JPH0316122B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing conductive footwear having an antistatic effect. In recent years, with the development of the electronics industry, unexpected disasters due to the accumulation of static electricity have been occurring frequently, and static electricity removal has become a major problem in related industries. For example, precision electronic machinery manufacturing factories use LSIs, long LSIs, etc. to mass produce high-mechanical equipment. LSI and VLSI circuits are constructed in micron units, and can be damaged by small charges or dust particles. In such workplaces, static electricity builds up due to the friction of workers' clothing, and the resulting dust builds up, so a lot of labor is spent removing static electricity, creating a dust-free factory, and special management is in place. In order to prevent dangers, disasters, accidents, unexpected shocks, etc. caused by static electricity, shoes with an electrical resistance value within a certain range must be worn. Various proposals have been made regarding the structure of such antistatic shoes, and conductive resin compositions having appropriate resistance values have been proposed as injection molding resins for shoe soles. These shoes comply with JIS-T-8103, which stipulates that the electrical resistance value be 1.0 × 10 ⁵ to 1.0 × 10 ⁸ Ω when worn as shoes, but the contact surface and A metal is used between the ground planes to lower the resistance value (the lower limit voltage for static electricity removal is lower)
etc. are also on the market. However, these antistatic shoes have a low electrical resistance value, so they are resistant to dynamic electricity.
The conductivity was too good and could cause an electric shock accident. By the way, even in workplaces that are isolated as dust-free factories, assembly machines use dynamic electricity, and the people who handle these machines also remove static electricity caused by friction on clothing, and prevent electrocution accidents caused by dynamic electricity. Ordinary antistatic shoes could not satisfy these conflicting requirements. An object of the present invention is to easily manufacture conductive footwear having an electrical resistance value suitable for the workplace when used in a workplace environment where static electricity is averse. In other words, the insole material itself has a conductive structure that is a conductive layer, or the insole material has a conductive structure in which a conductive layer with an area of 200 cm ² or less is provided and a conductive path is provided between the conductive layer and the contact surface. Sewn the laces, hang them on the last, attach the side molds and bottom molds, and adjust the bottom thickness.
A void of 0.2 to 3.0 cm is provided, and the void is injection molded with an injection moldable injection resin compound having a volume resistivity of 1.0×10 ⁶ to 1.0×10 ¹³ ohm-cm. The present invention relates to a method for manufacturing conductive footwear. Volume specific resistance value (ρΩ−cm) used in the present invention
There is the following relationship between the electrode area (Scm ² ), the sole thickness (lcm), and the electrical resistance value (R, Ω) of the shoe. R=ρ・l/S In the present invention, the range of (1) ρ=1.0×10 ⁶ to 1.0×10 ¹³ Ω−cm (2) S=200 cm ² or less (3) l=0.2 cm to 3.0 cm is specified. , by any combination thereof, any electrical resistance value suitable for the workplace can be obtained. Here, (1) the volume resistivity value (ρΩ−cm) is determined as a function of temperature, and must be determined under the temperature conditions of 0 to 35° C. under which the footwear is worn. (2) When the area (Scm) has a large value, the value of R can be reduced, but at most it can only take a value equivalent to the sole area of footwear. (3) The smaller (lcm) is, the lower the value of R can be, but the thickness must be made in consideration of shoe wear, foot feel, weight, moldability, etc. The volume resistivity value ρΩ-cm described above, the electrode area S
cm ² , shoe sole thickness lcm, and shoe electrode resistance RΩ, according to the present invention, the volume resistivity, which is generally considered an insulating pair, is 1.0×
Desired conductive footwear can also be obtained using resins or resin blends with a resistance of 10 ¹⁰ Ω or more. This is because the ratio of electrode area to sole thickness can be set to 1.0×10 ^-3 . The structure of the conductive layer used in the present invention includes a structure in which the insole material itself is the conductive layer, and a conductive structure in which a conductive layer with an area of 200 cm ² or less is provided and a conductive path is provided between the conductive layer and the contact surface. can be used. For a structure in which the insole material itself becomes a conductive layer, a conductive material such as carbon ink may be applied to both sides of the insole material to form a conductive layer, or a conductive material may be applied only to the injection resin surface of the insole material. The inner sole material may be sewn with conductive thread such as carbon-coated thread, or a fabric may be used as the inner sole material, and some or all of the threads of the fabric may be woven or netted fabric using conductive thread. You can also use it as Examples include: As shown in FIG. 1, conductive threads are woven at uniform intervals as constituent threads of the inner sole fabric. FIG. 1 is a perspective view showing the sole of the shoe. However, the cover is omitted. In the figure, 1 is a shoe sole resin, 2 is an insole fabric, and 3 is its conductive thread. As shown in FIG. 2, the paste surface of the insole fabric is coated with a polyvinyl chloride paste mixture under the insole, and is printed on the entire surface or locally (for example, in a pattern) using conductive printing ink, Uses insole fabric sewn with conductive thread so that both sides of the insole are exposed. Figure 2 is a schematic cross-sectional view showing this.
1 represents a shoe sole resin, 2 represents a high sole fabric, 3 represents a penetrating conductive thread, 4 represents a conductive printing ink layer, and 5 represents a polyvinyl chloride paste compound. An insole fabric is used in which both sides of a fabric with sparse threads are printed on the entire surface or locally using conductive printing ink, and the printing ink oozes out to make both sides conductive. As shown in FIG.
7cm x 2 pieces/one shoe were sewn in (manufactured by Mimaki Co., Ltd.), and conductive printing ink was applied to the sole of the insole fabric in a lattice pattern at 1cm intervals. FIG. 3 shows a schematic cross-sectional view of the inner sole fabric. The insole material has a structure in which a conductive layer with an area of 200 cm ² or less is provided and a conductive path is provided between the contact surfaces of the conductive layer. A conductive layer with an area of 200 cm ² or less is provided using a single layer or a laminated layer of conductive resin-containing film such as cloth, nonwoven fabric, net cloth, or carbon black, and then a defect that is a conductive path is formed in a part of the bottom material. It may also be a structure in which a portion is provided and then the conductive layer is adhered to the lower surface of the midsole material having the defective portion. Since these materials are easily expanded by the pressure of the injection resin, they are pushed out into the defective part of the insole material, and the conductive layer itself passes through the conductive path and is exposed on the surface of the insole material, which is the contact surface. Examples of the ingredients are listed below. FIG. 4 is a perspective view showing a part of the sole contacting part of the shoe sole according to the present invention. In the figure, 1 is a shoe sole resin, 2 is an insole fabric, 6 is a hole, and 7 is a conductive layer, specifically conductive treated cold sand (resistance value: 10 ³ Ω). At this time, a conductive resin film may be attached to the sole side of the cold sand. FIG. 5 is a schematic cross-sectional view of the hole, and due to the injection pressure of the injected molten resin,
This shows how the wire holes in the conductive layer are exposed on the resin surface. Such a conductive layer is provided between the sole conductive resin compound and the insole fabric, and a part of it is exposed in the insole hole to serve as a contact electrode with the sole of the foot. To provide footwear that can be safely used as antistatic footwear by preventing electric shock while providing a more stable electrical resistance value within an appropriate range even under low temperature and low humidity environments. FIG. 6 shows another embodiment. In this fabric, a ring shape and radiation from the ring are drawn with conductive paint on both the front and back sides of the fabric around the hole in the insole fabric 2, and the inside surface of the hole is painted with the same conductive paint. FIG. 7 is a sectional view showing the hole part, in which conductive paint is applied to the inner side 8 of the hole 6 of the insole fabric 2, the upper surface 9 around the hole, and the upper surface 10, respectively, and radiation 11 is applied from 9 and 10, respectively. , 12 are drawn with conductive paint. These types of conductive layers also function as electrostatic discharge electrodes to ensure that a constant resistance value is maintained at low temperatures and low humidity. As the main resin of the injection resin composition used in the present invention, resins commonly used for injection molding, such as polyvinyl chloride resin, can be used. Also, an example of an injection resin compound is polyvinyl chloride resin 100
Plasticizer (phthalic acid primary plasticizer,
0 to 60 parts of alkylbenzene-based secondary plasticizers, adipic acid-based polymeric plasticizers, etc. alone and mixtures, antistatic agents (cationic, anionic, nonionic surfactants, and combinations thereof) 0.1 to 60 parts 10 copies,
A formulation containing appropriate amounts of stabilizers, lubricants, pigments, etc. is used. As the footwear in the present invention, injection molded shoes (athletic shoes, casual shoes, rain boots, etc.), sandals, etc. can be used. Next, examples of the present invention will be explained in detail. Example 1 Kanreisha (thread; number 10, number of strokes is 15)
A conductive layer with an area of 56 cm ² was obtained by applying carbon ink to both sides of a book (1 inch) (coating amount: 200 g/m ² ) and cutting it by bias cutting. A hole with a diameter of 10 mm is made in the tread area and heel area of the insole material made of cotton fabric, and polyurethane adhesive is applied to one side. Next, the conductive layer is thermocompressed and fixed to the coated surface of the insole material. Next, the insole material with the conductive layer on the bottom side and the laces of the shoe are sewn together using the California method and hung from the last. Next, attach the side mold and bottom mold to approximately 4.5
A gap of mm is provided, and injection resin compound A is injection molded into the gap. Injection resin compound A Part by weight Polyvinyl chloride resin (resin polymerization degree = 1300) 100 DOP (dioctyl phthalate) 50 DBP (diptylphthalate) 30 Adipic acid polyester plasticizer 20 Antistatic agent (cationic/nonionic) 1.5 Calcium carbonate 20 NBR (nitrile butadiene rubber) / PVC kneaded product 5 Stabilizer (Organic tin mercapto type) 1.5 Lubricant (calcium stearate) 0.4 Pigment (anatase type titanium oxide) 3 After molding, release the side mold and bottom mold, and release from the last mold. Take off your shoes and get your shoes. The thickness of the sole was 4.5 mm, not including the mountain design on the tread area. The shoes thus obtained were able to provide a stable electrical resistance value within an appropriate range, and could be safely used as conductive footwear. these shoes
Based on test methods 6, 1, and 2 of JIS-T-8103,
The results of measuring the electrode resistance value [R]Ω are as follows.

[Table] From these results, the following equation was obtained between the electrical resistance value [R] MΩ and the temperature [t]°C. (however
1MΩ=1.0×10 ⁶ Ω) R (2.73×10 ^-3 ×t + 4.40×10 ^-4 ×t ² +
3.00×10 ^-6 ×t ³ ×1.7×10 ^-2 )=1 This result is graphed as shown in Figure 8,
Although the measured values and calculated values differed slightly at 30°C, they all agreed at other room temperatures. Example 2 Shoes were obtained using the same manufacturing method as in Example 1. However, the area of the conductive layer was 10 cm ² , the thickness of the sole was 5 mm, not including the mountain design on the tread part, and injection resin compound B was used.
was used. Injection resin compound B Part by weight polyvinyl chloride resin (resin polymerization degree = 1300)
100 DOP (dioctyl phthalate) 90 Alkylbenzene plasticizer 15 Antistatic agent (cationic/nonionic) 0.7 Calcium carbonate 20 Stabilizer (organic tin mercapto) 1.5 Lubricant (calcium stearate) 0.4 Pigment (anatase titanium oxide) 3 Like this The shoes obtained could provide a stable electrical resistance value within an appropriate range, and could be safely used as conductive footwear. This shoe is JIS
The results of measuring the electrical resistance value [R] Ω based on test methods 6, 1, and 2 of -T8103 are as follows.

[Table] From these results, the following equation was obtained between the electrical resistance value [R] MΩ and the temperature [t]°C. (however
1MΩ=0×10 ⁶ Ω) R(1.74×10 ^-3 ×t−1.35×10 ⁻⁴ ×t ² +
8.68×10 ^-6 ×t ³ +2.94×10 ^-3 )=1 Example 3 Shoes were obtained using the same manufacturing method as in Example 1. However, the area of the conductive layer is 60cm ² , the thickness of the sole is 5mm excluding the mountain design on the tread area, and the injection resin compound C
was used. Injection resin compound C Part by weight Polyvinyl chloride resin (resin polymerization degree = 1300)
100 DOP (dioctyl phthalate) 80 Alkylbenzene plasticizer 15 Antistatic agent (nonionic) 0.15 Calcium carbonate 15 Stabilizer (organotin mercapto) 1.3 Lubricant (calcium stearate) 0.4 Pigment (anatase titanium oxide) 3 In this way The obtained shoes were able to provide a stable electrical resistance value within an appropriate range, and could be safely used as conductive footwear. This shoe is JIS
The results of measuring the electrical resistance value [R] Ω based on test methods 6, 1, and 2 of -T8103 are as follows.

[Table] From these results, the following equation was obtained between the electrical resistance value [R] MΩ and the temperature [t]°C. (however
1MΩ=0×10 ⁶ Ω) R(1.0×10 ^-4 ×t−1.1×10 ^-5 ×t ² +6.
8×10 ^-7 ×t ³ +9.1×10 ^-5 )=1

[Brief explanation of the drawing]

Figure 1 shows the upper surface of the sole obtained according to the present invention.
A perspective view showing an example, and FIGS. 2 and 3 are schematic cross-sectional views showing an example of a shoe sole obtained by the present invention, respectively.
FIG. 4 is a perspective view showing a part of the sole contacting part of an example of a shoe sole obtained by the present invention, FIG. 5 is a schematic sectional view of the hole portion of the sole of FIG. 4, and FIG. A perspective view showing another aspect of the sole contacting part of the shoe sole obtained by the invention, FIG. 7 is a schematic cross-sectional view showing the hole part of the sole of the shoe in FIG. It is a graph showing the relationship between resistance value and temperature. DESCRIPTION OF SYMBOLS 1... Sole resin, 2... Insole fabric, 3... Conductive thread, 4... Conductive print ink layer, 5... Polyvinyl chloride paste formulation, 6... Hole, 7... Conductive layer.

Claims (1)

[Claims] 1 Has a conductive structure in which the insole material itself is a conductive layer, or
A conductive layer with an area of 200 cm ² or less is provided, an insole material having a conductive structure with a conductive path between the conductive layer and the contact surface is sewn, and the laces are hung from the last, and the side mold and bottom mold are attached. The bottom thickness is 0.2-3.0cm when attached.
A void with a volume resistivity of 1.0 is provided in the void.
1. A method for producing conductive footwear, comprising injection molding an injection resin compound having an injection resistance of 1.0 x 10 ⁶ to 1.0 x 10 ¹³ ohm-cm.