JP6997957B2 - Laminate - Google Patents

Description

The present invention relates to a laminate, and more particularly to a laminate using a recycled polyester resin as a raw material, which is recovered from a packaging material or the like so that it can be reused.

Plastic, which is a fossil fuel-derived material, is mainly used in the manufacture of packaging materials for filling products such as pharmaceuticals, cosmetics, and foods from the viewpoint of ease of molding and cost. Polyester-based resins, polyolefin-based resins, polyamide-based resins, and the like are used as plastic materials that are widely used as materials for packaging containers. Among them, polyester-based resins are widely used in various industrial applications such as films, sheets, and packaging containers because they are excellent in mechanical properties, chemical stability, heat resistance, transparency, etc., and are inexpensive.

Polyester is obtained by polycondensing a diol unit and a dicarboxylic acid unit. For example, polyethylene terephthalate (hereinafter, may be abbreviated as PET) is produced by using ethylene glycol and terephthalic acid as raw materials and subjecting them to an esterification reaction and then a polycondensation reaction. These raw materials are produced from petroleum, which is a fossil resource. For example, ethylene glycol is industrially produced from ethylene and terephthalic acid is industrially produced from xylene.

In recent years, with respect to such fossil fuel-derived materials, there has been an increasing movement year by year to reduce the use of fossil fuels for various purposes in consideration of the environment and to reduce CO ₂ emissions. As an attempt to reduce the use of such fossil fuels, a method has been proposed in which polyester resin recovered from used packaging materials such as PET bottles can be reused and recycled as recycled polyester for molding of packaging materials (). For example, see Patent Documents 1 and 2). In Patent Documents 1 and 2, CO ₂ emissions are reduced by using polyester as a part of the packaging material, which is made by recovering used products formed from fossil fuel-derived polyester so that they can be reused. It is proposed to try.

Japanese Unexamined Patent Publication No. 2011-256328 Japanese Unexamined Patent Publication No. 2012-41463

However, packaging materials using recycled PET recycled by mechanical recycling, in which recovered PET bottles and other polyester resin products are crushed, washed and reused, are contaminated due to foreign matter adhering to the recycled PET. There is an impression that nations may have occurred. For this reason, it is difficult to obtain the trust of consumers for packaging materials manufactured by using a laminated body made of recycled PET, particularly packaging materials for filling products such as foods.

An object of the present invention is to provide a laminate capable of effectively solving such a problem.

The present invention is a laminate including at least a base material layer, a barrier layer, and a sealant layer in this order. The base material layer contains ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as a dicarboxylic acid. The barrier layer is a laminated body containing polyethylene terephthalate as a unit and containing a metal foil.

The present invention is a laminate including at least a base material layer, a barrier layer, and a sealant layer in this order. The base material layer contains ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as a dicarboxylic acid. The barrier layer contains polyethylene terephthalate as a unit, and the barrier layer is a laminated body containing a vapor-deposited film.

In the laminated body according to the present invention, the barrier layer may include a metal-deposited film.

In the laminated body according to the present invention, the barrier layer may include a transparent vapor-deposited film.

The present invention is a laminate including at least a base material layer, a barrier layer, and a sealant layer in this order. The base material layer contains ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as a dicarboxylic acid. The barrier layer contains polyethylene terephthalate as a unit, and the barrier layer is a laminate containing a saponified product of an ethylene-vinyl acetate copolymer.

In the laminate according to the present invention, the content of the isophthalic acid may be 0.5 mol% or more and 5.0 mol% or less with respect to all the dicarboxylic acid units constituting the polyethylene terephthalate.

In the laminate according to the present invention, the ultimate viscosity of the polyethylene terephthalate may be 0.58 dl / g or more and 0.80 dl / g or less.

According to the present invention, it is possible to provide a laminated body having an excellent CO ₂ reduction effect and excellent hygiene as compared with a laminated body made of polyethylene terephthalate which is not recycled.

It is a schematic sectional drawing which shows an example of the laminated body by this invention. It is a schematic sectional drawing which shows an example of the laminated body by this invention. It is a schematic sectional drawing which shows an example of the laminated body by this invention. It is a schematic sectional drawing which shows an example of the laminated body by this invention. It is a schematic cross-sectional view which shows an example of the base material layer of the laminated body by this invention.

<Laminated body>
The laminate according to the present invention includes at least a base material layer, a barrier layer, and a sealant layer in this order. The laminate may further include an adhesive layer, a print layer, another layer, and the like. When the laminate includes two or more adhesive layers and other layers, each of them may have the same composition or different compositions.

The laminated body according to the present invention will be described with reference to the drawings. Examples of schematic cross-sectional views of the laminated body according to the present invention are shown in FIGS. 1 to 4. In the laminate 10 shown in FIG. 1, the barrier layer 12 includes at least a metal foil 121. In the laminate 20 shown in FIGS. 2 and 3, the barrier layer 22 includes at least a vapor-deposited film 220. In the laminate 30 shown in FIG. 4, the barrier layer 32 contains at least a kenside 321 of an ethylene-vinyl acetate copolymer.

The laminate 10 shown in FIG. 1 includes a base material layer 11, an adhesive layer 14, a barrier layer 12, an adhesive layer 15, and a sealant layer 13 in this order. In the packaging bag provided with the laminate 10, the sealant layer 13 is located on the innermost surface.

The laminate 20 shown in FIG. 2 includes a base material layer 21, an adhesive layer 24, a film base material layer 221 of a vapor-filmed film 220 constituting the barrier layer 22, and a vapor-deposited layer of the vapor-filmed film 220 constituting the barrier layer 22. The 222, the gas barrier coating film 223 of the thin-film film 220 constituting the barrier layer 22, the adhesive layer 25, and the sealant layer 23 are provided in this order. In the packaging bag provided with the laminate 20, the sealant layer 23 is located on the innermost surface.

The laminate 20 shown in FIG. 3 includes a base material layer 21, an adhesive layer 24, a gas barrier coating film 223 of a vapor-filmed film 220 constituting the barrier layer 22, and a vapor-deposited layer of the vapor-filmed film 220 constituting the barrier layer 22. The 222, the film base layer 221 of the thin-film film 220 constituting the barrier layer 22, the adhesive layer 25, and the sealant layer 23 are provided in this order. In the packaging bag provided with the laminate 20, the sealant layer 23 is located on the innermost surface.

The laminate 30 shown in FIG. 4 includes a base material layer 31, an adhesive layer 34, a kenside 321 of an ethylene-vinyl acetate copolymer constituting the barrier layer 32, an adhesive layer 35, and a sealant layer 33. Prepare in this order. In the packaging bag provided with the laminate 30, the sealant layer 33 is located on the innermost surface.

Hereinafter, each layer constituting the laminated body will be described.

[Base layer]
The base material layer contains polyethylene terephthalate recycled by mechanical recycling (hereinafter, polyethylene terephthalate is also referred to as PET). Specifically, the base material layer contains PET in which PET bottles are recycled by mechanical recycling, in which the diol unit is ethylene glycol and the dicarboxylic acid unit contains terephthalic acid and isophthalic acid. Here, mechanical recycling generally means that the collected polyethylene terephthalate resin products such as PET bottles are crushed and alkaline-cleaned to remove stains and foreign substances on the surface of the PET resin products, and then dried under high temperature and reduced pressure for a certain period of time. This is a method in which the contaminants remaining inside the PET resin are diffused and decontaminated, the stains on the resin product made of the PET resin are removed, and the resin is returned to the PET resin again. Hereinafter, in the present specification, polyethylene terephthalate obtained by recycling PET bottles is referred to as "recycled polyethylene terephthalate (hereinafter, also referred to as recycled PET)", and non-recycled polyethylene terephthalate is referred to as "virgin polyethylene terephthalate (hereinafter, also referred to as virgin PET)". ) ”.

Of the PET contained in the base material layer, the content of isophthalic acid is preferably 0.5 mol% or more and 5 mol% or less, preferably 1.0 mol%, based on all the dicarboxylic acid units constituting the PET. It is more preferably 2.5 mol% or more. If the content of isophthalic acid is less than 0.5 mol%, the flexibility may not be improved, while if it exceeds 5 mol%, the melting point of PET may be lowered and the heat resistance may be insufficient. The PET may be a biomass PET as well as a PET derived from a normal fossil fuel. The "biomass PET" contains ethylene glycol derived from biomass as a diol unit and contains a dicarboxylic acid derived from fossil fuel as a dicarboxylic acid unit. This biomass PET may be formed only of PET having a biomass-derived ethylene glycol as a diol unit and a fossil fuel-derived dicarboxylic acid as a dicarboxylic acid unit, or a biomass-derived ethylene glycol and a fossil fuel-derived diol. It may be formed of PET having a diol unit and a dicarboxylic acid derived from fossil fuel as a dicarboxylic acid unit.

The PET used in the PET bottle can be obtained by a conventionally known method of polycondensing the above-mentioned diol unit and dicarboxylic acid unit. Specifically, a general method of melt polymerization such as performing an esterification reaction and / or an ester exchange reaction between the above diol unit and a dicarboxylic acid unit and then performing a polycondensation reaction under reduced pressure, or an organic solvent. It can be produced by a known solution heating dehydration condensation method or the like using the above.

The amount of the diol unit used in producing the PET is substantially equimolar to 100 mol of the dicarboxylic acid or its derivative, but generally, esterification and / or transesterification reaction and / or depolymerization. Since there is distillation during the reaction, it is used in excess of 0.1 mol% or more and 20 mol% or less.

Further, the polycondensation reaction is preferably carried out in the presence of a polymerization catalyst. The timing of adding the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction, and it may be added at the time of charging the raw materials or at the start of reduced pressure.

PET bottles recycled from PET bottles are polymerized and solidified as described above, and then solid-phase polymerization is performed as necessary in order to further increase the degree of polymerization and remove oligomers such as cyclic trimers. You may go. Specifically, in solid phase polymerization, the PET is chipped and dried, and then heated at a temperature of 100 ° C. or higher and 180 ° C. or lower for about 1 to 8 hours to pre-crystallize the PET, followed by 190 ° C. It is carried out by heating at a temperature of 230 ° C. or lower for 1 hour to several tens of hours under an inert gas atmosphere or under reduced pressure.

The ultimate viscosity of PET contained in the base material layer is preferably 0.58 dl / g or more and 0.80 dl / g or less. If the ultimate viscosity is less than 0.58 dl / g, the mechanical properties required for the PET film as a base material may be insufficient. On the other hand, if the ultimate viscosity exceeds 0.80 dl / g, the productivity in the film forming process may be impaired. The ultimate viscosity is measured with an orthochlorophenol solution at 35 ° C.

The base material layer preferably contains recycled PET in a proportion of 50% by weight or more and 95% by weight or less, and may contain virgin PET in addition to recycled PET. As the virgin PET, the diol unit as described above may be ethylene glycol, the dicarboxylic acid unit may be PET containing terephthalic acid and isophthalic acid, and the dicarboxylic acid unit may be PET containing no isophthalic acid. May be good. Further, the base material layer may contain polyester other than PET. For example, as the dicarboxylic acid unit, an aliphatic dicarboxylic acid or the like may be contained in addition to the aromatic dicarboxylic acid such as terephthalic acid and isophthalic acid.

Specific examples of the aliphatic dicarboxylic acid include chains having 2 or more and 40 or less carbon atoms, such as oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid and cyclohexanedicarboxylic acid. The shape or alicyclic dicarboxylic acid can be mentioned. Examples of the derivative of the aliphatic dicarboxylic acid include lower alkyl esters such as the methyl ester of the aliphatic dicarboxylic acid, ethyl ester, propyl ester and butyl ester, and cyclic acid anhydride of the aliphatic dicarboxylic acid such as succinic anhydride. .. Among these, as the aliphatic dicarboxylic acid, adipic acid, succinic acid, dimer acid or a mixture thereof is preferable, and one containing succinic acid as a main component is particularly preferable. As the derivative of the aliphatic dicarboxylic acid, methyl esters of adipic acid and succinic acid, or mixtures thereof are more preferable.

The base material layer composed of such PET may be a single layer or a multilayer layer. As shown in FIG. 5, when the recycled PET as described above is used as the base material layer, the base material layer may be provided with three layers of the first layer 51, the second layer 52, and the third layer 53. In this case, in the laminated body, the third layer 53 of the base material layer is located on the sealant layer side. Further, in this case, the second layer 52 is a layer composed only of recycled PET or a mixed layer of recycled PET and virgin PET, and the first layer 51 and the third layer 53 are a layer composed only of virgin PET. It is preferable to do so. As described above, by using only virgin PET for the first layer 51 and the third layer 53, it is possible to prevent the recycled PET from being exposed from the front surface or the back surface of the base material layer. Therefore, the hygiene of the laminated body can be ensured. Further, the base material layer may be a base material layer including two layers of the second layer 52 and the third layer 53 without providing the first layer 51 shown in FIG. Further, the base material layer may be a base material layer including two layers of the first layer 51 and the second layer 52 without providing the third layer 53 shown in FIG. Also in these cases, the second layer 52 is a layer composed only of recycled PET or a mixed layer of recycled PET and virgin PET, and the first layer 51 and the third layer 53 are layers composed only of virgin PET. Is preferable.

When one layer is formed by mixing recycled PET and virgin PET, there are a method of separately supplying to a molding machine, a method of supplying after mixing with a dry blend or the like, and the like. Above all, a method of mixing with a dry blend is preferable from the viewpoint of easy operation.

Various additives can be added to the PET constituting the base material layer in the manufacturing process thereof or after the manufacturing thereof as long as the characteristics are not impaired. Additives include, for example, plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, mold release agents, antioxidants, ions. Examples include replacement agents and colored pigments. The additive is preferably added in the range of 5% by mass or more and 50% by mass or less, preferably 5% by mass or more and 20% by mass or less, based on the entire resin composition containing PET.

The base material layer can be formed by, for example, forming a film by the T-die method using the above-mentioned PET. Specifically, after the above-mentioned PET is dried, it is supplied to a melt extruder heated to a temperature equal to or higher than the melting point of PET (Tm) to Tm + 70 ° C. to melt the resin composition, for example, T-die. A film can be formed by extruding a sheet-like material from a die such as a die and quenching and solidifying the extruded sheet-like material with a rotating cooling drum or the like. As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder and the like can be used depending on the purpose.

The film obtained as described above is preferably biaxially stretched. Biaxial stretching can be performed by a conventionally known method. For example, the film extruded onto the cooling drum as described above is subsequently heated by roll heating, infrared heating, or the like, and stretched in the vertical direction to obtain a vertically stretched film. This stretching is preferably performed by utilizing the difference in peripheral speed between two or more rolls. The longitudinal stretching is usually performed in a temperature range of 50 ° C. or higher and 100 ° C. or lower. The magnification of longitudinal stretching is preferably 2.5 times or more and 4.2 times or less, although it depends on the required characteristics of the film application. When the draw ratio is less than 2.5 times, the thickness unevenness of the PET film becomes large and it is difficult to obtain a good film.

The vertically stretched film is subsequently subjected to each of the treatment steps of lateral stretching, heat fixing, and heat relaxation to obtain a biaxially stretched film. The transverse stretching is usually performed in a temperature range of 50 ° C. or higher and 100 ° C. or lower. The ratio of lateral stretching depends on the required characteristics of this application, but is preferably 2.5 times or more and 5.0 times or less. If it is less than 2.5 times, the thickness unevenness of the film becomes large and it is difficult to obtain a good film, and if it exceeds 5.0 times, breakage is likely to occur during film formation.

After the transverse stretching, a heat fixing treatment is subsequently performed, and a preferable heat fixing temperature range is Tg + 70 to Tm-10 ° C. of PET. Further, the heat fixing time is preferably 1 second or more and 60 seconds or less. Further, for applications that require a reduction in the heat shrinkage rate, heat relaxation treatment may be performed as necessary.

The thickness of the PET film obtained as described above is arbitrary depending on the intended use, but is usually 5 μm or more and 100 μm or less, preferably 5 μm or more and 25 μm or less. The breaking strength of the PET film is 5 kg / mm ² or more and 40 kg / mm ^{2 or less in the MD direction, 5 kg / mm 2 or more and 35 kg / mm 2 or less} in the TD direction, and the breaking elongation is 50 in the MD direction. % Or more and 350% or less, and 50% or more and 300% or less in the TD direction. The shrinkage rate when left in a temperature environment of 150 ° C. for 30 minutes is 0.1% or more and 5% or less.

The virgin PET may be fossil fuel polyethylene terephthalate (hereinafter, also referred to as fossil fuel PET) or biomass PET. Here, the "fossil fuel PET" is a fossil fuel-derived diol as a diol unit and a fossil fuel-derived dicarboxylic acid as a dicarboxylic acid unit. Further, the recycled PET may be obtained by recycling a PET resin product formed by using fossil fuel PET, or may be obtained by recycling a PET resin product formed by using biomass PET. There may be.

[Barrier layer]
Next, the barrier layer will be described.

{First configuration of barrier layer}
The barrier layer according to the first configuration includes a metal foil. As the metal foil constituting the barrier layer of the laminated body shown in FIG. 1, a conventionally known metal foil can be used. Aluminum foil is preferable from the viewpoint of gas barrier property that blocks the transmission of oxygen gas, water vapor, and the like, and light-shielding property that blocks the transmission of visible light, ultraviolet rays, and the like. The thickness of the metal foil is, for example, 5 μm or more and 15 μm or less. By making the thickness of the metal foil 5 μm or more, even if foreign matter adheres to the recycled PET used for the base material layer in the packaging bag provided with the laminated body, the foreign matter is exposed to the inner surface side of the barrier layer. It is possible to prevent problems that occur. Therefore, the hygiene of the contents can be ensured.

{Second configuration of barrier layer}
The barrier layer according to the second configuration includes a thin-film deposition film. The vapor-deposited film constituting the barrier layer of the laminate shown in FIGS. 2 and 3 includes a film substrate layer, a vapor-deposited layer provided on the film substrate layer, and a gas barrier coating provided on the vapor-deposited layer. Including with membrane.

(Film substrate layer)
As the film substrate layer, for example, a uniaxial or biaxially stretched film of a thermoplastic resin film such as polyethylene terephthalate (PET), polypropylene (PP), or nylon (ONy) can be preferably used. Further, the film base material layer may have a gas barrier property. In this case, the gas barrier property of the laminated body as a whole is improved, and in the packaging bag made from the laminated body, for example, the permeation of oxygen from the outside can be suppressed and the deterioration due to the oxidation of the contents can be suppressed. As an example, as the film substrate layer having a gas barrier property, a film having a high gas barrier property itself, for example, a saponified product (EVOH) of an ethylene-vinyl acetate copolymer, a polyvinylidene chloride resin (PVDC), or the like may be used. good. The thickness of the film substrate layer is, for example, 5 μm or more and 30 μm or less. If the thickness of the film substrate layer is less than 5 μm, the breaking strength and the tensile strength may be low, and the vapor deposition processability may not be sufficient.

(Embedded layer)
The thin-film deposition layer is a layer made of a thin-film deposition film that can be formed by a conventionally known method. By providing the thin-film deposition layer, it is possible to impart or improve the gas barrier property of blocking the permeation of oxygen gas, water vapor and the like. The thin-film deposition film constituting the barrier layer may include two or more thin-film deposition layers. When two or more thin-film deposition layers are provided, they may have the same composition or different compositions.

The thin-film deposition film may be a metal-deposited film made of a metal-deposited film, or may be a transparent vapor-deposited film made of an inorganic oxide-deposited film.

When the barrier layer contains a metal vapor-deposited film, in addition to the above-mentioned gas barrier property, it is possible to impart or improve a light-shielding property that blocks the transmission of visible light, ultraviolet rays, and the like. Further, since the packaging bag can be given a metallic luster, the design can be improved. When the barrier layer contains a transparent thin-film film, it is possible to impart or improve the gas barrier property of blocking the permeation of oxygen gas, water vapor and the like while maintaining the permeation of the contents.

Examples of the metal vapor deposition film include aluminum (Al), magnesium (Mg), tin (Sn), sodium (Na), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), and gold ( A metal vapor deposition film such as Au) or chromium (Cr) can be used. In particular, for packaging bags, it is preferable to provide a thin-film aluminum film.

The film thickness of the metal vapor deposition film varies depending on the type of metal used and the like, but for example, it is desirable to arbitrarily select and form the film within the range of 50 Å or more and 2000 Å or less, preferably 100 Å or more and 1000 Å or less. More specifically, in the case of a thin-film aluminum film, a film thickness of 50 Å or more and 600 Å or less, more preferably 100 Å or more and 450 Å or less is desirable.

Examples of the transparent vapor-deposited film include silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), and titanium ( A vapor-deposited film of an oxide such as Ti), lead (Pb), zirconium (Zr), or yttrium (Y) can be used. In particular, for packaging bags, it is preferable to provide a vapor-deposited film of aluminum oxide or silicon oxide.

The notation of the inorganic oxide is MO _X such as SiO _X , AlO _X , etc. (However, in the formula, M represents an inorganic element, and the value of X has a range different depending on the inorganic element). expressed. The range of the value of X is 0 to 2 for silicon (Si), 0 to 1.5 for aluminum (Al), 0 to 1 for magnesium (Mg), and 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, and titanium (Ti). Can take a value in the range of 0 to 2, lead (Pb) of 0 to 2, zirconium (Zr) of 0 to 2, and yttrium (Y) of 0 to 1.5. In the above, when X = 0, it is a completely inorganic simple substance (pure substance) and is not transparent, and the upper limit of the range of X is a completely oxidized value. Silicon (Si) and aluminum (Al) are preferably used as the packaging material, and silicon (Si) is in the range of 1.0 to 2.0 and aluminum (Al) is in the range of 0.5 to 1.5. You can use the one with the value of.

The film thickness of the transparent thin-film film varies depending on the type of inorganic oxide used, but it is desirable to arbitrarily select and form the film, for example, within the range of 50 Å or more and 2000 Å or less, preferably 100 Å or more and 1000 Å or less. For example, in the case of a vapor-filmed film of aluminum oxide or silicon oxide, a film thickness of 50 Å or more and 500 Å or less, more preferably 100 Å or more and 300 Å or less is desirable.

The thin-film film can be formed on the base material layer or the like by using the following forming method. Examples of the method for forming the vapor deposition film include a physical vapor deposition method (PVD method) such as a vacuum vapor deposition method, a sputtering method, and an ion plating method, or a plasma chemical vapor deposition method and thermochemistry. Examples thereof include a vapor phase growth method, a chemical vapor deposition method such as a photochemical vapor deposition method, and a CVD method.

(Gas barrier coating film)
If necessary, a gas barrier coating film may be provided on the above-mentioned thin-film deposition layer. The gas barrier coating film is a coating film that functions as a layer that suppresses the permeation of oxygen gas, water vapor, and the like. The gas barrier coating film has a general formula of R ¹ _n M (OR ² ) _m (wherein, in the formula, R ¹ and R ² represent organic groups having 1 to 8 carbon atoms, M represents a metal atom, and n. Represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents the valence of M), and at least one alkoxide, a polyvinyl alcohol-based resin and / or It is obtained by a gas barrier composition containing an ethylene / vinyl alcohol copolymer and further subjected to polycondensation by the solgel method in the presence of a solgel method catalyst, acid, water, and an organic solvent.

As the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m , at least one or more of a partial hydrolyzate of the alkoxide and a condensate of the hydrolysis of the alkoxide can be used. Further, as the partial hydrolyzate of the above alkoxide, it is not necessary that all of the alkoxy groups are hydrolyzed, and one or more of them may be hydrolyzed, or a mixture thereof. As the condensate of hydrolysis of alkoxide, one having a dimer or more of a partially hydrolyzed alkoxide, specifically, one having a dimer of 2 to 6 is used.

In the above-mentioned alkoxide represented by the general formula R ¹ _n M (OR ² ) _m , silicon, zirconium, titanium, aluminum, or the like can be used as the metal atom represented by M. In the present embodiment, examples of the preferred metal include silicon and titanium. Further, in the present invention, the alkoxide may be used alone or by mixing alkoxides of two or more different metal atoms in the same solution.

Further, in the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m , specific examples of the organic group represented by R ¹ include, for example, a methyl group, an ethyl group, an n-propyl group, and i. Alkyl groups such as -propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-octyl group and others can be mentioned. Further, in the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m , specific examples of the organic group represented by R ² include, for example, a methyl group, an ethyl group, an n-propyl group, and i. -Propyl group, n-butyl group, sec-butyl group, etc. can be mentioned. In addition, these alkyl groups may be the same or different in the same molecule.

When preparing the above gas barrier composition, for example, a silane coupling agent or the like may be added. As the above-mentioned silane coupling agent, known organic reactive group-containing organoalkoxysilanes can be used. In this embodiment, organoalkoxysilane having an epoxy group is particularly preferably used, and specifically, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β. -(3,4-Epylcyclohexyl) ethyltrimethoxysilane or the like can be used. The above-mentioned silane coupling agent may be used alone or in combination of two or more.

{Third configuration of the barrier layer}
The barrier layer according to the third configuration contains a saponified product (EVOH) of an ethylene-vinyl acetate copolymer. As the EVOH constituting the barrier layer of the laminated body shown in FIG. 4, for example, those described in JP-A-2008-307847 can be used. The thickness of the barrier layer according to the third configuration is preferably 5 μm or more and 40 μm or less, and more preferably 10 μm or more and 35 μm or less. By making the thickness of the barrier layer 5 μm or more, even if foreign matter adheres to the recycled PET used for the base material layer in the packaging bag provided with the laminated body, the foreign matter appears on the inner surface side of the barrier layer. It is possible to prevent problems that occur. Therefore, the hygiene of the contents can be ensured.

The barrier layer described above may be provided in two or more layers. When having two or more barrier layers, each may have the same composition or different compositions.

[Sealant layer]
The sealant layer is on the innermost layer side when it is used as a package. The sealant layer is a layer formed of a thermoplastic resin that can be fused to each other by heat. The sealant layer may contain a resin material derived from fossil fuel or may contain a resin material derived from biomass.

The resin material forming the sealant layer is not particularly limited as long as it is a resin that can be fused to each other by heat, and specifically, for example, low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high density polyethylene (MDPE). Density polyethylene (HDPE), linear (linear) low density polyethylene (LLDPE), ethylene-α / olefin copolymer polymerized using a metallocene catalyst, random or block copolymer of ethylene / polypropylene, polypropylene, Ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylate copolymer (EMAA), ethylene-methyl methacrylate Polypolymers (EMMA), ionomer resins, heat sealable ethylene / vinyl alcohol resins, or polyolefins such as methylpentene resins, ethylene-propylene copolymers, methylpentene polymers, polybutene polymers, polyethylene, polypropylene or cyclic olefin copolymers. Acid-modified polyolefin resin, polyvinyl acetate resin, poly (meth) acrylic obtained by modifying based resin and polyolefin resin with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid. Examples thereof include based resins, polyvinyl chloride-based resins, and other resins. These may be used alone or as a mixture of two or more. The sealant layer can be used as a resin film or sheet as described above, a coating film thereof, or the like.

When polyethylene is used as the resin material for forming the sealant layer, polyethylene derived from biomass may be polymerized in addition to ethylene obtained from fossil fuel as the raw material. As the biomass-derived ethylene, specifically, for example, those described in JP2012-251006 can be used. By using polyethylene obtained by polymerizing biomass-derived ethylene as a material constituting the sealant layer, it can be formed into a layer made of a carbon-neutral material. The amount of fuel used can be reduced and the environmental load can be reduced.

As the polyethylene derived from biomass, commercially available polyethylene may be used. For example, a linear sugarcane-derived polyethylene of "C4LL-LL118 (d = 0.916, MFR = 1.0 g / 10 minutes)" manufactured by Braskem Co., Ltd. may be used. A low-density polyethylene-based resin or a sugarcane-derived low-density polyethylene-based resin of "SBC118 (d = 0.918, MFR = 8.1 g / 10 minutes)" can be used.

In this embodiment, the sealant layer is a single layer, but two or more sealant layers may be provided. When having two or more sealant layers, each may have the same composition or different compositions. For example, the sealant layer is composed of three layers in which the first layer, the second layer, and the third layer are laminated in order, and the first layer and the third layer are made of a fossil fuel-derived resin material, and the second layer is used. The layer may be a resin material containing a biomass-derived resin material. When the sealant layer is composed of two or more layers, it can be laminated by using the co-extrusion method.

The thickness of the sealant layer is preferably 20 μm or more and 200 μm or less, and more preferably 30 μm or more and 130 μm or less.

[Adhesive layer]
The adhesive layer is a layer provided when adhering any two layers, and can be provided, for example, between the base material layer and the barrier layer, or between the barrier layer and the sealant layer.

When the two layers are bonded by the dry laminating method, the adhesive layer can be an adhesive layer formed by applying an adhesive to the surface of the layer on the side to be laminated and drying the adhesive layer. Examples of the adhesive include one-component or two-component curable or non-curable vinyl-based, (meth) acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber-based, and others. An adhesive such as a solvent type, an aqueous type, or an emulsion type can be used. As the two-component curable adhesive, a cured product of a polyol and an isocyanate compound can be used. As a coating method of the above-mentioned laminating adhesive, for example, a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a fonten method, a transfer roll coating method, or other methods can be applied. ..

The adhesive layer may be an adhesive resin layer used when the two layers are bonded by the sand laminating method. The thermoplastic resin that can be used for the adhesive resin layer includes a polyethylene resin, a polypropylene resin, a cyclic polyolefin resin, or a copolymer resin containing these resins as a main component, a modified resin, or a mixture (including an alloy). ) Can be used. Examples of the polyolefin-based resin include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear (linear) low-density polyethylene (LLDPE), polypropylene (PP), and metallocene catalysts. Ethylene-α / olefin copolymer polymerized using, random or block copolymer of ethylene / polypropylene, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene / Ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-maleic acid copolymer, ionomer resin, and adhesion between layers. It is possible to use an acid-modified polyolefin-based resin obtained by modifying the above-mentioned polyolefin-based resin with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid. can. Further, as the polyolefin resin, an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, a resin obtained by graft-polymerizing or copolymerizing an ester monomer and the like can be used. These materials can be used alone or in combination of two or more. As the cyclic polyolefin resin, for example, a cyclic polyolefin such as an ethylene-propylene copolymer, polymethylpentene, polybutene, or polynorbonene can be used. These resins can be used alone or in combination of two or more. As the polyethylene-based resin described above, a resin using the above-mentioned ethylene derived from biomass as a monomer unit can be used to further improve the degree of biomass.

When laminating the adhesive resin layer by the melt-extruded laminating method, an anchor coat layer formed by applying an anchor coating agent and drying may be provided on the surface of the layer on the laminated side. Examples of the anchor coating agent include any resin having a heat resistant temperature of 135 ° C. or higher, for example, an anchor coating agent made of a vinyl-modified resin, an epoxy resin, a urethane resin, a polyester resin, polyethyleneimine, or the like. An anchor coating agent which is a cured product of a polyacrylic or polymethacrylic resin (polyester) having two or more hydroxyl groups and an isocyanate compound as a curing agent can be preferably used. Further, a silane coupling agent may be used in combination with this as an additive, or nitrified cotton may be used in combination to enhance heat resistance.

The laminated body may have one adhesive layer or may include two or more adhesive layers. For example, when two adhesive layers are included in the laminate, one adhesive layer may be referred to as a first adhesive layer, and the other adhesive layer may be referred to as a second adhesive layer.

The dried anchor coat layer has a thickness of 0.1 μm or more and 1 μm or less, preferably 0.3 μm or more and 0.5 μm or less. The dried adhesive layer has a thickness of 1 μm or more and 10 μm or less, preferably 2 μm or more and 5 μm or less. The adhesive resin layer preferably has a thickness of 5 μm or more and 50 μm or less, preferably 10 μm or more and 30 μm or less.

[Other layers]
The laminate according to the present invention may further include a printing layer or the like as another layer. The printing layer is used for decoration, display of contents, display of best-by date, display of manufacturers, sellers, etc., and for the purpose of giving a sense of beauty, such as letters, numbers, patterns, figures, symbols, and patterns. A layer that forms any desired print pattern. The printed layer can be provided as needed, and can be provided, for example, between the base material layer and the barrier layer. The printing layer may be provided on the entire surface of the base material layer, or may be provided on a part of the base material layer. The printed layer can be formed by using a conventionally known pigment or dye, and the forming method thereof is not particularly limited.

The printed layer preferably has a thickness of 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less, and further preferably 1 μm or more and 3 μm or less.

<Manufacturing method of laminated body>
The method for producing the laminate according to the present invention is not particularly limited, and the laminate can be produced by using a conventionally known method such as a dry laminate method.

The laminate according to the present invention is provided with a chemical function, an electrical function, a magnetic function, a mechanical function, a friction / wear / lubrication function, an optical function, a thermal function, a surface function such as biocompatibility, and the like. It is also possible to perform secondary processing for the purpose. 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, etc.) Coating, etc.) and the like. Further, the laminated body according to the present invention may be subjected to laminating processing (dry laminating or extruded laminating), bag making processing, and other post-treatment processing to produce a molded product.

The laminate can be used, for example, in a packaging bag for filling a product such as food. For example, the above laminated body is used and folded in half, or two laminated bodies are prepared and the surfaces of the sealant are overlapped with each other facing each other, and the peripheral end thereof is, for example, a side seal type. , Two-way sticker type, three-way sticker type, four-way sticker type, envelope sticker sticker type, gassho sticker sticker type (pillow sticker type), fold sticker type, flat bottom sticker type, square bottom sticker type, gusset type, etc. Can be heat-sealed to produce various forms of packaging bags.

In the above, as the heat sealing method, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, and an ultrasonic seal can be used.

Since the packaging bag has excellent hygiene while reducing the environmental load, it can be particularly suitably used as a packaging bag for sealing and packaging foods and the like.

10 Laminated body 11 Base material layer 12 Barrier layer 13 Sealant layer 121 Metal leaf 20 Laminated body 21 Base material layer 22 Barrier layer 23 Sealant layer 220 Vaporized film 30 Laminated body 31 Base material layer 32 Barrier layer 33 Sealant layer 321 Ethylene-vinyl acetate Copolymer Kensei

Claims (3)

A laminate comprising at least a base material layer ( excluding a layer of a polyester resin foam sheet having a density of 700 kg / m ³ or less), a barrier layer, and a sealant layer in this order.
The base material layer contains virgin polyethylene terephthalate and recycled polyethylene terephthalate containing polyethylene terephthalate having ethylene glycol as a diol unit and terephthalic acid and isophthalic acid as a dicarboxylic acid unit.
The base material layer does not contain a biomass polyester resin having ethylene glycol derived from biomass as a diol unit and a dicarboxylic acid derived from fossil fuel as a dicarboxylic acid unit.
The barrier layer contains a metal foil and
The sealant layer is one or more selected from the group consisting of a polyolefin resin, an acid-modified polyolefin resin, a polyvinyl acetate resin, a poly (meth) acrylic resin, and a polyvinyl chloride resin . .. The laminate according to claim 1 , wherein the content of the isophthalic acid is 0.5 mol% or more and 5.0 mol% or less with respect to all the dicarboxylic acid units constituting the polyethylene terephthalate. The ultimate viscosity of the polyethylene terephthalate is 0.58 dl / g or more and 0.80 dl / g or less .
The thickness of the base material layer is 5 μm or more and 25 μm or less.
The laminate according to claim 1 or 2 , wherein the thickness of the metal foil is 5 μm or more and 15 μm or less .

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