert,

Figure 5 a Werkst off plate with recesses for Heating cables

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FIG. 6 laid plates made of the material and provided with folds

FIG. 7 shows the material in use as a substructure layer for a bucket sports field attachment

The material in Figure 1 consists of rubber chips 1 of

3 3

a volume in the range from 0.3 cm to 100 cm, with a proportion of 70 % in the range from 1 cm to 20 cm , in such a way that cavities 3 which are connected to one another arise.

In Figure 2, the material layer is made in the same way Rubber particles 1 and binder 2 built up, with cavities 3 being present. However, the top is fine-grained Rubber material 4 is overlaid, which is also covered by the binder 2 with one another, leaving cavities 3 is connected.

In FIG. 3, a fabric insert 5 is embedded between the rubber particles 1. Because of the wide mesh of the fabric insert 5, the rubber particles partially protrude through the mesh. Here, too, the binding agent 2 connects the rubber chips 2 to one another and of course also envelops the threads of the fabric insert 5. A top covering 6 made of a rigid material is glued to the top of the material layer.

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In FIG. 4, long fibers 7 are embedded in the material.

In Figure 5 is a purely schematic layer of the invention Material shown, which is provided on its top with recesses 8 for heating cables.

In Figure 6, individual boards 9 are shown from the inventive W _e rkstoff whose folds 10in laid state .einander overlap.

In the sports field according to figure 7 ^a fastening is placed a water permeable sheet 12 uf the substrate 11 on which a base layer of the erfindUÄgsgemäßen work cloth 13 rests. This remodeling layer is in the. constructed in the same way as the material according to FIG. Z ₁ , namely with a fine-grained additional layer 4 on its upper side. Finally, a top covering 6 made of a fiber fleece is also provided as an artificial turf. The rainwater penetrating through the fastening runs on the film 12 or through the cavities of the lower layer into a lateral drainage channel 14.

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Claims (12)

-IV claims: 231-666 1. Material made from rubber waste, in particular from shredded tires, and made of elastomeric plastics as a binder, characterized in that the individual rubber chips (1) a volume ranging from 0.1 cm to 3 3 100 cm with a predominant proportion in the range of 1 cm to 20 cm, and that the binder (2) cellular Has structure and only partially fills the cavities (3) between the rubber chips. 2. Material according to claim 1, characterized in that the proportion of binder (2) is 5% to 15 % , based on the dry weight of the rubber chips (1) 3. Material according to claim 1 or claim 2, characterized in that the binder (2) consists of a moisture-curing isocyanate. 4. Material according to claim 1 or 2, characterized in that the binder (2) consists of a moisture-curing polyisocyanate. 5. Material according to claim 1 or 2, characterized in that the binder (2) consists of a two-component polyurethane consists. 6. Material according to part 1 to 5, characterized by content of non-rubbery comminuted waste. 7. Material according to claim 1 to 6, characterized by reinforcements of large-meshed fabric (5) Le A 14 946 - 14 - 40983 8/09 ?? ./V 2317666 8. Material according to claim 1 to 7, characterized by the content of fiber material (7) 9. 'Material according to claim 1 to 8 as Umte rbauschicht for paths or places, characterized by a layered combination with a top surface (6). 10. Material according to claim 9, characterized in that the lower layer (13) consists of individual plates (9). 11. Material according to claim 9 or 10, characterized in that the substructure layer (13) or plates (9) have recesses for heating lines (8). 12. Material according to claim 9, 10 or 11, characterized in that that a waterproof film (12) is arranged below the lower layer (13). Le A14 946 409838/09 ?? Blank page