JPH02300263A - Polymer material - Google Patents

Abstract

PURPOSE:To obtain a polymer material capable of removing electrostatic interference without using earth by compounding a polymer with an ultrafine carbon fiber, thereby lowering the surface resistance of the polymer below a specified value. CONSTITUTION:The conductivity of a polymer is controlled by compounding a polymer (e.g. a rubbery material such as butadiene, a plastic material such as PE, or a coating material such as oil paint) with an ultrafine carbon fiber and lowering the surface resistance of the polymer to 10<11>OMEGA or below. It is thus possible to remove electricity without using earth and the electricity removing effect is extremely good. This polymer is effective when it is used for various products wherein electrostatic interference is apt to occur.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a new polymeric material with anti-static measures, and is particularly suitable for use in materials susceptible to electrostatic damage.

<Prior art and problems to be solved by the invention> Conventionally, when insulating materials such as paper and films are conveyed in equipment such as printing machines, copying machines, and printers, contact and I9 [rubbing] occur. Static electricity is generated due to peeling, etc., which causes problems such as wrapping and paper jams.

For this reason, in the past, antistatic agents were added,
A roller containing conductive carbon is used to reduce the generation of static electricity.

However, the former has problems in that it becomes less effective when the humidity is low, and the latter requires the use of a ground connection.

Further, there is a problem in that it is difficult to remove static electricity from paper or film that has become charged again after static electricity removal.

On the other hand, it is generally known that static electricity charged in the human body is discharged when the human body comes into contact with a conductor, causing a person to feel a strong shock.

For this reason, conventionally, various measures have been taken to prevent the human body from being charged with electricity, but there is no decisive factor since the causes of this occurrence are wide-ranging.

As described above, the current situation is that countermeasures against electrostatic disturbances (malfunction of 8i devices, discharge shock from the human body, etc.) are still insufficient.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a novel polymer material that can eliminate electrostatic interference without the need for grounding.

Means for Solving the Problems> The composition of the polymeric material of the present invention for achieving the above object is that ultrafine carbon la fibers are blended with a polymer, and the surface resistance of the polymer is 10" or less than 1 Ω. It is characterized by

Here, in the present invention, polymers include, for example, rubber materials, plastic materials, paints, and the like.

Examples of the above-mentioned rubber materials include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2
-Polybutadiene rubber (1,2-BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR).

Nitrile rubber (NBR), butyl rubber (IIR).

Ethylene-propylene rubber (EPM, EPDM).

Chlorosulfonated polyethylene (CSM).

Various rubber materials such as acrylic rubber (ACM, ANN), epichlorohydrin rubber (Go, EC0), multi-FIt rubber (T), silicone rubber (Q), fluorine rubber (FKM, FZ), urethane rubber (U), etc. Can you name it? For example, softeners and fillers are added to this rubber-based material.

Vulcanizing agents, vulcanization accelerators, vulcanization accelerators, antioxidants, ozone deterioration inhibitors, etc. may be appropriately blended depending on the purpose.

Examples of the above-mentioned plastic materials include polyethylene (
PE),,l? Ribrovirene (pp).

Polyolefin derivative, polystyrene (PS).

Halogen-containing plastics, acrylic plastics,
Addition polymer plastics such as polyvinyl acetate (PVAC) and its derivatives, such as alkyd resins, unsaturated polyester resins, polyethylene terephthalate (PET)
).

Polybutylene terephthalate (PB'T), polycarbonate, polyphenylene oxide (ppo), polyimide (pH), polyamide (PA), silicone resin (31
) and other polycondensation-based plus decks, such as phenolic resins (
Addition condensation plastics such as PF), urea resins (UF), and melamine resins (MF), such as polyurethane (AU:
Examples include various plastics such as polyaddition plastics such as ether type (EtJ: ester type), epoxy resins, and ring-opening polymerization plastics such as polyacetal and polyether plastics.

Examples of the above-mentioned paints include various paints such as oil-based paints, synthetic resin paints, cellulose derivative paints, alcoholic paints, water-based paints, emulsion paints, powder paints, and electrodeposition paints.

The ultrafine carbon fibers to be blended into the above polymer are those with extremely thin fiber diameters, for example, several micrometers, and the blending amount is 2 to 30 parts, preferably 5 parts to 100 parts of the polymer.
~10 parts is good.

This is because if the amount is 2 parts, the static elimination effect will be low, and if it is 30 parts or more, there will be problems with moldability.

This ultrafine carbon fiber discharges the generated static electricity into the air as a corona discharge, and its static elimination mechanism will be explained with reference to FIG. 1.

A charged object 10 charged with static electricity shown in FIG.
When approaching the ultra-fine carbon fiber CF (or vice versa), an electric field is generated in the ultra-fine carbon fiber CF, which is a conductor, due to electrostatic induction. Since the tip of the ultra-fine carbon fiber CF is extremely thin, the electric field is strong, causing dielectric breakdown of the surrounding air and ionization, generating ions of θ. This is a corona discharge, and among the generated ions, ions with the opposite polarity to the charged object are attracted and neutralization occurs (Figure 1 (bl
reference).

How can a charged object be neutralized?

Further, the corona discharge that occurs here is different from spark discharge and the like, and the energy generated due to the discharge is weak and does not have enough energy to ignite or destroy the IC.

In order to synergistically enhance this static elimination mechanism, the electrical resistance (Ω) of the rubber material may be set to 10' or less, preferably 10' or less, and the conductivity may be controlled.

Examples of things that control this conductivity include carbon black and fine metal powder.

A double salt of oxidized Ator or Zn can be mentioned.

In addition, when the polymeric material of the present invention is used particularly as a material for preventing static electricity on the human body, the electrical resistance (R) should be 106Ω<R<10”Ω, preferably 1
06Ω<R<1010Ω, and the blending amount (V) of the ultrafine carbon fiber is preferably 1 part <V<10 parts, preferably 3 parts to 8 parts, based on 100 parts of the polymer.

Since the polymer material of the present invention eliminates static electricity by corona discharge, it is not necessarily necessary to provide a ground, and furthermore, it has high dynamic durability and has no humidity dependence. These rubber-based materials are industrial products and household items that may generate static electricity.

It is useful for all other things.

An example of this reaction is shown in Table 1 (materials for functional parts) and Table 2 (materials for countermeasures against human body static electricity).

Table 1 (Materials for Functional Parts) Test Examples> Next, test examples using rubber materials that demonstrate the effects of the present invention will be described.

Test Example 1 A test example in which the material is used as a functional component material will be described with reference to FIG. 2 ta+ (C1).

The object 11 was charged using an electrostatic high-voltage generator 12 (see FIG. 2 (al). Next, ultrafine carbon fibers (fiber diameter 6 to
Added 7 μm "Tsurdion" (trade name: (manufactured by 11 Toshi; the same applies to this test example below), and the surface resistance (R)
Rubber material 13 for functional parts with 3 x 10'Ω,
The charge was removed by contacting the charged object 11.

At this time, the charged voltage before and after static elimination was measured using a charged voltage measurement@14 in the case where no grounding was performed (insulated) and when the grounding was performed (grounded).

The measurement results are shown in Table 3.

Comparative Example 1 In place of the rubber material used in Test Example 1, two types of general rubber materials (ratio -1-a: conductive state) were used.

The same procedure as in Test Example 1 was performed using Ratio-1-b: conductive.

These results are shown in Table 3.

As shown in Table 3, it can be seen that even in the case of no earthing, the polymer material of this test example has a high static elimination effect due to the synergistic effect of conductivity and air discharge. Furthermore, even when grounded, the static elimination effect was higher than that of highly conductive rubber materials.

Test Example 2 Next, with reference to FIGS. 3(a-1) to (c), a test example in which a moon is used as a countermeasure against electrostatic charge on the human body will be described.

In this test example, ultrafine carbon fiber was added and the surface resistance (
A rubber material (grounded) 15 for countermeasures against electrostatic charge on the human body was used in which R) was set to I×10I0Ω. With a charging voltage of 10 KV, static electricity is generated on the object 11 by the electrostatic high voltage generator 12, and the charged object 11 is moved while standing on the insulating plate 16.
The human body 17 was brought into contact with the human body 17, and the human body 17 was electrically charged. Next, it was brought into contact with the rubber material 15, and the charged voltage before and after that was measured by the charged voltage measuring device 14, and the static electricity removal rate was determined. We also investigated whether or not there was an electrical discharge sensation felt on the human body upon contact.

Comparative Example 2 In place of the rubber material used in Test Example 2, the rubber material of Test-1 and two types of general rubber materials (non-conductive, conductive) were used, and the same procedure as in Test Example 2 was carried out. did.

The results are shown in Table 4.

Table 4 Ratio-1-a General rubber material (conductive state) Ratio-1-b
(g conductivity) As shown in Table 4,
The rubber material used to prevent electrostatic charges on the human body in this test example can remove static electricity without feeling the electrostatic charge on the human body.

Example of implementation Preferred embodiments of the present invention will be described below.

Example 1 A roller for use in a conveyance roller of a copying machine was manufactured using the following formulation as a rubber material for functional parts.

Mixed medium high nitrile rubber 100 (parts) Stearic acid 1 Zinc white 5 Carbon black 20 Accelerator 2 Sulfur 2 total
140 * "Tsurdion" (Product name: @ Azuma) in diameter 6
~7 μm Similarly to Test Example 1 (no ground) described above, the reference voltage was set to 15 to 18 KV, and the charged voltage before and after static electricity removal and the static electricity removal rate were determined.

The results are shown in Table 5.

The material properties were as shown in Table 6.

Table 5 Table 6 When the above roller was used in a copying machine where paper jams sometimes occur, troubles such as paper jams almost disappeared.
two.

This is because when a conventional conductive roller is used, the electrically charged insulating paper is temporarily neutralized, but when it is conveyed and separated from the roller, charging and development occur again. However, if the roller according to this embodiment is used, even after contact with the roller and removing static electricity, the paper will be prevented from being charged due to the air discharge action of the ultra-fine carbon fibers blended in, even when separated from the roller. This is because it is.

Example 2 A sheet for use in a keyboard mat was manufactured using the following formulation as a rubber material for preventing static electricity on the human body.

Compound Medium high nitrile rubber 100 (parts) Stearic acid 1 Zinc white 5 White carbon 40 Process oil 10 Accelerator 2 Sulfur 2 total
168 * "Tsurdion" (Product name: ■ Made by Toshi) Fiber diameter 6
~7 μm In the same manner as in Test Example 2 described above, the charged voltage before and after static electricity removal and the static electricity removal rate were determined.

The results are shown in Table 7.

The properties of this material were as shown in Table 6.

When the sheet obtained above was used as a keyboard mat, no problems with static electricity were felt.

<Effects of the Invention> As described above in detail with the test examples and examples, the polymer material of the present invention combines ultrafine carbon fibers with the polymer and controls the conductivity, so that static electricity can be eliminated without the need for grounding. Furthermore, the static elimination effect is extremely efficient, making it suitable for use in products that are prone to various electrostatic disturbances.

4 Brief explanation of the drawings Figure 1 (al, tb) is a schematic diagram showing the static elimination mechanism of ultrafine carbon wA fibers, Figure 2 (al to (C) is a test of polymer materials used as materials for functional parts) Example explanatory diagram, Figure 3 (al
~tc+ is an explanatory diagram of a test example of a polymer material used as a material for preventing static electricity on the human body.

In the figure, 10 is a charged object, 11 is an object, 12 is an electrostatic high voltage generator; 13 is a rubber material for functional parts; 14 is a charging voltage measuring device; 15 is a rubber material for preventing static electricity on the human body; 16 is an insulating plate; 17 is a human body.

Patent applicant Hokushin Industries Co., Ltd. People

Claims (1)

[Claims] A polymeric material made by blending ultrafine carbon fibers with a polymer, and characterized in that the surface resistance of the polymer is 10^1^1Ω or less.