JP3239253B2 - Semiconductive fluororesin composition and semiconductive fluororesin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition having properties suitable for use in an electronic image forming process such as electrophotography, facsimile and laser printer, and a film obtained from the composition. , Comprising a polymer type antistatic agent, semiconductive fluororesin composition,
And a semiconductive fluororesin film.

[0002]

2. Description of the Related Art Conventionally, organic antistatic agents and conductive substances such as carbon black and metal powder have been added and mixed for the purpose of imparting antistatic properties and conductivity to thermoplastic resins. . However, while conductive substances such as carbon black and metal powder can impart extremely high conductivity, there has been a problem that a small change in the amount of addition significantly changes the volume resistivity or the surface resistivity. In particular, the volume resistivity is 1 × 10 ⁵ to 1 × 10 ¹¹ Ω ·
It was extremely difficult to control in the range of cm in the case of a system in which carbon black or metal powder was added. Further, when such a conductive substance is added, the transparency of the thermoplastic resin is impaired, and when mixed in a large amount, the mechanical strength of the product is reduced or the surface is roughened. .

[0003] On the other hand, in the case of an organic antistatic agent, although there is little problem of a decrease in transparency and mechanical strength, it does not exhibit a volume resistivity of 1 × 10 ¹¹ Ω · cm or less with a normal addition amount. It was difficult. In general, organic antistatic agents have a low molecular weight, so they are highly environmentally dependent.Furthermore, as the antistatic agent bleeds out over the surface of the thermoplastic resin over time, the surroundings are contaminated. And the volume resistivity changes.

In order to solve such a problem, for example, a permanent antistatic resin composition using a polyether-ester-amide having a specific structure (Japanese Patent Publication No. 4-7 / 1994)
No. 2855), and polymer-type antistatic agents such as acrylamide copolymers having a quaternary ammonium salt in the side chain (Japanese Patent Application Laid-Open No. 4-198307). These polymer-type antistatic agents have significantly improved environmental dependency and bleed-out problems compared to conventional organic antistatic agents, and can be blended in large amounts, so that 10 ¹⁰ Ω · Volume resistivity levels of around cm have also been achieved.

However, when such a polymer type antistatic agent is applied to a thermoplastic fluororesin having excellent properties such as non-staining property, heat resistance, weather resistance, ozone resistance and flame retardancy. In general, these polymer-type antistatic agents are designed so that they can be applied to general-purpose thermoplastic resins such as polyolefin resins, polystyrene, and ABS resins. However, there is a problem that it is difficult to obtain a thin film. In addition, environmental dependency was not sufficient.

Further, a stabilized conductive halogen-containing resin composition in which a perchlorate and a polyether-based polymer are blended with a halogen-containing resin (JP-A-3-39346) has been proposed. Of these, when perchlorate and polyether-based polymer are blended with polyvinyl fluoride, the melting point of polyvinyl fluoride is originally as high as 227 ° C, and its processing requires a considerably high temperature. The resulting polyether-based polymer has a problem in that its molecular weight is reduced by heat during processing, and a thermal decomposition product of this polyether-based polymer bleeds out to the surface of a molded article. Further, when a chlorine-based synthetic resin or a bromine-based synthetic resin is used as the halogen-containing resin, since the polarity of these resins is smaller than that of the fluorine-based resin, a polyether-based polymer, It is necessary to considerably increase the amount of perchlorate, which causes a problem that processability is reduced.
Further, there is a problem that the polyether polymer bleeds out to the surface of the molded article.

Furthermore, a resin composition having excellent antistatic properties comprising a thermoplastic resin blended with an alkylene oxide copolymer and an ion-dissociable metal salt (Japanese Patent Application Laid-Open No. Hei 6-200171) has been proposed. However, polyolefin resin, AB
Styrene resin such as S resin, thermoplastic resin such as polymethacrylic acid ester resin mixed with polyalkylene oxide, and ion dissociable metal salt provide semiconductivity due to the small polarity of the thermoplastic resin Therefore, it is necessary to considerably increase the blending amount of the polyalkylene oxide and the ion-dissociable metal salt, and if the blending amount of the polyalkylene oxide is increased, the thermal decomposition product of the polyalkylene oxide generated at the time of molding processing becomes a molded product. There was a problem of bleeding out to the surface.

[0008] In OA equipment such as a copying machine, a facsimile, a laser printer, etc., to which the principle of electrophotography is applied,
Generally, each process includes charging, exposure, development, transfer, fixing, and charge removal, and various rolls, belts, and blades are used to precisely control static electricity in each process. When these are used, in addition to the above-mentioned conditions, even if the amount of the antistatic agent to be added is not strictly controlled, 1 × 10 ⁵ to 1 × 10 ¹² Ω · cm, especially 1 × 10 ⁵ to 1 It is desired that a volume resistivity in the range of × 10 ¹¹ Ω · cm and a surface resistivity in the range of 1 × 10 ⁵ to 1 × 10 ¹² / □ can be stably provided. It is also desired to further reduce the environmental dependence of the volume resistivity and the surface resistivity and the bleed out of additives.

[0009]

DISCLOSURE OF THE INVENTION The present invention has good physical and mechanical properties and has a characteristic of 1 × 10 ⁸ to 1 × 10 ¹¹ Ω · c.
volume resistivity in the range m and 1 × 10 ⁸ to 1 × 10
Surface resistivity in the range of ¹² Ω / □ is stably and accurately expressed, with little change over time, environment dependency and bleed-out.
An object of the present invention is to provide a semiconductive resin composition which is excellent in processability and is suitable for an electronic image forming process, and a film obtained from the composition.

[0010]

Means for Solving the Problems In order to achieve the above object, the present inventors have studied in detail the combination of a polymer type antistatic agent and a thermoplastic resin. We paid attention to plastic fluororesin. As a result of extensive studies, the melting point is lower than 190 ° C. Po
One selected from vinylidene fluoride or a copolymer thereof;
Species, or two or more thermoplastic fluororesin 98-8 5 parts by weight, thermogravimetric analysis, a polymer type antistatic agent
Only a thermoplastic fluororesin composition composed of 2 to 15 parts by weight of a polyalkylene oxide having a 10% weight loss temperature by (TGA) of 240 ° C. or more and 0.05 to 5 parts by weight of an ionic electrolyte is generally used. Volume resistivity 1 × 10 ⁸ -1 × 1
0 ¹¹ Ω · cm, surface resistivity 1 × 10 ⁸ to 1 × 10 ¹² Ω
/ □ not only shows a stable ionic conductivity, but also shows that these electrical properties are less dependent on the environment and are excellent in processability. Further, the above semiconductive fluororesin composition has By adjusting the mixing ratio of the constituent fluorocarbon resin, polyalkylene oxide, and ionic electrolyte, easily and accurately,
The inventors have found that the intended volume resistivity and surface resistivity can be controlled, and have completed the present invention.

That is, according to the present invention, polyvinylidene fluoride and vinylidene fluoride hexafluoride having a melting point of less than 190 ° C.
Propylene copolymer, vinylidene fluoride-tetrafluoride
Tylene-propylene hexafluoride copolymer or vinyl fluoride
Nilidene-propylene hexafluoride copolymer and vinylidene fluoride
One selected from graft copolymers with den , or 98 to 85 parts by weight of two or more thermoplastic fluororesins,
24% 10% weight loss temperature by thermogravimetric analysis (TGA)
Polyalkylene oxide 2 to 15 parts by weight is 0 ℃ or higher, and Ri Na more ionic electrolyte 0.05-5 parts by weight,
The volume resistivity is 1 × 10 ⁸ to 1 × 10 ¹¹ Ω · cm.
One surface resistivity of ^{1 × 10 8 ~1 × 10 12} Ω / □ der Rukoto semiconductive fluororesin composition according to claim is provided. In addition, there is provided the semiconductive fluororesin composition, wherein the polyalkylene oxide is one kind selected from polyethylene oxide or a copolymer thereof, or a mixture of two or more kinds. Still more particularly, the ionic electrolyte is one selected from alkali metal thiocyanate, phosphate, sulfate, or a salt obtained from an alkali metal and a halogen-containing oxyacid, or a mixture of two or more thereof. The semiconductive fluororesin composition is provided. Further, according to the present invention, there is provided a semiconductive fluororesin film obtained by molding the above semiconductive fluororesin composition at a processing temperature of less than 240 ° C.

Hereinafter, the present invention will be described more specifically. Thermoplastic fluororesin having a melting point of less than 190 ° C. for use in the present invention, polyvinylidene fluoride or copolymers thereof,
There, polyvinylidene fluoride, vinylidene fluoride - hexafluoropropylene copolymer, vinylidene fluoride - tetrafluoroethylene - hexafluoropropylene copolymer, vinylidene fluoride - hexafluoropropylene copolymer and vinylidene fluoride a graft copolymer of, preferred in view of moldability. The compounding amount is preferably 85 to 98% by weight of the total amount of the thermoplastic fluororesin and the polyalkylene oxide. The melting point of the thermoplastic fluororesin is 190 ° C. to prevent thermal decomposition of the polyalkylene oxide during molding.
It is necessary to be less than, the melting point of the thermoplastic fluororesin of 190 ° C. or more, because it is necessary to raise the processing temperature even higher, at the time of kneading, or during the molding processing, polyalkylene oxide causes thermal decomposition, It is not preferable because it bleeds out to the surface of the molded product.

On the other hand, the polyalkylene oxide constituting the semiconductive fluororesin composition of the present invention is not particularly limited, and may be polyethylene oxide, polypropylene oxide, polytetramethylene oxide, a copolymer thereof, or the like. Is mentioned. Further, among these polyalkylene oxides, one or a mixture of two or more selected from polyethylene oxide or a copolymer thereof is preferable because the effect of lowering the volume resistivity and the surface resistivity is large. In addition, polyalkylene down oxide,
Even if it is partially crosslinked, it can be used as long as it has thermoplasticity.

Further, these polyalkylene oxides have a 10% weight loss temperature by thermogravimetric analysis (TGA) of 2%.
Bareru selected from those which are 40 ℃ or more. In the present invention, the thermogravimetric analysis (TGA) of the polyalkylene oxide was performed under the following conditions, and the 10% weight loss temperature referred to herein was read from a chart obtained by the thermogravimetric analysis (TGA). It means the temperature at which the weight of the polyalkylene oxide is reduced by 10% compared to the initial weight. <Conditions of thermogravimetric analysis (TGA)>-Sample amount: 10 mg-Cell: made of aluminum-Carrier gas: air-Initial temperature: 23 ° C-Heating rate: 10 ° C / min Molding when this temperature is lower than 240 ° C The reduction in molecular weight of the polyalkylene oxide due to heat during processing is remarkable, which is not preferable.

The polyalkylene oxide having a 10% weight loss temperature of 240 ° C. or more by thermogravimetric analysis includes polyethylene oxide having a number average molecular weight of 3,000 or more, and partially crosslinked thermoplastic polyethylene oxide.

[0016] These polyalkylene oxide proportion, the 2 to 15 parts by weight of the total amount of the heat-friendly plastic fluororesin and said polyalkylene oxide are preferred, more preferably 2 to 12 parts by weight, 3 to 10 parts by weight Is more preferred. If the compounding ratio exceeds 15 parts by weight, not only does the compatibility with the thermoplastic fluororesin deteriorate, so that the processability is lowered, but also the bleed out of components reduced in molecular weight by heat during processing is increased, which is preferable. Absent. On the other hand, if the blending ratio of the polyalkylene oxide is less than 2 parts by weight, the desired volume resistivity and surface resistivity cannot be exhibited, which is not preferable.

As the ionic electrolyte used in the present invention, a thiocyanate, a phosphate, a sulfate, or a salt obtained from an alkali metal and a halogen-containing oxyacid may be used alone or in combination of two or more. Of which, among others, lithium perchlorate, sodium perchlorate, potassium perchlorate, lithium thiocyanate,
Sodium thiocyanate and potassium thiocyanate are preferred. The addition amount is preferably 0.05 to 5 parts by weight,
In addition, 0.05 to 2 parts by weight is more preferable, and 0.1 to 2 parts by weight.
One part by weight is more preferred. If the addition amount of the ionic electrolyte is less than 0.05 parts by weight, sufficient semiconductivity is not exhibited, which is not preferable. Conversely, if the addition amount of the ionic electrolyte exceeds 5 parts by weight, not only is thermal decomposition of the polyalkylene oxide accelerated during processing, but also the resulting composition has a large environmental dependence on electrical properties, which is not preferable.

[0018] If necessary, the semiconductive fluororesin composition of the present invention, antioxidants does not impair the semiconductive, thermal stabilizers, slip agents, compatibilizers, pigments, reinforcing agents, etc. Can be added.

The semiconductive fluororesin composition of the present invention comprises the above thermoplastic fluororesin having a melting point of less than 190 ° C., a polyalkylene oxide, and an ionic electrolyte, which are mixed with a conventional kneader , roll, Banbury mixer, twin-screw kneader, or the like. It can be manufactured by kneading in a form, and depending on its use, it is used after being shaped into a film, sheet, tube, molded product or the like. In addition, a small amount of a synthetic resin other than the thermoplastic fluororesin can be blended as required, for example, to improve workability.

The method for obtaining the semiconductive fluororesin film of the present invention is not particularly limited. For example, the semiconductive fluororesin composition obtained as described above is pelletized, A method of feeding the pellets to an extruder equipped with an annular die or a T die to form a film, a method of forming a film by a calendar method,
A method of hot pressing and the like can be mentioned. Here, the processing temperature needs to be less than 240 ° C., preferably,
Less than 235 ° C. If the temperature is 240 ° C. or higher, the polyalkylene oxide is reduced in molecular weight by heat during processing, and the reduced molecular weight polyalkylene oxide bleeds out to the surface of the product, which is not preferable.

[0021]

The reason why the fluororesin composition of the present invention can exhibit volume resistivity and surface resistivity until it reaches the semiconductive region is that the CF bond in the thermoplastic fluororesin is electronegative among all elements. Polarized by the largest degree of fluorine atoms, it promotes the dissociation of the ionic electrolyte, and the metal ions dissociated in the polar matrix resin in which the lone pair of oxygen atoms forming the ether bond in the polyalkylene oxide is polar It is thought that this may be to promote the movement of the fish. Therefore, the semiconductive fluororesin composition of the present invention can easily prepare 1 × 10 ⁸ to 1 × by adjusting the compounding ratio of the constituent thermoplastic fluororesin, polyalkylene oxide, and ionic electrolyte.
A predetermined volume resistivity in the range of 10 ¹¹ Ω · cm, and 1
Not only can a predetermined surface resistivity in the range of × 10 ⁸ to 1 × 10 ¹² Ω / □ be accurately and stably expressed, but also volume resistivity under high temperature and high humidity, and surface resistivity and low temperature and low humidity. It has a feature that it has a small difference from those below and shows stable ionic conductivity even when the use environment changes. In addition, the semiconductive fluororesin composition of the present invention has a low processing temperature, so that the molecular weight of the polyalkylene oxide can be reduced to a minimum by heat during processing, so that bleed-out of additives and the like is small. Also, it has excellent physical properties such as non-staining, anti-fouling, heat resistance, weather resistance, ozone resistance, flame retardancy, etc.
It is preferably used as a resin for an electronic image forming process.

[0022]

Next, the present invention will be described in detail with reference to examples. Parts in Examples are parts by weight, and the blending ratio is on a weight basis. The thermoplastic fluororesin, polyalkylene oxide, and ionic electrolyte used in the examples are:
It is as follows.

Thermoplastic Fluororesin Fluororesin A: graft copolymer of vinylidene fluoride-propylene hexafluoride copolymer with vinylidene fluoride (Cefralsoft G180 manufactured by Central Glass)
Melting point: 165 ° C) Fluororesin B: Vinylidene fluoride-propylene hexafluoride copolymer (manufactured by Mitsubishi Yuka: Kainer 2800, melting point: 14)
8 ° C) Fluororesin C: Polyvinylidene fluoride (Atochem: F
ORAFLON4000HD melting point: 170 ° C)

Polyalkylene oxide PEO-A: polyethylene oxide (molecular weight: 20,000) PEO-B: polyethylene oxide (molecular weight: 600,000-
PEO-C: polyethylene oxide (molecular weight: 150,000-
400,000, manufactured by Sumitomo Seika Co., Ltd.) PEO-D: polyethylene oxide (Aqua Coke: partially crosslinked polyethylene oxide, manufactured by Sumitomo Seika Co., Ltd.) PEO-E: polyethylene glycol (molecular weight: 100)
0) In addition, the polyalkylene oxide described above subjected to thermogravimetric analysis (TGA) under the following conditions, the temperature at which the weight of the polyalkylene oxide from the resulting chart is less reduced by 10%, ie, read 10% weight reduction temperature . Table 1 shows the results.
Shown in <Thermogravimetric analysis (TGA) conditions> • Measuring instrument: Thermogravimetric analyzer (SSC / 5200 series TG / DTA220 manufactured by Seiko Instruments Inc.) • Sample amount: 10 mg • Cell: made of aluminum • Carrier gas: air • Initial temperature: 23 ° C · Temperature rise rate: 10 ° C / min

[0025]

[Table 1]

Ion electrolyte Ion electrolyte A: lithium perchlorate Ion electrolyte B: potassium thiocyanate

The method of evaluating the fluororesin composition in the examples is as follows. <Volume resistivity and surface resistivity> Volume resistivity,
And the surface specific resistance are Hiresta H manufactured by Mitsubishi Yuka Co., Ltd.
The measurement was performed at an applied voltage of 500 V using an RS probe. In addition, the measurement of the volume resistivity and the surface resistivity was performed at 23 ° C. and 50% RH unless otherwise specified. <Bleed-out> The film obtained by the hot press was allowed to stand in a dryer at 50 ° C. for one week, and the presence or absence of stickiness on the film surface was observed by finger touch. <Workability> The workability was measured using a flow tester manufactured by Shimadzu Corporation at 200 ° C., with a load of 100 kg and a die diameter of 1 m.
The evaluation was made based on the smoothness of the surface of the strand coming out of the die under high shear having a length of 10 mm and a length of 10 mm. That is, those having a smooth strand surface were evaluated as having good workability, and those having a rough surface were evaluated as having poor workability.

Examples 1 to 3 A thermoplastic fluororesin, polyethylene oxide, and an ionic electrolyte having the compositions shown in Table 2 were uniformly kneaded with a mixing roll at 180 ° C., followed by press molding to a thickness of about 12 mm.
A 0 μm film was produced. Table 2 also shows various properties of the obtained film.

Comparative Examples 1 to 5 Polyethylene, polypropylene or vinyl chloride
A vinyl acetate copolymer, polyethylene oxide, and an ionic electrolyte were uniformly kneaded with a mixing roll at 180 ° C., and then press-molded to produce a 120 μm thick film. Further, polychlorotrifluoroethylene, polyethylene oxide, and an ionic electrolyte were uniformly kneaded with a mixing roll at 245 ° C., and then press-molded to produce a 120 μm thick film. Various properties of the obtained film are also shown in Table 2.

[0030]

[Table 2] PE: polyethylene (made by Union Polymer, UP polyethylene-LD 186) PP: polypropylene (made by Union Polymer, UP Polypro ZS3022) PVC-PVAc: vinyl chloride-vinyl acetate copolymer (manufactured by Sekisui Chemical, Esmedica N 5142E) CTFE: polychlorotrifluoroethylene (manufactured by Daikin, NEOFLON CTF E, melting point: 210-212 ° C.)

As is apparent from Table 2, polyvinylidene fluoride or a copolymer thereof is used as a matrix resin.
The compositions of Examples 1, 2 and 3 using the selected thermoplastic fluororesin show good ionic conductivity by blending polyethylene oxide and an ionic electrolyte, but polyethylene, polypropylene,
Alternatively, in the compositions of Comparative Examples 1 to 4 using the vinyl chloride-vinyl acetate copolymer, the reduction in the volume resistivity and the surface resistivity was small, and the desired ion conductivity could not be obtained. Comparative Example 5 using polychlorotrifluoroethylene having a high melting point among thermoplastic fluororesins,
Since the kneading temperature by the mixing roll had to be as high as 245 ° C., the polyethylene oxide was decomposed and volatilized during kneading, so that the volume resistivity and the surface resistivity were less reduced. Therefore, it is understood that in order to obtain good ion conductivity with a small blending amount, it is essential to use a thermoplastic fluororesin having a melting point of less than 190 ° C. as a matrix resin.

Example 4 A mixture of fluororesin A and fluororesin B (3: 1) and a predetermined amount of PEO-A (100 parts by weight in total) were mixed with 0.5 parts by weight of ionic electrolyte A and mixed at 180 ° C. After uniform kneading with a roll, press-molded, about 120μm thick
Was obtained. FIG. 1 shows the relationship between the blending amount of PEO-A and the volume resistivity of the obtained film. In these compositions, the surface of the strand coming out of the die under high shear was smooth and the workability was good.

Comparative Example 6 A predetermined amount of carbon black (Ketjen black) was blended with 100 parts by weight of a mixture of fluororesin A and fluororesin B (3: 1), and the mixture was uniformly kneaded with a mixing roll at 180.degree. Thereafter, press molding was performed to obtain a film having a thickness of about 120 μm. FIG. 1 also shows the relationship between the blending amount of carbon black and the volume resistivity of the obtained film.

Comparative Example 7 0.5 part by weight of ionic electrolyte A was mixed with 100 parts by weight of a mixture of fluororesin A and fluororesin B (3: 1), and the mixture was uniformly kneaded with a mixing roll at 180.degree. Thus, a film having a thickness of about 120 μm was obtained. The volume resistivity of this film is 1.7 × 10 ¹² Ω · cm,
The surface resistivity was as high as 4.5 × 10 ¹³ Ω / □.

Comparative Example 8 20 parts by weight of PEO-A and 0.5 parts by weight of ionic electrolyte A were mixed with 80 parts by weight of a mixture composed of fluororesin A and fluororesin B (3: 1), and mixed with a 180 ° C. mixing roll. After uniform kneading, press molding, thickness about 120
A μm film was obtained. The volume resistivity of this film is 3.0 × 10 ⁸ Ω · cm, and the surface resistivity is 8.7 × 10 ⁹
Although good ion conductivity of Ω / □ was shown, stickiness was observed on the film surface when left indoors for 3 days. In this composition, the surface of the strand coming out of the die under high shear was rough, and the workability was poor.

As is clear from FIG. 1, the composition of Comparative Example 6 containing carbon black has a volume resistivity reduced by 100,000 times or more when the addition amount of carbon black is increased by only 1 part by weight. On the other hand, in the composition obtained by the present invention, the decrease in the volume resistivity is extremely moderate even when the amount of polyethylene oxide is increased.
However, a film in which the content of polyethylene oxide is increased to 20 parts by weight (Comparative Example 8) exhibits excellent ion conductivity, but is not preferred because stickiness due to bleeding occurs on the surface and processability is poor. Therefore, the composition of the present invention accurately expresses the desired predetermined volume resistivity without strictly controlling the blending amount, if the blending amount of polyethylene oxide is in the range of 2 to 15 parts by weight. It's clear what you can do. In addition, the film obtained in Comparative Example 7 containing no polyethylene oxide had high volume resistivity and surface resistivity, and could not achieve the object of the present invention.

Examples 5 to 10(Example 10 is a reference example)  95 parts by weight of fluororesin are polyethylene oxide of various molecular weights.
5 parts by weight of oxide and 0.5 parts by weight of ionic electrolyte A
Compounded and uniformly kneaded with a 180 ° C mixing roll
After press molding, a film with a thickness of about 120 μm is obtained.
Was. The composition of the film obtained in Table 3 and 50 ° C.
Of the film surface after leaving it in a dryer for 1 week
Table 4 shows the environmental dependence of the volume resistivity of each film.
Table 5 shows the environmental dependence of the surface resistivity.

Comparative Example 9 5 parts by weight of polyether-ester-amide and 0.5 parts by weight of ionic electrolyte A were mixed with 95 parts by weight of a fluororesin B, kneaded evenly with a mixing roll at 180 ° C., and then press-molded. A film having a thickness of about 120 μm was obtained.
Table 3 shows the composition of the obtained film, the presence or absence of stickiness on the film surface after being left in a dryer at 50 ° C. for one week, and Table 4 shows the environmental dependence of the volume resistivity of each film.
Table 5 shows the environmental dependence of the surface resistivity.

[0039]

[Table 3] PEEA: polyether-ester-amide

[0040]

[Table 4] LL / HH: ratio of volume resistivity under low temperature and low humidity (10 ° C., 37% RH) to volume resistivity under high temperature and high humidity (35 ° C., 85% RH). The smaller this value is, the less the environment dependency is.

[0041]

[Table 5] LL / HH: ratio of volume resistivity under low temperature and low humidity (10 ° C., 37% RH) to surface resistivity under high temperature and high humidity (35 ° C., 85% RH). The smaller this value is, the less the environment dependency is.

From the results shown in Tables 4 and 5, the film of the present invention not only exhibits the desired volume resistivity and surface resistivity at 23 ° C. and 50% RH, but also has a small LL / HH value. It turns out that there is little environmental dependency. In contrast, the film of Comparative Example 9 was LL / HH
Is large, and it is understood that the environment dependency is large. Furthermore, the composition of the present invention had no stickiness on the surface due to bleed-out, and the workability was evaluated well by a flow tester.

Examples 11 to 13 95 parts by weight of fluorocarbon resin, 5 parts by weight of PEO-B, and a predetermined amount of an ionic electrolyte were mixed, uniformly kneaded with a 180 ° C. mixing roll, and then press-molded to a thickness of about 12%.
A 0 μm film was obtained. Table 6 shows the volume resistivity and the surface resistivity of the obtained film.

[0044]

[Table 6]

As is clear from Table 6, the composition of the present invention shows a gradual change in the volume resistivity and the surface resistivity even when the mixing ratio of the ionic electrolyte is greatly changed. This fact does not have the inconvenience that the volume resistivity of the composition and the surface resistivity of the composition greatly change due to a slight change in the amount of the ionic electrolyte added, and the predetermined volume resistivity and the surface resistivity are accurately and furthermore reproducibly improved. It means that it can be expressed. It also means that the ionic electrolyte can be used without any problem as long as it is of the type disclosed in the present invention.

[0046]

The semiconductive resin composition of the present invention comprises, as a matrix resin, one or two or more thermoplastic fluororesins selected from polyvinylidene fluoride having a melting point of less than 190 ° C. or the above-mentioned specific copolymer. By using a polyalkylene oxide having a 10% weight loss temperature by thermogravimetric analysis (TGA) of 240 ° C. or higher as an antistatic agent in combination with an ionic electrolyte,
The compounding amount of these antistatic agents can be kept low, and 1 × 10 ⁸ to 1 × 10 ⁸
A predetermined volume resistivity within the range of ¹¹ Ω · cm, and 1 ×
A predetermined surface resistivity within the range of 10 ⁸ to 1 × 10 ¹² Ω / □ can be accurately expressed. In addition, despite the fact that the semiconductive fluororesin composition of the present invention contains an ionic electrolyte, the difference between the volume resistivity under high temperature and high humidity and the volume resistivity under low temperature and low humidity is small. It has low environmental dependence, shows stable ionic conductivity, and has little thermal decomposition products due to polyalkylene oxide at the time of processing, so there is little bleed-out based on the compound and excellent workability. Has features. The semiconductive resin composition of the present invention has excellent physical properties such as non-adhesiveness, antifouling property, heat resistance, ozone resistance, and flame retardancy, which are characteristics of the fluororesin. Therefore, the semiconductive resin composition of the present invention is suitably used as a semiconductive resin for an electronic image forming process requiring accurate semiconductivity, for example, in the field of electrophotographic materials. Furthermore, the semiconductive resin composition of the present invention can be easily formed into films, sheets, tubes, and other molded products.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the blending amount of an ion conductive material and the volume resistivity of the films obtained in Example 4 and Comparative Examples 6, 7, and 8.

[Explanation of symbols]

 ：: Film containing PEO-A. ●: Film blended with carbon black.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigetoshi Takechi 1515 Nakatsu-cho, Marugame-shi, Kagawa Prefecture Okura Industries, Ltd. (72) Inventor Takanori Okamoto 1515 Nakatsu-cho, Marugame-shi, Kagawa Okura Industries, Ltd. Inventor Kazuki Okunaka 1515 Nakatsu-cho, Marugame-shi, Kagawa Pref. Okura Industry Co., Ltd. (56) Reference JP-A-6-200171 (JP, A) JP-A 1-158051 (JP, A) JP-A-2- 106530 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 27/12-27/20

Claims (4)

(57) [Claims] 1. A copolymer of polyvinylidene fluoride and vinylidene fluoride-propylene hexafluoride having a melting point of less than 190 ° C.
Body, vinylidene fluoride-ethylene tetrafluoride-hexafluoride
Propylene copolymer or vinylidene fluoride-hexafluoride
Graft copolymer of propylene copolymer and vinylidene fluoride
98 to 85 parts by weight of one or more kinds of thermoplastic fluororesins selected from polymers, 2 to 15 parts by weight of a polyalkylene oxide having a 10% weight loss temperature of 240 ° C. or more by thermogravimetric analysis (TGA), and Ionic electrolyte
Ri Na from 05-5 parts by weight, volume resistivity of 1 × 10 ⁸ ~
1 × 10 ¹¹ Ω · cm and surface resistivity 1 × 10 ⁸
~1 × 10 ¹² Ω / □ der Rukoto semiconductive fluororesin composition characterized. 2. The semiconductive fluororesin according to claim 1, wherein the polyalkylene oxide is one kind or two or more kinds selected from polyethylene oxide or a copolymer thereof. Composition. 3. The method according to claim 1, wherein the ionic electrolyte is at least one selected from alkali metal thiocyanates, phosphates, sulfates, and salts obtained from alkali metals and halogen-containing oxygen acids. Claim 1 or
Is a semiconductive fluororesin composition according to any one of 2 . 4. A semiconductive fluororesin film obtained by molding a semi-conductive fluoroplastic composition below the processing temperature 240 ° C. according to any one of claims 1 to 3.