EP3442369A1

EP3442369A1 - Body protection element

Info

Publication number: EP3442369A1
Application number: EP17718716.8A
Authority: EP
Inventors: Gerhard Karall
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-04-11
Filing date: 2017-04-11
Publication date: 2019-02-20
Also published as: WO2017177251A1

Abstract

The invention relates to a body protection element (100, 200, 300) having at least one damping layer (110, 210, 310A, 310B), wherein the at least one damping layer (110, 210, 310A, 310B) has a plurality of damping bodies (112, 312A, 312B) in the form of hollow bodies having a substantially circular, elliptical, triangular, square and/or polygonal cross-section, which are arranged on a plate-shaped base body.

Description

Body protection element

The invention relates to a body protection element with at least one damping layer and its use in protective helmets and protectors.

In many sports, it is common and often required to use a body-worn protective equipment, so-called protectors, which usually consists of a hard shell and a cushioning padding. Thus, the currently available on the market back protectors are provided with a body protection element of visco-elastic foam, which is usually made on the basis of N / polyvinyl chloride, N / vinyl acetate / vinyl chloride copolymer, silicone blends, polyurethane and related plastics.

Depending on the thickness of the material and the foam type, the body protection elements used must fulfill the protective functions required by EN 1621-2, measured via the "transmitted force", in order to be suitable for use in protectors. The main disadvantage of these foams is their high thermal insulation, their rigidity at temperatures below 10 ° C, the required strength (for example, for Level 2 at least 18 mm) and the associated poor comfort. In particular, such protectors are unsuitable for wearing under ordinary everyday wear.

Likewise, other protective equipment for the head, namely protective helmets, for example, when riding a motorcycle, skiing, cycling used, which also have at least one body protection element. These protective helmets are usually made of an outer shell and a damping part and optionally a comfort part.

For the manufacture of helmets numerous standards are relevant, such as the test standard EN 1077 for ski helmets, which regulates in detail the testing of such helmets for a corresponding certification.

In virtually all polymers, the maximum attenuation is in the range of the glass transition temperature, a measure of the damping behavior is the loss factor tan6. It indicates the effectiveness of how dissipative materials react to an energy input, such as a shock, namely converting the kinetic energy into heat energy, thereby absorbing energy and subsequently reducing the transmitted energy and thus the HIC value , The Head Injury Criterion (HIC) value is a criterion for assessing acceleration head injury, for example, in a vehicle accident. This dimensionless value allows, for example, a comparison of the occupant safety of different vehicle models. with a: resulting head acceleration in [g]

ti, t ₂ : the considered time interval

In the polymers commonly used, a good damping behavior (tan6> 0.5) can generally be set over a maximum temperature range of about 40 ° C. This is due to the character of the glass transition itself from brittle to visco-elastic.

AT 512 078 B1 describes a helmet shell with a plastic mesh and / or honeycomb calotte body, which consists of an acrylonitrile rubber and at least two organic polymers. This substantially foam-like body protection element already has significant improvements in comparison to the body protection elements commonly used in the art, for example made of polystyrene.

Nevertheless, there is still a need for improvement, especially with helmets, especially since the already known structures can only partially dampen an off-center force input. In an off-center force input, for example, fall, the force does not act normally on the tangent intersection with the usually curved surface of the helmet, but at an angle not equal to 90 °. However, this essentially tangential force can lead to massive cranial brain trauma. So far, attempts have been made to prevent such injuries through a higher material structure. An increased material structure, however, requires a higher weight, which in particular precludes the comfort of use.

It is therefore an object of the invention to provide an improved body protection element, which is particularly suitable for use in protective helmets. This object is achieved by a body protection element of the type mentioned in that the at least one damping layer has a plurality of damping body in the form of hollow body having a substantially circular, elliptical, triangular, quadrangular and / or polygonal cross-section, on a plate-shaped body are arranged.

Investigations by the applicant have shown that when using the body protection element according to the invention with lower material thickness and lower weight due to the special shape equal or improved damping properties are achieved according to the applied test standards.

In a preferred embodiment of the invention, the damping bodies have a circular cross section with a diameter of 4 mm to 20 mm, preferably 12 mm. This form of damping body is easy to manufacture and provides excellent damping properties.

In a particularly preferred variant, the damping bodies have a height of 10 mm to 20 mm, preferably 13.5 mm, a wall thickness of 0.1 mm to 4 mm, preferably 1 mm and a mean distance from each other of 4.1 mm 20.1 mm, preferably 15 mm.

This geometric design of the damping layer is effective especially for eccentrically acting forces. The substantially cylindrical damping body whose central center axes are aligned in the normal state substantially perpendicular to the plate-shaped base plate are compressed at substantially perpendicular to them acting force, while at off-center force their central central axes are tilted so that they are not equal to 90 ° Cut plate-shaped base plate. This shift causes an energy distribution, so that the punctually acting force is significantly reduced.

In a first embodiment of the body protection element according to the invention, which is particularly suitable for use at higher ambient temperatures, the at least one damping layer is made of a compounded plastic polymer, wherein the plastic polymer by means of a mixture of trans polynorbornene, which initially with at least one preferred aromatic process oil is prepared in a second step with at least one further polymer and / or resin in a ratio of 1: 0.1 to 1: 5, preferably 5: 3 is prepared.

In the preparation of the trans polynorbornene, this is first treated with a RAE process oil as plasticizer in a ratio of 1: 0.5 to 1: 3, preferred wise 1: 1 mixed. In this case, the glass transition temperature of the trans-polyno-boron by means of the preferably aromatic process oil is adjusted to a value of about 15 ° C to 30 ° C, before this processed trans polynorbornene, the so-called "masterbatch", with the at least one further polymer and / or mixed resin and then vulcanized or crosslinked. By compounding the trans-polynorbornene with the at least one further polymer and / or resin, the glass transition temperature of the plastic polymer from which the damping layer according to the invention is produced is brought to the value in which a maximum of the damping behavior is achieved within a desired application temperature range ,

For processing with the trans-polynorbornene, it is particularly advantageous if the at least one further polymer and / or resin has a softening point according to ASTM D 3461 of 0 ° C. to 130 ° C., preferably 80 ° C. to 85 ° C. to achieve the desired glass transition temperature with the maximum damping effect. In particular, those polymers and / or resins which have the desired material-specific glass transition temperature and in combination with the prepared trans-polynorbornene in a corresponding concentration provide the required glass transition temperature between 15 ° C. and 65 ° C. are suitable for this purpose.

Investigations by the Applicant have shown that when using an inden-coumarone resin as at least one further polymer and / or resin particularly good damping properties are obtained in the body protection element according to the invention.

Depending on the application, the body protection elements according to the invention must be adapted to the environmental conditions, in particular to the outside temperature. For example, some plastics lose their elasticity when the outside temperature is low, become brittle and can break more easily. A body protection element for example for ski helmets must therefore be able to withstand particular loads corresponding to the test standard at temperatures between -20 ° C and + 23 ° C. For this purpose, a body protection element according to the invention has proven, in which the at least one damping layer is made of a compounded plastic polymer, wherein the plastic polymer by means of a mixture of trans polynorbornene, which is first - as already described above - treated with at least one preferably aromatic process oil, in a second step with a rubber, preferably homo-butyl rubber in a ratio of 5: 1 to 1: 1, preferably 5: 2 is prepared. In this way, a polymer polymer based on trans polynorbornenes having a glass transition temperature of 5 ° C to 25 ° C, preferably 15 ° C is obtained.

When testing this body protection element has been shown that with this second plastic polymer with lower material thickness and lower weight compared to commercial structures also equal or improved damping properties with significantly improved temperature behavior, especially at low temperatures are achieved.

Commercially available crosslinking methods, for example by means of sulfur crosslinking, peroxide crosslinking, imide crosslinking or physical crosslinking, are used during the compounding for the production of the plastic polymer according to the invention. During this vulcanization, the shaping of the damping layer according to the invention takes place in correspondingly suitable tools.

Furthermore, to increase the strength of the damping layer, it may be provided that the degree of crosslinking is increased and / or the addition of fillers, further polymers and / or resins is provided.

Depending on the field of application, it may also be necessary to reduce the hardness and strength of the plastic polymer. In this case, this can be achieved by a lower degree of crosslinking, by the addition of process oils, other polymers and / or resins.

Finally, the body protection element according to the invention should also be stable against environmental influences. For this purpose, in particular UV stabilizers, antioxidants and other additives customary in polymer production are added to the compound polymer produced by the compounding during compounding.

Protective equipment such as protective helmets for motorcyclists must be effective over a very wide temperature range, which can not be achieved practically with a body protection element of a single layer of material. In a further embodiment of the invention it is therefore provided that the body protection element is made of two damping layers, wherein preferably a first damping layer of the first aforementioned plastic polymer and a second damping layer of the second plastic polymer are made. By combining damping layers with different glass transition temperature values, the service temperature of a protective helmet, in particular a motorcycle helmet, can be set to the desired temperature range.

In a preferred embodiment of the invention, the prescribed by the motorcycle helmet standard EC 22-05 service temperature of -25 ° C to 50 ° C, ie a service temperature range of 75 ° C by two different, combined material layers combined with corresponding glass transition temperatures. These combined damping layers are in this case preferably arranged slidably with respect to one another, but may be adhesively bonded to one another at points, for example.

The above-mentioned damping layers are made of plastic polymers with high visco-elasticity to achieve the required damping properties. However, in order to give the body protection element a corresponding strength and protection against penetration by sharp objects, at least one outer layer is provided, which is formed in a development of the invention as a plastic film, preferably made of polyester.

The use of films as an outer layer is already known, especially in bicycle helmets, these are usually made of polycarbonate, ABS, etc. The polyester film used according to the invention is characterized, in contrast to the films used in the prior art, by a high impact strength, combined with a lower hardness for plastics, which makes this material particularly suitable for protection against penetration. Such films are sold under the brand name AXPET.

Particularly for use in protective helmets, the outer layer is particularly preferably glued to the at least one damping layer.

As already stated above, the body protection element according to the invention is particularly suitable for producing a protective helmet. It is characterized in particular by a low weight and excellent properties as required in the respective test standards. In order to ensure the comfort of the helmet is provided in a further embodiment of the invention that in addition an adjoining the at least one damping layer inner layer is provided, which consists of a foam, preferably acrylonitrile rubber in conjunction with two other organic polymers, in particular from the material group Polynorbornene, polyvinyl chloride, ethylene vinyl acetate, polyisoprenes, butyl and / or vinyl acetate. Thus, such a foam layer, which was produced, for example, as described in AT 512.078 Bl, also has excellent damping properties. Furthermore, such a foam adapts very well to the head, for example, which in turn increases the wearing comfort.

Alternatively, the body protection element according to the invention is used for producing a back protector, for example for motorcyclist protective clothing according to EN 1621. For this purpose, preferably at least one textile reinforcement is subsequently provided on the outer layer and / or the at least one damping layer is again provided for increasing the wearing comfort.

The invention is explained in more detail below with reference to non-limiting exemplary embodiments with associated figures. Show:

1 shows a cross section through a first embodiment of the body protection element according to the invention.

Fig. 2 is a schematic plan view of the damping layer of Fig. 1;

3 shows a second embodiment of the body protection element according to the invention in a schematic cross-sectional view; and

4 shows a third embodiment of the body protection element according to the invention in a schematic cross-sectional view.

A first variant of the body protection element 100 according to the invention is shown in FIGS. 1 and 2 shown. The damping layer 110 has a plate-shaped basic body 111, on which hollow damping bodies 112 are arranged. This damping body 112 are cylindrical in this embodiment and are entirely continuous, so formed as extensions of the base body 111 whose central center axes M intersect the surface plane of the base body 111 substantially perpendicular. The damping body 112 in this case preferably have a height of 13.5 mm, a diameter of 12 mm and a wall thickness of 1.5 mm. The distance between the central center axes M to each other is preferably 15 mm, wherein the damping body 112 are particularly preferably arranged in a hexagonal arrangement on the base body 111 (see Fig. 2).

On the main body 111 of the damping layer 110, a film is glued as the outer layer 120 on the side facing away from the damping bodies 112, which is preferably made of polyester, for example from AXPET ^® from Covestro Deutschland AG. The film thickness is in this embodiment of Invention 0.5 mm to 0.8 mm. This outer layer 120 serves for the penetration protection as well as the positional stability of the damping layer 110. This construction is much lighter than conventional constructions due to the reduced material height.

The in the Figs. Body protection element 110 shown in FIGS. 1 and 2 is used in a first application in a ski helmet, the layer structure of which is shown in FIG.

The damping body 210 here consists of a damping layer 210 with a geometric structure as described above. The damping layer 210 is in this case made of a compounded plastic polymer, which is mixed in a first step of trans polynorbornene and RAE process oil, usually in a mixing ratio of 1: 1 to a base polymer and then in a second step in a compounding with homo-butyl rubber in Ratio 5: 3 was made. Thus, the glass transition temperature of the trans Polynorbornen was set to about 15 ° C. This mixture was then vulcanized by conventional sulfur crosslinking and provided in a known manner with UV protection and ozone protection. This damping layer 210 is particularly suitable for use at low outside temperatures.

As outer layer 220 again acts a glued foil with a thickness of 0.8 mm. Finally, an inner layer 230 is provided as a comfort layer with a thickness of 5 mm. This inner layer 230, which is designed as a foam part, is hereby arranged loosely on the damping layer 210. By this freely movable arrangement of the damping layer 210 on the inner layer 230, which rests directly or by a thin glued textile layer separately at the head of the wearer, the damping layer 210, in particular their damping body in eccentric force against the inner layer 230 can rotate, creating a better distribution the applied energy, especially in off-center force entry is achieved.

In a second application, the body protection element 300 according to the invention is used for the manufacture of a motorized helm, here two damping layers 310A, 310B are used.

The first cushioning layer 310A is hereby made of Norsorex NS, a trans-polynorbornene of the company Startech Advanced Materials GmbH with a RAE processol of the company H & R in the ratio 1: 1, which is subsequently mixed with an Inden-Cumaron resin Type C30 of the Rütgers Novares GmbH with a Softening Point (ASTM D 3461) is prepared from 80 ° C to 85 ° C in a ratio of 1: 0.6 by compounding as Plast. By adding known additives and by selecting the type and extent of crosslinking the required material properties can be adjusted. The shaping of the first damping layer 310A takes place during vulcanization in a corresponding shaping tool.

The first damping layer 310A is used for damping, especially at higher outside temperatures above 15 ° C. Their damping bodies 312A have a height of about 13 mm.

The second damping layer 310B corresponds in its material composition to the damping layer 210 of the first application example, wherein its damping bodies 312B also have a height of about 13 mm and an inner diameter of 12 mm, this second damping layer 310B having a higher elasticity and a lower rigidity than the first Has damping layer 310A.

Both damping layers 310A, 310B are each provided with a base film 313A, 313B which has a film thickness of 0.8 mm and is preferably made of polyester. The respective damping bodies 312A, 312B are each spaced apart in a hexagonal arrangement by 20 mm, measured from their central center axes M-. Furthermore, the two damping layers 310A, 310B are preferably arranged slidingly relative to one another.

The second cushioning layer 310B is followed by an inner layer 330 of foam material having a thickness of 7 mm.

As the outer layer 320 again acts a polyester film with a thickness of 0.8 mm, which adhered to the first damping layer 310A.

Of course, the function of the outer layer can also be taken over by a hitherto customary outer shell made of plastic (PUR, ABS, etc.) or by a fiber-reinforced shell construction (carbon fibers or glass fibers in an epoxy matrix, etc.).

In addition, the inner layer 330 can be made with a thickness of about 20 mm and cover the application Ambient (normal temperature) and low temperature. Here you can also work with two foam layers.

The body protection element according to the invention is not only suitable for damping in protective helmets, but can also be used in protectors. For this purpose, at least one damping layer is optionally provided with at least one inner layer of foam and a corresponding outer layer.

Alternatively, a back protector according to the invention may also consist exclusively of a damping layer which is provided with textile supports. A back protector with this structure fulfills the requirements of EN 1621-2: 2014, whereby comparative values can be obtained with a market product in the following Table 1:

Table 1

MARKET PRODUCT OWNERSHIP

quality

PROTECTION LEVEL 2 2

Test result EN 1621-2 5.6 kN 5.7 kN

Weight 191 grams 163 grams

Thickness 19 mm 13.5 mm

Perforation 6 percent 40 percent

Agility means no limitation

Low temperature sensitivity yes low

It is understood that the present invention is not limited to the above embodiments. In particular, the shape of the damping layer may vary, as well as the combination of different damping layers with each other and with other additional layers such as hard shells, inner layers, in particular Helmkalotten example of EPS foam and the like may be provided.

Claims

PATENT APPLICATIONS

A body protection element (100, 200, 300) having at least one damping layer (110, 210, 310A, 310B), characterized in that the at least one damping layer (110, 210, 310A, 310B) comprises a plurality of damping bodies (112, 312A, 312B) in the form of hollow bodies having a substantially circular, elliptical, triangular, quadrangular and / or polygonal cross section, which are arranged on a plate-shaped base body.

Second body protection element (100, 200, 300) according to claim 1, characterized in that the damping body (112, 312A, 312B) have a circular cross section with a diameter of 4 mm to 20 mm, preferably 12 mm.

3. Body protection element (100, 200, 300) according to claim 1 or 2, characterized in that the damping body (112, 312A, 312B) has a height of 10 mm to 20 mm, preferably 13.5 mm, a wall thickness of 0.1 mm to 4 mm, preferably 1 mm and an average distance from each other from 4.1 mm to 20.1 mm, preferably 15 mm.

4. body protection element (100, 200, 300) according to one of claims 1 to 3, characterized in that the at least one damping layer (110, 210, 310A, 310B) is made of a compounded plastic polymer, wherein the plastic polymer by means of a mixture of trans Polynorbornene, which is initially treated with at least one preferably aromatic process oil, is prepared in a second step with at least one further polymer and / or resin in a ratio of 1: 0.1 to 1: 5, preferably 5: 3.

5. Body protection element (100, 200, 300) according to claim 4, characterized in that the at least one further polymer and / or resin Softening Point according to ASTM D 3461 from 0 ° C to 130 ° C, preferably 80 ° C to 85 ° C has.

6. body protection element (100, 200, 300) according to claim 3 or 4, characterized in that the at least one further polymer and / or resin is an indene coumarone resin.

7. Body protection element (100, 200, 300) according to claim 3, characterized in that the at least one damping layer (110, 210, 310A, 310B) is made of a compounded plastic polymer, wherein the Plastic polymer by means of a mixture of trans-polynorbornene, which is first prepared with at least one preferably aromatic process oil is prepared in a second step with a rubber, preferably homo-butyl rubber in a ratio of 5: 1 to 1: 1, preferably 5: 2 ,

8. Body protection element (100, 200, 300) according to one of claims 3 to 7, characterized in that the compounded plastic polymer is prepared by means of sulfur crosslinking, peroxide crosslinking, imide crosslinking or physical crosslinking and preferably additionally a UV protection and / or a Has ozone protection.

9. body protection element (100, 200, 300) according to one of claims 1 to 8, characterized in that at least two damping layers (110, 210, 310A, 310B) are provided, which are made of plastic polymers having different glass transition temperatures.

10. body protection element (100, 200, 300) according to one of claims 1 to 9, characterized in that in addition at least one outer layer (120, 220, 320) is provided which is formed as a plastic film, preferably made of polyester.

11. Body protection element (100, 200, 300) according to claim 10, characterized in that the outer layer (120, 220, 320) is glued to the at least one damping layer (110, 210, 310A, 310B).

12. Use of a body protection element (100, 200, 300) according to one of claims 1 to 11 for the production of a protective helmet.

13. Use according to claim 12, characterized in that in addition at least one of the at least one damping layer (110, 210, 310A, 310B) subsequent inner layer (230, 330) is provided which consists of a foam, preferably of acrylonitrile rubber in conjunction with two other organic polymers, in particular from the material group polynorbornene, polyvinyl chloride, ethylene vinyl acetate, polyisoprenes, butyl and / or vinyl acetate.

14. Use of a body protection element (100, 200, 300) according to one of claims 1 to 11 for the production of a back protector.

15. Use according to claim 14, characterized in that in addition at least one textile reinforcement subsequent to the outer layer (120, 220, 320) and / or the at least one damping layer (110, 210, 310A, 310B) is provided.

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