JPS6237447B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a cleaning tape for cleaning a magnetic head of a magnetic recording device. When a magnetic tape is used for a long time, a portion of the magnetic tape is scraped off and adheres to the surface of the magnetic head like glue. Furthermore, indoor dust and the like adhere to the magnetic head, causing it to become clogged. If the magnetic head becomes clogged, the sound quality and image quality will deteriorate, and recording and playback will no longer be possible. Therefore, a cleaning tape is used to remove the substances adhering to the magnetic head. As one type of cleaning tape, one in which Japanese or Western paper is laminated to a support is known (Utility Model Application Publication No. 55808/1983). However, this cleaning tape has the disadvantage that its cleaning effect is small. That is, the binder constituting the magnetic layer has a strong adhesive force, so if it adheres to the magnetic head, it cannot be removed sufficiently by rubbing it with paper. Another disadvantage is that paper fibers adhere to the magnetic tape, resulting in dropouts. On the other hand, another cleaning tape is known in which a cleaning layer is formed by coating particles having a size of 0.05 to 3 .mu.m on a support together with a binder (Japanese Patent Laid-Open No. 49-40504). This cleaning tape uses hard particles contained in the cleaning layer to cut (polish) the adhesion on the head and clean it, so it has a great cleaning effect, but it has the disadvantage of causing scratches on the head surface. be. These scratches may damage the magnetic tape, leading to deterioration in sensitivity and S/N ratio. Furthermore, since this method uses hard particles to cut off deposits, increasing the cleaning effect will cause scratches on the magnetic head. Therefore, it is extremely difficult to strike a balance between scratches on the magnetic head and cleaning effect. The present inventor has discovered that by adding relatively soft particles with large particle size and low hardness in place of the hard particles described above, the occurrence of scratches on the magnetic head can be eliminated and an excellent cleaning effect can be obtained.
The invention has been completed. SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning tape that has a good cleaning effect and can clean a magnetic head without damaging it. The cleaning tape of the present invention is a cleaning tape for a magnetic recording/reproducing device in which a cleaning layer made of abrasive particles and a binder is formed on a support, wherein the abrasive particles have an average particle size of 6 μm or more and 200 μm or less, and a Mohs hardness of 2 or more and 5 μm or less. The cleaning tape is characterized in that the cleaning layer contains abrasive particles of less than These abrasive particles with low hardness soften the contact pressure of the magnetic head, allowing cleaning to be performed with a small pressure, and thereby reducing the occurrence of scratches on the magnetic head. Therefore, there are fewer scratches on the magnetic head, and the deposits are cut off and removed, resulting in a good cleaning effect on the magnetic head. The present invention will be explained in detail below. The cleaning tape of the present invention is composed of a support 10 and a cleaning layer 11 formed on the support 10, as shown in FIG. The cleaning layer 11 has a particle size of 6 μm or more.
Contains abrasive particles 12 having a diameter of 200 μm or less and a Mohs hardness of 2 or more and less than 5. The abrasive particles are mixed with a binder and applied onto the support 10. The abrasive particles 12 scrape off deposits 14 attached to the magnetic head 13. Since these abrasive particles have a large particle size and are soft particles, the contact pressure of the magnetic head is relieved, and the abrasive particles are removed with a small pressure. Therefore, the hardness head will not be seriously scratched, and there is no risk of interfering with recording and reproducing. The abrasive particles have a function as a buffer material and have the function of removing attached substances. If desired, the cleaning tape may have surface resistance to lower electrical resistance or improve runnability.
A back coat with a resistance of 10 ⁸ Ω/cm or less is applied. This back coat also has the effect of reducing light transmittance. The cleaning tape is run in place of the magnetic tape to remove deposits 14 from the magnetic head 13, but if used as a leader tape, cleaning can be conveniently performed each time recording and reproduction are performed. Examples of the support include polyesters such as polyethylene terephthalate (PET) and polyethylene-2,6-naphthalate, polyolefins such as polyethylene and polypropylene, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, and cellulose acetate propionate. Cellulose derivatives such as nate are used. The abrasive particles contained in the cleaning layer have a particle size of 6 μm or more and 200 μm or less, and a Mohs hardness of 2 or more and less than 5. These abrasive particles have a cleaning effect and do not cause scratches on the surface of the magnetic head. The Mohs hardness of the abrasive particles is the hardness required to remove deposits from the magnetic head, and this varies depending on the ferromagnetic fine powder, binder, various additives, etc. used in the magnetic tape, and also depends on the material of the magnetic head. (For example, single crystal ferrite, hot pressed ferrite, metal head, etc.), the type of tape recorder, the relative speed between the tape and the magnetic head, etc., but the lower limit of Mohs hardness is generally 2 or more for these reasons and polishing ability. is necessary. Therefore, the Mohs hardness is preferably 2 or more and less than 5. On the other hand, if the particle size is larger than 200 μm, contact with the magnetic tape tends to deteriorate, the surface of the cleaning tape becomes extremely uneven, and the particles tend to fall off from the surface of the cleaning tape. For these reasons, the particle size of the abrasive particles is preferably 200 μm or less. Furthermore, if the particle size is too small, the polishing ability will be reduced, so the particle size must be at least 6 μm or more. Therefore, the particle size of the abrasive particles is between 6 and 200μ.
m, preferably 50 to 100 μm. These abrasive particles include CaCO ₃ , ZnO,
Al ₂ O ₃・4SiO ₂・H ₂ O (roxite clay), Al ₂ O ₃・
2SiO ₂・2H ₂ O (kaolin clay), 3CaO・
Al ₂ O ₃・3CaSO ₄・31H ₂ O (sachinholite),
BaSO ₄ (barium sulfate, natural product: Baryta, sedimentation product: Branphix), etc. are used. As the binder for dispersing the abrasive particles, those used in conventional magnetic tapes can be used as is. As these binders, thermoplastic resins, thermosetting resins, reactive resins, and mixtures thereof are used. As a thermoplastic resin, the softening temperature is 150℃ or less, the average molecular weight is 10,000 to 200,000, and the degree of polymerization is about 200 to 200.
500, such as vinyl chloride vinyl acetate copolymer, vinyl chloride vinylidene chloride copolymer,
Vinyl chloride acrylonitrile copolymer, acrylic acid ester acrylonitrile copolymer, acrylic acid ester vinylidene chloride copolymer, acrylic acid ester styrene copolymer, methacrylic acid ester acrylonitrile copolymer, methacrylic acid ester vinylidene chloride copolymer, methacrylic Acid ester styrene copolymer, urethane elastomer,
Polyvinyl fluoride, vinylidene chloride acrylonitrile copolymer, butadiene acrylonitrile copolymer, polyamide resin polyvinyl butyral, cellulose derivatives (cellulose acetate/butyrate, cellulose diacetate, cellulose triacetate, cellulose propionate, nitro/cellulose, etc.), Styrene-butadiene copolymers, polyester resins, chlorovinyl ether acrylate copolymers, amino resins, various synthetic rubber-based thermoplastic resins, and mixtures thereof are used. To form the cleaning layer, abrasive particles are mixed with the binder, dissolved in an organic solvent, and applied as a coating solution onto the support. Examples of these resins are given in Japanese Patent Publication Nos. 37-6877, 39-12528, 39
-19282, 40-5349, 40-20907, 41-9463
No. 41-14059, 41-16985, 42-6428, 42
-11621, 43-4623, 43-15206, 44-2889
No. 44-17947, No. 44-18232, No. 45-14020,
No. 45-14500, No. 47-18573, No. 47-22063, 47-
No. 22064, No. 47-22068, No. 47-22069, No. 47-22070
No. 47-27886. As a thermosetting resin or a reactive resin, it has a molecular weight of 2×10 ⁵ or less in the state of a coating solution, and is suitable for coating,
When heated after drying, the molecular weight becomes infinite due to reactions such as condensation and addition. Moreover, among these resins, those which do not soften or melt before the resin is thermally decomposed are preferable. Specifically, for example, phenolic resin, epoxy resin, polyurethane curable resin, urea resin, melamine resin, alkyd resin, silicone resin, acrylic reaction resin, epoxy-polyamide resin,
Nitrocellulose melamine resin, mixture of high molecular weight polyester resin and isocyanate prepolymer, mixture of methacrylate copolymer and diisocyanate prepolymer, mixture of polyester polyol and polyisocyanate, urea formaldehyde resin, low molecular weight glycol/high molecular weight diol/trifle Preferred examples include mixtures of enylmethane triisocyanates, polyamine resins, and mixtures thereof. Examples of these resins are given in Japanese Patent Publication No. 39-8103, 40-
No. 9779, No. 41-7192, No. 41-8016, No. 41-14275
No. 42-18179, No. 43-12081, No. 44-28023,
No. 45-14501, No. 45-24902, No. 46-13103, 47-
No. 2205, No. 47-22066, No. 47-22067, No. 47-22072
No. 47-22073, No. 47-28045, No. 47-28048,
It is described in publications such as No. 47-28922. The binder may be used alone or in combination of two or more, and other additives may be added. These additives include dispersants, lubricants, abrasives, and the like. Regarding the mixing ratio of abrasive particles to binder, if the binder is small, the particles tend to fall off, and if the ratio is too large, the cleaning effect will be reduced. According to experiments, the amount of particles is 5 to 400 parts per 100 parts by weight of binder.
It is preferably 50 to 200 parts by weight. The total thickness of the cleaning tape of the present invention is generally about 10 to 100 μm, but is preferably about 10 to 100 μm in order to ensure smooth contact with the magnetic head.
It is 20 to 60 μm. The thickness of the support is 5-50μ
m, preferably 12 to 40 μm. Therefore, the thickness of the binder film of the cleaning layer is about 5 to 50 μm, preferably 8 to 20 μm.
If this thickness is too thick, the contact between the magnetic head and the cleaning tape will be poor. In the present invention, the cleaning layer consisting of the above-mentioned abrasive particles and binder has a friction coefficient of 0.15 to 0.15.
Must be 0.4. This is because if it is too large, a strong force will be applied to the magnetic head during use, potentially clogging or destroying the magnetic head. The friction coefficient in the present invention was measured using the measuring device shown in FIG. In Figure 2, 2
1 is a sample, and the sample 21 is passed from the feed reel 22 to the capstan 23, the detection part T ₁ , the capstan 24, the fixed pole 25, the capstan 26, the detection part T ₂ , the capstan 27 and the pinch roller 28 to the take-up reel. It is wound up to 29. The material of the fixed pole 25 is SUS 402J.
(JIS) 5φ, capstan 23, 24, 2
6 and 27 are made of alumite, and the fixed pole 25 does not rotate. Also, the tape speed is
3.3 m/sec., and is driven by a capstan 27 made of alumite and a pinch roller 28 made of rubber. The detection part T ₁ is a fixed part on the inlet side tension side, and the detection part T ₂ is a tension measurement part on the outlet side. Using the above device, the friction coefficient μ is calculated by the following formula.
Measure. μ=1/πlogT ₂ /T _1The friction coefficient μ was measured using such a device.
Based on the following reasons. The cleaning tape comes into contact with the magnetic head, cylinder, and post of the magnetic recording device.
The post is where the most running resistance is applied. Therefore, the coefficient of friction against the post is a problem, but since the material of this post is SUS 420J (JIS), the fixed pole 25 should be made of the same material as the post so that the coefficient of friction can be measured more realistically. did. The friction coefficient of the cleaning tape of the present invention is 0.15
~0.4, but the following methods can be used to provide such a coefficient of friction. (a) The surface roughness of the cleaning layer is 0.1 mm to 0.1 μm.
The friction coefficient is adjusted by setting it within the range of . (b) Young's modulus of the cleaning layer is 4×10 ⁵ g/cm ²
The friction coefficient is adjusted within the range of ~1×10 ¹⁰ g/cm ² . (c) Additives (lubricants, antistatic agents, etc.) are added to the cleaning layer in addition to the abrasive particles, and the friction coefficient is adjusted by changing the amount of the additives. For the method (a) based on surface roughness, specifically, methods such as calendering the cleaning layer or adjusting the particle size of abrasive particles are effective. In the method using Young's modulus in (b), adjustment is specifically made by changing the type of binder, but
This can be achieved by adjusting with a curable binder or by adding a curing agent. In the method (c) using additives, the amount can be adjusted by adjusting the amount of lubricant, antistatic agent, etc. added. This additive is 10wt.% or less, preferably 0.01wt.% based on the abrasive particles.
%~5wt.% amount is good. This varies depending on the type of additive. For example, when using silicone oil, it is preferable to use 0.8 wt% or less based on the abrasive particles (2.4 parts by weight or less of silicone oil per 300 parts by weight of the abrasive particles), and When lecithin is used, it is preferably used in an amount of 1.0 wt% or less based on the abrasive particles (3 parts by weight or less of soybean lecithin per 300 parts by weight of the abrasive particles). As lubricants, conductive fine powder such as graphite; inorganic fine powder such as molybdenum disulfide and tungsten disulfide; polyethylene, polypropylene,
Fine plastic powder such as polyethylene vinyl chloride copolymer and polytetrafluoroethylene; α-
Olefin polymer; unsaturated aliphatic hydrocarbon that is liquid at room temperature (a compound in which an n-olefin double bond is bonded to the terminal carbon, prime number approximately 20); monobasic fatty acid with 12 to 20 carbon atoms and 3 carbon atoms Fatty acid esters consisting of ~12 monohydric alcohols; dialkylpolysiloxane (alkyl has 1 to 5 carbon atoms), dialkoxypolysiloxane (alkoxy has 1 to 5 carbon atoms)
-4), alkylalkoxypolysiloxane (alkyl has 1 to 5 carbon atoms, alkoxy has 1 to 4 carbon atoms), phenylpolysiloxane, fluoroalkylpolysiloxane (alkyl has 1 to 4 carbon atoms),
Silicone oil such as 5 pieces) can be used.
Regarding these, Special Publication No. 41-18064, 43-23889
No. 46-40461, No. 47-15621, No. 47-
No. 18482, No. 47-8043, No. 47-30207, No. 47-
No. 32001, No. 48-7442, No. 49-14249, No. 50-
5042, U.S. Patent No. 3470021; U.S. Patent No. 3492235;
No. 3497411; No. 3523086; No. 3625760; No. 3625760;
No. 3630772; No. 3634253; No. 3642539; No. 3634253; No. 3642539;
No. 3687725; “IBM Technical Disclosure
Bulletin “Vol.9, No.7, Page 779 (December 1966
month); “ELEKTRONIK” 1961, No. 12,
It is described on page 380 etc. Antistatic agents include conductive fine powders such as carbon black and carbon black graft polymer; natural surfactants such as soybean lecithin and saponin; nonionic surfactants such as alkylene oxide, glycerin, and glycidol; and higher alkyl amines. , quaternary ammonium salts, pyridine and other heterocycles, phosphonium or sulfonium, and other cationic surfactants; anionic surfactants containing acidic groups such as carboxylic acid, sulfonic acid, phosphoric acid, sulfuric ester groups, and phosphoric ester groups. ;
Ampholytic activators such as amino acids, aminosulfonic acids, sulfuric acid or phosphoric acid esters of amino alcohols, etc. are used. Some of the conductive fine powders and surfactant compounds that can be used as antistatic agents are
No. 22726, No. 47-24881, No. 47-26882, No. 48
-15440, 48-26761, US Patent 2271623
No. 2240472, No. 2288226, No. 2676122,
No. 2676924, No. 2676975, No. 2691566, No. 2676975, No. 2691566, No.
No. 2727860, No. 2730498, No. 2742379, No.
No. 2739891, No. 3068101, No. 3158484, No. 3158484, No.
No. 3201253, No. 3210191, No. 3294540, No.
No. 3415649, No. 3441413, No. 3442654, No. 3441413, No. 3442654, No.
3475174, 3545974, OLS 1942665, UK patent 1077317,
No. 1198450, etc., "Synthesis of surfactants and their applications" by Ryohei Oda et al. (Maki Shoten 1964 edition); AM
“Surf S Active Agents” by Schwarz & J.W. Peiri (Interscience)
Publication Incorporated (1958 edition); JP Sisley, Encyclopedia
It is described in books such as "Of Surf S Active Agents, Volume 2" (Chemical Publishing Company, 1964 edition); "Surfactant Handbook", 6th edition (Sangyo Tosho Co., Ltd., December 20, 1964). ing. The cleaning tape according to the present invention can improve the cleaning effect without causing scratches or other damage to the magnetic head, and when used as a leader tape of a magnetic tape, it does not affect the magnetic layer. It has the effect of not reducing the initial magnetic properties of the tape. Next, a detailed explanation will be given with reference to examples. In each example, all parts indicate parts by weight. Example 1 The following coating composition (1) was applied to a PET support with a thickness of 38μ.
As shown in Table 1, abrasive particles (CaCO ₃ ) with varying sizes and amounts of silicone oil added were applied to a binder film with a thickness of 10 μm, and then 1/2
Cleaning tape slit into inch width
I made Nos. 11-17. When this cleaning tape is set in a unified video tape recorder whose head has been clogged in advance, the time it takes to clear the clog, playback sensitivity, S/N ratio, and whether or not the tape gets scratched when running the magnetic tape after the clog is cleared. I looked into it. The results are shown in Table 4. Note that silicone oil was added to control the friction coefficient. Coating liquid composition (1) ● Abrasive particles (CaCO ₃ ) ...300 parts ● Vinyl chloride vinylidene chloride copolymer (copolymerization ratio = 7:3, degree of polymerization = 400 ... 46.4 parts ● Epoxy resin (bisphenol A and Reaction product of epichlorohydrin, molecular weight = 900, epoxy equivalent = 460-520, hydroxyl group content = 0.29%,
Shell Oil Co. Epicote 1001) ...28.3 parts ●Silicone oil (dimethylpolysiloxane)
...(See Table 1) ●Isocyanate compound (75wt% ethyl acetate solution of the reaction product of 3 moles of 2,4-tolylene diisocyanate compound and 1 mole of trimethylolpropane, Bayer AG's Desmodur L-75)
...5.6 parts●Butyl acetate ...800 parts

【table】

[Table] Example 2 Cleaning tapes Nos. 21 to 27 were made using the following coating composition (2) in place of the coating composition (1) of Example 1. The same test as in Example 1 was conducted using these cleaning tapes Nos. 21 to 27. The material (ZnO) of the abrasive particles and the particle size are shown in Table 2, and the results are shown in Table 4. Note that soybean lecithin was added to control the friction coefficient. Coating composition (2) ●Abrasive particles (ZnO)...300 parts ●Vinyl chloride-vinyl acetate copolymer (copolymerization ratio
87:13, degree of polymerization 350) ...34.7 parts ●Polyester polyol (reaction product of 1 mol of adipic acid, 1 mol of diethylene glycol, and 0.06 mol of trimethylolpropane) Viscosity (75℃)
1000CP, specific gravity 1.18OH value 60, acid value <2)
...21 parts ●Soybean lecithin ... (see Table 2) ●Silicone oil (dimethyl polysiloxane)
...0.1 part ●Polyisocyanate (75wt% ethyl acetate solution of the reaction product of 3 moles of 2,4-tolylene diisocyanate compound and 1 mole of trimethylolpropane) ...18 parts ●Methyl ethyl ketone ...400 parts ●Toluene... …400 copies

[Table] Example 3 A 6.5 μm thick cleaning layer of a binder film was provided on a 22 μm thick PET film using the following coating composition (3). The polishing particles used were CaCO ₃ with a Mohs hardness of 3 and a particle size of 5 μm. Silicone oil and soybean lecithin were added at 2.4 parts and 3 parts, respectively, to control the friction coefficient. Further, on the support opposite to the cleaning layer, a back layer having the following coating composition (4) was provided to a dry thickness of 3 μm. This cleaning tape is designated as sample No. 31. The measurement results are shown in Table 4. Coating liquid composition (3) ● Abrasive particles (CaCO ₃ , Mohs hardness: 3, particle size: 5 μm) ... 300 parts ● Vinyl chloride vinylidene chloride copolymer (copolymerization ratio = 7:3, degree of polymerization = 400) ... 46.4 parts Epoxy resin (reaction product of bisphenol A and epichlorohydrin, molecular weight = 900, epoxy equivalent = 460-520, hydroxyl group content = 0.29%,
Shell Oil Co. Epicote 1001) ...28.3 parts ●Silicone oil (dimethylpolysiloxane)
...2.4 parts●Soybean lecithin...3 parts●Isocyanate compound (75wt% ethyl acetate solution of the reaction product of 3 moles of 2,4-tolylene diisocyanate compound and 1 mole of trimethylolpropane Desmodur L- from Bayer AG
75) ...5.6 parts ●Butyl acetate ...800 parts Coating liquid composition (4) ●Carbon black (particle size 0.01 to 2 μm)
...300 parts ●Vinyl chloride vinylidene chloride copolymer (copolymerization ratio = 7:3, degree of polymerization = 400) ...46.4 parts ●Epoxy resin (reaction product of bisphenol A and epichlorohydrin, molecular weight = 900 Epoxy equivalent = 460-520, hydroxyl group content = 0.29%,
Shell Oil Co. Epicote 1001) ...28.3 parts ●Silicone oil (dimethylpolysiloxane)
……0.4 parts ●Isocyanate compound (75 wt% ethyl acetate solution of the reaction product of 3 moles of 2,4-tolylene diisocyanate compound and 1 mole of trimethylolpropane Desmodur L- from Bayer AG
75) ...5.6 parts ●Butyl acetate ...800 parts Comparative Example 1 In Samples 11 and 13 in Example 1, Cr ₂ O ₃ was used instead of the abrasive particles CaCo ₃ , and the amount of silicone oil added was reduced to 1 part by weight. A cleaning tape was made in the same manner as in Example 1 except for the following. Samples 41 and 42, respectively. Table 3 below shows the material of the particles, Mohs hardness, particle size, amount added, etc., and Table 4 shows the measurement results.

[Table] The cleaning characteristics of each of the samples of Examples 1, 2, and 3 and Comparative Example 1 were measured and are shown in Table 4 below. Comparative Example 2 50 parts of a copolymer of hexafluoropropylene and vinyl fluoride containing 20 mol% of hexafluoropropylene with an intrinsic viscosity of 10 as measured in DMF at 30°C was mixed with 1 part of methyl ethyl ketone, 2 parts of methyl isobutyl ketone, It was dissolved in 450 parts of a mixed solvent consisting of 1 part of Cellsolve Acetate and 1 part of diacetone alcohol. Add 85 parts of polytetrafluoroethylene powder with an average particle size of 5μ to this solution and
After adding 15 parts of glass powder of 20 μm or less and mixing in a ball mill for 10 hours, a solution of 2.5 parts of triethylenetetramine dissolved in 10 parts of dimethylformamide was added and mixed for 1 hour. Next, a PET film with a thickness of 38 μm was coated with an epoxy resin as an undercoat, and this mixture was applied to a thickness of 10 μm, and then slit into 1/2 inch width to prepare cleaning tape No. 43. This cleaning tape was evaluated in the same manner as in Example 1 and Comparative Example 1, and the results are shown in Table 4.

[Table] In Table 4 above, the friction coefficient μ is
This is a calculated value using the equation of μ using the device shown in the figure. Further, the definitions of time until recovery from clogging, playback sensitivity, S/N, and tape scratches shown in Table 4 are as follows. (1) Time required to recover from a clog After cleaning the magnetic head of a unified Type I VTR with a clogged head by applying a cleaning tape, the cleaning time is the time it takes for the magnetic tape playback to stabilize without dropouts. (2) Reproduction sensitivity and S/N Relative values when the 4MHz output and S/N measured before the head became clogged are each set to OdB. (3) Tape scratches A scratch with a width of 2 μm or more confirmed by looking at the gap surface of the magnetic head using a microscope. The magnetic tape used in the above test was prepared by applying a coating solution having the following coating composition (5) to a dry thickness of 6.5 μm on a polyethylene terephthalate film having a thickness of 22 μm. Coating composition (5) ●Magnetic material: γ-Fe ₂ O ₃ (Size 0.02φ×0.12μ)
Hc2800e...300 parts ●Vinyl chloride-vinyl acetate copolymer (copolymerization ratio
87:13, degree of polymerization 350) ...22.4 parts ●Polyester polyol (reaction product of 1 mol of adipic acid, 1 mol of diethylene glycol, and 0.06 mol of trimethylolpropane) Viscosity (75℃)
1000CP, specific gravity 1.18OH value 60, acid value <2))
...18.3 parts ●Soybean styrene ...1.2 parts ●Silicone oil (dimethyl polysiloxane)
……0.4 ●Polyisocyanate (75wt% ethyl acetate solution of the reaction product of 3 moles of 2,4-tolylene diisocyanate compound and 1 mole of trimethylolpropane...4.2 parts●Methyl ethyl ketone...400 parts●Toluene...400 According to the cleaning tape of the present invention having the above configuration, the results shown in Table 4 show that the cutting by the abrasive particles is performed lightly without damaging the magnetic head, and a good cleaning effect is obtained. It was confirmed that it is possible to prevent adverse effects on the magnetic properties of the tape.Also, from the results of Comparative Example 2, the time it takes to recover from clogging is 90 seconds.
You can see that it is longer than that. Thus, the cleaning tape of the present invention was found to be better than the combination of glass powder and polyfluoroethylene powder. It was also confirmed that the cleaning tape of the present invention can be bonded to a magnetic tape and used as a leader tape.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of the cleaning tape of the present invention showing a cleaning state, in which 10 is a support, 11 is a cleaning layer, 12 is an abrasive particle, 1
3 indicates a magnetic head, and 14 indicates a deposit. FIG. 2 is a schematic diagram showing a friction coefficient measuring device, in which 21 is a sample, 22 is a delivery reel, 23, 24,
26 and 27 are capstans, 25 is a fixed pole, 28 is a pinch roller, 29 is a take-up reel, and T ₁ and T ₂ are detection parts.

Claims (1)

[Claims] 1. In a cleaning tape for a magnetic recording and reproducing device comprising a cleaning layer formed of abrasive particles and a binder on a support, the abrasive particles are abrasive particles with an average particle size of 6 μm or more and 200 μm or less and a Mohs hardness of 2 or more and less than 5. , these abrasive particles include CaCO ₃ , ZnO, Al ₂ O ₃・4SiO ₂・H ₂ O
(siloxite clay), Al ₂ O ₃・2SiO ₂・2H ₂ O (kaolin clay), 3CaO・Al ₂ O ₃・3CaSO ₄・31H ₂ O (sachinholite), BaSO ₄ (barium sulfate, naturally occurring: baryta, A cleaning tape, characterized in that the cleaning layer has a friction coefficient of 0.15 to 0.4.