RU2281572C2 - X-ray shielding coating - Google Patents

Abstract

FIELD: roentgen-ray shielding materials.

SUBSTANCE: proposed X-ray shielding coating has sublayer incorporating cured and plasticized epoxy-containing compound and basic elastic X-ray shielding layer also based on epoxy-containing binder; curing agent from group of cold-curing agents; shielding filler in the form of powdered mixture of rare earth element oxides or mixture of rare earth element oxides with antimony oxide (III), or mixture of rare earth element oxides with tungsten or its compounds, proportion of ingredients being as follows, mass percent: binder, 13.3 - 20.8; shielding filler, 78.6 - 86.3; amine curing agent, o.4 - 0.6. In addition, it has solvent which is essentially mixture of acetic esters, aliphatic and aromatic solvents in the amount of 30 - 40 mass percent per every 100 g of basic X-ray shielding material. Shielding filler content of basic polymerized layer ranges between 78.5 and 88.7 mass percent.

EFFECT: enhanced effectiveness of shielding personnel and patients, improved mechanical and adhesive properties of material.

1 cl, 1 tbl, 4 ex

Description

The present invention relates to the field of production of X-ray protective materials, namely polymer X-ray protective coatings based on a binder and shielding filler.

The urgency of the problem to be solved is based on the acute need of modern technology for shielding materials to protect personnel serving X-ray units and patients from exposure to X-ray radiation (RI).

An X-ray protective coating is known, which is a layered X-ray protective material containing layers of an elastic polymer X-ray protective material based on a binder, dimethylsiloxane rubber with X-ray protective filler and woven material, and tin (IV) diethyl dicaprylate is used as a catalyst for the elastic layer.

The X-ray protective filler contains a mixture of oxides of rare-earth elements and antimony oxide (RF patent No. 2156509, IPC 7 G 21 F 1/00, 32 B 5/30, publ. BI No. 26/2000 from 09/20/2000).

However, this layered X-ray protective material has insufficiently high X-ray protective properties and an elasticity index, which is explained by the presence of tissue layers characterized by a limited value of elongation under tension. In addition, when using this material as a coating, it becomes necessary to use an additional adhesive layer to ensure its operability as a whole material.

It is known as the closest in technical essence and technical result achieved to the claimed X-ray protective coating based on a binder, hardener, screening filler, in the initial state representing a polymer composition based on silicone rubber (RF patent No. 2138865, IPC 6 G 21 F 1/10 , publ. BI No. 27/99, dated September 27, 1999) containing dimethylsiloxane rubber as a binder and a mixture of rare earth oxides (REE) and antimony (III) oxide as a filler.

However, the known coating has a relatively low adhesive strength to metal substrates, on the basis of which its relatively low quality is based.

The task of the authors of the invention is to develop the composition and type of mechanically durable elastic x-ray protective coating that effectively protects staff and patients from exposure to radiation.

A new technical result achieved by using the proposed coating is to increase the effectiveness of x-ray protection of staff and patients by ensuring the composition of the shielding filler and the maximum degree of filling of the finished coating with improved mechanical and adhesive properties.

The specified task and a new technical result is achieved by the fact that in the known X-ray protective coating, including a binder, hardener, shielding filler, in accordance with the proposed technical solution, the X-ray protective coating consists of a sublayer containing a cured plasticized epoxy-containing compound and the main elastic X-ray protective layer based on also an epoxy-containing binder, hardener from the group of amine hardeners of cold curing, shielding filler - powder a figurative mixture of rare earth oxides, or a mixture of rare earth oxides with antimony (III) oxide, or a mixture of rare earth oxides with tungsten or its compounds, with the following recipe contents of the ingredients, wt.%:

Binder 13.3-20.8 Shielding filler 78.6-86.3 Amine hardener 0.4-0.6

and, in addition, a solvent consisting of a mixture of acetic acid esters, aliphatic and aromatic solvents at a rate of 30-40 wt.% for every 100 g of the substance of the main x-ray protective layer, while the content of the shielding filler in the composition of the polymerized main layer is in the range of, wt. .%: 78.5-88.7.

The essence of the proposed x-ray protective coating is as follows.

The proposed x-ray protective coating is a multilayer material sprayed onto a metal substrate, polymerizing at room temperature. A sublayer consisting of a mixture of an epoxy-containing binder of 75.8% (by weight), plasticizer - dibutyl phthalate - 15-19%, hardener - polyethylene polyamine - 9-11% is applied to the prepared (cleaned and degreased) surface of the metal substrate. Layers of the main elastic X-ray protective coating layer are applied to the cured sublayer to a predetermined thickness. For this, a composition is prepared from the following ingredients, wt.%:

Binder 13.3-20.8 Shielding filler 78.6-86.3 Amine hardener 0.4-0.6

and additionally, a solvent consisting of a mixture of esters of acetic acid, aliphatic and aromatic solvents in the calculation of 30-40 wt.% for every 100 g of the substance of the main x-ray protective layer, while the content of the shielding filler in the composition of the polymerized main x-ray protective layer is in the range of values, wt .%: 78.5-88.7.

It was experimentally shown that when exceeding the maximum declared limits of the ratios of the ingredients of the binder, hardener or filler, the product is not formed. In batches of coating samples containing a binder, hardener, or filler below the declared limits of their ratios, the required X-ray protection and mechanical strength were not provided. The maximum prescription value of the filler content was determined experimentally - 86.3% (by weight), necessary to ensure the effectiveness of attenuation of X-ray radiation (X-ray radiation) while maintaining the required mechanical properties. It was found that an excess of the prescription filler content of more than 86.3% does not ensure the quality of the coating neither in terms of uniformity of the distribution of the filler, nor in strength. An X-ray protective coating was applied by spraying onto metal substrates.

The presence in the composition of the initial composition of the hardener of cold curing allows the curing process at normal temperature and pressure, which also positively affects the preservation of the physical and mechanical properties of the coating.

The use of a solvent makes it possible to improve the quality of the X-ray protective coating by providing the possibility of varying the viscosity of the initial composition to working viscosity values, which ultimately reduces the thickness variation and heterogeneity in the finished coating, which determine the quality of the latter.

After curing of the layers of the X-ray protective coating, the quality of the coating was checked for compliance of the finished X-ray protective coating with the requirements of quality standards. It was found that the X-ray protective coating containing all components within the claimed range of component ratios is characterized by high efficiency of protecting personnel and patients from exposure to radiation exposure, while ensuring the maximum degree of filling of the finished coating with a shielding powder filler and increasing the mechanical and adhesive properties through the use of this particular epoxy-containing binder complex filler based on a mixture of rare earth oxides and tungsten carbide, and t as well as cold curing hardener. When using the inventive x-ray protective coating, the following highest indicators were provided:

Density, g / cm ³ 4.8 Tear-off adhesive strength, MPa 5-6 Mechanical tensile strength, MPa 6 Lead equivalent with a coating thickness of 2 mm, mm Pb 1,1

These figures are significantly higher than the prototype. Thus, when using the proposed X-ray protective coating, higher indicators of the effectiveness of X-ray protection of personnel and patients are ensured by providing the composition of the shielding filler and the maximum degree of filling of the finished coating with it, increasing the mechanical and adhesive properties of the coating.

The possibility of industrial implementation of the proposed x-ray protective coating is confirmed by the following specific examples.

Example 1. In the laboratory, implemented x-ray coating. On the prepared (cleaned and degreased) surface of the metal substrate, a sublayer is applied, consisting of a binder mixture - 74.1% (by weight), plasticizer - dibutyl phthalate - 14.8%, hardener - polyethylene polyamine - 11.1, followed by bringing the sublayer to working viscosity 25 s in a mixture of solvents: acetone, butyl acetate and xylene.

Layers of the main X-ray protective coating material are applied to the cured sublayer to a predetermined thickness.

The proposed X-ray protective coating formulation is prepared by mixing a binder — PDI-ZAK polydienurethane rubber — with components of a powdered shielding filler, followed by bringing the mixture to a working viscosity of 25 s according to VZ-4 in a mixture of solvents — acetone, butyl acetate and xylene, at a rate of 40 wt.% For each 100 g of the substance of the main layer of the x-ray protective coating. In the resulting solution with stirring, a hardener is introduced at a ratio of ingredients, wt.%:

Polydieneurethane rubber PDI-ZAK, TU 38 103410-85 eighteen Polishing powder (Fluoropol-cerium dioxide in solid a solution of rare earth metal oxides), TU 334-97 81.6 Polyethylene polyamine, TU 6-02-594-85 0.4

The curing mode of each layer is 15-20 minutes, the time of complete curing of the coating is 24 hours.

For the manufacture of prototypes, an X-ray protective coating up to 2.0 mm thick was applied by spraying onto metal substrates from aluminum alloy D-16 and St-3 (steel).

To determine other physical and mechanical properties, an X-ray protective coating was applied to the fluoroplastic substrates (to facilitate film removal). The X-ray protective properties of the coatings were determined by calculation using the Monte Carlo method using experimental density values, density - according to GOST 267-63, mechanical properties: tensile strength and elongation in accordance with GOST 270-75, adhesive strength at break according to GOST14760-69.

Example 2. In the conditions of example 1, example 2 is implemented, with the following formulation ratios of the ingredients of the X-ray protective coating, wt.%:

Polydiurethane rubber PDI-ZAK 13.3 Filler - a mixture of fluorinated oxide powders rare earths and tungsten carbide with a mass ratio of 45:55 86.3 Polyethylene polyamine 0.4

Example 3. In the conditions of example 1, example 3 is implemented, with the following formulation ratios of the ingredients of the X-ray protective coating, wt.%:

Polydiurethane rubber PDI-ZAK 19.7 Epoxy resin ED-20 1,0 Filler - a mixture of powders of rare earth oxides elements and antimony oxide (III) at a ratio of mass of 50:50 78.7 Polyethylene polyamine 0.6

Example 4. In the conditions of example 1, example 4 is implemented, with the following formulation ratios of the ingredients of the X-ray protective coating, wt.%:

Polydiurethane rubber PDI-ZAK 16.5 Epoxy resin ED-20 0.8 Filler - a mixture of powders of gadolinium oxide (GD O-6) and antimony (III) oxide with a mass ratio of 60:40 82.1 Polyethylene polyamine 0.6

The data in examples 1-4 and the characteristics of the obtained samples of x-ray coating and prototype are shown in the table.

As experiments have shown, the use of the proposed X-ray protective coating provides high X-ray protection efficiencies for staff and patients by ensuring the composition of the shielding filler and the maximum degree of filling of the finished coating with it while improving the mechanical and adhesive properties.

Claims (1)

X-ray protective coating containing a binder, hardener, screening filler, characterized in that the X-ray protective coating consists of a sublayer containing a cured plasticized epoxy-containing compound, and the main elastic X-ray protective layer based on also an epoxy-containing binder, a hardener from the group of amine hardeners, cold curing, screening filler mixtures of rare earth oxides, or mixtures of rare earth oxides with antimony oxide (III), or a mixture of rare earth oxides with tungsten or its compounds in the following formulation of ingredients, wt.%: Binder 13.3-20.8, shielding filler 78.6-86.3, amine hardener 0.4-0 , 6 and additionally a solvent consisting of a mixture of acetic acid esters, aliphatic and aromatic solvents at a rate of 30-40 wt.% For every 100 g of the substance of the main x-ray protective layer, while the content of the shielding filler in the composition of the polymerized main layer is 78.5-88 7 wt.%.