JPS59121625A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a recording medium causing hardly friction and deformation during actual traveling by using a polyethylene terephthalate support having a certain ratio in X-ray diffraction intensity between two specified crystal faces. CONSTITUTION:A polyethylene terephthalate support having >=10X10<-2> ratio in X-ray diffraction intensity between the (1-10) and (100) crystal faces reduces the tension of a magnetic recording tape during use and causes hardly the deformation of the tape. For example, a polyethylene terephthalate film of 9.5-10.5mum thickness is coated with a magnetic layer of 4.5mum thickness by a convertional method to manufacture a magnetic recording tape. Fine powder of gamma-Fe2O3 having deposited Co is mixed with a binder consisting of, by weight, 5% urethane rubber, 3.5% nitrocellulose, 1.5% vinyl chloride and 90% methyl ethyl ketone. The amount of the fine powder is 70wt%. Polyisocyanate is added to the mixture as a curing agent by 15wt% basing on the amount of the resin component, and the resulting material is applied to the surface of a support, dried, and cured to form said magnetic layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium, particularly a film-like magnetic recording medium.

Magnetic recording tapes such as recording tapes and recording tapes generally have a support made of polyester (especially polyethylene terecrate) and a magnetic layer is provided on the Jt+fit of the support.

Of course, the characteristics of magnetic recording tape are largely controlled by the characteristics of the magnetic layer applied to the support, but
It is also greatly influenced by the characteristics of the support.

The surface m1 smoothness of the support is a sublime characteristic, and the S/'N of the magnetic recording tape increases due to this, so as the performance of magnetic recording tape improves, smooth supports are used. It is supposed to be done. Only ray 11
If a weak support body is used, the friction between the tape guide and the like will increase during use, increasing the tape tension and causing problems such as jitter and tape deformation. Magnetic recording tapes equipped with 1) have also appeared.

As a result of intensive research on uninvented methods, we found that the X-ray diffraction intensity ratio of the (11'O) crystal plane and the (1,020) crystal plane of the polyethylene terephthalene support body was 1- more than 10XIO. It was discovered that the tension of the magnetic recording tape becomes lower when the magnetic recording tape is used, making it difficult to prevent the tape from deforming.

Polyester terephthalate film is widely used as a magnetic recording tape support, and all supports with a high tensile strength of 12kg/mm or more, with a strength ratio of 12kg/mm or less. As far as the body l o misfire 1 reno shop knows, (1 0) crystal face and (100) kosho r
(rl = 2 X-ray diffraction strong IJe ratio or less than 10XIO).

Uninvented medicine is currently available in 1'-L, and we have tested as many free versions as possible (.

However, all of them were unsatisfactory in terms of tape deformation.

>k from 'II,, IX is j, notation X M +! The folding strength ratio is 1OX10-2''ρ, 1- is 4.5 and 51
(When this was prepared and used as a support for a magnetic recording medium, the desired effect (a) was achieved).Examples will be described below.

To Example 1 5 Jν 95-lo, 5 gm of seeds // of boi ethyre/terephthalate 1 film in scrap form, 4.5 jL m of rd? A magnetic recording tape was produced by drying the magnetic layer.

The magnetic layer was coated with 70'wt% CO and was coated with foil J-i1.
-Fe 203 fine powder and 5wt% urethane rubber
3.5 wt% nitrocellulose, ], 55 wt) J
, phenyl chloride and 90 wt% methyl ethyl carbonate were combined, 4 JL of poly incyanate (Bayer's Tesmon-J) was added as a curing agent, and 1 part of IIH was added (15 w as quasi). t% vise 11 was applied to the surface of the mixed body, dried and hardened.

The contact force and υ of the magnetic register SI force thus increased to 1+7
Measured for ￥￥￥￥￥￥ The results are shown in Table 1.

Comparative Examples 1 to 4 (Due to relative softness) Example] The magnetic recording tape was crushed into a V shape by turning 5 and 11'r. All polyethylene terephthalate 1 used in these tapes was analyzed by X-ray diffraction (mj I
The odor ratio was 10×10-212). De;
71 of the Pf rubbing of the tape and the deformation of the tape
111 results are shown in Table 1.

In addition, in the table, the thickness direction (nz) was determined by A111 at 25°C using a 7-tube refraction +tt 4 type (trade name) manufactured by Akugoka.

Density (ρ) is Shibayama H'￥Kiki Seisakusho's simplified specific gravity i'1
The 111 temperature device was filled at 5°C.

The surface roughness was measured using a stylus roughness grade 1 manufactured by Koita Research Institute.

As shown in Figure 1, the X-ray diffraction intensity ratio is (1 0) +/
Find the diffraction pattern including the diffraction of ij and (101) plane (
100) Heavy 11Lj iQ passing through the peak of surface diffraction intensity
Fold the recording paper at X, overlap part A with part B, and transfer part A to part B. As a result, a curve shown by a dashed-dotted line is obtained. The X between this - dotted chain line and the (ITO) plane peak is (1.
1. 0) surface intensity, and set the hese of the diffraction curve as a dotted line. y of the intensity peak of the (1 0 0) plane
, was defined as (1. O O ) plane strength. And the diffraction strength 1μ t< (J 1 0) surface strength + m/ (1
．． O O:) Surface strength-c”M4, Ru1-.

5% elongation UII11-(+ji +111 is 100 mrn of Zanburu R, mountain speed +1 m5 0 m m/m
'Al11' was tested using a 1-pull tester made by Paul L. Win and a 100-pound sheep.

The frictional force was measured by using a VH3 type video cassette L tape and then actually running it on a Matsushita NV-8700 (product name) video deck, and measuring the tension at exit 11 of the rotating tram.Comparative Example 1
It is expressed as a ratio.

In addition, the tape deformation was measured by actually running it on Matsuton 1 NV-8200 (product name) in an environment of 40°C and 180%.
The tape deformation after running 00 times was determined by 1" (the length of the tape was 240 m) + As can be seen from the table, the (
The X-ray diffraction intensity ratio between the 1〒0) 18ih plane and the (100) crystal plane is 10XIO-2, and the force is also 5% υ
Time intensity 1. 2 kg/mm Re-1-later I)/reduction is also low, 17, and the tape deformation in actual run 9-J is also a good Iff.

The invention is expected to be particularly applicable to polyester films.

[Brief explanation of the drawing]

The drawing is a graph for explaining the method of determining the X-ray diffraction intensity ratio. Procedural amendment (method) Indication of the April 12, 1980 Patent Office Commissioner Kazu Wakasugi Loss Case 1982 Patent Application No. 227569 Name of the invention Relationship with the case of the person making the magnetic recording-medium amendment Name of patent applicant Title
(306) Tokyo Denki Kagaku Kogyo Co., Ltd. Amendment Order Notification!
” dated March 29, 1980 ~ IJ′-ζ″-゛″′′
−−− −−Contents of correction

Claims (1)

[Claims] 1. X-ray diffraction of the (110) crystal plane and (100) crystal plane of the support I in a magnetic recording medium comprising a magnetic layer and a support in which magnetic powder is dispersed in a polymeric binder. 1. A magnetic recording medium comprising polyethylene terephthalate having an intensity ratio of 10×10 −2 or more. 2. 5% of the longitudinal direction of polyethylene terephthalate - 1.
A magnetic recording medium according to the above item 1, which has a magnetic density of 1 degree or more or more than 12 kg/mm.