JPH03208620A - Biaxially oriented thermoplastic resin film - Google Patents

Abstract

PURPOSE:To obtain the title film having excellent scratch resistance and friction coefficient by utilizing thermoplastic resin contg. particles and regulating a relation between the size of the particles and thickness of the film, the content and the thickness of the film to a specified range and specifying the Young's modulus of the film, the product of rupture strength and rupture strain and the flocculation energy density of thermoplastic resin. CONSTITUTION:A biaxially oriented thermoplastic resin film is constituted of thermoplastic resin A and particles as a main component. Young's modulus EA in the lengthwise direction of the film is regulated to at least 400 kg/mm<2>, the product sigmaA of rupture strength and rupture strain in the lengthwise direction is regulated to at least 20 kg/mm<2>. Mean particle diameter of these particles is regulated to 0.2-5 times of thickness of the film. The content of these particles is regulated to 0.1-30 wt.% and thickness of the film is regulated to 0.01-3mum. Further as the thermoplastic resin A, substance having flocculation energy density of at least 130 cal/mol is utilized and ethylene terephthalate and ethylene -2,6-naphthalate are prefereably utilized. As the particles, spherical silica particles based on colloidal silica and the particles (e.g. cross-linked polystyrene) based on a cross-linked high polymer, etc., are preferably utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a biaxially oriented thermoplastic resin film.

[Prior Art] As a biaxially oriented thermoplastic resin film, a film with improved runnability on at least one side is known (for example, JP-A-59-111818, etc.).

[Problems to be Solved by the Invention] However, with the above-mentioned conventional biaxially oriented thermoplastic resin film, for example, a magnetic layer coating process for magnetic media use, a calendering process, or a soft tape etc. by dubbing the finished videotape etc. As the process speed increases in the manufacturing process, etc., there has been a drawback that the film surface is scratched by the contacting rolls and guides. In addition, in the conventional
Due to the deterioration in image quality during dubbing, the image quality when converted to videotape, that is, the S/N (signal/noise ratio), was also insufficient.

The present invention solves these drawbacks, and has a film that is particularly resistant to scratches during high-speed processes (hereinafter referred to as "excellent scratch resistance"), has a small friction coefficient during running (hereinafter referred to as "excellent friction coefficient"), There is little deterioration in image quality when dubbing (
The purpose of the present invention is to provide a biaxially oriented thermoplastic resin film (hereinafter referred to as having excellent dubbing resistance).

[Means for Solving the Problems] In order to solve the problems, the present invention has the following structure. That is, (1) a film whose main components are thermoplastic resin A and particles, the longitudinal Young's modulus EA of the film is 400 kg/mm2 or more, and the product σ4 of the longitudinal breaking strength and breaking strain is 20kg/3M2 or more, the average particle size of the particles is 0.2 to 5 times the film thickness, and the content of the particles is 0.1 to 30% by weight. .01 to 3 μm biaxially oriented thermoplastic resin film, or (2) thermoplastic resin A
and particles as a main component, the cohesive energy density (C.E.D.) of the thermoplastic resin A is 130 cal/mol or more, and the average particle size of the particles is 0% of the thickness of the film. .2 to 5 times, the content of the particles is 0.
Thickness 0.0, characterized in that it is 1-30% by weight
This is a biaxially oriented thermoplastic resin film of 1 to 3 μm.

The thermoplastic resin A1 and thermoplastic resin B constituting the present invention are particularly limited to polyester, polyolefin, polyphenylene sulfide, polyamide, polyetheretherketone, polyethersulfone, polyetherimide, polysulfone, and various elastomers. It will not be done. However, thermoplastic resin A1 thermoplastic resin B
It is preferable to use polymers from the same group because the adhesion between the layers is good. In particular, polyesters, especially ethene terephthalate, ethylene-2,6-naphthalate, ethylene α,β-bis(2-chlorophenoxy)ethane- 4
, 4"-dicarboxylate units as the main component, as the scratch resistance and dabbing resistance are improved. Furthermore, the thermoplastic resin A constituting the present invention is preferably composed of at least one structural unit selected from the group consisting of crystalline and 4"-dicarboxylate units. It is extremely desirable that the material has good properties or optical anisotropy when melted, since this provides even better scratch resistance and dubbing resistance.

Crystallinity here indicates that it is not so-called poor quality, and quantitatively, the cold crystallization temperature Tcc in the crystallization parameter is detected, and the crystallization parameter Δ
Tcg is 150°C or less. Further, it is extremely desirable that the heat of fusion (change in enthalpy of fusion) measured by a differential scanning calorimeter exhibits crystallinity of 7.5 cal/g or more because scratch resistance, dubbing resistance, and friction coefficient will be even better.

The Young's modulus EA in the longitudinal direction of the film comprising the thermoplastic resin A and particles that constitute the present invention is 400 kg/
mm2 or more, preferably 500 kg/mm2 or more, more preferably 600 kg/mm2 or more, and
The product σ8 of the breaking strength and breaking strain in the longitudinal direction of the film is 2
In terms of scratch resistance, it is necessary that the weight is 0 kg/m2 or more, preferably 22 kg/m2 or more, and more preferably 24 kg/m+n2 or more.

The mechanism by which scratches occur on the film surface is that the unevenness of the guide pin, dust, and aggregates of debris from the film surface become hard scratches and invade the film surface, and the subsequent scratches scratch the film surface. It consists of a mechanism that takes

It is considered that when the Young's modulus of the film is 400 kg/mm2 or more, the penetration depth of the scratcher becomes smaller, and thus the scratch resistance of the film is improved.

Further, the product σA of the breaking strength and breaking strain of the film correlates with the amount of material falling off from the film. This is because σA has a positive correlation with the energy required to tear the polymer from the film surface, and the larger the value of σA, the smaller the amount of scraped material. And σ8 is 20kg/mm
It is considered that when the number is 2 or more, the amount of scraped matter is further reduced, and thus the scratch resistance of the film is improved.

Further, as the cohesive energy density of thermoplastic resin A increases, the attractive force between molecular chains increases, and the thermoplastic resin A becomes stronger against external forces. From the viewpoint of scratch resistance, it is necessary that the cohesive energy density of the thermoplastic resin A constituting the present invention be 130 cal/m01 or more.

Polyesters that meet the above conditions include polyethylene terephthalate, polyethylene-2,6-naphthalate, ethylene α,β-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate, etc. From this point of view, polyethylene-2,6-naphthalate and ethylene α,β-bis(2-chlorophenoxy)ethane-4,4′-dicarboxylate are particularly preferred.

The particles in the thermoplastic resin A of the present invention have a particle size ratio (longer diameter/breadth diameter of the particles) in the film of 1. Particles having a particle diameter of 0 to 1.73, particularly spherical particles, are preferable because the scratch resistance becomes even better.

Further, the particles in the thermoplastic resin A of the present invention have a single particle index in the film of 0. A value of 7 or more, preferably 0.9 or more is particularly desirable because scratch resistance and dubbing resistance become even better.

Further, the particles in the thermoplastic resin A of the present invention have a relative standard deviation of 0.6 or less, preferably 0.6 or less in the film. 5
The following cases are desirable because the scratch resistance and dubbing resistance become even better.

The type of particles in the thermoplastic resin A of the present invention is not particularly limited, but in order to satisfy the above preferable particle characteristics, alumina silicate, silica in a state where primary particles are aggregated, internally precipitated particles, etc. are not preferable. There are substantially spherical silicate particles caused by colloidal silica, particles made by crosslinked polymers (for example, crosslinked polystyrene), etc., but in particular, the temperature at 10% weight loss (in nitrogen using a thermogravimetric analyzer Shimadzu TG-30
Measured using M. It is particularly desirable to use crosslinked polymer particles in which the degree of crosslinking is increased to a temperature increase rate of 20'C/min) of 380°C or higher, since the scratch resistance and dabbing resistance will be even better. Note that in the case of spherical silica caused by colloidal silica force, substantially spherical silica with a low sodium content produced by an alkoxide method is particularly desirable because the scratch resistance is even better. However, other particles, such as particles of calcium carbonate, titanium dioxide, alumina, etc., can also be used satisfactorily with proper control of film thickness and average particle size.

The crystallization promotion coefficient of the particles in the thermoplastic resin A of the present invention is not particularly limited, but is -15 to 15°C, preferably -5 to 15°C.
A temperature of 10° C. is particularly preferable because the scratch resistance becomes even better.

The size of the particles contained in the thermoplastic resin A is such that the average particle size in the film is 0.00 mm thick of the film thickness. 2 to 5 times, preferably 0. 5 to 5 times, more preferably 1.1 to
A range of 3 times is required.

If the average particle diameter/film thickness ratio is smaller than the above range, the scratch resistance and friction coefficient will be poor, and if it is too large, the scratch resistance and dubbing resistance will be poor, which is not preferable.

Further, the average particle size (diameter) of the particles in the thermoplastic resin A in the film is 0.02 to 0.5 μm, preferably 0.03 μm.
Scratch resistance in the range of ~0.45 μm;
This is desirable because the dubbing resistance and friction coefficient are even better.

The content of particles in the thermoplastic resin A of the present invention is 0.1 to 3
It is necessary that the amount is 0% by weight, preferably 1 to 20% by weight, and more preferably 2 to 15% by weight. If the content of the particles is less than the above range, or conversely if it is greater than the above range, the scratch resistance will be poor, so it is not preferable.

The main component of the film of the present invention is a composition consisting of the thermoplastic resin A and particles, but other types of polymers may be blended within the range that does not impede the purpose of the present invention. Stabilizers, lubricants, ultraviolet absorbers, antistatic agents, etc. may be added to the extent that they are normally added.

The film of the present invention is a film in which the above composition is biaxially oriented. A uniaxial or non-oriented film is not preferable because it has poor scratch resistance. The degree of this orientation is not particularly limited, but the Young's modulus, which is a measure of the degree of molecular orientation of polymers, is 40 as described above in the longitudinal direction.
0 kg/mm2 or more, and also in the width direction
When it is 50 kg/mm' or more, the scratch resistance becomes even better, so it is extremely preferable. The upper limit of Young's modulus, which is a measure of the degree of molecular orientation, is not particularly limited, but usually
The manufacturing limit is about 5000 kg/mm2.

In addition, even if the Young's modulus of the film of the present invention is within the above range, the molecular orientation of the bolamer in a portion of the thickness direction of the film, for example, near the surface layer is not oriented or is not uniaxially oriented. It is particularly preferable that the molecular orientation of all the portions in the transverse direction be biaxial because the scratch resistance, dubbing resistance, and coefficient of friction will be even better.

In particular, when the molecular orientation measured by an Appe refractometer, a laser refractometer, a total internal reflection laser Raman method, etc. is biaxially oriented on both the front and back surfaces, scratch resistance, dubbing resistance, friction coefficient, etc. This is particularly desirable because it provides even better results.

Furthermore, thermoplastic resin A is crystalline polyester,
The total reflection Raman crystallization index of the surface of the film of the present invention containing this as a main component is 20 cm -1 or less, preferably 18 cm
-' or less, and furthermore 17 cm-'', this is extremely desirable because scratch resistance, dubbing resistance, and friction coefficient are even better.

2 of the film mainly composed of thermoplastic resin A of the present invention.
The particle surface concentration measured by secondary ion mass spectrometry is not particularly limited, but is 1/10 or less, especially 1/50.
It is particularly preferable that it is below, since the friction coefficient and scratch resistance will be even better.

The thickness of the film mainly composed of thermoplastic resin A of the present invention needs to be 0.01 to 3 μm, preferably 0.02 to 1 μm, and more preferably 0.03 to 0.5 μm. If the thickness of the film is smaller than the above range, the dubbing resistance and coefficient of friction will be poor, and if it is too thick, the scratch resistance will be poor, which is not preferable.

The average protrusion height on the surface of the film mainly composed of thermoplastic resin A of the present invention is 5 to 500 nm, preferably 10 to 3 nm.
A range of 00 nm, more preferably 15 to 200 nm is particularly preferable because scratch resistance, dubbing resistance, and friction characteristics become even better.

It is particularly preferable that the average distance between protrusions of the film containing thermoplastic resin A of the present invention as a main component is 6 μm or less, preferably 4 μm or less, since scratch resistance, dubbing resistance, and coefficient of friction become even better.

The centerline depth Rp of the film surface mainly composed of thermoplastic resin A of the present invention is not particularly limited, but Rp is 200n
It is particularly desirable to have a thickness of less than m, particularly less than 180 nm, since the dubbing resistance will be even better. In addition, the above Rp
It is particularly preferable that the ratio of Rt and maximum height Rt, Rt/Rp, be from 1.5 to 2.5, particularly from 1.7 to 2.3, since scratch resistance, dubbing resistance, and friction coefficient will be good.

The ratio of the center line average roughness Ra to the maximum height Rt of the film surface mainly composed of thermoplastic resin A of the present invention, R t /
When R a is 10.0 or less, scratch resistance, dubbing resistance, and coefficient of friction become even better, so it is particularly desirable.

As mentioned above, it is extremely desirable for the thermoplastic resin of the present invention film to be crystalline or optically anisotropic when melted, but in the case of a melting isotropic film, the crystallization parameter ΔTcg is 25 to 65°C. This is particularly desirable since the scratch resistance and friction coefficient will be even better.

In addition, when the thermoplastic resin A is polyester, it is particularly desirable that the refractive index of the thermoplastic resin A surface in the thickness direction is 1.5 or less, since scratch resistance and dubbing resistance become even better.

When the thermoplastic resin A constituting the present invention is polyester, it is particularly preferable that the intrinsic viscosity of the film is 0.6 or more, particularly 0.7 or more because the scratch resistance becomes even better.

When the thermoplastic resin A constituting the film of the present invention is polyester, the scratch resistance is even better when the content of low molecular components in the film is 0.8% by weight or less, especially 0.5% by weight or less. This is particularly desirable.

The film of the present invention can of course be used alone (single-layer film), but after laminating the film containing thermoplastic resin A as a main component on at least one side of the film containing thermoplastic resin B as a main component, the film may be biaxially oriented. When used in the form of a film, not only the mechanical properties are improved, but also the scratch resistance, dubbing resistance, and coefficient of friction are further improved, which is extremely preferable. Here, the thermoplastic resins A and B may be the same or different.

The above is a case where the laminated structure is A/B, A/B/A,
Of course, it may be an A/B/C structure in which a layer C having a surface condition different from that of A is provided on the opposite surface, or a multilayer structure having more than that. (Here, the types of thermoplastic resins for each of A1B and .C may be the same or different. However, at least one side must be layer A.) 15 Also, when such a laminated film is used, The Young's modulus of the laminated film is 350 kg in both the longitudinal and width directions.
/mm2 or more is preferable in terms of scratch resistance.

As the thermoplastic resin B, a crystalline bolimar is preferable, and it is particularly preferable when the crystallization parameter ΔTcg is in the range of 20 to 100° C., since the scratch resistance becomes even better. Specific examples include polyester, polyamide, polyphenylene sulfide, and polyolefin, but polyester is particularly preferred because it has better scratch resistance. In addition, the polyester mainly contains at least one structural unit selected from ethylene terephthalate, ethylene α,β-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate, and ethylene-2,6-naphthalate units. It is preferable that the structure is made of aluminum because the scratch resistance is particularly good. However, other components may be copolymerized, preferably within 5 mol %, within a range that does not impair the present invention and does not impair desirable crystallinity.

The thermoplastic resin B of the present invention may also be blended with other polymers as long as it does not impede the purpose of the present invention, and organic additives such as antioxidants, heat stabilizers, lubricants, and ultraviolet absorbers may be added. may be added to the extent that is normally added.

There is no particular need to contain particles in the film mainly composed of thermoplastic resin B, but particles with an average particle size of 0.01 to 2
μm, especially particles of 0.02 to 0.45 μm are 0.001
When the content is ~0.5% by weight, especially 0.005-0.2% by weight, and even 0.005-0.15% by weight, not only the scratch resistance and friction coefficient will be even better. This is extremely preferable since the film has a good winding appearance.

As for the types of particles contained, it is desirable to use those preferably used for thermoplastic resin A. The types and sizes of particles contained in thermoplastic resins A and B may be the same or different.

The difference (A-B) in crystallization parameter ΔTcg between thermoplastic resin A and thermoplastic resin B is not particularly limited, but is -3
A temperature of 0 to +20° C. is particularly desirable because the scratch resistance becomes even better.

Next, a method for producing the film of the present invention will be explained.

First, as a method for incorporating particles into thermoplastic resin A, when the thermoplastic resin is polyester, it is dispersed in the form of a slurry of ethylene glycol, which is a diol component, and this ethylene glycol is polymerized with a predetermined dicarboxylic acid component. This is effective in obtaining a film that does not tear during stretching, has a relationship between thickness and average grain size, has a content within the range of the present invention, and has an orientation state within a desirable range. In addition, by adjusting the melt viscosity and copolymerization components of the polyester containing the particles,
A method of keeping the crystallization parameter ΔTcg in the range of 40 to 65°C, and diol slurry containing particles at 140 °C.
~200°C, especially 180-200°C for 30 minutes to 5 hours,
In particular, a method of heat treatment for 1 to 3 hours is effective in preventing stretching and tearing and obtaining desired ranges of orientation, surface roughness, and average protrusion height.

In addition, as a method for incorporating particles into thermoplastic resin B (including polyester), particles may be mixed in ethylene glycol at a temperature of 140 to 200°C, particularly 180 to 200°C for 30 minutes to 5 hours, particularly 1 to 3 hours. After heat treatment, it is mixed with thermoplastic resin B in the form of a slurry in which the solvent is replaced with water,
A method of kneading using a vent type twin screw extruder is also effective.

After drying the thus obtained pellets containing particles as necessary, they are supplied to a known melt extruder and extruded into a sheet through a slit-shaped die at a temperature above the melting point and below the decomposition point of the thermoplastic resin. The film is extruded and cooled and solidified on a casting drum to form an unstretched film. In this case, when extruding into an unstretched film, the ratio of die slit gap/unstretched film thickness is 5 to 30, preferably 8 to 20.
In order to obtain a film with the relationship between thickness and average grain size, content range, orientation state within the desired range, surface layer particle concentration ratio, and total reflection Raman crystallization index within the range of the present invention without causing tearing due to stretching, It is valid.

Next, this unstretched film is biaxially stretched to provide biaxial orientation 19 . As the stretching method, a sequential biaxial stretching method or a simultaneous biaxial stretching method can be used. However, the method uses a sequential biaxial stretching method in which the longitudinal direction is first stretched and then the width direction, and the longitudinal direction stretching is divided into three or more stages, and the total stretching ratio is 3.5 to 6.5 times. is effective in obtaining a film that does not tear during stretching and has the relationship between thickness and average particle size, content, orientation state and surface layer particle concentration ratio within the desired range of the present invention.

However, when the thermoplastic resin has optical anisotropy when melted, the stretching ratio in the longitudinal direction is suitably 1 to 1.1 times. Although the longitudinal stretching temperature varies depending on the type of thermoplastic resin and cannot be determined unconditionally, it is usually 50 to 130°C in the first stage and higher in the second stage to achieve the thickness and average grain size within the range of the present invention. It is effective in obtaining a film with the relationship of diameter, content, desired orientation state, average protrusion height, and surface layer particle concentration ratio. The stretching speed in the longitudinal direction is suitably in the range of 5,000 to 50,000%/min. As a method for stretching in the width direction, a method using a stencil is generally used. Stretching ratio is 3.0 to 5.0
A double range is appropriate. Next, this 20-stretched film is heat treated. The heat treatment temperature in this case is 1
70-220°C, especially 170-200°C, time 0.
A range of 5 to 60 seconds is suitable.

Next, as a method for laminating a film mainly composed of thermoplastic resin A on at least one side of a film mainly composed of thermoplastic resin B, the following method can be considered.

Predetermined thermoplastic resin A composition and thermoplastic B resin (A, B
may be of the same type or different types) is supplied to a known extruder for melt lamination, extruded into a sheet form from a slit-shaped die,
It is cooled and solidified on a casting roll to form an unstretched film. i.e. 2 or 3 extruders, 2
Alternatively, thermoplastic resins A and B are laminated using a three-layer manifold or a merging block, and a two- or three-layer laminated sheet is extruded from a die and cooled with a casting roll to produce an unstretched film. In this case, a method of installing a static mixer and a gear pump in the volima flow path of thermoplastic resin A will prevent stretching and tearing, and the relationship between thickness and average particle size within the range of the present invention, content, desired orientation state, average protrusion height,
This is effective in obtaining a film with a good Rt/Rp ratio, Rt/Ra ratio, and surface particle concentration ratio.

Next, the points of the method for biaxially stretching this unstretched film to achieve biaxial orientation are basically the same as those for the single-layer film described above. However, in the case of a laminated film, the stretching temperature must be set based on thermoplastic resin B. Furthermore, in the heat treatment process of the two-layer laminated film, the temperature of the hot air blown onto the thermoplastic resin A layer is 3 to 20°C lower than that of the thermoplastic resin B layer. amount, desired orientation state, average protrusion height,
This is effective for obtaining the Rt/Rp ratio, the Rt/Ra ratio, the surface particle concentration ratio, and the total reflection Raman crystallization index.

[Function] The present invention provides a thermoplastic resin film or a laminated film thereof in which the relationship between the particle size and the film thickness, the content, and the film thickness are within specific ranges, so that conventional melt film forming/ It is presumed that the effect of the invention was achieved because it was possible to obtain a surface morphology that cannot be obtained by the biaxial stretching process.

Furthermore, the Young's modulus of the film, the product of breaking strength and breaking strain,
By specifying the cohesive energy density of the resin constituting the film, it was possible to provide the film of the present invention with excellent scratch resistance, abrasion resistance, dubbing resistance, and coefficient of friction.

[Method for Measuring Physical Properties and Evaluating Effects] The methods for measuring the characteristic values and evaluating the effects of the present invention are as follows.

(1) Plasma low-temperature ashing process (
For example, the particles are removed using a model PR-503 (manufactured by Yamato Kagaku Co., Ltd.) to expose the particles. The processing conditions are selected so that the thermoplastic resin is incinerated but the particles are not damaged. This is SEM (
A scanning electron microscope) is used to observe the particles, and an image of the particles (shades of light created by the particles) is connected to an image analyzer (for example, QTM900 manufactured by Cambridge Instruments), and by changing the observation location, when the number of particles is 5000 or more, the 23rd order value is obtained. The number average diameter D determined by the treatment is defined as the average particle diameter.

D=ΣDi/N Here, Di is the circle-equivalent diameter of the particles, and N is the number of particles.

(2) Particle content A solvent that dissolves the thermoplastic resin but does not dissolve the particles is selected, the particles are centrifuged from the thermoplastic resin, and the ratio (wt%) of the particles to the total weight of the film is defined as the particle content. In some cases, it is also effective to use optical measurement methods such as infrared spectroscopy, ultraviolet spectroscopy, and turbidity.

(3) Crystallization parameter ΔTcg. Heat of fusion was measured using a DSC (Differential Scanning Calorimeter) Model 2 manufactured by PerkinElmer. The DSC measurement conditions are as follows. That is, 10 mg of the sample was set in a DSC device and heated at 300°C for 5 minutes.
After melting for minutes, quench into liquid nitrogen. This cooled sample is heated at a rate of 10° C./min, and the glass transition point Tg is detected.

The temperature was further increased, and the exothermic peak temperature of crystallization from the glass state was defined as the cold crystallization temperature TCC. The temperature was continued to rise for another 24 hours, and the heat of fusion was determined from the melting peak.

Here, the difference between Tcc and Tg (Tcc - Tg) was defined as the crystallization parameter ΔTcg.

(4) Measurement was performed using an Appe refractometer using the molecularly oriented sodium D line (589 nm) on the surface as a light source. Methylene iodide was used as the mounting solution, and the measurement was performed at 25° C. and 65% RH. The biaxial orientation of a polymer is (Nl - N2) (where the refractive indices in the longitudinal direction, width direction, and thickness direction are N1, N2, and N3).
7) Absolute value is 0.07 or less, cut, N3 / [ (N
l +N2) /2)] F0. One standard can be that it is 95 or less. Alternatively, the refractive index may be measured using a laser refractometer. Furthermore, if measurement is difficult with this method, total internal reflection laser Raman method can also be used.

Total internal reflection laser Raman measurement is performed by Jobin-Yvon
The total reflection Ramanth vector was measured using a Ramanot U-1 0 0 0 Raman system, for example, in the case of polyethylene terephthalate, 1 6 1
5cm-” (skeletal vibration of benzene ring) and 1 7 3 0
cm-” (stretching vibration of carbonyl) band intensity ratio polarization measurement ratio (YY/XX ratio, etc. where YY: Raman light detection parallel to Y with the polarization direction of the laser set to Y;
It is possible to utilize the fact that Xx: Raman light detection parallel to X when the polarization direction of the laser is set to X) corresponds to the molecular orientation. The biaxial orientation of the volima can be determined from the absolute value, difference, etc. by converting the parameters obtained from Raman measurement into refractive indices in the longitudinal direction and width direction. The measurement conditions in this case are as follows.

■Light source Argon ion laser (5145A) ■Setting the sample Press the film surface to a total reflection prism, and the incident angle of the laser to the prism (angle with the film thickness direction) is 6
It was set to 0°.

■Detector PM: RCA31034/Photon Cool
ing S7stem (Hamamatsu C123
G) (supply 1600V) ■Measurement conditions SLIT 1000μm LASER
100mWGATE TIME
1. OsecSCAN SPEED
12cm-”/minSAMPLI.NG
INTERVAL O. 2cm ”-”RE
PEAT TIME 6(5) Total reflection Raman crystallization index Ramanor U - manufactured by Jobin-Yvon
The total reflection Raman spectrum was measured using a 1000 Raman system, and the 1
The half width of 730 cm −1 was taken as the total reflection Raman crystallization index of the surface. The measurement conditions are as follows. The measurement depth is about 500 to IOOOA from the surface.

■Light source Argon ion laser (5145A) ■Sample setting Press the film surface to a total reflection prism so that the laser polarization direction (S polarization) and the film longitudinal direction are parallel. The angle with respect to the direction was 60°.

27 ■Detector PM: RCA31034/Photon Coun
ting System (Hamarnajsu C1
230) (suppl7 1600D■Measurement conditions SLIT 1000μmLASER
l00mWGATE TIME
1. OsecSCAN SPEED
12cm-”/min, SAMPLING INTER
VAL O. 2cm-”REPI!AT TIM
E 6 (6) Average height of surface protrusions Two-detector scanning electron microscope [ESM-3200,
manufactured by Elionix Co., Ltd.] and a cross-sectional measuring device [PMS-1,
The measured height of the protrusions is sent to an image processing device [I BAS2 000, manufactured by Carl Zeiss Co., Ltd.] when the height of the flat surface of the film is set to 0. Reconstruct the film surface protrusion image on the processing device. Next, a circular equivalent diameter is determined from the area of each protrusion obtained by binarizing the protrusion portion using this surface protrusion image, and this is taken as the average diameter of the protrusion. Furthermore, the highest value among the binarized individual protrusion portions is determined as the height of the protrusion, and this value is determined for each protrusion. This measurement was repeated 500 times at different locations to determine the number of protrusions, and the average height of all the measured protrusions was taken as the average height.

Furthermore, the standard deviation of the height distribution was determined based on the height data of each protrusion. The magnification of a scanning electron microscope is 10
Select a value between 00 and 8000 times. In some cases, a high-precision optical interferometric three-dimensional surface analysis device (WYKO) may be used.
The height information obtained using TOPO-3D (manufactured by Co., Ltd., objective lens: 40 to 200 times, effective use of a high-resolution camera) may be read as the above-mentioned SEM value.

(7) Centerline average surface roughness Ra, centerline depth Rp, maximum height Rt, protrusion spacing Sm Measured using a high precision thin film step measuring instrument ET-10 manufactured by Kosaka Institute. The conditions were as follows, and the average value of 20 measurements was taken as the value.

・Stylus tip radius = 0.5μm ・Stylus load: 5mg ・Measurement length: 1mm ・Cutoff value: 0.08mm The definitions of Ra, Rp, Rt, and Sm can be found, for example, in "Surface Roughness" by Jiro Nara. "Measurement and Evaluation Methods" (Sogo Technological Center, 1983).

(8) Young's modulus, breaking strength, breaking strain.
Measurement was performed at 5° C. and 65% RH.

The Young's modulus, breaking strength, and breaking strain of each of the thermoplastic resin layers A and B were determined from a single-layer film produced under the same conditions as the laminated film. Furthermore, when the Young's modulus E of the thermoplastic resin layer A is known, the Young's modulus E of the layer B may be measured and calculated according to the following formula.

E=(EA-lA+EB●i.)/(lA+IB) Here, IA and 1B are the stacked thicknesses of layer A and layer B, respectively.

(9) Cohesive energy density Cohesive energy density of thermoplastic resin A (C.E.D.
, ) is calculated using Fedors' method (Reference: R.F.F.
Edors, Polym, Eng. Sci. ．． 14
, 147 (1974)).

(10) Intrinsic viscosity [η] (unit: d 1/g) A value calculated from the following formula from the melt viscosity measured at 25° C. in orthochlorophenol is used.

That is, ηsp/c=[η]+K[η]2 ・C, where η5P
= (solution viscosity / solvent viscosity) -1, C is the weight of dissolved polymer per 100 ml of solvent (g / 100 ml usually 1.2),
K is the Huggins constant (assumed to be 0.343). Also,
Solution viscosity and solvent viscosity were measured using an Ostwald viscometer.

(11) Surface layer particle concentration ratio Using secondary ion mass spectrometry (SIMS), the concentration 31 degree ratio of the element with the highest concentration among the elements caused by particles in the film and the carbon element of the thermoplastic resin is calculated as the particle concentration. and conduct an analysis in the thickness direction. SIMS
The ratio of the particle concentration A at the outermost layer particle concentration (point at depth O) measured by the method and the maximum concentration B obtained by further analysis in the depth direction, A/B, was defined as the surface layer concentration ratio. The measuring device and conditions are as follows.

■Measurement device Secondary ion mass spectrometer (SIMS) A-DIDA3000 manufactured by ATOMIKA, West Germany ■Measurement conditions Primary ion species = 02 Primary ion acceleration voltage: 12KV Primary ion current: 200nA Raster area: 400μm Analysis area: Gate 30% Measurement vacuum: 6. OXIO-9TorrE-GUN:0
．． 5KV-3. OA (12) Single Particle Index A cross section of the film is photographed and observed using a transmission electron microscope (TEM) to detect particles. If the observation magnification is set to about 1032 oooo times, a single particle that cannot be separated any further can be observed. The total area occupied by the particles is A1
When the area occupied by an aggregate in which two or more particles are aggregated is defined as B, (A-B)/A is taken as a single particle index. The TEM conditions are as follows, and 500 fields of view are measured by changing the field of view in which one field of view area = 2 μm 2 is measured.

・Equipment: JEOL JEM-1200EX ・Observation magnification:
100,000 times Accelerating voltage: 100 kV Section thickness: Approximately 100 OA (13) Particle size ratio In the measurement of (1) above, the average value of the major axis of each particle /
It is the ratio of the average value of the short axis.

That is, it can be obtained using the following formula.

Major axis = ΣDli/N Minor axis = ΣD2i/N Dli ,. D2+ is the major axis (maximum diameter) and minor axis (shortest axis) of each individual particle, and N is the total number.

(14) Relative standard deviation of particle size Standard deviation σ(={Σ(
It was expressed as the value (σ/D) obtained by dividing Di −D) 2/N) 2) by the average diameter D.

(15) Low molecular weight content Sample volima is crushed and extracted using a Soxhlet extractor under reflux using chloroform as a solvent.

The ratio (% by weight) of the weight of the extract obtained by evaporating chloroform to the weight of the original sample was taken as the low molecular component content.

(16) Crystallization acceleration coefficient Measure ΔTCg (■) of a polyester containing 1% by weight of particles by the method described in (3) above, and ΔTcg (II) of a polyester of the same viscosity from which particles have been removed, and ΔT
Difference between cg(II) and ΔTcg(I) [ΔTcg(II
) - ΔTcg (I) was defined as the crystallization promotion coefficient.

(17) Thickness of thermoplastic resin layer A in the laminated film Using a secondary ion mass spectrometer (SIMS), we determined the element attributable to the highest concentration of particles in the film and the carbon element in the thermoplastic resin. The concentration ratio (M+/C+) of the thermoplastic resin A layer is defined as the particle concentration, and analysis is performed in the depth (thickness) direction from the surface of the thermoplastic resin A layer. In the surface layer, the particle concentration is low because of the interface called the surface, and the particle concentration increases as you move away from the surface. In the case of the film of the present invention, the particle concentration once reached a maximum value at depth [I] begins to decrease again. Based on this concentration distribution curve, the depth at which the maximum particle concentration becomes 1/2 [■]
(Here, n>I) was taken as the lamination thickness.

The conditions are the same as (11).

In addition, if the most abundant particles in the film are organic polymer particles that are difficult to measure with SIMS, use X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), or confocal microscopy while etching from the surface. The depth profile of the particle concentration may be measured using a method similar to that described above, and the laminated thickness may be determined using a method similar to that described above.

Furthermore, the lamination thickness of the thermoplastic resin A layer may be determined not from the depth profile of the particle concentration described above but by observing the cross section of the film.

In addition, the thickness in the case of a single layer film can be determined by a known method, for example, a dial gauge method, a gravimetric method, or a thin film step measurement method.

(l8) Using a tape running tester, a scratch-resistant film slit into a 1/2 inch wide tape is run on a guide pin (surface roughness: 100 nm in Ra) (running speed 1
000 m/min, 10 passes, wrapping angle = 60°, running tension: 20 g). At this time, the scratches in the film were observed under a microscope, and less than 3 scratches with a width of 2.5 μm or more per tape width were determined to be good, 3 or more and less than 10 scratches were determined to be good, and 10 or more scratches were determined to be poor. Excellent is desirable, but good is still usable for practical purposes.

(19) A magnetic paint of the following composition is applied to a dubbing-resistant film using a gravure roll, magnetically oriented, and dried. In addition, a small test calender device (steel roll/nylon roll,
After calendering at a temperature of 70°C and a linear pressure of 200 kg/cm,
Cure for 48 hours. 17 pieces of the above tape
Slit into 2 inch pieces to make pancakes. A length of 250 m from this pancake was assembled into a VTR cassette to make a VTR cassette tape.

(Magnetic paint composition) - CO-containing iron oxide (BET value 50 m2/g): 100 parts by weight - S-LEC A (vinyl chloride/vinyl acetate copolymer manufactured by Sekisui Chemical) = 10 parts by weight - Nipporan 2304 (manufactured by Nippon Polyurethane) Polyurethane elastomer): 10 parts by weight Coronate L (Isocyanate manufactured by Nippon Polyurethane)
:5 parts by weight ●Lecithin
= 1 part by weight ●Methyl ethyl ketone = 75 parts by weight・Methyl isobutyl ketone: 75 parts by weight・
Toluene: 75 parts by weight, carbon plaque: 2 parts by weight, lauric acid
= 1.5 parts by weight Add household V to this tape
Using the TR, Shibasoku's TV test waveform generator (TG
7/U706) to record 100% chroma signal, and from the reproduced signal, use a Shibasoku color TV noise measuring device (
925D/1), and the chroma S/N was measured as A. In addition, a master tape pancake recorded with the same signals as above was printed using a magnetic field transfer video software high-speed print system (
For example, the chroma S/N of the same sample tape (unrecorded) used to measure A was dubbed onto a pancake using a Sony Magnescale ■ Sprinter), and the chroma S/N of the tape was measured in the same manner as above. And so. If the chroma S/N drop (A-B) due to dubbing is less than 3 dB, dubbing resistance is excellent; if it is 3 dB or more and less than 5 dB, it is good.
A score of B or higher was determined to be defective. Excellent is desirable, but good is still usable for practical purposes.

(20) Coefficient of friction μk A film was slit into a tape with a width of 1/2 inch, and a film was slit into tapes with a width of 1/2 inch. The vehicle was run in an atmosphere, and the initial coefficient of friction was determined using the following formula (
The film width was 1/2 inch).

μk=0. 7 3 3 l o g (T2 /T
I) Here, T1 is the inlet tension and T2 is the outlet tension.

The guide diameter is 6mmφ, and the guide material is SUS27 (
The surface roughness is 0.2S), the wrapping angle is 180, and the running speed is 3.3 cm/sec. μk obtained by this measurement
When the coefficient of friction was 0.35 or less, the friction coefficient was determined to be good, and when it exceeded 0.35, the friction coefficient was determined to be poor. This μk is a critical point that determines the handling properties when processing the film into magnetic recording media, capacitors, packaging, etc.

(21) Press one blade perpendicularly against a tape-like slit of a 172-inch wide scratch-resistant film, push it further 0.5 mm, and run it 20 cm (running tension: 500 g, running speed: 6.7 cm/ seconds).

At this time, the height of the scraped material 39 on the film surface attached to the tip of the single blade was read with a microscope and calculated as the scraped amount (unit: μm).
). For at least one side, if the amount of abrasion was less than 10 μm, the abrasion resistance was determined to be good, and if it was 10 μm or more, the abrasion resistance was determined to be poor. The value of this amount of abrasion = 10 μm is
This is the critical point for determining whether problems with the process or product performance will occur due to scratching of the film surface during printing, calendering, or other processing steps.

[Example] The present invention will be explained based on examples.

After preparing an ethylene glycol slurry containing silica particles and crosslinked polystyrene particles caused by colloidal silica having different average particle diameters and amounts added, and heat-treating this ethylene glycol slurry at 190 ° C. for 1.5 hours,
After transesterification with dimethyl terephthalate, polycondensation was performed to produce pellets of polyethylene terephthalate (hereinafter abbreviated as PET). In addition, Example 3 uses polyethylene 2,6-naphthalate, and Example 4 uses polyethylene α,
β-bis(2-chlorophenoxy)ethane 40-4,4"-dicarboxylate, Comparative Example 5 used isophthalic acid component (17.5 mol%) copolymerized PET, Comparative Example 6 used polyarylate (as acid component) Terephthalic acid/
Equimolar amount of isophthalic acid, 2,2 as diol component
- Bis(4-hydroxyphenyl)propane was copolymerized with PET in equal moles) to obtain thermoplastic resin A. In addition, PET having an intrinsic viscosity of 0.62 and containing substantially no particles was produced by a conventional method and used as a thermoplastic resin B. Each of these polymers was dried under reduced pressure (3 Torr) at 180° C. for 3 hours. Thermoplastic resin A is supplied to extruder 1, and thermoplastic resin B is further supplied to extruder 2, each melted at 290°C, these polymers are merged and laminated in a merging block (feed block), and electrostatic charge is applied. Using a casting method, the film was wound around a casting drum with a surface temperature of 30°C, and cooled and solidified to produce an unstretched film with a two-layer structure. At this time, an unstretched film was prepared with a ratio of die slit gap/unstretched film thickness of 10. In addition, the total thickness and the thickness of the thermoplastic resin A layer were adjusted by adjusting the discharge amount of each extruder. This unstretched film was stretched 2.5 to 5.0 times in the longitudinal direction at a temperature of 80° C. using the difference in circumferential speed of the rolls. This uniaxially stretched film was stretched in the width direction at 100°C at a stretching rate of 2000%/min using a stencil for 2.5 to 4. The film was stretched 0 times and heat treated at 200° C. for 5 seconds under constant length to obtain a biaxially oriented laminated film with a total thickness of 15 μm. The parameters and performance of the present invention of these films are shown in Table 1, and when the parameters of the present invention are within the range of the present invention, the coefficient of friction, scratch resistance, and dubbing resistance are excellent or good. However, it can be seen that if the parameters are outside the range of the present invention, a film having good friction coefficient, scratch resistance, and dubbing resistance cannot be obtained.

[Effects of the Invention] The present invention utilizes a thermoplastic resin containing particles by devising a manufacturing method, and sets the relationship between the particle size and film thickness, the content, and the film thickness within a specific range. The product of Young's modulus EAN breaking strength and breaking strain σ4, the cohesive energy density (C.E.D.,
), a film with excellent scratch resistance and friction coefficient was obtained, and a film with excellent dubbing resistance when used for magnetic recording media was obtained. It is capable of responding to increases in speed. Although the use of the film of the present invention is not particularly limited, it is particularly useful as a base film for magnetic recording media, where scratches on the film surface during processing pose problems in terms of processing and product performance.

In addition, for films of the present invention with a two-layer structure, the thermoplastic resin side A is the running surface (for magnetic recording media, the surface is not coated with a magnetic layer, and for other uses, it is the surface that is not coated with a magnetic layer, and for other uses, it is used for printing or other treatments such as coating with coating materials). It is preferable to use it as an unfinished surface.

In addition, the two-layer structure film of the present invention is a film made by direct composite lamination without any coating or other operations during the film-forming process, and compared to a laminated film made by coating during or after the film-forming process. The molecules in the outermost layer are also biaxially oriented, so in addition to the properties mentioned above, for example, the surface has much better abrasion resistance.
This is advantageous in terms of quality stability, etc.

Claims (4)

[Claims] (1) A film mainly composed of thermoplastic resin A and particles, the film having a longitudinal Young's modulus E_A of 400
kg/mm^2 or more, the product σ_A of longitudinal breaking strength and breaking strain is 20 kg/mm^2 or more, the average particle size of the particles is 0.2 to 5 times the thickness of the film, Thickness 0.1%, characterized in that the content is 0.1-30% by weight.
01-3 μm biaxially oriented thermoplastic resin film. (2) A film mainly composed of thermoplastic resin A and particles, the cohesive energy density (C.
E. D. ) is 130 cal/mol or more, the average particle diameter of the particles is 0.2 to 5 times the thickness of the film, and the content of the particles is 0.1 to 30% by weight. Biaxially oriented thermoplastic resin film of 0.01-3 μm. (3) Biaxially oriented film formed by laminating the biaxially oriented thermoplastic resin film according to claim (1) or (2) on at least one side of a film whose main component is thermoplastic resin B that does not substantially contain particles. Thermoplastic resin film. (4) 0.001 particles with an average particle size of 0.01 to 2 μm
Claim (1) or (2) on at least one side of a film whose main component is thermoplastic resin B containing ~0.5% by weight.
A biaxially oriented thermoplastic resin film obtained by laminating the biaxially oriented thermoplastic resin films described above.