JPH10221177A - Electronic clinic thermomerer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance antibacterial effect, reduce discoloration of resin, and improve moldability, by forming a case of a synthetic resin containing silver zirconium phosphate compound of specified wt.% SOLUTION: A window member 2 is composed of a transparent resin. A case member 3 is composed of an opaque resin. A trunk 4 consists of the window member 2 and the case member 2. An indicating window 25 is formed in the window member 2. A probe includes a probe cap 51 and potting material which fixes a probe cap 51 and a temperature detector to the inside and liquid- tightly bonds the probe cap 51 to the trunk 4. A battery holder 85 holds a power source battery. A rear cap 81 is liquid-tightly bonded to the trunk 4 via the battery holder 85. The case member 3, the rear cap 81 and the battery holder 85 are formed of an opaque resin or a resin which is made opaque by coloring. The resin is selected out of polyether like polyphenylene terephthalate, acrylic resin, etc. As antibacterial agent which is mixed in the resin of the case member 3 is silver zirconium phosphate compound of 1-2.5wt.% is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic thermometer, and more particularly to an electronic thermometer having a housing having antibacterial properties.

[0002]

2. Description of the Related Art Conventionally, a material to which an antibacterial agent is added has been used for manufacturing a housing of an electronic thermometer. The antibacterial properties of silver-based inorganic antibacterial agents such as silver zeolite and silver silica gel which have been conventionally performed are not always sufficient. Further, when the amount of the antibacterial agent added is increased in order to improve the antibacterial property, there is a problem that the moldability of the resin is impaired.

[0003]

SUMMARY OF THE INVENTION The present invention provides an electronic thermometer which eliminates the above-mentioned conventional disadvantages, has a higher antibacterial effect than silver zeolite, silver silica gel and the like, has less discoloration of resin, and has good moldability. I do.

[0004]

In order to solve this problem, an electronic clinical thermometer according to the present invention is an electronic clinical thermometer in which a circuit board, a power supply battery and the like are housed inside a housing, wherein the housing is made of zirconium phosphate. It is characterized by being formed of a synthetic resin containing approximately 1 to 2.5% by weight of a silver compound. Here, the synthetic resin is a polyether such as polyphenylene oxide; a polyester such as polyethylene terephthalate and polybutylene terephthalate; an acrylic resin such as polyacetal; polymethyl methacrylate; a styrene-based resin such as ABS resin and high impact styrene;
Polyolefin resins such as 2-methylpentene and polypropylene; opaque or colored opaque resins selected from at least one of polycarbonate resins.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the accompanying drawings. <Configuration Example of Electronic Thermometer of the Present Embodiment> FIG. 1 is a perspective view showing a configuration example of an electronic thermometer 1 of the present embodiment. 2 is a cross-sectional view in the longitudinal direction of FIG. 1, FIG. 3 is a cross-sectional view after completion of molding of the body of the housing, and FIG. 4 is a cross-sectional view taken along line CC 'of FIG.

Reference numeral 2 denotes a window member made of a transparent resin, 3 denotes a housing member made of an opaque resin, and 4 denotes a window member and a housing member 3.
25 is a display window consisting only of the window member 2 of the body 4, 5 is a metal probe cap 51 and a temperature measuring element (thermistor) 9 fixed inside, and the probe cap 51 and the body are fixed. A probe consisting of a potting material 55 for adhering 4 and 4 in a liquid-tight manner; 6 a control unit and a measuring circuit;
A calculation display unit including a display unit and the like on an integrated circuit board,
Reference numeral 85 denotes a battery holder that holds the power supply battery 7, and 81 denotes a rear cap that is adhered to the body 4 in a liquid-tight manner via the battery holder 85. The power supply battery 7 is stored in a battery holder 85,
This is a structure in which the rear cap 81 and the rear end of the body 4 are bonded with an adhesive. Incidentally, by selecting a combination of resins, an adhesive method such as ultrasonic welding is also possible. The housing of the electronic thermometer 1 is formed in a liquid-tight manner by the probe cap 51, the body 4 of the housing, and the rear cap 81 (battery holder 85).

In such a case, the housing member 3, the rear cap 81 and the battery holder 85 constituting the body 4 are made of polyether such as polyphenylene oxide; polyester such as polyethylene terephthalate and polybutylene terephthalate; polyacetal; polymethyl methacrylate. Acrylic resin such as ABS resin, styrene resin such as high impact styrene; polyolefin resin such as poly-2-methylpentene and polypropylene; opaque or colored opaque resin selected from polycarbonate resin . In the following examples, a styrene-based resin (high impact styrene, ABS resin is particularly preferable) is used.

The window member 2 is made of a transparent resin such as a polystyrene resin such as polystyrene and butadiene-styrene copolymer; a polyolefin resin such as poly-2-methylpentene and polypropylene; and an acrylic resin such as polymethyl methacrylate. A cellulose ester such as cellulose acetate; a polyester such as polyethylene terephthalate;

The probe cap 51 is made of a metal such as stainless steel or aluminum. In such a case, the window member 2 and the housing 3 made of an opaque resin may be any as long as the housing 3 is in liquid-tight contact with the display window 25 of the window member 2 and integrated. Therefore, as described above, the window member 2 may be formed in a plate shape without forming a cylindrical body.
However, as will be described later, it is preferable that the two are integrated by so-called two-color molding. At this time, it is preferable that the window member 2 be formed into a cylindrical body because the range in which the window member 2 comes into liquid-tight contact is widened. Extremely high waterproofness.
More preferably, the display window 25 formed on the outer surface of the window member 2 formed as a cylindrical body is formed so as to protrude outward from the cylindrical body, as shown in FIGS. Is preferred. As a result, a step locking portion is formed on the periphery of the display window 25, and the joining with the opaque resin housing 3 is extremely improved.

In order to form such a body 4, a multi-color molding machine is used to first form the window member 2 of a cylindrical body, and then form the housing 3 covering the outer surface, thereby forming the window. The joining portion between the member 2 and the housing 3 is joined in a liquid-tight manner to prevent water leakage. <Selection of antibacterial agent for casing of electronic thermometer according to the present embodiment> As a kind of the antibacterial agent mixed into the casing material used at the time of the secondary injection, there is a material shown in Table 1 below.

[0011]

[Table 1] Among them, 1. 1. safety data, clinical trials, proven antimicrobial agents; An antibacterial agent having good matching with the resin used was studied intensely, and a silver zirconium phosphate compound was selected.

The evaluation of the safety of the silver zirconium phosphate compound is shown in Table 2 below.

[0013]

[Table 2] [Eluate Evaluation Content] Ag ⁺ concentration (ppm) less than 0.01 (ppm) In the present embodiment, a silver zirconium phosphate compound used as an antibacterial agent has the following general formula: Ag _n1 H _m1 Zr ₂ (PO ₄ ) ₃ .. (1) or Ag _n2 H _m2 Zr ₂ (PO ₄ ) ₂ .k H ₂ O (2)

Here, n1 + m1 = 1.0, n1 =
0.1-0.2, n2 + m2 = 2.0, n2 = 0.0
1 to 0.03, k = 1.5 to 1.8. (Setting of the amount of addition) Next, the amount of the silver zirconium phosphate compound added is set to 1.0 under the condition that the antibacterial effect is surely observed, and that there is no problem in terms of molding, appearance and printing. ２．５2.5% by weight.

<Zirconium phosphate silverization of the present embodiment>
Production Example of Resin Material Added to Compound> 2 to 4% (% by weight) of silver
Supported zirconium phosphate compound [Ag_n1H_m1Zr _Two 
(PO_Four )_Three Or Ag_n2H_m2Zr_Two (PO_Four )_Two ・
k H_Two O] 20% by weight of zinc oxide 20%
80 parts by weight of ceramic powder mixed with 80% rilonite
, And mixed well, then molded and fired at 800 ° C.
You.

Through the above-described steps and the like, the pigment (Benga
La, titanium white, titanium yellow, etc.) 1-4 weight
%, Silver zirconium phosphate compound (Ag_n1H_m1Zr_Two 
(PO _Four )_Three ) Containing 1 to 2.5% by weight of the antibacterial agent
Tylene resin (High impact styrene, ABS tree
Fats), polyolefin resins (polypropylene, polyether)
Synthetic resin pellets (about 3 mm square) such as
You.

<Example of Manufacturing Process of Electronic Thermometer Housing of the Present Embodiment> Next, the manufacturing process of the electronic thermometer housing of the present embodiment will be described more specifically. In the electronic thermometer shown in FIGS. 1 to 4, a mold having a cavity having the outer shape of the window member 2 and a core having the shape of the cylindrical body is used as the primary injection machine. Then, primary injection is performed with the above-described transparent resin using this mold. Thereafter, the core and the molded window member 2 are both pulled out from the cavity, inverted, and the core is moved to the secondary injection machine.

The secondary injection machine has a cavity having the outer shape of the housing 3, into which the core having the window member 2 is inserted. Then, the synthetic resin pellets are mixed with each other for 180 to 25.
By performing the secondary injection with the material heated to 0 ° C., the opaque resin adheres to the portion except for the window, and the product is taken out.

[0019]

EXAMPLES The results of studies on the moldability, antibacterial properties and safety of the electronic thermometer of the present embodiment will be described below. <Moldability>. Moldability: Table 3 shows the results of confirming the prototype.

[0020]

[Table 3] From the above table, there is no problem in appearance after molding, up to the addition of 2.5% by weight of the silver zirconium phosphate compound. Appearance: Confirmed with a color difference meter after irradiating UV light for 5 years.
The color difference is less than 1.5 and there is no visual problem. . Yield: equivalent to no antimicrobial agent.

<Antibacterial property and safety> (Antibacterial property) << Representative of pathogenic microorganisms (bacteria causing food poisoning, infectious disease, etc.) >> Escherichia coli, Staphylococcus aureus << Evaluation method >> Film adhesion method << Setting criteria >> A brief summary of the Voluntary Standards '95 (unpublished in '95) below, based on the Voluntary Standards '95 of the "Study Group for Inorganic Antibacterial Agents such as Silver" sponsored by the Japan Food Research Laboratories.・ Test method Film adhesion method ・ Test bacteria Staphylococcus aureus (Staphylococcus aureus), Escherichia coli (E. coli) 1. Prepare three test pieces each cut into a 15 mm square and wiped with alcohol. 2. Each test piece is inoculated with a reference bacterial solution, and a 10 mm square designated coating film is placed thereon. 3. The inoculated reference bacterial solution was inoculated on the three sterilized petri dishes and covered with the specified coating film. The “control group” was used as the “control section” immediately after inoculation of the bacterial solution and after storage at 35 ° C. for 24 hours. The number of control cells is referred to as "the number of control cells". 4. Check the number of cells growing on each test piece after storage at 35 ° C. for 24 hours.

The sample without antimicrobial agent was added to the "No processing test zone".
The criteria are as follows:-Criteria The ratio between the sample and blank cell counts is 1/100 when the increase / decrease in the cell culture (the above three test plots) satisfies certain conditions. << Setting Contents >> 1.5% was set as the addition amount of the silver zirconium phosphate compound satisfying the above standard. << Setting Contents >> FIG. 5 shows the evaluation results.

FIG. 5 shows that the silver zirconium phosphate compound has an excellent antibacterial property in the range of 1 to 2.5%, particularly 1.5 to 2.5% by weight, and satisfies the above-mentioned voluntary standard '95. I understand. (Safety) Acute toxicity LD50 (oral mouse): 5,000 mg /
More than kg Primary skin irritation of rabbit skin: No skin irritation reaction was observed. Mutagenicity: Negative.

(Conclusion of Evaluation) Table 4 below shows an outline of the comparison and features of the conventional thermometer containing an antibacterial agent.

[0025]

[Table 4]As a housing for an electronic thermometer, changes over time, strength, and light weight
High impact styrene from the viewpoint of chemical conversion and chemical resistance
Resin and ABS resin are used. Note that the above embodiment and
The above-mentioned characteristics exhibiting similar properties without being limited to
Synthetic resin silver zirconium phosphate compound (Ag_n2H_m2Z
r_Two (PO_Four )_Two ・ K H _Two O) High impact ste
1.0-2.5% by weight kneaded into roll resin and ABS resin
Almost the same antibacterial properties and safety
Was.

In the present embodiment, a case for an electronic thermometer has been described as an antibacterial resin. However, a case for housing an electronic thermometer, a case for medical equipment such as an infusion pump, a syringe pump, and an electronic sphygmomanometer, The present invention can also be applied as a cuff or the like for an electronic sphygmomanometer.

[0027]

According to the present invention, it is possible to provide an electronic thermometer which has a higher antibacterial effect than silver zeolite, silver silica gel and the like, satisfies the voluntary standard '95, has less discoloration of the resin, and has good moldability.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration example of an electronic thermometer 1 according to the present embodiment.

FIG. 2 is a longitudinal sectional view of FIG.

FIG. 3 is a cross-sectional view after completion of molding of a body of a housing.

FIG. 4 is a sectional view taken along line CC ′ of FIG. 3;

FIG. 5 is a diagram showing a comparative example of antibacterial properties in this example.

[Explanation of symbols]

 2 Window member 3 Housing member 4 Body of housing 5 Probe 6 Operation display unit 7 Power supply battery 25 Display window 51 Probe cap 81 Rear cap 85 Battery holder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23/00 C08L 23/00 25/08 25/08 33/12 33/12 59/00 59/00 67/03 67/03 69/00 69/00 71/12 71/12

Claims (2)

[Claims] 1. An electronic thermometer for accommodating a circuit board, a power supply battery, and the like inside a casing, wherein the casing contains a silver zirconium phosphate compound substantially in the range of 1-2.
An electronic thermometer formed of a synthetic resin containing 5% by weight. 2. The synthetic resin is a polyether such as polyphenylene oxide; polyethylene terephthalate;
Polyester such as polybutylene terephthalate; polyacetal; acrylic resin such as polymethyl methacrylate; styrene resin such as ABS resin, high impact styrene; polyolefin resin such as poly-2-methylpentene and polypropylene; 2. The electronic thermometer according to claim 1, wherein the resin is selected from opaque or colored resin.