JPH04201560A - Laminated polyester type film - Google Patents

Abstract

PURPOSE:To obtain a polyester type laminated film having good adhesiveness and slip properties by laminating a water-insoluble polyester copolymer containing metal sulfonate group-containing dicarboxylic acid with respect to the total dicarboxylic acid component and having specific reduced viscosity to the single surface of a polyester type film. CONSTITUTION:A water-insoluble polyester copolymer containing 0.5-15mol% of metal sulfonate group-containing dicarboxylic acid with respect to the total dicarboxylic acid component and having reduced viscosity of 0.35-below 0.45(dl/g) is laminated to at least the single surface of a polyester type film as at least one component of laminating resins. Since this polyester type laminated film is constituted by laminating the sulfonic acid copolymer to the thermoplastic resin film, this film has good adhesiveness to all of a hydrophilic polymer, a hydrophobic polymer and inorg. matter.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a thermoplastic resin laminated film with excellent adhesiveness,
In particular, it relates to a polyester laminated film that has good adhesion to hydrophilic polymers, hydrophobic polymers, and inorganic substances, and has good slip properties.

(Prior art) Thermoplastic resin films such as polyester, polyamide, and polypropylene (especially polyester films such as polyethylene terephthalate) have excellent mechanical strength, heat resistance, chemical resistance, transparency, and dimensional stability, and are magnetic. It is widely used in applications such as heath film for tapes, insulating tapes, photographic films, tracing films, and food packaging films. However, these polyester films usually lack adhesion to hydrophilic polymers, hydrophobic polymers, and inorganic materials. Therefore, when a magnetic material, a photosensitive agent, a matte abrasion, etc. are to be laminated on this film, it is necessary to apply a corona discharge treatment to the film surface and then provide an anchor coat layer.

In addition, this film can be used as a food packaging film,
Even if a printed layer or a heat-sealing layer is provided, the adhesiveness between these layers and the polyester film is weak, and the heat-sealing strength may be reduced.

To improve the adhesion of polyester films,
In addition to corona discharge treatment, methods have been proposed in which the film is subjected to physical treatments such as ultraviolet irradiation treatment, plasma discharge treatment, fire treatment, and corona discharge treatment under a nitrogen atmosphere. Chemical treatment methods such as alkali treatment and primer treatment, as well as the combination of these and physical treatment methods, are also used. However, none of these methods can sufficiently improve the adhesiveness of polyester films. In particular, the adhesion between the hydrophilic polymer or hydrophobic polymer and the film is insufficient.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and its purpose is to provide a material that has good adhesion to hydrophilic polymers, hydrophobic polymers, and inorganic materials and is slippery. An object of the present invention is to provide a polyester laminated film with good properties.

(Means for Solving the Problems) According to the present invention, at least one side of a polyester film contains 0.5 to 15 mol% of a dicarboxylic acid containing a sulfonic acid metal base based on the total dicarboxylic acid component, and has a reduced viscosity of 0.
By laminating a water-insoluble polyester copolymer having a molecular weight of 35 (dl/g) or more and less than 0.45 as at least one component of the laminated resin, a polyester film with excellent adhesiveness and slipperiness can be obtained.

The copolymer to be laminated on the polyester film of the present invention is a sulfonic acid-modified copolymer polyester with a reduced viscosity of 0.35 (cll/g) or more of 0.45
It must be less than Copolymerized polyester polyurethane obtained by chain-extending these polymers with polyisocyanate can also be used.

In the present invention, any of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids can be used as the dicarboxylic acid. Aromatic dicarboxylic acids include, for example, terephthalic acid, isophthalic acid, orthophthalic acid,
, 6-naphthalene dicarboxylic acid. If the aromatic dicarboxylic acid is 40 mol% or more of the total carboxylic acid components,
preferable.

If it is less than 40 mol%, the mechanical strength and water resistance of the obtained copolyester will decrease. Examples of aliphatic dicarboxylic acids and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1.4 -cyclohexanedicarboxylic acid and the like.

Although these aliphatic dicarboxylic acids and alicyclic dicarboxylic acids may improve the adhesion of copolymerized polyester (polyurethane), they usually reduce mechanical strength and water resistance, so aromatic dicarboxylic acids are mainly used. is preferable.

Glycols to be reacted with the dicarboxylic acid include aliphatic glycols having 2 to 8 carbon atoms, and 6 to 12 carbon atoms.
There are cycloaliphatic glycols. Examples of glycols that can be used include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butadiol, neopentyl glycol, 1,6-hexanediol, and 1,2-cyclohexane dimeta. tool, 1
, 3-cyclohexane dimetatool, 1,4-cyclohexane dimetatool, P-xylene glycol, diethylene glycol, triethylene glycol and the like.

Polyethers are also used as glycols. Polyethers include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

This copolyester is obtained by a conventional melt polycondensation method. The 20-polycondensation method includes an ester method and a transesterification method. In the ester method, polycondensation is carried out by directly reacting a dicarboxylic acid component and a glycol component, and then distilling off water and esterifying them. In the transesterification method, a dimethyl ester component of a dicarboxylic acid and a glycol component are reacted, methyl alcohol is distilled off and transesterified, and then polycondensation is performed. Copolymerized polyesters are synthesized not only by the melt polycondensation method but also by the solution polycondensation method and the interfacial polycondensation method.

Furthermore, when this copolyester is used as an aqueous dispersion when coating a thermoplastic resin film, it can be copolymerized with an ester-forming sulfonic acid metal base-containing dicarboxylic acid during the production process of the copolyester. good.

This dicarboxylic acid is contained in the copolymer in a proportion of 0.5 to 15 mol%. This copolyester has a molecular weight of 40 to 120 in the coexistence of a water-soluble organic compound and water.
By stirring with water, it is made into an aqueous dispersion. Examples of sulfonic acid metal base-containing levonic acids include metal salts of the following compounds: levoterephthalic acid, 5-
Sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5-(4-sulfophenoxy)isophthalic acid. In particular, 5-sodium J
Lehoisophthalic acid and sodium sulfoterephthalic acid are preferred.

Isocyanates used for chain extension of copolymerized polyesters include, for example, 2.4-) lylene diisocyanate, 2.6-) lylene diisocyanate, p-phenylene diisocyanate, biphenylmethane diisocyanate, m-phenylene diisocyanate, hexamethylene diisocyanate, and tetra methylene diisocyanate,
3.3'-dimethoxy-4,4'-biphenylene diisocyanate, 2,4-naphthalene diisocyanate, 3
．． 3'-dimethyl-4,4'-biphenylene diisocyanate), 4,4'-diphenylene diisocyanate, 4
．． 4'-diisocyanate-diphenyl ether, 1,
5'-naphthalene diisocyanate, p-xylylene diisocyanate, m-quinlylene diisocyanate, 1
, 3-cyanocyanatomethylcyclohexane, 1.
4-cyenoneanatomethylcyclohexane, 4.4
'-Cyanoneanate dicyclohexane, 4,4'-
Diisocyanate compounds such as diisopropylene hexolmethane, isophorone diisopropylene, etc. These polyisocyanates include 2.4-) lylene diisocyanate trimer, hexamethylene diisocyanate trimer, etc. The triisocyanate compound may be contained in a proportion of 7 mol% or less of the total isocyanate groups.

In addition, these polyester copolymers are water-insoluble and water-dispersible, and at the same time, when made into an aqueous dispersion, the reduced viscosity in the dispersion is 0.35 (dl/g) or more and 0.4
Must be less than 5.

The reduced viscosity of the aqueous dispersion referred to here is not that of the raw material resin before dispersion, but the reduced viscosity of the resin after dispersion treatment, which is taken out by drying treatment from the aqueous dispersion liquid after it is made into an aqueous dispersion liquid by various dispersion methods described below. This refers to the value measured at 30°C for the resin solid content in a solvent of phenol/tetrachloroethane = 3/2.

In the present invention, the intrinsic viscosity of the polyester copolymer in the aqueous dispersion has an important meaning. That is, the present inventors
As a result of intensive studies on the interlayer adhesion of polyester film laminates, we found that when applying a specific polyester copolymer to the surface of a polyester film, it is important not only to consider the composition of the copolymer but also the reduced viscosity of the dispersion. The present invention was achieved by discovering that there is a difference in adhesive strength and water resistance.Therefore, the inventors discovered that there is a difference in the water resistance of the water-insoluble polyester copolymer. The object of the present invention can only be achieved if it has a reduced viscosity.

In order to obtain sufficient interlayer adhesion, which is the objective of the present invention, the reduced viscosity in the aqueous dispersion is preferably 0.37 (dl/g) or more, and more preferably 0.39 (dl/g) or more. This is particularly preferred.

As a method for forming the aqueous resin dispersion layer on the polyester film in the present invention, conventional gravure, roll coating such as reverse, knife coating, rod coating, nozzle coating, air knife coating, and other known coating methods can be employed. I can do it.

In particular, after a thermoplastic resin for film is applied to an unstretched film after melt extrusion, or a film that has been uniaxially stretched in the vertical or horizontal direction, and then stretched in the biaxial or uniaxial direction. A method of obtaining a two-wheel oriented coated film by heat treatment is preferred from the viewpoint of adhesion, transparency, and economical efficiency of the coated film. In particular, when considering the drying properties and workability of the coating film, it is preferable to apply the coating after stretching it in the -axial direction. Particularly preferred are methods for obtaining films.

The amount of coating to be applied is preferably o, oos to 5 g/rrf, particularly preferably 0.01 to 3 g/rrf, based on the amount present on the film after biaxial stretching. When the coating amount is less than 0.005 g/rr1, the desired effect cannot be obtained, and when it exceeds 5 g/nf, problems such as profking are likely to occur.

Further, if necessary, physical or chemical surface activation treatment such as corona treatment may be performed before or after the coating step.

In the present invention, the base film to which the aqueous resin dispersion is applied is preferably a polyester film typified by polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. In particular, the main component is polyethylene terephthalate,
It is preferable that 80% or more of it is polyethylene terephthalate. The remaining less than 20% of the polyester component can be a dicarboxylic acid component, and aromatic, aliphatic, or alicyclic dicarboxylic acids can be used.As the aromatic dicarboxylic acid,
Aliphatic and alicyclic dicarboxylic acids such as isophthalic acid, orthophthalic acid, and 2,6-naphthalene dicarboxylic acid include succinic acid, adipic acid, sebacic acid, oxalic acid,
1.3-cyclopenkunedicarboxylic acid, 1.2-cyclohexanedicarboxylic acid, 1.3-cyclohexanedicarboxylic acid, 1.4-cyclohexanedicarboxylic acid, etc.
- a part of oxyacid such as hydroxybenzoic acid, and the glycol component is an aliphatic glycol having 2 to 8 carbon atoms or an alicyclic glycol having 6 to 12 carbon atoms,
Specifically, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,2-cyclohexane dimetatool, 1
．． Esters consisting of 3-cyclohexane dimetatool, 1,4-cyclohexane dimetatool, p-xylylene glycol, diethylene glycol, triethylene glycol, and polyethers such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. may be included.

Components other than polyethylene terephthalate may be included by either copolymerization or polymer mixing.

The layer coated on the surface of the film is not particularly limited.

In the polyester resin layer film of the present invention, the copolymer layer may include a colored side, an antistatic agent, conductive 11tlPJ, i! ! A lubricant such as a lubricant, an antifogging agent, a crosslinking agent, an antiblocking agent, an inorganic particle or an organic particle, another polymer, an ultraviolet absorber, a deterioration inhibitor, etc. may be added.

(Example) The present invention will be described below with reference to examples.

m± Production of aqueous dispersion of polyester copolymer Dimethyl terephthalate 117 parts (49 mol%), dimethyl isophthalate 117 parts (49 mol%), ethylene glycol 1
03 parts (50 mol%), 58 parts of diethylene glycol (
50 mol%), 0.08 part of zinc acetate, and 0.08 part of antimony dioxide were heated to 40 to 220'C in a reaction vessel and transesterified for 3 hours, and then 9 parts of 5-sodium sulfoisophthalic acid ( 220 by adding 2 mol%)
The esterification reaction was carried out at ~260°C for 1 hour, and the polycondensation reaction was further carried out under reduced pressure (10 to 0.2 moHg) for 2 hours to obtain a polyester copolymer having an average molecular weight of 18,000 and a softening point of 140°C. This polyester copolymer 300
and 140 parts of n-butyl cellosolve in a container.
Stir at ~170°C for about 3 hours to obtain a homogeneous and viscous melt, and gradually add 560 parts of water to this melt to give about 1
After a period of time, a uniform pale white aqueous dispersion having a solid content concentration of 30% was obtained. The reduced viscosity was 0.40. In addition, Thyroid 150 was added to the polyester copolymer at a rate of 3000ρ.
Add rho and mix, 1 part of water 450f, ethyl alcohol 4
500 parts were added and diluted to obtain a coating liquid with a solid content concentration of 3%.

Manufacture of inline coated film Polyethylene terephthalate is melt extruded at 280-300°C, cooled with a cooling roll at 15°C to a thickness of 100°.
An unstretched film of 0 micron was obtained, and this unstretched film was rolled 3 times in the longitudinal direction between a pair of rolls at different peripheral speeds at 85°C.
．． Stretched 5 times, applied the above coating solution using an air knife method, dried with hot air at 70"C, then stretched 3.5 times in the transverse direction at 98°C with a tenter, and further heat-set at 200-210°C. A two-wheel stretch coated polyester film having a thickness of 100 microns was obtained.

Example 2-3 [2] Evaluation of polyester laminated film A 10% aqueous solution of gelatin (It aqueous polymer) and 10% DMF of polyvinyl chloride (PVC, hydrophobic polymer)
A 10% methyl cellosolve solution of cellulose acetate butyrate (commonly used as a photosensitizer) was prepared.

Each solution was colored with a red dye and printed separately on the modified copolymerized polyester layer side of the two polyester-based laminated films obtained in section (1) so that each coated amount was 2 g/%.

Cellophane tape (L-back, manufactured by Nichiban Co., Ltd.) was uniformly adhered to each printed surface of this thermoplastic resin laminated film, and then the tape was quickly peeled off in the 180-degree direction and the 360-degree direction. On the printed surface after peeling, the ratio of the area of the residual ink to the total area was visually determined, and the adhesion was evaluated according to the following criteria. If the ratio of the area of the residual ink area to the total area is 95% or more, it is classified as A grade, which is 50 or more.
95% was grade B, 10-50% was grade 0, and 10% or less was grade D.

Example 2 In Example 1, the water-based polyester copolymer composition was 5
A coated polyester film was obtained in the same manner as in Example 1 except that sodium sulfoisophthalate was changed to 5 mol% and dimethyl terephthalate was changed to 46 mol%.

Example 3 In Example 1, the reaction time was shortened and the reduced viscosity was reduced to 0.3.
A coated film was obtained in the same manner as in Example 1 except that the dl/g was adjusted to 7 (dl/g).

Comparative Examples 1 and 2 A coated film was obtained in the same manner as in Example 1 except that the reduced viscosity in Example 1 was changed to 0.33 (dl/g) and 0.29 (dl/g).

Comparative example 3 In Example 1, an uncoated film was prepared.

Furthermore, AI and SiO□ were evaluated as 70 for inorganic substances.
0 people crashed and evaluated in the same way as above.

Furthermore, the following magnetic paint coated film was also evaluated in the same way.

250 parts by weight of r-Fez03 fine powder particles, 2 parts by weight of dioctyl sulfonate, copolymerized polyester (dicarboxylic acid units are 45 mol% of terephthalic acid, 20 parts of isophthalic acid)
mol %, sebacic acid 32.5 mol % and 5-sodium sulfoisophthalic acid 2.5 mol %, and the glycol units are ethylene silicate:! (consisting of 50 mol% of neopentyl glycol and 50 mol% of neopentyl glycol)
48 parts by weight and 600 parts by weight of cellosolve acetate were placed in a ball mill and allowed to flow for about 24 hours. This mixture 4
00 parts by weight, 100 parts by weight of the above copolymerized polyester,
30 parts by weight of nitrocellulose, 70 parts by weight of vinyl chloride-vinyl acetate copolymer, 30 parts by weight of polyisocyanate and 400 parts by weight of methyl ethyl ketone were added, and polymerization was carried out for about 70 hours using a ball mill. After filtering and defoaming the resulting mixture, it was applied onto the thermoplastic resin laminated film obtained in section (1) using a gravure coater. When the coated surface was smoothed and dried at 80°C, a film with a coating thickness of 2 μm was obtained.

The friction coefficient is AST! This is a value measured on both the laminated surface and the non-laminated surface using Tensilon manufactured by Toyo Seiki Co., Ltd. in accordance with I-1894.

Table 4 As is clear from the Examples and Comparative Examples, the polyester film of the present invention has a reduced viscosity of 0.35 (dl, /g
) Since it has the above sulfonic acid compound-modified copolyester layer, it has good adhesion to any of hydrophilic polymers, hydrophobic polymers, and inorganic substances, and has good water purification properties. After printing or applying a hydrophilic polymer containing ink, a hydrophobic polymer, or a copolymer polyester containing magnetic paint to the copolyester layer of the polyester laminated film, a peeling test using cellophane tape was performed. However, ink and magnetic paint rarely transfer to the cellophane tape side. Conventional single-layer thermoplastic resin films made of polyethylene terephthalate or polyester biaxially oriented films lack adhesion to polymers and inorganic materials, so when a peel test similar to the above is performed, most of the ink and magnetic paints are removed. transfers to the cellophane tape side.

(Effects of the invention) The polyester laminated film of the invention thus has the following features:
Since it is constructed by laminating a sulfonic acid (one-primary copolymer) on a thermoplastic resin film, it has good adhesion to both hydrophilic polymers, hydrophobic polymers, and inorganic substances.

As a result, this polyester-based laminated film is suitably used for applications such as magnetic tape heath films, insulating tapes, photographic films, tracing films, and food packaging films.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Claims] 1. At least one side of the polyester film contains 0.5 to 15 mol% of dicarboxylic acid containing a sulfonic acid metal base based on the total dicarboxylic acid component, and has a reduced viscosity of 0.35.
(dl/g) or more and less than 0.45 of a water-insoluble polyester copolymer is laminated as at least one component of a laminated resin.