JPH07268117A - Readily bondable polyester film - Google Patents

Abstract

PURPOSE:To obtain the subject film, excellent in antistatic properties, easy slipperiness, adhesiveness and resistances to blocking, solvent and chipping and suitable as magnetic recording materials by forming a mixture film of a water-soluble copolyester with a wax on the surface. CONSTITUTION:This readily bondable polyester film is obtained by forming a film of a mixture consisting essentially of a water-soluble copolyester, containing 20-40wt.% polyoxyalkylene glycol component and having 1-20wt.% content of an ethylene glycol oligomer with an oxidized wax and/or natural wax on at least one surface of a polyester film substrate. The glycol content of A wt.% and the oligomer content of B mol% in the polyester film satisfy 1<=A/B<=10. The amounts of the components blended are 70-99.9wt.% copolyester and 30-0.1wt.% wax. A rosin-modified wax may be contained. A polyethylene glycol having 400-10000 number-average molecular weight is used and the substrate contains 5ppm to 20wt.% each of a sulfonic acid-based copolymer, a polyethylene glycol and a wax.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an easily adhesive polyester film. Specifically, it has excellent antistatic properties, slipperiness, adhesion, blocking resistance, etc., and is suitable as a base film used for magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials, general industrial materials, etc. It relates to an adhesive polyester film. Particularly, the present invention relates to an easily-adhesive polyester film suitable as a base film used for magnetic recording materials.

[0002]

2. Description of the Related Art Polyesters, particularly polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate or poly-1,4-cyclohexanedimethylene terephthalate and polyesters containing these as main constituents are excellent. It has physical and chemical properties and is widely used as a fiber, film or sheet, and also as a molded product thereof.

In particular, since polyester films have excellent heat resistance, chemical resistance and mechanical properties, they are used in many applications such as magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials and general industrial materials. It is used.

In these applications, the polyester film is not used alone, and various coatings such as a magnetic paint, a chemical mat paint, a diazo photosensitive paint, a gelatin composition, and a heat seal are applied to the film surface. It is used by applying or printing a composition, ink, or the like.

In particular, films used for magnetic tapes, floppy disks, etc. are required to have flatness and smoothness for high reliability and high density of magnetic recording. There is a strong demand for improvement of the adhesive force with the base film. However, when the film is provided with an adhesive force to the magnetic coating material, conversely, blocking occurs between the films, which deteriorates various workability and deteriorates magnetic recording performance. On the other hand, in the process of manufacturing a magnetic tape or the like using a base film or an easy-adhesive film, in general, when passing through a process having many various rolls at a high speed, the gap between the roll and the film is Alternatively, the friction between the films causes an electrification phenomenon, which often necessitates a stop from the viewpoint of explosion proof, resulting in a decrease in workability and a deterioration in magnetic recording performance. Therefore, for imparting adhesiveness to the film, antistatic property of the film, slipperiness,
At the same time, it is necessary to satisfy the performance such as antiblocking property. At the same time, there is a demand for an easily-adhesive substance which is resistant to various solvents contained in various coatings applied or printed on the film surface.

However, since polyester itself is generally inactive and poor in adhesiveness, various coatings such as magnetic paints, chemical mat paints, diazo photosensitive paints, gelatin compositions, heat seal imparting compositions are formed on the film surface. object,
When applying or printing ink, etc., physical treatment such as corona discharge or plasma or chemical treatment using alkali or amine chemicals is performed on the film surface to improve adhesion with the coating. Various methods are known, including a method of coating an easily adhesive substance and the like. However, the physical or chemical surface treatment method complicates the steps, not only increases the cost, but also fails to obtain sufficient adhesiveness.

On the other hand, the method of coating an easily adhesive substance can be carried out in the production process of the polyester film, is advantageous in terms of cost, and can select an adhesive substance which can be applied to various coatings. It is possible. Further, from the viewpoints of handleability of the polyester film and workability during film production, it has been proposed that various water-dispersed or water-soluble copolyesters and the laminating or coating of the copolyesters on the polyester film. For example, JP-A-50-83497 and JP-A-53-2
536 and JP-A-54-3848, polyesters obtained by copolymerizing an ester-forming sulfonic acid metal salt compound and an aliphatic dicarboxylic acid component, and further diethylene glycol, JP-A-59-215318. Examples of the film include a film undercoated with a polyester obtained by copolymerizing a metal salt compound capable of forming a sulfonic acid and an aliphatic dicarboxylic acid component.

[0008]

However, the above-mentioned prior art has the following problems. That is, JP-A-50-83497 and JP-A-53-253
6, JP-A-54-3848 and JP-A-5-3848.
As in JP-A 9-215318, when an ester-forming sulfonic acid metal salt compound, an aliphatic dicarboxylic acid component, and further diethylene glycol are copolymerized, adhesiveness is exhibited, but blocking resistance and slipperiness are improved. Inferior,
There are drawbacks such that good antistatic properties cannot be obtained. The present invention eliminates these drawbacks, antistatic properties, slipperiness,
The present invention provides an easily-adhesive polyester film which is excellent in adhesiveness, blocking resistance, water solubility, etc. and is suitable as a base film used for magnetic recording materials and the like.

[0009]

The above-mentioned object of the present invention is to provide a polyoxyalkylene glycol component of 20% by weight or more on at least one side of a polyester film substrate.
A coating film of a mixture mainly composed of a water-soluble copolyester containing less than 0% by weight and an ethylene glycol oligomer content of 1 mol% or more and 20 mol% or less and an oxidation wax and / or a natural wax is formed. And a polyoxyalkylene glycol content [A wt%] and an ethylene glycol oligomer content [B mol%] of the water-soluble copolyester satisfy the following formula (1). Easy-adhesive polyester film characterized by:

1 ≦ A / B ≦ 10 (1) The acid component of the water-soluble copolyester according to the present invention is not particularly limited, but aromatic dicarboxylic acid of 6 is used.
It is preferably 0 mol% or more, more preferably 70 mol% or more, and particularly preferably 80 mol% or more from the viewpoint of excellent antistatic property, antiblocking property and solvent resistance. If the aromatic dicarboxylic acid content is less than 60 mol%, the antistatic property, antiblocking property and solvent resistance are poor. The aromatic-aromatic dicarboxylic acid is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, diphenyletherdicarboxylic acid, and the like, and among these, preferable aromatic dicarboxylic acids include terephthalic acid and Isophthalic acid and naphthalenedicarboxylic acid.

From the viewpoint of imparting water solubility, the water-soluble copolyester of the present invention contains an ester-forming alkali metal sulfonate compound in an amount of 5 to 40 mol%, preferably 7 to 30 mol%, based on all acid components. It is more preferable to add 10 to 20 mol%, particularly preferably 11 to 15 mol%. If the amount of the ester-forming alkali metal sulfonate compound is less than 5 mol%, sufficient water solubility and adhesiveness cannot be obtained. On the other hand, when it exceeds 40 mol%, the adhesiveness reaches saturation, and conversely, antistatic property, antiblocking property,
Solvent resistance decreases. The ester-forming sulfonic acid alkali metal salt compound is not particularly limited,
For example, sulfoterephthalic acid, 5-sulfoisophthalic acid,
2-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4
Examples thereof include alkali metal salts such as -sulfonaphthalene-2,6-dicarboxylic acid, and among these, lithium, sodium and potassium salts of 5-sulfoisophthalic acid and sulfoterephthalic acid are more preferably used.

The glycol component of the water-soluble copolyester of the present invention is an aliphatic glycol having 2 to 8 carbon atoms and / or an aliphatic cyclic glycol having 6 to 16 carbon atoms 80 to 99.
Mol%, ethylene glycol oligomer 1 to 20 mol%, preferably C 2-8 aliphatic glycol and / or C 6-16 alicyclic glycol 82-95
Mol%, ethylene glycol oligomer 3-18 mol%
And more preferably 84 to 93 mol% of an aliphatic glycol having 2 to 8 carbon atoms and / or an aliphatic glycol having 6 to 16 carbon atoms and 6 to 6 ethylene glycol oligomers.
It is 15 mol%.

Aliphatic glycol having 2 to 8 carbon atoms and /
Or 80 mol% of alicyclic glycol having 6 to 16 carbon atoms
If the amount is less than 20 mol% or more than 20 mol% of ethylene glycol oligomer, other properties such as blocking resistance, slipperiness and solvent resistance will be significantly deteriorated, which is not preferable.
On the other hand, when the aliphatic glycol having 2 to 8 carbon atoms and / or the aliphatic glycol having 6 to 16 carbon atoms exceeds 99 mol%, or the ethylene glycol oligomer is less than 1 mol%, anti-blocking property is obtained. Although the sex is good,
Poor water solubility and adhesiveness.

Examples of the C2-C8 aliphatic glycol and / or C6-C16 alicyclic glycol of the present invention include ethylene glycol, 1,2-propanediol, and the like. 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2 -Cyclohexane dimethanol, 1,3
There may be mentioned glycols such as cyclohexane dimethanol and 1,4-cyclohexane dimethanol.
Preferred aliphatic glycols having 2 to 8 carbon atoms and / or alicyclic glycols having 6 to 16 carbon atoms include ethylene glycol, neopentyl glycol, 1,4-butanediol and 1 , 4-cyclohexane dimethanol. These glycols may be used alone or in combination of two or more.

The ethylene glycol oligomer referred to in the present invention is a low polymer of ethylene glycol represented by the following formula (2), preferably n = 2-5, particularly preferably n = 2 ( Diethylene glycol). These ethylene glycol oligomers may be used alone or in combination of two or more.

HO (CH ₂ CH ₂ O) _n H (2) (where n = 2 to 8) The ethylene glycol oligomer such as diethylene glycol in the present invention is usually produced by the production of polyester containing ethylene glycol as a glycol component. It contains an ethylene glycol oligomer such as diethylene glycol which is by-produced.

In the water-soluble copolyester of the present invention, in addition to the above-mentioned acid component and glycol component, an aliphatic dicarboxylic acid, an oxy acid or a monofunctional compound, and a trifunctional or higher functional compound are contained within a range not impairing the effects of the present invention. It may also contain other components such as polyfunctional compounds. The content of these other ingredients is
It is not particularly limited as long as it does not impair the effects of the present invention, but is usually about 30 mol% or less.

The water-soluble copolyester of the present invention can be produced by any conventionally known method and is not particularly limited. For example, acid components such as terephthalic acid, 5-sodium sulfoisophthalic acid and glyco-
Ethylene glycol, diethylene glycol
The copolymerized polyester consisting of terephthalic acid, 5-sodium sulfoisophthalic acid and ethylene glycol or diethylene glycol can be directly esterified or an alkyl ester of terephthalic acid, 5-sodium sulfoisophthalic acid Examples thereof include a method of producing by a first step in which an alkyl ester and ethylene glycol or diethylene glycol are transesterified, and a second step in which the reaction product of the first step is subjected to a polycondensation reaction. At this time, as a reaction catalyst, conventionally known alkali metal, alkaline earth metal, manganese, cobalt, zinc, antimony, germanium,
A titanium compound or the like may be brought in, and a phosphorus compound or the like may be used as a coloring preventing agent.

The water-soluble copolyester of the present invention comprises
It is necessary that the polyoxyalkylene glycol component is contained in an amount of 20% by weight or more and less than 40% by weight, preferably 20 to 30% by weight, particularly preferably 20 to 25% by weight. Generally, a water-soluble copolyester has an ester-forming sulfonic acid alkali metal salt compound as a copolymerization component in order to impart water solubility. However, since the sulfonic acid group promotes negative electrification in triboelectrification, the copolyester The easy-adhesive polyester film laminated with
It shows a strong negative charge in the usual peeling charge and in the process charge using a lot of silicon rolls. In the present invention, as a result of earnest research, by avoiding this negative charging, by introducing a polyether chain on the positive side of the polyethylene terephthalate in the charging train so that it becomes plus or minus zero in process charging, various As a result of the examination,
Polyoxyalkylene glycol can be positively charged by frictional charging and process charging, and its content is 20%.
It has been found that a suitable amount is not less than 40% by weight and not less than 40% by weight.

The relationship between the content of the polyoxyalkylene glycol component and the triboelectric charge has a maximum value, and if it is less than 20% by weight, sufficient antistatic property cannot be obtained. On the other hand, when the content of the polyoxyalkylene glycol component is 40% by weight or more, on the contrary, the antistatic property becomes poor, and the slipperiness,
It also becomes inferior in blocking resistance, which is not preferable. The type of the polyoxyalkylene glycol component is not particularly limited, but the number average molecular weight of the polyoxyalkylene glycol component is 400 to 10,000 from the viewpoint of combining excellent adhesiveness, water solubility, and antistatic property. The number average molecular weight is preferably 500 to 6000, more preferably the number average molecular weight is 600 to 4000.
Examples of such polyoxyalkylene glycol component include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like. Among them, polyethylene glycol is preferable from the viewpoint of water solubility, antistatic property and adhesiveness.

In the present invention, the polyoxyalkylene glycol content [A wt%] and the ethylene glycol oligomer content [B mol%] of the water-soluble copolyester are 1 ≦ A / B ≦ 10, preferably 2 ≦ A / B ≦ 7,
More preferably, it is necessary to satisfy the relationship of 3 ≦ A / B ≦ 5. When A / B is less than 1, the antistatic property becomes poor, and when it is 40 or more, the water solubility becomes poor, which is not preferable.

Generally, if the content of polyoxyalkylene glycol is increased for positive charging, the water solubility decreases. Therefore, as a result of earnest research on the antistatic property of the easily adhesive film in the process charging, the ethylene glycol oligomer content in the water-soluble copolyester is closely related to the solubility, and as the ethylene glycol oligomer content increases, It was found that the solubility is improved. That is, the polyoxyalkylene glycol-containing copolyester generally becomes difficult to be water-soluble due to the crystallinity of the polyoxyalkylene glycol, but by increasing the amount of the ethylene glycol oligomer, the polyoxyalkylene glycol-containing copolyester becomes soluble due to its amorphous effect. It is speculated that this can be improved. Therefore, the amount of polyoxyalkylene glycol can be increased, and the charging characteristics can be improved.

The method for incorporating the polyoxyalkylene glycol component of the present invention into the copolyester is not particularly limited. For example, the polyoxyalkylene glycol component may be added at any stage of the process for producing the copolyester. Examples thereof include a method of adding and a method of melt-kneading the copolyester and the polyoxyalkylene glycol component using an extruder or the like. On this occasion,
The polyoxyalkylene glycol component can be added by any method such as powder, melting or solution state.

The intrinsic viscosity of the water-soluble copolyester of the present invention is not particularly limited, but it is preferably 0.3 dl / g or more from the viewpoint of adhesiveness, and further 0.4 d.
It is preferably 1 / g or more.

If necessary, the water-soluble copolyester may include a flame retardant, a heat stabilizer, an ultraviolet absorber, a pigment,
Dyes, fatty acid esters, organic lubricants such as waxes or antifoaming agents such as polysiloxy acid may be blended, and clay, mica, titanium oxide, calcium carbonate, kaolin, wet type and wet type for the purpose of imparting lubricity. Inorganic particles such as dry-process silica, colloidal silica, calcium phosphate, barium sulfate, and alumina, as well as organic particles containing acrylic acid, styrene, or the like as a constituent component may be blended.

The water-soluble copolyester to be laminated on the polyester film of the present invention is dissolved in water and used as an aqueous solution. This aqueous solution does not have rigor in terms of physical and chemical senses, but also includes an aqueous solution that is mostly dissolved in water and partially dispersed.

The oxidative wax in the present invention is not particularly limited, but a wax obtained by oxidizing the ethylene chain portion of the wax by a method such as air oxidation to add a carboxyl group or a hydroxyl group is preferably used. The molecular weight and melting point are not particularly limited, but those having a molecular weight of 1000 or more are preferable.

As the natural wax, candelilla wax, carnauba wax, wood wax, oricure wax.
Examples thereof include re-wax and sugar cane wax, and carnauba wax is particularly preferable in the present invention.

In the present invention, the oxidized wax and the natural wax may be used alone or in combination with the water-soluble copolyester.

Furthermore, a rosin-modified wax may be further mixed with the oxidized wax and / or the natural wax. By mixing the rosin-modified wax, the dispersibility and uniformity of the oxidized wax and / or the natural wax can be further improved. The rosin-modified wax is not particularly limited, but in the present invention, a composition comprising the following compounds is particularly preferable. Ie {rosin or disproportionated rosin, or hydrogenated rosin ・ α,
β-substituted ethylene (α-substituent: carboxyl, β-substituent:
Hydrogen or methyl or carboxyl) adduct}. Alkyl or alkenyl (each having 1 to 8 carbon atoms) poly (repeating unit: 1 to 6) alcohol ester adduct is particularly preferably used. The mixing ratio of the oxidized wax and / or the natural wax (A) and the rosin-modified wax (B) is not particularly limited, but (A) / (B) is 10/9.
0-90 / 10, preferably 20 / 80-80 / 20,
More preferably, it is 30/70 to 70/30. The mixing ratio (A) / (B) of 90/10 or less is suitable for obtaining a uniform coating film with good uniform dispersibility when emulsifying or suspending in water. The reason for setting it to 10/90 or more is that the slipperiness after coating is good.

Although the slipperiness-imparting effect and blocking-preventing effect of the oxidized wax or natural wax of the present invention have not been sufficiently clarified, the wax of the present invention has a dispersive force component of its surface free energy as compared with paraffin wax. It is presumed that the same effect is exhibited even in a mixed system with a water-soluble copolyester, because it is large and the polar component is small. Various additives may be used in combination in the composition as long as the effects of the present invention are not impaired. Examples thereof include antistatic agents, heat-resistant agents, antioxidants, organic and inorganic particles, pigments and the like.

The coating film (coating) in the present invention is mainly formed of the above-mentioned water-soluble copolyester and the above-mentioned oxidized wax or natural wax or a mixture thereof. Is. In addition,
Mainly composed of water-soluble copolyester and wax means that the mixture is 80% by weight or more, preferably 90% by weight of the coating film.
It is desirable that the content is at least wt%.

In the present invention, 70 to 99.9% by weight of the water-soluble copolyester, preferably 8
It is preferable that 5 to 99% by weight of wax and 30 to 0.1% by weight of wax are mixed, preferably 15 to 1% by weight. If the content of the water-soluble copolyester is 70% by weight or less, the adhesiveness tends to be poor. On the other hand, when it is 99.9% by weight or more, slipperiness and blocking resistance tend to be poor. Within the range of the present invention, it is preferable in terms of compatibility of antistatic property, slipperiness, adhesiveness, and blocking resistance. A known crosslinking agent such as a silane coupling agent may be added to the coating film as another component. The thickness of the coating film is not particularly limited, but is 0.00
1 to 1 μm, particularly 0.01 to 0.2 μm is preferable.

The polyester film in the present invention is a polyester film formed by a known method, that is, a film formed by melting polyester, extruding it into a sheet, and stretching it in at least one direction. It is desirable that the mechanical properties are either a normal balance type, a uniaxially strengthened type, or a biaxially strengthened type. Further, the surface of the polyester film is preferably smooth, and specifically, the surface roughness of the film is a cutoff value of a stylus surface roughness meter of 0.08 mm and an Ra value of 0.003 to 0.
It is desirable to be in the range of 030 μm.

The Ra value means a center line (a part above the center line) in a roughness curve obtained by removing undulations from a sectional curve obtained from a stylus type surface roughness meter using an appropriate cutoff value. It is the arithmetic mean of the absolute values of the height (lowness) of the roughness curve (according to DIN 4768) from the area underneath).

The polyester forming the above film is
Any material may be used as long as it is mainly composed of linear polyester. For example, polyethylene terephthalate
Polytetramethylene terephthalate, poly-1,
Typical examples are 4-cyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, polyethylene-p-oxybenzoate and the like.

The above polyester may be a homopolyester or a copolyester. In the case of a copolyester, examples of components to be copolymerized include diethylene glycol, propylene glycol, neopentyl glycol, polyethylene glycol, p-xylylene glycol, and 1,4-cyclohexane dimethanoe. Diole component such as ale, adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid,
Examples thereof include dicarboxylic acid components such as 5-sodium sulfoisophthalic acid, polyfunctional carboxylic acid components such as tomellitic acid and pyromellitic acid, and p-oxyethoxybenzoic acid. In the case of copolymerization, the component to be copolymerized is 20 mol%
The following is desirable.

The method for producing the film of the present invention will be described. However, it is not limited to this. Substantially non-oriented, crystalline polyethylene terephthalate raw material,
Melt at 270 ° C to 290 ° C and extrude into a sheet,
A film is produced by cooling and solidifying with a casting drum at -30 ° C to obtain an unstretched sheet, followed by biaxial stretching and heat treatment. Biaxial stretching may be either longitudinal or transverse sequential stretching or biaxial simultaneous stretching, and the stretching ratio is not particularly limited, but usually 2.0 to 5.0 times both longitudinal and transverse are suitable. Alternatively, it may be stretched in the machine direction or in the transverse direction after the longitudinal or transverse stretching. The thickness of the polyester is not particularly limited, but 2 to 200 μm is preferably used.

The method for laminating the coating film for the easy-adhesion layer of the easy-adhesion polyester film of the present invention is most preferably a method of applying it during the production process of the polyester film and stretching it together with the substrate. For example, a melt-extruded polyester film before crystal orientation is stretched about 2.5 to 5 times in the longitudinal direction, a surface to be continuously coated is subjected to corona discharge treatment, and the coating liquid is coated to the treated surface. The applied film is dried while passing through a zone that is heated step by step, and the width of the film is 2.5.
It is stretched by about 5 times. More continuously 150-250
It is obtained by a method of introducing a heating zone at a temperature of ℃ to complete the crystal orientation. The coating liquid used in this case is preferably an aqueous system from the viewpoint of environmental pollution and explosion proof. As the method of coating on the substrate film, a known coating method such as a reverse coat method, a gravure coat method, a rod coat method, a die coat method, and a wire bar method can be used. . In the coating layer (easy-adhesion layer), known additives within a range that does not impair the effects of the present invention, for example, heat stabilizers, oxidation stabilizers, weathering stabilizers, ultraviolet absorbers, organic lubricants, pigments , Dyes, organic or inorganic fine particles, fillers, antistatic agents, nucleating agents and the like may be added. As the coating composition, the water-soluble copolyester preferably contains about 0.5 to 10% by weight of the water-soluble copolyester in water. The water-soluble copolyester paint can be prepared, for example, by adding the water-soluble copolyester to warm water of about 80 to 90 ° C. and stirring. The wax paint preferably contains a wax component in water in an amount of about 1 to 30% by weight.
It is preferable to add, for example, about 1% by weight of a nonionic surfactant, a phosphoric acid ester, ammonium oleate, 2-amino-2-methylpropanol, etc., because the wax can be easily dispersed in water. It is preferable that the water-soluble copolyester paint and the wax paint are mixed and then applied to a polyester film. Next, the method for producing the easily adhesive polyester film of the present invention will be described, but the method is not limited to this. After PET is dried according to a conventional method, it is melt extruded, and the extruded sheet-like melt is cooled and solidified to prepare an unstretched PET film. This film is heated to 80 to 120 ° C. and stretched 2.0 to 5.0 times in the longitudinal direction to obtain a uniaxially oriented film.
One side of this film is subjected to corona discharge treatment, and the treated surface is coated with an aqueous coating agent within the scope of the present invention diluted with water to a predetermined concentration. Then, the coated film is
While being heated to 140 ° C., it is stretched 2.5 to 5.0 times in the width direction, and subsequently, it is introduced into a heat treatment zone at 160 to 240 ° C. and heat treated for 1 to 10 seconds. During this heat treatment, a relaxation treatment of 3 to 12% in the width direction may be performed if necessary.

In the above example, the polyester substrate to which the easy-adhesion layer is applied is also copolymerized with a compound having a sulfonic acid and / or a salt thereof, a polymer, a polyethylene glycol, an oxidized wax and / or a natural wax. A wax can be included. in this case,
It has advantages such as improved slipperiness, blocking resistance, and adhesion between the coating layer and the base film. Sulfonic acid and /
Alternatively, a polymer obtained by copolymerizing a compound having a salt thereof,
When a composition containing polyethylene glycol and an oxide wax and / or a natural wax is added, the addition amount is 5 ppm or more and less than 20% by weight to improve slipperiness, blocking resistance, and adhesion. In terms of Needless to say, it may be a coating composition (including recycled pellets of the easily adhesive polyester film of the present invention) provided on the base film.

The easily-adhesive polyester film thus obtained has good winding and slitting properties, and by applying a coating agent according to the application to the coating layer side, various applications such as magnetic recording materials and cellophane are possible. For printing various inks such as inks, offset inks, UV curable inks, for easy adhesion of electrophotographic toners, for easy adhesion of chemical mat paints,
The diazo paint is preferably used as a base film for easy adhesion, for inorganic coating such as vapor deposition, and the like.

[0042]

[Characteristic value measuring method and evaluation method] The characteristic measuring method and the effect evaluating method in the present invention are as follows.

(1) Intrinsic viscosity of copolymerized polyester: [η] was measured at 25 ° C. using an o-chlorophenol solvent.

(2) Water solubility of copolyester 2 g of copolyester was added to 100 g of water to prepare 60
After stirring and dissolving at 2 ° C. for 2 hours and cooling, the mixture is filtered with a 2 μm filter. Water solubility was determined by the dissolved state and the amount of supernatant.

◯: The aqueous solution was transparent or slightly clouded, but almost no filtered matter was observed.

Δ: The aqueous solution was strongly clouded and a filtered substance was observed.

X: It was difficult to dissolve, or the aqueous solution was strongly clouded, and a large amount of filtered substances was observed.

(3) Adhesion An aqueous solution of copolyester and wax is applied on a polyester film substrate to form an easy-adhesion layer, and the easy-adhesion layer surface is coated with a magnetic material (Die Ferracoat CAD-430).
1: A coating consisting of 100 parts by weight of Dainichiseika Kogyo Co., Ltd. and 1 part by weight of a curing agent, Sumidule N75 (Sumitomo Bayer Co., Ltd.) was coated with a bar coat to a thickness of 5 μm after drying.
Coating, and dried at 100 ° C. for 5 minutes to form a coating layer.

Separately, on a PET film (50 μm) substrate, Seika Bond (E270) which is an adhesive manufactured by Dainichiseika Co., Ltd.
/ C-26 = 10/2 (weight ratio)) was applied by a bar coater so as to have a thickness of 8 μm after drying, and dried at 60 ° C. for 1 minute to form a coating layer. Two pieces of PET coated with this adhesive
The sample coated with the above-mentioned magnetic paint is sandwiched between the substrates, and they are laminated with a roller so that air bubbles do not enter. Further, the press roll of the laminator having a surface temperature of 100 ° C. is made to reciprocate once. After aging this sample at 40 ° C. for 48 hours or more, a strip sample having a width of 15 mm was peeled off at 90 ° between the easy-adhesion layer and the magnetic coating material using a Tensilon tensile tester (pulling speed: 200 mm / min) to improve adhesion. It was measured. It was judged according to the following criteria.

⊚: 250 g / 15 mm width or more ○: 200 g / 15 mm width or more, 250 g / 15 mm
Less than width Δ: 150 g / 15 mm width or more, 200 g / 15 mm
Less than width x: less than 150 g / 15 mm width (4) Antistatic property A polyester film on which no easy-adhesion layer is laminated is wound around the surface of the metal drum rotating body, and the easy-adhesion layer is laminated while rotating to form an easy-adhesion layer of the film. Load at the end is 255g
And rub along the metal drum rotating body for 5 seconds. Immediately after that, the electrostatic potential of the film was measured by an electrostatic meter to determine the antistatic property.

◯: Charge amount +3 KV or more to less than +7 KV Δ: Charge amount 0 KV or more to less than +3 KV ×: Charge amount less than 0 KV (negative charging) or +7 KV
Above static meter: Statidon TH type manufactured by Shishido Static Electricity Measurement distance; 50 mm from head opening Metal drum rotating body: Dimension 65 mm width x 150 mm
φ rotation speed 860 rpm Measurement sample: 30 mm width × 300 mm length (5) Blocking resistance Easy adhesion layer surface of film provided with easy adhesion layer and biaxially oriented PE
Stacked T-films (Stacking area: 3 cm x 4
cm) with a load of 500 g / 12 cm ² at 40 ° C 8
After leaving it in 0% RH for 24 hours, the shear stress of the overlapped portion was measured with a Tensilon tensile tester at a tensile speed of 20.
It was measured in cm / min and judged according to the following criteria.

⊚: 0 kg / cm 2 (no blocking) ○: 0.1 kg / cm 2 to 1 kg / cm 2 or less Δ: 1 kg / cm 2 to 3 kg / cm 2 or less ×: 3 kg / cm 2 or more (6) Sliding property (static friction coefficient) μs, dynamic friction coefficient μd) The coefficient of friction between films is ASTM-D-1894-
According to No. 63, static friction coefficient μs and dynamic friction coefficient μd were measured using a surface quality measuring device HEIDON-14DR manufactured by Shinto Kagaku Co., Ltd., sample moving speed 200 mm / min, load 200.
g, contact area 63.5 mm x 63.5 mm, measured under the conditions of: Analyzing recorder-TYPE: HEIDON
It was recorded and evaluated with 3655E-99, and the slipperiness was judged according to the following criteria.

○: μs = less than 0.8 Δ: μs = 0.8 or more and less than 1.3 ×: μs = 1.3 or more (7) Thickness of coating layer Hitachi transmission electron microscope HU-12 type Using, the ultrathin film section of the laminated film was observed to determine the thickness.

(8) Surface Roughness In accordance with JIS-B-0601, a stylus type surface roughness meter BE-3E manufactured by Kosaka Laboratory Ltd. was used to cut off 0.0.
The average surface roughness Ra was measured at 25 mm and a measurement length of 4 mm.

[0055]

EXAMPLES Next, the present invention will be explained based on examples, but the present invention is not necessarily limited to these.

Example 1 71 parts by weight of dimethyl terephthalate, 15 parts by weight of dimethyl 5-sodium sulfoisophthalate, ethylene glycol
50.0 parts by weight, diethylene glycol 6.0 parts by weight, polyethylene glycol 21 having a number average molecular weight of 600
Parts by weight, 0.1 parts by weight of calcium acetate, 0.3 parts by weight of lithium acetate and 0.03 parts by weight of antimony trioxide are added, and an ester exchange reaction is carried out according to a conventional method, and then 0.05 parts by weight of trimethyl phosphate is added. did. Then, the temperature was gradually raised and the pressure was reduced, and finally a polycondensation reaction was carried out at 280 ° C. and 1 mmHg or less to obtain a water-soluble copolyester.
The composition of the obtained water-soluble copolyester was analyzed by NMR (13
As a result of measurement by C-NMR spectrum), the acid component was 87.5 mol% terephthalic acid, 12.5 mol% 5-sodium sulfoisophthalic acid, and the glycol component was 95 mol% ethylene glycol and 5 mol% diethylene glycol. Mol%
The polyethylene glycol content was 20% by weight and the intrinsic viscosity was 0.83 dl / g.

2 g of the obtained water-soluble copolyester was put into 100 g of water, dissolved by stirring at 80 ° C. for 2 hours, cooled and filtered with a 2 μm filter to obtain a water-soluble copolyester aqueous solution having a concentration of 2% by weight. Got The aqueous solution of the water-soluble copolyester was almost transparent, and no filter-filtered substance was observed.

On the other hand, as the wax to be mixed with the water-soluble copolyester, 10 weight parts of the oxidized wax having a solid content of 2% by weight was added to the water-soluble copolyester aqueous solution, followed by thorough mixing and stirring to obtain the coating composition of the present invention. And

[Coating composition] 1) Water-soluble copolyester 90 parts by weight 2) Wax 10 parts by weight (a) Oxidized wax To make the above-mentioned oxidized wax an aqueous dispersion, a nonionic surfactant, a phosphoric acid ester, and oleic acid. Ammonium, 2-
1 part by weight of each of amino-2-methylpropanol was added,
The mixture was vigorously stirred in water, and an ultrasonic dispersion machine was used to prepare an aqueous dispersion having a total solid content of 2% by weight.

On the other hand, polyethylene terephthalate having an intrinsic viscosity of 0.60 containing 0.2% by weight of silicon dioxide having an average particle diameter of 0.2 μm was sufficiently dried and then fed to an extruder and melted at 280 ° C. Then, after passing through a 10 μm cut metal sintered filter, it is extruded into a sheet from a T-shaped die,
This was wound around a cooling drum having a surface temperature of 30 ° C. to be cooled and solidified. In order to improve the adhesion between the sheet and the surface of the cooling drum during this period, a wire electrode was arranged on the sheet side and a DC voltage of 6,000 V was applied. The unstretched PET film thus obtained was heated to 95 ° C. and stretched 3.5 times in the longitudinal direction to obtain a uniaxially stretched film. One surface of this film was subjected to corona discharge treatment in an air atmosphere, and the treated surface was coated with a coating composition having the above composition by a gravure coat method so that the coating layer thickness after biaxial stretching was 0.04 μm. Guide the coated uniaxially stretched film into the tenter 1
After drying the water in a preheating step at 10 ° C., the film was stretched 3.5 times in the width direction while being heated to 120 ° C. while being gripped by a clip, and subsequently heat-treated at 225 ° C. for 5 seconds to give a coating layer thickness of 0. An easily adhesive polyester film having a thickness of 04 μm and a film thickness of 10 μm was obtained. The characteristics of the obtained film are shown in Table 2.
Shown in. This film was excellent in charging characteristics, slipperiness, magnetic coating adhesion, blocking resistance, and surface smoothness.

Example 2 As in Example 1, the acid component was terephthalic acid 87.5.
Mol%, 12.5 mol% of 5-sodium sulfoisophthalic acid, glycol component is 94 mol% of ethylene glycol and 6 mol% of diethylene glycol, and the content of polyethylene glycol is 20% by weight. The intrinsic viscosity was 0.85 dl / g. As in Example 1, 2
An aqueous solution of a water-soluble copolymerized polyester of wt% was prepared.
On the other hand, the thickness of the coating layer was 0.04 μm in exactly the same manner as in Example 1 except that the type and compounding ratio of the added wax were changed as follows.
m and a film thickness of 10 μm were obtained to obtain an easily adhesive polyester film.

[Coating composition] 1) Water-soluble copolyester 94 parts by weight 2) Wax 6 parts by weight (a) Oxide wax 65 parts by weight (b) Rosin-modified wax 35 parts by weight {hydrogenated rosin / αβ-substituted ethylene (α Substituent: carboxyl group, β-substituent: methyl) adduct} -alkyl (6 carbon atoms) poly (repeating unit: 5) alcohol ester compound. To make (a) + (b) an aqueous dispersion, 1 part by weight of each of a nonionic surfactant, a phosphoric acid ester, ammonium oleate and 2-amino-2-methylpropanol is added, and the mixture is vigorously stirred in water. Then, an ultrasonic dispersion machine was used to prepare an aqueous dispersion having a total solid content ratio of 2.0% by weight. The characteristics of the easily adhesive polyester film obtained are shown in Table 2.

Comparative Example 1 As the water-soluble copolyester, the water-soluble copolyester having the same composition as that used in Example 2 was used to obtain a water-soluble copolyester aqueous solution having a concentration of 2% by weight. The aqueous solution of water-soluble copolyester is almost transparent,
No superficial items were found.

Using this coating agent alone without adding wax, the coating layer thickness was set to 0.0 in the same manner as in Example 1.
An easily adhesive polyester film having a thickness of 4 μm and a film thickness of 10 μm was obtained. The properties of the obtained easily adhesive polyester film are shown in Table 2, but the slipperiness was poor.

Examples 3 to 5 and Comparative Example 2 In the same manner as in Example 1, using a water-soluble copolyester having a composition as shown in Table 1 at a concentration of 2% by weight and a wax at a concentration of 2% by weight, respectively. An easily adhesive polyester film having a coating layer thickness of 0.04 μm and a film thickness of 10 μm as shown in Table 2 was obtained.

Examples 3 to 5 are within the scope of the present invention, and have antistatic properties, slipperiness, adhesive properties, blocking resistance,
The solvent resistance was good.

On the other hand, Comparative Example 2 is outside the scope of the present invention,
It was inferior in adhesiveness and slipperiness.

Comparative Example 3 As shown in Table 1, the acid component was 87.5 mol% terephthalic acid, 12.5 mol% 5-sodium sulfoisophthalic acid, and the glycol component was 99.2 mol% ethylene glycol. A water-soluble copolyester having a content of polyethylene glycol of 0.8 mol% and a content of polyethylene glycol of 20% by weight was obtained. The intrinsic viscosity was 0.65 dl / g.

20 parts of oxidized wax was added to this coating material, and the coating layer thickness was 0.04 μm in the same manner as in Example 1.
An easily-adhesive polyester film having a film thickness of 10 μm was obtained. The properties of the easily-adhesive polyester film obtained are shown in Table 2, but were inferior in antistatic property and adhesive property.

Comparative Example 4 As shown in Table 1, the acid component was 87.5 mol% terephthalic acid, 12.5 mol% 5-sodium sulfoisophthalic acid, and the glycol component was 90 mol% ethylene glycol.
A water-soluble copolyester having a content of polyethylene glycol of 10 mol% and a content of polyethylene glycol of 45% by weight was obtained. The intrinsic viscosity was 0.93 dl / g.

15 parts of oxidized wax was added to this coating material, and the coating layer thickness was 0.04 μm in the same manner as in Example 1.
An easily-adhesive polyester film having a film thickness of 10 μm was obtained. The properties of the obtained easily adhesive polyester film are shown in Table 2, but they were inferior in antistatic property and slipperiness.

Example 6 The procedure of Example 6 was repeated except that the polyethylene terephthalate used in Example 1 was replaced with a water-soluble copolyester and an oxidized wax as the base film. An adhesive polyester film having a coating layer thickness of 0.04 μm and a film thickness of 10 μm was obtained in exactly the same manner as in Example 1. That is, 80% by weight of a polyester composed of 87.5 mol% of terephthalic acid as an acid component, 12.5 mol% of 5-sodium sulfoisophthalic acid, 95 mol% of ethylene glycol as a diol component, and 5 mol% of diethylene glycol. And 10 parts by weight of a mixture of 90 parts by weight of a water-soluble copolyester consisting of 20% by weight of polyethylene glycol having a molecular weight of 600 and 10 parts by weight of oxidized wax were mixed with polyethylene terephthalate and used. As the coating agent, as shown in Table 1, water-soluble copolyester / oxidized wax = 90/10 was used. The characteristics of the film thus obtained are shown in Table 2.
Thus, it can be seen that the base layer having sulfonic acid sodium salt, polyethylene glycol and oxidized wax is more excellent in slipperiness, blocking resistance and adhesiveness.

[0073]

[Table 1]

[Table 2]

[0074]

The present invention mainly comprises a water-soluble copolymerized polyester containing a specific amount of a polyoxyalkylene glycol component and an ethylene glycol oligomer on at least one side of the polyester, and an oxide wax and / or a natural wax. Which is an easily-adhesive polyester film formed by forming a coating film of the mixture,
It has excellent smoothness, water solubility, blocking resistance and solvent resistance, and is preferably used for magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials, general industrial materials and the like.

Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location B32B 27/36 7421-4F G11B 5/704 // B29K 67:00 B29L 7:00 9:00 C08L 67:00

Claims (5)

[Claims] 1. A water-soluble polyester film substrate having a polyoxyalkylene glycol component of 20% by weight or more and less than 40% by weight and an ethylene glycol oligomer content of 1% by mole or more and 20% by mole or less on at least one side of the polyester film substrate. An easily-adhesive polyester film formed by forming a coating film of a mixture containing a copolymerized polyester and an oxide wax and / or a natural wax as a main component, wherein the water-soluble copolymerized polyester is a polyoxyalkylene glyco-
And a content of ethylene glycol oligomer [B mol%] satisfy the following formula (1). 1 ≦ A / B ≦ 10 (1) 2. The coating film is formed of a mixture containing 70 to 99.9% by weight of the water-soluble copolymerized polyester, 30 to 0.1% by weight of wax wax and / or natural wax. Item 3. The easily adhesive polyester film according to Item 1. 3. The easily adhesive polyester film according to claim 1 or 2, wherein the coating film further contains a rosin-modified wax. 4. The polyoxyalkylene glycol component is polyethylene glycol, and the number average molecular weight thereof is 400 to 10,000.
The easily-adhesive polyester film according to 3). 5. A polyester film substrate containing 5 ppm or more and less than 20% by weight of a polymer in which a compound having a sulfonic acid and / or a salt thereof is copolymerized, polyethylene glycol, and an oxide wax and / or a natural wax. The easily-adhesive polyester film according to any one of claims 1 to 4, which comprises the composition described above.