JP2002020595A - Copolyester resin composition and stretched film comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a copolyester resin composition for a heat shrinkable film excellent in strength, transparency and solvent adhesion and a stretched film comprising the copolyester resin composition. SOLUTION: This copolyester resin composition comprises the following components (A) to (D). (A) 10-70 wt.% of a resin in which teraphthalic acid is a principal component as a dicarboxylic acid component, ethylene glycol is a principal component as a diol component and cyclohexanedimethanol in an amount of 5-50 mol% based on the whole diol component is copolymerized, (B) 10-50 wt.% of a resin in which the terephthalic acid is a principal component as the dicarboxylic acid component, the ethylene glycol is a principal component as the diol component and isophthalic acid in an amount of 5-50 mol% based on the whole dicarboxylic acid component is copolymerized, (C) 5-50 wt.% of a resin in which the terephthalic acid and butanediol are principal components and 1-80 wt.% of a polyalkylene ether glycol is copolymerized and (D) 0-50 wt.% of a resin in which terephthalic acid and butanediol are principal components and the polyalkylene ether glycol is not substantially contained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a copolyester which is capable of obtaining a heat-shrinkable film which is excellent in heat shrinkability, has a small temperature dependency, excellent mechanical strength and transparency, and further has excellent solvent adhesion. A resin composition and a stretched film comprising the same, particularly a label material and a mouth sealing material for covering the outer peripheral surface of various food and beverage bottles and the like, or a material for wrapping, bundling, covering, etc. industrial parts and the like. The present invention relates to a copolymerized polyester resin composition suitably used for a heat-shrinkable film, and a stretched film comprising the same.

[0002]

2. Description of the Related Art Conventionally, a heat-shrinkable film has been used as a packaging material, a bundling material, a covering material, a sealing material, a label material, etc. by utilizing the property of contracting by heating to develop a binding force. Widely used, among them, heat-shrinkable film composed of uniaxially or biaxially stretched film of polyethylene terephthalate resin has excellent mechanical strength, chemical properties, transparency, gas barrier properties, safety and health properties of polyester resin In particular, with the increasing demand for polyethylene terephthalate resin food and beverage bottles,
As a label material for covering the outer peripheral surfaces of these bottles, there is an advantage that the bottles are made of the same material as the bottles in terms of the recycling of the bottles, and thus they have shown rapid growth.

[0003] However, polyethylene terephthalate resin is crystalline and has a high melting point, so that the heat shrinkage initiation temperature is high, the shrinkage rate is insufficient, and the temperature dependence of the heat shrinkage rate is also high. Is large, and
There was a problem that the adhesive strength by solvent adhesion was not sufficiently exhibited.

On the other hand, as a method for solving these problems, for example, a method using a copolymerized polyethylene terephthalate resin obtained by copolymerizing neopentyl glycol as a diol component (for example, Japanese Patent Application Laid-Open No. 63-202429).
No., refer to Japanese Patent Publication No. ), A method using a copolymerized polyethylene terephthalate-based resin obtained by copolymerizing cyclohexanedimethanol as a diol component, or a composition of the same with a polyethylene terephthalate resin (see, for example,
See 3-27235 and the like. ), A method of using a laminate of composition layers of a specific composition of a copolymerized polyethylene terephthalate resin obtained by copolymerizing cyclohexane dimethanol as a diol component, a polyethylene terephthalate resin, and a polybutylene terephthalate resin (for example, Japanese Patent Application Laid-Open No. 244644, etc.) have been proposed, but according to the study of the present inventors, although any of the above-mentioned problems can be solved to some extent, the mechanical strength, transparency, and the like are reduced at the same time. New problems such as

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned prior art. Therefore, the present invention has excellent heat shrinkability, low temperature dependency, and low mechanical strength and transparency. Excellent, a copolymerized polyester resin composition capable of obtaining a heat-shrinkable film further excellent in solvent adhesion,
And a stretched film comprising the same.

[0006]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the above object can be achieved by using a composition comprising a specific polyester resin. That is, the present invention provides the following (A) component, (B) component, (C) component,
And (D) [where the weight percent of each component is based on a total of 100 weight percent of these four components. The gist of the present invention is a copolymerized polyester resin composition and a stretched film comprising the same.

(A) A copolymerized polyethylene terephthalate resin comprising terephthalic acid as a dicarboxylic acid component, ethylene glycol as a diol component and cyclohexanedimethanol as a diol component in an amount of 5 to 50 mol% of all diol components; (B) Terephthalic acid as a dicarboxylic acid component, ethylene glycol as a diol component, and isophthalic acid as a dicarboxylic acid component is 5% of the total dicarboxylic acid component.
(C) terephthalic acid as a dicarboxylic acid component, butanediol as a diol component, and 1 to 80% by weight of a polyalkylene ether glycol. Copolymerized polybutylene terephthalate resin; 5 to 50% by weight (D) Mainly containing terephthalic acid as a dicarboxylic acid component, butanediol as a diol component, and substantially not copolymerized with a polyalkylene ether glycol Polybutylene terephthalate resin; 0 to 50% by weight

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The component (A) constituting the copolymerized polyester resin composition of the present invention comprises terephthalic acid as a dicarboxylic acid component, ethylene glycol as a diol component, and cyclohexanedimethanol as a diol component. It is a copolymerized polyethylene terephthalate resin in which 5 to 50 mol% of a diol component is copolymerized.

Here, cyclohexanedimethanol is
It is preferably from 10 to 40 mol% of the total diol component, and particularly preferably from 25 to 40 mol%. If the cyclohexane dimethanol relative to all diol components is less than the above range, the adhesive strength with a solvent when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like will be inferior. The thermal stability during the production of the product is reduced, and as a result, the mechanical strength of a heat-shrinkable film or the like is deteriorated.

As cyclohexanedimethanol, for example, 1,1-cyclohexanedimethanol,
Examples thereof include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol, among which 1,4-cyclohexanedimethanol is particularly preferred.

In the present invention, the copolymerized polyethylene terephthalate resin as the component (A) is mainly composed of terephthalic acid as a dicarboxylic acid component, ethylene glycol as a diol component, and cyclohexanedimethanol as a diol component. As far as it is satisfied, a dicarboxylic acid component other than terephthalic acid and a diol component other than ethylene glycol and cyclohexanedimethanol may be further copolymerized.

Specific examples of the dicarboxylic acid component other than terephthalic acid include, for example, phthalic acid, isophthalic acid,
Phenylenedioxydiacetic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenoxyethanedicarboxylic acid, 4,4′-diphenyletherdicarboxylic acid, 4,
Alicyclics such as aromatic dicarboxylic acids such as 4'-diphenylsulfone dicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid Dicarboxylic acid, malonic acid, succinic acid, adipic acid,
Aliphatic dicarboxylic acids such as azelaic acid and sebacic acid; In the present invention, the dicarboxylic acid component also includes, for example, an ester-forming derivative such as an alkyl ester thereof having about 1 to 4 carbon atoms at the stage of the raw material before being copolymerized.

The diol components other than ethylene glycol and cyclohexanedimethanol include, for example, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5- Pentanediol, 1,6-hexanediol, 1,10-
Aliphatic diols such as decanediol, 2,2-dimethyl-1,3-propanediol, diethylene glycol, polyethylene glycol, and polytetramethylene ether glycol; 1,2-cyclohexanediol;
Alicyclic diols such as cyclohexanediol, 4,
4'-dihydroxybiphenyl, 2,2-bis (4'-
Hydroxyphenyl) propane, 2,2-bis (4′-
β-hydroxyethoxyphenyl) propane, bis (4
Aromatic diols such as -hydroxyphenyl) sulfone and bis (4-β-hydroxyethoxyphenyl) sulfonic acid.

Further, for example, hydroxycarboxylic acids and alkoxycarboxylic acids such as glycolic acid, p-hydroxybenzoic acid and p-β-hydroxyethoxybenzoic acid, and stearic acid, stearyl alcohol, benzyl alcohol, benzoic acid, t- Monofunctional components such as butylbenzoic acid and benzoylbenzoic acid, tricarballylic acid, hexanetricarboxylic acid, trimellitic acid, trimesic acid, pyromellitic acid, benzophenonetetracarboxylic acid, naphthalenetetracarboxylic acid, 1,2,6-hexanetriol,
A trifunctional or higher polyfunctional component such as gallic acid, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, sorbitol, dipentaerythritol, or polyglycerol may be copolymerized.

The component (B) constituting the copolymerized polyester resin composition of the present invention contains terephthalic acid as a dicarboxylic acid component, ethylene glycol as a diol component, and isophthalic acid as a dicarboxylic acid component. It is a copolymerized polyethylene terephthalate resin in which 5 to 50 mol% of the components are copolymerized.

Here, the amount of isophthalic acid is preferably 10 to 40 mol% of the total dicarboxylic acid component, and is preferably 20 to 3 mol%.
Particularly preferred is 5 mol%. If the isophthalic acid relative to the total dicarboxylic acid component is less than the above range, the starting temperature at the time of heat shrinkage when the copolymerized polyester resin composition is formed into a heat shrinkable film or the like is high, and the heat shrinkage is also low, such as a small shrinkage ratio, and the heat shrinkage is poor. On the other hand, when the above range is exceeded,
When the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like, the mechanical strength is inferior.

In the present invention, the copolymerized polyethylene terephthalate resin as the component (B) is mainly composed of terephthalic acid as a dicarboxylic acid component, ethylene glycol as a diol component, and isophthalic acid as a dicarboxylic acid component. As long as it is satisfied, a dicarboxylic acid component other than terephthalic acid and isophthalic acid, and a diol component other than ethylene glycol may be further copolymerized, in which case a dicarboxylic acid component other than terephthalic acid and isophthalic acid, In addition, as the diol component other than ethylene glycol, the same diol components as those described in the component (A) can be used.

The component (C) constituting the copolymerized polyester resin composition of the present invention comprises terephthalic acid as a dicarboxylic acid component, butanediol as a diol component, and 1 to 80 polyalkylene ether glycol.
It is a copolymerized polybutylene terephthalate resin copolymerized by weight.

Here, the polyalkylene ether glycol is preferably copolymerized by 2 to 60% by weight.
It is particularly preferred that 5 to 30% by weight is copolymerized. When the copolymerization ratio of the polyalkylene ether glycol is less than the above range, the temperature dependence of the heat shrinkage when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like becomes large, while, when the copolymerization ratio exceeds the above range, the copolymerization occurs. It becomes difficult to produce the polybutylene terephthalate resin itself.

As the polyalkylene ether glycol, specifically, for example, polyethylene glycol, polypropylene glycol, polytrimethylene ether glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, a block of ethylene oxide and propylene oxide Or a random copolymer etc. are mentioned, and polytetramethylene ether glycol is especially preferable.

The polyalkylene ether glycol preferably has a number average molecular weight of 500 to 3,000, more preferably 500 to 2,000, more preferably 600 to 2,000.
It is particularly preferable that the number is from 1500 to 1500. When the number average molecular weight is less than the above range, the solvent adhesion when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like tends to be insufficient. Transparency when formed into a heat-shrinkable film or the like tends to decrease.

As butanediol, for example,
1,2-butanediol, 1,3-butanediol,
Examples thereof include 1,4-butanediol and 2,3-butanediol, among which 1,4-butanediol is particularly preferred.

The component (C) in the present invention includes:
The dicarboxylic acid component is preferably a copolymerized polybutylene terephthalate resin in which isophthalic acid is copolymerized at 50 mol% or less of the total dicarboxylic acid component, more preferably 40 mol% or less of isophthalic acid. 3
Particularly preferred is 0 mol%. When the isophthalic acid is copolymerized, the transparency when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like tends to be improved. On the other hand, if it exceeds the above range, the mechanical strength when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like tends to be inferior.

In the present invention, the copolymerized polybutylene terephthalate resin as the component (C) contains terephthalic acid as a dicarboxylic acid component, butanediol as a diol component, and polyalkylene ether glycol satisfies the above ratio. As long as a dicarboxylic acid component other than terephthalic acid and isophthalic acid to be preferable, and a diol component other than butanediol may be further copolymerized, a dicarboxylic acid component other than terephthalic acid and isophthalic acid at that time may be used. As the diol component other than butanediol, the same diol components as those described in the component (A) can be used.

The component (D) constituting the copolymerized polyester resin composition of the present invention comprises terephthalic acid as a dicarboxylic acid component, butanediol as a diol component, and substantially a polyalkylene ether glycol. It is a polybutylene terephthalate-based resin that has not been used. Here, "the polyalkylene ether glycol is not substantially copolymerized" means that the copolymerization ratio of the polyalkylene ether glycol is the lower limit of the copolymerization ratio of the polyalkylene ether glycol in the component (C). Less than.

Here, the component (D) in the present invention is preferably a copolymerized polybutylene terephthalate resin obtained by copolymerizing isophthalic acid as a dicarboxylic acid component at 50 mol% or less of the total dicarboxylic acid component. More preferably, the isophthalic acid content is 40 mol% or less.
It is particularly preferred that the content is 30 to 30 mol%. When the isophthalic acid is copolymerized, the transparency when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like tends to be improved. On the other hand, if it exceeds the above range, the mechanical strength when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like tends to be inferior.

The butanediol includes (C)
The same ones as described in the components can be used.

The polybutylene terephthalate resin of the component (D) in the present invention may be terephthalic acid as a dicarboxylic acid component and butanediol as a diol component other than terephthalic acid and isophthalic acid, which is preferable. A dicarboxylic acid component, and a diol component other than butanediol may be further copolymerized, in which case a dicarboxylic acid component other than terephthalic acid and isophthalic acid, and a diol component other than butanediol, The same as those described in the component (A) can be used.

In the present invention, the component (A) is a copolymerized polyethylene terephthalate resin, the component (B) is a copolymerized polyethylene terephthalate resin,
The copolymerized polybutylene terephthalate resin of the component and the polybutylene terephthalate resin of the component (D) are basically composed of a dicarboxylic acid component containing terephthalic acid as a main component and ethylene glycol or butanediol as a main component. And a diol component.

That is, a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing ethylene glycol or butanediol as a main component are esterified in an esterification reaction tank, and the obtained esterification reaction product is subjected to a polycondensation reaction. A direct polymerization method in which the dicarboxylic acid component mainly containing an ester-forming derivative of terephthalic acid and a diol component mainly containing ethylene glycol or butanediol are transesterified in an esterification reaction tank. A transesterification method in which the obtained transesterification reaction product is transferred to a polycondensation reaction tank and polycondensed, or a dicarboxylic acid component containing terephthalic acid as a main component in a slurry preparation tank containing ethylene glycol or butanediol as a main component. The slurries dispersed in the diol component are converted into an esterification reaction. In the above-obtained esterification reaction product or transesterification reaction product, esterification under normal pressure, and continuously or / and stepwise polycondensation of the obtained reaction product Any of a continuous direct polymerization method and the like which is transferred to a reaction tank and subjected to polycondensation can be employed.

Usually, the resin obtained by the polycondensation reaction is drawn out in a strand form from a discharge port provided at the bottom of the polycondensation reaction tank, and cut with a cutter with or after cooling with water, and then pelletized by a cutter. However, by heating the pellets after the polycondensation and subjecting them to solid-phase polymerization, the degree of polymerization can be further increased, and acetaldehyde and low-molecular-weight oligomers as reaction by-products can be reduced. it can.

In the above production method, the esterification reaction may be carried out, if necessary, for example, by using diantimony trioxide,
200 to 270 in the presence of an esterification catalyst such as an organic acid salt such as antimony, titanium, magnesium and calcium.
℃ a temperature of about made under a pressure of about ^{1 × 10 5 ~4 × 10 5} Pa, transesterification reaction is optionally, for example, lithium, sodium, potassium, magnesium,
It is carried out in the presence of a transesterification catalyst such as an organic acid salt of calcium, manganese, titanium, zinc or the like under a temperature of about 200 to 270 ° C. and a pressure of about 1 × 10 ⁵ to 4 × 10 ⁵ Pa.

The polycondensation reaction is carried out in the presence of, for example, orthophosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, and a phosphorus compound such as an ester or an organic acid salt thereof. In the presence of a metal oxide such as germanium dioxide and germanium tetroxide, or a polycondensation catalyst such as an organic acid salt such as antimony, germanium, zinc, titanium and cobalt, a temperature of about 240 to 290 ° C. and 1 × 10 ² ~ 2
It is performed under reduced pressure of about × 10 ³ Pa.

In the solid-phase polymerization, after pre-crystallization is performed by heating at a temperature of about 120 to 200 ° C. for 1 minute or more, a temperature of about 180 to 240 ° C. and an inert gas such as nitrogen gas are used. Under atmosphere and / or 1 × 10 ² to 2 × 10 ³
It is performed under reduced pressure of about Pa.

In the present invention, the copolymerized polyethylene terephthalate resin of the component (A) and the copolymerized polyethylene terephthalate resin of the component (B) are used in view of the mechanical strength of the copolymerized polyester resin composition. Having an intrinsic viscosity of 30 in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (weight ratio 1/1).
The value measured at ° C is preferably 0.4 dl / g or more, more preferably 0.5 dl / g or more, and particularly preferably 0.6 dl / g or more. or,
The copolymerized polybutylene terephthalate resin of the component (C) and the polybutylene terephthalate resin of the component (D) have an intrinsic viscosity of 0.6 dl / g or more as a value measured under the same conditions. Is preferred, and 0.7
dl / g or more, more preferably 0.8 dl / g.
The above is particularly preferred.

In the copolymerized polyester resin composition of the present invention, the copolymerized polyethylene terephthalate-based resin (A) is 10 to 70% by weight, and the copolymerized polyethylene terephthalate-based resin (B) is 10 to 50% by weight. %, 5 to 50% by weight of the copolymerized polybutylene terephthalate-based resin of the component (C), and 0 to 50% by weight of the polybutylene terephthalate-based resin of the component (D). Is based on a total of 100% by weight of these four components. The component (A) is 30 to 65% by weight, and the component (B) is 20% by weight.
Preferably, the component (C) is 10 to 35% by weight, and the component (D) is 5 to 30% by weight, and the component (A) is 40 to 50% by weight, It is particularly preferred that component 25) to 35% by weight, component (C) 15 to 25% by weight, and component (D) 10 to 20% by weight.

When the amount of the component (A) is less than the above range, the copolyester resin composition of the present invention has a low heat shrinkage when the copolyester resin composition is formed into a heat shrinkable film or the like, and the heat shrinkability is low. At the same time, the adhesive strength due to the solvent is inferior. On the other hand, when the above-mentioned range is exceeded, the thermal stability during the production of the copolymerized polyester resin composition is reduced, and as a result, the mechanical strength when a heat-shrinkable film or the like is formed Is inferior. When the component (B) is less than the above range, the starting temperature at the time of heat shrinkage when the copolymerized polyester resin composition is formed into a heat shrinkable film or the like is high, and further the heat shrinkage is small, and the heat shrinkage is poor. On the other hand, when the content exceeds the above range, the mechanical strength when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like is inferior. When the component (C) is less than the above range, the temperature dependence of the heat shrinkage when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like becomes large. When the resin composition is formed into a heat-shrinkable film or the like, the mechanical strength is inferior. Further, by containing the component (D), the mechanical strength when the copolymerized polyester resin composition is formed into a heat-shrinkable film or the like can be improved. When the material is made into a heat-shrinkable film or the like, the transparency is deteriorated.

Further, the copolymerized polyester resin composition of the present invention is characterized in that the above components (A), (B), (C) and (D) satisfy the above composition ratio, and the terephthalic acid in the composition is The total amount of the dicarboxylic acid component other than and the diol component other than ethylene glycol excluding the polyalkylene ether glycol is based on the total amount of all the dicarboxylic acid components and all the diol components excluding the polyalkylene ether glycol in the composition. Is preferably from 10 to 50 mol%, more preferably from 15 to 40 mol%, more preferably from 20 to 20 mol%.
Particularly preferred is 30 mol%. When the ratio of the total amount of the dicarboxylic acid component other than terephthalic acid and the diol component other than ethylene glycol excluding the polyalkylene ether glycol is less than the above range, the starting temperature at the time of heat shrinkage when the heat shrinkable film or the like is used. The heat shrinkability tends to be inferior, for example, the shrinkage ratio is low, and the heat shrinkage tends to be inferior when the heat shrinkable film or the like is in excess of the above range.

Here, the dicarboxylic acid component other than terephthalic acid and the ethylene glycol excluding the polyalkylene ether glycol with respect to the total amount of all the dicarboxylic acid component and all the diol components except the polyalkylene ether glycol in the composition. The total mol% with the diol component other than the above is based on the mol% of the polyester component of each of the components (A), (B), (C), and (D) excluding the polyalkylene ether glycol. Convert,
It is calculated by calculating the weight% of the composition from the weight% and the composition% when the resin composition is used, and further converting it to mol%.

The above-mentioned copolymerized polyester resin composition of the present invention contains inorganic or organic fine particles because it can impart anti-blocking properties, slipperiness and the like to a heat-shrinkable film or the like. It is preferable that the content is 0.005 to 1 with respect to the whole composition.
% By weight, more preferably 0.01 to 0.6% by weight, and particularly preferably 0.02 to 0.5% by weight.

Specific examples of the inorganic fine particles include silica, alumina, titania, kaolin,
Clay, calcium carbonate, calcium phosphate, lithium fluoride, carbon black, and alkali metal at the time of polyester polymerization, alkaline earth metal, precipitates caused by a catalyst such as a phosphorus compound, and the like, as organic fine particles, For example, various crosslinked polymers and the like can be mentioned, and these have an average particle diameter of preferably 0.001 to 6 μm, more preferably 0.005 to 4 μm, and preferably 0.1 to 4 μm.
It is particularly preferred that the thickness be from 01 to 3 μm. Here, the average particle diameter is a 50% volume average particle diameter (d50).

In order to incorporate the inorganic or organic fine particles into the copolymerized polyester resin composition of the present invention, the copolymerized polyethylene terephthalate resin of the component (A) and the copolymerized polyethylene of the component (B) are usually used. The terephthalate resin, the copolymerized polybutylene terephthalate resin of the component (C), and the polybutylene terephthalate resin of the component (D) are contained in at least one of the components. The fine particles other than the fine particles may be added at the time of preparing the later-described copolymerized polyester resin composition or at the time of forming the later-described film of the copolymerized polyester resin composition.

The copolymerized polyester resin composition of the present invention may be a polyolefin-based resin such as polyethylene, polypropylene, a maleic anhydride-modified product thereof, an ionomer, a polyamide-based resin, or the like, as long as the effects of the present invention are not impaired. It may contain other thermoplastic resins or thermoplastic elastomers such as polycarbonate resins and polystyrene resins, and further include antioxidants such as hindered phenols, phosphites, and thioethers, and benzotriazoles. , Benzophenone-based, benzoate-based, hindered amine-based, cyanoacrylate-based light stabilizers, inorganic and organic crystal nucleating agents, molecular weight regulators,
Additives such as hydrolysis stabilizers, antistatic agents, lubricants, release agents, plasticizers, flame retardants, flame retardant aids, foaming agents, coloring agents, dispersing aids, and glass fibers, carbon fibers, mica, and titanium A reinforcing material such as acid potassium fiber may be contained.

Incidentally, the copolymerized polyester resin composition of the present invention is added to the above-mentioned other thermoplastic resin or thermoplastic elastomer,
In order to contain additives, reinforcing materials, etc., the above (A) is usually used.
Component polyethylene terephthalate resin, component (B) copolymer polyethylene terephthalate resin, component (C) copolymerized polybutylene terephthalate resin, or component (D) polybutylene terephthalate resin May be added at the time of preparing the later-described copolymerized polyester resin composition or at the time of forming the later-described film of the copolymerized polyester resin composition or the like.

The copolymerized polyester resin composition of the present invention usually comprises the copolymerized polyethylene terephthalate resin of the component (A), the copolymerized polyethylene terephthalate resin of the component (B), and the component (C). The copolymerized polybutylene terephthalate-based resin and the polybutylene terephthalate-based resin of the component (D) may be further used, if necessary, by the aforementioned inorganic or organic fine particles, another thermoplastic resin or thermoplastic elastomer, an additive, After adding a reinforcing material and performing dry blending, using a melt-kneading apparatus such as a single-screw or twin-screw extruder, the temperature is usually 180 to 300 ° C, preferably 200 to 280 ° C, and usually 0.5 to 10 ° C. Minutes,
It is preferably prepared by melt-kneading for 1 to 5 minutes.

At this time, each resin of the components (A), (B), (C) and (D) is used after being dried in advance in order to suppress deterioration, coloring and the like during the preparation of the resin composition. The content of water is preferably 400 ppm or less, more preferably 200 ppm or less, and particularly preferably 50 ppm or less.

In place of the drying, in order to suppress the deterioration and coloring of the resin during the melt-kneading, and to remove by-products and the like generated by the kneading, the molten resin staying portion in the melt-kneading apparatus is provided. Preferably, the pressure is reduced, and the pressure is 2
It is preferably set to × 10 ⁴ Pa or less, and 3 × 10 ³ Pa
It is more preferable to set the following.

The copolymerized polyester resin composition of the present invention has an intrinsic viscosity of from 0.5 to 0.5 as measured by the same method as described above.
1.0 dl / g, preferably 0.6 to 0.85
dl / g, more preferably 0.65 to 0.8 d.
1 / g is particularly preferred. If the intrinsic viscosity of the composition is less than the above range, mechanical strength tends to be inferior,
Exceeding the above range tends to result in poor moldability.

The copolymerized polyester resin composition of the present invention can be obtained by molding various molded articles by a conventional molding method of a thermoplastic resin.
For example, extruded films or sheets, or
They are stretched into stretched films, or they are formed into trays or containers subjected to thermoforming such as vacuum forming, pressure forming, or various molded articles by injection molding, hollow molding, compression molding, etc., Alternatively, they are formed into a molded body having a laminated structure with other materials, and are particularly suitably used as packaging materials. In particular, label materials and mouth sealing materials for covering the outer peripheral surface of various food and beverage bottles and the like. Or, it is suitable for use as a heat-shrinkable film as a material or the like for packaging, bundling, covering, etc. industrial parts.

The heat-shrinkable film is molded in detail. Usually, the heat-shrinkable film is melt-extruded into a sheet or film by a film forming machine equipped with a T-die.
It is cooled and solidified into a flat unstretched sheet or film by bringing it into close contact with a cooling roll set at ~ 80 ° C by an electrostatic adhesion method or by using a casting roll, and then reheated. Or
Continuously with the melt extrusion, a stretching temperature of 60 to 120 ° C and a stretching ratio of 3 to 6 are applied by a stretching device such as a roll or a tenter.
As a factor, a method of uniaxially stretching in a direction (lateral direction) perpendicular to the extrusion direction is employed.

Further, for the purpose of suppressing shrinkage and distortion in a direction (longitudinal direction) perpendicular to the stretching direction, 60 to 1 after stretching.
Heat setting treatment at a temperature of 00 ° C., and / or before or after the uniaxial stretching or simultaneously with the uniaxial stretching, in the direction orthogonal to the stretching direction, usually 0.5 to 3 times, preferably 1 to
A longitudinal stretching process or the like for stretching at a stretching ratio of 2 may be performed.

Further, the stretching direction is reversed from the above-mentioned method, and shrinkage or the like in a direction (horizontal direction) perpendicular to the extrusion direction is suppressed by a tenter or the like. A method of uniaxial stretching may be employed, and a method of sequentially or simultaneously biaxial stretching may be employed. Further, a sheet or film formed into a tube shape using an annular die may be cut open, or the tube shape may be maintained, and a uniaxial or biaxial stretching process may be similarly performed.

The thickness of the stretched film comprising the copolymerized polyester resin composition of the present invention is preferably 15 to 80 μm, more preferably 30 to 50 μm.
If the thickness of the stretched film is less than the above range, the mechanical strength tends to be inferior. On the other hand, if the thickness is more than the above range, uniform heat shrinkability tends to be hardly exhibited.

The haze of the stretched film made of the copolymerized polyester resin composition of the present invention at a thickness of 50 μm measured according to JIS K7105 is preferably 10% or less, more preferably 5% or less. preferable. When the haze of the stretched film is in the above range, the content can be easily confirmed when used as a label material of a bottle for food and drink and the like, and the design tends to be excellent.

The stretched film made of the copolymerized polyester resin composition of the present invention is particularly useful for packaging and bundling label materials and mouth sealing materials for covering the outer peripheral surface of various food and beverage bottles and the like, or industrial parts. It is suitably used for a heat-shrinkable film as a material or the like for coating.

[0056]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. In addition, the copolymerized polyethylene terephthalate resin of the component (A), the copolymerized polyethylene terephthalate resin of the component (B), the copolymerized polybutylene terephthalate resin of the component (C) used in the following Examples and Comparative Examples, and The polybutylene terephthalate resin of the component (D) is as follows.

(A) Copolymerized polyethylene terephthalate
Based resin A-1; dicarboxylic acid component is 100 mol% of terephthalic acid, diol component is 67 mol% of ethylene glycol,
A copolymerized polyethylene terephthalate resin comprising 33 mol% of 1,4-cyclohexanedimethanol,
Contains 0.1% by weight of amorphous silica having an intrinsic viscosity of 0.83 dl / g and an average particle size of 2.4 μm. (In the resin composition,
Components secondary to the polycondensation process, such as diethylene glycol, were excluded. The same applies to the following. ). A-2 (for Comparative Example); dicarboxylic acid component was 100 mol% terephthalic acid, and diol component was ethylene glycol 34
It is a copolymerized polyethylene terephthalate-based resin composed of 66 mol% of 1,4-cyclohexanedimethanol and 0.65 dl / g in intrinsic viscosity and an average particle diameter of 2.
Contains 0.1% by weight of 4 μm amorphous silica.

(B) Copolymerized polyethylene terephthalate
Based resin B-1; a dicarboxylic acid component containing 70 mol% of terephthalic acid;
A copolymerized polyethylene terephthalate resin comprising 30 mol% of isophthalic acid and 100 mol% of a diol component having an intrinsic viscosity of 0.72 dl /
g, containing 0.1% by weight of amorphous silica having an average particle diameter of 2.4 μm. B-2 (for Comparative Example): a copolymerized polyethylene terephthalate resin composed of 34 mol% of terephthalic acid, 66 mol% of isophthalic acid, and 100 mol% of ethylene glycol as the dicarboxylic acid component, and having an intrinsic viscosity of 0.
Contains 0.1 wt% of amorphous silica having a particle size of 59 dl / g and an average particle size of 2.4 μm. B-3 (for comparative example); dicarboxylic acid component is 100 mol% of terephthalic acid, and diol component is ethylene glycol 10
A polyethylene terephthalate resin comprising 0 mol%, having an intrinsic viscosity of 0.66 dl / g and an average particle diameter of 2.4.
Contains 0.1% by weight of μm amorphous silica.

(C) Copolymerized polybutylene terephthalate
-Based resin C-1; polytetramethylene having a number average molecular weight of 1,000, excluding polytetramethylene ether glycol, wherein the dicarboxylic acid component is composed of 100 mol% of terephthalic acid and the diol component is composed of 100 mol% of 1,4-butanediol. A copolymerized polybutylene terephthalate resin in which ether glycol is copolymerized by 10% by weight, and has an intrinsic viscosity of 0.88 dl / g. C-2: excluding polytetramethylene ether glycol, 90 mol% of terephthalic acid, 10 mol% of isophthalic acid, and 1,4-
Consists of 100 mol% of butanediol and has a number average molecular weight of 1
2,000 polytetramethylene ether glycols
It is a copolymerized polybutylene terephthalate resin copolymerized by weight%, and has an intrinsic viscosity of 0.85 dl / g.

(D) polybutylene terephthalate resin D-1; a polybutylene terephthalate resin comprising a dicarboxylic acid component of 100 mol% of terephthalic acid and a diol component of 100 mol% of 1,4-butanediol,
The intrinsic viscosity is 0.89 dl / g.

Examples 1-4, Comparative Examples 1-8 The components (A), (B), (C) and (D) shown in Table 1 were mixed with a twin-screw extruder (L / D30, Toshiba). (TEM35, manufactured by Machinery Co., Ltd.)
rpm, temperature 260 ° C., melt kneading under reduced pressure of 1 × 10 ² Pa, extruding into strands, cooling in a water bath,
By cutting with a pelletizer, pellets of the copolymerized polyester resin composition were produced. The intrinsic viscosity of the obtained resin composition was measured by the method described below, and the results are shown in Table 1.

About 0.25 g of a sample of intrinsic viscosity resin was mixed with phenol / 1,1,2,2
-About 2 mixed solvents of tetrachloroethane (weight ratio 1/1)
After dissolving at 110 ° C. so as to be 1.0% by weight in 5 ml, the solution was cooled to 30 ° C. and measured at 30 ° C. with a fully automatic solution viscometer (“2CH type DJ504” manufactured by Chuo Rika Co., Ltd.).

The obtained resin composition pellets were supplied to a twin-screw film forming machine equipped with a T-die (“BT-30” manufactured by Plastics Engineering Laboratory Co., Ltd.).
After being melt-extruded into a film under a reduced pressure of 0 ° C. and 1 × 10 ² Pa, it is equipped with an electrostatic adhesion device, and is brought into close contact with a cooling roll set at a surface temperature of 40 ° C. to be rapidly cooled to thereby obtain a 200 μm-thick A stretched film is formed, and the unstretched film is preheated to 95 ° C. using a stretching device (manufactured by Long Corporation), and then stretched at a stretch ratio of 4 times in a direction (lateral direction) orthogonal to the extrusion direction. A stretched film having a thickness of 50 μm was formed.

The obtained stretched film was measured and evaluated for heat shrinkage, its temperature dependence, mechanical strength, transparency, and adhesion with a solvent by the following methods. The results are shown in Table 1. Was.

20 mm × 100 mm cut out with the heat-shrinkable stretching direction as the long side
Immersed in warm water of 80 ° C for 10 seconds,
Immediately after pulling up and leaving at 23 ° C. for 10 minutes, the length in the long side direction was measured, and the heat shrinkage was calculated from the value.
The number of test points was set to 5 and the average value was used. If it is 50% or more, it is determined to be acceptable. Temperature Dependency of Heat Shrinkage The heat shrinkage at 90 ° C. was measured in the same manner as the heat shrinkage at 80 ° C., and the difference between the heat shrinkage at 90 ° C. and the heat shrinkage at 80 ° C. was determined. Calculated. If it is 10.0% or less, it is determined to be acceptable.

Mechanical strength According to JIS K7127, a No. 2 type test piece was punched out so that the stretching direction was the tensile direction.
The tensile strength at break when pulled at a tensile speed of 10 minutes was measured. If it is 20 kgf / mm ² or more, it is judged to be acceptable. It was measured haze in compliance with transparency JIS K7105. 5.
If it is 0% or less, it is determined to be acceptable.

Adhesion with Solvent At 23 ° C., two films were superposed with the same stretching direction, a small amount of tetrahydrofuran was injected between the films, and the films were adhered to each other by using a hand press, and then left for 30 minutes. After standing, the peelability when the film was peeled by hand in the stretching direction was evaluated according to the following criteria. ；: Does not peel off even when a considerable force is applied. Δ: Not easily peeled, but peeled when a considerable force is applied. X: No adhesion at all.

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[Table 1]

[0069]

According to the present invention, a copolyester which is excellent in heat shrinkability, has low temperature dependency, excellent mechanical strength and transparency, and is capable of obtaining a heat shrinkable film excellent in solvent adhesion. A resin composition and a stretched film made thereof can be provided.

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) B29L 7:00 B29L 7:00 (72) Inventor Nishio Keitoku 1 Tohocho, Yokkaichi-shi, Mie Prefecture Yokkaichi, Mitsubishi Chemical Corporation In-house (72) Inventor Norio Kobe 1 Toho-cho, Yokkaichi-shi, Mie F-term in Yokkaichi office of Mitsubishi Chemical Corporation (reference) QG18 4J002 CF06W CF06X CF07Y CF07Z CF10Y DA036 DE136 DE146 DE236 DH036 DJ016 DJ036 FD016 GG00

Claims (6)

[Claims] 1. The following components (A), (B) and (C)
And component (D) [provided that the weight% of each component is
Is based on a total of 100% by weight of these four components. ] Copolyester resin composition characterized by the above-mentioned. (A) a copolymerized polyethylene terephthalate resin in which terephthalic acid is a main component of a dicarboxylic acid component, ethylene glycol is a main component of a diol component, and cyclohexanedimethanol is a diol component of 5 to 50 mol% of the total diol component; % By weight (B) Terephthalic acid as a dicarboxylic acid component, ethylene glycol as a diol component, and isophthalic acid as a dicarboxylic acid component are 5% of all dicarboxylic acid components.
(C) terephthalic acid as a dicarboxylic acid component, butanediol as a diol component, and 1 to 80% by weight of a polyalkylene ether glycol. Copolymerized polybutylene terephthalate resin; 5 to 50% by weight (D) Terephthalic acid as a dicarboxylic acid component, butanediol as a diol component, and no polyalkylene ether glycol substantially copolymerized Polybutylene terephthalate resin; 0 to 50% by weight 2. The copolymerized polyester according to claim 1, wherein the component (C) is a copolymerized polybutylene terephthalate resin in which isophthalic acid is copolymerized as a dicarboxylic acid component at 50 mol% or less of all dicarboxylic acid components. Resin composition. 3. The total amount of the dicarboxylic acid component other than terephthalic acid and the diol component other than ethylene glycol excluding the polyalkylene ether glycol in the composition is the total amount of the dicarboxylic acid component and the polyalkylene ether glycol in the composition. 3. The copolymerized polyester resin composition according to claim 1, wherein the content is 10 to 50 mol% based on the total amount of all diol components except for (c). 4. The copolymerized polyester resin composition according to claim 1, which contains 0.005 to 1% by weight of inorganic or organic fine particles having an average particle diameter of 0.001 to 6 μm. 5. A stretched film comprising the copolymerized polyester resin composition according to any one of claims 1 to 4. 6. The stretched film according to claim 5, wherein the haze at a thickness of 50 μm is 10% or less.