JPH06198828A - Production of easy bonding laminated film - Google Patents

Abstract

PURPOSE:To produce a polyeser laminated film excellent in heat-resistant adhesiveness and mechanical characteristics and useful as a magnetic recording medium, a packing material or a laminated material. CONSTITUTION:A layer (B) of polyester produced from a dicarboxylic acid component containing 30mol% or more of phenylindane dicarboxylic acid and a dihydroxy compd. component is laminated to at least the single surface of a layer (A) of polyester prepared from a dicarboxylic acid component containing 70mol% or more of terephthalic acid and/or 2,6-naphthalenedicarboxylic acid and a dihydroxy compd. by co-extrusion to form a non-stretched laminated film which is, in turn, biaxially stretched. The obtained film is again stretched at least uniaxially at 80-220 deg.C to produce an easy bonding laminated film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an easily-adhesive laminated film, more specifically, an easily-adhesive laminated film which is excellent in heat-resistant adhesiveness and mechanical properties and is useful as a magnetic recording medium, a packaging material, a laminating material and the like. The present invention relates to a method of manufacturing a film.

[0002]

2. Description of the Related Art Polyester film, especially polyethylene terephthalate film, polyethylene-2,6-naphthalene dicarboxylate film, is a magnetic tape,
Floppy disk, magnetic card, graphic material,
Although it is used for packaging materials and the like, it has a drawback that the film is oriented and crystallized and thus has a low adhesive force with a layer formed thereon.

Conventionally, this drawback is that the surface of the polyester film is coated with a layer of an easily adhesive resin and coextruded,
Although this has been overcome by laminating with a laminate or the like, this resin usually has low heat resistance, and various restrictions have been added to film forming conditions and processing conditions of the film. For example, in order to increase the strength of the polyester film, it is often stretched in three stages or four stages. However, when an easily adhesive layer is formed in this step, the layer has low heat resistance and may be heat-adhered to a roll during the process. Many. On the other hand, when a polymer having stronger crystallinity is used for the purpose of improving the heat resistance of the easy-adhesion layer, the adhesive force tends to decrease. Further, in many cases, lubricant fine particles are contained in the surface layer for the purpose of imparting runnability to the film, but in this case, when the thickness of the layer becomes thin, the adhesion force of the fine particles decreases.

Therefore, there is a demand for an easily adhesive resin which is excellent in both heat resistance and adhesive strength. Particularly in the case of lamination by the coextrusion method, the resin is preferably a polyester resin, but a resin having the above characteristics has not been obtained.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have found a polyester resin having both excellent heat resistance and adhesive strength, and by laminating it on a polyester film,
The present invention has been achieved as a result of intensive research to produce a film having excellent mechanical properties.

Accordingly, an object of the present invention is to provide a method for producing an easily adhering polyester laminated film which is excellent in heat resistance and mechanical properties.

Another object of the present invention is to provide a method for producing an easily-adhesive polyester laminated film which is excellent in heat-resistant adhesiveness, mechanical properties and slipperiness and is useful for magnetic recording media, packaging materials, laminated materials and the like. It is in.

[0008]

The present invention has the following constitution in order to achieve such an object.

At least one surface of the polyester layer (A) made of a dicarboxylic acid component containing terephthalic acid and / or 2,6-naphthalenedicarboxylic acid in an amount of 70 mol% or more and a dihydroxy compound component in an amount of 30 mol% or more in phenylindanedicarboxylic acid. A laminated unstretched film obtained by layering a polyester layer (B) made of a dicarboxylic acid component and a dihydroxy compound component by coextrusion is biaxially stretched, and then restretched at least uniaxially at a temperature of 80 to 220 ° C. A method for producing an easily-adhesive laminated film, which comprises:

In the present invention, the polyester of the layer A is a polyester prepared from a dicarboxylic acid component containing terephthalic acid and / or 2,6-naphthalenedicarboxylic acid in an amount of 70 mol% or more, preferably 80 mol% or more, and a dihydroxy compound component. Examples of the dicarboxylic acid component that can be used in a proportion of less than 30 mol% include isophthalic acid, phthalic acid, adipic acid and sebacic acid. As the dihydroxy compound component, ethylene glycol, 1,4-butanediol, 1,3-propanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, 1,6-cyclohexanedimethanol, p-xylylene glycol, Examples thereof include polyethylene glycol.

Specific examples of polyesters include polyethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, and polytetramethylene-2,6-.
Naphthalene dicarboxylate, terephthalic acid-2,6
-Naphthalenedicarboxylic acid-ethylene glycol copolymer, terephthalic acid-2,6-naphthalenedicarboxylic acid-
Preferred examples include 1,4-butanediol-ethylene glycol copolymer and the like. Among these, polyethylene terephthalate and polyethylene-2,6-naphthalene dicarboxylate are particularly preferable.

When the proportion of the above-mentioned two kinds of dicarboxylic acids, that is, terephthalic acid and / or 2,6-naphthalenedicarboxylic acid, is less than 70 mol%, it is not preferable because the film base has a poor rigidity and practically lacks in performance.

In the present invention, the polyester of the layer B is a polyester made from a dicarboxylic acid component containing 30 mol%, preferably 50 mol% or more of phenylindanedicarboxylic acid and a dihydroxy compound component.

As phenylindane dicarboxylic acid,
The following formula

[0015]

[Chemical 1]

(Wherein R ₁ , R ₂ and R ₃ are each hydrogen or lower alkyl). Examples of the lower alkyl include methyl,
Examples include ethyl and propyl. A preferred specific example is 1,1,3-trimethyl-3-phenylindane-4 ', 5-dicarboxylic acid.

Dicarboxylic acids other than phenylindane dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid. Examples thereof include acids, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid and dimer acid. Two or more of these components can be used. Further, a small proportion of an unsaturated polybasic acid such as maleic acid, fumaric acid or itaconic acid or a hydroxycarboxylic acid such as p-hydroxybenzoic acid or p- (β-hydroxyethoxy) benzoic acid may be used together with these components. it can. The ratio of the unsaturated polybasic acid component and the hydroxycarboxylic acid component is at most 10 mol%, preferably 5 mol% or less.

Examples of the dihydroxy compound include ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, and dimethylolpropion. Acid, glycerin, trimethylolpropane,
Examples thereof include poly (ethylene oxide) glycol and poly (tetramethylene oxide) glycol. These can use 2 or more types.

When the proportion of the phenylindanedicarboxylic acid is less than 30 mol%, the glass transition point (Tg) of the polyester is lowered and the heat resistance is lowered, which is not preferable. The Tg of the polyester is preferably 70 ° C or higher, more preferably 90 ° C or higher.

Polyester and B of layer A in the present invention
The polyester of the layer can be produced by a known method. For example, polyethylene terephthalate is produced by esterification reaction of terephthalic acid and ethylene glycol, or transesterification of an ester-forming derivative of terephthalic acid (lower alkyl ester, especially dimethyl ester) with ethylene glycol to form a monomer. Then, the polyester can be produced by polymerizing the monomer. In addition, phenylindane dicarboxylic acid (60 mol%) and terephthalic acid (40 mol%) and ethylene glycol (95 m
ole%) and 1,4-butanediol (5 mol%) through an esterification reaction, or dimethyl ester of phenylindanedicarboxylic acid (60 mol%) and dimethyl ester of terephthalic acid (40 mol%) and ethylene glycol (95 mol%). %) And 1,4-butanediol (5 mol%) are transesterified to form a monomer, and then the monomer is subjected to a polymerization reaction to obtain a polyester. The use of catalysts in these reactions is preferred.

The polyester of A layer and the polyester of B layer each have a number average molecular weight of 5,000 to 40,000.
Is preferred.

In the present invention, the polyester of the A layer and the polyester of the B layer are melt-coextruded to form a laminated unstretched film in which the B layer is laminated on at least one side of the A layer, and the laminated unstretched film is biaxially stretched. It is necessary to stretch in the machine direction and then restretch at a temperature of 80 to 220 ° C. in a few uniaxial directions, that is, the machine direction and / or the transverse direction.

The coextrusion can be carried out by a method known in the prior art, in which case the polyester of the A layer and / or
Alternatively, for the polyester of the B layer, inorganic particles such as silicon oxide, iron oxide, kaolin, aluminum oxide, aluminum silicate, calcium carbonate, titanium oxide, acrylic resin,
Organic particles such as polystyrene resin, silicone resin, melamine resin, carbon black, etc., antioxidants, lubricants, ultraviolet absorbers, colorants, pigments, antistatic agents, etc. can be contained as necessary. The structure of the coextrusion die and the extrusion temperature can be arbitrarily selected.

Stretching of the laminated unstretched film can be carried out by conventionally known methods and conditions, but the stretch ratio is preferably 6 to 10 times in area ratio. A sequential biaxial stretching method is preferable as the stretching method.

The re-stretching of the biaxially stretched film is 80 to 220.
The stretching is carried out at least uniaxially at a temperature of ° C, but the stretching ratio is preferably such that the final area ratio is 12 to 22 times.
If the re-stretching temperature is lower than 80 ° C, stretching is not performed uniformly, while if it is higher than 220 ° C, crystallization is excessively promoted or breakage easily occurs, which is not preferable. In this re-stretching, the film is heated but avoids sticking of the film surface to the roll during contact with the roll during the process. Further, the multi-stage drawing has the advantage that the Young's modulus of the film can be further increased and the unevenness of the film thickness can be reduced. Heating to a temperature of 80 to 220 ° C. may be either direct (contact) heating or indirect (non-contact) heating. It is preferable to appropriately select the stretching temperature depending on the combination of the A layer and the B layer.

In the laminated film obtained by the present invention, the thickness of the A layer can be arbitrarily selected, but it is preferably 2 to 250 μm, and the thickness of the B layer is 0.1 to 20 μm and 15% of the thickness of the A layer. The following is preferable. This is to avoid a decrease in Young's modulus of the laminated film. The Young's modulus of the laminated film is preferably 600 kg / mm ² or more.

The laminated film obtained by the present invention is
It has excellent 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.

[0028]

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

1. Adhesion <Magnetic paint> Sample polyester film (B)
The evaluation paint on the layer surface is about 4μ after dried with a Meyer bar.
It is applied so that the thickness becomes m and dried at 100 ° C. for 3 minutes. After that, aging was performed at 60 ° C. for 2 hours, and then Scotch tape No. 600 (manufactured by 3M), width 12.7 mm, length 15 c.
Adhere m to prevent air bubbles from entering, and then use JISC2
701 (1975), using a manual load roll to level the film and bring it into close contact, and cut into a tape width. The strength when peeled at 180 ° is measured.

[Evaluation paint] Urethane resin Nipporan 2304 (manufactured by Nippon Polyurethane) 25 parts PVC / vinyl acetate resin S-REC A (manufactured by Sekisui Chemical Co., Ltd.) 50 parts Dispersant Resion P (manufactured by Riken Vitamin) 1 part Magnetic Agent CTX-860 (manufactured by Toda Kagaku Co., Ltd.) (500 parts) is dissolved in a mixed solvent of methyl ethyl ketone / toluene / cyclohexanone to give a 40% solution, which is dispersed for 2 hours by a sand grinder. After that, 25 parts (corresponding to solid content) of the cross-linking agent Coronate L is added and well stirred to obtain a magnetic coating material.

2. Average molecular weight of polyester The polymer is dissolved in orthochlorophenol or tetrahydrofuran and measured by GPC (gel permeation chromatograph) method.

[0032]

Example 1 Polyethylene terephthalate (A-1) having an average molecular weight of 23,000 and phenylindanedicarboxylic acid (60mo)
1%, the following formula [I])-terephthalic acid (40 mol%)
-Ethylene glycol (95 mol%)-1,4-butanediol (5 mol%) Copolyester (B-
1) (Average molecular weight = 18,000)

[0033]

[Chemical 2]

Was coextruded from a two-layer die and rapidly cooled to obtain an unstretched film. The unstretched film was stretched 2.5 times in the machine direction and 3 times in the cross direction, and then stretched 2 times in the machine direction at 128 ° C. Further heat treatment was performed to obtain a laminated film. The first layer (A) and the second layer (B) of this three-stage stretched laminated film had a thickness of 14 μm and 1 μm, respectively.

The characteristics of this laminated film are shown in Table 1.

[0036]

Comparative Example 1 A three-layer stretched single-layer film was similarly obtained from the first layer (A) using (A-1) in Example 1. The characteristics of this film are shown in Table 1.

[0037]

Example 2 Copolyester (B-1) of Example 1
0.14w of calcium carbonate (average particle size 0.1μm)
t% was added, and both sides of the polyester (A-1) layer were coextruded from a three-layer die and stretched in the same manner to obtain a three-layer laminated film. B layer (1 μm) / A layer (20 μm) / B layer (1 μm
A film having the constitution of m) was obtained. The characteristics of this film are shown in Table 1.

[0038]

Example 3 Polyethylene having an average molecular weight of 21,000
2,6-naphthalenedicarboxylate (A-2) and phenylindanedicarboxylic acid (85 mol%)-terephthalic acid (15 mol%)-ethylene glycol (70 m
ol%)-1,4-butanediol (30 mol%) copolyester (B-2) (average molecular weight 2100)
0) was coextruded in the same manner as in Example 1, further stretched 2.6 times in the longitudinal direction and 2.8 times in the transverse direction, and then stretched 2 times in the longitudinal direction at 185 ° C., and further 1. After being stretched 6 times and heat-treated, a two-layer four-stage stretched laminated film was obtained. This film had a structure of A layer (10 μm) / B layer (0.5 μm) /. The characteristics of this laminated film are shown in Table 1.

[0039]

Examples 4 to 6 Laminated films were obtained in the same manner as in Example 1, except that the thickness of layer B was changed as shown in Table 1. The characteristics of this laminated film are shown in Table 1.

[0040]

Examples 7 to 9 Laminated films were obtained in the same manner as in Example 2 except that the thickness of the outer two layers (B) was changed as shown in Table 1. The characteristics of this laminated film are shown in Table 1.

[0041]

Examples 10 to 12 Laminated films were obtained in the same manner as in Example 3 except that the thickness of the second layer (B) was changed to Table 1. The characteristics of this laminated film are shown in Table 1.

[0042]

[Table 1]

[0043]

According to the present invention, it is possible to provide a method for producing a polyester laminated film which is excellent in heat-resistant adhesiveness, mechanical properties and slipperiness.

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Claims (1)

[Claims] 1. A phenylindanedicarboxylic acid of 30 mol% is formed on at least one side of a layer (A) of a polyester prepared from a dicarboxylic acid component containing 70 mol% or more of terephthalic acid and / or 2,6-naphthalenedicarboxylic acid and a dihydroxy compound component. A laminated unstretched film obtained by laminating a layer (B) of a polyester made of a dicarboxylic acid component and a dihydroxy compound component containing the above by coextrusion is biaxially stretched, and then at least uniaxially at a temperature of 80 to 220 ° C. A method for producing an easily-adhesive laminated film, which comprises re-stretching.