JP5515856B2 - Laminated body and packaging material using the same - Google Patents

Description

  The present invention relates to a laminate having at least a polyolefin-based resin layer, an adhesive layer, and an inorganic layer in this order, and in particular, snacks, frozen foods, retort foods, etc. using the laminate as various packaging materials. The present invention relates to packaging materials such as food packaging materials, pharmaceuticals, miscellaneous goods, and industrial materials.

Conventionally, plastic soft packaging bags of various forms have been developed for filling and packaging various foods and beverages, chemical products such as liquid detergents, cosmetics, pharmaceuticals, miscellaneous goods, industrial members, and other articles, Proposed. As a laminated material as a packaging material constituting the packaging bag described above, various properties having the property of blocking the permeation of oxygen gas, water vapor, etc. from the demands of protecting the quality of the contents, extending the storage period, etc. Attempts have been made to use these barrier materials. In addition, there are various light-shielding materials because sunlight, fluorescence, etc. are transmitted, and the transmitted light affects the contents, causing the contents to be decomposed or altered, or cause light deterioration such as fading. Considered and proposed.
As the above-mentioned barrier material or light-shielding material, the most common one is a metal foil or an inorganic vapor-deposited film. In particular, an aluminum foil or an aluminum vapor-deposited film is used as the metal.

  Furthermore, as a packaging material having an aluminum foil layer used for packaging foods and pharmaceuticals, for example, polyester layer / adhesive layer / aluminum foil layer / adhesive layer / polyester layer / anchor coat layer / sealant layer, Laminates having the layer structure as described above are widely used, and various packages are thus produced. Lamination of such a laminated structure is usually performed by dry lamination using a two-component curable polyurethane adhesive, and the anchor coat layer is formed by extrusion lamination. And such a laminated body has moderate lamination strength, gas barrier property, etc., and is suitably used as a packaging material for packaging foods, pharmaceuticals, etc. (for example, refer patent document 1).

On the other hand, polyolefin resins such as polypropylene are inexpensive, have excellent moldability, and have excellent oil resistance, sealant properties, etc., and therefore can exhibit excellent performance even when used as packaging materials as described above. However, since the polyolefin-based resin is hardly adhesive, there is a problem in that the adhesive strength is poor when an inorganic layer made of an inorganic material and a laminate are formed, and delamination occurs. In order to increase the adhesive strength, adhesion by high temperature or prolonged heating is required, or an adhesive dissolved in an organic solvent such as toluene or a two-component curable adhesive using a polyfunctional isocyanate as a crosslinking agent. It was necessary to use it. However, adhesion by heating at high temperature or for a long time is disadvantageous in terms of work efficiency and energy efficiency, and organic solvent adhesives have problems with the risk of ignition during work and the treatment of volatile organic solvents after drying. In addition, the two-component adhesive has a problem that the usable time is limited. Therefore, there has been a need for a laminate using an adhesive that is water-based, one-component, and can be bonded by heating at a low temperature for a short time.
A packaging material characterized by using an acid-modified polyolefin resin containing a (meth) acrylic acid ester component as an adhesive layer is also disclosed. As a polyolefin component, ethylene / (meth) acrylic acid ester copolymer is disclosed. A coalescence is used, and adhesion to a polypropylene resin, which is more difficult to adhere, is not sufficient (see, for example, Patent Document 2).

  Also, an aqueous resin dispersion obtained by dispersing a polymer (C) in which a hydrophilic polymer (B) is bonded to an acid-modified polyolefin (A) in an aqueous medium can be used as a polyolefin coating or primer. The laminated body as a thing is disclosed (for example, refer patent document 3 and patent document 4).

JP 2008-120062 JP JP 2009-172824 A JP 2007-246871 A JP 2007-270122 A

  Even a conventionally known technique has not led to the easy formation of a laminate by an adhesive layer having excellent adhesion to both the polyolefin resin layer and the inorganic layer represented by metal. In the present invention, the polyolefin resin layer (1) and the inorganic layer (3) are cooled at a low temperature by using the adhesive layer (2) excellent in low-temperature heat sealability and adhesiveness for the above problems. Providing a laminate that can be easily formed by heating in a short time, and by using the laminate, it has excellent light shielding properties, gas barrier properties, etc., has content protection suitability, and is mainly a retort food Another object of the present invention is to provide a packaging material that can be used for packaging bags and packaging containers useful for filling and packaging snacks, fats and oils, pharmaceuticals, miscellaneous goods, industrial components, etc.

As a result of intensive studies to solve the above-mentioned problems, the present inventor has made the polyolefin resin layer (1) and the inorganic layer (3) low-temperature using an adhesive layer (2) excellent in low-temperature heat sealability and adhesion. And it discovered that it can laminate | stack easily compared with the past by heating for a short time, and this laminated body is suitable for various packaging material uses, and it came to this invention. That is, the gist of the present invention is a laminate having at least a polyolefin-based resin layer (1), an adhesive layer (2) and an inorganic layer (3) in this order, and the adhesive layer (2) is acid- modified. hydrophilic polymer to the polyolefin (a) and (B), (a) :( B) = 100: 1~100: a 100 (polymer made by bonding in a weight ratio of) (C), said hydrophilic sex polymer (B) is a polyether amine, and inorganic layer (3) resides in the product layer which is a layer containing aluminum.

  The laminate of the present invention is excellent in light-shielding properties, gas barrier properties, etc., and packaging bags and packaging containers molded using this laminate have suitability for protecting contents, mainly retort foods, snacks, fats and oils It is useful for filling and packaging pharmaceuticals, miscellaneous goods, industrial materials, etc. In addition, the adhesive layer (2) used in the laminate of the present invention has excellent adhesion to both polyolefin resins and inorganic substances typified by metals, and excellent low-temperature heat sealability. Thus, a laminate of the polyolefin resin layer (1) and the inorganic layer (3) represented by metal can be easily formed. In addition, since the adhesive layer of the laminate of the present invention uses a water-based adhesive, it is excellent in safety and hygiene without using a dangerous and harmful organic solvent, and does not require a crosslinking agent. Since it can be used with only one liquid, it is excellent in workability.

It is a conceptual diagram of the typical laminated body of this invention.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Modes for carrying out the present invention will be described in detail below. However, the description of the constituent elements described below is an example of embodiments of the present invention, and the present invention is not limited to these contents. . In the present specification, “to” includes front and rear numerals.

  FIG. 1 shows a schematic cross-sectional configuration of a laminate according to the present invention. The laminate of the present invention is a laminate having a polyolefin resin layer (1), an adhesive layer (2), and an inorganic layer (3) in this order, and the adhesive layer (2) is an acid-modified polyolefin ( It is a polymer (C) obtained by bonding a hydrophilic polymer (B) to A) at a ratio of (A) :( B) = 100: 1 to 100: 100 (weight ratio). In addition, the laminate of the present invention may further include a thermoplastic resin layer (4) as shown in FIG. 1, but the thermoplastic resin layer (4) is not an essential constituent element in the present invention. .

  However, in this specification, “having the polyolefin-based resin layer (1), the adhesive layer (2), and the inorganic layer (3) in this order” is laminated in a relative positional relationship as shown in FIG. It means only that and does not prevent another layer from entering between each layer. Further, the order of stacking is not limited. The same applies to the thermoplastic resin layer (4).

<Polyolefin resin layer (1)>
The polyolefin resin layer (1) in the present invention is not particularly limited as long as it is a layer made of a polyolefin resin. Examples of the resin to be used include polyethylene such as low density polyethylene (LDPE) and high density polyethylene (HDPE). , Acid-modified polyethylene, polypropylene, acid-modified polypropylene, polypropylene-α olefin copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene- (meth) acrylic acid copolymer, Polyolefin resins such as polyolefin resins such as ionomers are used. Among them, polyethylene resins or polypropylene resins are preferable from the viewpoints of protection of contents as packaging materials and low-temperature sealing properties, and polypropylene or propylene-ethylene copolymers. , Propire N-butene copolymer and the like are particularly preferably used.

  The polyolefin-based resin layer (1) in the present invention may be formed by laminating the above-mentioned various polyolefin-based resins into a layer shape by a conventionally known method, but may be formed by a method such as coating on a substrate. The resin itself may be formed into a film shape or a sheet shape. In particular, a resin formed into a film or sheet can be suitably used.

  In the present invention, the surface of each of the above-mentioned various resin films or sheets is provided with a desired surface treatment layer as necessary in order to improve close adhesion with an adhesive layer described later. It is something that can be done. As the above-mentioned surface treatment layer, for example, pretreatment such as corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, etc. It can be applied arbitrarily. Furthermore, as a method for improving the above-mentioned tight adhesion, in addition, for example, a primer coat agent layer, an anchor coat agent layer, a vapor deposition anchor coat agent layer, or the like is arbitrarily provided in advance on the surface of various resin films or sheets. It can also be formed as a surface treatment layer.

  The thickness of the polyolefin resin layer is not particularly defined, but is usually in the range of 0.1 μm to 1 mm, preferably 1 μm to 300 μm, and more preferably 3 μm to 100 μm. When the thickness is less than 0.1 μm, there is a possibility that sufficient strength and adhesive force may not be obtained. When the thickness exceeds 1 mm, it is economically disadvantageous.

<Adhesive layer (2)>
The laminate of the present invention comprises a weight obtained by bonding a hydrophilic polymer (B) to an acid-modified polyolefin (A) at a ratio of (A) :( B) = 100: 1 to 100: 100 (weight ratio). It has the adhesive bond layer (2) which consists of unification (C).
The method for forming the adhesive layer (2) in the present invention will be described later, but the polymer (C) may be formed into a layer by a conventionally known method. For example, you may shape | mold by methods, such as application | coating, on the base material represented by the said polyolefin-type resin layer (1), and may laminate | stack, after shape | molding resin itself in the form of a film or a sheet. Since the polymer (C) has adhesiveness, it is preferably molded by coating on a substrate in a state dissolved, diluted or dispersed with an appropriate solvent.

<Acid-modified polyolefin (A)>
Although the olefin component which is the main component of the acid-modified polyolefin (A) is not particularly limited, it has 2 to 2 carbon atoms such as ethylene, propylene, isobutylene, 2-butene, 1-butene, 1-pentene, 1-hexene and 1-octene. Eight alkenes are preferred, and not only these homopolymers but also copolymers or mixtures may be used. Among these, alkene having 2 to 4 carbon atoms such as ethylene, propylene, 1-butene is more preferable, and particularly preferable polymers are propylene homopolymer, propylene-ethylene copolymer, propylene-butene copolymer, propylene. -A propylene polymer such as an ethylene-butene copolymer. The content of the propylene component in the polymer is preferably 50 mol% or more, more preferably 75 mol% or more. A part of these polyolefin resins may be chlorinated. The content of chlorine in the polyolefin is usually 30% by weight or less, preferably 20% by weight or less, more preferably 10% by weight or less, and still more preferably 5% by weight or less. When the chlorine content is higher than 30%, the adhesion to the polyolefin substrate tends to be lowered. Commercially available polyolefins include Wintec (manufactured by Nippon Polypro), Tuffmer XM (manufactured by Mitsui Chemicals), Tough Selenium (manufactured by Sumitomo Chemical), LMPO (manufactured by Idemitsu Kosan Co., Ltd.), Ricosen PP (manufactured by Clariant) ), Supercron, Auroren (manufactured by Nippon Paper Chemicals), Hardren (manufactured by Toyo Kasei Kogyo Co., Ltd.), and the like.

  About the manufacturing method of polyolefin used as the raw material of acid-modified polyolefin (A) of this invention, if the polymer which satisfy | fills the requirements of this invention can be manufactured, it will not specifically limit, Any manufacturing method may be sufficient. For example, radical polymerization, cationic polymerization, anionic polymerization, coordination polymerization and the like may be mentioned, and each may be living polymerization.

In the case of coordination polymerization, for example, a polymerization method using a Ziegler-Natta catalyst or a polymerization method using a single site catalyst or a Kaminsky catalyst can be used. A preferable production method includes a production method using a single site catalyst. The reason for this is that single-site catalysts are generally easy to control the reaction precisely due to the ligand design, yielding a polymer with a sharp molecular weight distribution and stereoregularity distribution, compared to polymers based on Ziegler-Natta catalysts. This is because the melting point of the polymer by the single site catalyst is low, and the resin dispersion using this polymer can lower the heating temperature for adhesion. As the single site catalyst, for example, a metallocene catalyst or a Brookhart catalyst can be used. As the metallocene catalyst, a preferable catalyst may be selected in accordance with the stereoregularity of the polyolefin to be polymerized, such as C ₁ symmetric type, C ₂ symmetric type, C _{2 V} symmetric type, C _S symmetric type and the like. Among these, it is preferable to use a C ₁ symmetric type or C ₂ symmetric type metallocene catalyst.

  When propylene is used as the acid-modified polyolefin (A), the stereoregularity of propylene preferably has an isotactic structure in whole or in part. For example, not only ordinary isotactic propylene and isotactic propylene-α-olefin copolymers but also isotactic ones described in JP-A No. 2003-231714 and US Pat. No. 4,522,982 A copolymer obtained by copolymerizing an α-olefin comonomer with block polypropylene, stereoblock polypropylene or the like can also be used.

  The polyolefin used for the adhesive layer (2) preferably has a weight average molecular weight Mw of 5,000 or more measured by GPC (Gel Permeation Chromatography) and converted by each calibration curve. When Mw is less than 5,000, the stickiness is large and the cohesive force is low, so that the adhesion to the substrate tends to be insufficient. A more preferable value of the lower limit value is 10,000, more preferably 20,000, and particularly preferably 30,000. As Mw is higher than the lower limit value, the degree of stickiness is reduced and the cohesive strength of the polymer is increased, so that the adhesive force is increased and the adhesive layer is easy to use.

  The weight average molecular weight Mw is usually 500,000 or less. A preferable value of the upper limit value is 300,000, more preferably 200,000, still more preferably 100,000, and particularly preferably 80,000. . As Mw is higher than the upper limit, the fluidity at the time of melting of the resin is lowered, and there is a tendency that a high heating temperature and time are required for bonding. The GPC measurement is performed by a conventionally known method using a commercially available apparatus using orthodichlorobenzene or tetrahydrofuran as a solvent.

  Moreover, it is preferable that molecular weight distribution Mw / Mn represented by ratio of the weight average molecular weight Mw and number average molecular weight Mn of acid-modified polyolefin (A) is 5.0 or less. This means that the molecular weight distribution is narrow, and the molecular weight of the copolymer is uniform, but by using a polyolefin with such a uniform molecular weight, a high adhesive force can be obtained by heating at a low temperature in a short time. . In addition, it is easy to control the particle size when the resin is dispersed in water, and there is an advantage that a resin dispersion in which the dispersed particle size is small, the particle size distribution is narrow, and stably dispersed can be obtained. Mw / Mn is preferably 4.0 or less, and Mw / Mn is particularly preferably 3.0 or less. Usually, Mw / Mw is 1.0 or more.

  Further, the acid-modified polyolefin (A) preferably has a melting point (Tm) of 100 ° C. or less. More preferably, it is 90 degrees C or less. It is preferable that the melting point (Tm) is lower than 100 ° C. because the crystallinity is low and the solubility in a solvent is improved, and the emulsification / dispersion work is easily performed at a low temperature. In addition, when this resin is used as an adhesive, it is advantageous in that it is melt-bonded at a low temperature. However, the melting point (Tm) of the copolymer (A) is usually 30 ° C. or higher, preferably 50 ° C. or higher. A melting point of 30 ° C. or higher is advantageous in terms of high heat resistance, cohesive strength, and non-stickiness.

  The acid-modified polyolefin (A) in the present invention is a polyolefin obtained by acid-modifying a polyolefin with an unsaturated carboxylic acid component. Examples of unsaturated carboxylic acid components include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and the like, as well as unsaturated dicarboxylic acid half esters and half amides. It is done. Of these, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferable, and maleic anhydride is particularly preferable. The unsaturated carboxylic acid component only needs to be copolymerized in the acid-modified polyolefin resin, and the form thereof is not limited. Examples of the copolymerization state include random copolymerization, block copolymerization, and graft copolymerization. (Graft modification) and the like.

  The content of the unsaturated carboxylic acid component is preferably 0.1 to 10% by mass from the balance of adhesiveness between the inorganic layer (3) and the polyolefin resin layer (1) described later. The lower limit of the content of the unsaturated carboxylic acid component is more preferably 0.5% or more, and further preferably 1% or more. The upper limit of the content of the unsaturated carboxylic acid component is more preferably 5% or less, still more preferably 4% or less, and particularly preferably 3% or less. When content is less than 0.1 mass, sufficient adhesiveness with metal layers, such as aluminum foil which is typical as an inorganic layer (3), may not be acquired. Moreover, when it exceeds 10 mass%, adhesiveness with polyolefin resin layer (I) may fall.

  Moreover, the acid-modified polyolefin (A) used for the adhesive layer (2) may contain a (meth) acrylic acid ester component as required in addition to the acid component. Examples of the (meth) acrylic acid ester component include an esterified product of (meth) acrylic acid and an alcohol having 1 to 30 carbon atoms, and (meth) acrylic acid and carbon number 1 from the viewpoint of easy availability. Esterified products with 18 to 18 alcohols are preferred. Specific examples of the (meth) acrylic acid ester component include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, (meta ) Lauryl acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like, and a mixture thereof may be used. Among these, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, and octyl (meth) acrylate are preferred from the viewpoint of availability and adhesiveness. ("(Meth) acrylic acid" means "acrylic acid or methacrylic acid").

  The content of the (meth) acrylic acid ester component in the acid-modified polyolefin (A) is preferably 25% by mass or less, more preferably 15% by mass or less, and still more preferably, from the viewpoint of improving content resistance. If the content of the 10% by mass (meth) acrylic acid ester component exceeds 25% by mass, the adhesion to the polyolefin resin layer (I) may be relatively lowered. Further, the (meth) acrylic acid ester component may be copolymerized in the acid-modified polyolefin resin, and the form thereof is not limited. Examples of the copolymerization state include random copolymerization, block copolymerization, and grafting. Examples include copolymerization (graft modification).

<Hydrophilic polymer (B)>
In the present invention, the hydrophilic polymer means a polymer having an insoluble content of 1% by weight or less when dissolved in water at 25 ° C. at a concentration of 10% by weight. The hydrophilic polymer (B) is not particularly limited as long as the effects of the present invention are not significantly impaired, and any of synthetic polymers, semi-synthetic polymers, and natural polymers can be used. These may have a reactive group.

  Although it does not specifically limit as a synthetic polymer, For example, a poly (meth) acryl resin, polyether resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin etc. can be used. Examples of natural polymers include, but are not limited to, starches such as corn starch and wheat starch, seaweed such as fungi, agar and sodium alginate, plant mucilages such as gum arabic and gum tragacanth, and animal proteins such as casein and gelatin. Can be used. Although it does not specifically limit as a semisynthetic polymer, For example, celluloses, such as carboxyl starch, cationized starch, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, etc. can be used.

  Among these, a synthetic polymer that can easily control the degree of hydrophilicity and has stable characteristics is preferable. More preferred are acrylic resins such as poly (meth) acrylic resins, polyvinyl alcohol resins, polyvinylpyrrolidone resins, polyethyleneimine resins, and polyether resins. These may be used individually by 1 type and may be used in combination of 2 or more type. Of these, polyether amine having high hydrophilicity is most preferable. Polyetheramine is a compound having a primary amino group as a reactive group at one or both ends of a resin having a polyether skeleton. As the polyetheramine, Jeffamine M series, D series, ED series, Surfonamin L series, etc. manufactured by Huntsman may be used.

  The hydrophilic polymer (B) used in the present invention preferably has at least one reactive group capable of reacting with the acid-modified polyolefin (A) before bonding with the acid-modified polyolefin (A). Examples of the reactive group include a carboxylic acid group, a dicarboxylic acid anhydride group, and a dicarboxylic acid anhydride monoester group, a hydroxyl group, an amino group, an epoxy group, and an isocyanate group, and preferably have at least an amino group. The amino group is highly reactive with various reactive groups such as a carboxylic acid group, a carboxylic anhydride group, a glycidyl group, and an isocyanate group, so that it is easy to bond the acid-modified polyolefin (A) and the hydrophilic polymer (B). is there. The amino group may be primary, secondary, or tertiary, but more preferably is a primary amino group. One or more reactive groups may be used, but more preferably, there is only one reactive group. If there are two or more reactive groups, there is a possibility that a three-dimensional network structure will be formed when the acid-modified polyolefin (A) is bonded.

  The hydrophilic polymer (B) in the present invention must be a polymer in order to impart sufficient hydrophilicity to the polymer (C), and is a weight average molecular weight measured by GPC and converted by a polystyrene calibration curve. It is assumed that Mw is 200 or more. The lower limit is preferably 300, more preferably 500. However, the weight average molecular weight Mw is preferably 100,000 or less. A more preferable value of the upper limit value is 50,000, more preferably 10,000, and particularly preferably 3,000. As the Mw is higher than the lower limit, the hydrophilicity of the polymer (C) is increased and the dispersed particle size tends to be smaller and stably dispersed. As the Mw is lower than the upper limit, the viscosity is low and the resin dispersion tends to be easily prepared. . The GPC measurement is performed by a conventionally known method using a commercially available apparatus using THF or the like as a solvent.

  The amount of the hydrophilic polymer (B) bonded to the acid-modified polyolefin (A) is preferably in the range of 0.01 to 1 mmol, ie 0.01 to 1 mmol / g, per 1 g of the polyolefin (A). A more preferred lower limit is 0.03 mmol / g, and even more preferably 0.05 mmol / g. The upper limit value is more preferably 0.5 mmol / g, further preferably 0.3 mmol / g, and particularly preferably 0.2 mmol / g. The higher the lower limit value, the higher the hydrophilicity of the polymer (C) and the smaller the dispersed particle size tends to be stably dispersed, and the lower the upper limit value, the higher the adhesion to the polyolefin as the substrate.

  The weight ratio of the acid-modified polyolefin (A) and the hydrophilic polymer (B) is (A) :( B) = 100: 1 to 100: 100. When the amount of the hydrophilic polymer is more than 100 parts by weight, the amount of polyolefin is relatively reduced, so that the adhesion to the polyolefin resin layer (1) is lowered, and the hydrophilic polymer ( Since the amount of B) increases, the water resistance of the adhesive layer (2) tends to decrease. On the other hand, when the amount is less than 1 part by weight, poor dispersion tends to occur when the polymer (C) is dispersed in water.

  The upper limit of the amount of the hydrophilic polymer (B) used is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and most preferably 20 parts by weight or less. Moreover, the lower limit of the amount of the hydrophilic polymer (B) used is preferably 3 parts by weight or more, and more preferably 5 parts by weight or more.

  The polymer (C) obtained by bonding the acid-modified polyolefin (A) and the hydrophilic polymer (B) includes a graft copolymer in which the hydrophilic polymer (B) is graft-bonded to the polyolefin (A), a polyolefin There may be a block copolymer of a polyolefin (A) and a hydrophilic polymer (B) containing a state in which the hydrophilic polymer (B) is bonded to one or both ends of (A), but preferably a graft copolymer It is a copolymer. When the polymer (C) is a graft copolymer, the content of the hydrophilic polymer (B) can be easily controlled, and the content of the hydrophilic polymer (B) can be easily increased as compared with the block copolymer. There are advantages.

  The hydrophilic polymer (B) can be bonded to the acid-modified polyolefin (A) by various reaction forms. Although the form is not specifically limited, For example, it is reaction using the acidic group and reactive group of polyolefin. The reaction using the reactive group has a reactive group in both of the acid-modified polyolefin (A) and the hydrophilic polymer (B), and reacts them to bond, and it is a covalent bond or an ionic bond. Is formed. Examples of this reaction include esterification reaction of carboxylic acid group and hydroxyl group, ring-opening reaction of carboxylic acid group and epoxy group, amidation reaction of carboxylic acid group and primary or secondary amino group, carboxylic acid group and 3 Examples thereof include a quaternary ammonium reaction of a primary amino group, a urethanization reaction of a carboxylic acid group and an isocyanate group. The reaction rate of each reaction may be arbitrarily selected from 1 to 100%, preferably 10 to 100%, and more preferably 50 to 100%. When the carboxylic acid group is a dibasic acid or an anhydride thereof, one equivalent or two equivalents may be reacted with respect to one equivalent of the dibasic acid or anhydride.

The amount of the adhesive layer (2) is not particularly limited, but is preferably in the range of 0.01 to 20 g / m ^{2 with} respect to the area of the adhesive surface, and is 0.1 to 10 g / m ² . More preferably, it is 0.3-5 g / m < ² >. If it is less than 0.01 g / m ² , sufficient adhesiveness cannot be obtained, and if it exceeds 20 g / m ² , a layer is formed by a coating method, and a solvent for dissolving, diluting or dispersing is used. In some cases, drying takes time, which is disadvantageous economically.

  Moreover, the adhesive bond layer (2) may contain resins other than the polymer (C). Examples of other resins include polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, ethylene- (meth) acrylic acid copolymer, styrene-maleic acid resin, styrene-butadiene resin, Examples include butadiene resin, poly (meth) acrylonitrile resin, (meth) acrylamide resin, polyester resin, nylon resin, urethane resin, phenol resin, silicone resin, and epoxy resin. The content of other resins is usually less than 80% by weight, preferably less than 50% by weight, and more preferably less than 30% by weight.

  Furthermore, the adhesive layer (2) of the present invention can use a crosslinking agent as necessary in order to improve its strength, water resistance, heat resistance and chemical resistance. There are no particular restrictions on the crosslinking agent that can be used, but examples thereof include compounds having a bifunctional or higher functional group. Specific examples include polyfunctional epoxy, polyfunctional isocyanate, polyfunctional amine, and polyfunctional oxazoline. Particularly preferred are polyfunctional epoxies and polyfunctional oxazolines from the viewpoint of reactivity with the carboxyl group of the acid-modified polyolefin.

<Inorganic layer (3)>
The inorganic layer (3) in the present invention is not particularly limited as long as it is a layer made of an inorganic substance in a solid state at room temperature, but suitable as the inorganic substance used in the inorganic layer (3) of the present invention includes metals and metal oxides. And glass. Although it does not restrict | limit especially as a metal used for an inorganic layer (3), Aluminum, gold | metal | money, copper, iron etc. are mentioned, These oxides are also used as a metal oxide.

  The inorganic layer (3) of the present invention can be formed using a metal foil as it is, or can be formed as a layer as a deposited film. In the case of a metal foil, one or more of the above metals may be used. In the case of a deposited film, one or more metals may be used, or binary deposition of metal and glass may be used. Preferable specific examples of these layers include aluminum foil, gold foil, aluminum vapor deposition layer, silica vapor deposition layer, alumina vapor deposition layer, and silica alumina binary vapor deposition layer. An aluminum foil or an aluminum vapor deposition film layer is particularly preferable because it is inexpensive, has high barrier properties, and can provide light shielding properties.

  In the case of metal foil, the thickness of the inorganic layer (3) is usually 0.1 to 100 μm, preferably 1 to 50 μm, particularly preferably 3 to 30 μm. In the case of an inorganic vapor deposition film layer, it is usually 10 to 5000 mm, preferably 50 to 1000 mm, particularly preferably 100 to 500 mm. If the inorganic layer is thin, there is a tendency that sufficient barrier properties cannot be obtained.If it is too thick, the weight of the packaging material increases and handling becomes inconvenient. is there.

  Moreover, when an aluminum foil is used as the inorganic layer (3) constituting the laminate, the surface in contact with the above-described adhesive layer (2) can be subjected to a hydrothermal modification treatment for improving adhesiveness. . Examples of the treated water used when hydrothermally transforming the surface of the aluminum foil include tap water, deionized water, distilled water, and distilled water distilled after deionization. Among them, deionized distilled water is preferably used. In the hydrothermal modification treatment on the aluminum foil surface, various hydrous oxide films are coated on the surface depending on the treatment temperature to form a hydrothermal modification treatment layer. As the hydrothermal modification treatment to be formed, those made of a boehmite film obtained by performing a boehmite treatment (hydrothermal modification treatment) in the range of about 80 to 100 ° C. under normal pressure are preferable.

<Thermoplastic resin layer (4)>
As a base material for the inorganic layer (3), a thermoplastic resin layer (4) can be used, although it is not essential in the laminate of the present invention. By forming the thermoplastic resin layer (4), this becomes a material constituting the light shielding, barrier laminate, packaging bag and the like according to the present invention, and a metal foil or a vapor deposition film is provided on the material. It has excellent mechanical, physical and chemical properties, in particular, has strength and toughness, and has heat resistance. In particular, in the case of a vapor deposition film, a resin film or sheet that can withstand the conditions for forming the film, etc., and can satisfactorily maintain the characteristics of the vapor deposition film can be used.

  Examples of resins that can be used as the thermoplastic resin layer (4) include polyethylene resins, polypropylene resins, cyclic polyolefin resins, fluorine resins, polystyrene resins, and acrylonitrile-styrene copolymers (AS resins). , Acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyethylene terephthalate, polyester resin such as polyethylene naphthalate, Various polyamide resins such as nylon, polyimide resins, polyamideimide resins, polyaryl phthalate resins, silicone resins, polysulfone resins, polyphenylene sulfide resins, polyethersulfone resins, polyurethane resins resin Acetals - Le resins, cellulose - scan resins, polyvinyl alcohol resins, various resins other such film or sheet - may be used and. In the present invention, it is particularly preferable to use a polypropylene resin, polyester resin, or polyamide resin film or sheet.

  When using one or more of the above-mentioned various resins and forming the film, for example, film processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, release properties, etc. Various plastic compounding agents and additives can be added for the purpose of improving and modifying the formability, flame retardancy, antifungal properties, electrical properties, strength, etc. Depending on the purpose, it can be added arbitrarily.

  In the above, general additives include, for example, colorants such as lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, antistatic agents, lubricants, antiblocking agents, dyes, pigments and the like. Others can be arbitrarily used, and further, a modifying resin or the like can also be used.

  In order to laminate a thermoplastic resin layer (4) as a base material and a vapor deposition film thereon as an inorganic layer (3), it is convenient to use a commercially available vapor deposition film, which can be used as such a vapor deposition film. As the film, for example, “IB series” manufactured by Dai Nippon Printing Co., Ltd., “GL, GX series” manufactured by Toppan Printing Co., Ltd., “Barrier Rocks” manufactured by Toray Film Processing Co., Ltd., VMPET, YM-CPP, VM-OPP, Examples thereof include “Tech Barrier” manufactured by Mitsubishi Plastics, “Metaline” manufactured by Tosero, “MOS”, “Tetrait”, and “Bright” manufactured by Oike Kogyo Co., Ltd. When a vapor deposition film is used as the inorganic layer by the vapor deposition film, a protective coating layer may be provided on the layer.

  The thickness of the thermoplastic resin layer (4) is usually 1 to 500 μm, preferably 3 to 300 μm, particularly preferably 5 to 100 μm.

<Method for producing laminate>
The method for producing the laminate of the present invention is not particularly defined. For example, a polymer (C) obtained by bonding a hydrophilic polymer (B) to an acid-modified polyolefin (A) is dissolved or dispersed in a solvent. A method of applying a coating agent to the inorganic layer (3) and drying the medium, and an adhesive obtained by applying a coating agent in which the polymer (C) is dissolved or dispersed on the release paper and drying the medium Examples thereof include a method of transferring the layer onto the metal film layer, a method of melt-extruding the polymer (C) directly onto the inorganic layer (3) using a T-die, and the like. Among these, from the viewpoint of environmental and performance, a method of applying a coating agent (aqueous resin dispersion) in which a polymer (C) is dissolved or dispersed in an aqueous medium to a substrate and drying the medium is an adhesive. It is preferable because the amount of the layer (2) can be easily adjusted, and the thickness can be easily controlled. When the aqueous resin dispersion is used, as described in Patent Document 2, the aqueous resin dispersion is applied to an aluminum layer (inorganic (3) in the present invention) and dried to form an adhesive resin. A method of laminating a polyolefin resin layer by forming a layer (adhesive layer (2) in the present invention) and then melt-extruding (extrusion laminating) the polyolefin resin in-line is also possible and is used as a preferred method. be able to. Examples of the aqueous resin dispersion of a polyolefin resin suitable for the above method include those described in Patent Document 3 and Patent Document 4.

  In the case of using an aqueous dispersion, known coating methods such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, and brush coating are used. The adhesive layer (2) having a uniform thickness can be formed in close contact with the surface of the inorganic layer (3) by uniformly coating the surface of the substrate by, for example, drying treatment or heat treatment for drying. it can.

<Other layers>
When the laminate of the present invention is used as a packaging material, the thermoplastic resin layer (4) having an inorganic layer (3) of a metal foil or a vapor-deposited film is usually outside and the polyolefin resin layer (1) is inside (contents). Used as the object side). However, when considering the use of the packaging material or the rigidity and durability required for the packaging material, other layers can be laminated as necessary. Usually, it is used with a base material such as a thermoplastic resin film, synthetic paper, paper, etc. outside the inorganic layer (3). Moreover, in order to raise the designability of a packaging material, providing a printing layer is also generally performed.

<Packaging materials>
The form of bag making as the packaging material of the present invention can be selected according to its use and is not particularly defined, but there are various types such as a three-side seal bag, a four-side seal bag, a gusset packaging bag, a pillow packaging bag, and the innermost layer. The polyolefin resin layer (1) may be provided with a polypropylene resin chuck to form a packaging bag with a chuck. Further, it can be used as a so-called PTP (press through package) packaging or a blister pack in which a plastic layer is dented into a tablet or a part and sealed with an aluminum film or the like.

  Since the packaging material of this invention has favorable tolerance with respect to various contents, it is suitable as a packaging material of various contents. Specifically, food products such as spices, frozen foods, snacks, fragrances, fragrances, bathing agents, cosmetics, toiletries, surfactants, shampoos, rinses, deodorants, toiletries such as detergents, It is suitably used for packaging materials such as insecticides, insecticides, poultices, dentifrices, pharmaceutical (external) products such as tablets, secondary batteries, electronic parts, and industrial parts such as ICs.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not restrict | limited to a following example, unless the summary is exceeded. In the following, when “part” is simply written, it means “part by weight”.

<Physical property measurement method and evaluation method>
-Weight average molecular weight [Mw] and molecular weight distribution [Mw / Mn]
First, 5 mg of a sample is taken into a 10 ml vial, 5 g of tetrahydrofuran containing 250 ppm of BHT is added as a stabilizer, and completely dissolved at 50 ° C. After cooling to room temperature, the mixture was filtered through a filter having a pore diameter of 0.45 μm to prepare a sample solution having a polymer concentration of 0.1% by weight. Next, GPC measurement was performed using Tosoh Corp. GPC HLC-8020 equipped with a guard column TSK guard column H _XL- H to TSK gel GMH _XL- L (30 cm × 2) as a column. Measurement conditions were as follows: injection volume of sample solution: 50 μl, column temperature: 40 ° C., solvent: tetrahydrofuran, flow rate: 1.0 ml / min.
When calculating the molecular weight, a commercially available monodisperse polystyrene standard sample was measured as a standard sample, and a calibration curve was created from the retention time and molecular weight of the standard sample.

Melting point [Tm]
Measurement was performed using a differential scanning calorimeter DSC 220C manufactured by Seiko Instruments Inc.
A sample of 5 ± 1 mg was placed in an Al pan, covered with Al, and an empty Al pan was used as a reference and placed on the detector. The temperature was raised to 200 ° C. at a rate of 100 ° C./min. After maintaining at the same temperature for 5 minutes, it was cooled at a rate of 10 ° C./min, and the amount of heat was detected at 0.5 second intervals to −10 ° C. After maintaining at the same temperature for 1 minute, the temperature was raised to 200 ° C. at a rate of 10 ° C./min, and the amount of heat was detected at 0.5 second intervals.
In each sample, one exothermic peak was observed in the cooling process and one endothermic peak was observed in the last temperature raising process. The temperature at the peak top of the peak in the final temperature raising process was defined as the melting point [Tm].

・ Graft rate (acid modification rate)
200 mg of polymer and 4800 mg of chloroform are placed in a 10 ml sample bottle and heated at 50 ° C. for 30 minutes to completely dissolve. Chloroform was placed in a liquid cell having a material NaCl and an optical path length of 0.5 mm as a background. Next, the dissolved polymer solution was put into a liquid cell, and an infrared absorption spectrum was measured using FT-IR460plus manufactured by JASCO Corporation at a total number of 32 times. The graft ratio of maleic anhydride was calculated using a calibration curve prepared by measuring a solution of maleic anhydride in chloroform. Then, from the area of the absorption peak of the carbonyl group (maximum peak near 1780 cm ⁻¹ , 1750 to 1813 cm ⁻¹ ), the acid component content in the polymer is calculated based on a separately prepared calibration curve, and this is calculated as the graft ratio ( % By weight).

-Dispersion particle diameter It measured using Microtrac UPA (model 9340 batch type dynamic light scattering method / laser Doppler method) by Nikkiso Co., Ltd. Measured with a dispersion time of 0.9 g / cm ³ , a particle shape of a true sphere, a particle refractive index of 1.50, a dispersion medium of water and a dispersion medium of 1.33, and a measurement time of 120 seconds. Then, the particle diameter at the time of 50% cumulative from the smaller particle diameter in terms of volume was determined.

-Peel peel strength A test piece having a width of 15 mm was taken from the film laminate, and the strength was measured by peeling the interface between the barrier layer and the polyolefin resin layer from the end of the test piece by a 180 degree peel method using a tensile tester. . The measurement was performed in an atmosphere of 23 ° C. and 65% RH at a tensile speed of 50 mm / min.

[Production Example 1] Production of aqueous resin dispersion In a glass flask equipped with a reflux condenser, a thermometer, and a stirrer, 250 g of toluene, a propylene-ethylene copolymer polymerized by a metallocene catalyst (propylene content 89 mol%, 750 g of polystyrene-equivalent weight average molecular weight 40,000, melting point 71 ° C. was added, the inside of the container was replaced with nitrogen gas, and the temperature was raised to 110 ° C. After heating, 22.5 g of maleic anhydride was added, 7.5 g of t-butylperoxyisopropyl monocarbonate (manufactured by NOF Corporation: Perbutyl I) was added, and the reaction was continued for 7 hours at the same temperature. . After completion of the reaction, the system was cooled to around room temperature, acetone was added, and the precipitated polymer was filtered off. Further, precipitation and filtration were repeated with acetone, and the polymer obtained after washing was dried under reduced pressure to obtain a maleic anhydride-modified polymer in the form of a white powder. As a result of measuring the infrared absorption spectrum of this modified polymer, the content (graft ratio) of maleic anhydride groups was 2.1% by weight (0.21 mmol / g as maleic anhydride groups, 0.42 mmol as carboxylic acid groups). / G). The weight average molecular weight after acid modification was 70,000 (polystyrene conversion).

Next, 75 g of the obtained maleic anhydride-modified polymer and 152 g of toluene were added to a glass flask equipped with a reflux condenser, a thermometer, and a stirrer, and the temperature was raised to 110 ° C. to completely dissolve. Next, 7.5 g (7.5 mmol) of methoxypoly (oxyethylene / oxypropylene) -2-propylamine (molecular weight 1,000) dissolved in 2-propanol (206 ml) is hydrophilic to 100 parts by weight of acid-modified polyolefin (A). Polymer (B) (corresponding to 10 parts by weight) was added and reacted at 70 ° C. for 1 hour. Thereafter, 0.75 g (7.6 mmol) of 2-aminomethylpropanol was added to neutralize the system. While maintaining the temperature of the obtained reaction liquid at 45 ° C., heating and stirring, adding 300 g of water in several portions over 2 hours, dropping the pressure reduction in the system to a polymer concentration of 30% by weight. 2-propanol and water were distilled off under reduced pressure to obtain a milky white aqueous resin dispersion. As a result of measuring the dispersed particle size, the 50% particle size was 190 nm.
The methoxypoly (oxyethylene / oxypropylene) -2-propylamine used in Example 1 had an insoluble content of 1% by weight or less when dissolved in water at 25 ° C. at a concentration of 10% by weight. Is a molecule.

[Production Example 2]
Aqueous in the same manner as in Production Example 1 except that the polyolefin resin was a propylene-ethylene copolymer polymerized with a metallocene catalyst (propylene content 90 mol%, polystyrene-converted weight average molecular weight 30,000, melting point 73 ° C.). A resin dispersion was obtained. As a result of measuring the dispersed particle size, the 50% particle size was 160 nm.

[Production Example 3]
An aqueous resin dispersion was obtained in the same manner as in Production Example 1, except that the amount of maleic anhydride added was 7.5 g and the amount of perbutyl I added was 2.5 g. As a result of measuring the dispersed particle size, the 50% particle size was 230 nm.

[Production Example 4]
An aqueous resin dispersion was obtained in the same manner as in Production Example 1, except that the amount of maleic anhydride group added was 15.0 g and the amount of perbutyl I added was 5.0 g. As a result of measuring the dispersed particle size, the 50% particle size was 230 nm.

Example 1
Using a polypropylene film (thickness 60 μm) having a corona treatment on the surface as a polyolefin resin layer (1), the aqueous resin dispersion produced in Production Example 1 was applied using a Mayer bar (No. 12), and 100 What was dried at 0 ° C. for 1 minute was used as an adhesive layer (2). The thickness of the adhesive layer (2) was 3 μm. A 12 μm thick polyester film (thermoplastic resin layer (4)) on which aluminum is deposited as a barrier layer (3) is aligned so that the aluminum surface and the adhesive surface overlap, and then a heating temperature of 120 ° C., pressure A laminate was manufactured by heating at 1 kgf / cm ² for 1 second.
A peel peel test was performed using a test piece obtained by cutting the laminate into a width of 15 mm. The results are shown in Table 1.

Example 2
A laminate was produced in the same manner as in Example 1 except that the aqueous resin dispersion of Production Example 2 was used as the adhesive layer (2), and a peel peel test was performed. The results are shown in Table 1.

Example 3
A laminate was produced in the same manner as in Example 1 except that the aqueous resin dispersion of Production Example 3 was used as the adhesive layer (2), and a peel peel test was performed. The results are shown in Table 1.

Example 4
A laminate was produced in the same manner as in Example 1 except that the aqueous resin dispersion of Production Example 4 was used as the adhesive layer (2), and a peel peel test was performed. The results are shown in Table 1.

Comparative Example 1
A laminate was prepared in the same manner as in Example 1 except that a chlorinated polyolefin emulsion (Super Clon E-415, manufactured by Nippon Paper Chemicals Co., Ltd.) obtained by emulsifying chlorinated polyolefin with a surfactant was used as the adhesive layer (2). A peel peel test was made. The results are shown in Table 1.

Comparative Example 2
A polyolefin emulsion obtained by emulsifying (meth) acrylic acid ester-modified non-chlorinated polyolefin using a surfactant as the adhesive layer (Aurolen S6032, manufactured by Nippon Paper Chemical Co., Ltd.) was used, and the pressure during bonding was 2 kgf / cm ^2. A laminate was prepared in the same manner as in Example 1 except that the heating time was 2 seconds, and a peel peel test was performed. The results are shown in Table 1.

  Examples 1 to 3 showed superior values in peel peel strength as compared with Comparative Examples 1 and 2. In particular, in Comparative Example 2, the adhesiveness was not obtained despite the heating time being longer than in the Examples and applying a high pressure. This means that the adhesive used in the examples was not emulsified with a conventional surfactant and adhesion was not inhibited by the emulsifier. In addition, Examples 1, 2 and 3 are excellent in peel peel strength in this order. This is because the higher the acid modification rate, the higher the affinity for inorganic materials, and the higher the molecular weight of the polyolefin, the higher the cohesive force. Because.

The laminate of the present invention is excellent in light-shielding properties and gas barrier properties such as oxygen and water vapor. In particular, when the laminate is used as various packaging materials, it is excellent in the protection of contents, snacks, frozen foods. It is suitable for packaging materials such as food packaging materials such as retort foods, pharmaceuticals, miscellaneous goods, and industrial materials.

Claims (8)

A laminate having at least a polyolefin-based resin layer (1), an adhesive layer (2) and an inorganic layer (3) in this order, wherein the adhesive layer (2) is hydrophilic to the acid-modified polyolefin (A). A polymer (C) obtained by bonding a polymer (B) at a ratio of (A) :( B) = 100: 1 to 100: 100 (weight ratio), and the hydrophilic polymer (B) is a polyether amine, and inorganic layer (3) is a layer containing aluminum product Sotai. Acid modification ratio of the acid-modified polyolefin emission (A) is 0.1% or more, the laminated body according to claim 1 is 10% or less. Acid-modified polyolefin down weight average molecular weight of 5,000 or more on the (A), the laminate according to claim 1 or claim 2 which is under 300,000 or less. Furthermore, it is a laminate having a thermoplastic resin layer (4), and the laminate comprises a polyolefin resin layer (1), an adhesive layer (2), an inorganic layer (3), and a thermoplastic resin layer (4). The laminate according to any one of claims 1 to 3 , wherein the layers are laminated in this order. The thermoplastic resin layer (4) is a polyester resin, a polyamide resin or a laminate according to the resin layer der Ru請 Motomeko 4 consisting of any one of polyolefin resins. The laminate according to any one of claims 1 to 5, wherein the acid-modified polyolefin (A) is a polypropylene resin polymerized by a metallocene catalyst and has a melting point of 100 ° C or lower. The adhesive layer (2) is obtained by bonding the hydrophilic polymer (B) to the acid-modified polyolefin (A) at a ratio of (A) :( B) = 100: 1 to 100: 100 (weight ratio). The laminate according to any one of claims 1 to 6, wherein the laminate (C) is obtained by coating and drying an aqueous resin dispersion in which the coalescence (C) is dispersed in an aqueous medium. The packaging material which uses the laminated body of any one of Claims 1-7.

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