JP2015182785A - food package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a food package using a polymer having as a monomer β-phellandrene as a material which can be obtained from microorganisms and vegetables as a carbon neutral material.SOLUTION: A food package is such that: (1) the food package having at least one resin layer includes based on the total mass of the one resin layer, 50-100 mass% of a β-phellandrene polymer having a specific gravity of 0.85 or more and less than 1.0, and a glass-transition temperature of 80°C or more; (2) a number-average molecular weight Mn of the β-phellandrene polymer is 40,000 or more; (3) at least part of olefinic carbon-carbon double bond which the β-phellandrene polymer has is hydrogenated; (4) the food package further includes a gas barrier layer; and (5) at least one layer selected from a polyester layer, a polyamide layer and a polyolefin layer is further laminated.

Description

  The present invention relates to a food packaging body using a β-ferrandylene polymer.

  Conventionally, a food package made of a resin material such as vinyl chloride resin or vinylidene chloride resin has been used. These resin materials are widely used because they have excellent properties such as elongation, gas barrier properties, and transparency, but they may generate endocrine disrupting substances such as dioxins when incinerated after disposal. Are required as food packaging materials.

  Generally, in order to maintain the freshness and flavor of food, it is required that the water vapor barrier property and gas barrier property are high as the properties of the resin material of the food package. As such a resin material, an example using a norbornene resin in addition to a polyolefin resin such as polypropylene and polyethylene has been proposed (see Patent Document 1).

However, since polypropylene and polyethylene have low heat resistance, there are problems such as deformation due to heating in a microwave oven or the like. In addition, norbornene-based resins have a problem of discoloration when irradiated with radiation such as electron beams used to sterilize food.
In addition, since the monomers that are the raw materials for these conventional resin materials are petroleum-derived compounds, they meet today's needs for products that use carbon-neutral materials that suppress carbon dioxide emissions. I can't say that.

  As carbon-neutral polymer materials, compounds that can be produced through biosynthetic pathways in living organisms have attracted attention. For example, a polymer having a glass transition point of 80 ° C. obtained by polymerizing β-pinene derived from terpene oil extracted from pine or the like has been proposed (Patent Document 2). However, in order to obtain a polymer having a high polymerization degree that exhibits practical strength using β-pinene as a monomer, it was necessary to polymerize in the presence of a bifunctional vinyl compound. Furthermore, it is necessary to make the polymerization temperature as low as -80 ° C to 0 ° C. In order to manufacture at a low cost and from the viewpoint of recent environmental problems, further improvement of reaction conditions and natural materials with good polymerization characteristics are required. Use was desired.

JP-A-11-217491 Japanese Patent No. 5275633

  The present invention has been made in view of the above circumstances, and is a material that can be obtained from microorganisms, plants, etc. as a carbon neutral material. provide.

＜３＞ 前記βフェランドレン重合体に、下記化学式（Ｉ−１）、（Ｉ−２）、（ＩＩ−１）及び（ＩＩ−２）で表されるβフェランドレン単位が合計５０質量％以上含有されていることを特徴とする前記＜１＞又は＜２＞に記載の食品包装体。

＜４＞ 前記βフェランドレン重合体の数平均分子量Ｍｎが４万以上であることを特徴とする前記＜１＞〜＜３＞の何れか一項に記載の食品包装体。
＜５＞ 前記βフェランドレン重合体が有するオレフィン性炭素−炭素二重結合の少なくとも一部が水素化されていることを特徴とする前記＜１＞〜＜４＞の何れか一項に記載の食品包装体。
＜６＞ 前記βフェランドレン重合体の水素添加率が、７０％以上であることを特徴とする前記＜５＞に記載の食品包装体。
＜７＞ ２０℃、６５％ＲＨの条件下での酸素透過度が１ｃｃ・２０μｍ／ｍ^２・ｄａｙ・ａｔｍ以下であるガスバリア層を、更に含むことを特徴とする前記＜１＞〜＜６＞の何れか一項に記載の食品包装体。
＜８＞ ポリエステル層、ポリアミド層及びポリオレフィン層から選ばれる少なくとも１つの層が、更に積層されていることを特徴とする前記＜１＞〜＜７＞の何れか一項に記載の食品包装体。 <1> A food packaging body having at least one resin layer, wherein the β-ferrandrene polymer having a specific gravity of 0.85 or more and less than 1.0 and a glass transition temperature of 80 ° C. or more is A food package comprising 50 to 100% by mass with respect to the total mass of one resin layer.
<2> The food according to <1>, wherein the β-ferrandol polymer is obtained by polymerizing at least one of β-ferrandolene represented by the following chemical formulas (I) and (II): Packaging body.

<3> The β-ferrandolene units represented by the following chemical formulas (I-1), (I-2), (II-1) and (II-2) are added to the β-ferrandylene polymer in a total of 50% by mass or more. The food packaging body according to <1> or <2>, which is contained.

<4> The food packaging body according to any one of <1> to <3>, wherein the β-ferrandylene polymer has a number average molecular weight Mn of 40,000 or more.
<5> At least a part of the olefinic carbon-carbon double bond of the β-ferrandylene polymer is hydrogenated, as described in any one of <1> to <4>, Food packaging.
<6> The food package according to <5>, wherein a hydrogenation rate of the β-ferrandylene polymer is 70% or more.
<7> The above <1> to <6>, further comprising a gas barrier layer having an oxygen permeability of 1 cc · 20 μm / m ² · day · atm or less at 20 ° C. and 65% RH. The food package according to any one of the above.
<8> The food package according to any one of <1> to <7>, wherein at least one layer selected from a polyester layer, a polyamide layer, and a polyolefin layer is further laminated.

  In the present specification and claims, the term “layer” is synonymous with “film”.

According to the present invention, it is possible to provide a food package having excellent properties such as water vapor permeability, gas barrier properties, transparency, lightness, heat resistance and mechanical strength, and also excellent properties such as high light resistance and low water absorption. .
By using the food packaging body of the present invention, it is possible to block the packaged food from the outside and maintain its flavor and freshness, and to visually visually check the state of the packaged food. And it can be confirmed accurately.

The first aspect of the present invention is a food package.
First, a method for producing a β-ferrandylene polymer that is a material of the present invention will be described.
<Method for Producing β Ferrandrene Polymer>
β-Ferlandene, which is a monomer constituting the β-ferrandylene polymer, may be extracted and purified from a living organism, or may be chemically synthesized from a petroleum-derived compound. For example, β-ferrandrene contained in essential oil obtained by steam distillation from plant seeds and roots may be used, or existing chemical substances are used as raw materials, and β-ferrandrene obtained by a known chemical synthesis method is used. Also good.

  For example, when using an existing chemical as a raw material, a known chemical synthesis method (Organic & Biomolecular Chemistry, 9 (7), 2433-2451, 2011) in which 4-Isopropylcyclohexanone is used as a starting material and synthesized via Crypron The resulting β-ferrandrene can be used.

  When chemical substances extracted from living organisms are used as materials, for example, plants or plants containing β-ferrandrene, such as Todomatsu, Ginger, Fennel, Neroli, Rosewood, Tomato, Lavender, Canadian Balsam, Angelica, etc. The extract from may be purified and used. In particular, it is preferable to use high-purity β-ferrandrene. In that case, the purity (pure content) can be increased by a method such as precision distillation or separation using a silica gel column.

  By using biologically-derived β-ferrandrene as a carbon neutral material, it is possible to reduce the environmental load in the production process and to reduce carbon dioxide emissions.

In order to increase the glass transition temperature Tg related to heat resistance by increasing the number average molecular weight Mn of β-ferrandylene polymer, a β-ferrandylene polymer was synthesized in order to achieve the purpose of obtaining excellent light transmission and mechanical strength. In this reaction system, it is preferable that the purity (pure content) of β-ferrandol in the reaction solution containing β-ferrandol is as high as possible. Further, the reaction system is more preferably a reaction system in which a compound having a double bond that interferes with the polymerization of β-ferrandrene is excluded as much as possible.
Particularly preferably, for example, a substance that reacts with a cis-type conjugated double bond such as a Diels-Alder reaction reagent is added, and a cis-type conjugated double bond substance other than β-ferrandrene is removed as an insoluble substance, thereby It is preferable to increase the purity, and it is preferable to increase the purity by combining with precision distillation or column separation using silica gel.

  Specifically, the content of β-ferrandol, that is, the purity (pure content) of β-ferrandol is preferably 50% by mass or more, and 70% by mass or more with respect to the total mass of the polymerizable compound in the reaction solution. Is more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more. The content may be 100% by mass. Here, “purity” does not mean optical purity that distinguishes optical isomers of β-ferrandolene, but simply chemical purity that does not distinguish optical isomers of β-ferrandylene. The “polymerizable compound” means a compound having a double bond polymerizable with β-ferrandolene.

In the present specification and claims, the purity of β-ferrandol used in the reaction is a value determined by the percentage of peak area of β-ferrandol by a gas chromatography (GC) method or a GC-MS method. .
For example, a β-ferrandrene reaction solution is diluted with a chloroform solution (for high-performance liquid chromatograph manufactured by Wako Pure Chemical Industries, Ltd., purity 99.7%) so as to be 1% by mass, and a gas chromatograph analyzer (HP6890 manufactured by HEWLETT PACKARD) is used. Series GC System). At this time, DB-5 (a capillary column made by Agilent Technologies, 30 m × 0.25 mm ID × 0.25 μ) was used as a column for component separation, and the column temperature: start 50 ° C., final 300 ° C., heating rate 15 It is preferable to measure at ° C / min and injection temperature: 300 ° C. The β-ferrandol peak can be identified from the β-ferrandol standard solution or MS spectrum. It is preferable that the pure amount of β-ferrandrene is calculated as an area ratio of β-ferrandrene, where the sum of the total areas of peaks having an area value of 1000 or more observed in the GC analysis is 100.

  By adding a Lewis acid as a catalyst and dispersing well in an organic solvent constituting the reaction solution, slowly dropping high-purity β-ferrandrene, starting cationic polymerization, and reacting for a predetermined time, The intended β-ferrandylene polymer can be obtained.

  In performing cationic polymerization by such a solution polymerization method, the concentration of β-ferrandylene as a monomer is preferably 1 to 90% by mass, more preferably 10 to 80% by mass, based on the total mass of the reaction solution. More preferably, it can be adjusted to 10 to 50% by mass. When the concentration is less than 1% by mass, the productivity is low, while when it exceeds 90% by mass, it is difficult to remove the heat of polymerization.

The type of organic solvent constituting the reaction solution is not particularly limited as long as it can dissolve β-ferrandrene, and a solvent used in conventional cationic polymerization can be applied. Among these, a solvent with little chain transfer is preferable. Examples of such a solvent include halogenated hydrocarbons, aromatic hydrocarbons, and aliphatic hydrocarbons from the viewpoint of solubility and reactivity under polymerization conditions of the polymer. More specifically, for example, halogenated carbonization such as methylene chloride, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, n-propyl chloride, 1-chloro-n-butane, 2-chloro-n-butane and the like. Hydrogen solvents; aromatic hydrocarbon solvents such as benzene, toluene, xylene, anisole; aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, cyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, decalin, etc. Can be mentioned.
As the organic solvent, one organic solvent may be used alone, or two or more organic solvents may be used in combination.

The organic solvent may be a nonpolar solvent or a polar solvent.
In order to further increase the degree of polymerization of the β-ferrandylene polymer and obtain a tough polymer, it is particularly preferable to use a nonpolar solvent. Chlorinated solvents (solvents composed of compounds having chlorine atoms) such as halogenated aliphatic hydrocarbons and halogenated aromatic hydrocarbons can be used. However, since there are some chlorinated solvents that cannot be used from the viewpoint of disposal of waste solvents, desalting of polymerized products, and recent VOC regulations, it is not always preferable from the viewpoint of environmental problems.

As the Lewis acid, a Lewis acid used in conventional cationic polymerization is applicable. For example, EtAlCl ₂ , AlCl ₃ , Et ₂ AlCl, Et ₃ Al ₂ Cl ₃ , BCl ₃ , SnCl ₄ , TiCl ₄ , Ti (OR) _4-y Cl ₄ [R represents an alkyl group or an aryl group, and y represents an integer of 1 to 3. ] Is preferable because of high reactivity and selectivity. Other than these, metal halides such as BF ₃ , BBr ₃ , AlF ₃ , AlBr ₃ , TiBr ₄ , TiI ₄ , FeCl ₃ , FeCl ₂ , SnCl ₂ , WCl ₆ , MoCl ₅ , SbCl ₅ , TeCl ₂ , ZnCl _{2 , (i-Bu) 3 Al} , (i-Bu) 2 AlCl, (i-Bu) AlCl 2, Me 4 Sn, Et 4 Sn, Bu 4 Sn, Bu 3 metal alkyl compound such as SnCl [Me represents a methyl group Et represents an ethyl group and Bu represents a butyl group. _{], Al (OR) 3-} x Cl x [R represents an alkyl group or an aryl group, x is an integer of 1 or 2. And the like.
As the Lewis acid, one Lewis acid may be used alone, or two or more Lewis acids may be used in combination.

  As the polymerization catalyst, only the above-mentioned Lewis acid may be used, but an initiator used in combination as a Lewis acid may be used. In this case, the initiator is one that reacts with a Lewis acid to generate a carbon cation, and any initiator having such characteristics may be used. Specifically, alkyl vinyl ether-hydrogen chloride adduct, chloroalkyl vinyl ether-hydrogen chloride adduct, α-chloroethylbenzene, α-chloroisopropylbenzene, 1,3-bis (α-chloroisopropyl) benzene, 1,4- Bis (α-chloroisopropyl) benzene, 1,3-bis (α-chloroisopropyl) -5-t-butylbenzene, 1,3,5-tris (α-chloroisopropyl) benzene, t-butyl chloride, 2- Chlorine initiators such as chloro-2,4,4-trimethylpentane: alkyl vinyl ether-acetic acid adduct, α-acetoxyethylbenzene, α-acetoxyisopropylbenzene, 1,3-bis (α-acetoxyisopropyl) benzene, 1, Esters such as 4-bis (α-acetoxyisopropyl) benzene Agents, alpha-hydroxy ethylbenzene, alpha-hydroxy isopropylbenzene, 1,3-bis (alpha-hydroxy isopropyl) benzene, 1,4-bis (alpha-hydroxy isopropyl) alcohol initiator such as benzene.

Moreover, you may use the electron donor used with a living cationic polymerization catalyst. As such an electron donor, known ones can be used. Specifically, ethers such as diethyl ether (Et ₂ O), methyl-t-butyl ether, dibutyl ether; ethyl acetate (EtOAc), methyl acetate, isopropyl acetate, butyl acetate, methyl isobutyrate, ethyl isobutyrate, isobutyric acid Esters such as propyl; pyridine, 2-methylpyridine, 2,6-dimethylpyridine, 2,6-di-butylpyridine, 2,6-diphenylpyridine, 2,6-di-t-butylpyridine, 2,6 -Pyridines such as di-t-butyl-4-methylpyridine; Amines such as trimethylamine, triethylamine and tributylamine; Amides such as dimethylacetamide and diethylacetamide; Sulphoxides such as dimethylsulfoxide and the like. In particular, diethyl ether and ethyl acetate are preferably used because they are economical and easy to remove after the reaction.

  The concentration of these Lewis acids in the reaction solution is preferably 0.001 to 100 parts by weight, more preferably 0.01 to 50 parts by weight, with respect to 100 parts by weight of β-ferrandolene added later. More preferably, it is 1 to 10 parts by weight. If the amount of the Lewis acid catalyst used is too small, the reaction may stop before the completion of the polymerization, and conversely if too large, it is uneconomical.

  The added β-ferrandrene may be previously dissolved in the same type of organic solvent as the organic solvent constituting the reaction solution. The temperature of the reaction solution at the time of the dropwise addition can usually be set to -120 ° C to 150 ° C, and preferably set to -90 ° C to 100 ° C. If the reaction temperature is too high, it may be difficult to control the reaction and it may be difficult to obtain reproducibility, and if it is too low, the production cost increases.

  In the method for producing a β-ferrandylene polymer, the reaction at a low temperature is advantageous in terms of increasing the degree of polymerization. For example, by reacting at −80 to 70 ° C., the number average molecular weight Mn is 100,000 or more. A β-ferrandylene polymer of about 140,000 can be easily obtained. Moreover, you may make it react at -15-40 degreeC, The beta ferrandylene polymer whose number average molecular weight Mn is about 50,000-100,000 can be obtained easily at this temperature.

  The reaction time of the cationic polymerization is not particularly limited, and may be appropriately adjusted so as to obtain a β-ferrandylene polymer having desired characteristics according to the conditions such as the type and amount of the polymerization catalyst, the reaction temperature, and the reaction equipment. it can. In general, a β-ferrandylene polymer having desired characteristics can be obtained by reacting for about 1 second to 100 hours, preferably about 10 seconds to 1 hour, more preferably about 30 seconds to 10 minutes.

  The β-ferrandol polymer used in the present invention may be a homopolymer of β-ferrandol, or a copolymer of β-ferrandol and one or more other copolymerizable monomers. May be.

  In order to terminate the reaction, a terminator may be added after the reaction for a predetermined time. As the terminator, alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol and t-butanol are preferably used. The amount of addition of the terminator is not strictly defined, but is usually 0.01 to 10 times the volume of the reaction solvent, preferably 0.1 to 1 times the volume.

  Examples of the method for separating the β-ferrandylene polymer obtained by polymerization in the reaction solution from the solvent include reprecipitation, evaporation of the solvent by heating, removal of the solvent by reduced pressure, and removal of the solvent by water vapor (coagulant). And other known methods such as removal of the deaerated solvent by an extruder can be applied.

  When it is necessary to neutralize and remove the chlorine-based Lewis acid catalyst when the polymer is separated from the solvent, a generally known neutralizing agent such as sodium hydroxide, sodium hydrogen carbonate, ammonia, etc. A neutralizing agent can be used and is not particularly limited. Furthermore, in applications where the requirements for transparency and thermal stability are severe, it is desired to sufficiently remove chlorine and neutralized salts remaining as impurities in the resulting polymer. The removal method is not particularly limited. For example, it is preferable to purify the polymer by a treatment such as water addition at the time of re-pillowing the polymer. In particular, in order to improve optical properties and electrical insulation, the content of residual neutralized salt is preferably 100 ppm or less with respect to the mass of the polymer. Especially preferably, it is 10 ppm or less.

<Β Ferrandylene Polymer>
The number average molecular weight Mn of the β-ferrandylene polymer obtained as described above increases the viscosity and melt viscosity of the polymerization solution, moldability, and the strength and heat resistance of the resin layer containing the molded β-ferrandylene polymer. From the viewpoint, 10,000 to 1,000,000 is preferable. The number average molecular weight Mn of the β-ferrandylene polymer used in the present invention can be adjusted to 20,000 to 500,000, 30,000 to 400,000, or 40,000 to 300,000. It can also be prepared, 50,000 to 250,000 can be prepared, 60,000 to 200,000 can be prepared, 70,000 to 150,000 can be prepared, 80,000 to 12 It can also be prepared in a million. If the molecular weight of the polymer is too large, the viscosity of the polymerization solution increases and the productivity of the polymer deteriorates, or the melt viscosity of the polymer increases and the moldability may deteriorate. On the other hand, if the molecular weight is too small, the strength of the resin layer containing the β-ferrandylene polymer is lowered, and the glass transition temperature is less than 80 ° C., so that sufficient heat resistance may not be exhibited.

  The glass transition temperature Tg of the β-ferrandylene polymer is preferably about 80 to 350 ° C., preferably 85 to 250 ° C., from the viewpoint of increasing the heat resistance, moldability, and strength of the resin layer containing the molded β-ferrandylene polymer. More preferably, 90-200 degreeC is still more preferable. The glass transition temperature Tg of the β-ferrandylene polymer used in the present invention can be adjusted to 80 ° C. or higher and 200 ° C. or lower, 85 ° C. or higher and 200 ° C. or lower, or 90 ° C. or higher and 200 ° C. or lower. It can be prepared at 95 ° C. or less, can be prepared at 95 ° C. or more and 200 ° C. or less, can be prepared at 100 ° C. or more and 200 ° C. or less, and can be prepared at 110 ° C. or more and 200 ° C. or less. In addition, it can be adjusted to 120 ° C. to 200 ° C., 125 ° C. to 200 ° C., and 130 ° C. to 200 ° C. When the glass transition temperature Tg is too high, the melt viscosity of the β-ferrandylene polymer becomes high and the moldability may be deteriorated. On the other hand, if the glass transition temperature Tg is too low, the heat-resistant use temperature of the resin layer containing the molded β-ferrandylene polymer becomes low, which is not practical. Usually, the glass transition temperature Tg and heat resistance can be improved by increasing the molecular weight of the β-ferrandylene polymer and by hydrogenating the β-ferrandylene polymer.

In the present specification and claims, the number average molecular weight Mn of β-ferrandylene polymer is obtained according to the size exclusion chromatography method defined in JIS-K-0124-2002, and is a gel. It is obtained from the value of the differential refraction detector measured by permeation chromatography (GPC) and the calibration curve of standard polystyrene. The glass transition temperature Tg was measured according to the method defined in JIS-K-7121-1987 “Method for Measuring Plastic Transition Temperature”. More specifically, the glass transition temperature Tg (T _The temperature determined as _mg ) is the glass transition temperature Tg in the present specification and claims.

<Optical isomerism of β-ferrandrene>
The β-ferrandolene, which is a material of the β-ferrandylene polymer used in the present invention, is a mixture or a racemate of compounds that are optical isomers (enantiomers) represented by the following chemical formulas (I) and (II). Alternatively, only one of the optical isomers may be used. Chemically synthesized β-ferrandolene is usually a mixture or a racemate. When using β-ferrandolene consisting only of one of the optical isomers, it can be obtained by optical isomerization separation by using a method such as chromatography using a chiral column, diastereomer method using an optical resolving agent, etc. Materials may be used.

  The β-ferrandol polymer obtained by using the above-mentioned mixture or racemate of β-ferrandol as a material includes the following chemical formulas (I-1), (I-2), (II-1) and (II-2). Any one or more of monomer units (repeating units) represented by In each chemical formula, parentheses indicate a bond with an adjacent monomer unit that is polymerized (bonded).

  The β-ferrandylene polymer used in the present invention may have one, two, or three types of monomer units represented by the above chemical formulas. You may have, and you may have 4 types.

  In the β-ferrandylene polymer used in the present invention, when the mixture or racemate of the chemical formulas (I) and (II) is used as the material, the chemical formulas (I-1), (I-2), It is considered that β ferrandolene units represented by (II-1) and (II-2) are contained in a total of 50% by mass or more with respect to the total mass of the β ferrandolene polymer. The content is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, further preferably 80 to 100% by mass, and most preferably 90 to 100% by mass.

<Hydrogenation to β-ferrandylene polymer>
It is preferable that hydrogenation (hydrogenation) is performed on the olefinic carbon-carbon double bond of the β-ferrandylene polymer used in the present invention. By performing hydrogenation, the glass transition temperature Tg of the β-ferrandylene polymer is increased, and a polymer with further improved heat resistance, light resistance, weather resistance and the like can be obtained.

  As a method of adding hydrogen to the β-ferrandylene polymer, a known method of adding hydrogen to a conventional polymer can be applied. As the hydrogenation catalyst used in this case, catalysts generally used for hydrogenation reactions of olefins and aromatic compounds can be applied. For example, transition metals such as palladium, platinum, nickel, rhodium, ruthenium and the like are used as carbon. , Supported metal catalyst supported on a carrier such as alumina, silica, diatomaceous earth; homogeneous catalyst composed of organic transition metal compounds such as titanium, cobalt, nickel and organometallic compounds such as lithium, magnesium, aluminum, tin; Examples thereof include metal complex catalysts such as rhodium and ruthenium.

  Examples of the supported metal catalyst include nickel / silica, nickel / diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth, palladium / alumina, platinum / silica, platinum / alumina, rhodium / Examples of the catalyst include silica, rhodium / alumina, ruthenium / silica, and ruthenium / alumina.

  Examples of the homogeneous catalyst include acetic acid / cobalt triethylaluminum, nickel trioctylate / triisobutylaluminum, nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n-butyllithium, zirconocene dichloride / sec-butyllithium, tetrabutoxy A combination of titanate and dimethylmagnesium can be mentioned.

  Examples of the metal complex catalyst include chlorotris (triphenylphosphine) rhodium, dihydridotetra (triphenylphosphine) ruthenium, hydrido (acetonitrile) tris (triphenylphosphine) ruthenium, carbonylchlorohydridotris (triphenylphosphine) ruthenium, Examples include carbonyl dihydridotris (triphenylphosphine) ruthenium.

Among the catalysts used in the hydrogenation reaction exemplified here, the supported metal catalyst is particularly preferable because it can be easily separated and recovered by filtration together with the polymerization catalyst after the hydrogenation reaction.
The said catalyst may be used individually by 1 type, and may use 2 or more types together.

  The reaction temperature at the time of hydrogenation can usually be carried out at -20 ° C to 250 ° C, preferably -10 ° C to 220 ° C, more preferably 0-200 ° C. If the reaction temperature is too high, the polymer may be thermally decomposed, and if it is too low, the reaction rate may be slow and the reaction may not be completed.

The hydrogen pressure at the time of hydrogenation can be usually 0.1-100 kgf / cm ² , preferably 0.5-70 kgf / cm ² , more preferably 1-50 kgf / cm ² . . If the hydrogen pressure is too low, the hydrogenation reaction is slow, and if it is too high, a high pressure reactor is required.

The solvent for the hydrogenation is not particularly limited as long as the polymer is dissolved and the catalyst is inert. From the viewpoint of the solubility and reactivity of the hydrogenated product of the polymer, examples include aliphatic hydrocarbons, halogenated hydrocarbons, and aromatic hydrocarbons. Specifically, aromatic hydrocarbon solvents such as benzene and toluene; aliphatic carbonization such as n-pentane, n-hexane, n-heptane, n-octane, cyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane and decalin Hydrogen solvents; ether solvents such as tetrahydrofuran and ethylene glycol dimethyl ether; methylene chloride, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, n-propyl chloride, 1-chloro-n-butane, 2-chloro-n -Halogenated hydrocarbon solvents such as butane. Of these organic solvents, hydrocarbon solvents are particularly preferable from the viewpoints of solubility and reactivity.
The said organic solvent may be used individually by 1 type, and may use 2 or more types together.

  In the hydrogenation, it is also possible to carry out the hydrogenation reaction as it is without exchanging the solvent of the reaction solution after the polymerization reaction of β-ferrandrene is completed. When hydrogenation is performed without replacing the solvent in this way, waste liquid discharged from the production process is reduced, which is preferable from the viewpoint of reducing the environmental load.

  The reaction time of the hydrogenation can be usually performed for about 0.1 to 20 hours. As a measure of completion of the hydrogenation reaction, for example, among the olefinic carbon-carbon double bonds (unsaturated bonds) of the polymer before hydrogenation, preferably 70% or more, more preferably 80% or more, It is desirable to continue the hydrogenation until preferably 90% or more, particularly preferably 95% or more is saturated, most preferably 100% is saturated. By sufficiently hydrogenating the β-ferrandylene polymer, a polymer having excellent heat resistance and light resistance can be obtained.

As a method for obtaining the hydrogenation rate of the olefinic carbon-carbon double bond in the polymer before and after the hydrogenation, in general, iodine titration method, infrared spectroscopic measurement, nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum) A method of calculating from an analysis value such as measurement is known.

In the present specification and claims, the hydrogenation ratio of the β-ferrandylene polymer to the olefinic carbon-carbon double bond is a nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum) using deuterated chloroform as a solvent. It is calculated using the measured value. Specifically, the integrated value of the signal detected at δ = 5.0 to 6.0 ppm, that is, the integrated value of the signal derived from the proton of the olefinic carbon-carbon double bond, assuming that the proton of tetramethylsilane is 0 ppm. The ratio (A / B) between A and the integral value of the signal detected at 0.5 to 2.5 ppm, that is, the integral value B of the signal derived from the saturated hydrocarbon proton is calculated. This ratio decreases as the hydrogenation rate increases. By calculating the ratio before hydrogenation (A / B (before hydrogenation)) and the ratio after hydrogenation (A / B (after hydrogenation)), respectively, and substituting them into the following formula, hydrogenation The rate can be determined.

Hydrogenation rate (%) =
(Ratio (A / B (before hydrogenation))-ratio (A / B (after hydrogenation)) × 100 ÷ ratio (A / B (before hydrogenation))

The glass transition temperature Tg of the polymer obtained by hydrogenating the β-ferrandylene polymer is preferably higher from the viewpoint of withstanding heating using a microwave oven or the like, and the glass transition temperature Tg is 100 ° C. or higher. It is more preferable that For the resin layer constituting the food packaging according to the present invention, a known surface treatment (surface) is used to improve the solvent resistance and gas shielding property, to provide antistatic properties, and to impart conductivity. Processing). Since these surface treatments can be easily performed, the Tg of the hydrogenated β-ferrandylene polymer is preferably 120 ° C. or higher. When Tg exceeds about 200 ° C., the melt viscosity of the β-ferrandylene polymer increases, and the moldability may be deteriorated. On the other hand, if the Tg is less than 80 ° C., the heat resistant use temperature of the molded product (resin layer constituting the food package) is lowered, which is not preferable.
The method for measuring the glass transition temperature Tg of the hydrogenated β-ferrandylene polymer may be the same as the method for measuring the glass transition temperature Tg of the non-hydrogenated β-ferrandylene polymer.

The total light transmittance of the β-ferrandylene polymer, which is a material of the resin layer constituting the food packaging body of the present invention, is preferably as high as the properties usually required for its use, preferably 80% or more, and 85% or more. More preferably, 90% or more is more preferable. For example, when a flat test piece having a thickness of about 100 μm made only of β-ferrandylene polymer is measured, its total light transmittance is preferably 80% or more, more preferably 85% or more, 90 % Or more is more preferable, and 95% or more is most preferable.
Here, the total light transmittance is a value measured in accordance with JIS-K-7361: 1997 (ISO13468-1: 1996).

The β-ferrandylene polymer used in the present invention preferably has a low water absorption rate from the viewpoint of dimensional stability. The water absorption of the β-ferrandylene polymer is 0.2 when the mass change of the test piece when the test piece is placed in an atmosphere of 60 ° C. and 90% RH (relative humidity) for 24 hours is measured as the saturated water absorption. % Or less is preferable, 0.1% or less is more preferable, and 0.05% or less is more preferable.
Here, the water absorption is a numerical value measured according to JIS-K-7209: 2000.

Since the specific gravity of the β-ferrandylene polymer used in the present invention is small, a light food package can be obtained. The specific gravity of the β-ferrandylene polymer used in the present invention is 0.85 or more and less than 1.0, preferably 0.85 to 0.98.
It is usually difficult to obtain a β-ferrandylene polymer having a specific gravity of less than 0.85. Further, if the specific gravity is 1.0 or more, the object of weight reduction cannot be sufficiently achieved.
Here, the specific gravity is a numerical value measured according to A method of JIS-K-7112: 1999.

  Generally, when the photoelastic coefficient of the resin constituting the molded product is large at a temperature equal to or higher than Tg, there is a problem that the optical distortion of the obtained molded product (resin layer constituting the food package) is increased. Therefore, when trying to obtain a molded product with a small optical distortion, the range in which the molding conditions can be selected becomes narrow, and there is a problem that productivity is lowered.

  Accordingly, it is preferable that the β-ferrandylene polymer used in the present invention has a small photoelastic coefficient, and it is more preferable that the photoelastic coefficient is small even at a temperature equal to or higher than the glass transition temperature Tg. By using a β-ferrandylene polymer having a small photoelasticity, a food package with little optical distortion can be obtained.

A suitable photoelastic coefficient at a temperature equal to or higher than Tg (for example, Tg + 20 ° C.) of the β-ferrandylene polymer to be used cannot be generally specified depending on the use, but is −3000 × 10 ^{−13 to} 3000 × 10 ⁻¹³ cm ² / dyn. Is preferable, and −1000 × 1000 ^{−13 to} 1000 × 10 ⁻¹³ cm ² / dyn is more preferable. By having a photoelastic coefficient in this range, an optical plastic film with small optical distortion can be obtained with high productivity. Note that 1 dyn = 10 ⁻⁵ N.

  The refractive index nD (25 ° C.) of the β-ferrandylene polymer used in the present invention is preferably in the range of 1.450 to 1.600. When the refractive index is within this range, a food package can be formed in the same manner as a conventional transparent resin (PMMA has a refractive index of 1.49 and PC has a refractive index of 1.59). Here, the said refractive index nD (25 degreeC) is a numerical value measured by the method based on JIS-K-7142.

<Food packaging>
The shape of the food package of the present invention is not particularly limited as long as it is a shape capable of packaging food, and examples thereof include a sheet shape, a tray shape, a cup shape, a tube shape, and a bottle shape. Here, in addition to human food, the food includes animal food such as pets and livestock. The form of these foods may be solid, liquid, or a paste body that is in an intermediate state between solid and liquid.
The form of wrapping food by the food packaging body of the present invention is not limited to the form of completely wrapping the food to be packaged, the form of partially wrapping the food, the form of placing the food, the form of covering the food, and sandwiching the food It may be a form, a form surrounding the periphery of the food, or a form separating a plurality of foods.

The food package of the present invention is a food package having at least one resin layer. One layer may be sufficient as the number of the resin layers which comprise a package, and two or more layers may be sufficient as it. The food package of the present invention has at least one resin layer containing a β-ferrandylene polymer.
The resin layer containing the β-ferrandylene polymer has a specific gravity of 0.85 or more and less than 1.0, and a β-ferrandol polymer having a glass transition temperature Tg of 80 ° C. or more includes the β-ferrandylene polymer. 50-100 mass% is contained with respect to the total mass of the resin layer containing coalescence.

  The content of the β-ferrandylene polymer contained in the resin layer may be 60 to 100% by mass or 70 to 100% by mass with respect to the total mass of the resin layer. 80-100 mass% may be sufficient, 90-100 mass% may be sufficient, 95-100 mass% may be sufficient, and 98-100 mass% may be sufficient.

  In order to improve the mechanical strength and heat resistance of the food packaging body of the present invention, the mechanical strength and heat resistance of the β-ferrandylene polymer as the main component of the resin layer may be improved. From the viewpoint of improving the mechanical strength and heat resistance of the β-ferrandylene polymer, suitable Tg is preferably 80 to 350 ° C., more preferably 85 to 250 ° C., and still more preferably 90 to 200 ° C. as described above. . From the same viewpoint, the preferred number average molecular weight Mn of the β-ferrandylene polymer is preferably as large as possible, preferably 40,000 or more, more preferably 60,000 or more, still more preferably 80,000 or more, and even more preferably 100,000 or more. Preferably, 120,000 or more is particularly preferable, and 140,000 or more is most preferable. The upper limit of the number average molecular weight Mn is not particularly limited, but is usually preferably 800,000 or less, more preferably 600,000 or less, and still more preferably 400,000 or less, from the viewpoint of improving moldability and workability.

Further, from the same viewpoint as described above, the preferred weight average molecular weight Mw of the β-ferrandylene polymer is preferably as large as possible, preferably 50,000 or more, more preferably 70,000 or more, still more preferably 90,000 or more, and 110,000 or more. Even more preferred is 130,000 or more, most preferred is 150,000 or more. The upper limit of the weight average molecular weight Mw is not particularly limited, but is usually preferably 1 million or less, more preferably 800,000 or less, and still more preferably 600,000 or less from the viewpoint of improving moldability and workability. The weight average molecular weight can be calculated from measurement data obtained by the same method as the number average molecular weight.
From the same viewpoint as described above, the Mw / Mn of the β-ferrandylene polymer is preferably 1 to 25, more preferably 1.05 to 20, and still more preferably 1.1 to 10.

  The specific gravity of the resin layer constituting the food package of the present invention is more preferably 70 to 100 mass when the β-ferrandylene polymer constitutes 50 to 100 mass% of the total mass of the resin layer. % Is usually in the range of 0.85 to 1.0. Since β-ferrandol polymer has a lighter specific gravity than conventional PET resin, polyvinyl chloride resin, etc., the resin layer having β-ferrandylene polymer as a main component is lighter than resin layers made of these conventional resins. Excellent in properties.

  From the viewpoint of improving the heat resistance, light resistance, etc. of the food packaging body of the present invention, at least a part of the olefinic carbon-carbon double bond of the β-ferrandylene polymer used in the present invention is hydrogenated. It is preferable.

When light transmittance is required in the use of the food package of the present invention, the total light transmittance of the food package is preferably as high as possible. The total light transmittance is preferably 80% or more, more preferably 85% or more, and still more preferably 90% or more. For example, when a flat test piece having a thickness of about 100 μm is measured as an example of the food package, its total light transmittance is preferably 80% or more, more preferably 85% or more, 90 % Or more is more preferable, and 95% or more is most preferable.
Here, the total light transmittance is a value measured in accordance with JIS-K-7361: 1997 (ISO13468-1: 1996).

The water absorption rate of the food packaging body of the present invention is 0. When the mass change when the food packaging body is placed in a 60 ° C., 90% RH (relative humidity) atmosphere for 24 hours is measured as the saturated water absorption rate. 2% or less is preferable, 0.1% or less is more preferable, and 0.05% or less is more preferable. Here, the water absorption is a numerical value measured according to JIS-K-7209: 2000.
Since β-ferrandylene polymer has lower water absorption than conventional acrylic resins, the food packaging body of the present invention having the resin layer containing β-ferrandylene polymer as a main component is made of a conventional acrylic resin. Excellent dimensional stability than food packaging.

  The photoelastic coefficient of the food packaging body of the present invention is preferably in the same range as the suitable photoelastic coefficient of the β-ferrandylene polymer described above.

  The refractive index of the food package of the present invention is preferably in the range equivalent to the preferred refractive index of the β-ferrandylene polymer described above.

  In the β-ferrandylene polymer of the resin layer constituting the food packaging body of the present invention, various known compounding agents may be used alone or in combination, as necessary, within a range not impairing the object of the present invention. The above may be combined and mixed.

  The compounding agent is not particularly limited as long as it is usually used in the conventional resin industry. For example, an antioxidant, an ultraviolet absorber, a light stabilizer, a near infrared absorber, a colorant such as a dye or a pigment. , Lubricants, plasticizers (softening agents), antistatic agents, fluorescent brighteners, fillers and the like.

  Examples of the antioxidant include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, and the like. Among these antioxidants, phenolic antioxidants are preferable, and alkyl-substituted phenolic antioxidants are particularly preferable.

  Examples of the phenolic antioxidant include 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,4-di-t- Acrylate compounds such as amyl-6- (1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl) phenyl acrylate; octadecyl-3- (3,5-di-t-butyl-4- Hydroxyphenyl) propionate, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis (methylene-3- (3 ′, 5′-di-) -Butyl-4'-hydroxyphenylpropionate) methane [i.e. pentaerythrimethyl-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenylpropionate)], triethylene glycol bis (3- Alkyl-substituted phenolic compounds such as (3-t-butyl-4-hydroxy-5-methylphenyl) propionate); 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctyl Thio-1,3,5-triazine, 4-bisoctylthio-1,3,5-triazine, 2-octylthio-4,6-bis- (3,5-di-t-butyl-4-oxyanilino)- Examples include triazine group-containing phenol compounds such as 1,3,5-triazine.

  Examples of the phosphorus antioxidant include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4- Di-t-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, etc. Monophosphite compounds; 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecylphosphite), 4,4′-isopropylidene-bis (phenyl-di-alkyl ( And diphosphite compounds such as C12 to C15) phosphite). Among these, monophosphite compounds are preferable, and tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and the like are particularly preferable.

  Examples of the sulfur antioxidant include dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3-thio. Dipropionate, pentaerythritol-tetrakis- (β-lauryl-thiopropionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane Etc.

  The said antioxidant can be used individually or in combination of 2 or more types, respectively. The blending amount of the antioxidant may be appropriately determined as long as the object of the present invention is not impaired, for example, about 0.001 to 5 parts by mass with respect to 100 parts by mass of the β-ferrandylene polymer, Preferably it can be used in the range of 0.01 to 1 part by mass.

  Examples of the ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) 2H-benzotriazole, 2- (3-tert-butyl-2-hydroxy-5-methylphenyl) -5-chloro-2H. -Benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-t-amyl-2-hydroxy Benzotriazole ultraviolet absorbers such as phenyl) -2H-benzotriazole; 4-t-butylphenyl-2-hydroxybenzoate, phenyl-2-hydroxybenzoate Zoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2- (2H- Benzotriazol-2-yl) -4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzotriazole Benzoate ultraviolet absorbers such as 2- (2-hydroxy-4-octylphenyl) -2H-benzotriazole; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone -5-sulfonic acid trihydrate, 2-hydroxy-4-octyloxybenzophenone, 4- Benzophenone ultraviolet rays such as decyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone Absorber; acrylate ultraviolet absorber such as ethyl-2-cyano-3,3-diphenyl acrylate, 2′-ethylhexyl-2-cyano-3,3-diphenyl acrylate; [2,2′-thiobis (4-t -Octylphenolate)] A metal complex ultraviolet absorber such as 2-ethylhexylamine nickel can be used.

  Examples of the light stabilizer include 2,2,6,6-tetramethyl-4-piperidylbenzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, and bis (1,2, 2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonate, 4- (3- (3,5- Di-t-butyl-4-hydroxyphenyl) propionyloxy) -1- (2- (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) ethyl) -2,2,6 And hindered amine light stabilizers such as 1,6-tetramethylpiperidine.

  Examples of the near-infrared absorber include cyanine-based near-infrared absorbers; pyrylium-based near-infrared absorbers; squarylium-based near-infrared absorbers; croconium-based near-infrared absorbers; Dithiol metal complex near infrared absorbers; naphthoquinone near infrared absorbers; anthraquinone near infrared absorbers; indophenol near infrared absorbers; As commercially available near infrared absorbers, SIR-103, SIR-114, SIR-128, SIR-130, SIR-132, SIR-152, SIR-159, SIR-162 (above, Mitsui Toatsu Dye Co., Ltd.) Company-made), Kayasorb IR-750, Kayasorb IRG-002, Kayasorb IRG-003, Kayasorb IR-820B, Kayasorb IRG-022, Kayasorb IRG-023, Kayasorb CY-2, Kayasorb CY-2 , Manufactured by Nippon Kayaku Co., Ltd.).

  The dye is not particularly limited as long as it is uniformly dispersed or dissolved in the β-ferrandylene polymer to be used. For example, an oil-soluble dye (various C.I. Solvent dyes). Specific examples of the oil-soluble dye include, for example, “Color Index” published by The Society of Dyers and Colorists, Vol. 3. Various C.I. I. Solvent dyes may be mentioned.

  Among the pigments, organic pigments include, for example, diarylide pigments such as Pigment Red 38; azo lake pigments such as Pigment Red 48: 2, Pigment Red 53, and Pigment Red 57: 1; Pigment Red 144 and Pigment Red 166. Pigment Red 220, Pigment Red 221 and Pigment Red 248; condensed azo pigments such as Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185 and Pigment Red 208; Pigment Red 122 and the like Quinacridone pigments; perylene pigments such as Pigment Red 149, Pigment Red 178, and Pigment Red 179; and anthraquinone pigments such as Pigment Red 177. Examples of inorganic pigments include titanium oxide, carbon black, red pepper, chrome red, molybdenum red, resurge, and iron oxide.

  When coloring is required for the food package of the present invention, any of the dyes and pigments can be used within the scope of the present invention. For example, in applications that require consideration of micro optical properties, coloring with dyes is preferred. In addition, the ultraviolet absorber may visually show a yellow to red color, and the near-infrared absorber may visually show a black color. Therefore, these light absorbers and the dyes and pigments are strictly used. There is no need to distinguish between them. Moreover, you may use combining these light absorption materials, the said dye, and a pigment.

Examples of the lubricant include organic compounds such as aliphatic alcohol esters, polyhydric alcohol esters, and partial esters, and inorganic fine particles.
Examples of the organic compound include glycerol monostearate, glycerol monolaurate, glycerol distearate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and the like.
Examples of the inorganic fine particles include oxides, sulfides, hydroxides, nitrides, halides, carbonates, sulfates, acetates of Group 1, Group 2, Group 4, and Group 6-14 elements of the Periodic Table. Examples thereof include fine particles such as phosphates, phosphites, organic carboxylates, silicates, titanates, borates, and hydrates thereof, complex compounds centered on them, and natural compounds.

  Examples of the plasticizer include tricresyl phosphate, trixylenyl phosphate, triphenyl phosphate, triethylphenyl phosphate, diphenyl cresyl phosphate, monophenyl dicresyl phosphate, diphenyl monoxylenyl phosphate Phosphoric acid triester plasticizers such as monophenyldixylenyl phosphate, tributyl phosphate, triethyl phosphate; dimethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-2 phthalate -Phthalic acid ester plasticizers such as ethylhexyl, diisononyl phthalate, octyldecyl phthalate, and butylbenzyl phthalate; fatty acid monobasic acid esters such as butyl oleate and glycerol monooleate System plasticizers; dihydric alcohol ester-based plasticizers; oxy ester plasticizer and the like. Among these, phosphate triester plasticizers are preferable, and tricresyl phosphate and trixylenyl phosphate are particularly preferable.

  Other specific examples of the plasticizer include squalane (C30H62, Mw = 422.8), liquid paraffin (white oil, ISO VG10, ISO VG15, ISO VG32, ISO VG68, ISO VG100 as defined in JIS-K-2231. ISO VG8 and ISO VG21), polyisobutene, hydrogenated polybutadiene, hydrogenated polyisoprene and the like. Among these, squalane, liquid paraffin, and polyisobutene are preferable.

  Examples of the antistatic agent include long-chain alkyl alcohols such as stearyl alcohol and behenyl alcohol, fatty acid esters of polyhydric alcohols such as glycerin monostearate and pentaerythritol monostearate, and stearyl alcohol and behenyl alcohol are particularly preferable.

  The said compounding agent can be used individually or in mixture of 2 or more types. The mixing ratio is appropriately selected as long as the object of the present invention is not impaired. The amount of each compounding agent is appropriately selected within a range that does not impair the object of the present invention. However, for each compounding agent, the amount is usually 0. 100 parts by mass of the β-ferrandylene polymer. It is preferable to use in the range of about 001-5 parts by mass, preferably 0.01-1 part by mass.

  Other polymer components can also be blended with the β-ferrandylene polymer constituting the food packaging according to the present invention, if necessary, within a range that does not impair the object of the present invention.

  The thickness of the resin layer containing the β-ferrandylene polymer constituting the food packaging body of the present invention is not particularly limited, and may be appropriately set depending on the use, for example, the thickness over the entire resin layer, It is preferably 1 μm to 1000 μm, and more preferably 5 μm to 400 μm. When the thickness is in the above preferable range, the mechanical strength of the resin layer can be easily exhibited, and the ease of handling in various applications can be further enhanced.

The thickness variation of the resin layer is preferably 3.0% or less, and more preferably 2.4% or less of the thickness of the resin layer. When the variation in thickness is so small, the rotation accuracy of the optical disk of the present invention can be improved.
Here, as a method for measuring the film thickness, there are a radiation method (β-ray, γ-ray, χ-ray, fluorescent χ-ray, etc.), optical interference method, laser method, capacitance method, microwave method, contact method, and the like. However, it is not particularly limited. In the case of the contact method, it is preferable to conform to JIS-K-7130: 1999.

About the food packaging body of this invention, 60 MPa or more is preferable, as for the tensile strength when it measures by a 100-micrometer-thick film shape, 70 MPa or more is more preferable, and 80 MPa or more is still more preferable. The upper limit of the tensile strength is not particularly limited, and the higher the strength, the better. However, the upper limit is usually about 100 MPa.
Here, the said tensile strength is a numerical value calculated | required by the measuring method based on ISO527.

<Method for producing food packaging>
The method for molding the food packaging body of the present invention is not particularly limited, and known molding methods can be applied. For example, injection molding, extrusion molding, extrusion blow molding, injection blow molding, multilayer blow molding , Connection blow molding method, double wall blow molding method, stretch blow molding method, vacuum molding method, rotational molding method, solution casting method and the like. By adopting these molding methods, food packaging bodies such as films, sheets, tubes, and bottles can be molded.
As an example, when forming into a sheet form (film form), the thickness may be suitably adjusted according to the purpose, and can be adjusted to a thickness of about 5 μm to 5000 μm or about 10 μm to 500 μm, for example.

  A sheet-like or film-like food package is formed by forming a composition containing β-ferrandylene polymer into a sheet or film shape by a known method, and then stretching in the axial or biaxial direction, and further heat-treating as necessary. The stretched sheet or stretched film obtained by this may be sufficient. The sheet-like or film-like food package is a rolled sheet or film obtained by further rolling after forming a composition containing β-ferrandylene polymer into a sheet or film shape by a known method. Also good. In addition, the food packaging body of the present invention is obtained by forming a composition containing β-ferrandylene polymer into a sheet or film shape or a desired shape by a known method, and further vacuum forming, pressure forming, vacuum pressure forming, etc. It may be a tray or cup-shaped container obtained by performing the thermoforming process. The food package of the present invention is a bottle or cup obtained by forming a composition containing β-ferrandylene polymer into a pipe shape or a desired shape by a known method, and further performing stretch blow molding or the like. It may be a container.

  The food package of the present invention may have a single-layer structure composed only of the resin layer containing the β-ferrandylene polymer described above, or a multilayer structure in which other thermoplastic resins are laminated. It may be. As the multilayer structure, one layer or two or more layers is a resin layer (resin layer A) containing the β-ferrandylene polymer described above, and the remaining resin layer (resin layer B) is made of another resin material. The multilayer structure which is the formed layer can be illustrated.

  The order of lamination of the resin layer A and the resin layer B is not particularly limited, and the resin layer B may be laminated on one side or both sides of the resin layer A, or the resin layer A is provided on one side or both sides of the resin layer B. It may be laminated. Resin layer A and resin layer B can constitute any layer in the multilayer structure. At this time, each resin layer may be one layer or two or more layers. In addition, the thickness of each resin layer can be set to an arbitrary thickness independently. In many applications, the thickness is preferably 5 μm to 50000 μm, more preferably 5 μm to 10000 μm, and more preferably 5 μm to 5000 μm. Is more preferable.

Examples of the other resin materials include polyamide resins such as nylon 6, nylon 66, and nylon 12; polyester resins such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, and copolymers thereof; polypropylene Irradiation-crosslinked polypropylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid ester copolymer Examples thereof include polyolefin resins such as polymers; thermoplastic resins such as polystyrene resins, polyvinyl chloride resins, acrylic resins, polyvinylidene chloride resins, polyacetal resins, and polycarbonate resins. By using a polyamide-based resin, a polyester-based resin, or a polyolefin-based resin, the impact resistance, heat resistance, drop strength, and the like of the food packaging body of the present invention can be further improved.
One type of the resin material may be used alone, or two or more types may be used in combination.

  The method for forming the food package of the present invention as a laminate having the multilayer structure is not particularly limited, and a known lamination method can be applied. Examples thereof include a co-extrusion method, a dry lamination method, a sand lamination method, an extrusion lamination method, a co-extrusion lamination method, and a solution coating method. Here, the co-extrusion method is a method of laminating a plurality of molten thermoplastic resins while simultaneously extruding them, and forming a film at the die outlet. After film formation, stretching, thermoforming and the like can be further performed as necessary.

  As one of the remaining resin layers (resin layer B), for example, a known gas barrier layer having excellent oxygen barrier properties can be provided. The thickness of the gas barrier layer is not particularly limited, and can usually be selected from the range of about 5 μm to 250 μm, preferably 10 μm to 100 μm. In addition, by applying a known resin material capable of improving performance such as moisture permeability, heat resistance, heat sealability, and transparency as the other thermoplastic resin constituting the remaining resin layer, the food of the present invention The performance of the package can be further improved.

  Examples of the resin material constituting the gas barrier layer include thermoplastic resins such as ethylene-vinyl alcohol copolymer, polyamide resin, polyvinylidene chloride resin, polyvinyl alcohol resin, and fluorine resin. More specifically, for example, a saponified copolymer obtained by saponifying an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol% so that the saponification degree is 96 mol% or more. Nylon 6, nylon 6,6, nylon 6 / 6,6 copolymer, metaxylylene adipamide (MXD6 nylon), nylon 6,10, nylon 11, nylon 12, nylon 13, etc. per 100 carbons And polyamide resins having a number of amide groups in the range of 5 to 50. In addition, inorganic substances such as clay, silica, and aluminum, and starch are also applicable as the material of the gas barrier layer.

When the film thickness is 20 μm, the gas barrier layer preferably has an oxygen permeability of 1 cc · 20 μm / m ² · day · atm or less at 20 ° C. and 65% RH (relative humidity). Usually, as the film thickness increases, the gas barrier property tends to increase. By providing the gas barrier layer having such oxygen permeability, the gas barrier property as the whole of the food packaging body of the present invention can be enhanced as compared with the gas barrier layer.

The resin layer containing β-ferrandylene polymer constituting the food package of the present invention is a polyolefin-based resin with respect to lightness, light transmission, heat resistance, water absorption, water vapor barrier property, gas barrier property, mechanical strength, and the like. Compared to a resin layer made of a petroleum-derived conventional resin such as polyester, it has the same or better physical properties.
In addition, a resin layer made of a conventionally known β-pinene polymer has excellent lightness equivalent to that of a resin layer containing a β-ferrandylene polymer constituting the food packaging body of the present invention. In terms of mechanical strength, the resin layer containing β-ferrandylene polymer is superior. As one of the factors, it can be considered that β-ferrandylene tends to form a polymer having a large number average molecular weight and easily forms a resin layer having excellent mechanical strength.
Therefore, by using the food packaging body of the present invention, a thin and lightweight food packaging body having the same strength as the conventional one can be obtained.
The food package of the present invention is excellent in mechanical strength, heat resistance, transparency, water vapor barrier property, gas barrier property, does not generate harmful halogen-containing gas at the time of incineration, and is lightweight. It is useful as a packaging material for many foods such as fresh foods such as meat and fish, frozen foods, retort foods, soups, cereals, confectionery and bread.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.

[Synthesis Example 1]
As a food packaging material according to the present invention, a hydrogenated product of β-ferrandylene polymer was synthesized as follows.
[Production of β-ferrandylene polymer]
In a dried glass flask, 68 parts by weight of hexane (manufactured by Kanto Chemical Co., Inc.) was added and cooled to 0 ° C. A Lewis acid catalyst EtAlCl ₂ (ethylaluminum dichloride) (17% hexane solution, about 1 mol / L, manufactured by Tokyo Chemical Industry Co., Ltd.), 0.37 parts by weight, was dispersed well and obtained by chemical synthesis. Then, 5.1 parts by weight of β-ferrandolene (purity 83.3%) was slowly added dropwise. After 1 minute, 8 parts by weight of methanol was added to stop the polymerization reaction. After the reaction solution was transferred to a separatory funnel, 20 parts by weight of 1% sodium hydroxide solution was added and stirred well, and then the aqueous phase was separated and removed. Next, the organic solvent phase was slowly evaporated by an evaporator, and the reaction solution was concentrated. About 40 parts by weight of the concentrated reaction solution was slowly added dropwise to 240 parts by weight of methanol to reprecipitate the polymer. The resulting precipitate was separated from the solution by filtration and sufficiently dried to obtain a β-ferrandylene polymer. The reaction rate of the monomer during the reaction was 100%.

  The obtained β-ferrandylene polymer had a number average molecular weight of 105,300 and a glass transition temperature of 85 ° C.

[Hydrogenation]
In a pressure vessel sufficiently purged with nitrogen, 61 parts by weight of dehydrated hexane and 4 parts by weight of the obtained β-ferrandrene polymer were charged and sufficiently dissolved. Next, 10 parts by weight of a palladium / alumina catalyst (Pd: 5%, manufactured by Wako Pure Chemical Industries, Ltd.) was added, and a hydrogenation reaction was performed at 120 ° C. for 10 hours in an 8 MPa hydrogen atmosphere. The reaction solution is filtered using a filter made of Teflon (registered trademark) with a pore size of 1 μm, and after removing the catalyst, it is reprecipitated with methanol, the precipitate is sufficiently dried, and a hydrogenated product of β-ferrandylene polymer 4.5 parts by weight were obtained.

The hydrogenation proportion of the resulting β-phellandrene polymer was calculated by ^{1 H-NMR} spectrum measurement, it was 99.9%. The number average molecular weight of the polymer was 104,000, the glass transition temperature was 130 ° C., and the specific gravity was 0.93.

(Reaction yield)
By the method using o-dichlorobenzene as an internal standard, it was calculated from the reduction rate of the signal area of the signal of 5.5 to 6.5 ppm derived from the conjugated double bond of β-ferrandolene monomer.

(Number average molecular weight)
It was measured in terms of standard polystyrene. As the apparatus, an LC-20AD liquid feeding unit manufactured by Shimadzu Corporation and a RID-10 differential refractive index detector were used. Two columns, Shodex KF803, manufactured by Showa Denko KK were used. As the solvent, THF (40 ° C.) was used.

(Hydrogen addition rate)
Deuterated chloroform was used as the solvent. A 0 ppm correction was made with TMS. The H-NMR spectrum was measured using an NMR device manufactured by JEOL Ltd., JNM-ECX400 (400 MHz). The measurement was performed at room temperature.
The reduction rate of the peak of 5.0 to 6.0 ppm due to the unsaturated bond in the spectrum before hydrogenation was determined. At this time, the ratio A / B of the integral value A of the signal derived from the proton of the olefinic double bond of 5.0 to 6.0 ppm and the integral value B of the signal derived from the proton of the saturated hydrocarbon of 0.5 to 2.5 ppm is Using. The hydrogenation rate (%) was calculated by (A / B (Before) −A / B (After)) × 100 / A / B (Before).

(Total light transmittance)
A test piece having a thickness of 0.1 mm made of the above-prepared β-ferrandylene polymer hydrogenated product was formed by melt extrusion, and this was used as a measurement sample to measure the total light transmittance.
The total light transmittance was measured according to JIS-K-7361: 1997 (ISO13468-1: 1996). As a measuring device, a haze meter TC-H3DPK / II manufactured by Tokyo Denshoku Co., Ltd. was used.

(Glass-transition temperature)
According to JIS-K-7121-1987 “Plastic Transition Temperature Measuring Method”, the glass transition temperature Tg of the hydrogenated β-ferrandylene polymer prepared above was measured using a differential calorimeter. As the apparatus, DSC-60 manufactured by Shimadzu Corporation was used.

(Water absorption rate)
A plate having a length of 140 mm, a width of 60 mm, and a thickness of 0.8 mm was press-molded using the β-ferrandylene polymer hydrogenated product prepared above. This plate was placed in an atmosphere of 60 ° C. and 90% RH for 10 days, the ratio of the mass increased from the initial mass was calculated by the following formula, and the water absorption rate was determined.
Water absorption rate (%) = increase in mass x 100 / initial mass

(Light resistance)
A 1.0 mm thick test piece made of the hydrogenated β-ferrandrene polymer prepared above was molded by melt extrusion, and the light resistance was evaluated using this as a measurement sample.
The test piece was placed in an ultraviolet exposure test apparatus and subjected to an accelerated exposure test for 100 hours, and the yellowing degree (ΔYI) before and after the YI (yellow index) test was measured. YI was measured according to ASTM-G53 and evaluated according to the following criteria.
ΔYI = (YI after 100 hours of UV exposure) − (YI before UV exposure)
A: ΔYI ≦ 1 ... Long-term light resistance is very good
B: 1 <ΔYI: long-term light resistance is poor

(Tensile strength)
By a melt extrusion method, a 0.1 mm thick test piece made of the hydrogenated β-ferrandylene polymer prepared above was molded, and this was used as a measurement sample to evaluate the tensile strength.
In accordance with ISO 527, using an autograph (manufactured by Shimadzu Corporation), the tensile strength at 23 ° C. was measured and evaluated according to the following criteria.
A: 60 MPa or more: Strong tensile strength and good.
B: Less than 60 MPa ... It has a weak tensile strength and is defective.

(chemical resistance)
By a melt extrusion method, a 0.1 mm thick test piece made of the hydrogenated β-ferrandrene polymer prepared above was molded, and this was used as a measurement sample to evaluate chemical resistance as follows.
The test pieces were individually immersed in a pH 9 sodium carbonate aqueous solution, pH 4 hydrochloric acid, and ethanol solvent for 48 hours, and then the appearance of each test piece was observed and judged according to the following criteria.
A: The appearance was not changed in any solvent, and the turbidity and the total light transmittance were not changed.
B: Appearance changed with any of the solvents, and turbidity or total light transmittance decreased.

(specific gravity)
The specific gravity of the food package produced by the method described later was measured according to A method of JIS-K-7112: 1999 and evaluated according to the following criteria.
A: Specific gravity <1.0 ... Specific gravity is light and good.
B: 1.0 ≦ specific gravity <1.1 ... The specific gravity is heavy and it is defective.
C: 1.1 ≦ specific gravity: The specific gravity is heavier and poor.

(Moisture resistance)
About the food packaging body produced with the method mentioned later, the durability test of 1000 hours was done on 80 degreeC and 90% RH conditions, and the external appearance change was observed visually. Judgment was made according to the following criteria.
A: There was no visual change and a good appearance was maintained.
B: Cloudiness or deformation was observed, and the appearance was deteriorated.

(Water absorption rate)
The food package produced by the method described later was placed in an atmosphere of 60 ° C. and 90% RH for 10 days, and the ratio of the increased mass from the initial mass was calculated by the following formula to determine the water absorption rate.
Water absorption rate (%) = increase in mass x 100 / initial mass

<Manufacture of food packaging>
[Example 1]
By a multilayer extrusion molding method, an ethylene-vinyl alcohol copolymer resin (“Soarnol” manufactured by Nippon Gosei Kagaku) is formed on the resin layer (thickness: 100 μm) of the β-ferrandylene polymer hydrogenated product obtained in Synthesis Example 1 above. A food package having a multilayer structure in which layers (thickness: 100 μm) were laminated was produced. The evaluation results are shown in the following table.

[Comparative Example 1]
The pellets of the alicyclic polyolefin resin (ZEONOR 1060R manufactured by Nippon Zeon Co., Ltd., glass transition temperature: 102 ° C.) were dried at 80 ° C. for 4 hours using a hot air dryer. Next, using the same apparatus as in Example 1, the dried pellets were melt extruded at 260 ° C. to form a food package. Each physical property of the prepared food package was measured in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Comparative Example 2]
The pellets of polymethyl methacrylate resin (Acrypet TF-8, manufactured by Mitsubishi Rayon Co., Ltd.) were dried at 85 ° C. for 6 hours using a hot cloth drier. Next, using the same apparatus as in Example 1, the dried pellets were melt extruded at 220 ° C. to form a food package. Each physical property of the prepared food package was measured in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Comparative Example 3]
Polycarbonate resin (Mitsubishi Engineering Plastics, Iupilon H-3000)
Was melt extruded at 280 ° C. to form a food package. Each physical property of the prepared food package was measured in the same manner as in Example 1. The evaluation results are shown in Table 1.

  From the above results, it is clear that the food packaging body of Example 1 is a food packaging body having high light transmittance, heat resistance, light resistance and tensile strength, low water absorption, and excellent light weight. It is understood that the food packaging body of Example 1 has an excellent balance of physical properties as compared with the food packaging bodies of Comparative Examples 1 to 3, and is advantageous in the use of the food packaging body.

  The configurations and combinations thereof in the embodiments described above are examples, and the addition, omission, replacement, and other modifications of the configurations can be made without departing from the spirit of the present invention. Further, the present invention is not limited by each embodiment, and is limited only by the scope of the claims.

  The present invention can be widely used in fields such as food distribution.

Claims (8)

A food package having at least one resin layer,
The β-ferrandylene polymer having a specific gravity of 0.85 or more and less than 1.0 and a glass transition temperature of 80 ° C. or more is contained in an amount of 50 to 100% by mass with respect to the total mass of the one resin layer. A food packaging body characterized by that. The food packaging body according to claim 1, wherein the β-ferrandlene polymer is obtained by polymerizing at least one of β-ferrandolene represented by the following chemical formulas (I) and (II).

The β ferrandylene polymer contains a total of 50 mass% or more of β ferrandylene units represented by the following chemical formulas (I-1), (I-2), (II-1) and (II-2). The food packaging body according to claim 1, wherein the food packaging body is provided.

The food packaging body according to any one of claims 1 to 3, wherein the β-ferrandylene polymer has a number average molecular weight Mn of 40,000 or more. The food packaging body according to any one of claims 1 to 4, wherein at least a part of the olefinic carbon-carbon double bond of the β-ferrandylene polymer is hydrogenated. The food packaging body according to claim 5, wherein a hydrogenation rate of the β-ferrandylene polymer is 70% or more. 7. The gas barrier layer according to claim 1, further comprising a gas barrier layer having an oxygen permeability of 1 cc · 20 μm / m ² · day · atm or less at 20 ° C. and 65% RH. The food packaging described. The food packaging body according to any one of claims 1 to 7, wherein at least one layer selected from a polyester layer, a polyamide layer, and a polyolefin layer is further laminated.