JP2989069B2 - Laminated film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film, and more particularly, to a magnetic recording medium having excellent heat-resistant adhesion and slipperiness.
The present invention relates to a polyester laminated film useful as a packaging material, a laminated material, and the like.

[0002]

2. Description of the Related Art Polyester films, especially polyethylene terephthalate films and polyethylene-2,6-naphthalenedicarboxylate films, have mechanical properties,
Due to its excellent thermal and chemical properties, it can be used in a wide range of fields such as magnetic tapes, floppy disks, magnetic cards,
It is used as a base film for graphic materials and packaging materials. At that time, the polyester film is required to have excellent adhesive properties, but has a disadvantage that the adhesive strength is low because the film is highly oriented and crystallized.

[0003] Therefore, a treatment or processing for imparting an easy-adhesion property to the polyester film is performed. One of the means is to form a thin layer (or a film) having an easy-adhesion on the surface of the polyester film in the production process of the polyester film. Layer). In this case, an in-line coating method or a co-extrusion method is used for forming a thin layer (or a film layer) having easy adhesion.

It is required that the polymer forming the thin layer (or film layer) having good adhesion has excellent adhesion and does not cause any trouble in the film production process. The heat resistance is low or the adhesive force of the lubricant is low, and various conditions are often added to the drawing conditions and co-extrusion conditions. In particular, it has heretofore been difficult to obtain a co-extruded material with polyester having excellent processing conditions and quality. For example, when the layer thickness of the co-extruded product is thin, it is necessary to select an amorphous and high heat-resistant polymer in order to increase the adhesive force of the lubricant fine particles contained in the layer. Was not obtained.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyester laminated film which is excellent in heat-resistant adhesiveness and slipperiness and is useful for magnetic recording media, packaging materials, laminated materials and the like.

[0006]

The present invention has the following configuration in order to achieve the above object.

On at least one side of the polyester film, a film layer of a copolyester having an acid component of 50 to 99 mol% of naphthalenedicarboxylic acid, 1 to 50 mol% of phenylindane dicarboxylic acid and 0 to 49 mol% of another dicarboxylic acid is provided. Laminated film.

In the present invention, the copolyester forming at least one layer of the laminated film comprises naphthalenedicarboxylic acid having a rigid acid component and phenylindanedicarboxylic acid having a bulky non-planar chemical structure. Therefore, it has a feature that the secondary transition point is high, the heat resistance is excellent, and the crystallinity is low. Therefore, the copolyester layer has high heat resistance and exhibits excellent adhesion to magnetic paints and the like. Further, the adhesiveness to a lubricant is excellent, and the formation of voids is suppressed even if the layer contains a lubricant.

The naphthalenedicarboxylic acid constituting the acid component of the copolyester includes, for example, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid,
1,5-naphthalenedicarboxylic acid and the like can be mentioned. Of these, 2,6-naphthalenedicarboxylic acid is preferred. This naphthalenedicarboxylic acid is used in an amount of 50 to 99 per total acid component.
It is used in the ratio of mol%. If this proportion is less than 50 mol%, the heat resistance and film-forming properties of the copolyester are undesirably reduced.

The phenylindanedicarboxylic acid constituting the acid component of the copolyester is represented by the following formula:

[0011]

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(Wherein R ₁ , R ₂ , and R ₃ are each hydrogen or lower alkyl). Examples of the lower alkyl include methyl,
Ethyl, propyl and the like can be mentioned. Preferred specific examples include 1,1,3-trimethyl-3-phenylindane-4 ', 5-dicarboxylic acid. The phenylindane dicarboxylic acid is used in a proportion of 1 to 50 mol% based on the total acid components. When this ratio exceeds 50 mol%,
It is not preferable because the film forming property of the copolyester decreases.

As the acid component of the copolyester, other dicarboxylic acids can be used in addition to naphthalenedicarboxylic acid and phenylindanedicarboxylic acid. Other dicarboxylic acids include, for example, terephthalic acid, isophthalic acid, phthalic acid, 4,4'-biphenyldicarboxylic acid,
Adipic acid, sebacic acid and the like can be mentioned. The other dicarboxylic acid is used at a ratio of 0 to 49 mol% based on the total acid component. If this proportion exceeds 49 mol%, the heat resistance of the copolyester is undesirably reduced.

The dihydroxy compound component of the copolyester includes, for example, ethylene glycol, tetramethylene glycol, 1,3-propanediol, 1,6-
Hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol,
p-xylylene glycol, polyethylene glycol and the like.

The above-mentioned copolyester can be produced by a known method. The average molecular weight of the copolyester is 5,
It is preferably from 000 to 40,000.

In the present invention, the polyester forming the polyester film layer is a saturated polyester having oriented crystallinity. Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, adipic acid, sebacic acid, and the like. Examples of the dihydroxy compound component include ethylene glycol, tetramethylene glycol, 1,3-propanediol, 1,6-hexanediol, and neopentyl. Glycol, diethylene glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, polyethylene glycol and the like. The dicarboxylic acid component is preferably an aromatic dicarboxylic acid, particularly terephthalic acid,
2,6-Naphthalenedicarboxylic acid is preferred. The dihydroxy compound component is ethylene glycol,
—Cyclohexanedimethanol is preferred, and ethylene glycol is particularly preferred.

The polyesters are known per se,
It can be manufactured by a known method. The molecular weight of the polyester is the intrinsic viscosity (orthochlorophenol, 35 ° C)
Is preferably from 0.45 to 0.90.

In the present invention, the polyester film may be any of an unstretched film, a uniaxially stretched film and a biaxially stretched film, but a biaxially stretched film is particularly preferred.
The thickness of the film depends on the application, but is 3 ~ 300μ
m is preferable.

The laminated film of the present invention comprises a polyester film (first layer) having, on one or both sides thereof, an acid component containing 50 to 99 mol% of naphthalenedicarboxylic acid, 1 to 50 mol% of phenylindane dicarboxylic acid and other dicarboxylic acids. The film has a structure in which a copolyester film layer (second layer) of 0 to 49 mol% is laminated, and the thickness of the second layer is preferably 0.1 to 200 μm.

In the present invention, various methods can be used for laminating the polyester film of the first layer and the film layer of the copolyester of the second layer, such as a coextrusion method, an extrusion lamination method, and a hot lamination method. Any of a melt coating method, a dry lamination method, a thermocompression bonding method, and the like can be used. Of these, the coextrusion method is preferred.

In producing the laminated film, polyester (first layer), copolyester (second layer)
Among them, for example, silicon oxide, iron oxide, kaolin, aluminum oxide, aluminum silicate, calcium carbonate, titanium oxide, lubricant inorganic fine particles such as carbon black, acrylic resin, polystyrene resin, silicone resin, lubricant organic fine particles such as melamine resin, Antioxidants, ultraviolet absorbers, colorants, pigments, antistatic agents, and the like can be added as needed.

The method for producing the laminated film can be arbitrarily selected, but a method in which the first layer finally becomes a biaxially stretched film is preferred. In the case of co-extrusion, the second layer is also biaxially stretched. The oriented crystallization of the biaxially stretched film can be performed by a conventional method, but is preferably performed by a sequential biaxial stretching method.

The laminated film thus obtained is excellent in heat-resistant adhesiveness and slipperiness, and is useful for magnetic tapes, magnetic disks, magnetic cards, printing materials, graphic materials, photosensitive materials, packaging materials and the like.

[0024]

The present invention will be described in more detail with reference to the following examples. In addition, the part in an Example means a weight part. Each characteristic value was measured by the following method.

1. Adhesiveness (A) Magnetic paint The evaluation paint is applied to a sample polyester film using a Meyer bar so that the thickness after drying becomes about 4 μm.
Dry at 00 ° C. for 3 minutes. Thereafter, aging was performed at 60 ° C. for 24 hours. A 600 (manufactured by 3M) width of 12.7 mm and a length of 15 cm are adhered so as to prevent air bubbles from entering, and the top thereof is leveled with a manual load roll described in JIS C2701 (1975), and cut into a tape width. The strength at 180 ° peeling is measured.

[Evaluation paint] In terms of solid content, urethane resin Nipporan 2304 (manufactured by Nippon Polyurethane) 25 parts PVC / vinyl acetate resin Esrec A (manufactured by Sekisui Chemical) 50 parts Dispersant Ratio P (manufactured by Riken Vitamin) 1 part Agent CTX-860 (Toda Chemical) 500 parts

Is dissolved in a mixed solvent of methyl ethyl ketone / toluene / cyclohexanone to make a 40% solution, and dispersed by a sand grinder for 2 hours. Thereafter, 25 parts (in terms of solid content) of coronate L as a cross-linking agent are added and stirred well to obtain a magnetic paint.

(B) UV Ink A UV-curable printing ink (flash dry FDO Beni AP manufactured by Toyo Ink Co., Ltd.) is placed on a sample polyester film.
N) after printing with an RI tester (made by Mei Seisakusho)
Curing was performed using a medium pressure mercury lamp (80 W / cm, single-lamp type: manufactured by Nippon Battery) UV curing device, and a UV having a thickness of 7.0 μm was obtained.
Form an ink layer.

A cut is made on the UV ink layer using a knife knife, a cellophane tape is applied, and 90 ° peeling is performed. The peeled state is displayed in five stages (good: 5 ← → 1: evil). 5 No ink is removed 4 70% or more of ink remains 3 50% or more of ink remains 2 30% or more of ink remains 1 All ink is removed

2. Polymer molecular weight A polymer is dissolved in tetrahydrofuran and measured by GPC (gel permeation chromatography).

[0031]

Example 1 Polyethylene terephthalate (A) having an intrinsic viscosity [η] of 0.63 and 2,6-naphthalenedicarboxylic acid (60 mol%)-phenylindane dicarboxylic acid of the following formula (35 mol%)-terephthalic acid (5 mol%) )
-Ethylene glycol (85mol%)-neopentyl glycol (15mol%) copolymerized polyester (B)
(Average molecular weight = 18,000)

[0032]

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Is extruded from a two-layer die and quenched and solidified to form an unstretched film.
The film was stretched 3.6 times in the transverse direction and then heat-treated at 225 ° C. to obtain a laminated film. The first layer (A) has a thickness of 10 μm,
The second layer (B) had a thickness of 1 μm. Table 1 shows the characteristics of the laminated film.

[0034]

Comparative Example 1 A biaxially stretched film was obtained in the same manner as in Example 1 except that only the polyethylene terephthalate of the first layer (A) was used. Table 1 shows the properties of the biaxially stretched film.

[0035]

Example 2 0.11% by weight of silicon oxide (average particle size: 0.1 μm) was added to the copolymerized polyester (B) of Example 1, and co-extrusion was performed on both sides of the polyester (A) layer from a three-layer die. In the same manner as in Example 1, a laminated film was obtained. This laminated film has a layer B (2 μm) / layer A (25 μm).
m) / B layer (2 μm).
Shown in

[0036]

Examples 3 to 8 2,6- with intrinsic viscosity [η] of 0.64
Naphthalenedicarboxylic acid (95mol%)-4,4'-
Biphenyldicarboxylic acid (5 mol%)-ethylene glycol copolymer polyester (C) and 2,6-naphthalenedicarboxylic acid (60 mol%)-phenylindanedicarboxylic acid (38 mol%)-terephthalic acid (2 mol)
%)-Ethylene glycol (75 mol%)-1,4-
C layer (50 μm) / D, except that co-extrusion with butanediol (25 mol%) copolymerized polyester (D) (average molecular weight = 21,000) was performed.
A biaxially stretched laminated film having a layer (change in thickness) was obtained. Table 1 shows the characteristics of this film.

[0037]

Example 9 Polyethylene-2,6-naphthalenedicarboxylate (E) having an intrinsic viscosity [η] of 0.61 and 2,2
(E) layer (14 μm) / (F) in the same manner as in Example 1 except that 6-naphthalenedicarboxylic acid (80 mol%)-phenylindanedicarboxylic acid (20 mol%)-ethylene glycol copolymerized polyester (F) was used. A layer (0.8 μm) biaxially stretched laminated film was obtained. Table 1 shows the characteristics of this film.

[0038]

[Table 1]

[0039]

According to the present invention, it is possible to provide a polyester laminated film having excellent heat resistance and slipperiness and useful for magnetic recording media, packaging materials, laminated materials and the like.

(56) References JP-A-3-164251 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 C08J 7/04 G11B 5 / 704

Claims (2)

(57) [Claims] 1. A film layer of a copolyester in which the acid component comprises 50 to 99 mol% of naphthalenedicarboxylic acid, 1 to 50 mol% of phenylindane dicarboxylic acid and 0 to 49 mol% of other dicarboxylic acids on at least one surface of the polyester film. Laminated film. 2. The laminated film according to claim 1, wherein the laminated film is used as a base film of a magnetic recording medium.