JPS59215319A - Copolyester and its stretching product - Google Patents

Abstract

PURPOSE:A copolyester excellent in melt moldability, mechanical strength, transparency and gas barrier property, and suitable for use in stretched blow-molded containers, films, etc., comprising a specified copolyester. CONSTITUTION:A product obtained by transesterification among 30-45mol% 8- 12C aromatic dicarboxylic acid component containing 70-100mol% terephthalic acid, 30-49mol% diol component containing 70-100mol% ethylene glycol, 2- 40mol% 5C or lower aliphatic alpha-hydroxycarboxylic acid component (e.g., lactic acid), and 0-5mol% 3-15C polyfunctional component having at least three carboxyl or hydroxyl groups (e.g., trimellitic acid or glycerin) is cocondensed to obtain a copolyester of an intrinsic viscosity of 0.4-1.8 and a glass transition point of 40-100 deg.C. This polyester is molded into a film, sheet, fiber, or container and is uniaxially stretched at a stretch ratio of 1.1-8 or biaxially stretched at a stretch ratio of 1.1-7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a co-condensed polyester and a stretched product thereof, which are excellent in melt molding and have excellent mechanical strength, transparency, and gas barrier properties and are suitable as materials for containers. .

Conventionally, /i! for seasonings, oil, beer, sake, etc. Glass was widely used as a container material for Class 3I, soft drinks such as carbonated drinks, cosmetics, and detergents. However, glass containers have gas barrier properties, but their manufacturing costs are high, so the method of collecting empty containers after normal use and recycling them has been adopted. However, glass containers are heavy and cannot be transported. In addition to being expensive, they also had drawbacks such as being easily damaged and inconvenient to handle.

In order to overcome the aforementioned disadvantages of glass containers, there is a growing shift from glass containers to various plastic containers. Various plastics are used as materials depending on the type of stored item and its intended use. Among these plastic materials, polyethylene terephthalate has excellent gas barrier properties and transparency, and is therefore used as a material for containers for seasonings, soft drinks, detergents, cosmetics, and the like. However, polyethylene terephthalate is still not sufficient for beer and carbonated beverage containers, which require the most stringent gas barrier properties, and it is necessary to use thicker polyethylene terephthalate for use in these containers. The gas barrier properties had to be improved by increasing the amount of carbon. Currently, the demand for polyester containers is increasing, and in order to expand these uses, there is a strong demand for polyesters that have excellent gas barrier properties and excellent melt moldability.

Conventionally, various polyesters have been known, and among these polyesters, polyethylene terephthalate is the most widely used, but modified polyethylene terephthalate is produced by cocondensation polymerization of a third component during the production of polyethylene terephthalate. Various proposals have also been made. Among Gore et al.'s modified polyethylene terephthalate, a method of cocondensation polymerization of an aliphatic hydroxycarboxylic acid as a third component has also been proposed in many documents [for example,
JP 26016, JP 43-1632, JP 43-13232, JP 47-28119, JP 47-45198, JP 4!11
-5633 Publication, Special Publication No. 4.9-42918,
Japanese Patent Publication No. 50-2196, Japanese Patent Publication No. 4040-4040, Japanese Patent Publication No. 38648-1987; Japanese Patent Publication No. 49-6
554, Japanese Patent Publication No. 50-1.5510, Japanese Patent Publication No. 53-1320, and others]. In many of these cocondensation-modified polyethylene terephthalates, even the cocondensation composition of the third component aliphatic hydroxycarboxylic acid is not clearly indicated, and β-hydroxypropionic acid and ε Polyethylene terephthalate, which is co-condensed with a hydroxycarboxylic acid having a hydroxyl group other than the α-position, such as -hydroxycaproic acid, has also been proposed. Even if biaxially stretched containers are formed from these cocondensation-modified polyethylene terephthalates by blow molding, containers with excellent gas barrier properties and melt moldability cannot be obtained. For example, among the above-mentioned prior art documents, Japanese Patent Publication No. 39-26016 discloses aliphatic hydroxycarboxylic acid in the range of 0.02 to 0.6 mole per mole of terephthalic acid component unit, specifically β A modified polyethylene terephthalate in which hydroxypropionic acid and a polyfunctional crosslinking agent component unit in the range of 0.00002 to 0.01 mol are co-condensed has been proposed, and Japanese Patent Publication No. 50-38648 describes the total composition of Polyethylene terephthalate containing ε-hydroxycaproic acid component units in the range of 70 to 70% by weight has been proposed, but biaxially oriented containers formed from these modified polyethylene terephthalates do not have sufficient gas barrier properties. It's hard to say.

The present inventors recognized that the technology related to a stretch blow molded container made of polyethylene terephthalate exists in the above-mentioned situation, and created a container that has excellent gas barrier properties and melt moldability and can exhibit excellent performance as a stretch blow molded container. As a result of studying the development of modified polyethylene terephthalate, a new co-condensed polyethylene terephthalate with a specific composition obtained by co-condensing a specific aliphatic α-hydroxycarboxylic acid component unit and a specific polyfunctional component unit was discovered. It has been discovered that a stretch-blown container molded from co-condensed polyethylene terephthalate, which is a polymer, achieves the above object, and the present invention has been achieved.

To summarize the present invention, the present invention comprises (al) 30 to 49 mol% of aromatic dicarboxylic acid component units mainly composed of terephthalic acid component units, (b
l 30 to 49 mol% of diol component units mainly composed of ethylene glycol component units, 2 to 40 mol% of dicarboxylic acid component units, and (dl having 3 to 15 carbon atoms and 3
A substantially bilinear co-condensed polyester consisting of O to 5 mol% of cross-linking agent component units having at least 1 carboxyl group or hydroxyl group, the physical properties of which are (e) co-condensed polyester [η] is 0.4 to 1.8
dβ/g; and (f) a glass transition point in the range of 40 to 100°C. The gist of the second material invention is a stretched product.

The co-condensed polyester of the present invention comprises an aromatic dicarboxylic acid component unit (al) containing terephthalic acid as a main component, a diol component unit (bl) containing ethylene glycol as a main component, and an aliphatic α-hydroxycarboxylic acid component unit (C1). In some cases, it is a ternary co-condensed polyester consisting of terephthalic acid as the main component (al, an aromatic dicarboxylic acid component unit mainly composed of terephthalic acid, a diol component unit mainly composed of ethylene glycol component (bl, an aliphatic dicarboxylic acid component unit) - It may also be a quaternary co-condensed polyester consisting of an oxycarboxylic acid component unit (C) and a polyfunctional component unit fd).In either case, the co-condensed polyester of the present invention is a A polymer molecular chain is formed by the condensation of the carboxyl group and the hydroxyl group to form a bond.The molecular terminal of the co-condensed polyester may be arranged with any of the above-mentioned component units, and the molecule The carboxyl group present at the end of the molecule may be esterified with another lower alcohol, and similarly the hydroxyl group present at the end of the molecule may be esterified with another lower carboxylic acid. A diol component unit (bl is a diol component unit whose main component is an ethylene glycol component unit constituting the co-condensed polyester, such as a small portion (for example, 5 mol% or less) of a diethylene glycol component unit, which forms an ether bond due to a reaction between diol component units) There is no problem even if the containing diol component unit is formed.

The co-condensed polyester of the present invention has a substantially linear structure. Here, the term "substantially linear structure" means a linear or branched chain structure, and means not having a gel-like crosslinked structure (network structure). This means that
The co-condensed polyester of the present invention is p-chlorophenol,
It is confirmed by completely dissolving it in 0-chlorophenol or a mixed solvent of phenol and tetrafluoroethane. When the co-condensed polyester is a co-condensed polyester consisting of the three constituent components, it is linear,
When the polyester is a co-condensed polyester consisting of the four components mentioned above, it is a branched chain.

The composition of the co-condensed polyester of the present invention is such that (a) aromatic dicarboxylic acid component units mainly composed of terephthalic acid component units are in the range of 30 to 49 mol%, preferably 35 to 48 mol%; Diol component units mainly composed of ethylene glycol component units are in the range of 30 to 49 mol%, preferably 35 to 48 mol%, (aliphatic α-hydroxycarboxylic acid component having 5 or less C1 carbon atoms) units are in the range of 2 to 40 mol%, preferably 4 to 30 mol%, and (dl has a carbon atom number in the range of 3 to 15, and has a carboxyl group or a hydroxyl group of 3(]M or more) The polyfunctional component unit is in the range of O to 5 mol%, preferably 0 to 4 mol%. As the polyester increases in size, when the content of the aromatic dicarboxylic acid component unit (a) becomes less than 30 mol% and the content of the diol component unit becomes less than 30 mol%, the polyester no longer exhibits crystallinity. The glass transition point is lowered. It is difficult to economically carry out the necessary drying process for polyesters that are unsatisfactory and have a low glass transition temperature prior to melt molding. Sometimes, the molecular weight tends to decrease, and therefore the mechanical strength of molded products manufactured from the polyester decreases.Also, the content of the aliphatic α-hydroxycarboxylic acid component unit (c) becomes less than 2 mol%. In addition, the aromatic dicarphonic acid component unit (
When the content of al is greater than 49 mol% and the content of ethylene glycol component units is greater than 49 mol%, the gas barrier of the polyester and its stretched product is
As a result, gas barrier properties superior to those of polyethylene terephthalate (l-), which is a feature of the present invention, are no longer exhibited. Furthermore, when the content of the polyfunctional component unit in the co-condensed polyester is greater than 5 mol%, the co-condensed polyester contains a large amount of gel-like structure and is no longer substantially linear, resulting in poor melt moldability. begins to decline.

The co-condensed polyester of the present invention has an intrinsic viscosity [η] [25
The value measured in a mixed solvent of equal amounts of phenol and tetrafluoroethane at
dl/H is preferably in the range, and the glass transition point is required to be in the range of 40 to 100°C, and more preferably in the range of 45 to 95°C. Regarding other physical properties of the co-condensed polyester,
The fluidization start temperature is usually in the range of 140 to 250°C, preferably 150 to 240°C. When the intrinsic viscosity [η] of the co-condensed polyester becomes greater than 1.8 dl/g, the melt moldability of the co-condensed polyester decreases, and when it becomes less than 0.4 a/g, the co-condensed polyester and its stretched product decrease. mechanical strength will decrease.

The co-condensed polyester of the present invention is composed of aromatic dicarboxylic acid component units (al means terephthalic acid component units as a main component), and the ratio of terephthalic acid component units to all aromatic dicarboxylic acid component units is Usually 70 to 100 mol%, preferably 80 to 100 mol%
is within the range of Examples of aromatic dicarboxylic acid component units other than terephthalic acid component units include isophthalic acid,
Examples include aromatic dicarboxylic acid component units having 8 to 12 carbon atoms such as phthalic acid and 2,6-naphthalene dicarboxylic acid.

The diol component unit fb) constituting the co-condensed polyester of the present invention has ethylene glycol as its main component, and the ratio of the ethylene glycol component unit to the total diol component units is usually 70 to 100 mol%, preferably 80 to 100 mol%. The range is 100 mol%. Examples of diol component units other than ethylene glycol include C3-propanediol, C4-bucundiol, neopentyl glycol, cyclohexanediol, dichlorohexane dimetatool, 1,4-bis(β-hydroxyethoxy)benzene, A diol component having 3 to 15 carbon atoms such as bis(β-hydroxyethoxy)benzene, 2,2-bis(4-β-hydroxyethoxyphenyl)propane, and bis(4-β-hydroxyethoxyphenyl)sulfone. I can give an example.

The number of carbon atoms constituting the co-condensed polyester 4 of the present invention is 5
The following aliphatic α-hydroxycarboxylic acid component units (C
Examples of 1 include lactic acid, glycolic acid, α-hydroxy n-butyric acid, α-hydroxyisobutyric acid, α-hydroxy n-valeric acid, etc.; Polyester and its stretched products are particularly preferred because they have excellent gas barrier properties. Even if the number of carbon atoms in the aliphatic α-hydroxycarboxylic acid component unit is greater than 6, or
When the aliphatic hydroxycarboxylic acid component unit does not have a hydroxyl group in the position, the gas barrier properties of the co-condensed polyester and its stretched products are low.

The polyfunctional component unit +di constituting the co-condensed polyester of the present invention has a carbon atom number of 3 to 15 (G).
A trifunctional or higher polyfunctional component unit having two carboxyl or hydroxyl groups, and also includes a polyfunctional component unit having 3 or more carboxyl groups and hydroxyl groups in total. Specifically, the sexual component units include trimellitic acid, trimesic acid, 3,
Aromatic polybasic acids such as 3°, 5.5'-tetracarboxydiphenyl, aliphatic polybasic acids such as butanetetracarboxylic acid, aromatic acids such as phloroglucin, C2,4,5-tetrahydroxybenzene, etc. Examples include aliphatic polyols such as glycerin, l-lyncholeethane, trimethylolpropane, and pentaerythritol.

The co-condensed polyester of the present invention can be produced according to a conventionally known polycondensation method used in the production of polyethylene terephthalate.

The aromatic dicarboxylic acid component unit as a constituent component can be supplied to the reaction system as the aromatic dicarboxylic acid, or as a dialkyl ester thereof, or as a bis β of the aromatic dicarboxylic acid. -Can also be supplied as hydroxyethyl ester.

Further, the diol component unit of the constituent component can be supplied as a diol, or can be supplied to the reaction system in the form of a diol ester of each carboxylic acid of the constituent component.

Further, the aliphatic α-hydroxycarboxylic acid component unit as a constituent component can be supplied to the reaction system as the aliphatic α-hydroxycarboxylic acid, or as its alkyl ester, or as its β-hydroxycarboxylic acid. -It is also possible to supply it as a hydroxyethyl ester.

As a catalyst for co-condensation, conventionally known catalysts used in the production of polyethylene terephthalate can be used. As these catalysts, metals such as antimony, germanium, titanium, etc. or compounds thereof can be used. Examples of the form of the compound include oxides, hydroxides, halides, inorganic acid salts, organic acid salts, complex salts, double salts, alcoholades, and phenolates. These catalysts can be used alone or as a mixture of two or more. These catalysts can be supplied to the reaction system from the initial stage of the esterification reaction or transesterification reaction, or can be supplied to the reaction system before proceeding to the polycondensation reaction stage.

In addition, during co-condensation, catalysts for transesterification used in the production of polyethylene terephthalate, diethylene glycol production inhibitors, heat stabilizers, light stabilizers, lubricants,
Various additives such as pigments and dyes can be used.

As catalysts for these transesterification reactions, metal compounds such as calcium, magnesium, lithium, zinc, kohal'l-, and manganese can be used. The forms of these compounds include oxides, hydroxides, halides, inorganic acid salts, and organic acid salts. Further, as a diethylene glycol inhibitor, amines such as triethylamine and tri-n-butylamine, and quaternary ammonium compounds such as tetrabutylammonium hydroxide and tetrabutylammonium hydroxide can be used. In addition, as stabilizers such as heat stabilizers,
Phosphorus compounds such as phosphoric acid, phosphorous acid, hypophosphorous acid, or esters thereof can be used.

The co-condensed polyester of the present invention is produced by a conventionally known melt polymerization method, and in some cases, by employing a melt polymerization method followed by a solid phase polymerization method.

In such a melt polymerization method, a so-called direct polycondensation method can be employed, and a so-called transesterification polycondensation method can also be employed. That is, to explain the melt polymerization method more specifically, for example, terephthalic acid or an aromatic dicarboxylic acid containing this as a main component or an ester derivative thereof (4, ethylene glycol or a diol containing this as a main component, an aliphatic dicarboxylic acid containing terephthalic acid as a main component) α-Hydroxycarboxylic acid or its ester derivative, and in some cases, a polyfunctional compound containing three or more carboxyl or hydroxyl groups are esterified or transesterified simultaneously or sequentially to form these initial polymers. An example of a method is to polymerize the polymer at a temperature higher than its melting point, preferably from 200 to 280° C., under vacuum or with stirring under an inert gas flow.

Further, the co-condensed polyester of the present invention can be produced by further solid-phase polymerizing the polyester obtained by the melt polymerization method to increase the molecular weight. To explain this solid-phase polymerization method specifically, for example, polyester obtained by melt polymerization is made into fine particles, and the resulting particles are held at a temperature below the melting point, preferably 160 to 240°C, under vacuum or under inert gas flow. A method can be adopted.

The co-condensed polyester of the present invention can also be used in an unstretched state as a material for films, sheets, fibers, containers, and other molded bodies of various shapes by ordinary molding methods.

Furthermore, when the co-condensed polyester is molded into a film, Sea I, or container in a stretched state, a molded product with even better gas barrier properties can be obtained. Next, the stretched product of the co-condensed polyester of the present invention will be explained.

The stretched products of the co-condensed polyester of the present invention include -axially stretched products and biaxially stretched products, and may be in the form of a film, sheet, fiber, or blow-molded container. Here, if the stretched product of the co-condensed polyester is uniaxially stretched, the stretching ratio is usually 1.1 to 8.
times, preferably 1.2 to 7 times, particularly preferably 1
．． In the range of 5 to 6 times. Further, when the stretched product is biaxially stretched, the stretching ratio in the longitudinal axis direction is usually 1.1 to 7 times, preferably 1.2 to 6 times,
It is particularly preferably in the range of 1.5 to 5 times, and usually 1.1 to 7 times in the lateral direction, preferably 1.2 to 6 times.
times, particularly preferably in the range of 1.1 to 5 times.

The drawn product is heat-set depending on its purpose of use.The drawn product of the co-condensed polyester of the present invention may contain a nucleating agent, an inorganic filler, a lubricant, a slip agent, an anti-blocking agent, which are blended into conventional polyesters as necessary. Appropriate amounts of various additives such as additives, stabilizers, antistatic agents, antifogging agents, and pigments may be blended.

As a method for producing a stretched product of the co-condensed polyester of the present invention, any conventionally known method can be employed. Generally, an original molded product such as a film, sheet, or parison formed from the polyester or a composition containing the above additives as necessary is used as it is or once cooled to a temperature below the glass transition point. After solidification, the original molded product is reheated and then stretched at a temperature ranging from the glass transition point to the melting point, preferably from the glass transition point to a temperature 50° C. higher than the glass transition point. In order to apply heat cera I. to the stretched product, an appropriate short-time heat treatment is performed at the above-mentioned stretching temperature or a higher temperature.

As a method for producing a stretched product of the co-condensed polyester of the present invention, when the original molded product is a film-like product or a sheet-like product, a method of stretching an unstretched film-like product or sheet-like product in a uniaxial direction (- axial stretching), a method of stretching in the longitudinal direction and then further stretching in the transverse direction (biaxial stretching), a method of simultaneously stretching in the longitudinal and transverse directions (biaxial stretching),
A method of repeating sequential stretching in any one direction after biaxial stretching, a method of further stretching in both directions after biaxial stretching, and reducing the pressure in the space between the film or sheet material and the mold. A specific example is the so-called vacuum forming method in which stretch forming is performed. Further, it is also possible to produce a stretched product of these co-condensed polyesters in the form of a laminate with other resins such as polyethylene terephthalate. As such a manufacturing method, the film or sheet original molded product of the co-condensed polyester is laminated with a film or sheet original molded product of other resin such as polyethylene terephthalate in a single layer or multiple layers, respectively. Examples include a method of stretching the co-condensed polyester, and a method of adhering a film or sheet of another resin such as polyethylene terephthalate to the stretched product of the co-condensed polyester. The original molded product is a parison, and the method for producing a stretch blow molded container is to stretch the parison at the above temperature in the longitudinal axis direction, and then blow mold it to further stretch it in the transverse direction (biaxial stretch blow molding). ), etc. can be exemplified. Furthermore, in these stretching steps, the co-condensed polyester and another resin such as polyethylene terephthalate are subjected to the above-mentioned stretch-blow molding using a parison laminated in a single layer or multiple layers, respectively. For example, a method for producing a laminated blow-molded article made of other resins such as polyethylene terephthalate can also be exemplified.

The stretched product of the co-condensed polyester of the present invention has excellent heat resistance and gas barrier properties and can be used for various purposes. In particular, biaxially stretched blow-molded containers made of co-condensed polyester have excellent gas barrier properties, so they can be used for seasonings, oils, beer, Western products such as Nippon Nishi, soft drinks such as cola, cider, juice, and cosmetics. It is used as a container for detergent, etc., but especially when used as a container for beer or carbonated drinks, it becomes possible to reduce the wall thickness of the container and extend the shelf life.

In addition, when the stretched product of the co-condensed polyester of the present invention is a stretched film-like product, it can be specifically used for electrical insulation, magnetic tape, photographic film, metallized film, etc. can be used.

Next, the present invention will be specifically explained using examples. In addition, in Examples and Comparative Examples, performance evaluation was performed according to the following method.

The intrinsic viscosity of polyester was measured at 25°C using a 1:1 (weight ratio) mixed solution of phenol and tetrachloroethane. The composition of the polyester was determined by measuring the nuclear magnetic resonance spectrum of a trifluoroacetic acid solution.

Further, the glass transition temperature of the polyester was determined by measuring at a heating rate of 10° C./min using a differential scanning calorimetric needle. In addition, the gas barrier properties of polyester sheets, stretched films, or stretched bottles were determined by using an OXTRAN device manufactured by MOCON for the oxygen gas permeability coefficient and by using an OXTRAN device manufactured by MOCON for the carbon dioxide gas permeability coefficient. Permatran(l)E
R-MATRAN) C-I', ' was measured at 25°C, respectively.

Example 1 398.6 g of terefucuric acid, 178 g of ethylene glycol
．． A mixed solution of 0.05 g of germanium dioxide and 0.23 g of a 20% aqueous solution of tetraethylammonium hydroxide was added to a mixture of 8 g of glycolic acid and 27.4 g of glycolic acid, and the mixture was heated at 230 °C under a nitrogen pressure of 2 kg/cl.
The esterification reaction was carried out at 45°C for 3.5 hours with stirring,
The produced water was distilled out of the system. Then, after adding 0.22 g of trimethyl phosphate to the generated esterified product,
The reaction system was heated to 250°C or 6270°C for 1 hour with stirring.
While raising the temperature to
The reaction was carried out while distilling off the ethylene glycol produced in 1 g. The thus obtained copolyester made from terephthalic acid, ethylene glycol and glycolic acid was transparent and colorless, and the intrinsic viscosity of this copolyester was 0.69 dl/g. Furthermore, the contents of component units of terephcuric acid, ethylene glycol, and glycolic acid in this copolyester are 46.6 mol%, 45.3 mol%, and 6.8 mol%, respectively, and the glass transition temperature of this copolyester is was 67°C. Furthermore, this copolyester is heated at 10°C above the glass transition temperature.
After drying at a low temperature under reduced pressure for 20 hours, a pressed sheet was prepared and its gas barrier properties were measured. As a result, the oxygen gas permeability coefficient was 1.9 m1mm/m-day-atm
sAlso, the carbon dioxide gas permeability coefficient is 17 m1-mm/r+?
-day, ATM.

Comparative Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.70 dl/g was produced from terephthalic acid and ethylene glycol according to a conventional method. The press sheet of this polyethylene terephthalate prepared in the same manner as in Example 1 had an oxygen gas permeability coefficient of 4.5 ml・mm/rd・day・atm and a carbon dioxide gas permeability coefficient of 25 ml/mm/rrF-d.
ay-atm Example 2 Terephthalic acid 398.6g, ethylene glycol 17
A copolyester was synthesized in the same manner as in Example 1 except that 8.8 g and 8.3 g of glycolic acid were used. The intrinsic viscosity of this copolyester is 0.15 dl/g, and the contents of each component unit of terephthalic acid, ethylene glycol, and glycolic acid in this copolyester are 47.6 mol%, 45.9 mol%, and 4.7 mol%, respectively. mole%, and the glass transition temperature of this copolyester is 69°
It was C. Furthermore, the carbon dioxide gas permeability coefficient of a press sheet made of this copolyester in the same manner as in Example 1 was 2.
It was 0 m1 mm/% ay-atm.

Comparative Example 2 Terephthalic acid 398.6g, ethylene glycol 17
A copolyester was synthesized by the same method as in Example 1 except that 8.8 g and 7.3 g of glycolic acid were used. The intrinsic viscosity of this copolyester was 0.74 dl/g.
, and the contents of each component unit of terephthalic acid, ethylene glycol, and glycolic acid in this copolyester were 49.1 mol%, 47.4 mol%, and 1.9 mol%, respectively.
% by mole, and the glass transition temperature of this copolyester was 71°C. However, when the carbon dioxide gas permeability coefficient of the press sheet 1- produced using this copolyester in the same manner as in Example 1 was measured, it was found to be 24 m1-mm.
/r+Lday-atm, which was almost the same value as the value of the polyethylene terephthalate press sheet shown in Comparative Example 1.

Example 3 Terephthalic acid 398.6g, ethylene glycol 17
A copolyester was synthesized in the same manner as in Example 1 except that 8.8 g of glycolic acid and 7.3 g of glycolic acid were used. The intrinsic viscosity of this copolyester is 0.67 dI! /g
, and the contents of each component unit of terephthalic acid, ethylene glycol, and glycolic acid in this copolyester were 35.7 mol%, 33.9 mol%, and 28.4 mol%, respectively.
mole%, and the glass transition temperature of this copolyester is 5
It was 6°C. Furthermore, Example 1 of this copolyester
The carbon gas permeability coefficient of the press sheet produced in the same manner as above was 9.6 m1-mm/rd·day-atm.

Comparative Example 3 Terephthalic acid 398.6g, ethylene glycol 17
A copolyester was synthesized in the same manner as in Example 1 except that 8.6 g of glycolic acid and 246.4 g of glycolic acid were used. The intrinsic viscosity of this copolyester is 0.66a! f
, /g, and the contents of each component unit of terephthalic acid, ethylene glycol, and glycolic acid in this copolyester are 30.0 mol%, 27.7 mol%, and 4 mol%, respectively.
0.1 mol%, and the glass transition temperature of this copolyester was 39°C. Furthermore, this copolyester was dried in the same manner as in Example 1, and then a press sheet was produced. However, the obtained press sheet has low strength (
However, gas barrier properties could not be measured due to the occurrence of cracks.

Example 4 Bis(β-hydroxyethyl)terephthalic acid 1-508
．． Example 1 was carried out using 0.20 g of a mixed solution of 0.04 g of germanium dioxide and a 20% aqueous solution of tetraedylammonium hydroquine and 0.19 g of trimethyl phosphate, which were the same as in Example 1, in a mixture of 5 g and 38.4 g of glycoxide. Copolyester was synthesized by melt polycondensation under similar conditions. The intrinsic viscosity of this copolyester is 0.12 dl/g, and the contents of each component unit of terephthalic acid, ethylene glycol, and glycolic acid in this copolyester are 43.5 mol% and 41.6 mol%, respectively.
mol% and 13.0 mol%, and the glass transition temperature of this copolyester was 66°C. Furthermore, the carbon dioxide gas permeability coefficient of a press sheet made of this copolyester in the same manner as in Example 1 was 15 ml/mm/%.
day, it was ATM.

Example 5 A copolyester using terephthalic acid, ethylene glycol, and lactic acid as raw materials was synthesized in the same manner as in Example 1 except that 32.4 g of lactic acid was used instead of glycolic acid. The intrinsic viscosity of this copolyester is 0.10 dl/g,
The contents of each component unit of terephthalic acid and lactic acid in this copolyester were 46.6 mol% and 45.2 mol%, respectively.
and 6.9 mol%, and the glass transition temperature of this copolyester was 65°C. Furthermore, the carbon dioxide gas permeability coefficient of a press sheet made of this copolyester in the same manner as in Example 1 was 18 m1mm/m・da
It was y-atm.

Example 6 A copolyester using α-hydroxybutyric acid instead of glycolic acid as a raw material was synthesized. The intrinsic viscosity of this copolyester is 0.68a! /g, the contents of each component unit of terephthalic acid, ethylene glycol, and α-hydroxybutyric acid in the copolyester of the copolyester are 46.5 mol%, 45.1 mol%, and 6.9 mol%, respectively. The glass transition temperature of the polyester was 63°C.

Further, the carbon dioxide gas permeability coefficient of a press sheet of this copolyester produced in the same manner as in Example 1 was 20 ml·mm/r+f·day-atm.

Example 7 Example 1 except that a mixture of 358.7 g of terephthalic acid and 39.9 g of isophthalic acid is used instead of terephthalic acid.
In the same manner as above, a copolyester using terephthalic acid, isophthalic acid, ethylene glycol, and glycolic acid as raw materials was synthesized. The intrinsic viscosity of this copolyester is 0.
74 Cll/g, and the content of each component unit of terephthalic acid, isophthalic acid, ethylene glycol, and glycolic acid in this copolyester was 41.9 mol%, respectively.
, 4.7 mol%, 45.0 mol% and 6.8 mol%, and the glass transition temperature of this copolyester was 62°C. Furthermore, the carbon dioxide gas permeability coefficient of a press sheet made of this copolyester in the same manner as in Example 1 was 14.
m1mm/m-day-atm.

Example 8 Ethylene glycol 16 instead of ethylene glycol
Terephthalic acid,
A copolyester using ethylene glycol, neopentyl glycol, and glycolic acid as raw materials was synthesized. The intrinsic viscosity of this copolyester is 0.73 dl/g, and the contents of each component unit of terephthalic acid, ethylene glycol, neopentyl glycol, and glycolic acid in this copolyester are 46.5 mol% and 41.2 mol%, respectively. , 3.6 mol% and 6.8 mol%, and the glass transition temperature of this copolyester was 64°C. Furthermore, the carbon dioxide gas permeability coefficient of a press sheet made of this copolyester in the same manner as in Example 1 was 17 ml.
mm/rr? It was an ATM.

Example 9 Ethylene glycol 16 instead of ethylene glycol
Terephthalic acid, ethylene glycol, and bis(4-hydroxyethoxyphenyl) sulfone were prepared in the same manner as in Example 1, except that a mixture of 0.9 g and 81.2 g of bis(4-β-hydroxyethoxyphenyl) sulfone was used. A copolyester containing glycolic acid and glycolic acid was synthesized. The intrinsic viscosity of this copolyester is 0.7 g/g, and the copolyester contains terephthalic acid, ethylene glycol, and his(4-β-hydroxyethoxyphenyl).
The contents of each component unit of sulfone and glycolic acid are 46.5 mol%, 40.2 mol%, 4.5 mol% and 6.8 mol%, respectively, and the glass transition temperature of this copolyester is 82°C. Met. Further, the carbon gas permeability coefficient of a press sheet of this copolyester produced in the same manner as in Example 1 was 18 ml-mm/ra·dayatm.

Example 10 Terephthalic acid, trimellitic acid, ethylene glycol and glycolic acid were used as raw materials in the same manner as in Example 1 except that a mixture of 398.6 g of terephthalic acid and 1.51 g of trimellitic acid was used instead of terephthalic acid. A copolyester was synthesized. The intrinsic viscosity of this copolyester is 0.68 dl/g, and the content of each component unit of terephthalic acid, ethylene glycol, and glycolic acid in this copolyester is 46.3 mol%, 45.
1 mol% and 6.9 mol%, and the glass transition temperature of this copolyester was 67°C. Further, the carbon gas permeability coefficient of a press sheet of this copolyester produced in the same manner as in Example 1 was 16 ml-mm/body ay-a Lm.

Example 11 Ethylene glycol 17 instead of ethylene glycol
A copolyester using terephthalic acid, ethylene glycol, glycerin, and glycolic acid as raw materials was synthesized in the same manner as in Example 1 except that a mixture of 8.8 g and 0.80 g of glycerin was used. The intrinsic viscosity of this copolyester is 0.65 d1/g, and the content of each component unit of terephthalic acid, ethylene glycol, and glycolic acid in this copolyester is 46.5 mol%, 44.
5 mol% and 6.9 mol%, and the glass transition temperature of this copolyester was 67°C. Furthermore, the carbon dioxide gas permeability coefficient of a press sheet of this copolyester produced in the same manner as in Example 1 was 16 ml·mm/m·day-atm.

Example 12 Ethylene glycol 17 instead of ethylene glycol
8.8g and 1.1. L) Limethylolethane 0.87
A copolyester using terephthalic acid, ethylene glycol, LLI-)limethylolethane, and glycolic acid as raw materials was synthesized in the same manner as in Example 1 except for using a mixture with g. The intrinsic viscosity of this copolyester is 0.
67 Lll/g, or the contents of each component unit of terephthalic acid, ethylene glycol and glycolic acid in this copolyester are 46.5 mol% and 45.5 mol%, respectively.
and 6.8 mol%, and the glass transition temperature of this copolyester was 66°C. Furthermore, the carbon dioxide gas permeability coefficient of a press sheet made of this copolyester in the same manner as in Example 1 was 16 ml-mm/r.
+fday-atm.

Example 13 Ethylene glycol 17 instead of ethylene glycol
A copolyester using terephthalic acid, ethylene glycol, pentaerythritol, and glycolic acid as raw materials was synthesized in the same manner as in Example 1 except that a mixture of 8.8 g of pentaerythritol and 0.65 g of pentaerythritol was used. The intrinsic viscosity of this copolyester is 0.67 dl/g, and the contents of each component unit of terephthalic acid, ethylene glycol, and glycolic acid in this copolyester are 46.6 mol%, 44.9 mol%, and 6.0 mol%, respectively. 8 mol%, and the glass transition temperature of this copolyester was 68°C. Furthermore, Example 1 of this copolyester
The carbon dioxide gas permeability coefficient of the press sheet produced in the same manner as above was 17 ml-mm/m-day-atm.

Example 14 A copolyester made from terephthalic acid, ethylene glycol, and glycolic acid and having an intrinsic viscosity of 0.10 dl/g was synthesized by melt polymerization under the same conditions as in Example 1.
After crystallization at 150°C for 2 hours under a dry nitrogen atmosphere, solid phase polymerization was carried out by holding at 190 to 200°C for 12 hours under a dry nitrogen atmosphere. The intrinsic viscosity of the solid phase polymerized copolyester thus obtained was 0.83 d1/g.
, and the glass transition temperature of this copolyester is 69°C
Met. Furthermore, the carbon dioxide gas permeability coefficient of a press sheet of this solid phase polymerized copolyester produced in the same manner as in Example 1 was 1.6 ml·mm/m-day-atm.

Example 15 A copolyester made from terephthalic acid, ethylene glycol and glycolic acid and having an intrinsic viscosity of 0.70 dl/g was synthesized by melt polymerization under the same conditions as in Example 1.
After crystallization at 150° C. for 2 hours under a dry nitrogen atmosphere, solid phase polymerization was carried out at 190 to 210° C. for 12 hours under reduced pressure of 1 mmHg or less.

The intrinsic viscosity of the solid phase polymerized copolyester thus obtained was 1.20 dl/g, and the glass transition temperature of this copolyester was 69°C. Furthermore, the carbon dioxide gas permeability coefficient of a press sheet produced in the same manner as in Example 1 of this solid phase polymerized copolyester was 15 ml-mm/rI.
? -day-atm.

Comparative Example 4 Melt polycondensation was carried out under the same conditions as in Example 1 except that the time for melt polycondensation was 30 minutes at a pressure of 1 mm). Polyester was synthesized. The intrinsic viscosity of this copolyester was 0.38 dl/g, and the force transition temperature of this copolyester was 65°C. Furthermore, an attempt was made to produce a press sheet of this copolyester under the same conditions as in Example 1. However, since the press sheet after production was very brittle and had cracks, it was not possible to measure the gas barrier properties.

Comparative Example 5 A copolyester made from terephthalic acid, ethylene glycol, and glycolic acid and having an intrinsic viscosity of 0.70 df/g was synthesized by melt polymerization under the same conditions as in Example 1.
After crystallization at 150°C for 2 hours under a dry nitrogen atmosphere, solid phase polymerization was carried out at 200°C to 210°C for 36 hours under reduced pressure of 11 g or less.

The intrinsic viscosity of the solid phase polymerized copolyester thus obtained was 1.77 dl/g. From this, in order to obtain a copolyester with an intrinsic viscosity of 1.8 a/g or more, solid phase polymerization would require a very long time, which was thought to be unfavorable from an economic point of view. Furthermore, a press sheet of this copolyester was prepared in Example 1.
When tried under the same conditions as above, a pressed sheet was obtained that was slightly thicker depending on the location.

Example 16 A press sheet of approximately 200 μm was produced using the copolyester of Example 1, and was further simultaneously stretched at 85° C. by a factor of 3 in the longitudinal and transverse directions using a biaxial stretching device. A two-wheeled stretched film with a thickness of about 22 μm was produced. The difference between the maximum and minimum thicknesses of this biaxially stretched film was about 3μ. Furthermore, the oxygen gas permeability coefficient of this biaxially stretched film is 1.1 ml-mm/rrr-day-
atm, and the carbon dioxide gas permeability coefficient is 12 ml/mm.
/m-day-attn.

Comparative Example 6 Using the polyethylene terephthalate of Comparative Example 1, 90
A biaxially stretched film having an average thickness of about 22 μm was produced in the same manner as in Example 16, except that the film was stretched at °C.

The difference between the maximum and minimum thicknesses of this biaxially stretched film was about 3μ. Furthermore, the oxygen gas permeability coefficient of this biaxially stretched film is 2.6 ml・mm/%-day-atm,
Also, the carbon dioxide permeability coefficient is 18 ml・mm/rl・d
It was ay-atm.

Example 17 Using the copolyester of Example 4, a biaxially stretched film having an average thickness of about 22 μm was produced in the same manner as in Example 16. The difference between the maximum and minimum thicknesses of this biaxially stretched film was about 3μ. Furthermore, the carbon dioxide gas permeability coefficient of this biaxially stretched film is 9.3 mm/m-day・at
It was m.

Example 18 Using the copolyester of Example 5, a biaxially stretched film having an average thickness of about 22 μm was produced in the same manner as in Example 16. The difference between the maximum and minimum thicknesses of this biaxially stretched film was about 3μ. Furthermore, the carbon dioxide gas permeability coefficient of this biaxially stretched film is 13 ml・ia/m-day
-It was an ATM.

Example 19 Using the copolyester of Example 12, a biaxially stretched film having an average thickness of about 22 μm was produced in the same manner as in Example 16. The difference between the maximum and minimum thicknesses of this biaxially stretched film was about 2μ. Furthermore, the carbon dioxide gas permeability coefficient of this biaxially stretched film was 12 ml-+im/m·day-atm.

Example 20 Using the copolyester of Example 14, a biaxially stretched film having an average thickness of about 22 μm was produced in the same manner as in Example 16.

The difference between the maximum and minimum thicknesses of this biaxially stretched film was about 2μ. Furthermore, the carbon dioxide gas permeability coefficient of this biaxially stretched film was 11 ml −+n+n/m-day-atm.

Example 21 About 2% of the copolyester made from terephthalic acid, ethylene glycol and glycolic acid in Example 16
The 00μ press sheet and the approximately 200μ press sheet of polyethylene terephthalate I in Comparative Example 6 were overlapped and further press-molded to a thickness of approximately 200μ.
A multilayer press sheet of μ was produced. The adhesion between the copolyester layer and the polyethylene terephthalate layer of this multilayer press sheet was good. Further, this multilayer press sheet was simultaneously biaxially stretched under the same conditions as in Example 16 to produce a biaxially stretched film having an average thickness of 22μ.

Since the thicknesses of the copolyester layer and the polyethylene terephthalate layer of this biaxially stretched film were both approximately 11 μm, it was confirmed that both the copolyester layer and the polyethylene terephthalate layer were uniformly stretched. Furthermore, the adhesion between the copolyester layer and the polyethylene terephthalate layer of this biaxially stretched film was also good.

Furthermore, the carbon dioxide gas permeability coefficient of this biaxially stretched film is 14.
ml-mm/m-day-atm.

Example 22 Under the same conditions as Example 1, the intrinsic viscosity was 0.7 using terephthalic acid, ethylene glycol, and glycolic acid as raw materials.
A large quantity of 1 dl/g copolyester was produced. This copolyester is injection molded to produce a preformed product (cold parison), and this preformed product is further heated to 85°C to 90°C using a far-infrared heating device) and then stretch-blow molded. Using a machine A, the material was stretched approximately 2.5 times in length and approximately 4.3 times in width to form a stretched bottle with a minimum wall thickness of 300 μm and an internal volume of approximately 112 mm.

Next, the oxygen gas permeability and carbon dioxide gas permeability of this stretched bottle were measured, and they were each 0.5 ml/day.
-bottle-atm and 2.6 ml/day-
It was bottle-atm.

Comparative Example 7 Synthesized under the same conditions as Comparative Example 1, with an intrinsic viscosity of 0.1 Ld
1/g of polyethylene terephthalate in the same manner as in Example 22.The stretched bottle has a minimum wall thickness of 300μ and an internal volume of approximately 1β.The oxygen gas permeability of this stretched bottle is 1.1 ml. /day-bottle-atm,
Also, the carbon dioxide permeability is 4.0ml/day. bot
It was tle-atm.

Example 23 First, the polyethylene terephthalate of Comparative Example 7 was injection molded, and then the copolyester of Example 22 made from terephthalic acid, ethylene glycol, and glycolic acid was injection molded again to form a polyethylene terephthalate layer. Preforms were prepared, each having a thickness of about 1.5 mm, with the copolyester layer on the inside and the copolyester layer on the outside. Then, this preform was stretched using a stretch blow molding machine in the same manner as in Example 22, so that the polyethylene terephthalate layer at the minimum thickness part was approximately 150 μm, and the copolyester layer made from terephthalic acid, ethylene glycol, and glycolic acid was approximately 150 μm thick. It is 150μ and the internal volume is about 11
A stretched bottle was produced. The oxygen gas permeability of this stretched bottle is 0.8 ml/day・bottle・atm, and the carbon dioxide gas permeability is 3.2 ml/day.

It was a bottle-atm.

Applicant: Mitsui Petrochemical Industries, Ltd. Agent Kazu Yamaguchi

Claims (1)

[Scope of Claims] (11(al) mainly composed of terephthalic acid component units (2) 30 to 4 aromatic dicarboxylic acid component units
9 mol%, (b) 30 to 49 mol% of diol component units mainly composed of ethylene glycol component units, (CI) 2 to 40 mol% of aliphatic α-hydroxycarboxylic acid component units having 5 or less carbon atoms. %, and (dl 0 to 5 mol % of polyfunctional component units having a carbon number ranging from 3 to 15 and having 3 or more carboxyl or hydroxyl groups). A polyester whose physical properties include (e) an intrinsic viscosity [η] in the range of 0.4 to 1.8 dl/g, and (f) a glass transition point in the range of 40 to 100°C; A co-condensed polyester characterized by: (30 to 49 mol% of aromatic dicarboxylic acid component units mainly composed of 81 terephthalic acid component units, 30 to 49 mol% of diol component units mainly composed of ethylene glycol component units) 49 mol%, (2 to 40 mol% of aliphatic α-hydroxycarboxylic acid component units having 5 or less C1 carbon atoms, and (dl having 3 to 15 carbon atoms and 3 or more carboxyl units) A substantially linear co-condensed polyester consisting of O to 5 mol% of polyfunctional component units having groups or hydroxyl groups, the physical properties of which are (e) an intrinsic viscosity [η] of 0.4 to 1; .8 dl/g; and [f) a glass transition point in the range of 40 to 100°C.