JPH0762211A - Polyester aqueous dispersion and readily bondable polyester film - Google Patents

Abstract

PURPOSE:To obtain the subject aqueous dispersion, capable of forming a film excellent in antistatic properties and easy adhesion and useful as magnetic tapes, etc., by dispersing fine particles of an amorphous copolyester composed of a specific glycol component and having a specific glass transition temperature in water. CONSTITUTION:This aqueous dispersion is obtained by dispersing fine particles of an amorphous copolyester in which 0.1-10mol% glycol component is an aromatic glycol, preferably a compound, expressed by formula I {X<1> is H or a 1-5C alkyl; Y is single bond, CH2, C(CH3)2 or SO2; M<1> is one equiv. cation; Z is H or SO3M<1>; m and n are mnot equal to 0; nnot equal to 0; [m+n] is 2-50} or formula II [X<2> is X<1>; M<2> is M<1>; p and q are m and n] and having >=55 deg.C glass transition temperature in water. Furthermore, this readily bondable polyester film can be obtained by coating a polyester film with the aqueous dispersion and forming a primer layer having 0.01-5mum thickness thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous polyester dispersion and an easily adhesive polyester film coated with the aqueous dispersion. More specifically, a polyester water dispersion capable of forming a coating film (easy adhesion layer) having low electrification and excellent in blocking resistance and easy adhesion, and a packaging material, magnetic card, magnetic tape, magnetic disk coated with the same. , An easily-adhesive polyester film useful as a printing material and the like.

[0002]

BACKGROUND OF THE INVENTION Thermoplastic polyesters such as polyethylene terephthalate or its copolymers, polyethylene naphthalene dicarboxylate or its copolymers, or blends of these with small proportions of other resins are melt extruded and biaxially stretched. Then, the polyester film obtained by heat fixing is excellent in mechanical strength, heat resistance, chemical resistance and the like, and is used in various industrial fields. However, since its surface is highly oriented, it has a drawback that it is poor in accepting ink, magnetic paint and the like.

As a method of increasing the receptivity of the surface of the polyester film, there is a method of previously forming a primer layer (easy adhesion undercoat layer) of a synthetic resin on the surface of the film to form a thin surface primer layer different from the base film. The primer layer is formed by applying a solution of a synthetic resin in an organic solvent or an aqueous solution (aqueous solution, water dispersion) to the surface of the film.

As a resin aqueous solution for forming the primer layer, an aqueous solution of a polyester polymer, an aqueous solution of an acrylic polymer and the like are known. Among them, the aqueous liquid of polyester polymer is Japanese Patent Publication No. 56-5476.
JP-A No. 60-248232 and JP-A No. 60-248232. Further, Japanese Patent Publication No. 4-332756 proposes a measure for sticking (blocking) a film by fusing a primer layer under moist heat. However, a film coated with a primer layer formed from an aqueous liquid of a polyester-based polymer disclosed in Examples of the prior art has a large charging property, and an electric charge is accumulated at the time of rewinding, so that the accumulated electric charge is discharged. There is a risk that an explosive fire may occur, and further, there is a drawback that dust and the like are adsorbed by the accumulated electric charge, which causes dropout in magnetic applications, for example.

[0005]

DISCLOSURE OF THE INVENTION The present inventor has conducted earnest research to solve the drawbacks of the prior art and to develop a material for a primer layer having a small charging property, excellent blocking resistance and easy adhesion. As a result, the chargeability of the primer layer formed from the aqueous solution of the conventional polyester-based polymer is the same as that of the sulfonic acid metal salt such as 5-sodium sulfoisophthalic acid copolymerized to impart hydrophilicity to the polyester-based polymer. Due to the aromatic dicarboxylic acid component containing,
Further, it was clarified that the glass transition temperature of the polyester-based polymer is deeply involved in the blocking resistance, and based on these findings, the polyester water of the present invention which gives a primer layer having a small amount of electrostatic charge and good blocking resistance. Reached the dispersion.

Therefore, an object of the present invention is to reduce the charge,
An object of the present invention is to provide an aqueous polyester dispersion capable of forming a coating film (primer layer: easy adhesion layer) having excellent blocking resistance and easy adhesion, and an easily adhesive polyester film coated with the same.

[0007]

The object of the present invention is to:
According to the present invention, firstly, 0.1 to 1 of the glycol component is used.
This is achieved by a polyester water dispersion characterized in that 0 mol% consists of a sulfoaromatic glycol component and an aqueous dispersion of fine particles of an amorphous copolyester having a glass transition temperature of 55 ° C. or higher.

In the amorphous copolyester of the present invention, 0.1 to 10 mol% of the glycol component is composed of the sulfoaromatic glycol component. As the sulfoaromatic glycol component, for example, the following formula (1)

[0009]

[Chemical 1]

Here, X ¹ is a hydrogen atom or has 1 to 1 carbon atoms.
5 is an alkyl group of 5, Y is a single bond, —CH ₂ —, —C
(CH _{3) 2} - or -SO ₂ - and is, M ¹ is one equivalent of a cation, Z is a hydrogen atom or -SO ₃ M ₁ (the definition of M ₁ are as defined above), and the n m is not zero, but n +
It is a number that satisfies m = 2 to 50,

A lower alkylene oxide adduct of sulfobisphenols represented by the following formula (2)

[0012]

[Chemical 2]

Here, X ² is a hydrogen atom or a carbon number of 1 to
5 is an alkyl group, M ² is one equivalent of cation, p and q are not zero, and are numbers satisfying p + q = 2 to 50,

A preferable example is a lower alkylene oxide adduct of sulfohydroquinone represented by:

In the above formulas (1) and (2), the number of carbon atoms is 1 to
The alkyl group of 5 may be linear or branched. As one equivalent of cation, for example, an alkali metal cation, 1/2 of an alkaline earth metal cation, or a phosphonium ion can be preferably mentioned.

The proportion of the sulfoaromatic glycol component is 0.1 to 10 mol% of the total glycol component, preferably 0.1 to 5 mol%. When the sulfoaromatic glycol component is less than 0.1 mol%, it is difficult to uniformly disperse the obtained polyester in water, and when it exceeds 10 mol%, blocking occurs due to moisture absorption of the primer layer when used as a primer layer. Like

Examples of glycols other than sulfoaromatic glycols include ethylene glycol, cyclohexanedimethanol, lower alkylene oxide adducts of bisphenols, and neopentyl glycol. These glycols can be used alone or in combination of two or more.

Examples of the dicarboxylic acid component forming the amorphous copolyester in the present invention include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid and phenylindane dicarboxylic acid. These dicarboxylic acid components may be used alone or in combination of two or more.

The glass transition temperature of the amorphous copolyester must be 55 ° C. or higher. When the glass transition temperature of the amorphous copolyester is less than 55 ° C., blocking easily occurs due to fusion of the primer layer under high humidity heat.

The amorphous copolyester referred to in the present invention is a polyester which shows no or almost no melting point peak when measured with a differential thermal analyzer Du Pont DSC2100 at a heating rate of 20 ° C./min. . When the polyester has a melting point peak, the solubility of the polymer in a hydrophilic organic solvent is remarkably deteriorated and water dispersion becomes impossible, which is not preferable.

The amorphous copolyester is a copolymer of isophthalic acid, phenylindanedicarboxylic acid and other dicarboxylic acids and / or lower alkylene oxide adducts of bisphenols, glycol such as cyclohexanedimethanol and neopentyl glycol in an amount of 20 mol% or more. It can be advantageously achieved by polymerizing. It is particularly advantageous to use a combination of 10 mol% or more of isophthalic acid and 10 mol% or more of a lower alkylene glycol adduct of bisphenol A.

The polyester water dispersion of the present invention, particularly the polyester water dispersion for coating a polyester film, can be produced, for example, by the following method.

The amorphous copolyester is first treated at 20 ° C.
At a solubility of 20 g or more in 1 liter of water and a boiling point of 100 ° C. or lower, or at 100 ° C. or lower, it is dissolved in a hydrophilic organic solvent that is azeotropic with water. As this organic solvent,
Examples thereof include dioxane, acetone, tetrahydrofuran, methyl ethyl ketone and the like. It is also possible to add a small amount of surfactant to such a solution.

Next, water is added to the organic solvent in which the amorphous copolyester is dissolved, with stirring, preferably with heating and high speed stirring, to obtain a pale white to milky white dispersion. A bluish white to milky white dispersion can also be obtained by a method of adding the organic solvent to water under stirring.

The resulting dispersion is further distilled under normal pressure or reduced pressure, and the hydrophilic organic solvent is distilled off to obtain the desired polyester aqueous dispersion. When a hydrophilic organic solvent that is azeotropic with water is used as the organic solvent, water is azeotroped when the organic solvent is distilled off, so the amount of water loss (azeotrope) should be taken into consideration. It is desirable to disperse in

The polyester aqueous dispersion of the present invention preferably has a solid content concentration of 40% by weight or less. When the solid content concentration exceeds 40% by weight, re-aggregation of fine particles of the amorphous copolyester dispersed in water is likely to occur and the stability of the aqueous dispersion is reduced. On the other hand, there is no particular lower limit of the solid content concentration, but if the concentration is too low, the time required for drying becomes long. The average particle size of the copolyester fine particles is usually 1 μm or less, preferably 0.8 μm or less. The polyester aqueous dispersion thus obtained can be applied to one side or both sides of a polyester film described below and dried to impart easy adhesion to the film.

The polyester aqueous dispersion may be used by appropriately containing a surfactant such as an anionic surfactant or a nonionic surfactant during coating. As an effective surfactant, the surface tension of the polyester aqueous dispersion can be lowered to 40 dyne / cm or less, and the wetting of the polyester film is promoted. Many known surfactants can be used. As examples thereof, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, glycerin fatty acid ester, fatty acid metal soap, alkyl sulfate, alkyl sulfonate, alkyl sulfosuccinate, quaternary ammonium chloride, alkyl Examples thereof include amine hydrochloride and sodium dodecylbenzene sulfonate. Further, an antistatic agent, a filler, an ultraviolet absorber, a lubricant, a colorant and the like may be added to the polyester aqueous dispersion, if necessary.

In the present invention, a preferable example of the polyester film is a film made of polyethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, polybutylene terephthalate, or a copolymer obtained by copolymerizing these with other copolymerization components. Can be mentioned. The polyester film may be an unstretched film, a uniaxially stretched film, or a biaxially stretched film,
A uniaxially or biaxially stretched film is suitable.

The step of applying the polyester aqueous dispersion to the polyester film can be arbitrarily selected. The polyester aqueous dispersion is applied to an unstretched film or a uniaxially stretched film, then dried by heating and then further stretched, or applied to a biaxially stretched film and dried. Of these, it is preferable to apply it to a uniaxially stretched film. The coating can be carried out by a conventional method, and for example, kiss coat, reverse coat, gravure coat, die coat and the like are used. The coating amount is 0.01
To 5 μm (dry), more preferably 0.0
1-2 μm (dry), most preferably 0.01-3 μm
m (dry).

Thus, according to the present invention, at least a layer composed of an amorphous copolyester having a sulfoaromatic glycol component as a glycol component in an amount of 0.1 to 10 mol% and a glass transition temperature of 55 ° C. or higher. An easily adhesive polyester film characterized in having on one side is also provided.

The easily-adhesive polyester film of the present invention has a high adhesive force, a low electrostatic charge, and an excellent blocking resistance, so that it can be applied to, for example, magnetic cards, magnetic tapes, magnetic disks, printing materials, graphic materials, photosensitive materials and the like. It is useful. Above all, it is particularly effective for a thin magnetic tape having a base thickness of 10 μm or less.

[0032]

EXAMPLES The present invention will be described in more detail with reference to examples. In addition, "part" in an Example means a weight part.
The glass transition temperature and melting point of the copolyester are Du P
It is a value measured using a differential thermal analyzer type 2100 manufactured by Ont. Each characteristic value was measured by the following method.

(1) Adhesiveness A polyester film (primer-coated) was coated with the following magnetic paint under predetermined conditions, and Scotch tape No. 600 (manufactured by Three M) width 19.4 m.
m, 8 cm in length without sticking bubbles, and leveled with a manual load roll described in JIS C2701 (1975). Adhesive layered part 5 cm was using Tensilon UM-II manufactured by Toyo Baldwin. Head speed 300
This sample was T-peeled at mm / min, the peel strength at this time was determined, and this was divided by the tape width to determine g / cm. In addition, in the T-shaped peeling, the tape side of the laminated body is faced down and the distance between the take-up chucks is set to 5 cm.

Preparation of magnetic coating material for evaluation: Nitrocellulose RS1 / 2 (Flakes containing 25% isopropanol: manufactured by Daicel Co., Ltd.) was dissolved in a paint lacquer thinner to prepare a 40% by weight solution. 9 parts, followed by 32.5 parts of polyester resin (Desmophen # 1700: manufactured by Bayer), 26.0 parts of chromium dioxide magnetic powder, soybean oil fatty acid (Reciion P: manufactured by Riken Vitamin Co., Ltd.) as a dispersant / wetting agent. , Cationic surfactants (cation A
B: Nihon Yushi Co., Ltd.) and squalene (shark liver oil) are put into a ball mill at 1 part, 0.5 part and 0.8 part, respectively. Methyl ethyl ketone / cyclohexanone / toluene = 3 /
282 parts of a mixed solution of 4/3 (weight ratio) is further mixed and sufficiently pulverized to prepare a mother liquor paint (45% by weight). To 50 parts of this mother liquor, 48 parts of an addition reaction product of trimethylolpropane and tolulane diisocyanate (Coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.) and 6.25 parts of butyl acetate were added, and finally 42.75. A magnetic paint for evaluation of weight% was obtained.

(2) Chargeability: 2 polyester films (treated with a primer coating)
Ionized air blower (model 12 manufactured by Hugle Electronics Co., Ltd.) cut into a size of 10 cm x 10 cm
After the charge was removed in 0), the amount of charge after rubbing 5 times with a chromium-plated iron roll was measured using a static electricity measuring device (Stachilon-TL manufactured by Shishido Electrostatic Co., Ltd.).

(3) Blocking resistance The treated surface and the untreated surface of two sheets of polymer were superposed, and a pressure of 6 kg / cm ² was applied to this for 17 hours in an atmosphere of 50 ° C. × 70% RH, followed by peeling. The peeling force is used for evaluation (5
g per cm).

Example 1 <Production of Copolyester> Dimethyl terephthalate 1
00 parts, dimethyl isophthalate 18 parts, 3,3'-disodium sulfoethylene oxide 2 mol adduct 4 parts,
64 parts of ethylene glycol and 55 parts of ethylene oxide adduct of bisphenol A were charged into a transesterification reactor, 0.07 part of tetrabutoxytitanium was added thereto, and the temperature was controlled to 230 ° C. under a nitrogen atmosphere to heat. The produced methanol was distilled off to carry out a transesterification reaction. Then, in this reaction system, Irganox 1
After adding 0.6 parts of 010 (manufactured by Ciba-Geigy), the temperature was gradually raised to 255 ° C., the inside of the system was depressurized to 1 mmHg to carry out a polycondensation reaction, an intrinsic viscosity of 0.60 and a glass transition temperature of 65 ° C. Amorphous copolyester of was obtained.
The composition of the copolyester is shown in Table 1.

<Preparation of Polyester Aqueous Dispersion> 20 parts of this copolymerized polyester was dissolved in 80 parts of tetrahydrofuran, and 180 parts of water was added dropwise to the resulting solution under high speed stirring of 10,000 rpm to give a bluish tinge. A milky white dispersion was obtained. Next, this dispersion was distilled under a reduced pressure of 20 mmHg to remove tetrahydrofuran. Thus, a polyester aqueous dispersion having a solid content concentration of 10% by weight was obtained.

Further, 2 parts of a nonionic surfactant: polyoxyethylene nonylphenyl ether (HLB = 12.8) was added to 180 parts of the polyester aqueous dispersion, and 618 parts of water was further added to prepare a coating solution.

<Production of easily adhesive polyester film>
Polyethylene terephthalate having an intrinsic viscosity of 0.65 measured in 35 ° C. o-chlorophenol was melt extruded to obtain an unstretched film having a thickness of 158 μm, which was then stretched 3.5 times in the machine axis direction and then prepared as above The coating solution was applied to one side of the uniaxially stretched film. Then 105
The film was stretched 3.9 times in the transverse direction at ℃ and heat-treated at 200 ℃ for 4.2 seconds. The average coating amount was 20mg / m ² and the thickness was 12.2μ.
A biaxially stretched primer-coated polyester film of m was obtained. The adhesiveness and chargeability of the treated surface of this film were measured. The results are summarized in Table 1.

Examples 2,3,3'-Disodium sulfobisphenol A 2 mol of ethylene oxide adduct and the composition shown in Table 1 were carried out in the same manner as in Example 1 except that the copolymerization amount of ethylene glycol was changed. An amorphous copolyester having a glass transition temperature of 65 to 66 ° C. was obtained. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and blocking resistance of the treated surface of this film were measured.
The results are summarized in Table 1.

Examples 4 to 6 The 3,3'-disodium sulfobisphenol A ethylene oxide 2 mol adduct of Example 1 was changed to sodium sulfohydroquinone ethylene oxide 2 mol adduct, and sodium sulfohydroquinone ethylene oxide 2 mol was added. The same procedure as in Example 1 was carried out except that the copolymerization amount and the amount of ethylene glycol were changed to obtain an amorphous copolyester having a composition shown in Table 1 and a glass transition temperature of 65 to 66 ° C. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and blocking resistance of the treated surface of this film were measured. The results are summarized in Table 1.

Examples 7 and 8 The same procedure as in Example 1 was repeated except that the sodium, lithium and tetrabutylphosphonium salts were changed from the sodium salt to the 2,3'-disodium sulfobisphenol A ethylene oxide 2 mol adduct. Glass transition temperature of the composition shown: 65
An amorphous copolyester having a temperature of ˜66 ° C. was obtained. Then
A polyester aqueous dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolymerized polyesters were used. Further, Example 1 was repeated except that these coating solutions were used.
A biaxially stretched primer-coated polyester film was obtained in the same manner as in. The adhesiveness and chargeability of the treated surface of this film were measured. The results are summarized in Table 1.

Examples 9 to 11 An amorphous copolymer having a composition shown in Table 1 and a glass transition temperature of 84 to 90 ° C. was prepared in the same manner as in Example 1 except that the dicarboxylic acid and glycol components used and the amount of copolymerization were changed. A polymerized polyester was obtained. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and chargeability of the treated surface of this film were measured. The results are summarized in Table 1.

Example 12 An amorphous copolyester having a composition shown in Table 1 and a glass transition temperature of 55 ° C. was obtained in the same manner as in Example 1 except that the copolymerization amounts of terephthalic acid and isophthalic acid were changed. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and chargeability of the treated surface of this film were measured. The results are summarized in Table 1.

Comparative Example 1 Glass transition temperature 67 of the composition shown in Table 1 was carried out in the same manner as in Example 1 except that 2,3'-disodium sulfobisphenol A ethylene oxide 2 mol adduct was not used.
A copolyester of ℃ was obtained. Next, an attempt was made to prepare a polyester aqueous dispersion in the same manner as in Example 1 except that these copolymerized polyesters were used, but water dispersion could not be achieved.

Comparative Example 2 The composition shown in Table 1 was carried out in the same manner as in Example 1 except that dimethyl 5-sodium sulfoisophthalate was used in place of 2,3'-disodium sulfobisphenol A ethylene oxide 2 mol adduct. A copolymerized polyester having a glass transition temperature of 65 ° C. was obtained. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and chargeability of the treated surface of this film were measured. The results are summarized in Table 1. The amount of charge was large and not suitable for practical use.

Comparative Example 3 The composition shown in Table 1 was carried out in the same manner as in Example 1 except that dimethyl 5-lithium sulfoisophthalate was used in place of 2,3'-disodium sulfobisphenol A ethylene oxide 2 mol adduct. A copolymerized polyester having a glass transition temperature of 65 ° C. was obtained. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and chargeability of the treated surface of this film were measured. The results are summarized in Table 1. The amount of charge was large and not suitable for practical use.

Comparative Example 4 Glass having the composition shown in Table 1 was carried out in the same manner as in Example 1 except that the copolymerization amount of 3,3′-disodium sulfobisphenol A ethylene oxide 2 mol adduct was changed to 20 mol%. A copolyester having a transition temperature of 63 ° C. was obtained. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and chargeability of the treated surface of this film were measured. The results are shown in Table 1. The blocking was large and it was not suitable for practical use.

Comparative Example 5 Example 3 was repeated, except that the 2 mol adduct of 3,3′-disodium sulfobisphenol A ethylene oxide was changed to sodium sulfohydroquinone ethylene oxide to change the copolymerization amount of the component to 20 mol%. Go to Table 1
A copolyester having a glass transition temperature of 64 ° C. having the composition shown in was obtained. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and chargeability of the treated surface of this film were measured. The results are shown in Table 1. The blocking was large and it was not suitable for practical use.

Comparative Example 6 A copolymerized polyester having a composition shown in Table 1 and a glass transition temperature of 52 ° C. was obtained in the same manner as in Example 1 except that the copolymerization amounts of terephthalic acid and isophthalic acid were changed. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and chargeability of the treated surface of this film were measured. The results are shown in Table 1. The blocking was large and it was not suitable for practical use.

Comparative Example 7 A copolymerized polyester having a composition shown in Table 1 and a glass transition temperature of 26 ° C. was obtained in the same manner as in Example 1 except that tetramethylene glycol was used instead of ethylene glycol. Next, an aqueous polyester dispersion and a coating liquid were prepared in the same manner as in Example 1 except that these copolyesters were used. Further, a biaxially stretched primer-coated polyester film was obtained in the same manner as in Example 1 except that these coating solutions were used. The adhesiveness and chargeability of the treated surface of this film were measured. The results are shown in Table 1.
The blocking was large and it was not suitable for practical use.

Comparative Example 8 A polymer having a Tg of 78 ° C. and a melting point of 250 ° C. was obtained in the same manner as in Example 1 except that the isopropanol and the bisphenol ethylene oxide 2 mol adduct were not used. Then, an aqueous dispersion was tried in the same manner as in Example 1, but the aqueous dispersion could not be performed because it was insoluble in tetrahydrofuran.

Comparative Example 9 Table 1 shows the properties of the biaxially oriented polyester film obtained in Example 1 without coating. The adhesive strength was low and it was not practically satisfactory.

[0055]

[Table 1]

Note: * 1 3,3'-Disodium sulfobisphenol A ethylene oxide 2 mol adduct * 2 Sodium sulfohydroquinone ethylene oxide 2 mol adduct * 3 3,3'-dilithium sulfobisphenol A ethylene oxide 2 mol Adduct * 4 3,3'-diphosphonium sulfobisphenol A
2 mol of ethylene oxide adduct * 5 5-sodium sulfoisophthalic acid * 6 5-lithium sulfoisophthalic acid * 7 terephthalic acid * 8 naphthalene dicarboxylic acid * 9 isophthalic acid * 10 phenylindanedicarboxylic acid * 11 diphenyldicarboxylic acid * 12 ethylene Glycol * 13 Trimethylene glycol * 14 Bisphenol A ethylene oxide 2 mol adduct * 15 Magnetic paint adhesion: ○ 90 g / cm or more × less than 90 g / cm

[0057]

Industrial Applicability According to the present invention, it is possible to provide an aqueous polyester dispersion capable of forming an easily adhesive coating film (primer layer) with less charge and an easily adhesive polyester film coated with the same.

Claims (2)

[Claims] 1. A glycol dispersion comprising 0.1 to 10 mol% of a sulfoaromatic glycol component and an aqueous dispersion of fine particles of an amorphous copolyester having a glass transition temperature of 55 ° C. or higher. And polyester aqueous dispersion. 2. A layer comprising at least one surface of an amorphous copolyester having a sulfoaromatic glycol component at 0.1 to 10 mol% of the glycol component and a glass transition temperature of 55 ° C. or higher. Characteristically easy-adhesive polyester film.