JP5743491B2 - Film laminate for extrusion lamination and method for producing the same - Google Patents

Description

  The present invention relates to an extrusion lamination film laminate in which a resin layer containing an acid-modified polyolefin resin, a urethane resin, and an acetylene glycol surfactant 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 have excellent mechanical properties, heat resistance, pinhole resistance, chemical resistance Due to its 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 film, and 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.

  In Patent Document 1, 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. With increasing interest, this cross-linking agent is one of the substances whose use is restricted by laws and regulations.

  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 described. Since the adhesives described in these documents are for laminating the mating material immediately after being applied to the base film, the two base films coated with the adhesive are applied to the coated surface and the non-coated surface. When they are stacked so that they come into contact with each other, they are easy to block. Therefore, it has been impossible to produce in-line a film coated with this adhesive as a film for extrusion lamination.

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

  In the present invention, it is possible to obtain a good adhesive force even when a heat-seal resin is laminated on a biaxially stretched film by extrusion lamination on the biaxially stretched film, and it can be manufactured by an in-line method. Furthermore, the present invention intends to provide a film laminate excellent in environmental compatibility.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have solved the above-mentioned problems by laminating a resin layer containing an acid-modified polyolefin resin, a polyurethane resin and a specific surfactant on a biaxially stretched film. The inventors have found that this can be solved and have reached the present invention.
That is, the gist of the present invention is as follows.
(1) A resin layer containing an acid-modified polyolefin resin (A), a polyurethane resin (B) and an acetylene glycol surfactant (C) and not containing a melamine crosslinking agent is formed on at least one surface of a biaxially stretched film. The mass ratio (A) / (B) of (A) and (B) is 60/40 to 97/3, and (C) with respect to a total of 100 parts by mass of (A) and (B) The film laminate for extrusion lamination, wherein is 1 to 30 parts by mass.
(2) The film for extrusion lamination according to (1), wherein the melt flow rate (MFR) of the acid-modified polyolefin resin (A) is 0.01 to 100 g / 10 min at 190 ° C. and a load of 2160 g. Laminated body.
(3) Acid-modified polyolefin resin (A), polyurethane resin (B), acetylene glycol surfactant (C) and aqueous medium, and (A) / (B) mass ratio (A) / (B) Is 60/40 to 97/3, and (C) is 1 to 30 parts by mass with respect to 100 parts by mass in total of (A) and (B).
(4) A method for producing a film laminate for extrusion lamination according to (1) or (2) above, wherein the aqueous dispersion according to (3) is applied to at least one surface of a biaxially stretched film. A method for producing a laminated film for extrusion lamination.
(5) A method for producing a film laminate for extrusion lamination according to (1) or (2) above, wherein the aqueous dispersion according to (3) 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.

  Since the film laminate of the present invention is excellent in adhesion to a heat-sealable resin such as polyethylene, a heat-seal layer having a practically sufficient laminate strength can be formed without using an adhesive during extrusion lamination. . Moreover, since the film laminated body of this invention is excellent in blocking resistance, it can be manufactured by an in-line method.

The present invention will be described in detail below.
In the film laminate of the present invention, a resin layer containing an acid-modified polyolefin resin (A), a polyurethane resin (B), and an acetylene glycol surfactant (C) is formed on at least one surface of a biaxially stretched film. It is a film laminate.
Hereinafter, the biaxially stretched film is referred to as “base film” and contains an acid-modified polyolefin resin (A), a polyurethane resin (B), and an acetylene glycol surfactant (C) formed on the biaxially stretched film. Such a layer may be simply referred to as a “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, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and a mixture thereof. Examples thereof include polyamide resins such as resin, 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 polyamide resin or polyester 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), acrylic acid or methacrylic acid (A3).

  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 using the polyolefin resin comprised from (A1)-(A3), (A1) component is 0.01 mass% or more of this resin whole, less than 5 mass%, More preferably, 0.1 mass% or more, 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.

  In addition, from the viewpoint that the polyolefin resin is easily 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. Furthermore, in order to give good adhesiveness, 60/40 to 98/2 is preferable, and 75/25 to 95/5 is particularly preferable.

  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 an MFR of 190 to 100 g / 10 min at 190 ° C. and a load of 2160 g, which is a measure of molecular weight. More preferably 1 to 50 g / 10 min, more preferably 2 to 30 g / 10 min can be used. If the melt flow rate is less than 0.01 g / 10 minutes, it becomes difficult to make the resin water-based. On the other hand, if it exceeds 100 g / 10 minutes, the resin layer tends to be hard and brittle, and mechanical properties and workability tend to decrease. It is in.

  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 into 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) 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 capable of reacting 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.

(Acetylene glycol surfactant)
The acetylene glycol surfactant (C) used in the present invention is an acetylene glycol nonionic surfactant having an acetylene group in the center and a symmetrical structure, and is obtained by adding ethylene oxide to acetylene glycol. Can be illustrated. It is preferable that the addition number of ethylene oxide is 6-16 mol with respect to 1 mol of acetylene glycol. This surfactant (C) is particularly suitable for application to aqueous materials as a wetting agent having excellent antifoaming properties. When applying on a polyester or polyamide biaxially stretched film, it is preferable to add 0.3 mass% or more of acetylene glycol type surfactant (C) in the aqueous solution actually applied.

(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). Is required and is preferably 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-based heat-sealable resin cannot be obtained, and when it is more than 97% by mass, biaxial stretching is performed. Adhesiveness with a film is insufficient, and a desirable laminate strength cannot be obtained.

  Moreover, about acetylene glycol surfactant (C), it is required that it is 1-30 mass parts with respect to a total of 100 mass parts of (A) and (B), and is 3-10 mass parts. It is preferable. When the amount of the acetylene glycol surfactant (C) is less than 1 part by mass, it is difficult to apply a thin resin layer having excellent blocking resistance described later. On the other hand, when the amount is more than 30 parts by mass, the acetylene glycol surfactant (C) plasticizes, the resin layer becomes brittle, and the laminate strength decreases.

  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 adhesiveness cannot be obtained, and even when the thickness is greater than 10 μm, the performance is saturated. Therefore, 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), an acetylene glycol surfactant (C), and an aqueous dispersion containing an aqueous medium (Hereinafter, it may be referred to as “aqueous dispersion for forming a resin layer”.) Is 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

  The composition of the acid-modified polyolefin resin (A), polyurethane resin (B), and acetylene glycol surfactant (C) in the aqueous dispersion may be any composition that can form the resin layer. The acid-modified polyolefin resin (A) The mass ratio (A) / (B) of the polyurethane resin (B) needs to be 60/40 to 97/3, and preferably 70/30 to 85/15. Moreover, about acetylene glycol surfactant (C), it is required that it is 1-30 mass parts with respect to a total of 100 mass parts of (A) and (B), and is 3-10 mass parts. It is preferable.

  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, and ethyl acetoacetate. 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.

  In addition, 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 colloid action generally used in the production of an aqueous dispersion. In order to further facilitate dispersion in the medium, 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 Polypropylene wax, carboxyl group-containing polyethylene-propylene wax and other acid-modified polyolefin waxes having a number average molecular weight of usually 5000 or less 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. 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 used as 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, the method for producing the film laminate of the present invention includes an aqueous dispersion for forming a resin layer containing an acid-modified olefin resin (A), a polyurethane resin (B), and an acetylene glycol surfactant (C). A method of applying the body on a biaxially stretched film is exemplified. 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 the aqueous dispersion for resin layer formation is applied to the base film, it may be dried and heat-treated after being applied to the biaxially stretched film, or the unstretched film before the orientation is completed, or the end of uniaxial stretching The aqueous dispersion may be applied to the film, and the film may be 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) Bondain HX-8290 (MFR: 65 g / 10 min, melting point 81 ° C.) manufactured by Arkema
(A-2) Bondain TX-8030 (MFR: 3 g / 10 min, melting point 95 ° C.) manufactured by Arkema
(A-3) Bondain HX-8140 (MFR: 20 g / 10 min, melting point 80 ° C.) manufactured by Arkema

(B) Polyurethane resin:
(B-1) Hydran manufactured by Dainippon Ink & Chemicals, Inc.

(C) Acetylene glycol surfactant:
(C-1) Olfin E1004 manufactured by Nissin Chemical Industry Co., Ltd.

Reference example 1
(Preparation of acid-modified polyolefin aqueous dispersion E-1)
Using a stirrer equipped with a 1 liter glass container that can be sealed with a heater, 60.0 g of acid-modified polyolefin resin (Bondane HX-8290 manufactured by Arkema), 90.0 g of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd. and below) , Sometimes referred to 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 were charged into a glass container. . And the rotational speed of the stirring blade was 300 rpm, the system temperature was maintained at 140 to 145 ° C., and stirring was performed for 30 minutes. 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) Coating property The aqueous dispersion for forming a resin layer was applied by a hand coating method. The hand coating method is a method in which an arbitrarily prepared solution is applied manually on a film using a Mayer bar. The coatability was evaluated as follows.
○: Coating is possible.
Δ: Coating is possible, but it is repelled at a thin portion at the end of the coat layer.
X: The film repels liquid and cannot be applied.

(2) Blocking test Two film laminates cut out to 50 mm × 50 mm are stacked so that the resin layer surface and the non-resin layer surface are in contact with each other, placed on a flat surface sandwiched between stainless steel plates, and a 10 kg weight is placed on the surface. After leaving still at 24 degreeC for 24 hours or more, weight and the stainless steel flat plate were removed, and it was set as evaluation of blocking property by investigating the adhesion state of a film surface. The case where no adhesion was found between the films was indicated as ◯, the film which could be easily peeled off was indicated as Δ, and the film where adhesion was observed was indicated as x.

(3) Adhesive strength Using a laminator equipped with an extruder, LDPE (L211 manufactured by Sumitomo Chemical Co., Ltd.) was melt-extruded at 300 ° C. onto the resin layer surface of the film laminate, and a heat seal layer composed of an 18 μm LDPE layer was formed. 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.

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 0.05 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 1-6
Except having changed the compounding ratio of each component in the aqueous dispersion for forming a resin layer and the thickness of the 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.

Comparative Example 7
A blocking test was performed using a biaxially stretched polyethylene terephthalate film (Embret manufactured by Unitika Ltd., thickness 12 μm). Further, the film was subjected to extrusion lamination without forming a resin layer to obtain a laminate film on which a heat seal layer composed of an LDPE layer was formed, and the adhesive strength of the laminate film was measured. The evaluation results are shown in Table 1.

The film laminates obtained in the examples were excellent in blocking resistance and excellent in adhesion to the heat-sealable resin layer. Moreover, there existed a tendency for blocking resistance to improve, so that the resin layer thickness was thin.
On the other hand, in Comparative Examples 1 to 3, 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. Moreover, in Comparative Examples 4 and 5, since the acetylene glycol surfactant (C) was not contained or the content was small, the film repelled the aqueous dispersion and became unapplicable. On the other hand, in Comparative Example 6, since the content of the acetylene glycol surfactant (C) was large, the adhesive strength was inferior.

Claims (5)

On at least one surface of the biaxially stretched film, a resin layer containing the acid-modified polyolefin resin (A), the polyurethane resin (B) and the acetylene glycol surfactant (C) and not containing the melamine crosslinking agent is formed. The mass ratio (A) / (B) of A) and (B) is 60/40 to 97/3, and (C) is 1 to 100 parts by mass with respect to a total of 100 parts by mass of (A) and (B). A film laminate for extrusion lamination, which is 30 parts by mass. The film laminate for extrusion lamination according to claim 1, wherein the melt flow rate (MFR) of the acid-modified polyolefin resin (A) is 0.01 to 100 g / 10 min at 190 ° C and a load of 2160 g .   An acid-modified polyolefin resin (A), a polyurethane resin (B), an acetylene glycol surfactant (C) and an aqueous medium are contained, and the mass ratio (A) / (B) between (A) and (B) is 60 / 40 to 97/3, and (C) is 1 to 30 parts by mass with respect to 100 parts by mass in total of (A) and (B).   A method for producing an extrusion lamination film laminate according to claim 1 or 2, wherein the aqueous dispersion according to claim 3 is applied to at least one surface of a biaxially stretched film. Body manufacturing method.   It is a manufacturing method of the film laminated body for extrusion lamination of Claim 1 or 2, Comprising: It stretches, after apply | coating the aqueous dispersion of Claim 3 to the at least single side | surface of an unstretched film or a uniaxially stretched film. A method for producing a film laminate for extrusion lamination.