JP2014198472A - Laminate and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate which is formed by laminating a polypropylene as a sealant resin on a substrate, has excellent adhesion between a sealant layer and a substrate and also has excellent content resistance, retort resistance, boiling resistance and tear resistance, and provide a method for stably producing the laminate at a low cost.SOLUTION: A laminate is formed by laminating at least a substrate layer, an adhesive layer and a sealant layer containing a polypropylene in this order, wherein the adhesive layer comprises a polyolefin resin, a specific amount of a crosslinking agent and/or a polyurethane resin, the polyolefin resin contains a propylene component (A) as an olefin component and an olefin component (B) other than the propylene component in a range of 60/40 to 95/5 by mass ratio (A/B) and contains a specific amount of an unsaturated carboxylic acid unit based on the total 100 pts.mass of (A)+(B), and the polyolefin resin has a weight average molecular weight of 15,000 or more.

Description

  The present invention relates to a laminate suitable for packaging materials such as snacks and retort foods. In detail, it is related with the laminated body provided with the sealant layer comprised from a polypropylene, and its manufacturing method.

  Many packaging materials have a laminated structure composed of a plurality of layers. In particular, a laminate in which a sealant layer is laminated on a base material made of a thermoplastic resin film such as a polyester resin film or a polyamide resin film, aluminum, or the like via an adhesive layer is often used. As the sealant layer, polyethylene resin and polypropylene resin are widely used, but as a sealant layer for packaging materials applied to products using edible oil such as snacks, bread, and noodles, retort food, etc., heat resistance, Polypropylene resin which is more excellent in oil resistance is used.

  When the laminate is used as a packaging material, the packaging material is filled with various contents such as food. However, if the contents contain volatile substances such as oil or medicinal ingredients, these will penetrate between the base material and the sealant layer, causing the adhesive layer to swell or dissolve, There exists a problem that the adhesive strength between a base material and a sealant layer falls with time, or peels off (delamination).

  In addition, resistance to heat and humidity during retort treatment and boil treatment for sterilizing microorganisms adhering to or mixed in food is also required.

Furthermore, when a package for retort is produced using a laminate, if the heat resistance and adhesiveness of the adhesive layer are insufficient, the tear resistance at the time of opening is large, or the sealant layer is stretched at the time of opening. There was a problem that the contents were easily spilled due to tearing.

  On the other hand, in order to produce a laminate as described above, a dry laminating method in which an adhesive layer is provided on a substrate, and then a pre-filmed sealant resin film is pressed onto the adhesive layer while pressing with a heating roll. (Also referred to as dry lamination), an extrusion laminating method (also referred to as extrusion lamination) in which an adhesive layer is provided on a substrate, a molten sealant resin is extruded onto the adhesive layer from an extruder, and a sealant layer is formed. It has been adopted.

  The extrusion laminating method can form a sealant layer by directly melt-extruding a sealant resin on a substrate provided with an adhesive layer, so that there is no need to mold the sealant resin into a film in advance, Therefore, it is possible to mass-produce laminates at low cost because there is an advantage that sufficient adhesive strength can be obtained even when the thickness of the laminate is thin. Among them, it is preferably adopted.

However, when polypropylene resin is used as a sealant resin due to requirements such as heat resistance and oil resistance, it has good adhesion suitability that enables production by an extrusion laminating method, and at the same time, content resistance, retort resistance, There is no adhesive that satisfies boil resistance, tearing properties, etc., and a laminate is produced exclusively by the dry laminating method with many steps and high cost.

In Patent Document 1, a laminate including an adhesive layer made of an acid-modified polyolefin elastomer is described. This laminate was excellent in adhesiveness even when a polypropylene resin, which is said to have difficulty in adhesion, was used as the sealant resin, and made it possible to produce a laminate by extrusion lamination.

JP 2012-71491 A

  However, in the invention described in Patent Document 1, the adhesion when polypropylene is used as the sealant resin is good, but the content resistance, retort resistance, boil resistance, tear characteristics, etc. are not satisfactory. There wasn't.

  The present invention is a laminate in which polypropylene is laminated as a sealant layer on a base material layer, which has excellent adhesion between the sealant layer and the base material, content resistance, retort resistance, boil resistance and tearing characteristics. It is an object of the present invention to provide an excellent laminate and a method for stably producing the laminate at a low cost.

  As a result of intensive studies to solve the above problems, the present inventors have found that when an adhesive layer is formed by using a polyolefin resin having a specific composition and at least one of a cross-linking agent and a polyurethane resin in a specific ratio, the adhesion resistance and resistance are improved. It has been found that a laminate having excellent content properties, retort resistance, boil resistance, and tearing properties can be obtained, and this laminate can be efficiently produced by using an extrusion laminating method. It has been found that the use of an aqueous dispersion for the formation is preferable not only in productivity but also in terms of environment and quality, and has reached the present invention.

  That is, the gist of the present invention is as follows.

(1) A laminate in which at least a base material layer, an adhesive layer and a polypropylene-containing sealant layer are laminated in this order, and the adhesive layer comprises 100 parts by mass of a polyolefin resin, 0 to 50 parts by mass of a crosslinking agent, and 0 to 300 parts by mass of a polyurethane resin (however, one of the components is contained in an amount of 1 part by mass or more), and the polyolefin resin is an olefin component other than the propylene component (A) and the propylene component as the olefin component (B) In a range of 60/40 to 95/5 by mass ratio (A / B), and 0.1 to 10 mass of unsaturated carboxylic acid units with respect to 100 mass parts in total of (A) + (B). A laminate comprising a part and a weight average molecular weight of the polyolefin resin of 15000 or more.
(2) The laminate according to (1), wherein the olefin component (B) other than the propylene component is a butene component.
(3) The laminate according to (1) or (2), wherein the crosslinking agent is a compound containing an oxazoline group and / or a compound containing a carbodiimide group.
(4) The laminate according to any one of (1) to (3), wherein the amount of the adhesive layer is in the range of 0.001 to 5 g / m ² .
(5) The laminate according to any one of (1) to (4), wherein the base material layer is any one of a polyester film, a polyamide film, an aluminum foil, an aluminum vapor deposition film, and an inorganic compound vapor deposition film.
(6) The method for producing a laminate according to any one of (1) to (5), wherein the melted sealant resin is laminated on the surface of the adhesive layer formed on the base material layer by extrusion lamination.
(7) The adhesive layer is formed by applying and drying an aqueous dispersion containing a polyolefin resin and a crosslinking agent and / or a polyurethane resin on the surface of the base material layer. The manufacturing method of the laminated body as described in (6).

  According to the present invention, at least a base material layer, an adhesive layer and a polypropylene-containing sealant layer are laminated in this order, and are excellent in adhesiveness between the sealant layer and the base material layer, and resistant to content In addition, an excellent laminate can be provided. In addition, the laminate of the present invention has excellent retort resistance and boil resistance, and is excellent in tear characteristics. The laminate of the present invention is suitable as a packaging material that can be applied to various contents, and is particularly suitable as a packaging material that is applied to snacks, retort foods, and the like. Furthermore, according to the manufacturing method of the present invention, such a laminate can be stably manufactured at a low cost.

  Hereinafter, the present invention will be described in detail.

  The laminate of the present invention is a laminate having at least a base material layer, an adhesive layer, and a sealant layer in this order.

  In the present invention, a soft metal foil such as a thermoplastic resin film or an aluminum foil can be used as the base material layer.

  The thermoplastic resin is not particularly limited, but is a polyester resin such as polyethylene terephthalate (hereinafter abbreviated as PET), polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and a mixture thereof; polycapronamide (nylon 6, Polyamide resin such as polyhexamethylene adipamide (nylon 66), poly-p-xylylene adipamide (MXD nylon), and mixtures thereof; polyethylene, polypropylene, and mixtures thereof Polyolefin resins such as polyvinyl chloride; polyvinyl alcohol; random copolymers of ethylene and vinyl alcohol, and the like, and laminates of these may also be used. Among these, polyester resins and polyamide resins are preferable, and PET and Ny6 are particularly preferable in consideration of mechanical properties when used as a packaging material.

  What was manufactured by the well-known method can be used for a base material layer. The thermoplastic resin film may be either an unstretched film or a stretched film, but is preferably a uniaxial or biaxially stretched film, more preferably a biaxially stretched film from the viewpoint of imparting transparency and gloss.

  In the laminate of the present invention, the base material layer itself may have a barrier property. Since the packaging material that wraps the boiled retort food and the like is required to have moisture resistance and oxygen barrier properties, the base material layer preferably has a barrier property. The base material layer having the barrier property may be composed of any material as long as it is a material capable of blocking liquid and gas. Specifically, a soft metal foil such as an aluminum foil, an aluminum vapor deposition layer, and the like. Various vapor-deposited films provided with inorganic compound vapor-deposited layers such as silica and alumina, and vinylidene chloride resin films, ethylene-vinyl alcohol copolymer films, MXD nylon films, etc. can be used as barrier resin films. Among these, an aluminum foil, an aluminum vapor deposition film, and an inorganic compound vapor deposition film are preferable from the viewpoint of barrier properties.

  Moreover, when making a thermoplastic resin film into a base material layer, it is preferable that the surface activation process is given to the surface which provides the adhesive layer of a base material layer for adhesive improvement. Examples of the surface activation treatment include corona discharge treatment, flame plasma treatment, atmospheric pressure plasma treatment, low pressure plasma treatment, ozone treatment, electron beam irradiation treatment, ultraviolet ray irradiation treatment, chemical treatment, solvent treatment, and the like. Corona discharge treatment is preferred from the balance of effects.

  Although the thickness of a base material layer is not specifically limited, 5-500 micrometers is preferable normally, 5-100 micrometers is more preferable, 10-50 micrometers is further more preferable, and 12-25 micrometers is especially preferable.

  A material containing a polypropylene resin is applied to the sealant layer in the present invention. Polypropylene resin is inexpensive and excellent in heat resistance and oil resistance. For this reason, it is suitable for the packaging material which wraps snack confectionery, a retort foodstuff, etc. by using a polypropylene resin as a sealant layer. The polypropylene resin may be a copolymer polypropylene resin.

  In order to improve the sealing property and adhesiveness at low temperature, other olefin resins, olefin-based elastomers, and the like may be added to the sealant layer within a range that does not reduce the effects of the present invention.

In this invention, the contact bonding layer which comprises a laminated body contains polyolefin resin of a specific composition.
The polyolefin resin contains a propylene component (A) and an olefin component (B) other than the propylene component as the olefin component, and an unsaturated carboxylic acid unit.
The mass ratio (A / B) between the propylene component (A) and the olefin component (B) other than the propylene component is in the range of 60/40 to 95/5 from the viewpoint of improving the adhesion between the adhesive layer and the sealant layer. It is necessary to be in the range of 60/40 to 80/20. When the proportion of the propylene component is outside this range, sufficient adhesion with the sealant layer cannot be obtained.

  Examples of the olefin component (B) other than the propylene component include ethylene, 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-hexene, 1-octene and norbornenes. And alene such as butadiene, and dienes such as butadiene and isoprene. Among these, a butene component (1-butene, isobutene, etc.) is preferable from the viewpoints of easy resin production, easy aqueous formation, and particularly adhesion to a sealant resin.

  In the polyolefin resin, the copolymerization form of each component is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. From the viewpoint of ease of polymerization, random copolymerization is preferable. Moreover, you may mix and use multiple types of polyolefin resin as needed.

  The polyolefin resin may contain components other than those described above as necessary. Other components include (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate, maleic acid such as dimethyl maleate, diethyl maleate, and dibutyl maleate. Acid esters, (meth) acrylic amides, alkyl vinyl ethers such as methyl vinyl ether and ethyl vinyl ether, vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl versatate and vinyl esters Vinyl alcohol, 2-hydroxyethyl acrylate, glycidyl (meth) acrylate, (meth) acrylonitrile, styrene, substituted styrene, vinyl halides, vinylidene halides, carbon monoxide, Diacid Sulfur and the like, may be a mixture thereof.

  As content (mass ratio) of said other component, 10 mass% or less of the whole polyolefin resin is preferable.

In the present invention, a commercially available polyolefin resin may be used. Examples include the Tuffmer series manufactured by Mitsui Chemicals, the APAO series (amorphous polyalphaolefin) manufactured by REXtac, the Lycocene PP series manufactured by Clariant, and the best plast manufactured by Evonik Degussa. In addition, when using a commercially available polyolefin resin that is not acid-modified, an unsaturated carboxylic acid unit may be introduced by a known method.
The polyolefin resin in the present invention has a total of 100 parts by mass of (A) + (B) contained in the polyolefin resin from the viewpoint of improving the dispersibility of the aqueous dispersion described later and improving the adhesion with the substrate. On the other hand, it is necessary to contain 0.1-10 mass parts of unsaturated carboxylic acid units. Preferably it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts, More preferably, it is 1-7 mass parts, Most preferably, it is 1.5-5 mass parts. When the unsaturated carboxylic acid unit is less than 0.1 part by mass, it becomes difficult to make the polyolefin resin water-based, and it cannot be sufficiently adhered to the base material layer. On the other hand, if it exceeds 10 parts by mass, the resin can be easily made water-based, but the adhesion to the sealant layer is lowered, and the content resistance, retort resistance, and boil resistance are also lowered.

  As unsaturated carboxylic acid units, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, fumaric acid, crotonic acid, citraconic acid, mesaconic acid, allyl succinic acid, etc. In addition, compounds having at least one carboxyl group or acid anhydride group in the molecule (in the monomer unit), such as unsaturated dicarboxylic acid half esters and half amides, can also be used. Of these, maleic anhydride, acrylic acid and methacrylic acid are preferred, and maleic anhydride is more preferred from the viewpoint of easy introduction into the unmodified polyolefin resin.

  The unsaturated carboxylic acid unit is not particularly limited as long as it is copolymerized in the polyolefin resin. Examples thereof include random copolymerization, block copolymerization, and graft copolymerization. In addition, the acid anhydride unit introduced into the polyolefin resin easily takes an acid anhydride structure in a dry state, and in an aqueous medium containing a basic compound described later, a part or all of the ring is opened, and the carboxylic acid unit Or it tends to be its salt.

  The method for introducing the unsaturated carboxylic acid unit into the unmodified polyolefin resin is not particularly limited. For example, in the presence of a radical generator, the unmodified polyolefin resin and the unsaturated carboxylic acid are heated and melted to a temperature equal to or higher than the melting point of the unmodified polyolefin resin. Graft copolymerization of unsaturated carboxylic acid units to the unmodified polyolefin resin by a method of reacting or by dissolving the unmodified polyolefin resin in an organic solvent and then heating and stirring in the presence of a radical generator. Can do. In particular, the former method is preferable because the operation is simple. Examples of the radical generator used for graft copolymerization include di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, tert-butyl cumyl peroxide, benzoyl peroxide, dilauryl peroxide, Examples thereof include organic peroxides such as cumene hydroperoxide, tert-butyl peroxybenzoate, ethyl ethyl ketone peroxide, and di-tert-butyl diperphthalate, and azonitriles such as azobisisobutyronitrile. These may be appropriately selected and used depending on the reaction temperature.

  In the present invention, examples of the polyolefin resin include propylene / butene / maleic anhydride terpolymer and propylene / ethylene / maleic anhydride terpolymer, the former being most preferred.

  Further, the weight average molecular weight of the polyolefin resin in the present invention needs to be 15000 or more, preferably 20000 or more, and more preferably 30000 or more. When the weight average molecular weight is less than 15,000, not only the adhesion to the base material layer and the sealant layer is lowered, but sufficient content resistance, retort resistance, and boil resistance cannot be obtained. On the other hand, when the weight average molecular weight exceeds 200,000, it becomes difficult to make the resin aqueous later, and therefore the weight average molecular weight is preferably 200,000 or less. In addition, the weight average molecular weight of resin can be calculated | required on the basis of polystyrene resin using a gel permeation chromatography (GPC).

  The adhesive layer in the laminate of the present invention further contains a crosslinking agent and / or a polyurethane resin in addition to the polyolefin resin having a specific composition.

As the crosslinking agent used in the present invention, a crosslinking agent having a self-crosslinking property, a compound having a plurality of functional groups that react with an unsaturated carboxylic acid component in the molecule, a metal having a polyvalent coordination site, or the like may be used. it can.
Specific examples include oxazoline group-containing compounds, carbodiimide group-containing compounds, isocyanate group-containing compounds, melamine compounds, urea compounds, epoxy compounds, zirconium salt compounds, silane coupling agents, etc. A mixture may be used. Among these, it is preferable to add a compound containing an oxazoline group and / or a compound containing a carbodiimide group from the viewpoint of easy handling and adhesion.

  As the oxazoline group-containing compound, compounds having two or more oxazoline groups in the molecule can be preferably used. For example, 2,2'-bis (2-oxazoline), 2,2'-ethylene-bis (4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis (2-oxazoline) , A compound having an oxazoline group such as bis (2-oxazolinylcyclohexane) sulfide, an oxazoline group-containing polymer, and the like. These 1 type (s) or 2 or more types can be used. Among these, an oxazoline group-containing polymer is preferable because it is easy to handle.

  The oxazoline group-containing polymer is generally obtained by polymerizing an addition polymerizable oxazoline such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline. The oxazoline group-containing polymer may be copolymerized with other monomers as necessary. The polymerization method of the oxazoline group-containing polymer is not particularly limited, and a known polymerization method can be employed. Examples of commercially available oxazoline group-containing polymers include Nippon Shokubai Epocross series. Specific product names include, for example, water-soluble type “WS-500”, “WS-700”; emulsion type “K-1010E”, “K-1020E”, “K-1030E”, “K-” 2010E "," K-2020E "," K-2030E "and the like.

  The compound containing a carbodiimide group is not particularly limited as long as it has at least two carbodiimide groups in the molecule. For example, compounds having a carbodiimide group such as p-phenylene-bis (2,6-xylylcarbodiimide), tetramethylene-bis (t-butylcarbodiimide), cyclohexane-1,4-bis (methylene-t-butylcarbodiimide) And polycarbodiimide which is a polymer having a carbodiimide group. These 1 type (s) or 2 or more types can be used. Among these, polycarbodiimide is preferable from the viewpoint of easy handling.

  The production method of polycarbodiimide is not particularly limited, and can be produced, for example, by a condensation reaction involving decarbonization of an isocyanate compound. The isocyanate compound is not limited, and any of aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate may be used. The isocyanate compound may be copolymerized with a polyfunctional liquid rubber, polyalkylene diol or the like, if necessary. As a commercially available product of polycarbodiimide, there is a carbodilite series manufactured by Nisshinbo. Specific products include, for example, water-soluble type “SV-02”, “V-02”, “V-02-L2”, “V-04”; emulsion type “E-01”, “E -02 "; organic solution type" V-01 "," V-03 "," V-07 "," V-09 "; solvent-free type" V-05 "and the like.

  The compound containing an isocyanate group is not particularly limited as long as it has at least two isocyanate groups in the molecule. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane 2,4′- or 4,4′-diisocyanate, polymethylene polyphenyl diisocyanate, tolidine diisocyanate, 1,4-diisocyanatobutane, Hexamethylene diisocyanate, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- or 1,4-diisocyanatocyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane, 4,4'-diisocyanatodicyclohexylmethane, hexahydrotoluene 2, 4- or 2,6-diisocyanate, perhydro-2,4'- or 4,4'-diphenylmeta Polyisocyanate compounds such as diisocyanate, naphthalene 1,5-diisocyanate, xylylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethyl xylylene diisocyanate, or modified products thereof. Here, the modified product is obtained by modifying the diisocyanate of the polyfunctional isocyanate compound by a known method, for example, allophanate group, burette group, carbodiimide group, uretonimine group, uretdione group, Examples thereof include a polyfunctional isocyanate compound having an isocyanurate group and the like, and an adduct type polyfunctional isocyanate compound modified with a polyfunctional alcohol such as trimethylolpropane. In addition, the said isocyanate group containing compound may contain monoisocyanate in 20 mass% or less.

  The compound containing an isocyanate group can be usually obtained by reacting a polyfunctional isocyanate compound with a monovalent or polyvalent nonionic polyalkylene ether alcohol. Commercially available products of such water-based polyfunctional isocyanate compounds include Bayhydur 3100, Bihydur VPLS 2150/1, SBU Isocyanate L801, Desmodur N3400, Desmodur VPLS2102, Desmodur manufactured by Sumitomo Bayer Urethane Co., Ltd. VPLS2025 / 1, SBU isocyanate 0772, Death Module DN, Takenate WD720, Takenate WD725, Takenate WD730, Duranate WB40-100, Duranate WB40-80D, Duranate WX-1741, BASF There are Basonat HW-100, Basonat LR-9056, etc. manufactured by the company.

  As the polyurethane resin, a polymer containing a urethane bond in the main chain can be used. For example, a polymer obtained by a reaction between a polyol compound and a polyisocyanate compound can be used.

  In the present invention, the polyol component constituting the polyurethane resin is not particularly limited. For example, water, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,2- Propanediol, 1,3-propanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, methyl-1,5-pentanediol, 1,8-octanediol, 2-ethyl-1 , 3-hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol and other low molecular weight glycols, trimethylolpropane, glycerin, pentaerythritol and other low molecular weight polyols, ethylene oxide and propylene oxide units Polyol compounds, polyether diols, high molecular weight diols such as polyester diols, bisphenols such as bisphenol A, bisphenol F, dimer diol, and the like to the carboxyl group of the dimer acid was converted to hydroxyl groups.

  As the polyisocyanate component, one or a mixture of two or more known diisocyanates belonging to aromatic, aliphatic or alicyclic groups can be used. Specific examples of diisocyanates include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-naphthalene diisocyanate, isophorone diisocyanate, dimethyl diisocyanate, lysine diisocyanate. , Hydrogenated 4,4′-diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, dimerized isocyanate obtained by converting a carboxyl group of dimer acid into an isocyanate group, and adducts, biurets, and isocyanurates. As the diisocyanates, trifunctional or higher functional polyisocyanates such as triphenylmethane triisocyanate and polymethylene polyphenyl isocyanate may be used.

  In the present invention, commercially available water-based polyurethane resins include Takelac series (product numbers: W-615, W-6010, W-511, etc.) manufactured by Mitsui Chemicals, and Adekabon titer series (product number: HUX, manufactured by Adeka). -232, HUX-320, HUX-380, HUX-401, etc.), Superflex series (part numbers: 500, 550, 610, 650, etc.) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hydran manufactured by Dainippon Ink & Chemicals, Inc. Series (product number: HW-311, HW-350, HW-150, etc.) can be mentioned.

  The adhesive layer in the present invention contains either or both of a crosslinking agent and a polyurethane resin.

  In the adhesive layer, when a crosslinking agent is used without using a polyurethane resin, the content needs to be 1 to 50 parts by mass, preferably 1 to 40 parts by mass, with respect to 100 parts by mass of the polyolefin resin. More preferably, it is 1-30 mass parts. If the content of the crosslinking agent is less than 1 part by mass, the adhesion between the base material layer and the adhesive layer is inferior because the crosslinking is insufficient, and sufficient adhesion as a laminate, retort resistance, boil resistance, It becomes difficult to obtain tear characteristics. On the other hand, when it exceeds 50 parts by mass, the adhesion between the sealant layer and the adhesive layer becomes insufficient, and it is difficult to obtain sufficient adhesion, retort resistance, boil resistance, and tearing properties as a laminate.

  In the adhesive layer, when a polyurethane resin is used without using a crosslinking agent, the content thereof needs to be 1 to 300 parts by mass, preferably 1 to 150 parts by mass with respect to 100 parts by mass of the polyolefin resin. More preferably, it is 2-130 mass parts, More preferably, it is 3-100 mass parts. When the content of the polyurethane resin is less than 1 part by mass, the adhesion between the base material layer and the adhesive layer becomes insufficient, and it is difficult to obtain sufficient adhesion, retort resistance, boil resistance, and tearing properties as a laminate. Become. On the other hand, when it exceeds 300 parts by mass, the adhesion between the sealant layer and the adhesive layer becomes insufficient, and it is difficult to obtain sufficient adhesion, retort resistance, boil resistance, and tearing properties as a laminate.

  When both the cross-linking agent and the polyurethane resin are included in the adhesive layer, the amount of the cross-linking agent is 50 parts by mass or less and the polyurethane resin is 300 parts by mass or less with respect to 100 parts by mass of the polyolefin resin. It is necessary to contain at least part by mass. If any component is less than 1 part by mass, the adhesion between the base material layer and the adhesive layer becomes insufficient, and sufficient adhesion, retort resistance, boil resistance, and tearing properties as a laminate are difficult to obtain. Become. On the other hand, if one of the components exceeds the above range, the adhesion between the sealant layer and the adhesive layer becomes insufficient, and sufficient adhesion, retort resistance, boil resistance, and tearing properties are obtained as a laminate. It becomes difficult.

  Further, the adhesive layer in the present invention contains a small amount of a polymer other than the above for the purpose of improving the adhesion with the base material layer and improving the content resistance property as a laminate. May be.

  Examples of other polymers include polyester resin, acrylic resin, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, ethylene-vinyl acetate copolymer, styrene-maleic acid resin, styrene. -Resins such as butadiene resin, butadiene resin, acrylonitrile-butadiene resin, poly (meth) acrylonitrile resin, (meth) acrylamide resin, chlorinated polyethylene resin, chlorinated polypropylene resin, modified nylon resin, phenol resin, silicone resin, epoxy resin Ingredients. These other polymers are preferably used in a range that does not impair the effect of the adhesive layer, particularly the adhesion to the sealant layer, and the content thereof is 20% by mass or less of the entire adhesive layer. Preferably, it is 10 mass% or less, More preferably, it is 5 mass% or less.

The amount of the adhesive layer is preferably in the range of 0.001 to 5 g / m ² , more preferably 0.01 to 3 g / m ² with respect to the area of the adhesive surface, and 0.02 to ² g. further preferably / ^{m 2,} particularly preferably from 0.03~1g / ^{m 2,} and most preferably 0.05 to 1 g / ^{m 2.} If it is less than 0.001 g / m ² , sufficient resistance to physical properties tends not to be obtained, whereas if it exceeds 5 g / m ² , it tends to be economically disadvantageous.

  When the laminate of the present invention is used as a packaging material, the substrate is usually used as the outside and the sealant layer as the inside (content side). Other layers may be provided as necessary in consideration of the use of the packaging material or other performance required for the packaging material. Specifically, on the outside of the base material layer, in addition to the thermoplastic resin film and the barrier material as exemplified above, synthetic paper or paper is appropriately provided using an adhesive or the like as necessary. Can do. Each layer and other layers of the laminate of the present invention may be subjected to processing such as printing.

  As described above, the base material layer, the adhesive layer, and the sealant layer in the laminate of the present invention are optionally provided with an antistatic agent, an antioxidant, a light stabilizer, an ultraviolet absorber, a heat stabilizer, and a colorant. Further, a foaming agent or the like may be added in an arbitrary amount.

  Next, a preferred method for producing the laminate of the present invention will be described.

  In the manufacturing method of the laminated body of this invention, an adhesive layer is first provided on the base material layer prepared beforehand. The method for providing the adhesive layer is not particularly limited. For example, a liquid material containing a polyolefin resin and a cross-linking agent and / or a polyurethane resin is prepared, and the liquid material is applied to the surface of the base material. A method of drying the liquid medium is preferred. The liquid form is preferably a solution or dispersion, and the liquid medium may be either an aqueous medium or an organic solvent. In the present invention, the polyolefin resin and the crosslinking agent and / or the polyurethane resin are dispersed in the aqueous medium. It is preferable to use an aqueous dispersion. However, in the present invention, the adhesive layer may be formed directly from the resin or other solid content by means such as hot melt without being processed into a liquid material, and this is not excluded, but the liquid material should be used. Thus, it is preferable in that the amount of the adhesive layer can be easily adjusted, the thickness of the adhesive layer can be controlled thinly, and mass production can be performed at low cost. And it is preferable from an environmental viewpoint and a performance surface to use an aqueous dispersion also in a liquid substance.

  A method for preparing a liquid material containing a polyolefin resin and a crosslinking agent and / or a polyurethane resin is not particularly limited as long as each component is uniformly mixed in a liquid medium. Examples thereof include a method of mixing a dispersion or solution of a polyolefin resin and a dispersion or solution of a crosslinking agent and / or a polyurethane resin, a method of liquefying a mixture of a polyolefin resin and a crosslinking agent and / or a polyurethane resin, and the like. In the present invention, the former method is preferable. In the present invention, it is particularly preferable to prepare an aqueous dispersion by adding an aqueous dispersion or aqueous solution of a crosslinking agent and / or polyurethane resin to an aqueous dispersion of a polyolefin resin.

  In addition, the liquid material includes various agents such as a leveling agent, an antifoaming agent, an anti-waxing agent, an antistatic agent, a pigment dispersant, and an ultraviolet absorber as necessary, and titanium oxide, zinc white, carbon black, etc. Pigments or dyes may be added. Furthermore, organic or inorganic compounds other than those described above can be added to the liquid as long as the stability of the liquid is not impaired.

  When using a liquid substance for formation of an adhesive layer, the content rate of the solid content is not particularly limited, and can be appropriately selected according to the lamination conditions, the desired thickness and performance of the adhesive layer, and the like. However, the solid content is preferably 1 to 60% by mass and more preferably 5 to 30% by mass from the viewpoint of maintaining the viscosity of the liquid material moderately and forming a good adhesive layer. preferable.

  The weight average particle diameter of the polyolefin resin in the aqueous polyolefin resin dispersion is preferably 0.15 μm or less. In addition, the resin particle diameter in the aqueous dispersion of polyolefin resin does not usually change even when mixed with an aqueous dispersion or aqueous solution of a crosslinking agent or polyurethane resin.

  An aqueous dispersion of a polyolefin resin can be produced without using a non-volatile aqueous additive. Although it does not exclude the use of a non-volatile aqueous additive, it is possible to stably disperse a polyolefin resin in an aqueous medium with a weight average particle diameter of 0.15 μm or less without using an aqueous additive. it can. When such an aqueous dispersion is used to form a film by low-temperature drying, an adhesive layer having excellent water resistance, adhesion to a substrate, retort resistance, boil resistance, and tearing properties can be obtained. Hardly changes over the long term.

  Here, the “aqueous auxiliary” is a drug or compound added for the purpose of promoting aqueous formation or stabilizing the aqueous dispersion in the preparation of the aqueous dispersion, and “nonvolatile” means It means that it does not have a boiling point at normal pressure or has a high boiling point (for example, 300 ° C. or higher) at normal pressure.

  The non-volatile hydrating aid is preferably less than 0.5% by mass, particularly preferably not contained, relative to the polyolefin resin component. Examples of the non-volatile auxiliary agent used in the present invention include an emulsifier, a compound having a protective colloid action, a modified wax, an acid-modified compound having a high acid value, and a water-soluble polymer.

  Examples of the emulsifier include a cationic emulsifier, an anionic emulsifier, a nonionic emulsifier, and an amphoteric emulsifier. In addition to those generally used for emulsion polymerization, surfactants are also included. For example, anionic emulsifiers include higher alcohol sulfates, higher alkyl sulfonates, higher carboxylates, alkyl benzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, vinyl sulfosuccinates. And the like. Nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyethylene glycol fatty acid esters, ethylene oxide propylene oxide block copolymers, polyoxyethylene fatty acid amides, ethylene oxide-propylene oxide copolymers, etc. Examples thereof include compounds having an oxyethylene structure and sorbitan derivatives such as polyoxyethylene sorbitan fatty acid esters. Examples of amphoteric emulsifiers include lauryl betaine and lauryl dimethylamine oxide.

  And compounds having protective colloid action, modified waxes, high acid value acid-modified compounds, water-soluble polymers include polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, modified starch, Polyvinylpyrrolidone, polyacrylic acid and salts thereof, carboxyl group-containing polyethylene wax, carboxyl group-containing polypropylene wax, carboxyl group-containing polyethylene-propylene wax, etc., acid-modified polyolefin waxes having a number average molecular weight of usually 5000 or less and salts thereof, acrylic acid -Maleic anhydride copolymer and salts thereof, styrene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid copolymer, isobutylene-maleic anhydride A carboxyl group-containing polymer having an unsaturated carboxylic acid content of 10% by mass or more, such as an acid alternating copolymer, a (meth) acrylic acid- (meth) acrylic acid ester copolymer, and a salt thereof, polyitaconic acid and a salt thereof, amino Examples thereof include water-soluble acrylic copolymers having a group, gelatin, gum arabic, and casein, and compounds generally used as fine particle dispersion stabilizers.

  Examples of basic compounds include ammonia, triethylamine, N, N-dimethylethanolamine, isopropylamine, aminoethanol, dimethylaminoethanol, diethylaminoethanol, ethylamine, diethylamine, isobutylamine, dipropylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, n-butylamine, 2-methoxyethylamine, 3-methoxypropylamine, 2,2-dimethoxyethylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine , Pyrrole, pyridine and the like. As a compounding quantity of a basic compound, it is preferable that it is 0.5-10 times equivalent with respect to the carboxyl group in polyolefin resin, 0.8-5 times equivalent is more preferable, 0.9-3.0 times Equivalent weight is particularly preferred. When the amount is less than 0.5 times equivalent, the addition effect of the basic compound is not recognized, and when the amount exceeds 10 times equivalent, the drying time during the formation of the adhesive layer is prolonged or the stability of the aqueous dispersion is lowered. There is.

  When preparing an aqueous dispersion of a polyolefin resin, it is preferable to add an organic solvent at the time of aqueous formation from the viewpoint of promoting the aqueous formation of the polyolefin resin and reducing the dispersed particle diameter.

  As content of an organic solvent, 50 mass% or less is preferable with respect to the whole aqueous medium, It is more preferable that it is 1-45 mass%, 2-40 mass% is further more preferable, 3-35 mass% is especially preferable. When the content of the organic solvent exceeds 50% by mass, the stability of the aqueous dispersion may be lowered depending on the organic solvent used.

  As the organic solvent, from the viewpoint of obtaining an aqueous dispersion having good dispersion stability, the solubility in water at 20 ° C. is preferably 10 g / L or more, more preferably 20 g / L or more, and 50 g / L or more. Is more preferable.

  As the organic solvent, those having a boiling point of 150 ° C. or less are preferable from the viewpoint of efficiently removing them from the adhesive layer in the course of film formation. An organic solvent having a boiling point exceeding 150 ° C. tends to be difficult to scatter from the adhesive layer by drying, and in particular, the adhesion of the adhesive layer and the content resistance of the laminate may be deteriorated. Preferred organic solvents include, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol. , Alcohols such as 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol and cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone and cyclohexanone, ethers such as tetrahydrofuran and dioxane , Ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate , Esters such as ethyl propionate, diethyl carbonate, dimethyl carbonate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, glycol derivatives such as ethylene glycol ethyl ether acetate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate, 1,2 -Dimethyl glycerol, 1, 3- dimethyl glycerol, a trimethyl glycerol, etc. are mentioned. In the production method of the present invention, a plurality of these organic solvents may be mixed and used.

  Among the above organic solvents, ethanol, n-propanol, isopropanol, n-butanol, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether are resins. It is more effective and effective in promoting aqueous formation.

  A method for obtaining an aqueous dispersion of a polyolefin resin is not particularly limited, but a container capable of sealing the above-described components, that is, a polyolefin resin, an aqueous medium, an organic solvent, a basic compound, and the like as necessary. Among them, a method of heating and stirring can be adopted, and this method is most preferable.

  As a container, a well-known solid / liquid stirring apparatus and an emulsifier can be used, It is preferable to use the apparatus which can pressurize 0.1 Mpa or more. The stirring method and the rotation speed of the stirring are not particularly limited, but may be stirring at a low speed such that the resin is in a floating state in the aqueous medium. High-speed stirring (for example, 1000 rpm or more) is not essential, and an aqueous dispersion can be prepared with a simple apparatus.

  For example, raw materials such as a polyolefin resin and an aqueous medium are charged into the above apparatus, and the mixture is preferably stirred and mixed at a temperature of 40 ° C. or lower. Next, while maintaining the temperature in the tank at 70 to 240 ° C., preferably 100 to 220 ° C., more preferably 100 to 200 ° C., particularly preferably 110 to 190 ° C., preferably until there are no coarse particles (for example, Continue stirring (5 to 300 minutes). Here, when the temperature in the tank is less than 70 ° C., it becomes difficult to make the polyolefin resin water-based. On the other hand, when the temperature in the tank exceeds 240 ° C., the molecular weight of the polyolefin resin may decrease.

  In this method, a basic compound, an organic solvent, and water may be added as appropriate, and the ratio at that time may be appropriately determined according to the desired solid content concentration, particle size, degree of dispersion, and the like. The method of adding a basic compound, an organic solvent, or water is not particularly limited, and there are a method of adding under pressure using a gear pump, a method of lowering the temperature in the system, and then opening and adding. The total amount of the basic compound, organic solvent or water to be added is preferably adjusted so that the solid content concentration after mixing is 1 to 50% by mass, more preferably 2 to 45% by mass, An amount of 3 to 40% by mass is particularly preferred.

  When the above organic solvent is used at the time of preparation of the aqueous dispersion, after the resin is made aqueous, a part thereof is distilled out of the system by a solvent removal process generally called “stripping”. The content may be reduced. By stripping, the content of the organic solvent in the aqueous dispersion can be set to 10% by mass or less, and if it is set to 5% by mass or less, it is environmentally preferable. In the stripping process, it is possible to distill off substantially all of the organic solvent used to make the aqueous solution, but it is necessary to increase the degree of vacuum of the equipment and lengthen the operation time. In consideration, the lower limit of the organic solvent content is preferably about 0.01% by mass. However, even if it is less than 0.01% by mass, there is no particular influence on performance, and there is no problem in use.

  Examples of the stripping method include a method in which the aqueous dispersion is heated with stirring at normal pressure or reduced pressure to distill off the organic solvent. Further, since the solid content concentration is increased by distilling off the aqueous medium, for example, in the case where the viscosity increases and the workability deteriorates, water may be added to the aqueous dispersion in advance. Good.

  Examples of the method for adjusting the solid content concentration of the aqueous dispersion thus obtained include a method in which the aqueous medium is distilled off or diluted with water so as to obtain a desired solid content concentration.

  By adopting the above preparation method, the polyolefin resin is efficiently dispersed or dissolved in the aqueous medium, and can be prepared in a uniform liquid state. Here, the uniform liquid state means that, in terms of appearance, a portion where the solid content concentration is locally different from other portions such as precipitation, phase separation or skinning is not found in the aqueous dispersion. Say.

  As described above, a liquid material for forming the adhesive layer can be prepared. Thereafter, this liquid material is applied to the surface of the base material layer. A conventionally well-known method can be employ | adopted as a coating method at this time. Examples include gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, and brushing. In addition, as above-mentioned, it is preferable that the base material layer application surface is surface-activation-processed, and it is preferable that the form of a liquid substance is an aqueous dispersion. In addition, an undercoat layer may be provided on the base material layer application surface as necessary.

  By such a method, the liquid material can be uniformly applied to the surface of the base material layer or the surface of the undercoat layer provided on the surface. And after setting to near room temperature as needed, a uniform contact bonding layer can be formed on a resin film by using for the drying process or the heat processing for drying.

  As a heating device at this time, a normal hot air circulation type oven, an infrared heater, or the like may be used. Further, the heating temperature and the heating time may be appropriately determined in consideration of the characteristics of the resin film to be coated and the various organic solvents and additives that can be arbitrarily added to the liquid. As an example, from the economical viewpoint, the heating temperature is preferably 30 to 250 ° C, more preferably 60 to 180 ° C, and particularly preferably 80 to 150 ° C. On the other hand, the heating time is preferably 1 second to 20 minutes, more preferably 5 seconds to 60 seconds, and particularly preferably 5 seconds to 30 seconds.

  Furthermore, when applying a liquid material to the substrate surface, it may be applied to a biaxially stretched film, followed by drying and heat treatment. Also, the substrate during the manufacturing process, that is, unstretched before the orientation is completed The liquid may be applied to the film or the film after uniaxial stretching, and the orientation may be completed by stretching after drying or simultaneously with drying. From the viewpoint of cost, the above-mentioned unstretched film or the film after uniaxial stretching is coated with a liquid material, dried, and stretched and oriented, so that the adhesive layer can be laminated simultaneously with the formation of the substrate. preferable. Further, after providing the adhesive layer as described above, a barrier material may be provided separately.

  Conventionally, polypropylene resin has excellent properties as a sealant resin, as described above, and is excellent in adhesion, content resistance, retort resistance, boil resistance, and tearing properties by using an extrusion laminate method. It was difficult to obtain a laminate. However, according to the production method of the present invention, a laminate having excellent adhesion, content resistance, retort resistance, boil resistance, and tearing properties can be obtained even when the extrusion laminating method is used.

  Specifically, when the sealant resin containing polypropylene is melt-extruded from the T die for forming the sealant layer, the resin temperature immediately after being extruded from the T die is preferably set to 230 to 300 ° C. In particular, from the viewpoint of suppressing thermal decomposition of polypropylene, the resin temperature is desirably low, and preferably 230 to 270 ° C. Furthermore, it is more preferable that it is 240-260 degreeC from a viewpoint of improving adhesiveness and suppressing thermal decomposition.

  In the present invention, when laminating the sealant resin (sealant layer) containing polypropylene through the adhesive layer as described above, an extrusion laminating method is preferably employed. However, the sealant resin can be adhered with good adhesion even by a method other than the extrusion laminating method. Any other method may be employed as long as it can be stacked. Examples of methods other than the extrusion laminating method include a method of laminating an adhesive layer and a resin film containing polypropylene by heat (dry laminating method).

  After the sealant resin is laminated on the surface of the adhesive layer, it may be subjected to an aging treatment for the purpose of improving the adhesion, content resistance, retort resistance, boil resistance and tearing properties of the obtained laminate. The aging treatment is preferably performed at a temperature of about room temperature to about 100 ° C., more preferably performed at 30 to 60 ° C. from the viewpoint of heat damage to the laminate and economic efficiency, and further performed at 40 to 50 ° C. preferable.

  The laminate strength of the laminate can be evaluated by performing a T-type peel test under a tensile strength of 200 mm / min in an atmosphere of 20 ° C. and 65% RH using a tensile tester. At this time, if the laminate strength is 1.5 N / 15 mm or more, it is preferably at a level that is not problematic for use as a packaging material, more preferably 2.0 N / 15 mm or more. When the laminate strength is very high, the sealant layer is stretched or cut at the time of measurement and cannot be peeled off, so that an accurate laminate strength may not be measured. Such a phenomenon can be said to be the most preferable state as a laminated state and supports excellent adhesiveness. Further, the laminate strength is preferably maintained at 1.5 N / 15 mm or more after storage of the contents or after the retort treatment and the boil treatment, and most preferably the laminate strength is not lowered.

  The laminate of the present invention can be used for various applications, and is particularly suitable for packaging materials. When using the laminated body of this invention as a packaging material, the content is not specifically limited, It can apply to arbitrary things, such as a liquid, a viscous body, powder, solid, or these combination. The laminate of the present invention is particularly suitable as a packaging material for food, for example, potato chips, cookies, biscuits, chocolate snacks, rice crackers, hail, popcorn-like snacks, curry, coconut, stew, soup, rice cake, pasta. Retort food such as sauce, cooking sauce, rice cake, rice cooker, rice, oden, hamburger, meatball, yakitori, meat potato, sour pork, mapo tofu, boiled vegetable, zenzai, baby food, liquid food , Konjac, chikuwa, koji, koji, smoked foods such as ham, sausage, marine products, dried products such as tea, bonito, kelp powder soup, ketchup, spices, sauce, soy sauce, vinegar, miso, soup Seasonings, breads, noodles, frozen foods, pickles, boiled fish, luxury foods, salad oils, edible oils, sesame oil, olives Oil, margarine is suitable oils and fats such as butter packaging material to contents. In addition, the laminate of the present invention can be used for agrochemicals, insecticides, insecticides, poultices, toothpastes, tablets (medicinal products) such as tablets, fragrances, fragrances, bathing agents, cosmetics, toiletry products, and surfactants. For packaging materials containing industrial products such as toiletries, shampoos, rinses, deodorants, toiletries such as detergents, miscellaneous goods, secondary batteries, electrolytes, electronic parts, ICs, mechanical parts, etc. Is preferred.

  In conventional packaging materials, if moisture, volatile substances, permeable substances or irritating substances contained in the contents penetrate into the adhesive layer in the packaging material, the adhesiveness of the packaging material decreases with time, sometimes both. There was a phenomenon in which the layers were peeled off (delamination) and the packaging material was damaged. However, since the laminate of the present invention is excellent in content resistance characteristics, if such a laminate is used, it is possible to provide a packaging material in which adhesiveness is hardly lowered even when such a content is wrapped.

  Moreover, in the conventional packaging material, the adhesiveness of packaging material fell with time by the hot water and high-pressure steam of retort processing and boil processing, and the phenomenon that a packaging material was damaged by delamination sometimes was seen. Moreover, even if the adhesiveness fall by retort processing or boil processing was suppressed, there existed a problem that the tearing characteristic at the time of opening was inferior, and the content was easy to spill. However, since the laminate of the present invention is excellent in retort resistance and boil resistance, if such a laminate is used, the adhesiveness is hardly lowered even if retort treatment or boil treatment is performed, and the tear property is also excellent. Packaging materials can be provided.

  When making a packaging material using the laminate of the present invention, the form of the packaging material includes a vertical bag filling seal bag, a three-side seal bag, a four-side seal bag, a gusset packaging bag, a jointed bag, a pillow packaging bag, Laminated tube containers, infusion bags, cup-shaped containers and container lids, gable-top containers, brick containers, pouches with spouts, stand-up pouches, composite cans, etc., and the innermost sealant layer is polypropylene A resin-made chuck can be provided to form a packaging bag with a chuck, or to have a window so that the contents can be seen. Moreover, you may add a corner cut, a crease | fold, etc. with respect to the said bag as needed.

  Moreover, the easy-open technique may be given to the laminated body of this invention, if the tearing characteristic is not impaired by the combination with this invention. Examples of the easy-opening technology include, for example, using a thermoplastic resin film having linear tearability in a specific layer or a plurality of layers of a laminate, providing through holes and / or non-through holes on a straight line or the entire surface, or reducing the thickness. In addition to techniques for providing processing, there are notching and perforation. It does not specifically limit as a manufacturing method of the thermoplastic resin film which has linear tearability, A well-known manufacturing method is employable. As a commercial item of the thermoplastic resin film which has a linear tearability, the emblem NC by the Unitika company, emblet PC, Uniathlon TB by Idemitsu Petrochemical Co., Ltd., etc. are mentioned, for example.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Various characteristics were measured or evaluated by the following methods.

1. Polyolefin resin (1) Content of unsaturated carboxylic acid unit The content was determined by infrared absorption spectrum analysis (Perkin Elmer System-2000 Fourier transform infrared spectrophotometer, resolution 4 cm ⁻¹ ).
(2) Constitution of Resin Other than Unsaturated Carboxylic Acid Unit ¹ H-NMR and ¹³ C-NMR analysis (manufactured by Varian, 300 MHz) was performed at 120 ° C. in orthodichlorobenzene (d ₄ ). ^{In 13} C-NMR analysis, measurement was performed based on a gated decoupling method in consideration of quantitativeness.
(3) Weight average molecular weight of resin The weight average molecular weight was measured using a GPC apparatus (HLC-8020 manufactured by Tosoh Corp., and two KF-804L columns and one KF805L column manufactured by SHODEX were used as the column) and tetrahydrofuran as an eluent. Was measured under the conditions of a flow rate of 1 ml / min and 40 ° C. About 10 mg of resin was dissolved in 5.5 mL of tetrahydrofuran and filtered through a PTFE membrane filter as a measurement sample. The weight average molecular weight was determined from a calibration curve prepared with a polystyrene standard sample. When it was difficult to dissolve in tetrahydrofuran, it was dissolved in orthodichlorobenzene.

2. Laminated body (1) Amount of adhesive layer (application amount)
An aqueous dispersion containing a polyolefin resin and a crosslinking agent and / or a polyurethane resin was applied to a substrate whose area and mass were measured in advance, and dried at 100 ° C. for 1 minute. The mass of the obtained laminate was measured, and the coating amount was determined by subtracting the mass of the base material before coating. The coating amount per unit area (g / m ² ) was calculated from the coating amount and the coating area.
(2) Laminate strength A test piece having a width of 15 mm was taken from the obtained laminate, and from the end of the test piece by T-type peeling using a tensile tester (manufactured by Intesco, precision universal material tester type 2020). The interface between the substrate and the sealant layer was peeled off and the strength was measured. The measurement was performed in an atmosphere of 20 ° C. and 65% RH at a tensile speed of 200 mm / min.
(3) Content resistance characteristics Using two 10cm square laminates, with the sealant layer of the laminate as the inside, filled with 5g of salad oil as the contents, and heat-sealed the four sides of the laminate with a seal width of 1cm The material was made. This was stored at 40 ° C. After 1 month, the sealed packaging material was opened, and in the same manner as in (2) above, a test piece of the laminate was collected from the packaging material, and the laminate strength was measured. The laminate strength at this time is preferably 1.5 N / 15 mm or more, and more preferably less changed compared to (2).
(4) Retort resistance test Packaging material using two 10cm square laminates, with the sealant layer of the laminate as the inner side and filling 40g of water as the contents, and heat-sealing all sides of the laminate with a seal width of 1cm Was made. Thereafter, the sample was retorted at 125 ° C. for 30 minutes in an autoclave. After the treatment, when the sealed packaging material was opened, the tear characteristics when the cut was cut and manually torn were evaluated using the following indices.
A: Less resistance and smooth opening.
○: There is a little resistance, and the opening is slightly distorted.
×: High resistance and heavy opening feeling. Or the sealant is stretched and difficult to open.
Further, in the same manner as in the above (2), a laminate test piece was collected from the packaging material, and the laminate strength was measured. The laminate strength at this time is preferably 1.5 N / 15 mm or more, and more preferably less changed compared to (2).
(5) Boil resistance test Using two 10 cm square laminates, with the sealant layer of the laminate inside, filling 40 g of water as the contents, and heat-sealing all sides of the laminate with a seal width of 1 cm. Was made. Thereafter, the sample was boiled in boiling water for 30 minutes. After the treatment, the sealed packaging material was opened, and a laminate test piece was taken from the packaging material in the same manner as in (2) above, and the laminate strength was measured. The laminate strength at this time is preferably 1.5 N / 15 mm or more, and more preferably less changed compared to (2).

(Production Example 1: Production of polyolefin resin P-1)
280 g of propylene-butene copolymer (mass ratio: propylene / 1-butene = 80/20) was dissolved in 470 g of xylene under a nitrogen atmosphere in a four-necked flask, and the system temperature was kept at 140 ° C. Under stirring, 40.0 g of maleic anhydride as an unsaturated carboxylic acid and 28.0 g of dicumyl peroxide as a radical generator were added over 2 hours, respectively, and then reacted for 6 hours. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate a resin. This resin was dried under reduced pressure in a vacuum dryer to obtain polyolefin resin P-1.

(Production of polyolefin resins P-2, P-7, P-8)
Production examples except that the mass ratio of propylene / 1-butene was changed to propylene / 1-butene = 65/35 (P-2), 97/3 (P-7), and 50/50 (P-8), respectively. Polyolefin resins P-2, P-7 and P-8 were obtained in the same manner as in Example 1.

(Production of polyolefin resin P-3)
A polyolefin resin P-3 was obtained in the same manner as in Production Example 1, except that a propylene-ethylene copolymer (mass ratio: propylene / ethylene = 92/8) was used instead of the propylene-butene copolymer. .

(Production of polyolefin resin P-4)
The same as Production Example 1 except that the amount of maleic anhydride added was changed to 26.0 g instead of 40.0 g, and the amount of dicumyl peroxide added was changed to 50.0 g instead of 28.0 g. Polyolefin resin P-4 was obtained by this method.

(Manufacture of polyolefin resin P-5)
The same as in Production Example 1 except that the amount of maleic anhydride added is 48.0 g instead of 40.0 g, and the amount of dicumyl peroxide added is 13.0 g instead of 28.0 g. Polyolefin resin P-5 was obtained by this method.

(Manufacture of polyolefin resin P-6)
The same as Production Example 1 except that the amount of maleic anhydride added is 65.0 g instead of 40.0 g, and the amount of dicumyl peroxide added is 7.0 g instead of 28.0 g. Polyolefin resin P-5 was obtained by this method.

(Production of polyolefin resin P-9)
The same as in Production Example 1 except that the amount of maleic anhydride added is 4.8 g instead of 40.0 g, and the amount of dicumyl peroxide added is 9.3 g instead of 28.0 g. Polyolefin resin P-9 was obtained by this method.

(Production of polyolefin resin P-10)
Same as Production Example 1 except that the addition amount of dicumyl peroxide is 35.0 g instead of 40.0 g and that the addition amount of dicumyl peroxide is 70.0 g instead of 28.0 g Polyolefin resin P-10 was obtained by the method.

  The properties of the polyolefin resins P-1 to P-10 obtained above are shown in Table 1.

(Preparation Example 1)
Using a stirrer equipped with a heat-resistant 1 L glass container with a heater, 60.0 g polyolefin resin (P-1), 45.0 g ethylene glycol monobutyl ether (manufactured by Wako Pure Chemical Industries, Ltd.), 8.0 g N, N-dimethylethanolamine and 137.0 g of distilled water were charged in a glass container and stirred at a rotation speed of the stirring blade of 300 rpm. It was confirmed that Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 160 ° C. and further stirred for 60 minutes. Thereafter, it is cooled by air cooling until the internal temperature becomes 80 ° C., opened, and 45.0 g of tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.), 5.0 g of N, N-dimethylethanolamine and 30.0 g of distillation. Water was added. Thereafter, the mixture was sealed, and the stirring speed was 300 rpm, the system temperature was kept at 140 ° C., and the mixture was further stirred for 60 minutes. Then, after cooling to room temperature (about 25 ° C.) while stirring with air rotation at 300 rpm, pressure filtration (air pressure 0.2 MPa) is performed with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave). A slightly cloudy aqueous dispersion E-1 was obtained. At this time, almost no resin remained on the filter.

(Preparation Examples 2-5, 7-10)
Aqueous dispersions E-2 to 5 and 7 to 10 were obtained in the same manner as in Preparation Example 1, except that P-2 to 5 and 7-10 were used as the polyolefin resin. In Preparation Example 9 (E-9) using P-9, a stable dispersion could not be obtained.

(Preparation Example 6)
An aqueous dispersion E-6 was obtained in the same manner as in Preparation Example 1, except that P-6 was used as the polyolefin resin and the amount of the polyolefin resin was changed to 30.0 g instead of 60.0 g.

Example 1
First, the polyolefin resin aqueous dispersion E-1 and an aqueous solution of an oxazoline group-containing compound (Nippon Shokubai Co., Ltd., Epocros WS-700) are used, and the content of the oxazoline group-containing compound is 10 masses per 100 mass parts of the polyolefin resin. Aqueous dispersion was prepared by mixing to make parts. Next, a 12 μm-thick biaxially stretched polyester resin film (Embret, manufactured by Unitika Co., Ltd.) is prepared, and the aqueous dispersion is applied onto the corona discharge treated surface of the polyester resin film using a gravure coater. It apply | coated so that the quantity might be 0.5 g / m < ² >, Then, it dried at 100 degreeC for 10 second, and formed the contact bonding layer. Then, using an extrusion laminator, polypropylene (Novatech PP FL02A manufactured by Nippon Polypro Co., Ltd.) was melt-extruded as a sealant resin on the surface of the adhesive layer to obtain a laminate in which a sealant layer composed of a 30 μm polypropylene layer was formed. At this time, the temperature of the sealant resin extruded from the T-die was 240 ° C.

(Examples 2, 3, 8, Comparative Examples 7-9)
Instead of aqueous polyolefin resin dispersion E-1, aqueous polyolefin resin dispersion E-2 (Example 2), E-3 (Example 3), E-6 (Example 8), E-7 (Comparative Example) 7), E-8 (Comparative Example 8) and E-10 (Comparative Example 9) were used, respectively, and a laminate was obtained in the same manner as in Example 1.

Example 4
Except for using the polyolefin resin aqueous dispersion E-4 instead of the polyolefin resin aqueous dispersion E-1 and changing the content of the oxazoline group-containing compound to 5 parts by mass with respect to 100 parts by mass of the polyolefin resin, A laminate was obtained in the same manner as in Example 1.

(Examples 5-7)
The polyolefin resin aqueous dispersion E-5 was used in place of the polyolefin resin aqueous dispersion E-1, and the content of the oxazoline group-containing compound was 20 parts by mass with respect to 100 parts by mass of the polyolefin resin (Example 5), A laminate was obtained in the same manner as in Example 1 except that the amount was 1 part by mass (Example 6) and 50 parts by mass (Example 7).

(Examples 9, 10 and Comparative Examples 12 and 13)
Using an aqueous solution of a carbodiimide group-containing compound (Nisshinbo Co., Ltd., Carbodilite V-02-L2) instead of the aqueous solution of the oxazoline group-containing compound, the content of the carbodiimide group-containing compound with respect to 100 parts by mass of the polyolefin resin Example 1 is the same as Example 1 except that 30 parts by mass (Example 9), 1 part by mass (Example 10), 0.5 part by mass (Comparative Example 12), and 60 parts by mass (Comparative Example 13), respectively. A laminate was obtained by this method.

(Examples 11 and 12)
The polyolefin resin aqueous dispersion E-2 was used instead of the polyolefin resin aqueous dispersion E-1, and the content of the carbodiimide group-containing compound was 30 parts by mass with respect to 100 parts by mass of the polyolefin resin (Example 11). A laminate was obtained in the same manner as in Example 9, except that the amount was 1 part by mass (Example 12).

(Example 13, Comparative Examples 14 and 15)
Instead of the aqueous solution of the oxazoline group-containing compound, a 10% by mass aqueous solution of an isocyanate group-containing compound (BASF Corporation, Vasonate HW-100, solid content concentration: 100% by mass) was used. The same method as in Example 1 except that it was 25 parts by mass (Example 13), 0.5 part by mass (Comparative Example 14), and 60 parts by mass (Comparative Example 15) with respect to 100 parts by mass of the polyolefin resin. A laminate was obtained.

(Examples 14 and 15, Comparative Examples 16 and 17)
Instead of the aqueous solution of the oxazoline group-containing compound, an aqueous polyurethane resin dispersion (manufactured by Mitsui Chemicals, Takelac W-6010) was used, and the polyurethane resin content was 1 part by mass with respect to 100 parts by mass of the polyolefin resin ( Example 14), 50 parts by mass (Example 15), 0.5 parts by mass (Comparative Example 16), 350 parts by mass (Comparative Example 17). Obtained.

(Examples 16 and 17)
The polyolefin resin aqueous dispersion E-2 was used in place of the polyolefin resin aqueous dispersion E-1, and the polyurethane resin content was 100 parts by mass (Example 16) and 300 parts by mass with respect to 100 parts by mass of the polyolefin resin. A laminate was obtained in the same manner as in Example 14 except that the part (Example 17) was used.

(Example 18)
Epocros WS-700 and Carbodilite V-02-L2 were added so that the content of the oxazoline group-containing compound was 5 parts by mass and the content of the carbodiimide group-containing compound was 30 parts by mass with respect to 100 parts by mass of the polyolefin resin. A laminate was obtained in the same manner as in Example 1 except that the aqueous dispersion was mixed.

(Example 19)
Example 18 except that the content of the oxazoline group-containing compound was changed to 10 parts by mass with respect to 100 parts by mass of the polyolefin resin, and the content of the carbodiimide group-containing compound was changed to 1 part by mass with respect to 100 parts by mass of the polyolefin resin. A laminate was obtained in the same manner as above.

(Example 20)
Epocros WS-700 and Takelac W-6010 are mixed with water so that the content of the oxazoline group-containing compound is 10 parts by mass and the content of the polyurethane resin is 100 parts by mass with respect to 100 parts by mass of the polyolefin resin. A laminate was obtained in the same manner as in Example 1 except that the dispersion was used.

(Example 21)
The same as Example 20 except that the content of the oxazoline group-containing compound was changed to 15 parts by mass with respect to 100 parts by mass of the polyolefin resin, and the content of the polyurethane resin was changed to 30 parts by mass with respect to 100 parts by mass of the polyolefin resin. Thus, a laminate was obtained.

(Example 22)
Carbodilite V-02-L2 and Takelac W-6010 are mixed so that the content of the carbodiimide group-containing compound is 1 part by mass and the content of the polyurethane resin is 100 parts by mass with respect to 100 parts by mass of the polyolefin resin. A laminate was obtained in the same manner as in Example 1 except that the aqueous dispersion was used.

(Example 23)
The same as Example 22 except that the content of the carbodiimide group-containing compound was changed to 30 parts by mass with respect to 100 parts by mass of the polyolefin resin, and the content of the polyurethane resin was changed to 30 parts by mass with respect to 100 parts by mass of the polyolefin resin. Thus, a laminate was obtained.

(Examples 24 to 30)
Example 1 except that instead of the biaxially stretched polyester resin film, a 15 μm thick biaxially stretched nylon film (Emblem, manufactured by Unitika Co., Ltd.) was used, the aqueous dispersion was applied to the corona discharge treated surface of the nylon film. The laminated body (Examples 24-30) was obtained by the method similar to -3, 9, 11, 15, 16.

(Examples 31-38)
Using a biaxially stretched polyester resin film (Uniteka, Emblet) with a thickness of 12 μm and using a gravure coater, a two-component curing type polyurethane adhesive (manufactured by Toyo Morton) on the corona surface of the polyester resin film Was coated and dried so that the coating amount after drying was 5 g / m ² to obtain a base material on which an aluminum foil having a thickness of 7 μm was bonded.

  A laminate (in the same manner as in Examples 1 to 3, 9, 11, 13, 15, and 16 except that the above base material was used instead of the biaxially stretched polyester resin film and an adhesive layer was provided on the aluminum surface. Examples 31-38) were obtained.

(Example 39)
Using an extruder equipped with a T-die (slow compression type single screw with a diameter of 75 mm and L / D of 45), a polyethylene terephthalate resin (manufactured by Nihon Ester Co., Ltd., intrinsic viscosity 0.6) is treated with a cylinder temperature of 260 ° C., T Extruded into a sheet at a die temperature of 280 ° C., and then brought into close contact with a cooling roll adjusted to a surface temperature of 25 ° C. and rapidly cooled to obtain an unstretched film having a thickness of 120 μm.

Subsequently, the unstretched film was stretched 3.4 times in the longitudinal direction at 90 ° C., and then the aqueous dispersion used in Example 1 was dried on the film surface using a gravure coater, and the coating amount after stretching was 0. The film was applied so as to be ² g / m ² , preheated at a temperature of 90 ° C. for 2 seconds, and then stretched 3.5 times in the transverse direction. The total thickness of the obtained polyester film and the adhesive layer was 12 μm.

  Thereafter, a sealant layer was laminated in the same manner as in Example 1 to obtain a laminate.

(Example 40)
A laminate was obtained in the same manner as in Example 39 except that the aqueous dispersion used in Example 9 was used as the aqueous dispersion.

(Example 41)
A laminate was obtained in the same manner as in Example 39 except that the aqueous dispersion used in Example 13 was used as the aqueous dispersion.

(Example 42)
A laminate was obtained in the same manner as in Example 39 except that the aqueous dispersion used in Example 15 was used as the aqueous dispersion.

(Comparative Examples 1 and 2)
A laminate (Comparative Examples 1 and 2) was obtained in the same manner as in Examples 1 and 5 except that the oxazoline group-containing compound in the aqueous dispersion was omitted.

(Comparative Examples 3-6)
Laminated bodies (Comparative Examples 3 to 6) were obtained in the same manner as in Examples 1, 9, 13, and 14 except that the polyolefin resin in the aqueous dispersion was omitted.

(Comparative Examples 10 and 11)
In the same manner as in Example 1, except that the content of the oxazoline group-containing compound was 0.5 parts by mass (Comparative Example 10) and 60 parts by mass (Comparative Example 11) with respect to 100 parts by mass of the polyolefin resin, respectively. A laminate was obtained.

(Comparative Examples 18 and 22)
A laminate (Comparative Examples 18 and 22) was obtained in the same manner as in Examples 24 and 31, respectively, except that the oxazoline group-containing compound in the aqueous dispersion was omitted.

(Comparative Examples 19-21, 23-26)
A laminate (Comparative Examples 19-21, 23-26) was obtained in the same manner as in Examples 24, 27, 29, 31, 34, 36, and 37, respectively, except that the polyolefin resin in the aqueous dispersion was omitted. .

(Comparative Example 27)
A laminate was prepared in the same manner as in Example 1 except that polyethylene (Novatec LD LC600A, manufactured by Nippon Polyethylene Co., Ltd.) was melt-extruded on the surface of the adhesive layer as a sealant resin to form a sealant layer composed of a 30 μm polyethylene layer. Obtained. At this time, the temperature of the sealant resin extruded from the T-die was 270 ° C.

(Comparative Example 28)
A laminate was prepared in the same manner as in Example 31 except that polyethylene (Novatec LD LC600A, manufactured by Nippon Polyethylene Co., Ltd.) was melt-extruded on the surface of the adhesive layer as a sealant resin to form a sealant layer composed of a 30 μm polyethylene layer. Obtained. At this time, the temperature of the sealant resin extruded from the T-die was 270 ° C.

  Table 2 shows the properties of the laminates obtained in Examples 1 to 42.

  Table 3 shows the characteristics of the laminates obtained in Comparative Examples 1 to 28.

  As shown in Table 2, the laminates obtained in Examples 1 to 42 are excellent in adhesion, content resistance, retort resistance, boil resistance, and tearing properties, and are suitable for various packaging materials. It was usable. In addition, the manufacturing process is stable and advantageous in terms of cost.

On the other hand, as shown in Table 3, in the case of the laminate lacking the configuration of the present invention, that is, when the adhesive layer is composed only of the polyolefin resin (Comparative Examples 1, 2, 18, and 22), only the crosslinking agent or the polyurethane resin. When the adhesive layer is configured (Comparative Examples 3-6, 19-21, 23-26), the composition and molecular weight of the polyolefin resin do not satisfy the configuration of the present invention (Comparative Examples 7-9), the polyolefin resin, When the content ratio of the crosslinking agent and the polyurethane resin does not satisfy the configuration in the present invention (Comparative Examples 10 to 17), the laminate strength of the laminate is low, and the content resistance, retort resistance, and boil resistance are all low. The tear properties were inferior. Therefore, it was unsuitable for use as a laminate for packaging materials.
When polyethylene is used as the sealant resin (Comparative Examples 27 to 28), the laminate has sufficient laminate strength, but is inferior in content resistance, retort resistance, boil resistance, and tearing properties. It was unsuitable for use as a laminate.

Claims (7)

  At least a base material layer, an adhesive layer, and a sealant layer containing polypropylene are laminated in this order, and the adhesive layer comprises 100 parts by mass of a polyolefin resin, 0 to 50 parts by mass of a crosslinking agent, and 0 polyurethane resin. ~ 300 parts by mass (however, any one of the components is contained in an amount of 1 part by mass or more), and the polyolefin resin contains the propylene component (A) and the olefin component (B) other than the propylene component as the olefin component. The ratio (A / B) is in the range of 60/40 to 95/5, and 0.1 to 10 parts by mass of unsaturated carboxylic acid unit is contained with respect to 100 parts by mass in total of (A) + (B). And the weight average molecular weight of the said polyolefin resin is 15000 or more, The laminated body characterized by the above-mentioned.   The laminate according to claim 1, wherein the olefin component (B) other than the propylene component is a butene component.   The laminate according to claim 1 or 2, wherein the crosslinking agent is a compound containing an oxazoline group and / or a compound containing a carbodiimide group. The amount of the adhesive layer, the laminated body according to any one of claims 1 to 3, characterized in that in the range of 0.001 to 5 g / ^{m 2.}   The laminate according to any one of claims 1 to 4, wherein the substrate layer is any one of a polyester film, a polyamide film, an aluminum foil, an aluminum vapor deposition film, and an inorganic compound vapor deposition film.   The method for producing a laminate according to any one of claims 1 to 5, wherein the melted sealant resin is laminated on the surface of the adhesive layer formed on the base material layer by extrusion lamination.   The adhesive layer is formed by applying and drying an aqueous dispersion containing a polyolefin resin and a crosslinking agent and / or a polyurethane resin on the surface of the base material layer. The manufacturing method of the laminated body of 6.