One-piece covering of radiation protection material and use thereof

Abstract

Use of a one-piece covering consisting of a thermosetting polymer for protecting a radiation protection element 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 the group consisting of lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba), and wherein the cover has a Shore A hardness of 50 to 90, a method for producing such a cover and radiation-protective elements and accessories of the package produced from a radiation-protective material.

Description

Technical Field

[0001] The present application relates to the use of a one-piece covering (one-piece shell) composed of a thermosetting polymer for protecting a radiation protection element composed of at least one elastic radiation protection material, a method for producing the covering and a radiation protection material or a radiation protection element provided with the covering. Background Art

[0002] Radiation sources that emit ionizing radiation are often used in medical, industrial and scientific facilities. Such radiation, such as X-ray radiation, can have harmful biological effects on the human body and pose considerable health risks if shielding is inadequate.

[0003] While conventional shielding methods, such as solid walls with lead inserts or fixed mounted lead screens, provide effective protection, they are inflexible and cannot be easily adapted to different working requirements or room layouts.

[0004] Therefore, there is a growing demand for flexible, adaptable and efficient radiation protection accessories. Radiation protection elements, such as radiation protection slats, 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 protection barrier as required. This not only enables dynamic protection against ionizing radiation, but also allows adaptation to specific requirements. Radiation protection slats can be used in a variety of ways, for example as curtains or as under-table radiation protection (where the slats are mounted on the patient table). Examples of slats and their use are disclosed in DE 10 2009 025 380 A1 and DE 10 2015208 829 A1.

[0005] It is well known that radiation protection elements have covers, especially for hygienic reasons and for the protection of radiation protection materials. The covers of radiation protection materials described in the prior art and used in practice are composed of thermoplastic films (such as PVC or thermoplastic polyurethane (TPU)). This cover, which is usually designed as a bag type, is produced by connecting at least two sides of the formed film part together (such as by heat sealing or other treatment). Importantly, the film parts are connected in an airtight manner so that the radiation protection element is airtightly sealed. However, the connection points (such as welds) of the film parts are very sensitive to mechanical stress and therefore the cover (especially at the seams) will open. If such covers are damaged, the radiation protection element must be replaced. The recovery of elements is usually difficult.

[0006] In addition to the problem of seams, the production of encapsulated radiation protection elements is also complicated, since care must be taken when encapsulating the element to ensure that wrinkles do not form and that air pockets do not occur. In particular, air pockets can lead to premature aging of the radiation protection material, primarily due to oxidation processes. EP 3748652 A1 describes such a covering and a method for producing an encapsulated radiation protection element, in which the problems of wrinkling and air pockets described above are avoided.

[0007] However, the described method for encapsulating radiation protection materials and components also has the disadvantage that the covering has weak points at the connection lines.

[0008] A further problem when encapsulating with thermoplastic polymers is that, when sealing the seams, airtightness can only be ensured if there are no loose particles on the film to be sealed. However, radiation protection materials are treated with talc, especially in the case of a matrix consisting of natural rubber. In order to avoid any defects in the sealing tightness of the covering, the surface of the material to be encapsulated must be cleaned. Summary of the invention

[0009] The present application represents in particular an alternative to the technology described in EP 3748 652 A1 and EP 1613 217 A1 and is a further development of the technology. With regard to the use of the coated radiation protection element concerned, the entire contents of these applications are hereby incorporated by reference.

[0010] Therefore, as described herein and / or in the independent claims and dependent claims, the present invention relates to a method for one-piece encapsulation of radiation protection elements produced from radiation protection material, the method using a thermosetting solvent-free polymer having a Shore A hardness of 50 to 90 (measured according to DIN 53505), the use of such polymers for encapsulating these radiation protection elements, radiation protection elements encapsulated with such polymers, and radiation protection equipment or accessories produced from the encapsulated elements. DETAILED DESCRIPTION

[0011] In one embodiment [A], the present invention therefore relates to the use of a one-piece covering composed of a thermosetting polymer for protecting a radiation protection element, which radiation protection element is composed of at least one radiation protection material, which at least one radiation protection material is formed by 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).

[0012] The polymer cover is elastic and has a Shore A hardness of 50 to 90, preferably 60 to 70. The radiation protection material is thus surrounded by the thermosetting polymer and can also be said to be encapsulated.

[0013] The Shore hardness test is a simple and effective material testing method and a simple hardness measurement method for elastomers and deformable synthetic materials. The measurement according to the Shore method is known and partly defined in DIN standards. In essence, a hardness tester is used to measure the penetration depth and time of a penetrating body (indenter) of a specific shape and to determine the hardness of the material from this.

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

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

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

[0018] In one embodiment [F], the invention relates to the use according to any 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), which is in each case optionally vulcanized.

[0019] In one embodiment [G], the present invention relates to a radiation protection element encapsulated with a thermosetting polymer and consisting of a radiation shielding material, as defined in any of the embodiments for use or method in this case, wherein the covering is a single piece and has a thickness 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.

[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] to [I], wherein the radiation protection material has a Shore A hardness of 50-70 and / or has a lead equivalent value of at least 0.5 mm lead.

[0023] In one embodiment [K], the invention relates to a radiation protection element as defined in any one of embodiments [G] to [J], wherein the element is a slat for off-stage radiation protection or a slat for a curtain. A curtain consisting of such slats represents a radiation protection accessory. In particular, the element can be a vertical slat for a curtain as well as a box-type cover or a cover angle.

[0024] Compared to prior art film pockets, the outer shell (cover) forms a mechanically integral part of the entire system and therefore also allows new fastening methods (such as clamping) without the need for riveting or screwing (ie drilling through) the protective material.

[0025] In one embodiment [L], the present invention relates to a method for producing a radiation protection element as defined in any one of embodiments [G] to [K], comprising the following method steps:

[0026] Step (1) provides a radiation protection material comprising an elastomer and a heavy chemical element, which is optionally in the form of a sheet, 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 (W), tin (Sn), antimony (Sb) and barium (Ba);

[0027] Step (2) processing, cutting or punching the radiation protection material into the shape of the radiation protection element;

[0028] Step (3) encapsulates the component by simultaneously applying a crosslinking agent and a hardener as defined in any of the preceding embodiments and optional additives, wherein the application is optionally carried out as a thermal spraying method using a multi-component high-pressure device, wherein the thickness of the covering 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 of 50 to 90.

[0029] In one embodiment [M], the invention relates to a method for producing a radiation protection element as defined in embodiment [L], wherein an element consisting of a radiation protection material is provided for the covering and step (2) is omitted.

[0030] In one embodiment [N], the present invention relates to a method for producing a radiation protection element as defined in embodiment [L] or embodiment [M], wherein the element is a slat for a curtain. In particular, the element can be a vertical slat for a curtain or an under-table radiation protection accessory, as well as a box cover or a cover corner.

[0031] In one embodiment [O], the present invention relates to the production of a radiation protection element by a method as defined in one of embodiments [L] to [N].

[0032] Thermosetting polymers according to the invention are characterized by their high resistance to chemicals, extreme temperatures and physical stress.

[0033] The radiation protection 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 (W), tin (Sn), antimony (Sb) and barium (Ba). Preference is given to lead and bismuth, and particular preference is given to lead.

[0034] The invention makes it possible to provide a covering which does not require connection points (such as welds) and thus avoids the disadvantages of the prior art. The covering is produced directly after the curing of the polymer components (crosslinker (base) and hardener) applied to the radiation protection material to be encapsulated or the element produced from the radiation protection material to be encapsulated. The covering also has a high degree of wear resistance and elongation at break.

[0035] The covering according to the invention, which is composed of a cross-linked thermosetting polymer, is seamless and is therefore also referred to in this case as a one-piece covering. The radiation protection material is hermetically encapsulated by the covering.

[0036] This method usually uses multi-component high-pressure equipment. In this method, component A and component B (and other additives) are heated and atomized under high pressure. When leaving the nozzle, the two components mix at the surface. The material cures to a touch dry state in a short time.

[0037] The reaction time is less than 30 seconds and the coating is touch dry after less than 5 minutes. Hard-drying takes longer, i.e. about 24 hours. After drying, a further layer can be applied, for example to protect against UV radiation or in order to achieve the desired color or brightness.

[0038] Thermosetting polymers according to the invention, such as in particular polyureas and polyurethanes, are produced by polymerizing at least two components, namely a base (crosslinker, component A) and a hardener (component B) immediately after application to the radiation protection material or an element consisting of the radiation protection material.

[0039] The advantage of a one-piece cover is not only the simplicity of production, but also primarily the fact that there are no connection points that can be torn apart. In addition, the radiation protection material to be encapsulated does not require any pretreatment, since, for example, the surface of an element consisting of radiation protection material does not specifically require any substances produced during the production process to be removed therefrom.

[0040] If so-called lead rubber is used as radiation protection material, this can be talc, for example. In the case of multi-piece thermoplastic coverings according to the prior art, talc often produces defects in the sealing tightness at the connection points because of the presence of impurities in the connection points during sealing.

[0041] By means of a one-piece covering, the radiation protection material is effectively protected against oxidation and rapid aging and has a long service life. Likewise, accidental contamination with substances that are potentially harmful to health (e.g. heavy metals, lead, bismuth, etc.) is minimized or excluded. The coating can also be mechanically loaded and is easy to clean.

[0042] To date, the inventive use of thermosetting polymers for encapsulating radiation protection materials and components produced from radiation protection materials is not known.

[0043] Furthermore, due to the process for producing the covering, it is preferred to use such crosslinking agents and hardeners that are liquid at room temperature or melt at temperatures up to 250° C. without decomposing.

[0044] Among the polyureas which can be used, preference is given to those which consist of aromatic polyamines as crosslinking agents.

[0045] Among the polyurethanes which can be used, preference is given to those which have aliphatic polyols as crosslinkers.

[0046] The covering according to the invention may likewise contain additives which provide, for example, UV protection.

[0047] Radiation protection materials are materials that are able to block or absorb harmful ionizing radiation, such as X-ray radiation. Such radiation protection materials contain at least one of the following heavy chemical elements: such as lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba). These elements are usually embedded in a polymer matrix. They can be composed of a variety of materials. The polymer matrix according to the present invention includes a thermosetting elastomer, in particular an optionally vulcanized polyurea.

[0048] The radiation protection material may also be present in the form of a composite material, in which various radiation protection materials are combined to achieve a low weight and a high level of wearing comfort while having a sufficient lead equivalent value.

[0049] In the present invention, lead rubber is preferably used. It is an elastomeric material mainly composed of a polymer matrix dispersed or filled with lead powder or lead particles (elemental or oxidized form of lead), wherein the lead is mainly used to change the radiation absorption properties of the elastomeric material.

[0050] The elastomer, ie the elastic component, may be natural rubber (NR), synthetic rubber (BR) or chlorosulfonated polyethylene (CSM). Other rubbers having a Shore A hardness comparable to that of natural rubber are also possible.

[0051] Natural rubber (NR) has, in particular, a high degree of elasticity, low-temperature flexibility and excellent dynamic properties. However, without corresponding provision of protective additives, the aging and ozone resistance is only low, and, moreover, natural rubber does not tolerate contact with mineral oils and fats.

[0052] NR is available in a hardness range of 30 to 90 Shore A. CSM is available in a hardness range of 45 to 90 Shore A.

[0053] In one embodiment of the invention, a lead rubber monolayer material is produced which is suitable for use as a radiation protection element, in particular as a vertical slat of a curtain or an under-stage radiation protection accessory and as a box-type covering, a covering corner, etc. This lead rubber monolayer material comprises a radiation protection matrix, in particular a lead-containing and sulfur-crosslinked lead rubber sheet, and a covering produced with a thermosetting polymer according to the invention.

[0054] The material consisting of leaded rubber may optionally have a central, optionally friction glazed tissue insert and may have an additional coating. The material preferably has a lead equivalent value of 0.5 mm to 2.00 mm lead, with a Shore A hardness of typically 50 to 70.

[0055] The radiation protection material is processed to form elements, which are joined together to form a radiation protection device. Such a radiation protection device can be, for example, a curtain, or can be a lower body protection device. The radiation protection device can be fastened, for example, in front of a window or fastened to 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 and a plurality of slats, which are arranged on a carrier track fastened to a use position (such as a table), and the plurality of slats are fastened to the lower side of the carrier track and are arranged to overlap laterally close to each other. Such a device is shown in Fig. 1 in EP 1613217B1.

[0056] In one embodiment, the lead protection material is in the form of (curtain) slats. These slats are mounted on a curtain track. They consist of a specific material, such as, for example, aluminum. The track support of such slatted curtains has a stable track support, preferably formed of a hard synthetic material. The slat receiver is made of a material, such as carbon fiber, that can withstand very heavy loads.

Claims

1. A one-piece covering composed of a thermosetting polymer for use in protecting a radiation protection element, wherein the radiation protection element is composed of at least one radiation protection material, wherein the at least one radiation protection material is formed by 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), wherein the Shore A hardness of the covering is 50 to 90.

2. The method according to claim 1, wherein the thermosetting polymer is a polyurea or a polyurethane, wherein at least one polyisocyanate compound is used as a hardener.

3. Use according to any one of the preceding claims, wherein the layer thickness of the thermosetting polymer is less than or equal to 2 mm.

4. Use according to any one of the preceding claims, wherein the crosslinking agent for the polymer is selected from aliphatic or aromatic diamine or polyamine compounds and aliphatic or aromatic diol or polyol compounds.

5. Use according to any of the preceding claims, wherein the polymer comprises additives such as fillers, UV filters, colour pigments.

6. Use according to any one of the preceding claims, characterised 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), optionally vulcanized.

7. A radiation protection element encapsulated with a thermosetting polymer and consisting of a radiation protection material as defined in any one of the preceding claims, wherein the cover is formed in a single piece and has a thickness less than or equal to 2 mm.

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

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

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

11. The radiation protection element according to any one of claims 7 to 10, wherein the element is a slat for under-table radiation protection or a slat for a curtain, or a box-type cover or a cover corner.

12. A method for producing a packaged radiation protection element as defined in any one of the preceding claims 7 to 11, comprising the following method steps: (1) providing the radiation shielding material comprising an elastomer and a heavy chemical element, which is optionally in the form of a sheet, wherein the elastomer is natural rubber (NR), synthetic rubber (BR) or chlorosulfonated polyethylene (CSM) and wherein the heavy element is selected from the group consisting of lead (Pb), bismuth (Bi), tungsten (W), tin (Sn), antimony (Sb) and barium (Ba); (2) processing, cutting or punching the radiation protection material into the shape of the radiation protection element; (3) Encapsulating the component by simultaneously applying the crosslinking agent and the hardener as defined in any of the preceding claims and optional additives, wherein the application is optionally carried out with a multi-component high-pressure device as a thermal spraying method, wherein the covering has a thickness of less than or equal to 2 mm and has a Shore A hardness of 50 to 90.

13. The method according to claim 12, wherein an element consisting of a radiation protection material is provided for the covering and step (2) is omitted.

14. The method according to claim 12 or 13, wherein the element is a slat for under-stage radiation protection or a slat for a curtain, or a box-type covering or a covering corner.

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