JP3088145B2 - Aromatic polyester resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent aromatic polyester resin having excellent gas barrier properties.

[0002]

2. Description of the Related Art Polyethylene terephthalate (hereinafter abbreviated as PET) is processed into various containers such as films, sheets, cups, bottles and trays due to its excellent mechanical and chemical properties. Widely used as packaging material. However, the gas barrier performance of PET is not always sufficient for use as a packaging material for protecting the contents from oxygen gas, water vapor, or the like, or as a packaging material for preventing gas from escaping from the contents.

[0003] Therefore, development of a resin having the same excellent transparency and moldability as PET and exhibiting a sufficient gas barrier property has been demanded.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found an aromatic polyester resin which is transparent and has excellent gas barrier properties, and completes the present invention. Reached. That is, the present invention uses the formula
0 to 95 mol% of the repeating unit represented by (1), and formula (2)
An aromatic polyester resin comprising 5 to 100 mol% of a repeating unit represented by the following formula, provided that-(-O-
CO-CHR '-)-(where R' is a hydrogen atom or methyl
Represents a hydroxyl group. ) Except when it contains a repeating unit
Good. ] Is provided.

[0005]

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(Wherein m represents an integer of 2 to 10) The aromatic polyester resin of the present invention comprises terephthalic acid or an ester-forming derivative thereof (dimethyl terephthalate, diethyl terephthalate, etc.), and a compound represented by the formula (3)

[0007]

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(2-Hydroxy-2-oxoethoxy) benzoic acid or an ester-forming derivative thereof (methyl 4- (2-methoxy-2-oxoethoxy) benzoate, 3- (2-methoxy-2-benzoic acid) Oxoethoxy) methyl benzoate, etc.)
It is obtained by copolymerizing a diol component selected from linear aliphatic glycols having 2 to 10 carbon atoms. The composition of the dicarboxylic acid component is 0 to 95 mol% of terephthalic acid or its ester-forming derivative, and 5 to 10 mol of (2-hydroxy-2-oxoethoxy) benzoic acid or its ester-forming derivative.
0 mol%. If the latter ratio is less than 5 mol%, the effect of the gas barrier property exhibited is not sufficient. Examples of the linear aliphatic glycol having 2 to 10 carbon atoms used as the diol component include ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol and the like.

The aromatic polyester resin of the present invention may be copolymerized with a copolymer component other than the above essential components at a ratio of 20 mol% or less. That is, aromatic dicarboxylic acids and aliphatic dicarboxylic acids other than the above essential components may be copolymerized as dicarboxylic acid components, and aliphatic diols, aromatic diols and diphenols other than the above essential components may be copolymerized as diol components. Further, a hydroxycarboxylic acid component such as an aromatic hydroxycarboxylic acid may be copolymerized. Further, a small amount of a polyfunctional component having three or more functional groups may be copolymerized within a range in which melt molding is possible. Among these copolymerizable compounds, for example, dicarboxylic acid components include 1,5-,
1,6-, 1,7-, 2,6-, 2,7-naphthalenedicarboxylic acid, phthalic acid, cyclohexanedicarboxylic acid, isophthalic acid, dibromoisophthalic acid, sodium-sulfoisophthalic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid , Diphenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid, diphenoxyethane dicarboxylic acid, aromatic dicarboxylic acids such as phenylenedioxy diacetic acid, adipic acid, sebacic acid, succinic acid, glutaric acid, piperic acid, suberic acid, azelaic acid, An aliphatic dicarboxylic acid such as undecadionic acid and dodecadionic acid may be used alone or as a mixture of two or more. Examples of the diol component include aliphatic diols such as propylene glycol, neopentyl glycol, diethylene glycol, and polyethylene glycol, alicyclic diols such as cyclohexane dimethanol, o-, p-xylylene glycol, and 2,2-bis (4- Aromatic diols such as (hydroxyethoxyphenyl) propane or a mixture of two or more aromatic diols, and diphenols such as hydroquinone, resorcinol, dihydroxydiphenyl, and dihydroxydiphenylether. Still aromatic hydroxycarboxylic acid component, arsenate Dorokishi benzoic acid, hydroxynaphthoic acid, and the like.

The method for synthesizing the aromatic polyester resin of the present invention using the above-mentioned monomers includes a direct polymerization method,
Any method for synthesizing a general polyester such as a transesterification method may be used. The aromatic polyester resin of the present invention obtained by the above method preferably has an intrinsic viscosity of not less than 0.5 g / dl measured at 25 ° C. in a mixed solvent of phenol / tetrachloroethane (weight ratio: 60/40). If the intrinsic viscosity is less than 0.5 g / dl, the mechanical properties deteriorate, which is not preferable.

[0011] The aromatic polyester resin of the present invention can be melt-formed such as a melt-formed film, whereby a molded article such as a sheet or a film can be obtained. Further, a hollow molded article can be obtained by direct blow molding, injection blow molding, biaxial stretching blow molding, or the like. Further, additives such as a coloring agent, an oxidation stabilizer, an ultraviolet absorber, an antistatic agent and a flame retardant may be added to the aromatic polyester resin of the present invention to the extent that the moldability is not impaired.

[0012]

Embodiments of the present invention will be described below in detail, but the present invention is not limited to the following embodiments unless it exceeds the gist. The measurement of the intrinsic viscosity in the examples was performed at 25 ° C. using a mixed solvent of phenol / tetrachloroethane = 60/40 (weight ratio). The oxygen permeability was measured by using a gas permeation measuring device GPM250 manufactured by Gaschrom Industry Co., Ltd. at 23 ° C. and normal pressure to measure the oxygen permeability coefficient of the film (unit: cm ³ · mm / m ² · 24 hr · atm). Water vapor permeability is L
Measured at 40 ° C using yssy WATER VAPER PERMIATION TESTER L80-4000 (unit: g · mm / m ² · day).

Example 1 Dimethyl terephthalate as a dicarboxylic acid component was placed in a separable flask equipped with a stirring blade, a nitrogen inlet, and a vacuum port.
8.7 g (0.92 mol), 17.9 g (0.08 mol) of methyl 3- (2-methoxy-2-oxoethoxy) benzoate, 124.2 g (2.0 mol) of ethylene glycol as a diol component, and Zn (CH ₃ COO) ₂ as a catalyst・ Add 0.1g each of 2H ₂ O and GeO ₂ . The mixture is heated to 180 to 230 ° C under a nitrogen stream to carry out a transesterification reaction, and methanol is distilled off. After 4 hours, almost the theoretical amount of methanol is distilled off.
The temperature was raised to ℃, the pressure was gradually reduced, and the polymerization was carried out at 0.1 to 0.3 Torr for 3 hours. The intrinsic viscosity of the obtained polymer was 0.74 g / dl. Also, the obtained polymer was melt-pressed at 280 ° C,
By quenching, a polyester film having a thickness of about 0.2 mm was obtained. Using this film, the oxygen permeability and the water vapor permeability were measured. Table 1 shows the results.

Example 2 155.4 dimethyl terephthalate as a dicarboxylic acid component
g (0.8 mol) and 44.8 g (0.2 mol) of methyl 4- (2-methoxy-2-oxoethoxy) benzoate were used in the same manner as in Example 1 to obtain a polymer. The intrinsic viscosity of the obtained polymer was 0.77 g / dl. Table 1 shows the oxygen and water vapor transmission rates measured in the same manner as in Example 1.

Example 3 Dimethyl terephthalate was used as a dicarboxylic acid component.
g (0.6 mol), and a polymer was obtained in the same manner as in Example 1 except that 89.7 g (0.4 mol) of methyl 4- (2-methoxy-2-oxoethoxy) benzoate was used. The intrinsic viscosity of the obtained polymer was 0.76 g / dl. Table 1 shows the oxygen and water vapor transmission rates measured in the same manner as in Example 1.

Example 4 The procedure of Example 2 was repeated, except that methyl 3- (2-methoxy-2-oxoethoxy) benzoate was used instead of methyl 4- (2-methoxy-2-oxoethoxy) benzoate. To obtain a polymer. The intrinsic viscosity of the obtained polymer is 0.
It was 73 g / dl. Table 1 shows the oxygen and water vapor transmission rates measured in the same manner as in Example 1.

Example 5 The procedure of Example 3 was repeated except that methyl 3- (2-methoxy-2-oxoethoxy) benzoate was used instead of methyl 4- (2-methoxy-2-oxoethoxy) benzoate. To obtain a polymer. The intrinsic viscosity of the obtained polymer is 0.
It was 74 g / dl. Table 1 shows the oxygen and water vapor transmission rates measured in the same manner as in Example 1.

Example 6 A polymer was obtained in the same manner as in Example 1 except that only 224.3 g (1.0 mol) of methyl 4- (2-methoxy-2-oxoethoxy) benzoate was used as the dicarboxylic acid component. The intrinsic viscosity of the obtained polymer was 0.78 g / dl. Table 1 shows the oxygen and water vapor transmission rates measured in the same manner as in Example 1.

Example 7 A polymer was obtained in the same manner as in Example 1 except that only 224.3 g (1.0 mol) of methyl 3- (2-methoxy-2-oxoethoxy) benzoate was used as the dicarboxylic acid component. The intrinsic viscosity of the obtained polymer was 0.76 g / dl. Table 1 shows the oxygen and water vapor transmission rates measured in the same manner as in Example 1.

Example 8 112.2 g (0.5 mol) of methyl 3- (2-methoxy-2-oxoethoxy) benzoate as a dicarboxylic acid component,
A polymer was obtained in the same manner as in Example 1 except that 112.2 g (0.5 mol) of methyl (2-methoxy-2-oxoethoxy) benzoate was used. The intrinsic viscosity of the obtained polymer is 0.
It was 75 g / dl. Table 1 shows the oxygen and water vapor transmission rates measured in the same manner as in Example 1.

Comparative Example 1 Dimethyl terephthalate 194.2 g as dicarboxylic acid component
(1.0 mol) was obtained in the same manner as in Example 1 except that only the polymer (1.0 mol) was used. The intrinsic viscosity of the obtained polymer is 0.72 g /
dl. Table 1 shows the oxygen and water vapor transmission rates measured in the same manner as in Example 1.

Comparative Example 2 Dimethyl terephthalate 188.4 g as dicarboxylic acid component
(0.97 mol) and 6.73 g (0.03 mol) of methyl 4- (2-methoxy-2-oxoethoxy) benzoate were used in the same manner as in Example 1 to obtain a polymer. The intrinsic viscosity of the obtained polymer was 0.75 g / dl. Table 1 shows the oxygen and water vapor transmission rates measured in the same manner as in Example 1.

[0023]

[Table 1]

[0024]

The aromatic polyester resin of the present invention has P
It has the same transparency and moldability as ET, and has better oxygen barrier properties and water vapor barrier properties than PET. Therefore, it is useful in the application of bags, containers, and the like in the case where a barrier property of water vapor and oxygen is required. By using the aromatic polyester resin of the present invention and blow molding, transparency, gas barrier property and impact resistance are obtained. A hollow container excellent in the above can be obtained.

(56) References JP-A-59-138224 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 63/00-63/91 CA (STN) REGISTRY ( STN)

Claims (1)

(57) [Claims] 1. An aromatic polyester resin comprising 0 to 95 mol% of a repeating unit represented by the formula (1) and 5 to 100 mol% of a repeating unit represented by the formula (2).
[However,-(-O-CO-CHR '-)-(where R'
Represents a hydrogen atom or a methyl group. )
Except when including units. ] . Embedded image (In the formula, m represents an integer of 2 to 10.)