JPH03215550A - Antistatic polyester resin composition and polyester film laminated with same composition - Google Patents

Abstract

PURPOSE:To provide the title composition giving a coating film excellent in transparency, etc., and being nonflammable by mixing a specified water-soluble polyester copolymer with a specified water-soluble polyester ether, an alkali metal salt and a surfactant in a specified weight ratio. CONSTITUTION:A water-soluble polyester copolymer (A) of an intrinsic viscosity of 0.25-0.55dl/g having a group of an alkali metal organic sulfonate in the molecule, a water-soluble polyester ether (B) which is a polyester ether comprising a dicarboxylic acid component and a diol component containing polyethylene glycol with a number-average mol.wt. of 1000-6000 and has a polyethylene glycol content of 80-95wt.%, an alkali metal salt (C) (e.g. lithium chloride) and anionic and/or nonionic surfactants (D) are mixed together in such amounts that component A is 75-95wt.% based on the total weight of components A, B and C, component B is 3-23wt.%, component C is 2-20wt.%, and component D is 2-8wt.% to produce an antistatic polyester resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an antistatic agent and an antistatic polyester film having excellent coating properties, film transparency, adhesive properties, and antistatic properties.

[Conventional technology]

Polyester films, particularly biaxially oriented polyethylene terephthalate films, are used in applications such as hems for photographic films, drafting bases, and hems for magnetic recording films because of their transparency, dimensional stability, and excellent mechanical properties. In these applications, a subbing layer is usually provided between the polyester support and the surface material to improve the adhesion between the two. On the other hand, conventional efforts have been made to improve the adhesion between linear polyester, metal foil, and various plastics.
Water-soluble or water-dispersible polyester copolymers have been proposed as an undercoat layer due to problems in the working environment and advantages such as eliminating the need for explosion-proof equipment. For example, in Japanese Patent Publication No. 47-40873, for the purpose of water dissipation, 8 mol% or more of an ester-forming sulfonic acid metal base-containing compound based on the total acid component and polyethylene glycol based on the total glycol component are used. Copolymers used in an amount of 20 mol% or more are described. In addition, regarding the undercoat layer, Japanese Patent Publication No. 61-39658 and Japanese Patent Publication No. 56-8
No. 8454 and Japanese Unexamined Patent Publication No. 60-248231.

(Problems to be Solved by the Invention) All of the above resins are insufficient in terms of antistatic performance and reduce workability in subsequent steps or processing of the film, especially when a light absorbing agent is provided in the upper layer. The problem is that static marks are generated in the process.

The purpose of the present invention is to obtain an antistatic agent that has excellent coating properties and antistatic properties, and to provide an antistatic agent that is transparent and has excellent adhesive properties by providing this antistatic agent on at least one surface of a polyester film. The purpose of this invention is to obtain a polyester film with a high quality.

[Means to solve the problem]

The present inventors have conducted intensive studies to obtain an antistatic agent and an antistatic polyester film having the above properties, and as a result, have discovered the present invention. That is, the above object of the present invention is to prepare (A) a water-soluble polyester copolymer having an organic sulfonic acid alkali metal salt group in the molecule and having an intrinsic viscosity of 0.25 to 0.55 dl2/g. B) and (C)
75 to 95% by weight based on the total weight of (B) dicarboxylic acid component and polyethylene glycol (
It is a polyester ether consisting of a diol component containing a number average molecular weight of 1000 to 6000, and the polyethylene glycol is 8% by weight of the polyester ether.
0-95% by weight of water-soluble polyester ether (
3 to 2 for the total weight of A), (B) and (C)
3% by weight, (C) alkali metal salts (A), (B) and (C)
(D) anionic or/and nonionic surfactant in an amount of 2 to 20% by weight based on the total weight of (A), (B) and (C).
This is achieved by providing a polyester resin composition characterized in that it consists of at least four compositions of 8% by weight.

The water-soluble polyester copolymer (8) having an organic sulfonic acid alkali metal salt in the molecule used in the present invention is basically produced by polycondensation of dicarboxylic acid and/or its ester-forming derivative with glycol, Hydroxycarboxylic acids and/or ester-forming derivatives thereof may also be used.

In order to introduce a group of an organic sulfonic acid alkali metal salt into the molecule, 4-sulfoisophthalic acid, 5-sulfoisostalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid,
Alkali metal salts such as 5-[4-sulfophenoxy]isophthalic acid or ester-forming derivatives thereof are used, and 5-sulfoisophthalic acid sodium salt or ester-forming derivatives thereof are preferred. These copolymerization components having an alkali metal sulfonic acid salt group are used in an amount of 5 to 15 mol%, particularly preferably 6 to 10 mol%, based on the aromatic dicarboxylic acid component in terms of water solubility and melt viscosity. .

As the other dicarboxylic acid components, aromatic dicarboxylic acid components and/or alicyclic dicarboxylic acid components are mainly used, but some aliphatic dicarboxylic acid components may also be used in combination. - Examples of the dicarboxylic acid component in F are terephthalic acid, isophthalic acid,
Aromatic dicarboxylic acids such as phthalic acid, 2,5-dimethylterephthalic acid, 2,6-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, biphenyl dicarboxylic acid,
1.4-cyclohexanedicarboxylic acid, 1.3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1.3-cyclopencunedicarboxylic acid, 4 4
Examples include alicyclic dicarboxylic acids such as '-bicyclohexyldicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid, bimelic acid, suberic acid, azelaic acid, and sebacic acid, and ester-forming derivatives thereof, but especially terephthalic acid. , isophthalic acid, 1,4-cyclohexanedicarboxylic acid or ester-forming derivatives thereof are preferred.

When aliphatic dicarboxylic acids are used, there is a general tendency to reduce heat resistance. Furthermore, when only the aromatic dicarboxylic acid component is used, the water solubility tends to be poor. As the glycol component, ethylene glycol is mainly used, but 1,4-butanediol, neobentyl glycol, l4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, and polyethylene glycol may also be used in combination.

The intrinsic viscosity is preferably 0.25 to 0.55 dl/g,
0.25 dI! ．． If it is less than 0.55 dff/g, the resin will have poor mechanical properties and be brittle, and if it exceeds 0.55 dff/g, it will usually show a significantly high aqueous solution viscosity, which will cause problems in coating properties, although it depends on the copolymer composition of the resin. occurs.

The dicarboxylic acid component used in the production of the water-soluble polyester ether (B) used in the present invention can be the same as that used in the production of the polyester copolymer (8), but from the viewpoint of heat resistance Terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid or ester-forming derivatives thereof are preferred. The glycol component mainly consists of polyethylene glycol and ethylene glycol, but polyethylene glycol has a number average molecular weight of 100.
0 to 6,000, preferably 80 to 95% by weight based on the weight of the water-soluble polyester ether (B). If it is less than 80% by weight, the water solubility will be poor, and if it is more than 95% by weight, polycondensation will be difficult. In addition, the number average molecular weight of polyethylene glycol is 1
If it is less than 000, the polymer becomes a sticky liquid at room temperature, making it difficult to handle. If it exceeds 6,000, not only the viscosity of the aqueous solution becomes high, but also problems arise in the uniformity of the aqueous solution. Diethylene glycol, triethylene glycol, 1,4-cyclohexanedimethanol, etc. may be used in combination as glycol components other than those mentioned above.

Examples of the alkali metal salt (D) used in the present invention include lithium chloride, lithium bromide, lithium iodide, lithium perchlorate, sodium bromide, sodium thiocyanate,
Potassium thiocyanate and the like are used, but halides, perchlorates, and thiocyanates are preferred, and lithium bromide, lithium chloride, and lithium perchlorate are particularly preferred.

Examples of the anionic and/or nonionic surfactants used in the present invention include the following (a) to (c).

However, it is not limited to this.

In the present invention, the ratio of (A) to (D) is A, B and C.
Based on the total weight of the components, component A is 75 to 95% by weight, B
The component is 3 to 23% by weight, the C component is 2 to 20% by weight, and the D component is 2 to 8% by weight. If (A) is less than 75% by weight, the adhesiveness will be poor, and if (B) is less than 3% by weight, the antistatic property will be insufficient. If (C) is less than 2% by weight, stable antistatic properties cannot be obtained, and if it exceeds 20% by weight, problems arise in forming a uniform coating film.

If (D) is less than 2% by weight, the antistatic properties will be insufficient;
In addition, the transparency of the coating film is impaired due to salt precipitation.

Further, as a method for polymerizing the volister copolymer (A) and the water-soluble polyester ether (B), a conventional method can be used. For example, after transesterifying dimethyl ester of dicarboxylic acid with glycol and distilling methanol, the pressure is gradually reduced to high vacuum ■, polycondensation is carried out, or the esterification reaction of dicarboxylic acid and glycol is carried out. After distilling the produced water, the pressure is gradually reduced and polycondensation is carried out under high vacuum, or when dimethyl ester of dicarboxylic acid and dicarboxylic acid are used together as raw materials, dimethyl ester of dicarboxylic acid and ester of glycol. There is a method in which the exchange reaction is further carried out by adding dicarboxylic acid to carry out the esterification reaction, and then polycondensation is carried out under high vacuum. Manganese acetate, calcium acetate,
Zinc acetate, etc., as a polycondensation catalyst, antimony trioxide, etc.
Known materials such as germanium oxide, dibutyltin oxide, and titanium tetrabutoxide can be used.

Furthermore, phosphorus compounds such as trimethyl phosphate and triphenyl phosphate, and hindered phenol compounds such as Irganox 1010 may be used as stabilizers.

However, various conditions such as the polymerization method, catalyst, stabilizer, etc. are not limited to the above-mentioned examples. The polyester copolymer (A) and polyester ether (B) used in the present invention have water solubility, but water solubility as described in the present invention is not strictly physicochemically defined; Also includes those that are finely dispersed.

The antistatic polyester resin composition of the present invention is usually used as an aqueous solution, such as (A), (
Prepare each aqueous solution of B) and (C) separately,
After mixing, (D) can be added thereto to obtain a predetermined composition ratio, but the method is not limited to this method.

Furthermore, anti-blocking agents such as inorganic particles, A of the present invention, etc.
Water-soluble or water-dispersible polymers other than component B may be added within a range that does not impair the effects of the present invention.

In the present invention, at least one layer of the antistatic polyester resin composition as described above is applied to the polyester film.
・Produce a laminated polyester film by providing it on one side. In the polyester film of the present invention, the polyester support on which the antistatic polyester resin composition layer is provided is made of a linear saturated polyester synthesized from an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol. Can be mentioned. Specific examples of such polyesters include polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, etc., and also include copolymers of these and those obtained by blending small amounts of other resins. Furthermore, polyester supports kneaded with white pigments such as titanium oxide, zinc oxide, barium sulfate, etc. can also be mentioned. Further, the polyester film of the present invention is prepared by applying an aqueous solution of the antistatic polyester resin composition of the present invention to at least one surface of the polyester support before completion of crystal orientation, drying, and then stretching in at least one direction. It is preferable to complete the crystal orientation by heat setting.

Application of an aqueous solution of an antistatic polyester resin composition to a polyester support involves a normal application process, that is, a step of applying an aqueous solution to a biaxially stretched and heat-set polyester support separately from the manufacturing process of the support. Of course, this method can also be used, but such a method requires a separate process and is disadvantageous in terms of cost. Therefore, from this point of view, it is advantageous to apply the coating during the polyester support manufacturing process.

In particular, it is preferable to coat at least one side of the polyester support at some point during the process before crystal orientation is completed as described above, for example, by cooling the volustel melt-extruded onto the film from a die on a cooling drum. There is a method in which the stretched film obtained is preheated, stretched vertically, coated with an aqueous solution of an antistatic polyester resin composition, dried, preheated, stretched horizontally, and then fixed. Furthermore, a surface treatment such as corona discharge or glow discharge may be performed before applying the antistatic polyester resin composition.

In the present invention, the polyester support before completion of crystal orientation is an unstretched film obtained by thermally melting polyester and made into a film as it is, or a uniaxial film obtained by stretching this unstretched film J in one direction either vertically or horizontally. It refers to a stretched film, and furthermore, a biaxially stretched film that has been stretched vertically or horizontally, and which has not yet been restretched either vertically or horizontally to complete crystal orientation.

Note: Vertical stretching and horizontal stretching are both normally performed at a magnification of 2.0 to 5.0 times. Further, the solid content concentration of the aqueous solution of the antistatic bonoester resin composition is usually 15% by weight or less, but it can be changed as appropriate depending on the final film thickness.

Various known methods can be applied as the coating method. For example, a roll coating method, a gravure roll method, a spray coating method, an air knife coating method, a Harcoat method, an impregnation method, a curtain coating method, etc. can be applied alone or in combination.

The polyester film coated as described above before completion of crystal orientation is dried and subjected to processes such as stretching and heat setting.

The polyester film having a layer of the antistatic polyester resin composition obtained in this way has excellent antistatic performance, which prevents troubles caused by static electricity in the next processing step, and also provides excellent adhesion as an undercoat layer. Furthermore, due to its transparency, it does not impair the appearance of the polyester support. The present invention can be applied to various photographic light-sensitive materials such as X-ray scattering materials, printing light-sensitive materials, photographic light-sensitive materials, ornamental light-sensitive materials, and other uses requiring antistatic performance.

[Effects of the invention] (1) Since the antistatic polyester resin composition of the present invention can be used as an aqueous solution, there are no problems such as flammability, and compared to organic solvent-based compositions, equipment can be simplified and safety is high. .

(2) The coating film of the antistatic polyester resin composition of the present invention has excellent transparency and does not impair the appearance of the object to be coated.

(3) The polyester film coated with the polyester resin composition of the present invention provides good adhesion when a layer of photographic emulsion or printing ink is further provided on the upper layer.

(4) By providing a coating of the antistatic polyester resin composition of the present invention, various troubles caused by static electricity can be effectively prevented during post-processing steps or during use.

〔Example〕

Hereinafter, the present invention will be explained in more detail by giving Examples. The polyester film obtained by laminating the obtained polyester copolymer (eight components), polyester ether (component B), and polyester resin composition was evaluated by the following method.

(1) Intrinsic viscosity; phenol/L 1, 2. 2-Tetrachloroethane - 20 in a 60/40 (weight ratio) mixture
Measured at °C.

(2) Water solubility; 3 depending on the polymer in hot water at 95°C.
Stir for ~8 hours and visually evaluate solubility and uniformity. (
Concentration: 15% by weight) (3) Spreadability: Total concentration of components A, B and C is 8% by weight
A coating solution was prepared so that the coating solution was coated onto a uniaxially stretched polyethylene terephthalate support using a wire harness (coating solution film thickness: 13.7 μm), and the coating state at that time was visually evaluated.

(4) Surface resistivity: An unstretched film (thickness 100
bzm) was preheated to 75°C, stretched vertically (3 times) and then subjected to corona discharge, the coating solution was applied to the surface-treated support surface, dried in a stenter, and stretched horizontally (3x) at 100°C.
Further heat setting at 220°C results in a film thickness of 0.3 g/m" (
A subtracted polyethylene terephthalate film (in a dry state) was obtained.

This film was temperature-controlled and humidified at 23°C and 55% R1 (relative humidity) for 24 hours, and the surface stiffness resistance of the coated surface was measured.

(5) Adhesion: A gelatin layer containing hard [IJ4] was coated on the undercoated polyethylene terephthalate film obtained in (4), dried, and tilted at 45 degrees with respect to the hardened film surface. A cut was made on the lower arch surface with a razor, and Sellotape was applied, and the peeled area of the gelatin layer when the arch was rapidly peeled off was graded into five grades.

The evaluation criteria are as follows.

1: Adhesion is very weak and completely peeled off 2: 50%
The above is peeled off.

3: About 10-50% is peeled off.

4: Adhesive strength is quite strong<less than 10% peeled off.

5: Adhesive strength is very strong and does not peel off at all.

If the evaluation is 4 or more, it can be considered that the adhesiveness is sufficient for practical use.

A-1 and A- as water-soluble polyester copolymers (component A) having an alkali metal sulfonic acid salt group in the molecule
2 was synthesized. The copolymer composition is shown in Table 1.

B-1 and B-2 were synthesized as water-soluble polyester ethers (component B). The copolymer composition is shown in Table 2.

Also, alkali metal salt (C component), surfactant (D component)
Also shown in Tables 3 and 4.

Regarding the polycondensation method of the above A component and B component and the method for preparing the antistatic polyester resin composition of the present invention from these components (A-1), (B-1), (f,-1)
, (D-1) is shown below.

Synthesis of water-soluble polyester copolymer (A-1) having an alkali metal sulfonate group in the molecule: dimethyl terephthalate 38. 74 parts by weight, dimethyl isophthalate 3
1.95 parts by weight, 10.34 parts by weight of sodium salt of dimethyl sulfoisophthalate, and 54 parts by weight of ethylene glycol.
．． 48 parts by weight, 0.073 parts by weight of calcium acetate hydrate and 0.02 parts of manganese acetate tetrahydrate as transesterification catalysts.
After carrying out a transesterification reaction while distilling methanol off at 170 to 230°C using 4 parts by weight, 0.05 parts by weight of trimethyl phosphate, 0.04 parts by weight of antimony trioxide as a polycondensation catalyst, and 1, 4-Cyclohexanedicarboxylic acid 17. 17 parts by weight was added, and approximately the theoretical amount of water was distilled off at a reaction temperature of 220 to 235°C to carry out esterification. After that, the pressure inside the reaction system was further reduced and the temperature was increased to reach a final temperature of 28
Polycondensation was carried out at 0''C and 0.2 mmHg for 2 hours.

Analysis of the obtained copolymer revealed that the intrinsic viscosity was 0.45.
dl. /g. 95% of the polyester copolymer
The mixture was stirred in hot water at °C for 3 hours to obtain a 15% by weight aqueous solution.

Synthesis of water-soluble polyester (B-1): 11.44 parts by weight of dimethyl terephucrate, 21.8 parts by weight of ethylene glycol
9 parts by weight, 0.03 parts by weight of lucium acetate hydrate, 0.03 parts by weight of manganese acetate tetrahydrate. After carrying out a transesterification reaction while distilling methanol off at 170 to 220°C under a nitrogen stream, 0.043 parts by weight of trimethyl phosphate, 0.04 parts by weight of antimony dioxide as a polycondensation catalyst, and polycondensate were added. Ethylene glycol (number average molecular weight 3000
) 90. 52 parts by weight was added, and the pressure inside the system was further reduced and the temperature was raised to 280° C. and 0.2 mmHg, and polycondensation was carried out for 3 hours. After the system was brought to normal pressure with nitrogen upon completion of polycondensation, 2.00 parts by weight of Irganox 1010 was added and mixed.

Analysis of the obtained copolymer revealed that the intrinsic viscosity was 1.48.
dl2/g, and the melting point was 56°C. The polyester ether was stirred in hot water at 95°C for 3 hours.
A 5% by weight aqueous solution was prepared.

Lithium bromide (C-
1) and sodium dodecylbenzenesulfonate (D-1) as a surfactant (component D), and the ratio of each component was set to 90% of the total weight of components A, B, and C (A-1).
．． 25% by weight, 4.75% by weight of (B-1), (C-1
) is 5% by weight, (D-1) is 5% by weight, and A, B
An aqueous solution of an antistatic polyester resin composition was prepared so that the total concentration of components C and C was 8% by weight.

This aqueous solution is used as a coating liquid, and applied to a vertically stretched support.
By drying, horizontal stretching and heat setting, a biaxially stretched polyethylene terephthalate film having an antistatic undercoat layer of 0.3 g/m2 in terms of dry weight was obtained, and surface resistivity and other properties were evaluated. Surface resistivity is 1.6 x 1
0"Ω, and the appearance was good and transparent. Details are shown in Section 5.
Shown in the table.

A coating solution was prepared in substantially the same manner as in Example 1 by changing the components and composition ratios of A-D so that the total concentration of A, B and C was 8% by weight, and the process was further carried out. A polyethylene terephthalate biaxially stretched film and a gelatin laminated film having an F-stretch layer were obtained in the same manner as in Example 1. The composition and evaluation results are shown in Table 5. All of them exhibited surface resistivities in the range of 10I1 to 10I0Ω, indicating that they had excellent antistatic performance.

In this comparison, a copolymer having the composition shown in B-3 in Table 6 was synthesized as component B. A homogeneous aqueous solution could not be obtained even after stirring for 6 hours in hot water at 95°C.

A copolymer having the composition shown in B-4 in Table 6 was synthesized as the component A and B. It did not dissolve even after stirring for 8 hours in hot water at 95°C.

A coating solution was prepared using each component in Tables 1, 2, and 7 in the same manner as in Example 1 so that the total concentration of components A, B, and C was 8% by weight. did. The results are shown in Table 8.

In Comparative Example 3 using only component A, the surface resistivity was 10Ω2Ω or more, and there was almost no antistatic property.

In Comparative Examples 4 and 5, in which calcium chloride or magnesium chloride, which are alkaline earth metal salts, were used instead of an alkali metal salt as component C, the polymer in the aqueous solution precipitated and could not be coated.

In Comparative Examples 6 and 7 in which the A component was less than 75% by weight, the adhesiveness decreased as the proportion of the A component decreased.

In Comparative Example 8, which did not contain component D, alkali metal salt crystals precipitated and the coating film became cloudy. Surface specific resistance is also 1012Ω
or showed unstable values.

In Comparative Example 8, in which 15% by weight of component D was used, the adhesiveness decreased.

Copolymer composition and physical properties of component A in Table 1 Note) DMT: Dimethyl terephthalate ■: Dimethyl isophthalate SIP? I: 5-sulfoisophthalic acid dimethyl sodium salt 1.4-CHDA; 1,4-cyclohexanedicarboxylic acid EG: ethylene glycol 1.4-CHDM: L4-cyclohexanedimethanol (cis/trans #30/60) Table 2 Copolymer composition and physical properties of component B Note: DMT: dimethyl terephthalate EG: ethylene glycol PEG: polyethylene glycol: number average molecular weight The amount of PEGO copolymerized is expressed in weight % rather than mol %.

Table 3 C component Table 4 D component Table 6 Copolymer composition and physical properties of component B Table 7 Metal salt as a substitute for component C

Claims (1)

[Claims] 1. (A) a water-soluble polyester copolymer having an organic sulfonic acid alkali metal salt group in the molecule and having an intrinsic viscosity of 0.25 to 0.55 dl/g; and (C), 75 to 9
5% by weight, (B) dicarboxylic acid component and polyethylene glycol (
It is a polyester ether consisting of a diol component containing a number average molecular weight of 1000 to 6000, and the polyethylene glycol is 8% by weight of the polyester ether.
0-95% by weight of water-soluble polyester ether (
3 to 23% by weight based on the total weight of A), (B) and (C), and 2 to 20% by weight of (C) alkali metal salt based on the total weight of (A), (B) and (C). %, (D) anionic or/and nonionic surfactant (A), (B) and (
A polyester resin composition comprising at least four compositions of 2 to 8% by weight based on the total weight of C). 2. On at least one side of the polyester film, (A) a water-soluble polyester copolymer having an organic sulfonic acid alkali metal salt group in the molecule and having an intrinsic viscosity of 0.25 to 0.55 dl/g (A), (B) and (C), 75 to 95% by weight, (B) dicarboxylic acid component and polyethylene glycol (number average molecular weight 1000 to 6000
), and the polyethylene glycol is 80 to 95% by weight based on the weight of the polyester ether, and the total weight of (A), (B) and (C) is (C) alkali metal salt in an amount of 2 to 20% by weight based on the total weight of (A), (B) and (C); (D) anionic or/and nonionic surfactant; (A), (B) and (
A polyester film characterized by laminating layers consisting of at least four compositions of 2 to 8% by weight based on the total weight of C).