JP4404664B2 - Ethylene resin laminate for sealant - Google Patents

Description

  The present invention relates to an ethylene-based resin. Specifically, heat sealability, hot tackiness, low temperature impact strength, etc. are good, heat resistance blocking property, piercing strength is excellent, and it has very good low odor and low taste, beverage, cooked rice, food, medicine, etc. It is related with the ethylene-type resin used suitably for the sealant layer of various packaging materials.

Ethylene-based resins have moderate flexibility and are excellent in strength, transparency, heat sealability, moisture resistance, chemical resistance, low temperature impact strength, etc., and are widely used in sealant layers for various packaging materials such as foods, beverages, and pharmaceuticals. in use. Under such circumstances, in recent years, characteristics such as heat-resistant blocking properties, low odor, and low taste have been required for ethylene resins used in the sealant layer. For example, Patent Document 1 proposes a method for improving the heat-resistant blocking property.
On the other hand, it has been conventionally known to adopt an inflation molding method for improving low odor and taste. This is because the inflation molding method is performed at a relatively low temperature compared to the cast molding method, so that the thermal degradation of the resin is suppressed, and the generation of odor can be reduced accordingly.

Further, in the extrusion laminate molding method, a method using a low-odor, high-pressure method, low-density polyethylene has been adopted for beverage paper packs such as milk, juice and alcoholic beverages. Alternatively, Patent Document 2 describes a method for low bromination of a polymer obtained by polymerization in the presence of a supported geometrically constrained single site catalyst (hereinafter abbreviated as a metallocene catalyst).
However, these methods are inadequate for the recent advanced demands considering the generation of odors and taste changes due to high temperature filling, radiation for sterilization and sterilization before and after filling, ultraviolet irradiation treatment, and heat treatment. The problem remains.
JP 2000-109570 A JP 2004-2744 A

  The present invention has been made in view of the above situation, and has good heat sealing properties, hot tack properties, low temperature impact strength, etc., excellent heat resistance blocking properties, piercing strength, and extremely good low odor. -It aims at providing the ethylene-type resin for sealants which has low taste property and is used suitably for the sealant layer of various packaging materials, such as a drink, cooked rice, a foodstuff, and a medicine.

  The present inventor has good heat sealing properties, hot tack properties, low temperature impact strength, etc., excellent heat resistance blocking properties, piercing strength, and very good low odor and low taste, and various foods, beverages, pharmaceuticals, etc. As a result of extensive research to develop an ethylene-based resin that can be suitably used as a sealant layer for packaging materials, it was found that using a specific ethylene-based resin can meet the above objectives. The present invention has been completed.

That is, the present invention
[1] melt flow rate of 0.1 g / 10min or more, 50 g / 10min or less, a density of 925 kg / ^{m 3} or more, 975 kg / ^{m 3} or less, the molecular weight distribution represented by the ratio of weight average molecular weight to number average molecular weight of 2 The number of methyl carbon atoms contained in 1000 carbon atoms of the ethylene polymer having an equivalent molecular weight of 10,000 or less in the ethylene resin is 1 or more and 100 or less. A laminate comprising a layer made of an ethylene-based resin for a sealant characterized in that as a sealant layer ,
[2] A polymerization method in which the ethylene-based resin for sealant uses a supported geometrically constrained single-site catalyst (hereinafter abbreviated as a metallocene catalyst), and after contacting the metallocene catalyst with hydrogen in advance, the catalyst [1] laminate, wherein the obtained the by methods polymerized by supplying to the polymerisation reactor,
[ 3 ] A beverage packaging material comprising the laminate of [1] or [2] ,
[ 4 ] A packaging material for cooked rice comprising the laminate of [1] or [2] ,
It is.

  According to the present invention, heat sealing properties, hot tack properties, low temperature impact strength, etc. are good, heat blocking properties, puncture strength are excellent, and low odor and low taste are extremely good. Excellent for sterilization / sterilization of radiation, ultraviolet irradiation treatment, odor generation during heat treatment, suppression of taste change, and suitable for sealant layers of various packaging materials such as beverages, cooked rice, foods, pharmaceuticals, etc. The ethylene-based resin used can be provided.

Hereinafter, the present invention will be described in detail.
The ethylene-based resin of the present invention has a melt flow rate (hereinafter abbreviated as MFR) of 0.1 g / 10 min or more and 50 g / 10 min or less, preferably 0.3 g / 10 min or more, 20 g / 10 min or less, and a density of 925 kg / m ³ or more, 975 kg / ^{m 3} or less, preferably 930 kg / ^{m 3} or more, 970 kg / ^{m 3} or less, the molecular weight expressed as the ratio of weight average molecular weight to number average molecular weight distribution of 2 or more, 10 or less, preferably 3 or more 1 or more, and the number of methyl carbon atoms contained in 1000 carbon atoms in the ethylene polymer having an equivalent molecular weight in the ethylene resin of 10,000 or less (hereinafter abbreviated as terminal methyl group concentration) is 1 or more. , 100 or less (hereinafter, methyl carbon atoms contained in 1000 carbon atoms in an ethylene polymer having a reduced molecular weight of 10,000 or less) Is expressed as number / 1000 (C)), preferably 1/1000 (C) or more, 80/1000 (C) or less, more preferably 1/1000 (C) or more, 50/1000. (C) It is the following.

The ethylene-based resin of the present invention has MFR, density, molecular weight distribution, terminal methyl from the viewpoint of low odor / low taste improvement effect, and from the viewpoints of heat blocking resistance, piercing strength, heat sealability, hot tack, and low temperature impact strength. The group concentration needs to be in the above range. In particular, the terminal methyl group concentration needs to be within the above range from the viewpoint of the effect of improving the low odor and low taste, particularly the effect of improving the low odor and low taste during the radiation and ultraviolet irradiation treatment and the heat treatment.
In the ethylene-based resin of the present invention, after a metallocene catalyst is brought into contact with hydrogen in advance, the catalyst is introduced into a polymerization reactor to polymerize ethylene alone or copolymerize ethylene with an α-olefin having 3 to 20 carbon atoms. Can be obtained by doing.

Various known methods can be used as the polymerization method, for example, fluidized bed gas phase polymerization or sales phase gas phase polymerization in an inert gas, slurry polymerization in an inert solvent, bulk polymerization using a monomer as a solvent, etc. Among them, slurry polymerization in an inert solvent is preferable.
The ethylene resin of the present invention may be a polymer composed of ethylene alone or a copolymer composed of ethylene and an α-olefin having 3 to 20 carbon atoms, and has 3 to 20 carbon atoms to be copolymerized with ethylene. As the α-olefin, propylene, butene-1, pentene-1, hexene-1, octene-1, decene-1, dodecene-1, tetradecene-1, hexadecene-1, octadecene-1, eicosene-1, 3- And methyl-butene-1, 4-methyl-pentene-1, 6-methyl-heptene-1. Two or more of these may be dry blended or melt blended at an arbitrary ratio.

The metallocene catalyst used in the polymerization method in which the metallocene catalyst is previously brought into contact with hydrogen and then introduced into the polymerization reactor and the method for contacting the catalyst with hydrogen will be described below.
The metallocene catalyst used in the polymerization method includes (a) a support material, (b) an organoaluminum, (c) a transition metal compound having a cyclic η-bonding anion ligand, and (d) the cyclic η bond. It is a supported geometrically constrained single-site catalyst prepared from an activator capable of forming a complex that exhibits catalytic activity by reacting with a transition metal compound having a cationic anionic ligand. In particular, the transition metal in the transition metal compound having a cyclic η-bonding anion ligand (c) is preferably titanium.

The carrier substance (a) may be either an organic carrier or an inorganic carrier. As an organic carrier,
Preferably, (1) an α-olefin polymer having 2 to 20 carbon atoms such as ethylene resin, propylene resin, butene-1 resin, ethylene-propylene copolymer resin, ethylene-hexene-1 copolymer resin, propylene -Butene-1 copolymer resin, ethylene-hexene-1 copolymer, etc., (2) Aromatic unsaturated hydrocarbon copolymers such as styrene resin, styrene-divinylbenzene copolymer resin, and (3 ) Polar group-containing polymer resins such as acrylic ester resins, methacrylic ester resins, acrylonitrile resins, vinyl chloride resins, amide resins, carbonate resins. As the inorganic carrier, (4) inorganic oxides such _{as, SiO 2, Al 2 O 2} , MgO, TiO 2, B 2 O 3, CaO, ZnO, BaO, ThO, SiO 2 -MgO, SiO 2 -Al 2 O ₃ , SiO ₂ —MgO, SiO ₂ —V ₂ O _5, etc. (5) Inorganic halogen compounds such as MgCl ₂ , AlCl ₃ , MnCl _2, etc. (6) Inorganic carbonates, sulfates, nitrates such as Na ₂ CO ₃ , K ₂ CO ₃ , CaCO ₃ , MgCO ₃ , Al ₂ (SO ₄ ) ₃ , BaSO ₄ , KNO ₃ , Mg (NO ₃ ) _2, etc. (7) Hydroxides such as Mg (OH) ₂ , Al (OH) ₃ , Ca (OH) _{3 and the} like. The most preferred carrier is SiO _2.

The particle size of the carrier is arbitrary, but generally 1 μm to 3000 μm, and from the viewpoint of particle dispersibility, the particle shape distribution is preferably in the range of 10 to 1000 μm.
The carrier material is treated with (a) an organoaluminum compound as necessary. As a preferable organoaluminum compound, a linear or cyclic polymer represented by the general formula (—Al (R) O—) n (R is a hydrocarbon group having 1 to 10 carbon atoms, and a part of halogen atoms and And / or those substituted with RO groups, where n is the degree of polymerization and is 5 or more, preferably 10 or more.), And specific examples include R being a methyl group, an ethyl group, or an isobutylethyl group. Examples thereof include methylalumoxane, ethylalumoxane, isobutylethylalumoxane and the like.

Still other organoaluminum compounds include trialkyl aluminum, dialkyl halogeno aluminum, sesquialkyl halogeno aluminum, armenyl aluminum, dialkyl hydroaluminum, sesquialkyl hydroaluminum and the like.
Specific examples of other organoaluminum compounds include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum, dialkylhalogenoaluminum such as dimethylaluminum chloride and diethylaluminum chloride, and sesquimethylaluminum. Examples thereof include sesquialkyl halogenoaluminum such as chloride and sesquiethylaluminum chloride, ethylaluminum dichloride, diethylaluminum hydride, diisobutylaluminum hydride, and sesquiethylaluminum hydride. Of these, trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum hydride and diisobutylaluminum hydride are most preferred.
The supported catalyst contains, for example, a transition metal compound having (u) a cyclic η-bonding anion ligand represented by the following formula (1).

In the formula, M is a group 4 transition metal of a long-period type periodic table having an oxidation number of +2, +3, +4 having η ⁵ bond with one or more ligands L, and titanium is particularly preferable as the transition metal. .
L is a cyclic η-bonding anion ligand, and each independently represents a cyclopentadienyl group, an indenyl group, a tetrahydroindenyl group, a fluorenyl group, a tetrahydrofluorenyl group, or an octahydrofluorenyl group. These groups are hydrocarbon groups containing up to 20 non-hydrogen atoms, halogens, halogen-substituted hydrocarbon groups, aminohydrocarbyl groups, hydrocarbyloxy groups, dihydrocarbylamino groups, dihydrocarbylphosphino groups, silyl groups Optionally having 1 to 8 substituents each independently selected from a group, an aminosilyl group, a hydrocarbyloxysilyl group, and a halosilyl group, and further, two L's may contain up to 20 non-hydrogen atoms. Carbadiyl, halohydrocarbadiyl, hydrocarbyleneoxy, hydrocarbyleneamino Jirajiiru, Haroshirajiiru, may be linked by a divalent substituent such as an aminosilane.

Each X is independently a monovalent anionic σ-bonded ligand having up to 60 non-hydrogen atoms, a divalent anionic σ-bonded ligand that binds to M divalently, or M and L Are each a divalent anion σ-bonded ligand that binds with one valence.
X ′ is a neutral Lewis base coordinating compound independently selected from phosphine, ether, amine, olefin and / or conjugated diene having 4 to 40 carbon atoms.
L is an integer of 1 or 2. p is an integer of 0, 1 or 2, and X is a monovalent anionic σ-bonded ligand or a divalent anionic σ-bonded coordination in which M and L are each bonded with a single valence. P is less than the formal oxidation number of M when it is a child, or p is smaller than the formal oxidation number of M when X is a divalent anionic σ-bonded ligand that binds to M in a divalent manner. Less than l + 1. Q is 0, 1 or 2. The transition metal compound is preferably 1 = 1 in the above formula (4).
For example, a suitable example of the transition metal compound is represented by the following formula (2).

In the formula, M is titanium, zirconium or hafnium having a formal oxidation number of +2, +3 or +4, and titanium is particularly preferable.
Also, each R ³ is independently hydrogen, hydrocarbon group, silyl group, germyl group, cyano group, halogen, or a composite machine thereof, and each can have up to 20 non-hydrogen atoms. Further, adjacent R ³ may be cyclic by forming a divalent derivative such as hydrocarbadiyl, diradii, or germaniyl.
X ″ each independently represents a halogen, a hydrocarbon group, a hydrocarbyloxy group, a hydrocarbylamino group, or a silyl group, each having up to 20 non-hydrogen atoms, and two X ″ having 5 to 30 carbon atoms. Neutral conjugated dienes or divalent derivatives may be formed.

Y is ^{-O -, - S -, -} NR * -, - PR * - a and, Z is _{^{SiR * 2, CR * 2,}} SiR * 2 SiR * 2, CR * 2 CR * 2, CR * = CR ^* , CR ^* ₂ SiR ^* ₂ or GeR ^* ₂ , wherein each R ^* is independently an alkyl or aryl group having 1 to 12 carbon atoms. N is an integer of 1 to 3.
Furthermore, as a transition metal compound, a more suitable example is represented by following formula (3) and following formula (4).

In the formula, each R ³ independently represents hydrogen, a hydrocarbon group, a silyl group, a germyl group, a cyano group, a halogen, or a composite machine thereof, and each may have up to 20 non-hydrogen atoms. The transition metal M is titanium, zirconium or hafnium, with titanium being preferred.
The definitions of Z, Y, X and X ′ are as described above. p is 0, 1 or 2, and q is 0 or 1. However, when p is 2 and q is 0, the oxidation number of M is +4, and X is halogen, hydrocarbon group, hydrocarbyloxy group, dihydrocarbylamino group, dihydrocarbyl phosphide group, hydrocarbyl sulfide group, silyl group Group or a composite group thereof, having up to 20 non-hydrogen atoms.

When p is 1 and q is 0, the oxidation number of M is +3, and X is an allyl group, 2- (N, N-dimethylaminomethyl) phenyl group or 2- (N, N-dimethyl). -A stabilized anionic ligand selected from aminobenzyl groups, or the oxidation number of M is +4 and X is a derivative of a divalent conjugated diene, or both M and X are metallocyclopentene groups Is forming.
When p is 0 and q is 1, the oxidation number of M is +2, and X ′ is a neutral conjugated or non-conjugated diene, which may be optionally substituted with one or more hydrocarbons. The X ′ may contain up to 40 carbon atoms and forms a π-type complex with M.
Further, in the present invention, the most suitable examples of the transition metal compound are represented by the following formula (5) and the following formula (6).

In the formula, each R ³ independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms. The M is titanium, Y is ^{-O -, - S -, -} NR * -, - PR * - a and, ^{Z *} is _{^{SiR * 2, CR * 2,}} SiR * 2 SiR * 2, CR * 2 _{^{CR * 2, CR * = CR}} *, a _CR * 2 SiR _2, or ^GeR _{* 2,} wherein ^{R *} are each independently hydrogen or a hydrocarbon group, hydrocarbyloxy group, a silyl group, a halogenated alkyl group, halogen Aryl group or a composite group thereof. The R ^* may have a non-hydrogen atoms up to 20, also be made with R ^* annular R ^* and in Y medium Z ^* 2 one R ^* s or Z medium ^* optionally Good.
p is 0, 1 or 2, and q is 0 or 1. However, when p is 2 and q is 0, the oxidation number of M is +4, and X is each independently a methyl group or a hydrobenzyl group.

When p is 1 and q is 0, the oxidation number of M is +3 and X is a 2- (N, N-dimethyl) -aminobenzyl group, or the oxidation number of M is +4 and X is 2-butene-1,4-diyl.
When p is 0 and q is 1, the oxidation number of M is +2, and X ′ is 1,4-diphenyl-1,3-butadiene or 1,3-pentadiene. The dienes are examples of asymmetric dienes that form metal complexes, and are actually mixtures of geometric isomers.
In addition, the metallocene catalyst includes (d) an activator capable of forming a complex that reacts with a transition metal compound and exhibits catalytic activity. Usually, in a metallocene catalyst, a complex formed by a transition metal compound and the above activator exhibits high olefin polymerization activity as a catalytically active species.
Examples of the activator include a compound defined by the following formula (7).

In the formula, [L—H] ^{d +} is a proton-provided Bronsted acid, and L is a neutral Lewis base. [M _m Q _t ] ^d- is a compatible non-coordinating anion, M is a metal or metalloid selected from Groups 5 to 15 of the periodic table, and Q is independently a hydride or dialkylamide. Group, halide, alkoxide group, allyloxide group, hydrocarbon group, substituted hydrocarbon group having up to 20 carbon atoms, and Q which is a halide is 1 or less. M is an integer from 1 to 7, p is an integer from 2 to 14, d is an integer from 1 to 7, and t−m = d.
A more preferred example of the activator is a compound defined by the following formula (8).

In the formula, [L—H] ^{d +} is a proton-provided Bronsted acid, and L is a neutral Lewis base. Also a _{[M m Q w (G u} (T-H) r) z] d- is a non-coordinating anion compatible, M is a metal or metalloid selected from Group 5 to Group 15 of the periodic table Each Q is independently a hydride, a dialkylamide group, a halide, an alkoxide group, an allyloxide group, a hydrocarbon group or a substituted hydrocarbon group having up to 20 carbon atoms, and the Q as a halide is 1 or less. G is a polyvalent hydrocarbon group having a valence of r + 1 which binds to M and T, and T is O, S, NR or PR, where R is a hydrocarbyl group, a trihydrocarbylsilyl group, a trihydrocarbylgermanium. A group or hydrogen.
M is an integer from 1 to 7, w is an integer from 0 to 7, u is an integer from 0 or 1, r is an integer from 1 to 3, and z is an integer from 1 to 8. , W + z−m = d.
A further preferred example of the activator is a compound defined by the following formula (9).

In the formula, [L—H] ^{d +} is a proton-provided Bronsted acid, and L is a neutral Lewis base. [BQ ₃ Q ^* ] ⁻ is a compatible non-coordinating anion, B is a boron atom, Q is a pentafluorophenyl group, and Q ^* has 6 to 6 carbon atoms having one OH group as a substituent. 20 substituted aryl groups.

Specific examples of non-coordinating anions include triphenyl (hydroxyphenyl) borate, diphenyl-di (hydroxyphenyl) borate, triphenyl (2,4-dihydroxyphenyl) borate, tri (p-tolyl) phenyl (hydroxyphenyl). ) Borate, Tris (pentafluorophenyl) (hydroxyphenyl) borate, Tris (2,4 dimethylphenyl) (hydroxyphenyl) borate, Tris (3,5 dimethylphenyl) (hydroxyphenyl) borate, Tris (3,5-di-) -Trifluoromethylphenyl) (hydroxyphenyl) borate, tris (pentafluorophenyl,) (2-hydroxyethyl) borate, tris (pentafluorophenyl,) (4-hydroxybutyl) borate, tris (pentafluorophenyl) Nyl,) (4-hydroxy-cyclohexyl) borate, tris (pentafluorophenyl,) (4- (4′-hydroxyphenyl) phenyl) borate, tris (pentafluorophenyl) (6-hydroxy-2-naphthyl) borate, etc. Most preferred is tris (pentafluorophenyl) (hydroxyphenyl) borate.
Specific examples of other preferable compatible non-coordinating anions include borates in which the hydroxy group of the borate exemplified above is replaced with NHR. Here, R is preferably a methyl group, an ethyl group or a tert-butyl group.

  Specific examples of the proton-providing Bronsted acid include, for example, triethylammonium, tripropylammonium, tri (n-butyl) ammonium, trimethylammonium, tributylammonium, and tri (n-octyl) ammonium, diethylmethylammonium. , Dibutylmethylammonium, dibutylethylammonium, dihexylmethylammonium, dioctylmethylammonium, didecylmethylammonium, didodecylmethylammonium, ditetradecylmethylammonium, dihexadecylmethylammonium, dioctadecylmethylammonium, diicosylmethylammonium, Trialkyl group-substituted ammonium cations such as bis (hydrogenated tallow alkyl) methylammonium N, N-dimethylanilinium, N, N-diethylanilinium, N, N-2,4,6-pentamethylanilinium, N, N-dimethylbenzylanilinium, etc. Also suitable are dialkylanilinium cations.

  Next, a method for bringing the metallocene catalyst into contact with hydrogen will be described. Before the metallocene catalyst is introduced into the polymerization reactor, it is previously brought into contact with 0.5 to mol and 50000 mol or less of the transition metal compound contained in the catalyst. The method of contacting is a method in which a metallocene catalyst is transferred to a polymerization reactor using a medium, hydrogen is contained in the transfer medium and contacted during transfer, and hydrogen is directly supplied to the vicinity of a catalyst supply port inside the polymerization reactor. There are a method of bringing the catalyst into contact with the metallocene catalyst while introducing the catalyst into the polymerization reactor, a method of bringing hydrogen into the metallocene catalyst storage tank and the like, and a method of bringing hydrogen into contact with the metallocene catalyst storage tank. In addition, since the method of bringing the metallocene catalyst into contact with hydrogen or the method of supplying hydrogen directly to the vicinity of the catalyst supply port simultaneously introduces hydrogen into the polymerization reactor, the introduced hydrogen is used as a chain transfer agent. Works. The purity of hydrogen used is desirably 99.99 mol% or more.

  The ethylene resin of the present invention may be dry blended or melt blended with a high-pressure low-density ethylene resin, a medium-low-pressure slurry polymerization method, a high-density ethylene resin obtained by a solution polymerization method or a gas phase polymerization method. The high pressure method low density polyethylene may be a copolymer with an α-olefin having 3 to 20 carbon atoms, vinyl acetate, an acrylate ester or the like as long as the object of the present invention is not impaired. The high-pressure low-density polyethylene can be obtained by radical polymerization of ethylene in a tubular type or autoclave type reactor, and either type may be used. When a tubular type reactor is employed, the polymerization conditions may be set to a polymerization reaction peak temperature of 180 to 400 ° C. and a polymerization pressure of 100 to 400 MPa in the presence of a radical generating catalyst and a chain transfer agent. It is desirable to set the polymerization reaction peak temperature at ˜350 ° C. and the polymerization pressure at 150 to 350 MPa.

  Further, the ethylene resin of the present invention includes fillers such as aluminosilicate, talc, diatomaceous earth, kaolin, clay, aliphatic hydrocarbons, higher fatty acids, higher fatty acid metal salts, fatty acid esters of alcohols, waxes, higher You may add well-known additives, such as slip agents, such as fatty acid amide, a silicone oil, and a rosin, or a phenolic antioxidant, phosphorus antioxidant, an antistatic agent, and a neutralizing agent. Phenol antioxidants include 2,6-di-t-butyl-4-methylphenol (dibutylhydroxytoluene), n-octadecyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate And tetrakis (2,4-di-t-butylphenyl) -4,4 as phosphorus antioxidants such as tetrakis (methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate)) methane '-Biphenylene-di-phosphonite, tris (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,4-t-butylphenyl phosphite), etc. May be used, or two or more types may be used in combination.

Examples of the antistatic agent include nonionic active agents, ionic active agents, amphoteric active agents and mixtures thereof, and each may be used alone or in combination of two or more. Examples of the neutralizing agent include various metal stearates and hydrotalcite, and each may be used alone or in combination of two or more. Furthermore, in addition to the above additives, additives such as weathering agents, flame retardants, flame retardant aids, dispersants, organic or inorganic pigments can be added as necessary.
The laminate of the present invention is a laminate having a layer made of the ethylene resin of the present invention as a sealant layer. The sealant layer refers to a layer that can be heat-sealed and is in direct contact with the contents, and its thickness is not particularly limited, but in general, the thickness of the layer made of an ethylene-based resin is in the range of 3 to 300 μm. .

  Cellophane, ethylene resin, ethylene / vinyl acetate resin, PP resin, CPP resin, PET resin, nylon resin, vinyl chloride resin, vinylidene chloride resin, vinyl alcohol resin, eval resin, styrene Resin, acrylonitrile resin, carbonate resin, ionomer resin, ethylene / acrylic acid copolymer resin, ethylene / methacrylic acid copolymer resin, ethylene / methyl acrylate copolymer resin, ethylene / methyl acrylate copolymer resin, ethylene / ethyl Acrylate resins and their K coat type, aluminum vapor deposition, silica vapor deposition type, alumina vapor deposition type, and various papers such as fine paper, kraft paper, glassine paper, parchment paper, aluminum foil, etc. Sea May be laminated with a cement layer, it may be laminated in combination of two or more. As a lamination method, a known method such as a dry lamination method, an extrusion lamination method, a wet lamination method, a hot melt lamination method, a coextrusion inflation molding method, or a coextrusion cast molding method can be employed. In addition, when laminating | stacking a sealant layer beforehand in a film form, the film obtained by the inflation molding method or the cast molding method can be used.

  Laminates of the present invention include water, juice, milk, various beverages such as liquors such as sake and shochu, cooked foods, intermediate products, confectionery / bread, agricultural products, livestock products, marine products, kneaded products, water It is suitably used for packaging various foods such as foods, oils, chilled foods, retort foods, frozen foods, seasonings, pharmaceuticals / medical supplies, agricultural chemicals and the like. Especially, it is used suitably as packaging materials, such as various drinks, such as alcohol, such as water, juice, milk, sake, and shochu, and cooked rice.

The present invention will be specifically described below. The physical property measurement method and evaluation method are as follows.
(1) Melt mass flow rate (MFR)
JIS K7210: 1999 (temperature = 190 ° C., load = 2.16 kg)
(2) Density JIS K7112: 1999
(3) Molecular weight distribution The ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) obtained from gel permeation chromatography (GPC) is defined as the molecular weight distribution. For GPC measurement, GPCV2000 manufactured by Waters Co., Ltd. was used, and the column was used by connecting UT-807 (1) manufactured by Showa Denko KK and GMHHR-H (S) HT (2) manufactured by Tosoh Corporation in series. And a mobile phase trichlorobenzene (TCB), a column temperature of 140 ° C., a flow rate of 1.0 ml / min, a sample concentration of 20 mg / 15 ml (TCB), a sample dissolution temperature of 140 ° C., and a sample dissolution time of 2 hours. The molecular weight calibration is performed at 12 points in the range of Mw of standard polystyrene manufactured by Tosoh Corporation, and the Mw of each standard polystyrene is multiplied by a coefficient of 0.43 to obtain a molecular weight equivalent to polyethylene, and elution time and polyethylene Create a primary calibration line from the converted molecular weight plot and determine the molecular weight.

(4) Terminal methyl group concentration The terminal methyl group concentration is attributed to the methylene group by simultaneously performing infrared spectroscopic analysis of the eluted components with FT-IR 1760X manufactured by PerkinElmer Co., Ltd. in the above molecular weight distribution measurement. From the absorbance I (methylene) (absorption wave number: 2925 cm ⁻¹ ) and the absorbance I (methyl) attributed to the methyl group (absorption wave number: 2960 cm ⁻¹ ), the ratio between the two, I (methyl) / I (methylene) is converted to molecular weight Can be obtained by calculating for each eluted component of 10000 or less and weighted averaging. The converted molecular weight is obtained from a primary calibration line of the elution time obtained by the GPC measurement, the elution time prepared in advance and the polyethylene converted molecular weight, and the elution amount of each eluted component having a converted molecular weight of 10,000 or less is also obtained by GPC measurement. Use the value.

(5) Heat-seal properties A single layer film having a thickness of 0.06 mm is obtained by forming an ethylene-based resin by an inflation molding method at 170 ° C., and then dry-laminated on an oriented nylon film (15 μm) to obtain a laminate sample. Make it. The temperature is changed sequentially from 100 ° C. by 10 ° C., sealing is performed under the conditions of pressure = 0.2 MPa, time = 1 second, and a sample cut out with a width of 15 mm is used as a sample to perform a tensile test at a tensile speed of 500 mm / min. The seal strength is plotted against the seal temperature, and the seal strength 10 ° C. higher than the temperature at which the seal strength reaches equilibrium is defined as heat sealability. If the heat seal strength is 60 N / 15 mm or more, the heat sealability is evaluated as good, while if less than that, it is evaluated as defective.

(6) Hot tack property Using a laminate sample for evaluating heat seal property, the temperature was changed sequentially from 100 ° C. by 10 ° C., under the conditions of pressure = 0.2 MPa, time = 1 second, peel load = 45 g × 2. evaluate. The difference between the temperature at which the peel distance is minimum with respect to the seal temperature and the temperature at which the incremental distance exceeds 30 mm increases when the seal temperature is further increased. Let it be tacky. If the temperature difference is 30 ° C. or more, it is evaluated that the hot tack property is good, while if it is less than that, it is evaluated as defective.

(7) Low-temperature impact strength A four-side sealed bag having an inner size of 23 cm × 30 cm filled with 2 L of a 1 mol / L saline solution is prepared using the laminate sample. Next, after cooling at −5 ° C. for a whole day and night, 10 seal bags are dropped from a height of 100 cm under the temperature condition, and the bag breaking rate is examined. If the bag breaking rate is 50% or less, the low-temperature impact strength is good.

(8) Heat-resistant blocking property The blocking force is measured by the following test method and sample pretreatment conditions. If the blocking force is 1 g or less, it is evaluated that the heat-resistant blocking property is good. On the other hand, if the blocking force exceeds 1 g, Evaluated as poor blocking ability.
Test method: ASTM D-1893
Sample: the above blown film, size = 20 cm × 25 cm
Pre-treatment conditions: heat treatment at 50 ° C. × 24 hr with a load of 25 kg, then 23 ° C.
Cooling at 50% RH for 24 hours (9) Puncture strength A film sample obtained by the above inflation molding is fixed at a size of 50 mmφ, and a puncture strength is measured by pressing a 5 R tip indenter at a speed of 100 mm / min. If the piercing strength is 2 kg or more, it is evaluated as good, while if it is less than that, it is evaluated as defective.

(10) Low odor property The sealant layer surface of the laminate sample is irradiated with ultraviolet light having an intensity of 700 mW / cm ² for 3 seconds, and the odor of the sample before and after irradiation is evaluated by a panel of 10 persons. If the judgment that the odor before and after the irradiation hardly changes is obtained from eight or more panelists, it is evaluated as being excellent in low odor, and if it is less than that, it is evaluated as defective.
(11) Low taste A four-sided sealed bag having an internal size of 20 cm × 25 cm filled with 1 L of commercially available natural water is prepared using the laminate sample after the above-described ultraviolet irradiation. After production, the taste of the natural water filled after standing at room temperature for 1 hour is sensorially evaluated by 10 panelists. If the judgment that it is almost the same as the original natural water taste is obtained from 8 or more panelists, it is evaluated as being excellent in low taste, and if it is less than that, it is evaluated as poor.

[Production of ethylene resin using metallocene catalyst in contact with hydrogen]
6.2 g (8.8 mmol) of triethylammonium tris (pentafluorophenyl) (4-hydroxyphenyl) borate was added to 4 liters of toluene and stirred at 90 ° C. for 30 minutes. Next, 40 ml of a 1 mol / l trihexylaluminum toluene solution was added to this solution and stirred at 90 ° C. for a minute. On the other hand, silica P-10 (manufactured by Fuji Silysia Co., Ltd .: trade name) was treated in a nitrogen stream at 500 ° C. for 3 hours, and the treated silica was placed in 1.7 l of toluene and stirred. The toluene solution of triethylammonium triethylammonium tris (pentafluorophenyl) (4-hydroxyphenyl) borate and trihexylaluminum was added to the silica slurry solution, and the mixture was stirred at 90 ° C. for 3 hours. Next, 206 ml of a 1 mol / l trihexylaluminum toluene solution was added, and the mixture was further stirred at 90 ° C. for 1 hour. Thereafter, the supernatant was decanted with 90 ° C. toluene to remove excess trihexylaluminum. 0.218 mol / l dark purple titanium (N-1,1-dimethylethyl) dimethyl (1- (1,2,3,4,5-eta) -2,3,4,5-tetramethyl-2 , 4-Cyclopentadien-1-yl) silanaminate) ((2-) N- (η4-1,3-pentadiene) in 20 ml of ISOPAR TME (manufactured by Exxon Chemical Co., Ltd.) in the above mixture was added to the above mixture for 3 hours. A green metallocene catalyst was obtained.

  The obtained metallocene catalyst is brought into contact with hydrogen by supplying a necessary amount of hydrogen as a chain transfer agent to the catalyst transfer line and introduced into the polymerization reactor, using hexane as a solvent, ethylene and butene-1 as monomers, Each monomer was supplied so as to have a predetermined gas composition, and an ethylene resin was polymerized at a reaction temperature of 75 ° C. and a total pressure of 0.8 MPa. The obtained ethylene resin was granulated by extrusion at 200 ° C. using an extruder manufactured by Nippon Steel Co., Ltd. (screw diameter 65 mm, L / D = 28).

[Production of high-density polyethylene resin using titanium catalyst]
A 15 liter reactor sufficiently purged with nitrogen was charged with 3 liters of trichlorosilane as a 2 mol / liter n-heptane solution, kept at 65 ° C. with stirring, and the composition formula AlMg ₆ (C ₂ H ₅ ) ₃ ( n-C ₄ H ₉ ) _6.4 (On-C ₄ H ₉ ) 7 liters of an n-heptane solution of an organic magnesium component represented by _5.6 (5 mol in terms of magnesium) was added over 1 hour, and 65 The reaction was allowed to stir at 1 ° C. for 1 hour. After completion of the reaction, the supernatant was removed and washed 4 times with 7 liters of n-hexane to obtain a solid material slurry. This solid was separated, dried and analyzed, and as a result, it contained 7.45 mmol of Mg per gram of the solid.

  Of these, a slurry containing 500 g of solid was reacted with 0.93 liter of n-butyl alcohol 1 mol / liter n-hexane solution at 50 ° C. for 1 hour with stirring. After completion of the reaction, the supernatant was removed and washed once with 7 liters of n-hexane. This slurry was kept at 50 ° C., and 1.3 liters of n-hexane solution of 1 mol / liter of diethylaluminum chloride was added with stirring and reacted for 1 hour. After completion of the reaction, the supernatant was removed and washed twice with 7 liters of n-hexane. This slurry was kept at 50 ° C., 0.2 liter of n-hexane solution of 1 mol / liter of diethylaluminum chloride and 0.2 liter of n-hexane solution of 1 mol / liter of titanium tetrachloride were added and reacted for 2 hours. After completion of the reaction, the supernatant was removed and the solid catalyst was isolated and washed with hexane until no free halogen was detected. The solid catalyst had 2.3 wt% titanium.

Using the catalyst obtained above, an ethylene resin was produced in the following manner.
In a single-stage polymerization process, polymerization was performed in a polymerization vessel having a volume of 230 L. The polymerization temperature is 86 ° C. and the polymerization pressure is 0.98 MPa. The titanium catalyst synthesized in this polymerization vessel was introduced at a rate of 0.3 g / hr, triisobutylaluminum at 15 mmol / hr, and hexane at a rate of 60 liter / hr. To this, ethylene, hydrogen and butene-1 are introduced so as to have a predetermined gas composition, polymerization is performed, 1000 ppm of calcium stearate is added to the obtained ethylene resin, and an extruder manufactured by Nippon Steel Co., Ltd. ( Using a screw diameter of 65 mm, L / D = 28), the mixture was extruded and granulated at 200 ° C.

[Production method of film and laminate]
3% dry blend of 4% masterbatch of n-octadecyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate made of the same resin with the granulated ethylene resin, and 120φ-gap 3. In a 50mmφ extruder equipped with a 0mm die and a dual type air ring, it is blown by corona treatment so that the wetting tension is 45mN / m or more after forming by inflation at a temperature of 170 ° C and a blow ratio of 2. An inflation molded film was obtained.
A polyester-based two-component solvent type dry laminate adhesive was applied to an oriented nylon film having a thickness of 15 μm, and the ethylene resin film was dry laminated and aged to obtain a laminate.

[Examples 1 to 5]
Ethylene resin was obtained by the ethylene resin production method using the metallocene catalyst in contact with the gas composition of ethylene, butene-1 and hydrogen listed in Table 1, and the above hydrogen. Table 1 also shows the evaluation results of the obtained blown film of ethylene resin and laminate.

[Comparative Example 1]
In Example 1, an ethylene resin was obtained in the same manner except that the metallocene catalyst was previously introduced into the polymerization reactor without contacting with hydrogen. Table 2 also shows the evaluation results of the resulting blown molded film of ethylene resin and laminate.

[Comparative Examples 2 to 4]
Ethylene resin was obtained by the gas composition of ethylene, butene-1 and hydrogen described in Table 2, and the production method of high-density polyethylene resin using the titanium catalyst. Table 2 also shows the evaluation results of the resulting blown molded film of ethylene resin and laminate.

  Since the ethylene-based resin of the present invention exhibits the above-mentioned effects, various beverages such as water, juice, milk, sake, shochu and other alcoholic beverages, cooked rice, cooked foods, cooked intermediate products, confectionery / bread, agricultural products, It is suitably used for packaging livestock products, marine products, paste products, various foods such as water products and oil products, chilled food products, retort food products, frozen food products, seasonings, pharmaceutical / medical supplies, agricultural chemicals and the like.

Claims (4)

A melt flow rate of 0.1 g / 10min or more, 50 g / 10min or less, a density of 925 kg / ^{m 3} or more, 975 kg / ^{m 3} or less, the molecular weight distribution represented by the ratio of weight average molecular weight to number average molecular weight of 2 or more, 10 It is the following ethylene resin, wherein the number of methyl carbon atoms contained in 1000 carbon atoms of the ethylene polymer having an equivalent molecular weight of 10,000 or less in the ethylene resin is 1 or more and 100 or less. A laminate comprising a layer made of an ethylene-based resin for sealant as a sealant layer. The ethylene resin for sealant is a polymerization method of an ethylene resin using a supported geometrically constrained single site catalyst, wherein the catalyst is brought into contact with hydrogen in advance and then supplied to a polymerization reactor for polymerization. The laminate according to claim 1, wherein the laminate is obtained. A beverage packaging material comprising the laminate according to claim 1 or 2 . A packaging material for cooked rice comprising the laminate according to claim 1 or 2 .