JPH0310638Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a synthetic resin molded product having an antistatic effect.More specifically, a void is provided along the side wall or plane wall of the synthetic resin molded product, and the inner periphery of this void is provided. By encircling the conductive layer made of antistatic agent, the antistatic effect is extremely high.
The present invention relates to a synthetic resin molded product that is durable and effective regardless of changes in the humidity of the outside air.

The surface of a synthetic resin has the property of being easily charged, and therefore it is necessary to change these properties by modifying the surface. This antistatic treatment can be roughly divided into coating methods and kneading methods, and both of these methods form a layer consisting of an antistatic agent on the surface, but these conventional antistatic agents rely on the action of hydroxide ions. This allows it to constantly absorb moisture and be effective. Figure 1 is a graph showing the correlation between humidity and antistatic effect.The effect does not decrease significantly up to about 50% humidity, but when the humidity drops below 20%, the effect decreases so much that it is no longer practical. There are many cases.
As the outside air or indoor humidity decreases, static electricity is more likely to be generated on the surface of the synthetic resin, but at the same time, the antistatic effect decreases. In other words, the conventional treatment method using an antistatic agent has the drawback that its effectiveness is greatly affected by the outside air, especially humidity. Further, in conventional synthetic resins in which an antistatic layer is provided on the surface, there is a risk that these layers will gradually peel off due to contact with other substances, water, solvents, etc., and the durability is poor. Furthermore, when this was used in a container, the antistatic layer was exposed on the inner and outer surfaces of the container, which could have an adverse effect on the stored items.

This idea was made in consideration of these points. When dielectric materials such as synthetic resins are stacked on top of each other, static electricity is generated due to contact pressure (frictional force). Electromagnetically, it is also possible to generate static electricity due to contact with the surrounding air. Focusing on the fact that static electricity is likely to be generated on surfaces, but it is even more likely to be generated and accumulated due to contact between high dielectric materials or close interfaces,
The present invention provides a molded product in which a conductive material made of an antistatic agent or the like is formed in areas where static electricity is likely to be generated and stored, and voids are provided between the conductive layers, thereby preventing the generation of static electricity and Even if static electricity occurs, it has a high antistatic effect that instantly removes it, and the conductive layer is not exposed on the outer surface, so there is no contact with other objects, and it is highly durable.
A molded product with safe antistatic treatment can be obtained.

An embodiment of this invention will be described below with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a plastic cardboard box. This cardboard box 1 is made up of a number of ribs 4 provided at regular intervals between upper and lower plates 2 and 3 that are parallel to each other at regular intervals. An extremely thin film 6 made of an antistatic agent is provided on the inner circumferential wall of each cavity 5 surrounded by the ribs 4 and 4.

For example, in this embodiment, when extrusion molding molten plastic, air is sent to hold the void 5 of the cardboard 1 immediately after being extruded from the mold, and this air is mixed with an antistatic agent. By spraying this aerosol with air, including an aerosol consisting of a large number of particles formed from a solution containing water, the aerosol particles adhere to the heated inner peripheral wall of the cavity 5, and the water instantly evaporates. The antistatic agent remains as a film,
Particles do not adhere to this surface, but instead adhere to the periphery of the coating one after another, forming an extremely thin film 6 over the entire inner circumference of the cavity 5.

The thickness of the upper and lower boards 2 and 3 of the cardboard box above is
The thickness of the ultra-thin film is about 100-400μ, about 0.001μ-0.01μ,
The conductivity is preferably about 10 ⁸ to 10 ¹² Ω.

In this embodiment, the upper and lower plates 2 and 3 are thin,
Since the opposing ultra-thin films 6 on the inner periphery of the cavity 5 have the cavity 5 interposed therebetween, the area becomes a high dielectric material,
Static electricity generated on the inner and outer surfaces of the lower plates 2 and 3 is concentrated on these extremely thin films 6, and the different charges cancel each other out, and are instantly erased. Therefore, even if another object comes into contact with or rubs against the outer surface of the cardboard 1, static electricity is not generated, and even if static electricity is generated, it is instantly erased. Furthermore, when the upper plates 2 and 3 are somewhat movable, the ultra-thin film 6 moves, allowing electricity to move easily, and furthermore, the antistatic effect is high. In addition, this cardboard 1 has an ultra-thin film 6 made of an antistatic agent formed only in the cavity 5, so the antistatic agent is not exposed to the outside surface and this cardboard 1 does not come into contact with other substances such as water or solvent. The ultra-thin film 6 is also durable without peeling. Furthermore, even when a container is made from this cardboard 1, the ultra-thin film 6 does not come into contact with the items stored in the container and does not affect the items stored therein. Furthermore, although both ends of the voids 5 of this cardboard box 1 are open, the inside of each void 5 is made of a narrow cloth so that no air flows in and has the same effect as if it were sealed. Even if the agent contains the required amount of water, it can retain the water and therefore maintain its antistatic effect regardless of changes in the humidity of the outside air. Further, if the antistatic agent used in the ultra-thin film 6 is a type of surfactant, an antifogging effect is produced and the upper and lower plates 2 and 3 of the cardboard 1 do not fog.

Fig. 3 shows a case 7 made of plastics or the like made by extrusion molding, and this case 7 has an outer peripheral wall 8 with a thickness of 200 μm and an inner peripheral wall 9 with a thickness of 200 μm that is approximately similar to the outer peripheral wall 8, and between these A rib 10 is provided on the outer circumferential wall 8, an inner circumferential wall 9, or a rib 10 to connect these.
An ultra-thin film 12 made of an antistatic agent is formed on the inner circumferential wall of each void 11 surrounded by.
Electronic components such as ICs and LSIs are sensitive to static electricity, and therefore cases for storing and transporting these must be treated with antistatic treatment. The coating film moves and scatters, causing a so-called island phenomenon, which causes the antistatic agent to lose its effectiveness and at the same time adhere to the electronic components, which are the contents, which could have an adverse effect on the electronic components. In this regard, in this embodiment, as described above, the ultra-thin film 12 is provided inside the side wall of the case 7 with the cavity 11 interposed therebetween.
The static electricity generated on the inner and outer surfaces of the case 7 is concentrated and immediately eliminated. Therefore, even if the electronic component 13 is placed in the case 7, static electricity will not flow to the electronic component 10.
It is safe, and the ultra-thin film 11 is not exposed on the inner and outer surfaces of the case 7, so the antistatic agent does not adhere to the electronic component 10, and the electronic component 10 is not affected. Also, this embodiment can be easily manufactured in the same way as the one shown in FIG.

FIG. 4 also shows a part of a side wall 18 of a molded product, which has a conductive layer 16 between the outer peripheral layer 14 and the inner peripheral layer 15, and has voids 17 at appropriate intervals along the conductive layer 16. Yes, and Fig. 5 shows the side wall 19 of the molded product.
Convex portions 20 are provided at regular intervals along the side wall 19 on the outer surface of each of the convex portions 20, and a void portion 21 is provided along the convex shape, and a conductive layer 22 is provided on the inner circumferential wall of each void portion 21. It has been established.

Further, FIG. 6 shows a synthetic resin fiber 23, which has a void 24 along the longitudinal direction, and a conductive layer 25 covers the inner circumferential wall of this void 24. It is something.

In the case shown in FIG. 7, gaps 28 are bored in the longitudinal direction at intervals along the side wall 27 of a plastic hose or tube 26.
8, a conductive layer 29 is provided on the inner circumference. What is shown in FIG. 8 is a hose or tube 26' in which the cross section of the cavity 28 is greatly extended along the circumference, and a conductive layer 29' is also provided on the inner periphery of the cavity 28'.

In the case of these embodiments as well, electrical conductivity is provided opposite to each other through a gap in locations where static electricity is likely to be generated or stored, so that the static electricity generated on the inner and outer surfaces of the molded product is collected here and immediately erased. , has an extremely high antistatic effect, and furthermore, these conductive layers are not exposed on the inner and outer surfaces of the molded product, are durable, and do not adversely affect other objects with which it comes in contact. Furthermore, even if conventional antistatic agents that require a certain amount of moisture are used, the voids are small in diameter or narrow, so no air enters except for the openings, making it the same as if they were sealed, making it impossible to retain moisture. , the antistatic effect can be maintained regardless of changes in the humidity of the outside air.

[Claims for Utility Model Registration] Inside the side wall, along the side wall, small diameter or narrow voids are provided integrally or continuously in close proximity to the inner and outer surfaces of the side wall, and these voids are open on at least one side. 1. A synthetic resin molded product having an antistatic effect, characterized in that the inner peripheral wall of the cavity is provided with a conductive layer made of an antistatic agent or the like.

[Brief explanation of the drawing]

Figure 1 is a graph showing the correlation between humidity and antistatic effect, Figure 2 is a perspective view showing an example of this invention being used for plastic cardboard, and Figure 3 is an example of using this invention for an electronic component case. FIGS. 4 and 5 are partial perspective views showing other embodiments of this invention, FIG. 6 is a perspective view showing an example in which this invention is applied to synthetic resin fibers, and FIG. 7 is a perspective view showing an example. Figure, 8th
The figures are perspective views showing examples in which this invention is applied to a plastic hose or tube. In the figure, 1 is a plastic cardboard, 2 is an upper plate, 3 is a lower plate, 4 is a rib, 5 is a cavity, 6 is an extremely thin film, 8 is an outer peripheral wall, 9 is an inner peripheral wall, 11 is a cavity,
12 is an extremely thin film, 23 is a synthetic fiber, 24 is a void,
25 is a conductive layer.