JPH0422781B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a packaging resin container whose wall is made of a specific crystalline polyamide and has excellent barrier properties against gases such as oxygen, carbon dioxide, and water vapor. Packaging containers made from plastic have excellent weighability and impact resistance, and are therefore widely used for various purposes. Among plastic containers, containers made from polyethylene terephthalate PET, especially containers made by biaxial stretch blow molding, have better gas barrier properties to some extent than containers made from polyethylene or polypropylene. Although this container has outstanding transparency and impact resistance, gas permeation through the container wall cannot be ignored compared to glass bottles or metal containers. The shelf life of beer, drinks, etc. is limited to a relatively short period of about 2 to 4 months. Conventionally, various gas barrier resins have been used to improve the preservation of the contents of plastic containers.
Many proposals have been made. For example, ethylene-
Vinyl alcohol copolymer (saponified ethylene-vinyl acetate copolymer) has one of the lowest oxygen permeability coefficients among various resins. Many proposals have been made to reduce the gas permeability of the container as a whole by laminating polyethylene terephthalate or polyolefins as inner and outer surface layers. However, the above-mentioned ethylene-vinyl alcohol copolymer has the disadvantage that even though the gas permeability coefficient for oxygen, etc. is small under low humidity conditions, the gas permeability coefficient increases by about one order of magnitude under high humidity conditions. . Such a tendency is similarly observed for other gas barrier resins. For example, polyamides such as nylon 6 and nylon 66 exhibit gas barrier properties that are about 4 to 5 times better than polyethylene terephthalate in the dry state;
It has a water absorption rate of 11%, and when water is absorbed, its gas barrier properties tend to be lower than that of polyethylene terephthalate. Recently, it has been proposed to use aromatic ring-containing polyamides such as metaxylylene adipamide in place of aliphatic polyamides to improve the gas barrier properties of resin containers (Japanese Patent Laid-Open No. 119858/1983). However, this polyamide is generally amorphous, has low mechanical strength, and has drawbacks such as being scientifically unstable. Thus, conventional attempts to use polyamides as materials for constructing containers have not yet yielded sufficiently satisfactory results. Therefore, an object of the present invention is to provide a packaging plastic whose container wall is made of a specific thermoplastic polyamide that has a low permeability coefficient for gases such as oxygen, carbon dioxide, and water vapor, and also has a low humidity dependence of this gas permeability coefficient. There are containers to provide. According to the present invention, at least one combination of each of the following diamine components and dibasic acid components (a) trans-1,4-cyclohexane bis(methylamine) or 1,4-based mainly trans-1,4-cyclohexane bis(methylamine);
- Cyclohexane bis(methylamine) and succinic acid, adipic acid, sebacic acid or decanedicarboxylic acid (b) paraxylylene diamine or a diamine mixture mainly containing paraxylylene diamine and metaxylylene diamine or hexamethylene diamine and adipic acid , sebacic acid or 1,4-cyclohexane dimethylene dicarboxylic acid (c) bis(aminoethyl)benzene and succinic acid (d) decamethylene diamine and phenylene diacetic acid or (e) combination of trans-4-aminocyclohexane carboxylic acid and caprolactam is a crystalline polyamide mainly composed of, and contains an alkylene group based on each component of the above-mentioned combination and a symmetrical or asymmetrical divalent cyclic hydrocarbon group in the amide skeleton chain, and has a symmetrical cyclic carbonization per total cyclic hydrocarbon group. The average proportion of hydrogen groups is 30 mol% or more, the average number of linear methylene units per symmetrical cyclic hydrocarbon group is 4 to 15, and the glass transition temperature (Tg)
Provided is a packaging resin container whose wall is made of crystalline polyamide having a temperature of 70° C. or higher and a melting point of 370° C. or lower. The thermoplastic polyamide used in the present invention is characterized in that the ratio of symmetrical cyclic hydrocarbon groups and linear methylene groups contained in the amide backbone chain is within a certain range compared to ordinary polyamides. ing. That is, the present invention provides a polyamide comprising a combination of the above-mentioned specific diamine component and a dibasic acid component or a combination of a specific aminocarboxylic acid and caprolactam, in which the above-mentioned diamine is contained in the amide skeleton constituting the polyamide. The average number of linear methylene units per divalent symmetrical cyclic hydrocarbon group is 4 to 15, especially 5 to 15, based on the combination of
A polyamide within the range of 13 has the moldability and processability required for packaging containers, and if this polyamide is used as the container wall material, it has a significantly low permeability coefficient for gases such as oxygen, carbon dioxide, and water vapor. This is based on the knowledge that the dependence of the gas permeability coefficient on humidity is extremely small. Conventionally, in packaging materials made of thermoplastic resins, it has been known that the higher the degree of crystallinity of the resin constituting the packaging material, the smaller the gas permeation coefficient through the resin (for example, polymer
Handbook 2nd Ed.by J.Brandrup, EH
Immergut Wiley−Intersciince (1975) III Solid
(see State Properties). In the polyamide used in the present invention, the symmetrical cyclic hydrocarbon group and linear methylene group are contained in a well-balanced manner in the amide repeating unit, making it possible to have a dense crystal structure with high crystallinity. Since this crystal structure is maintained stably, excellent gas barrier properties and mechanical properties are maintained. Furthermore, the presence of a symmetrical aromatic ring in the amide chain significantly reduces water absorption, which is a common defect in polyamides, and also significantly reduces the humidity dependence of gas barrier properties. In addition, the glass transition temperature (Tg) of nylon 6 and nylon 6,6 is approximately 50 to 65℃ under normal atmosphere.
However, in the polyamide used in the present invention, the amide repeating temperature is within the range of Because the unit contains a symmetrical cyclic hydrocarbon group, the glass transition temperature (Tg) shifts to the high temperature side of 70℃ or higher, and even under high humidity conditions,
Since the degree of decrease in Tg is small, it is thought that excellent gas barrier properties can be obtained. Like ordinary polyamides, the polyamide used in the present invention also contains repeating units represented by the following formulas (-OC-R ¹ -CONH-R ² -NH)- and/or (-OC-R ³ -NH)-. Here, each of the divalent groups R ¹ , R ² and R ³ is an alkylene group, a divalent symmetrical or asymmetrical cyclic hydrocarbon group, or a divalent symmetrical or asymmetrical cyclic hydrocarbon group based on the combination of the specific components. and the average proportion of symmetrical cyclic hydrocarbon groups per total cyclic hydrocarbon groups is 30 mol% or more, especially based on the sum of all R ¹ , R ² and R ³ in the polyamide chain. The groups R ¹ , R 2 ^and R ³ are selected such that the proportion is at least 45 mol % and the average number of linear methylene units per symmetrical cyclic hydrocarbon group is from 4 to 15, in particular from 5 to 13. It is something. The divalent symmetrical cyclic hydrocarbon group defined in the present invention includes point-symmetric, axial-symmetric or plane-symmetric divalent cyclic hydrocarbon groups, such as p-phenyllene group and trans-type 1,4-cyclohexylene group. be able to. On the other hand, the linear methylene chains contained in these components may exist in the form of methylene groups, ethylene groups, propylene groups, tetramethylene groups, and the like. The polyamide used in the present invention has a specific amide skeleton based on the combination of the above-mentioned specific diamine and dibasic acid components, and further has a symmetrical cyclic hydrocarbon group per cyclic hydrocarbon group in the amide skeleton chain. The proportion is 30 mol% or more and symmetrical cyclic hydrocarbon 1
Number of linear methylene units per unit (simply referred to as M/R
Polyamides having a polyamide ratio of 4 to 15 are specifically exemplified by the following polyamides. Poly(decamethylene phenylene diacetamide) M/R ratio: 12 Poly(p-xylylene sebacamide) M/R ratio: 10 Poly(p-phenylene diethylene succiamide) M/R ratio: 6 Poly(trans-1,4-cyclohexane dimethylene adivamide) M/R ratio: 6 Poly(trans-1,4-cyclohexane dimethylene sepacamide) M/R ratio: 10 Poly(trans-1,4-cyclohexane dimethylene/cis-1,4-cyclohexane dimethylene adipamide) molar ratio 6/4, MR ratio: 10 Note that the 1,4-cyclohexylene unit is trans type and has a symmetrical structure for the first time; It is necessary to pay attention to the fact that the mold does not have a symmetrical structure. In the present invention, it will be immediately clear by referring to the description of the examples described later that it is important to set the M/R ratio to a number of 15 or less in order to suppress the gas permeability coefficient to a small value. . On the other hand, if there are no methylene chains at all, such as when the M/R ratio is zero, the melting point of the polyamide will be high, which will likely cause difficulties in terms of thermoformability and processability.
The ratio should be at least 4 times. Similarly, this polyamide should have a Tg of 70°C or higher in terms of gas barrier properties, and desirably has a Tg of 180°C or lower in terms of moldability and processability. In addition, since the polyamide used in the present invention has a symmetrical ring in its backbone chain, it is generally
It has a high melting point above 260°C, but in terms of thermoformability its melting point should be below 370°C, especially below 340°C. In addition, depending on the purpose such as improving thermoformability, this polyamide resin may contain additives known per se, such as plasticizers, nucleating agents, etc., within a range that does not impair gas barrier properties. lubricant, stabilizer,
Antioxidants, ultraviolet absorbers, pigments, fillers, etc. can be added according to known formulations. The crystalline polyamide used in the present invention should generally have a molecular weight sufficient to form a film. This polyamide is prepared using concentrated sulfuric acid (98% H ₂ SO ₄ )
It is preferable that the viscosity is 0.65 to 1.6 dl/g when measured at a temperature of 30° C. and a concentration of 0.50 g/100 ml using as a solvent. The crystalline polyamide used in the present invention has the above-mentioned amide skeleton chain structure and has high crystallinity, so it exhibits high gas barrier properties, and this high gas barrier property is impaired even under high humidity conditions. Never get caught. For example, this polyamide
It has a significantly lower oxygen permeability coefficient than that of nylon 6.6, and the oxygen permeability coefficient at 25℃ and 0%RH is
It is smaller than 2.5×10 ^-13 cccm/cm ²・sec・cmHg, and its value is at most 25 even under high humidity at 25℃ and 97%RH.
%, and the dependence of the oxygen permeability coefficient on humidity is small. This also applies to gases other than oxygen, such as carbon dioxide and nitrogen. The molding into a container is carried out by blow molding, in which the above-mentioned thermoplastic polyamides alone or in combination are melt-extruded into a parison, the extruded parison is supported in a split mold, and a fluid is blown into the inside of the mold. Therefore, it is easily obtained. In addition, in order to improve the impact resistance and transparency of the container, a parison or preform is manufactured in advance by melt extrusion or injection molding, and this parison or preform is stretched at a temperature below its melting point. temperature, it is mechanically stretched in the axial direction and stretched in the circumferential direction by blowing fluid,
It is also possible to use a plastic container with biaxial molecular compounding. Furthermore, the present invention is advantageously applied to wide-mouthed containers such as wide-mouthed bottles made by drawing or stretching a sheet or film previously formed from the polyamide by vacuum forming, pressure forming, plug-assisted pressure forming, etc. be able to. The wall thickness of plastic containers can be varied over a wide range, from relatively thin containers such as so-called squeeze containers or lightweight cups to relatively thick containers such as rigid containers.
That is, the mass per internal volume may be selected from a range of 0.001 to 5 g/ml depending on the end use. This highly crystalline polyamide can be used alone as a packaging container, but also in the form of a laminate with other resins such as conventional container-forming resins such as polyethylene terephthalate, polycarbonate nylons, or polyolefins. It can be used as a container. If sufficient adhesiveness cannot be obtained between the two due to the combination of resins or molding or processing conditions, a blend of both resins or other thermal adhesives may be used.
For example, by interposing a copolyester-based thermal adhesive, a urethane-based adhesive, etc., a satisfactory laminated structure can be obtained. Further, although this highly crystalline polyamide has some difficulty in moldability and processability, by forming it into a laminate, it becomes possible to improve moldability and processability. Formation of the laminate is preferably carried out by multilayer coextrusion. According to this multilayer coextrusion, since both resins are well mixed at the adhesive interface between the two resins, a laminated structure with particularly excellent adhesive strength can be obtained. For multilayer coextrusion, the above-mentioned crystalline polyamide and other thermoplastic resin are extruded through a multilayer die, with an adhesive resin interposed between them if necessary, to produce films, sheets, bottle pipes,
Molded into the shape of a bottle preform, etc. The laminate can be formed by a method called sandwich coating, lamination, or extrusion coating. For example, a laminate can be produced by extruding an adhesive into a thin film between a pre-formed crystalline polyester film and another resin film, and pressing them under heat if necessary. Furthermore, when molding a multilayer preform, a method of manufacturing a multilayer preform by successively injecting crystalline polyamide and other resins may also be adopted. The laminate can be molded into a container by the molding method described above. When polyethylene terephthalate, polycarbonate, or nylon is selected as the other resin to be laminated, a container with excellent creep resistance and transparency can be obtained, and when polyolefin is selected, flexibility and pliability are obtained. A container with excellent properties such as flexibility and squeezing properties can be obtained. When crystalline polyamide is A and other resin is B, A/
Any laminated structure such as B, B/A/B, etc. can be taken. From the viewpoint of preventing gas permeation, the thickness of the crystalline polyamide is preferably in the range of 2 μm or more, particularly 5 μm or more. According to the present invention, since gas barrier properties are excellent and humidity dependence of gas barrier properties is small,
In addition to providing a container with excellent long-term storage stability for the contents, this polyamide also has excellent heat resistance, hot water resistance, creep resistance, impact resistance, and mechanical strength, so it can be used as a container even if it is relatively thin. It is an object of the present invention to provide a packaging container that satisfies various characteristics and that allows the contents to be subjected to hot filling or retort sterilization. The invention is illustrated by the following example. Example 1 A mixture of 65 parts of paraxylylenediamine adipate and 35 parts of hexamethylenediamine adipate was prepared as a nylon salt by reprecipitation from an aqueous solution in the presence of an excess of adipic acid. Melt by heating to 220~230℃ under air flow, 1~
The temperature began to rise to 300°C over 1.5 hours, polymerization was carried out at normal pressure for 2 hours, and then polymerization was carried out under vacuum of 1 to 5 mmHg for 0.5 to 1 hour. The obtained copolymerized nylon (poly(paraxylylene adipamide/hexamethylene adipamide), HBR-1, has a reduced viscosity of 0.92 at 30°C in a 0.50 g/100 ml concentrated sulfuric acid (98%) solution. dl/g
According to nuclear magnetic resonance absorption spectrum (NMR) analysis, the average ratio of symmetrical cyclic hydrocarbon groups to all cyclic hydrocarbon groups (hereinafter simply referred to as symmetrical ring ratio) is 99%, and the M/R ratio is 9.4. It was hot. Next, this lumpy resin is hot pressed ~
After forming into a 50μm film, it is rapidly cooled in water.
It was vacuum dried at room temperature and the following physical properties were measured. The melting point (Tm) and glass transition temperature (Tg) of the crystal were measured by differential thermal analysis using a Perkin-Elmer DSC-2C at a heating rate of 10°C/10°C, respectively.
min, 40℃/min, Tm=295℃,
Tg=103℃. In addition, the oxygen permeability coefficient Po ₂ at 25℃, 25℃ is calculated from “Diffusion in Polymers”
J. Crak, GS Park Ed. Academic Press London
and New York (1968) Chap. 1, and measured using the high vacuum method.
It was 1.5×10 ^-13 cc・cm/cm ²・sec・cmHg. On the other hand, metaxylylenediamine adipate
65 parts, hexamethylenediamine adipate 35
Copolymerized nylon (poly(methaxylylene adipamide/hexamethylene adipamide), CR-
1) was polymerized. The reduced viscosity of this polymer is
It was 0.86 dl/g, the symmetry ring rate was 1%, and the M/R ratio was 620. In addition, when the physical properties were measured using the same method as above, Tm252℃, Tg64℃, Po ₂ , 25℃4.5×10 ^-13
It was cc・cm/cm・sec/cmHg. Next, polyethylene terephthalate resin (PET) having an intrinsic viscosity of 0.91 dl/g at 30°C in a mixed solvent with a weight ratio of phenol/tetrachloroethane of 50/50 was used as the outermost layer resin, and HBR-1 (invention 1 ) and CR-1 (Comparative Example 3) were used as the intermediate layer resins, and a urethane adhesive resin layer (ADH ₁ ) was placed between the outermost layer and the intermediate layer. Extruder for outermost layer with built-in flight type screw, diameter 38mm, effective length 950mm
An extruder for the intermediate layer with a built-in full-flight screw of 40 mm in diameter and an effective length of 1000 mm, an extruder for the adhesive layer that has a built-in full-flight screw with a diameter of 40 mm and an effective length of 1000 mm, a feed pipe, and an extrusion combining three types of 5-layer dies. Using molding equipment, PET/
ADH ₁ /HBR-1/ADH ₁ /PET, PET/
A 5-layer pipe of ADH ₁ / CR-1 / ADH ₁ / PET was melt-extruded and pre-blow molded in a split mold, with an inner diameter of 27.7 mm, a length of 138 mm, and an average wall thickness.
A 3.5mm bottomed preform was molded. Furthermore, this preform's PET/ADH ₁ /HBR-1/
ADH ₁ /PET, PET/ADH ₁ /CR-1/
The weight ratio of ADH ₁ /PET is 50/3/
Molding was carried out by setting extrusion conditions so that the temperature was 9/3/35. This bottomed preform is heated with an infrared heater, and the maximum temperature of the bottomed preform is 108℃,
After setting the minimum temperature to 98℃, it was stretch-blow-molded using a sequential biaxial stretch blow molding method so that the axial stretch ratio was 2.0 times and the circumferential stretch ratio was 3.0 times, and the average wall thickness was 0.40 mm.Contents Product is 1040c.c., bottle weight is 36g
Bottles were manufactured. As Comparative Example 1, a bottomed preform with the same dimensions as above was molded using only polyethylene terephthalate (PET), and then a biaxially stretched blow bottle with the same dimensions was manufactured in the same manner as above. Furthermore, as Comparative Example 2, the vinyl alcohol content was 69 mol% and the residual vinyl ester concentration was 0.6.
An ethylene-vinyl alcohol copolymer resin (PEVA) with a mol% of 182°C and a melting point is used as the intermediate layer resin,
_PET /
ADH ₁ / PEVA / ADH ₁ / PET 5-layer pipe,
The extrusion conditions were set so that the composition ratio by weight was 50/3/9/3/35. Furthermore, a biaxially stretched blow bottle having the same dimensions was manufactured from this preform in the same manner as above. These bottles were evaluated for bolt transparency (haze), oxygen permeability, and drop impact strength using the methods shown in the footnotes of Table 1. Furthermore, after filling the synthetic carbonated beverage so that the gas volume is 4.0 vol at room temperature,
They were stored in an atmosphere of 30°C and relative humidity (RH) of 35% and 80%, respectively, and the gas volume was measured after 3 months, and the rate of decrease based on the initial value of 4.0 vol was expressed as a percentage. Table 1 shows these results.

[Table] Example 2 Using the diamine and dibasic acid components shown in Table 2 as raw materials, a nylon salt was prepared by the reprecipitation method according to the procedure described in Example 1, and then each resin was prepared by melt polymerization. Obtained. The temperature, time, etc. in each step depend on the melting point of each nylon salt and the resin to be produced, and the reduced viscosity at 30℃ while melting concentrated sulfuric acid (98%) with a degree of polymerization of 0.50 g/100 ml is 0.7 to 1.2 dl. /g
The range was selected accordingly. In these compositions, the desired resin was polymerized at a polymerization temperature of 270 to 390°C and a polymerization time of 4 to 6 hours. Table 2 shows rough values estimated from the monomers charged as the composition, and further shows the symmetrical ring ratio and M/R ratio determined from the analysis results of NMR and gas chromatography. In addition, as described in Example 1, film samples were prepared, and the melting point Tm, glass transition Tg temperature, and oxygen permeability coefficient Po ₂ at 25°C, 25°C (cc cm/cm ²・sec・
cmHg) was measured. Next, the intrinsic viscosity at 30℃ in a mixed solvent with a weight ratio of phenol/tetrachloroethane of 50/50 is
A polyester layer made of 0.85 dl/g polyethylene terephthalate (PET), a separate layer (HBR layer) made of each resin shown in Table 2, and a urethane adhesive layer (ADH ₂ ) as an intermediate layer between them.
An extruder with a built-in screw with a diameter of 30 mm and an effective length of 1300 mm is used as an extruder for the adhesive layer, and an extruder with a built-in screw with a diameter of 30 mm and an effective length of 750 mm is used as an extruder for the adhesive layer. The extruder for the HBR layer is used as the extruder for the HBR layer, and the total thickness of the PET layer/ADH ₂ /HBR layer is
A two-layer sheet with a thickness of 2.07 mm (PET/ADH ₂ /HBR = 85/5/10 thickness ratio) and a width of 400 mm was molded. The sheet was sufficiently rapidly cooled to prevent the PET layer from crystallizing (the density of the PET layer in the obtained sheet was
It was 1.339g/ ^cm2 or less. ), and since the sheet could not be rolled, it was cut into lengths of 1000 mm using a traveling cutter immediately after forming. Next, the obtained sheet was heated to the Tg of the HBR layer resin + 10℃ using an infrared heater, and then molded using a plug assist vacuum/pressure forming machine to form a sheet with a flange width of 5 mm, mouth inner diameter of 60 mm, bottom outer diameter of 40 mm, and height of 80 mm.
It was molded into a cup with a PET layer as the inner wall. For these cups, Table 1 of Example 1 above
Oxygen permeability was measured according to the method described in footnote *2 under conditions where the humidity outside the container was adjusted to a relative humidity of 35% and 80%, respectively.

【table】

【table】

[Table] Example 3 Trans-4-aminocyclohexanecarboxylic acid
A mixture of 50 parts of caprolactam and 50 parts of caprolactam was melt-polymerized in the presence of a water catalyst, followed by hot water extraction to remove monomers and oligomers, and further heated at 100°C.
Resin pellets were obtained by drying in a nitrogen stream (HBR-14). The degree of polymerization of this copolymer is 0.50g/
The reduced viscosity at 30°C in 100 ml of concentrated sulfuric acid (98%) solution was 0.87 dl/g, and NMR analysis showed that the symmetrical reduction was 99% and the M/R ratio was 6.8. In addition, when the physical properties of this resin were measured according to Example 1,
Tm279℃, Tg84℃, Po ₂ , 25℃2.0×10 ¹³ cc・
The temperature was cm/cm ²・sec・cmHg. Using this resin as an intermediate layer, three types of five-layer bottles with the same dimensions and basis weight were prepared according to the same method as in Example 1 (Invention 14), and the same evaluation was performed.
The transparency of this bottle is 4.7% and the oxygen permeability is 3.0c.
c./m ²・day・atm, drop impact strength is no problem at all, and carbon dioxide loss is 8.2% at RH35%, RH80
% showed good performance at 9.9%. Example 4 Using the resin HBR-4 shown in Example 2 (invention 15), HBR-13 and nylon 6 (weight ratio 50/50 with a reduced viscosity of 0.91 dl/g measured by the above method) were used.
(Invention 16), molding a bottomed preform with the same dimensions as in Example 1,
Next, a single-layer biaxially stretched blow bottle having the same dimensions was created. When this bottle was evaluated for each item listed in the footnotes of Table 1, the bottle of the present invention had a transparency of 2.4%, an oxygen permeability of 0.5cc/ ^m2・day・atm, no damage due to drop impact, and a carbon dioxide loss of RH35.
% is 2.5%, RH80% is 3.0%, and the bottle of the present invention 16 has a transparency of 9.4% and an oxygen permeability of 3.6cc/m ²・day・
ATM, there was no damage due to drop impact, and carbon dioxide gas loss was 8.1% at RH35% and 11.8% at RH80%, showing good performance. Example 5 Nylon 66 resin with a reduced viscosity of 1.02 dl/g at 30°C in a 0.50 g/100 ml concentrated sulfuric acid (98%) solution was used as the outer layer, and HBR-10 in Example 2 was used as the inner layer. An extruder with a built-in screw with a diameter of 50 mm and an effective length of 1300 mm is used as an extruder for nylon 66 layers, an extruder with a built-in screw with a diameter of 30 mm and an effective length of 750 mm is used as an extruder for HBR layers, and a feed for two layers is used. Block adapter, single manifold T
A two-layer film with a total thickness of 520 μm (nylon 66/HBR-10 = 85/15 thickness ratio) and a width of 300 mm is made using a mold die and a three-roll film forming/pulling machine. Mold and further 2
A two-layer stretched two-layer film with a total thickness of 60 μm was produced by axial stretching. Further, a 30 μm thick polypropylene (PP) film was laminated on the two-layer film side via a urethane adhesive to obtain a multilayer film having a composition of nylon 66/HBR-10/PP. Next, this film piece of 300 mm x 200 mm was heat-sealed on three sides so that the PP layer was on the inside to create a bag (Invention 17). This was filled with bonito flavored flakes, the other half was heat-sealed, and then retort sterilized at 145°C for 2 minutes, and then stored at room temperature. Even after approximately one year of storage, not only was there no deterioration, but there was also almost no browning of the contents, which is thought to occur when a large amount of oxygen permeates into the bag. Example 6 Polycarbonate (0.5g/
The reduced viscosity of dl in tetrahydrofuran solution at 25℃ is
1.3 dl/g), and polystyrene (reduced viscosity of 0.5 g/dl cyclohexane solution at 35°C is 0.6 dl/g)
were used, and the resin in Example 2 was used as the intermediate layer.
Using HBR-5, cups with two types and three layers having the same layer composition ratio and dimensions were molded according to the same method as in Example 2 (Invention No. 18 and Invention No. 19, respectively). When the oxygen permeability of these cups was measured in the same manner as in Example 2, it was found that in the present invention 18, RH 35
10.3 at %, 14.1 at RH80%, RH35% in Invention 19
and 12.4RH and 17.3 at 80% (both cc/m ²・day・
atm) and both had significantly improved barrier properties compared to the case where resin alone was used for the inner and outer layers.

Claims (1)

[Scope of Claims] 1. At least one combination of each of the following diamine components and dibasic acid components (a) trans-1,4-cyclohexane bis(methylamine) or 1,4-based mainly trans-1,4-cyclohexane bis(methylamine)
- Cyclohexane bis(methylamine) and succinic acid, adipic acid, sebacic acid or decanedicarboxylic acid (b) paraxylylene diamine or a diamine mixture mainly containing paraxylylene diamine and metaxylylene diamine or hexamethylene diamine and adipic acid , sebacic acid or 1,4-cyclohexane dimethylene dicarboxylic acid (c) bis(aminoethyl)benzene and succinic acid (d) decamethylene diamine and phenylene diacetic acid or (e) combination of trans-4-aminocyclohexane carboxylic acid and caprolactam is a crystalline polyamide mainly composed of, and contains an alkylene group based on each component of the above-mentioned combination and a symmetrical or asymmetrical divalent cyclic hydrocarbon group in the amide skeleton chain, and has a symmetrical cyclic carbonization per total cyclic hydrocarbon group. The average proportion of hydrogen groups is 30 mol% or more, the average number of linear methylene units per symmetrical cyclic hydrocarbon group is 4 to 15, and the glass transition temperature (Tg)
A packaging resin container whose wall is made of crystalline polyamide with a temperature of 70°C or higher and a melting point of 370°C or lower.