JP7261396B2 - Laminate provided with polyolefin resin layer and packaging product provided with the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a laminate provided with a polyolefin resin layer containing biomass polyolefin, and more particularly, a polyolefin resin layer containing at least a paper base layer and a biomass polyolefin that is a polymer of a monomer containing biomass-derived ethylene. and a laminate. Furthermore, it relates to a packaging product and a paper container for liquid comprising the laminate.

In recent years, along with the increasing demand for building a recycling-based society, the use of biomass has been attracting attention in the field of materials as well as the use of fossil fuels, as is the case with energy. Biomass is an organic compound that is photosynthesised from carbon dioxide and water, and is a so-called carbon-neutral renewable energy that is regenerated into carbon dioxide and water by using it. In recent years, biomass plastics using biomass as raw materials have been rapidly put to practical use, and attempts have been made to produce various resins from biomass raw materials.

As a biomass-derived resin, polylactic acid (PLA), which is produced through lactic acid fermentation, began commercial production first, but its performance as a plastic, including its biodegradability, has fallen behind that of today's general-purpose plastics. Since it is very different from the standard, it has not been widely used due to limitations in product applications and product manufacturing methods. In addition, PLA is subjected to Life Cycle Assessment (LCA) evaluation, and discussions are being made on energy consumption during PLA production and equivalence when replacing general-purpose plastics.

Here, various kinds of general-purpose plastics such as polyethylene, polypropylene, polyvinyl chloride, and polystyrene are used. In particular, polyethylene is molded into films, sheets, bottles, etc., and is used in various applications such as packaging materials, and is widely used around the world. Therefore, the use of conventional fossil fuel-derived polyethylene imposes a large environmental load.

Therefore, it is desired to reduce the consumption of fossil fuels by using biomass-derived raw materials for the production of polyethylene. For example, until now, research has been conducted to produce ethylene and butylene, which are raw materials for polyolefin resins, from renewable natural raw materials (see, for example, Patent Document 1).

Japanese Patent Publication No. 2011-506628

The present inventors focused on ethylene, which is the raw material of polyolefin resin, and instead of ethylene obtained from conventional fossil fuels, biomass polyolefin (hereinafter simply referred to as "biomass polyolefin") using biomass-derived ethylene as the raw material A laminate comprising a polyolefin resin layer containing a polyolefin resin layer made of polyolefin produced using ethylene obtained from conventional fossil fuel (hereinafter sometimes simply referred to as "fossil fuel-derived polyolefin") Polyolefin resin layer It was found that a laminate having physical properties such as mechanical properties comparable to a laminate having The present invention is based on such findings.

Accordingly, an object of the present invention is to provide a laminate comprising a polyolefin resin layer containing biomass polyolefin, which is comparable in physical properties such as mechanical properties to conventional laminates comprising a polyolefin resin layer made of polyolefin derived from fossil fuel. That is.

In aspects of the invention,
A liquid paper container having a square cylindrical body portion including side surfaces, a square plate-shaped bottom portion, and an upper portion,
The laminate constituting the liquid paper container comprises at least a first polyolefin resin layer, a paper base layer, an adhesive resin layer, a barrier layer, and a second polyolefin resin layer in this order,
The first and second polyolefin resin layers are composed only of biomass-derived polyethylene, or composed of a mixed resin of biomass-derived polyethylene and fossil fuel-derived polyethylene,
The biomass degree in the first and second polyolefin resin layers is 5% or more,
The biomass-derived polyethylene has a density of 0.91 g/cm ³ or more and 0.93 g/cm ³ or less,
A paper container for liquid is provided, wherein the adhesive resin layer is an ethylene-methacrylic acid copolymer or an ionomer resin.

In an aspect of the present invention, the laminate may include a plastic film positioned between the adhesive resin layer and the second polyolefin resin layer.

In an aspect of the present invention, the barrier layer may include a deposited film formed on the plastic film.

In aspects of the invention, the barrier layer may comprise an aluminum foil.

In the aspect of the present invention, the first and second polyolefin resin layers are composed only of biomass-derived low-density polyethylene, or are composed of biomass-derived low-density polyethylene and fossil fuel-derived low-density polyethylene. It may be composed of a mixed resin.

In an aspect of the present invention, the first or second polyolefin resin layer may contain 50% by mass or more of the biomass-derived polyethylene.

In another aspect of the present invention, a method for manufacturing a laminate used for the paper container for liquid described above, comprising:
A method for producing a laminate is provided, wherein the second polyolefin resin layer is laminated using a melt extrusion lamination method.

The laminate according to the present invention includes at least a paper base layer and a polyolefin resin layer containing biomass polyolefin, so that the amount of fossil fuel used can be reduced compared to the conventional one, and the environmental load can be reduced. can. In addition, since the laminate according to the present invention is comparable in physical properties such as mechanical properties to conventional laminates of polyolefin resin derived from fossil fuel, it can be used as a substitute for laminates of conventional polyolefin resin derived from fossil fuel. be able to.

1 is a schematic cross-sectional view showing an example of a laminate according to the present invention; FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to the present invention; FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to the present invention; FIG. It is a perspective view showing an example of a liquid paper container.

In the present invention, “biomass polyolefin” and “polyolefin resin layer containing biomass polyolefin” refer to those using biomass-derived raw materials as raw materials at least in part, and all of the raw materials are derived from biomass. does not mean

<Laminate>
A laminate according to the present invention comprises a first polyolefin resin layer containing biomass polyolefin, a paper substrate layer, and a second polyolefin resin layer containing biomass polyolefin. When a paper container for liquid is produced using a laminate, the layer of the laminate positioned outside the paper container for liquid is the first polyolefin resin layer, and the layer of the laminate positioned inside the paper container for liquid is the second polyolefin resin layer. of the polyolefin resin layer. Since the laminate includes a polyolefin resin layer containing biomass polyolefin, it is possible to reduce the amount of fossil fuel used compared to conventional laminates, thereby reducing the environmental load. In addition, the laminate according to the present invention is comparable in terms of physical properties such as mechanical properties to conventional polyolefin resin laminates produced from raw materials obtained from fossil fuels. can be substituted for

The laminate according to the present invention may further have at least one other layer such as a thermoplastic resin layer, a printed layer, a barrier layer, a plastic film, an adhesive layer, etc., in addition to the above layers. When two or more other layers are provided, they may have the same composition or may have different compositions.

A laminate according to the present invention will be described with reference to the drawings. Examples of schematic cross-sectional views of laminates according to the present invention are shown in FIGS.
A laminate 10 shown in FIG. 1 includes a first polyolefin resin layer 11, a paper substrate layer 12, and a second polyolefin resin layer 13 in this order. In the case of the paper container for liquid comprising the laminate 10, the first polyolefin resin layer 11 is positioned on the outside of the paper container for liquid and the second polyolefin resin layer 13 is positioned on the inside of the paper container for liquid.
The laminate 20 shown in FIG. 2 comprises a first polyolefin resin layer 11, a paper base layer 12, an adhesive layer 14, a barrier layer 15, and a second polyolefin resin layer 13 in this order. be. In the case of the paper container for liquid comprising the laminate 20, the first polyolefin resin layer 11 is positioned on the outside of the paper container for liquid and the second polyolefin resin layer 13 is positioned for the inside of the paper container for liquid.
A laminate 30 shown in FIG. It is prepared in this order. In the case of the paper container for liquid comprising the laminate 30, the first polyolefin resin layer 11 is positioned on the outside of the paper container for liquid and the second polyolefin resin layer 13 is positioned on the inside of the paper container for liquid.
In any laminate, a printed layer, a thermoplastic resin layer, or the like may be further laminated.
Each layer constituting the laminate will be described below.

(Paper base layer)
In the present invention, the paper base layer functions as a base layer for holding the polyolefin resin layer, and is preferably capable of imparting strength to the laminate as a packaging product. The paper used as the paper base layer has a basis weight of 100 g/m ² or more and 700 g/m ² or less, preferably 150 g/m ² or more and 600 g/m ² or less, more preferably 200 g/m ² or more and 500 g/m ^{2 or} less. have. As the paper substrate layer, white paperboard in general is used, but ivory paper, milk carton base paper, cup base paper, etc. using natural pulp are particularly preferable from the viewpoint of safety.

The paperboard used in the present invention may use neutral rosin, alkylketene dimer, alkenyl succinic anhydride as a sizing agent, and cationic polyacrylamide, cationic starch, etc. as a fixing agent. good too. Moreover, it is also possible to make paper in a neutral range of pH 6 or more and pH 9 or less using aluminum sulfate. In addition to the above sizing agents as necessary, fixing agents, various fillers for papermaking, retention improvers, dry strength enhancers, wet strength enhancers, binders, dispersants, flocculants, plasticizers Agents and adhesives may be contained as appropriate.

(Polyolefin resin layer)
In the present invention, the polyolefin resin layer contains a biomass polyolefin that is a polymer of a monomer containing biomass-derived ethylene, and may further contain a fossil fuel-derived polyolefin. The first and second polyolefin resin layers may contain 5% by mass or more and 100% by mass or less of biomass polyolefin and 0% by mass or more and 95% by mass or less of fossil fuel-derived polyolefin with respect to the entire polyolefin resin layer. , 5% by mass or more and less than 100% by mass of biomass polyolefin and more than 0% by mass and 95% by mass or less of fossil fuel-derived polyolefin, and 25% by mass or more and 75% by mass or less of biomass polyolefin and 25% by mass. 75% by mass or more and 75% by mass or less of fossil fuel-derived polyolefin. The concentrations of biomass polyolefin in the first and second polyolefin resin layers may be the same or different. It suffices if the polyolefin resin layer as a whole can achieve the following biomass degree. In the present invention, since the polyolefin resin layer contains biomass polyolefin, it is possible to reduce the amount of polyolefin derived from fossil fuels and reduce the environmental load compared to the prior art.

In the present invention, the “biomass degree” (biomass-derived carbon concentration in biomass polyolefin) in the polyolefin resin layer is a value obtained by measuring the content of biomass-derived carbon by radioactive carbon (C14) measurement. Since carbon dioxide in the atmosphere contains a certain proportion of C14 (105.5 pMC), the C14 content in plants that grow by taking in carbon dioxide in the atmosphere, such as corn, is also about 105.5 pMC. It is known. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the ratio of C14 contained in all carbon atoms in the polyolefin, the ratio of biomass-derived carbon can be calculated. In the present invention, the biomass-derived carbon content _Pbio can be determined as follows, where _Pc14 is the content of C14 in the polyolefin.
P _bio (%) = P _C14 /105.5 x 100

In the present invention, theoretically, if all biomass-derived ethylene is used as the raw material for polyolefin, the biomass degree is 100%, and the biomass degree of the biomass-derived polyolefin is 100%. In addition, the biomass-derived carbon concentration in the fossil-fuel-derived polyolefin produced only from fossil-fuel-derived raw materials is 0%, and the biomass degree of the fossil-fuel-derived polyolefin is 0%.

In the present invention, the degree of biomass in the first and second polyolefin resin layers is 5% or more, preferably 10% or more, more preferably 15% or more, and still more preferably 20% or more. . The biomass degrees in the first and second polyolefin resin layers may be the same or different. The biomass degree in the first and second polyolefin resin layers does not need to be 100%. This is because if biomass-derived raw materials are used for at least a part of the laminate, the purpose of the present invention is to reduce the amount of fossil fuel used compared to the conventional method. If the degree of biomass in the first and second polyolefin resin layers is 5% or more, the amount of polyolefin derived from fossil fuels can be reduced and the environmental load can be reduced compared to the conventional case.

The first and second polyolefin resin layers are preferably 0.91 g/cm ³ or more and 0.93 g/cm 3 or less, more preferably 0.911 g/cm ^{3 or} more and 0.928 g/cm ³ or less, still more preferably 0 It has a density of 0.915 g/cm ³ or more and 0.925 g/cm ³ or less. The densities of the first and second polyolefin resin layers may be the same or different. The densities of the first and second polyolefin resin layers are values measured according to the A method of JIS K7112-1980 after annealing according to JIS K6760-1995. If the density of the polyolefin resin layer is 0.91 g/cm ³ or more and 0.93 g/cm ³ or less, processing and molding can be facilitated.

The first and second polyolefin resin layers preferably have a thickness of 5 μm or more and 100 μm or less, more preferably 10 μm or more and 60 μm or less, still more preferably 15 μm or more and 40 μm or less. The thicknesses of the first and second polyolefin resin layers may be the same or different. When the thicknesses of the first and second polyolefin resin layers are within the above range, they can sufficiently function as sealing layers of packaging containers.

(biomass polyolefin)
In the present invention, the biomass polyolefin is a polymer of monomers containing biomass-derived ethylene. As the biomass-derived ethylene, it is preferable to use one obtained by the production method described below. Since biomass-derived ethylene is used as a raw material monomer, the polymerized polyolefin is derived from biomass. Note that the polyolefin raw material monomer does not have to contain 100% by mass of biomass-derived ethylene.

The monomer that is the raw material for the biomass polyolefin may further contain a fossil fuel-derived ethylene monomer and/or a fossil fuel-derived α-olefin monomer, or may further contain a biomass-derived α-olefin monomer.

Although the number of carbon atoms of the α-olefin is not particularly limited, those having 3 to 20 carbon atoms can usually be used, and preferably butylene, hexene, or octene. This is because butylene, hexene, or octene can be produced by polymerization of ethylene, which is a raw material derived from biomass. In addition, by containing such an α-olefin, the polymerized biomass polyolefin has an alkyl group as a branched structure, so that it can be made more flexible than a simple linear one.

As the biomass polyolefin, polyethylene or a copolymer of ethylene and α-olefin may be used alone, or two or more of them may be mixed and used. In particular, the biomass polyolefin is preferably polyethylene. This is because the use of ethylene, which is a biomass-derived raw material, theoretically enables production from 100% biomass-derived components.

The biomass polyolefin may contain two or more biomass polyolefins with different biomass degrees, and the biomass degree of the entire polyolefin resin layer may be within the above range.

The biomass polyolefin is 0.91 g/cm ³ or more and 0.93 g/cm 3 or less, preferably 0.912 g/cm ³ or more and 0.928 g/cm ^{3 or} less, more preferably 0.915 g/cm ³ or more and 0.925 g/cm 3 or more. It has a density of cm ³ or less. The density of biomass polyolefin is a value measured according to the method specified in A method of JIS K7112-1980 after annealing according to JIS K6760-1995. If the density of the biomass polyolefin is 0.91 g/cm ³ or more, the rigidity of the polyolefin resin layer containing the biomass polyolefin can be increased, and it can be suitably used as the inner layer of packaging products. Also, if the density of the biomass polyolefin is 0.93 g/cm ³ or less, the transparency and mechanical strength of the polyolefin resin layer containing the biomass polyolefin can be enhanced, and it can be suitably used as the inner layer of packaging products.

Biomass polyolefin is preferably 0.1 g/10 min or more and 10 g/10 min or less, more preferably 0.2 g/10 min or more and 9 g/10 min or less, still more preferably 1 g/10 min or more and 8.5 g/10 min or less. of melt flow rate (MFR). The melt flow rate is a value measured by method A under conditions of a temperature of 190° C. and a load of 21.18 N in the method specified in JIS K7210-1995. If the MFR of the biomass polyolefin is 0.1 g/10 minutes or more, the extrusion load during molding can be reduced. Moreover, if the MFR of the biomass polyolefin is 10 g/10 minutes or less, the mechanical strength of the polyolefin resin layer containing the biomass polyolefin can be increased.

In the present invention, the biomass polyolefin that is preferably used is a biomass-derived low-density polyethylene manufactured by Braskem (trade name: SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 min, biomass degree 95%), Braskem's biomass-derived low-density polyethylene (trade name: SPB681, density: 0.922 g/cm ³ , MFR: 3.8 g/10 min, biomass degree 95%), and the like.

(Method for producing ethylene derived from biomass)
In the present invention, the method for producing biomass-derived ethylene, which is a raw material for biomass polyolefin, is not particularly limited, and can be obtained by a conventionally known method. An example of a method for producing biomass-derived ethylene will be described below.

Biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. Plant raw materials are not particularly limited, and conventionally known plants can be used. For example, corn, sugar cane, beets, and manioc can be mentioned.

In the present invention, biomass-derived fermented ethanol refers to purified ethanol produced by contacting a culture medium containing a carbon source obtained from a plant material with a microorganism that produces ethanol or a product derived from a crushed product thereof. Conventionally known methods such as distillation, membrane separation, and extraction can be applied to purify ethanol from the culture medium. For example, a method of adding benzene, cyclohexane or the like to cause azeotropy or removing water by membrane separation or the like can be mentioned.

In order to obtain the ethylene of the present invention, at this stage, further purification such as reducing the total amount of impurities in ethanol to 1 ppm or less may be performed.

A catalyst is usually used to obtain ethylene by the dehydration reaction of ethanol, but the catalyst is not particularly limited, and conventionally known catalysts can be used. Advantageous in terms of process is a fixed bed flow reaction in which the catalyst and product can be easily separated, and for example, γ-alumina is preferred.

Since this dehydration reaction is an endothermic reaction, it is usually carried out under heating conditions. Although the heating temperature is not limited as long as the reaction proceeds at a commercially useful reaction rate, a temperature of preferably 100° C. or higher, more preferably 250° C. or higher, and even more preferably 300° C. or higher is suitable. Although the upper limit is not particularly limited, it is preferably 500° C. or lower, more preferably 400° C. or lower from the viewpoint of energy balance and equipment.

The reaction pressure is also not particularly limited, but a pressure equal to or higher than normal pressure is preferable in order to facilitate subsequent gas-liquid separation. Industrially, a fixed bed flow reaction is suitable for easy separation of the catalyst, but a liquid phase suspension bed, a fluidized bed, or the like may also be used.

In the dehydration reaction of ethanol, the yield of the reaction depends on the amount of water contained in ethanol supplied as a raw material. In general, when a dehydration reaction is performed, it is preferable that there is no water in consideration of water removal efficiency. However, it has been found that in the case of ethanol dehydration using a solid catalyst, the amount of other olefins, especially butene, tends to increase in the absence of water. It is presumed that this is probably because ethylene dimerization after dehydration cannot be suppressed unless a small amount of water exists. The lower limit of the allowable water content should be 0.1% or more, preferably 0.5% or more. Although the upper limit is not particularly limited, it is preferably 50% by mass or less, more preferably 30% or less, and still more preferably 20% or less from the viewpoint of material balance and heat balance.

By carrying out the dehydration reaction of ethanol in this way, a mixed portion of ethylene, water and a small amount of unreacted ethanol is obtained. Ethylene can be obtained by removing water and ethanol. This method may be performed by a known method.

Ethylene obtained by gas-liquid separation is further distilled, and the distillation method, operating temperature, residence time, etc. are not particularly limited except that the operating pressure at this time is normal pressure or higher.

When the raw material is biomass-derived ethanol, the resulting ethylene contains carbonyl compounds such as ketones, aldehydes, and esters, which are impurities mixed in the ethanol fermentation process, and carbon dioxide, which is a decomposition product thereof. Nitrogen-containing compounds such as amines and amino acids, which are contaminants, and ammonia, which are decomposition products thereof, are contained in extremely small amounts. Depending on the use of ethylene, these trace amounts of impurities may pose a problem, so they may be removed by refining. The purification method is not particularly limited, and a conventionally known method can be used. A suitable purification operation is, for example, an adsorption purification method. The adsorbent to be used is not particularly limited, and conventionally known adsorbents can be used. For example, a material with a high surface area is preferable, and the type of adsorbent is selected according to the type and amount of impurities in ethylene obtained by the dehydration reaction of biomass-derived ethanol.

As a method for purifying impurities in ethylene, caustic water treatment may be used in combination. If caustic water is to be treated, it is desirable to do so before adsorption purification. In that case, after the caustic treatment, it is necessary to apply moisture removal treatment before adsorption purification.

(Method for producing biomass polyolefin)
In the present invention, the method for polymerizing the biomass-derived ethylene-containing monomer is not particularly limited, and conventionally known methods can be used. The polymerization temperature and polymerization pressure should be appropriately adjusted according to the polymerization method and polymerization apparatus. The polymerization apparatus is also not particularly limited, and a conventionally known apparatus can be used. An example of a method for polymerizing a monomer containing ethylene is described below.

Polymerization methods for polyolefins, particularly ethylene polymers and copolymers of ethylene and α-olefins, vary depending on the type of polyethylene desired, for example, high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE). ), and linear low-density polyethylene (LLDPE) can be appropriately selected depending on the difference in density and branching.
For example, using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as a polymerization catalyst, by any method of gas phase polymerization, slurry polymerization, solution polymerization, and high pressure ion polymerization, It is preferable to carry out in one stage or in multiple stages of two or more stages.

The above-mentioned single-site catalyst is a catalyst capable of forming uniform active species, and is usually prepared by contacting a metallocene-based transition metal compound or a non-metallocene-based transition metal compound with an activating cocatalyst. . A single-site catalyst has a more uniform active site structure than a multi-site catalyst, and is therefore preferable because it can polymerize a polymer having a high molecular weight and a highly uniform structure. As the single-site catalyst, it is particularly preferable to use a metallocene-based catalyst. The metallocene catalyst is a catalyst containing a transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, an organometallic compound if necessary, and each catalyst component of a carrier. be.

In the transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, the cyclopentadienyl skeleton is a cyclopentadienyl group, a substituted cyclopentadienyl group, or the like. . Substituted cyclopentadienyl groups include hydrocarbon groups having 1 to 30 carbon atoms, silyl groups, silyl-substituted alkyl groups, silyl-substituted aryl groups, cyano groups, cyanoalkyl groups, cyanoaryl groups, halogen groups, haloalkyl groups and halosilyl groups. It has at least one substituent selected from groups and the like. The substituted cyclopentadienyl group may have two or more substituents, and the substituents are bonded to each other to form a ring such as an indenyl ring, a fluorenyl ring, an azulenyl ring, hydrogenated forms thereof, and the like. may be formed. A ring formed by combining substituents with each other may further have a substituent with each other.

In the transition metal compound of group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, examples of the transition metal include zirconium, titanium, hafnium and the like, with zirconium and hafnium being particularly preferred. The transition metal compound usually has two ligands having a cyclopentadienyl skeleton, and each ligand having a cyclopentadienyl skeleton is preferably bonded to each other by a bridging group. The bridging group includes an alkylene group having 1 to 4 carbon atoms, a silylene group, a dialkylsilylene group, a substituted silylene group such as a diarylsilylene group, and a substituted germylene group such as a dialkylgermylene group and a diarylgermylene group. A substituted silylene group is preferred.

In the transition metal compounds of Group IV of the periodic table, typical examples of ligands other than ligands having a cyclopentadienyl skeleton include hydrogen, hydrocarbon groups having 1 to 20 carbon atoms (alkyl groups , an alkenyl group, an aryl group, an alkylaryl group, an aralkyl group, a polyenyl group, etc.), a halogen, a metaalkyl group, a metaaryl group, and the like.

One or a mixture of two or more of the transition metal compounds of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton can be used as a catalyst component.

The co-catalyst is one that can make the above Group IV transition metal compound of the periodic table effective as a polymerization catalyst, or one that can balance the ionic charges in a catalytically activated state. Examples of co-catalysts include benzene-soluble aluminoxanes of organoaluminumoxy compounds, benzene-insoluble organoaluminumoxy compounds, ion-exchange layered silicates, boron compounds, cations containing or not containing active hydrogen groups, and non-coordinating anions. ionic compounds, lanthanide salts such as lanthanum oxide, tin oxide, and phenoxy compounds containing a fluoro group.

The transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton may be supported on an inorganic or organic compound carrier and used. As the carrier, porous oxides of inorganic or organic compounds are preferred, and specific examples include ion-exchange layered silicates such as montmorillonite, SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ and B ₂ O. ₃ , CaO, ZnO, BaO, _ThO2 , etc. or mixtures thereof.

Examples of organometallic compounds that may be used if necessary include organoaluminum compounds, organomagnesium compounds, and organozinc compounds. Of these, organic aluminum is preferably used.

Various additives other than the main component polyolefin may be added to the biomass polyolefin as long as the characteristics are not impaired. Additives include, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, release agents, anti- Oxidizing agents, ion exchange agents, color pigments, and the like can be added. These additives are added in an amount of preferably 1% by mass or more and 20% by mass or less, preferably 1% by mass or more and 10% by mass or less with respect to the entire biomass polyolefin.

(Thermoplastic resin layer)
The thermoplastic resin layer can be formed using a conventionally known thermoplastic resin. By further comprising a thermoplastic resin layer, the laminate has heat resistance, pressure resistance, water resistance, heat sealability, pinhole resistance, puncture resistance, and other physical properties similar to those of conventional laminates. be able to.

Examples of thermoplastic resins include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, polypropylene, propylene-ethylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer. Copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ionomer resin, polyester resin, polyvinyl chloride resin, polystyrene resin, nylon, etc. Low density polyethylene, linear low density polyethylene, medium density polyethylene, and ethylene-methacrylic acid copolymer are preferred.

The thermoplastic resin layer may contain a biomass-derived material or a fossil fuel-derived material. When the thermoplastic resin layer contains a biomass-derived material, it may contain biomass polyolefin, which is a polymer of a biomass-derived ethylene-containing monomer, similarly to the polyolefin resin layer.

(Print layer)
The printed layer contains letters, numbers, patterns, figures, symbols, patterns, etc. It is a layer that forms any desired printed pattern. The printed layer can be provided as necessary. For example, it can be provided on the surface of the paper substrate layer facing the first polyolefin resin layer or on the surface of the first polyolefin resin layer opposite to the paper substrate layer. can be done. The print layer may be provided on the entire surface of the paper base material layer, or may be provided on a part thereof. The print layer can be formed using conventionally known pigments and dyes, and the formation method is not particularly limited.

(barrier layer)
The barrier layer is composed of an inorganic substance and/or an inorganic oxide, preferably a deposited film of an inorganic substance or an inorganic oxide, or a metal foil. The deposited film can be formed by a conventionally known method using a conventionally known inorganic substance or inorganic oxide, and the composition and formation method are not particularly limited. By further including a barrier layer in the laminate, it is possible to impart or improve a gas barrier property that prevents permeation of oxygen gas and water vapor, and a light shielding property that prevents permeation of visible light, ultraviolet light, and the like. Note that the laminate may have two or more barrier layers. When there are two or more barrier layers, they may have the same composition or different compositions.

Examples of deposited films include silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti ), lead (Pb), zirconium (Zr), yttrium (Y), or the like, or a deposited film of an inorganic oxide. In particular, as materials suitable for packaging materials (bags) and the like, vapor-deposited films of aluminum metal, or vapor-deposited films of silicon oxide, aluminum metal, or aluminum oxide are preferably used.

Inorganic oxides are represented by MO _X such as SiO _X and AlO _X (wherein M represents an inorganic element, and the value of X varies depending on the inorganic element). expressed. The range of values of X is 0 to 2 for silicon (Si), 0 to 1.5 for aluminum (Al), 0 to 1 for magnesium (Mg), 0 to 1 for calcium (Ca), Potassium (K) is 0 to 0.5, Tin (Sn) is 0 to 2, Sodium (Na) is 0 to 0.5, Boron (B) is 0 to 1,5, Titanium (Ti) can range from 0 to 2, lead (Pb) from 0 to 1, zirconium (Zr) from 0 to 2, and yttrium (Y) from 0 to 1.5. In the above, when X=0, it is a completely inorganic substance (pure substance) and not transparent, and the upper limit of the range of X is the fully oxidized value. Silicon (Si) and aluminum (Al) are preferably used for packaging materials, with silicon (Si) in the range of 1.0 to 2.0 and aluminum (Al) in the range of 0.5 to 1.5. values can be used.

In the present invention, the film thickness of the vapor-deposited film of the inorganic substance or inorganic oxide as described above varies depending on the type of the inorganic substance or inorganic oxide used. It is desirable to select and form arbitrarily within the range of. More specifically, in the case of a vapor deposited film of aluminum, the film thickness is desirably 50 Å or more and 600 Å or less, more preferably 100 Å or more and 450 Å or less. Desirable film thickness is about 50 to 500 Å, more preferably about 100 to 300 Å.

A vapor deposition film can be formed on a plastic film such as polyethylene terephthalate or nylon using the following forming method. Examples of methods for forming a deposited film include physical vapor deposition methods such as vacuum deposition, sputtering, and ion plating (physical vapor deposition, PVD), plasma chemical vapor deposition, thermochemical vapor deposition, and the like. A chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a chemical vapor deposition method and a photochemical vapor deposition method can be used.

Also, according to another aspect, the barrier layer may be a metal foil obtained by rolling a metal. A conventionally known metal foil can be used as the metal foil. Aluminum foil is preferable from the viewpoint of gas barrier properties that prevent permeation of oxygen gas and water vapor, and light shielding properties that prevent permeation of visible light, ultraviolet rays, and the like.

(plastic film)
In the present invention, various plastic films may be used as other layers. For example, an oriented polyethylene terephthalate film, an oriented nylon film, an oriented polypropylene film, a nylon 6/meta-xylylenediamine nylon 6 coextruded and coextended film, or a polypropylene/ethylene-vinyl alcohol copolymer coextruded and coextended film, or the like, or A composite film obtained by laminating two or more of these films may be used. The plastic film may be coated with polyvinyl alcohol or the like.

(adhesion layer)
The adhesive layer can be an adhesive layer formed by applying an adhesive to the surface of the layer to be laminated and drying it when two layers are adhered by a dry lamination method.
Examples of adhesives include one-component or two-component curing or non-curing vinyl, (meth)acrylic, polyamide, polyester, polyether, polyurethane, epoxy, rubber, and others. A solvent-type, water-based, or emulsion-type adhesive can be used. Examples of coating methods for the lamination adhesive include direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, fonten method, transfer roll coating, and other methods to form a laminate. It can be applied to the coated side of the layer. The coating amount is preferably 0.1 g/m ² or more and 10 g/m ² or less (dry state), more preferably 1 g/m ² or more and 5 g/m ² or less (dry state).

Further, the adhesive layer is an anchor formed by applying an anchor coating agent to the surface of the layer to be laminated and drying it when laminating a polyolefin resin layer or a thermoplastic resin layer by a melt extrusion lamination method. It may be a coat layer. The anchor coating agent includes any resin having a heat resistance temperature of 135° C. or higher, such as an anchor coating agent made of a vinyl-modified resin, an epoxy resin, a urethane resin, a polyester resin, or the like. An anchor coating agent comprising a polyacrylic or polymethacrylic resin having a hydroxyl group and an isocyanate compound as a curing agent can be preferably used. In addition, a silane coupling agent may be used together as an additive, and nitrocellulose may be used together to improve heat resistance.

Also, the adhesive layer may be an adhesive resin layer used for bonding two layers by a sand lamination method or a melt extrusion lamination method. Thermoplastic resins that can be used for the adhesive resin layer include polyethylene-based resins, polypropylene-based resins, cyclic polyolefin-based resins, or copolymer resins, modified resins, or mixtures (including alloys) containing these resins as main components. ) can be used. Polyolefin resins include, for example, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), polypropylene (PP), metallocene catalyst Ethylene-α-olefin copolymer, ethylene-polypropylene random or block copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-α-olefin copolymer polymerized using Ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-maleic acid copolymer, ionomer resin, adhesion between layers In order to improve the above, it is possible to use an acid-modified polyolefin resin obtained by modifying the above polyolefin resin with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, or itaconic acid. can. Further, a resin obtained by graft polymerization or copolymerization of an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or an ester monomer can be used as the polyolefin resin. These materials can be used singly or in combination of two or more. Cyclic polyolefins such as ethylene-propylene copolymers, polymethylpentene, polybutene, and polynorbonene can be used as cyclic polyolefin resins. These resins can be used singly or in combination. Needless to say, as the above-described polyethylene-based resin, one using the above-described biomass-derived ethylene as a monomer unit can be used.

The adhesive resin layer may contain a biomass-derived material or a fossil fuel-derived material. When the adhesive resin layer contains a biomass-derived material, it may contain biomass polyolefin, which is a polymer of a biomass-derived ethylene-containing monomer, similarly to the polyolefin resin layer.

(Laminate manufacturing method)
The method for producing the laminate according to the present invention is not particularly limited, and it can be produced using a conventionally known method such as a dry lamination method, a melt extrusion lamination method, a sand lamination method, or the like. In the present invention, it is preferable to form a polyolefin resin layer on the surface of the layer to be laminated using a melt extrusion lamination method. Alternatively, the polyolefin resin layer and another layer may be laminated by a co-extrusion method.

For example, a resin composition for forming a polyolefin resin layer by supplying it to a melt extruder heated to a temperature above the melting point Tm of the resin composition for forming the polyolefin resin layer by the following method to Tm + 70 ° C. A polyolefin resin layer is laminated by melting an object, extruding it into a sheet from a die such as a T-die onto the surface of the layer to be laminated, and rapidly solidifying the extruded sheet with a rotating cooling drum or the like. can do. As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder, or the like can be used depending on the purpose.

The thickness of the laminate obtained as described above is arbitrary according to its use, but is usually 5 μm or more and 500 μm or less, preferably 20 μm or more and 300 μm or less.

The laminate according to the present invention is imparted with chemical functions, electrical functions, magnetic functions, mechanical functions, friction/wear/lubricating functions, optical functions, thermal functions, surface functions such as biocompatibility, and the like. For the purpose, it is also possible to apply secondary processing. Examples of secondary processing include embossing, painting, adhesion, printing, metallizing (plating, etc.), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.). Also, the laminate according to the present invention can be subjected to lamination (dry lamination or extrusion lamination), bag making, and other post-treatments to produce a molded product.

(Application)
The laminate according to the present invention can be used for packaging products such as paper containers for liquids, paper cups, label materials, lids and the like.

(liquid paper container)
Since the liquid paper container according to the present invention has excellent barrier properties, it can be used for food such as alcohols such as sake, shochu and wine, milk drinks such as milk, soft drinks such as orange juice and tea, car wax, shampoo and detergents. It can be suitably used as a wrapping paper container for general liquids such as chemical products. A case where a paper container is formed using the laminate according to the present invention will be described. For example, the liquid paper container 40 shown in FIG. 4 can be formed after the laminate shown in FIGS. 1 to 3 is creased.

As shown in FIG. 4, the paper container for liquid 40 has a rectangular cylindrical body portion 41 including side surfaces, a rectangular plate-like bottom portion 42, and an upper portion 43, and is a so-called gobel-top type container. there is The upper portion 43 has a pair of opposing inclined plates 44 and a pair of folding portions 45 positioned between the pair of inclined plates 44 and folded between the inclined plates 44 . Also, the pair of inclined plates 44 are adhered to each other by glue margins 46 provided at their upper ends. Alternatively, one of the pair of inclined plates 44 may be fitted with a spout and the spout may be sealed with a cap. A flat-top container may also be formed.

(Other aspects)
In another aspect of the invention,
A laminate comprising at least a first polyolefin resin layer, a paper base layer, and a second polyolefin resin layer,
The first and second polyolefin resin layers contain biomass polyolefin, which is a polymer of monomers containing biomass-derived ethylene,
The biomass degree in the first and second polyolefin resin layers is 5% or more,
A laminate is provided in which the biomass polyolefin has a density of 0.91 g/cm ³ or more and 0.93 g/cm ³ or less.

In another aspect of the present invention, it is preferable that the first or second polyolefin resin layer further contains polyolefin derived from fossil fuel.

In another aspect of the present invention, the first or second polyolefin resin layer contains 5% to 100% by mass of the biomass polyolefin and 0% to 95% by mass of the fossil fuel-derived polyolefin. preferably included.

In another aspect of the present invention, the first or second polyolefin resin layer preferably contains polyethylene.

In a further aspect of the invention there is provided a packaging product comprising said laminate.

In a further aspect of the present invention, a paper container for liquid comprising the laminate,
A paper container for liquid is provided, wherein the innermost layer of the paper container for liquid is the second polyolefin resin layer.

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

<Measurements/Conditions>
In the following reference examples, reference comparative examples, examples, and comparative examples, the degree of biomass is the value of biomass-derived carbon concentration measured by radioactive carbon (C14).

The conditions of the extrusion film-forming machine used below were as follows.
Screw diameter: 90mm
Screw type: full flight L/D: 28
T-die: 11S type straight manifold T-die effective opening length: 560mm

[Example 1]
<Production of Laminate 1>
Milk carton base paper (manufactured by Clearwater Co., basis weight 320 g/m ² ) was prepared as a paper base layer, and biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ ) was coated on one side. , MFR: 8.1 g / 10 min, biomass degree: 95%) is melt extrusion laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a first polyolefin resin layer (biomass degree: 95%, thickness 17 μm). Next, biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 minutes , biomass degree: 95%) is melt extrusion laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a second polyolefin resin layer (biomass degree: 95%, thickness 28 μm), and the first A laminate 1 was obtained in which the polyolefin resin layer of No. 1, the paper substrate layer, and the second polyolefin resin layer were laminated in this order.

[Example 2]
<Production of laminate 2>
Milk carton base paper (manufactured by Clearwater Co., basis weight 320 g/m ² ) was prepared as a paper base layer, and biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ ) was coated on one side. , MFR: 8.1 g / 10 minutes, biomass degree: 95%) 50 parts by mass and fossil fuel-derived low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g / cm ³ , MFR: 3.6 g / 10 minutes, biomass degree: 0%) and 50 parts by mass of the mixed resin are melt-extruded and laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a first polyolefin resin layer (biomass degree: 48 %, thickness 17 μm). Next, biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 minutes , biomass degree: 95%) 50 parts by mass and fossil fuel-derived low-density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., LC520, density: 0.923 g / cm ³ , MFR: 3.6 g / 10 minutes, biomass degree: 0%) A mixed resin obtained by dry blending 50 parts by mass of the above is melt-extruded and laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a second polyolefin resin layer (biomass degree: 48%, thickness 28 μm). , the first polyolefin resin layer, the paper substrate layer, and the second polyolefin resin layer were laminated in this order to obtain a laminate 2 .

[Comparative Example 1]
<Production of Laminate 3>
A milk carton base paper (manufactured by Clearwater Co., basis weight 320 g/m ² ) was prepared as a paper base layer, and one surface was coated with low-density polyethylene derived from fossil fuel (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g/ cm ³ , MFR: 3.6 g/10 min, biomass degree: 0%) was melt-extrusion laminated at a resin temperature of 320° C. and a line speed of 100 m/min to form a resin layer (biomass degree: 0%, thickness: 17 μm). formed. Next, on the surface of the paper substrate layer opposite to the resin layer, low-density polyethylene derived from fossil fuel (LC520, manufactured by Japan Polyethylene Co., Ltd., density: 0.923 g/cm ³ , MFR: 3.6 g/10 minutes, biomass degree: 0%) is extruded at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a resin layer (biomass degree: 0%, thickness 28 μm), a resin layer, a paper base layer, a resin A laminate 3 in which layers were laminated in order was obtained.

[Example 3]
<Production of Laminate 4>
Milk carton base paper (manufactured by Clearwater Co., basis weight 400 g/m ² ) was prepared as a paper base layer, and biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ ) was coated on one side. , MFR: 8.1 g / 10 minutes, biomass degree: 95%) is melt extrusion laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a first polyolefin resin layer (biomass degree: 95%, thickness 20 μm) was formed. Next, a fossil fuel-derived ethylene-methacrylic acid copolymer (Nucrel N0908C, manufactured by Mitsui DuPont Polychemicals Co., Ltd.) is applied to the surface of the paper base layer opposite to the first polyolefin resin layer using a sand lamination method. While extruding, aluminum foil (manufactured by Toyo Aluminum Co., Ltd., 1N30, thickness 7 μm) and fossil fuel-derived polyethylene terephthalate film (manufactured by Toyobo: E5100 , thickness 12 μm) were dry-laminated using a two-liquid curing adhesive (manufactured by DIC Graphics: main agent LX-703A/curing agent KR-90), and the aluminum foil surface of the dry laminate film was laminated. Subsequently, the surface of the polyethylene terephthalate film of the dry laminate film was coated with a two-liquid curing anchoring agent (manufactured by Mitsui Chemicals: A3210/A3075) to form an anchor coat layer. After that, biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 minutes, degree of biomass: 95%) was applied on the anchor coat layer at a resin temperature of 320°C. , melt extrusion lamination at a line speed of 100 m / min to form a second polyolefin resin layer (biomass degree: 95%, thickness 55 μm), a first polyolefin resin layer, a paper base layer, an adhesive resin layer , a barrier layer, an adhesive layer, a plastic film, an anchor coat layer, and a second polyolefin resin layer in this order.

[Example 4]
<Production of laminate 5>
Milk carton base paper (manufactured by Clearwater Co., basis weight 400 g/m ² ) was prepared as a paper base layer, and biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ ) was coated on one side. , MFR: 8.1 g / 10 minutes, biomass degree: 95%) 50 parts by mass and fossil fuel-derived low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g / cm ³ , MFR: 3.6 g / 10 minutes, biomass degree: 0%) and 50 parts by mass of the mixed resin are melt-extruded and laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a first polyolefin resin layer (biomass degree: 48 %, thickness 20 μm). Next, a fossil fuel-derived ethylene-methacrylic acid copolymer (Nucrel N0908C, manufactured by Mitsui DuPont Polychemicals Co., Ltd.) is applied to the surface of the paper base layer opposite to the first polyolefin resin layer using a sand lamination method. While extruding, aluminum foil (manufactured by Toyo Aluminum Co., Ltd., 1N30, thickness 7 μm) and fossil fuel-derived polyethylene terephthalate film (manufactured by Toyobo: E5100 , thickness 55 μm) were dry-laminated using a two-liquid curing adhesive (manufactured by DIC Graphics: main agent LX-703A/curing agent KR-90), and the aluminum foil surface of the dry laminate film was laminated. Subsequently, the surface of the polyethylene terephthalate film of the dry laminate film was coated with a two-liquid curing anchoring agent (manufactured by Mitsui Chemicals: A3210/A3075) to form an anchor coat layer. After that, on the anchor coat layer, 50 parts by mass of biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 min, biomass degree: 95%) and fossil fuel A mixed resin obtained by dry-blending 50 parts by mass of low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g/cm ³ , MFR: 3.6 g/10 min, biomass degree: 0%) from 320 C. resin temperature, line speed 100 m/min, melt extrusion lamination to form a second polyolefin resin layer (biomass degree: 48%, thickness 55 μm), first polyolefin resin layer, paper base layer , an adhesive resin layer, a barrier layer, an adhesive layer, a plastic film, an anchor coat layer, and a second polyolefin resin layer were laminated in this order to obtain a laminate 5 .

[Comparative Example 2]
<Production of laminate 6>
A milk carton base paper (manufactured by Clearwater Co., basis weight 400 g/m ² ) was prepared as a paper base layer, and one surface was coated with a fossil fuel-derived low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g/ cm ³ , MFR: 3.6 g/10 min, biomass degree: 0%) is melt extrusion laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a resin layer (biomass degree: 0%, thickness 20 μm ) was formed. Next, a fossil fuel-derived ethylene-methacrylic acid copolymer (Nucrel N0908C, manufactured by Mitsui DuPont Polychemicals Co., Ltd.) is applied to the surface of the paper base layer opposite to the first polyolefin resin layer using a sand lamination method. While extruding, aluminum foil (manufactured by Toyo Aluminum Co., Ltd., 1N30, thickness 7 μm) and fossil fuel-derived polyethylene terephthalate film (manufactured by Toyobo: E5100 , thickness 12 μm) were dry-laminated using a two-liquid curing adhesive (manufactured by DIC Graphics: main agent LX-703A/curing agent KR-90), and the aluminum foil surface of the dry laminate film was laminated. Subsequently, the surface of the polyethylene terephthalate film of the dry laminate film was coated with a two-liquid curing anchoring agent (manufactured by Mitsui Chemicals: A3210/A3075) to form an anchor coat layer. After that, a fossil fuel-derived low-density polyethylene (LC520 manufactured by Nippon Polyethylene Co., Ltd., density: 0.923 g/cm ³ , MFR: 3.6 g/10 minutes, biomass degree: 0%) was applied on the anchor coat layer at 320°C. At a resin temperature of 100 m / min, melt extrusion lamination is performed to form a resin layer (biomass degree: 0%, thickness 55 μm), resin layer, paper base layer, adhesive resin layer, barrier layer, adhesive A laminate 6 was obtained in which the agent layer, the plastic film, the anchor coat layer and the resin layer were laminated in this order.

[Example 5]
<Production of Laminate 7>
As the aluminum-deposited polyethylene terephthalate film 1, a fossil-fuel-derived polyethylene terephthalate film (manufactured by Saichi Kogyo Co., Ltd., MWR7, thickness 12 μm) on which an aluminum deposition film was formed was prepared.

Milk carton base paper (manufactured by Clearwater Co., basis weight 400 g/m ² ) was prepared as a paper base layer, and biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ ) was coated on one side. , MFR: 8.1 g / 10 minutes, biomass degree: 95%) is melt extrusion laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a first polyolefin resin layer (biomass degree: 95%, thickness 20 μm) was formed. Next, a fossil fuel-derived ethylene-methacrylic acid copolymer (Nucrel N0908C, manufactured by Mitsui DuPont Polychemicals Co., Ltd.) is applied to the surface of the paper base layer opposite to the first polyolefin resin layer using a sand lamination method. was extruded, the vapor-deposited surface of the aluminum vapor-deposited polyethylene terephthalate film 1 was bonded via this adhesive resin layer (0% biomass, 20 μm thick). Subsequently, the polyethylene terephthalate film surface of the aluminum-deposited polyethylene terephthalate film 1 was coated with a two-liquid curing anchoring agent (manufactured by Mitsui Chemicals: A3210/A3075) to form an anchor coat layer. After that, biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 minutes, degree of biomass: 95%) was applied on the anchor coat layer at a resin temperature of 320°C. , melt extrusion lamination at a line speed of 100 m / min to form a second polyolefin resin layer (biomass degree: 95%, thickness 55 μm), a first polyolefin resin layer, a paper base layer, an adhesive resin layer , a barrier layer, a plastic film, an anchor coat layer, and a second polyolefin resin layer in this order.

[Example 6]
<Production of laminate 8>
Milk carton base paper (manufactured by Clearwater Co., basis weight 400 g/m ² ) was prepared as a paper base layer, and biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ ) was coated on one side. , MFR: 8.1 g / 10 minutes, biomass degree: 95%) 50 parts by mass and fossil fuel-derived low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g / cm ³ , MFR: 3.6 g / 10 minutes, biomass degree: 0%) and 50 parts by mass of the mixed resin are melt-extruded and laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a first polyolefin resin layer (biomass degree: 48 %, thickness 20 μm). Next, a fossil fuel-derived ethylene-methacrylic acid copolymer (Nucrel N0908C, manufactured by Mitsui DuPont Polychemicals Co., Ltd.) is applied to the surface of the paper base layer opposite to the first polyolefin resin layer using a sand lamination method. was extruded, the vapor-deposited surface of the aluminum vapor-deposited polyethylene terephthalate film 1 was bonded via this adhesive resin layer (0% biomass, 20 μm thick). Subsequently, the polyethylene terephthalate film surface of the aluminum-deposited polyethylene terephthalate film 1 was coated with a two-liquid curing anchoring agent (manufactured by Mitsui Chemicals: A3210/A3075) to form an anchor coat layer. After that, on the anchor coat layer, 50 parts by mass of biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 min, biomass degree: 95%) and fossil fuel-derived 50 parts by mass of low-density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., LC520, density: 0.923 g/cm ³ , MFR: 3.6 g/10 min, biomass degree: 0%). at a resin temperature of 100 m/min and a line speed of 100 m/min to form a second polyolefin resin layer (biomass degree: 48%, thickness 55 μm), a first polyolefin resin layer, a paper base layer, A laminate 8 was obtained in which an adhesive resin layer, a barrier layer, a plastic film, an anchor coat layer, and a second polyolefin resin layer were laminated in this order.

[Comparative Example 3]
<Production of laminate 9>
A milk carton base paper (manufactured by Clearwater Co., basis weight 400 g/m ² ) was prepared as a paper base layer, and one surface was coated with a fossil fuel-derived low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g/ cm ³ , MFR: 3.6 g/10 min, biomass degree: 0%) is melt extrusion laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a resin layer (biomass degree: 0%, thickness 20 μm ) was formed. Next, a fossil fuel-derived ethylene-methacrylic acid copolymer (Nucrel N0908C, manufactured by Mitsui DuPont Polychemicals Co., Ltd.) is applied to the surface of the paper base layer opposite to the first polyolefin resin layer using a sand lamination method. was extruded, the vapor-deposited surface of the aluminum vapor-deposited polyethylene terephthalate film 1 was bonded via this adhesive resin layer (0% biomass, 20 μm thick). Subsequently, the polyethylene terephthalate film surface of the aluminum-deposited polyethylene terephthalate film 1 was coated with a two-liquid curing anchoring agent (manufactured by Mitsui Chemicals: A3210/A3075) to form an anchor coat layer. After that, on the anchor coat layer, fossil fuel-derived low-density polyethylene (LC520 manufactured by Japan Polyethylene Co., Ltd., density: 0.923 g/cm ³ , MFR: 3.6 g/10 minutes, biomass degree: 0%) was added at 320 ° C. Melt extrusion lamination is performed at a resin temperature and a line speed of 100 m/min to form a resin layer (biomass degree: 0%, thickness 55 μm), resin layer, paper base layer, adhesive resin layer, barrier layer, plastic film. , an anchor coat layer and a resin layer were laminated in this order to obtain a laminate 9 .

[Example 7]
<Production of laminate 10>
Milk carton base paper (manufactured by Clearwater Co., basis weight 400 g/m ² ) was prepared as a paper base layer, and biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ ) was coated on one side. , MFR: 8.1 g / 10 minutes, biomass degree: 95%) is melt extrusion laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a first polyolefin resin layer (biomass degree: 95%, thickness 20 μm) was formed. Next, on the surface of the paper substrate layer opposite to the first polyolefin resin layer, a low-density polyethylene derived from fossil fuel (LC520 manufactured by Japan Polyethylene Co., Ltd., density: 0.923 g/cm) was applied using a sand lamination method. ³ , MFR: 3.6 g / 10 minutes, biomass degree: 0%), through this adhesive resin layer (biomass degree: 0%, thickness 15 μm), a fossil fuel-derived polyethylene terephthalate film (Toyobo Co., Ltd. (T4100, thickness 12 μm) were bonded together. Subsequently, an anchor coat agent (EL540/CAT-RT32 manufactured by Toyo-Morton Co., Ltd.) was applied onto the polyethylene terephthalate film and dried to form an anchor coat layer. After that, biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 minutes, degree of biomass: 95%) was applied on the anchor coat layer at a resin temperature of 320°C. , melt extrusion lamination at a line speed of 100 m / min to form a second polyolefin resin layer (biomass degree: 95%, thickness 55 μm), a first polyolefin resin layer, a paper base layer, an adhesive resin layer , a plastic film, an anchor coat layer, and a second polyolefin resin layer were laminated in this order to obtain a laminate 10 .

[Example 8]
<Production of laminate 11>
Milk carton base paper (manufactured by Clearwater Co., basis weight 400 g/m ² ) was prepared as a paper base layer, and biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ ) was coated on one side. , MFR: 8.1 g / 10 minutes, biomass degree: 95%) 50 parts by mass and fossil fuel-derived low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g / cm ³ , MFR: 3.6 g / 10 minutes, biomass degree: 0%) and 50 parts by mass of the mixed resin are melt-extruded and laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a first polyolefin resin layer (biomass degree: 48 %, thickness 20 μm). Next, on the surface of the paper substrate layer opposite to the first polyolefin resin layer, a low-density polyethylene derived from fossil fuel (LC520 manufactured by Japan Polyethylene Co., Ltd., density: 0.923 g/cm) was applied using a sand lamination method. ³ , MFR: 3.6 g / 10 minutes, biomass degree: 0%), through this adhesive resin layer (biomass degree: 0%, thickness 15 μm), a fossil fuel-derived polyethylene terephthalate film (Toyobo Co., Ltd. (T4100, thickness 12 μm) were bonded together. Subsequently, an anchor coat agent (EL540/CAT-RT32 manufactured by Toyo-Morton Co., Ltd.) was applied onto the polyethylene terephthalate film and dried to form an anchor coat layer. After that, on the anchor coat layer, 50 parts by mass of biomass-derived low-density polyethylene (manufactured by Braskem, SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 min, biomass degree: 95%) and fossil fuel A mixed resin obtained by dry-blending 50 parts by mass of low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g/cm ³ , MFR: 3.6 g/10 min, biomass degree: 0%) from 320 C. resin temperature, line speed 100 m/min, melt extrusion lamination to form a second polyolefin resin layer (biomass degree: 48%, thickness 55 μm), first polyolefin resin layer, paper base layer , an adhesive resin layer, a plastic film, an anchor coat layer, and a second polyolefin resin layer were laminated in this order to obtain a laminate 11 .

[Comparative Example 4]
<Production of laminate 12>
A milk carton base paper (manufactured by Clearwater Co., basis weight 400 g/m ² ) was prepared as a paper base layer, and one surface was coated with a fossil fuel-derived low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., LC520, density: 0.923 g/ cm ³ , MFR: 3.6 g/10 min, biomass degree: 0%) is melt extrusion laminated at a resin temperature of 320 ° C. and a line speed of 100 m / min to form a resin layer (biomass degree: 0%, thickness 20 μm ) was formed. Next, on the surface of the paper substrate layer opposite to the first polyolefin resin layer, a low-density polyethylene derived from fossil fuel (LC520 manufactured by Japan Polyethylene Co., Ltd., density: 0.923 g/cm) was applied using a sand lamination method. ³ , MFR: 3.6 g / 10 minutes, biomass degree: 0%), through this adhesive resin layer (biomass degree: 0%, thickness 15 μm), a fossil fuel-derived polyethylene terephthalate film (Toyobo Co., Ltd. (T4100, thickness 12 μm) were bonded together. Subsequently, an anchor coat agent (EL540/CAT-RT32 manufactured by Toyo-Morton Co., Ltd.) was applied onto the polyethylene terephthalate film and dried to form an anchor coat layer. After that, a fossil fuel-derived low-density polyethylene (LC520 manufactured by Nippon Polyethylene Co., Ltd., density: 0.923 g/cm ³ , MFR: 3.6 g/10 minutes, biomass degree: 0%) was applied on the anchor coat layer at 320°C. and a line speed of 100 m/min at a resin temperature of 100 m/min to form a resin layer (biomass degree: 0%, thickness 55 μm), resin layer, paper base layer, adhesive resin layer, plastic film, anchor A laminate 12 was obtained in which the coat layer and the resin layer were laminated in this order.

[Production Examples 1 to 12]
<Production of liquid paper container>
By pressing the laminates 1 to 12 with a male die and a female die, a creasing process was applied and blanks for paper containers were punched out. After that, using a liquid paper container filling machine "DR-10", the center value of the sealing temperature conditions is set to 320 ° C. for the top heater temperature and 340 ° C. for the bottom heater temperature, and the blank is made into a paper container 1 to the form shown in FIG. 12 was produced.

(leakage and pinhole test)
After cutting off the top and bottom of liquid paper containers 1 to 12 prepared above, the test liquid (Microcheck penetrating liquid (manufactured by Taiho Kozai)) is injected into the top and bottom, left at room temperature for 30 minutes, and then Microcheck. Washing was performed with a washing liquid (manufactured by Taiho Kozai Co., Ltd.). Thereafter, the container was heated with hot air, the top and bottom portions were opened into a flat plate, and liquid leakage and pinholes were visually evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.
(Evaluation criteria for liquid leakage)
◯: There was no liquid leakage from the top seal portion and the bottom seal portion, and the performance as a paper container for liquid was good.
x: There was liquid leakage from the top seal portion and the bottom seal portion, and the performance as a paper container for liquid was unsatisfactory.
(Evaluation criteria for pinholes)
◯: No pinholes were found in the top and bottom portions, and the performance as a paper container for liquid was good.
x: There were pinholes in the top and bottom parts, and the performance as a paper container for liquid was poor.

REFERENCE SIGNS LIST 10, 20, 30 laminate 11 first polyolefin resin layer 12 paper substrate layer 13 second polyolefin resin layer 14 adhesive layer 15 barrier layer 16 plastic film 40 paper container for liquid 41 body 42 bottom 43 top 44 inclined plate 45 Folding part 46 Paste margin

Claims (6)

A liquid paper container having a square cylindrical body portion including side surfaces, a square plate-shaped bottom portion, and an upper portion,
The laminate constituting the liquid paper container comprises at least a first polyolefin resin layer, a paper base layer, an adhesive resin layer, a barrier layer, and a second polyolefin resin layer in this order,
The first and second polyolefin resin layers are composed only of biomass-derived polyethylene, or composed of a mixed resin of biomass-derived polyethylene and fossil fuel-derived polyethylene,
The content of biomass-derived polyethylene in the first and second polyolefin resin layers is 50% by mass or more,
The biomass-derived polyethylene has a density of 0.91 g/cm ³ or more and 0.93 g/cm ³ or less,
The adhesive resin layer is an ethylene-methacrylic acid copolymer or an ionomer resin,
The liquid paper container, wherein the paper base layer has a basis weight of 200 g/m ² or more and 500 g/m ² or less. 2. A paper container for liquids according to claim 1, wherein said laminate comprises a plastic film positioned between said adhesive resin layer and said second polyolefin resin layer. 3. The paper container for liquid according to claim 2, wherein the barrier layer comprises a vapor deposited film formed on the plastic film. 4. A paper container for liquids according to any preceding claim, wherein the barrier layer comprises aluminum foil. The first and second polyolefin resin layers are composed only of biomass-derived low-density polyethylene, or composed of a mixed resin of biomass-derived low-density polyethylene and fossil fuel-derived low-density polyethylene. A liquid paper container according to any one of claims 1 to 4. A method for manufacturing a laminate used for the liquid paper container according to any one of claims 1 to 5 ,
A method for producing a laminate, wherein the second polyolefin resin layer is laminated using a melt extrusion lamination method.

Images