JPH0132853B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an antistatic fluorine-based resin molded product, which is a fluorine-based resin whose surface properties are modified by low-temperature plasma of an organosilicon compound to provide durable and permanent antistatic properties. The purpose is to provide molded products. Fluorine-based resins, such as polytetrafluoroethylene, generally have excellent chemical and thermal stability, as well as excellent properties such as electrical properties, slip properties, and weather resistance. Various molded products such as films, sheets, and coated wires are manufactured and sold to take advantage of these properties. For example, in recent years, with advances in electrical and electronic technology, there has been a strong demand for higher performance and smaller size for wire materials, and in this field, there has been a strong demand for high performance, corrosion resistance,
Demand for fluorine resins with excellent dielectric properties is increasing, and they are used in coaxial cables, hook-up wires, aircraft wires, corrosion-resistant wires, etc., as well as computer wires, coaxial feeders for electronic equipment parts, etc.
Widely used for telephone exchange panel wires, telephone lines, etc. However, fluorine-based resin molded products have the drawback of being extremely easily charged. For this reason, this molded product is dusty and
The appearance may become dirty due to the adhesion of dust, etc., and when used in electronic equipment wiring, telephone line wire, etc., there is a problem that the accumulated static electricity may cause noise and crosstalk phenomena, and furthermore, it may cause damage to the human body. There are also problems such as the influence of electricity (electric shock) and spark discharge. To prevent this charging (accumulation of static electricity),
Attempts have been made to make the surface of fluororesin molded products hydrophilic through corona discharge treatment or low-temperature plasma treatment, thereby suppressing static charging, but simple low-temperature plasma treatment or corona treatment alone does not provide an excellent antistatic effect. That is difficult. There are also attempts to prevent static electricity by introducing hydrophilic functional groups through chemical treatment or surface grafting or surface oxidation treatment using active rays (electron beams, ultraviolet rays, radiation, etc.), but the treatment process is complicated. Therefore, it is not possible to obtain a sufficient antistatic effect. The present inventors have completed the present invention as a result of intensive research to solve these problems.This invention is based on the general formula R _a H _b SiX _4-ab ( In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group, X is a halogen atom or an alkoxy group, a is 1, 2 or 3, b is 0 or 1, where a+b is 1, 2 or 3. This invention relates to an antistatic fluorine-based resin molded article formed by treating with low-temperature plasma an organosilicon compound selected from the organosilane shown in () or its hydrolyzed condensate. Fluorine-based resin molded products treated with low-temperature plasma of this organosilicon compound have a more pronounced antistatic effect than those treated with low-temperature plasma of other organic or inorganic compounds, and their sustainability and durability are longer. It also has the advantage of being extremely superior. This is because when the surface of a fluorine-based resin molded product is treated with the low-temperature plasma of the organosilicon compound described above, an extremely thin modified layer is formed on the surface of the molded product, and this layer is strong against the fluorine-based resin. It is thought that this is because the formation rate of this modified layer is faster than when the molded product is made of other polymers, and the effect of the low-temperature plasma treatment is noticeable. The fluorine-based resin molded products targeted by the present invention include:
This includes films, sheets, other general molded products, and various coverings such as plastic wires. stability, etc.) without any loss. The organosilicon compound used in the present invention is an organosilane represented by the above-mentioned general formula and a hydrolyzed condensate thereof, where R is an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, etc. ,
Monovalent hydrocarbon groups such as alkenyl groups such as vinyl groups and allyl groups, alkynyl groups such as ethynyl groups, propynyl groups, butynyl groups, aryl groups such as phenyl groups and naphthyl groups, and hydrogen atoms of these monovalent hydrocarbon groups. represents a substituted monovalent hydrocarbon group partially substituted with another atom (such as a halogen) or group (such as a cyano group), and X in the formula represents a halogen such as chlorine or bromine, a methoxy group, an ethoxy group, or a butoxy group. Indicates an alkoxy group such as a group. Specific examples of such organic silicon compounds are as follows. First, those represented by the formula R ₃ SiX include trimethylchlorosilane,
Trimethylmethoxysilane, trimethylethoxysilane, vinyldimethylchlorosilane, vinyldimethylmethoxysilane, vinyldimethylethoxysilane, ethynyldimethylmethoxysilane, ethynyldimethylchlorosilane, methylchloromethylmethoxychlorosilane, triethylmethoxysilane, dimethylchloromethylethoxysilane, dimethylchloromethyl Chlorosilane, dimethylphenylmethoxysilane, 2-chloroethynyldimethylchlorosilane, 2-chloroethyldimethylmethoxysilane, etc., and those represented by the formula R ₂ SiX ₂ include dimethyldichlorosilane, dimethyldimethoxysilane, diethyldimethoxysilane, dimethyldimethoxysilane, etc. Ethoxysilane, vinylmethyldichlorosilane, vinylmethyldimethoxysilane, 2-chloroethylmethyldimethoxysilane, vinylmethyldiethoxysilane, chloromethylmethyldichlorosilane, dimethoxymethylphenylsilane, chloromethylmethyldimethoxysilane, etc.
Examples of RSiX ₃ include methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, chloromethyltrimethoxysilane, and 2-chloroethyltrimethoxysilane. Further, examples include those having a ≡Si-H bond, that is, those corresponding to the formulas (R)(H)Si(X) ₂ and (R) ₂ (H)Si(X). Although the case where X is an alkoxy group and chlorine is illustrated above, the same applies to the case where X is another halogen element such as bromine. All of the organosilicon compounds exemplified above correspond to organosilane compounds, but in the present invention, hydrolyzed condensates of these compounds can also be used, including divinyltetramethyldisiloxane, dichlorosiloxane, Examples include methyltetramethyldisiloxane, diethynyltetramethyldisiloxane, and tetramethyldisiloxane. Of course, other hydrolysis condensates can also be used, but high condensates that are difficult to gasify are unsuitable. The fluorine-based resin used in the present invention may be either a homopolymer or a copolymer having a C-F bond in the molecule, and common examples include polytetrafluoroethylene, polychlorotrifluoroethylene, and polyvinylidene fluoroethylene. Ride, polyvinyl fluoride, tetrafluoroethylene/hexafluoropropene copolymer, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/ethylene copolymer, chlorotrifluoroethylene/ethylene copolymer, vinylidene fluoride Examples include Ride-hexafluoroisobutene copolymer and fluorinated ethylene-fluorinated propylene copolymer. Methods for obtaining molded products from these fluorine-based resins include compression molding, ram extrusion, paste extrusion,
Any molding method conventionally used for molding fluorine-based resins, such as calendar molding, dispersion processing, or melt molding, may be used; therefore, there are no restrictions on the type, shape, etc. of these molded products. In addition, fillers such as glass fiber, graphite, molybdenum disulfide, and bronze powder, which are added during molding, and plasticizers such as surfactants, emulsifiers, stabilizers, and fluorine oil are added. The presence of these components has little effect on achieving the effects of the present invention. The present invention improves the surface properties of such fluorine-based resin molded products by treating them with low-temperature plasma of the organosilicon compound described above, resulting in highly durable and long-lasting antistatic properties. It is intended to give. A method for treating fluorine-based resin molded products with such low-temperature plasma is to charge the fluorine-based resin molded products into a low-temperature plasma generator, and to flow the organosilicon compound gas through the device. 10
A method may be used in which the pressure is adjusted and maintained at a pressure of Torr or less, low-temperature plasma is generated under this gas pressure, and the molded article is exposed to the low-temperature plasma. In addition, inert gases such as helium and argon, inorganic gases such as nitrogen, oxygen, air, hydrogen, water vapor, carbon dioxide, and carbon monoxide, and organic compound gases other than organosilicon compounds are allowed to coexist with the organosilicon compound. Good too. In the above treatment method, if the pressure inside the organosilicon compound device is 10 Torr or more, it will be difficult to obtain a treated molded product with excellent antistatic properties, so the gas pressure of this low-temperature plasma should be 10 Torr or less. is preferably in the range of 1 to 0.005 Torr. Low-temperature plasma treatment at this gas pressure imparts excellent antistatic properties, but when the gas pressure exceeds 10 Torr, the antistatic properties rapidly decrease (accompanied by an increase in surface resistance). Such a phenomenon is completely unexpected from the knowledge obtained in conventional plasma polymerization and plasma treatment. As conditions for generating low-temperature plasma, for example, a power of 10 KHz to 100 MHz and 10 W to 100 KW may be applied to the electrodes, and either an internal electrode method or an external electrode (electrodeless) method may be used. Further, a sufficient reforming effect can be obtained regardless of the type of discharge (glow discharge, corona discharge, etc.). The plasma processing time varies depending on the applied power and the like, but generally several seconds to several tens of minutes is sufficient. In the low-temperature plasma treatment, two or more organosilicon compounds may be mixed or used in combination, and a synergistic effect may be expected in some cases. In addition, in order to impart not only antistatic properties but also other properties to fluorine-based resin molded products, it is not possible to mix or use the organosilicon compound with other organic compounds and/or the above-mentioned inorganic gases. This method not only provides good antistatic properties (reduced surface resistance) with excellent durability and sustainability, but also provides wettability and
It has the advantage that printability, adhesiveness, etc. are also provided. Next, specific examples will be given. Example 1 A Teflon TFE (trade name, polytetrafluoroethylene manufactured by DuPont) sheet was set in a plasma generator, and after reducing the pressure inside the device to 10 ^-4 Torr, the atmosphere was introduced and the inside of the device was heated under atmospheric circulation. After adjusting and holding at 0.1 torr, trimethylchlorosilane vapor is introduced and mixed with the circulating atmosphere, and the atmospheric partial pressure under the circulating air is 0.1 torr.
The partial pressure of trimethylchlorosilane was adjusted and maintained at 0.1 torr, and a high frequency power of 13.56 MHz and 300 W was applied to generate low temperature plasma, and the sheet was treated for 2 minutes. The tobacco ash adsorption distance (cm), surface specific resistance value (ohm), and frictional charging voltage value (volts) were measured for the sheet treated in this way and the sheet that was not subjected to plasma treatment (untreated sheet). The preventive properties were evaluated. The results were as shown in Table 1. Cigarette ash adsorption distance: After rubbing the sample surface 10 times with a cotton cloth, bring it close to cigarette ash and measure the distance (cm) at which cigarette ash begins to adhere. Conditions: 25℃60%RH Surface specific resistance value: Measured using SM-10 manufactured by Toa Denpa Kogyo Co., Ltd. (ohm). Frictional charge voltage value: Measured using a rotary static tester manufactured by Koa Shokai (volts). Conditions: Cotton cloth, 200g load, 750rpm, 60 seconds.

[Table] Example 2 A Teflon TFE sheet similar to that used in the previous example was set in a plasma generator, and while the pressure inside the device was reduced to 10 ^-4 Torr, vinyldimethylchlorosilane vapor was introduced and the inside of the device was circulated. Adjusted and held at 0.05 Torr. A high frequency power of 13.56 MHz and 200 W was applied to this system to generate low temperature plasma, and the sheet was treated for 5 minutes. Regarding this treated sheet, Example 1
The same physical property test was conducted to evaluate the antistatic property.
The results were as shown below. Cigarette ash adsorption distance 0 cm Surface specific resistance value 2×10 ⁹ ohm Frictional charging voltage value 250 volts Example 3 A Teflon TFE sheet similar to that used in Example 1 was set in a plasma generator, and the inside of the device was set at 10 ^-5
After reducing the pressure to Torr, nitrogen gas was introduced and the inside of the apparatus was adjusted and maintained at 0.1 Torr while nitrogen gas was flowing. Next, while introducing trimethylmethoxysilane vapor and mixing it with circulating nitrogen gas, adjust and maintain the nitrogen gas partial pressure and trimethylmethoxysilane partial pressure as shown in Table 2, and then apply high frequency power of 110KHz2KW to generate a low-temperature plasma. generate 30 sheets
Processed for seconds. This treated sheet was subjected to the same physical property test as in Example 1 to evaluate its antistatic properties. The results were as shown in Table 2.

【table】

[Table] Example 4 A Tedlar (trade name, polyvinyl fluoride, manufactured by Dupont) sheet was set in a plasma generator, and after reducing the pressure inside the device to 0.01 Torr, argon gas was introduced, and under argon flow, the pressure inside the device was reduced to 0.2 Torr. Adjusted and held to the torque. Next, dimethyldimethoxysilane vapor was introduced, and while mixing with circulating argon gas, the argon gas partial pressure was 0.2 Torr, and the dimethyldimethoxysilane partial pressure was
After adjusting and maintaining the temperature at 0.2 Torr, high-frequency power of 13.56 MHz and 200 W was applied to generate low-temperature plasma, and the sheet was treated for 4 minutes. This treated sheet was subjected to the same physical property test as in Example 1 to evaluate its antistatic properties. The results were as follows. Cigarette ash adsorption distance 0 cm Surface specific resistance value 8×10 ⁹ ohm Frictional charging voltage value 300 volts Example 5 A Tedlar sheet similar to that used in Example 4 was set in a plasma generator, and the inside of the device was heated to 10 ^-5 Torr. After reducing the pressure, atmospheric air was introduced, and the inside of the apparatus was adjusted and maintained at 0.1 Torr under atmospheric circulation. Next, dimethyldichlorosilane vapor is introduced,
After adjusting and maintaining atmospheric partial pressure at 0.1 torr and dimethyldichlorosilane partial pressure at 0.5 torr while mixing with the circulating atmosphere,
A high-frequency power of 13.56 MHz and 300 W was applied to generate low-temperature plasma, and the sheet was treated for 3 minutes. The sheets thus treated and the sheets not subjected to plasma treatment (untreated sheets) were subjected to the same physical property tests as in Example 1 to evaluate antistatic properties. The results were as shown in Table 3.

[Table] Example 6 A Tedlar sheet similar to that used in Example 4 was set in a plasma generator, and dimethyldichlorosilane vapor was introduced while the pressure inside the device was reduced to 10 ^-4 Torr. The inside was adjusted and maintained at 0.005 Torr. A high-frequency power of 13.56 MHz and 200 W was applied to this system to generate low-temperature plasma, and the sheet was treated for 5 minutes. This treated sheet was subjected to the same physical property test as in Example 1 to evaluate its antistatic properties. The results were as follows. Cigarette ash adsorption distance 2 cm Surface specific resistance value 1×10 ¹¹ ohm Frictional charging voltage value 1600 volts Example 7 Afrex (trade name, manufactured by Asahi Glass Co., Ltd., tetrafluoroethylene-ethylene copolymer) sheet was set in the plasma generator, After reducing the pressure inside the device to 10 ^-5 Torr, dry air was introduced into the device.
Adjusted and held at 0.1 Torr. Next, vinylmethyldimethoxysilane vapor is introduced and mixed with the circulating dry air, and the partial pressure of the dry air is
0.1 torr, vinylmethyldimethoxysilane partial pressure 0.1
After adjusting and maintaining the torque, high-frequency power of 13.56 MHz and 200 W was applied to generate low-temperature plasma, and the sheet was treated for 2 minutes. This treated sheet was subjected to the same physical property test as in Example 1 to evaluate its antistatic properties.
The results were as follows. Cigarette ash adsorption distance 0 cm Surface specific resistance value 7×10 ⁹ ohm Frictional charging voltage value 80 volts Example 8 An Afflex sheet similar to that used in Example 7 was set in a plasma generator, and the inside of the device was heated to 10 ^-5
After reducing the pressure to 0.0 Torr, the inside of the apparatus was adjusted and maintained at 0.01 Torr while introducing carbon dioxide gas. Next, methyltrimethoxysilane vapor is introduced and mixed with circulating carbon dioxide gas, and the partial pressure of carbon dioxide gas is
After adjusting and maintaining the partial pressure of methyltrimethoxysilane at 0.01 torr and 0.2 torr, a high frequency power of 13.56 MHz and 200 W was applied to generate low temperature plasma, and the sheet was treated for 10 minutes. This treated sheet was subjected to the same physical property test as in Example 1 to evaluate its antistatic properties. The results were as follows. Cigarette ash adsorption distance 0 cm Surface specific resistance value 6×10 ⁹ ohm Frictional charge voltage value 150 volts Example 9 A wrapping connection wire for a computer covered with Afrex was set in the plasma generator, and the pressure inside the device was reduced to 0.001 Torr. After that, the inside of the device was adjusted and maintained at 0.1 torr while introducing air. Next, vinyl dimethylmethoxysilane vapor is introduced and mixed with circulating air, and after adjusting and maintaining the partial pressure of air at 0.05 torr and the partial pressure of vinyldimethylmethoxysilane at 0.05 torr, high-frequency power of 13.56MHz2KW is applied to generate low-temperature plasma. The coated wire was then treated for 30 seconds. The surface resistivity values of the coated wire treated in this manner are as shown below, and the antistatic property was dramatically improved compared to the untreated case. Surface specific resistance value (ohm) Plasma treatment 2×10 ⁹ Untreated 6×10 ¹⁴ Examples 10 Teflon A high voltage ignition cable for aircraft coated with TFE is set in a plasma generator, and the inside of the device is heated to 0.001 Torr. After reducing the pressure, the pressure was adjusted and maintained at 0.1 torr while introducing dimethylchloromethylchlorosilane vapor. High-frequency power of 13.56 MHz and 200 W was applied to generate low-temperature plasma, and the coated cable was treated for 5 minutes. The surface resistivity values of the coated cable treated in this manner are as shown below, and the antistatic property was dramatically improved compared to the untreated case. Surface resistivity value (ohm) Plasma treatment 3×10 ⁹ Untreated 1×10 ¹⁵

Claims (1)

[Claims] 1. The surface of the fluorine-based resin molded product is defined by the general formula R _a H _b SiX _4-ab (wherein R is a substituted or unsubstituted monovalent hydrocarbon group, and X is a halogen atom or an alkoxy group). , a is 1, 2 or 3, b is 0 or 1, where a+b is 1, 2 or 3) or a hydrolyzed condensate thereof. Antistatic fluorine-based resin molded product made by processing.