ONE-PIECE ENVELOPE OF RADIATION PROTECTION MATERIALS AND THEIR USE

Description

[0001] The application relates to the use of a one-piece coating made of thermosetting polymer(s) for the protection of radiation protection elements consisting of at least one elastic radiation protection material, the method for producing the coating and the radiation protection material or radiation protection element provided with the coating.

[0002] Medical, industrial, and scientific facilities frequently use radiation sources that emit ionizing radiation. This radiation, such as X-rays, can have harmful biological effects on the human body and poses a significant health risk if shielding is inadequate.

[0003] Conventional shielding methods such as solid walls with lead inserts or permanently mounted lead screens offer effective protection, but are inflexible and cannot be easily adapted to different work requirements or room layouts.

[0004] There is therefore a growing need for flexible, adaptable, yet highly effective radiation protection devices. Radiation protection elements such as radiation shielding louvers offer an ideal solution to this challenge. They combine the ability to effectively block high-energy radiation with the flexibility to open or close the radiation barrier as needed. This enables not only dynamic protection against ionizing radiation but also adaptation to specific requirements. Radiation shielding louvers can be used in a variety of ways, for example, as a curtain or as under-table radiation protection where the louvers are mounted on a patient table. Examples of louvers and their use are disclosed in DE 10 2009 025 380 A1 and DE 10 2015 208 829 A1.

[0005] It is known that radiation shielding elements have a covering – among other reasons, for hygiene and to protect the radiation shielding material. The coverings of radiation shielding materials described in the prior art and used in practice consist of thermoplastic films (e.g., PVC or thermoplastic polyurethanes (TPU)). This covering, often designed as a kind of pocket, is created by joining at least two sides of shaped film sections together (e.g., by thermal welding or other treatment). It is important that the film sections are airtight so that the radiation shielding element is hermetically sealed. However, the joints of the film sections, e.g., the weld seams, are very sensitive to mechanical stress, so the coverings tend to open, especially at the seams. If such coverings are damaged, the radiation shielding element must be replaced.Recycling the element is often difficult.

[0006] Besides the problems with the seams, the production of encapsulated radiation shielding elements is also complex, as care must be taken during the encapsulation process to prevent wrinkles and air inclusions. Air inclusions, in particular, can lead to premature aging of the radiation shielding material, primarily through oxidation. EP 3748652 A1 describes such an encapsulation and a method for producing encapsulated radiation shielding elements that avoids the aforementioned problems of wrinkling and air inclusions.

[0007] EP 3 504 715 discloses a radiation protection element for a radiation protection curtain for use at an entrance and / or an exit of a radiation tunnel of an X-ray inspection system, wherein the radiation protection element has an integrated exchange indicator. Specifically, the application relates to radiation protection elements that have a core shielding ionizing radiation, which is surrounded by at least one protective layer, wherein the protective layer consists of at least one outer layer and at least one indicator layer, wherein the indicator layer consists of at least one layer that is distinguishable from the outer layer (122) by color; characterized in that the indicator layer consists of several layers, wherein adjacent layers are distinguishable from each other by color; and the outer layer (122) contains or consists of at least one of the following materials: rubber, PVC, protective lacquer.

[0008] However, the described method for encasing radiation protection materials and elements still has the disadvantage that the encasing has a vulnerable point at the connection lines.

[0009] Another problem with encapsulation using thermoplastic polymers is that airtightness is only guaranteed when sealing the seams if there are no loose particles on the films being sealed. However, radiation shielding material, especially when the matrix is ​​made of natural rubber, is treated with talc. To prevent leaks in the encapsulation, the surface of the material to be encapsulated must be cleaned.

[0010] The present application represents in particular an alternative and further development to the technologies described in EP 3748 652 A1 and EP 1613 217 A1.

[0011] The invention thus relates to a method for the one-piece encapsulation of radiation protection elements made from radiation protection material, using thermosetting solvent-free polymers with a Shore A hardness (measured according to DIN 53505) in the range of 50 to 90, the use of such polymers for encapsulating these radiation protection elements, the radiation protection element encapsulated with such polymers, and radiation protection devices or equipment made from the encapsulated elements as described here and / or in the independent and dependent claims.

[0012] In one embodiment, the invention relates to the use of a one-piece encapsulation made of thermosetting polymer(s) for the protection of radiation shielding elements, which consist of at least one radiation shielding material formed from at least one elastomer and at least one heavy chemical element - in ionic or elemental form - wherein the chemical element is selected from lead (Pb), bismuth (Bi), tungsten (T), tin (Sn), antimony (Sb) and barium (Ba).

[0013] The polymer coating is elastic and has a Shore A hardness in the range of 50 to 90, preferably in the range of 60 to 70. The radiation shielding material is thus surrounded and, so to speak, encapsulated by the thermosetting polymer.

[0014] For elastomers and deformable plastics, Shore hardness testing is a simple and effective material testing method and a straightforward method for measuring hardness. The Shore test is well-established and partially defined in DIN standards. Essentially, a hardness tester is used that measures the penetration depth and time of a specially shaped indenter and determines the material's hardness from this data.

[0015] In a further embodiment, the invention relates to the use as defined in the previous embodiment, wherein the thermosetting polymer is a polyurea or a polyurethane in which at least one polyisocyanate compound is used as a hardener. Aromatic polyureas are preferred because they dry faster during production. Solvent-free two-component systems are also preferred.

[0016] In a further embodiment, the invention relates to the use according to one of the preceding embodiments, wherein the layer thickness of the thermosetting polymer is at most 2 mm, preferably at most 1 mm, particularly preferably at most 0.6 mm.

[0017] In a further embodiment, the invention relates to the use according to one of the preceding embodiments, wherein the crosslinker of the polymer is selected from aliphatic or aromatic di- or polyamine compounds and aliphatic or aromatic di- or polyol compounds.

[0018] In a further embodiment, the invention relates to the use according to one of the preceding embodiments, wherein the polymer contains additives such as fillers, UV filters, and color pigments.

[0019] In a further embodiment, the invention relates to the use according to one of the preceding embodiments, characterized in that the heavy chemical element is lead or bismuth and the elastomer is selected from natural rubber (NR), synthetic rubber (BR) or chlorosulfonated polyethylene (CSM), each optionally vulcanized.

[0020] In a further embodiment, the invention relates to a radiation protection element consisting of radiation protection material and encased in thermosetting polymer as defined in one of the embodiments directed here to the use or the method, wherein the encasement is one-piece and has a thickness of less than or equal to 2 mm, preferably less than or equal to 1 mm, particularly preferably less than or equal to 0.6 mm.

[0021] In a further embodiment, the invention relates to a radiation protection element as defined in the previous embodiment, wherein the elastomer of the radiation protection material is selected from natural rubber (NR), synthetic rubber (BR) and chlorosulfonated polyethylene (CSM), each of which may be vulcanized.

[0022] In a further embodiment, the invention relates to a radiation protection element as defined in the previous embodiment, wherein the heavy chemical element is lead or bismuth.

[0023] In a further embodiment, the invention relates to a radiation protection element as defined in one of the three preceding embodiments, wherein the Shore A hardness of the radiation protection material is in the range of 50-70 and / or has a lead equivalent of at least 0.5 mm lead.

[0024] In a further embodiment, the invention relates to a radiation protection element as defined in one of the four preceding embodiments, wherein the element is a slat for under-table radiation protection or a curtain. A curtain made of such slats constitutes a radiation protection device. The element can, in particular, be a vertical slat for curtains, a cassette cover, or a cover angle.

[0025] In contrast to the foil pouches of the state of the art, the covering forms a mechanically integral part of the overall system, and therefore new fastening methods without riveting or screwing - i.e. drilling through - the protective material are permitted, such as clamps.

[0026] In one embodiment [L] the invention relates to a method for manufacturing a radiation protection element as defined in one of the embodiments [G] to [K], comprising the following process steps: Step (1) Providing the radiation shielding material comprising an elastomer and a heavy chemical element, optionally in web form, wherein the elastomer is natural rubber (NR), synthetic rubber (BR) or chlorosulfonated polyethylene (CSM) and wherein the heavy element is selected from lead (Pb), bismuth (Bi), tungsten (T), tin (Sn), antimony (Sb) and barium (Ba); Step (2) Processing, cutting or stamping the radiation shielding material into the shape of the radiation shielding element; Step (3) Coating the element by simultaneously applying the crosslinker and the hardener, as well as optionally additives, as defined in one of the preceding embodiments, wherein the application is optionally carried out using a multi-component high-pressure device as a hot spray process, wherein the coating thickness is less than or equal to 2 mm, preferably less than or equal to 1 mm, particularly preferably less than or equal to 0.6 mm and has a Shore A hardness in the range of 50 to 90.

[0027] In one embodiment [M] the invention relates to a method for manufacturing a radiation protection element as defined in embodiment [L], wherein the elements are provided from radiation protection material for the encapsulation and step (2) is omitted.

[0028] In one embodiment [N], the invention relates to a method for manufacturing a radiation protection element as defined in embodiment [L] or [M], wherein the element is a slat for a curtain. The element can, in particular, be a vertical slat for curtains or under-table radiation protection devices, as well as a cassette cover or a cover angle.

[0029] In one embodiment [O] the invention relates to a radiation protection element which is manufactured by a method as defined in one of the embodiments [L] to [N].

[0030] The thermosetting polymers according to the invention are characterized by their high resistance to chemicals, extreme temperatures and physical stress.

[0031] The radiation shielding material contains at least one heavy chemical element – ​​in ionic or elemental form – wherein the chemical element is selected from lead (Pb), bismuth (Bi), tungsten (T), tin (Sn), antimony (Sb), and barium (Ba). Lead and bismuth are preferred, lead is particularly preferred.

[0032] The invention makes it possible to provide coatings that do not require joints, such as welds, thus avoiding the disadvantages of the prior art. The coating is formed directly after the curing of the applied polymer components (crosslinker (base) and hardener) on the radiation shielding material to be coated or the elements manufactured from it. The coating also exhibits high abrasion resistance and elongation at break.

[0033] The coating according to the invention, made of cross-linked thermoset polymer, is seamless and is therefore also referred to here as a one-piece coating. The radiation shielding material is hermetically enclosed by the coating.

[0034] A multi-component high-pressure device is typically used for this process. In this process, components A and B (and other additives) are heated and atomized under high pressure. Upon exiting the nozzle, the two components mix on the surface. The material hardens to a touch-dry consistency within a short time.

[0035] The reaction time is less than 30 seconds, and the coating is touch-dry in less than 5 minutes. Complete drying takes longer, approximately 24 hours. After drying, another layer can be applied, for example, to protect against UV radiation or to achieve the desired color or gloss.

[0036] The thermosetting polymers according to the invention, such as in particular polyureas and polyurethanes, are formed by the polymerization of at least two components, namely a base (a crosslinker, component A) and a hardener (component B) immediately after application to the radiation protection material or the elements consisting thereof.

[0037] The advantage of the one-piece encapsulation, besides its ease of manufacture, lies primarily in the fact that there are no seams that can tear. Furthermore, the radiation protection material to be encapsulated requires no pretreatment; for example, the surfaces of the elements made of radiation protection material do not need to be cleaned of substances from the manufacturing process.

[0038] This can be, for example, talc when so-called lead rubber is used as radiation shielding material. According to current technology, talc regularly leads to leaks at the joints of multi-part thermoplastic encapsulations because impurities are present at the joint during sealing.

[0039] The one-piece encapsulation effectively protects the radiation shielding material from oxidation and rapid aging, ensuring a long service life. It also minimizes or eliminates the risk of unintentional contamination with potentially harmful substances (e.g., heavy metals, lead, bismuth, etc.). Furthermore, the coating is mechanically durable and easy to clean.

[0040] The use of thermosetting polymers according to the invention for coating radiation protection material and elements produced therefrom is not yet known.

[0041] Furthermore, due to the manufacturing process of the coatings, crosslinking agents and hardeners that are liquid at room temperature or melt at temperatures up to 250 °C without decomposition are preferred.

[0042] Among the usable polyureas, those made from aromatic polyamines are preferred as crosslinking agents.

[0043] Among the polyurethanes that can be used, those with aliphatic polyols as crosslinkers are preferred.

[0044] The coating according to the invention may also contain additives that, for example, provide UV protection.

[0045] Radiation shielding materials are materials capable of blocking or absorbing harmful ionizing radiation, such as X-rays. These materials contain at least one of the following heavy chemical elements: lead (Pb), bismuth (Bi), tungsten (T), tin (Sn), antimony (Sb), and barium (Ba). The elements are typically embedded in a polymer matrix, which can consist of various materials. Polymer matrices according to the invention include thermosetting elastomers, particularly polyureas and polyureas, which may be vulcanized.

[0046] The radiation protection material can also be in the form of composite materials, in which different radiation protection materials are combined to achieve a lower weight and high wearing comfort with sufficient lead equivalent.

[0047] In the present invention, lead rubber is preferably used. It is an elastomeric material consisting mainly of a polymer matrix permeated or loaded with lead powder or lead particles (lead in elemental or oxidized form), the lead mainly serving to modify the elastomeric material with respect to its radiation-absorbing properties.

[0048] The elastomer, i.e., the elastic component, can be natural rubber (NR), synthetic rubber (BR), or chlorosulfonated polyethylene (CSM). Other rubbers with a Shore A hardness comparable to natural rubber are also possible.

[0049] Natural rubber (NR) possesses, among other things, high elasticity, cold flexibility, and excellent dynamic properties. However, without appropriate treatment with protective additives, its resistance to aging and ozone is low, and it is also not resistant to contact with mineral oils and greases.

[0050] NR is available for hardness ranges Shore A 30-90. CSM is available for hardness ranges Shore A 45 to 90.

[0051] In one embodiment of the invention, a single-layer lead rubber material is produced that is suitable for use as radiation protection elements, in particular as vertical slats for curtains, or under-table radiation protection devices, as well as cassette covers, cover angles, and the like. This single-layer lead rubber material comprises a radiation protection matrix, in particular a lead-containing and sulfur-crosslinked lead rubber sheet, and the coating produced with the thermosetting polymer according to the invention.

[0052] The lead-containing rubber material may optionally have a central, possibly friction-fit, fabric reinforcement and additional coatings. The material preferably has a lead equivalent in the range of 0.5 to 2.00 mm lead, and the Shore A hardness is typically in the range of 50 to 70.

[0053] The radiation shielding material is processed into elements, which are then assembled into radiation shielding assemblies. Such a radiation shielding assemblies can be, for example, a curtain or a lower body shielding arrangement. These assemblies can be mounted, for example, in front of a window or on at least one side of a treatment table. This radiation shielding assemblies, particularly lower body shielding arrangements, consist of an upper section mounted on a support rail attached to the point of use (e.g., the table), and several louvers attached to the underside of the support rail, overlapping laterally. Figure 1 in EP 1613217 B1 illustrates such an arrangement.

[0054] In one embodiment, the lead protection material is in the form of (curtain) slats. These slats are mounted on curtain tracks. These tracks are made of special materials such as aluminum. The carriage of such slat curtains has a stable, preferably hard plastic, support. The slat holder is made of a very durable material, such as carbon fiber.

Claims

1. Radiation protection element, which is coated with thermosetting polymer, consisting of at least one radiation shielding material formed from at least one elastomer and at least one heavy chemical element in ionic or elemental form, wherein the chemical element is selected from lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba), characterised in that the Shore A hardness of the coating is in the range of 50 to 90, wherein the coating is one-piece and has a thickness of less than or equal to 2 mm.

2. Radiation protection element according to claim 1, characterised in that the thermosetting polymer of the coating is a polyurea or a polyurethane in which at least one polyisocyanate compound is used as a hardener.

3. Radiation protection element according to claim 1 or 2, wherein the cross-linking agent of the thermosetting polymer is selected from aliphatic or aromatic di- or polyamine compounds and aliphatic or aromatic di- or polyol compounds.

4. Radiation protection element according to one of the preceding claims, wherein the thermosetting polymer contains additives such as fillers, UV filters, colour pigments.

5. Radiation protection element according to one of the preceding claims, wherein the elastomer of the radiation shielding material is selected from natural rubber (NR), synthetic rubber (BR) and chlorosulphonated polyethylene (CSM).

6. Radiation protection element according to one of the preceding claims, wherein the heavy chemical element in the radiation shielding material is lead or bismuth.

7. Radiation protection element according to one of the preceding claims, wherein the Shore A hardness of the radiation shielding material is in the range of 50 to 70 and / or has a lead equivalent of at least 0.5 mm lead.

8. Radiation protection element according to one of the preceding claims, wherein the element is a slat for under-table radiation protection or a curtain, or is a cassette cover or a cover bracket.

9. Method for manufacturing a coated radiation protection element as defined in one of the preceding claims, comprising the following steps: (1) providing the radiation protection material comprising an elastomer and a heavy chemical element, optionally in sheet form, wherein the elastomer is natural rubber (NR), synthetic rubber (BR) or chlorosulphonated polyethylene (CSM) and wherein the heavy element is selected from lead (Pb), bismuth (Bi), tungsten (T), tin (Sn), antimony (Sb) and barium (Ba); (2) Machining, cutting or punching the radiation shielding material into the shape of the radiation shielding element; (3) Coating the element by simultaneously applying the cross-linking agent and the hardener, as well as any additives as defined in one of the preceding claims, wherein the application is carried out, if necessary, with a multi-component high-pressure device as a hot spray process, wherein the thickness of the coating is less than or equal to 2 mm and has a Shore A hardness in the range of 50 to 90.

10. Method according to claim 9, wherein elements made of radiation protection material are provided for the coating and step (2) is omitted.

11. Use of a one-piece coating consisting of thermosetting polymer for the protection of radiation protection elements consisting of at least one radiation protection material formed from at least one elastomer and at least one heavy chemical element - in ionic or elemental form - wherein the chemical element is selected from lead (Pb), bismuth (Bi), tungsten (T), tin (Sn), antimony (Sb) and barium (Ba), the Shore A hardness of the casing being in the range from 50 to 90.

12. Use according to claim 11, wherein the thermosetting polymer is a polyurea or a polyurethane in which at least one polyisocyanate compound is used as a hardener.

13. Use according to claim 11 or 12, wherein the layer thickness of the thermosetting polymer is less than or equal to 2 mm.

14. Use according to any of claims 11 to 13, wherein the cross-linking agent of the polymer is selected from aliphatic or aromatic di- or polyamine compounds and aliphatic or aromatic di- or polyol compounds.

15. Use according to any of claims 11 to 14, wherein the polymer contains additives such as fillers, UV filters, colour pigments.