KR100249546B1 - Polyester film having low electrostatic and high adhesion properties - Google Patents

Abstract

Water-dispersible having a softening point of 100 to 170 ° C. and containing sulfonic acid metal salt group-containing compound in an amount of at least 0.01 mol% and not more than 0.5 mol% of the total dicarboxylic acid compound (component A) as copolymer component. Low chargeability and high adhesion, consisting essentially of polyester resin (1) and polyethylene oxide-monoalkyl ether (2) or mixtures thereof and polyethylene oxide-polypropylene oxide block copolymer (component B); Polyester film which has a primitive film produced | generated above. The adhesive polyester film has low chargeability and high heat resistance and is useful as a base film for magnetic recording media.

Description

Low charge and high adhesive polyester film {POLYESTER FILM HAVING LOW ELECTROSTATIC AND HIGH ADHESION PROPERTIES}

The present invention relates to a polyester film having low chargeability and high adhesion, and more particularly, to a polyester film having excellent heat resistance and coating properties on its surface and having low chargeability and high adhesion.

Polyester films are used in a wide range of fields (such as magnetic recording media, graphic materials, printing materials, packaging materials, electronic materials, etc.) because of their excellent chemical and physical properties. However, polyester films have high crystallinity and must be provided with surface properties to meet their application purpose in order to develop sufficient film properties.

As a means for providing adhesiveness to the polyester film, it has been proposed and supplemented to apply an adhesive polyester resin aqueous solution such as an aqueous dispersion to produce an adhesive film (primary layer). For example, it is known to introduce a hydrophilic aqueous solution of a polyester resin having a sulfonic acid base of 0.5 mol% or more into a molecule of a polymer by forming the priming layer. However, the hydrophilic polyester resin has a disadvantage of having a low secondary transition point (Tg) and low moisture heat resistance. Further, the surfactant is further added to stabilize the aqueous solution or the coating step, but the heat resistance is deteriorated by the surfactant, and as a result, the polyester resin has poor coating properties.

It is effective to introduce a hard component to increase the secondary transition point (Tg) of the polyester resin. In this case, the adhesion tends to be lower and the hydrophilicity is lowered as a result of the decrease in the solubility of the resin.

JP-A 63-115747 (the term " JP-A " as used herein means " Japanese Patent Application, published as an unexamined publication) " Water-insoluble polyester copolymers (A) and HO- (R consisting of a mixed dicarboxylic acid component and a glycol component containing sulfonic acid metal salt group-containing dicarboxylic acids in an amount of 15 mol%_OneO)_n-(R₂O)_m-H (wherein n and m are integers from 6 to 1,200, R is_One And R₂Are not the same and one of them is a mixture of copolymers (B) represented by an alkylene group having 3 or more carbon atoms or an arylene group, and an alkylene group having 1 to 4 carbon atoms) A transparent thermoplastic resin laminated film having a primitive layer produced on at least one surface thereof is disclosed.

However, the laminated film does not have satisfactory antistatic properties, and the copolymer is likely to have low adhesion due to low HLB (hydrophilic-lipophilic balance).

Therefore, the first object of the present invention is to provide a polyester film having a primitive layer having low chargeability and high adhesion.

A second object of the present invention is to provide a polyester film having a primitive layer having excellent heat resistance.

A third object of the present invention is to provide a coating layer that can produce a coating film uniformly on the surface of a polyester film and has excellent coating processability.

Another object of the present invention is to provide a polyester film having a primitive layer having excellent kinetic properties upon contact with a heating roll.

Another object of the present invention is to provide an adhesive polyester film suitable for use as a magnetic recording medium.

According to a study carried out by the inventors of the present invention, the above object of the present invention has a softening point of 100 to 170 ° C, and (1) in the amount of 0.01 to 0.5 mol% of the total dicarboxylic acid compound as a copolymer component. With water-dispersible polyester resins (component A) and (2) polyethylene oxide-monoalkyl ethers or mixtures thereof with polyethylene oxide-polypropylene oxide block copolymers (component B) containing sulfonic acid metal salt group-containing compounds It has been found that an essentially composed first layer can be achieved by a polyester film having low chargeability and high adhesion, characterized in that it is produced on at least one side.

The invention is described in detail below.

1 is a schematic representation of a conventional apparatus for measuring the coefficient of kinetic friction (μk) of a film surface.

<Description of the symbols for the main parts of the drawings>

1: unwinding reel

2: tension regulator

3, 5, 6, 8, 9 and 11: free rollers

4: tensile tension meter (inlet)

7: fixed pin made of stainless steel SUS304

10: tensile tension meter (outlet)

12: guide roller

13: winding reel

In the present invention, the polyester constituting the polyester film as the base film is a polyester composed of aromatic dicarboxylic acid as the main acid component and aliphatic glycol as the main glycol component. Polyesters are substantially linear and have film-producing properties, in particular film-producing properties by melt molding.

Examples of aromatic dicarboxylic acid compounds that produce polyesters include terephthalic acid, naphthalenedicarboxylic acid, isophthalic acid, diphenoxy ethane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, di Phenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid, anthracene dicarboxylic acid, and the like.

Examples of aliphatic glycol components include polymethylene glycols having 2 to 10 carbon atoms such as ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol and decamethylene glycol; Cyclohexane dimethanol and the like.

In the present invention, polyesters consisting of alkylene terephthalate and / or alkylene naphthalate as the main component are preferred for use as polyester.

Of these polyesters, particularly preferred are 2,6-naphthalene dicarboxylate and total glycol in amounts of at least 80 mole% of polyethylene terephthalate, polyethylene-2,6-naphthalate and terephthalic acid and / or total dicarboxylic acid compounds. Copolyesters consisting of ethylene glycol in an amount of at least 80 mole% of the components. 20 mole% or less of the total acid component is the aromatic dicarboxylic acid other than terephthalic acid and / or 2,6-naphthalene dicarboxylic acid; Aliphatic dicarboxylic acids such as adipic acid and sebacic acid; Alicyclic dicarboxylic acids such as cyclohexane-1,4-dicarboxylate and the like. 20 mol% or less of all glycol components is said glycol other than ethylene glycol; Hydroquinone, resorcin and 2,2-bis (4-hydroxyphenyl) propane; Aliphatic diols having an aromatic ring such as 1,4-dihydroxydimethyl benzene; Polyalkylene glycols (polyoxyalkylene glycols) such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol.

The polyesters used in the present invention are aliphatic typed by aromatic oxyacids or ω-hydroxycaproic acids embodied by hydroxybenzoic acid in amounts of up to 20 mole% of the total dicarboxylic acid component and the oxycarboxylic acid component. Copolymers copolymerized with oxycarboxylic acids such as oxyacids.

The polyesters used in the present invention may also contain at least three functional groups, such as trimellitic acid or pentaerythritol, in a polycarboxylic acid component or in a substantially linear amount, for example in an amount of up to 2 mole% of the total acid component. It includes a copolymer consisting of a polyhydroxy compound component having a.

Polyesters are known per se and can be prepared by methods known per se. Preferably the polyester has an intrinsic viscosity of about 0.4 to 0.9, measured at 35 ° C. in o-chlorophenol solution.

Inert inorganic particles or crosslinked polymer particles in the present invention may be contained alone or in desired combinations in the polyester as lubricant. Preferred examples of inert inorganic particles include kaolin, calcium carbonate, silica, aluminum oxide (alumina) and the like. Preferred examples of the crosslinked polymer include crosslinked silicone resins, crosslinked polystyrene resins, crosslinked acrylic resins and the like. Preferably, when the polyester is prepared, for example at the desired stage during the transesterification or polycondensation when using the transesterification process, or at the desired stage when using the direct polymerization process, the particles in the glycol Are added to the reaction system as a slurry. The average particle size of the lubricant is preferably 0.005 to 2 μm or more preferably 0.01 to 1.8 μm. The amount of lubricant added is preferably 0.01 to 2% by weight, more preferably 0.03 to 1.5% by weight.

In the present invention, the polyester film is preferably a biaxially oriented film. The thickness of the film is preferably 3 to 20 mu m. In addition, the polyester film preferably has a Young module in the biaxial direction of 450 kg / mm ² or more or 2,000 kg / mm ² or less.

Although the manufacturing method of a polyester film is not specifically limited, A polyester film can be manufactured by any conventionally well-known method.

In the present invention, the first layer formed on one or both sides of the polyester film as the base film is substantially composed of the following components A and B:

Component A: Water-dispersible polyester resin containing sulfonic acid metal salt group-containing compound in an amount of at least 0.01 mol% and not more than 0.5 mol% of the total dicarboxylic acid compound.

Component B: A mixture of (i) polyethylene oxide-monoalkyl ether (component B-1) or (ii) component B-1 and polyethylene oxide-propylene oxide block copolymer (component B-2).

In the primary layer of the present invention, the water-dispersible polyester resin (component A) is an amount of 0.01 mol% or more, 0.5 mol% or less, preferably 0.04 to 0.3 mol% of the total dicarboxylic acid compound as a copolymer component. And sulfonic acid metal salt group-containing compounds. When the copolymerization ratio of the compound is 0.01 mol% or less, the water dispersibility of the resin and the stability of the coating solution are extremely bad. If it is 0.5 mole% or more, the resulting film will have high chargeability. As a result, low chargeability, which is a characteristic feature of the polyester film of the present invention, cannot be obtained.

Preferred examples of sulfonic acid metal salt group-containing compounds include dicarboxylic acids having sulfonic acid salt groups (such as sodium sulfonate groups, lithium sulfonate groups, potassium sulfonate groups, ammonium sulfonate groups, sulfonic acid phosphine polyalkyl groups and the like). Specific examples thereof include 5-sodium sulfoisophthalate, 5-potassium sulfophthalate, 5-sodium sulfoterephthalate, 5-potassium sulfoterephthalate, and the like.

Preferred examples of the dicarboxylic acid compound constituting the water-dispersible polyester resin (A) include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, 4,4'-di Phenyldicarboxylic acid, phenylindandicarboxylic acid, adipic acid, sebacic acid, trimellitic acid and the like. The water-dispersible polyester resin in an amount of 30 to 100 mol%, preferably 35 to 90 mol% of the total dicarboxylic acid compound provides high heat resistance to the primary layer.

Preferred examples of the glycol component constituting the polyester resin as component A include ethylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexane dimethanol, dimethylol Additives of bisphenol A with propionic acid, glycerin, trimethylolpropane, alkylene oxide and the like. These can be used as a combination of two or more.

The water-dispersible polyester resin (component A) can be produced by a conventional known method. The number average molecular weight of the water-dispersible polyester resin (component A) is preferably 3,000 to 30,000, more preferably 5,000 to 15,000. Although the coating solution is prepared using the water-dispersible polyester resin (component A) as the water dispersion, the average particle size is preferably several tens of nm.

Preferred examples of component A include 30 to 99.06 mole% of 2,6-naphthalenedicarboxylic acid, dicarboxylic acid consisting of 0 to 69.7 mole% of isophthalic acid, and 0.04 to 0.3 mole% 5-sodium sulfoiso Water-dispersible polyesters consisting of a dicarboxylic acid consisting of phthalates and a glycol component consisting of 40-100 mol% ethylene glycol and bisphenol A additives with 0-60 mol% propylene oxide (1-10 mol additive) Include.

Component B constituting the primary layer of the present invention is component B-1 or a mixture of component B-1 and component B-2.

Component B-1 is a polyethylene oxide-monoalkyl ether, preferably a polyethylene oxide-monoalkyl ether in which the monoalkyl ether in the alkyl moiety has from 8 to 18 carbon atoms. Component B-1 preferably has 5 to 15 ethylene oxide recovery units. Component B-1 is an ether compound represented by formula

RO- (C ₂ H ₄ O) _q -H

(Wherein R is an alkyl group having 8 to 18 carbon atoms and q is a number from 3 to 15).

In Formula 1, the alkyl group represented by R is preferably first or second alkyl having 8 to 18 carbon atoms. Preferred examples of the alkyl include octyl, lauryl, myristyl, pentadecyl, stearyl and the like, with alkyl having 12 to 14 carbon atoms being particularly preferred. q is preferably a number from 5 to 9. In Chemical Formula 1, the alkyl group represented by R functions as a component providing a lipophilic property and the ethylene oxide unit [-(C ₂ H ₄ O) _q -H] functions as a component providing a hydrophilic property. Thus, depending on the carbon number of the alkyl group, the lower the degree of addition polymerization of ethylene oxide (ie q is a smaller number), the greater the lipophilic property, and the higher the degree of addition polymerization of ethylene oxide (ie, q is a larger number) The nature is greater. Ether compounds in which R is an alkyl group having 12 to 14 carbon atoms and q is a number from 5 to 9 are particularly preferred in that they balance the above properties.

As component B, the component B-1 can be used alone. However, component B-1 can be used in combination with a polyethylene oxide-polypropylene oxide block copolymer (component B-2). The polyethylene oxide-polypropylene oxide block copolymer as component B-2 is a block copolymer having polyethylene oxide units represented by the following general formula (2) at both ends.

HO- (C ₂ H ₄ O) _n- (C ₃ H ₆ O) _m- (C ₂ H ₄ O) _p -H

In Formula 2, m is 20 to 80, (n + p) is preferably 80 to 600, more preferably 100 to 600, n and p are each preferably 20 or more.

Although the ratio of polyethylene oxide-polypropylene oxide in the polyethylene oxide-polypropylene oxide block copolymer (component B-2) can be adjusted to a desired value, the proportion of polyethylene oxide units is in the range of 50 to 90% by weight, more preferably Is 70 to 86% by weight. The number average molecular weight of the block copolymer is preferably 5,000 to 30,000.

The contents of component A and component B in the primary layer of the present invention are 93 to 70% by weight and 7 to 30% by weight, respectively, particularly preferably 90 to 80% by weight and 10 to 20% by weight. If the amount of component A is 93% by weight or more, the coating film forming property will be poor, and if it is 70% by weight or less, the adhesion of the primary layer will be low. If the amount of component B is 7 wt% or less, the coating film forming property will be low, and the chargeability will be insufficient. On the other hand, if the amount of component B is 30% by weight or more, the adhesion, anti-blocking properties and heat resistance of the obtained film will be deteriorated adversely.

In the first layer of the present invention, component B is B-1 alone or a mixture of component B-1 or component B-2. Thus, the ratio of component B-1 to component B-2 is 10: 1 to 2: 8, preferably 10: 0 to 1: 2.

In the present invention, the primary layer produced on the surface of the polyester base film has a thickness of 0.005 to 1 mu m, preferably 0.01 to 0.7 mu m. The surface roughness of the first layer is 0.002 to 0.02 µm, preferably 0.004 to 0.01 µm with respect to the center line average roughness Ra. If the center line average roughness (Ra) of the surface of the first layer is 0.002 µm or less, the operating characteristics will deteriorate in the film processing step, and if 0.02 µm or more, the electron-magnetic conversion characteristics deteriorate adversely when the film is used in a magnetic recording medium. Will be.

In the properties carried out by the inventors in the properties of the adhesive polyester film obtained according to the ratio of component A to component B and according to component B, component B-1 alone or a mixture of component B-1 and component B-2 I noticed a slight difference. Desired properties in operability or heat resistance can be achieved by using the above difference when the film is used as a magnetic recording medium.

That is, when a priming layer composed of 93 to 70 wt% of component A and 7 to 30 wt% of component B-1 alone is produced, an adhesive poly having a kinetic friction coefficient when heated at 65 ° C. and 105 ° C. Obtain an ester film. Particularly preferably, when the first layer consists of 90 to 75% by weight of component A and 10 to 25% by weight of component B-1, it has a coefficient of kinetic friction of 0.10 to 0.65 at the time of heating at 65 ° C and 105 ° C. An adhesive polyester film is obtained. Thus, when component B-1 is used as component B and when mixed with component A in the above ratio, a film having a small coefficient of kinetic friction at time heated at 65 ° C. and 105 ° C. is obtained. Thus, a polyester film is obtained that can be easily manipulated at high speeds.

When the first layer is produced using component B-1 and component B-2 as component B, that is, the first layer comprises components at ratios of 93 to 80% by weight, 10 to 2% by weight and 15 to 5% by weight, respectively. When composed as A, component B-1 and component B-2, an adhesive polyester film having a relatively high softening point of 140 to 170 ° C. and good heat resistance is obtained. In this case, when the ratio of component A, component B-1 and component B-2 is 90 to 80% by weight, 7 to 3% by weight and 13 to 7% by weight, respectively, the obtained first layer is more preferably 146 to 165 캜. It has a softening point of and has excellent adhesive coating processability.

The first layer of the present invention is applied by applying a coating solution to an unstretched polyester film, a stretched polyester film or a biaxially oriented film to provide a film by drying. Among the films, the coating is preferably carried out on a monoaxially oriented film drawn in the longitudinal direction. In this case, after coating, the film can be drawn in the diagonal direction, in which case it can be further redrawn in the length or diagonal direction. The stretching itself can be carried out under commonly known conditions by conventionally known methods. For example, the film is drawn in a biaxial direction at a draw ratio of at least 2.5, preferably at least 3.0, or at an area draw ratio of at least 8, preferably from 8 to 30.

The solids content of the coating solution (primary coating solution) is preferably 0.5 to 30% by weight, more preferably 1 to 15% by weight. The coating solution may contain inert fine particles, heat stabilizers and the like as desired, and may also contain water-dispersible polyester resins (component A), polyethylene oxide-monoalkyl ethers (component B-1) and polyethylene oxide-polypropylene. It may further contain an oxide block copolymer (component B-2).

The obtained laminated polyester film having the primary layer has excellent coating and adhesion, heat resistance and low chargeability, and is particularly useful as a base material for magnetic recording media.

Example

The following examples further illustrate the invention. The characteristic value was measured according to the following method.

1.adhesive

The coating for the following evaluation was applied onto a polyester film (surface of the primitive layer) with a Meyer bar to make the film thickness about 4 μm after drying and then dried at 100 ° C. for 3 minutes. Thereafter, the film was aged at 60 ° C. for 24 hours, and then Scotch Tape No. 12.7 mm wide and 15-cm long. 600 (manufactured by 3M) was attached to the film in such a way that no air entered between the tape and the film. The tape is firmly pressed onto the film with a manual load roll specified in JIS C2701 (1975), and the width of the tape is cut out. The film is peeled off at an angle of 180 ° C. and the peel force is measured.

○: 50 g or more

△: 30 g or more and 50 g or less

×: 30 g or less

(Evaluation coating)

In terms of solids content,

(1) 25 parts by weight of urethane resin (Nipporan 2304 from Nippon Polyurethane)

(2) 50 parts by weight of vinyl chloride-vinyl acetate resin (S-Lec A from Sekisui Chemical)

(3) 1 part by weight of dispersant (Resin P from Riken Vitamin)

(4) 500 parts by weight of magnetic agent (CTX-860 from Toda Chemical)

Were dissolved in a mixed solvent of methyl ethyl ketone to prepare a 40% solution and dispersed with a sand mill for 2 hours. Thereafter, 25 parts by weight of crosslinker (Coronate L) (for solid content) was added and stirred well to obtain a magnetic coating.

Young's Modulus

The film is cut into 10 mm wide and 150 mm long sample pieces, with a tensile speed of 10 mm / min and a feed rate of 500 mm / min, medium to 100 mm intervals using an Instron-type general tensile tester. Tensioned to engage.

Young's modulus was calculated from the tangent of the rise of the obtained load-extension curve.

3. Center Line Average Roughness (Ra)

The chart (film surface roughness curve) was drawn using a tracer type surface roughness gauge manufactured by Kosaka Laboratories under conditions such as a needle radius of 2 μm and a tracer load of 30 mg. The length L measured in the direction of the center line is extracted from the film surface roughness curve, and the roughness curve is represented by Y = f (X) with the center line of the extracted portion as the X axis and the vertical size direction as the Y axis. Ra [μm] given by the following formula is defined as the center line average roughness of the film surface.

4. Kinetic friction coefficient at heating (μk)

The above was measured by the following method using the apparatus shown in FIG. In Fig. 1, reference numeral 1 is an unwound reel, 2 is a tension regulator, 3, 5, 6, 8, 9 and 11 are free rollers, 4 is a tension tension meter (inlet), 7 is stainless steel SUS304 (OD: 5 mm pin), 10 is a tensile tension meter (outlet), 12 is a guide roller and 13 is a winding reel.

Fixing pin 7 (surface) heated at 65 ° C. or 105 ° C. by a heater at an angle [θ = (90/180) π (radius)] of 90 ° with the surface of the priming layer of the polyester film cut to 1/2 inch width Roughness: 10 nm) and move (friction) at a speed of 2 m / min. Tensile T ₁ at the inlet is taken to 30 g in tension regulator 2 and the film is run 40 m and the tension (T ₁ : g) is measured at the outlet. The maximum tension is expressed by T ₂ (g), and the kinetic friction coefficient (k) is calculated from the following equation.

μk = 1 / θ and log and T _2/30

5. Daejeon

The polyester film (10 μm × 500 mm × 3,000 mm) was rewound at a speed of 150 m / min in an atmosphere of 23 ° C. × 75% RH, and the amount of peeling chargeability of the obtained roll was measured by Model- of Hugel Electronics. Measure using 203 digital electrical measuring instrument.

○: 2.5 kv or less

△: 2.5 to 50 kv

×: 5.0 kv or more

6. Softening point (ring and ball method)

A dry-solid product of the coating solution for producing the first layer is prepared and its softening point is measured according to JIS K-3531-1960. Glycerin is used as a heating bath and heated at a rate of about 5 ° C./min.

7. Heat resistance

The polyester film is brought into contact with a heating roll whose primary layer is heated at 110 ° C. and has a rotating surface speed of 4 m / min at a nip pressure of 2 kg / cm 2, and the surface of the roll is evaluated after 40 minutes.

○: No foreign matter is observed on the surface of the roll.

(Triangle | delta): A foreign material is slightly observed on the surface of a roll.

X: A large amount of foreign matter is observed on the surface of the roll.

8. Evaluation of coating properties

When applying the priming coating solution to the film, the coating surface of the film is observed to visually assess whether the coating is applied uniformly.

○: No spots or streaks are observed.

(Triangle | delta): Several points or streaks are observed.

X: A large amount of spots or streaks are observed.

9. Coating Solution Stability

The initial coating solution is kept at 60 ° C. for 3 days and the precipitate is observed.

(Circle): A deposit is not observed.

(Triangle | delta): Some sediment is observed.

X: A large amount of precipitate is observed.

2.3 times the length of the unstretched sheet of polyethylene terephthalate having an intrinsic viscosity of 0.62 in the longitudinal direction, followed by 2,6-naphthalenedicarboxylic acid component (40 mol%), isophthalic acid component (59.95 mol%), 5 Bisphenol A with 15% by weight of polyethylene oxide-monoalkyl (12 to 14) with sodium sulfoisophthalate component (0.05 mol%), ethylene glycol component (70 mol%), and 4 mol propylene oxide (30 mol%) 85% by weight of water-dispersible polyester resin (number average molecular weight: about 23,500) consisting of an additive of ether (number average molecular weight: about 500, alkyl group: alkyl mixture having 12 to 14 carbon atoms) A 2 wt% aqueous solution of the composition consisting of) was applied to one side of the sheet as a roll coater. Thereafter, the sheet was stretched 3.7 times in the diagonal direction during drying, 2.3 times more in the longitudinal direction and heated at 220 ° C. to obtain a 10 μm thick film. The film thickness of the primary layer was 0.015 μm. The film had a surface roughness of 0.005 μm and had Young's modulus of 830 kg / mm 2 in the longitudinal direction. The properties of the film are shown in Table 1.

Examples 2 and 3 and Comparative Examples 1-4

The procedure of Example 1 was repeated except that the composition ratio of the coating composition was changed as in Table 1. Comparative Example 2 is the same as Example 2 except that the polyethylene oxide-polyoxypropylene copolymer is used as a surfactant instead of the polyethylene oxide-monoalkyl ether. The properties of the obtained film are shown in Table 1.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Copolyester (Component A) Acid component (mol%) Naphthalene-dicarboxylic acid 40.00 40.00 40.00 40.00 40.00 50.00 50.00 Isophthalic acid 59.95 59.95 59.80 59.95 59.95 46.00 50.00 Sulfoisophthalic acid 0.05 0.05 0.20 0.05 0.05 4.00 0.00 Surfactant (Component B) 15 10 10 0 10 10 10 Adhesive ○ ○ ○ ○ ○ ○ ○ Softening Point (℃) 120 128 126 148 128 119 134 Friction Coefficient (65 ℃) 0.62 0.60 0.63 0.60 Stationary exercise 0.71 0.62 Friction coefficient (105 ℃) 0.34 0.33 0.34 0.31 Stationary movement 0.39 0.32 Daejeon ○ ○ ○ ○ × × ○ Coating properties ○ ○ ○ × ○ ○ × Gotting Solution Stability ○ ○ ○ ○ ○ ○ △

Example 4

Preparation of the first coating solution:

40 mole% 2,6-naphthalenedicarboxylic acid component, 59.95 mole isophthalic acid component, 0.05 mole% 5-sodium sulfoisophthalate component, 70 mole% ethylene glycol with a number average molecular weight of about 10,000 82.5 weight% of water-dispersible polyester resin (component A) which consists of a component and 30 mol% addition of bisphenol A with 4 mol propylene oxide;

5% by weight (number average molecular weight: about 500, alkyl group: alkyl mixture having 12 to 14 carbon atoms) polyethylene oxide-monoalkyl ether (component B-1); And

12.5% by weight of a block copolymer (component B-2) consisting of polyethylene oxide (80% by weight) and polypropylene oxide (20% by weight) (number average molecular weight: about 23,500) was used and sufficiently blended with water as a medium. A primary aqueous coating solution with a solids content of 10% by weight was prepared.

Preparation of Adhesive Polyester Film:

An unstretched sheet of polyethylene terephthalate having an intrinsic viscosity of 0.62 was stretched 2.3 times in the longitudinal direction and the initial aqueous solution was applied to one side of the sheet as a roll coater. Thereafter, the sheet was stretched 3.7 times diagonally, 2.3 times longer in the longitudinal direction, and then heated at 220 ° C. to obtain a 10 μm thick film during drying. The film thickness of the primary layer was 0.015 μm. The properties of the film are shown in Table 2.

Examples 5-7 and Comparative Examples 5-7

The procedure of Example 5 was repeated except that the amount of polyester resin component was changed to 85% by weight and the ratio of coating composition was changed as shown in Table 2. The properties of the obtained film are shown in Table 2.

Example 4 Example 5 Example 6 Example 7 Comparative Example 5 Comparative Example 6 Comparative Example 7 Copolyester (Component A) Acid component (mol%) 2,6-naphthalenedicarboxylic acid (mol%) 40 40 40 40 40 50 50 Isophthalic acid (mol%) 59.95 59.95 59.95 59.8 59.95 46 50 5-sodium sulfoisophthalic acid (mol%) 0.05 0.05 0.05 0.2 0.05 4 0 Glycol ¹⁾ sodium EG (mol%) 70 70 70 70 70 70 70 BPA-P (mol%) 30 30 30 30 30 30 30 Component B EOPO copolymer (% by weight): component B-2 12.5 7.5 10 7.5 15 7.5 7.5 Polyethylene oxide-monoalkyl ether (% by weight): component B-1 5 7.5 5 7.5 0 7.5 7.5 Adhesive ○ ○ ○ ○ ○ ○ ○ Softening Point (℃) 152 147 154 145 164 138 153 Heat resistance ○ ○ ○ ○ ○ △ ○ Daejeon ○ ○ ○ ○ ○ × ○ Coating properties ○ ○ ○ ○ × ○ × Coating solution stability ○ ○ ○ ○ ○ ○ △ Note 1) EG: ethylene glycol BPA-P: addition product of bisphenol A with 4 mol of propylene oxide

The adhesive polyester film of the present invention has a specific amount of sulfonic acid metal salt groups in the polyester resin, and at a specific ratio, a composition consisting of polyethylene oxide-monoalkyl ether or a mixture thereof and a polyethylene oxide-polypropylene oxide block copolymer is used as a base layer. Characterized in that. This provides a polyester film with excellent heat resistance, high adhesion and low chargeability and improved coating processability. Therefore, the film has excellent properties as a base film for magnetic recording media.

Claims (17)

(Correction) Low-elasticity and high-adhesion polyester film, wherein a film having a softening point of 100 to 170 ° C. and a first layer composed of the following components A and B is formed on one or both surfaces thereof: (1) a water-dispersible polyester resin (component A) containing a sulfonic acid metal base-containing compound in an amount of 0.01 mol% to 0.5 mol% with respect to the total dicarboxylic acid compound, and (2) A mixture of polyethylene oxide-monoalkyl ether or polyethylene oxide-monoalkyl ether and polyethylene oxide-polypropylene oxide block copolymer (component B). (Correction) The polyester film according to claim 1, wherein the first layer contains 93 to 70% by weight of component A and 7 to 30% by weight of component B. (Correction) The method according to claim 1, wherein component B in the first layer is (i) polyethylene oxide-monoalkyl ether (component B-1), or (ii) component B-1 and polyethylene oxide-polypropylene oxide block air. A polyester film characterized in that it is a mixture of copolymers (component B-2), wherein the weight ratio of component B-1 to component B-2 is from 10: 0 to 2: 8. (Correction) The polyester film according to claim 1, wherein the monoalkyl ether of the polyethylene oxide-monoalkyl ether (component B-1) in the primary layer has 8 to 18 carbon atoms in the alkyl portion. (Correction) The polyester film according to claim 1 or 4, wherein the polyethylene oxide-monoalkyl ether (component B-1) in the primary layer has 3 to 15 ethylene oxide repeat units. (Correction) The block copolymer according to claim 1, wherein the polyethylene oxide-polypropylene oxide block copolymer (component B-2) in the primary layer contains a polyethylene oxide unit and a polypropylene oxide unit in a weight ratio of 50:50 to 90:10. Polyester film, characterized in that the chain. (Correction) The polyester film according to claim 1, wherein the polyethylene oxide-polypropylene oxide block copolymer (component B-2) in the primary layer is a polyethylene oxide-polypropylene oxide block copolymer having a number average molecular weight of 5,000 to 30,000. . (Correction) The water-dispersible composition according to claim 1, wherein the water-dispersible polyester resin (component A) in the primary layer contains 0.04 to 0.3 mol% of sulfonic acid metal salt group-containing compound of the total dicarboxylic acid compounds. It is a polyester resin, The polyester film characterized by the above-mentioned. (Correction) The method according to claim 1, wherein the water-dispersible polyester resin (component A) in the primary layer contains 30 to 100 mol% of 2,6-naphthalenedicarboxylic acid component with respect to the total dicarboxylic acid compounds. It is a water-dispersible polyester resin, The polyester film characterized by the above-mentioned. The polyester film according to claim 1, wherein the thickness of the first layer is 0.005 to 1 µm. The polyester film according to claim 1, wherein the first layer has a center line average surface roughness Ra of 0.002 to 0.02 µm. The polyester film according to claim 1, wherein the polyester film has a thickness of 3 to 20 µm. (Twice correction) The method according to claim 1, wherein the primary layer is composed of a water-dispersible polyester resin (component A) and a polyethylene oxide-monoalkyl ether (component B-1), wherein the proportion of component A is 93 to 70 weight%, the proportion of component B-1 is 7 to 30 weight%, and the kinetic friction coefficient at the time of heating at 65 degreeC and 105 degreeC is 0.05 to 0.75, The polyester film characterized by the above-mentioned. (Correction) The method according to claim 1, wherein the primary layer is composed of a water-dispersible polyester resin (component A) and a polyethylene oxide-monoalkyl ether (component B-1), and the proportion of component A is 90 to 75% by weight. And the proportion of component B-1 is 10 to 25% by weight, and the coefficient of kinetic friction when heated at 65 ° C and 105 ° C is 0.10 to 0.65. (Twice correction) The method according to claim 1, wherein the first layer is a water-dispersible polyester resin (component A), polyethylene oxide-monoalkyl ether (component B-1) and polyethylene oxide-polypropylene oxide block copolymer (component B-2), wherein the proportion of component A is 93 to 80% by weight, the proportion of component B-1 is 10 to 2% by weight, the proportion of component B-2 is 15 to 5% by weight, and prime The softening point of the layer is 140 to 170 ℃ polyester film, characterized in that. (Correction) The method according to claim 1, wherein the primary layer is a water-dispersible polyester resin (component A), polyethylene oxide-monoalkyl ether (component B-1) and polyethylene oxide-polypropylene oxide block copolymer (component B- 2), wherein the proportion of component A is 90 to 80% by weight, the proportion of component B-1 is 7 to 3% by weight, the proportion of component B-2 is 13 to 7% by weight, and A softening point is 146 ℃ to 165 ℃ polyester film, characterized in that. The polyester film according to claim 1, for use as a base film for magnetic recording media.

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