JP3492425B2 - X-ray shielding laminate - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray shielding laminate,
For example, the present invention relates to an X-ray shielding laminate that can be used as a packaging material suitably used for storing a film or the like that is easily affected by X-rays. 2. Description of the Related Art Non-destructive tests using X-rays have been performed in various fields since the state of the inside of a test object can be known without destroying the test object. At airports around the world, X-ray fluoroscopy is performed on passenger baggage to prevent carry-on of dangerous goods into aircraft. [0003] However, X-ray fluoroscopy has the above-mentioned advantages, but has the drawback that the functions of films, cameras, various transistor products, pharmaceuticals and the like may be impaired by the influence of X-rays. ing. [0004] Therefore, in order to protect the above-mentioned articles which are easily affected by X-rays from X-rays, X-ray shielding bags using a laminate having an X-ray shielding layer have been put to practical use. That is, in this X-ray shielding bag, articles susceptible to X-rays, such as films, cameras, various transistor products, pharmaceuticals, etc., are stored, and then subjected to X-ray fluoroscopy to remove the stored items from X-rays. To protect. [0005] The layer constitution of the X-ray shielding laminate used for the conventional material for forming the X-ray shielding bag includes, for example, a substrate /
A four-layer structure including a base material / X-ray shielding layer / sealing layer is known. [0006] However, in the conventional X-ray shielding laminate, since the X-ray shielding layer is formed of a lead foil, the X-ray shielding layer is bulky and stiff when used, and the weight is reduced. However, there is a problem that it is difficult to reduce the size. Furthermore, in order to control the thickness of the X-ray shielding layer, there is also a manufacturing disadvantage that a lead foil having a desired thickness must be prepared as needed. The present invention has been made in view of such circumstances, and an object of the present invention is to eliminate bulkiness and stiffness during use, to reduce the weight and size of the X-ray shielding layer, and to reduce the thickness of the X-ray shielding layer. An object of the present invention is to provide an X-ray shielding laminate which is easy to control and has excellent production efficiency. [0008] In order to solve the above-mentioned problems, an X-ray shielding laminate of the present invention has a three- or more-layer structure having a substrate, an X-ray shielding layer, and a sealing layer. A laminate, wherein the X-ray shielding layer is formed of an X-ray shielding coating agent containing a metal component and a binder component, wherein the metal component has an atomic number Z of a constituent metal of the metal component and a density ρ When [g · cm ⁻² ], Z · ρ> 1,000. The X-ray shielding laminate of the present invention is a laminate composed of three or more layers having a base material, an X-ray shielding layer and a sealing layer, wherein the X-ray shielding layer is made of a metal component. When the metal component is formed by an X-ray shielding coating agent containing a metal component and a binder component, and the atomic number of the constituent metal of the metal component is Z and the density is ρ [g · cm ⁻² ],・ Ρ ＞
It satisfies 1,000. Here, as for the X-ray absorption characteristics of a metal, when the quality of X-rays is the same, the absorption coefficient increases as the weight of the metal increases and as the atomic number increases, and the X-ray transmittance decreases. That is, the absorption coefficient μ of the substance for X-rays of wavelength λ
Is the following formula: μ = C · λ ³ · Z · ρ [cm ³ ] (where C is a constant, λ is a wavelength, Z is an atomic number, and ρ is the density of a substance. ), The above Z · ρ value is Z · ρ> 1,00
In the X-ray shielding laminate of the present invention having an X-ray shielding layer comprising an X-ray shielding coating agent containing a metal component satisfying 0, X-rays are absorbed by the X-ray shielding layer. The transmittance is reduced, and as a result, X-rays are shielded by the X-ray shielding laminate. Further, since such an X-ray shielding layer is formed by applying an X-ray shielding coating agent to a substrate, the thickness of the X-ray shielding layer can be easily adjusted by adjusting the coating thickness. Controllable. Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the X-ray shielding laminate 1 of the present embodiment includes a first base material layer 2, a second base material layer 3, and an X-ray shielding layer 4.
The seal layer 5 is stacked in this order to form a four-layer structure, and an anchor coat agent or an adhesive is appropriately used for bonding between the layers. The first base material layer 2 and the second base material layer 3
This layer has a function or function of supporting the line shielding layer 4 and the sealing layer 5, and is further printed as necessary. Examples of the material for forming the first base material layer 2 having such an action or function include stretched polyester, stretched polypropylene, stretched polyamide, and the like. The thickness of the first base material layer 2 cannot be determined uniformly because it differs depending on the use, purpose, etc. of the X-ray shielding laminate. When used as a material for forming a bag, it is usually 8 to 50 μm, preferably 15 to 40 μm. The second base material layer 3 is laminated on the first base material layer 2. As described above, the second base material layer 3 has an action or function of supporting the X-ray shielding layer 4 and the sealing layer 5 together with the first base material layer 2, and further has a function of supporting the X-ray shielding layer 4 containing a metal component. This is a layer having a function or function of hiding coloring. As a material for forming the second base material layer 3, for example, a colored film such as white polyethylene, white polyester, and white polypropylene can be used. Similarly to the thickness of the first base material layer 2, the thickness of the second base material layer 3 differs depending on the use and purpose of the X-ray shielding laminate, and therefore cannot be determined uniformly. When the X-ray shielding laminate 1 is used as a material for forming an X-ray shielding bag, usually 2
It is 0 to 50 μm, preferably 30 to 40 μm. In this embodiment, the base material is the first base material layer 2
And the second base material layer 3, but the base material may be constituted by only one layer or may be constituted by three or more layers according to the use and purpose of the X-ray shielding laminate 1. . As shown in FIG. 1, an X-ray shielding layer 4 is laminated on the second base material layer 3. The X-ray shielding layer 4 is a layer having a function or function of absorbing X-rays by itself and preventing X-rays from transmitting through the X-ray shielding laminate 1. The X-ray shielding layer 4 is formed by applying an X-ray shielding coating agent on the second base material layer 3.
The X-ray shielding coating agent used for forming the X-ray shielding layer 4 contains a metal component and a binder component. The atomic number of the metal constituting the metal component is Z, and the density is ρ [g · c.
m ⁻² ], Z · ρ> 1,000 is satisfied. The metal having a Z · ρ value of more than 1,000 includes, for example, W (Z · ρ value: 1,42
8.2), Ir (Z · ρ value: 1,732.5), Pt
(Z · ρ value: 1,673.1), Au (Z · ρ value: 1,
526.28). The metal component is preferably used in the form of a physically stable oxide so that the curing rate of the binder component is not too fast. The binder component is used as a vehicle separately for applications such as overcoating agents, adhesives and pressure-sensitive adhesives. Specific examples include resin-based binder components, elastomer-based binder components, and natural-based binder components. Among the above-mentioned resin-based binder components, examples of thermosetting ones include urea-based, melamine-based, resorcinol-based, phenol-based (water-soluble, alcohol-soluble, novolak), epoxy-based, polyurethane-based, and polyaromatic-based ( Polyimides, polybenzimidazoles, polyamideimides, etc.), polyesters (alkyd type, unsaturated polyester, diallyl phthalate type, polyester acrylate, acrylate diester, etc.) and the like can be mentioned. Examples of the thermoplastic resin include vinyl acetate (emulsion, solution), polyvinyl alcohol, polyvinyl acetal (butyral, acetal, formal, etc.), vinyl chloride,
Acrylic (emulsion, solution, reaction type), polyolefin (PE, EVA, etc.), cellulose (cellulose, nitrocellulose, cellulose acetate, ethyl cellulose, water-soluble cellulose, etc.), silicone, polyacrylamide, polyvinyl methyl ether , Polyisobutylene, polyvinyl ether and the like. As the elastomeric binder component,
For example, chloroprene rubber (solution, latex), nitrile rubber (solution, latex), SBR, styrene-ethylene-butylene block copolymer (SEBS)
Based, styrene-isoprene block copolymer (SIS)
Styrene-butadiene block copolymer (SBS)
System, polysulfide system, butyl rubber system, silicon rubber system (RTV type, vulcanization type, pressure sensitive type), isobutylene rubber system, isoprene rubber system, butyl rubber system and the like. Examples of the mixed system include phenolic vinyl, epoxy phenol, phenol chloroprene, phenol nitrile, epoxy polyamide, epoxy polysulfide, nitrile epoxy, epoxy Nylon-based and the like. The natural binder component includes, for example, a natural rubber component. Particularly preferred binder components include OH compounds, which are used alone or as a mixture of two or three types. At this time, isocyanate (NCO) is used as a curing agent. As a solvent for such an X-ray shielding coating agent, for example, toluene, methyl ethyl ketone (ME
K), ethyl acetate, butyl acetate, xylene, methyl isobutyl ketone (MIBK), isopropyl alcohol (IPA) and the like. For example, the mixing ratio of each component in the X-ray shielding coating agent using these solvents is such that the metal component is usually 20 to 70 parts by weight and the binder component is usually 10 to 10 parts by weight.
-30 parts by weight and the solvent is usually 20-60 parts by weight. The ratio of the pigment (P) to the vehicle (V) (P / V ratio) in the X-ray absorbing coating agent
Is usually 40 to 90, preferably 70 to 80.
When the P / V ratio is as high as 60 or more, various precipitation inhibitors may be used. X obtained by applying this X-ray shielding coating agent
The dry thickness of the line shielding layer 4 is usually about 10 to 60 μm, and preferably about 30 to 50 μm. A seal layer 5 is provided on the X-ray shielding layer 4. The seal layer 5 has heat sealing properties. For example, when an X-ray shielding bag is formed using the X-ray shielding laminate 1, the seal layers 5 are heat-sealed at predetermined portions. The sealing layer 5 is made of an X-ray shielding layer 4 containing a metal component.
Has the function or function of hiding the coloring of As a material for forming the sealing layer 5, a polyolefin resin having a sealing property can be used. Specifically, for example, any of low-density polyethylene (high-pressure low-density polyethylene, linear low-density polyethylene, etc.), medium-density polyethylene, and high-density polyethylene can be used. In addition to ethylene homopolymer, ethylene and propylene, butene-1, pentene-
A copolymer with an α-olefin such as 1 or vinyl acetate, or a mixture thereof can also be used. In propylene-based resins, random copolymers of propylene and α-olefins such as ethylene, butene-1, pentene-1, 3-methylbutene-1, and 4-methylpentene-1 and mixtures thereof are particularly suitable for low-temperature sealability. Excellent. Further, the sealing layer 5 is made of barium (B
a) It may contain a compound. When the seal layer 5 contains a barium (Ba) compound, the X-ray shielding laminate 1
X-ray shielding effect is further improved. That is, when the seal layer 5 contains a barium (Ba) compound, such a seal layer 5 has an action or function of assisting X-ray shielding. The thickness of the sealing layer 5 is usually 30 to 80 μm.
m, preferably 40 to 80 μm. X having the above configuration
The line shielding laminate 1 is, for example, a film,
The present invention can be suitably used as a material for forming an X-ray shielding bag for storing articles susceptible to X-rays such as cameras, various transistor products, and pharmaceuticals, and protecting these articles from X-rays. Next, experimental examples of the present invention will be shown, and the present invention will be described more specifically. Experimental Example 1 Preparation of X-ray shielding coating agent Acrylic polyol (heating residue 50%, OH value 30) 1
Toluene and methyl ethyl ketone (MEK) were added to a mixture of 3 parts by weight, 6 parts by weight of polyvinyl chloride and 1 part by weight of cellulose.
20 parts by weight each, and 1,200 rpm
80 parts by weight of tungsten trioxide (Z · ρ value of W: 1,428.8) was added little by little while stirring with a mixer of m, and sufficiently dispersed to obtain 140 parts by weight of an X-ray shielding coating agent sample solution. Was. Next, the isocyanate curing agent [XEL curing agent (D) manufactured by The Inktech Co., Ltd.] was mixed with the above sample solution and the isocyanate curing agent, and the ratio of the binder component to the isocyanate curing agent in the sample solution was changed. (Binder component) /
(Isocyanate curing agent) = 100/5 was mixed and stirred to obtain an X-ray shielding coating composition. Preparation of X-ray shielding laminate and X-ray shielding bag The above coating solution was coated on a polyethylene (PE) film having a thickness of 80 μm with a comma coat,
Curing was performed at 48 ° C. for 48 hours to prepare three types of samples having a coating thickness of 15 μm, 30 μm, and 45 μm, and a milky white polyethylene film having a thickness of 35 μm and a biaxial stretching of 25 μm on the coating surface of each sample. A polyethylene terephthalate film is laminated in this order and three types of X
Each of the X-ray shielding laminates was made into a X-ray shielding laminate to prepare an X-ray shielding bag. Nondestructive inspection test The above X-ray shielding bags have a film sensitivity of ISO400 35
mm film and put it through an X-ray non-destructive inspection tester.
The X-ray shielding ability was evaluated in the following four grades. The results are shown in Table 1. A: There is no damage to the film B: Partially damaged film was found C: 1/5 to 1/2 of the film was damaged D: More than half of the film was damaged and non-destructive The test conditions of the inspection test are as follows. Test machine used: EV-150 manufactured by Uniheight Co., Ltd. Tube voltage: 70 kv Tube current: 3 mA Comparative Example 1 The same procedure as in Experimental Example 1 was repeated except that 80 parts by weight of tungsten trioxide was replaced with barium sulfate (Z · ρ value of Ba: 202.
72) An X-ray shielding coating composition was prepared in the same manner as in Experimental Example 1 except that 80 parts by weight was used.
An X-ray shielding laminate and an X-ray shielding bag were prepared and a nondestructive inspection test was performed in the same manner as in Experimental Example 1. Table 1 shows the results. Experimental Example 2 Preparation of X-ray shielding coating agent Acrylic polyol (50% heating residue, OH value 16) 3
1. 2.5 parts by weight, 15 parts by weight of polyvinyl chloride and cellulose
50 parts by weight of toluene and methyl ethyl ketone (MEK) were added to 5 parts by weight of the mixture,
While stirring with a mixer at 200 rpm, 50 parts by weight of tungsten trioxide (Z · ρ value of W: 1,428.8) was added little by little and dispersed sufficiently to obtain 200 parts by weight of an X-ray shielding coating agent sample solution. Was. Next, the isocyanate curing agent [XEL curing agent (D) manufactured by The Inktec Co., Ltd.] was mixed with the above sample solution and the isocyanate curing agent, and the ratio of the binder component to the isocyanate curing agent in the sample solution was changed. (Binder component) /
(Isocyanate curing agent) = 100/5, and the mixture was stirred to obtain an X-ray absorbing coating agent coating liquid. Preparation of X-ray shielding laminate and X-ray shielding bag Except for using the above-mentioned coating solution, the coating thickness of the coating solution was 15 μm, 30 μm and 45 μm in the same manner as in Experimental Example 1. Each X-ray shielding laminate was made into an X-ray shielding laminate, and an X-ray shielding bag was prepared. Nondestructive Inspection Test The X-ray shielding ability of each X-ray shielding bag was evaluated in the same manner as in Experimental Example 1 except that the above-mentioned X-ray shielding bags were used. The results are shown in Table 1. Comparative Example 2 The same procedure as in Experimental Example 2 was repeated except that 50 parts by weight of tungsten trioxide was used instead of barium sulfate (Z · ρ value of Ba: 202.
72) An X-ray shielding coating composition was prepared in the same manner as in Experimental Example 2 except that 50 parts by weight was used.
An X-ray shielding laminate and an X-ray shielding bag were prepared and a non-destructive inspection test was performed in the same manner as in Experimental Example 2. Table 1 shows the results. Comparative Example 3 A polyethylene (PE) film having a thickness of 75 μm and a thickness of 5
A lead foil of 0 μm is attached, and on this lead foil, a milky white polyethylene film having a thickness of 35 μm and a thickness of 25 μm
The biaxially stretched polyethylene terephthalate film was laminated in this order to form an X-ray shielding laminate, and the X-ray shielding laminate was made to prepare an X-ray shielding bag. The X-ray shielding ability of the obtained X-ray shielding bag was evaluated in the same manner as in Experimental Example 1. Table 1 shows the results
Shown in Examination of Results As is clear from Table 1, the X-ray shielding ability of the X-ray shielding bags using the X-ray shielding laminates obtained in Experimental Examples 1 and 2 is comparative example 1 and comparative example, respectively. X obtained in 2
It was confirmed that the X-ray shielding bag using the X-ray shielding laminate was superior to the X-ray shielding ability. The X-ray shielding ability of the X-ray shielding bag using the X-ray shielding laminate obtained in Comparative Example 3 was determined by using the X-ray shielding laminates obtained in Experimental Examples 1 and 2. Although the X-ray shielding bag was slightly superior to the X-ray shielding ability of the X-ray shielding bag, there was bulkiness and stiffness during use, and the feeling of use was lower than that of the X-ray shielding bags of Experimental Examples 1 and 2. It was much worse. From this, it was confirmed that the X-ray shielding bag using the X-ray shielding laminates obtained in Experimental Examples 1 and 2 had a better feeling of use than conventional products. As described in detail above, the X-ray shielding laminate of the present invention comprises an X-ray shielding coating agent containing a binder component and a metal component having a certain or more X-ray shielding ability. It has an X-ray shielding layer made of, so that it has excellent X-ray shielding ability, and is excellent in usability without bulk and stiffness when using a bag, for example. The thickness of the X-ray shielding layer can be easily controlled only by adjusting the coating thickness of the agent, and the production efficiency is excellent.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing an example of the X-ray shielding laminate of the present invention. [Description of Signs] 1 ... X-ray shielding laminate 2 ... First substrate 3 ... Second substrate 4 ... X-ray shielding layer 5 ... Seal layer

Claims (1)

(57) Claims 1. An X-ray shielding bag laminate comprising three or more layers having a base material, an X-ray shielding layer, and a sealing layer, wherein the X-ray shielding layer Is formed of an X-ray shielding coating material containing a metal component and a binder component, wherein the metal component has an atomic number Z of a constituent metal of the metal component and a density ρ
[G · cm ⁻² ], Z · ρ> 1000, and the X-ray shielding layer has a dry thickness of 10
An X-ray shielding laminate having a thickness of from about 60 μm to about 60 μm .