Anti-radiation coating based on emulsion polymerization and preparation method thereof

Abstract

The preparation method comprises the following steps: stirring unsaturated carboxylic acid, a monomer containing double bonds and an anti-ionizing radiation metal oxide for reaction, and then performing reflux condensation to obtain an anti-ionizing radiation metal unsaturated carboxylate solution; and mixing the ionizing radiation resistant metal unsaturated carboxylate solution with deionized water, an emulsifier, an initiator and an auxiliary agent, and carrying out emulsion polymerization to obtain the anti-radiation coating. The unsaturated carboxylate forms a polymer network through emulsion polymerization, and the metal oxide is uniformly dispersed in the coating, so that a compact anti-radiation layer is formed on the surface of the coating, the problem of dispersity caused by taking anti-radiation particles as filler in a conventional method is solved, and the coating can meet the requirements of fabrics of different materials on the hardness and binding force of the coating; the finally obtained anti-radiation layer is resistant to washing and good in long-term use performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a radiation-proof coating based on emulsion polymerization and a preparation method thereof. Background Art

[0002] The damage effects of ionizing radiation on the human body mainly include many aspects such as the blood system, nervous system, immune system, skin, eyes, etc. Long-term low-dose ionizing radiation has brought varying degrees of damage to different systems of radiation workers (including the blood system, nervous system, digestive system, endocrine system, immune system, skin, eyes, etc.), and with the prolongation of radiation time, the damage effect becomes more obvious. Although with the rapid development of science and technology, the anti-ionizing radiation technology has been continuously improved, and the radiation exposure dose of radiation workers during their practice has gradually decreased. Medical institutions / enterprises and radiation workers should attach great importance to and pay attention to health monitoring and radiation protection work, minimize radiation exposure, reduce radiation damage, and effectively ensure the health and safety of radiation workers. Lead has good nuclear radiation protection effect and low cost, and has been widely used in the field of radiation protection, but it has defects such as low protection efficiency, poor stability, and low reuse rate.

[0003] The anti-ionizing radiation performance fabric is a fabric with a certain function of shielding ionizing radiation. There are two common ways for this fabric to achieve anti-ionizing radiation. The first way is to make masterbatch from functional powders of anti-ionizing radiation metals or metal oxides, blend and spin them with polymers such as polyester and polyamide, and make them into yarns and fabrics. This way has problems such as uneven distribution of functional powders in fibers and the inability to add too high proportion of functional powders. The second way is to attach metal or metal oxide particles with anti-ionizing radiation function to the fibers after treatment with coupling agents or disperse them in a polymer emulsion and then coat them on the fabric; this is the current mainstream treatment method. Since there is only physical aggregation between the particles and the fibers, this treatment method has disadvantages such as large particle size, difficult uniform dispersion of particles, low particle addition amount, and easy particle shedding during the washing process. For example, a certain research shows that after 10 washes, the anti-radiation efficiency of traditional coated fabrics drops by more than 40% (Zhao Yifan, Lu Shiyan. Design and production of wash-resistant and comfortable electromagnetic shielding fabrics [J]. Journal of Zhongyuan University of Technology, 2023, 34(02): 30-33.). Summary of the Invention

[0004] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title of the invention, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above problems and / or those existing in the prior art, the present invention is proposed.

[0006] Therefore, an object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a radiation-proof coating based on emulsion polymerization.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] After stirring and reacting unsaturated carboxylic acid, a monomer containing a double bond, and an anti-ionizing radiation metal oxide, reflux condensation is carried out to obtain an anti-ionizing radiation metal unsaturated carboxylate solution;

[0009] By weight, take 2 - 10 parts of the anti-ionizing radiation metal unsaturated carboxylate solution, 1 - 100 parts of deionized water, 0.1 - 0.5 part of an emulsifier, 0.01 - 0.1 part of a water-soluble initiator, and 0 - 5 parts of an auxiliary agent, mix them evenly, and carry out an emulsion polymerization reaction to obtain a radiation-proof coating.

[0010] As a preferred embodiment of the method for preparing a radiation-proof coating based on emulsion polymerization according to the present invention, wherein: the unsaturated carboxylic acid is an unsaturated carboxylic acid containing a carboxyl group and a carbon-carbon double bond.

[0011] As a preferred embodiment of the method for preparing a radiation-proof coating based on emulsion polymerization according to the present invention, wherein: the unsaturated carboxylic acid containing a carboxyl group and a carbon-carbon double bond includes one or more of acrylic acid, methacrylic acid, maleic acid, undecylenic acid.

[0012] As a preferred embodiment of the method for preparing a radiation-proof coating based on emulsion polymerization according to the present invention, wherein: the anti-ionizing radiation metal oxide includes one of bismuth oxide, tungsten oxide, lanthanum oxide, gadolinium oxide, europium oxide.

[0013] As a preferred embodiment of the method for preparing a radiation-proof coating based on emulsion polymerization according to the present invention, wherein: the monomer containing a double bond includes one of acrylic acid, methyl methacrylate, acrylonitrile, vinyl acetate.

[0014] As a preferred embodiment of the method for preparing a radiation-proof coating based on emulsion polymerization according to the present invention, wherein: the molar ratio of the unsaturated carboxylic acid, the monomer containing a double bond, and the anti-ionizing radiation metal oxide is 4 - 8:0 - 6:1.

[0015] As a preferred embodiment of the method for preparing a radiation-proof coating based on emulsion polymerization according to the present invention, wherein: in the stirring reaction of the unsaturated carboxylic acid, the monomer containing a double bond, and the anti-ionizing radiation metal oxide, the reaction temperature is 50 - 90 °C, and the reaction time is 1 - 3 h.

[0016] As a preferred embodiment of the preparation method of the radiation - resistant coating based on emulsion polymerization of the present invention, wherein: the water - soluble initiator includes one of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0017] Another object of the present invention is to overcome the deficiencies in the prior art and provide a radiation - resistant coating prepared by the preparation method of the radiation - resistant coating based on emulsion polymerization.

[0018] Another object of the present invention is to overcome the deficiencies in the prior art and provide an application of the radiation - resistant coating based on emulsion polymerization in the preparation of a functional fabric for shielding ionizing radiation.

[0019] Advantages of the present invention:

[0020] (1) Through emulsion polymerization, the present invention converts radiation - resistant metal particles into unsaturated dibasic acid mono - ester salts, thoroughly solving the dispersion problem of radiation - resistant particles as fillers in the conventional method; using the unsaturated dibasic acid mono - ester salt as a polymerization monomer, a polymer emulsion is obtained by a conventional method, and this process is mature and the method is simple.

[0021] (2) The method provided by the present invention can freely adjust the formula to meet the requirements of different material fabrics for the hardness and bonding strength of the coating. During the use process, no special processes such as electrostatic spinning technology are required, and the obtained radiation - resistant layer is resistant to washing and brushing, and has good long - term use performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. Among them:

[0023] Figure 1 This is the radiation - resistant fabric prepared with the radiation - resistant coating in Example 1 of the present invention.

[0024] Figure 2 This is the radiation - resistant fabric prepared with the radiation - resistant coating in Comparative Example 6 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To make the above - mentioned objects, features, and advantages of the present invention more obvious and understandable, the following will give a detailed description of the specific embodiments of the present invention in combination with the embodiments of the specification.

[0026] In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, the present invention may be practiced in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0027] Secondly, as used herein, an "embodiment" or "embodiments" refers to specific features, structures, or characteristics that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an individual or alternative embodiment that is mutually exclusive with other embodiments.

[0028] Unless otherwise specified, the raw materials used in the present invention are commercially available.

[0029] The method for preparing the radiation-proof fabric of the present invention is as follows: Coat the coating on a polyester non-woven fabric with a gram weight of 100, heat and dry it, and control the gram weight after coating to be 300 to obtain the radiation-proof fabric.

[0030] The present invention refers to GB / T 18318-2001 "Standard for the Determination of Bending Length of Textiles" and uses a bending length tester to test the softness of the radiation-proof fabric.

[0031] The present invention refers to GBZ / T 147-2002 "Determination of Attenuation Performance of X-ray Protection Materials" and uses an X-ray air kerma (protection level) standard device to test the radiation protection performance of the radiation-proof fabric, with a measurement range of 1.0×10 -5 ~1.0 Gy / h.

[0032] Example 1

[0033] This example provides a method for preparing a radiation-proof coating based on emulsion polymerization, specifically as follows:

[0034] Stir acrylic acid (unsaturated carboxylic acid), acrylonitrile (monomer containing a double bond), and bismuth oxide (ionizing radiation-proof metal oxide) evenly according to a molar ratio of 6:2:1, react at 60 °C for 2 h, and reflux and condense to obtain a clear liquid, which is an ionizing radiation-proof metal unsaturated carboxylate solution;

[0035] By weight, take 5 parts of the clear liquid, 10 parts of deionized water, 0.3 part of sodium dodecyl sulfate (emulsifier), 0.07 part of potassium persulfate (water-soluble initiator), and 0.04 part of sodium hydroxide, stir evenly, react at 70 °C for 1.5 h, and obtain the radiation-proof coating after the reaction ends.

[0036] The radiation-proof fabric obtained by coating the coating prepared in Example 1 on the fabric is as Figure 1As shown, it can be seen that the radiation - proof coating prepared by the present invention can be well combined with the fabric. There are no cracks on the surface of the fabric coated with the radiation - proof coating, which enables the fabric to still maintain a high radiation - proof performance after multiple washings and has a long service life.

[0037] Example 2

[0038] This example provides a preparation method of a radiation - proof coating based on emulsion polymerization. The difference from Example 1 is that the molar ratio of unsaturated carboxylic acid, monomer containing double bond, and anti - ionization radiation metal oxide is adjusted to 6:4:1, and the rest of the preparation processes are the same as those in Example 1, and the radiation - proof coating of this example is prepared.

[0039] Example 3

[0040] This example provides a preparation method of a radiation - proof coating based on emulsion polymerization. The difference from Example 1 is that the molar ratio of unsaturated carboxylic acid, monomer containing double bond, and anti - ionization radiation metal oxide is adjusted to 6:6:1, and the rest of the preparation processes are the same as those in Example 1, and the radiation - proof coating of this example is prepared.

[0041] The coatings prepared in Examples 1 - 3 are coated on the fabric to obtain radiation - proof fabrics, and the softness, radiation - proof property, and service life of the radiation - proof fabrics are tested. The results are shown in Table 1.

[0042] Table 1 Influence of acrylonitrile dosage on the performance of radiation - proof fabrics

[0043]

[0044] According to Table 1, the radiation - proof fabrics prepared by coating the coatings obtained by the preparation method of the present invention on the fabric all have a high ray protection efficiency. The protection efficiency can still reach more than 80% after 10 washings and can be used for a long time. With the increase of acrylonitrile dosage, the softness of the radiation - proof fabric decreases slightly.

[0045] Comparative Example 1

[0046] This comparative example provides a preparation method of a radiation - proof coating based on emulsion polymerization. The difference from Example 1 is that the molar ratio of unsaturated carboxylic acid, monomer containing double bond, and anti - ionization radiation metal oxide is adjusted to 6:8:1, and the rest of the preparation processes are the same as those in Example 1, and the radiation - proof coating of this comparative example is prepared.

[0047] Comparative Example 2

[0048] This comparative example provides a preparation method of a radiation - resistant coating based on emulsion polymerization. The difference from Example 1 is that the molar ratio of unsaturated carboxylic acid, monomer containing double bond, and anti - ionization radiation metal oxide is adjusted to 6:10:1, and the rest of the preparation processes are the same as those in Example 1, thus obtaining the radiation - resistant coating of this comparative example.

[0049] Comparative Example 3

[0050] This comparative example provides a preparation method of a radiation - resistant coating based on emulsion polymerization. The difference from Example 1 is that acrylonitrile is not added, and the rest of the preparation processes are the same as those in Example 1, and the radiation - resistant coating of this comparative example cannot be prepared.

[0051] The coatings prepared in Comparative Examples 1 - 3 were coated on fabrics to obtain radiation - resistant fabrics, and the softness, radiation resistance, and service life of the radiation - resistant fabrics were tested. The results are shown in Table 2.

[0052] Table 2 Influence of acrylonitrile dosage on the performance of radiation - resistant fabrics

[0053]

[0054]

[0055] It can be seen from Table 2 that too high an acrylonitrile dosage leads to a significant reduction in the protection efficiency. After multiple washings, the protection efficiency is reduced to 75%, the service life is shortened, and the prepared radiation - resistant fabric becomes significantly harder. On the contrary, without adding acrylonitrile, the radiation - resistant coating cannot be prepared.

[0056] Example 4

[0057] This example provides a preparation method of a radiation - resistant coating based on emulsion polymerization, specifically:

[0058] Stir acrylic acid and europium oxide evenly according to a molar ratio of 7:1, react at 60 °C for 2 h, and reflux and condense to obtain europium acrylate;

[0059] By weight, take 2 parts of europium acrylate, 10 parts of deionized water, 0.1 part of sodium dodecyl sulfonate, 0.5 part of OP - 10, 0.05 part of ammonium persulfate, 0.1 part of dibutyl phthalate, and 0.2 part of polyvinyl alcohol, stir evenly, and react at 60 °C for 2 h. After the reaction, a radiation - resistant coating is obtained.

[0060] Example 5

[0061] This example provides a preparation method of a radiation - resistant coating based on emulsion polymerization. The difference from Example 4 is that the amount of europium acrylate is adjusted to 4 parts, and the rest of the preparation processes are the same as those in Example 4, thus obtaining the radiation - resistant coating of this example.

[0062] Example 6

[0063] This example provides a method for preparing a radiation - resistant coating based on emulsion polymerization. The difference from Example 4 is that the amount of europium acrylate is adjusted to 6, and the rest of the preparation process is the same as that of Example 4, obtaining the radiation - resistant coating of this example.

[0064] The coatings prepared in Examples 4 - 6 were coated on fabrics to obtain radiation - resistant fabrics, and the softness, radiation resistance, and service life of the radiation - resistant fabrics were tested. The results are shown in Table 3.

[0065] Table 3 Influence of the dosage of metal unsaturated carboxylates for anti - ionizing radiation on the properties of radiation - resistant fabrics

[0066]

[0067] As can be seen from Table 3, based on the preparation method of the present invention, the coating prepared with europium acrylate as the metal unsaturated carboxylate for anti - ionizing radiation can also achieve high ray protection efficiency and long service life when used for radiation - resistant fabrics. With the increase in the amount of europium acrylate, the protection efficiency has a certain increase. When the amount of europium acrylate is 6 parts, the protection efficiency reaches the highest 90.2%, and the protection efficiency can still reach 87.5% after 10 washes. At this time, the prepared radiation - resistant fabric maintains good softness.

[0068] Comparative Example 4

[0069] This comparative example provides a method for preparing a radiation - resistant coating based on emulsion polymerization. The difference from Example 4 is that the amount of europium acrylate is adjusted to 8, and the rest of the preparation process is the same as that of Example 4, obtaining the radiation - resistant coating of this example.

[0070] Comparative Example 5

[0071] This comparative example provides a method for preparing a radiation - resistant coating based on emulsion polymerization. The difference from Example 4 is that the amount of europium acrylate is adjusted to 10, and the rest of the preparation process is the same as that of Example 4, obtaining the radiation - resistant coating of this example.

[0072] The coatings prepared in Comparative Examples 4 - 5 were coated on fabrics to obtain radiation - resistant fabrics, and the softness, radiation resistance, and service life of the radiation - resistant fabrics were tested. The results are shown in Table 4.

[0073] Table 4 Influence of the dosage of metal unsaturated carboxylates for anti - ionizing radiation on the properties of radiation - resistant fabrics

[0074]

[0075] Combined with Table 3 and Table 4, it is obvious that when the dosage of europium acrylate reaches 8 - 10 parts, it will cause a significant reduction in the softness of the radiation protection fabric. At this time, compared with the case where the dosage of europium acrylate is 6, the protection efficiency begins to decrease, and the protection efficiency after 10 washes also begins to decrease. Thus, it can be seen that only with an appropriate dosage of europium acrylate can a radiation protection fabric with both protection efficiency, softness, and service life be prepared.

[0076] Comparative Example 6

[0077] This comparative example provides a conventional preparation method for a radiation protection coating, specifically as follows:

[0078] By weight, 2 parts of europium oxide are mixed evenly with 1 part of polyurethane emulsion to prepare the radiation protection coating of this comparative example.

[0079] The coating prepared in Comparative Example 6 is coated on the fabric to obtain a radiation protection fabric, and the softness, radiation protection property, and service life of the radiation protection fabric are tested. The results are shown in Table 5 and Figure 2 as follows.

[0080] Table 5 Influence of different preparation methods on the properties of radiation protection fabrics

[0081]

[0082]

[0083] The conventional preparation method is to coat a radiation protection coating prepared by dispersing metal oxide particles in a polymer emulsion on the fabric to obtain a radiation protection fabric. It can be seen from Table 5 that compared with the conventional method, the protection efficiency of the preparation method of the present invention is increased by more than 10%, and the protection efficiency is increased by about 20% after multiple washes. This is because the metal oxide used as a filler in the conventional preparation method is easily removed during washing, thus losing part of its radiation protection performance. At the same time, the radiation protection fabric prepared by the present invention has good softness, while the bending stiffness of the fabric prepared by the conventional preparation method is about 3 times that of the present invention.

[0084] From Figure 2 it can be seen that for the radiation protection fabric prepared by the conventional method, cracks appear on the surface, and the radiation protection metal oxide particles agglomerate. After multiple washes, the radiation protection efficiency will decrease significantly.

[0085] In summary, the present invention provides a radiation protection coating based on emulsion polymerization and its preparation method. By converting radiation protection metal particles into unsaturated dibasic acid monoester salts, the problem of the dispersion of radiation protection particles in the conventional method is completely solved; the present invention can freely adjust the formula to meet the requirements of different material fabrics for the coating hardness and bonding force, and the obtained radiation protection layer is resistant to washing and has good long-term use performance.

[0086] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a radiation-proof coating based on emulsion polymerization, characterized in that: include, An unsaturated carboxylic acid, a double bond-containing monomer, and an ionizing radiation-proof metal oxide are stirred for reaction, and then refluxed and condensed to obtain an ionizing radiation-proof metal unsaturated carboxylate solution; By weight, 2 to 10 parts of an ionizing radiation-proof metal unsaturated carboxylate solution, 1 to 100 parts of deionized water, 0.1 to 0.5 parts of an emulsifier, 0.01 to 0.1 parts of a water-soluble initiator, and 0 to 5 parts of an auxiliary agent are mixed evenly, and an emulsion polymerization reaction is carried out to obtain a radiation-proof coating.

2. The method for preparing the radiation-proof coating based on emulsion polymerization according to claim 1, characterized in that: The unsaturated carboxylic acid is an unsaturated carboxylic acid containing a carboxyl group and a carbon-carbon double bond.

3. The method for preparing the radiation-proof coating based on emulsion polymerization according to claim 2, characterized in that: The unsaturated carboxylic acid containing a carboxyl group and a carbon-carbon double bond includes one or more of acrylic acid, methacrylic acid, maleic acid, and undecylenic acid.

4. The method for preparing the radiation-proof coating based on emulsion polymerization according to claim 1, characterized in that: The ionizing radiation protection metal oxide includes one of bismuth oxide, tungsten oxide, lanthanum oxide, gadolinium oxide and europium oxide.

5. The method for preparing the radiation-proof coating based on emulsion polymerization according to claim 1, characterized in that: The monomer containing double bonds includes one of acrylic acid, methyl methacrylate, acrylonitrile and vinyl acetate.

6. The method for preparing the radiation protection coating based on emulsion polymerization according to claim 1, characterized in that: The molar ratio of the unsaturated carboxylic acid, the double bond-containing monomer and the ionizing radiation-proof metal oxide is 4-8:0-6:

1.

7. The method for preparing the radiation-proof coating based on emulsion polymerization according to claim 1, characterized in that: The unsaturated carboxylic acid, the monomer containing double bonds and the ionizing radiation-proof metal oxide are stirred for reaction at a temperature of 50 to 90° C. and a reaction time of 1 to 3 hours.

8. The method for preparing the radiation protection coating based on emulsion polymerization according to claim 1, characterized in that: The water-soluble initiator includes one of ammonium persulfate, potassium persulfate and sodium persulfate.

9. A radiation protection coating prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the radiation-proof coating according to claim 9 in preparing functional fabrics for shielding ionizing radiation.

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