JPS62135557A - Tape guide - Google Patents

Abstract

PURPOSE:To provide a tape guide which is lightweight and has excellent dimensional stability and sliding characteristics on polyester films, by blending a polyamide resin having a law satd. water absorption ratio with electrically conductive potassium titanate whisker in a specified weight ratio and molding the mixture. CONSTITUTION:A compsn. contg. a polyamide resin (A) having a satd. water absorption ratio of 5% or below in water at 20 deg.C (e.g., nylon 12) and electrically conductive potassium titanate whisker (B) in a mixing ratio of 10-50wt% as essential ingredients is prepd. The compsn. is molded to obtain the desired tape guide. The component B can be prepd. by reducing potassium titanate whisker to form positive holes within a crystal. The resulting tape guide is used to change the direction of a tape or remove the slack of the tape in using a magnetic tape composed of a polyester base in a tape recorder, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of application on shaft systems) The present invention applies to tape recorders, video tape recorders (
When polyester-based magnetic tape is used in VTRs, information storage devices, etc., it is used for purposes such as changing the direction of the tape, removing tape barrels, or applying excessive tension to the tape. The present invention relates to tape guides over which the tape runs, and more particularly to tape guides molded from certain polyamide resins containing certain amounts of conductive titanium-branched potassium whiskers.

Prior Art and Problems Traditionally, highly machined metal, primarily stainless steel, has been used for tape guides. Metal tape guides have good sliding characteristics and are four-core, so they have excellent performance and do not cause problems due to static air. However, there were drawbacks such as the cost of dimensional precision and machining to obtain a good surface, and the tape guide being expensive.

In recent years, injection molded products of polyoxymethylene resin have begun to be used as tape guides in order to reduce costs and increase bulk. However, polyoxymethylene resin has a high shrinkage rate when it is cooled and solidified from a bath molten state, so the dimensional accuracy of the tape guide is at risk, resulting in problems such as deformation of the tape. Historically, static electricity generated as the tape runs has caused accidents such as wrapping the film around the tape guide.

In order to solve this problem, the present inventors have conducted intensive research and found that by using a specific polyamide resin containing conductive potassium titanate whiskers of a specific bone, it is possible to improve dimensional accuracy and dimensional stability. The present inventors have discovered that it is possible to obtain a tape guide that has excellent properties and is less likely to generate static electricity, leading to the present invention.

(Means for Solving the Problems) That is, the present invention contains, as essential components, potassium titanate whiskers and a polyamide resin having a saturated water absorption rate of 5.0% or less in water at 20° C., and a conductive material. Mixing ratio of potassium titanate whiskers is 10 to 50 M t6=%
This is a tape guide made of a composition.

The polyamide resin used in the present invention has a water absorption rate of 5.0% by weight or less in water at 20°C, preferably 3.0% by weight or less.
Om value % or less, such as nylon 11, nylon 12, nylon 6.1
I can list 2 etc.

The conductive potassium titanate whiskers contained in this polyamide resin are obtained by reducing the titanium swamp potassium whiskers and generating holes in the crystal.

To prevent static electricity from forming on the tape guide, the volume resistivity of the conductive potassium titanate whiskers is 10'Ωcrr.
t or less, and more preferably 102Ωt'm or less.

In the present invention, the mixing ratio of the 4-injected titanium Nt potash whisker to the polyamide resin is in the range of 10 to 50% by weight. If the mixing ratio is less than 10% by weight, the sliding and static resistance effects will not be sufficient (if it is more than 50%, the surface condition of the tape guide will deteriorate and there is a risk of damaging the polyester tape. , Moreover, the cost becomes unnecessarily high.

The tape guide of the present invention is made by solidifying a polyamide resin containing conductive titanium whiskers from a molten state. Examples of the molding method include extrusion molding and injection molding, but injection molding is preferably used.

(Effects of the Invention) The tape guide according to the present invention is lightweight and has excellent sliding characteristics with the polyester film, so that the tape can run smoothly and at a constant speed. In addition, the polyamide resin containing the conductive potassium titanate whiskers of the present invention has a shrinkage rate upon solidification that is 4 times higher than that of the polyoxymethylene resin.
~λ, and the dimensional change due to moisture absorption is also small, so the tape guide has good dimensional precision and dimensional stability, and does not interfere with the running of the tape or damage the tape.

Furthermore, the tape guide of the present invention generates static electricity due to the tetraelectricity of the conductive potassium titanate whiskers, and there is no problem caused by this.

(Example) -1) - (Ron 12 powder (Diamid L-1940P manufactured by Daicel Huels) 100 parts by weight and volume resistivity 1
Tetraelectric potassium titanate 2 iscar (
Otsuka Chemical 1+i > 24! J Tismo BK-200
) 15 heavy waste parts were blended and mixed and extruded into pellets using a 301 tick-screw extruder. Using this pellet, a tape guide for a VTR was injection molded at a cylinder temperature of 250'C to obtain a tape guide with good dimensional accuracy and surface condition.

I disassembled a commercially available VTR cassette, attached it in place of the metal tape guide, and used this cassette to perform recording, screen playback, fast forwarding, frame forwarding, and backtracking, but it was completely different from the metal tape. The operation remained the same and a good screen was obtained.

Claims (1)

[Claims] A composition containing conductive potassium titanate whiskers and a polyamide resin having a saturated water absorption rate of 5.0% or less in water at 20°C as essential components, and the mixing ratio of the conductive potassium titanate whiskers is 10 to 50% by weight. A tape guide made of materials.