WO2014119743A1 - Radiation-shielding material containing boron compound and/or lead - Google Patents

Abstract

The purpose of the present invention is to provide a radiation-shielding material which is easy to mold and can be molded into a desired shape. This radiation-shielding material is obtained by mixing the following ingredients (1) to (4), and ingredient (1), a mixture of ingredient (2) and water, ingredient (3), and ingredient (4) are contained therein each in an amount of 5-95 wt%: (1) a composition including a polymer ingredient which comprises a homopolymer of vinyl acetate, a product of partial hydrolysis of the homopolymer, a copolymer of vinyl acetate and one or more monomers selected from the group consisting of acrylic esters, acrylamide, acrylic acid, methacrylic acid, methacrylic esters, maleic acid, maleic anhydride, and fumaric acid, or a product of partial hydrolysis of the copolymer; (2) sap; (3) a boron compound and/or a lead powder; and (4) a silicone compound.

Description

Radiation shielding material containing boron compound and / or lead

The present invention relates to a radiation shielding material capable of shielding and absorbing radiation, which has viscosity and plasticity when wet, has elasticity when solidified, and can be molded into an arbitrary shape. The present invention also relates to a radiation shielding material capable of shielding and absorbing radiation, which has viscosity and plasticity when wet and becomes a film when solidified.

A material composition which contains a polymer containing vinyl acetate, has viscosity and plasticity when wet, and has elasticity when solidified is known, and is used for various applications by mixing metal powder and the like (Patent Document 1, etc.) See).

In addition, a material composition that contains a polymer containing vinyl acetate, has viscosity and plasticity when wet, and becomes a film when solidified is known, and is used for a printing film or the like (see Patent Document 2). .

WO2003 / 095553 International Publication Pamphlet JP 2009-298003 JP

The present invention aims to provide a radiation shielding material that is easy to mold and can be molded into an arbitrary shape.

The present inventors include a polymer containing vinyl acetate, have viscosity and plasticity when wet, and absorb neutrons by mixing a boron compound or lead powder into a material composition that has elasticity when solidified, and A radiation shielding material that shields radiation by blocking α rays, β rays, and γ rays was manufactured, and the present invention was completed.

That is, the present invention is as follows.

[1] A radiation shielding material obtained by mixing the following components (1) to (4), which is a mixture of component (1), component (2) and water, component (3) and component (4) Radiation shielding material containing 5 to 95% by weight in any case:
(1) Vinyl acetate homopolymer or partially hydrolyzed product thereof, or vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumaric acid A composition comprising a polymer component comprising a copolymer with one or two or more monomers selected from the group or a partial hydrolyzate thereof,
(2) sap,
(3) Boron compound, lead powder, or boron compound and lead powder, and (4) silicone compound.

[2] Component (1) has a solid content of 45 to 60 Wt%, and contains a copolymer composed of vinyl acetate and acrylate in the solid content, and the weight ratio of vinyl acetate and acrylate is 75 to 85:15 The content of the copolymer of vinyl acetate and acrylate in the solid content is 80 to 95 Wt%, 4 to 6 Wt% of nonylphenol EO adduct and 1 to 2 Wt as a surfactant in the solid content. The radiation shielding material according to [1], which is a polymer containing vinyl acetate containing 1% polyethylene glycol.

[3] The radiation shielding material according to [2], wherein the acrylate is n-butyl acrylate.

[4] The radiation shielding material according to any one of [1] to [3], wherein the sap is birch sap.

[5] A mixture of component (1), component (2) and water is obtained by mixing component (1), component (2) and water in a volume ratio of 4 to 8: 1: 1 to 3, The radiation shielding material according to any one of [1] to [4].

[6] The radiation shielding material according to any one of [1] to [5], wherein the silicone compound is a silicone sealant.

[7] The radiation shielding material according to any one of [1] to [6], wherein the boron compound is boric acid.

[8] The radiation shielding material according to any one of [1] to [7], wherein boric acid shields neutron rays and lead powder shields α rays, β rays, and γ rays.

[9] A radiation shielding material for shielding neutron beams obtained by mixing the following components (1) to (3), comprising a mixture of component (1), component (2) and water, and component (3) Radiation shielding material containing 5 to 95% by weight in any case:
(1) Vinyl acetate homopolymer or partially hydrolyzed product thereof, or vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumaric acid A composition comprising a polymer component comprising a copolymer with one or two or more monomers selected from the group or a partial hydrolyzate thereof,
(2) sap,
(3) Boron compound.

[10] Component (1) has a solid content of 45 to 60 Wt%, and contains a copolymer composed of vinyl acetate and acrylate in the solid content, and the weight ratio of vinyl acetate and acrylate is 75 to 85:15 The content of the copolymer of vinyl acetate and acrylate in the solid content is 80 to 95 Wt%, 4 to 6 Wt% of nonylphenol EO adduct and 1 to 2 Wt as a surfactant in the solid content. The radiation shielding material according to [9], which is a polymer containing vinyl acetate containing 1% polyethylene glycol.

[11] The radiation shielding material according to [10], wherein the acrylate is n-butyl acrylate.

[12] The radiation shielding material according to any one of [9] to [11], wherein the sap is birch sap.

[13] A mixture of component (1), component (2) and water is obtained by mixing component (1), component (2) and water in a volume ratio of 4 to 8: 1: 1 to 3, [9] The radiation shielding material according to any one of [12].

[14] The radiation shielding material according to any one of [9] to [13], which is in the form of a film.

[15] A radiation shielding material obtained by mixing the following components (3) and (4), wherein the component (3) and the component (4) are contained in an amount of 5 to 95% by weight. Radiation shielding material:
(3) Boron compound, lead powder, or boron compound and lead powder, and (4) silicone compound.

[16] The radiation shielding material according to [15], wherein the silicone compound is a silicone sealant.

[17] The radiation shielding material according to [15] or [16], wherein the boron compound is boric acid.

[18] The method for producing a radiation shielding material according to any one of [1] to [8], comprising mixing the following components (1) to (4):
(1) Vinyl acetate homopolymer or partially hydrolyzed product thereof, or vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumaric acid A composition comprising a polymer component comprising a copolymer with one or two or more monomers selected from the group or a partial hydrolyzate thereof,
(2) sap,
(3) Boron compound, lead powder, or boron compound and lead powder, and (4) silicone compound.

[19] A method for producing a radiation shielding material for shielding a neutron beam according to any one of [9] to [14], comprising mixing the following components (1) to (3):
(1) Vinyl acetate homopolymer or partially hydrolyzed product thereof, or vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumaric acid A composition comprising a polymer component comprising a copolymer with one or two or more monomers selected from the group or a partial hydrolyzate thereof,
(2) sap,
(3) Boron compound.

[20] The method for producing a radiation shielding material according to any one of [15] to [17], comprising mixing the following components (3) and (4):
(3) Boron compound, lead powder, or boron compound and lead powder, and (4) silicone compound.

This specification includes the contents described in the specification and / or drawings of Japanese Patent Application No. 2013-017536, which is the basis of the priority of the present application.

Since the radiation shielding material of the present invention contains a boron compound, it absorbs neutrons and shields neutron beams. Further, since the radiation shielding material of the present invention contains lead powder, the α, β, and γ rays are shielded by blocking the α, β, and γ rays. The radiation shielding material of the present invention can be molded into an arbitrary shape that is rich in plasticity and viscosity before solidification, and has a certain strength (hardness, resistance to cracking, resistance to cracking, etc.) and elasticity after solidification. However, it can be processed into an arbitrary shape and used as a radiation shielding material in various places and facilities. Moreover, since the characteristic of the radiation shielding material of this invention can be changed suitably by changing the component mixing ratio, the radiation shielding material which has a desired characteristic according to a use can be obtained. Moreover, the film-form radiation shielding material of this invention can be affixed on various objects, and can exhibit the radiation shielding effect.

It is a figure which shows a composition of a radiation shielding material, a manufacturing method, and a radiation shielding effect.

Hereinafter, the present invention will be described in detail.
1. The composition of the radiation shielding material of the present invention The radiation shielding material of the present invention is obtained by mixing the following component (1), component (2), component (3), component (4) and water, or the following component ( It is obtained by mixing boron compound and water among 1), component (2) and component (3).

The radiation shielding material of the present invention includes those obtained by mixing the following components (3) and (4).

A. Ingredient (1)
Component (1) is a component containing a polymer containing vinyl acetate.

Component (1) is a homopolymer of vinyl acetate or a partial hydrolyzate thereof, or vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumarate A polymer component comprising a copolymer with one or two or more monomers selected from the group consisting of acids, or a partial hydrolyzate thereof.

Vinyl acetate homopolymer or partially hydrolyzed product thereof, or selected from the group consisting of vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumaric acid It is desirable that the polymer component including a copolymer with one or two or more monomers or a partial hydrolyzate thereof is in an emulsion state. In this sense, component (a) in component (1) of the present invention is an aqueous latex emulsion. Here, latex refers to an aqueous dispersion containing polymer or copolymer molecules.

An emulsion containing a homopolymer or copolymer of vinyl acetate can be obtained as a commercial product. For example, the following product groups sold at handicraft stores can be applied. “Bond for woodworking (made by Konishi, adhesive)”, “Motoposi (MOD ポ ジ PODGE) (made by PLAID, finishing agent)”, “Porea (made by PLAID, finishing agent)”, “Shine finish (Janty Co., Ltd.) Made, finishing agent) "," Hull Gloss (made by Hull Enterprise, finishing agent) "," Clear Poggi (made by American Handicraft, finishing agent) "," Top Coat Gloss (made by JANTY Co., Ltd., finishing agent) ", Product name "Transfer Coat (manufactured by JANTY Co., Ltd., transfer solution)", "Hull Transfer (manufactured by Halen Couprice Co., Ltd., transfer solution)", "Sun Finishe (manufactured by Sanyu Co., Ltd., finishing agent)" Is mentioned. Accordingly, the material of the present invention can include one or more of these commercially available products. Of these, MOTOPOSY is preferably used, and PLAID catalog ITEM # CS11222, CS11221, CS11220, CS11219, CS11218, CS11217, CS11213, CS11211, CS11201, CS11202, CS11203, CS11204, CS11205, CS11207, CS11301, CS11302, CS11303, etc. The following motoposi may be used. Further, latex emulsions described in US Pat. No. 3,616,005 can also be suitably used.

The vinyl acetate homopolymer used in the present invention is a conventionally known method in which a vinyl acetate monomer is appropriately diluted with an emulsifier, a polymerization initiator, a catalyst, a protective stabilizer, a plasticizer, and various additives and mixed. It can be easily obtained by emulsion polymerization.

A vinyl acetate copolymer is prepared by mixing a vinyl acetate monomer and a monomer (comonomer) to be copolymerized therewith, selecting an emulsifier, a polymerization initiator, a catalyst, a protective stabilizer, a plasticizer, and various additives as appropriate. Thus, it can be easily obtained by emulsion polymerization by a conventionally known method. In this case, one or more monomers selected from acrylic ester, acrylic amide, acrylic acid, methacrylic acid, methacrylic ester, maleic acid, maleic anhydride, and fumaric acid can be used as a comonomer. Is mentioned. Among these, preferable comonomer is an acrylate ester, acrylate amide, acrylic acid, methacrylic acid, judging from the viewpoint of the function that it can be easily shaped, processed and molded into an arbitrary shape of the obtained material and the plasticity and elasticity can be adjusted. One or more monomers selected from the group consisting of acids, methacrylic acid esters, maleic acid, maleic anhydride and fumaric acid. More preferred comonomers include one or more monomers selected from the group consisting of acrylic acid esters, acrylic acid amides, acrylic acid, methacrylic acid, methacrylic acid esters, maleic acid, and maleic anhydride. Particularly preferred comonomers include one or more monomers selected from the group consisting of acrylic acid esters, acrylic acid amides, acrylic acid, methacrylic acid, and methacrylic acid esters.

In addition, the component (1) may itself contain water, for example, an aqueous latex containing a non-volatile component, a vinyl acetate as a main component, and a copolymer containing a plasticizer or stabilizer such as dibutyl phthalate. It can be illustrated. Examples of such an aqueous latex include a non-volatile component, a copolymer containing vinyl acetate as a main component and acrylate as a minor component, and further mixed with dibutyl phthalate.

As the component (1) of the material composition of the present invention, for example, a film-forming emulsion composition described in International Publication WO02 / 24801 can be used. This film-forming emulsion composition has the component composition described in International Publication No. WO02 / 24801, and can be prepared according to the description in the publication.

In addition, component (1) is an emulsion containing a solid content. Solid content means what remained when the raw material component was vacuum-dried.

The component (1) containing a polymer containing vinyl acetate has a solid content of 30 to 80 Wt%, preferably 40 to 70 Wt%, more preferably 45 to 60 Wt%.

In the solid content of the component (1), a copolymer polymer composed of vinyl acetate and acrylate is included as an organic compound.

The weight ratio of vinyl acetate and acrylate is 70 to 90:10 to 30, preferably 75 to 85:15 to 25. The content of the copolymer of vinyl acetate and acrylate in the solid content is 75 to 95 Wt%, preferably 85 to 95 Wt%.

As acrylates, acrylic acid, methacrylic acid, butyl acrylate, butyl methacrylate, hexyl acrylate, hexyl methacrylate, 2-ethylbutyl acrylate, 2-ethylbutyl methacrylate, isooctyl acrylate, isooctyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl Examples include methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, and tridecyl methacrylate. Among these, butyl acrylate (n-butyl acrylate) is preferable.

The chemical formula of vinyl acetate and n-butyl acrylate is shown in the following chemical formula I.

A vinyl acetate copolymer is prepared by mixing a vinyl acetate monomer and a monomer (comonomer) to be copolymerized therewith, and appropriately selecting an emulsifier, a polymerization initiator, a catalyst, a protective stabilizer, a plasticizer, and various additives. It is easily obtained by mixing and emulsion polymerization by a known method.

Further, the solid content of the component (1) includes a nonionic surfactant as a surfactant. As a nonionic surfactant, chemical formula RO (—CH ₂ CH ₂ O—) nH (R is a hydrocarbon group or hydrogen) having an ethylene oxide group (—CH ₂ CH ₂ O—) as a hydrophilic group. An ether type nonionic surfactant represented by an oleophilic group, n represents the average number of moles of added ethylene oxide groups (average number of moles of EO added) and is 1 to 20, preferably 5 to 20. It is done. Examples of such ether type nonionic surfactants include nonylphenol EO adducts represented by the following chemical formula II and polyethylene glycols represented by the following chemical formula III. Component I may contain only nonylphenol EO adduct as a nonionic surfactant, or may contain nonylphenol EO adduct and polyethylene glycol.

n represents the average number of moles of ethylene oxide groups added, and is 1 to 20, preferably 5 to 20, and particularly preferably 13.

N represents the average number of moles of ethylene oxide groups added, and is 1 to 20, preferably 5 to 20.

The total content of the surfactant in the solid content of the component (1) is 1 to 10 Wt%, preferably 2.5 to 7.5 Wt%, particularly preferably about 5 Wt%. The content of the component (1) of the nonylphenol EO adduct represented by the above chemical formula II in the solid content is 1 to 8 Wt%, preferably 2 to 4 Wt%, particularly preferably about 3 Wt%. When polyethylene glycol is included as a surfactant, the total content of polyethylene glycol is about 1-2 Wt%.

The solid content of component (1) may further contain 2 to 10 Wt%, preferably 4 to 8 Wt% of at least one compound selected from the group consisting of propylene glycol, dipropylene glycol and ethylene glycol. .

Component (1) may be prepared by mixing components (1a) and (1b) described below.

Component (1a) contains vinyl acetate and has a solid content of 30 to 70 Wt%, preferably 40 to 60 Wt%, more preferably 45 to 55 Wt%, and particularly preferably 49 Wt%.

In the solid content of component (1a), a copolymer polymer composed of vinyl acetate and acrylate is included as an organic compound.

The weight ratio of vinyl acetate and acrylate is 70 to 90:10 to 30, preferably 75 to 85:15 to 25, and particularly preferably 80:20. The content of the copolymer of vinyl acetate and acrylate in the solid content is 75 to 95 Wt%, preferably 85 to 95 Wt%, preferably about 89 Wt%.

As acrylates, acrylic acid, methacrylic acid, butyl acrylate, butyl methacrylate, hexyl acrylate, hexyl methacrylate, 2-ethylbutyl acrylate, 2-ethylbutyl methacrylate, isooctyl acrylate, isooctyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl Examples include methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, and tridecyl methacrylate. Among these, butyl acrylate (n-butyl acrylate) is preferable.

A vinyl acetate copolymer is prepared by mixing a vinyl acetate monomer and a monomer (comonomer) to be copolymerized therewith, and appropriately selecting an emulsifier, a polymerization initiator, a catalyst, a protective stabilizer, a plasticizer, and various additives. It is easily obtained by mixing and emulsion polymerization by a conventionally known method.

Further, the solid content of the component (1a) contains a nonionic surfactant as a surfactant. As a nonionic surfactant, chemical formula RO (—CH ₂ CH ₂ O—) nH (R is a hydrocarbon group or hydrogen) having an ethylene oxide group (—CH ₂ CH ₂ O—) as a hydrophilic group. An ether type nonionic surfactant represented by an oleophilic group, n represents the average number of moles of ethylene oxide added (average number of moles of EO added), and is 1 to 20, preferably 5 to 20. Can be mentioned. Examples of such ether type nonionic surfactants include nonylphenol EO adducts represented by the following chemical formula II and polyethylene glycols represented by the following chemical formula III. Component I may contain only nonylphenol EO adduct as a nonionic surfactant, or may contain nonylphenol EO adduct and polyethylene glycol.

The total content of the surfactant in the solid content of the component (1a) is 1 to 10 Wt%, preferably 2.5 to 7.5 Wt%, particularly preferably about 5 Wt%. Further, the content of the component (1a) of the nonylphenol EO adduct represented by the above chemical formula II in the solid content is 1 to 8 Wt%, preferably 2 to 4 Wt%, particularly preferably about 3 Wt%. When polyethylene glycol is included as a surfactant, the total content of polyethylene glycol is about 1-2 Wt%.

The solid content of the component (1a) may further contain 2 to 10 Wt%, preferably 4 to 8 Wt%, particularly preferably about 6 Wt% of propylene glycol and ethylene glycol.

The component (1) containing a polymer containing vinyl acetate has a solid content of 35 to 75 Wt%, preferably 45 to 65 Wt%, more preferably 50 to 60 Wt%, and particularly preferably 54 Wt%.

In the solid content of the component (1b), a copolymer polymer composed of vinyl acetate and acrylate is included as an organic compound.

The weight ratio of vinyl acetate and acrylate is 75 to 95: 5 to 25, preferably 77.5 to 87.5: 12.5 to 22.5, particularly preferably 83:17. The content of the copolymer of vinyl acetate and acrylate in the solid content is 80 to 95 Wt%, preferably 85 to 95 Wt%, preferably about 91 Wt%.

As acrylates, acrylic acid, methacrylic acid, butyl acrylate, butyl methacrylate, hexyl acrylate, hexyl methacrylate, 2-ethylbutyl acrylate, 2-ethylbutyl methacrylate, isooctyl acrylate, isooctyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl Examples include methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, and tridecyl methacrylate. Among these, butyl acrylate (n-butyl acrylate) is preferable.

A vinyl acetate copolymer is prepared by mixing a vinyl acetate monomer and a monomer (comonomer) to be copolymerized therewith, and appropriately selecting an emulsifier, a polymerization initiator, a catalyst, a protective stabilizer, a plasticizer, and various additives. It is easily obtained by mixing and emulsion polymerization by a conventionally known method.

Further, the solid content of the component (1b) contains a nonionic surfactant as a surfactant. As a nonionic surfactant, chemical formula RO (—CH ₂ CH ₂ O—) nH (R is a hydrocarbon group or hydrogen) having an ethylene oxide group (—CH ₂ CH ₂ O—) as a hydrophilic group. An ether type nonionic surfactant represented by an oleophilic group, n represents the average number of moles of added ethylene oxide groups (average number of moles of EO added) and is 1 to 20, preferably 5 to 20. It is done. A preferred ether type nonionic surfactant is nonylphenol EO adduct.

The total content of the surfactant in the solid content of the component (1b) is 0.5 to 5 Wt%, preferably 1 to 5 Wt%, particularly preferably 1 to 2 Wt%.

The solid content of component (1b) may further contain 2 to 10 Wt%, preferably 4 to 8 Wt%, particularly preferably about 6 Wt% of propylene glycol, dipropylene glycol and ethylene glycol.

Component (1) has a solid content of 45 to 60 Wt%, preferably a solid content of 45 to 55 Wt%, more preferably a solid content of 50 Wt%, and a copolymer comprising vinyl acetate and acrylate in the solid content. The weight ratio of vinyl acetate and acrylate is 75 to 85:15 to 25, and the content of the copolymer of vinyl acetate and acrylate in the solid content is 80 to 95 Wt%, preferably 90 Wt%. A polymer containing vinyl acetate containing 4 to 6 Wt%, preferably 4.5 to 5.5 Wt%, more preferably 5 wt% nonylphenol HO adduct and 1 to 2 Wt% polyethylene glycol as a surfactant in the solid content. You can also.

The component (1), component (1a) and component (1b), which are components of the radiation shielding material of the present invention, can be subjected to composition analysis, for example, by the following method. About 1 g of the sample stock solution of the above components is weighed into a petri dish and vacuum-dried at 50 ° C. for 2 hours to measure the solid content.

The above components can be separated into an additive component and a polymer component, and the additive component can be further subjected to preparative gas chromatography and subjected to composition analysis by a method of performing spectrum measurement.

The sample stock solution of the above components is diluted twice with water and then ultracentrifuged to separate into a supernatant and a precipitate, and the supernatant is freeze-dried to obtain a soluble component.

It is possible to analyze the components in the solvent by diluting the sample stock solution of the above components with acetone and performing GC and GC / MS measurement.

Investigate IR and NMR for soluble components obtained by centrifugation. By the analysis, the presence of ethylene glycol (EG) and propylene glycol (PG) can be estimated, and the absorption of the ester component (polymer) can be observed.

Chloroform extraction is performed on the soluble fraction by centrifugation, and the soluble fraction and the insoluble fraction are separated, and IR and NMR analyzes are performed on the chloroform soluble fraction.

Furthermore, the chloroform-soluble matter is fractionated by chloroform-based GPC. The analysis can analyze the polymer mixture.

B. Ingredient (2)
The component (2) is a component containing one or more selected from the group consisting of sap, fruit juice, nectar, honey and sugar.

“Sap” means a liquid component of a plant body, and sap of pine, white birch, persimmon, maple, sugar millet, sugar beet is preferable. Sap obtained from these plants can be used alone, or a mixture of two or more can be used. As the sap, one that naturally flows out from the surface of the plant body can be used, and one extracted from the plant body by various methods can also be used. For example, the surface of a tree such as a white birch can be used to leak sap, and a tube of an appropriate thickness is inserted into a trunk such as a white birch, and the liquid flowing through the plant body is collected and used. You can also. Further, the sap thus obtained may be used after, for example, filtering to remove solid components. As long as a part of the components of the sap is included, it is included in the “sap” of the present invention. For example, commercially available birch sap may be used. Examples of the components of birch sap include fructose, glucose, amino acids, malic acid, polysaccharides (Kirelan), glycosides (syringarezinol), and other minerals. The composition of white birch sap varies depending on the time and place of collection.

Artificial sap containing the main component of sap can be used instead of sap.

For example, birch sap contains a relatively large amount of fructose, glucose, a small amount of arabinose, xylose, mannose, galactose as a monosaccharide, a small amount of sucrose, maltose, and lactose as a disaccharide, and a small amount of xylitol as a sugar alcohol, Contains sorbitol, mannitol, maltitol. Of these, fructose and glucose are contained in 0.02g / 100g to 1g / 100g, and arabinose, xylose, mannose, galactose, sucrose, maltose, lactose, xylitol, sorbitol, mannitol, maltitol are contained in less than 0.02g / 100g. It is. Furthermore, Ca ²⁺ (5 mg / L to 150 mg / L), Mg ²⁺ (1 mg / L to 30 mg / L), K ⁺ (50 mg / L to 250 mg / L), Na ⁺ (0.1 mg / L to 10 mg / L) L) and other cations, SO ₄ ^2- (2 mg / L to 200 mg / L), NO ^3- (0 mg / L to 30 mg / L), Cl ⁻ (0.5 mg / L to 10 mg / L), P ⁻ ( Contains anions such as 10 mg / L to 150 mg / L) and HCO ³⁻ (0 mg / L to 1000 mg / L). The contents in parentheses indicate the concentration of each ion.

The artificial sap is at least 0.02g / 100g-1g / 100g, preferably 0.2g / 100g-0.6g / 100g fructose and 0.02g / 100g-1g / 100g, preferably 0.1g / 100g-0.5g / 100g. Contains glucose. Furthermore, as a cation, 5 mg / L to 150 mg / L, preferably 5 mg / L to 100 mg / L Ca ²⁺ and / or 1 mg / L to 30 mg / L, preferably 1 mg / mL to 25 mg / mL Mg ^2+. May be included. Further, in addition to Ca ²⁺ and Mg ²⁺ , 50 mg / L to 250 mg / L K ⁺ and / or 0.1 mg / L to 10 mg / L Na ⁺ may be contained.

The above sap contains water (for example, white birch sap contains about 90 to about 95% water), and depending on the water content to be finally included in the material composition of the present invention, water is appropriately added. Or may be concentrated to reduce the water content. The pH of birch sap is weakly acidic to weakly alkaline, for example, pH 5 to pH 9, preferably pH 5 to 8, and more preferably pH 5.5 to 7.

The “saccharide solution” includes monosaccharides, disaccharides and polysaccharides, and examples thereof include fructose, glucose, sucrose, chitosan, chitin, mannan, guar gum, and xylitol. These sugars can be used alone, or a mixture of two or more can be used. Preferably, fructose and glucose are included, and more preferably only fructose and glucose are included. Moreover, either fructose or glucose may be contained. The fructose concentration contained in the “saccharide solution” of the present invention is 0.02 g / 100 g to 1 g / 100 g, preferably 0.2 g / 100 g to 0.6 g / 100 g, and the glucose concentration is 0.02 g / 100 g to 1 g / 100 g, preferably It is 0.1g / 100g-0.5g / 100g. Preferred is a solution of glucose and fructose containing glucose and fructose at the same concentration, and more preferred is a solution containing glucose and fructose at a concentration of 0.5 g / 100 g. The pH of the “saccharide solution” is weakly acidic to weakly alkaline, for example, pH 5 to pH 9, preferably pH 5 to 8, and more preferably pH 5.5 to 7.

C. Ingredient (3)
Component (3) is a boron compound, lead, or a boron compound and lead powder.

Boron compounds include boron carbide, boron nitride, boric anhydride (boric oxide), boron iron, perovskite, orthoboric acid, metaboric acid, etc. Among them, boric anhydride is preferable. Boric anhydride is a boron oxo acid represented by the chemical formula B (OH) ₃ and has the effect of absorbing neutrons. Lead can shield radiation such as α rays, β rays, and γ rays. In the present invention, the term including shielding is referred to as shielding. By combining the boron compound and the lead powder into the radiation shielding material of the present invention, α rays, β rays, γ rays and neutron rays generated by the nuclear reaction can be shielded.

The composition of the present invention may further contain a plasticizer, a storage stabilizer, a filler, a dye, a pigment, a fragrance, a light resistance agent, an oxidation stabilizer, and the like. Plasticizers, storage stabilizers, fillers, dyes, pigments, fragrances, light proofing agents, oxidation stabilizers, and the like may be mixed according to their purpose. For example, as the plasticizer, general-purpose products such as phthalate esters containing dibutyl phthalate are preferably used.

Also, other substances having a radiation shielding effect can be used instead of boron compounds and lead. For example, gold, tungsten, cadmium, etc. are mentioned. Of these, cadmium is effective in shielding neutrons.

D. Ingredient (4)
Component (4) is a component containing one or two compounds selected from the group consisting of a silicone compound, polyvinyl acetate, cetylmethylcellulose, and polyvinyl alcohol.

The component containing one or two compounds selected from the group consisting of a silicone compound, polyvinyl acetate, cetylmethyl cellulose and polyvinyl alcohol is a gel-like or paste-like component.

From the characteristics, the component of the radiation shielding material of the present invention is preferably a component containing a silicone compound. The silicone compound added to the radiation shielding material of the present invention is not limited to a specific silicone compound as long as it can impart properties such as viscosity and elasticity to the radiation shielding material of the present invention. A gel-like silicone compound is desirable. For example, those commercially available as silicone rubber, silicone resin, silicone elastomer, and RTV rubber can be used. Moreover, as a component containing a silicone compound, a commercially available silicone sealant (silicone sealing agent) and a silicone caulking agent can be used. As the sealant that can be used in the present invention, a sealant containing an oxime type or acetic acid type silicone resin as a main component and containing a filler, a crosslinking agent, or the like can be used. For example, there is a sealant agent mainly composed of silicone (organopolysiloxane). The silicone in the silicone compound used in the present invention is a bifunctional type having diorganosiloxane (R ₂ SiO) as its structural unit, and a trifunctional type having organosilsesquioxane (RSiO _1.5 ) as its structural unit. Those of the type or those in which these are mixed, and those containing tetrafunctional type having silicate (SiO ₂ ) as a structural unit are preferred. In particular, those containing a trifunctional type or a tetrafunctional type are preferable as the component (4) of the radiation shielding material of the present invention because a dense three-dimensional network structure can be taken.

In addition, the composition containing the silicone compound used for the radiation shielding material of the present invention may appropriately contain a silica-based reinforcing filler, additive and the like.

For example, KE45, KE44, KE106, KE4525, KE40RTV, KE4560, KE4576, KE348, KE3490, KE3491, KE3492, KE3493, KE3494, KE4898, KE4890, KE4866, KE4805, KE1830, KE1842, KE119, manufactured by Shin-Etsu Chemical Co., Ltd. KE1206, KE66, KE67, KE109, KE1051, KE1052, FE53, KE1204, KE1302, KE1223, KE1861, KE1212, KE1800, KE513, KE521, KE1225, KE10, KE12, KE17, KE20, KE30, KE111, KE112, KE113, KE24, KE26, KE1400, KE1402, KE1404, KE1300, KE1600, KE1603, Sealant 45, Sealant 4588, Sealant Master 300, Binder Sealant 40, Pure Sealant, KE4578, KE4579, Sealant 72, KE42, KE420, KE422, Sealant 70, Sealant 701 Otsubo sealant 74, marine sealant GX, sealant 79, Shin-Etsu silicone M coat 56, Shin-Etsu silicone S coat 57, Shin-Etsu silicone S coat 58, etc. can be used.

Some of these silicone compositions are used by mixing two liquids, and such compositions may be mixed according to the instruction manual.

In addition, as a sealant containing a commercially available silicone compound, for example, DOW CORNING 732 (based on RTV rubber) manufactured by Dow Corning, “Bass Coke Transparent CEMEDINE” (Part No. HJ-133) manufactured by Cemedine Co., Ltd. Silicone sealant Cemedine 8060 Pro ”, silicone sealant JP-01 manufactured by Shin-Etsu Polymer Co., Ltd. (based on a deoxime-type silicone compound), and the like can be used. These three sealant agents impart good properties such as viscosity, elasticity, plasticity and the like, particularly when used in the radiation shielding material of the present invention. A composition containing a silicone compound having the same or similar properties and composition as those of these sealant agents can be used in the production of the radiation shielding material of the present invention.

A good radiation shielding material can be obtained by mixing these components. If necessary, water may be added.

Furthermore, alcohol or an antifoaming agent may be added as a radiation shielding material.

Alcohol increases the uniformity of the mixture when the above composition is mixed, so the time for kneading the radiation shielding material can be shortened. Examples of the alcohol include methanol, ethanol, propanol, and polyhydric alcohol. Alcohol can be 70 to 99.9% of commercially available alcohol, and it can be added at 10 to 40 (w / w)%, preferably 20 to 40 (w / w)% when manufacturing a radiation shielding material. Good.

When manufacturing a radiation shielding material, it is necessary to mix and dry the above composition. The drying time can be shortened by heating and drying, but bubbles are generated at this time. Therefore, the addition of an antifoaming agent, or the generation of bubbles during heat drying can be suppressed by degassing by depressurization or ultrasonic treatment, so that it is possible to dry quickly. As the antifoaming agent, a known antifoaming agent such as a surfactant can be used, but even if it is not used as an antifoaming agent, it has an antifoaming effect in the heating and drying step during the production of the radiation shielding material. Any compound or composition can be used. As a composition having such an antifoaming effect, for example, Gummy Cast (Nisshin Resin Co., Ltd.) can be mentioned. Gummy cast is a mixture of liquid A (polyol, dibasic acid ester as a component) and liquid B (4,47-MDI, dibasic acid ester as a component). The antifoaming agent may be added in an amount of 5 to 30 (w / w)%, preferably 5 to 20 (w / w)% when producing the radiation shielding material.

By adding an antifoaming agent or alcohol, the production of the radiation shielding material of the present invention is facilitated.

2. Production method of radiation shielding material of the present invention The radiation shielding material of the present invention is obtained by mixing the above component (1), component (2), component (3) and water, and the radiation shielding material is in the form of a fill. It can be molded as a shielding material. The radiation shielding material of the present invention is obtained by mixing the above component (1), component (2), component (3), component (4) and water, and the radiation shielding material is an arbitrary elastic material. It can be manufactured as a shielding material that can be molded into a shape. Furthermore, the radiation shielding material of this invention is obtained by mixing said component (3) and component (4).

A. Production method of film-shaped radiation shielding material The film-shaped radiation shielding material of the present invention, for example, first mixes component (1) and component (2) with water. A mixture of component (1), component (2) and water is referred to as OK liquid.

Component (1), component (2) and water are in a volume ratio of 4 to 8: 1: 1 to 3, preferably 5 to 7: 1: 1 to 3, and more preferably 5 to 7: 1: 2 to 3. More preferably, the mixture may be 5 to 7: 1: 2, most preferably 7: 1: 2. Purified water or tap water can be used as the water. Since water is contained in component (2) and component (3), the amount of water added may be determined in consideration of the water content when the radiation shielding material of the present invention is finally produced. In addition, since the moisture content when producing the radiation shielding material of the present invention also affects the drying rate of the radiation shielding material composition, (1) to (3) depending on the desired drying rate. What is necessary is just to determine the water content at the time of mixing these components. For example, if it is desired to dry quickly, the water content may be reduced.

At this time, the component (1) may have any composition as long as it has the above composition. For example, the non-volatile component 55%, the aqueous latex of polyvinyl acetate and the weight percent of dibutyl phthalate are 80 to 95% and 5%, respectively. Examples include compositions containing -20%, preferably 85-95% and 5-15%, more preferably 90-95% and 5-10%. More specifically, a composition containing 92.5% by weight of an aqueous latex of polyvinyl acetate having a nonvolatile content of 55% and 7.5% by weight of dibutyl phthalate can be exemplified.

Next, the component (3) is mixed with the mixture (OK liquid) of the component (1), the component (2) and water. As the component (3), a boron compound, lead powder, or a boron compound and lead powder can be used. However, the component (3) of the radiation shielding material finally formed into a film is composed of a boron compound, particularly boric acid. preferable. It contains 60 to 95%, preferably 70 to 95%, more preferably 75 to 95% of a mixture of component (1), component (2) and water (OK solution) by weight, and 5 to 5 of component (3). 40%, preferably 5 to 30%, more preferably 5 to 25%. For example, for 50 mL (55 g) of the mixture of component (1), component (2) and water, component (3) is 1 to 14 g, preferably 5 to 12 g, more preferably 5 to 10 g, more preferably 6 to What is necessary is just to mix 9g. Mixing can be carried out at room temperature, preferably 27 ° C. to 40 ° C., more preferably 30 ° C. When the OK solution is used, the boron compound can be dissolved and mixed in a larger amount than can be dissolved and mixed in water, and the radiation shielding material of the present invention can efficiently absorb neutrons. For example, boric acid dissolves at 6.35g / 100mL in pure water at room temperature (30 ° C), but when OK solution is used, it dissolves at a concentration of about 12-30g / 100mL and a concentration of about 2-5 times that of water. Can be dissolved. When the temperature of the radiation shielding material in which boric acid is completely dissolved at 30 ° C. is lowered to room temperature, 1 part of boric acid may precipitate, but even if 1 part of boric acid is precipitated, the radiation shielding material Can be used as Moreover, even if it contains the quantity which boric acid does not melt | dissolve completely, as long as the boron compound is contained in the film-form radiation shielding material, it can be used as a shielding material. The radiation shielding material of the present invention includes a shielding material containing a boron compound in a powder state in a powder state.

A film-shaped radiation shielding material can be obtained by molding a mixture obtained by mixing the component (1), the component (2), and water with the component (3) into a film. The film-like radiation shielding material may be molded by casting the liquid immediately after mixing into a flat plate shape and solidifying it, for example.

B. Method for Producing Radiation Shielding Material Formable in Arbitrary Shape The radiation shielding material moldable in an arbitrary shape of the present invention, for example, first mixes component (1) and component (2) with water. A mixture of component (1), component (2) and water is referred to as OK liquid.

Component (1), component (2) and water are in a volume ratio of 4 to 8: 1: 1 to 3, preferably 5 to 7: 1: 1 to 3, and more preferably 5 to 7: 1: 2 to 3. More preferably, the mixture may be 5 to 7: 1: 2, most preferably 7: 1: 2. Purified water or tap water can be used as the water. Since water is contained in component (2) and component (3), the amount of water added may be determined in consideration of the water content when the material composition of the present invention is finally produced. In addition, since the water content when producing the material composition of the present invention also affects the drying rate of the material composition, the components (1) to (4) according to the desired drying rate. What is necessary is just to determine the water content at the time of mixing. For example, if it is desired to dry quickly, the water content may be reduced.

At this time, the component (1) may have any composition as long as it has the above composition. For example, the non-volatile component 55%, the aqueous latex of polyvinyl acetate and the weight percent of dibutyl phthalate are 80 to 95% and 5%, respectively. Examples include compositions containing -20%, preferably 85-95% and 5-15%, more preferably 90-95% and 5-10%. More specifically, a composition containing 92.5% by weight of an aqueous latex of polyvinyl acetate having a nonvolatile content of 55% and 7.5% by weight of dibutyl phthalate can be exemplified.

Next, the component (3) and the component (4) are mixed with the mixture (OK liquid) of the component (1) and the component (2). As the component (3), a boron compound, lead powder, or a boron compound and lead powder can be used.

Mixture (OK) liquid of component (1) and component (2), mixing ratio (w / w%) of component (3) and component (4), when component (3) is boron compound, lead powder In the case of a boron compound and lead powder, the following is performed.

When the component (3) is a boron compound, the OK liquid (component (1) + component (2)), the mixing ratio (w / w%) of the component (4) and the boron compound is 20 to 75%, 10 to 40% and 5 to 75%, preferably 40 to 60%, 20 to 30%, and 10 to 40%, respectively. For example, the OK liquid (component (1) + component (2)), component (4), and boron compound may be mixed in 4 g, 2 g, and 1 to 4 g (weight ratio 4: 2: 1 to 4).

When component (3) is lead powder, the OK liquid (component (1) + component (2)), component (4) and lead powder mixing ratio (w / w%) are 5-60%, 2.5- 40% and 60 to 95%, preferably 5 to 40%, 4 to 20%, and 70 to 95%, respectively. For example, the OK liquid (component (1) + component (2)), component (4), and boron compound may be mixed in 4 g, 2 g, and 6 to 36 g (weight ratio 4: 2: 6 to 36).

When component (3) is a boron compound and lead powder, the OK liquid (component (1) + component (2)), component (4), boron compound, and lead powder mixing ratio (w / w%) are respectively 10-20%, 5-15%, 1-5% and 50-95%. For example, the OK liquid (component (1) + component (2)), component (4), boron compound, and lead powder may be mixed with 4 g, 2 g, 0.5 to 4 g, and 6 to 36 g, respectively (weight ratio 4: 2: 0.5-4: 6-18).

The boron compound may be completely dissolved in the mixture of the component (1) and the component (2), but may be contained in a state where it is not dissolved, that is, in a powder state.

The radiation shielding material of the present invention can be obtained by mixing component (1), component (2), component (3) and component (4) in the above ratio and stirring well. The order of mixing is not limited, and a mixture of the components (1) and (2) may be prepared first, and components (3) and (4) may be mixed therewith, or the component (1), You may mix a component (2), a component (3), and a component (4) in random order. When components (1) and (2) are first mixed, an appropriate amount of water may be mixed with the mixture of components (1) and (2) as described above. When mixing in random order, an appropriate amount of water may be mixed according to the final required water content. As a mixing method, for example, a method using a mixer, a method of mixing with a spatula, or the like can be appropriately employed.

C. Method of manufacturing radiation shielding material containing component (3) and component (4) Silicone compound etc. of component (4) and boron compound of component (3), lead powder or boron compound and lead powder are mixed to shield radiation The material can also be manufactured.

In this case, for example, the boron compound and the component (4) may be mixed at a weight ratio of 1: 1 to 5. When lead powder is used, the lead powder and component (4) may be mixed at a mixing ratio of 10: 0.5 to 2.

The radioactive shielding material of the present invention produced by the above methods A, B and C has a milky, creamy, pasty or clay-like form containing a certain amount of water immediately after production, and is easy Can be formed into a desired shape. The radiation shielding material of the present invention can be quickly dried from its composition. For example, in natural drying, it can be dried in about 1 to 2 days, and when a dryer is used, it can be dried in several hours. The radiation shielding material of the present invention is not broken, cracked or cracked during the drying process. Further, it can be easily molded into a desired shape even during the drying process. It solidifies after drying and is viscous and elastic. Viscosity and elasticity can be arbitrarily adjusted by the component ratio.

Also, it solidifies when exposed to air, but has plasticity and flexibility as long as it is not exposed to air and can be molded into any shape. For example, it can be molded into an arbitrary shape by filling a container such as a tube or a can without touching air and taking it out of the container at the time of use. Moreover, since it has plasticity after drying, it can be molded into an arbitrary shape.

The radiation shielding material of the present invention is easy to manufacture and can be easily molded and produced at room temperature and atmospheric pressure. Moreover, it has flexibility and elasticity and can be molded into an arbitrary shape. Moreover, processing is also easy, and it can be easily cut with a knife or the like. Furthermore, by shielding the radiation shielding material from contact with air, it can be stored for a certain period as a material having flexibility, elasticity, and plasticity without solidifying.

Furthermore, the radiation shielding material of the present invention has heat resistance. The heat resistant temperature is 100 ° C. or higher.

3. Usage of the radiation shielding material of the present invention The radiation shielding material containing the boron compound of the present invention can shield neutrons because the boron compound shields neutrons. Moreover, since the radiation shielding material containing the lead powder of the present invention can block α rays, β rays and γ rays, the lead powder can shield these radiations. Furthermore, the radiation shielding material containing the boron compound and lead powder of the present invention can shield neutron rays because the boron compound absorbs neutrons. Moreover, since lead powder can block α rays, β rays, and γ rays, these radiations can be blocked. In the present invention, the radiation is absorbed and shielded, or the progress of radiation is shielded and the radiation is shielded.

The radiation shielding material of the present invention is processed into an arbitrary shape and size, and can be used, for example, as a radiation shielding filler, wall material, plate material, film material, backing, block, deep and the like. Also, for example, materials for protective clothing, shielding of concentrates containing radioactive substances, provisional shielding of decontamination objects containing radioactive substances, protection from radiation of electronic equipment, and application to shielding on walls, floors, and roofs. It can be used for shielding from radiation, forming in an arbitrary shape and shielding in facilities and sites where radioactive materials exist. Moreover, it can also be used for shielding medical devices (X-ray imaging devices, PET) that use radiation.

Furthermore, the radiation shielding material of the present invention can be used for controlling and controlling pests (microorganisms, termites, cockroaches, etc.). In this case, it is called a pest control material.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Production of Mixture of Component (1), Component (2), and Water (OK Liquid) Component (1) was prepared by combining motoposi (MOD PODGE GROSS, PLAID Catalog No. Item # CS11201), birch sap and water. It was prepared by mixing at a weight ratio of 1: 2. The birch sap was collected by making a hole in the trunk and attaching a pipe to the hole before the young birch leaves in April sprouted.

Motopositive has a solid content of 50 Wt% and contains a copolymer of vinyl acetate and acrylate in the solid content, the weight ratio of vinyl acetate and acrylate is 82:18, and a copolymer of vinyl acetate and acrylate. The polymer is a polymer containing vinyl acetate having a solid content of 90 Wt% and containing about 5 Wt% nonylphenol EO adduct and 1-2 Wt% polyethylene glycol as a surfactant in the solid content.

The mixture of component (1), component (2) and water produced in this way is called OK liquid.

Example 2 Production of film-shaped radiation shielding material containing boric acid Boric acid (Kenei Pharmaceutical Co., Ltd.) 6, 9, 12 and 15 g was added to 50 mL (55 g) of the OK solution produced in Example 1, The mixture was heated to 30 ° C. and stirred to dissolve boric acid in the OK solution. The ratios of added boric acid (w / w%) were 9.8%, 14.0%, 17.9% and 21.4%, respectively. When boric acid was added in an amount of 6 g or 9 g, boric acid was completely dissolved. The one added with 12 g dissolved, but partially precipitated when the temperature was lowered to room temperature. What added 15g did not melt | dissolve completely. However, in the radiation shielding material of the present invention, the boron compound such as boric acid does not need to be completely dissolved, and there is no problem even if it is contained as a powder, so even if it is not completely dissolved, the radiation shielding material Can be used as

The radiation shielding material produced by mixing boric acid with the above OK solution was cast on a flat surface in a liquid or slurry state, allowed to stand, and solidified to produce a film-like radiation shielding material.

Example 3 Production of radiation shielding material containing lead OK liquid produced in Example 1 (mixture of component (1), component (2) and water), composition containing silicone compound (referred to as silicone composition, Cemedine stock) “Silicone sealant Cemedine 8060 Pro” (component (4)) and lead powder (component (3)) manufactured by the company were mixed in the weight ratio shown in Table 1. In Table 1, the content of lead contained in the mixture (w / w%) is the content after solidification, and after solidification, the water content of the mixture decreases, so the lead content (w / w%) is higher than immediately after mixing.

During mixing, 1 was emulsion, 2, 3 and 4 were creamy, and 5 was clayy, which could be molded into any shape. When each was allowed to stand, it solidified and a good radiation shielding material was obtained.

Example 4 Production of radiation shielding material containing boric acid and lead powder OK liquid (mixture of component (1), component (2) and water) produced in Example 1, “Silicone Sealant Cemedine 8060 Pro manufactured by Cemedine Co., Ltd.” (Component (4)) and boric acid and lead powder (component (3)) were mixed at a weight ratio shown in Table 2.

The obtained mixture was in the form of clay and could be molded into an arbitrary shape. When the mixture was allowed to stand, it solidified and a good radiation shielding material was obtained.

Example 5 Production of radiation shielding material containing boric acid OK liquid (mixture of component (1), component (2) and water) produced in Example 1 and a composition containing a silicone compound (referred to as a silicone composition, cemedine) “Silicone sealant Cemedine 8060 Pro” (component (4)) and boric acid (component (3)) manufactured by Co., Ltd. were mixed at a weight ratio shown in Table 3. In Table 3, the content of boric acid contained in the mixture (W / w%) is the content at the time of mixing. Since the water content of the mixture decreases after solidification, the boric acid content (w / w%) becomes higher.

During mixing, 1 was emulsion, 2 and 3 were creamy, 4 was soft clay, and could be molded into any shape. When each was allowed to stand, it solidified and a good radiation shielding material was obtained.

Example 6
In the same manner as in Example 5, 4 g of OK liquid, 8 g of boric acid and 2 g of the silicone composition were mixed to produce a radiation shielding material containing boric acid. The content of boric acid contained in the radiation shielding material was 68.9%.

The radiation shielding material was molded into a 3mm sheet with a size of 12cm x 8.5cm, and when the thermal neutron shielding rate was measured, about 90% of thermal neutrons were shielded (shielding rate, about 90%). This thermal neutron shielding effect was measured by irradiating a sample with neutrons generated by 30 MeV electron irradiation from LINAC with Ta as the target nucleus at the Kyoto University Reactor Laboratory, and using a Li glass scintillator detector. The energy distribution of neutrons was analyzed by the time method and judged by the shielding effect of thermal neutrons with energy equivalent to 0.025VeV. Specifically, if the measured neutron count is 0.025 eV with Z and the neutron count measured with a radiation shielding material is Y, the shielding effect against thermal neutrons (%) Calculated as (ZY) / Z × 100.

Example 7
The OK liquid (mixture of component (1), component (2) and water) prepared in Example 1 was mixed with various silicone compositions (compositions containing a silicone compound) and lead powder, and the composition was mixed. A shielding material was produced.

Furthermore, a radiation shielding material to which ethanol (99.9%) or an antifoaming agent was added was also manufactured.

The radiation shielding effect of the manufactured radiation shielding agent was confirmed.

Composition of radiation shielding material produced in FIG. 1 (type of silicone composition used, name and manufacturer of silicone composition, amount of silicone composition added, name and amount of antifoam, amount of OK liquid used, ethanol (EtOH use amount, lead powder addition amount and content (w / w (%))), kneading time of the composition mixture when manufacturing the radiation shielding material, temperature and time when drying the mixed composition As well as the shielding effect.

The lead powder used was Kanto Chemical Co., Ltd. lead powder, 4N (99.99%) (CAT No. 24036-08).

A commercially available silicone composition was used. In the silicone composition used, silicone KE-106 is used by mixing two liquids (agent A and agent B) and mixed in the column “Use amount of silicone composition and antifoaming agent” in FIG. The used amount (g) of each liquid (A agent, B agent) is shown.

As an antifoaming agent, Gummy Cast (Nissin Resin Co., Ltd.) was used. Gummy cast is a mixture of liquid A (polyol, dibasic acid ester as a component) and liquid B (4,47-MDI, dibasic acid ester as a component). The amount of use (g) of each liquid (the A liquid and the B liquid) to be mixed is shown in the column “Use amount of silicone composition and antifoaming agent”. Gummy cast has an antifoaming effect, and by adding this, it could be dried quickly without foaming even when heated. In the case where the gummy cast is not added, since it foams during heating, it takes time to dry.

By adding ethanol, the uniformity of the mixture when the above composition was mixed was increased, so the time for kneading the radiation shielding material could be shortened. In FIG. 1, 99.8% ethanol was used, but it was confirmed that 70-99.9% ethanol can obtain the same effect as 99.9% ethanol.

The radiation shielding effect was determined by gamma ray shielding effect using Cs137 as a radiation source. The radiation source and the gamma ray counter (HCS Aroca Medical Co., Ltd., TCS-172B) are separated by about 2 cm, and the radiation shielding material (about 10 cm long, 15 cm wide, about 1-2 mm thick) manufactured in front of the radiation source Was placed so as to cover the radiation source, and γ-rays were measured about 30 times at three locations on the lead plate, and the average of the three locations was taken. At this time, a lead plate (Toho Zinc) with a thickness of 99.99% as a comparative standard was used, and the effect of each radiation shielding material when the shielding effect when the lead plate was placed was set to 100 was shown. Specifically, a radiation shielding material with a gamma ray count measured from a radiation source with nothing, Z, a gamma ray count measured with a 1 mm thick lead plate, X, and a d mm thickness When the γ-ray count measured when the γ-ray is placed is Y and the background γ-ray count is B, the shielding effect of each radiation shielding material is compared with that of a 1 mm thick lead plate, ln [(YB) / (ZB)] / ln [(XB) / (ZB)] × (1 / d) × 100 (ln represents a natural logarithm). In the column of “shielding effect (%)” in FIG.

As the silicone composition, the radiation shielding material to which silicone KE-106 is added and the radiation shielding material to which silicone sealant is added have the same physical properties such as flexibility, elasticity and plasticity of the radiation shielding material. The effect was equivalent.

The radiation shielding material of the present invention can be used as a shielding material for neutrons, α rays, β rays, γ rays, and X rays.

All publications, patents and patent applications cited in this specification shall be incorporated into this specification as they are.

Claims (20)

A radiation shielding material obtained by mixing the following components (1) to (4), wherein component (1), component (2) and water mixture, component (3) and component (4) are in weight percent. In any case, the radiation shielding material contains 5 to 95%:
(1) Vinyl acetate homopolymer or partially hydrolyzed product thereof, or vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumaric acid A composition comprising a polymer component comprising a copolymer with one or two or more monomers selected from the group or a partial hydrolyzate thereof,
(2) sap,
(3) Boron compound, lead powder, or boron compound and lead powder, and (4) silicone compound. Ingredient (1) has a solid content of 45-60 Wt% and contains a copolymer of vinyl acetate and acrylate in the solid content, and the weight ratio of vinyl acetate and acrylate is 75 to 85:15 to 25 The content of the copolymer of vinyl acetate and acrylate in the solid content is 80 to 95 Wt%, 4 to 6 Wt% of nonylphenol EO adduct and 1 to 2 Wt% of polyethylene as a surfactant in the solid content. The radiation shielding material according to claim 1, which is a polymer containing vinyl acetate containing glycol. The radiation shielding material according to claim 2, wherein the acrylate is n-butyl acrylate. The radiation shielding material according to any one of claims 1 to 3, wherein the sap is birch sap. The mixture of component (1), component (2) and water is obtained by mixing component (1), component (2) and water in a volume ratio of 4 to 8: 1: 1 to 3. 5. The radiation shielding material according to any one of 1 to 4. The radiation shielding material according to any one of claims 1 to 5, wherein the silicone compound is a silicone sealant. The radiation shielding material according to any one of claims 1 to 6, wherein the boron compound is boric acid. The radiation shielding material according to any one of claims 1 to 7, wherein boric acid shields neutron rays and lead powder shields α rays, β rays and γ rays. A radiation shielding material for shielding a neutron beam obtained by mixing the following components (1) to (3), wherein the component (1), the component (2), a mixture of water and the component (3) are in weight percent. In any case, the radiation shielding material contains 5 to 95%:
(1) Vinyl acetate homopolymer or partially hydrolyzed product thereof, or vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumaric acid A composition comprising a polymer component comprising a copolymer with one or two or more monomers selected from the group or a partial hydrolyzate thereof,
(2) sap,
(3) Boron compound. Ingredient (1) has a solid content of 45-60 Wt% and contains a copolymer of vinyl acetate and acrylate in the solid content, and the weight ratio of vinyl acetate and acrylate is 75 to 85:15 to 25 The content of the copolymer of vinyl acetate and acrylate in the solid content is 80 to 95 Wt%, 4 to 6 Wt% of nonylphenol EO adduct and 1 to 2 Wt% of polyethylene as a surfactant in the solid content. The radiation shielding material according to claim 9, which is a polymer containing vinyl acetate containing glycol. The radiation shielding material according to claim 10, wherein the acrylate is n-butyl acrylate. The radiation shielding material according to any one of claims 9 to 11, wherein the sap is birch sap. The mixture of component (1), component (2) and water is obtained by mixing component (1), component (2) and water in a volume ratio of 4 to 8: 1: 1 to 3. The radiation shielding material according to any one of 1 to 12. The radiation shielding material according to any one of claims 9 to 13, which is in the form of a film. A radiation shielding material obtained by mixing the following components (3) and (4), wherein the radiation shielding material contains 5 to 95% by weight of component (3) and component (4): :
(3) Boron compound, lead powder, or boron compound and lead powder, and (4) silicone compound. The radiation shielding material according to claim 15, wherein the silicone compound is a silicone sealant. The radiation shielding material according to claim 15 or 16, wherein the boron compound is boric acid. The method for producing a radiation shielding material according to any one of claims 1 to 8, comprising mixing the following components (1) to (4):
(1) Vinyl acetate homopolymer or partially hydrolyzed product thereof, or vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumaric acid A composition comprising a polymer component comprising a copolymer with one or two or more monomers selected from the group or a partial hydrolyzate thereof,
(2) sap,
(3) Boron compound, lead powder, or boron compound and lead powder, and (4) silicone compound. The method for producing a radiation shielding material for shielding a neutron beam according to any one of claims 9 to 14, comprising mixing the following components (1) to (3):
(1) Vinyl acetate homopolymer or partially hydrolyzed product thereof, or vinyl acetate and acrylic acid ester, acrylic acid amide, acrylic acid, methacrylic acid, methacrylic acid ester, maleic acid, maleic anhydride, and fumaric acid A composition comprising a polymer component comprising a copolymer with one or two or more monomers selected from the group or a partial hydrolyzate thereof,
(2) sap,
(3) Boron compound. The method for producing a radiation shielding material according to any one of claims 15 to 17, comprising mixing the following components (3) and (4):
(3) Boron compound, lead powder, or boron compound and lead powder, and (4) silicone compound.

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