JP2008246681A - Laminated polyester film roll for magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated polyester film roll improved in magnetic tape characteristics or the processability to a vapor decomposition magnetic recording medium when especially used as a base for the vapor decomposition magnetic recording medium. <P>SOLUTION: The laminated polyester film roll is constituted by winding a laminated polyester film having at least a two-layered constitution around a cylindrical core and the ratio Ra<SB>A</SB>/Ra<SB>B</SB>of the center line average surface roughness Ra<SB>A</SB>of a layer (A-layer) constituting one side of the laminated polyester film and the center line average surface roughness Ra<SB>B</SB>of a layer (B-layer) constituting the other side of the laminated polyester film is 0.05-0.7 and the surface layer wrinkles of the surface layer part of the film roll satisfy (1) the total width of the surface layer wrinkles is 0.5-15%, (2) the occurring length of the surface layer wrinkles is 30-500 m from the surface of the film roll, (3) the height of one surface layer wrinkle is 0.05-3 mm and (4) the number of surface layer wrinkles in a width direction is 1-10 lines/1,000 mm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laminated polyester film roll for a magnetic recording medium, particularly a magnetic material suitable for producing a vapor deposition type magnetic recording medium for recording digital data such as for digital video cassette tape and data storage tape with high quality and high productivity. The present invention relates to a laminated polyester film roll for recording media.

  Polyester films have excellent properties such as strength, heat resistance, transparency, and chemical resistance, so they are used in a variety of applications, but by adding functionality, they can be used as a base for magnetic recording media. Widely used as a film.

  Magnetic recording media are roughly classified into a vapor deposition type in which a metal thin film is vapor-deposited on a base to provide a magnetic layer and a coating type in which a magnetic layer is provided by coating. In any case, improvement of the recording density by further reducing the thickness of the magnetic layer has been studied.

  Among the above, the vapor deposition type magnetic recording medium in which the use of the polyester film is most advanced will be described in detail below.

  Digital video tape for consumer use put into practical use in 1995 is a ferromagnetic metal thin film of cobalt (Co) provided as a magnetic layer on a polyester base film with a thickness of 6-7 μm, and a diamond-like carbon film on the surface. Coating. In the case of a camera-integrated video using a digital video (DV) mini-cassette, the basic specification (SD specification) has a recording time of 1 hour.

  This digital video cassette (DVC) is the world's first for home use and has many advantages as described below, and is highly evaluated in the market.

a. Can record a large amount of information in a small body b. Since the signal does not deteriorate, the image quality and sound quality will not deteriorate no matter how many years c. High image quality and high sound quality can be enjoyed without being disturbed by noise d. The video does not deteriorate even if dubbing is repeated. In 1998, a DV mini-cassette tape with a recording time of 1 hour and 20 minutes was put into practical use with SD specifications, and the base film was made of polyethylene-2, 6-Naphthalate film is used, and this tape also has a long recording time and is highly evaluated in the market.

  For example, in consumer DVC tape, a ferromagnetic metal thin film is deposited on one side of the base film, but the film thickness is as thin as 100 to 300 nm, and the surface characteristics of the base film are magnetic tape characteristics (electromagnetic conversion characteristics, dropout, etc.) Greatly affects. In particular, in recent years, the thickness of the deposited film has been reduced in order to improve the recording density, and the surface smoothness of the base film is strongly desired more than ever before. On the other hand, it is preferable that the surface is rough from the viewpoint of film formation of the base film and transportability at the time of vapor deposition, or winding up of the film roll product.

  As a base film that simultaneously satisfies the contradictory characteristics, a polyester base film or a polyester film roll shown in the following (1) to (5) is used.

(1) A laminated biaxially oriented polyester film obtained by laminating a polyester A layer containing a lubricant on one side of a polyester B layer, (a) the thickness of the entire film is 2 to 10 μm, and (b) The Young's modulus in the machine direction and the transverse direction of the film is 450 to 2,000 kg / mm ² respectively, the ratio (width / length) of both is 1.0 to 3.0, and (c) the film is 60 ° C. × 55 The thermal shrinkage in the vertical direction when held under no load for 72 hours at% RH is 0.5% or less, and (d) the total number of protrusions on the surface of the polyester A layer is 1.4 × 10 ⁴ _A projection distribution curve representing the relationship between the number of projections (Y _A : pieces / mm ² ) and the projection height (H _A : nm) obtained in a region of / mm ² or more and the number of projections of 30 pieces / mm ² or more. Intersects the straight line of the following formula (A), does not intersect the straight line of the following formula (B), and (e) poly The total number of protrusions on the surface of the ester B layer is 1.4 × 10 ² pieces / mm ² or more, and the number of protrusions (Y _B : pieces / mm ² ) determined in the region where the number of protrusions is 30 pieces / mm ² or more A laminated biaxially oriented polyester film for high-density magnetic recording media, wherein a projection distribution curve representing a relationship with the projection height (H _B : nm) does not intersect with a straight line of the following formula (C).

log ₁₀ Y _A = −0.15 × H _A +5 (A)
log ₁₀ Y _A = −0.05 × H _A +5 (B)
log ₁₀ Y _B = −0.15 × H _B +5 (C)
(2) slit speed 10～600M / min, oscillation speed 10～600Mm / min, upon winding the polyester film to the core in the oscillation width ±. 10 to ± 200 mm, the winding start to winding end, a slit velocity _{V s} The magnetic recording medium is wound while the ratio V _o / V _s with respect to the oscillation speed V _o is in the range of 3.3 × 10 ⁻⁴ to 10 × 10 ⁻⁴ and the variation rate is controlled to 10% or less. For producing polyester film rolls.

  (3) A laminated polyester film comprising layer A and layer B which are two polyester layers, the surface of the layer A side having an arithmetic average roughness Ra value of 1.5 to 5 nm, ten-point average roughness The Rz value is 10 to 60 nm, and the content of inert particles β having a particle size in the layer B of 0.1 μm or more and less than 0.22 μm is 0.2 to 1.6% by weight with respect to the layer B. The content of the inert particles α2 having a particle size of 0.22 μm or more and less than 0.4 μm is 0.01 to 0.7% by weight with respect to the layer B, and the particle size is 0.4 μm or more and less than 1.0 μm The content of the inert particles α1 is 0.0005 to 0.01% by weight with respect to the layer B, and the total content of the inert particles α1, α2, and β is 0.4 to 2. A laminated polyester comprising 0% by weight and a layer B having a thickness of 1 to 10 nm provided on the surface of the layer B. Tel film.

(4) A laminated film of at least two layers containing the thermoplastic resin A and the thermoplastic resin B, the center line average surface roughness Ra _{A of the} thermoplastic resin layer A constituting one surface, and the opposite surface side The ratio Ra _A / Ra _B to the center line average surface roughness Ra _B of the thermoplastic resin layer B is 0.2 to 0.7, the thermoplastic resin layer B contains inert particles α and β, The difference (d _β -d _α ) between the average particle diameters d _α and d _β of the active particles α and β is 80 to 300 nm, and the number of projections Nβ derived from the inactive particles β on the surface of the thermoplastic resin layer B is 4. was 150 pieces / mm ^2, and the outer layer surface of the thermoplastic resin layer B are laminated film lubricity coating layer C is formed in a thickness of 1 to 10 nm.

  However, in recent years, the demand for tape price reduction from the market has rapidly increased along with the expansion and maturation of the DVC tape market, and tape manufacturers are striving to reduce various costs accordingly. In particular, it is important to increase the speed of the vapor deposition process for vacuum-depositing a ferromagnetic metal thin film, and we are trying to improve the efficiency of the vapor deposition process by performing vacuum degassing earlier and depositing earlier. Therefore, what the tape manufacturer strongly demands for the base film is that the film roll can be vacuum-deposited in a stable state in a high-speed vapor deposition process along with the lengthening of the film roll. Temporarily, if the film is degassed before vapor deposition, or if film misalignment or mayoy (displacement in both lateral directions) occurs, the deposition stops, the atmosphere is released, the film roll treatment (cuts or replaces misalignment), and the vacuum is applied again. Although deaeration is necessary, the loss regarding time and material becomes great.

However, in the methods described in (1) to (5) above, when a long film roll product exceeding 15,000 m or even 25,000 m is used and the vapor deposition process is speeded up, the vacuum release before vapor deposition is performed. It is difficult to achieve the efficiency improvement of the magnetic tape productivity because the film is likely to be misaligned or may be at the beginning of the vapor deposition or at the start of vapor deposition.
JP-A-9-277475 JP-A-2005-85321 JP 2005-205825 A JP-A-2005-254808

  An object of the present invention is to solve the above-described problems, and to provide a thermoplastic resin film roll having good processability to a vapor-deposited magnetic recording medium when used as a base film for a vapor-deposited magnetic recording medium. .

  In order to achieve the above object, the present invention has the following configuration.

1. A laminated polyester film having a layer structure of at least two layers is wound around a cylindrical core, and the center line average surface roughness Ra _{A of} the layer (A layer) constituting one surface of the laminated polyester film and the other surface The ratio Ra _A / Ra _B to the center line average surface roughness Ra _B of the layer constituting layer (B layer) is 0.05 to 0.7, and the surface layer wrinkle of the film roll surface layer part is (1) to (1) to A laminated polyester film roll for a magnetic recording medium satisfying (4).

(1) The total width of the surface wrinkles is 0.5 to 15% of the film width
(2) Generation length of surface wrinkles is 30 to 500 m from the surface of the film roll
(3) The height of the surface wrinkles per piece is 0.05 to 3 mm.
(4) The number of surface wrinkles in the width direction is 1 to 10 / 1,000 mm
2. 2. The laminated polyester film roll for magnetic recording media according to 1 above, wherein the laminated polyester film has a width of 500 to 1,000 mm and a winding length of 15,000 to 50,000 m.

  3. 3. The laminated film according to 1 or 2 above, wherein the polyester constituting the laminated polyester film is polyethylene terephthalate or polyethylene-2,6-naphthalate.

  4). The magnetic recording medium according to any one of the above 1 to 3, wherein the slippery coating layer D is provided on the outer surface of the layer B, and the slippery coating layer C containing particles is provided on the outer surface of the layer A. Laminated polyester film roll.

  5. 5. The laminated polyester film roll for magnetic recording media according to 4 above, wherein the particles contained in the slippery coating layer C are inorganic particles.

  6). 6. The laminated polyester film roll for magnetic recording media according to 5 above, wherein the inorganic particles are composed of silicon dioxide.

  7. The laminated polyester film roll for magnetic recording media according to any one of 1 to 6, wherein the laminated polyester film is used as a base film for a magnetic tape of a digital recording system.

  According to the present invention, as will be described below, even when the film roll product is longer than 15,000 m, and more than 25,000 m, the lateral deviation at the time of vacuum deaeration in the vapor deposition process or at the start of vapor deposition is reduced. There can be obtained a laminated polyester film roll for a magnetic recording medium that can produce a magnetic tape with excellent processability and good productivity.

  The laminated polyester film used in the present invention is composed of polyester. In the present invention, the polyester is a polymer obtained by condensation polymerization from a diol and a dicarboxylic acid. Further, dicarboxylic acids are typified by terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, adipic acid, sebacic acid and the like, and diols are ethylene glycol, trimethylene glycol, tetramethylene glycol, cyclohexane dicyclohexane. It is represented by methanol or the like. Specific examples of such polyester include, for example, polyethylene terephthalate, polyethylene-p-oxybenzoate, poly-1,4-cyclohexylenedimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate (polyethylene-2,6 -Naphthalate) and the like can be used.

  Of course, these polyesters may be homopolyesters or copolyesters. Examples of the copolyester copolymer component include diol components such as diethylene glycol, neopentyl glycol, polyalkylene glycol, adipic acid, Dicarboxylic acid components such as sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 5-sodium sulfoisophthalic acid can also be used.

  As the polyester used in the present invention, polyethylene terephthalate and polyethylene-2,6-naphthalate are particularly preferably used since they are excellent in strength, heat resistance, water resistance, chemical resistance and the like.

  The intrinsic viscosity of the polyester is not particularly limited, but is preferably 0.4 to 1.2 dl / g, more preferably 0.5 to 1.0 dl / g, when measured in orthochlorophenol at 25 ° C. Furthermore, what is in the range of 0.5-0.8 dl / g can be used conveniently.

  Further, for the purpose of improving the color tone and heat resistance of the resulting polyester, it may contain an alkali metal compound, an alkaline earth metal compound, an aluminum compound, a zinc compound, a tin compound and the like.

  Furthermore, it contains additives such as anti-coloring agents, stabilizers, antioxidants, light-proofing agents, weathering agents, fillers, nucleating agents, dispersing agents, coupling agents and the like within the range not impairing the object of the present invention. There is no problem.

The laminated polyester film used in the present invention has a layer configuration of at least two layers, and a layer (A layer) having a center line average surface roughness Ra _A of one side and a layer ( It is important that the ratio Ra _A / Ra _B to the center line average surface roughness Ra _B of the (B layer) is 0.05 to 0.7.

That is, making one surface (A layer side) a relatively smooth magnetic layer processed surface and the other surface (B layer side) a relatively rough running surface is a film transport during film formation and processing. This is a preferable configuration in order to satisfy both the properties, the magnetic tape characteristics after processing, and the tape transportability. When the ratio Ra _A / Ra _B is out of the above range, the transportability of the film or magnetic tape and the magnetic tape characteristics are likely to deteriorate. Furthermore, more preferable range of the ratio _Ra A / Ra _B is 0.1 to 0.6, more preferably a 0.2 to 0.55.

The preferable ranges of Ra _A and Ra _B in the present invention are 0.7 to 7 nm and 2 to 20 nm, respectively, and more preferably 1 to 5 nm and 3 to 15 nm, respectively. In addition, about centerline average surface roughness, when the below-mentioned slippery layer is laminated | stacked on the film surface, the value which measured the slippery layer surface is meant.

  In addition, as a method of forming a laminate of two or more layers in the present invention, either a method of compounding by co-extrusion during melt film formation or a method of laminating after forming each film separately may be used. In view of the above, the former method is more preferable.

  Although this invention relates to the film roll which wound the said laminated polyester film around the cylindrical core, as for this polyester film roll, surface layer wrinkles satisfy | fill following formula (1)-(4).

(1) The total width of the surface wrinkles is 0.5 to 15% of the film width
(2) Generation length of surface wrinkles is 30 to 500 m from the surface of the film roll
(3) The height of the surface wrinkles per piece is 0.05 to 3 mm.
(4) The number of surface wrinkles in the width direction is 1 to 10 / 1,000 mm
When the surface layer wrinkles satisfy the above (1) to (4), it is a long film roll product exceeding 15,000 m, and even when the vapor deposition processing step is accelerated, during vacuum deaeration before vapor deposition, Alternatively, it is possible to maintain a stable state free from misalignment and joy of the film at the start of vapor deposition and further to the end of vapor deposition, and a magnetic tape can be manufactured with excellent processability.

  When each of the above requirements exceeds the upper limit, that is, when the total width of the surface wrinkles is larger than 15% of the film width, when the generation length of the surface wrinkles is longer than 500 m from the surface of the film roll, the surface wrinkles per one When the height of the film is larger than 3 mm, when the number of surface wrinkles in the width direction is larger than 10 / 1,000 mm, the output characteristics of the magnetic tape particularly at the vapor deposition start portion tend to be deteriorated. On the other hand, when each of the above requirements is smaller than the lower limit, that is, when the total width of the surface wrinkles is less than 0.5% of the film width, when the generation length of the surface wrinkles is shorter than 30 m from the surface of the film roll, When the surface wrinkle height is less than 0.05 mm, when the number of surface wrinkles in the width direction is less than 1 / 1,000 mm, when the vapor deposition process is accelerated, and during vacuum deaeration before vapor deposition Or, the film is likely to be misaligned or may be at the start of vapor deposition, making it difficult to maintain a stable state.

  A preferable range of each of the above requirements is that the total width of the surface wrinkles is 1 to 12%, more preferably 1.5 to 10% of the film width. Moreover, the generation | occurrence | production length of surface layer wrinkles is 40-400 m from the surface of a film roll, Furthermore, 50-350 m. Moreover, the height of the surface layer wrinkles per one is 0.1-2 mm, Furthermore, 0.2-1.5 mm. The number of surface wrinkles in the width direction is 1 to 8 / 1,000 mm, and further 2 to 6 / 1,000 mm.

  The width of the laminated polyester film forming the film roll of the present invention is preferably from 500 to 1,000 mm, more preferably from 600 to 850 mm. Moreover, it is preferable that the winding length of a laminated polyester film exists in the range of 15,000-50,000m, More preferably, it is 18,000-40,000m. When the product width is less than 500 mm or the winding length is less than 15,000 m, it is difficult to increase the magnetic tape collecting efficiency when processing for a vapor-deposited magnetic recording medium. On the other hand, if the product width is wider than 1,000 mm, it becomes difficult to eliminate air contained in the film roll, resulting in a long time for vacuum degassing, resulting in reduced efficiency of the vapor deposition process, or output characteristics of magnetic tape characteristics. Is prone to decline. Also, when the winding length is longer than 50,000 m, when the vapor deposition process is speeded up, the film is likely to be misaligned or may be misaligned at the time of vacuum degassing before vapor deposition or at the start of vapor deposition. It becomes difficult.

  The thickness ratio of the A layer and the B layer is preferably 2/1 to 30/1, more preferably 3/1 to 25/1, based on the B layer. When the thickness ratio is out of this range, the transportability of the film or magnetic tape, the magnetic tape characteristics, or the cost reduction effect tends to be lowered.

  The total thickness of the laminated film is not particularly limited, but is usually in the range of 3 to 12 μm, more preferably 4 to 10 μm, and more preferably 4 to 8 μm, and film forming properties, dimensional stability, and practical handling properties. It is preferable at such points. The preferable range of the thickness of the B layer is 130 to 1,400 nm, and more preferably 150 to 1,200 nm. When the thickness is less than 130 nm, inactive particles β, which will be described later, tend to drop off, and the dropped particles are transferred to the A layer side and the magnetic tape characteristics are likely to deteriorate. On the other hand, when the thickness exceeds 1,400 nm, the surface of the B layer becomes too rough, and when the magnetic layer is left in a roll shape after vapor deposition, the outer surface shape of the B layer is transferred to the magnetic layer surface side, and the surface is wavy. Thus, the magnetic tape characteristics are likely to deteriorate.

In the laminated polyester film used in the present invention, the B layer contains the inert particles α and β, and the difference between the average particle diameters d _α and d _β of the inert particles α and β (d _β -d _α ). Is 300 to 1,000 nm, and the number of projections N _β derived from the inert particles β on the surface of the B layer is preferably 3 × 10 ² to 4 × 10 ³ / mm ² . Note that d _β > d _α . By having such a configuration on the running surface side, air present in the film roll can be uniformly removed, and the stability of the unwinding state at the time of vapor deposition processing can be easily ensured. Moreover, although mentioned later for details, when the slit conditions which wind up a film roll are made into a specific range, it is easy to satisfy said (1)-(4), and it can maintain favorable winding form other than surface wrinkles. Easy. (D _β -d _α) of less than 300 nm, the N _beta is 3 × 10 than ^two / mm ^2, the tape productivity and magnetic tape properties become unstable unwinding state at the time of deposition process tends to decrease. On the other hand, when (d _β -d _α ) is larger than 1,000 nm and N _β is larger than 4 × 10 ³ pieces / mm ² , the outer side of the B layer is formed when the magnetic layer is left in a roll shape after vapor deposition. The surface shape is transferred to the surface side of the magnetic layer, and the surface is wavy, so that the magnetic tape characteristics are likely to deteriorate.

The preferred range of the above characteristics is described in order. D _β -d _α is preferably 320 to 900 nm, more preferably 350 to 800 nm, and N _β is 4 × 10 ^{2 to} 3.5 × 10 ³ pieces / mm ² , further 5 × ¹⁰ 2 ~3 × ^{10 3} cells / mm ² is preferred.

In the present invention, it is preferable that the ratio d _beta / _{T B} of the laminated layer thickness _{T B} of the average particle diameter d _beta and B layer of the inert particles beta is 0.5 to 3.2, more preferably 0. 55 to 2.5, most preferably 0.6 to 2.0. If is less than 0.5 d β _/ T _B, the tape productivity and magnetic tape properties become unstable unwinding state at the time of deposition process tends to decrease. On the other hand, when d _β / T _B is larger than 3.2, the inert particles β are likely to fall off, and the dropped particles are transferred to the A layer side, and the magnetic tape characteristics are likely to be deteriorated.

In the present invention, it is preferable that the ratio d _alpha / T _B of the laminated layer thickness T _B of the average particle diameter d _alpha and B layer of the inert particles alpha is 0.2 to 2, more preferably 0. 3 to 1.7, most preferably 0.35 to 1.3. When d _α / T _B is less than 0.2, the stability of the roll shape of the film roll product and the magnetic tape characteristics are likely to deteriorate. On the other hand, when d _α / T _B is larger than 2, the inert particles α are likely to fall off, and the dropped particles are transferred to the A layer side, and the magnetic tape characteristics are likely to be deteriorated.

  In the present invention, in order to realize the above-described surface roughness and the number of protrusions, when the inert particles α and β are included in the B layer, the average particle diameter and the preferable range of the content in the B layer are as follows. Street.

  Inactive particles α: The average particle diameter is preferably 150 nm or more and less than 400 nm, more preferably 180 to 380 nm, and still more preferably 200 to 350 nm. The content in the B layer is preferably 0.4 to 2.0% by weight, more preferably 0.42 to 1.5% by weight, and still more preferably 0.42 to 1.0% by weight.

  Inactive particles β: The average particle diameter is preferably 400 nm or more and less than 1,200 nm, more preferably 420 to 1,000 nm, and still more preferably 420 to 900 nm. The content in the B layer is preferably 0.01 to 0.3% by weight, more preferably 0.02 to 0.2% by weight, and still more preferably 0.03 to 0.01% by weight.

  When both the average particle size and the content are less than the lower limit of the above range, the outer surface of the B layer is too smooth to inhibit air removal in the roll, and the unwinding state during vapor deposition processing becomes unstable, resulting in tape productivity. In addition, the magnetic tape characteristics are likely to deteriorate. Further, the film and tape transportability is lowered, and the handling property is likely to be lowered. On the other hand, when the average particle diameter and the content both exceed the upper limit of the above range, on the other hand, it becomes too rough, and when the magnetic layer is left in a roll shape after vapor deposition, the outer surface shape of the B layer is the surface of the magnetic layer. Transfer to the side and surface waviness tends to deteriorate the magnetic tape characteristics.

  Preferred examples of the particles used as the inert particles α and β include silica, colloidal silica, calcium carbonate, alumina, silica-alumina composite, etc. for inorganic systems, and crosslinked polystyrene, polyacryl, crosslinked divinylbenzene for organic systems. A homopolymer or copolymer of a crosslinked silicone can be used. Among the above, organic particles are preferred from the viewpoint of the influence on the magnetic layer surface side when the magnetic layer is left in a roll form after vapor deposition processing, and a homopolymer or copolymer of crosslinked polystyrene, crosslinked divinylbenzene, crosslinked silicone Is particularly preferred. As the inorganic particles, silica and alumina can be preferably used from the viewpoint of easy adjustment when adding the particles. Silica is preferably spherical. Various types of alumina, α-type, β-type, γ-type, and θ-type, exist depending on the crystal form, and any of them may be used. Further, the B layer may contain other kinds of particles finer than the inert particles as long as the object of the present invention is not impaired. The inert particles α and β may be of the same type or different types, but it is particularly preferable that both are organic.

  In this invention, when it is set as the laminated | multilayer film of A layer / B layer, it is preferable that the easy-slip coating layer D is provided by the thickness of 1-10 nm on the outer surface of B layer, Preferably it is 2-8 nm. When the thickness of the easy-slip coating layer D is less than 1 nm, a thermal decomposition product of the base film material is likely to be deposited during the magnetic layer deposition processing of the ferromagnetic metal thin film, and this thermal decomposition product is cooled and transported during the process. It adheres to the roll, which causes a decrease in cooling efficiency, and transfer to the vapor-deposited magnetic layer tends to deteriorate the magnetic tape characteristics. On the other hand, when the thickness exceeds 10 nm, the slippery coating layer is likely to be scraped and peeled off by the cooling can and the transport roll during film formation / deposition processing, and this is easily transferred to the magnetic surface side and the magnetic tape characteristics are likely to deteriorate. .

  The slippery coating layer D is preferably slippery between the cooling can and the transport roll, is not easily scraped, and has a function of not allowing degradation products from the film to pass through. It preferably contains a water-dispersible polymer. In particular, it is preferable that a silicone and a silane coupling agent are added to a water-soluble polymer and / or a water-dispersible polymer. Examples of the water-soluble polymer used in the easy-to-slip coating layer D include polyvinyl alcohol, tragacanth gum, gum arabic, casein, or cellulose derivatives such as methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, carboxymethylcellulose, polyester ether copolymer Polymers, water-soluble polyester copolymers, and the like can be used. As the water-dispersible polymer emulsion, polymethyl methacrylate emulsion, polyacrylate emulsion, and the like can be used. Among these, a polymer blend of a cellulose derivative and a water-soluble polyester copolymer is particularly preferable. The water-soluble polyester copolymer is a polyester obtained by polycondensation of a dicarboxylic acid component and a glycol component. Although what gave water solubility by copolymerizing and / or 2-70 mol% of polyalkylene ether glycol components as a glycol component is preferable, it is not limited to these. As the dicarboxylic acid having a sulfonic acid group, 5-sulfoisophthalic acid, 2-sulfoterephthalic acid and the like, metal salts thereof, phosphonium salts and the like can be preferably used, and 5-sodium sulfoisophthalic acid is particularly preferable. As other dicarboxylic acid components when 5-sodium sulfoisophthalic acid is copolymerized, isophthalic acid, terephthalic acid, sebacic acid, trimellitic acid and the like are preferable. As glycol components, ethylene glycol, diethylene glycol, neopentyl glycol, 1, 4-Butanediol is preferred. The cellulose derivative contributes to prevent precipitation of the polyester degradation product, and the water-soluble polyester copolymer contributes to increase the adhesion between the cellulose derivative and the polyester film surface. In addition, it is preferable that the glass transition point of a water-soluble polyester copolymer is 40 degreeC or more, Furthermore, it is preferable that it is 50 degreeC or more. Since the film receives heat in both the film forming process and the magnetic layer processing process, the film easily sticks to the transport roll in the process by the slippery coating layer D when a resin having a glass transition point of less than 40 ° C. On the contrary, it may cause wrinkles.

  Examples of silicone include polydimethylsiloxane, polypropyldimethyl [γ- (β-aminoethylamino)] siloxane, polypropylmethyldimethyl {3- [2- (aminoethyl) amino]} siloxane, and polypropylmethyldimethylhydroxy {3. -[2- (aminoethyl) amino]} siloxane, polypropylethylmethyl [N- (aminopropyl) iminoethyl] siloxane, etc. are used. it can. Silicone improves the slipperiness of the surface of the slippery coating layer D, ensures abrasion resistance by a cooling can and a transport roll, and at the same time improves the film transportability. Moreover, when a film is wound up in roll shape, blocking between films is prevented. In addition, you may use a fluorine-type compound as a lubricant.

  As the silane coupling agent, an organosilicon monomer having two or more different reactive groups in its molecule is used, and one of the reactive groups is a methoxy group, an ethoxy group, a silanol group, etc. One reactive group is a vinyl group, an epoxy group, a methacryl group, an amino group, a mercapto group, or the like. The reactive group is selected from those which are bonded to the side chain, terminal group and polyester of the water-soluble polymer, but as the silane coupling agent, vinyltrichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxyethoxy). ) Silane, β- (3,4 epixycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyl Dimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane and the like can be applied. The silane coupling agent contributes to prevent silicone from being released from the slippery coating layer D, and further contributes to improving the adhesion between the slippery coating layer D and the film.

  In order to prevent the slippery coating layer D from being scraped, it is preferable that fine particles are not substantially present in the slippery coating layer D. However, the use of fine particles having a particle diameter equal to or smaller than the thickness of the slippery coating layer D as a reinforcing material for the purpose of reinforcing the slippery coating layer D without inhibiting the present invention is permitted.

In the present invention, when a laminated film is used, the addition of inert particles is preferable for the B layer on the running surface side, but the A layer on the magnetic layer processed surface side contains substantially inert particles. It is preferable that the slippery coating layer C containing particles is provided on the outer surface of the layer A at the same time, so that both the anti-blocking effect between the films and the magnetic tape characteristics can be achieved. This is a preferred embodiment because it is within the scope of the present invention. The particles preferably have an average particle diameter of 3 to 200 nm, more preferably 5 to 70 nm, and even more preferably 7 to 40 nm, and the content in the slippery coating layer is 0.005 to 0.4% by weight, Is preferably 0.007 to 0.2% by weight. Further, the density of existence on the film surface is preferably 5 × 10 ^{5 to} 5 × 10 ⁸ pieces / mm ^{2, and} more preferably 1 × 10 ⁶ to 1 × 10 ⁸ pieces / mm ² . When the average particle size is smaller than 3 nm or when the content is less than 0.005% by weight, the anti-blocking effect is reduced, or the particles tend to aggregate, and the particles fall off or are larger than necessary. When the thickness is larger than 200 nm or larger than 0.4% by weight, the magnetic tape characteristics tend to be deteriorated. Also, in less than 5 × 10 ⁵ cells / mm ² for the density, easily faded substantial blocking prevention effect becomes too wide distance between the particles, whereas, if 5 × 10 greater than ⁸ / mm ² Are likely to cause particle dropping and formation of protrusions larger than necessary due to aggregation. Moreover, it is preferable that the thickness of the slippery coating layer C is 2-20 nm, Furthermore, it is 4-15 nm. If the thickness is less than 2 nm, the particles easily fall off and adhere to the cooling can and the transport roll in the process, which causes a decrease in cooling efficiency or transfer to the vapor-deposited magnetic layer, resulting in a decrease in magnetic tape characteristics. It becomes easy. In addition, the film and magnetic tape transportability is also likely to deteriorate. On the other hand, when the thickness exceeds 20 nm, the surface roughness of the A layer on the magnetic layer processed surface side increases, and the magnetic tape characteristics tend to be deteriorated.

  The particles used in the slippery coating layer C include polyacrylic acid, polystyrene, polyethylene, polypropylene, polyester, silicone, polyepoxy, polyvinyl acetate, polyethylene / propylene, cross-linked divinylbenzene, poly (meth) acrylic acid ester. , Organic particles such as poly (meth) acrylic acid amide, acrylic-styrene, styrene-butadiene or the like, or various modified products thereof, inorganic particles such as calcium carbonate, silicon dioxide, and alumina, or Composite particles coated with an organic polymer using the inorganic particles as nuclei can be used. As the organic particles, those having a terminal group modified with an epoxy, an amine, a carboxylic acid, a hydroxyl group or the like are also preferable. Of the above, polystyrene, crosslinked divinylbenzene, and silicone are preferable as the organic particles, and silicon dioxide is preferable as the inorganic particles (inorganic particles) in terms of durability and heat resistance. From the viewpoint of cost, silicon dioxide is preferable, and spherical silica, colloidal silica and the like are particularly preferable. The spherical ratio of the particles is preferably 1.0 to 1.3.

  When using a resin as a binder in the slippery coating layer C, it is preferable to use a water-soluble polymer and / or a water-dispersible polymer used for the slippery coating layer C. Examples thereof include polyvinyl alcohol, tragacanth rubber, Casein, gelatin, cellulose derivatives, water-soluble polyesters, polyurethanes, acrylic resins, acrylic-polyester resins, isophthalic acid ester resins, methacrylic acid ester resins, and the like can be used, and any of these is preferably used in combination.

  The method for forming the slippery coating layers C and D in the present invention is preferably a method in which a slippery coating layer forming coating solution is applied to a film and dried. Examples of the application method of the easy-sliding coating layer forming coating liquid include reverse (roll) coating, gravure coating, knife coating, air knife coating, roll coating, blade coating, bead coating, rotating screen coating, slot orifice coating, and rod coating. , Bar coat, die coat, spray coat, curtain coat, die slot coat, champlex coat, brush coat, two coat, metering blade type press coat, bill blade coat, short dwell coat, gate roll coat, gravure reverse coat, Methods such as extrusion coating and extrusion coating can be used.

  Moreover, as an application | coating process of an easy slip coating layer formation coating liquid, either the method of apply | coating in the film forming process of a film (in-line coating), and the method of apply | coating and drying on the film after film forming (off-line coating) However, in-line coating is a more excellent method in terms of uniform coating, thin film coating, economy, and the like. Furthermore, in the case of in-line coating, for example, a polyester film is preferably applied before the orientation and crystallization of the polyester film is completed. For example, in the sequential biaxial stretching film forming process, it is applied to the film after longitudinal stretching. In general, a method of improving the adhesion between the easy-sliding layer and the film main body during the transverse stretching and heat setting is common. In addition, the surface before coating may be subjected to pretreatment such as corona discharge treatment or plasma treatment on the surface in advance for the purpose of improving coatability.

  In addition, the liquid medium of the easy-sliding coating layer-forming coating liquid may be any of water, solvent, or a mixture of both, but in the case of using the in-line coating method, in terms of safety such as handling and explosion prevention. An aqueous medium or a mixed liquid medium mainly composed of water is preferably used. Further, a surfactant (anionic type, nonionic type) may be added to the coating liquid in order to improve the wettability to the film.

  Next, an example in which the method for producing a thermoplastic resin film roll of the present invention is a laminated film will be described. In addition, it demonstrates by an example at the time of using polyester as a thermoplastic resin which comprises a laminated film.

  The polyester raw material used in the present invention can be produced by various commonly used esterification reactions, transesterification reactions, and subsequent polycondensation reactions. For example, polyethylene terephthalate can be usually produced by a method in which terephthalic acid or dimethyl terephthalate and ethylene glycol are esterified or transesterified, and then polycondensed under reduced pressure. Here, as the catalyst, for example, a compound containing an element such as manganese, magnesium, calcium, titanium, germanium, antimony, cobalt, or a phosphorus compound can be used. In addition, stabilizers, pigments, dyes, nucleating agents, fillers, and the like may be used.

  The polyester thus obtained is formed into particles (chip shape) by a sheet cutting method, a strand cutting method or the like. The shape of the chip may be arbitrary, but if it is too small and becomes a fine powder, it causes troubles in the heat treatment process and the subsequent molding process (especially the extrusion process). When the shape is large, there is no particular problem in terms of reducing the cyclic compound, but problems are likely to occur from the viewpoint of operability. From these viewpoints, the size of the polyester chip is preferably 1 mm to 50 mm, more preferably 2 mm to 20 mm in terms of equivalent sphere diameter. Here, the equivalent sphere diameter is the diameter of a sphere having the same volume as the particle.

  In order to form A layer on the magnetic layer processed surface side, dried polyester chips are supplied to Extruder A, and for forming B layer on the running surface side, polyester chips and inert particles α having an average particle diameter of 150 nm or more and less than 400 nm are used. And an inert particle β master chip having an average particle diameter of 400 nm or more and less than 1,200 nm, the inert particle α is 0.4 to 2.0% by weight, and the inert particle β is 0.01 to 0.3% by weight. Then, the mixture is fed to the extruder B, melted, introduced into the T die composite die, and joined to be laminated in two layers of A layer / B layer in the die, and then in sheet form Are coextruded into a melt-laminated sheet. The thickness ratio of the A layer / B layer is preferably 2/1 to 30/1.

  This melt-laminated sheet is closely cooled and solidified by static electricity on a drum cooled to a surface temperature of 10 to 60 ° C. to produce an unstretched laminated film. The unstretched film is guided to a roll group heated to 70 to 120 ° C., stretched 2 to 5 times in the longitudinal direction (longitudinal direction, that is, the traveling direction of the film), and cooled with a roll group of 20 to 30 ° C.

  Subsequently, the surface of the laminated film stretched in the longitudinal direction is subjected to a corona discharge treatment as it is or, if necessary, after which a slippery coating layer forming coating solution is applied. At this time, coating is performed so that the slippery coating layer C is provided on the A layer side and the slippery coating layer D is provided on the B layer side. At this time, 0.005 to 0.4% by weight of inorganic particles having an average particle diameter of 3 to 200 nm is contained in the easy-slip coating layer C. 2 to 5 times in the direction perpendicular to the longitudinal direction (lateral direction) in an atmosphere heated to 90 to 150 ° C while being guided to a tenter while holding both ends of the laminated film coated with this easy-sliding coating layer forming coating solution with clips Stretch to.

  The stretching ratio is preferably 2 to 5 times in the longitudinal and lateral directions, but the area ratio (longitudinal stretching ratio x lateral stretching ratio) is preferably 6 to 20 times. When the area magnification is less than 6 times, the obtained film strength is insufficient. Conversely, when the area magnification exceeds 20 times, the film tends to be broken during stretching.

  In order to complete the crystal orientation of the biaxially stretched laminated film thus obtained and to give flatness and dimensional stability, heat treatment is subsequently performed at 150 to 230 ° C. for 1 to 30 seconds in the tenter, The laminated film of the present invention can be obtained by uniformly cooling and then cooling to room temperature and winding. In addition, in the said heat processing process, you may give a 1-12% relaxation process (relaxation) to a horizontal direction or a vertical direction as needed. The biaxial stretching may be simultaneous biaxial stretching in addition to the above-described sequential stretching, and in-line coating in the case of simultaneous biaxial stretching is performed on the surface of the unstretched film obtained by tightly cooling and solidifying the molten sheet on the drum as necessary. After the corona discharge treatment, an easy-slip layer-forming coating solution may be applied and stretched. Further, after biaxial stretching, it may be re-stretched in either the longitudinal or transverse direction.

  The biaxially stretched laminated polyester film thus obtained is used as an intermediate product, slit into the product width using a slitter, and wound around a cylindrical core to obtain the laminated polyester film roll for magnetic recording media of the present invention. The film width of the film roll is preferably 500 to 1,000 mm, and the winding length is preferably 15,000 to 50,000 m.

  In order to obtain the laminated polyester film roll of the present invention, it is particularly preferable that the slit condition is within the following range, for example.

  (I) The slit winding pattern is basically based on the speed increasing portion (a1), the constant speed portion (b1), the speed reducing portion (c1), the constant speed portion (b2), the speed reducing portion ( It is preferable to configure as in c2) (Pattern 1: FIG. 1). Among these, the winding speed of the constant speed portion (b1) (steady winding portion) is preferably 80 to 450 m / min, more preferably 100 to 400 m / min, and the constant speed portion (b2) (low speed winding portion). Is preferably 1 to 80 m / min, more preferably 1.5 to 60 m / min. Moreover, it is preferable that ratio of both speed (constant speed part (b2) / constant speed part (b1)) is 0.005-0.2, More preferably, it is 0.01-0.1. When the speed ratio of each constant speed part is out of the above range, it becomes difficult to make the surface wrinkles within the range of the formulas (1) to (4). Further, it is more preferable to provide the speed increasing portion again in the middle of the speed reducing portion (c1) or the constant speed portion (b2) from the viewpoint of easily making the surface wrinkle within the range of the formulas (1) to (4). That is, in the order from the winding start to the winding end, the speed increasing part (a1), the constant speed part (b1), the speed reducing part (c1), the speed increasing part (a2), the speed reducing part (c2), the constant speed part (b2), Deceleration part (c3) (Pattern 2: FIG. 2) or acceleration part (a1), constant speed part (b1), deceleration part (c1), constant speed part (b2), acceleration part (a2), It is preferable to set it as the deceleration part (c2) (pattern 3: FIG. 3). Regarding the provision of the speed increasing portion again, a plurality of speed increasing portions may be provided in two or more sections, only in the speed reducing portion (c1) section, or only in the constant speed portion (b2) section, or the speed reducing portion (c1). ), May be provided in both sections of the constant speed portion (b2). As an example provided in both sections, a speed increasing part (a1), a constant speed part (b1), a speed reducing part (c1), a speed increasing part (a2), a speed reducing part (c2), a constant speed part (b2), a speed increasing part (A3), deceleration part (c3) (pattern 4: FIG. 4) is preferable. The acceleration for the speed increasing part (a1, a2, a3) and the deceleration for the speed reducing part (c1, c2, c3) are preferably 2-10 m / min / s (s represents sec), more Preferably it is 3-8 m / min / s. The speed increase of each speed increasing portion and the speed reduction of each speed reducing portion may be the same or different.

  (II) The tension is preferably 10 N / m to 45 N / m, more preferably 15 N / m to 35 N / m. Further, the surface pressure is preferably 100 N / m to 400 N / m, more preferably 150 N / m to 350 N / m. When the tension is less than 10 N / m or the surface pressure is less than 100 N / m, the film roll tends to contain a large amount of air, and the film roll winding shape tends to cause misalignment and may be immediately after winding. Film misalignment and may easily occur at the time of vacuum deaeration before vapor deposition or from the start of vapor deposition to the end of vapor deposition. On the other hand, if the tension is greater than 45 N / m or the surface pressure is greater than 400 N / m, wrinkles are likely to occur from the beginning of winding the slit, or the magnetic tape corresponding to the film roll core (end of the vapor deposition process) Characteristics are likely to deteriorate.

  It becomes possible to satisfy the formulas (1) to (4) for the surface layer wrinkles of the laminated polyester film roll by the production conditions as described above, and the currently required winding length is 15,000 m or more, and further 25,000 m or more. In addition, the film roll of the 30,000 to 50,000 m class, which is the ultimate target, has little lateral deviation at the time of vacuum degassing or at the start of vapor deposition in a high-speed vapor deposition process, and can realize stable processing characteristics.

  In order to satisfy the formulas (1) to (4), it is important to employ the above-mentioned production conditions, but in more detail, the following tendencies tend to be obtained. That is, by setting the slit winding pattern to patterns 2, 3, and 4, particularly pattern 2 or pattern 4, it becomes easy to control the value closer to the upper limit of each range of the formulas (1) to (4). On the contrary, in the pattern 1, it is possible to control the value closer to the lower limit of each range. Regarding the requirements of the equations (1) to (4), individually, regarding the total width of the surface wrinkles of (1), the greater the acceleration of the speed increasing portion 2 and the smaller the deceleration of the speed reducing portion 2, the more The width tends to increase. Regarding the generation length of the surface wrinkles of (2), the generation length tends to increase as the ratio of the speed of the constant speed portion (constant speed portion (b2) / constant speed portion (b1)) increases. The height of the surface wrinkles of (3) tends to increase as the tension and surface pressure increase. The number of surface wrinkles in (4) tends to increase as the tension and surface pressure increase.

  The laminated polyester film roll for a magnetic recording medium of the present invention has particularly good properties as a vapor-deposited magnetic recording medium and good processability to the vapor-deposited magnetic recording medium, and can be suitably used as a base substrate for the application. However, it can be suitably used not only as a vapor deposition type but also as a base substrate for a coating type magnetic recording medium.

  As a particularly preferable application, it is suitably used for a base film for magnetic tape of a digital data recording system such as digital video cassette, data storage, DLT, LTO, digital AIT, AIT turbo, etc. In particular, it is most preferably used as a base material for a digital video cassette tape in which a ferromagnetic metal thin film such as cobalt is deposited as a recording layer.

  The evaluation methods and evaluation criteria used in the examples of the present invention are as follows.

(1) Intrinsic viscosity of polymer Measured at 25 ° C. using orthochlorophenol as a solvent.

(2) Average particle size of particles (inert particles) Particles (inert particles) used on a microscope test stand are scattered so that these particles do not overlap as much as possible, and the particle size is measured by a transmission electron microscope (TEM). Accordingly, observation was performed at the following magnification, the area equivalent circle diameter was determined for at least 100 particles, and the number average value was used as the average particle diameter.

(Inert particle size)
1,000 nm or more: 50,000 times 500 nm or more and less than 1,000 nm: 100,000 times 300 nm or more and less than 500 nm: 200,000 times 300 nm or less: 300,000 times (3) Number of protrusions N _β derived from inert particles β on the surface of the B layer
The laminated film is cut out to 10 × 10 cm, the layer A side is painted with black magic, the layer B side is the top surface, and a surface shape measuring microscope manufactured by Keyence Corporation (measurement unit VF-7510, controller VF-7500) is used. The number of protrusions per unit area (1 mm ² ) was determined from an average value in 100 visual fields selected arbitrarily.

(4) Thicknesses of A layer, B layer, and slippery coating layers C, D A small piece of the laminated film was fixed with resin or ice, and an ultrathin section cut in parallel with the film longitudinal direction using a microtome was prepared. This ultrathin slice was observed by TEM at the following magnification according to the thickness, and the thicknesses of the A layer, the B layer, and the slippery coating layers C and D were determined. In addition, the measurement of both thickness was calculated | required from the average value of a total of 10 places, changing a place arbitrarily.

(A layer thickness)
12 μm or more: 5,000 times 8 μm or more and less than 12 μm: 10,000 times 5 μm or more and less than 8 μm: 20,000 times 3 μm or more and less than 5 μm: 30,000 times Less than 3 μm: 50,000 times (B layer thickness)
1,000 nm or more: 50,000 times 500 nm or more and less than 1,000 nm: 100,000 times 300 nm or more and less than 500 nm: 200,000 times 300 nm or less: 300,000 times (Thickness of the slippery coating layers C and D)
10 nm or more: 1 million times 5 nm or more and less than 10 nm: 2 million times Less than 5 nm: 5 million times (5) Average particle diameter and abundance of particles in easy-slip coating layer C Using a scanning electron microscope (SEM) From a SEM photograph taken at the following magnification according to the average particle diameter of the particles in the slippery coating layer C at any location on the laminated surface of the slippery coating layer C, a total of 100 fine particles arbitrarily selected The maximum diameter and the minimum diameter were measured, and the particle diameter of each particle was determined as an average of the maximum diameter and the minimum diameter. Furthermore, the average value of the particle diameters of the particles to be measured was calculated as the average particle diameter. Further, regarding the abundance density, the number of particles per sheet was counted from five SEM photographs obtained by photographing five arbitrary positions at the following magnification according to the average particle diameter of the particles in the easy-slip coating layer C, and five photographs. The number of particles per unit area was calculated from the average value of the value to determine the existence density.

(Average particle size)
25 nm or more and less than 50 nm: 300,000 times 15 nm or more and less than 25 nm: 500,000 times Less than 15 nm: 1 million times (existence density)
25 nm or more and less than 50 nm: 10,000 times 15 nm or more and less than 25 nm: 30,000 times 8 nm or more and less than 15 nm: 50,000 times Less than 8 nm: 100,000 times (6) Film surface roughness (centerline average surface roughness Ra)
Measurement was performed using a desktop probe microscope “Nanopics” (measurement head NPX100 [NPX1MAP001] and controller Nanopics1000 [NPX1EBP001]) manufactured by Seiko Instruments Inc. The measurement area was 40 μm square on the A layer (magnetic layer processed surface) side and 100 μm square on the B layer (running surface) side. Other measurement conditions are as follows.

Scan speed: 380 sec / FRAME
Number of scans: 512 Amplitude degree: LL mode on the magnetic layer processed surface side, HH mode on the traveling surface side (7) Total thickness of film Using a dial gauge, find the thickness ΣH (μm) of 10 stacked films, The value obtained by multiplying ΣH by 0.1 was defined as the total thickness H (μm) of the film.

(8) Surface layer wrinkle After the roll roll of the film roll, the surface layer wrinkle after 5 hours was evaluated as follows. In addition, 10 film rolls were sampled under the same raw material formulation, film forming conditions, and slit conditions, and after evaluating the total width, height, and number of each, five arbitrary rolls were selected and the generation length was evaluated. Furthermore, vapor deposition processing appropriateness and magnetic tape characteristics were evaluated for the remaining five.

(8-1) Ratio of Total Width to Film Width The width D (mm) of the surface wrinkle generating portion in the film roll width direction was measured using a measure. When multiple surface wrinkles are generated, the total width ΣD (mm) is calculated for the total, and when the film roll width is M (mm), the ratio of the surface wrinkles to the film width is ΣD / M × 100 (%) As sought.

(8-2) Generation length Cut the film roll surface layer part until the surface layer wrinkles disappear or turn it over and remove it. The film weight W (kg) of the removed portion was measured, and the generation length L (m) of the surface wrinkles was determined from the total film thickness H (μm), the film width M (mm) and the following formula.

L = (1,000 × W) / (1.4 × H × M)
(8-3) Height The displacement profile in the width direction (film lateral direction) of the roll diameter was measured using an original fabric shape measuring instrument (manufactured by Kitano Planning Co., Ltd.). A linear gauge (LGB-100), which is a detector attached to the measuring instrument, is brought into contact with the surface of the product roll and travels on a dedicated rail at a speed of 12.5 mm / sec, in the width direction from both ends of the product roll. It was allowed to pass through (the (both) end portions referred to here indicate a portion entering 5 mm inside from the roll end portion). The change in the roll diameter detected by the detection unit was output via the D / A conversion unit (LG-DA1) and the linear gauge counter (LG-S1), and recorded on the chart recorder at a chart speed of 200 mm / min. The surface wrinkle height was obtained by reading the amount of change of the portion corresponding to the surface wrinkle from the obtained chart, using the portion without surface wrinkle as the baseline. When the surface wrinkles are convex, the vertical distance from the baseline to the maximum height (see Fig. 5) is read. When the surface wrinkles are concave, the vertical distance from the baseline to the maximum depth (see Fig. 6) is read. The surface wrinkle height. However, when the surface wrinkle has a convex shape with a convex center at both ends, or a concave shape at both ends, or a convex shape at both ends, the former is the vertical distance from the base line connecting the concaves at both ends to the maximum height of the central convexity (Figure 7), the latter reads the vertical distance (see FIG. 8) from the base line connecting the protrusions at both ends to the maximum depth of the central recess and determines the surface wrinkle height.

(8-4) Number Even if the film roll circumferential direction (film longitudinal direction) is completely continuous or non-continuous, the adjacent distance is 100 mm or less in the circumferential direction, 50 mm or less in the width direction, and the total length of the surface wrinkles is a film roll circle. When the circumference is 60% or more, it is regarded as a continuous surface wrinkle, and this is regarded as one surface wrinkle, and the total number n of surface wrinkles in the width direction on the film roll surface is counted, and from the film width M (mm) The number N per 1,000 mm width was calculated from the following formula.

N = n / M × 1,000
(9) Vapor Deposition Processing Appropriate deviation and good at the time of vacuum deaeration and at the start of vapor deposition in the vapor deposition process were evaluated as follows.

(9-1) At the time of vacuum degassing A film roll is installed in the vapor deposition machine, and low-speed exhaust (a degree of pressure reduction of 2 × 10 ⁻² Pa is reached in 45 minutes from the start of exhaust) and high-speed exhaust (2 × in 15 minutes from the start of exhaust). The state of misalignment and mayoi when vacuum deaeration was performed at 10 ⁻² Pa was observed, and the determination was made according to the following four criteria. ◎ or ○ was accepted. Of the five film rolls used, the one with the worst judgment was used as the representative result.

Neither deviation nor mayoi: ◎
Misalignment or Mayoy width is less than 10mm: ○
Misalignment or Mayoy width of 10 mm or more and less than 100 mm: Δ
Misalignment or Mayoi width of 100mm or more: ×
Here, the deviation means that a part of the surface layer of the film has moved in one direction of the width direction of the film roll, and the “mayoy” means that a part of the surface layer of the film has moved in both the width direction of the film roll. Represents that. Of the five film rolls used, the one with the worst judgment was used as the representative result.

(9-2) At the start of vapor deposition After vacuum deaeration in the vapor deposition process, the film roll conveyance start state at low acceleration (1 m / min / sec) and high acceleration (8 m / min / sec) at the start of vapor deposition was observed. The determination was made according to the following four criteria. ◎ or ○ was accepted.

Neither deviation nor mayoi: ◎
Misalignment or Mayoy width is less than 10mm: ○
Misalignment or Mayoy width of 10 mm or more and less than 100 mm: Δ
Misalignment or Mayoi width of 100mm or more: ×
(10) Magnetic tape characteristics A magnetic tape (DVC tape) was prepared from a film roll by the method described later. At this time, the vapor deposition process was performed under conditions of high-speed exhaust and high acceleration. Recording and playback were performed in a quiet room using the LP mode of a commercially available camera-integrated digital video tape recorder, and the number of dropouts was determined. To measure the number of dropouts, the DVC tape produced by the method described in Example 1 was recorded with a commercially available camera-integrated digital video tape recorder, played back for 10 minutes, and the number of block mosaics that appeared on the screen. Done by counting. The initial characteristics after tape production were measured by the number of dropouts (DO) of the film roll surface layer equivalent part and the film roll core equivalent part. The smaller the number of DOs, the better the tape characteristics. The number of DO was measured under the conditions of a temperature of 25 ° C. and a relative humidity of 65%.

Example 1
(1) Production of Polyester Raw Material 100 parts by weight of dimethyl terephthalate and 64 parts by weight of ethylene glycol were weighed as raw materials and charged into a transesterification reactor. After charging the raw materials, the temperature in the apparatus was heated to 150 ° C. to dissolve the contents and stirred. Next, 0.06 parts by weight of magnesium acetate tetrahydrate and 0.03 parts by weight of antimony trioxide were weighed as catalysts while stirring, and charged into a transesterification reactor.

  After the catalyst was charged, the temperature of the reaction contents was increased from 150 ° C. to 235 ° C. over 3 hours to proceed the transesterification reaction, and the methanol produced was distilled from the reactor.

  When the transesterification reaction was completed and methanol was no longer distilled, 0.023 parts by weight of trimethyl phosphoric acid was added.

  Ten minutes after the addition of the particle slurry, the reaction product in the transesterification reactor was transferred to the polymerization reactor.

  While stirring the contents of the polymerization apparatus, the temperature was raised from 235 ° C. to 290 ° C. over 120 minutes, and at the same time, the pressure in the reaction apparatus was reduced from normal pressure to 150 Pa or less over 120 minutes.

  After the stirring torque of the polymerization apparatus reached a predetermined value, the stirring of the polymerization apparatus was stopped, and nitrogen gas was fed into the polymerization apparatus to return to normal pressure.

  The valve at the bottom of the polymerization apparatus was opened, and the polyester resin was extruded in a strand form while pressurizing the apparatus with nitrogen gas. The strand was cooled and solidified in a water tank, led to a cutter, and a cylindrical polyethylene terephthalate (hereinafter referred to as PET) chip having a diameter of about 5 mm and a length of about 7 mm was obtained. This PET chip had an equivalent spherical diameter of 6.4 mm and an intrinsic viscosity of 0.63.

(2) Manufacture of polyester film In order to form A layer, after drying PET chip manufactured by the method of said (1) at 180 degreeC for 3 hours, it is supplied to the extruder A, and is melted at 285 degreeC by a conventional method. And introduced into the T-die composite base.

  On the other hand, in order to form the B layer, based on PET, 0.43% by weight of crosslinked styrene-divinylbenzene particles having an average particle diameter of 340 nm as inert particles α and crosslinked styrene having an average particle diameter of 830 nm as inert particles β -Chip raw material containing 0.035% by weight of divinylbenzene particles was dried under reduced pressure at 180 ° C for 3 hours, then supplied to the extruder B side, and melted at 285 ° C by a conventional method. Introduced. The production and addition method of the crosslinked styrene-divinylbenzene particles is as follows.

(Method for producing and adding crosslinked styrene-divinylbenzene)
"Polymer Papers" Vol. 31, no. 9 (issued in September 1974) on the basis of the technique described on pages 576 to 586.

  Specifically, 30 ml of styrene, 1.36 g of “Emulgen” 920 (manufactured by Kao Atlas Co., Ltd.) and 1.36 g of “Pronon” 208 (manufactured by NOF Corporation) are dissolved in 170 ml of water as emulsifiers. As a polymerization initiator, 136 mg of potassium persulfate, 136 mg of sodium thiosulfate, and 204 mg of benzoyl peroxide were added and reacted at 35 ° C. for 48 hours in a nitrogen atmosphere to prepare an aqueous dispersion of styrene seed particles. Next, 45 ml of water, 20 ml of divinylbenzene and 10 ml of styrene are added to 100 ml of this aqueous dispersion, and 0.9 g each of “Emulgen” 920 and “Pronon” 208 are added, and the reaction is carried out at 70 ° C. for 20 hours in a nitrogen atmosphere. Thus, an aqueous slurry containing crosslinked styrene-divinylbenzene having an average particle diameter of 340 nm in which styrene and divinylbenzene were crosslinked in the seed particles was obtained.

  On the other hand, 45 ml of water, 20 ml of divinylbenzene and 10 ml of styrene were added to 100 ml of an aqueous dispersion of styrene seed particles reacted at 40 ° C. for 72 hours, and 0.9 g each of “Emulgen” 920 and “Pronon” 208 were added. The slurry was reacted at 70 ° C. for 30 hours in a nitrogen atmosphere to obtain a water slurry containing crosslinked styrene-divinylbenzene having an average particle diameter of 830 nm in which styrene and divinylbenzene were crosslinked in seed particles.

  A PET chip raw material containing a crosslinked styrene-divinylbenzene obtained by adding a PET chip and a water slurry of crosslinked styrene-divinylbenzene having an average particle diameter to a predetermined particle composition in a biaxial kneader with a vent was used. .

Subsequently, after making it join so that it might be laminated | stacked by the thickness ratio of A layer / B layer = 7/1 in this nozzle | cap | die, it coextruded in the sheet form and was set as the melt lamination sheet. Then, the molten sheet was closely cooled and solidified by an electrostatic charge method on a cooling drum maintained at a surface temperature of 25 ° C. so that the B layer was on the drum side to obtain an unstretched laminated film. Subsequently, the unstretched laminated film is stretched 3.0 times in the longitudinal direction (hereinafter referred to as MD) using a roll group heated to 105 ° C. according to a conventional method, and cooled and uniaxially stretched with a roll group at 25 ° C. A film was obtained. Further, a metal coating bar having a wet coating thickness of 5.0 μm and 2.7 μm, respectively, is formed on the surface of the B layer and A layer side of the uniaxially stretched film with an easy-to-slip coating layer C and D forming coating solution (aqueous solution) having the following composition. It was applied by a bar coat method using
[Easy-slip coating layer D forming coating solution]
Water-soluble polyester 0.23% by weight
Methylcellulose 0.17% by weight
Silane coupling agent 0.02% by weight
[Ease of slippery coating layer C]
Water-soluble polyester 0.31% by weight
Methyl cellulose 0.10% by weight
Colloidal silica with an average particle diameter of 18 nm 0.04% by weight
The manufacturing method of each composition is as follows.

(Water-soluble polyester)
Acid content: terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid = 34/8/8 (mol%)
Glycol component: ethylene glycol / neopentyl glycol / diethylene glycol = 40/7/3 (mol%)
It is a polyester having no carboxylic acid group in the side chain, obtained by transesterification using the acidic component and glycol component.

(Methylcellulose)
Cellulose (pulp) treated with sodium hydroxide and then reacted with ethylene oxide to form water-soluble cellulose ether (average number of hydroxyl groups substituted with methoxyl groups per glucose ring unit of cellulose) .

(Silane coupling agent)
(1) γ-aminopropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd. KBE903)
(2) γ-glycidoxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd. KBM403)
It is a mixture obtained by mixing the above (1) / (2) at a weight ratio of 75/25.

(Colloidal silica with an average particle diameter of 18 nm)
It was manufactured with reference to the techniques described on pages 330 to 331 of “New Experimental Chemistry Course” 18 interface and colloid (published on Mar. 20, 1977).

Specifically, a 2.5 wt% aqueous solution of sodium silicate (in terms of SiO ₂ ) was desalted with an H-type ion exchange resin, and a 1.0 wt% aqueous sodium hydroxide solution was added to adjust the pH to 9. The reaction was conducted by heating at 85 ° C. for 10 minutes while stirring to obtain an aqueous dispersion containing colloidal silica having an average particle diameter of 18 nm.

  While holding both ends of the uniaxially stretched film coated with the easy-to-slip coating layers C and D with a clip, it is guided to a preheating zone in the tenter, preheated and dried at 105 ° C, and then continuously heated to 110 ° C. The film was stretched 3.8 times in the transverse direction (hereinafter referred to as TD). Subsequently, a heat treatment at 210 ° C. is performed in the heat treatment zone in the tenter to complete the crystal orientation, and after uniform cooling, the film is wound up, and the total thickness of the laminated polyester film is 6.3 μm, of which the B layer has a thickness of 800 nm, An intermediate product of a laminated polyester film having a thickness of 5.9 nm of the coating layer C and a thickness of 3 nm of the slippery coating layer D was obtained.

  The obtained laminated polyester film intermediate product was further slit with a slitter to a width of 620 mm and a winding length of 23,000 m to obtain a laminated polyester film roll. At this time, the slit winding conditions were tension = 30 N / m and surface pressure = 220 N / m. The slit pattern is pattern 2, the speed of the constant speed part (b1) is 150 m / min, the speed of the constant speed part (b2) is 8 m / min, and the speed increase of the speed increasing parts (a1, a2) is 3.2 m. / Min / s, and the deceleration of the deceleration parts (c1, c2) was 6.2 m / min / s. The speed increasing portion at the time of 1/2 of the deceleration portion (c1) with respect to the pattern 1 (that is, when the speed reaches (the speed of the constant speed portion (b1) −the speed of the constant speed portion (b2)) / 2). (A2).

  Next, cobalt was deposited on the film A layer side of the laminated polyester film roll by a vacuum deposition method to form a 110 nm thick ferromagnetic metal thin film layer. At this time, the vapor deposition process was performed under conditions of high-speed exhaust and high acceleration. Next, a diamond-like carbon film was formed with a thickness of 10 nm by a sputtering method, and a fluorine-based lubricant layer was provided with a thickness of 6 nm. Subsequently, a back coat layer made of carbon black, polyurethane, and silicone is provided on the B layer with a thickness of 400 nm, slitted to a width of 6.35 mm by a slitter, and a magnetic tape (DVC tape) for vapor deposition magnetic recording medium is prepared. Produced.

  The properties of the laminated polyester film are shown in Table 1, the slit winding conditions are shown in Table 2, the properties of the film roll, the suitability for vapor deposition processing, and the magnetic tape properties are shown in Table 3. The surface wrinkles satisfy all the requirements (1) to (4), and there is no or no misalignment even at the start of vacuum degassing by high-speed exhaust and deposition by high acceleration. The processability was demonstrated, and the characteristics of the obtained magnetic tape were good both in the film roll surface layer part and the core part.

(Example 2)
As shown in Tables 2 and 3, in Example 1, the winding length was changed to 47,000 m, the slit winding condition tension was 35 N / m, the surface pressure was 280 N / m, and the speed increasing part (a2) A laminated polyester film roll was obtained in the same manner as in Example 1 except that the increasing rate was changed to 7.5 m / min / s.

  As shown in Table 3, this film roll was good in both vapor deposition suitability and magnetic tape characteristics.

(Example 3)
As shown in Tables 2 and 3, in Example 1, the width was changed to 930 mm, the winding length was changed to 17,000 m, the slit winding condition tension was 18 N / m, the surface pressure was 330 N / m, and the constant speed part A laminated polyester film roll was obtained in the same manner as in Example 1 except that the speed of (b1) was changed to 340 m / min and the speed of the constant speed part (b2) was changed to 60 m / min.

  As shown in Table 3, this film roll was good in both vapor deposition suitability and magnetic tape characteristics.

Example 4
As shown in Tables 2 and 3, in Example 1, the winding length was changed to 30,000 m, the slit pattern of the slit winding condition was changed to Pattern 3, and the speed of the constant speed part (b1) was 250 m / min. The speed of the constant speed part (b2) is 2 m / min, the speed of the speed increasing part (a1, a2) is 5.0 m / min / s, and the speed of the speed reducing part (c1, c2) is 2.5 m / min. A laminated polyester film roll was obtained in the same manner as in Example 1 except that the value was changed to min / s. It should be noted that the speed is increased at the time of 1/2 of the constant speed portion (b2) with respect to the slit pattern 1 (that is, when the time of 1/2 of the winding time at the constant speed portion (b2) in the pattern 1 has elapsed). Part (a2).

  As shown in Table 3, this film roll was good in both vapor deposition suitability and magnetic tape characteristics.

(Example 5)
As shown in Tables 2 and 3, in Example 1, the width was changed to 810 mm, the winding length was changed to 25,000 m, the tension of the slit winding condition was 40 N / m, the surface pressure was 170 N / m, and the slit pattern was A laminated polyester film roll was obtained in the same manner as in Example 1 except that the speed of the constant speed part (b1) was changed to 200 m / min and the speed of the constant speed part (b2) was changed to 20 m / min. It was.

  As shown in Table 3, this film roll was good in both vapor deposition suitability and magnetic tape characteristics.

(Example 6)
As shown in Table 1, in Example 1, the particle composition contained in the B layer is 0.55% by weight of a crosslinked silicone having an average particle size of 220 nm as an inert particle α (manufacturing and adding method is as follows). Spherical silica having an average particle diameter of 1,000 nm was changed to 0.20% by weight as the active particles β (manufacturing and addition method is as follows), and the lamination ratio in the T-die composite die was set to A layer / B layer = 10. / 1, the thickness of the B layer was 560 nm, and colloidal silica contained in the slippery coating layer D having an average particle diameter of 10 nm was used, and the content in the coating solution was 0.015% by weight (production) A laminated polyester film was obtained in the same manner as in Example 1 except that the method was as follows.

  Next, this laminated polyester film was wound in the same manner as in Example 5 except that the width was 620 mm, the winding length was 40,000 m, the tension was 27 N / m, and the surface pressure was 260 N / m. A laminated polyester film roll was obtained.

  As shown in Table 3, this film roll was good in both vapor deposition suitability and magnetic tape characteristics.

(Method for producing crosslinked silicone having an average particle size of 220 nm)
It was produced with reference to the example of Japanese Patent Publication No. 3-30620.

Specifically, the average composition formula _{CH 2 = CH (CH 3)} 2 SiO [(CH 3) 2 Si0] m · Si (CH 3) 2 CH = CH 2
(CH ₃ ) ₃ SiO [(CH ₃ ) HSiO] ₃ 0Si (CH ₃ ) _{3 in} 100 parts by weight of dimethylpolysiloxane having vinyl groups represented by the formula (m = 30) at both ends
5 parts by weight of methylhydropolysiloxane represented by the formula, an isopropyl alcohol solution of chloroplatinic acid in an amount corresponding to 10 ppm by weight of platinum with respect to the total amount of the polysiloxane, and 3-methyl-1-butyn-3-ol 0 The mixture obtained by adding 1 part by weight was sprayed into a spray dryer using a two-fluid nozzle and cured to obtain crosslinked silicone particles. At this time, the inlet temperature of the hot air of the spray dryer was 230 ° C. The crosslinked silicone was collected by a cyclone and a back filter, and a back filter collection (average particle size 220 nm) was used.

(Method for producing spherical silica having an average particle diameter of 1,000 nm)
It was manufactured with reference to the techniques described on pages 330 to 331 of “New Experimental Chemistry Course” 18 interface and colloid (published on Mar. 20, 1977).

Specifically, a 3.5 wt% aqueous solution of sodium silicate (in terms of SiO ₂ ) was desalted with an H-type ion exchange resin, and adjusted to pH 9 by adding a 1.5 wt% aqueous sodium hydroxide solution thereto. . A part of this aqueous solution was collected, heated at 100 ° C. for 10 minutes with stirring, and then maintained at 90 ° C. Next, a sodium silicate aqueous solution desalted to this aqueous solution and adjusted to pH = 9 was gradually added with stirring to carry out the reaction to obtain an aqueous dispersion containing 220 nm silica particles. A part of this aqueous solution was separated again, heated at 100 ° C. for 10 minutes with stirring, and then maintained at 90 ° C. Next, a sodium silicate aqueous solution desalted to this aqueous solution and adjusted to pH = 9 was gradually added with stirring to carry out the reaction, thereby obtaining an aqueous dispersion containing silica having an average particle diameter of 1,000 nm.

(Method for adding crosslinked silicone and spherical silica)
The obtained crosslinked silicone was dispersed in ethylene glycol to form a 10 wt% ethylene glycol slurry. On the other hand, ethylene glycol was added to the obtained spherical silica aqueous solution and heated to 100 ° C. to distill water to obtain a 10 wt% ethylene glycol slurry of spherical silica.

  In the production of the polyester raw material of (1) of Example 1, 5.5 parts by weight of an ethylene glycol slurry containing 10% by weight of a crosslinked silicone was spherically added 5 minutes after the transesterification reaction was completed and trimethyl phosphoric acid was added. 2 parts by weight of an ethylene glycol slurry containing 10% by weight of silica was added.

(Method for producing colloidal silica having an average particle diameter of 10 nm)
In the production of colloidal silica of Example 1, 1.0% by weight sodium hydroxide aqueous solution was added to adjust the pH to 9, and then the reaction was carried out by heating at 85 ° C. for 5 minutes with stirring to obtain colloidal silica having an average particle size of 10 nm. An aqueous dispersion containing was obtained.

(Example 7)
As shown in Table 1, in Example 1, the particle composition contained in the B layer is 0.40% by weight of a crosslinked silicone having an average particle size of 220 nm as an inert particle α (addition method is as follows), inert particles The cross-linked silicone having an average particle diameter of 550 nm is changed to 0.012% by weight as β (manufacturing and addition method is as follows), and the stacking ratio in the T-die composite die is A layer / B layer = 14/1. The thickness of the layer was 410 nm, and the colloidal silica contained in the easy-sliding coating layer D had an average particle diameter of 24 nm, and the content in the coating liquid was 0.065 wt% (the manufacturing method was as follows) A laminated polyester film was obtained in the same manner as in Example 1 except that.

  Next, the laminated polyester film was subjected to slit winding in the same manner as in Example 2 except that the width was 560 mm, the winding length was 40,000 m, and the tension was 25 N / m to obtain a laminated polyester film roll. It was.

  As shown in Table 3, this film roll was good in both vapor deposition suitability and magnetic tape characteristics.

(Production method and addition method of crosslinked silicone)
In the production method of the crosslinked silicone of Example 1, except that the compound represented by m = 52 in the chemical formula of dimethylpolysiloxane having vinyl groups at both ends was used, the crosslinked silicone having an average particle size of 550 nm was produced. Silicone was obtained. The resulting crosslinked silicone was then dispersed in ethylene glycol to give a 1 wt% ethylene glycol slurry.

  In the production of the polyester raw material of (1) of Example 1, the transesterification reaction was completed, and 5 minutes after the addition of trimethyl phosphoric acid, 10% by weight of the crosslinked silicone having an average particle size of 220 nm obtained in Example 2 was contained. 4.0 parts by weight of ethylene glycol slurry and 1.2 parts by weight of ethylene glycol slurry containing 1% by weight of the above crosslinked silicone having an average particle diameter of 550 nm were added.

(Method for producing colloidal silica having an average particle size of 24 nm)
In the production of colloidal silica of Example 1, 1.0% by weight aqueous sodium hydroxide solution was added to adjust the pH to 9, followed by reaction by stirring at 85 ° C. for 15 minutes with stirring to produce colloidal silica having an average particle size of 24 nm. An aqueous dispersion containing was obtained.

(Comparative Example 1)
As shown in Tables 2 and 3, in Example 6, a laminated polyester film roll was obtained in the same manner as in Example 6 except that the slit pattern under the slit winding condition was changed to Pattern 1.

  As shown in Table 3, this film roll had good magnetic tape characteristics, but it was suitable for vapor deposition processing, especially when it was vacuum degassed at high speed exhaust or at the start of vapor deposition at high acceleration. Decreased, and the vapor deposition processing suitability was poor.

(Comparative Example 2)
As shown in Table 1, the particle composition contained in the B layer is 0.43 wt% of crosslinked styrene-divinylbenzene having an average particle diameter of 340 nm as inert particles α and styrene having an average particle diameter of 480 nm as inert particles β. Divinylbenzene (manufacturing method and addition method are as follows) is changed to 0.001% by weight, the stacking ratio in the T-die composite die is set to A layer / B layer = 12/1, and the thickness of B layer is 500 nm. A laminated polyester film was produced in the same manner as in Example 1 except that.

  Next, the laminated polyester film was slit and wound in the same manner as in Example 1 to obtain a laminated polyester film roll.

  As shown in Table 3, the film roll had good vapor deposition suitability, but was inferior in magnetic tape characteristics, particularly in output characteristics corresponding to the film roll surface layer portion.

(Method for producing crosslinked styrene-divinylbenzene having an average particle size of 480 nm)
In the production of the crosslinked styrene-divinylbenzene of Example 1, 45 ml of water, 20 ml of divinylbenzene and 10 ml of styrene were added to 100 ml of an aqueous dispersion of seed particles of styrene reacted at 35 ° C. for 62 hours, “Emulgen” 920 and “Pronon”. 0.9 g of each of “208” was added and reacted in a nitrogen atmosphere at 70 ° C. for 24 hours, and water containing crosslinked styrene-divinylbenzene having an average particle diameter of 480 nm in which styrene and divinylbenzene were crosslinked in seed particles. A slurry was obtained.

  A crosslinked styrene-divinylbenzene-containing PET chip raw material obtained by adding a PET chip and an aqueous slurry of crosslinked styrene-divinylbenzene having an average particle size of 480 nm to a biaxial kneader with a vent so as to have a predetermined particle composition was used.

(Comparative Example 3)
As shown in Table 1, the particle composition contained in the B layer is defined as inert particles α, and spherical silica having an average particle diameter of 220 nm (manufacturing method and addition method are as follows), 0.43% by weight, and inert particles β. The cross-linked silicone having an average particle size of 720 nm is changed to 0.1% by weight (manufacturing method and addition method are as follows), and the layering ratio in the T-die composite die is set as A layer / B layer = 5/1. The thickness of the coating liquid was set to 1,050 nm, and the colloidal silica contained in the slippery coating layer D had an average particle diameter of 6 nm, and the content in the coating solution was 0.004% by weight. Produced a laminated polyester film in the same manner as in Example 1.

  Next, the laminated polyester film was slit and wound in the same manner as in Example 6 except that the winding length was 30,000 m to obtain a laminated polyester film roll.

  As shown in Table 3, this film roll had good vapor deposition suitability, but was inferior in magnetic tape characteristics, particularly in output characteristics corresponding to the film roll core portion.

(Method for producing spherical silica having an average particle size of 220 nm)
A 3.5 wt% aqueous solution of sodium silicate (in terms of SiO ₂ ) is desalted with an H-type ion exchange resin, and a 1.5 wt% aqueous sodium hydroxide solution is added thereto to adjust the pH to 9. A part of this aqueous solution is taken, heated at 100 ° C. for 10 minutes with stirring, and then kept at 90 ° C. Next, a sodium silicate aqueous solution desalted to this aqueous solution and adjusted to pH = 9 was gradually added with stirring to carry out the reaction, thereby obtaining an aqueous dispersion containing 220 nm spherical silica particles.

(Method for producing and adding crosslinked silicone having an average particle size of 720 nm)
In the production method of the crosslinked silicone of Example 1, except that the compound represented by m = 60 in the chemical formula of the dimethylpolysiloxane having vinyl groups at both ends was used, the crosslinked silicone having an average particle size of 720 nm was produced. Silicone was obtained.

(Method for adding spherical silica and crosslinked silicone)
Ethylene glycol was added to the resulting aqueous solution of spherical silica and heated to 100 ° C. to distill water to obtain a 10 wt% ethylene glycol slurry of spherical silica. On the other hand, the crosslinked silicone was dispersed in ethylene glycol to form a 5 wt% ethylene glycol slurry.

  In the production of the polyester raw material of (1) in Example 1, the transesterification reaction was completed, and 5 minutes after the addition of trimethyl phosphoric acid, 2 parts by weight of ethylene glycol slurry containing 5% by weight of crosslinked silicone and spherical silica were added. 4.3 parts by weight of ethylene glycol slurry containing 10% by weight was added.

(Comparative Example 4)
As shown in Table 1, the particle composition contained in the B layer was 0.60% by weight of crosslinked styrene-divinylbenzene having an average particle size of 340 nm as inert particles α and styrene having an average particle size of 480 nm as inert particles β. The same as Comparative Example 2, except that divinylbenzene was changed to 0.03% by weight, the lamination ratio in the T-die composite die was A layer / B layer = 30/1, and the thickness of B layer was 200 nm. A laminated polyester film was manufactured.

  Next, the laminated polyester film was slit and wound in the same manner as in Example 1 except that the winding length was 40,000 m to obtain a laminated polyester film roll.

  As shown in Table 3, the film roll had good vapor deposition suitability, but was inferior in magnetic tape characteristics, particularly in output characteristics corresponding to the film roll surface layer portion.

(Comparative Example 5)
As shown in Table 1, the particle composition contained in the B layer is 0.22% by weight of spherical silica having an average particle size of 220 nm as inert particles α (addition method is as follows), and the average particle size as inert particles β. The spherical silica of 1,500 nm is changed to 0.001% by weight (manufacturing method and addition method are as follows), and the lamination ratio in the T-die composite die is set to A layer / B layer = 30/1, and B layer A laminated polyester film was produced in the same manner as in Example 7 except that the thickness of the laminate was 200 nm.

  Next, the laminated polyester film was subjected to slit winding in the same manner as in Comparative Example 1 to obtain a laminated polyester film roll.

  As shown in Table 3, this film roll had good magnetic tape characteristics but was inferior in vapor deposition processing suitability.

(Method for adding spherical silica having an average particle size of 220 nm)
In the production of the polyester raw material of (1) in Example 1, the transesterification reaction was completed, and 5 minutes after the addition of trimethyl phosphoric acid, 2.2 parts by weight of ethylene glycol slurry containing 10% by weight of spherical silica was added. .

(Method for producing and adding spherical silica having an average particle diameter of 1,500 nm)
A part of the aqueous dispersion containing silica having an average particle diameter of 1,000 nm obtained in Example 1 is further collected, heated at 100 ° C. for 15 minutes with stirring, and then maintained at 90 ° C. Next, a sodium silicate aqueous solution desalted to this aqueous solution and adjusted to pH = 9 was gradually added with stirring to carry out the reaction to obtain an aqueous dispersion containing spherical silica having an average particle diameter of 1,500 nm.

  Ethylene glycol was added to the obtained spherical silica aqueous solution and heated to 100 ° C. to distill water to obtain a 0.1 wt% ethylene glycol slurry of silica.

  In the production of the polyester raw material of (1) in Example 1, 1 part by weight of ethylene glycol slurry containing 0.1% by weight of spherical silica was added 5 minutes after the transesterification reaction was completed and trimethyl phosphoric acid was added. .

(Comparative Example 6)
As shown in Table 1, in Example 1, 0.01% by weight of spherical silica having an average particle size of 120 nm is contained in the A layer as an inert particle (manufacturing method and addition method are as follows), and are contained in the B layer. The particle composition is 0.29% by weight of spherical silica having an average particle size of 120 nm with inert particles α (the production method and addition method are as follows), and 0.015 of crosslinked silicone with an average particle size of 500 nm as inert particles β. (The manufacturing method and addition method are as follows), the lamination ratio in the T-die composite die is A layer / B layer = 12/1, the thickness of B layer is 500 nm, and the total film thickness is The thickness was changed to 5.2 μm. A laminated polyester film was produced in the same manner as in Example 1 except that the slippery coating layer C was not provided on the outer surface of the A layer.

  Next, the laminated polyester film was slit and wound in the same manner as in Comparative Example 1 except that the winding length was 20,000 m, to obtain a laminated polyester film roll.

  As shown in Table 3, this film roll had good magnetic tape characteristics but was inferior in vapor deposition processing suitability.

(Method for producing spherical silica having an average particle size of 120 nm)
A 3.5 wt% aqueous solution of sodium silicate (in terms of SiO ₂ ) is desalted with an H-type ion exchange resin, and a 1.5 wt% aqueous sodium hydroxide solution is added thereto to adjust the pH to 9. A part of this aqueous solution is taken, heated at 100 ° C. for 5 minutes with stirring, and then kept at 90 ° C. Next, a sodium silicate aqueous solution desalted to this aqueous solution and adjusted to pH = 9 was gradually added with stirring to carry out the reaction to obtain an aqueous dispersion containing 120 nm spherical silica particles.

(Method for producing crosslinked silicone having an average particle size of 500 nm)
In the production method of the crosslinked silicone of Example 1, except that the compound represented by m = 50 in the chemical formula of dimethylpolysiloxane having vinyl groups at both ends was used, a crosslinked product having an average particle diameter of 500 nm was produced. Silicone was obtained. The resulting crosslinked silicone was then dispersed in ethylene glycol to give a 1 wt% ethylene glycol slurry.

(Addition method of spherical silica and crosslinked silicone)
Ethylene glycol was added to the aqueous spherical silica solution obtained above, and water was distilled by heating to 100 ° C. to prepare a 1 wt% ethylene glycol slurry and 10 wt% ethylene glycol slurry of spherical silica. .

In the production of the polyester raw material of (1) in Example 1, 1 part by weight of ethylene glycol slurry containing 1% by weight of spherical silica was added 5 minutes after the transesterification reaction was completed and trimethyl phosphoric acid was added. The obtained PET chip was used as the raw material for the A layer.
On the other hand, in the production of the polyester raw material 1), 5 minutes after the completion of the transesterification reaction and the addition of trimethyl phosphoric acid, 2.9 parts by weight of ethylene glycol slurry containing 10% by weight of spherical silica and 1 part of crosslinked silicone were added. 1.5 parts by weight of ethylene glycol slurry containing wt% was added.

(Comparative Example 7)
As shown in Table 1, the particle composition contained in the layer B does not contain inert particles α, and 0.36% by weight of spherical silica having an average particle size of 220 nm as inert particles β (addition method is as follows) In addition, a laminated polyester film was produced in the same manner as in Example 1 except that the lamination ratio in the T-die composite die was A layer / B layer = 6/1 and the thickness of the B layer was 900 nm. .

  Next, the laminated polyester film was slit and wound in the same manner as in Example 4 except that the winding length was 20,000 m to obtain a laminated polyester film roll.

  As shown in Table 3, this film roll had good vapor deposition suitability, but was inferior in magnetic tape characteristics, particularly output characteristics corresponding to the film roll surface layer.

(Method for adding spherical silica)
In the production of the polyester raw material of (1) of Example 1, 5 minutes after the completion of the transesterification reaction and the addition of trimethyl phosphoric acid, an ethylene glycol slurry containing 10% by weight of spherical silica having an average particle size of 220 nm was used. 6 parts by weight were added.

(Comparative Example 8)
As shown in Table 1, two kinds of particle compositions contained in the B layer are used as the inert particles α, and 0.41% by weight of aluminum silicate having an average particle diameter of 200 nm (manufacturing method and addition method are as follows). And 0.05% by weight of crosslinked polystyrene having an average particle size of 300 nm (production method and addition method are as follows), and 0.001% by weight of crosslinked polystyrene having an average particle size of 380 nm as inert particles β (production method and addition) The method is as follows), and further the colloidal silica in which the lamination ratio in the T-die composite die is A layer / B layer = 11/1, the thickness of the B layer is 530 nm, and the slippery coating layer D is contained. A laminated polyester film was produced in the same manner as in Example 6 except that the content in the coating liquid was 0.03% by weight.

  Next, the laminated polyester film was slit and wound in the same manner as in Example 1 except that the winding length was 25,000 m to obtain a laminated polyester film roll.

  As shown in Table 3, this film roll had good vapor deposition suitability, but was inferior in magnetic tape characteristics, particularly output characteristics corresponding to the film roll surface layer.

(Aluminum silicate with an average particle size of 200 nm)
Part of silicon in the silicate is replaced with aluminum and sodium, and the weight content of the metal components is 27% by weight of silicon (Si), 15% by weight of aluminum (Al), and 5% by weight of sodium (Na). did. The obtained aluminum silicate was dried for 24 hours and then pulverized to prepare a fine powder dispersed in ethylene glycol at 10% by weight.

(Method for producing crosslinked polystyrene having an average particle size of 300 nm and 380 nm)
30 ml of styrene and 1.36 g of “Emulgen” 920 (manufactured by Kao Atlas Co., Ltd.) and 1.36 g of “Pronon” 208 (manufactured by NOF Corporation) as emulsifiers are dissolved in 170 ml of water as a polymerization initiator. 136 mg of potassium persulfate, 136 mg of sodium thiosulfate, and 204 mg of benzoyl peroxide were added and reacted at 35 ° C. for 48 hours in a nitrogen atmosphere to prepare an aqueous dispersion of styrene seed particles. Next, 45 ml of water and 10 ml of styrene are added to 100 ml of this aqueous dispersion, and 0.9 g each of “Emulgen” 920 and “Pronon” 208 are added and reacted in a nitrogen atmosphere at 70 ° C. for 18 hours to obtain seed particles. A water slurry containing crosslinked polystyrene having an average particle size of 300 nm, in which styrene was crosslinked, was obtained. On the other hand, a water slurry containing a crosslinked polystyrene having an average particle diameter of 380 nm was obtained by reacting in a nitrogen atmosphere at 70 ° C. for 22 hours in the final reaction to crosslink styrene in the seed particles.

(Method of adding aluminum silicate and cross-linked polystyrene)
In the production of the polyester raw material of (1) of Example 1, 5 minutes after the completion of the transesterification reaction and addition of trimethyl phosphoric acid, 4 ethylene glycol slurries containing 10% by weight of aluminum silicate having an average particle diameter of 200 nm were obtained. .1 part by weight was added to obtain an aluminum silicate-containing PET chip. Next, the above PET chip and an aqueous slurry of crosslinked polystyrene having an average particle size were added to a vented biaxial kneader so as to have a predetermined particle composition.

(Comparative Example 9)
As shown in Table 1, the particle composition contained in the B layer is 0.47% by weight of crosslinked silicone having an average particle diameter of 220 nm as the inert particle α (the production method is as in Example 6. The addition method is as follows). The cross-linked silicone having an average particle diameter of 340 nm as the inert particles β is changed to 0.003% by weight (manufacturing method and addition method are as follows), and the lamination ratio in the T-die composite die is changed to A layer / B layer = A laminated polyester film was produced in the same manner as in Example 1 except that the thickness of the B layer was 12 nm as 12/1.

  Next, the laminated polyester film was slit and wound in the same manner as in Example 6 except that the winding length was 30,000 m to obtain a laminated polyester film roll.

  As shown in Table 3, this film roll had good vapor deposition suitability, but was inferior in magnetic tape characteristics, particularly output characteristics corresponding to the film roll surface layer.

(Method for producing crosslinked silicone having an average particle size of 340 nm)
In the production method of the crosslinked silicone of Example 1, except that the compound represented by m = 40 in the chemical formula of dimethylpolysiloxane having vinyl groups at both ends was used, the crosslinked silicone having an average particle diameter of 340 nm was produced. Silicone was obtained. Next, the obtained crosslinked silicone was dispersed in ethylene glycol to obtain a 0.1 wt% ethylene glycol slurry.

(Method for adding crosslinked silicone)
In the production of the polyester raw material of (1) of Example 1, the transesterification reaction was completed, and 5 minutes after the addition of trimethyl phosphoric acid, 10% by weight of the crosslinked silicone having an average particle diameter of 220 nm obtained in Example 6 was contained. 4.7 parts by weight of ethylene glycol slurry and 3 parts by weight of ethylene glycol slurry containing 0.1% by weight of the crosslinked silicone having an average particle size of 340 nm obtained above were added.

(Comparative Example 10)
As shown in Table 1, the particle composition contained in the B layer is 0.42% by weight of spherical silica having an average particle diameter of 220 nm as the inert particle α (the production method is as in Comparative Example 5. The addition method is as follows). The cross-linked silicone having an average particle diameter of 450 nm is changed to 0.0003% by weight (the production method and the addition method are as follows) as the inert particles β, and the lamination ratio in the T-die composite die is changed to A layer / B layer = A laminated polyester film was produced in the same manner as in Example 1 except that the thickness of the B layer was 12 nm as 12/1.

  Next, the laminated polyester film was slit and wound in the same manner as in Example 6 except that the winding length was 30,000 m to obtain a laminated polyester film roll.

  As shown in Table 3, this film roll had good vapor deposition suitability, but was inferior in magnetic tape characteristics, particularly output characteristics corresponding to the film roll surface layer.

(Method for producing crosslinked silicone having an average particle diameter of 450 nm)
In the production method of the crosslinked silicone of Example 1, except that the compound represented by m = 46 in the chemical formula of dimethylpolysiloxane having vinyl groups at both ends was used, a crosslinked product having an average particle diameter of 450 nm was produced. Silicone was obtained. Next, the obtained crosslinked silicone was dispersed in ethylene glycol to obtain a 0.1 wt% ethylene glycol slurry.

(Addition method of spherical silica and crosslinked silicone)
In the production of the polyester raw material (1) of Example 1, the transesterification reaction was completed, and 5 minutes after the addition of trimethyl phosphoric acid, 10% by weight of spherical silica having an average particle diameter of 220 nm obtained in Comparative Example 2 was contained. 4.2 parts by weight of ethylene glycol slurry and 0.3 parts by weight of ethylene glycol slurry containing 0.1% by weight of the crosslinked silicone having an average particle diameter of 450 nm obtained above were added.

  As is clear from the results of Tables 1 to 3, the film roll of the present invention is obtained by setting the slit winding tension, surface pressure, and speed pattern to specific conditions for the laminated polyester film having a specific surface roughness ratio. Could be manufactured. Also, in the vapor deposition process using this film roll, it can be processed in a stable state without misalignment of the film at the time of vacuum degassing at high speed exhaust, at the start of vapor deposition at high acceleration, and the film roll surface layer part, All the magnetic tapes obtained from the corresponding portions of the core could obtain good output characteristics.

  The laminated polyester film roll of the present invention has particularly good characteristics as a vapor-deposited magnetic recording medium and good workability to the vapor-deposited magnetic recording medium, and can be suitably used as a base substrate for the application. In addition, it can be suitably used as a base substrate for a coating type magnetic recording medium.

It is the schematic which shows the basis of the slit winding pattern which concerns on one embodiment of this invention. It is the schematic which shows the representative example of the slit winding pattern (what provided the speed increasing part (a2) in the middle of the deceleration part (c1)) which concerns on the other embodiment of this invention. It is the schematic which shows the representative example of the slit winding pattern (what provided the speed increasing part (a2) in the middle of the constant speed part (b2)) which concerns on the other embodiment of this invention. The slit winding pattern according to another embodiment of the present invention (the speed increasing portion (a2) provided in the middle of the speed reducing portion (c1) and the speed increasing portion (a3) provided in the middle of the constant speed portion (b2)). It is the schematic which shows a representative example. It is the schematic which shows a typical displacement profile in case a surface layer wrinkle is convex shape. It is the schematic which shows a typical displacement profile in case a surface layer wrinkle is concave shape. It is the schematic which shows the typical displacement profile in case the center of a surface wrinkle is convex and both ends are dented. It is the schematic which shows the typical displacement profile in case the center of a surface layer wrinkle is a dent and the both ends are convex shape.

Explanation of symbols

a1: Speed increasing part 1
b1: Constant speed part 1 (steady winding part)
c1: Deceleration part 1
a2: Speed increasing part 2
b2: Constant speed part 2 (low speed winding part)
c2: Deceleration unit 2
a3: Speed increasing part 3
c3: Deceleration unit 3
d: Baseline e: Surface wrinkle height

Claims (7)

A laminated polyester film having a layer structure of at least two layers is wound around a cylindrical core, and the center line average surface roughness Ra _{A of} the layer (A layer) constituting one surface of the laminated polyester film and the other surface The ratio Ra _A / Ra _B to the center line average surface roughness Ra _B of the layer constituting layer (B layer) is 0.05 to 0.7, and the surface layer wrinkle of the film roll surface layer part is (1) to (1) to A laminated polyester film roll for a magnetic recording medium satisfying (4).
(1) The total width of the surface wrinkles is 0.5 to 15% of the film width
(2) Generation length of surface wrinkles is 30 to 500 m from the surface of the film roll
(3) The height of the surface wrinkles per piece is 0.05 to 3 mm.
(4) The number of surface wrinkles in the width direction is 1 to 10 / 1,000 mm The laminated polyester film roll for magnetic recording media according to claim 1, wherein the laminated polyester film has a width of 500 to 1,000 mm and a winding length of 15,000 to 50,000 m. The laminated film according to claim 1 or 2, wherein the polyester constituting the laminated polyester film is polyethylene terephthalate or polyethylene-2,6-naphthalate. The magnetic recording medium according to claim 1, wherein an easy-slip coating layer D is provided on the outer surface of the B layer, and an easy-slip coating layer C containing particles is provided on the outer surface of the A layer. Laminated polyester film roll. The laminated polyester film roll for a magnetic recording medium according to claim 4, wherein the particles contained in the slippery coating layer C are inorganic particles. The laminated polyester film roll for magnetic recording media according to claim 5, wherein the inorganic particles are composed of silicon dioxide. The laminated polyester film roll for magnetic recording media according to any one of claims 1 to 6, wherein the laminated polyester film is used as a base film for a magnetic tape of a digital recording system.

Images