Radiation-shielding multi-layer coating and article with radiation-shielding multi-layer coating

Abstract

The present invention provides an article coated with a multi-layer coating that is applicable to various articles and has high radiation shielding properties. [Solution] An article 1 is coated with a radiation-shielding multilayer coating including at least (A) a radiation-shielding coating primer layer 3, (B) a radiation-shielding layer 4, and (C) a color-coating primer layer 5, wherein (A) the radiation-shielding coating primer layer contains at least organosiloxanes, an organometallic titanium compound, and an acrylic resin; (B) the radiation-shielding layer contains at least organosiloxanes, an organometallic titanium compound, an acrylic resin, and tungsten powder; and (C) the color-coating primer layer contains at least organosiloxanes, an organometallic titanium compound, an acrylic resin, and silicate oligomers.

Description

[Technical Field]

[0001] The present invention relates to a multi-layer coating including a radiation-shielding layer, and to an article, particularly protective eyewear, equipped with said multi-layer coating. [Background technology]

[0002] In the medical field, radiation is used in X-ray and CT scans and cancer radiation therapy. In such situations, protective glasses and clothing have traditionally been used to protect the eyes and body from radiation.

[0003] Patent Document 1 describes radiation protection glasses with lead-containing glass lenses and a frame made of a material containing lead, and by arranging metal plates in the side armor, upper visor, and lower visor of the frame, it is possible to provide sufficient shielding against radiation entering the eyeball from directions other than the front. However, the protective glasses described in Patent Document 1 have problems in that the heavy use of lead makes the glasses themselves heavy, making them unsuitable for long-term use, and also imposes limitations on the frame design. Patent Document 2 describes an apron-type protective clothing that is provided with a radiation shielding function by using a lead-containing resin sheet. However, although the protective clothing described in Patent Document 2 is relatively lightweight, it is heavy because it uses a lead-containing resin sheet, and prolonged use of the clothing places a great burden on the user. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-043642 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-189805 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a multi-layer coating that has excellent radiation shielding properties and can be applied to a variety of articles, and an article, particularly protective eyewear, that is provided with the multi-layer coating. [Means for solving the problem]

[0006] This invention consists of the following ideas: [1] A multilayer coating comprising at least (A) a radiation shielding coating primer layer, (B) a radiation shielding layer, and (C) a color coating primer layer, The radiation-shielding coating primer layer (A) contains at least an organosiloxane, an organometallic titanium compound, and an acrylic resin, the radiation-shielding layer (B) contains at least an organosiloxane, an organometallic titanium compound, an acrylic resin, and tungsten powder; The (C) color coating primer layer is a multi-layer coating containing at least organosiloxanes, organometallic titanium compounds, acrylic resins, and silicate oligomers. [2] The organosiloxanes are R 1 Si(OR 2 )3(R 1 Si(OR 2 )3(wherein, R 1 is an organic group having 1 to 8 carbon atoms, R 2 and are the same or different and represent an alkyl group having 1 to 5 carbon atoms), or a hydrolyzate or condensate thereof. [3] The multilayer coating according to [1], wherein the particle size of the tungsten powder is 3 to 10 μm. [4] The multilayer coating according to [1], wherein the silicate oligomers are polycondensates of tetramethoxysilane represented by Si(OCH3)4 or tetraethoxysilane represented by Si(OC2H5)4. [5] An article coated with the multilayer coating described in [1]. [6] The article according to [5], wherein the article is a plastic molded product, a metal molded product, or a fabric. [7] The article according to [6], wherein the plastic molded product is protective glasses. [Effects of the Invention]

[0007] The present invention provides a multi-layer coating that has sufficient radiation shielding properties and can be applied to a variety of articles, such as protective eyewear and clothing, which are lighter than conventional radiation protection articles and offer greater design flexibility. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of a multi-layer coating according to one embodiment of the present invention; [Figure 2] 1 is a photograph of protective glasses according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The coating of the present invention is a multi-layer coating with at least three layers, which include, from the substrate (article) side, (A) a radiation-shielding paint primer layer (hereinafter referred to as (A) layer), (B) a radiation-shielding layer (hereinafter referred to as (B) layer), and (C) a color-painting primer layer (hereinafter referred to as (C) layer). Each layer and its constituent components are described in detail below.

[0010] <(A) Layer: Radiation shielding coating base layer> Layer (A) is a layer containing at least organosiloxanes, an organometallic titanium compound, and an acrylic resin. Layer (A) is obtained by applying a composition for forming Layer (A) (hereinafter referred to as composition (a)) containing at least organosiloxanes, an organometallic titanium compound, an acrylic resin, and an organic solvent to the surface of an article and drying it, and serves to enhance adhesion between the article and Layer (B). Note that composition (a) preferably contains 1 to 10 wt% organosiloxanes, 0.1 to 0.5 wt% organometallic titanium compound, 30 to 40 wt% acrylic resin, and approximately 50 to 70 wt% organic solvent, with a solids concentration of 10 to 40 wt%. The method for preparing composition (a) can be to mix the above components and thoroughly disperse them using a roll mill, a ball mill, a stirrer, or the like, but is not limited to this preparation method. The composition (a) can be applied by any known method, such as brush coating, roller coating, spraying, etc. In this case, the composition (a) can be applied 1 to 5 times, preferably 1 time. In the case of multiple applications, a heating and drying treatment may be carried out after each application.

[0011] <(B) layer: Radiation shielding layer> Layer (B) contains at least organosiloxanes, an organometallic titanium compound, an acrylic resin, and tungsten powder, and has the function of shielding radiation. Layer (B) is obtained by mixing a composition for forming layer (B) (hereinafter referred to as composition (b)) containing at least organosiloxanes, an organometallic titanium compound, an acrylic resin, and an organic solvent with tungsten powder, applying the mixture onto layer (A), and drying. Composition (b) preferably contains 1 to 10 wt% organosiloxanes, 0.1 to 0.5 wt% organometallic titanium compound, 30 to 40 wt% acrylic resin, and approximately 50 to 70 wt% organic solvent, with a solids concentration of 10 to 40 wt%. The method for preparing composition (b) can be, but is not limited to, mixing the above components and dispersing them thoroughly using a roll mill, ball mill, stirrer, etc. Furthermore, when tungsten powder is added to composition (b), it is also desirable to disperse it thoroughly using a roll mill, ball mill, stirrer, etc. The mixing ratio of tungsten powder in composition (b) is 50 to 300 parts by weight, preferably 70 to 200 parts by weight, and most preferably about 100 parts by weight, per 100 parts by weight of composition (b). If the amount is less than 50 parts by weight, the radiation-shielding properties obtained will be poor, while if the amount exceeds 300 parts by weight, the specific gravity will be high and the composition will be heavy and the price will increase, which is not economical. The mixture of composition (b) and tungsten powder can be applied by any known method, such as brush coating or roller coating. The mixture of composition (b) and tungsten powder can be applied 1 to 5 times, preferably 2 to 3 times. When applying multiple coats, a heating and drying treatment may be performed after each coat.

[0012] <(C) Layer: Base layer for color painting> Layer (C) contains at least organosiloxanes, an organometallic titanium compound, an acrylic resin, and silicate oligomers, and functions to improve adhesion between Layer (B) and the color coating described below. Layer (C) is obtained by applying a composition for forming Layer (C) (hereinafter referred to as composition (c)) containing at least organosiloxanes, an organometallic titanium compound, an acrylic resin, silicate oligomers, and an organic solvent onto Layer (B) and drying the composition. Composition (c) preferably contains 20 to 40 wt% organosiloxanes, 0.1 to 5.0 wt% organometallic titanium compound, 1 to 10 wt% acrylic resin, 30 to 40 wt% silicate oligomers, and approximately 20 to 40 wt% organic solvent, with a solids concentration of 30 to 60 wt%. The method for preparing composition (c) can be to mix the above components and thoroughly disperse them using a roll mill, a ball mill, a stirrer, or the like, but is not limited to this preparation method. The composition (c) can be applied by any known method, such as brush coating, roller coating, spraying, etc. In this case, the composition (c) can be applied 1 to 5 times, preferably 1 time. In the case of multiple applications, a heating and drying treatment may be carried out after each application.

[0013] <Other layers> In the multilayer coating of the present invention, a color coating layer can be laminated on top of the (C) layer. Any layer that imparts functionality to the article can also be laminated. Furthermore, depending on the type of article and the type of color coating, the composition of compositions (a) and (c) can be changed depending on the characteristics of the article's substrate, and the (A) layer and / or the (C) layer can be omitted.

[0014] <Articles> The articles to which the multilayer coating of the present invention can be applied are not particularly limited, but suitable are plastic molded articles, metal molded articles, or fabrics for radiation shielding. Examples of such plastic molded articles include protective glasses, helmets, insoles, neck guards, etc.; examples of metal molded articles include screens, etc.; and examples of fabrics include protective clothing, protective gloves, protective draperies, protective underwear, protective curtains, etc.

[0015] <Organosiloxanes> In the present invention, compositions (a) to (c) contain organosiloxanes. The organosiloxanes are R 1 Si(OR 2 )3(wherein, R 1 is an organic group having 1 to 8 carbon atoms, R 2 are the same or different and represent an alkyl group having 1 to 5 carbon atoms), a hydrolyzate thereof, or a condensate thereof. Examples of trifunctional organoalkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, methyltrippropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrippropoxysilane, and ethyltributoxysilane, with methyltrimethoxysilane being preferred. One or more types of organosiloxanes can be used.

[0016] <Organometallic titanium compounds> In the present invention, compositions (a) to (c) contain an organometallic titanium compound that functions as a catalyst for the hydrolysis and condensation of organosiloxanes. Examples of the organometallic titanium compound that can be used include tetrapropoxytitanium (TPT) and tetrabutoxytitanate (TBT).

[0017] <Acrylic resin> In the present invention, compositions (a) to (c) contain an acrylic resin, which can be obtained by radical copolymerization of an acrylic monomer and another monomer copolymerizable with the acrylic monomer. Among these, the acrylic monomer is not particularly limited, but examples thereof include alkyl group-containing (meth)acrylic monomers such as methyl(meth)acrylate (representing either methyl acrylate or methyl methacrylate; the same applies hereinafter), ethyl(meth)acrylate, n-butyl(meth)acrylate, i-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and cyclohexyl(meth)acrylate; hydroxyl group-containing (meth)acrylic monomers such as 2-hydroxyethyl(meth)acrylate; ethylenically unsaturated carboxylic acids such as (meth)acrylic acid; amino group-containing (meth)acrylic monomers such as dimethylaminoethyl(meth)acrylate and dimethylaminopropyl(meth)acrylate; amide-containing (meth)acrylic monomers such as (meth)acrylamide and ethyl(meth)acrylamide; nitrile group-containing (meth)acrylic monomers such as acrylonitrile; and epoxy group-containing (meth)acrylic monomers such as glycidyl(meth)acrylate. Examples of other monomers copolymerizable with acrylic monomers include aromatic hydrocarbon vinyl monomers such as styrene, methylstyrene, chlorostyrene, and vinyltoluene; ethylenically unsaturated carboxylic acids such as maleic acid, itaconic acid, crotonic acid, fumaric acid, and citraconic acid; sulfonic acid-containing vinyl monomers such as styrene sulfonic acid and vinyl sulfonic acid; acid anhydrides such as maleic anhydride and itaconic anhydride; chlorine-containing monomers such as vinyl chloride, vinylidene chloride, and chloroprene; hydroxyl group-containing alkyl vinyl ethers such as hydroxyethyl vinyl ether and hydroxypropyl vinyl ether; alkylene glycol monoallyl ethers such as ethylene glycol monoallyl ether, propylene glycol monoallyl ether, and diethylene glycol monoallyl ether; α-olefins such as ethylene, propylene, and isobutylene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl pivalate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether; and allyl ethers such as ethyl allyl ether and butyl allyl ether. The acrylic resin can be obtained, for example, by emulsion polymerization. The emulsion polymerization method is not particularly limited, and can be produced by a conventionally known method in which the monomers are polymerized in an aqueous medium in a dispersion system containing the above-mentioned monomers, a chain transfer agent, a surfactant, a radical polymerization initiator, and other additive components used as necessary as basic components to produce an emulsion.

[0018] <Tungsten powder> In the present invention, tungsten powder is used to impart radiation shielding properties to the multi-layer coating. The tungsten powder used in this invention includes not only pure tungsten powder, but also tungsten alloys (for example, those with tungsten as the main component and a binder layer made of nickel, copper, iron, etc.), tungsten compounds such as tungsten oxide, and powders of tungsten particles coated with other materials, which can be called tungsten-based metal powders. Tungsten powder is usually produced by hydrogen reduction of oxide. The particle size of the tungsten powder is determined by the size of the oxide used and the reduction conditions. The particle size of the tungsten powder used in the present invention is usually 3 to 10 μm, preferably about 3.5 μm. In addition, commercially available tungsten powder can also be used as the tungsten powder of the present invention.

[0019] <Silicate oligomers> The silicate oligomers used in this invention are oligomers obtained by polycondensation of tetraalkoxysilanes, such as methyl silicate oligomers obtained by polycondensation of tetramethoxysilane represented by Si(OCH3)4, or ethyl silicate oligomers obtained by polycondensation of tetraethoxysilane represented by Si(OC2H5)4. Commercially available silicate oligomers include methyl silicate 51, methyl silicate 53, and ethyl silicate 40 (all manufactured by Colcoat Co., Ltd.).

[0020] <Organic solvents> The organic solvent used in the present invention is not particularly limited, but examples thereof include alcohol-based solvents such as methanol, ethanol, 2-propanol (isopropyl alcohol), and tert-butanol; ether-based solvents such as diethyl ether, diisopropyl ether, tetrahydrofuran, methylcyclopentyl ether, and 1,4-dioxane; aromatic hydrocarbon-based solvents such as benzene, toluene, chlorobenzene, anisole, and xylene; ester-based solvents such as ethyl acetate and methyl acetate; aprotic solvents such as acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, and dimethyl sulfoxide; and mixtures thereof, with 2-propanol (isopropyl alcohol) and ethyl acetate being preferred.

[0021] <Other ingredients> In addition to the above, compositions (a) to (c) of the present invention may contain appropriate amounts of components commonly used in coating compositions, such as fillers, surfactants, dispersants, antifoaming agents, anti-settling agents, pH adjusters, and wetting adjusters. [Example]

[0022] The present invention will be explained in more detail below with reference to examples.

[0023] Reference Example 1: Preparation of composition (a) The components were mixed and stirred according to the following formulation to prepare an emulsion composition (a). Composition (a) Formulation Isopropyl alcohol 55.13% → Acrylic acid ester polymer NK 11% Acrylic ester polymer KE 29% MTMS 4.8% TPT 0.06% H2O20.01%

[0024] Reference Example 2: Preparation of composition (b) The components were mixed and stirred according to the following formulation to prepare an emulsion composition (b). Composition (b) Formulation Ethyl acetate 50% Acrylic ester 33.33% Isopropyl alcohol 14.25% MTMS 2.39% TPT 0.025% H2O20.005%

[0025] Reference Example 3: Preparation of composition (c) The components were mixed and stirred according to the following formulation to prepare an emulsion composition (c). Composition (c) Formulation Isopropyl alcohol 28% MTMS 31.72% TPT 3% Acrylic acid ester polymer KE 1.7% Methyl silicate MS 34% Platinum catalyst 0.01% TPR silicone 1.39% TSF silicone oil 0.18%

[0026] Example: Fabrication of protective eyewear with multi-layer coating The composition (a) prepared in Reference Example 1 was applied to a plastic protective eyeglass frame with a brush at approximately 1 g per frame, and then allowed to dry naturally at room temperature for 30 minutes, followed by mechanical drying at 70°C for 45 minutes, forming a layer (A) on the surface of the protective eyeglass frame. Next, an equal amount of tungsten powder (manufactured by Toho Metals Co., Ltd., particle size: 3.5 μm) was added to the composition (b) prepared in Reference Example 2 and stirred. The mixture was applied three times with a brush to the protective eyeglass frames having the above-mentioned layer (A) at approximately 4 g per frame, and each application was allowed to air dry at room temperature for 15 minutes. After the third application, the mixture was air dried at room temperature for 1 hour, and then mechanically dried at 80°C for 10 minutes. This process formed layer (B) on the surface of the protective eyeglass frames. Next, the composition (c) prepared in Reference Example 3 was applied with a brush to the protective eyeglass frames having the above-mentioned layer (B) at a rate of 5 g per frame, and the frames were allowed to dry naturally at room temperature for 1 hour, followed by mechanical drying at 80°C for 45 minutes to form layer (C) on the surface of the protective eyeglass frames. The surfaces were then color-painted with a cup gun (nozzle diameter: 1.0 mm) to complete the coating. The cross-sectional structure of the multi-layer coating of the present invention, which is made up of three layers, is shown in FIG. Figure 2 shows the measurement data for the protection rate of coated safety glasses. [Industrial Applicability]

[0027] The multi-layer coating obtained by this invention has a high radiation shielding effect, so by applying it to various articles, various tools with excellent radiation shielding properties can be obtained. Examples of articles include frames or lenses of protective glasses, helmets, hats, insoles, neck guards, partitions, protective clothing, protective gloves, protective aprons, protective drapes, protective underwear, protective curtains, wallpaper, building materials, etc. Depending on the type of article, the compounds in the liquid formulations of Layer (A) and / or Layer (C) may be changed for the intended article or may be omitted.

[0028] 1. Articles with multi-layer coatings for radiation shielding 2 Goods 3 layers (A) 4 layers (B) 5 layers (C) 6 color paint layers 7. Multilayer coating for radiation shielding

Claims

1. A radiation-shielding multi-layer coating comprising at least (A) a base layer for radiation-shielding paint, (B) a radiation-shielding layer, and (C) a base layer for color paint, The radiation-shielding coating primer layer (A) contains at least an organosiloxane, an organometallic titanium compound, and an acrylic resin, the radiation-shielding layer (B) contains at least an organosiloxane, an organometallic titanium compound, an acrylic resin, and tungsten powder; The radiation-shielding multi-layer coating (C) contains at least an organosiloxane, an organometallic titanium compound, an acrylic resin, and a silicate oligomer.

2. The organosiloxanes are R １ Si(OR ２ ) ３ (In the formula, R １ is an organic group having 1 to 8 carbon atoms, R ２ and R 1 and R 2 are the same or different and represent an alkyl group having 1 to 5 carbon atoms, or a hydrolyzate or condensate thereof.

3. 2. The radiation shielding multi-layer coating according to claim 1, wherein the particle size of the tungsten powder is 3 to 10 μm.

4. The silicate oligomers are Si(OCH ３ ) ４ Tetramethoxysilane or Si(OC ２ H ５ ) ４ 2. The radiation-shielding multi-layer coating according to claim 1, wherein the tetraethoxysilane is a polycondensate of tetraethoxysilane represented by the formula:

5. An article coated with the radiation shielding multi-layer coating of claim 1.

6. 6. The article according to claim 5, wherein the article is a plastic molded article, a metal molded article, or a fabric.

7. 7. The article of claim 6, wherein the plastic molded article is a pair of safety glasses.

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