JPS59159320A - Biaxially orientated copolymer polyester film - Google Patents

Abstract

PURPOSE:To produce a biaxially orientated copolymer polyester film that is high in Young's modulus, excellent in dimension stability and impact resistance and suitable to be used as a magnetic tape, or a condenser. CONSTITUTION:The present film consists of a copolymer polyester wherein the total of the cyclic units of the formulae I and II is 95mol% or more of the total of all of the constitutional units, the proportion of the unit of the formula I to the unit of the formula II is 0.1-25mol%, the refractive index of the film measured in the direction of the thickness is 1.500-1.580, the density is in the range of 1.445-1.490, and the melt viscosity is 800-1,500 poises at a temperature of 290 deg.C at a shear rate of 200/sec.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a biaxially oriented polyester film, more specifically a biaxially oriented copolyester with a high modulus of elasticity (high Young's modulus) suitable for use in magnetic tapes and capacitors. It's about film.

[Prior art]

Phantom, on the basis of magnetic tape and content derivatives.

Biaxially oriented polyethylene terephthalate (hereinafter referred to as PET)
(abbreviated as ) film is used.

However, such a biaxially oriented PET film has a low Young's modulus, so when the film is made thinner in order to miniaturize magnetic tapes and capacitors, the running properties and electromagnetic conversion characteristics of the magnetic tape may be poor, or the film may not be easily shattered. However, this method had the disadvantage of poor handling during capacitor manufacturing. on the other hand,
Further re-stretching of the biaxially oriented PET film yields a film with a somewhat high Young's modulus, but is 7 dimensionally stable.
There was a drawback that it became defective.

[Purpose of the invention]

The present invention overcomes the drawbacks of the prior art to the second degree.

It is an object of the present invention to provide a biaxially oriented copolymerized polyester film that has a high Young's modulus, excellent dimensional stability, and also excellent impact resistance.

〔composition〕

In order to achieve the above object, the present invention has a secondary 114 structure.

That is, the repeating unit (I) represented by the following general formula
and (n) is equal to or more than 95 moles φ, which is the middle value of the total composition.

and), a film made of a copolyester in which the ratio of (n) to (I) is in the range of 01 to 25 molar ratio, and the refractive index in the thickness direction of the film is 1.500 to 1.
．． 580, the density is in the range of 1445 to 1490,
The biaxially oriented copolymerized polynisder film is characterized by having a melt viscosity of 800 to 15,000 poise at a temperature of 291]c and a shear rate of 200/sec.

OCj (Here, choose from 1.2, 4.6 for 11; 11 /,
- is an integer, and the earth atom in structural units (I) and (Ir) is 7 to the adjacent oxygen atom in the penden term.
It is connected to the 11th place. ) The copolymerized poly-[sprue d of the present invention has a total sum of repeating units (T) and (II) represented by the following general formula of 1.7. li
It is a polynisdel having a structural unit ratio of 95 moles or more. If the sum of (T) and (n) is less than 95 moles, the film will have a poor Young's modulus, which is not preferable. (1
) (!-Although the copolymerization mode of (II) may be Landano or block copolymerization, it is preferable to use Landano-copolymerization, which gives a particularly good -A' rate. 3.- Also, among the structural units of the copolymerized polyester of the present invention, other copolymerized components may be included as long as the molar ratio is less than 5. In this case, other copolymerized components include prephthalic acid, isonotalic acid, etc. acid, 2,6-naphthalene dicarboxylic acid, 4,4/-sifubonyldicarboxylic acid, α, β
-Bis(phenoxy)ethane 4,4/-)carboxylic acids and other dioxylic acids, or 1,4-cyclohexane dimetatool and other dioxy compounds are common.

In addition, n in the above formulas (I) and (II) is 2,4
．． Young's modulus of the film, which is an integer selected from 6.

The case where n=2 is particularly preferred from the viewpoint of dimensional stability.

I cut it. - The chlorine atom in the above formulas (1) and (n) must be bonded to the 5- position ortho to the adjacent chlorine atom of the benzene ring. If the 3 earths are connected to the ono Ll and place 2, the dimensional stability of the A' song ratio of fill 1 will be poor, so ftL<no.

According to the copolymerized polyvarnish of the present invention...'' (9 notes structure) The ratio of position (T) and (■1) ['(1'l) /
(T) ]Zai 4-Hayabusa'- is 01.~25. t=)1
．． /, preferably 7 to 20 L φ. i for (1), (the ratio of iQ is -1
: If the ratio is smaller than the above range, the impact resistance of the film will be poor; conversely, if the Ll- ratio of (II) to I is larger than the above range, the Young's modulus of the film; I don't think there are many buildings because it will be defective.

The copolymerized polyester used in the present invention may be blended with other polymers within a range that does not impede the purpose of the present invention.
5. - Soil antioxidant, heat stabilizer, lubricant,
Nucleating agents 9 Inorganic and/or organic additives such as surface protrusion forming agents may be added to the extent normally added 3
゜The film of the present invention is a film 1 in which the above-mentioned co-Φ-polyester is oriented in the knee axis, and the refractive index in the thickness direction of the film is 1500 to 1580. Preferably, 6-1 is 1.510 = 1.570, and it is also necessary that the number of cases is in the range of -1,565 to 152D. If the flexural index in the direction of 19 and 19 is in the upper range of 14, it is not preferable because the -A' index of the film will be poor. Conversely, Jtt' in the thickness direction, 4
A film with a fi-factor smaller than the specified range is not only difficult to produce stably, but also has poor impact resistance, so it is not preferred.

Density f of the film of the present invention: l-11,445 to 1.4
90.

It is necessary that ij is preferably in the range of 1455 to 1.480, more preferably 1.460 to 1475. If the density is smaller than the above range, the film's stability will be poor, and if it is larger than the above range, the impact properties will be poor. Not bad 1, f: + Inventive film temperature 290°C, rubbing speed 20
Melt viscosity at 07 seconds is 800 to 15,000 bois, good 1
If the melt viscosity is smaller than the above range, the impact resistance of the film will be poor, and conversely, if the melt viscosity is larger than the above range, it is safe. is the -・Fugu rate of the film,
, J-method stability is poor, so it is not suitable for women.

Furthermore, in the heather invention film, the difference in refractive index between the longitudinal direction and the width direction (longitudinal direction - width direction) of the film is -02
~02. "Good": A Schiff value in the range of -01 to 01 is desirable because the film's impact resistance is particularly good. The copolyester used in the present invention can be synthesized by the following method. That is, the m-position (I) in the above structure is σ, β-bis\(2-li-I-fluphenoxy)ethane-4,4'-dicarboxylic acid and /'
+ It is a unit obtained by polycondensing an ester-forming derivative of bamboo shoots with rrugyl/glycol (carbon number: 2.4 i and 6).

The α,β-bis(2-Li-L1-rufu-unoxy)-tan is synthesized by (÷), especially (';

(1-1): +°-ogy7benzoic acid and/- or -
Nisder-forming derivatives of fE (such as methylgose-al) are nuclear chlorinated with chlorine gas.
oxinebenzoic acid, 7,/- or a nisple-forming derivative thereof, and react this compound with ethylene dihalide in the presence of an alkali compound.

(1-2) aJ-his(phenoxy)ethane-4,
The 4/--dicarboxylic acid and the /' ester-forming derivative (methyl ester, etc.) are nuclear chlorinated with chlorine gas.

Furthermore, the royal structural unit (II) in the copolymerized polyester of the present invention
phenoxy)ethane-4,4'-dicarboxylic acid and/or
Or, it is obtained by polycondensing a Nisder-forming derivative thereof with an alkylene glycol (carbon number: 2, 4 or 6).

This α(2-chlorophenoxy)-β(phenoxy-9-ethane-4,4'-carboxylate, carboxylic acid) is synthesized as (4-) by 1. be able to.

(2-1) iTh description (1-1)-Sat/r is (1-7)
3-chloro-4-oxybenzoic acid T) obtained by the method of 1. .

(2-2) α,β-bis()J-nogishi)ethane-
4,4'-dicarboxylic acid and/or ester-forming derivatives (such as methyl ester) are nuclear chlorinated with chlorine gas. After esterifying the two types of chlorine-containing dicarboxylic acids and alkylene glycol (carbon number: 2.44 or 6) in the presence of titanium and tin compounds, antimony,
22 in high vacuum in the presence of a catalyst such as a germanium compound.
Polycondensation at a temperature of 0-300°C, -10°C, direct polymerization method, or d, the above two types of chlorine-containing dicarboxylic acid varnish-chill-forming derivatives and monoalgylene glycol (carbon number: 2 , 4" and 7C 6) are subjected to an E/D exchange reaction at a temperature of 130 to 260°C, followed by the presence of catalysts such as calcium, magnesylano, and lithium compounds. A transesterification method can be used in which polycondensation is carried out at a temperature of 220 to 300°C in a high vacuum in the presence of phosphorus compounds.
It is common to add a heating agent and carry out the second process.

In addition, in order to make the melt viscosity of the film within the range of the present invention, the polymerization time should be adjusted and the melt viscosity of the polynisder obtained should be adjusted to 850 to 6ooo, preferably 1.
It is preferable to keep it in the range of 100 to 8,500 voices. Of course, in order to obtain a copolymerized polyester having a melt viscosity within the preferred range of 1-, a method of solid phase polymerization after completion of polymerization may be used.

The thus obtained polyester pellets) were sufficiently air-dried and then fed to a known melt extruder to form 727 [] to 3
20℃, good size F, 2 to 5 to 315℃, melt extruded from a slit-shaped die into a shape of 1, 1, 1, 1, 2.

Control sale frc at surface temperature 10-80 *
It is wound around a yasting drum and allowed to solidify, creating an unstretched filter. In this case, 2f! , quickly, and.

The electrostatic stamp JJ', -A'-Yast method is effective for uniform cooling. Next, this unstretched film is biaxially stretched and oriented. For the biaxial stretching method and step 12, a known simultaneous biaxial stretching method or sequential biaxial stretching method can be used.

In the case of the sequential biaxial stretching method, it is common to stretch in the longitudinal direction and in the width direction, but it is also possible to stretch in the reverse order. The conditions for biaxial stretching are not necessarily constant depending on the stretching method, the viscosity of the polymer, etc.

Normally, both the longitudinal and width directions are 'f-thermal temperature 70~1
Ov, weight is 8[] ~ 125c, stretching temperature 90-
- 140°C, a range of 100 to 1 to 5°C is appropriate, and a suitable tF and stretching speed is 103 to 'IO6 factors/min. Second, the stretching ratio to obtain the refractive index of the film of the present invention is such that the longitudinal direction magnification α and the width direction magnification β satisfy the following formula (a) and the following formula (1)). 6, 12.55 (12+β2≦55.0
(a,') 180≦α2do β2≦40.0
(b) The method of further stretching (second stretching) the -1 biaxially stretched filtrate (one P+ stretching) in at least one direction increases the Young's modulus even further and improves running properties as a magnetic tape. It is effective in further improving the The conditions for this second stretching and ~.

Preheating temperature 80-150°C, preferably 90-140°C,
Stretching temperature: 110-190℃, weight: 120-180℃
℃ range is appropriate; 1. Ta. Stretching speed is 105~I
O'%/min is suitable.

Dimensions. When using this method of further stretching, the stretching ratio is as follows: the longitudinal direction magnification α9 the width direction magnification β of the first stretching is expressed by the following formula (C), i 1−, < (d)
00≦a2+β2≦40.0 (c)12
5≦α2+β2≦30.0 (a) (however, α〉2.β〉2) is satisfied, and the magnification 79 in the longitudinal direction of the second stretching and the magnification δ in the width direction are the following formula (e), preferably Satisfying (f)16
- 1.500 to 1 of the refractive index range of the present invention
Particularly suitable for obtaining a range of 540.

22≦γ2+δ2≦150 (θ)2 5
・Lever, γ2 + δ2 ・-Ting 8. 5
(t-)(
However, γ・te1. δ1) Next, this stretched film is heat treated. The heat treatment conditions for obtaining the film of the present invention are 2rlO-260°C.
, at 220-250℃ for 2 hours 05-1.20
seconds, preferably 10 to 60 seconds. Note 2
The film of the present invention is characterized by the biaxially oriented copolymerized polyester described above, and the film of the present invention is subjected to a known discharge treatment (in air).

It can be used in a nitrogen atmosphere, carbon dioxide gas, etc.), and has good adhesion, moisture resistance, heat sealability, and slipperiness.

Forms in which other types of polymers are laminated for the purpose of imparting surface smoothness, other types of polymers, and /'! Alternatively, it may be used in the form of being coated with an inorganic composition.

The characteristic values of the present invention are based on the following measurement method and evaluation criteria.

(1) Young's modulus 14 - Tested at 25°C using an Instron type tensile tester according to the method specified in JIS Z-1702.
, 65%R)T, the Young's modulus in the longitudinal direction and width direction of the film was measured. Longitudinal direction -- the first in the width direction is 120
If 0 flex/mm2 or more, Young's modulus: Good, 900
- Young's modulus was determined to be unsatisfactory if it was in the range of -1200 kg/mm2, and Young's modulus was determined to be poor if it was less than 900 kg/mm2.

In addition, this ranking assumes that the film is magnetic tape,
Also, it corresponds to the quality of running performance over time)Z).

(2) Kj legal qualitative heat shrinkage rate) Test water film width 10n:un, length 250'mn+
Cut out 2. Insert two marked lines at an interval of about 200mm1
1゜Measure the distance accurately (this is defined as Amm)
.

15 with a load of 3.0 g applied to the tip of this sample.
Leave it in hot air at 0℃ for 30 minutes and then measure the distance between the marked lines (this will be designated as B111111), 1
0Dx(8-B)/A was taken as the heat shrinkage rate.

If the arithmetic average value of the heat shrinkage rate of the two widths in the longitudinal direction is less than 5%, the dimensional stability is good.

5 or more 1. Dimensional stability: No, 1-determined f
c.

(3) 1 Impact resistance (1i) Impact strength ASTM-I)-256, using a Chargy impact desk manufactured by Toyo Seiki Co., Ltd., at 25°C and 65°C. In relation 1 (■), when the film is set horizontally with the longitudinal direction as the fulcrum, 1-T = L, and when it is set horizontally with the width direction as the fulcrum. cm/mm2) was measured, and the arithmetic average value in both directions was taken as the impact strength.

(1)) Tear wire resistance According to the method specified in JIS-P-8116, using Toyo Seiki's new 5R Lummendorf tear test rock, 25°C, 65 inches) (H), Filno length)
Measure the tear track resistance (medium: g/mm) in the j direction and the width direction (-72 The additive average value in both directions is taken as the tear track resistance.

Ta.

The above impact strength is 20 or more, and the tear resistance is 1
00 or higher: Impact resistance: Good.

If at least one of the conditions (a) and (b) above is satisfied, the impact resistance is determined to be poor.

(4) Using a melt viscosity enhancement type flow tester, measure the melt viscosity at a temperature of 290°C and a sliding speed of 2007 seconds. The measurements were carried out at 25° C. and 65° RH using Atsube's refractive index cutter as a light source.

(6) Density Measured at 25°C using a density gradient tube made of carbon tetrachloride and n-hebutane 〇 [Function] The present invention uses a specific copolymerized polyester.

A biaxially oriented film having a refractive index and melt viscosity within a specific range is used, and as a result of fc, the film becomes a film containing many extended chain crystals (crystals that are curved in a fully extended form). If we obtain a linear effect ψ of the first order, we have the following.

[Effects of the present invention: T]

(1) - A film with a high Young's modulus and excellent legal stability and impact resistance.

(2) The film of the present invention can be applied to all the applications in which biaxially oriented polyethylene prephthalate has been used since then, but it is particularly suitable for applications 5. Base film for magnetic tape for video cameras and audio.

Magnetic disk base, Sufilno 4. and a filler for capacitors. The thickness of the film of the present invention is not particularly limited, but for magnetic tapes and condensers, the thickness is 1 to 157 zm.

Preferably, a film with a thickness of 4 to 1211 m is suitable for making magnetic tapes smaller and longer, and capacitors smaller. For magnetic disks, a film with a thickness of 30 to 10018 μm, preferably 2 to 40 m, is suitable. - 80 μm film is suitable from the viewpoint of handling properties of the glass.

Next, embodiments of the present invention will be described based on Examples.

Example 1 α,β-bis(2-chlorphenoquine)ethane-4,4
'-Dimethyl dicarboxylate 85 heavy liver part (hereinafter abbreviated as part) and α(2-chlorophenoxy)-β(phenoxy)
137 parts of methyl ethane-4,4'-dicarboxylate (molar ratio 85:15), 29.5 parts of ethylene glycol (
The molar ratio of ethylene glycol:total dimethyl dicarboxylate is 1.9 + 1), calcyanoacetate, 0.07
5 parts of anti-ceph trioxide and 0.04 parts of anti-ceph trioxide were charged into a reactor equipped with a rectification column, and the temperature was gradually increased over 4 hours under stirring at a reaction temperature of 140 to 245°C to obtain 99 volumes of the theoretical amount of methanol. (159 parts) was distilled off and after 7 days, 0.02 parts of trimethyl phosphate was added. Next, the transesterification reaction product was transferred to a polymerization reactor and heated to 245-290°C over 1 hour, and at the same time, heated to a high vacuum of 0.5 Torr or less for 1 hour. Another 2 hours of polycondensation. After that, the pressure was returned to normal with nitrogen, and the polymer was discharged into water under 1IJ[] pressure, and then ink was applied and bound.・Obtained/C copolymerized polynisdel 1
The values are as shown in the table below, and it can be seen that they match the calculated value from the structural formula below, 'r<, 3 (elemental analysis value) *0 stop) = 100 (chi) - C stop) -I ((person in charge) -CZ < system 9 was issued.

(Here, l'4 / m = 85 / 15 (
Molar ratio)) The melt viscosity of this copolymerized polyester was 1900 voids.

This copolymerized polyester was heated at 180°C for 3 hours.

After drying under reduced pressure (3 Torr), this was supplied to an extruder with a screw diameter of 35 mm, and melt-extruded at 300°C into a sheet shape using an electrostatic casting method.

It was wound around a casting drum with a surface temperature of 20° C. and cooled and solidified to produce a substantially non-oriented unstretched film with a thickness of about 110 μm. This unstretched film was heated to 100°C.
While preheating to , the stretching temperature is 120° C. and the stretching is 1 to 62 times in the longitudinal direction. This stretching was carried out using a difference in peripheral speed between two sets of rolls, and the stretching speed was 21-50, []OO%. - axially stretched fin.

Preheat to 110℃ using a stenter, hang, and stretch at 1
It was stretched 64 times in the width direction at 20°C. In this case, the stretching speed was 5,000%/min, and the biaxially stretched film was further heat-treated at 230°C for 15 seconds at a constant length to a thickness of 1.
A film of 0 μrn was obtained 3. The Young's modulus of this film was: longitudinal direction: 550 kg/mm2° width direction: 65
0 kHz, 7mm2, which is good, and the method stability is good.
ITiITi properties were also good.

Examples 2 and 3 Comparative Example-10 a, β-bis(2-di-fluphenoxy)ethane-4,
Dimethyl 4'-dicarboxylate (2-chlorophenoxy); β(phenoxy)ethane-4,4'-dicarboxylic acid dimethyl and ethylene glycol were added to Example 2 in Table 1. They were each added in such proportions as in Example 1, and polycondensation was carried out under the same conditions as in Example 1.

Each of these copolyesters was formed into a film under the following conditions.

No trench, about 120μ thick made from 1-7 in the same way as in Example 1.
The substantially non-oriented unstretched film of M was preheated to 122-10°C and stretched 33 times in the longitudinal direction at a stretching temperature of 125°C]. This stretching is performed by using a difference in peripheral speed between the two sets of rolls, and the stretching speed is 50. [It was 100%/min. This -axially stretched film was 11
Preheat to 0℃ and stretch at 120℃ in the width direction.
The stretching is 1~. The stretching speed in this case was 5,000%/min. This biaxially stretched film was heat treated at 23D° C. for 15 seconds under constant length to obtain a film with a thickness of 10 μm. The physical properties of these films are shown in Table 1, and it can be seen that the films of Jl also have good Young's modulus, and are also excellent in dimensional stability and impact resistance. but.

Even if the polymer composition is the same as that of the present invention, Comparative Example 1 in Table 1
Comparative Example 2, whose refractive index is outside the scope of the present invention, as in
If the density of the film is outside the scope of the invention as in Example 3, or the melt viscosity is outside of the scope of the invention as in Comparative Examples 4 and 5, the results are as shown in the table.

No material with a good Young's modulus and excellent two-dimensional stability and impact resistance was obtained. When the polymer composition is outside the scope of the present invention, as in Comparative Examples 6 to 10 in Table 1, no matter how the refractive index, melt viscosity, film density, and even stretching method are changed. As shown in the same table, no product with a -V tongue ratio of fair f and excellent two-dimensional stability and impact resistance was obtained.

Procedural Amendment, 69.5.16, 1939, Month 1] Commissioner of the Japan Patent Office Kazuo Wakasugi1, Indication of matter f1, Patent Application No. 33468 of 1982, Title of Invention Biaxially Oriented Copolymerized Polyester Film 3, Amendment Relationship with the case filed by the patent applicant Address: 2-2-4 Nihonbashi Muromachi, Chuo-ku, Tokyo, Date of amendment order: Voluntary 5, Increased due to amendment (number of inventions: 1) Specification, page 2, item 127) [ Correct dielectric-1 as “dielectric-1.”

(2) Same 15th line 1st line N 702 rl 1 702 or △S 'TM
Add 1 to -11-882.

(3) "Measured." in the 17th true line 14 of the same sentence means "I measured it." Incidentally, a sulfur-methylene chloride solution was used as the Maun 1 solution. Correct it to 1.

2-

Claims (1)

[Claims] The repeating middle positions (1) and (II) represented by the following general formula
) is greater than or equal to 95 molar proportions of all structural units, and. A film consisting of a copolymerized polynisdel in which the ratio of (H) to (T) is in the range of 01 to 25 molar ratio,
The refractive index in the thickness direction of the film is in the range of 1500 to 1580, and the density is in the range of 1.445 to 1490. A biaxially oriented copolymerized polyester film having a melt viscosity of 800 to 15,000 poise at a temperature of 290°C and a shear rate of 200/sec. 0 0(
Here, n is an integer selected from 2 and 4.6, and the chlorine atom in structural units (1) and (1) is bonded to the ortho position to the adjacent oxygen atom of the benzene ring. )