JPS62109738A - Multilayer oriented polyester bottle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a multilayer stretched polyester bottle, and more particularly to a multilayer stretched polyester bottle with excellent gas barrier properties.

<Prior art> Biaxially stretched blow-molded bottles made of polyethylene terephthalate have excellent transparency, impact resistance, and good safety and hygiene properties, so they are used for beverages, v! Although polyester bottles are widely used as seasoning containers, their barrier properties against oxygen gas and carbon dioxide gas pressure are not necessarily sufficient, and further improvements are expected.

Various proposals have been made to improve this gas barrier property, and among them, a multilayer method in which a polyester layer is laminated with a layer made of a resin having better gas barrier properties than the polyester is expected to be an effective measure. Ru.

However, resins with good gas barrier properties used in such multilayer bottles must have good moldability under polyester molding conditions, and the reality is that existing resins have not been satisfactory. For example, ethylene
Although vinyl alcohol copolymers have excellent gas barrier properties, they have the disadvantage that if the layer thickness is increased to obtain sufficient gas barrier properties, they will not be sufficiently stretched and oriented under polyester molding conditions. Therefore, the thickness of the gas barrier layer must be made thinner, and as a result, a bottle having the desired gas barrier properties cannot be obtained.

Furthermore, although nylon 6 and nylon 66 have better gas barrier properties than Boriesdel, they have the disadvantage that their gas barrier properties are inferior in the presence of moisture, that is, under high humidity, and it is desirable to develop better materials. It was rare.

<Objective of the Invention> An object of the present invention is to provide a polyester bottle with excellent gas barrier properties and good moldability.

<Structure of the Invention> The present invention is a multilayer stretched polyester bottle comprising a multilayer structure including a polyethylene terephthalate layer and a copolyamide layer comprising tetramethylene adipamide units and tetramethylene isophthalamide units.

In the present invention, polyethylene terephthalate refers to a polyester in which 80% or more of the repeating units are ethylene terephthalate units, and within this range, a portion of the terephthalic acid component is, for example, isophthalic acid, naphthalene dicarboxylic rR, diphenyldicarboxylic acid, diphenoxyethane dicarboxylic acid. acid.

Aromatic dicarboxylic acids such as diphenyl ether dicarboxylic acid and diphenyl sulfone dicarboxylic acid; hexahydroterephthalic acid; alicyclic dicarboxylic acids such as hexahydroin heptacuric acid; such as adipic acid, sepatic acid, azelain, etc. with one or more components of other difunctional carboxylic acids such as oxyacids, and/or a portion of the ethylene glycol component, such as trimethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neobenzene gelylcol. , diethin glycol, 1,1-cyclohexane dimethylol, 1,4-cyclohexane dimethylol, 2,2-bis(4-β-hydroxyethoxyphenyl)propane, bis(4-β-hydroI): I Kishie)-? Copolyesters substituted with one or more components of other glycols such as diphenyl)sulfone are included.

From the viewpoint of mechanical properties, polyethylene terephthalate has a low (
Both preferably have an intrinsic viscosity ([η]) of 0.5 or more, more preferably 0.6 or more.

The polyamide used in the present invention consists of tetramethylene adipamide units and tetramethylene isophthalamide units, and the ratio of both units is preferably 90:10 to 10:90, more preferably 20:80 to 80:20. . A preform in which a copolyamide layer having 90 or less tetramethylene adipamide units is multilayered with a polyethylene terephthalate layer has a good crystallization rate because it can be stretched and oriented. Furthermore, when a copolyamide having 90 or less tetramethylene isophthalamide units is used, it can be stretched and oriented under stretching and orientation conditions suitable for polyethylene terephthalate.

In the present invention, the copolyamide consisting of tetramethylene adipamide units and tetramethylene isophthalamide units refers to a copolyamide in which the two types of amide units account for 80% or more of the repeating units, and the range that satisfies this. A part of tetramethylene diamine and a part of adipic acid or isophthalic acid are combined with other diamines, aminocarboxylic acids,
It includes copolyamides substituted with one or more of lactam and dicarboxylic acid. Specifically, such a copolymer component is an aliphatic diamine.

For example, ethylenediamine, trimethylenediamine, hexamethylenediamine, etc.; aromatic diamines, such as phenylenediamine, -? Silylene diamine, 3,6-diamitacridine, N-methyl-p-phenylene diamine, N,N-dimethyl-p-phenylene diamine, tolylene diamine, etc.; Alicyclic diamines, such as 1.
2-diaminocyclobutane, etc.; aliphatic 7-minocarboxylic acid.

For example, glycine, alanine, valine, etc.; Aromatic aminocarboxylic acids, such as phenylalanine, aminobenzoic acid, etc.; Alicyclic aminocarboxylic acids, such as aminocyclohexanecarboxylic acid, etc.; Lactams, such as β-p-p
Violactam, r-butyrolactam, 8-caprolactam, etc.; aromatic dicarboxylic acids such as terephthalic acid, knack dicarboxylic acid, diphenyl dicarboxylic acid, synenoxyethane dicarboxylic acid.

Diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid #R, diphenyl ketone dicarboxylic acid, moussulfoisophthalic acid.

dinoromodephthalic acid, etc.; fatty R group dicarboxylic acid;

Examples include decalindicarboxylic acid and the like; aliphatic dicarboxylic acids such as succinic acid and sepatic acid.

The copolyamide of the present invention preferably has a relative viscosity of 2.0 or more (ηrel; measured at 20° C. after dissolving 0.1% by weight in 96% sulfuric acid as a solvent).

Such a copolymerized polyamide is produced using a method for producing polyamide (
It can be manufactured by a conventionally known method. For example, it can be produced by condensing tetramethylene diamine and inphthalic acid, and tetramethylene diamine and adipic acid to form salts, and then polycondensing the resulting salts.

The structure of the multilayer structure in the present invention may be any combination of two or more layers, but in particular, a two-layer structure with a polyethylene terephthalate layer as an inner layer and a copolymerized polyamide layer as an outer layer, with adhesive bonded between the two layers. 3-layer structure with laminated adhesive layers, layer #I structure with polyethylene terephthalate layers as inner and outer layers, and copolymerized polyamide as an intermediate layer.To the east, a 5-layer structure with an adhesive layer laminated in the middle of each of these 3-layer structures. Structures are preferred. The weight proportion of the copolyamide layer is preferably 5 to 50% by weight, particularly 10 to 30% by weight from the viewpoint of maintaining the physical properties and gas barrier properties of the resulting multilayer stretched polynisder bottle.

The multilayer stretched bottle of the present invention is basically manufactured by a conventional polyester bottle molding method, and is manufactured by first molding a multilayer preform and subjecting it to a stretching process.

Multilayer preforms are produced by, for example, molding a pipe-like multilayer structure consisting of a polyethylene terephthalate layer and a copolymerized polyamide layer by multilayer coextrusion, cutting this into a certain length, and heat-forming both ends into the desired mouth and bottom. It can be molded. Alternatively, a multilayer injection molding method may be used in which a preform having a multilayer structure is manufactured by sequentially injecting copolyamide onto the inner surface, outer surface, or middle of a polyethylene terephragm.

When this multilayer preform is stretched or expanded by blowing, the stretching ratio of the body of the bottle is desirably 1.2 times or more in terms of area ratio, more preferably 2 times or more.

The polyethylene terephthalate and copolyamide of the present invention may contain colorants, ultraviolet absorbers, antistatic agents, thermal oxidative deterioration inhibitors, lubricants, nucleating agents, thermoplastic resins other than those mentioned above, etc., as necessary, to impair the purpose of the present invention. It can be contained within a certain range.

<Examples> Hereinafter, the present invention will be explained in more detail with reference to Examples. The measurement conditions for the main physical property values are as follows.

(1) Intrinsic viscosity of thermoplastic polyester: 0-rip
Measured at 35°C using lophenol as a solvent (2) Relative viscosity of polyamide: Measured at 20°C at 0.1 wt% using 96% sulfur dispersion (3) Gas permeability coefficient (Pelt) Gas permeation measuring device (Lymsy) 111GPM-200 model) in a 30°C atmosphere. Examples 1 to 3 and Comparative Examples 1 to 4 Polyethylene terephthalate (hereinafter abbreviated as PET) with an intrinsic viscosity of 0.74 was measured at 160°C for 5 On the other hand, the copolyamide shown in Table 1 was dried at 100℃ for 2 hours.
After vacuum drying for 4 hours, the 8-precision ASB machine @RA S
Supplied to cylinders A and H of the B-50EX-T co-injection oriented blow molding machine, set temperature 2 of cylinder A.
60-280℃, Cylinder B (for middle layer) setting -1
- A preform was molded at a temperature of 240 to 300°C, cooled with 15°C cooling water, and co-injected into a mold so that the weight ratio of the intermediate layer was 20% by weight. The preform has a cylindrical body with an outer diameter of 25 to 26 wx and a wall thickness of 3
．． It is 5m in length, with a total length of 155cm, and has a bottomed end.

After heating and controlling the preform to 120 to 150°C,
Stretched in the axial direction inside the bottle storage room and expanded laterally using compressed air pressure, body outer diameter 82m, total height 280u+, body wall thickness 250-360μ, internal volume 1040-10501
A 1/1 bottle was molded. Table IK shows the stretchability (blow moldability) of the preform and the gas barrier properties measured using a test piece cut out from the body of the resulting bottle.

For comparison, a polyester bottle having a copolyamide layer having the composition shown in Table 1 and a multilayer bottle consisting only of PFJT had the same moldability.

and gas barrier properties were measured and the results are also shown in Table IK.

From Table 1, the bottle of the present invention has excellent moldability.

It can be seen that it has gas barrier properties.

Examples 4 to 6 Example 2 except that the copolyamide used in Example 2 was used and the thickness with the PET layer was changed as shown in Table 2.
The stretchability and gas barrier properties of the preform were evaluated in the same manner as above.

The results are shown in Table-2.

Table 2 also shows that the bottle of the present invention has excellent moldability.

It can be seen that it has gas barrier properties.

Table-2 Hand UCneri1. -F: 'book 1.Display of the incident Patent Application No. 1986-244111 No. 2, Title of the invention Multilayer Stretched Polyester Texture 1-1 Representative: Okamoto Sashibe

Claims (1)

[Claims] A multilayer stretched polyester bottle comprising a multilayer structure including a polyethylene terephthalate layer and a copolyamide layer comprising tetramethylene adipamide units and tetramethylene isophthalamide units.