JP2013028084A - Film laminate for extrusion lamination and method for manufacturing thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film laminate that has a resin layer excellent in the solvent resistance on the biaxially stretched film, can obtain excellent content resistance and adhesion even if the heat seal resin is accumulated on the resin layer by the extrusion lamination and also is excellent in the environmental compatibility.SOLUTION: In the film laminate, the resin layer that contains the acid-modified polyolefin resin (A), polyurethane resin (B), and crosslinking agent (C) is formed at least one side of the biaxially stretched film, and in the film laminate for the extrusion lamination, the crosslinking agent (C) contains the oxazoline system crosslinking agent (C1), wherein the mass ratio of (A) and (B), ((A)/(B)) is 60/40-97/3, and (C) is 1-20 pts.mass based on 100 pts.mass of total of (A) and (B).

Description

  The present invention relates to a film laminate for extrusion lamination in which a resin layer containing an acid-modified polyolefin resin, a polyurethane resin, and an oxazoline-based crosslinking agent is formed on at least one surface of a biaxially stretched film.

  Polyamide biaxially stretched film typified by polycapronamide (nylon 6, N6) film and polyester biaxially stretched film typified by polyethylene terephthalate film have excellent mechanical properties, heat resistance, pinhole resistance, Due to its chemical nature, it is used in a wide range of applications. When these biaxially stretched films are used as packaging applications, in many cases, resins having heat sealing properties such as polyethylene (PE), polypropylene (PP), and ethylene-vinyl acetate copolymer (EVA) are used. Laminated on one or both sides of a biaxially stretched film, and heat-sealed to this, it is made into various packaging forms.

When laminating such a heat-sealable resin on a biaxially stretched film, (1) a method of laminating a heat-sealable resin film on a biaxially stretched film using an adhesive (dry lamination method), (2) melting A method (extrusion laminating method) in which the heat-sealable resin thus extruded is extruded on a biaxially stretched film and then cooled and solidified for lamination is generally used. In the latter case, a method of extruding and laminating the same or different types of heat-sealable resin between the biaxially stretched film and the heat-sealable resin layer, or laminating the two-axis stretched film in two stages. There are methods such as extrusion lamination.
In the extrusion laminating method of (2) above, the heat-sealable resin film is laminated on the biaxially stretched film by extruding the raw material resin directly onto the biaxially stretched film without using the heat-sealable resin film. Therefore, the cost is lower than that of the dry laminating method (1), and the number of cases employed is increasing.

  However, in this extrusion laminating method, a biaxially stretched film made of polyamide or polyester and a heat-sealable resin are essentially poor in adhesiveness, so it is common to provide an adhesive layer between the two layers. is there. At this time, as the adhesive, adhesive compounds such as organic titanate, organic isocyanate, and polyethyleneimine are generally dissolved in an organic solvent. However, the use of an organic solvent may deteriorate the working environment. Due to the danger of fire and the growing interest in environmental problems in recent years, there is a need for a method that avoids use as much as possible.

  Adhesives that do not use organic solvents (non-solvent adhesives) may be used, but the adhesive strength is generally inferior to that of the solvent type, and there is a problem with wettability when applied to films. Used only for limited purposes.

  From such a viewpoint, a technique for performing extrusion lamination on a biaxially stretched film without using an adhesive is desired.

  Patent Document 1 discloses that a resin layer containing a melamine-based crosslinking agent is laminated on a biaxially stretched film in order to impart easy adhesion performance with a heat-sealable resin layer. In recent years, performance needs have increased, and higher adhesion performance has been demanded.

  In Patent Document 2, a heat-sealable resin is extruded into a film, and then the surface thereof is subjected to ozone treatment, and this is bonded to the surface of an activated thermoplastic resin film, thereby adhering to the thermoplastic resin film. A method for expressing sex has been proposed. However, this method had to introduce special equipment for implementation.

  Patent Documents 3 and 4 describe an adhesive containing an acid-modified polyolefin resin and a polyurethane resin, and through these adhesives, a sealant resin is extruded and laminated, or various base films are bonded together. It is disclosed. However, the resin layer formed from this adhesive may have inferior solvent resistance, and the laminate film obtained by extruding the sealant resin on this resin layer is resistant to content when used for packaging applications. There was a problem that the physical properties were inferior.

JP 2004-148729 A JP 2001-246660 A JP 2008-229971 A JP 2009-286920 A

  The present invention has a resin layer having excellent solvent resistance on the biaxially stretched film, and the heat-sealable resin may be laminated on the resin layer by an extrusion lamination method. It is an object of the present invention to provide a film laminate that can obtain resistance to contents and adhesion, and is excellent in environmental compatibility.

As a result of intensive studies to solve the above problems, the present inventors solved the above problems by laminating a resin layer containing an acid-modified polyolefin resin, a polyurethane resin and a specific crosslinking agent on a biaxially stretched film. We have found out that we can do it and have reached the present invention.
That is, the gist of the present invention is as follows.
(1) A film laminate in which a resin layer containing an acid-modified polyolefin resin (A), a polyurethane resin (B) and a crosslinking agent (C) is formed on at least one side of a biaxially stretched film. ) Contains the oxazoline-based crosslinking agent (C1), the mass ratio of (A) to (B) ((A) / (B)) is 60/40 to 97/3, and (A) and (B The film laminate for extrusion lamination, wherein (C) is 1 to 20 parts by mass with respect to 100 parts by mass in total.
(2) The film laminate for extrusion lamination according to (1), further comprising a melamine-based crosslinking agent (C2) as the crosslinking agent (C).
(3) The extrusion lamination according to (1) or (2), wherein the acid-modified polyolefin resin (A) has a melt flow rate (MFR) at 190 ° C. and a load of 2160 g of 0.01 to 100 g / 10 minutes. Film laminate.
(4) An aqueous dispersion containing an acid-modified polyolefin resin (A), a polyurethane resin (B), a crosslinking agent (C) and an aqueous medium, and the crosslinking agent (C) contains an oxazoline-based crosslinking agent (C1). , (A) and (B) have a mass ratio ((A) / (B)) of 60/40 to 97/3, with respect to a total of 100 parts by mass of (A) and (B), (C ) Is 1 to 20 parts by mass.
(5) A method for producing a film laminate for extrusion lamination according to (1) above, wherein the aqueous dispersion according to (4) is applied to at least one surface of a biaxially stretched film. A method for producing a film laminate for extrusion lamination.
(6) A method for producing a film laminate for extrusion lamination according to (1) above, wherein the aqueous dispersion according to (4) is applied to at least one surface of an unstretched film or a uniaxially stretched film, A method for producing a film laminate for extrusion lamination, characterized by stretching.

  The resin layer formed on the film laminate of the present invention is excellent in solvent resistance and excellent in adhesion to heat-sealable resins such as polyethylene, so that it is practically sufficient without using an adhesive during extrusion lamination. A heat seal layer having laminate strength can be formed, and the package obtained therefrom is excellent in content resistance.

The present invention will be described in detail below.
The film laminate of the present invention is a film laminate in which a resin layer containing an acid-modified polyolefin resin (A), a polyurethane resin (B), and a crosslinking agent (C) is formed on at least one surface of a biaxially stretched film. is there.
Hereinafter, the biaxially stretched film is referred to as a “base film”, and the layer containing the acid-modified polyolefin resin (A), the polyurethane resin (B), and the crosslinking agent (C) formed on the biaxially stretched film, It may be simply referred to as “resin layer”.

(Biaxially stretched film)
In the present invention, as the resin constituting the biaxially stretched film, various thermoplastic resins can be used. Among them, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and mixtures thereof. Or polyamide resins such as polycapronamide (nylon 6), polyhexamethylene adipamide (nylon 66), poly-p-xylylene adipamide (MXD6 nylon), and mixtures thereof. These polyester films and polyamide films are excellent in moldability, processability, mechanical properties, gas barrier properties, etc., and have excellent performance as packaging materials. Moreover, you may use the laminated body containing said polyester or polyamide as a base film, or the laminated body of the film which consists of another thermoplastic resin. Although the thickness of a film is not specifically limited, The range of 5-500 micrometers is preferable.

  The biaxially stretched film can be produced by a generally known method using a thermoplastic resin as a raw material. For example, the above-mentioned polyester resin or polyamide resin is heated and melted with an extruder and extruded from a T-die and cooled and solidified by a cooling roll to obtain an unstretched film, or extruded from a circular die and solidified by water cooling or air cooling. To obtain an unstretched film. In order to produce a stretched film, a method in which an unstretched film is once wound up or continuously stretched by a simultaneous biaxial stretching method or a sequential biaxial stretching method is preferable. From the viewpoint of performance such as mechanical properties and thickness uniformity of the film, a method in which a flat film forming method using a T die and a tenter stretching method are combined is preferable.

(Acid-modified polyolefin resin)
The acid-modified polyolefin resin (A) used in the present invention is obtained by acid-modifying a polyolefin with an unsaturated carboxylic acid component. The acid-modified polyolefin resin (A) is most preferably a resin composed of three components of an unsaturated carboxylic acid or its anhydride (A1), an olefin compound (A2), and an alkyl ester (A3) of acrylic acid or methacrylic acid.

  Examples of the component (A1) include (meth) acrylic acid, maleic acid, itaconic acid, fumaric acid, and crotonic acid. The unsaturated carboxylic acid may be a derivative such as a salt, an acid anhydride, a half ester, and a half amide. Among these, acrylic acid, methacrylic acid, and (anhydrous) maleic acid are preferable, and acrylic acid and maleic anhydride are particularly preferable. Moreover, the unsaturated carboxylic acid should just be copolymerized in polyolefin resin, The form is not limited, For example, random copolymerization, block copolymerization, graft copolymerization etc. are mentioned. The maleic acid unit in the polyolefin resin containing a maleic anhydride unit is likely to have a maleic anhydride structure in which the adjacent carboxyl group is dehydrated and cyclized in a dry state, while in an aqueous medium containing a basic compound described later. Then, a part or all of the ring is opened, and the structure of maleic acid or a salt thereof is easily formed.

  (A2) As a component, C2-C6 olefins, such as ethylene, propylene, isobutylene, 1-butene, 1-pentene, 1-hexene, are mentioned, You may use these mixtures. Among these, olefins having 2 to 4 carbon atoms such as ethylene, propylene, isobutylene and 1-butene are more preferable, and ethylene is particularly preferable.

  Specific examples of the component (A3) include lower alkyl esters of (meth) acrylic acid such as methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and methyl acrylate and ethyl acrylate are preferable.

  The acid-modified polyolefin resin having the components (A1) to (A3) as described above is most preferably a terpolymer composed of ethylene, methyl acrylate, ethyl acrylate, or maleic anhydride. Here, the acrylic ester unit may be converted into an acrylic acid unit by hydrolyzing a small part of the ester bond when the resin is made into an aqueous solution as described later. It suffices if the ratio of each constituent component taking into account the change is within a specified range.

  When the acid-modified polyolefin resin composed of (A1) to (A3) is used, the component (A1) is 0.01% by mass or more and less than 5% by mass, more preferably 0.1% by mass, based on the entire resin. The content is preferably less than 5% by mass, more preferably 0.5% by mass or more and less than 5% by mass, and most preferably 1 to 4% by mass. When the content of the component (A1) is less than 0.01% by mass, it becomes difficult to make the resin aqueous as described above, it is difficult to obtain a good aqueous dispersion, and the alkali resistance and polyester film are difficult to obtain. From the viewpoint of adhesiveness, the content of the component (A1) is preferably less than 5% by mass.

  Further, from the viewpoint that the polyolefin resin can be easily made water-based and the performance such as water resistance is improved, the mass ratio ((A2) / (A3)) of (A2) to (A3) is 55/45 to 99 / 1 is preferable, and 60/40 to 98/2 is preferable and 75/25 to 95/5 is particularly preferable in order to have good adhesiveness.

  In the acid-modified polyolefin resin (A) used in the present invention, other monomers may be copolymerized at 20% by mass or less of the entire resin. Examples thereof include alkyl vinyl ethers having 3 to 30 carbon atoms such as methyl vinyl ether and ethyl vinyl ether, dienes, (meth) acrylonitrile, halogenated vinyls, vinylidene halides, carbon monoxide, sulfur disulfide and the like.

  The acid-modified polyolefin resin (A) used in the present invention preferably has a melt flow rate (MFR) at 190 ° C. and a load of 2160 g, which is a measure of molecular weight, of 0.01 to 100 g / 10 minutes, and preferably 1 to 50 g. / 10 minutes is more preferable, and 2 to 30 g / 10 minutes is more preferable. If the MFR is less than 0.01 g / 10 minutes, it becomes difficult to make the resin water-based. On the other hand, if the MFR exceeds 100 g / 10 minutes, the resin layer becomes hard and brittle, and mechanical properties and workability tend to decrease.

  The method for synthesizing the acid-modified polyolefin resin (A) is not particularly limited, but is generally obtained by high-pressure radical copolymerization of a monomer constituting the polyolefin resin in the presence of a radical generator. Further, the unsaturated carboxylic acid or its anhydride may be graft copolymerized (grafted modification).

(Polyurethane resin)
The polyurethane resin (B) used in the present invention is a polymer containing a urethane bond in the main chain, and is obtained, for example, by a reaction between a polyol compound and a polyisocyanate compound. In the present invention, the structure of the polyurethane resin is not particularly limited, but from the viewpoint of boil resistance, the glass transition temperature is preferably 0 ° C or higher, and from the viewpoint of blocking resistance, 30 ° C or higher is preferable. More preferably, it is 60 ° C. or higher.

  The polyol component constituting the polyurethane resin is not particularly limited. For example, 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, Low molecular weight glycols such as diethylene glycol, triethylene glycol and dipropylene glycol, low molecular weight polyols such as trimethylolpropane, glycerin and pentaerythritol, polyols having ethylene oxide and propylene oxide units Compounds, polyether diols, high molecular weight diols such as polyester diols, bisphenols such as bisphenol A, bisphenol F, dimer diol or the like carboxyl group was converted to a hydroxyl group of the dimer acid.

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

  The polyurethane resin (B) used in the present invention preferably has an anionic group from the viewpoint of dispersibility in an aqueous medium. An anionic group is a functional group that becomes an anion in an aqueous medium, and examples thereof include a carboxyl group, a sulfonic acid group, a sulfuric acid group, and a phosphoric acid group. Among these, it is preferable to have a carboxyl group.

  In order to introduce an anionic group into the polyurethane resin, a polyol component having a carboxyl group, a sulfonic acid group, a sulfuric acid group, a phosphoric acid group or the like may be used. As a polyol compound having a carboxyl group, 3,5-dihydroxy is used. Benzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxyethyl) propionic acid, 2,2-bis (hydroxypropyl) propionic acid, bis (hydroxymethyl) acetic acid, bis (4- Hydroxyphenyl) acetic acid, 2,2-bis (4-hydroxyphenyl) pentanoic acid, tartaric acid, N, N-dihydroxyethylglycine, N, N-bis (2-hydroxyethyl) -3-carboxyl-propionamide and the like. It is done.

  Further, the molecular weight of the polyurethane resin can be appropriately adjusted using a chain extender. Examples of such compounds include compounds having two or more active hydrogens such as amino groups and hydroxyl groups that can react with isocyanate groups. For example, diamine compounds, dihydrazide compounds, and glycols can be used. Examples of the diamine compound include ethylenediamine, propylenediamine, hexamethylenediamine, triethyltetramine, diethylenetriamine, isophoronediamine, dicyclohexylmethane-4,4′-diamine, and the like. Other examples include diamines having a hydroxyl group such as N-2-hydroxyethylethylenediamine and N-3-hydroxypropylethylenediamine, and dimer diamine obtained by converting the carboxyl group of dimer acid into an amino group. Furthermore, diamine type amino acids such as glutamic acid, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid and diaminobenzenesulfonic acid are also included. Dihydrazide compounds include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacin dihydrazide, etc., saturated aliphatic dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, etc. And unsaturated dihydrazides such as itaconic acid dihydrazide and phthalic acid dihydrazide, carbonic acid dihydrazide, carbodihydrazide, and thiocarbodihydrazide. As glycols, they can be appropriately selected from the aforementioned polyols.

  Examples of the polyurethane resin (B) used in the present invention include ionomer-type self-emulsifying polyurethane resins and ionomer-type self-emulsifying polyurethane-polyurea resins. In order to improve the solvent resistance, it is preferable to use an aromatic component for at least one of both components. Moreover, in order to improve adhesiveness, it is preferable to use what introduce | transduced the hydroxyl group, the carboxyl group, and the amino group into the polymer principal chain or the terminal.

(Oxazoline-based crosslinking agent (C1))
The oxazoline-based crosslinking agent (C1) is not particularly limited as long as it has two or more oxazoline groups in the molecule. For example, 2,2'-bis (2-oxazoline), 2,2'-ethylene-bis (4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis (2-oxazoline) And a cross-linking agent having an oxazoline group such as bis (2-oxazolinylcyclohexane) sulfide and an oxazoline group-containing polymer. These 1 type (s) or 2 or more types can be used.
Among these, an oxazoline group-containing polymer is preferable because of ease of handling. The oxazoline group-containing polymer is obtained by polymerizing an addition polymerizable oxazoline such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline. Other monomers may be copolymerized as necessary. The polymerization method of the oxazoline group-containing polymer is not particularly limited, and various known polymerization methods can be employed.
This crosslinking agent (C1) is characterized by good adhesion to polyester. It is also suitable for application to water-based materials. When coating on a polyester or polyamide biaxially stretched film, it is preferable to add 1 part by mass or more of the oxazoline-based crosslinking agent (C1) to 100 parts by weight of the solid content in the aqueous solution.

(Melamine cross-linking agent (C2))
The melamine crosslinking agent (C2) used in the present invention is a so-called melamine [1,3,5-triazine-2,4,6-triamine] in which an amino group is bonded to each of three carbon atoms of a triazine ring. A generic term for compounds in which various modifications are made to the amino group, including those in which a plurality of triazine rings are condensed. As a kind of modification, some of hydrogen atoms of three amino groups are alkylated or methylolated. In general, methylolated or unsubstituted hydrogen atoms are more reactive than alkylated ones, and an appropriate type of melamine compound can be selected depending on the application. Among them, the average number of condensed triazine rings is 3 or less, and at least one amino group is methylol-substituted, and these are dispersible in an aqueous medium and reactive with a resin. Is excellent. When coating on a polyester or polyamide biaxially stretched film, it is preferable to add 1 part by mass or more of the melamine-based crosslinking agent (C2) with respect to 100 parts by weight of the solid content in the aqueous solution.

(Resin layer)
The composition of the resin layer laminated on the biaxially stretched film is 60/40 to 97/3 for the mass ratio ((A) / (B)) of the acid-modified polyolefin resin (A) and the polyurethane resin (B). It is necessary that it is 70/30 to 85/15. When the amount of the acid-modified polyolefin resin (A) is less than 60% by mass, sufficient adhesion to the target polyolefin heat-sealable resin cannot be obtained, and when it exceeds 97% by mass, biaxial stretching is performed. Adhesiveness with a film is insufficient, and a desirable laminate strength cannot be obtained.

  Moreover, about a crosslinking agent (C), it is required that it is 1-20 mass parts with respect to a total of 100 mass parts of (A) and (B), and it is preferable that it is 2-10 mass parts. When the amount of the crosslinking agent (C) is less than 1 part by mass, the solvent resistance is poor. On the other hand, when it exceeds 20 mass parts, a crosslinking agent (C) will carry out a hardening effect | action, a resin layer will become weak, and laminate strength will fall.

In the present invention, the resin layer needs to contain an oxazoline-based crosslinking agent (C1) as the crosslinking agent (C). By containing the oxazoline-based crosslinking agent (C1), the resin layer is excellent in solvent resistance, and the resulting package is excellent in content resistance.
In the present invention, the resin layer may further contain a melamine-based crosslinking agent (C2). By containing the melamine-based crosslinking agent (C2) in addition to the oxazoline-based crosslinking agent (C1) as the crosslinking agent (C), the adhesion to the heat-sealable resin is further improved.

  Various known additives such as an antistatic agent and a slip agent can be added to the resin layer as needed, as long as the adhesiveness and film performance are not affected.

  The thickness of the resin layer formed on the biaxially stretched film is preferably 0.03 to 10 μm, and more preferably 0.05 to 0.2 μm. When the thickness of the resin layer is less than 0.03 μm, sufficient adhesion may not be obtained, and even if it is thicker than 10 μm, the performance is saturated, so it is not economical to form a thickness larger than that. . Moreover, when the thickness of the resin layer is thinner than 0.2 μm, the film laminate is advantageous in blocking resistance.

(Aqueous dispersion)
In the present invention, as a method for forming a resin layer on a biaxially stretched film, an acid-modified olefin resin (A), a polyurethane resin (B), a crosslinking agent (C), an aqueous dispersion containing an aqueous medium (hereinafter referred to as “ A resin layer-forming aqueous dispersion ") may be applied to a film and then dried. The aqueous dispersion for forming a resin layer used in the present invention is preferably in the form of a coating solution in which each component is mixed and has practically sufficient stability. Practically sufficient stability means that the uniformity, viscosity, performance, etc. do not change over 6 hours or more, preferably 24 hours or more, more preferably several days or more when the coating solution is stored at room temperature or at a predetermined temperature. Say that. The aqueous dispersion in the present invention is a resin in which a resin is dispersed or dissolved in an aqueous medium. The aqueous medium contains water as a main component, and if necessary, a water-soluble organic solvent or basic compound described later. Refers to a liquid containing

  In the aqueous dispersion, the crosslinking agent (C) needs to contain an oxazoline-based crosslinking agent (C1). The composition of the acid-modified polyolefin resin (A), the polyurethane resin (B), and the cross-linking agent (C) may be any composition that can form the resin layer, and the acid-modified polyolefin resin (A) and the polyurethane resin (B). The mass ratio ((A) / (B)) needs to be 60/40 to 97/3, and preferably 70/30 to 85/15. Moreover, about a crosslinking agent (C), it is required that it is 1-20 mass parts with respect to a total of 100 mass parts of (A) and (B), and it is preferable that it is 2-10 mass parts.

  In the present invention, in order to obtain an aqueous dispersion of the acid-modified polyolefin resin (A), for example, the acid-modified polyolefin resin (A) and water can be sealed together with a basic compound or an organic solvent as necessary. A method of heating and stirring in a container can be used.

  At this time, the addition of the basic compound neutralizes the carboxyl group of the acid-modified polyolefin resin (A), and the electrostatic repulsion between the generated anions prevents aggregation between the fine particles and stabilizes the aqueous dispersion. It is preferable because it imparts properties. The addition amount of the basic compound is preferably 0.5 to 3.0 times equivalent to the carboxyl group in the acid-modified polyolefin resin (A), more preferably 0.8 to 2.5 times equivalent. 0.0 to 2.0 times equivalent is particularly preferable. If it is less than 0.5 times equivalent, the addition effect of a basic compound is not recognized, and if it exceeds 3.0 times equivalent, drying time at the time of resin layer formation may become long or an aqueous dispersion may color.

  Specific examples of the basic compound include metal hydroxides such as LiOH, KOH, and NaOH, ammonia, and organic amine compounds. Especially, it is preferable on the manufacturing process of a film laminated body to use the compound which volatilizes at the time of resin layer formation, and an organic amine compound with a boiling point of 250 degrees C or less is preferable. Specific examples of such organic amine compounds include triethylamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, 3- Ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, N-methylmorpholine And N-ethylmorpholine.

  In the production of the aqueous dispersion of the acid-modified polyolefin resin (A), when the molecular weight of the resin is large to some extent, it is preferable to add an organic solvent. The addition amount of the organic solvent used at this time is preferably 1 to 40 parts by mass, more preferably 2 to 30 parts by mass, and particularly preferably 3 to 20 parts by mass with respect to 100 parts by mass of the aqueous dispersion. When the addition amount of the organic solvent exceeds 20 parts by mass, the aqueous dispersion is heated with stirring under normal pressure or reduced pressure (stripping) to reduce the content of the organic solvent to 0.01% by mass. %.

  As the organic solvent, those having a solubility in water at 20 ° C. of 5 g / L or more are preferably used, and those having 10 g / L or more are more preferably used. Specific examples of such organic solvents include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert. -Alcohols such as amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, isophorone, tetrahydrofuran Ethers such as dioxane, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, Esters such as methyl pionate, ethyl propionate, diethyl carbonate, dimethyl carbonate, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol , Glycol derivatives such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol methyl ether acetate, and 3 Examples include methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate and the like. Among them, the resin can be easily made aqueous, and an organic solvent can be removed from the aqueous medium. From the viewpoint of easy removal, ethanol, n-propanol, isopropanol, n-butanol, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether are preferable, and low temperature drying properties are preferable. From the viewpoint, isopropanol is particularly preferable.

  According to the production method as described above, an aqueous dispersion can be obtained without adding an emulsifier component or a compound having a protective colloidal action generally used in the production of an aqueous dispersion. In order to further facilitate dispersion in the reaction system, an emulsifier or a compound having a protective colloid effect can be added to the reaction system. However, since these compounds are generally non-volatile, they remain in the resin layer of the film laminate and have the effect of plasticizing them, thereby deteriorating water resistance and chemical resistance. When the water resistance is deteriorated, there is a possibility that the bag may be ruptured when a content containing moisture is packaged using the film laminate. Further, when the chemical resistance is deteriorated, the surface of the film is eroded by the ink solvent when printing is performed on the surface of the film, and the performance is deteriorated and the print quality is easily deteriorated. Therefore, it is better to use an emulsifier or a compound having a protective colloid action as little as possible.

  Examples of the emulsifier referred to in the present invention 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. Nonionic emulsifiers include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, ethylene oxide-propylene oxide. Examples thereof include compounds having a polyoxyethylene structure such as copolymers and sorbitan derivatives, and amphoteric emulsifiers include lauryl betai , Lauryl dimethylamine oxide, and the like.

  The compounds having protective colloid action include polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, modified starch, polyvinyl pyrrolidone, polyacrylic acid and salts thereof, carboxyl group-containing polyethylene wax, carboxyl group-containing Acid-modified polyolefin waxes having a number average molecular weight of usually 5000 or less, such as polypropylene wax and carboxyl group-containing polyethylene-propylene wax, and salts thereof, acrylic acid-maleic anhydride copolymers and salts thereof, styrene- (meth) acrylic acid Unsaturated carbohydrate such as copolymer, isobutylene-maleic anhydride alternating copolymer, (meth) acrylic acid- (meth) acrylic ester copolymer, etc. As a dispersion stabilizer for fine particles, such as carboxyl group-containing polymers having an acid content of 10% by mass or more, salts thereof, polyitaconic acid and salts thereof, water-soluble acrylic copolymers having amino groups, gelatin, gum arabic, casein, etc. The compound currently used is mentioned.

  As an apparatus for producing the aqueous dispersion, any apparatus may be used as long as it has a tank into which a liquid can be charged and can appropriately stir the mixture of the aqueous medium and the resin powder or granular material charged in the tank. As such an apparatus, an apparatus widely known to those skilled in the art as a solid / liquid stirring apparatus or an emulsifier can be used, and an apparatus capable of pressurization of 0.1 MPa or more is preferably used. The stirring method and the rotation speed of stirring are not particularly limited. In addition, from the viewpoint of increasing the speed of aqueous formation, it is preferable to use a granular or powdery material resin having a particle diameter of 1 cm or less, preferably 0.8 cm or less.

  Each raw material described above is put into a tank of this apparatus, and preferably stirred and mixed at a temperature of 40 ° C. or lower. Next, while maintaining the temperature in the tank at 50 to 200 ° C., preferably 60 to 200 ° C., preferably the resin is sufficiently aqueousized by continuing stirring for 5 to 120 minutes, and then preferably 40 ° C. under stirring. An aqueous dispersion can be obtained by cooling to the following. When the temperature in the tank is less than 50 ° C., it becomes difficult to make the resin water-based. When the temperature in a tank exceeds 200 degreeC, there exists a possibility that the molecular weight of polyolefin resin may fall.

  As a heating method in the tank, heating from the outside of the tank is preferable. For example, the tank can be heated using oil or water, or a heater can be attached to the tank for heating. Examples of the cooling method in the tank include a method of naturally cooling at room temperature and a method of cooling using 0 to 40 ° C. oil or water.

  After this, jet pulverization may be further performed as necessary. The jet pulverization treatment referred to here is a method in which an aqueous dispersion is ejected from pores such as nozzles and slits under high pressure, and resin particles are collided with each other and a collision plate or the like. In order to further refine the particles, specific examples of an apparatus for that purpose include: P. V. A. Examples include a homogenizer manufactured by GAULIN, and a microfluidizer M-110E / H manufactured by Mizuho Industries.

(Mixing method)
As described above, as a method for producing the film laminate of the present invention, an aqueous dispersion for forming a resin layer containing an acid-modified olefin resin (A), a polyurethane resin (B), and a crosslinking agent (C) is biaxial. The method of apply | coating on a stretched film is illustrated. This aqueous dispersion can be prepared by mixing a predetermined amount of the above-described aqueous dispersion of the acid-modified polyolefin resin (A) and other components in a suitable container. The order of charging into the container may be either first or simultaneously.

(Resin layer forming method)
When applying an aqueous dispersion for forming a resin layer to a base film, it may be dried and heat-treated after being applied to a biaxially stretched film. The aqueous dispersion may be applied to the finished film and stretched after drying or simultaneously with drying to complete the orientation. Since the film laminate of the present invention is excellent in blocking resistance, an aqueous dispersion is applied to an unstretched film or a uniaxially stretched film to form a resin layer, and then manufactured by applying an in-line method of stretching the film. Can do.

  The coating method of the aqueous dispersion for forming a resin layer is not particularly limited, and is usually selected from known methods. For example, various coating methods such as a gravure roll method, a reverse roll method, an air knife method, a reverse gravure method, a Mayer bar method, an inverse roll method, or a combination thereof, or various spray methods can be employed. Moreover, a corona treatment apparatus etc. can be installed in front of a coater, and the wetting tension of a base film can be adjusted.

  Next, the present invention will be specifically described based on examples. The raw materials used and the method for preparing the aqueous dispersion of the acid-modified polyolefin resin are as follows.

(A) Acid-modified polyolefin resin:
(A-1) Bondaine HX-8290 (ethylene / ethyl acrylate / maleic anhydride = 80/18/2 (mass%), MFR: 65 g / 10 min, melting point 81 ° C.) manufactured by Arkema
(A-2) Bondain TX-8030 (ethylene / ethyl acrylate / maleic anhydride = 85/12/3 (mass%), MFR: 3 g / 10 min, melting point 95 ° C.) manufactured by Arkema
(A-3) Bondain HX-8140 (ethylene / ethyl acrylate / maleic anhydride = 78/19/3 (mass%), MFR: 20 g / 10 min, melting point 80 ° C.) manufactured by Arkema

(B) Polyurethane resin:
(B-1) Hydran WLA-404 manufactured by DIC

(C1) Oxazoline-based crosslinking agent:
(C1-1) Nippon Shokubai Co., Ltd. Epocross WS-700

(C2) Melamine crosslinking agent:
(C2-1) Cymel 325 manufactured by Nippon Cytec Industries

(C3) Carbodiimide crosslinking agent:
(C3-1) Carbodilite V-02 manufactured by Nisshinbo Chemical Co., Ltd.

Reference example 1
(Preparation of acid-modified polyolefin aqueous dispersion E-1)
Using a stirrer equipped with a hermetic pressure-resistant 1 liter glass container with a heater, 60.0 g of acid-modified polyolefin resin (Arkema Bondin HX-8290), 90.0 g of isopropyl alcohol (Wako Pure Chemical Industries, Ltd., Hereinafter, it may be abbreviated as IPA), 3.0 g of N, N-dimethylethanolamine (manufactured by Wako Pure Chemical Industries, Ltd., hereinafter abbreviated as DMEA) and 147.0 g of distilled water in a glass container. Prepared. And it stirred for 30 minutes, setting the rotational speed of a stirring blade to 300 rpm, maintaining system temperature at 140-145 degreeC. Thereafter, it was placed in a water bath and cooled to room temperature (about 25 ° C.) while stirring at a rotational speed of 300 rpm to obtain an acid-modified polyolefin resin aqueous dispersion. Furthermore, an acid-modified polyolefin resin aqueous dispersion and 180 g of distilled water were charged into a two-necked round bottom flask, a mechanical stirrer and a Liebig condenser were installed, and the flask was heated in an oil bath to retain the aqueous medium. Left. When about 180 g of water and IPA were distilled off, heating was terminated and the mixture was cooled to room temperature. After cooling, the liquid component in the flask is filtered under pressure (air pressure 0.2 MPa) with a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave), thereby producing a milky white acid-modified polyolefin resin aqueous dispersion E-1. Got.

Reference example 2
(Preparation of acid-modified polyolefin aqueous dispersion E-2)
An acid-modified polyolefin aqueous dispersion E-2 was obtained in the same manner as in Reference Example 1, except that “Bondyne TX-8030 manufactured by Arkema Co., Ltd.” was used as the acid-modified polyolefin resin.

Reference example 3
An acid-modified polyolefin aqueous dispersion E-3 was obtained in the same manner as in Reference Example 1, except that “Bondyne HX-8140 manufactured by Arkema Co.” was used as the acid-modified polyolefin resin.

The evaluation method in the present invention is as follows.
(1) Solvent resistance The aqueous dispersion for resin layer formation was applied to a biaxially stretched PET film (Embret made by Unitika, thickness 12 μm) by a hand coating method. After coating, the film was dried at 140 ° C. for 30 seconds. Thereafter, 16 sheets of gauze soaked with ethanol was fixed to the head of a hammer (907 g (2 pounds)), and this was rubbed 5 times on the coating surface, and the state was observed. At this time, no force was applied in the vertical direction so that only the weight of the hammer was loaded.
○: No change.
Δ: Whitening.
X: Coat peeling.

(2) Adhesive strength Using a laminating apparatus equipped with an extruder, LDPE (L211 manufactured by Sumitomo Chemical Co., Ltd.) was melt extruded at 300 ° C. on the surface of the resin layer of the film laminate. A formed laminate film was obtained. A test piece having a width of 15 mm was taken from this laminate film, and the interface between the heat seal layer and the film laminate layer was peeled off from the end of the test piece by 180 ° peeling method using a tensile tester AG-IS type manufactured by Shimadzu Corporation. Then, the adhesive strength was measured. The measurement was performed in an atmosphere of 23 ° C. and 50% RH at a tensile speed of 300 mm / min. Practically, the adhesive strength is preferably 400 g / 15 mm or more.

(3) Resistance to content The packaging body (pillow type, dimensions: 80 mm × 150 mm) prepared using the laminate film described in (2) above is filled with 30 cc of 10% ethanol aqueous solution, at 20 ° C. and 65% RH. After storage for 14 days under the environment, a test piece having a width of 15 mm was taken from the laminate film in contact with the 10% aqueous ethanol solution, and the adhesive strength was measured by the method described in (2) to evaluate the content resistance.

Example 1
Each component was mixed so that it might become a compounding ratio shown in Table 1, and the aqueous dispersion for resin layer formation was prepared. The solid content concentration was adjusted with pure water so as to be 11.7% by mass.
Using a polyethylene terephthalate resin (manufactured by Nihon Ester Co., Ltd., intrinsic viscosity 0.6) with an extruder (75 mm diameter, slow compression type single screw with L / D of 45) equipped with a T die, a cylinder temperature of 260 ° C., T Extruded into a sheet form at a die temperature of 280 ° C., closely contacted on 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 film was stretched 3.4 times in the longitudinal direction at 90 ° C., then led to a gravure roll coater, and combined with the Meyer bar method, the resin layer-forming aqueous dispersion had a resin layer thickness after drying. The film was applied to a thickness of 0.2 μm, then preheated at a temperature of 90 ° C. for 2 seconds, and then stretched in the transverse direction at a magnification of 3.5 times. The lateral relaxation rate was 2%. The thickness of the polyethylene terephthalate layer in the obtained film laminate was 12 μm.
The evaluation results of the obtained film laminate are shown in Table 1.

Examples 2-9, Comparative Examples 1-7
Except having changed the compounding ratio of each component in the aqueous dispersion for forming a resin layer as shown in Table 1, the same operation as in Example 1 was performed to obtain a film laminate. The evaluation results of the obtained film laminate are shown in Table 1.

The film laminates obtained in the examples were excellent in solvent resistance and adhesiveness with the heat-sealable resin layer, and the package obtained therefrom was excellent in content resistance.
On the other hand, in Comparative Examples 1 and 2, since the mass ratio of the acid-modified polyolefin resin (A) and the polyurethane resin (B) was outside the range specified in the present invention, the adhesive strength was inferior. In Comparative Examples 3 and 4, the content of the cross-linking agent was outside the range specified in the present invention, so that the solvent resistance was poor or the adhesive strength was poor. In Comparative Example 5, since a crosslinking agent other than the oxazoline-based crosslinking agent (C1) specified in the present invention was used, the solvent resistance was poor. In Comparative Example 6, since only the melamine-based crosslinking agent (C2) was used as the crosslinking agent, the adhesive strength and the solvent resistance were sufficient, but the resistance to resistance was higher than that using the oxazoline-based crosslinking agent (C1). The contents were inferior in physical properties. Moreover, since the comparative example 7 did not use the crosslinking agent, it was inferior to solvent resistance and content resistance.

Claims (6)

  A film laminate in which a resin layer containing an acid-modified polyolefin resin (A), a polyurethane resin (B) and a crosslinking agent (C) is formed on at least one surface of a biaxially stretched film, and the crosslinking agent (C) is an oxazoline A cross-linking agent (C1), the mass ratio of (A) and (B) ((A) / (B)) is 60/40 to 97/3, and the sum of (A) and (B) (C) is 1-20 mass parts with respect to 100 mass parts, The film laminated body for extrusion lamination characterized by the above-mentioned.   The film laminate for extrusion lamination according to claim 1, further comprising a melamine-based crosslinking agent (C2) as the crosslinking agent (C).   3. The film laminate for extrusion lamination according to claim 1, wherein the acid-modified polyolefin resin (A) has a melt flow rate (MFR) at 190 ° C. under a load of 2160 g of 0.01 to 100 g / 10 minutes.   An aqueous dispersion containing an acid-modified polyolefin resin (A), a polyurethane resin (B), a crosslinking agent (C) and an aqueous medium, the crosslinking agent (C) containing an oxazoline-based crosslinking agent (C1), (A ) And (B) mass ratio ((A) / (B)) is 60/40 to 97/3, and (C) is 1 with respect to a total of 100 parts by mass of (A) and (B). An aqueous dispersion characterized in that it is ˜20 parts by mass.   A method for producing an extruded lamination film laminate according to claim 1, wherein the aqueous dispersion according to claim 4 is applied to at least one surface of a biaxially stretched film. A manufacturing method of a layered product. A method for producing a film laminate for extrusion lamination according to claim 1, wherein the aqueous dispersion according to claim 4 is applied to at least one surface of an unstretched film or a uniaxially stretched film, and then stretched. A method for producing a film laminate for extrusion lamination.