JP3398587B2 - Moldable antistatic resin molded product - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic resin molded article which has an antistatic property on its surface and is not accompanied by a substantial increase in surface resistivity even by a molding process.

[0002]

2. Description of the Related Art An antistatic synthetic resin molded article imparts antistatic property to the surface of the molded article, releases static electricity accumulated on the surface, and dislikes adhesion and accumulation of dust and dust on the surface of the molded article. Used for purposes.

To impart antistatic properties to synthetic resin molded articles,
Conventionally, conductive fine particles such as tin oxide and conductive fine particles such as carbon or fibers have been blended with a resin and uniformly dispersed. The mutual contact between these particles or between the fibers causes antistatic property and reduces the electrical resistance of the molded product.

It is also possible to impart the antistatic property only to the surface of the molded product by incorporating conductive particles or fibers only in the surface layer of the molded product. There is one formed by adhering a coating film or a film formed by containing conductive particles or fibers in a synthetic resin on the surface, and is used as an antistatic resin plate or the like.

[0005]

The above-mentioned conventional antistatic resin plate has a good antistatic property on the surface by forming a thermoplastic resin substrate and then laminating and forming the antistatic film. A resin plate having a surface resistivity of 10 ¹¹ Ω / □ or less is obtained. However, if the resin plate formed in this way is further heated and deformed such as bending or vacuum forming to expand the surface area, the surface resistivity after secondary molding becomes high, and the antistatic property is increased. There was a problem that it decreased. The surface resistivity generally increases due to the tensile deformation of the antistatic resin plate,
The reason for this is that the frequency of mutual contact between the conductive particles and fibers decreases due to the elongation of the resin in which the conductive particles and fibers are dispersed,
It is also considered that the mutual distance between particles becomes large.

Further, when the amount of deformation in the forming process is large and plastic deformation occurs, the fibrous conductive material is oriented in the direction of deformation, and therefore, mutual contact between fibers and maintenance of a conductive space. It can be seen that the frequency of is decreased and the surface resistivity is increased. This tendency is more likely to occur when the conductive material is a rigid short fiber.

As described above, if the antistatic resin plate is subsequently subjected to a forming process such as a secondary process, the surface resistivity of the processed product is increased and the antistatic property is deteriorated. Its use is limited. In such a case, it is possible to impart antistatic property by applying an antistatic coating to a desired site on the surface of the molded article after molding from a normal thermoplastic resin plate, but antistatic property is possible. A process for applying a conductive coating is required, and it is difficult to form a coating film having a complicated shape and a good surface property, and it is impossible to impart uniform antistatic property.

In view of the above problems, the present invention intends to provide a thermoformable antistatic resin molded article which does not cause a substantial increase in surface resistivity even by secondary processing after imparting antistatic property. To do.

[0009]

An antistatic resin molded article of the present invention comprises a thermoplastic resin substrate and an antistatic resin layer adhered to any surface of the resin substrate. However, the antistatic resin layer is formed by a coating film in which conductive long fibers are twisted and dispersed in a thermoplastic resin while being held in contact with each other and / or at intervals having conductivity. It will be. Even if this molded product undergoes deformation such as rolling down, stretching, bending, etc. of the antistatic resin layer due to subsequent heat processing, the meandering long fibers will only try to straighten and maintain a distance where they can contact and conduct each other. Therefore, the antistatic property of the resin layer can be maintained even after molding. As a result, it is possible to obtain an antistatic resin molded product that retains the antistatic moldability and the antistatic property at the same time even by secondary processing such as heat molding.

As such conductive long fibers, carbon fibers, metal fibers, electrically conductive organic fibers, etc. can be used, and the thin and long fibers that are as thin as possible are easily entangled with each other and easily contact and bend. Therefore, it is preferable. Particularly preferred are ultra-fine long carbon fibers. The ultrafine long carbon fibers have a property that they are easily entangled with each other and easily aggregate in a pill-like shape, and a large number of fibers are released from the pill-like fiber aggregate, and the pill-like fiber aggregate is uniformly dispersed in the thermoplastic resin. By making the fiber aggregates in the resin layer contact with each other and / or hold a conductive interval,
Antistatic property is imparted to the resin layer.

Conventional carbon fibers have a large wire diameter and are rigid, and there is no entanglement between the fibers. However, the long fibers used in the present invention, particularly the ultrafine carbon fibers, have ultrafine fibers, that is, Since the length is longer than the wire diameter, the carbon fibers are dispersed in the resin layer in a entangled state. The ultrafine carbon fibers entwined in a pill shape are easily dispersed in a pill shape and easily entangled. In order to make the carbon fibers into a pilllike aggregate, it is desirable that the wire diameter is 3.5 to 500 nm and the aspect ratio (ratio of the length to the wire diameter) is 100 to 3000. A large number of carbon fibers are released from this fluffy carbon fiber aggregate, and when the pilllike aggregates are close to each other, the carbon fibers radially protruding from the pill are extended in the resin layer. An electrically conductive state is formed by contacting each other or maintaining a space capable of conducting.

According to the present invention, a coating film of a resin coating solution containing conductive long fibers is formed on the surface of a substrate in order to maintain a wide range of dispersed state of the conductive long fibers in a resin layer in a small amount. .
Even if the film is heated and deformed for secondary processing after forming the coating film, the entanglement of the conductive long fibers in the resin layer can be maintained as a short circuit without being unraveled, and the reduction in antistatic property due to the processing is small. In the coating film containing ultra-fine long carbon fiber, the antistatic property is not lowered by the processing, but rather, by the appropriate reduction of the coating film due to the appropriate processing and molding, the pill-like aggregates or the aggregates in the coating film are separated from each other. The frequency with which a large number of protruding carbon fibers come in contact with each other or close to each other in a conductive manner increases, and the effect of increasing the antistatic property is recognized.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The antistatic resin molded article for molding of the present invention comprises a thermoplastic resin base material and an antistatic resin layer. The thermoplastic resin base material is It is selected from thermoplastic resins that are more suitable for different purposes, and examples include olefin resins such as polyethylene and polypropylene, polyvinyl chloride, vinyl resins such as polymethylmethacrylate,
Examples include ester resins such as polycarbonate, polyethylene terephthalate, unsaturated polyester and aromatic polyester. Among these, polyvinyl chloride having excellent chemical resistance, heat resistance of 70 to 80 ° C. and strength is preferably used.

The form of the substrate is a plate, a sheet, a film,
There are pipes, others, wires, strips, rods, etc., and this base material is not particularly limited as long as it is suitable for the use of the molded product and the formation of the antistatic resin layer, but preferably it is thermoformed later. Is selected from those suitable for. In particular, plates or sheets are preferably applied since they can be used for thermoforming.

The antistatic resin layer is a coating film formed by dispersing electrically conductive long fibers, preferably pilllike fiber aggregates of electrically conductive long carbon fibers, in a thermoplastic resin, and is applied to the surface of a molded article. The resin layer is made of a thermoplastic resin to impart electrical properties, but this resin layer is also capable of being molded by secondary processing.

For this resin layer, the same or different thermoplastic resin as the above-mentioned thermoplastic resin constituting the above-mentioned base material is selected. In particular, since this resin layer is formed from the coating film, the resin for forming the coating film is the same type of resin as the base resin, and can be formed in the coating liquid to easily disperse the conductive long fibers. The thing is preferable from a point of adhesiveness with a base material. It is possible to use different kinds of resins, but especially when it is difficult to form a coating liquid from the same kind of resin or when the same kind of resin is inferior in weather resistance, surface hardness, abrasion resistance, etc. , A different type of thermoplastic resin that can form a coating liquid, has better weather resistance, surface hardness and abrasion resistance than the same type of resin, and has a large adhesive force with the base resin after the coating liquid is cured. It is selected from the resins.

When the resin base material is polyvinyl chloride, the coating liquid for the antistatic resin layer contains polyvinyl chloride, its copolymer and acrylic resin, and a volatile solvent having a high compatibility, for example,
A coating solution that is dissolved in methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, or the like is used. Even when the resin base material is polycarbonate, the above coating liquid of polyvinyl chloride, its copolymer or acrylic resin is used, and when the resin base material is acrylic resin, the above coating liquid of acrylic resin is used. .

The resin layer is formed as a coating film on the surface of the base material, for example, any surface or both surfaces of the substrate. The coating film may be formed by directly applying it to the surface of the substrate with a gravure roll or by diving. There is also a method in which a coating film containing conductive long fibers is formed on the surface of a thermoplastic resin film and the back surface of this film is attached to the above-mentioned substrate. In this case, a method of adhering the back surface of the film to the surface of the base material with an adhesive interposed, or a method of directly performing thermocompression bonding with a heating press or a roll press is adopted.

As the conductive long fibers used in the present invention, carbon fibers, metal fibers such as stainless steel and copper, organic fibers containing copper sulfide and the like are used. These fibers are serpentine and electrically conductive, spaced apart such that they are in contact and / or electrically conductive with each other. It is useful that the diameter of each fiber is 50 μm or less in order to make a meandering contact in the resin layer or to bring them close to each other in a conductive manner.

As the conductive long fibers, long carbon fibers sufficiently long with respect to the wire diameter are preferable, and as the long carbon fibers, ultrafine fibers are particularly preferably used. Such long carbon fibers include both amorphous carbonaceous fibers and graphite fibers, and as the long carbon fibers, carbon fibers in which amorphous carbon and graphite coexist in elementary fibers are also used. It is preferable that all of these are ultrafine fibers and have the property of forming an aggregate by entanglement of fibers.

As the conductive long carbon fiber, the best one is a graphite fiber structurally, and a graphite fine ultrafine filament fiber having a circular cross section in which graphite layers are laminated coaxially on the fiber axis. And the wire diameter is 1 μm
It is as follows.

A method for producing such a graphite fiber is disclosed in Japanese Patent Publication No. 3-64606, but an iron group metal is contained in a mixed gas flow of an aromatic or non-aromatic hydrocarbon and hydrogen. Alternatively, it is an ultrafine fiber formed by depositing a coaxial graphite layer on the fiber axis by the catalytic reaction of its oxide. This fiber is a layered crystal of graphite C
A structure in which the axis is orthogonal to the fiber axis and precipitation of amorphous carbon is reduced is preferable.

Particularly, the shape of the ultra-fine long carbon fiber has a wire diameter (diameter of a single fiber) of 1 μm or less, preferably 3.5 to
It is 500 nm. For ultrafine long carbon fibers, the smaller the wire diameter, the easier it may be to aggregate in the resin layer. , It is disadvantageous to gather.

The ultra-fine long carbon fiber has an aspect ratio (ratio of length to wire diameter) of 5 or more to facilitate entanglement and entanglement of the fiber. As a result, the fibers tend to form aggregates. In particular, it is preferable to set the aspect ratio to 100 to 3,000. If the aspect ratio is less than 100, it is difficult to form an aggregate, the frequency of contact between the respective fibers is reduced, or the conductive intervals cannot be maintained. At the time of thermoforming, the contact short circuit between the aggregates in the coating film may be dissolved, and the antistatic property may be lowered. On the other hand, when the aspect ratio is 3,000 or more, the aggregate of carbon fibers becomes too large, and the frequency of contact between the aggregates and holding of the interval at which conduction is possible is reduced for the added amount.

As shown in FIG. 1 (A), since the ultrafine long carbon fiber 1 has a small wire diameter and a large aspect ratio, the fibers 1 and 1 are entangled with each other, and in a microscopic appearance,
The pill-like fiber aggregates 2 are aggregated in a pill shape, and the diameter a is about 0.2 to 10 μm, and the fibers 1 meandering around the pill form are released radially. As shown in FIG. 1 (B), the pill-shaped fiber aggregates 2 also form aggregates 3 which are aggregated and agglomerated while being in contact with each other and maintaining an interval allowing mutual conduction.

When such aggregated pill-shaped aggregates 2 are added to the coating liquid, the resin liquid permeates into the pills to dissolve the aggregates between the pills and to disperse the pills and distribute them uniformly. . When this is applied to the resin surface, the solvent in the coating liquid volatilizes, and then the pills also release some of the fibers to the surroundings even in the cured resin layer. While the balls cross-contact or bring the fibers close to each other, the fluffy carbon fiber aggregates 2 are electrically connected,
The electric resistance of the resin layer is reduced.

The antistatic resin layer is formed by dissolving a thermoplastic resin in a volatile solvent to form a solution, dispersing the long carbon fibers in the solution to form a coating solution, and coating the surface of the base material. Then, the solvent is volatilized and cured to form a coating film. For the coating on the substrate surface, knife edge coating, roll coating, spray coating, etc. can be used,
When the substrate is a flat plate having a flat surface, the gravure printing method by roll coating may be adjusted to a constant coating thickness.

In the present invention, the antistatic resin layer is used as the coating film.
This is because the antistatic layer is formed on the surface of the base material while maintaining the dispersion state of the aggregate of long carbon fibers in the resin layer.

The amount of long carbon fibers added to the antistatic resin layer is
It is preferable to set it to about 1 to 8% by weight. Below 1% by weight,
This is because the antistatic property cannot be obtained, and if it is 8% by weight or more, the surface resistivity does not decrease so much despite the large addition amount. Particularly preferred is 3 to 8% by weight. It is preferable to prepare a coating solution by adding a solvent so that the amount of long carbon fibers added to the coating solution will be 0.2 to 0.8% by weight and uniformly coating. This is because within this range, the coating liquid has an appropriate viscosity and uniform coating is possible.

The thickness of the antistatic resin layer, which is a coating film after dried and evaporated to be cured, is 0.1 to 10 μm, whereby the surface resistivity of the molded product is 10 ⁴ to 10 ¹¹ Ω. /
□ The degree can be easily obtained. If the thickness is less than 0.1 μm, a sufficiently low surface resistivity cannot be obtained, and by further processing and stretching the molded product, the thickness of the coating film further decreases and the antistatic performance cannot be maintained. When the thickness is 10 μm or more, the surface resistivity is almost the same as the surface resistivity at 10 μm, and it is meaningless for a thick film to exceed 10 μm. Further, if the thickness of the coating film is increased, the transparency is deteriorated. From this point as well, the thickness is preferably 10 μm or less. When a transparent resin is used as the base material, it is superfine and the addition amount is as low as 1 to 8% by weight, even though black long carbon fibers are used for the antistatic resin layer. Considering the material and thickness of the material, a molded product having a transparency of about 30 to 90% of total light transmittance can be obtained.

In the molded article having the antistatic resin layer formed on the surface as described above, since the base material and the resin layer are both thermoplastic resins, secondary processing can be performed depending on the application. The secondary processing includes bending, which is performed by heating the molded product, press molding, vacuum molding, pressure molding, blow molding, and stamping molding.The secondary processing causes tensile deformation of the resin layer on the surface. , Thickness reduction and area expansion accompanying it occur, but unless extreme processing is performed, the surface resistivity hardly increases, but rather tends to decrease.
It has sufficient antistatic property even after secondary processing.

As described above, the surface resistivity is not substantially increased by the heating process because the pill-like aggregates dispersed in the antistatic resin layer and in contact with each other or at intervals having electrical conductivity are carbon fibers. Since they are twisted or entangled even if they meander, even if each assembly separates due to deformation due to thermoforming, the entangled fibers maintain contact with each other or the twisted fibers simply stretch while maintaining an interval having conductivity. This is because the conduction state does not change. However, when the fiber is bent so much that it is deformed too much and the length of the fiber becomes more than the limit of elongation, the fiber is cut and it becomes impossible to maintain a conductive interval between the fibers. Therefore, the deformation, that is, the molding magnification should be up to 10.0 times. Also,
In the case of a resin layer in which pill-shaped aggregates are dispersed, the molding ratio is 2
When it is -5 times, the surface resistivity tends to decrease. This is because, as shown in FIG. 2, when the antistatic resin layer is compressed in the vertical direction during thermoforming, the aggregates distributed above and below the resin layer and not conducting are brought into close contact with each other. Alternatively, the distance becomes conductive, and the fibers are electrically connected to each other to increase the conduction point, so that it is considered that the surface resistivity is lowered by thermoforming.

Since a transparent antistatic resin molded product using a transparent resin as a base material also retains the antistatic property even after the secondary processing, the antistatic property and the secondary processability are maintained. It is possible to obtain a molded article having both transparency. Furthermore, the molded article of the present invention has antistatic property, secondary processability, and antistatic property by adding a colorant to the transparent resin and adjusting the color of the base material to a desired color in advance. It is possible to obtain a molded product having a good transparency and a deep color tone that does not impair the intended color in combination with the excellent transparency.

[0034]

[Examples] Polyvinyl chloride powder as a thermoplastic resin was added to cyclohexanone as a solvent and dissolved, and graphite fibers (manufactured by Hypillion Catalysis International Co., product name "Graphite Fibrils" mean line) were added to the solution. (Diameter 10 nm, average length 10 μm) was added at various concentrations to form a coating liquid.

A polyvinyl chloride sheet having a thickness of 2.0 mm is used as a resin base material, and the surface of the sheet is coated with the above coating solution by a bar coater so that the thickness of the coating film becomes two levels of approximately 2 μm and 4 μm and dried. It was cured to form an antistatic coating. Next, this sheet was heated to 200 ° C. and vacuum-formed. The forming magnification (the ratio of the area after forming to the area of the original plate before forming) during vacuum forming was set to 2 to 10, and the surface resistivity measured before and after vacuum forming was compared.

The amount of graphite fiber added to the coating film is
Table 1 summarizes the results of the surface resistivity measurement test before and after vacuum forming for the 4.5 wt% sample (Example 1) and the 3.6 wt% sample (Example 2).

As Comparative Example 1, fine particle tin oxide S
An antistatic polyvinyl chloride sheet was formed using an nO ₂ -based antistatic paint. In this comparative example 1, 9 wt% of the above polyvinyl chloride was added to cyclohexanone, SnO ₂ (Catalyst Kasei Co., Ltd., product name “ELCOM TL35”, particle size 2
(00 nm or less) to prepare a coating solution by adding 15% by weight,
The same polyvinyl chloride sheet as in the example was applied to form a coating film, and similarly, the surface resistivity was measured before and after vacuum forming and compared.

As Comparative Example 2, a polyvinyl chloride sheet was similarly coated with an antistatic paint containing needle-shaped conductive titanium oxide (manufactured by Dainichiseika Co., Ltd., "Neoconcoat S2120"). Was formed, and similarly, the surface resistivity before and after vacuum forming was compared.

[0039]

[Table 1]

It can be seen from Table 1 that the molded article containing the graphite fiber of the example has a surface resistivity of 10 ⁷ to 10 ⁹ Ω / □ after the coating film formation and before the vacuum forming (molding ratio 1), It has sufficient antistatic properties. On the other hand, the molded article containing fine particle SnO ₂ of Comparative Example 1 has a surface resistivity of about 10 ⁶ Ω / □, which is lower than that of the example, and has a sufficient antistatic property. The molded product containing the acicular titanium oxide of Comparative Example 2 has a sufficient antistatic property of about 10 ⁶ to 10 ⁷ Ω / □. Further, in both the examples and the comparative examples, the surface resistivity decreases as the film thickness increases.

When these samples were vacuum-molded, the molded products of Comparative Examples 1 and 2 had a surface resistivity increased to 10 ¹² Ω / □ or more from the molding ratio of 3.0 and no longer had antistatic property. Examples of the use of the graphitic fibers of the present invention are:
Even at a molding ratio of 5.0, a phenomenon in which the surface resistivity was lowered rather than that before molding was observed, and the surface resistivity was 10 ⁷ Ω / □ or less. The reason for such a result is that, in the process of vacuum forming, the coating film stretches and thins at the same time as the molded article stretches, or the molded article contacts the mold and the coating film is also pressed down. In the examples, only the winding fibers are stretched to maintain the contact between the fibers and the interval where conduction is possible, and further, the aggregate of the graphite fibers dispersed in the coating film is deformed into a flat shape without changing the position. It is considered that the contact between the aggregates which are distributed vertically and are not in contact with each other, and the approach in which conduction is possible newly occur, and the frequency of the approach in which contact or conduction is possible is higher than these.

On the other hand, in Comparative Example 1, since the particulate SnO ₂ is used, when the coating film is extended, the particulate SnO 2 is added.
It is considered that the contact and approach of ₂ disappear and the surface resistivity increases. In Comparative Example 2 as well, since needle-shaped conductive titanium oxide is used, when the coating film extends, the mutual distance of the conductive titanium oxide increases and the contact or contact required for conduction disappears. It is considered that it is oriented in the direction of deformation and there is no vertical contact or approach. However, since Comparative Example 2 is needle-shaped, it may be possible to maintain a slight contact or approach between the particles as compared with the fine-grained Comparative Example 1. (It is 2 × 10 ⁸ Ω / □ when the molding ratio is 2 times, but this is not practical because the molding ratio is up to 2 times.)

Using the antistatic polyvinyl chloride sheets produced by changing the addition amount of the above graphite fiber "graphite fibrils" in the coating film, the addition amount in the coating film and the surface resistivity before and after vacuum forming were used. Table 2 shows the measurement results of the relationship with. From Table 2, it can be seen that when the added amount is 0.93 wt%, it does not have antistatic property, and when it becomes 1.3 wt%, it has some antistatic property, and the lower limit of the added amount is 1 wt%. .
Further, even if the addition amount is 8.6 wt%, the surface resistivity is almost the same as 7 wt%, and it can be seen that further increase of the addition amount is meaningless. From this result, it is understood that when the addition range of the long carbon fiber "graphite fibrils" is in the range of 1 to 8% by weight, appropriate antistatic property can be imparted.

[0044]

[Table 2]

Next, the amount of "graphite fibrils" added in the coating film was 4.5 parts by weight, and the coating film thickness was 4.1 μm.
Using the polyvinyl chloride sheet having the resin layer of No. 3, the relationship between the molding ratio by vacuum molding and the surface resistivity was determined, and Table 3
It was shown to. From the table, it can be seen that when the molding magnification is 7 times, the surface resistivity is slightly increased, and when the molding magnification is 10 times, it becomes 10 ¹² Ω / □ or more and the antistatic property is lost. This is because even if the fiber is meandering, if it is processed at a molding ratio of 7 times, the fiber will stretch and it will be difficult to follow the deformation of the resin, and it will not be possible to make contact or conduction approach. It is considered to be a thing. From this, as can be seen from Table 4 described later, the possibility of the molding ratio that can maintain the antistatic property tends to increase as the film thickness increases, and considering the practical molding workability, the molding ratio is It is considered that the antistatic property can be maintained up to about 10 times. Further, from Table 3, the surface resistivity is lowered by the secondary processing until the molding ratio is up to 5, and the preferable molding ratio is up to 7.

[0046]

[Table 3]

Next, the addition amount of "graphite fibrils" in the coating film was fixed to 4.5 parts by weight, and the effect of the film thickness on the surface resistivity was investigated by changing the coating film thickness, and Table 4
It was shown to. From Table 4, it can be seen that the surface resistivity decreases as the film thickness increases, and this tendency holds even when the molding ratio is high. However, even if the film thickness is 15 μm, the surface resistivity is almost the same as when it is 8 μm, and it is 10 μm.
The degree is enough. If the film thickness is as thin as 0.3 μm, it is 1
When it is 0 ¹² Ω / □ or more, it does not have sufficient antistatic property, but when it is molded three times, it becomes 10 ¹⁰ Ω / □ and it has sufficient antistatic property. Taking into consideration that the surface resistivity tends to decrease as the amount added in the coating film increases, the film thickness is preferably about 0.1 to 10 μm, and preferably 1 to 8 μm.

[0048]

[Table 4]

Further, the relationship between the film thickness and the transparency was investigated, and the results are shown in Table 5. Although the transparency decreases as the film thickness increases, it can be seen that the 2.3 μm-thickness has a total light transmittance of 57.1% and can be sufficiently seen through a molded product. This one, as shown in Table 4,
It has a surface resistivity of 0 ⁸ Ω / □ and sufficient secondary workability.

[0050]

[Table 5]

In this way, the antistatic resin molded article of the present invention is stable to processing, especially by using an appropriate amount of a small amount of graphite fiber and forming an extremely thin coating film. Thus, excellent surface antistatic property can be obtained.

[0052]

According to the present invention, the antistatic resin layer formed on the surface of the resin base material is such that the conductive long fibers are twisted and in contact with each other in the thermoplastic resin, or a space having conductivity is maintained. Since the coating film is dispersed as described above, it is possible to obtain an antistatic resin molded article for thermoforming which enables secondary processing molding while maintaining the antistatic property of the molded article. In addition, the antistatic resin molded product coated with ultrafine long carbon fibers as the conductive long fibers must maintain the antistatic function on the surface of the molded product even when the molded product is secondarily processed. You can

By using a graphite fiber having an ultra-fine shape and a large aspect ratio as the conductive material contained in the antistatic resin layer, a pilllike aggregate can be obtained, so that the surface antistatic property of the molded article can be efficiently obtained. Further, since the antistatic resin layer is a coating film formed by applying the coating liquid containing the graphite fiber, the work of imparting the antistatic property to the molded product can be easily performed. Further, by adding a small amount of graphite fiber, sufficient antistatic property can be exhibited, and by using a transparent substrate, a molded article having transparency can be obtained.

In order to impart the antistatic property to the antistatic resin layer, a molded article having good transparency can be obtained by adding a small amount of an extremely fine graphite fiber as the conductive fiber, Further, by pre-coloring the base material with a coloring agent, the molded product can be toned to a desired color, and easily, a molded product having various depths and a color that does not impair the intended color tone can be easily obtained. be able to.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a pilllike aggregate (A) of graphite fibers used in the present invention and a state (B) in which the pilllike aggregate is aggregated.

FIG. 2 is a conceptual diagram showing a state of a pilllike aggregate of graphite fibers dispersed in an antistatic resin layer.

[Explanation of symbols]

1 long carbon fiber 2 pilllike aggregates 3 aggregates

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-132963 (JP, A) JP-A-61-254636 (JP, A) JP-A-7-102197 (JP, A) JP-A-61- 218669 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 B29C 51/00-51/46 C09D 1/00-201/10

Claims (11)

(57) [Claims] 1. A thermoformable antistatic resin molded article comprising a thermoplastic resin base material and an antistatic resin layer adhered to the surface of the resin base material, wherein the antistatic resin The layer is a coating film in which electroconductive long fibers are dispersed in a thermoplastic resin in a meandering manner and in contact with each other and / or at intervals having electroconductivity, and the film is formed after thermoforming. A thermoformable antistatic resin molded product, which is characterized in that the antistatic property of the molded part does not deteriorate. 2. A thermoformable antistatic resin molded article comprising a thermoplastic resin base material and an antistatic resin layer adhered to the surface of the resin base material, wherein the antistatic resin is The layer has a wire diameter of 3.5 to 5 in the thermoplastic resin.
A coating film in which conductive long carbon fibers of 00 nm are dispersed in a meandering shape and in contact with each other and / or at intervals having a conductive property, and after thermoforming, antistatic property of a molded portion of the coating film is obtained. thermoformable antistatic resin molded article sex characterized in that it does not decrease. 3. The antistatic resin layer according to claim 1, wherein even after molding, the long fibers are dispersed in contact with each other and / or at a conductive spacing. Electric resin molded product. 4. The coating film according to claim 1, wherein the coating film is formed on a separate thermoplastic resin film, and the coating film on the film is thermocompression-bonded to the thermoplastic resin substrate. Antistatic resin molded product. 5. The antistatic resin molded article according to claim 2, wherein the long carbon fiber is a graphite material having a circular cross section. 6. The long carbon fiber forms a pill-shaped aggregate in which the respective fibers are entangled with each other, and the fibers meandering around the aggregate are radially released. Antistatic resin molded product of. 7. The antistatic resin molded article according to claim 6, wherein the long carbon fibers form an aggregate in which a large number of the pilllike aggregates are aggregated. 8. The antistatic resin molded article according to claim 2, wherein the coating film contains 1 to 8% by weight of long carbon fibers in the coating film and has a thickness of 0.1 to 10 μm. . 9. The antistatic resin molded article according to claim 2, wherein the antistatic resin molded article has a total light transmittance of 30 to 90%. 10. The antistatic resin molding has a molding ratio of 1.1.
Thermoformed by 10 to 10 times, the molded product is 10 ¹¹ Ω /
□ The antistatic resin molded product according to any one of claims 2 to 9, which has the following surface resistivity. 11. The antistatic resin according to claim 2, wherein the antistatic resin molded product is formed with a molding magnification of 2 to 5 times, and the antistatic property of the molded coating film portion is further improved. Molding.