JP2008137671A - Foodstuff container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foodstuff container which is excellent in not only safety and heat resistance but also oil resistance and impact resistance, and has a small haze value. <P>SOLUTION: The foodstuff container is obtained by molding a norbornene ring-opening polymer hydrogenated product which is obtained by hydrogenating ≥80% of C-C double bonds of a ring-opening polymer obtained by ring-opening polymerization of 2-norbornene or a monomer mixture consisting of 2-norbornene and a substituted group-containing norbornene monomer, and which keeps the presence ratio of 2-norbornene-derived repeating units (A) to the whole repeating units ranging 90-100 wt.%, and the presence ratio of the substituted group-containing norbornene monomer-derived repeating units (B) to the whole repeating units is 0-10 wt.%, and the melting point is in a range of 110-145°C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention comprises 2-norbornene or a hydrogenated norbornene-based ring-opening polymer obtained by ring-opening polymerization and hydrogenation of a monomer mixture comprising 2-norbornene and a substituent-containing norbornene-based monomer. It relates to food containers.

Conventionally, synthetic resins have been frequently used in dishes used for canteens, containers for storing and selling processed foods such as retort foods, etc. because they are economical and lightweight.
As synthetic resins used in these containers, melamine resin, polypropylene (PP), polycarbonate (PC), alicyclic structure-containing polymer (COP), and the like have been proposed.

However, a container made of melamine resin has a problem in terms of safety because it has a low mechanical strength and is brittle, and an uncured product may be eluted and mixed into food.
A PP container has a problem that it has a low surface hardness and is easily damaged, and has insufficient heat resistance, so that it is easily deformed when sterilized by steam.
In addition, when a container made of PC is sterilized by steam, there is a problem that it may be whitened by hydrolysis and the appearance may be significantly impaired.

On the other hand, a COP container has little elution of impurities, is excellent in safety, is not easily deformed or whitened even when subjected to high-temperature treatment such as steam sterilization, and has excellent heat resistance.
However, when this COP container comes into contact with cooking oils such as fats and fats and salad oil contained in foods, the impact resistance decreases, and when used for a long period of time, it will crack and crack due to the impact of dropping or washing. There was a problem that it was likely to occur.

In order to solve these problems, Patent Document 1 proposes a food container that is composed of an alicyclic structure-containing polymer and normally does not crack when immersed in methyl oleate at 75 ° C. for 24 hours. .
However, in recent years, the treatment temperature has been set higher (about 90 ° C.) in order to further improve hygiene management and increase the efficiency of disinfection treatment. Therefore, the food containers described in this document are not necessarily oil-resistant. It is no longer satisfactory in terms.

Patent Documents 2 and 3 disclose an injection molded product obtained by injection molding of a norbornene polymer having a melting point and a blow molded product obtained by blow molding.
In these documents, crystalline norbornene monomer ring-opening polymer hydrides are extensively described as “norbornene-based polymers having a melting point”. It is a ring-opening polymer hydride of cyclopentadiene.

This dicyclopentadiene ring-opened polymer hydride is a high melting point polymer having a melting point (Tm) of 200 to 400 ° C. For this reason, the dicyclopentadiene ring-opening polymer hydride must be molded at a high temperature, and there is a problem that resin burn (resin discoloration) is likely to occur in addition to the heavy load on the molding machine. . Also, dicyclopentadiene ring-opening polymer hydride is inferior in impact resistance when immersed in salad oil, has a large haze value, and is hardly soluble in organic solvents, so it is derived from the catalyst. There is a problem that it is difficult to remove and purify the metal.
JP 2001-010626 A JP 2002-20464 A JP 2002-249554 A

  The present invention has been made in view of the actual situation of the prior art, and provides a food container having not only safety and heat resistance, but also excellent oil resistance and impact resistance and a low haze value. Is an issue.

  In order to solve the above-mentioned problems, the present inventors have intensively studied a food container made of a synthetic resin. As a result, the carbon-carbon double bond of the ring-opening polymer obtained by ring-opening polymerization of 2-norbornene or a monomer mixture composed of 2-norbornene and a substituent-containing norbornene monomer as a synthetic resin Norbornene-based ring-opening polymer hydride obtained by hydrogenating 80% or more of the above, which is a repeating unit derived from 2-norbornene (A) and a repeating unit derived from a substituent-containing norbornene monomer (B ) Is present in a specific range, and a norbornene-based ring-opening polymer hydride having a specific melting point is used, not only in safety and heat resistance, but also in oil resistance and impact resistance, haze The present inventors have found that a food container having a small value can be obtained and have completed the present invention.

  Thus, according to the first aspect of the present invention, carbon-carbon of the ring-opening polymer obtained by ring-opening polymerization of 2-norbornene or a monomer mixture comprising 2-norbornene and a substituent-containing norbornene-based monomer. A hydrogenated norbornene-based ring-opening polymer obtained by hydrogenating 80% or more of double bonds, wherein the proportion of the repeating unit (A) derived from 2-norbornene is 90 to 100% by weight based on all repeating units. And the norbornene ring-opening weight in which the proportion of the repeating unit (B) derived from the substituent-containing norbornene monomer is 0 to 10% by weight with respect to all repeating units and the melting point is in the range of 110 to 145 ° C. A food container obtained by molding a combined hydride is provided.

  In the food container of the present invention, the norbornene-based ring-opening polymer hydride has a weight average molecular weight (Mw) in terms of standard polystyrene by gel permeation chromatography (GPC) of 50,000 to 200,000. And the molecular weight distribution (Mw / Mn) is preferably 1.5 to 5.0.

  According to the present invention, a food container having not only safety and heat resistance but also oil resistance and impact resistance and a low haze value is provided.

Hereinafter, the present invention will be described in detail.
The food container of the present invention is a carbon-carbon double of a ring-opening polymer obtained by ring-opening polymerization of a monomer mixture comprising 2-norbornene or 2-norbornene and a substituent-containing norbornene monomer. A hydride of a norbornene-based ring-opening polymer obtained by hydrogenating 80% or more of the bonds, the abundance ratio of the repeating unit (A) derived from 2-norbornene with respect to all repeating units is 90 to 100% by weight, Norbornene ring-opening polymer hydrogen having a repeating unit (B) derived from a substituent-containing norbornene monomer in an existing ratio of 0 to 10% by weight and a melting point of 110 to 145 ° C. It is obtained by molding a chemical.

(Norbornene ring-opening polymer hydride)
The norbornene-based ring-opening polymer hydride used in the present invention is obtained after (i) 2-norbornene is obtained by ring-opening polymerization of 2-norbornene in the presence of a metathesis polymerization catalyst. Or (ii) a monomer mixture comprising 2-norbornene and a substituent-containing norbornene-based monomer, obtained by hydrogenating 80% or more of the carbon-carbon double bonds of the ring-opening polymer obtained A ring-opening copolymer of 2-norbornene and a substituent-containing norbornene monomer is obtained by ring-opening polymerization in the presence of a metathesis polymerization catalyst, and then the carbon-carbon double of the resulting ring-opening copolymer is obtained. It is obtained by hydrogenating 80% or more of the bonds.

  2-Norbornene is a known compound and can be obtained, for example, by reacting cyclopentadiene with ethylene.

  The substituent-containing norbornene-based monomer is a compound having a norbornene skeleton in the molecule (excluding 2-norbornene). The “substituent-containing norbornene monomer” used in the present invention includes a norbornene compound having a condensed ring in addition to a 2-norbornene derivative having a substituent.

  Examples of the substituent-containing norbornene monomer include a norbornene monomer that does not have a ring condensed with a norbornene ring in the molecule, and a polycyclic norbornene monomer having three or more rings.

  Specific examples of the norbornene-based monomer having no ring condensed with the norbornene ring in the molecule include 5-methylnorbornene, 5-ethylnorbornene, 5-butylnorbornene, 5-hexylnorbornene, 5-decylnorbornene, 5 Norbornenes having an alkyl group such as cyclohexyl norbornene and 5-cyclopentylnorbornene; norbornene having an alkenyl group such as 5-ethylidenenorbornene, 5-vinylnorbornene, 5-propenylnorbornene, 5-cyclohexenylnorbornene and 5-cyclopentenylnorbornene Norbornenes having an aromatic ring such as 5-phenylnorbornene; 5-methoxycarbonylnorbornene, 5-ethoxycarbonylnorbornene, 5-methyl-5-methoxycarbonylno Bornene, 5-methyl-5-ethoxycarbonylnorbornene, norbornenyl-2-methylpropionate, norbornenyl-2-methyloctanoate, 5-hydroxymethylnorbornene, 5,6-di (hydroxymethyl) norbornene, 5,5- Norbornenes having a polar group containing an oxygen atom such as di (hydroxymethyl) norbornene, 5-hydroxyisopropylnorbornene, 5,6-dicarboxynorbornene, 5-methoxycarbonyl-6-carboxynorbornene; and 5-cyanonorbornene And norbornenes having a polar group containing a nitrogen atom.

  The polycyclic norbornene monomer having three or more rings is a norbornene monomer having a norbornene ring and one or more rings condensed with the norbornene ring in the molecule. Specific examples thereof include monomers represented by the following formula (1) or formula (2).

(Wherein R ¹ and R ² are each independently a hydrogen atom; a halogen atom; an optionally substituted hydrocarbon group having 1 to 20 carbon atoms; or a substitution containing a silicon atom, an oxygen atom or a nitrogen atom) And R ³ is a divalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent.

(Wherein R ^{4 to} R ⁷ are each independently a hydrogen atom; a halogen atom; an optionally substituted hydrocarbon group having 1 to 20 carbon atoms; or a substitution containing a silicon atom, an oxygen atom or a nitrogen atom) And R ⁴ and R ⁶ may be bonded to each other to form a ring, and m is 1 or 2.)

Specific examples of the monomer represented by the formula (1) include dicyclopentadiene, methyldicyclopentadiene, dimethyldicyclopentadiene, and tricyclo [5.2.1.0 ^2,6 ] dec-8-ene. And so on. In addition, tetracyclo ^{[9.2.1.0 2,10.} 0 ^3,8 ] tetradeca-3,5,7,12-tetraene (also referred to as 1,4-methano-1,4,4a, 9a-tetrahydro-9H-fluorene), tetracyclo [10.2.1.0 ^{2 , 11} . Norbornene derivatives having an aromatic ring such as 0 ^4,9 ] pentadeca-4,6,8,13-tetraene (also referred to as 1,4-methano-1,4,4a, 9,9a, 10-hexahydroanthracene) Can also be mentioned.

  Examples of the monomer represented by the formula (2) include tetracyclododecenes in which m is 1 and hexacycloheptadecenes in which m is 2.

  Specific examples of tetracyclododecenes include tetracyclododecene, 8-methyltetracyclododecene, 8-ethyltetracyclododecene, 8-cyclohexyltetracyclododecene, and 8-cyclopentyltetracyclododecene. Tetracyclododecenes having a substituted or alkyl group; 8-methylidenetetracyclododecene, 8-ethylidenetetracyclododecene, 8-vinyltetracyclododecene, 8-propenyltetracyclododecene, 8-cyclohexenyltetra Tetracyclododecenes having a double bond outside the ring such as cyclododecene and 8-cyclopentenyltetracyclododecene; tetracyclododecenes having an aromatic ring such as 8-phenyltetracyclododecene; 8-methoxy Carbonyltetracyclododecene, 8-methyl 8-methoxycarbonyltetracyclododecene, 8-hydroxymethyltetracyclododecene, 8-carboxytetracyclododecene, tetracyclododecene-8,9-dicarboxylic acid, tetracyclododecene-8,9-dicarboxylic anhydride Tetracyclododecenes having substituents containing oxygen atoms such as tetracyclododecenes having substituents containing nitrogen atoms such as 8-cyanotetracyclododecene and tetracyclododecene-8,9-dicarboxylic imides Decenes; tetracyclododecenes having a substituent containing a halogen atom such as 8-chlorotetracyclododecene; tetracyclododecenes having a substituent containing a silicon atom such as 8-trimethoxysilyltetracyclododecene Etc.

  Specific examples of hexacycloheptadecenes include hexacycloheptadecene, 12-methylhexacycloheptadecene, 12-ethylhexacycloheptadecene, 12-cyclohexylhexacycloheptadecene, and 12-cyclopentylhexacycloheptadecene. Hexacycloheptadecenes having a substituted or alkyl group; 12-methylidenehexacycloheptadecene, 12-ethylidenehexacycloheptadecene, 12-vinylhexacycloheptadecene, 12-propenylhexacycloheptadecene, 12-cyclohexenylhexa Hexacycloheptadecenes having a double bond outside the ring such as cycloheptadecene and 12-cyclopentenylhexacycloheptadecene; having an aromatic ring such as 12-phenylhexacycloheptadecene Hexacycloheptadecenes; 12-methoxycarbonylhexacycloheptadecene, 12-methyl-12-methoxycarbonylhexacycloheptadecene, 12-hydroxymethylhexacycloheptadecene, 12-carboxyhexacycloheptadecene, hexacycloheptadecene Hexacycloheptadecenes having a substituent containing an oxygen atom such as 12,13-dicarboxylic acid and hexacycloheptadecene 12,13-dicarboxylic anhydride; 12-cyanohexacycloheptadecene, hexacycloheptadecene 12,13 -Hexacycloheptadecenes having a substituent containing a nitrogen atom such as dicarboxylic imide; hexacycloheptadecenes having a substituent containing a halogen atom such as 12-chlorohexacycloheptadecene; Such as hexamethylene cycloheptanone decene compound having a substituent containing a silicon atom such as trimethoxysilyl hexamethylene cycloheptanone decene and the like. These norbornene monomers can be used alone or in combination of two or more.

  In the present invention, the aforementioned 2-norbornene and / or substituent-containing norbornene-based monomer and other monomers capable of ring-opening copolymerization can be used in combination.

Examples of other monomers capable of ring-opening copolymerization with 2-norbornene and / or substituent-containing norbornene monomers include monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene and their derivatives; cyclohexadiene, cyclohepta And cyclic dienes such as dienes and derivatives thereof.

  The composition of 2-norbornene or a monomer mixture comprising 2-norbornene and a substituent-containing norbornene-based monomer is such that 2-norbornene is usually 90 to 100% by weight, preferably 95 to 99% by weight, more preferably Is 97 to 99% by weight, and the substituent-containing norbornene monomer is usually 0 to 10% by weight, preferably 1 to 5% by weight, more preferably 1 to 3% by weight.

  Examples of the metathesis polymerization catalyst include, for example, Japanese Patent Publication No. 41-20111, Japanese Patent Publication No. 46-14910, Japanese Patent Publication No. 57-17883, Japanese Patent Publication No. 57-61044, Japanese Patent Publication No. 54-86600, A general metathesis polymerization catalyst consisting essentially of (a) a transition metal compound catalyst component and (b) a metal compound co-catalyst component, as described in JP-A-58-127728 and JP-A-1-240517; Schrock type polymerization catalyst (Japanese Patent Application Laid-Open No. 7-179575, Schrock et al., J. Am. Chem. Soc., 1990, Vol. 112, page 3875-) and Grubbs type polymerization catalyst (Fu et al. , J. Am. Chem. Soc., 1993, 115, 9856-; Nguyen et al., J. Am. . M.Soc, 1992 years, 114th volume, 3974 pp ~;., And the like; Grubbs et al, such as WO98 / 21214 pamphlet) living ring-opening metathesis catalyst such as.

  Among these, a metathesis polymerization catalyst comprising (a) a transition metal compound catalyst component and (b) a metal compound promoter component is preferable in order to adjust the molecular weight distribution of the obtained polymer to a suitable range.

The (a) transition metal compound catalyst component is a compound of a transition metal of Groups 3 to 11 of the periodic table. For example, halides, oxyhalides, alkoxyhalides, alkoxides, carboxylates, (oxy) acetylacetonates, carbonyl complexes, acetonitrile complexes, hydride complexes, derivatives of these, or derivatives of these transition metals. Examples thereof include a complexed product of a complexing agent such as P (C ₆ H ₅ ) ₅ .

Specific examples include TiCl ₄ , TiBr ₄ , VOCl ₃ , WBr ₃ , WCl ₆ , WOCl ₄ , MoCl ₅ , MoOCl ₄ , WO ₂ and H ₂ WO ₄ . Of these, W, Mo, Ti, or V is preferred from the viewpoint of polymerization activity, and these halides, oxyhalides, or alkoxy halides are particularly preferred.

  The (b) metal compound promoter component is a metal compound of Groups 1 to 2 and Groups 12 to 14 of the periodic table, and has at least one metal element-carbon bond or metal element-hydrogen bond. is there. Examples thereof include organic compounds such as Al, Sn, Li, Na, Mg, Zn, Cd, and B.

  Specific examples include organoaluminum compounds such as trimethylaluminum, triisobutylaluminum, diethylaluminum monochloride, methylaluminum sesquichloride, ethylaluminum dichloride; organotin compounds such as tetramethyltin, diethyldimethyltin, tetrabutyltin, and tetraphenyltin. Organic lithium compounds such as n-butyl lithium; organic sodium compounds such as n-pentyl sodium; organic magnesium compounds such as methyl magnesium iodide; organic zinc compounds such as diethyl zinc; organic cadmium compounds such as diethyl cadmium; Organoboron compounds; and the like. Of these, Group 13 metal compounds are preferred, and Al organic compounds are particularly preferred.

  In addition to the components (a) and (b), a metathesis polymerization activity can be increased by adding a third component. As the third component to be used, aliphatic tertiary amine, aromatic tertiary amine, molecular oxygen, alcohol, ether, peroxide, carboxylic acid, acid anhydride, acid chloride, ester, ketone, nitrogen-containing compound , Halogen-containing compounds, and other Lewis acids.

  The compounding ratio of these components is the molar ratio of the (a) component: (b) component to the metal element, and is usually in the range of 1: 1 to 1: 100, preferably 1: 2 to 1:10. Moreover, (a) component: 3rd component is the range of 1: 0.005 to 1:50, preferably 1: 1 to 1:10 by molar ratio.

The polymerization catalyst is used in a molar ratio of (transition metal in the polymerization catalyst) :( total monomer), usually 1: 100 to 1: 2,000,000, preferably 1: 1,000. ~ 1: 20,
000, more preferably 1: 5,000 to 1: 8,000. If the amount of catalyst is too large, it may be difficult to remove the catalyst after the polymerization reaction, and the molecular weight distribution may be widened. On the other hand, if the amount is too small, sufficient polymerization activity cannot be obtained.

The ring-opening polymerization can be carried out without a solvent, but is preferably carried out in a suitable solvent.
The organic solvent to be used is not particularly limited as long as the polymer and the polymer hydride are dissolved or dispersed under predetermined conditions and do not affect the polymerization and the hydrogenation reaction. Is preferred.

  Examples of such organic solvents include aliphatic hydrocarbons such as pentane, hexane, and heptane; cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptane, tri Cycloaliphatic hydrocarbons such as cyclodecane, hexahydroindenecyclohexane and cyclooctane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated aliphatic hydrocarbons such as dichloromethane, chloroform and 1,2-dichloroethane; chlorobenzene, Halogen-based aromatic hydrocarbons such as dichlorobenzene; Nitrogen-containing hydrocarbons such as nitromethane, nitrobenzene and acetonitrile; Diethyl ether and tetrahydrofuran What d - can be used solvents such as ethers. These organic solvents can be used alone or in combination of two or more.

  Among these, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons and ethers that are widely used in industry are preferable.

  When polymerization is carried out in an organic solvent, 2-norbornene and optionally other monomers capable of ring-opening copolymerization with 2-norbornene, or a single monomer comprising 2-norbornene and a substituent-containing norbornene-based monomer The concentration of the body mixture and other monomers capable of ring-opening copolymerization therewith (hereinafter sometimes collectively referred to as “monomer”) is preferably 1 to 50% by weight. -45 wt% is more preferable, and 3-40 wt% is particularly preferable. If the concentration of the monomer is less than 1% by weight, the productivity may be lowered, and if it is more than 50% by weight, the solution viscosity after polymerization may be too high, and the subsequent hydrogenation reaction may be difficult. .

  In the ring-opening polymerization, a molecular weight regulator can be added to the reaction system. The molecular weight of the resulting ring-opening polymer can be adjusted by adding a molecular weight regulator.

  It does not specifically limit as a molecular weight regulator to be used, A conventionally well-known thing can be used. For example, α-olefins such as 1-butene, 1-pentene, 1-hexene and 1-octene; styrenes such as styrene and vinyltoluene; ethers such as ethyl vinyl ether, isobutyl vinyl ether and allyl glycidyl ether; allyl chloride and the like Halogen-containing vinyl compounds of the following: oxygen-containing vinyl compounds such as glycidyl methacrylate; nitrogen-containing vinyl compounds such as acrylamide; 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 2-methyl- Non-conjugated dienes such as 1,4-pentadiene, 2,5-dimethyl-1,5-hexadiene, or 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3- Butadiene, 1,3-pentadiene, 1,3-hexa Such as a conjugated diene such as circles can be mentioned. Among these, α-olefins are preferable because of easy molecular weight adjustment.

  The molecular weight regulator may be added in an amount sufficient to obtain a polymer having a desired molecular weight, and is usually in a molar ratio of (molecular weight regulator) :( total monomer), usually 1:50 to 1: 1,000,000, preferably 1: 100 to 1: 5,000, more preferably 1: 300 to 1: 3,000.

Ring-opening polymerization is initiated by mixing the monomer and the polymerization catalyst.
Although the temperature which performs ring-opening polymerization is not specifically limited, Usually, -20- + 100 degreeC, Preferably it is 10-80 degreeC. If the temperature at which the ring-opening polymerization is carried out is too low, the reaction rate decreases, and if it is too high, the molecular weight distribution may be widened due to side reactions.
The polymerization time is not particularly limited, and is usually 1 minute to 100 hours.
Although the pressure conditions at the time of superposition | polymerization are not specifically limited, Usually, superposition | polymerization is performed under the 0-1 Mpa pressurization.

  After completion of the reaction, the desired norbornene-based ring-opening polymer can be isolated by ordinary post-treatment operation.

The obtained norbornene-based ring-opening polymer is subjected to the next hydrogenation reaction step.
Further, as described later, the hydrogenation catalyst can be continuously performed without adding a hydrogenation catalyst to the reaction solution subjected to the ring-opening polymerization and isolating the norbornene-based ring-opening polymer.

  The hydrogenation reaction of the norbornene-based ring-opening polymer is a reaction in which the norbornene-based ring-opening polymer is hydrogenated to a carbon-carbon double bond existing in the main chain and / or side chain. This hydrogenation reaction is performed by adding a hydrogenation catalyst to an inert solvent solution of a norbornene-based ring-opening polymer and supplying hydrogen into the reaction system.

  As the hydrogenation catalyst, any one of a homogeneous catalyst and a heterogeneous catalyst can be used as long as it is generally used for hydrogenation of an olefin compound. Considering the removal of residual metals in the resulting polymer, a heterogeneous catalyst is preferred.

  Examples of the homogeneous catalyst include a combination of cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n-butyllithium, zirconocene dichloride / sec-butyllithium, tetrabutoxytitanate / dimethylmagnesium, etc. Catalyst systems comprising combinations of transition metal compounds and alkali metal compounds; noble metal complex catalysts such as dichlorobis (triphenylphosphine) palladium, chlorohydridocarbonyltris (triphenylphosphine) ruthenium, chlorotris (triphenylphosphine) rhodium, etc. .

  Examples of the heterogeneous catalyst include nickel, silica, nickel / diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth, palladium / alumina, nickel, palladium, platinum, rhodium, ruthenium, Alternatively, a solid catalyst system in which these metals are supported on a carrier such as carbon, silica, diatomaceous earth, alumina, titanium oxide or the like can be mentioned.

  The usage-amount of a hydrogenation catalyst is 0.05-10 weight part normally with respect to 100 weight part of norbornene-type ring-opening polymers.

  As the inert organic solvent used for the hydrogenation reaction, the same aliphatic hydrocarbons as those exemplified as the organic solvent that can be used in the ring-opening polymerization of 2-norbornene and a substituent-containing norbornene monomer described above. , Alicyclic hydrocarbons, aromatic hydrocarbons, halogenated aromatic hydrocarbons, nitrogen-containing hydrocarbons, ethers and the like.

  The temperature range of the hydrogenation reaction varies depending on the hydrogenation catalyst used, but the hydrogenation temperature is usually -20 ° C to + 300 ° C, preferably 0 ° C to + 250 ° C. If the hydrogenation temperature is too low, the reaction rate may be slow, and if it is too high, side reactions may occur.

  The hydrogen pressure is usually from 0.01 to 20 MPa, preferably from 0.1 to 10 MPa, more preferably from 1 to 5 MPa. If the hydrogen pressure is too low, the hydrogenation rate is slow, and if it is too high, a high pressure reactor is required, which is not preferable.

  Norbornene-based ring-opening polymer hydride (hereinafter sometimes referred to as “ring-opening polymer hydride”) has a hydrogenation rate of carbon-carbon double bonds in the polymer of 80% or more, preferably 90% or more. More preferably, it is 95% or more, more preferably 99% or more, and particularly preferably 99.9% or more. When it exists in said range, the resin composition obtained is excellent in a weather resistance.

The hydrogenation rate of the ring-opened polymer hydride can be determined by measuring by ¹ H-NMR using deuterated chloroform as a solvent.

  After completion of the hydrogenation reaction, the hydrogenation catalyst and the like are filtered from the reaction solution, and the target ring-opening polymer hydride is obtained by removing volatile components such as a solvent from the polymer solution after the filtration. Can do.

  As a method for removing volatile components such as a solvent, a known method such as a coagulation method or a direct drying method can be employed.

  The coagulation method is a method in which a polymer is precipitated by mixing a polymer solution with a poor solvent for the polymer. Examples of the poor solvent to be used include polar solvents such as alcohols such as ethyl alcohol, n-propyl alcohol and isopropyl alcohol; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate and butyl acetate;

  The particulate component obtained by solidification is dried by heating, for example, in vacuum, nitrogen or air, or is extruded into a pellet from a melt extruder as necessary. be able to.

  The direct drying method is a method in which the polymer solution is heated under reduced pressure to remove the solvent. This method can be carried out using a known apparatus such as a centrifugal thin film continuous evaporation dryer, a scratched heat exchange type continuous reactor type dryer, or a high viscosity reactor device. The degree of vacuum and temperature are appropriately selected depending on the device and are not limited.

  The abundance ratio of the repeating unit (A) derived from 2-norbornene of the ring-opening polymer hydride obtained as described above is 90 to 100% by weight, preferably 95 to 99% by weight, more preferably The proportion of the repeating unit (B) derived from the substituent-containing norbornene monomer is 97 to 99% by weight, based on all repeating units, 0 to 10% by weight, preferably 1 to 5% by weight, more preferably 1 ~ 3 wt%.

  If the proportion of the repeating unit (B) is too large, the heat resistance of the resulting food container may be deteriorated. When the proportion of the repeating unit (B) is in the above range, the heat resistance is excellent and the mechanical properties of the resulting food container are excellent and suitable. Moreover, when there are too few ratios of a repeating unit (B), there exists a possibility that the mechanical characteristic of the container for foodstuffs obtained may fall.

  The obtained ring-opened polymer hydride has a weight average molecular weight (Mw) of usually 50 in terms of standard polystyrene by gel permeation chromatography (GPC) using 1,2,4-trichlorobenzene as an eluent. , 000 to 200,000, preferably 70,000 to 180,000, more preferably 80,000 to 150,000.

  When Mw is within the above range, the solubility of the ring-opened polymer hydride in the solvent becomes good, so that purification of the polymer becomes easy. Moreover, shaping | molding is easy, content (elution amount) of the metal component derived from the catalyst in the food container obtained decreases, and the mechanical strength and heat resistance of a food container become favorable.

  On the other hand, if Mw is too large, it is necessary to raise the temperature when molding the ring-opened polymer hydride, and the food container may be colored due to resin baking. If Mw is too small, the mechanical strength and heat resistance of the food container may be reduced. Further, since the ring-opened polymer hydride is crystalline, it is difficult to dissolve in a solution, and it may be difficult to purify the polymer.

The molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually 1.5 to 5.0, more preferably 2 for the ring-opened polymer hydride. It is 0.0-4.5, More preferably, it is 2.5-4.0, Most preferably, it is 2.5-3.5.
If Mw / Mn is too narrow, moldability may be deteriorated. If Mw / Mn is too wide, the oil resistance, mechanical strength, and heat resistance of the resulting food container may be reduced.

  Incidentally, Mn is a number average molecular weight measured as standard polystyrene conversion by gel permeation chromatography (GPC) using 1,2,4-trichlorobenzene as an eluent.

  The melting point of the ring-opening polymer hydride is 110 to 145 ° C, preferably 120 to 145 ° C, more preferably 130 ° C to 145 ° C. When it is in the above range, the molded product is excellent in heat resistance, which is preferable. In particular, the melting point of 130 to 145 ° C. is preferable because it can withstand steam sterilization.

  Incidentally, the melting point of the ring-opened polymer hydride varies depending on the molecular weight, molecular weight distribution, isomerization rate, purity of the monomer used, etc. of the ring-opened polymer hydride.

  The isomerization rate of the ring-opened polymer hydride is usually 0 to 40%, preferably 0 to 20%, more preferably 1 to 10%, and particularly preferably 1 to 5%.

The isomerization rate can be calculated from 33.0 ppm peak integrated value / (31.8 ppm peak integrated value + 33.0 ppm peak integrated value) × 100 measured by ¹³ C-NMR using deuterated chloroform as a solvent.

  By the way, the 31.8 ppm peak is derived from the cis isomer of 2-norbornene repeating units in the polymer, and the 33.0 ppm peak is derived from the trans isomer of 2-norbornene repeating units in the polymer. is there.

  In the present invention, it is preferable to synthesize a substantially cis ring-opening polymer by ring-opening polymerization and hydrogenate it to obtain a hydrogenated ring-opening polymer. In the hydrogenation reaction, isomerization to the trans isomer usually occurs, but it is preferable to suppress this isomerization and to keep the content of the trans isomer low.

  If the isomerization rate of the ring-opened polymer hydride is too high, the heat resistance may decrease. On the other hand, if the isomerization rate is too low, the solubility of the ring-opened polymer hydride in an organic solvent is lowered, which may cause deterioration in polymer productivity and difficulty in purification of the polymer. There is a risk that the transparency of the material will be lowered.

  In order to make the isomerization ratio within the above range, in the hydrogenation reaction of the ring-opening polymer, the reaction temperature is preferably 120 to 170 ° C., more preferably 130 to 160 ° C., and the use of the hydrogenation catalyst to be used The amount is preferably 0.2 to 5 parts by weight, more preferably 0.2 to 1 part by weight with respect to 100 parts by weight of the ring-opening polymer.

(Food containers)
The food container of the present invention can be obtained by molding one or more of the ring-opened polymer hydrides or a resin composition obtained by adding an additive to the ring-opened polymer hydride as desired. it can. The ratio of the ring-opening polymer hydride in the resin composition is usually 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more.

  The additive is generally used in the resin industry and is not particularly limited as long as it is safe. For example, polymers other than the ring-opened polymer hydride, polymers such as soft polymers; antioxidants, fillers, ultraviolet absorbers and / or light stabilizers, plasticizers, pigments, near infrared absorbers, antistatic agents And other compounding agents such as alcoholic compounds.

  Examples of the resin include polyvinyl chloride, polymethyl methacrylate, polystyrene, polymethyl methacrylate styrene copolymer, polyacrylonitrile, polyacrylonitrile styrene copolymer, high impact polystyrene (HIPS), acrylonitrile butadiene styrene copolymer (ABS resin). ), Amorphous resins such as polycarbonate, polyarylate, polysulfone, polyethersulfone, polyphenylene ether; high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, polypropylene, polypropylene, polymethylpentene, ultra high molecular weight polyethylene Chain polyolefin polymers such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, aromatic polyester Polyester polymers such as tellurium, polyamide polymers such as nylon 6, nylon 66, nylon 12, and polyamideimide, vinyl polymers such as polyvinyl alcohol and polyvinylidene chloride, fluorine such as polyvinylidene fluoride and polytetrafluoroethylene And crystalline resins whose crystalline melting point is observed by thermal measurement, such as a polymer, polyacrylonitrile, syndiotactic polystyrene, polyoxymethylene, polyphenylene sulfide, polyether ether ketone, and liquid crystal polymer.

  The soft polymer is usually a polymer having a glass transition temperature (Tg) of 30 ° C. or lower, but a polymer having a plurality of Tg and having the lowest Tg of 30 ° C. or lower, Tg and melting point A polymer having both of (Tm) and having a lowest Tg of 30 ° C. or lower is also included.

  Examples of such soft polymers include (a) olefin-based soft polymers mainly composed of α-olefins such as ethylene and propylene, (b) isobutylene-based soft polymers composed mainly of isobutylene, and (c) mainly butadiene, isoprene. Diene-based soft polymers composed of conjugated dienes such as (d) soft polymers (organic polysiloxanes) having a silicon-oxygen bond as a skeleton, (e) soft heavy materials composed mainly of α, β-unsaturated acids and their derivatives And (f) a soft polymer mainly composed of an unsaturated alcohol or an acyl derivative thereof, (g) a polymer of an epoxy compound, (h) a fluorine-based rubber, (i) another soft polymer, and the like.

  As specific examples of these soft polymers, for example, (a) includes liquid polyethylene, atactic polypropylene, 1-butene, 4-methyl-1-butene, 1-hexene, 1-octene, 1-decene and the like. Homopolymer of ethylene / α-olefin copolymer, propylene / α-olefin copolymer, ethylene / propylene / diene copolymer, ethylene / cycloolefin copolymer, ethylene / propylene / styrene copolymer, etc. A copolymer is mentioned.

  Examples of (b) include polyisobutylene, isobutylene / isoprene rubber, and isobutylene / styrene copolymer.

  (C) is a conjugated diene homopolymer such as polybutadiene or polyisoprene; butadiene / styrene random copolymer, isoprene / styrene random copolymer, acrylonitrile / butadiene copolymer, acrylonitrile / butadiene copolymer hydrogen , Random copolymers of conjugated dienes such as acrylonitrile / butadiene / styrene copolymers; butadiene / styrene / block copolymers, styrene / butadiene / styrene / block copolymers, isoprene / styrene / block copolymers, styrene -Block copolymers of conjugated dienes and aromatic vinyl hydrocarbons such as isoprene / styrene / block copolymers, and their hydrides.

  Examples of (d) include silicone rubbers such as dimethylpolysiloxane, diphenylpolysiloxane, and dihydroxypolysiloxane.

  (E) includes a homopolymer of an acrylic monomer such as polybutyl acrylate, polybutyl methacrylate, polyhydroxyethyl methacrylate, polyacrylamide, and polyacrylonitrile; an acrylic monomer such as a butyl acrylate / styrene copolymer and other monomers A copolymer is mentioned.

  Examples of (f) include polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, vinyl polymaleate, and vinyl acetate / styrene copolymer.

Examples of (g) include polyethylene oxide, polypropylene oxide, epichlorohydrin rubber, and the like.
Examples of (h) include vinylidene fluoride rubber and tetrafluoroethylene-propylene rubber.

Examples of (i) include natural rubber, polypeptides, proteins, and polyester-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, polyamide-based thermoplastic elastomers described in JP-A-8-73709.
These soft polymers may have a cross-linked structure or may have a functional group introduced by modification.

  Among the above-mentioned soft polymers, (a), (b), (c) soft polymers, more preferably (c) diene-based soft polymers, and more preferably carbon-carbon unsaturated bonds of conjugated diene bond units. A hydrogenated diene-based soft polymer hydride is preferable because it is particularly excellent in rubber elasticity and mechanical strength, flexibility and dispersibility.

  Preferred examples of the diene polymer include a hydride of a homopolymer such as polybutadiene, a hydride of a random copolymer such as a butadiene / styrene copolymer; a butadiene / styrene / block copolymer, and a styrene / butadiene / styrene. -Block copolymer, hydride of block copolymer such as isoprene / styrene / block copolymer, styrene / isoprene / styrene / block copolymer; and the like.

  The said resin or soft polymer can be used individually by 1 type or in combination of 2 or more types. The amount of the resin or soft polymer used may be appropriately determined within a range not impairing the object of the present invention, but is usually less than 50% by weight, preferably less than 30% by weight, more preferably less than 10% by weight.

When antioxidant is mix | blended, the container for foodstuffs in which mechanical strength cannot fall easily can be obtained.
The antioxidant is not particularly limited, and examples thereof include phenolic antioxidants, phosphorus antioxidants, thioether antioxidants, and lactone antioxidants. Among these, heat resistance and elution resistance are exemplified. Therefore, a phenolic antioxidant is preferable because a food container with excellent quality can be obtained.

  A conventionally well-known thing can be used as a phenolic antioxidant, for example, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2 , 4-di-tertiary amyl-6- (1- (3,5-di-tertiary amyl-2-hydroxyphenyl) ethyl) phenyl acrylate and the like, and JP-A Nos. 63-179953 and 1-168643. Acrylate-based phenolic compounds described in the publication No .;

  2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol), 4,4′-butylidene-bis (6-tert-butyl-m-cresol), 4,4′-thiobis (3 -Methyl-6-tert-butylphenol), bis (3-cyclohexyl-2-hydroxy-5-methylphenyl) methane, 3,9-bis (2- (3- (3-tert-butyl-4-hydroxy-5) -Methylphenyl) propionyloxy) -1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,1,3-tris (2-methyl-4-hydroxy- 5- -Butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis (methylene-3- (3 ', 5 '-Di-t-butyl-4'-hydroxyphenylpropionate) methane [ie, pentaerythrimethyl-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenylpropionate)], tri Alkyl-substituted phenolic compounds such as ethylene glycol bis (3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate) and tocophenol;

  6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, 6- (4-hydroxy-3,5-dimethylanilino)- 2,4-bisoctylthio-1,3,5-triazine, 6- (4-hydroxy-3-methyl-5-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, And triazine group-containing phenolic compounds such as 2-octylthio-4,6-bis- (3,5-di-t-butyl-4-oxyanilino) -1,3,5-triazine; Among these, acrylate-based phenol compounds and alkyl-substituted phenol compounds are preferable, and alkyl-substituted phenol compounds are particularly preferable.

  The phosphorus antioxidant is not particularly limited as long as it is usually used in the general resin industry. For example, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) Phosphite, Tris (dinonylphenyl) phosphite, Tris (2,4-di-t-butylphenyl) phosphite, Tris (2-t-butyl-4-methylphenyl) phosphite, Tris (cyclohexylphenyl) phos Phyto, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (3,5- Di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa 10 phospha-phenanthrene-10-oxide, mono-phosphite compounds such as 10-decyloxy-9,10-dihydro-9-oxa-10-phospha-phenanthrene;

  4,4'-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl phosphite), 4,4'-isopropylidene-bis (phenyl-di-alkyl (C12-C15) phosphite) ), 4,4′-isopropylidene-bis (diphenylmonoalkyl (C12-C15) phosphite), 1,1,3-tris (2-methyl-4-di-tridecylphosphite-5-t-butyl) Phenyl) butane, tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphite, cyclic neopentanetetraylbis (isodecylphosphite), cyclic neopentanetetraylbis ( Nonylphenyl phosphite), cyclic neopentanetetraylbis (2,4-di-t-butylphenyl phosphite) ), Cyclic neopentanetetraylbis (2,4-dimethylphenylphosphite), diphosphite compounds such as cyclic neopentanetetraylbis (2,6-di-t-butylphenylphosphite), and the like. . 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-thiodipropioate. And pentaerythritol-tetrakis- (β-lauryl-thio-propionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane be able to.

  The lactone antioxidant is not particularly limited as long as it is a compound containing a lactone structure, but an aromatic lactone compound is preferable. Among these, those having a benzofuranone skeleton are more preferable, and 3-arylbenzofuran-2-one having an aryl group as a substituent in the side chain of the furan ring is more preferable. An example is 5,7-di-tert-butyl-3- (3,4-di-methylphenyl) -3H-benzofuran-2-one.

  The blending amount of the antioxidant is usually 0.001 to 1 part by weight, preferably 0.005 to 0.5 part by weight, more preferably 0.01 to 0 part per 100 parts by weight of the ring-opened polymer hydride. .3 parts by weight. When the amount of the antioxidant is excessively large, it may be eluted from the obtained food container.

  Antioxidants can be used singly or in combination of two or more. The amount used is appropriately selected within a range that does not impair the object of the present invention.

  When a filler is added, the impact resistance of the container is improved. Depending on the filler used, the container can be opaque. In addition, when a filler having a large specific gravity is used, the container can be submerged in water, so that cleaning is facilitated particularly when used for tableware.

  The filler is not particularly limited as long as it is usually used in the polymer industry, and any of organic fillers and inorganic fillers can be used, but from the viewpoint of obtaining a preferable appearance, specific gravity, etc. It is preferable to use an inorganic filler.

  Inorganic fillers include oxides, hydroxides, sulfides, nitrogen, group 1, group 2, group 4, group 6, group 7, group 8 to group 10, group 11, group 12, group 13 and group 14 elements. Natural mineral particles and compounds containing fluoride, halide, carbonate, sulfate, acetate, phosphate, phosphite, organic carboxylate, silicate, titanate, borate and their water-containing compounds Examples include inorganic compound particles.

  Specific examples include group 1 element compounds such as lithium fluoride and borax (sodium borate hydrate); magnesium carbonate, magnesium phosphate, magnesium oxide, magnesium chloride, magnesium acetate, magnesium fluoride, magnesium titanate, magnesium silicate, silicic acid Magnesium hydrate (talc), calcium carbonate, calcium phosphate, calcium phosphite, calcium sulfate (gypsum), calcium acetate, calcium terephthalate, calcium hydroxide, calcium silicate, calcium fluoride, calcium titanate, strontium titanate, carbonic acid Group 2 element compounds such as barium, barium phosphate, barium sulfate, barium phosphite; titanium dioxide (titania), titanium monoxide, titanium nitride, zirconium dioxide (zirconia), -zirconium oxide, etc. Group element compounds; Group 6 element compounds such as molybdenum dioxide, molybdenum trioxide, and molybdenum sulfide; Group 7 element compounds such as manganese chloride and manganese acetate; Group 8-10 element compounds such as cobalt chloride and cobalt dartrate; Group 11 element compounds such as monocopper; Group 12 element compounds such as zinc oxide and zinc acetate; Group 13 element compounds such as aluminum oxide (alumina), aluminum fluoride, aluminosilicate (alumina silicate, kaolin, kaolinite); oxidation Examples include Group 14 element compounds such as silicon (silica, silica gel), graphite, carbon, graphite, and glass; particles of natural minerals such as carnal stone, kainite, mica (mica, quinumo), and pyrose ore.

  Among these, barium sulfate, calcium carbonate, and magnesium carbonate are preferred from the viewpoint that the whiteness can be increased and a composition having a large specific gravity can be easily obtained from the appearance of the obtained food container.

  The average particle size of the inorganic filler is an average particle size measured from the diameter of 3,000 to 5,000 particles by an electron microscope or the like, and any particle size can be selected according to the application. The range is usually 0.05 to 100 μm, preferably 1 to 50 μm. When the particle size is in this range, a balance between the appearance and moldability of the molded body can be obtained.

  Each of these fillers can be used alone or in combination of two or more. However, when using any of the fillers, it is preferable to use a filler having a higher specific gravity. It is preferable because the specific gravity can be increased with a small blending amount without impairing the performance of the container made of the combined hydride.

  The specific gravity of the filler is usually from 2 to 5, preferably from 3.5 to 5. When in this range, the impact resistance, appearance, mechanical strength, etc. of the container are highly balanced.

  Although the compounding quantity of a filler is suitably selected according to a use purpose, it is the range of 0.1 to 50 weight% normally with respect to the total amount with a ring-opening polymer hydride.

  Examples of the method for molding a ring-opening polymer hydride or a resin composition obtained by mixing the above-mentioned additives with a ring-opening polymer hydride include an injection molding method, an injection compression molding method, an injection blow molding method, a direct Examples include blow molding, compression molding, press molding, and vacuum molding. Among these, an injection molding method, an injection blow molding method, and a direct blow molding method are preferable, and an injection molding method is particularly preferable because a food container having more excellent impact resistance can be obtained.

  The food container of the present invention may have a multilayer structure of two or more layers including at least a layer containing a ring-opening polymer hydride, in accordance with the purpose.

  For example, a food container having at least one layer comprising a ring-opening polymer hydride and a layer comprising a composition containing a ring-opening polymer hydride and a filler has a high specific gravity and is decorative. The effect can also be expected. If a pattern, a pattern, or the like is applied to the interface between a layer made of a ring-opened polymer hydride and a layer made of a composition containing the ring-opened polymer hydride and a filler, a decorative effect is produced. It can protect the pattern and is excellent in durability and is suitable.

  In this case, the layer made of the ring-opened polymer hydride is preferably used as a layer on the side in contact with food from the viewpoint of environmental safety and hygiene.

  Such a multi-layered food container is formed by, for example, forming a layer made of a ring-opened polymer hydride as an inner core, and then applying a pattern or a pattern to the surface that does not come into contact with food by printing or the like. It can be obtained by a method in which a layer on the side that does not come into contact with food is further stacked and molded with the inserted mold.

For the formation of the layer not in contact with the food, it is also possible to use a resin composition obtained by adding a compounding agent such as a filler and / or an elastomer, if desired, to a resin other than the ring-opening polymer hydride. it can.
Examples of the resin other than the ring-opening polymer hydride include those exemplified as the resin of the additive.

  There is no restriction | limiting in particular as a shape of the food container of this invention, According to the intended purpose, it can select suitably. Examples thereof include a bowl shape, a dish shape, a bowl shape, a cylindrical shape, a conical shape, a polygonal cylinder shape, a polygonal pyramid shape, or a combination thereof.

  The thickness of the food container (total of two or more layers) is not particularly limited, but is usually 0.3 to 20 mm, preferably 0.5 to 10 mm.

  The thickness of the food container does not have to be constant throughout the entire container. For example, the thickness of the curved surface portion may be increased. When the thickness of the food container is within the above range, the container is excellent in oil resistance, impact resistance, and heat resistance.

  The food container of the present invention is excellent in oil resistance. The food container of the present invention is excellent in oil resistance because, for example, 10 food containers are immersed in methyl oleate at a temperature of 90 ° C. for 24 hours, and then the methyl oleate adhering to the container is washed away with acetone. It can be confirmed by drying and observing whether cracks have occurred. If the crack has a length of 10 mm or more, and the shape of the crack is not a single line, but a plurality of cracks such as radial lines, the total length of each crack in the plane direction is 10 mm or more. Is also included. In the food container of the present invention, no cracks are observed.

  The food container of the present invention is excellent in impact resistance. The food container of the present invention is excellent in impact resistance. For example, 10 food containers are immersed in salad oil at a temperature of 90 ° C. for 72 hours, and then the salad oil adhering to the container is washed off with acetone and then naturally dried. It can be confirmed by performing a falling ball test and then observing whether a crack having a length of 5 mm or more has occurred.

  The falling ball test is performed by placing a container on a concrete floor with the bottom face up and dropping a 300 g steel ball from directly above. In the food container of the present invention, no cracks are observed.

  The food container of the present invention has a small haze value and excellent transparency. The haze value (%) is a value expressed as a percentage of transmitted light measured according to JIS K7136 and deviated by 0.04 rad (2.5 degrees) or more from incident light due to forward scattering. .

  The haze value of the food container of the present invention is, for example, 20% or less when measured using a haze meter on a test piece having a thickness of 2.4 mm cut out from the produced container.

  The food container of the present invention is, for example, a container for packaging, storing and transporting foods such as fresh ingredients, seasonings, spices, cooked foods, dried foods, frozen foods and beverages; rice cakes, dishes, trays, cups It can be used for a container used for eating as tableware, etc .; a container that is used for packaging, storage and transportation and for eating;

  The food container of the present invention is not only safe and heat resistant, but also excellent in oil resistance and impact resistance, and has a low haze value, so it is particularly suitable as tableware. It is more suitable for the tableware for lunch.

  Next, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to the following examples. In the following examples and comparative examples, “part” or “%” is based on weight unless otherwise specified.

In the following Examples and Comparative Examples, various physical properties are measured as follows.
(1) The weight average molecular weight (Mw) and number average molecular weight (Mn) of the ring-opening polymer were measured as standard polystyrene conversion values by gel permeation chromatography (GPC) eluting with toluene.
(2) The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the ring-opened polymer hydride are standard by gel permeation chromatography (GPC) using 1,2,4-trichlorobenzene as an eluent. The polystyrene conversion value was measured at 140 ° C.

(3) The hydrogenation rate of the ring-opened polymer hydride was measured by ¹ H-NMR using deuterated chloroform as a solvent.
(4) The isomerization rate of the ring-opening polymer hydride was 33.0 ppm peak integrated value / (31.8 ppm peak integrated value + 33.0 ppm peak integrated value) measured by ¹³ C-NMR using deuterated chloroform as a solvent. Calculated from x100. By the way, the 31.8 ppm peak is derived from the cis isomer of 2-norbornene repeating units in the polymer, and the 33.0 ppm peak is derived from the trans isomer of 2-norbornene repeating units in the polymer. is there.

(5) The melting point was measured at room temperature at a cooling rate of −10 ° C./min after heating the sample to 30 ° C. or higher from the melting point based on JIS K7121, using a differential scanning calorimeter (DSC 6220, manufactured by SII Nanotechnology). Then, the temperature was measured at a temperature elevation rate of 10 ° C./min.
(6) The glass transition temperature was measured based on JIS K6911 using the differential scanning calorimeter (SII nanotechnology company make, DSC6220).

(7) In the oil resistance test, the container was immersed in methyl oleate (manufactured by Wako Pure Chemicals, grade 1 reagent) at a temperature of 90 ° C. for 24 hours, and then the methyl oleate adhering to the container was washed off with acetone and then naturally dried. Then, the presence or absence of cracks was observed. At this time, a crack having a length of 10 mm or more was assumed to have occurred. In the case where the shape of the crack is not a single line but is a combination of a plurality of cracks such as a radial shape, the case where the total length of each crack in the plane direction is 10 mm or more is also included. The test was performed on 10 containers and was performed by counting the number of containers in which cracks occurred.

(8) Impact resistance was determined by immersing the container in salad oil at a temperature of 90 ° C. for 72 hours, washing off the salad oil adhering to the container with acetone and then drying it naturally, and performing a ball drop test. The falling ball test was placed on a concrete floor with the bottom of the container turned upside down, and a steel ball of 300 g was dropped from directly above a height of 2 m to evaluate whether a crack occurred in the formed body. At this time, a crack having a length of 5 mm or more was regarded as a crack. The test was performed on 10 containers and was performed by counting the number of containers in which cracks occurred.

(9) The haze was measured using a haze meter (Nippon Denshoku Industries Co., Ltd., NDH2000) for a test piece having a thickness of 2.3 mm cut out from the produced container.

[Production Example 1]
(Ring-opening copolymerization)
In a nitrogen atmosphere, 500 parts by weight of dehydrated cyclohexane, 0.55 parts by weight of 1-hexene, 0.30 parts by weight of diisopropyl ether, 0.20 parts by weight of triisobutylaluminum, and 0.075 parts by weight of isobutyl alcohol were reacted at room temperature. The mixture was mixed and then kept at 55 ° C., while adding 250 parts by weight of 2-norbornene (hereinafter sometimes abbreviated as “2-NB”) and 15 parts by weight of tungsten hexachloride 1.0 wt% toluene solution over 2 hours. Continuously added and polymerized. The resulting ring-opening polymer (A) had a weight average molecular weight (Mw) of 83,000 and a molecular weight distribution (Mw / Mn) of 1.8.

(Hydrogenation reaction)
The polymerization reaction liquid containing the ring-opening polymer (A) obtained above was transferred to a pressure-resistant hydrogenation reactor, and diatomaceous earth-supported nickel catalyst (Nissan Zudhemy, T8400, nickel support rate: 58% by weight) 0.5% Part was added and reacted at 160 ° C. and hydrogen pressure 4.5 MPa for 6 hours. This solution was filtered with a filter equipped with a stainless steel wire mesh using diatomaceous earth as a filter aid to remove the catalyst.
The obtained reaction solution was poured into 3000 parts by weight of isopropyl alcohol with stirring to precipitate a hydride, which was collected by filtration. Further, after washing with 500 parts by weight of acetone, it was dried in a vacuum drier set at 0.13 × 10 ³ Pa or less and 100 ° C. for 48 hours to obtain 190 parts by weight of the ring-opened polymer hydride (A). .

(Polymer physical properties)
The hydrogenation rate of the obtained ring-opened polymer hydride (A) was 99.9%, the weight average molecular weight (Mw) was 82,200, the molecular weight distribution (Mw / Mn) was 2.9, and the isomerization rate was It was 5% and the melting point was 140 ° C.

(Preparation of resin composition)
To 100 parts by weight of the ring-opened polymer hydride (A), an antioxidant (Irganox 1010, manufactured by Ciba Geigy Inc., tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) ) Propionate] Methane) 0.1 part by weight was added, kneaded with a biaxial kneader (Toshiki Machine Co., Ltd., TEM35), pelletized to obtain a resin composition (A).

[Production Example 2]
(Ring-opening copolymerization and hydrogenation reaction)
In Production Example 1, instead of 250 parts by weight of 2-norbornene, 240 parts by weight of 2-norbornene and 10 parts by weight of dicyclopentadiene (hereinafter sometimes abbreviated as “DCP”) were used, and 0.55 weight of 1-hexene was used. Parts, diisopropyl ether 0.40 parts by weight, triisobutylaluminum 0.27 parts by weight, isobutyl alcohol 0.10 parts by weight, tungsten hexachloride 1.0% by weight toluene solution 20 parts by weight Polymerization was performed. The resulting ring-opening polymer (B) had a weight average molecular weight (Mw) of 83,000 and a molecular weight distribution (Mw / Mn) of 2.7. The polymerization addition rate was almost 100%. Then, it carried out similarly to manufacture example 1, and performed hydrogenation reaction, and obtained 190 weight part of ring-opening copolymer hydrides (B).

(Polymer physical properties)
The hydrogenation rate of the obtained ring-opening copolymer hydride (B) was 99.9%, the weight average molecular weight (Mw) was 81,300, the molecular weight distribution (Mw / Mn) was 3.8, the isomerization rate. Was 9% and the melting point was 134 ° C.

(Preparation of resin composition)
In Production Example 1, a resin composition (B) was obtained in the same manner as in Production Example 1 except that the ring-opening copolymer hydride (B) was used instead of the ring-opening copolymer hydride (A). .

[Production Example 3]
(Ring-opening copolymerization and hydrogenation reaction)
In Production Example 1, instead of 250 parts by weight of 2-norbornene, 245 parts by weight of 2-norbornene and 5 parts by weight of methylnorbornene (hereinafter sometimes abbreviated as “MNB”) were used, and 0.40 part by weight of 1-hexene was used. In the same manner as in Production Example 1, except that 0.31 part by weight of diisopropyl ether, 0.20 part by weight of triisobutylaluminum, 0.08 part by weight of isobutyl alcohol, and 15 parts by weight of a tungsten hexachloride 1.0% by weight toluene solution were used. Ring-opening copolymerization was performed. The polymerization conversion rate was almost 100%. Mw of the obtained ring-opening copolymer (C) was 103,000, and Mw / Mn was 1.9. Then, it carried out similarly to manufacture example 1, and performed hydrogenation reaction, and obtained 190 weight part of ring-opening copolymer hydrides (C).

(Polymer physical properties)
The hydrogenation rate of the obtained ring-opening copolymer (C) was 99.9%, Mw was 100,000, Mw / Mn was 2.9, the isomerization rate was 8%, and the melting point was 136 ° C. It was.

(Preparation of resin composition)
In Production Example 1, a resin composition (C) was obtained in the same manner as in Production Example 1 except that the ring-opening copolymer hydride (C) was used instead of the ring-opening copolymer hydride (A). .

[Production Example 4]
(Ring-opening copolymerization)
In a nitrogen atmosphere, add 33.4 parts by weight of a 70 wt% 2-norbornene toluene solution, 2.86 parts by weight of dicyclopentadiene, 0.020 parts by weight of 1-hexene, and 49.3 parts of cyclohexane to an autoclave equipped with a stirrer. And stirred. Subsequently, a solution prepared by dissolving 0.023 parts by weight of bis (tricyclohexylphosphine) benzilidineruthenium (IV) dichloride in 8.6 parts by weight of toluene was added and reacted at 60 ° C. for 30 minutes. The polymerization conversion rate was almost 100%. Mw of the obtained ring-opening polymer (D) was 81,000 and Mw / Mn was 3.6.

(Hydrogenation reaction)
After adding 0.020 part by weight of ethyl vinyl ether to the polymerization solution obtained above and stirring, a hydrogenation reaction was performed at a hydrogen pressure of 1.0 MPa and 150 ° C. for 20 hours. Thereafter, the mixture was cooled to room temperature, a solution in which 0.5 parts by weight of activated carbon powder was suspended in 10 parts by weight of cyclohexane was added, and the mixture was reacted at a hydrogen pressure of 1.0 MPa and 150 ° C. for 2 hours. Next, the reaction solution was filtered through a filter having a pore size of 0.2 μm to remove the activated carbon powder. The reaction solution was poured into a large amount of isopropanol to completely precipitate the polymer, which was collected by filtration. Furthermore, after washing | cleaning with acetone, it dried for 48 hours in the vacuum dryer set to 0.13 * 10 < ³ > Pa or less and 100 degreeC, and the ring-opening copolymer hydride (D) was obtained.

(Polymer physical properties)
The hydrogenation rate of the obtained ring-opening copolymer hydride (D) was 99.9%, Mw was 85,000, Mw / Mn was 3.9, and the melting point was 101 ° C.

(Preparation of resin composition)
In Production Example 1, a resin composition (D) was obtained in the same manner as in Production Example 1 except that the ring-opening copolymer hydride (D) was used instead of the ring-opening copolymer hydride (A). .

[Production Example 5]
(Ring-opening polymerization)
Under a nitrogen atmosphere, 1.1 parts by weight of tungsten (phenylimide) tetrachloride / diethyl ether and 18.5 parts by weight of cyclohexane were added to an autoclave equipped with a stirrer. Further, a solution prepared by dissolving 0.87 parts by weight of diethylaluminum ethoxide in 9.26 parts by weight of hexane was added, and the mixture was stirred at room temperature for 30 minutes. To the obtained mixture, 139 parts by weight of dicyclopentadiene and 0.33 parts by weight of 1-hexane were added, and a polymerization reaction was carried out at 50 ° C. for 3 hours. Mw of the obtained ring-opening polymer (E) was 78,000, and Mw / Mn was 3.5.

(Hydrogenation reaction)
A hydrogenation catalyst solution prepared by dissolving 0.87 parts by weight of bis (tricyclohexylphosphine) benzilidineruthenium (IV) dichloride and 20.4 parts by weight of ethyl vinyl ether in 650 parts by weight of cyclohexane was added to the polymerization solution obtained above, The hydrogenation reaction was carried out at a hydrogen pressure of 1.0 MPa and 160 ° C. for 20 hours. The reaction solution was poured into a large amount of isopropanol to completely precipitate the polymer, which was collected by filtration. Further, after washing with 500 parts by weight of acetone, drying was performed for 48 hours in a vacuum drier set at 0.13 × 10 ³ Pa or less and 100 ° C. to obtain 130 parts by weight of a ring-opened polymer hydride (E). .

(Polymer physical properties)
The obtained ring-opened polymer hydride (E) was not dissolved in the GPC solvent, and the molecular weight could not be measured. The melting point was 273 ° C.

(Preparation of resin composition)
In Production Example 1, a resin composition (E) was obtained in the same manner as in Production Example 1 except that the ring-opening polymer hydride (E) was used instead of the ring-opening copolymer hydride (A).

[Production Example 6]
(Ring-opening copolymerization and hydrogenation reaction)
Production Example 1, in place of 2-norbornene 250 parts by weight, tetracyclo ^{[7.4.0.1 10,13.} 0 ^2,7 ] trideca-2,4,6,11-tetraene (also referred to as 1,4-methano-1,4,4a, 9a-tetrahydrofluorene; hereinafter abbreviated as “MTF”), 62.5 parts by weight, Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -dodec-3-ene (hereinafter abbreviated as “TCD”) 87.5 parts by weight and tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene (dicyclopentadiene) Polymerization was carried out in the same manner as in Production Example 1 except that 100 parts by weight and 1-hexene was changed to 0.70 parts by weight. The obtained ring-opening polymer (F) was subjected to a hydrogenation reaction in the same manner as in Production Example 1 to obtain 190 parts by weight of the ring-opening copolymer hydride (F).

(Polymer physical properties)
The hydrogenation rate of the obtained ring-opening copolymer hydride (F) is 99.9%, Mw is 38,100, Mw / Mn is 2.8, and the glass transition temperature (Tg) is 142 ° C., No melting point was observed.

(Preparation of resin composition)
In Production Example 1, a resin composition (F) was obtained in the same manner as in Production Example 1 except that the ring-opening polymer hydride (F) was used instead of the ring-opening copolymer hydride (A). .

[Example 1]
Using an injection molding machine (manufactured by FANUC), the resin composition (A) is cylinder temperature 230 ° C., mold temperature 120 ° C., injection speed 45 cm ³ / s, injection pressure 1,000 kg / cm ² , holding pressure 800 kgf. A circular container (A) having an opening diameter of 120 mm, a bottom surface diameter of 75 mm, a depth of 35 mm, and a thickness of 2.4 mm under the conditions of / cm ² and a back pressure of 70 kgf / cm ² was produced.
About the obtained container (A), the oil resistance test, the impact resistance test, and the haze measurement were performed. The results are summarized in Table 1.

[Example 2]
In Example 1, a container (B) was produced in the same manner as in Example 1 except that the resin composition (B) was used instead of the resin composition (A) and the mold temperature was 115 ° C.
About the obtained container (B), the oil resistance test, the impact resistance test, and the haze measurement were performed. The results are summarized in Table 1.

[Example 3]
In Example 1, a container (C) was produced in the same manner as in Example 1 except that the resin composition (C) was used instead of the resin composition (A) and the mold temperature was 115 ° C.
About the obtained container (C), the oil resistance test, the impact resistance test, and the haze measurement were performed. The results are summarized in Table 1.

[Comparative Example 1]
In Example 1, the resin composition (D) was used in place of the resin composition (A), the container temperature (D) was the same as in Example 1 except that the cylinder temperature was 210 ° C and the mold temperature was 80 ° C. Was made.
About the obtained container (D), the oil resistance test, the impact resistance test, and the haze measurement were performed. The results are summarized in Table 1. Incidentally, deformation was observed in the container after being immersed in methyl oleate at a temperature of 90 ° C. for 24 hours in the oil resistance test and the container after being immersed in a salad oil at a temperature of 90 ° C. in the impact resistance test for 72 hours.

[Comparative Example 2]
In Example 1, the resin composition (E) was used instead of the resin composition (A), and the container (E) was prepared in the same manner as in Example 1 except that the cylinder temperature was 320 ° C and the mold temperature was 180 ° C. Was made.
About the obtained container (E), the oil resistance test, the impact resistance test, and the haze measurement were performed. The results are summarized in Table 1.

[Comparative Example 3]
In Example 1, the resin composition (F) was used instead of the resin composition (A), the container temperature (F) was the same as in Example 1 except that the cylinder temperature was 300 ° C. and the mold temperature was 130 ° C. Was made.
About the obtained container (F), the oil resistance test, the impact resistance test, and the haze measurement were performed. The results are summarized in Table 1.

  From Table 1, the containers (A) to (C) of Examples 1 to 3 were excellent in oil resistance and impact resistance and had a small haze value. In the container (D) of Comparative Example 1, deformation was observed in the oil resistance and impact resistance tests, and the oil resistance was inferior. The container (E) of Comparative Example 2 was inferior in impact resistance and had a large haze value. The container (F) of Comparative Example 3 was inferior in oil resistance and impact resistance.

Claims (2)

  Hydrogenation of 80% or more of carbon-carbon double bonds of ring-opening polymer obtained by ring-opening polymerization of 2-norbornene or a monomer mixture comprising 2-norbornene and a substituent-containing norbornene monomer And a norbornene-based ring-opening polymer hydride obtained by carrying out the above process, wherein the content of the repeating unit (A) derived from 2-norbornene is 90 to 100% by weight, and the substituent-containing norbornene-based monomer A food product obtained by molding a hydrogenated norbornene-based ring-opening polymer in which the proportion of the derived repeating unit (B) is 0 to 10% by weight with respect to all repeating units and the melting point is in the range of 110 to 145 ° C. Container.   The norbornene-based ring-opening polymer hydride has a polymerization average molecular weight (Mw) in terms of standard polystyrene by gel permeation chromatography (GPC) of 50,000 to 200,000, and a molecular weight distribution ( The food container according to claim 1, wherein Mw / Mn) is 1.5 to 5.0.