JPH04211983A - Antistatic polyester printing film - Google Patents

Abstract

PURPOSE:To improve an adhesion of a printing layer and antistatic properties by a method wherein a polyester resin film layer having a low melting point is laminated on at least one surface of a crystalline polyester resin film layer containing a specific amount of a sulfonic acid metallic salt derivative, and a printing layer is provided on the surface thereof. CONSTITUTION:A polyethylene terephthalate containing 0.1-5.0wt.% dodecyl benzenesulfonic acid soda which is a crystalline polyester resin and a copolymer polyester resin which is a low-melting point polyester resin are melted in individual extruding machines. A laminate film in which a low-melting point polyester resin layer 3 is laminated on one surface of a crystalline polyester resin layer 2 is obtained by the extrusion of the melted materials. This laminate film is oriented lengthwise and crosswise. Cellulose printing ink is printed in a predetermined pattern on the side of the low-melting point polyester layer 3 of the biaxially oriented polyester film for forming a printing film 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic polyester film, and more particularly to a printed antistatic polyester printed film.

0002

[Prior art and its problems] Polyester films are used in a wide range of applications, such as packaging materials for foods, pharmaceuticals, and chemicals, packaging materials for industrial parts, transfer films, tracing papers, and films for projectors. There is. Printing is applied to such polyester films for various purposes. For example, on polyester films for food packaging, the product name, manufacturing date, production area, etc. are displayed by printing.

[0003] In printed polyester films, the solvent of the printing ink tends to remain. Such residual solvent gives the film an odor and is also unfavorable from a sanitary standpoint. For this reason, recent printing films use cellulose derivatives as binders with less residual solvent. However, this printing ink has insufficient adhesion to polyester films. For this reason, when the film is subjected to boiling treatment or hot water treatment, or when the film is hardened and deformed at low temperatures, the printed layer may peel off from the film. Therefore, in order to increase the adhesive strength between the polyester film and the printed layer, surface treatments such as corona discharge treatment and plasma treatment are applied to the polyester film, and an adhesive layer is interposed between the polyester film and the printed layer. ing. However, surface treatment does not sufficiently improve adhesion, and the effect does not last long. On the other hand, when an adhesive layer is interposed, although adhesiveness is improved, it takes time and effort to form the adhesive layer, which is a hindrance to speeding up printing operations.

[0004] Furthermore, conventional polyester films are easily charged. For this reason, when the object to be packaged is a dry powder, granule, or flake-like substance, the object to be packaged adheres to the film due to frictional electrification, making it difficult to handle. Particularly, when the above-mentioned items to be packaged are packed into bags by heat-sealing, the items to be packaged may get caught in the heat-sealed portion.

[0005] Therefore, a polyester resin film has been proposed which has improved adhesion to printing ink containing a cellulose derivative as a binder component and also has improved antistatic properties (for example, see Japanese Patent Laid-Open No. 87483/1983). ). This polyester film is a block copolymer polyester film containing a sulfonic acid metal salt derivative and a low melting point soft polymer segment. In this film, antistatic properties are improved by the sulfonic acid metal salt derivative, and adhesion with printing inks containing cellulose derivatives is improved by the low melting point soft polymer segment. However, in the polyester film, since the low melting point soft polymer segments are widely dispersed in the surface layer and inside of the film, the adhesion with the printed layer is not sufficiently improved. In addition, when a heat-sealable packaging film is produced by laminating a thermoplastic resin film on the polyester film, the adhesiveness between the thermoplastic resin film and the polyester film is not sufficient for the same reason as described above. . For this reason, the heat-sealed portion, particularly the bonded portion between the thermoplastic resin film and the polyester film, is likely to break. Therefore, there are practical problems in applying the conventional polyester film to a film for heat sealing.

[0006] An object of the present invention is to provide an antistatic polyester printed film that has good adhesion of the printed layer, good adhesion to a heat-sealing film, and good antistatic properties.

[0007]

[Means for Solving the Problems] The antistatic polyester printing film of the present invention contains a sulfonic acid metal salt derivative at 0.0%.
A crystalline polyester resin film containing 1 to 5.0% by weight, a low melting point polyester resin film with a thickness of 0.01 to 1.0 μm laminated on one or both sides of the crystalline polyester resin film, and a low melting point polyester resin film containing 1 to 5.0% by weight. It includes a printed layer laminated on a polyester resin film.

The printing layer is made of a printing ink containing a binder component whose main component is, for example, a cellulose derivative or a urethane resin.

Further, the low melting point polyester resin film is, for example, a low crystalline polyester resin film. ＊＊＊＊＊＊＊

FIG. 1 is a partial vertical cross-sectional view of an example of the antistatic polyester printed film of the present invention. The antistatic polyester printed film 1 of the present invention includes a crystalline polyester resin film layer 2, a low melting point polyester resin film layer 3 laminated on one side of the crystalline polyester resin film layer 2, and a printed layer 4 applied to the surface thereof. We are prepared.

Further, in the polyester printing film of the present invention, as shown in FIG. 2, low melting point polyester resin film layers 3 may be laminated on both sides of the low melting point polyester resin film layer 2. In this case, a printed layer 4 may be formed on the surface of one low melting point polyester resin film layer 3 as shown in FIG. 2, or a printed layer 4 may be formed on the surface of both low melting point polyester resin film layers 3. It may be formed.

As described above, in the antistatic polyester printed film of the present invention, since the printed layer 4 is formed on the low melting point polyester resin film layer 3, the adhesion of the printed layer 4 is good. . Further, since the antistatic polyester printed film of the present invention has the low melting point polyester resin film 3, it has good adhesion to a heat sealing film. Further, the antistatic polyester printed film of the present invention has good antistatic properties because it contains the sulfonic acid metal salt derivative described below in the crystalline polyester resin film layer.

Crystalline Polyester Resin The crystalline polyester resin used in the present invention is a polymer containing an ester group obtained by polycondensation of a dicarboxylic acid and a diol component. Examples of dicarboxylic acids include aliphatic and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, 2,6-naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, succinic acid, and oxalic acid. . Examples of diols include ethylene glycol, 1,
Examples include 4-butanediol, diethylene glycol, polyethylene glycol, neopentyl glycol, cyclohexanedimethanol, polyethylene glycol, and the like. Two or more types of each of the dicarboxylic acid and diol may be used. Moreover, other monomers and polymers may be copolymerized in addition to the dicarboxylic acid and diol. Furthermore, two or more types of polyester resins may be melt-mixed and used.

The crystalline polyester resin used in the present invention has a crystallization parameter ΔTcg of 40 to 80°C. Here, the crystallization parameter ΔTcg is a value measured using a differential scanning calorimeter (DSC). DSC
The measurement method is as follows. First, a 10 mg sample of crystalline polyester resin was set in a DSC device,
After melting at a temperature of 300° C. for 5 minutes, it is rapidly cooled in liquid nitrogen. The rapidly cooled sample is heated at a rate of 10° C./min, and the glass transition point Tg is measured. The temperature is further increased, and the crystallization exothermic peak temperature during crystallization from the glass state is measured, and this is defined as the cold crystallization temperature Tcc. Then, the difference between Tcc and Tg (Tcc-Tg) is calculated, and this is set as the crystallization parameter ΔTcg.

A desirable crystalline polyester resin used in the present invention is, for example, polyethylene terephthalate. In particular, the constituent component of ethylene terephthalate is 85 mol% or more (preferably 90 mol% or more)
Preferably included.

The crystalline polyester resin used in the present invention includes a sulfonic acid metal salt derivative. The sulfonic acid metal salt derivative used in the present invention is a sulfonic acid metal salt derivative compound having heat resistance such that a substantial weight loss initiation temperature is 200° C. or higher when heated in air, for example. Such sulfonic acid metal salt derivative compounds include:
The following structure (chemical formula 1) can be exemplified.

[Chemical formula 1]

In the formula, R is an alkyl group having 8 to 20 carbon atoms, such as an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, and an octadecyl group. In addition, Me is an alkali metal or alkaline earth metal, including sodium, potassium, calcium,
Examples include barium and magnesium. In addition, the said sulfonic acid metal salt derivative may be used individually, and may be used in mixture of 2 or more types.

The sulfonic acid metal salt derivative is contained in an amount of 0.1 to 5.0% by weight based on the crystalline polyester resin.
It is preferably contained in an amount of 0.2 to 3.0% by weight. If the content is less than 0.1% by weight, it is difficult to obtain a polyester film with sufficient antistatic properties. On the other hand, if the content exceeds 5.0% by weight, no further improvement in antistatic properties is observed, but rather promotes thermal deterioration of the crystalline polyester resin film. Note that the sulfonic acid metal salt derivative and the crystalline polyester resin can be mixed using, for example, a blender.

The crystalline polyester resin used in the present invention may also contain other UV absorbers, lubricants, pigments, antioxidants, antistatic agents, stabilizers, and the like. In particular, in order to impart lubricity to the film, inorganic particles with an average particle size of 0.1 to 2.0 μm are added to the polyester resin.
．． It is desirable to contain 01 to 0.5% by weight. Examples of such inorganic particles include thyroid, talc,
Examples include silica and crosslinked silicon particles.

Low melting point polyester resin The low melting point polyester resin used in the present invention is a polyester resin similar to the above-mentioned crystalline polyester resin, and has a melting point (Tm) of 150 to 245°C. If the melting point is less than 150°C, it will be difficult to dry and difficult to handle. On the other hand, if the melting point exceeds 245°C, the adhesion to the heat-sealing film will be poor. In addition, the difference in melting point between the low melting point polyester resin and the above-mentioned crystalline polyester resin is 20°C or more and 110°C or less, and further 30°C.
It is desirable that the temperature is above 80°C or below. If the difference in melting point exceeds the above range, the adhesiveness of the printed layer and the beauty of the film may be impaired.

[0021] Preferred as the low melting point polyester resin is a copolyester containing polyethylene terephthalate as a main component. Examples of copolymerization components include aliphatic dicarboxylic acids such as adipic acid, sebacic acid and dodecanedioic acid, and diols such as 1,4-butanediol and 1,6-hexanediol. Note that when an aliphatic dicarboxylic acid is used as a copolymerization component, adhesiveness is improved. This effect can be expected more when adipic acid or sebacic acid is selected. When an aliphatic dicarboxylic acid is selected as a copolymerization component, the copolymerization amount is set to 5 to 45 mol%, preferably 10 to 40 mol%, and more preferably 10 to 35 mol%. If the copolymerization amount is less than 5 mol%,
Adhesion and scratch resistance of printed inks are reduced. On the other hand, if it exceeds 45 mol%, a large amount of solvent will remain on the printed surface.

[0022] Also, as a low melting point polyester resin,
A low crystallinity polyester resin having a crystallization parameter ΔTcg exceeding 80° C. may be used. The crystallization parameter ΔTcg here is a value determined by the same measurement method as ΔTcg of the above-mentioned crystalline polyester resin. The melting point of such a low-crystalline polyester resin is particularly within the range of 150°C or more and 240°C or less, and furthermore 170°C or less.
The temperature is preferably from 0.degree. C. to 220.degree. Further, the difference in melting point between the low crystalline polyester resin and the above-mentioned crystalline polyester resin is more preferably 40°C or more and 90°C or less. Furthermore, low crystallinity polyester resin has a heat of crystal fusion of 2 to 2.
More preferably, it is 6 cal/g. In addition, as the low crystalline polyester resin, polyethylene terephthalate resin containing 10 mol% or more of isophthalic acid units, 1
, polyethylene terephthalate resin containing 8 mol % or more of 4-cyclohexanedimethanol units, and mixtures thereof.

[0023] The low melting point polyester resin used in the present invention may contain stabilizers, ultraviolet absorbers, etc. similar to those added to the above-mentioned crystalline polyester resin. Further, inorganic particles similar to those mentioned above may be contained in order to impart lubricity to the film.

Printing Layer The printing ink used in the printing layer of the present invention mainly contains a binder component whose main component is a cellulose derivative or a urethane resin, and an organic solvent to dilute this binder component.

Cellulose derivatives used in the binder component include nitrified cotton, methylcellulose, ethylcellulose, hydroxycellulose, and cellulose ester (
For example, cellulose acetate). For example, when nitrified cotton is used as a binder, cellulose dinitrate is preferable. Cellulose dinitrate is obtained by esterifying two (average value) of three hydroxyl groups in D-glucopyranose, which is a constituent unit of cellulose, with a nitro group. Such cellulose dinitrate has a degree of nitrification of 10
．． There are two types, the L type with a content of 7 to 11.5% and the H type with a content of 11.5 to 12.2%, and either one may be used. Also,
The viscosity is preferably 1/16 to 1/2 second. These cellulose dinitrates may be used alone or in combination with
A mixture of two or more species may be used. In addition, if nitrified cotton is used as a binder, 200%
Can print at high speeds of over m/min. Furthermore, since the glass transition temperature of nitrified cotton is as high as 60° C., blocking is less likely to occur during film winding.

The urethane resin used as the binder component can be obtained by adding a low molecular weight chain extender to a mixture of a diisocyanate compound and a polyol compound and subjecting the mixture to a polyaddition reaction. Examples of diisocyanate compounds include aromatic diisocyanates such as tolylene diisocyanate and 4,4-diphenylmethane diisocyanate, araliphatic diisocyanates such as xylylene diisocyanate, hexamethylene diisocyanate, and diisocyanate.
, 2,4-trimethylhexamethylene diisocyanate and the like are used. The diisocyanate compounds may be used alone or in combination of two or more. Note that in the present invention, aliphatic diisocyanates are mainly used. Examples of polyol compounds include saturated alcohols such as ethylene glycol, propylene glycol, tetramethylene glycol, trimethylolpropane, 1,6-hexanediol, and 1,4-butanediol;
polyethylene glycol, polypropylene glycol,
Polyakylene glycols such as polytetramethylene glycol are used. The polyol compounds may be used alone or in combination of two or more. Since such urethane resin has many functional groups and highly polar groups, it has good adhesion to the resin film and forms a robust printing layer.

In addition to the cellulose derivatives and urethane resins mentioned above, binders used in printing inks include polyamide resins, synthetic rubbers, rosins, ester rubbers such as glycerin esters, and amino resins such as urea resins and melanin resins. Alternatively, it may be used in combination with the cellulose derivatives and the like. However, the above examples do not limit the present invention. In addition, when the cellulose derivative or urethane resin and the other binder component are used together, it is desirable that the cellulose derivative or urethane resin is contained in an amount of 30 to 95% by weight, more preferably 60 to 95% by weight of the total binder component. It is desirable that the content be % by weight. If the content is less than 30% by weight, the adhesiveness between the printed layer and the film layer may decrease.

[0028] An inorganic or organic pigment or dye may be added to the binder component, if desired. As such pigments or dyes, for example, titanium white, yellow lead, copper powder, phthalocyanine blue, etc. are used depending on the color to be printed.

The binder component or the mixture of the binder component and the pigment or dye is diluted with a solvent such as alcohols, esters, and ketones, and various organic solvents such as benzole, triol, ethyl acetate, benzene, and xylene. It is used after adjusting the viscosity. The viscosity of the printing ink after dilution with these solvents is 15 to 80.
cps is desirable, and 20 to 60 cps is more desirable.

Note that a color vehicle such as a volatile varnish is usually added to the printing ink. In addition, additives such as stabilizers, plasticizers, weathering agents, natural resins, rubber derivatives, lubricants, and gloss-imparting agents may be added to the printing ink.

Manufacture of antistatic polyester printed film Next, the manufacturing process of the antistatic polyester printed film of the present invention will be explained. First, a laminate of a film made of a crystalline polyester resin and a film made of a low melting point polyester resin is manufactured. Examples of the lamination method include a method of coating a crystalline polyester resin film with a low melting point polyester resin, and a method of coextruding a crystalline polyester resin and a low melting point polyester resin. Here, manufacturing by coextrusion method will be explained.

First, a crystalline polyester resin and a low melting point polyester resin are supplied to separate extruders and melted, and the melts are combined in a pipe or a die and extruded to form a resin film laminate. Manufacture.

The obtained resin film laminate is stretched in the longitudinal and transverse directions. The stretching ratio is 2 in both the vertical and horizontal directions.
．． 5 to 5.0 times is desirable. Further, the temperature during the stretching treatment is desirably higher than the secondary dislocation point of the crystalline polyester resin and lower than the melting point of the low melting point polyester resin, and is usually 80 to 150°C. In this way, the biaxially stretched resin film is transferred to a heat treatment step and subjected to post-treatment. The heat treatment in this case is carried out in a temperature range that is higher than the crystal melting temperature of the low melting point polyester resin and lower than the crystal melting temperature of the crystalline polyester resin.

The thickness of the resin film laminate thus obtained is usually 6 to 250 μm, of which the thickness of the low melting point polyester resin film is 0.01 to 1.0 μm.
It is m. If this value is less than 0.01 μm, the adhesion to the printed layer will not be improved. On the other hand, if it exceeds 1.0 μm, the slipperiness will deteriorate.

[0035] Desired printing such as letters and patterns is applied to the upper surface of the low melting point polyester resin film of the obtained biaxially stretched resin film laminate using the printing ink. As the printing method, for example, various roll coating methods such as gravure roll method, kiss roll method, bar coating method, and reverse roll method, blade coating method, lip coating method, spray coating method, etc. are used. The amount of printing ink applied is 0.1 to 15 g/m2, preferably 1 to 10 g/m2.
m2. Note that the surface of the low melting point polyester resin film may be previously subjected to surface treatment such as corona discharge treatment, plasma treatment, flame treatment, acid treatment, etc. In this case, the adhesion between the printed layer and the low melting point polyester resin film layer is further improved.

Note that a transparent thermoplastic resin film may be further laminated on the printing layer of the polyester printing film of the present invention. As such a film, a film made of a resin having a lower melting point than the low melting point polyester resin used in the present invention, such as polypropylene resin, polyethylene resin, ethylene-vinyl acetate copolymer resin, etc., is used. When such films are laminated, heat-sealability is imparted to the antistatic polyester printed film of the present invention. Moreover, such a thermoplastic resin film adheres well to the low melting point polyester resin film layer. Therefore, when the polyester printed film of the present invention is applied to a film for heat sealing, tearing is unlikely to occur at the heat sealing portion.

Use of antistatic polyester printed film The antistatic polyester printed film of the present invention is used, for example, as a packaging material for foods, medicines, chemicals, industrial parts, and the like.

[0038]

Effects of the Invention The antistatic polyester printed film of the present invention has a low melting point polyester resin film and a printed layer thereon. Therefore, the film of the present invention has good adhesion to the printed layer and good adhesion to the heat-sealing film. Further, in the present invention, since the crystalline polyester resin film layer contains a sulfonic acid metal salt derivative, antistatic properties are good.

[0039]

【Example】

Example 1 Polyethylene terephthalate (ΔTcg=50°C) containing 0.04% by weight of silica particles with an average particle size of 1.2 μm, which are crystalline polyester resins, and 1.5% by weight of sodium dodecylbenzenesulfonate, and a low melting point A copolymerized polyester resin with a melting point (Tm) of 234°C containing 0.1% by weight of silica particles with an average particle size of 1.2 μm (acid components: 90 mol% terephthalic acid, 10 mol% sebacic acid, diol) Components (ethylene glycol) were melted in separate extruders. The melts were combined in a pipe and extruded to obtain a laminated film in which a low melting point polyester resin layer was laminated on one side of the crystalline polyester resin layer. This laminated film was stretched 3.3 times in the machine direction at 90°C, and then stretched 3.4 times in the transverse direction at 100°C. Then, this film was heated to 240°C.
After heat treatment for 4 seconds at 170° C., and holding the temperature for 3 seconds at 170° C., the surface was cooled to 30° C. at a cooling rate of 30° C./second with a breeze of 1 m/minute. The biaxially stretched polyester film thus obtained has a thickness of 12 μm, of which the low melting point polyester film has a thickness of 0.20 μm.
It was m. The static friction coefficient of the low melting point polyester film was measured for the obtained biaxially stretched polyester film.

[0040] Further, cellulose printing ink CC-ST633 white (manufactured by Toyo Ink Co., Ltd.) was applied to the low melting point polyester layer side of the obtained biaxially stretched polyester film using a gravure roll to a solid content of 2 g/m2. A predetermined pattern was printed to create a printed film. Similarly, urethane printing ink Lamister R
A printing film was prepared using 61S white (manufactured by Toyo Ink Co., Ltd.). The resulting printed film was examined for adhesion between the printed layer and the biaxially stretched polyester film, heat sealability, and antistatic properties.

Example 2 Polyethylene terephthalate (Δ
A low melting point polyester resin (Tm = 230°C, ΔTcg =
(85°C) were melted in separate extruders. Then, a biaxially stretched polyester film was obtained from this melt in the same manner as in Example 1. The resulting biaxially stretched polyester film had a thickness of 12 μm, of which the thickness of the low melting point polyester layer was 0.2 μm.

The static friction coefficient of this biaxially stretched polyester film was measured. In addition, a printed film on which a printed layer was formed using cellulose-based and urethane-based printing inks was prepared from a biaxially stretched polyester film as in Example 1, and the adhesion, heat sealability, and antistatic properties of the printed layer were examined. Ta.

Example 3 In place of the low melting point polyester resin used in Example 1, a mixed resin of 84% by weight of polyethylene terephthalate and 16% by weight of polyethylene isophthalate (Tm=218°C,
ΔTcg=90° C.), a biaxially stretched polyester film similar to that in Example 1 was obtained. However, the heat treatment temperature after the stretching treatment was set at 220°C. A printed film similar to that in Example 1 was prepared from the obtained biaxially stretched polyester film, and the same measurements and property tests as in Example 1 were conducted.

Comparative Example 1 A mixture of polyethylene terephthalate (ΔTcg=50°C) containing 1.5% by weight of sodium dodecylbenzenesulfonate, 95% by weight of polyethylene terephthalate, and 5% by weight of polyethylene isophthalate (Tm=250°C, Δ
Tcg=65°C) were melted in separate extruders. Then, a biaxially stretched polyester film was obtained from this melt in the same manner as in Example 1. The resulting biaxially stretched polyester film has a thickness of 12 μm, of which Tm is 2 μm.
The thickness of the polyester layer at 50°C was 0.2 μm.

The static friction coefficient of the obtained biaxially stretched polyester film was measured. In addition, a printed film was prepared in the same manner as in Example 1, and the adhesion, heat sealability, and antistatic properties of the printed layer were examined.

Comparative Example 2 Polyethylene terephthalate (ΔTcg=50°C) containing 0.04% by weight of silica particles with an average particle size of 1.2 μm and 1.0% by weight of sodium oleyl sulfonate and an average particle size of 2.0 μm. Tm containing 0.1% by weight of silica particles of
A copolymerized polyester resin (acid components: 85 mol % of terephthalic acid and 15 mol % of sebacic acid, diol component: ethylene glycol) whose temperature was 223° C. was melted in separate extruders. Then, a biaxially stretched polyester film was obtained from this melt in the same manner as in Example 1. The resulting biaxially stretched polyester film has a thickness of 12 μm, of which the thickness of the polyester layer with Tm of 223° C. is 1.5 μm.
Met.

The static friction coefficient of the obtained biaxially stretched polyester film was measured. In addition, a printed film was prepared from a biaxially stretched polyester film in the same manner as in Example 1, and the adhesion, heat sealability, and antistatic property of the printed layer were examined.

In this comparative example, the polyester resin layer having a Tm of 223° C. had poor slipperiness and was easily wrinkled, resulting in poor workability during printing.

Comparative Example 3 Instead of the copolyester resin with a Tm of 223° C. used in Comparative Example 2, a mixed resin of 84% by weight of polyethylene terephthalate and 16% by weight of polyethylene isophthalate (
Comparative Example 2
A biaxially stretched polyester film similar to the above was obtained. A printed film similar to that in Comparative Example 2 was prepared from the obtained biaxially stretched polyester film, and the same measurements and property tests as in Comparative Example 2 were conducted. In addition, in this comparative example, Tm is 218
℃ polyester resin layer had poor slipperiness and wrinkled easily, resulting in poor workability during printing.

Comparative Example 4 A biaxially stretched polyester film was obtained using the same material as in Example 1. This biaxially stretched polyester film had a thickness of 12 μm, of which the thickness of the low melting point polyester layer was 0.005 μm.

The static friction coefficient of the obtained biaxially stretched polyester film was measured, and the adhesion, heat sealability and antistatic properties of the printed layer were examined.

Comparative Example 5 Polyethylene terephthalate (Tm=260°C, Δ
Tcg=50°C) and polyethylene terephthalate containing 0.1% by weight of silica particles with an average particle size of 1.2 μm
Tm=260°C and ΔTcg=50°C) were melted in separate extruders. Then, a biaxially stretched polyester film was obtained from this melt in the same manner as in Example 1. Obtained 2
The axially stretched polyester film has a thickness of 12 μm,
Among these, the thickness of the thin polyester layer was 0.1 μm.

The static friction coefficient of the obtained biaxially stretched polyester film was measured, and the adhesion, heat sealability and antistatic properties of the printed layer were examined.

Comparative Example 6 Polyethylene terephthalate (ΔTcg=50°C) containing 0.04% by weight of silica particles with an average particle size of 1.2 μm, which is a crystalline polyester resin, and a low melting point polyester resin, with an average particle size of 1.2 μm. A mixture of 84% by weight polyethylene terephthalate and 16% by weight polyethylene isophthalate containing 0.1% by weight 2 μm silica particles (T
m=220°C, ΔTcg=90°C) were melted in separate extruders. The melts were combined in a pipe and extruded to obtain a laminated film in which a low melting point polyester resin layer was laminated on one side of a crystalline polyester layer. This laminated film was stretched in the same manner as in Example 1 to obtain a biaxially stretched polyester film with a thickness of 12 μm.

[0055] The obtained biaxially stretched polyester film was examined for static friction coefficient, adhesion, heat sealability, and antistatic property in the same manner as in Example 1. Table 1 shows the results of each of the Examples and Comparative Examples. The test method and evaluation criteria are as follows.

Static friction coefficient was measured using a slip tester according to ASTM-T-1894-B63. ○: Less than 1.0 μs. ×: 1.0 μs or more.

Cellotape (trade name) was applied to the adhesive printed layer and quickly peeled off, and the state of the printed layer coming off was examined. ○: Less than 30% of the printed layer came off. ×: 30% or more of the printed layer came off.

[0058] Isocyanate adhesives AD300A and AD300B (both manufactured by Toyo Morton Co., Ltd.) were applied at 1.5 g/m2 on the heat-sealable printing layer, and a 40 μm thick unstretched polypropylene (CPP) film T3401 was formed. (manufactured by Toray Synthetic Film Co., Ltd.) was laminated. Then, the CPP film surfaces were thermocompressed for 0.5 seconds at 140° C. and 2 kg/cm 2 to measure the heat seal strength. For cellulose-based printing inks. ○: 1.5 kg/15 mm or more. ×: Less than 1.5 kg/15 mm. For urethane printing ink. ○: 3.0 kg/15 mm or more. ×: less than 3.0 kg/15 mm.

The surface specific resistance value was measured at a temperature of 25° C. and a humidity of 65% using an antistatic super megohmmeter MMA II-17 model (manufactured by Kawaguchi Electric Co., Ltd.). ○: Surface specific resistance value is 1×1013Ω/□ or less. ×: Surface specific resistance value is greater than 1×1013Ω/□.

[Table 1]

[Brief explanation of the drawing]

FIG. 1 is a partial vertical cross-sectional view of an antistatic polyester printed film according to an example of the present invention.

FIG. 2 is a partial vertical cross-sectional view of an antistatic polyester printed film according to another example of the present invention.

[Explanation of symbols]

1 Antistatic polyester printed film 2 Crystalline polyester resin film layer 3 Low melting point polyester resin film layer 4 Printed layer

Claims (4)

[Claims] Claim 1: 0.1 to 5 sulfonic acid metal salt derivatives
．． A crystalline polyester resin film containing 0% by weight,
A low melting point polyester resin film with a thickness of 0.01 to 1.0 μm laminated on one or both sides of the crystalline polyester resin film, and a printing layer laminated on the low melting point polyester resin film. Antistatic polyester printing film. 2. The antistatic polyester printed film according to claim 1, wherein the printing layer is made of a printing ink containing a binder component containing a cellulose derivative as a main component. 3. The antistatic polyester printed film according to claim 1, wherein the printing layer is made of a printing ink whose main component is a urethane resin as a binder component. 4. The antistatic polyester printed film according to claim 1, wherein the low melting point polyester resin film is a low crystalline polyester resin film.