JPS6156274B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a conductive lubricant for discs, which is used to prevent static electricity and lubricate records and discs (hereinafter abbreviated as "discs"), which are contact-type recording and reproducing media, and which rubs the signal recording surface of the disc under extreme pressure. It reduces the coefficient of friction between the contact needle (hereinafter referred to as the needle) that picks up signals recorded on the disk while sliding, and prevents deterioration of playback characteristics due to wear.
This reduces the lifespan of records and needles due to deformation, prevents scratching noise caused by adsorption of dust in the air caused by static electricity, prevents wear on records, and prevents trace conditions caused by the attraction of pickups due to static electricity. Fluctuations, friction, etc.
This is intended to improve various troubles that occur during record playback due to charging. Conventionally, plastic materials have been used as materials for audio and video records due to industrial aspects such as processability, recording accuracy, and mass productivity (for example, for audio, semi-rigid vinyl chloride resin, which is a copolymer of vinyl chloride and vinyl acetate) has been used. ) is widely used. However, when playing records made of such plastic materials, the contact surfaces between the record and the stylus generally wear out due to friction with the stylus, which is made of ultra-hard materials such as diamond or sapphire. Confirmed. In audio records, this wear causes negative effects such as increased acoustic distortion and deterioration of characteristics. Another problem is that plastic resin materials including semi-rigid vinyl chloride resin generally have a high surface resistance of 10 ⁹ to ^{10 20} Ωcm, so they are easily charged with static electricity, and static electricity is also generated by the sliding friction between the record and the stylus. However, as a result, dirt and dust adsorbed from the air obstruct the movement of the needle and generate scratch noise, and electric discharge occurs between the needle and the pickup, generating noise. In particular, with the recent improvements in the performance of audio equipment, the various phenomena described above have become acoustic problems. In the past, many improvements have been made to solve these problems, including methods for preventing static electricity and removing adsorbed dust, but there have been few examples regarding lubrication. Examples of recent improvements to the friction between records and needles include surface coatings with lubricants such as silicone-based lubricating oil and surfactant materials, and fluorine-based surfactant solutions as methods for modifying the surface of records. There are surface coatings (Japanese Unexamined Patent Publication No. 545456/1983) and coatings using a thin film of polytetrafluoroethylene resin (Japanese Unexamined Patent Application No. 22102/1989), but these methods have problems depending on each case. included, but not complete. In other words, not only do silicone oils and fluorine-based surfactants not provide sufficient lubricity under the conditions of friction between the record and the stylus, but oil-based and liquid coating agents leave the surface viscous even after application. Because of the residual dirt and dust that remains, it becomes a source of noise, and the stability of the frictional force becomes unstable, making tracing conditions unstable. In addition, the method requires a large-scale coating system for tetrafluoroethylene, and the surface resistance of tetrafluoroethylene is 10 ¹⁵ to 10 ¹⁹ Ωcm, which is among the highest among general resins, and there are problems due to electrostatic charge. . The present invention thus eliminates the drawbacks of the conventional methods of lubricating the record and the needle, easily and inexpensively modifies the surface of the record, and provides antistatic and antistatic methods.
The present invention provides a conductive lubricant that forms a strong protective film with excellent lubricity. In general, a surfactant is a substance that dissolves in a liquid and adsorbs from the solution to an interface, significantly reducing interfacial energy (surface tension, interfacial tension), and by its surface active ability, it has properties such as wetting, lubrication, dispersion, etc. It refers to a substance that has cleaning effects, and there are currently a large number of these substances being produced. The record cleaning liquid described above utilizes the lubricating effect and the lubrication effect among the effects of such a surfactant, or the static elimination effect due to ion conduction. The lubricating effect of surfactants has been utilized for a long time, mainly in the textile industry, and is used to reduce the coefficient of friction at the contact area between fast-moving fibers and jigs. Conventionally, polyhydric alcohols, higher fatty acids, and ester compounds thereof have been used as lubricants for such uses, and recently, fatty acid-modified silicones, fluorinated alkyl esters, and the like have been used as high-performance lubricants. The polyoxyethylene alkyl ether and the antistatic agent used in the present invention are both types of surfactants mentioned above, but in the polyoxyethylene alkyl ether, the number m of polyoxyethylene (POE) added is 1 to 3. It was thought that as the number of moles increased, hygroscopicity would be promoted and the lubricating effect would decrease. Furthermore, it is generally known that when such surfactants are dissolved in a solvent or when multiple surfactants are mixed, properties such as antistatic ability and lubricity change significantly depending on the combination. and
At the same time, in addition to the above-mentioned characteristics, the adhesion force of the surfactant changes depending on the material (resin) with which the surfactant is used and the friction conditions. The present inventors selected semi-rigid vinyl chloride resin and ultra-hard materials such as diamond from among the many surfactants.
A new conductive lubricant for discs was discovered using an evaluation method that matches the friction conditions during the performance of records that slide under extreme pressure (cm ² ). When the conductive lubricant for disks according to the present invention is actually used, the concentration and application amount significantly affect the friction conditions, and the antistatic effect is proportional to the concentration of the antistatic agent mixture, but the friction coefficient and frictional force This does not apply to the stability of the coating, and if the coating amount exceeds a certain amount, the lubricity and stability will deteriorate. When using this lubricant with a sprayer (pump type or aerosol), the preferred concentration is about 0.03 to 0.2% by weight, and if possible, it is better to apply a low concentration liquid in many areas to ensure uniform adhesion and stability of frictional force. will improve. However, when ethanol is used as a solvent, its boiling point is 78.3°C and the evaporation rate is slow. This will improve the dryness of the disk surface. In addition to this, it is also conceivable to use a special wiping jig as a method of applying the lubricant according to the present invention. In such cases, good results can be obtained even when the dilution concentration is higher than 0.2% by weight, and sufficient stability of frictional force can be obtained even at 98% by weight. In addition, the concentration ratio of the base agent and antistatic agent varies depending on the lubricity and antistatic ability of each ethanol solution, and the degree of mutual influence when both, and optional components, are mixed, but the approximate value is A sufficient effect can be obtained with a ratio of about 4:1 to 20:1. Examples of the present invention will be described below. Examples 1 to 6 5, 7, and 8 moles of polyoxyethylene (POE) were added to cetyl alcohol (C ₁₆ H ₃₃ OH)
POE addition alkyl ether and alkyl sulfonate ( _RSO3Na ), (R= _C15 ) or alkyltrimethylammonium chloride

[Formula] was mixed in a ratio of 4:1, diluted and dissolved with ethanol so that the total amount was 0.05% by weight, mixed and stirred to prepare a lubricant. Examples 7-10 Adding 3.5 moles of polyoxyethylene (POE) to stearyl alcohol (C ₁₈ H ₃₇ OH)
POE addition alkyl ether and alkyl sulfonate ( _RSO3Na ), (R= _C15 ) or alkyltrimethylammonium chloride

[Formula] was mixed in a ratio of 4:1, diluted and dissolved with ethanol so that the total amount was 0.05% by weight, mixed and stirred to prepare a lubricant. Examples 11-14 Polyoxyethylene (POE) was added to cetyl alcohol (C ₁₆ H ₃₃ OH), and alkyl sulfonate (RSO ₃ Na), (R=C 15 ), alkyl sulfonate was added to the POE-added alkyl ether in which 5.5 mol of polyoxyethylene (POE) was added to cetyl alcohol (C ₁₆ H 33 OH). Eight

[Formula] Alkyltrimethylammonium chloride

[Formula] Alkylhydroxyethyl-methylammonium chloride

[Formula] were mixed in a ratio of 20:1, diluted and dissolved with ethanol so that the total amount was 0.2% by weight, mixed and stirred to prepare a lubricant. Comparative Examples 1 to 4 3 moles and 23 moles of polyoxyethylene (POE) were added to cetyl alcohol (C ₁₆ H ₃₃ OH)
POE addition cetyl ether to alkyl sulfonate (RSO ₃ Na), (R=C ₁₅ ) or alkyl trimethyl ammonium chloride

[Formula] was mixed in a ratio of 4:1, diluted and dissolved with ethanol so that the total amount was 0.05% by weight, mixed and stirred to prepare a lubricant. Comparative Examples 5 to 8 Alkyl sulfonate (RSO ₃ Na), (R=C ₁₅ ) or alkyl ether added with 1 mol or 15 mol of polyoxyethylene (POE) to stearyl alcohol (C ₁₈ H ₃₇ OH) trimethylammonium chloride

[Formula] was mixed in a ratio of 4:1, diluted and dissolved with ethanol so that the total amount was 0.05% by weight, mixed and stirred to prepare a lubricant. The friction coefficient and antistatic ability of the lubricants of Examples 1 to 16 and Comparative Examples 1 to 8 were evaluated by the following methods. (A) Measuring method of friction coefficient Using the friction coefficient measuring device shown in Figure 1, approximately 0.3 lubricant was applied to the surface of test piece 1 made of semi-hard vinyl chloride resin using a pump sprayer.
After spraying and drying, a diamond indenter (tip radius 10 μm) 2 is pressed with a vertical load W of 1 to 4 g, and the force F that pulls the indenter 2 generated when the test piece 1 is moved at a constant speed is applied to a parallel leaf spring 3.
The friction coefficient was determined from the F/W by measuring with a strain gauge 4 installed in the. In FIG. 1, 5 is a moving table, 6 is a holder, 7 is a fulcrum, 8 is a load adjustment weight, 9 is a needle tip height adjusting screw, and 10 is a needle tip height fixing screw. (B) Method for measuring antistatic ability Approximately 0.3 lubricant was applied to a test piece made of semi-hard vinyl chloride resin using a pump sprayer.
After being sprayed with cc and dried, evaluation was made based on the half-life time of the charge generated by corona discharge using a static honest meter. Conditions Atmosphere 22℃, 20%RH Corona discharge voltage -10KV Evaluation results using (A) and (B) are shown below.

【table】

[Table] As is clear from the results, the conductive lubricant for disks of the present invention has excellent antistatic effects and lubricity. The reason for using an antistatic agent in combination will be described below. First, the POE-added alkyl ether has a remarkable effect of lowering the coefficient of friction between the record and the diamond stylus, but the amount of electrostatic charge is also significant, and the antistatic ability is insufficient in either case. Sideways
It is necessary to use an antistatic agent that has good compatibility with the POE-added alkyl ether and the solvent methanol and does not deteriorate the lubricating performance of the alkyl ether. Based on this background, the present invention shows that three types of antistatic agents are effective, and in order to better evaluate the effect of their combined use, Examples and Comparative Examples are shown in the table above in terms of charge amount half-life. It shows. FIGS. 2a and 2b each show the effect when the conductive lubricant is applied to an audio record. FIG. 2a shows the output level-frequency characteristic, and FIG. 2b shows the third-order distortion level-frequency characteristic. In Figures 2a and b, 1 indicates the initial characteristics of the audio record without applying lubricant, 2 indicates the characteristics after tracing the audio record without applying lubricant 100 times, and 3 indicates the initial characteristics of the audio record with no lubricant applied. 4 shows the characteristics after applying the lubricants of Comparative Examples 2 and 6 to an audio record and tracing them 100 times. FIG. 3 shows the effect of removing dust attracted to the audio disk by static electricity. In Fig. 4, a and b are wiped and removed by a conventional brush cleaner and a conventional wet cleaner, respectively, and c
is the case where the conductive lubricant of the present invention is also used,
With conventional cleaners a and b, it is difficult to remove dust that is attracted by static electricity, and a large number of noises are generated.However, when using the lubricant of the present invention, the dust and dirt removal effect is high, and the number of noises generated is low. There are few. Figure 4 shows polyoxyethylene (C ₂ H ₄ O) added to cetyl alcohol (C ₁₆ H ₃₃ OH) regarding the specification of the number of POE additions to alkyl ethers.
Number of moles added and friction coefficient μ when _n・H is added
FIG. Figure 5 shows polyoxyethylene (C ₂ H ₄ O) in stearyl alcohol (C ₁₈ H ₃₇ OH).
Number of moles added and friction coefficient μ when _n・H is added
FIG. Figure 6 shows a characteristic diagram showing the relationship between the amount of charge and the coefficient of friction for cetyl alcohol and stearyl alcohol, depending on the number of moles of POE added. ,
Rub the record with a cloth a certain number of times to charge it,
The generated static electricity was measured using an electrostatic electrometer. In Figures 4 to 6, the number of moles of POE added is 5 to 8 moles for cetyl alcohol and 3 to 5 moles for stearyl alcohol, which gives the lowest friction coefficient and The amount was also in a relatively low range, and taking both into consideration, this range was set as the range in which the effect can be achieved. In this way, the use of the conductive lubricant of the present invention eliminates the decrease in output level due to record wear during long-term tracing and the increase in harmonic distortion due to increased frictional force, making it possible to record on records for a long time. This makes it possible to accurately reproduce the recorded signal. Furthermore, the conductive lubricant of the present invention has the advantage of reducing static electricity discharge and the ability to attract dust due to static electricity, thereby reducing noise generation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an apparatus for measuring the coefficient of friction using a conductive lubricant for disks according to the present invention, and FIG.
b is a diagram showing the lubricating effect of the conductive lubricant for discs of the present invention, Figure 3 is a characteristic diagram showing the static elimination effect of the conductive lubricant for discs of the present invention, and Figure 4 is a diagram showing the effect of POE added to cetyl alcohol. Figure 5 shows the coefficient of friction for stearyl alcohol.
Characteristic diagram showing the friction coefficient when POE is added,
FIG. 6 is a characteristic diagram showing the relationship between the amount of charge and the coefficient of friction. 1... Test piece, 2... Diamond indenter, 3... Leaf spring, 4... Strain gauge.

Claims (1)

[Scope of Claims] 1 The main component is a mixture of a nonionic surfactant and an antistatic agent, and the nonionic surfactant is a mixture of cetyl alcohol (C ₁₆ H ₃₃ OH) and polyoxyethylene of 5 to 8 The antistatic agent is a substance in which 3 to 5 moles of polyoxyethylene are added to stearyl alcohol (C ₁₈ H ₃₇ OH), and the antistatic agent contains methanol as a diluting solvent and is compatible with methanol. A conductive lubricant for discs that is characterized by being a high-quality substance. 2. In the conductive lubricant for disks according to claim 1, the antistatic agent is an alkyl sulfonate [general formula (R-SO ₃ Na)], and R is _Co.H.
A conductive lubricant for disks, characterized in that n is a substance of 11 to 18 in _2o+1 . 3. In the conductive lubricant for disks according to claim 1, the antistatic agent is an alkyl phosphate. A conductive lubricant for disks characterized by: 4. In the conductive lubricant for disks according to claim 1, the antistatic agent is alkyltrimethylammonium chloride. A conductive lubricant for disks characterized by: 5. In the conductive lubricant for disks according to claim 1, the antistatic agent is alkylhydroxyethyl-methylammonium chloride. A conductive lubricant for disks characterized by: