Single-piece cover of radiation protection material and use thereof

Abstract

To provide use of a single-piece cover (one-piece enclosure), a method for producing the cover, and a radiation protection material or radiation protection element including the cover.SOLUTION: Use of a single-piece cover consisting of thermosetting polymer for protecting a radiation protection element that consists of at least one radiation protection material that is formed from at least one elastomer and at least one heavy chemical element in an ionic or elemental form, wherein the chemical element is selected from lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba), and wherein the Shore A hardness of the cover is in a range of 50 to 90, a method for protecting such a cover, and an enclosed radiation protection element and an enclosed radiation protection tool which are produced from the radiation protection material.SELECTED DRAWING: None

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0002] Radiation sources that emit ionizing radiation are frequently used in medical, industrial and scientific facilities. This radiation, such as X-rays, can have harmful biological effects in the human body and pose a significant health risk if inadequately shielded.

[0003] However, while traditional shielding methods such as solid walls with lead inserts or fixedly mounted lead screens provide effective protection, they are inflexible and cannot be easily adapted to different work requirements or room layouts.

[0004] Therefore, there is an increasing need for flexible, adaptable, but highly effective radiation protection. Radiation protection elements, such as radiation protection slats, offer an ideal solution to this problem. They combine the ability to effectively block high-energy radiation with the flexibility to open and close the radiation protection barrier as needed. This not only allows for dynamic protection against ionizing radiation, but also allows for adaptation to specific requirements. Radiation protection slats can be used in various ways, for example as curtains or as under-table radiation protection, where the slats are attached to the patient table. Examples of slats and their use are disclosed in DE 102009025380 A1 and DE 102015208829 A1.

[0005] It is known that radiation protection elements have covers, inter alia, for hygiene reasons and for the protection of the radiation protection material. Covers of radiation protection materials described in the prior art and used in practice consist of thermoplastic films (e.g. PVC or thermoplastic polyurethane (TPU)). This cover, which is often designed as a kind of bag, is produced by connecting at least two sides of a molded film part to each other (e.g. by heat sealing or other processes). It is important that the film parts are hermetically connected so that the radiation protection element is hermetically sealed. However, the connections of the film parts, for example the welded seams, are very sensitive to mechanical stresses, so that the cover opens, especially at the joints. If the cover is damaged in this way, the radiation protection element has to be replaced. Recycling of this element is often difficult.

[0006] In addition to the joint problems, the production of encapsulated radiation protection elements is complicated because care must be taken to ensure that no wrinkles are formed and no air pockets are created during the encapsulation of the elements. In particular, air pockets can lead to premature degradation of the radiation protection material, mainly due to oxidation processes. EP 3748652 A1 describes a method for producing such covers and encapsulated radiation protection elements, in which the above-mentioned wrinkle and air pocket problems are avoided.

[0007] However, the described method of encapsulating the radiation protection material and elements also has the disadvantage that the cover has weak points on the connecting lines.

[0008] A further problem when encapsulating thermoplastic polymers is that when sealing the seams, hermeticity is only guaranteed if there are no loose particles on the film to be encapsulated. However, radiation protection materials are treated with talcum powder, especially if the base material consists of natural rubber. To avoid poor sealing of the cover, the surface of the material to be encapsulated must be cleaned.

[0009] The present application represents in particular an alternative and further development of the technology described in EP 3748652 and EP 1613217. Reference is made in its entirety hereto insofar as the use of the encapsulated radiation protection elements is concerned.

[0010] The present invention therefore relates to a method for the integral encapsulation of radiation protection elements made from radiation protection material using a thermosetting, solvent-free polymer having a Shore A hardness (measured according to DIN 53505) in the range of 50 to 90, to the use of such a polymer for encapsulating these radiation protection elements, to radiation protection elements encapsulated with such a polymer and to radiation protection devices or gear made from the encapsulation elements as described in this specification and / or in the independent and dependent claims.

[0011] Thus, in one embodiment [A], the present invention relates to the use of a one-piece cover made of a thermosetting polymer for the protection of a radiation protection element made 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, where the chemical element is selected from lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba).

[0012] The polymer cover 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 protection material is thus surrounded, so to speak encapsulated, by the thermosetting polymer.

[0013] For elastomers and deformable synthetic materials, the Shore hardness test is a simple and effective method of material testing and a straightforward method of hardness measurement. Shore measurements are known and partly defined in DIN standards. Basically, hardness testers are used that measure the penetration depth and time of a penetrator (indenter) of a specific shape and then determine the hardness of the material.

[0014] In one embodiment [B], the present invention relates to the use defined in embodiment [A], wherein the thermosetting polymer is a polyurea or polyurethane, in which at least one polyisocyanate compound is used as a curing agent. Preferably, aromatic polyureas are used, since they dry faster during production. More preferably, a solvent-free two-component system is used.

[0015] In one embodiment [C], the invention relates to the use according to any 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.

[0016] In one embodiment [D], the invention relates to the use according to any one of the previous embodiments, wherein the crosslinker for the polymer is selected from an aliphatic or aromatic diamine or polyamine compound, and an aliphatic or aromatic diol or polyol compound.

[0017] In one embodiment [E], the invention relates to the use according to any one of the previous embodiments, wherein the polymer comprises additives such as fillers, UV filters, color pigments, etc.

[0018] In one embodiment [F], the invention relates to the use according to any one of the previous embodiments, wherein the heavy chemical element is lead or bismuth and the elastomer is selected from natural rubber (NR), synthetic rubber (BR) or chlorosulfonated polyethylene (CSM), in each case optionally vulcanized.

[0019] In one embodiment [G], the present invention relates to a radiation protection element encapsulated in a thermosetting polymer and consisting of a radiation shielding material, as defined by any one of the embodiments relating to the use or method, wherein the cover is integral and has a thickness of 2 mm or less, preferably 1 mm or less, particularly preferably 0.6 mm or less.

[0020] In one embodiment [H], the present invention relates to a radiation protection element as defined in embodiment [G], wherein the elastomer of the radiation protection material is selected from natural rubber (NR), synthetic rubber (BR) and chlorosulfonated polyethylene (CSM), each of which is optionally vulcanized.

[0021] In one embodiment [I], the present invention relates to a radiation protection element as defined in embodiment [H], wherein the heavy chemical element is lead or bismuth.

[0022] In one embodiment [J], the present invention relates to a radiation protection element as defined in any one of embodiments [G]-[I], wherein the radiation protection material has a Shore A hardness in the range of 50-70 and / or a lead equivalent value of at least 0.5 mm of lead.

[0023] In one embodiment [K], the invention relates to a radiation protection element as defined in any one of the embodiments [G]-[J], the element being a slat for under-table radiation protection or for a curtain. A curtain consisting of such slats represents a radiation protection device. In particular, the element may be a vertical slat for a curtain as well as a cassette cover or a cover angle.

[0024] In contrast to the prior art film bags, the enclosure (cover) forms a component that mechanically integrates the entire system, thus also allowing new fastening methods such as clamps without riveting or screwing (i.e. drilling through) the protective material.

[0025] In one embodiment [L], the present invention relates to a method for manufacturing a radiation protection element as defined in any one of the embodiments [G] to [K], comprising the following method steps: Step (1) Providing a radiation protection material, optionally in the form of a sheet, comprising an elastomer and a heavy chemical element, wherein the elastomer is natural rubber (NR), synthetic rubber (BR) or chlorosulfonated polyethylene (CSM), and the heavy element is selected from lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba). Step (2) machining, cutting or punching the radiation protection material into the shape of the radiation protection element. Step (3) Encapsulating the element by simultaneously applying a crosslinking agent, a hardener and optionally additives as defined in any one of the previous embodiments, the application being carried out by hot spraying, optionally using a multi-component high pressure device, the thickness of the cover being equal to or less than 2 mm, preferably equal to or less than 1 mm, particularly preferably equal to or less than 0.6 mm, and having a Shore A hardness in the range of 50-90.

[0026] In one embodiment [M], the present invention relates to a method for the manufacture of a radiation protection element as defined in embodiment [L], in which a component consisting of a radiation protection material is provided for the cover, and step (2) is omitted.

[0027] In one embodiment [N], the invention relates to a method for manufacturing a radiation protection element as defined in embodiment [L] or [M], the element being a slat for a curtain. In particular, the element may be a vertical slat for a curtain or an under-table radiation protection device, as well as a cassette cover or a cover angle.

[0028] In one embodiment [O], the present invention relates to a radiation protection element manufactured by the method defined in any one of the embodiments [L] to [N].

[0029] The thermosetting polymers according to the invention are characterized by their high resistance to chemicals, extreme temperatures and physical stress.

[0030] The radiation protection material comprises at least one heavy chemical element in ionic or elemental form, the chemical element being selected from lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba). Lead and bismuth are preferred, with lead being particularly preferred.

[0031] The present invention makes it possible to provide a cover that does not require connections, such as welded seams, and thus avoids the disadvantages of the prior art. The cover is produced directly after curing of the polymer components (crosslinker (base) and hardener) applied to the radiation protection material to be encapsulated or to the element produced therefrom. The cover also has high abrasion resistance and breaking elongation.

[0032] The cover according to the invention, which consists of a crosslinked thermosetting polymer, is seamless and is therefore also called a one-piece cover in this case. The radiation protection material is enclosed by the cover.

[0033] This method typically uses a multi-component high pressure device, in which components A and B (and further additives) are heated and sprayed under high pressure. Upon exiting the nozzle, the two components mix at the surface. The material hardens to a semi-dry state within a short period of time.

[0034] The reaction time is less than 30 seconds and the coating is semi-dry after less than 5 minutes. Drying takes longer, i.e., about 24 hours. After drying, further layers may be applied, for example to protect against UV radiation or to achieve a desired color or gloss.

[0035] The thermosetting polymers according to the invention, in particular polyureas and polyurethanes, are prepared by polymerization of at least two components, namely a base (crosslinker, component A) and a hardener (component B), immediately after application to the radiation protection material or to an element consisting of same.

[0036] The advantage of a one-piece cover is not only the simplicity of production, but also mainly the fact that there are no connections that can be broken, and furthermore, the encapsulated radiation protection material does not require any pre-treatment, in that, for example, the surface of the element made of radiation protection material does not have to be cleaned of any substances resulting from the production process.

[0037] This can be, for example, talcum powder when so-called lead rubber is used as radiation protection material. In the case of multi-piece thermoplastic covers according to the prior art, talcum powder usually causes defects in the sealing tightness at the joints due to impurities being mixed into the joints during sealing.

[0038] Due to the one-piece cover, the radiation protection material is effectively protected against oxidation and rapid deterioration and has a long service life. Likewise, unintentional contamination with substances potentially harmful to health (e.g. heavy metals, lead, bismuth, etc.) is minimized or eliminated. The coating can also be mechanically loaded and is easy to clean.

[0039] The inventive use of thermosetting polymers and elements made therefrom for encapsulating radiation protection materials has heretofore not been known.

[0040] Furthermore, due to the manufacturing process of the cover, it is preferable to use crosslinking and curing agents that are liquid at room temperature or that melt without decomposing at temperatures up to 250°C.

[0041] Among the polyureas that can be used, those comprising aromatic polyamines as crosslinking agents are preferred.

[0042] Among the polyurethanes that can be used, those having an aliphatic polyol as a crosslinking agent are preferred.

[0043] Covers according to the present invention can also include additives that provide, for example, UV protection.

[0044] Radiation protection materials are materials capable of blocking or absorbing harmful ionizing radiation, such as X-rays. These radiation protection materials contain at least one heavy chemical element, such as lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba). The elements are typically embedded in a polymer matrix. They can be made of a variety of materials. The polymer matrix according to the invention comprises a thermosetting elastomer, in particular a polyurea, optionally vulcanized.

[0045] The radiation protection materials may also be present in the form of composite materials, in which various radiation protection materials are combined to achieve a higher level of wearing comfort, while still having a sufficient lead equivalent value, and at a lower weight.

[0046] In the present invention, lead rubber is preferably used: it is an elastomeric material consisting essentially of a polymer matrix interspersed or filled with lead powder or lead particles (elemental or oxidized form of lead), the lead serving primarily to modify the elastomeric material with regard to its radiation absorbing properties.

[0047] 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 that of natural rubber are also possible.

[0048] Natural rubber (NR) has, inter alia, a high degree of elasticity, low temperature flexibility and good dynamic properties, but unless provided with appropriate protective additives, it has low resistance to degradation and ozone, and furthermore, natural rubber does not tolerate contact with mineral oils and fats.

[0049] NR offers a hardness range of Shore A30 to 90. CSM is available in a hardness range of Shore A45 to 90.

[0050] In one embodiment of the invention, a lead-rubber single-ply material is produced which is suitable for use as a radiation protection element, in particular as a vertical slat for curtains or under-table radiation protection, as well as for use as a cassette cover, cover angle, etc. This lead-rubber single-ply material comprises a radiation protection matrix, in particular a lead-containing and sulfur-crosslinked lead rubber plate, and a cover made of a thermosetting polymer according to the invention.

[0051] The lead-rubber material may optionally have a central, optionally friction-fitted fabric insert and may have additional coatings. The material preferably has a lead equivalent value in the range of 0.5-2.00 mm and a Shore A hardness typically in the range of 50-70.

[0052] The radiation protection material is processed to form elements, which are joined together to form a radiation protection device. Such a radiation protection device may be, for example, a curtain or a lower body protection device. The radiation protection device may be, for example, fixed in front of a window or in at least one lateral area of ​​a treatment table. This radiation protection device, especially if it is a lower body protection device, consists of an upper part arranged on a carrier rail fixed to the place of use (for example a table) and a number of slats fixed to the underside of the carrier rail and arranged so as to overlap each other laterally adjacently. Such a device is shown in FIG. 1 of EP 1 613 217.

[0053] In one embodiment, the lead protection material is present in the form of slats (curtains). These slats are attached to a curtain track. They consist of a specific material, for example aluminum. The track carriage of such a slat curtain has a stable track carriage, preferably made of a hard synthetic material. The slat receiver is manufactured from a material capable of bearing very heavy loads, for example carbon fiber.

Claims

1. 1. Use of a one-piece cover made of a thermosetting polymer for protection of a radiation protection element made 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, said chemical elements being selected from lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba), said cover having a Shore A hardness in the range of 50 to 90.

2. The use according to claim 1, wherein the thermosetting polymer is a polyurea or polyurethane, in which at least one polyisocyanate compound is used as a curing agent.

3. 3. The use according to claim 1 or 2, wherein the layer thickness of the thermosetting polymer is less than or equal to 2 mm.

4. 4. The use according to claim 1 , wherein the crosslinking agent of the polymer is selected from aliphatic or aromatic diamine or polyamine compounds, and aliphatic or aromatic diol or polyol compounds.

5. 5. The use according to any one of claims 1 to 4, wherein the polymer comprises additives such as fillers, UV filters, colour pigments, etc.

6. 6. Use according to any one of claims 1 to 5, wherein the heavy chemical element is lead or bismuth and the elastomer is chosen from natural rubber (NR), synthetic rubber (BR) or chlorosulphonated polyethylene (CSM), optionally vulcanised.

7. 7. A radiation protection element encapsulated in a thermosetting polymer and made of a radiation protection material as defined in any one of claims 1 to 6, wherein the cover is integrally molded and has a thickness of 2 mm or less.

8. 8. The radiation protection element according to claim 7, wherein the elastomer of the radiation protection material is selected from natural rubber (NR), synthetic rubber (BR) and chlorosulfonated polyethylene (CSM).

9. 9. The radiation protection element according to claim 8, wherein the heavy chemical element is lead or bismuth.

10. 10. Radiation protection element according to any one of claims 7 to 9, wherein the Shore A hardness of the radiation protection material is in the range of 50 to 70 and / or has a lead equivalent value of at least 0.5 mm of lead.

11. 11. Radiation protection element according to any one of claims 7 to 10, wherein the element is a slat for under-table radiation protection or for a curtain, or a cassette cover or a cover angle.

12. A method for manufacturing a radiation protection element as defined in any one of claims 7 to 11, said method comprising the steps of: (1) Providing the radiation protection material, optionally in the form of a sheet, comprising an elastomer and a heavy chemical element, wherein the elastomer is natural rubber (NR), synthetic rubber (BR) or chlorosulfonated polyethylene (CSM), and the heavy element is selected from lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba); (2) machining, cutting or stamping the radiation protection material into the shape of the radiation protection element; (3) Encapsulating the element by simultaneously applying the crosslinking agent, the hardener, and optionally an additive as defined in any one of claims 1 to 11, the application being carried out by a hot spray method, optionally using a multi-component high pressure device, the thickness of the cover being 2 mm or less and having a Shore A hardness in the range of 50 to 90; A method comprising the steps of:

13. 13. The method of claim 12, wherein a component made of a radiation protective material is provided for the cover, and step (2) is omitted.

14. 14. The method according to claim 12 or 13, wherein the element is a slat for under-table radiation protection or a curtain, or a cassette cover or a cover angle.

15. A radiation protection element manufactured by the method according to any one of claims 12 to 14.