JPH1180380A - Sliding member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sliding member used for magnetic tapes and having a sufficient mechanical strength and a high dimensional accuracy. SOLUTION: This sliding member used in a portion brought into contact with magnetic tapes is obtained by molding a resin composition comprising 100 pts.wt. of one or more kinds of resins among polyarylene sulfide resins, polycarbonate resins, polyetherimide resins, polyaromatic ethers or thioether resins, polyaromatic ester resins and polysulfone resins, or 100 pts.wt. of a mixture comprising (A) a polyarylene sulfide resin and (B) one or more kinds of resins among polyetherimide resins, polyaromatic ether resins and polysulfone resins, and (C) 50-300 pts.wt. of an inorganic filler, and further treating the surface of the molded product with one or more kinds of organic solvents among halogen compounds, ketone compounds and ester compounds which have vapor pressures of >=30 mmHg at 20 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sliding member made of a resin composition using a resin such as polyarylene sulfide (hereinafter sometimes referred to as PAS). More specifically, the present invention relates to a sliding member used in a portion where a magnetic tape comes into contact and travels, such as a magnetic drum such as a video tape recorder (VTR) or a tape guide.

[0002]

2. Description of the Related Art Conventionally, a video tape recorder (VT)
In a magnetic recording / reproducing apparatus such as R), the magnetic drum is formed into an approximate shape by casting or forging aluminum, and then subjected to cutting, drilling, tapping, and the like to finish the product into a predetermined shape to obtain a product. Things are used.
In this case, there is a drawback that the number of processing steps is large, and thus the production cost is high.

[0003] In order to solve such a drawback, the use of a resin instead of aluminum as a material for the magnetic drum has been studied. However, simply replacing the resin with the resin makes the magnetic tape inferior in running property to the aluminum material, so that the tape is stuck to the magnetic drum and cannot run, or the magnetic drum drive motor is excessively large. The problem is that heat is generated due to the load of the tape, and a fatal noise is generated in audio equipment, and the tape itself is damaged. It was a big challenge.

Various studies have been made on this problem.
For example, in Japanese Patent Application Laid-Open No. 05-314599, a polymer composite material containing a conductive filler in a crystalline resin,
Alternatively, it is proposed to use a material obtained by molding the material in a low-temperature mold and then heat-treating the material. However, simply using a polymer composite material containing a conductive filler in a crystalline resin does not sufficiently improve the slidability.
It has been shown that by molding with a low-temperature mold, the skin layer can be thinned and the filling material can be easily exposed to the surface of the molded product to obtain slidability, but heat treatment reduces dimensional accuracy. In addition, the filling material is not stably exposed on the surface of the molded product, and does not exhibit sufficient slidability.

In Japanese Patent Application Laid-Open No. 05-342711, a molded article obtained by mixing a conductive compound and a moldable compound with a resin is used to cut the surface resin skin layer on the tape running surface by physical means such as cutting. It has been proposed that the removal of the compound causes the compounding agent to emerge on the surface to smooth the running of the tape. Further, Japanese Patent Application Laid-Open No. 09-1110
In No. 37, a molded product is obtained by using a material obtained by mixing a fine filling material and a filling material having an isotropic shape with a thermoplastic resin, and a skin layer on a sliding surface with a tape is removed, and the fine filling material is removed. It has been proposed that by exposing the resin, the contact area between the resin and the tape is reduced to improve the slidability.

However, in any of these, the idea is to obtain slidability by minimizing the direct contact between the tape and the resin as much as possible.
A step of cutting and removing the surface of a molded product once formed by physical means is indispensable. In addition, the cutting requires extremely high precision, and a new process of removing the cutting powder generated by the cutting by washing or the like is required. It was not possible to obtain it, and further improvement technology was desired.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been developed in view of the fact that a molded article of a resin composition using a resin such as polyarylene sulfide is treated by a simple means to provide a magnetic material. Provided is a sliding member which is excellent in slidability against a tape, has sufficient mechanical strength and extremely high dimensional accuracy, and is therefore suitably used for a contact portion with a magnetic tape such as a VTR cylinder (magnetic drum). The purpose is to:

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have achieved the above object by subjecting a molded article of a resin composition using a resin such as polyarylene sulfide to a surface treatment with an organic solvent. I found that. The present invention has been made based on such findings. That is, the present invention provides the following sliding member. (1) 100 parts by weight of at least one resin selected from polyarylene sulfide resin, polycarbonate resin, polyetherimide resin, polyaromatic ether or thioether resin, polyaromatic ester resin or polysulfone resin, and inorganic filling A sliding member obtained by molding a resin composition comprising 50 to 300 parts by weight of a material, and further performing a surface treatment with an organic solvent. (2) at least one resin (B) selected from a polyarylene sulfide resin (A), a polyetherimide resin, a polyaromatic ether-based resin, and a polysulfone-based resin, and the above (A) and (B) A sliding member obtained by molding a polyarylene sulfide resin composition comprising 50 to 300 parts by weight of an inorganic filler (C) with respect to 100 parts by weight of the total amount of the above, and further performing a surface treatment with an organic solvent. (3) The inorganic filler (C) is at least one selected from a particulate filler, a plate-like filler, a milled fiber and a whisker.
The sliding member according to the above (1) or (2), which is a seed. (4) A sliding member formed by molding the resin composition according to (1) or a sliding member formed by molding the polyarylene sulfide resin composition according to (2). The above (1), which is erodible on the surface
The sliding member according to any one of (1) to (3). (5) The above (1) to (4), wherein the organic solvent is at least one selected from a halogen compound, a ketone and an ester, and has a vapor pressure at 20 ° C. of 30 mmHg or more. The sliding member according to any one of the above. (6) The sliding member according to any one of (1) to (5), wherein the sliding member is used for a contact portion with a magnetic tape.

[0009]

Embodiments of the present invention will be described below in detail. 1. Resin (1) Polyarylene sulfide resin Polyarylene sulfide (PA) used in the present invention
S) is a polymer containing a repeating unit represented by the structural formula -Ar-S- (where Ar is an arylene group) in an amount of 70 mol% or more, and a typical substance is the following structural formula (Formula 1)

[0010]

Embedded image

(Wherein R ¹ is an alkyl group having 6 or less carbon atoms, an alkoxy group, a phenyl group, a carboxylic acid / metal salt,
A substituent selected from an amino group, a nitro group, a halogen atom such as fluorine, chlorine, and bromine, and m is an integer of 0 to 4. N is an average degree of polymerization and is in the range of 1.3 to 30), and is a polyphenylene sulfide having a repeating unit represented by at least 70 mol%. Among them, α-chloronaphthalene solution (concentration 0.4 g / dl), logarithmic viscosity at 206 ° C. is 0.1 to 0.5 (dl / g), preferably 0.13 to 0.4 (dl / g), Preferably 0.
Those in the range of 15 to 0.35 (dl / g) are suitable. In general, PAS is known to have a substantially linear, molecular structure having no branched or cross-linked structure, and a structure having a branched or cross-linked structure, according to the present invention. Is also effective. Preferred PASs for use in the present invention are homopolymers or copolymers containing at least 70 mol%, more preferably at least 80 mol%, of paraphenylene sulfide units as repeating units (hereinafter abbreviated as PPS). The copolymer in the copolymer may have a structural formula -Ar-S- (where Ar is, for example, a divalent aromatic residue containing at least one carbon 6-membered ring as shown in the following Chemical Formula 2). A halogen atom such as fluorine, chlorine or bromine, or an alkyl group such as a methyl group, a nitro group, an amino group, a carboxylate / metal salt or the like. May be included), a polymerized portion comprising a repeating unit represented by
Metaphenylene sulfide unit, orthophenylene sulfide unit, p, p′-diphenylene ketone sulfide unit, p, p′-diphenylene sulfone sulfide unit, p, p′-diphenylene sulfide unit, p, p ′
-Diphenylene ether sulfide unit, p, p'-diphenylene methylene sulfide unit, p, p'-diphenylene cumenyl sulfide unit, naphthyl sulfide unit and the like.

[0012]

Embedded image

The polyarylene sulfide of the present invention includes, in addition to the above-mentioned substantially linear polymer, a branched or crosslinked polyarylene polymerized by using a small amount of a monomer having three or more functional groups as a part of the monomer. A sulfide can also be used, and a blended polymer obtained by blending the sulfide with the linear polymer can also be used. Furthermore, as the PAS used as the component (A-1) used in the present invention, a polymer obtained by increasing the melt viscosity of a linear polymer having a relatively low molecular weight by oxidative crosslinking or thermal crosslinking and improving moldability can be used. . The PAS resin can be obtained, for example, by subjecting a dihaloaromatic compound and a sulfur source to a polycondensation reaction in an organic polar solvent by a method known per se. Preferable examples of the PAS resin include, for example, polyphenylene sulfide (hereinafter, sometimes referred to as PPS) resin represented by the following structural formula (Formula 3).

[0014]

Embedded image

(2) The polycarbonate resin is represented by the following general formula (Formula 4), and 4,4′-dihydroxydiarylalkane-based polycarbonate, particularly bisphenol A-based polycarbonate is preferably used. Further, modified bisphenol A-based polycarbonate and flame-retarded bisphenol A-based polycarbonate can also be used.

[0016]

Embedded image

(3) Examples of the polyaromatic ether or thioether resin include polyphenylene ether, polyphenylene ether grafted with styrene, polyether nitrile, and polyether ether ketone. (4) Examples of the polyaromatic ester resin include polyarylate and the like. (5) Polysulfone resins include, for example, polysulfone,
Polyether sulfone, polyaryl sulfone and the like can be mentioned. 2. Inorganic Filler (C) The inorganic filler is not particularly limited, but at least one selected from granular fillers, plate-like fillers, milled fibers and whiskers is preferably used. (1) The particulate filler is an amorphous or spherical filler having an average aspect ratio of about 2 or less. Specifically, Ketjen black, calcium carbonate, silica, glass beads, calcined carbon, alumina,
Examples include aluminum borate and carbon black. (2) The plate-like filler is plate-like in shape,
It means that the thickness is smaller than the length in the width direction in the vertical and horizontal directions. Specific examples include mica, graphite, kaolin, talc, glass flake, and the like. (3) Milled fiber refers to a fibrous material obtained by pulverizing a so-called fibrous material with a mill or the like or a fibrous material obtained by pulverizing and classifying lump minerals. Specifically, a milled carbon fiber, a milled glass Fibers and the like are exemplified, and milled carbon fibers are preferably used. (4) A whisker refers to a fiber having a needle shape, for example, potassium titanate whisker, zinc oxide whisker,
Aluminum borate whisker, potassium carbonate whisker,
Examples thereof include calcium metasilicate whiskers and calcium silicate whiskers. Among them, calcium metasilicate whiskers and calcium silicate whiskers are preferably used.

The inorganic filler (C) may be surface-treated with a coupling agent, preferably amino silane, vinyl silane, phenyl silane, epoxy silane, another silane coupling agent, or the like. 3. Mixing ratio of each component (1) Resin component At least one resin selected from polyarylene sulfide resin, polycarbonate resin, polyetherimide resin, polyaromatic ether or thioether resin, polyaromatic ester resin and polysulfone resin. When a resin is used, it may be used alone, or two or more of them may be used in combination at an arbitrary ratio.

Regarding the resin component, the following cases are mentioned as preferred embodiments in the above. That is, the case where the polyarylene sulfide resin (A) is essential and at least one resin (B) selected from a polyetherimide resin, a polyaromatic ether resin and a polysulfone resin is used. When a polyarylene sulfide homopolymer represented by the general formula (1) or (3) is used as the polyarylene sulfide resin (A), the polyarylene sulfide resin (A) is 20 to 70% by weight. The content of at least one resin (B) selected from polyetherimide resins, polyaromatic ether resins and polysulfone resins is preferably in the range of 80 to 30% by weight. Polyarylene sulfide resin (A) is 2
When the amount is less than 0% by weight, the effect of the organic solvent treatment in the subsequent step is too strong, and the surface of the molded article may be affected. However, even in this case, the range of the polyarylene sulfide resin (A) does not need to be limited to the above, since it can be dealt with by reducing the concentration of the solvent used. On the other hand, when the content is more than 70% by weight, the effect of the subsequent organic solvent treatment may not be sufficiently exhibited. However, even in this case, it is possible to cope with the problem by increasing the processing time or the like, so that the present invention is not limited to the above.

In the case where the polyarylene sulfide resin (A) is a copolymer, particularly one having a structural unit as shown in the above formula (2), preferably a p, p'-diphenylene sulfone sulfide unit, , A polyarylene sulfide resin (A) and a polyetherimide resin,
The mixing ratio with at least one resin (B) selected from a polyaromatic ether-based resin and a polysulfone-based resin is not particularly limited, and can be used in any ratio. (2) Inorganic filler (C) The mixing ratio of the inorganic filler (C) is 50 to 300 parts by weight, preferably 100 to 300 parts by weight, based on 100 parts by weight of the resin component.
250 parts by weight. If the amount is more than 300 parts by weight, the viscosity at the time of melting becomes high, and molding processing may be difficult or impossible. If the amount is less than 50 parts by weight, the shrinkage rate of the composition may increase, and May not be able to maintain the required dimensional accuracy. 4. Other components In addition to the above components, the resin composition which is a molding material of the sliding member of the present invention may contain other components as required, as long as the object of the present invention is not impaired. Is also good. Other components include, for example, antioxidants, heat stabilizers,
Various additives such as lubricants, coloring agents, plasticizers, conductivity-imparting agents, polyamides, epoxy resins, silicone resins, silicone oils, silicone oils having various functional groups introduced, thermosetting resins, hydrogenated SBS, hydrogen Added NBR,
Rubbers such as silicone rubber and fluorine rubber, pigments and the like can be mentioned. The content of other components can be appropriately selected within a range that does not impair the purpose of the present invention. 5. Preparation of Resin Composition The resin composition, which is a molding material for the sliding member of the present invention, can be prepared by blending the above-mentioned components and kneading them, for example.

The above-mentioned melt-kneading can be carried out by a commonly known method. In any case, the above-mentioned components are uniformly mixed and dispersed in a resin to obtain a predetermined resin composition. I do. For the melt-kneading, a twin-screw extruder, a single-screw extruder or the like can usually be suitably used.

The conditions for the melt-kneading are not particularly limited. However, in order to limit the decomposition or foaming of other components added as necessary, an extremely high temperature or an extremely long residence time should be avoided. Is preferred. The specific temperature is usually 280 to 400 ° C., and is appropriately selected depending on the type and the amount of the resin used. The resin composition thus prepared is usually granulated or cut into a shape and size suitable as a material for secondary processing such as pellets, particularly a material for injection molding, and is appropriately provided for each application. 6. Molding into Sliding Member Shape It is obtained by subjecting a pellet of the resin composition prepared as described above to injection molding using a known method. The molding conditions may be appropriately selected according to the shape of the molded article and the like. 7. Surface Treatment with Organic Solvent In the present invention, by subjecting the sliding member obtained by molding as described above to a surface treatment with an organic solvent, slidability with a magnetic tape can be remarkably improved.

Organic solvent to be used The surface of the sliding member obtained by molding as described above,
It is appropriately selected from those having erodibility. Preferably, it is a single solvent of a halogen compound, preferably an alkyl halide, a ketone, or an ester, or a mixed solvent of two or more thereof, and has a vapor pressure of 30 mmH at 20 ° C.
What shows g or more is used. In the case where a material having a viscosity of less than 30 mmHg is used, the organic solvent tends to remain on the surface of the sliding member after the treatment, and a step of re-cleaning is required. There is a possibility that it may not be satisfactory. Specifically, dichloromethane, 1,1-dichloroethane, tetrachloroethane, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, ethylene chlorohydrin; acetone, methyl ethyl ketone, cyclohexanone;

Treatment Method The surface treatment of a sliding member with an organic solvent is performed by bringing the sliding member into contact with an organic solvent until the sliding member exhibits a desired slidability represented by, for example, a coefficient of friction. . It is efficient that the contact between the sliding member and the organic solvent is performed while the two members relatively move, and it is desirable that the contact be performed under the action of a force for wiping the surface of the sliding member. Specifically, an operation may be performed in which a cloth, a brush, or the like impregnated with the above-mentioned organic solvent is applied to the contact surface of the sliding member with the tape and the contact surface is wiped by applying a load. The processing conditions such as the load, the number of times of wiping the contact surface, and the time may be appropriately selected according to the type of the resin composition used for the sliding member, the shape of the sliding member, the type of the organic solvent used, and the like. 8. A sliding member, which is a molded product obtained by molding the resin composition and is used for a contact portion with a magnetic tape.

The molded article obtained by molding the resin composition which is the molding material of the sliding member of the present invention has excellent mechanical strength and extremely high dimensional accuracy in addition to excellent sliding properties with respect to a magnetic tape. Therefore, it is suitably used for a sliding member used in a contact portion with a magnetic tape, such as a VTR cylinder (magnetic drum), a tape, particularly a tape guide for an audio tape recorder, and a guide for the tape.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The sliding member according to the present invention will be described more specifically below with reference to embodiments. [Examples 1 to 15 and Comparative Examples 1 to 11] Using a twin-screw extruder (TEM35, manufactured by Toshiba Machine Co., Ltd.), the following composition of each component including polyphenylene sulfide resin (PPS resin) was used. The materials A to G were prepared, uniformly mixed using a Henschel mixer, and then melt-kneaded at a cylinder temperature of 310 to 400 ° C. to produce pellets. Using these pellets, the resin temperature was set to 320 to 40 by an injection molding machine (J50E-P manufactured by Japan Steel Works, Ltd.).
Injection molding was performed with the temperature set to 0 ° C. and the mold temperature set to 140 ° C., and a 40 mmφ × 7 mm high magnetic drum (8 mmV
TR upper cylinder equivalent) A to G were obtained. Table 2 and Table 3
As shown in FIG. 2, with respect to these magnetic drums, using a simplified surface treatment apparatus shown in FIG. 2, the polypropylene non-woven fabric impregnated with each of the organic solvents was rotated at 300 times / minute and a pressing load of 100 g was applied. By contacting for 10 seconds, the tape contact surface was wiped.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

(1) Components Used (A) Component (PPS-1) Hydrous sodium sulfide (Na ₂ S) was placed in a polymerization tank equipped with a stirrer.
5H ₂ O) 833 mol lithium chloride (LiCl) 830
145 ° C under reduced pressure
, And dehydrated for 1 hour. Then, set the reaction system to 4
After cooling to 5 ° C., 905 mol of dichlorobenzene (DCB) was added, and polymerization was carried out at 260 ° C. for 3 hours. 5 contents with hot water
Times, N-methyl-2-pyrrolidone (NMP) at 170 ° C
And once with water three times, and dried at 185 ° C. to obtain PPS-1. (A) Component (PPS-2) Hydrous sodium sulfide (Na ₂ S) is placed in a polymerization tank equipped with a stirrer.
5H ₂ O) 833 mol lithium chloride (LiCl) 830
145 ° C under reduced pressure
, And dehydrated for 1 hour. Then, set the reaction system to 4
After cooling to 5 ° C., 814.5 mol of dichlorobenzene (DCB) and 90.5 mol of dichlorodiphenylsulfone were added, and 2
Polymerization was performed at 60 ° C. for 3 hours. 170 times the contents with hot water
The resultant was washed once with N-methyl-2-pyrrolidone (NMP) at 3 ° C., three times with water, and dried at 185 ° C. to obtain PPS-2. <Other components blended in PPS resin> (B) component ・ Polysulfone (PSF) Polysulfone manufactured by Teijin Amoco Engineering Plastics (trade name: Udel P1700) ・ Polyethersulfone (PES) Teijin Amoco Engineering Plastics manufactured by Poly Ethersulfone (trade name Radel A-200)-Polyetherimide (PEI) Polyetherimide (trade name Ultem 1000) manufactured by GE Plastics Co., Ltd. (C) component-Glass beads: trade name GB, manufactured by Toshiba Barotini
731A ・ Calcium carbonate: Shiraishi Industry Co., Ltd., trade name Whiteton P-30 ・ Mica: Kuraray Co., trade name 200D ・ Milled carbon fiber: Kureha Chemical Co., trade name M
101T ・ Potassium titanate whisker: Otsuka Chemical Co., Ltd., trade name
Tismo D • Calcium metasilicate whisker: NYCO, USA, product grade NYGLOS (average fiber diameter 5 μm or less, average aspect ratio 10 or more) • Ketjen black: Lion Corporation, trade name EC-600
JD (2) Evaluation of Sliding Property with Magnetic Tape Using the magnetic drum formed above, the friction coefficient with the magnetic tape was measured with a shuttle type sliding tester shown in FIG.
The measurement was performed using a magnetic surface of a video tape Hi8 MP120 manufactured by Sony Corporation as the tape.

The measurement was performed as follows. About 60c
m, a load of 20 g is applied to one end of the tape, and the other end is connected to a tensiometer.
The tape was slid on the surface of the molded product by reciprocating 100 times at a speed of 30 seconds over a distance of 30 mm. Thereafter, when the tension of the T ₁ at one end, to measure the tension T ₂ of the time of pulling the tape was determined μ friction coefficient by the following equation. μ = (2 / π) · ln (T ₂ / T ₁ ) The evaluation results are shown in Tables 2 and 3.

[0032]

As described above, by processing a molded article of a specific resin composition by a simple means, not only the slidability with respect to a magnetic tape but also the sufficient mechanical strength and extremely high dimensional accuracy are obtained. Therefore, it is possible to provide a sliding member suitably used for a contact portion with a magnetic tape such as a VTR cylinder (magnetic drum).

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a shuttle type sliding test machine.

FIG. 2 Simple surface treatment device

[Explanation of symbols]

 1: Magnetic drum 2: Load 3: Tensiometer 4: Load 5: Tape sliding surface of resin magnetic drum 6: Buff impregnated with organic solvent

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 81/02 C08L 81/02 81/04 81/04 81/06 81/06 101/00 101/00 G11B 15/60 G11B 15 / 60 B 15/61 15/61 A N

Claims (6)

[Claims] 1. 100 parts by weight of at least one resin selected from polyarylene sulfide resin, polycarbonate resin, polyetherimide resin, polyaromatic ether or thioether resin, polyaromatic ester resin and polysulfone resin. A sliding member formed by molding a resin composition comprising 50 to 300 parts by weight of an inorganic filler, and further subjected to a surface treatment with an organic solvent. 2. A polyarylene sulfide resin (A),
At least one resin (B) selected from a polyetherimide resin, a polyaromatic ether resin, and a polysulfone resin, and an inorganic filler based on 100 parts by weight of the total of (A) and (B) (C) A sliding member obtained by molding a polyarylene sulfide resin composition comprising 50 to 300 parts by weight, and further surface-treated with an organic solvent. 3. The sliding member according to claim 1, wherein the inorganic filler (C) is at least one selected from a particulate filler, a plate-like filler, milled fibers, and whiskers. 4. A sliding member formed by molding the resin composition according to claim 1 or a sliding member formed by molding the polyarylene sulfide resin composition according to claim 2 by an organic solvent. On the other hand, it has erosion property.
The sliding member according to any one of the above. 5. The organic solvent is at least one selected from a halogen compound, a ketone and an ester,
The sliding member according to any one of claims 1 to 4, wherein a vapor pressure at 20C is 30 mmHg or more. 6. The sliding member according to claim 1, wherein the sliding member is used for a contact portion with a magnetic tape.