JP6961957B2 - Stretched molded product and method for producing stretched molded product - Google Patents

Description

The present invention relates to a stretch-molded article and a method for producing a stretch-molded article.

Conventionally, an inorganic filler has been blended with a polyamide resin.
For example, in Patent Document 1, at least one polyamide resin selected from the group consisting of (A) nylon 6 and nylon 6,6 resin, and (B) a diamine component and / or a dicarboxylic acid component constituting the polyamide resin are aromatic. It contains an aromatic polyamide resin which is a compound having a group ring, a polyolefin resin modified with (C) α, β-unsaturated carboxylic acid or a derivative thereof, and (D) a ceramic whisker having an aspect ratio of 10 or more and 100 or less. A fiber-reinforced polyamide-based resin composition is disclosed.

Japanese Unexamined Patent Publication No. 07-188550

Patent Document 1 describes that when an inorganic filler is added to a polyamide resin, a polyamide resin composition having low hygroscopicity, excellent mechanical strength, and good surface smoothness can be obtained. However, it cannot be said that the mechanical strength, particularly the tensile elastic modulus, is sufficient. In addition, the polyamide resin used for the housing of electronic device parts and the packaging of foods and pharmaceuticals is also required to have an oxygen barrier property.
An object of the present invention is to solve such a problem, and an object of the present invention is to provide a molded product having a high tensile elastic modulus and an excellent oxygen barrier property, and a method for producing the molded product.

As a result of studies by the present inventor based on this problem, a polyamide resin composition in which a ceramic whiskers are mixed with a polyamide resin having a relatively long semi-crystallization time is stretched to obtain a high tensile elastic modulus. We have found that a molded product having excellent oxygen barrier properties can be obtained, and have completed the present invention.
Specifically, the above problems were solved by the following means <1>, preferably by <2> to <15>.
<1> A polyamide resin composition containing 5 to 25 parts by mass of a ceramic whisker with respect to 100 parts by mass of a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2. Stretched molded body formed from.
<2> The polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 50 mol% or more of the diamine-derived structural unit is derived from xylylene diamine, and the dicarboxylic acid-derived structural unit. The stretched molded product according to <1>, wherein 50 mol% or more of the above is derived from α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms.
<3> The stretched molded product according to <2>, wherein the xylylenediamine is composed of 30 to 100 mol% of metaxylylenediamine and 0 to 70 mol% of paraxylylenediamine.
<4> The stretched molded article according to <2> or <3>, wherein 50 mol% or more of the constituent unit derived from the dicarboxylic acid is derived from at least one of sebacic acid and adipic acid.
<5> The stretched molded product according to any one of <1> to <4>, wherein the phosphorus atom concentration in the stretched molded product is 0.1 to 10 mass ppm.
<6> The stretch-molded article according to any one of <1> to <5>, wherein the ceramic whiskers have an aspect ratio of 10 to 100.
<7> The stretch-molded article according to any one of <1> to <6>, wherein the number average fiber length of the ceramic whiskers is 5 to 20 μm.
<8> 90% by mass or more of the polyamide resin composition is composed of a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2 and a ceramic whisker. The stretched molded product according to any one of <1> to <7>.
<9> The stretched molded product according to any one of <1> to <8>, wherein the stretched molded product is a stretched film.
<10> The stretched molded product according to <9>, wherein the stretched film has a thickness of 1 to 100 μm.
<11> The tensile elastic modulus of 5 GPa or more when measured under the conditions of a width of 10 mm of a test piece, a distance between chucks of 100 mm, and a tensile speed of 100 mm / min according to JIS K 7127, according to <9> or <10>. Stretched molded product.
<12> Described in any one of <1> to <11>, wherein the oxygen permeability coefficient at 23 ° C. and 60% relative humidity is 0.045 (cc · mm) / (m ^{2 · day · atm) or less.} Stretched molded product.
<13> A polyamide resin composition containing 5 to 25 parts by mass of a ceramic whisker with respect to 100 parts by mass of a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2. A method for producing a stretched molded product, which comprises stretching.
<14> The method for producing a stretched molded product according to <13>, wherein the stretched molded product is a film.
<15> The method for producing a stretched molded product according to <14>, which comprises stretching the stretched molded product so that the final draw ratio is 3 times or more.

INDUSTRIAL APPLICABILITY According to the present invention, it has become possible to provide a stretch-molded article having a high tensile elastic modulus and an excellent oxygen barrier property, and a method for producing a stretch-molded article.

It is the schematic which shows an example of the process of manufacturing the stretch film of this invention.

Hereinafter, the contents of the present invention will be described in detail. In addition, in this specification, "~" is used in the meaning that the numerical values described before and after it are included as the lower limit value and the upper limit value.

The stretched molded article of the present invention contains 5 to 25 parts by mass of a ceramic whisker with respect to 100 parts by mass of a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2. It is characterized by being formed from a polyamide resin composition containing the mixture. With such a configuration, a stretched molded product having a high tensile elastic modulus and an excellent oxygen barrier property can be obtained.
In general, it is known that when an inorganic filler is added to a thermoplastic resin, stretching becomes difficult. However, in the present invention, the thermoplastic resin is a thermoplastic resin containing an inorganic filler by using a polyamide resin in which semi-crystallization proceeds relatively slowly and by adding a small amount of ceramic whisker as an inorganic filler. Nevertheless, it was successfully stretched. Surprisingly, with such a configuration, the tensile elastic modulus is remarkably improved and the oxygen barrier property is also improved. The reason for this is that by using a ceramic whisker for the polyamide resin having a relatively long semi-crystallization time, the semi-crystallization rate of the polyamide resin composition containing the inorganic filler is suppressed from becoming excessively high, and the ceramic-based whiskers are used. Since the whiskers are thin and short fibers, it is presumed that the average surface area of the inorganic filler is small, the interface between the polyamide resin and the inorganic filler is less likely to peel off, and stretching is possible. Further, since the ceramic whiskers have a high aspect ratio, it is presumed that the orientation direction is adjusted during stretching, the tensile elastic modulus is remarkably improved, and the oxygen barrier property is also improved.

<Polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2>
In the present invention, a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2 (hereinafter, may be referred to as “specific polyamide resin”) is used. If the semi-crystallization time is less than 15 seconds, crystallization proceeds quickly and it becomes difficult to stretch the polyamide resin. Further, if the semi-crystallization time exceeds 300 seconds, it takes time to fix the heat, which is not realistic from the viewpoint of productivity.
The lower limit of the semi-crystallization time is preferably 20 seconds or more, more preferably 25 seconds or more, and even more preferably 28 seconds or more. The upper limit of the semi-crystallization time is preferably 250 seconds or less, more preferably 200 seconds or less, 100 seconds or less, 75 seconds or less, and 50 seconds or less from the viewpoint of improving production efficiency.
The semi-crystallization time is measured according to the method described in Examples described later.

The specific polyamide resin is not particularly specified as long as it satisfies the semi-crystallization time, but a polyamide resin containing an aromatic ring in the molecule is preferable, and a semi-aromatic polyamide resin is more preferable. Here, the semi-aromatic polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 30 to 70 mol% of the total structural unit of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit is 30 to 70 mol%. It means that it is a structural unit containing an aromatic ring, and it is preferable that 40 to 60 mol% of the total structural unit of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit is the structural unit containing an aromatic ring. By using such a semi-aromatic polyamide resin, the mechanical strength of the obtained stretched molded product can be further increased.

Examples of the semi-aromatic polyamide resin include polyamide 6T, polyamide 9T, and XD-based polyamide resin, which will be described in detail later, and XD-based polyamide resin is preferable.
The XD-based polyamide resin that can be used in the present invention is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 50 mol% or more of the diamine-derived structural unit is derived from xylylene diamine. A polyamide resin in which 50 mol% or more of the acid-derived constituent unit is derived from an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms is preferable.

The XD-based polyamide resin is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more, still more preferably 99 mol% or more of the constituent unit derived from diamine. The above is derived from at least one of xylylene diamines, and the constituent units derived from dicarboxylic acid are preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more. , More preferably 99 mol% or more, is derived from at least one of α, ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms.

The xylylenediamine that can be used as the raw material diamine component of the XD-based polyamide resin is preferably composed of 30 to 100 mol% of metaxylylenediamine and 0 to 70 mol% of paraxylylenediamine, preferably 40 to 100 mol%. It is more preferably composed of m-xylylenediamine of 0 to 60 mol%, and further preferably composed of 70 to 100 mol% of m-xylylenediamine and 0 to 30 mol% of paraxylylenediamine. ..

Examples of diamines other than xylylenediamine that can be used as the raw material diamine component of the XD-based polyamide resin include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, and nonamethylene. Diamines, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, aliphatic diamines such as 2,4,4-trimethylhexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1 , 4-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) ) Examples of alicyclic diamines such as decalin and bis (aminomethyl) tricyclodecane, diamines having an aromatic ring such as bis (4-aminophenyl) ether, paraphenylenediamine and bis (aminomethyl) naphthalene can be exemplified. It can be used alone or in combination of two or more.
When a diamine other than xylylenediamine is used as the diamine component, it is used in an amount of 30 mol% or less, preferably 1 to 25 mol%, and more preferably 5 to 20 mol% of the constituent unit derived from diamine.

The α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms used as the raw material dicarboxylic acid component of the XD-based polyamide resin is preferably an α, ω-linear aliphatic dicarboxylic acid having 6 to 16 carbon atoms. Α, ω-linear aliphatic dicarboxylic acids having 6 to 10 carbon atoms are more preferable. Examples of α, ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms include succinic acid, glutaric acid, pimeric acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, dodecanedioic acid and the like. The aliphatic dicarboxylic acid of the above can be exemplified, and one kind or a mixture of two or more kinds can be used. Among these, at least one of adipic acid and sebacic acid is preferable, and adipic acid is particularly preferable, because the melting point of the XD-based polyamide resin is in an appropriate range for molding.

Examples of the dicarboxylic acid component other than the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid and orthophthalic acid, 1,2-naphthalenedicarboxylic acid, 1, 3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3- Examples of naphthalenedicarboxylic acids such as isomers such as naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid can be exemplified, and one kind or a mixture of two or more kinds can be used.

When a dicarboxylic acid other than α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms is used as the dicarboxylic acid component, terephthalic acid and / or isophthalic acid is used from the viewpoint of molding processability and barrier property. Is preferable. The total proportions of terephthalic acid and / or isophthalic acid are preferably 30 mol% or less of the dicarboxylic acid-derived constituent units, more preferably 1-30 mol%, particularly preferably 5-20 mol%. be.

In the present invention, "composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit" means that the amide bond constituting the XD-based polyamide resin is mainly formed by the bond between the dicarboxylic acid and the diamine. say. Further, the XD-based polyamide resin contains other sites such as a terminal group in addition to the dicarboxylic acid-derived structural unit and the diamine-derived structural unit. Further, it may contain a repeating unit having an amide bond not derived from the bond between the dicarboxylic acid and the diamine, a trace amount of impurities, and the like. Specifically, the XD-based polyamide resin contains lactams such as ε-caprolactam and laurolactam, and aminocapron as components constituting the polyamide resin in addition to the diamine component and the dicarboxylic acid component, as long as the effects of the present invention are not impaired. An aliphatic aminocarboxylic acid such as an acid or aminoundecanoic acid can also be used as a copolymerization component. In the present invention, preferably 90% by mass or more, more preferably 95% by mass or more of the XD-based polyamide resin is a diamine-derived structural unit or a dicarboxylic acid-derived structural unit.

The specific polyamide resin used in the present invention preferably has a phosphorus atom concentration of 0.1 to 10 mass ppm, more preferably 1 to 8 mass ppm. Within such a range, both prevention of yellowing of the film and improvement of continuous productivity by suppressing clogging of the polymer filter are achieved, and the effect of the present invention is more effectively exhibited.
The stretched film used in the present invention preferably has a phosphorus atom concentration in the above range, but the phosphorus atom is usually derived from a polyamide resin.

The specific polyamide resin used in the present invention preferably has a number average molecular weight (Mn) of 6,000 to 30,000, more preferably 8,000 to 28,000, and even more preferably 9,000 to 26. It is 000. Within such a range, the molding processability becomes better.

The number average molecular weight (Mn) referred to here is _{the following formula from the terminal amino group concentration [NH 2} ] (μ equivalent / g) and the terminal carboxyl group concentration [COOH] (μ equivalent / g) of the polyamide resin. It is calculated.
Number average molecular weight (Mn) = 2,000,000 / ([COOH] + [NH ₂ ])

The specific polyamide resin used in the present invention preferably has a molecular weight distribution (weight average molecular weight / number average molecular weight (Mw / Mn)) of 1.8 to 3.1. The molecular weight distribution is more preferably 1.9 to 3.0, still more preferably 2.0 to 2.9. By setting the molecular weight distribution in such a range, it tends to be easy to obtain a stretched body having excellent mechanical properties.
The molecular weight distribution of the specific polyamide resin can be adjusted by appropriately selecting, for example, the type and amount of the initiator and catalyst used at the time of polymerization and the polymerization reaction conditions such as reaction temperature, pressure and time. Further, it can be adjusted by mixing a plurality of specific polyamide resins having different average molecular weights obtained under different polymerization conditions, or by fractionally precipitating the specific polyamide resin after polymerization.

The molecular weight distribution can be determined by GPC measurement. Specifically, Tosoh's "HLC-8320GPC" is used as an apparatus, and Tosoh's "TSK gel Super HM-H" is used as a column, and an eluent is used. Measured under the conditions of hexafluoroisopropanol (HFIP) having a sodium trifluoroacetate concentration of 10 mmol / L, a resin concentration of 0.02% by mass, a column temperature of 40 ° C., a flow velocity of 0.3 mL / min, and a refractive index detector (RI), and standard. It can be obtained as a value converted to polymethylmethacrylate. In addition, the calibration curve is prepared by dissolving 6 levels of PMMA in HFIP and measuring.

The method for producing the specific polyamide resin can be described in paragraphs 0052 to 0053 of JP-A-2014-173196, and these contents are incorporated in the present specification.

In the present invention, the lower limit of the melting point (Tm) of the specific polyamide resin is preferably 150 ° C. or higher, more preferably 180 ° C. or higher, further preferably 200 ° C. or higher, and 210 ° C. The above is more preferable, and the temperature may be 220 ° C. or higher. The upper limit of the melting point of the specific polyamide resin is preferably 350 ° C. or lower, more preferably 300 ° C. or lower, and further preferably 250 ° C. or lower.
The glass transition temperature (Tg) of the specific polyamide resin preferably has a lower limit of 50 ° C. or higher, more preferably 55 ° C. or higher, may be 60 ° C. or higher, and further 70. It may be ℃ or more and 80 ℃ or more. On the other hand, the upper limit of the glass transition temperature of the specific polyamide resin is preferably 100 ° C. or lower, more preferably 90 ° C. or lower. Within this range, the heat resistance tends to be better.
The melting point and glass transition temperature of the polyamide resin are measured according to the methods described in Examples described later.

The lower limit of the content of the specific polyamide resin in the polyamide resin composition is preferably 70% by mass or more, more preferably 80% by mass or more, and further preferably 85% by mass or more. The upper limit of the amount of the specific polyamide resin in the polyamide resin composition is preferably 95% by mass or less.
The specific polyamide resin may contain only one type, or may contain two or more types. When two or more kinds are included, the total amount is preferably in the above range.

The above-mentioned polyamide resin composition may contain a polyamide resin other than the specific polyamide resin. Examples of such other polyamide resins include polyamide 4, polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyhexamethylene isophthalamide (polyamide 6I), and polyamide 66 / 6T. Examples thereof include polyamide 9MT and polyamide 6I / 6T. Among these, when other polyamide resins are contained, at least one of polyamide 6 and polyamide 66 is preferable.
The content of the other polyamide resin in the above-mentioned polyamide resin composition is preferably 5 to 50 parts by mass, more preferably 5 to 40 parts by mass with respect to 100 parts by mass of the specific polyamide resin when blended.
However, it is preferable that the above-mentioned polyamide resin composition substantially does not contain other polyamide resins. The term "substantially free" means that the content of the other polyamide resin in the above-mentioned polyamide resin composition is 3% by mass or less, preferably 1% by mass or less of the specific polyamide resin. With such a configuration, the effect of the present invention is more effectively exhibited.

<Ceramic whiskers>
The above-mentioned polyamide resin composition contains a ceramic whiskers. Ceramic whiskers are short fibrous or needle-like crystals of inorganic compounds such as oxides, carbides, nitrides, and borides, whether metal or non-metal.
Specifically, as raw materials for ceramic whisker, zinc oxide, potassium titanate, aluminum borate, silicon carbide, silicon nitride, magnesium oxide, magnesium borate, basic magnesium sulfate, titanium diborate, graphite, calcium sulfate , Α-Alumina, chrysotile, wallastonite, calcium carbonate, aluminum silicate, calcium silicate, titanium oxide, zirconium oxide. In the present invention, potassium titanate whiskers and aluminum borate whiskers are preferred.

The ceramic whiskers used in the present invention have been subjected to known surface treatments (for example, surface treatments with surface treatment agents such as metal oxides, silane coupling agents, titanium coupling agents, organic acids, polyols, and silicones). It may be a thing. By applying such a surface treatment, it becomes possible to improve the compatibility and dispersibility with other components in the above-mentioned polyamide resin composition.

The ceramic whiskers preferably have an aspect ratio of 10 to 100, more preferably 10 to 70, still more preferably 10 to 40, and even more preferably 15 to 40. By setting it in such a range, the appearance of the obtained molded product can be further improved.
For ceramic whiskers, the lower limit of the number average fiber length is preferably 5 μm or more, and more preferably 10 μm or more. The upper limit of the number average fiber length is preferably 20 μm or less, and more preferably 18 μm or less. By setting it in such a range, the appearance of the obtained molded product can be further improved.
For ceramic whiskers, the lower limit of the number average fiber diameter is preferably 0.1 μm or more, and more preferably 0.3 μm or more. The upper limit of the number average fiber diameter is preferably 10 μm or less, more preferably 5.0 μm or less, further preferably 3.0 μm or less, and more preferably 1.5 μm or less. It is more preferably 1.0 μm or less, and even more preferably 1.0 μm or less. By setting it in such a range, the appearance of the obtained molded product can be further improved.
The number average fiber length and the number average fiber diameter of the ceramic whiskers can be measured by observation with an electron microscope in a state of being dispersed in a solvent such as alcohol. Usually, the average value of 100 pieces is taken.

The ceramic whiskers preferably have a Mohs hardness of 2.5 to 10.0, more preferably 2.5 to 8.0.
The ceramic whiskers preferably have a specific gravity of 2.0 to 4.0, more preferably 2.2 to 3.8, and even more preferably 2.5 to 3.8. By using a ceramic whisker in such a range, the volume ratio in the stretched molded product can be reduced, the volume of the specific polyamide resin in the stretched molded product can be increased, and the appearance of the stretched molded product tends to be further improved. ..

Examples of commercially available ceramic whiskers include the trade names "Panatetra WZ-0501", "Panatetra WZ-0501L", "Panatetra WZ-0511", "Panatetra WZ-0511L", "Panatetra WZ-0531", and "Panatetra WZ-0531". WZ-05E1 "," Panatetra WZ-05F1 "(above, zinc oxide ceramic whiskers, manufactured by Amtec Co., Ltd.); trade names" FTL-100 "," FTL-110 "," FTL-200 "," FTL- 300 "(above, titanium oxide ceramic whisker, manufactured by Ishihara Sangyo Co., Ltd.); trade name" TOFIX-P "(titanium oxide ceramic whisker, manufactured by Toho Titanium Co., Ltd.); trade name:" Tismo D-101 " Commercial products such as (potassium titanate whiskers, manufactured by Otsuka Chemical Co., Ltd.); trade name "Albolex YS3" (aluminum borate whiskers, manufactured by Shikoku Kasei Kogyo Co., Ltd.) can also be used.

The lower limit of the content of the ceramic whiskers in the above-mentioned polyamide resin composition is 5 parts by mass or more, preferably 6 parts by mass or more, with respect to 100 parts by mass of the specific polyamide resin. The upper limit of the content is 25 parts by mass or less, preferably 20 parts by mass or less, more preferably 19 parts by mass or less, further preferably 18 parts by mass or less, and further 10 parts by mass with respect to 100 parts by mass of the specific polyamide resin. It may be 10 parts or less and 8 parts by mass or less.
The ceramic whiskers contained in the above-mentioned polyamide resin composition may be only one kind or two or more kinds. In the case of two or more types, the total amount is preferably in the above range.

Further, the above-mentioned polyamide resin composition may or may not contain an inorganic filler other than the ceramic whiskers. In the present invention, in the above-mentioned polyamide resin composition, the blending amount of the inorganic filler other than the ceramic whiskers is preferably 10% by mass or less, more preferably 5% by mass or less of the blending amount of the ceramic whiskers. It is more preferably 1% by mass or less. Within such a range, the effect of the present invention is more effectively exhibited.

<Other ingredients>
The above-mentioned polyamide resin composition further includes a thermoplastic resin other than the polyamide resin, a stabilizer such as an antioxidant and a heat stabilizer, a hydrolysis resistance improver, and a weather resistance, as long as the object and effect of the present invention are not impaired. Add additives such as stabilizers, matting agents, UV absorbers, nucleating agents, plasticizers, dispersants, flame retardants, antistatic agents, anticoloring agents, antigelling agents, coloring agents, and mold release agents. Can be done. These details can be referred to in paragraphs 0130 to 0155 of Japanese Patent No. 4894982, and these contents are incorporated in the present specification.
Examples of the thermoplastic resin other than the polyamide resin include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate resins, polyoxymethylene resins, polyether ketones, polyether sulphon, and polyetherimide. Illustrated. Further, the above-mentioned polyamide resin composition may have a structure that does not substantially contain a thermoplastic resin other than the polyamide resin. "Substantially free" means, for example, that the content of the thermoplastic resin other than the polyamide resin in the above-mentioned polyamide resin composition is 5% by mass or less of the content of the polyamide resin.

In particular, in the present invention, the above-mentioned polyamide resin composition is preferably measured at a temperature of (glass transition temperature + melting point) / 2, preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass or more. It is composed of a polyamide resin having a semi-crystallization time of 15 to 300 seconds and a ceramic whisker.

<Manufacturing method of stretch-molded article and stretch-molded article>
The molded product of the present invention is a stretched molded product. Stretching in the present invention refers to an operation of mechanically stretching a polyamide resin composition at a temperature equal to or lower than the melting point of a specific polyamide resin. When the polyamide resin composition contains two or more kinds of specific polyamide resins, the temperature below the melting point means an operation of stretching at a temperature below the melting point of the specific polyamide resin having the highest melting point contained in the polyamide resin composition.
The stretch-molded product of the present invention is formed from the above-mentioned polyamide resin composition. The stretch-molded article of the present invention may consist only of the stretch-molded article of the present invention, such as a single-layer film or a single-layer bottle, or may have other structures such as one layer of a multilayer film or a single layer of a multilayer bottle. It may be incorporated into a part of the body.
In the method for producing a stretched molded article of the present invention, a ceramic whisker is used in an amount of 5 to 100 parts by mass of a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2. Includes stretching a polyamide resin composition containing 25 parts by mass. With such a configuration, a stretched molded product having high mechanical strength and excellent oxygen barrier properties can be obtained.
Hereinafter, embodiments of a stretched molded product and a method for producing the same will be described. Needless to say, the stretched molded product and the method for producing the same in the present invention are not limited to these embodiments.

<< Stretched film and its manufacturing method >>
The first embodiment of the stretched molded article of the present invention is a stretched film. By using the stretched film, it can be used as it is or by further secondary processing for various purposes.
The stretched film may be a single-layer film or a multilayer film with another film.
The final MD (Machine direction) stretching ratio and the final TD (Transverse Direction) stretching ratio of the stretched film of the present invention are each independently preferably 1.5 times or more, more preferably 2.5 times or more. The upper limits of the final MD stretching ratio and the final TD stretching ratio are not particularly specified, but for example, 5.0 times or less is a practical level.
The final draw ratio of the stretched film of the present invention is preferably 3.0 times or more, more preferably 5.0 times or more, still more preferably 6.0 times or more. The upper limit of the final draw ratio is not particularly defined, but for example, 12.0 times or less is a practical level.
Here, the final draw ratio means the draw ratio of the finally obtained stretched film based on the total draw ratio and the relaxation ratio as compared with that before stretching, and in the case of biaxial stretching, the final MD draw ratio and The product of the final TD stretch ratios. The final MD stretching ratio means the stretching ratio of the finally obtained stretched film in the MD direction as compared with that before stretching, based on the MD stretching ratio and the MD relaxation ratio, and the final TD stretching ratio is the TD stretching ratio and the TD. Based on the relaxation rate, it means the draw ratio of the finally obtained stretched film in the TD direction as compared with that before stretching, and is a value calculated from the following formula.
Final MD stretch ratio = (MD stretch ratio-1) x {(100-MD relaxation rate) / 100} + 1
Final TD stretching ratio = (TD stretching ratio-1) x {(100-TD relaxation rate) / 100} + 1

According to JIS K 7127, the stretched film of the present invention can have a tensile elastic modulus of 5 GPa or more when measured under the conditions of a test piece width of 10 mm, a chuck distance of 100 mm, and a tensile speed of 100 mm / min. It can be 5.5 GPa or more. The upper limit of the tensile elastic modulus is not particularly specified, but can be, for example, 7.0 GPa or less. The detailed conditions of the tensile elastic modulus here follow the description of Examples described later.

The thickness of the stretched film of the present invention is preferably 1 μm or more, more preferably 3 μm or more, and further, 4 μm or more, 15 μm or more, or 20 μm or more. The thickness of the stretched film of the present invention is preferably 100 μm or less, more preferably 90 μm or less, 80 μm or less, or 40 μm or less.
The length of the stretched film of the present invention is not particularly specified, but for example, in the case of continuous production by roll-to-roll, it will usually be 10 m or more.

The phosphorus atom concentration of the stretched film of the present invention is preferably 0.1 to 10 mass ppm, more preferably 1 to 8 mass ppm. Within such a range, yellowing of the film can be effectively suppressed, clogging of the polymer filter can be effectively suppressed, and continuous productivity can be further improved.
The oxygen permeability coefficient of the stretched film of the present invention at 23 ° C. and 60% RH relative humidity (RH) can be 0.045 cc · mm / (m ² · day · atm) or less. The lower limit ^{value, 0cc · mm / (m 2} · day · atm) is preferred, a ^{0.002cc · mm / (m 2 ·} day · atm) sufficiently practical level in extent.
The method for measuring the oxygen permeability coefficient in the present invention follows the method described in Examples described later.

The stretched film of the present invention may be used as it is as a single-layer stretched film, but is beneficially used as a multilayer film having a stretched polypropylene resin film.
The stretched film of the present invention includes transport machine parts such as automobiles, general machine parts, precision machine parts, electronic / electrical equipment parts, OA equipment parts, building materials / housing related parts, medical equipment, leisure sports equipment, play equipment, medical products. Widely used in daily necessities such as food packaging films, defense and aerospace products.

Next, the details of the method for producing the stretched film of the present invention will be described with reference to FIG. It goes without saying that the present invention is not limited to these.
In the method for producing a stretched film of the present invention, first, 5 ceramic whiskers are applied to 100 parts by mass of a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2. The polyamide resin composition containing ~ 17 parts by mass is extruded from the T die 11 onto the casting roll 12 in a state of being melt-kneaded. The extrusion temperature at the time of extrusion is not particularly specified as long as the polyamide resin composition is melted. The thickness of the polyamide resin film made of the melt-extruded polyamide resin composition depends on the application and the draw ratio, but as an example, it is preferably 1 to 20 times the thickness of the stretched film after stretching. More preferably, it is ~ 15 times thicker.

In the method for producing a stretched film of the present invention, the polyamide resin film is stretched. In FIG. 1, stretching is performed in the stretching / relaxation zone 13.
The stretching may be performed in only one direction (uniaxial stretching) or in two orthogonal directions (biaxial stretching), and biaxial stretching is preferable. It is preferable to stretch the polyamide resin film in one direction (more preferably MD) in the transport direction or the width direction of the polyamide resin film, or in two directions of MD and TD. In the case of biaxial stretching, bidirectional stretching may be performed simultaneously or sequentially.
MD stretching can be carried out by passing a polyamide resin film between rolls having different peripheral speeds. In this case, the peripheral speed is set to be faster when the polyamide resin film passes later. It can also be stretched using a tenter. On the other hand, TD stretching can be stretched using a tenter. Further, a batch type biaxial stretching machine may be used.

When the polyamide resin film is biaxially stretched, the stretching ratio is preferably 1.5 times or more in each direction. The upper limit of each stretching ratio in the case of biaxial stretching is not particularly determined, but can be, for example, 8.0 times or less, respectively.
The total draw ratio in the present invention is preferably 2.0 times or more, more preferably 2.5 times or more, and further preferably 3.0 times or more. The upper limit of the total draw ratio is not particularly specified, but may be, for example, 15.0 times or less. Here, the total stretch ratio is the ratio of the stretched amount to the film before stretching, and is a value represented by the following formula.
Total draw ratio = MD draw ratio x TD draw ratio

Stretching may be carried out at room temperature, but is preferably carried out under heating conditions. For heating, it is preferable to perform stretching while passing through the polyamide resin film in the heating zone. The stretching is preferably carried out at a melting point of the specific polyamide resin of −200 ° C. to less than the melting point, more preferably at a melting point of the specific polyamide resin of −150 ° C. to a melting point of −100 ° C., and a melting point of the specific polyamide resin of −145 ° C. It is more preferable to carry out the process at a melting point of −110 ° C.
When two or more kinds of the specific polyamide resin are contained, the temperature of the specific polyamide resin at the time of stretching may be set based on the melting point of the specific polyamide resin having the lowest melting point. Further, even when the specific polyamide resin has two or more melting points, the temperature may be set based on the lowest melting point.
When the stretched film of the present invention is used as a multilayer film containing the stretched film and another resin film, it is preferable that the polyamide resin film made of the above-mentioned polyamide resin composition and the other film are co-extruded and stretched at the same time.

In the method for producing a stretched film of the present invention, it is preferable to perform heat fixation and relaxation after stretching (13 in FIG. 1). The relaxation is preferably carried out during the process of heat fixation. The heat fixing time is preferably 5 seconds to 5 minutes, more preferably 10 seconds to 1 minute. When the relaxation is performed during the heat fixing step, for example, when the heat fixing time is 30 seconds, the relaxation can be started from 15 to 16 seconds after the start of the heat fixing.
The heat fixing is preferably performed at a melting point of the specific polyamide resin of −70 ° C. to less than the melting point, more preferably at a melting point of the specific polyamide resin of −50 ° C. to a melting point of −5 ° C., and a melting point of the specific polyamide resin of −40 ° C. to −40 ° C. It is more preferable to carry out at a melting point of −10 ° C.
The relaxation is preferably performed by returning the inter-chuck distance in the direction opposite to the stretching direction, for example.

The stretched film obtained by obtaining the above steps is usually wound on a roll or the like and stored (step 14 in FIG. 1). Further, the stretched film is cut and used for various purposes.
It is preferable to adjust the stretching amount and the relaxing amount so that the final stretching ratio of the stretched film obtained by the production method of the present invention becomes the final stretching ratio of the stretched film described above.

<< Stretched container and its manufacturing method >>
A second embodiment of the stretched molded article of the present invention is a stretched container. The stretched container may be a single-layer container or a multi-layer container having the stretched molded product of the present invention and another layer.
Examples of the stretched container include a multi-layer container for medical use (vial, syringe, ampoule, etc.) and a multi-layer container for food (beverage bottle, food bag such as retort pack).
The stretched container is preferably formed by, for example, blowing air into the preform and biaxial stretching blow. In the case of a multi-layer container, an injection molding machine having two or more injection cylinders is used, and the above-mentioned polyamide resin composition and the thermoplastic resin composition constituting the other layer are separated from each injection cylinder with gold. It is obtained by injecting into a mold cavity through a mold hot runner to obtain a preform, and biaxially stretching blow molding the preform.
Details of the stretched container are described in JP-A-2015-214344, in particular, paragraphs 0041 to 0047, paragraphs 0124 to 0143 of JP-A-2014-172222, and paragraphs 008-50120 of JP-A-2016-169027. The description of the above can be taken into consideration, and these contents are incorporated in the present specification.

Hereinafter, the present invention will be described in more detail with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

Raw material <Synthesis of polyamide resin MXD6>
Put 8.9 kg of adipic acid in a reaction vessel equipped with a stirrer, a splitter, a total crimp, a thermometer, a dropping funnel and a nitrogen introduction tube, and a strand die, and further, sodium hypophosphate monohydrate 0. After adding 3 g and 0.1 g of sodium acetate and heating in a reaction can at 170 ° C. at 0.1 MPaA to melt, gradually add 8.3 kg of metaxylylene diamine over 2 hours while stirring the contents. It was added dropwise and the temperature was raised to 250 ° C. After the temperature rose, the pressure was gradually lowered to 0.08 MPaA over 1 hour and maintained for 0.5 hours. After completion of the reaction, the contents were taken out in a strand shape and pelletized with a pelletizer to obtain 15 kg of pellets. The obtained pellets were placed in a tumbler (rotary vacuum chamber) having a heat medium heating cloak and heated at 200 ° C. for 1 hour under reduced pressure (0.5 to 10 Torr) to solidify the obtained pellets. Phase polymerization was carried out to obtain a polyamide resin (MXD6).

<Synthesis example of polyamide resin MP10>
Put 10 kg of sebacic acid (manufactured by Itoh Oil Chemicals Co., Ltd., TA grade) in a reaction vessel equipped with a stirrer, a splitter, a total shrinker, a thermometer, a dropping funnel and a nitrogen introduction tube, and a strand die. 0.2 g of sodium monohydrate monohydrate and 0.1 g of sodium acetate were added, and the mixture was heated at 170 ° C. at 0.1 MPaA in a reaction can to melt, and then the contents were mixed with m-xylylenediamine while stirring. 6.7 kg of mixed xylylenediamine having a molar ratio of paraxylylenediamine of 70/30 was gradually added dropwise over 2 hours to raise the temperature to 250 ° C. After the temperature rose, the pressure was gradually lowered to 0.08 MPaA over 1 hour and maintained for 0.5 hours. After completion of the reaction, the contents were taken out in a strand shape and pelletized with a pelletizer to obtain a polyamide resin (MP10).

<Other polyamide resins>
PA6: UBE Nylon 1024B (manufactured by Ube Industries, Ltd.)

<Measurement of melting point (Tm) and glass transition temperature (Tg)>
The above polyamide resin was heated from 25 ° C. to a temperature higher than the expected melting point at a heating rate of 10 ° C./min based on the heat flux differential scanning calorimetry, and the temperature at the top of the endothermic peak was defined as the melting point. .. Next, the molten polyamide resin was rapidly cooled with dry ice, and the temperature was raised again to a temperature equal to or higher than the melting point at a rate of 10 ° C./min to determine the glass transition temperature. As the measuring device, "DSC-60" manufactured by Shimadzu Corporation (SHIMADZU CORPORATION) was used.

<Semi-crystallization time>
The semi-crystallization time of the polyamide resin was measured by melting the sample at a temperature higher than the melting point of the polyamide resin by 15 ° C. or more by the depolarizing luminosity method. Specifically, it was measured under the following conditions using a polymer crystallization rate measuring device (manufactured by Kotaki Seisakusho, model: MK701).
Sample melting temperature: 260 ° C
Sample melting time: 3 minutes Crystallization oil bath temperature: (glass transition temperature + melting point) / 2 (unit: ° C)

The results are shown in Table 1 below.

<Inorganic filler>
<< Ceramic whiskers >>
Potassium titanate whisker: manufactured by Otsuka Chemical Co., Ltd., Tismo D-101, aspect ratio 35, number average fiber length 14 μm, number average fiber diameter 0.4 μm, Mohs hardness 4.0, specific gravity 3.5
Aluminum borate whiskers: manufactured by Shikoku Kasei Kogyo Co., Ltd., Arborex YS3, aspect ratio 21, number average fiber length 17 μm, number average fiber diameter 0.8 μm, Mohs hardness 7.0, specific gravity 2.9
<< Other Inorganic Fillers >>
Glass fiber: Nippon Electric Glass Co., Ltd., ECS03T-24, aspect ratio 250, number average fiber length 3 mm, number average fiber diameter 12 μm, moth hardness 6.0, specific gravity 2.6

Example 1
<Manufacturing method of stretched film>
Using an extruder, 100 parts by mass of the polyamide resin shown in Table 2 is supplied from the hopper, and the inorganic filler shown in Table 2 is supplied from the middle of the extruder at the ratio (unit: parts by mass) shown in Table 2. , Kneaded and extruded to pelletize. The obtained pellets were vacuum dried by continuing heating at 150 ° C. for 5 hours under reduced pressure (0.5 to 10 Torr). The pellets of the obtained polyamide resin composition were melt-extruded from a die. Specifically, the polyamide resin composition obtained by melt-kneading each component was extruded to a width of 130 mm and cut into 90 mm squares with the thickness before stretching shown in Table 2. Then, using a biaxial stretching device (Tenter method, EX105S, manufactured by Toyo Seiki Seisakusho Co., Ltd.), stretching was performed in the MD direction and the TD direction so as to have the stretching ratios shown in Table 2, and then, as shown in Table 2. While heat-fixing at the heat process temperature shown, the stretched film was obtained by relaxing so as to have the relaxation rate shown in Table 2.
Various characteristics of the obtained film were evaluated as follows. The results are shown in Table 2 below.

<Measurement of melting point of film>
It was measured in the same manner as the melting point of the above-mentioned polyamide resin.

<Measurement of phosphorus atom concentration in film>
0.5 g of the film was weighed, 20 mL of concentrated sulfuric acid was added, and wet decomposition was performed on a heater. After cooling, 5 mL of hydrogen peroxide was added, and the mixture was heated on a heater and concentrated to a total volume of 2 to 3 mL. It was cooled again to make 500 mL with pure water. The phosphorus atom concentration of the obtained sample was quantified at a wavelength of 213.618 nm by high frequency inductively coupled plasma (ICP) emission analysis using IRIS / IP manufactured by Thermo Jarrell Ash, and the phosphorus atom concentration of the film was measured. bottom.

<Tensile modulus, tensile strength and tensile fracture point elongation of film>
According to JIS K 7127, the measurement was performed under the conditions of a width of the test piece of 10 mm, a distance between chucks of 100 mm, and a tensile speed of 100 mm / min. At the time of measurement, a tensile test was performed in the MD direction of the film.

<Oxygen permeability coefficient of film>
The oxygen permeability coefficient of the film was measured using an oxygen permeability measuring device (manufactured by MOCON, model: OX-TRAN2 / 21) in an atmosphere of 23 ° C. and 60% relative humidity according to ASTM D3985. The lower the measured value, the better the oxygen barrier property.

<Improvement rate of tensile elastic modulus>
The improvement rate of the tensile elastic modulus of the stretched film was calculated with respect to the unstretched film not containing the ceramic whiskers.
Improvement rate of tensile modulus = [(Tension modulus of stretched film-tensile modulus of unstretched film without ceramic whiskers) / Tension modulus of unstretched film without ceramic whiskers] x 100 (Unit: %)
The composition of the unstretched film that does not contain the ceramic whiskers corresponds to the composition of the stretched film excluding the ceramic whiskers.

<Decrease rate of oxygen permeability coefficient>
The rate of decrease in the oxygen permeability coefficient of the stretched film was calculated with respect to the unstretched film not containing the ceramic whiskers.
Decrease rate of oxygen permeability coefficient = [(Oxygen permeability coefficient of unstretched film without ceramic whiskers-Oxygen permeability coefficient of stretched film) / Oxygen permeability coefficient of unstretched film without ceramic whiskers] x 100 (Unit: %)
The composition of the unstretched film that does not contain the ceramic whiskers corresponds to the composition of the stretched film excluding the ceramic whiskers.
It can be said that the higher the rate of decrease in the oxygen permeability coefficient, the higher the barrier property is maintained.

<Appearance of film>
The appearance of the obtained film was visually evaluated as follows.
A: No unevenness can be seen.
B: Slight unevenness is seen.
C: Unevenness is seen.

<Examples 2 to 5, Comparative Examples 1 to 14>
In Example 1, as shown in Tables 2 to 4, the raw materials and production conditions were changed, and the others were carried out in the same manner. For the comparative examples that could not be stretched or the comparative examples that were not stretched, various evaluations were performed on the unstretched polyamide resin film.

The results are shown in the table below.

As is clear from the above results, the stretched molded product (stretched film) of the present invention had a high rate of improvement in tensile elastic modulus and a high rate of decrease in oxygen permeability coefficient. Further, the stretched molded product of the present invention was excellent in appearance. That is, the tensile elastic modulus was high and the oxygen barrier property was excellent.
On the other hand, in Comparative Example 1, although the thickness was almost the same as that in Example 1, wrinkles were generated during stretching because the ceramic whiskers were not blended. Further, in Comparative Example 2 in which the film thickness was thicker than that in Comparative Example 1, although stretching was possible, the improvement rate of the tensile elastic modulus was low and the reduction rate of the oxygen permeability coefficient was also low. Further, as is clear from Comparative Examples 6 to 9, when no stretching was performed, the tensile elastic modulus was low and the oxygen permeability coefficient was high regardless of whether a ceramic whisker was blended or not.
That is, by blending a ceramic whisker, stretching becomes easy, and further, by stretching, the improvement rate of the tensile elastic modulus becomes high, and the reduction rate of the oxygen permeability coefficient also becomes high. It is generally known that stretching an film becomes difficult when an inorganic filler is blended, and it is surprising that a ceramic whisker can be blended and stretched.
Further, as is clear from the results of Example 4, it was found that the effect of the present invention is achieved regardless of the type of ceramic whiskers.
On the other hand, when glass fiber was blended as the inorganic filler instead of the ceramic whiskers (Comparative Example 3), it broke during stretching.
Further, even if the ceramic whiskers were blended, when the blending amount was outside the range of the present invention (Comparative Example 4, Comparative Example 5), the tensile elastic modulus was low and the oxygen permeability coefficient was high.

上記結果から明らかなとおり、ポリアミド樹脂の種類を変えても、上記半結晶化時間が１５〜３００秒であるポリアミド樹脂を用いれば、同様の効果を奏することが確認された。

As is clear from the above results, it was confirmed that even if the type of the polyamide resin is changed, the same effect can be obtained by using the polyamide resin having the semi-crystallization time of 15 to 300 seconds.

上記結果から明らかなとおり、半結晶化時間が１５秒未満であるポリアミド樹脂以外のポリアミド樹脂を用いた場合、ウィスカーを配合すると、延伸できなかった（比較例１２）。ウィスカーを配合しない場合（比較例１３）、延伸はできたが、延伸しない場合（比較例１４）よりも、酸素透過係数が低くかった。

As is clear from the above results, when a polyamide resin other than the polyamide resin having a semi-crystallization time of less than 15 seconds was used, it could not be stretched when a whisker was added (Comparative Example 12). When the whiskers were not blended (Comparative Example 13), stretching was possible, but the oxygen permeability coefficient was lower than when no whiskers were blended (Comparative Example 14).

Example B
<Preform molding>
Using an injection molding machine with two injection cylinders (manufactured by Sumitomo Heavy Industries, Ltd., model DU130CI) and a two-piece mold (manufactured by Kortec, model), the layers (manufactured by Koratec, model) are used under the following conditions. The material constituting the layer (X) is injected from the injection cylinder, then the material constituting the layer (Y) is injected from another injection cylinder at the same time as the resin constituting the layer (X), and then the material constituting the layer (X) is formed. By injecting a required amount of the resin to be used to fill the cavity, a multi-layer preform (25.0 g) having a three-layer structure of (X) / (Y) / (X) was obtained. The shape of the preform was a total length of 95 mm, an outer diameter of 22 mm, and a wall thickness of 4.0 mm. As the resin constituting the layer (X), a polyethylene terephthalate resin (manufactured by Nippon Unipet Co., Ltd., product name: "BK-2180", hereinafter abbreviated as "PET") was used. As the resin constituting the layer (Y), a polyamide resin composition having the composition shown in Table 5 was used.

(Preform molding conditions)
Injection cylinder temperature for layer (X): 285 ° C
Injection cylinder temperature for layer (Y): 265 ° C
Resin flow path temperature in injection mold: 285 ° C
Mold cooling water temperature: 15 ° C
Cycle time: 40 seconds

<Bottle molding>
The preform obtained above was blow-molded by a biaxial stretching blow molding apparatus (EFB1000ET, manufactured by Frontier Co., Ltd.) to obtain a bottle. The total length of the bottle is 223 mm, the outer diameter is 65 mm, the inner volume is 500 mL, and the bottom is petaloid-shaped. No dimples were provided on the body. The biaxial stretch blow molding conditions are as shown below.
Preform heating temperature: 103 ° C
Pressure for drawing rod: 0.7MPa
Primary blow pressure: 1.1 MPa
Secondary blow pressure: 2.5 MPa
Primary blow delay time: 0.30 seconds Primary blow time: 0.30 seconds Secondary blow time: 2.0 seconds Blow exhaust time: 0.6 seconds Mold temperature: 30 ° C

For the obtained multilayer bottle, the reduction rate of the oxygen permeability coefficient and the oxygen permeability coefficient, and the improvement rate of the carbon dioxide shelf life and the carbon dioxide shelf life were measured.

<Oxygen permeability coefficient>
The oxygen permeability coefficient (OTR) of the multi-layer container at 23 ° C., 100% relative humidity inside the multi-layer bottle, and 50% relative humidity outside the multi-layer bottle is measured by an oxygen permeability measuring device (manufactured by MOCON) according to ASTM D3985. , Product name: "OX-TRAN (registered trademark) 2/61"). The lower the measured value, the better the oxygen barrier property.

<Decrease rate of oxygen permeability coefficient>
The rate of decrease in the oxygen permeability coefficient of the multi-layer bottle containing the ceramic whiskers (multi-layer bottle of Example B) was calculated with respect to the multi-layer bottle not containing the ceramic whiskers (multi-layer bottle of Comparative Example B described later).
Decrease rate of oxygen permeability coefficient = [(Oxygen permeability coefficient of multilayer bottle of Comparative Example B-Oxygen permeability coefficient of multilayer bottle of Example B) / Oxygen permeability coefficient of multilayer bottle of Comparative Example B] × 100 (Unit:%)

<Carbon dioxide shelf life>
The multilayer bottle was filled with 500 mL of 4.2 GV carbonated water, the cap was closed, and the bottle was stored in an environment of 23 ° C. and 50% relative humidity for 7 days. Subsequently, the shelf life of the carbon dioxide gas loss rate of 20% in the multi-layer container at 23 ° C., 100% relative humidity inside the multi-layer bottle, and 50% relative humidity outside the multi-layer bottle is used with a carbon dioxide gas permeability measuring device (manufactured by MOCON). Product name: Measured using "PERMATRAN-C Model 10" (registered trademark). The longer the measured shelf life, the better the carbon dioxide barrier property.

<Improvement rate of carbon dioxide shelf life>
The improvement rate of the carbon dioxide shelf life of the multi-layer bottle containing the ceramic whiskers (multi-layer bottle of Example B) was calculated with respect to the multi-layer bottle not containing the ceramic whiskers (multi-layer bottle of Comparative Example B described later).
Carbon dioxide shelf life improvement rate = [(Carbon dioxide shelf life of the multi-layer bottle of Example B-Carbon dioxide shelf life of the multi-layer bottle of Comparative Example B) / Carbon dioxide shelf life of the multi-layer bottle of Comparative Example B) ] × 100 (Unit:%)

Comparative Example B
In Example B, as shown in Table 5, the raw materials and production conditions were changed, and the others were carried out in the same manner. The results are shown in the table below.

As is clear from the above results, the stretched molded article (multilayer bottle) of the present invention had a high reduction rate of the oxygen permeability coefficient and a high shelf life improvement rate of carbon dioxide gas.

11 T-die 12 Casting roll 13 Stretching / relaxation zone 14 Winding process

Claims (14)

It is formed from a polyamide resin composition containing 5 to 25 parts by mass of a ceramic whisker with respect to 100 parts by mass of a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2. a that stretched molded body,
Stretch molding composed of a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at the temperature of (glass transition temperature + melting point) / 2 and the ceramic whiskers in which 98% by mass or more of the stretched body is formed. Body . The polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 50 mol% or more of the diamine-derived structural unit is derived from xylylene diamine, and 50 mol of the dicarboxylic acid-derived structural unit. The stretched molded product according to claim 1, wherein% or more is derived from α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. The stretched molded product according to claim 2, wherein the xylylenediamine comprises 30 to 100 mol% of metaxylylenediamine and 0 to 70 mol% of paraxylylenediamine. The stretched molded article according to claim 2 or 3, wherein 50 mol% or more of the constituent unit derived from the dicarboxylic acid is derived from at least one of sebacic acid and adipic acid. The stretched molded product according to any one of claims 1 to 4, wherein the phosphorus atom concentration in the stretched molded product is 0.1 to 10 mass ppm. The stretch-molded article according to any one of claims 1 to 5, wherein the ceramic whiskers have an aspect ratio of 10 to 100. The stretched molded article according to any one of claims 1 to 6, wherein the ceramic whiskers have a number average fiber length of 5 to 20 μm. The stretched molded product according to any one of claims 1 to 7 , wherein the stretched molded product is a stretched film. The stretched molded product according to claim 8 , wherein the stretched film has a thickness of 1 to 100 μm. The stretched molded product according to claim 8 or 9 , wherein the tensile elastic modulus is 5 GPa or more when measured under the conditions of a width of a test piece of 10 mm, a distance between chucks of 100 mm, and a tensile speed of 100 mm / min according to JIS K 7127. The stretched molded product according to any one of claims 1 to 10 , wherein the oxygen permeability coefficient at 23 ° C. and 60% relative humidity is 0.045 (cc · mm) / (m ² · day · atm) or less. The method for producing a stretched molded article according to any one of claims 1 to 11.
A polyamide resin composition containing 5 to 25 parts by mass of a ceramic whisker is stretched with respect to 100 parts by mass of a polyamide resin having a semi-crystallization time of 15 to 300 seconds measured at a temperature of (glass transition temperature + melting point) / 2. A method for producing a stretched molded product, including the above. The method for producing a stretched molded product according to claim 12 , wherein the stretched molded product is a film. The method for producing a stretched molded product according to claim 13 , which comprises stretching the stretched molded product so that the final draw ratio is 3 times or more.

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