JPS62198434A - Co-extruded multi-layer sheet and mutli-layer structure - Google Patents

Abstract

PURPOSE:To obtain a co-extruded multi-layer sheet, excellent in rigidity, resistance to heat and gas barrier properties and provided with the fabrication quality of orientation, by a method wherein an adhesive agent layer consisting of two layer is provided between PET and EVOH while the side of the PET is made of modified PAR containing sulfonic group and the side of the EVOH is made of polyamide. CONSTITUTION:An adhesive agent layer consisting of at least two layers is provided between a polyester resin layer having the principal constituent of polyethylene terephthalate and a vinyl series resin layer having the principal constituent of the partially saponificated resin of the co-polymer of ethylene- vinyl acetate while the polyester resin layer side of the adhesive agent layer is made of a resin compound consisting of 10-90wt% of polyester containing sulfonic group and the 90-10wt% of aromatic polyester and the vinyl series resin side thereof is made of polyamide. Polyester containing a sulfonic group is co-polymerized so as to contain 0.5-10mol% sodium sulfoisophthalic acid and/or sodium sulfotereththalic acid while the polyamide is the co-polymerized polyamide containing 5-30wt% of nylon 66 constituent.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a coextruded multilayer sheet and structure with excellent heat resistance and gas barrier properties, and furthermore, to a coextruded multilayer sheet and structure suitable for forming deep-drawn containers with excellent rigidity. The present invention relates to coextruded multilayer sheets and multilayer structures such as deep-drawn containers formed therefrom.

(Prior Art) Linear polyester in general, and polyethylene terephthalate (hereinafter referred to as PET) in particular, has attracted attention as a material for various containers including bottles due to its excellent mechanical and chemical properties. Deep-drawn containers made from PUT sheets, as typified by the method described in the above publication, are also in increasing demand as containers with excellent rigidity and gas barrier properties.

However, improvements in packaging technology and expansion of packaging applications are requiring higher functionality to be added to PET containers, especially when considering alternative uses for metal cans and glass containers. Although it has many advantages in terms of performance and safety, its lack of performance in terms of gas barrier properties and heat resistance has been a bottleneck, greatly limiting the development of its applications.

As a means of improving the gas barrier properties and heat resistance of such PET containers, we have developed a partially saponified resin of ethylene/vinyl acetate copolymer (hereinafter referred to as EV O1+), which is a material with even better gas barrier properties than PET. Or vinyl resin based on this and pH! A resin composition (hereinafter referred to as modified PAR) consisting of aromatic polyester, which is a material with even better heat resistance than T, and PET is called PI.
A multilayer bottle co-injected with ET and biaxially stretched blow molded is known from Japanese Patent Application Laid-Open No. 59-214047, and a multilayer sheet having such a structure with excellent heat resistance and gas barrier properties and a container molded from it are also available. has not yet been put into practical use.

(Problems to be solved by the invention) Although it is highly predicted that the composite of PBT/EVOII/modified PAR will provide high functionality such as heat resistance and gas barrier, 1. The biggest reason for the delay in the development of these materials is the problem of adhesion between these materials. PET and modified PAR each have a non-polar molecular structure and exhibit excellent mutual adhesion under coextrusion conditions, whereas EVOll has a polar molecular structure with hydroxyl groups with large molecular cohesive energy. Direct adhesion to PUT and modified PAR is therefore completely impossible.

Therefore PF! Although an adhesive layer is essential for forming a multilayer sheet of T/EVOI+/modified PAR in the middle, an adhesive suitable for forming such a sheet has not yet been found. Of course, inside PET and EV
011, adhesives based on acid anhydride group-containing polyolefin, epoxy group-containing polyolefin, or polyurethane have already been put into practical use.

In addition, the development of adhesives based on polyamides and polyesters is actively progressing, but adhesives for coextruded multilayer sheets intended for secondary processing such as deep drawing must not only have adhesive strength but also suitability for melt extrusion. It goes without saying that secondary processability, such as compatibility with stretching and stretching processes, and further transparency, if necessary, are also required.

However, in order to improve adhesion, it is a general tendency that moldability decreases as the degree of modification advances, such as various copolymerizations and polymer alloys, so it is necessary to balance these properties comprehensively. This difficulty can be said to be one of the major reasons for delaying the practical application of highly functional multilayer sheets of PET/EVOII/modified PAR.

(Means for Solving the Problems) The present inventors have solved the above problems, and have developed a material that has excellent rigidity, heat resistance, and gas barrier properties, can maintain transparency if necessary, and is also capable of deep drawing processing. In order to develop a coextruded multilayer sheet that is also provided with stretching and secondary processability, the present invention was arrived at as a result of extensive research, particularly regarding the adhesive layer.

That is, the present invention is a multilayer sheet having a structure in which a two-layer adhesive layer is provided between PET and EVOll.

The PBT side of the adhesive layer is made of 10 to 90% by weight of sulfone group-containing polyester and 90 to 10% by weight of aromatic polyester.
% by weight (hereinafter referred to as sulfone group-containing modified PAR), and is a coextruded multilayer sheet characterized in that the EVOll side is polyamide.

Furthermore, the sulfone group-containing polyester used in the sulfone group-containing modified PAR is a sulfone group-containing modified F.
AI? PE copolymerized with sodium sulfoisophthalic acid and/or sodium sulfoterephthalic acid in an amount of 0.5 to 10 mol% based on the total acid components.
T, and the polyamide contains 5 to 3 nylon 66 components.
This is a coextruded multilayer sheet characterized by being a copolymerized polyamide containing 0 weight percent strain.

Furthermore, there is a container molded from these coextruded multilayer sheets.

PI used in the present invention! T is a polyester whose main repeating unit is ethylene terephthalate, and phthalic acid in an amount of 10 mol% or less of the total acid component.

Dicarboxylic acids such as isophthalic acid, hexahydrophthalic acid, naphthalene dicarboxylic acid, adipic acid, and sebacic acid, polyhydric carboxylic acids such as trimellitic acid and pyromellitic acid, or oxyacids such as P-oxybenzoic acid as acid components. 1.2-propanediol, 1.3-propanediol, 1. 21ii alcohols such as mubutanediol, 116-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, cyclohexane dimetatool, trimethylolpropane, trimethylolpropane.

Polyhydric alcohols such as pentaerythritol can be used as the alcohol component. Such PET is obtained by a conventional melt polycondensation reaction,
If necessary, the degree of polymerization can be further increased by solid phase polymerization reaction.

EVOH used in the present invention is a crystalline polymer obtained by saponifying a random copolymer of ethylene/vinyl acetate represented by the trade name "EVAL".

It has polar hydroxyl groups and exhibits extremely excellent gas barrier properties due to its large molecular cohesive energy.

The sulfone group-containing polyester in the sulfone group-containing modified PAR, which is one of the constituent components of the adhesive layer of the present invention, is
It can be easily obtained by a melt polycondensation reaction using a conventional method using sodium sulfoisophthalic acid or sodium sulfoterephthalic acid as part of the acid component in polyester, and when a high polymerization degree polymer is required, a solid phase polymer can be used. Polymerization reactions can also be used.

The amount of copolymerized sodium sulfoisophthalic acid and/or sodium sulfoterephthalic acid is determined by the amount of the sulfone group-containing modified FAI? 0.0% based on the total acid component when closed.
If the content is 5 mol % or more, it can have sufficient adhesive strength to PUT and polyamide, which are adjacent layers. Also 1
At a copolymerization amount of 0 mol% or more, the adhesive strength reaches saturation,
No further effect can be expected, and at the same time the hygroscopic effect due to the sulfone group occurs, which does not give good results to the gas barrier properties of EVOI.

What are the basic properties of sulfone group-containing polyester?

Pl as much as possible in terms of heat resistance, workability, etc. It is desirable that the polyester be close to T, and this can be solved by using PET containing sulfone groups as the polyester. Similarly, the aromatic polyester in the sulfone group-containing modified PAR is composed of an aromatic dicarboxylic acid or its derivative and a dihydric phenol or its derivative. Preferred aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, etc.
In particular, these mixtures are preferred in terms of melt processability and overall performance. In the case of such a mixture, the mixing ratio should not be limited, but terephthalic acid/isophthalic acid/isophthalic acid/f
f1=9/1 to 1/9 <air m ratio) is preferable.

Especially in terms of melt processability and performance balance, it is 7/3 to 3/7.
(weight ratio) is desirable. Dihydric phenol has the following general formula % R'x HR'3 + R'4 is selected from the group consisting of hydrogen atom, halogen atom, hydrocarbon group, and halogenated hydrocarbon group, and X is 0. S, S(h, Co, 7
/L/kL/7 or an alkylidene group (if necessary, the alkylene or alkylidene group may be substituted with one or more halogen groups).

As the dihydric phenol used in the present invention, for example, 2
．． 2-bis(4-hydroxyphenyl)-propane, 2
．． 2-bis(4-hydroxy-3,5-dibromophenyl)-propane, 2,2-bis(4-hydroxy-3,
5-dichlorophenyl)-propane, 4.4'-dihydroxyphenyl sulfone, 4゜4゛-dihydroxydiphenyl ether, 4.4'-dihydroxydiphenyl sulfide, 4.4'-dihydroxydiphenyl ketone, 4.4'-dihydroxydiphenylmethane,
2,2-bis(4-hydroxy3゜5dimethylphenyl)propane, l11-bis(4-hydroxyphenyl)
-ethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4°4°-dihydroxydiphenyl, benzoquinone, etc. These may be used alone or as a mixture. Although these dihydric phenols are para substituted, other isomers may also be used, and ethylene glycol is also used for these dihydric phenols.

Propylene glycol or the like may be used in combination.

The most typical dihydric phenol is 2,2-bis(4-hydroxyphenyl)propane, commonly called bisphenol A. Such aromatic polyester solution polymerization 5 melt polymerization.

Manufactured by various methods such as interfacial polymerization. Sulfone group-containing modified PAR can be obtained by extruding this sulfone group-containing polyester and an aromatic polyester using a melt extruder, or by stirring and mixing the sulfone group-containing polyester and aromatic polyester while melting them in a reaction can with stirring blades. A randomization-promoting catalyst such as sodium acetate may be added in order to promote randomization due to the transesterification reaction that occurs during this process and to obtain a uniform polymer alloy.

Such sulfone group-containing modified PAR exhibits a higher glass transition temperature Tg and has improved heat resistance as the amount of aromatic polyester increases.

The polyamide that is another component of the adhesive layer of the present invention is selected from polycapramide, polylaurinlactam, polyhexamethylene adipamide, poly-11-aminoundecanoic acid, and the like. Although these may be used alone, as a copolymer, or as a mixture, a nylon 6.66 copolyamide containing 5 to 30% by weight of a nylon 66 component is particularly preferred.

The structure of the multilayer sheet according to the present invention is obtained by extruding PET/sulfone group-containing modified f'AR/polyamide/HVO11 from a multilayer gouey using four extruders dedicated to each resin. Group-containing modified PAR/polyamide/HVO11/polyamide/
It is possible to have a seven-layer structure of sulfone group-containing modified PAR/PUT or, if necessary, a multi-layer structure.

The multilayer sheet obtained by the present invention can be easily improved in rigidity, gas barrier properties, and heat resistance by heating in a temperature range 20 to 50°C higher than the Tg of the sulfone group-containing modified PAR and then performing vacuum forming or pressure forming. (Function) In the present invention, PET and EVO, which have no adhesive strength to each other, can be made into an excellent multilayer structure such as a container.
A two-layer adhesive layer is provided between I+, of which IN
By making PE a polyamide with excellent adhesion to IEVOI+, and making the other layer a sulfone group-containing modified PAR with excellent adhesion to both PET and polyamide, PE
Not only can it be made into a multilayer sheet that integrates T and EVOI+, but it can also be made into a multilayer sheet that integrates T and EVOI+.
Utilizing the heat resistance of PUT, this multilayer sheet has many advantages of PUT and [! In addition to the gas barrier properties provided by Vo11,
Furthermore, it also imparts heat resistance. The amount of sulfone group-containing modified PAR necessary for imparting such heat resistance to at least 3% of the total sheet weight can sufficiently exhibit the effect.

In addition, each of the constituent components of such a multilayer sheet is selected from materials that are excellent in secondary drawing processability such as deep drawing processing,
For this reason, it is extremely easy to mold, but when considering alternative uses for metal cans and glass containers, this container is a revolutionary product that combines heat resistance and gas barrier properties that were previously not possible with POET containers themselves. It is a multilayered structure such as a container.

(Example) Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Example 1 Terephthalic acid 97.5 mol% 15-sodumsulfoisophthalic acid 2.5 mol%, ethylene glycol 100
A melt polycondensation reaction was carried out by a conventional method using mol % to obtain a sulfone group-containing polyester having an ultimate clay of 0.70 as measured at 20° C. in an equal weight mixed solvent of phenol/tetrachloroethane.

On the other hand, it consists of terephthalic acid/isophthalic acid (mixed molar ratio 1) and bisphenol A, and the logarithmic viscosity measured at 25°C in a 6/4 mixed solvent of phenol/tetrachloroethane is 0.
．． 60 aromatic polyesters were prepared. 6:4 of this sulfone group-containing polyester and aromatic polyester
A sulfone group-containing modified PAR having a Tg of 99° C. was obtained by melt blending at a ratio of . At this time, the amount of 5-sodium sulfoisophthalic acid based on the total acid components was 1.5 mol%.

Separately, nylon 6.6 contains 15% by weight of nylon 66 component and has a relative viscosity of 4.5 as measured at 25°C in 96% concentrated sulfuric acid.
6 copolymer polyamide and a PUT with an intrinsic viscosity of 1.0 and a load of 2160 g at 190°C for 10 minutes.The value of 1 is 1.
．． 40g of EVOII (Eval Er'- manufactured by Kuraray)
Prepare f'), thoroughly dry these materials, and then extrude them from a multilayer goo using four extruders dedicated to each.

PET (300μ)/modified PAR containing sulfone group
(40μ) / Copolymerized polyamide (20p) / IE
VOH (80μ) / Copolymer polyamide (20μ) / Sulfone group-containing modified PAR (40μ) / PET (3
A sheet with a thickness of 800μ and having a seven-layer structure of 00μ) was obtained. −
The thickness between each glabella was uniform with no unevenness, and although there was some cloudiness due to EVOll, it was a transparent sheet, and each layer was firmly adhered to the extent that it could not be peeled off.

This sheet was heated at 140° C. for 5 seconds and then formed into a cup with a diameter of 100 mm and a depth of 40 mm by vacuum forming, resulting in a uniformly stretched transparent product. When this cup was filled with hot water and the degree of deformation was observed, no deformation occurred at temperatures up to 85°C. In addition, when the oxygen gas permeability of the film cut out from this container was measured using a measuring device manufactured by Moran Control, it was found to be 1.3 cc - m + n / 2 of 4 PET sheets.
4hr-rd = 0.5 c, less than 1/2 compared to ATM
It was confirmed that the value was c-mm/24hr-rd-atm.

Example 2. Comparative Examples 1-2 According to the method of Example 1, only the composition of the adhesive layer was changed to obtain the results shown in Table 1.

Table 1 In the table, Na5IPA-P[ET represents PUT copolymerized with 2.5 mol% of 5-sodium sulfoisophthalic acid, and PAR represents aromatic polyester. Further, the structure of the multilayer sheet is seven layers as in Example 1, and therefore, the thickness of each layer in the table indicates the thickness of the layers on both sides centering on the IEVO II layer.

The heat-resistant temperature of the container is the temperature at which deformation does not occur when it is filled with hot water.

(Effects of the Invention) As is clear from Example 1.2, a coextruded multilayer sheet having PET/sulfone group-containing modified PAR/polyamide/EVOll as basic units that satisfies the requirements of the present invention has extrusion moldability, It has excellent uniformity and adhesion between two layers, and multilayer structures such as containers formed from this sheet also have excellent gas barrier properties and excellent heat resistance corresponding to the heat resistance of sulfone group-containing modified PAR. ing.

Patent applicant Unitika Co., Ltd.] Nijo A Ne Ichimasa ↑ (spontaneous) Mouth”l-December 2061 260,, Indication of the case Patent application No. 1986-40586 2, Title of invention Co-extruded multilayer sheet (・Sai) Multi-layer structure 3, connection with the amended person case 1 Patent applicant address 1-50 Higashihonmachi, Amiseki City, Hyogo Prefecture (1) Section 5 of “Claims” in the specification, '?ii Correct content (11 Claims are corrected as per the number column.

Claims (11) At least two layers between polyethylene terephthalate or a polyester resin layer mainly composed of polyethylene terephthalate and a partially saponified resin of ethylene/vinyl acetate copolymer or a vinyl resin layer mainly composed of this This is a multilayer sheet having an adhesive layer, the adhesive layer having a polyester resin layer side made of sulfone group-containing polyester 1.
0-90% by weight.

A coextruded multilayer sheet characterized in that it is a resin composition consisting of 90 to 10% by weight of aromatic polyester, and the vinyl resin layer side is polyamide.

(2) The sulfone group-containing polyester used in the resin composition consisting of the sulfone group-containing polyester and the aromatic polyester contains sodium sulfoisophthalic acid and/or sodium sulfoterephthalate relative to the total acid components in the resin composition. The coextruded multilayer sheet (3) according to claim 1, characterized in that the polyamide is polyethylene terephthalate copolymerized with an acid content of 0.5 to 10 mol%. The coextruded multilayer sheet according to claim 1, which is a copolymerized polyamide containing 30 ffl(]%.

(4) Sulfone group-containing polyester 10-
90Eff amount%, aromatic polyester 90-10% by weight
A multilayer structure molded from a coextruded multilayer sheet provided with an adhesive layer consisting of at least two layers of a resin composition consisting of a polyamide resin and a polyamide resin.

Claims (4)

[Claims] (1) An adhesive layer consisting of at least two layers is provided between a polyester resin layer mainly composed of polyethylene terephthalate or a partially saponified resin of ethylene/vinyl acetate copolymer or a vinyl resin layer mainly composed of this. A multilayer sheet having the above structure, wherein the adhesive layer includes a polyester resin layer containing sulfone group-containing polyester 10.
1. A coextruded multilayer sheet comprising a resin composition comprising ~90% by weight of aromatic polyester and 90~10% by weight of aromatic polyester, the vinyl resin layer side being polyamide. (2) The sulfone group-containing polyester used in the resin composition consisting of the sulfone group-containing polyester and the aromatic polyester contains sodium sulfoisophthalic acid and/or sodium sulfoterephthalic acid relative to the total acid component in the resin composition. The coextruded multilayer sheet according to claim 1, which is polyethylene terephthalate copolymerized with an acid content of 0.5 to 10 mol%. (3) Polyamide contains 5-30% by weight of nylon 66 component
The coextruded multilayer sheet according to claim 1, characterized in that it is a copolymerized polyamide containing. A coextruded multilayer sheet according to item 1. (4) Sulfone group-containing polyester 10-
A multilayer structure molded from a coextruded multilayer sheet provided with an adhesive layer consisting of at least two layers of a resin composition comprising 90% by weight of aromatic polyester and 90 to 10% by weight of polyamide resin.