JPH05132612A - Modified polyester and film - Google Patents

Abstract

PURPOSE:To obtain a modified polyester, excellent in adhesiveness, transparency and flatness by blending a polyester with specified amounts of an ester-forming sulfonic acid alkali metal salt compound and a polylactone compound. CONSTITUTION:A polyester such as polyethylene terephthalate is blended with (A) 3-30wt.%, preferably 5-17wt.% ester-forming sulfonic acid alkali metal salt compound such as sodium 5-sulfoisophthalate and (B) 1-20wt.%, preferably 6-15wt.% polylactone compound such as poly-epsilon-caprolactone to give the objective modified polyester. A film having excellent mechanical characteristics and adhesiveness is obtained from the modified polyester.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a modified polyester and a film thereof, and more particularly to a modified polyester and a film having excellent adhesiveness, transparency and flatness. More specifically, the present invention relates to a modified polyester having excellent adhesiveness, transparency and flatness suitable for a photographic support, packaging, general industrial use, magnetic tape, etc., and a film thereof.

[0002]

2. Description of the Prior Art Polyester, especially polyethylene terephthalate, polybutylene terephthalate or poly-
1,4-Cyclohexane dimethylene terephthalate and polyesters mainly containing these have excellent physical and chemical properties, and are widely used as fibers, films or sheets, and molded articles thereof. There is.

In particular, polyester films have excellent heat resistance, chemical resistance, and mechanical properties, and are therefore used in many applications such as magnetic tape, electricity, photography, packaging, and drawing. Has been.

However, since polyester itself is generally inactive, there is a problem that adhesiveness and printability with hydrophilic ink are poor. Conventionally, a method of subjecting the film surface to corona discharge treatment or coating an adhesive substance to improve the adhesiveness of the polyester film is known. However, these methods have drawbacks that not only the process is complicated and the cost is increased, but also the transparency of the film is lowered.

Therefore, these steps are not required, and
Attempts have been made to improve the adhesion from the film itself. For example, in JP-A-52-151365, polyalkylene glycol is used to copolymerize a polyether segment to improve the adhesiveness and printability of the film, but the characteristics are not sufficient.

On the other hand, as a photographic support, a plastic film made of triacetyl cellulose and polyester typified by polyethylene terephthalate is generally used. However, although the polyester film has excellent mechanical properties, transparency, and dimensional stability, in the roll form, the curling curl remains strongly, so that the handleability after development is poor, and the film for X-rays and plate making Its scope has been limited to use in sheet-like forms such as film for use.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art. In particular, it has excellent adhesiveness without the need for extra high-order processing, transparency, and winding. It is an object of the present invention to provide a modified polyester and a film which have good curl recovery properties and mechanical properties.

[0008]

The above-mentioned object of the present invention is characterized by containing 3 to 30% by weight of an ester-forming alkali metal sulfonate compound and 1 to 20% by weight of a polylactone compound based on polyester. It can be achieved by the modified polyester and the film thereof.

The polyester in the present invention is a polyester having an aromatic dicarboxylic acid or an alicyclic dicarboxylic acid and diol as main constituent components. Examples of the aromatic dicarboxylic acid component include terephthalic acid, isophthalic acid and phthalic acid. , 1,4-naphthalenedicarboxylic acid, 1,
5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4
Examples thereof include aromatic dicarboxylic acids such as ′ -diphenyl ether dicarboxylic acid and 4,4′-diphenyl sulfone dicarboxylic acid, and examples of alicyclic dicarboxylic acid components include 1,4-cyclohexanedicarboxylic acid. You can Two or more of these acid components may be used in combination,
Further, aliphatic dicarboxylic acids such as adipic acid, suberic acid, sebacic acid and dodecanedioic acid, and oxy acids such as hydroxyethoxybenzoic acid may be partially copolymerized.
Examples of the diol component include ethylene glycol
1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol
1,3-butanediol, 1,5-pentanediol
1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol
, 1,4-cyclohexane dimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2'-bis (4'-β-hydroxyethoxyphenyl) propane, bis (4 ' Examples thereof include aliphatic, alicyclic and aromatic diols such as -β-hydroxyethoxyphenyl) sulfone. These diol components may be used alone or in combination of two or more. Further, the polyester may be copolymerized with another compound such as a trifunctional or higher functional compound or a monofunctional compound in an amount range in which the polymer is substantially linear. A typical example of polyester is polyethylene terephthalate.
, Polybutylene terephthalate, polyethylene naphthalate, poly-1,4-cyclohexane dimethylene terephthalate and the like.

Examples of the ester-forming sulfonic acid alkali metal salt compound in the present invention include sulfoterephthalic acid and 5
-Sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-
Sulfoisophthalic acid, 4-sulfonaphthalene-2,6-
Examples thereof include alkali metal salts of dicarboxylic acids and the like, and ester-forming derivatives thereof. Among them, sodium and potassium salts of 5-sulfoisophthalic acid and sulfoterephthalic acid are more preferably used.

The amount of the ester-forming alkali metal sulfonate compound should be 3 to 30% by weight, preferably 4 to 20% by weight, more preferably 5 to 17% by weight, based on the polyester. If the amount of the ester-forming alkali metal sulfonate compound is less than 3% by weight based on the polyester, sufficient adhesiveness and curl curl recovery cannot be obtained, which is not preferable. On the other hand, when it exceeds 30% by weight, the adhesiveness reaches saturation, and on the contrary, a high molecular weight polyester cannot be obtained, which makes film formation difficult and the mechanical strength of the obtained film is lowered, which is not preferable.

The method for copolymerizing or incorporating the ester-forming alkali metal sulfonate compound of the present invention into polyester is not particularly limited. The compounding or adding method to the polyester and the timing thereof are arbitrary and are not particularly limited. You may mix | blend with polyester in a powder or a molten state, and may add it. In addition, as the blending and addition timing, during the polyester synthesis reaction, the molten state after the reaction,
You may mix and add in a pellet state or at any time before shaping | molding.

The polylactone compound in the present invention has a repeating unit represented by the following formula. -O (C (= O) C i H 2i 0) n - where the i wherein 1 to 5, n is a positive integer.

Particularly preferred polylactone compounds include poly-ε-caprolactone.

The molecular weight of the polylactone compound is preferably in the range of 500 to 25,000 in terms of average molecular weight, and more preferably in order to obtain good heat resistance, curl curl recovery, mechanical properties and transparency. Is 550 to 2000
It is 0, and more preferably 600 to 10,000.

The amount of the polylactone compound of the present invention must be 1 to 20% by weight based on the polyester, more preferably 3 to 17% by weight, and further preferably 6 to 15%.
% By weight. If the amount of the polylactone compound is less than 1% by weight, the adhesiveness and curling curl recovery are insufficient, and if it exceeds 20% by weight, the mechanical properties and heat resistance deteriorate, which is not preferable.

The modified polyester of the present invention contains a polylactone compound in the polyester, and the presence state of the polylactone compound may be either the polylactone compound alone or a copolymer with the polyester, and is not particularly limited. Although not a thing, a thing in which a polylactone compound and a polyester form a block-shaped copolymer is particularly preferable in terms of curl curl recovery and transparency.
The method and time of addition to the polyester are arbitrary and are not particularly limited. As a method for copolymerizing the polylactone compound in a block form, it is preferable to stir and knead the polyester and the polylactone compound in a molten state within 2 hours. A method of melt kneading by adding a polylactone compound to the polyester in a molten state in
Or polyester and polylactone compound bent 2
Examples thereof include a method of charging in a shaft extruder and melt-kneading.

As a specific method for producing the modified polyester of the present invention, for example, a polyethylene terephthalate modified polyester comprising a terephthalic acid component and an ethylene glycol component will be described. Terephthalic acid, ester-forming sulfonic acid alkali metal salt compound (for example, 5-sodium sulfoisophthalic acid) and ethylene glycol are directly esterified, or dimethyl terephthalate, ester-forming sulfonic acid alkali metal salt compound ( For example, the first stage reaction in which 5-sodium sulfoisophthalate (dimethyl)) and ethylene glycol are transesterified and polycondensed, and the reaction product of this first stage is made into a polyester in a molten state with poly-ε A second step of adding caprolactone and kneading, B. Terephthalic acid or its ester-forming derivative,
Examples thereof include a method in which a polyester is polymerized from an ester-forming alkali metal sulfonate compound and ethylene glycol, and then the resulting pellet and poly-ε-caprolactone are remelted and kneaded.

At this time, conventionally known alkali metals, alkaline earth metals, manganese, cobalt, zinc, antimony, germanium, titanium compounds and the like are used as the reaction catalyst, and phosphorus compounds and the like are further used as the coloring preventing agent. Good.

The glass transition temperature of the modified polyester of the present invention is preferably 30 ° C. or higher, more preferably 50 ° C. or higher, and further preferably 60 ° C. or higher in order to obtain good heat resistance.

The intrinsic viscosity of the modified polyester of the present invention is preferably 0.3 or more, more preferably 0.35 or more, still more preferably 0.4 or more in order to enhance the strength of the formed film.

If necessary, the modified polyester of the present invention may contain an organic lubricant such as a flame retardant, a heat stabilizer, an ultraviolet absorber, a pigment, a dye, a fatty acid ester or wax, or an antifoaming agent such as polysiloxane. May also be blended with clay, mica, titanium oxide, calcium carbonate, kaolin, silica, calcium phosphate, barium sulfate, alumina, or organic particles having acrylic, styrene or the like as a constituent component for the purpose of improving the slipperiness. You may.

The modified polyester obtained above is dried, melt-extruded into an unstretched sheet, and then biaxially stretched and heat-treated to obtain a target film.

The biaxial stretching may be either longitudinal and transverse sequential stretching or biaxial simultaneous stretching, and the stretching ratio is not particularly limited, but usually a longitudinal and transverse ratio of 2.0 to 5.0 is suitable. Alternatively, it may be stretched in the machine direction or in the transverse direction after stretching in the machine direction. Further, fibers and other molded products can be produced from the modified polyester of the present invention by a conventional method.

[0025]

EXAMPLES The present invention will now be described in more detail with reference to examples. The characteristics in the examples were measured as follows.

A. Intrinsic viscosity of polyester: Measured at 25 ° C. using a [η] o-chlorophenol solvent.

B. Glass transition temperature of polyester (T
g) and melting point (Tm) Measured by a differential scanning calorimeter.

C. Transparency The film obtained from polyester is ASTM-D10.
The film haze was measured according to 03-59.

D. Adhesiveness Aluminum was vapor-deposited on the surface of a film obtained from polyester, and cellophane tape was pressure-bonded to the vapor-deposited surface, and the state when peeled off was evaluated. ⊚: No peeling on the cellophane tape side. ◯: 20% or less of the portion peeled off to the cellophane tape side. Δ: 20% to 70% of the portion is peeled off to the cellophane tape side. X: 70% or more of the portion was peeled off to the cellophane tape side.

E. Breaking strength 10mm width x 50 from film obtained from polyester
A sample with a length of mm was prepared and measured at a pulling speed of 300 mm / min.

F. Winding curl recovery 35mm width x 13 from film obtained from polyester
Make a sample with a length of 3 mm and wind it on a core with a diameter of 10 mm.
℃ × 30% RH × 72hr treatment, then released from the core and soaked in distilled water at 40 ℃ for 30 minutes, then hang the sample vertically, load 30g in a constant temperature air bath at 50 ℃ 5 Dry for minutes. The treated film sample was placed on a flat surface and evaluated how much the sample length was restored with respect to the original sample length of 133 mm.

G. Heat shrinkage 10mm width x 25 from the film obtained from polyester
Make a sample with a length of 0-300 mm, apply a weight to the sample with a 3 g clip, and set it to 150 ° C with hot air.
The sample was treated in a oven and the sample length before and after the treatment was measured to determine the heat shrinkage rate.

Example 1 100 parts by weight of dimethyl terephthalate, 10 parts by weight of dimethyl 5-sodium sulfoisophthalate, 70 parts by weight of ethylene glycol and 0.1 part by weight of calcium acetate as a transesterification reaction catalyst, polycondensation reaction After adding 0.03 part by weight of antimony trioxide as a catalyst and carrying out an ester exchange reaction according to a conventional method, 0.05 part by weight of trimethyl phosphate was added to carry out a polycondensation reaction. Then, 10 parts by weight of poly-ε-caprolactone having an average molecular weight of 4000 was added as a polylactone compound, and the mixture was stirred under reduced pressure for 30 minutes to obtain a polyester. The intrinsic viscosity measured at 25 ° C using an o-chlorophenol solvent was 0.55.
The Tg was 65 ° C and the Tm was 230 ° C.

The polyester obtained was formed into a film at 280 ° C. by a film molding machine, and then stretched at a longitudinal stretching ratio of 3.6 times and a transverse stretching ratio of 3.8 times by a biaxial stretching machine, and then at 190 ° C.
The film was heat-treated at 80 ° C. to obtain a film having a thickness of 80 μm. The characteristics of the obtained film are shown in Table 2. The haze of the film is 1.
It was 2%, the adhesiveness was good, and when the curl curl recovery was evaluated, the film became almost flat without curling. The heat shrinkage rate at 150 ° C. was 1.3%.

Comparative Example 1 In the same manner as in Example 1, a 5-sodium sulfoisophthalic acid copolymerized polyester and a film were obtained without adding poly-ε-caprolactone. The intrinsic viscosity of the polyester was 0.50, and the haze of the film was good at 0.9%, but the adhesiveness and curl curl recovery were poor.

Examples 2-5, Comparative Examples 2-4 As shown in Table 1, the type and amount of various ester-forming sulfonic acid metal salt compounds and polylactone compounds were changed in the same manner as in Example 1, A polyester and film were obtained.

[0037]

[Table 1]

The abbreviations in the table indicate the following compounds.

PCL: Polycaprolactone The characteristics of the obtained polyester and flume are shown in Table 2.
It was shown to.

[0040]

[Table 2]

As shown in Table 2, Examples 2 to 5 were within the scope of the present invention and had good film haze, adhesiveness and curl curl recovery. On the other hand, Comparative Example 2
No ester-forming metal sulfonate compound was used, and although the haze of the film was good, both the adhesiveness and curl curl recovery were poor. Also,
In Comparative Example 3, the amount of the ester-forming sulfonic acid metal salt compound was outside the range of the present invention, and in Comparative Example 4, the amount of the polylactone compound was outside the range of the present invention, and both were inferior in adhesiveness and curl curl recovery. It was

[0042]

INDUSTRIAL APPLICABILITY As described above, the present invention is a modified polyester obtained by adding a specific amount of an ester-forming metal sulfonate compound and a polylactone compound to polyester, and a film thereof, which has excellent adhesiveness. It has transparency and curl curl recovery property, and is preferably used for photographic support, packaging, general industry, magnetic tape and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C08L 67/04 // C08J 5/12 CFD 9267-4F

Claims (2)

[Claims] 1. A modified polyester comprising 3 to 30% by weight of an ester-forming alkali metal salt compound and 1 to 20% by weight of a polylactone compound, based on the polyester. 2. A film comprising the modified polyester according to claim 1.