JPH0470904B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a heat generating mat for medical diagnostic equipment.
More specifically, computerized tomography (hereinafter referred to as
A heating mat for medical diagnostic equipment that can keep the patient's body warm during CT (abbreviated as CT), nuclear magnetic resonance imaging (hereinafter referred to as MRI), X-ray photography, etc., and has excellent X-ray transmittance. . <Prior art> Conventionally, in medical diagnostic equipment that performs CT, MRT, X-ray photography, etc., materials such as glass are used for the parts that come into direct contact with the patient's body. In this case, it has the disadvantage of giving the patient a cold sensation. In order to solve the above-mentioned drawbacks, a heat-retaining mat made of carbon black molded into a sheet has been proposed. However, although mats equipped with carbon black have excellent heat retention properties, when used for example in X-ray photography, the transmittance of X-rays is low, so it is necessary to increase the emissivity of X-rays.
Therefore, there is a drawback that the exposure rate increases. <Problems to be Solved by the Invention> An object of the present invention is to provide a heating mat for medical diagnostic equipment that has a stable heating effect and extremely good X-ray transmittance. <Means for Solving the Problems> According to the present invention, there is provided a medical diagnosis comprising a conductive metal foil for current supply and/or a conductive paste, and a planar heating sheet containing carbon fibers and pulp. A heating mat for a device, wherein the planar heating sheet contains 3 to 20% by weight of carbon fibers having at least two different lengths: 3 mm or more and less than 5 mm, and 5 mm or more and 10 mm or less; Pulp 97~80
A heating mat for medical diagnostic equipment is provided, which is characterized by being made by mixing and dispersing % by weight, and making a paper. The present invention will be explained in more detail below. The heat-generating mat for medical diagnostic equipment of the present invention includes a conductive metal foil and/or a conductive paste, and is made by mixing and dispersing carbon fibers having specific different lengths and pulp in a specific mixing ratio. It is characterized in that it is provided with a planar heat-generating sheet. The carbon fibers used in the planar heat-generating sheet are preferably polyacrylo-based carbon fibers and/or pitch-based carbon fibers. In order to obtain a planar heat-generating sheet that has a particularly stable heat-generating effect, the carbon fibers are preferably 3 mm or more in length, It is necessary to use carbon fibers having at least two different lengths: less than 5 mm, and 5 mm or more and 10 mm or less. Further, the thickness of the carbon fiber is not particularly limited, but is preferably 4 to 10 μm, particularly preferably 6 to 8 μm. Moreover, as the pulp, vegetable pulp is preferable, and synthetic pulp can also be added as needed. Preferred examples of the vegetable pulp include wood fibers, seed fibers, bast fibers, leaf fibers, and fibers of the same family, and raw material monomers for obtaining synthetic pulp include acrylonitrile, vinyl acetate, and vinylidene chloride. , (meta)
A monomer selected from the group consisting of acrylic acid or its ester, (meth)acrylamide, styrene, vinylpyridine, a vinyl monomer containing sulfone or its salt, an allyl monomer containing sulfone or its salt, vinyl alcohol, a mixture thereof, etc. It is preferable to have one. The thickness of the vegetable pulp and synthetic pulp is preferably 100μ or less, particularly preferably 10 to 80μ. The planar heat generating sheet can be obtained by mixing and dispersing the carbon fibers and pulp and then forming the sheet. The blending ratio of the carbon fiber and pulp is 3 to 20% by weight of carbon fiber and 97 to 80% by weight of pulp.
is within the range of At this time, if the carbon fiber content is less than 3% by weight, the electrical resistance becomes high and the desired exothermic temperature cannot be obtained. In order to manufacture the planar heat generating sheet used in the present invention, it can be obtained, for example, by mixing and dispersing the carbon fibers and pulp, and forming the sheet to a desired thickness and basis weight. The mixing and dispersing may be carried out by mixing and dispersing the carbon fibers and pulp using a known stirrer such as a pulper, preferably in water for 10 to 50 minutes, particularly preferably 20 to 30 minutes, or mixing and dispersing the carbon fibers. A method may be used in which the pulp and the pulp are separately dispersed in water, and then mixed and dispersed. At this time, silicon,
Ester compounds, paraffin wax, mineral oil,
It is also possible to add antifoaming agents such as polyalkylene-based and/or dryer release agents such as polyethylene-based, wax-based, silicone-based, etc. Next, the obtained raw material solution can be made into paper using a known cylinder paper machine (Yankee machine), Fourdrinier paper machine, or the like. Further, the conductive metal foil and/or conductive paste provided in the planar heating sheet may be selected from the group consisting of silver, aluminum, copper, nickel, stainless steel, and mixtures thereof, as long as they are conductive. Preferred examples include metal foils or pastes, which can be used, for example, by being attached to both ends of the same side of a planar heat generating sheet. The thickness of the conductive metal foil and/or conductive paste can be varied within the range of several μ to several mm as desired, but in order to make the planar heat generating sheet flexible, the thickness is 30 to 100 μ. It is preferable to set it as thickness. Further, the planar heating sheet provided with the conductive metal foil and/or conductive paste may be made of a covering material such as resin, woven fabric, non-woven fabric, or synthetic fiber such as acrylic fiber or polyester fiber that does not undergo thermal deformation due to heat generation. It can also be used by being coated with. Furthermore, the planar heat generating sheet can also be impregnated with a resin. The resin is not particularly limited as long as it does not undergo thermal deformation due to heat generation, and includes, for example, silicone resin, phenol resin, urea resin, melamine resin, polyester, epoxy resin, diallyl phthalate resin, vinyl chloride resin, polystyrene,
Preferred examples include resins selected from the group consisting of SAN resin, ABS resin, methyl methacrylate resin, polypropylene, polyamide, polyacetal, polycarbonate, polyphenylene oxide, poly(4-methylpentene-1), and mixtures thereof. . In order to manufacture the mat for a medical diagnostic device of the present invention, a planar heating sheet provided with the conductive metal foil and/or conductive paste is used, for example, with a urethane-based resin or acrylic resin having good X-ray transmittance. It can be obtained by embedding or pasting into a known resin mat such as resin, foamed polyethylene, or a commercially available mat such as the product name "Pef" (manufactured by Toray Industries, Inc.). In order to prevent exposure to X-rays as much as possible, the mat for medical diagnostic equipment of the present invention is preferably adjusted to have an X-ray transmittance of 90% or more, particularly close to 100%. To use the mat for medical diagnostic equipment of the present invention, in the case of a bed or a part that patients normally come into contact with during medical diagnosis, the mat for medical diagnostic equipment is pasted or placed on the entire bed, and then It can be used by passing a current of . <Effects of the Invention> Since the mat for medical diagnostic equipment of the present invention is equipped with a planar heat generating sheet containing carbon fiber and pulp, a stable heat generating effect can be obtained, and when used for X-ray photography, etc., it has excellent X-ray performance. Since it shows radiation transmittance, it is possible to reduce the exposure rate. <Examples> The present invention will be explained in more detail below using Examples and Comparative Examples, but the present invention is not limited thereto. Example 1 2 g of PAN-based carbon fiber with a length of 8 mm, Manila pulp
15 g of kraft pulp (N-BKP) and 75 g of kraft pulp (N-BKP) were put together with water into a small mixer for testing, and mixed and stirred for 10 seconds to disperse each component. Next, length 4mm
8 g of PAN-based carbon fiber was added, and the mixture was mixed and stirred again for 10 seconds. The obtained dispersion was poured into a Tatsupi machine with a size of 250 x 250 mm to form a sheet with a basis weight of 40 g/m ² , and then passed through a drying drum to obtain a test piece of a carbon fiber-mixed heat generating sheet with a thickness of 0.1 mm. .
A heat generating sheet obtained in the same manner as the test piece was cut to 1700 x 550 mm, silver paste was pasted along two opposing sides of the heat generating sheet, and then copper foil auxiliary electrodes were attached along the silver paste. A planar heat-generating sheet was prepared by attaching it. Next, the obtained planar heat generating sheet was coated with urethane resin mat [trade name "Pef"].
(Toray Industries, Inc.)] to prepare a mat for medical diagnostic equipment. When a current of 100 V was applied to the resulting mat for medical diagnostic equipment, the surface temperature of the mat rose to 35° C. in 3 minutes, and after that the surface temperature of the mat remained approximately constant. Next, in order to measure the X-ray transmittance of the planar heating sheet, a 14 x 14 inch (35.56
x 35.56 cm) on a Geiger counter [trade name "RADCON" (manufactured by Victorin Co., Ltd.,
330c.c. ionization volume)], tube voltage 50KV, tube current
Measurements were performed four times under the conditions of 100 mA, irradiation time 0.08 seconds, and irradiation distance 30 cm. The results are shown in Table 1. Comparative Example 1 A heat generating sheet was produced in the same manner as in Example 1, except that the planar heat generating sheet was prepared using only carbon black instead of carbon fibers and pulp. When a current was passed through the heat generating sheet made of the obtained carbon black in the same manner as in Example 1, stable heat generation was obtained. In addition, the transmittance of X-rays was measured in the same manner as in Example 1. The results are shown in Table 1. Reference examples 1 to 3 10×10×0.02cm (Reference example 1), 10×10×0.14cm
The transmittance of X-rays was measured in the same manner as in Example 1 using the aluminum plate of (Reference Example 2) or with no obstructions (Reference Example 3). The results are shown in Table 1. Note that the transmittance shown in Table 1 is a value calculated by setting Reference Example 3 as 1.

[Table] From the results in Table 1, the mat for medical diagnostic equipment of the present invention has a higher X-ray transmittance than a heat generating sheet made of carbon black, and the thickness of the aluminum plate is
It was found that the transmittance was similar to that of 0.02 cm.

Claims (1)

[Scope of Claims] 1. A heating mat for a medical diagnostic device, comprising a conductive metal foil and/or a conductive paste for energization, and a planar heating sheet containing carbon fibers and pulp, The planar heat generating sheet is made of 3 to 20% by weight carbon fibers having at least two different lengths: 3 mm or more and less than 5 mm, and 5 mm or more and 10 mm or less.
and 97 to 80% by weight of pulp are mixed and dispersed to form a paper.